Bacteroides

J Clin Periodontol, 2005 Jan, 32(1), 21 - 8
Clinical effects of scaling and root planing on untreated teeth; Pawlowski AP et al.; Pawlowski AP, Chen A, Hacker BM, Mancl LA, Page RC, Roberts FA: Clinical effects of scaling and root planing on untreated teeth . J Clin Periodontol 2004; doi: 10.1111/j.1600-051X.2004.00626.x . (c) Blackwell Munksgaard, 2004 . Abstract Objective: The aim of this report is to examine whether scaling and root planing (SRP) in one area of the mouth may affect periodontal improvement in untreated areas in the same patient, possibly through systemic effects of treatment . Material and Methods: Twenty patients diagnosed with generalized aggressive periodontitis were randomized into treatment (n=11) and no treatment (n=9) groups . Within the treatment group, three quadrants were treated by SRP at week 0, 3, 12, and 24, while a single experimental quadrant remained untreated throughout the study . The outcome for all teeth was assessed using clinical parameters, subtraction radiography, and pathogenic bacteria levels in the subgingival flora over the 24-week study period . Results: Compared with sites in no treatment patients, the treated sites in the treated patients showed a 1 mm decrease in probing depth (PD) (p<0.01) and a 0.5 mm increase in bone height (p<0.01) by 24 weeks . In untreated sites within treated subjects, however, PDs tended to improve (p=0.09) but at a reduced rate compared with treated sites . The levels of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythensis (Bacteroides forsythus) remained unchanged in untreated sites while levels of Prevetolla intermedia and Treponema denticola tended to decrease as compared with controls but did not reach significance . Conclusions: This study indicates that untreated sites in treated periodontitis patients show a trend towards clinical improvement and exhibit reductions in some but not all periodontopathic bacterial species tested.

Antibiot Khimioter, 2004, 49(6), 25 - 9
{Clinical and bacteriological substantiation of the use of cefoperazone/sulbactam in complex therapy of patients with pyo-destructive forms of lower respiratory tract infection (LRTI)}; Pneumocephalus associated with Bacteroides fragilis meningitis; University of Ottawa, Timmins & District Hospital, Timmins, Ontario P4N 8R1, Canada . atbeat@ntl.sympatico.caGas within the intracranial cavity (pneumocephalus) commonly results from trauma or after surgery and rarely from infection by gas-forming organisms . The presence of pneumocephalus in the absence of injury or surgery should raise the suspicion of anaerobic infection of the central nervous system . I present a case of pneumocephalus associated with Bacteroides fragilis meningitis where the diagnosis was suspected after CT findings become available . Bacteroides fragilis meningitis is rare and often occurs in premature infants and neonates; only few cases are reported in adults . Pneumocephalus associated with Bacteroides fragilis meningitis is not described in the literature . This case also illustrates the absence of classic findings of meningeal irritation in the elderly . The literature is reviewed.

FEMS Microbiol Lett, 2005 Jan 15, 242(2), 339 - 44
Interaction between H(2)-producing and non-H(2)-producing cellulolytic bacteria from the human colon; Chassard C et al.; The cellulose-degrading species recently isolated from the human colon showed diverse ability to degrade and ferment cellulose . In the present study, the nature of the inter-relation existing between one H(2)-producing cellulolytic isolate (Ruminococcus sp . nov.) and one non-H(2)-producing cellulose-degrading species (Bacteroides sp . nov.) was investigated in vitro . Coculture experiments revealed synergism in cellulose degradation between these two cellulolytic species . An increase in total bacterial population was measured in the coculture, Bacteroides sp . being the predominant organism . As a result, a large decrease in H(2) production from cellulose fermentation was observed . Predominance of Bacteroides sp . might thus contribute to limit gas produced from fibre fermentation in the gut.

FEMS Microbiol Lett, 2005 Jan 15, 242(2), 297 - 303
Molecular phylogenetic diversity of bacteria associated with the leachate of a closed municipal solid waste landfill; Huang LN et al.; A 16S rDNA-based molecular study was performed to determine the nature of the bacterial constituents of the leachate from a closed municipal solid waste landfill . Total community DNA was extracted and bacterial 16S rRNA genes were subsequently amplified and cloned . Recombinant rDNA clones in the library were randomly selected, and they were sequenced for a single run and then grouped . A total of 76 sequence types representing 138 randomly selected nonchimeric clones were identified . Full-length sequencing and phylogenetic analysis of the sequence types revealed that more than 90% of the screened clones were affiliated with low-G+C gram-positive bacteria (38.4%), Proteobacteria (35.5%), the Cytophaga Flexibacter Bacteroides group (11.6%), and Spirochaetes (5.1%) . Minor portions were affiliated with Verrucomicrobia (2.9%), candidate division OP11 (2.2%), and the green nonsulfur bacteria, Cyanobacteria and the Deinococcus Thermus group (each <1.0%) . Although some rDNA sequences clustered with genera or taxa that were classically identified within anaerobic treatment systems and expected with known functions, a substantial fraction of the clone sequences showed relatively low levels of similarity with any other reported rDNA sequences and thus were derived from unknown taxa . These results suggest that bacterial communities in landfill environment are far more complex than previously expected and remain largely unexplored.

Pediatr Emerg Care, 2004 Sep, 20(9), 636 - 40
Anaerobic pulmonary infections in children; Brook I; Pulmonary infections due to anaerobic bacteria usually occur in children prone to aspiration . The source of the anaerobic bacteria is the oropharyngeal bacterial flora, where these organisms outnumber aerobic and facultative organisms in a 10:1 ratio . The most common lower respiratory tract infections where anaerobic bacteria are recovered mixed with aerobic organisms are aspiration pneumonia, lung abscess, and empyema . The predominant isolated anaerobic bacteria are Peptostreptococcus, Fusobacterium, pigmented Prevotella, and Porphyromonas spp . and Bacteroides fragilis group . Management of these infections includes the administration of antimicrobials effective against the anaerobic as well as the aerobic pathogens.

Clin Ther, 2004 Oct, 26(10), 1564 - 77
Use of ciprofloxacin in the treatment of hospitalized patients with intra-abdominal infections; Madan AK; BACKGROUND: Numerous combination and single-agent antimicrobial regimens are available for the treatment of intra-abdominal infections . Selection of empiric agents must be directed at providing reliable activity against endotoxin-generating Escherichia coli, other gram-negative facultative bacteria, and anaerobes such as Bacteroides fragilis . Safety profiles, pharmacokinetic profiles, and cost-effectiveness must also be considered . Use of fluoroquinolones for the treatment of intra-abdominal infections has recently been advocated . METHODS: We review 2 prospective, comparative clinical trials conducted between 1992 and 2002 that evaluated the efficacy and safety of IV ciprofloxacin in patients with intra-abdominal infections . Separate pharmacoeconomic analyses conducted for each study are also reviewed . RESULTS: A total of 4 ciprofloxacin studies (2 clinical, 2 pharmacoeconomic) comprise the database . The combination of ciprofloxacin plus metronidazole was at least as effective as imipenem/cilastatin and clinically more effective than piperacillin/tazobactam therapy, based on clinical success end points . In 1 trial, treatment success for the clinically valid population was reported for 84% (93/111) of patients treated with IV ciprofloxacin/metronidazole, 86% (91/106) of those treated with IV/oral ciprofloxacin/metronidazole, and 81% of those treated with IV imipenem/cilastatin (91/113) . The IV/oral ciprofloxacin/metronidazole regimen had a statistically significant lower mean infection-related cost than the IV only ciprofloxacin/metronidazole plus imipenem groups (difference of approximately 1100 US dollars; P = 0.029) . In the second clinical trial, clinical resolution rates were statistically different for patients receiving IV/oral ciprofloxacin/metronidazole (74%) versus IV piperacillin/tazobactam therapy (63%; P = 0.047) . Ciprofloxacin/metronidazole was more cost-effective compared with piperacillin/tazobactam (2200 US dollars-3600 US dollars lower cost-effective ratios per patient) regardless of whether the patient had a diagnosis of appendicitis or whether a switch to an oral drug was permissible . CONCLUSIONS: In the studies reviewed herein, the combination of ciprofloxacin plus metronidazole was an effective and safe regimen for the treatment of intra-abdominal infections . This regimen has potential advantages over exclusively IV regimens, including the option of sequential IV/oral therapy, patient convenience, cost savings, and reduced hospital stay.

Nippon Rinsho, 2004 Dec, 62(12), 2330 - 6
{Incidence, treatment and outcome of anaerobic bacteremia}; Watanabe K et al.; In this paper, we discussed the incidence and clinical significance of blood cultures positive for anaerobes . Anaerobic bacteria is uncommon, accounting for 0.5-13% of all positive cultures . The incidence depend on the institution . Recent findings of a multicenter prospective observational trials showed that in vitro activity of the agents directed at Bacteroides species reliably predicts outcome . When a positive anaerobic blood culture was noted, appropriate action must be taken, since negligence in this respect may seriously impair the outcome of patients.

Biochem Biophys Res Commun, 2005 Jan 21, 326(3), 607 - 13
Bacteroides fragilis interferes with iNOS activity and leads to pore formation in macrophage surface; Vieira JM et al.; Bacteroides fragilis is the anaerobe most commonly recoverable from clinical specimens . The wide genetic diversity of this bacterium related with virulence potential is still an open question . In this study, we analyzed the morphological aspects and microbicide action of MO during interactions with B . fragilis . A filamentous cytoplasm content release and a different actin organization colocalized with iNOS were detected . It was also possible to observe the reduction of NO production in the same conditions . The scanning electron microscopy showed the formation of pore-like structures in the surface of macrophages in the bacterial presence and by transmission electron microscopy we could observe the extrusion of cytoplasm contents as well as the condensation of chromatin in the nucleus periphery . These data suggest the existence of an inhibitory mechanism developed by B . fragilis strains for one of the macrophage microbicide actions.

J Clin Microbiol, 2004 Dec, 42(12), 5565 - 70
"Bacteroides nordii" sp . nov . and "Bacteroides salyersae" sp . nov . isolated from clinical specimens of human intestinal origin; Song YL et al.; Two groups of unknown bacteria, which phenotypically resemble members of the Bacteroides fragilis group but phylogenetically display >5% 16S rRNA gene sequence divergence from their nearest validly described species, Bacteroides thetaiotaomicron, were characterized by phenotypic and molecular taxonomic methods . Phylogenetically and phenotypically, the unidentified bacteria displayed a relatively close association with each other . However, a 16S rRNA gene sequence divergence of approximately 4% between the two unknown bacteria, as well as distinguishable biochemical characteristics, demonstrates that these organisms are genotypically and phenotypically distinct, and each group may represent a previously unknown subline within the Bacteroides phylogenetic cluster . Subsequent DNA-DNA hybridization studies confirmed that the two novel organisms were indeed distinct from each other . The previously described species closest to both of them is B . thetaiotaomicron (approximately 94% sequence similarity), but they can be differentiated easily from B . thetaiotaomicron by virtue of not utilizing trehalose . DNA-DNA pairing studies also documented the separateness of the unknown species and B . thetaiotaomicron . Based on the phenotypic and phylogenetic findings, two new species, "Bacteroides nordii" sp . nov . and "Bacteroides salyersae" sp . nov, are proposed . The G+C content of the DNA is 41.4 mol% for Bacteroides nordii and 42.0 mol% for Bacteroides salyersae . The type strains of Bacteroides nordii and Bacteroides salyersae are WAL 11050 (ATCC BAA-998 or CCUG 48943) and WAL 10018 (ATCC BAA-997 or CCUG 48945), respectively.

Res Microbiol, 2004 Dec, 155(10), 843 - 6
Plasmid-related beta-lactamase production in Bacteroides fragilis strains; Nakano V et al.; Twenty Bacteroides fragilis group species isolated from children with and without diarrhea were analyzed . Antibiotic susceptibility was performed using an agar dilution method; beta-lactamase production was determined using a nitrocefin method, and plasmids were extracted using a commercial Miniprep System . MIC values ranged from 16 to 256 microg/ml for penicillin, 4-128 microg/ml for amoxicillin/clavulanic acid, 0.25-256 microg/ml for clindamycin, and 16-256 microg/ml for penicillin . beta-Lactamase was detected in all isolates . Only five isolates harbored plasmids varying from 7.8 to 1.8 kb . Loss of 6.4- and 3.8-kb plasmids in B . fragilis C68c was related to antibiotic resistance . Low molecular weight plasmids of 2.8-1.8 kb were stable . PCR amplification of cfiA and cepA genes was observed using total DNA, and the cfiA gene was also amplified from the 6.4-kb plasmid.

Antonie Van Leeuwenhoek, 2004 Oct, 86(3), 263 - 81
16S rDNA library-based analysis of ruminal bacterial diversity; E Edwards J et al.; Bacterial 16S rDNA sequence data, incorporating sequences > 1 kb, were retrieved from published rumen library studies and public databases, then were combined and analysed to assess the diversity of the rumen microbial ecosystem as indicated by the pooled data . Low G+C Gram positive bacteria (54%) and the Cytophaga-Flexibacter-Bacteroides (40%) phyla were most abundantly represented . The diversity inferred by combining the datasets was much wider than inferred by individual studies, most likely due to different diets enriching for bacteria with different fermentative activities . A total of 341 operational taxonomic units (OTU) was predicted by the Chao1 non-parametric estimator approach . Phylogenetic and database analysis demonstrated that 89% of the diversity had greatest similarity to organisms which had not been cultivated, and that several sequences are likely to represent novel taxonomic groupings . Furthermore, of the 11% of the diversity represented by cultured isolates (> 95% 16S rDNA identity), not all of the bacteria were of ruminal origin . This study therefore reinforces the need to reconcile classical culture-based rumen microbiology with molecular ecological studies to determine the metabolic role of uncultivated species.

Bioinformatics . 2004 Nov 11; {Epub ahead of print}
Operon prediction without a training set; Westover BP et al.; MOTIVATION: Annotation of operons in a bacterial genome is an important step in determining an organism's transcriptional regulatory program . While extensive studies of operon structure have been carried out in a few species, such as E . coli, fewer resources exist to inform operon prediction in newly sequenced genomes . In particular, many extant operon finders require a large body of training examples to learn the properties of operons in the target organism . For newly sequenced genomes, such examples are generally not available; moreover, a model of operons trained on one species may not reflect the properties of other, distantly related organisms . We encountered these issues in the course of predicting operons in the genome of Bacteroides thetaiotaomicron, a common anaerobe that is a prominent component of the normal adult human intestinal microbial community . RESULTS: We describe an operon predictor designed to work without extensive training data.We rely on a small set of a priori assumptions about the properties of the genome being annotated that permit estimation of the probability that two adjacent genes lie in a common operon . Predictions integrate several sources of information, including intergenic distance, common functional annotation, and a novel formulation of conserved gene order . We validate our predictor both on the known operons of E . coli and on the genome of B . theta, using expression data to evaluate our predictions in the latter . AVAILABILITY: software is available online at http://www.cse.wustl.edu/~jbuhler/research/operons.

Folia Microbiol (Praha), 2004, 49(4), 423 - 9
Soil microbial counts and identification of culturable bacteria in an extreme by arid zone; Su J et al.; Sixteen samples of two soil cores (about 550 and 180 cm in depth) were drilled at intervals in the lower reach of Heihe river basin (northwest of China) in order to illustrate soil microbial characteristics and diversity of culturable bacteria in an extreme by arid environment . Soil water content, organic matter, total nitrogen, pH, direct cell counts, and culturable microorganism counts were evaluated . The total cell concentration was 19-1120/microg (i.e . 0.19-11.2 x 10(8) per g) soil, the culturable bacteria count being 0.2-10.9 per microg (i.e . 2 x 10(5)-10.9 x 10(6) CFU/g) soil . The number of direct cell counts obtained by 4',6-diamidino-2-phenylindole-staining or the cound of culturable microbes after enrichment with different media were statistically significantly correlated with soil organic matters, total nitrogen content, soil water content and surface vegetation; this partly explained the larger number in the deeper first core than in the shallower one . As part of identification of 228 colonies isolated from the two cores, thirty-two were selected for 16S rDNA amplification, sequencing and molecular identification . These 32 isolates were affiliated to 5 major groups of bacteria: alpha-Proteobacteria, 5-Proteobacteria, gamma-Proteobacteria, the high-G+C G+-bacteria, the low-G+C G- -bacteria, and the Cytophaga-Flexibacter-Bacteroides group . Twenty-eight were rod- or short-rod shaped, which accounted for >87.5% of all species; only 4 of 32 species were cocci (<12.5%).

J Obstet Gynaecol, 1997, 17(3), 290 - 2
The determination of phospholipase A2 enzyme activity in the vaginal secretions of pregnant and non-pregnant women with bacterial vaginosis-and in culture exudates of its causative organisms; M Jones And S Al-Mushrif B; Summary Bacterial vaginosis (BV) is presently being cited as a probable cause of premature labour, where it is thought that an abnormal excess of phospholipase A2 enzyme (PLA2 ), generated by infecting organisms, prematurely liberates prostaglandins, which trigger-off the labour process . PLA levels of pregnant and non-pregnant women, with and without BV infection were compared . The in vitro concentrations of PLA2 in broth cultures of infecting organisms were also measured . Mean PLA2 level in non-infected pregnant women was 777 units per mg but was raised to 1226 U/mg in those with BV ( P=0.001) . Mean level in non-infected normal women was 21 U/mg, but was raised to 97 U/mg in those having BV ( P=0.001) . PLA2 concentrations in broth cultures of the causative organisms showed that most Bacteroides strains produced the enzyme, having a mean concentration of 95 U/mg, but that it was generated by only 34% of Gardnerella vaginalis strains, their mean concentration being 32 U/mg.

J Oral Sci, 2004 Sep, 46(3), 149 - 56
Intra-familial distribution of nine putative periodontopathogens in dental plaque samples analyzed by PCR; Okada M et al.; It is of great importance to understand the distribution of periodontopathogens within family members when considering the risk of periodontitis in children . The purpose of this study was to investigate the distribution of periodontopathogens among family members . We used the polymerase chain reaction method to test 4,8, and 7 probands with healthy gingiva, gingivitis, and periodontitis, respectively, and their 60 immediate family members . Plaque samples were collected from all erupted teeth sites using a sterile toothbrush . In 161 of the 165 positive cases, if a child harbored one of the periodontopathogens then at least one of the parents was also positive for the same bacterium . The prevalence of parent-child co-infection was 42.9% for Actinobacillus actinomycetemcomitans, 21.4% for Porphyromonas gingivalis, 29.2% for Treponema denticola, 59.5% for Tannerella forsythensis (Bacteroides forsythus) and 16.7% for Prevotella intermedia . Our results indicate that parents could be an important source of periodontopathogens for the colonization that occurs in their children.

Antimicrob Agents Chemother, 2004 Nov, 48(11), 4195 - 9
Pharmacodynamics of pulse dosing versus standard dosing: in vitro metronidazole activity against Bacteroides fragilis and Bacteroides thetaiotaomicron; Ibrahim KH et al.; Pulse dosing is a novel approach to dosing that produces escalating antibiotic levels early in the dosing interval followed by a prolonged dose-free period . Antibiotic is frontloaded by means of four sequential bolus injections, after which antibiotic levels are allowed to diminish until the next dose . This study compares standard thrice-daily dosing and pulse dosing of metronidazole against Bacteroides spp . in an in vitro model . Two American Type Culture Collection Bacteroides fragilis isolates (metronidazole MIC for each organism = 1 mg/liter) were exposed to metronidazole for 48 or 96 h . Human pharmacokinetics were simulated for an oral 500-mg dose given every 8 h (maximum concentration of drug {C(max)} = 12 mg/liter; half-life = 8 h; area under the curve {AUC} = 294 mg . h/liter) and for pulse dosing . Pulses, each producing an increase in metronidazole concentration of 9 mg/liter, were administered at times 0, 2, 4, and 6 h of each 24-h cycle, with a targeted half-life of 8 h (AUC = 347 mg . h/liter) . A metronidazole-resistant B . fragilis strain (metronidazole MIC = 32 mg/liter) was exposed to both dosing regimens and, additionally, to a regimen of 1,500 mg administered once daily (C(max) = 36 mg/liter; AUC = 364 mg . h/liter) . Furthermore, regimens against one B . fragilis isolate and one B . thetaiotaomicron isolate corresponding to one-fourth and one-eighth of the thrice-daily and pulse dosing regimens, mimicking peak metronidazole concentrations achieved in abscesses, were simulated in 48-h experiments (metronidazole MIC = 1 mg/liter) . Time-kill curves were generated for each experiment and analyzed for bactericidal activity, defined as a bacterial burden reduction >/= 3 log(10) CFU/ml . The results of paired (Wilcoxon matched-pair signed-rank test) and nonpaired (Mann-Whitney test) statistical analyses conducted on time to 3 log(10) kill data and area under the kill curve data from each of the thrice-daily dosing experiments versus each of the pulse dosing experiments were considered not significant for a given isolate-dosing regimen combination . The thrice-daily dosing, pulse dosing, and once-daily dosing regimens all exhibited bactericidal activity . Metronidazole administered in standard or pulse dosing fashion was highly active against both susceptible and resistant strains of Bacteroides spp.

Turk J Pediatr, 2004 Jul-Sep, 46(3), 279 - 82
Pyogenic liver abscesses in a child spreading to pulmonary and subcutaneous tissues: case report; Arslan N et al.; Pyogenic liver abscess is a rare and life-threatening disease in children . Our case is noteworthy because of the rapid advancement of liver abscesses without any other systemic disorder . A 16-year-old girl was admitted to the hospital with fatigue, pallor, weight loss and high fever . In physical examination a fluctuating mass was observed under the scapular area and hepatosplenomegaly was found . In computed tomography, three septated cystic lesions which looked like abscesses were demonstrated in the liver . The abscess was drained through percutaneous route . Right pleural empyema with clinical features of adult respiratory distress syndrome appeared after the first day of treatment . Bacteroides sp . was isolated from pus . On the twentieth day of the therapy, control abdominal computed tomography revealed two new abscesses in the liver . They were drained and the antibiotic therapy was continued with ticarcillin-clavulanate, fluconazole and levofloxacin . By the end of the first week of the therapy, the fever of the patient had abated . This therapy was continued for four weeks; 15 days after the end of the therapy there was prominent healing of the liver lesions with only one necrotic remnant 2 cm in diameter on abdominal computed tomography.

J Biol Chem, 2004 Dec 31, 279(53), 55840 - 9 Epub 2004 Oct 18.
Structural basis of 5-nitroimidazole antibiotic resistance: the crystal structure of NimA from Deinococcus radiodurans; Leiros HK et al.; 5-Nitroimidazole-based antibiotics are compounds extensively used for treating infections in humans and animals caused by several important pathogens . They are administered as prodrugs, and their activation depends upon an anaerobic 1-electron reduction of the nitro group by a reduction pathway in the cells . Bacterial resistance toward these drugs is thought to be caused by decreased drug uptake and/or an altered reduction efficiency . One class of resistant strains, identified in Bacteroides, has been shown to carry Nim genes (NimA, -B, -C, -D, and -E), which encode for reductases that convert the nitro group on the antibiotic into a non-bactericidal amine . In this paper, we have described the crystal structure of NimA from Deinococcus radiodurans (drNimA) at 1.6 A resolution . We have shown that drNimA is a homodimer in which each monomer adopts a beta-barrel fold . We have identified the catalytically important His-71 along with the cofactor pyruvate and antibiotic binding sites, all of which are found at the monomer-monomer interface . We have reported three additional crystal structures of drNimA, one in which the antibiotic metronidazole is bound to the protein, one with pyruvate covalently bound to His-71, and one with lactate covalently bound to His-71 . Based on these structures, a reaction mechanism has been proposed in which the 2-electron reduction of the antibiotic prevents accumulation of the toxic nitro radical . This mechanism suggests that Nim proteins form a new class of reductases, conferring resistance against 5-nitroimidazole-based antibiotics.

J Periodontal Res, 2004 Dec, 39(6), 442 - 6
Periodontal pathogens in atheromatous plaques . A controlled clinical and laboratory trial; Cairo F et al.; OBJECTIVE: A possible relationship between periodontitis and cardiovascular disease has been suggested . The aims of this controlled clinical study were: (i) to ascertain the presence of periodontal bacteria DNA {Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis (formerly Bacteroides forsythus)} in carotid atheromatous plaques and (ii) to assess the concomitant presence of the same periodontal bacteria DNA, if any, in periodontal pockets and in carotid atheroma in the same patient . METHODS: A total of 52 patients scheduled for carotid endarderectomy were enrolled in this study . The test group consisted of 26 dentate patients; the control group included 26 edentulous patients . A complete periodontal examination, including radiographic orthopanoramic and subgingival plaque sample, was performed in the test population . Oral and X-ray examinations were performed in the control group . Atheromatous plaques were harvested during surgical procedure for each dentate and edentulous patient and then sent to the microbiological laboratory . Subgingival plaque samples and carotid specimens were examined using the polymerase chain reaction (PCR) technique by means of specific primers for periodontal bacteria . Amplification of extracted DNA was tested using human beta-globin specific-primers . RESULTS: Out of 52 endarterectomy samples, 12 (seven dentate, five edentulous patients) were excluded as negative to DNA amplification . In subgingival plaque samples of 19 test patients, T . forsythensis (79%), F . nucleatum (63%), P . intermedia (53%), P . gingivalis (37%) and A . actinomycetemcomitans (5%) were found . No periodontal bacteria DNA was detected by PCR in any of the carotid samples in either patient group . CONCLUSION: The presence of periodontal bacteria DNA in atheromatous plaques could not be confirmed by this study and thus no correlation could be established between species associated with periodontal disease and putative bacteria contributing to atheromatous plaques . (c)Blackwell Munksgaard 2004

Dig Dis Sci, 2004 Sep, 49(9), 1425 - 32
Are Helicobacter species and enterotoxigenic Bacteroides fragilis involved in inflammatory bowel disease?
Basset C, Holton J, Bazeos A, Vaira D, Bloom S.
The aim of this study was to determine if either Helicobacter or enterotoxigenic Bacteroidesfragilis (ETBF) was linked to inflammatory bowel disease (IBD), using PCR . We analyzed the luminal washings and colonic biopsies of 35 patients with IBD and 37 control patients . The presence of Helicobacter was confirmed in the luminal washing of one IBD patient and three control patients and in the biopsies of two IBD patients . Ten of 28 control patients and 8 of 32 IBD patients had a positive luminal washing for the enterotoxin gene . Six of 33 control patients and 4 of 32 IBD patients had positive biopsies . The prevalence of the enterotoxin gene was higher in IBD patients with active disease compared with patients with inactive disease, although it did not achieve statistical significance . In conclusion, Helicobacter was not associated with IBD in our population of patients, although ETBF may be associated with active disease.

An Med Interna, 2004 Sep, 21(9), 425 - 32
{Anaerobic bacteriemias: clinical and epidemiological characteristics of anaerobic bacteremias in ten years}; Ruiz-Giardin JM et al.; BACKGROUND: The anaerobic bacteremia incidence is decreasing during the last years, and although it carries a high mortality rate there are studies that ask about the possibility of avoid anaerobic blood cultures thinking about the clinical prediction capacity of them . The objective of this study is the analysis of incidence and clinical characteristics of anaerobic bacteremias in two periods with 10 years of difference and empiric antibiotic treatment received, and if it was changed when microbiological results were received . METHODS: Prospective study of anaerobic bacteremias during 1985-86 and 1996-97, at university hospital analyzing clinical characteristics, incidence, analysis, evolution and empiric antibiotic treatment received . The statistical analysis was performed with the chi square test or exact Fisher test with statistical significance with p<0.05, talking about variables with p<0.10 . RESULTS: The incidence of anaerobic bacteremias was higher in 1996-97 with 24 cases (5.08%), that during 1985-86 with 22 cases (4.24%) . The variables with statistical significative differences with p<0.10 were: intrahospitalary adquisition (p<0.10); genitourinary and vascular manipulation (p=0.02 and p=0.06), and hypotension (p=0.034) more frequent during the first period than during the second one . There isn t statistical difference in evolution to cure although the percentage was higher during the second period (62.5%), that during the first one (54.6%), being the empiric treatment very high in both periods . Bacteroides fragilis was the most frequent microorganism and abdominal origin the most frequent one in both periods . CONCLUSION: Although there is a low anaerobic bacteremia incidence this one hasn't diminished in ten years . Anaerobic bacteremias have a high mortality index although the most part of empirical antibiotic treatments are correct . It could ask about the possibility of avoid anaerobic blood cultures or ask about them only in clinic suspicion of them.

Proc Natl Acad Sci U S A, 2004 Oct 12, 101(41), 14919 - 24 Epub 2004 Oct 04.
Genomic analysis of Bacteroides fragilis reveals extensive DNA inversions regulating cell surface adaptation; Kuwahara T et al.; Bacteroides are predominant human colonic commensals, but the principal pathogenic species, Bacteroides fragilis (BF), lives closely associated with the mucosal surface, whereas a second major species, Bacteroides thetaiotaomicron (BT), concentrates within the colon . We find corresponding differences in their genomes, based on determination of the genome sequence of BF and comparative analysis with BT . Both species have acquired two mechanisms that contribute to their dominance among the colonic microbiota: an exceptional capability to use a wide range of dietary polysaccharides by gene amplification and the capacity to create variable surface antigenicities by multiple DNA inversion systems . However, the gene amplification for polysaccharide assimilation is more developed in BT, in keeping with its internal localization . In contrast, external antigenic structures can be changed more systematically in BF . Thereby, at the mucosal surface, where microbes encounter continuous attack by host defenses, BF evasion of the immune system is favored, and its colonization and infectious potential are increased.

Appl Environ Microbiol, 2004 Oct, 70(10), 5955 - 62
Bacterial community associated with black band disease in corals; Frias-Lopez J et al.; Black band disease (BBD) is a virulent polymicrobial disease primarily affecting massive-framework-building species of scleractinian corals . While it has been well established that the BBD bacterial mat is dominated by a cyanobacterium, the quantitative composition of the BBD bacterial mat community has not described previously . Terminal-restriction fragment length polymorphism (T-RFLP) analysis was used to characterize the infectious bacterial community of the bacterial mat causing BBD . These analyses revealed that the bacterial composition of the BBD mat does not vary between different coral species but does vary when different species of cyanobacteria are dominant within the mat . On the basis of the results of a new method developed to identify organisms detected by T-RFLP analysis, our data show that besides the cyanobacterium, five species of the division Firmicutes, two species of the Cytophaga-Flexibacter-Bacteroides (CFB) group, and one species of delta-proteobacteria are also consistently abundant within the infectious mat . Of these dominant taxa, six were consistently detected in healthy corals . However, four of the six were found in much higher numbers in BBD mats than in healthy corals . One species of the CFB group and one species of Firmicutes were not always associated with the bacterial communities present in healthy corals . Of the eight dominant bacteria identified, two species were previously found in clone libraries obtained from BBD samples; however, these were not previously recognized as important . Furthermore, despite having been described as an important component of the pathogenetic mat, a Beggiatoa species was not detected in any of the samples analyzed . These results will permit the dominant BBD bacteria to be targeted for isolation and culturing experiments aimed at deciphering the disease etiology.

Appl Environ Microbiol, 2004 Oct, 70(10), 5853 - 8
Characterization of plasmid pOR1 from Ornithobacterium rhinotracheale and construction of a shuttle plasmid; Jansen R et al.; The bacterium Ornithobacterium rhinotracheale has been recognized as an emerging pathogen in poultry since about 10 years ago . Knowledge of this bacterium and its mechanisms of virulence is still very limited . Here we report the development of a transformation system that enables genetic modification of O . rhinotracheale . The system is based on a cryptic plasmid, pOR1, that was derived from an O . rhinotracheale strain of serotype K . Sequencing indicated that the plasmid consisted of 14,787 nucleotides . Sequence analysis revealed one replication origin and several rep genes that control plasmid replication and copy number, respectively . In addition, pOR1 contains genes with similarity to a heavy-metal-transporting ATPase, a TonB-linked siderophore receptor, and a laccase . Reverse transcription-PCR demonstrated that these genes were transcribed . Other putative open reading frames exhibited similarities with a virulence-associated protein in Actinobacillus actinomycetemcomitans and a number of genes coding for proteins with unknown function . An Escherichia coli-O . rhinotracheale shuttle plasmid (pOREC1) was constructed by cloning the replication origin and rep genes from pOR1 and the cfxA gene from Bacteroides vulgatus, which codes for resistance to the antibiotic cefoxitin, into plasmid pGEM7 by using E . coli as a host . pOREC1 was electroporated into O . rhinotracheale and yielded cefoxitin-resistant transformants . The pOREC1 isolated from these transformants was reintroduced into E . coli, demonstrating that pOREC1 acts as an independent replicon in both E . coli and O . rhinotracheale, fulfilling the criteria for a shuttle plasmid that can be used for transformation, targeted mutagenesis, and the construction of defined attenuated vaccine strains.

J Biol Chem, 2004 Dec 10, 279(50), 52346 - 52 Epub 2004 Dec 10.
TetX is a flavin-dependent monooxygenase conferring resistance to tetracycline antibiotics; Yang W et al.; The tetracycline antibiotics block microbial translation and constitute an important group of antimicrobial agents that find broad clinical utility . Resistance to this class of antibiotics is primarily the result of active efflux or ribosomal protection; however, a novel mechanism of resistance has been reported to be oxygen-dependent destruction of the drugs catalyzed by the enzyme TetX . Paradoxically, the tetX genes have been identified on transposable elements found in anaerobic bacteria of the genus Bacteroides . Overexpression of recombinant TetX in Escherichia coli followed by protein purification revealed a stoichiometric complex with flavin adenine dinucleotide . Reconstitution of in vitro enzyme activity demonstrated a broad tetracycline antibiotic spectrum and a requirement for molecular oxygen and NADPH in antibiotic degradation . The tetracycline products of TetX activity were unstable at neutral pH, but mass spectral and NMR characterization under acidic conditions supported initial monohydroxylation at position 11a followed by intramolecular cyclization and non-enzymatic breakdown to other undefined products . TetX is therefore a FAD-dependent monooxygenase . The enzyme not only catalyzed efficient degradation of a broad range of tetracycline analogues but also conferred resistance to these antibiotics in vivo . This is the first molecular characterization of an antibiotic-inactivating monooxygenase, the origins of which may lie in environmental bacteria.

Infect Immun, 2004 Oct, 72(10), 5832 - 9
Bacteroides fragilis enterotoxin induces intestinal epithelial cell secretion of interleukin-8 through mitogen-activated protein kinases and a tyrosine kinase-regulated nuclear factor-kappaB pathway; Wu S et al.; Enterotoxigenic Bacteroides fragilis (ETBF) secretes a 20-kDa metalloprotease toxin termed B . fragilis toxin (BFT) . ETBF disease in animals is associated with an acute inflammatory response in the intestinal mucosa, and lethal hemorrhagic colitis may occur in rabbits . In this study, we confirmed recent reports (J . M . Kim, Y . K . Oh, Y . J . Kim, H . B . Oh, and Y . J . Cho, Clin . Exp . Immunol . 123:421-427, 2001; L . Sanfilippo, C . K . Li, R . Seth, T . J . Balwin, M . J . Menozzi, and Y . R . Mahida, Clin . Exp . Immunol . 119:456-463, 2000) that purified BFT stimulates interleukin-8 (IL-8) secretion by human intestinal epithelial cells (HT29/C1 cells) and demonstrate that stimulation of IL-8 production is dependent on biologically active BFT and independent of serum . Induction of IL-8 mRNA expression occurs rapidly and ceases by 6 h after BFT treatment, whereas IL-8 secretion continues to increase for at least 18 h . Our data suggest that BFT-stimulated IL-8 secretion involves tyrosine kinase-dependent activation of nuclear factor-kappaB (NF-kappaB) as well as activation of the mitogen-activated protein kinases (MAPKs), p38 and extracellular signal-related kinase . Simultaneous activation of NF-kappaB and MAPKs appears necessary for secretion of IL-8 by HT29/C1 cells treated with BFT.

J Clin Microbiol, 2004 Sep, 42(9), 4127 - 9
Isolation of metronidazole-resistant Bacteroides fragilis carrying the nimA nitroreductase gene from a patient in Washington State; Schapiro JM et al.; Members of the Bacteroides fragilis group are among the most common anaerobic bacterial isolates in clinical specimens . Metronidazole, a 5-nitroimidazole, is often used as empirical therapy for anaerobic infections . Susceptibility testing is not routinely performed because of nearly universal susceptibility of Bacteroides spp . to this agent . We report a case of metronidazole-resistant Bacteroides fragilis in the United States and demonstrate the presence of the nimA gene, encoding a nitroreductase previously shown to mediate resistance to 5-nitroimidazole antimicrobial agents in B . fragilis strains from Europe and Africa . Because clinical failures in Bacteroides infections have been associated with the use of inactive antimicrobial agents, clinicians need to be aware of the possibility of metronidazole-resistant B . fragilis strains in the United States and the importance of susceptibility testing in selected situations.

Eur J Obstet Gynecol Reprod Biol, 2004 Oct 15, 116(2), 152 - 6
Relationship between a toll-like receptor-4 gene polymorphism, bacterial vaginosis-related flora and vaginal cytokine responses in pregnant women; Genc MR et al.; OBJECTIVE: The relationship between a single nucleotide polymorphism (TLR4 896 A > G) in the toll-like receptor-4 (TLR4) gene, qualitative and quantitative changes in vaginal micro-flora and vaginal interleukin (IL)-1beta and IL-1 receptor antagonist (IL-1ra) concentrations in pregnant women were evaluated . STUDY DESIGN: Qualitative and quantitative microbial methods were used to characterize vaginal micro-flora of 238 women at 18-22 weeks gestation . Polymerase chain reaction was used to determine TLR4 genotype . IL-1beta and IL-1ra concentrations in vaginal lavage samples were measured by ELISA . RESULTS: The TLR4 variant was identified in 10.3% of women . Carriage of this variant was associated with a median increase in vaginal pH (P = 0.05), a greater than 10-fold increase in vaginal Gardnerella vaginalis levels (P < 0.0001) and a 10-fold increase in the vaginal concentration of three species of anaerobic Gram-negative rods, Prevotella, Bacteroides, and Porphyromonas (P = 0.08 ) . Colonization with G . vaginalis and/or the anaerobic Gram-negative rods resulted in elevated vaginal IL-1 (P = 0.01) and IL-1ra (P < 0.0002) concentrations in women who were TLR4 896A homozygotes, but not in TLR4 896G carriers . CONCLUSION: The TLR4 896 A > G polymorphism contributes to inter-individual differences in the vaginal immune defense against G . vaginalis and anaerobic Gram-negative rods.

Am J Orthod Dentofacial Orthop, 2004 Sep, 126(3), 363 - 6
Clinical and microbiologic changes after removal of orthodontic appliances; Sallum EJ et al.; The goal of this study was to evaluate the clinical and microbiological factors associated with orthodontic appliances during an episode of gingival inflammation and the impact of appliance removal on periodontal health . This prospective study included 10 patients, aged 12 to 20 years, with clinical signs of gingival inflammation at the final phase of orthodontic treatment (appliance removal) . Plaque index, gingival index, and probing depth were evaluated, and microbiological samples were collected from teeth 16, 11, and 26 at 2 times: during the gingival inflammation (baseline) and 30 days after the removal of the appliance and professional prophylaxis . Polymerase chain reaction analysis was used to detect Porphyromonas gingivalis, Bacteroides forsythus, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Prevotella nigrescens . A statistically significant improvement of the plaque and gingival indexes was seen, as well as a reduction in probing depth (P <.05) . Periodontal pathogens were associated with gingival inflammation during orthodontic treatment . The improvement in periodontal health at 30 days was concomitant with a reduction of sites positive for A . actinomycetemcomitans and B . forsythus (P <.05) . Periodontal pathogens associated with gingival inflammation during orthodontic treatment can be significantly reduced by orthodontic appliance removal and professional prophylaxis.

J Bacteriol, 2004 Sep, 186(18), 6077 - 92
The Bacteroides fragilis pathogenicity island is contained in a putative novel conjugative transposon; Franco AA; The genetic element flanking the Bacteroides fragilis pathogenicity island (BfPAI) in enterotoxigenic B . fragilis (ETBF) strain 86-5443-2-2 and a related genetic element in NCTC 9343 were characterized . The results suggested that these genetic elements are members of a new family of conjugative transposons (CTns) not described previously . These putative CTns, designated CTn86 and CTn9343 for ETBF 86-5443-2-2 and NCTC 9343, respectively, differ from previously described Bacteroides species CTns in a number of ways . These new transposons do not carry tetQ, and the excision from the chromosome to form a circular intermediate is not regulated by tetracycline; they are predicted to differ in their mechanism of transposition; and their sequences have very limited similarity with CTnDOT or other described CTns . CTn9343 is 64,229 bp in length, contains 61 potential open reading frames, and both ends contain IS21 transposases . Colony blot hybridization, PCR, and sequence analysis indicated that CTn86 has the same structure as CTn9343 except that CTn86 lacks a approximately 7-kb region containing truncated integrase (int2) and rteA genes and it contains the BfPAI integrated between the mob region and the bfmC gene . If these putative CTns were to be demonstrated to be transmissible, this would suggest that the bft gene can be transferred from ETBF to nontoxigenic B . fragilis strains by a mechanism similar to that for the spread of antibiotic resistance genes.

Plasmid, 2004 Sep, 52(2), 119 - 30
Factors required in vitro for excision of the Bacteroides conjugative transposon, CTnDOT; Sutanto Y et al.; Four genes have been found to be essential for excision of the Bacteroides conjugative transposon CTnDOT in vivo: intDOT, orf2c, orf2d, and exc . The intDOT gene encodes an integrase that is essential for integration and excision . The function of the other genes is still uncertain . Previously, we developed an in vitro system for the integration reaction . We have now developed an in vitro system for excision . In this system, the left and right junctions of CTnDOT, attL, and attR, are provided on separate plasmids . The excision reaction produced a cointegrate which contained the attDOT (the joined ends of CTnDOT) and attB (the chromosomal target site) . Cointegrate formation was observed after electroporation of Escherichia coli with the assay mixture and was also detected directly in the assay mixture by Southern hybridization . The highest reaction frequencies (10(-3)) were obtained with a mixture that contained purified IntDOT and a cell extract from Bacteroides thetaiotaomicron 4001, which contained the excision region of CTnDOT carried on a plasmid . An unexpected finding was that the addition of purified Exc, which is essential for excision in vivo, was not required for excision in vitro, nor did it increase the frequency of cointegrate formation.

Acta Microbiol Pol, 2004, 53(1), 35 - 9
Enterotoxigenic Bacteroides fragilis (ETBF) strains isolated in The Netherlands and Poland are genetically diverse; Obuch-Woszczatynski P et al.; Gram-negative anaerobic rods isolated in The Netherlands and Poland from extraintestinal and intestinal sources were identified as Bacteroides fragilis (n = 210) on the basis of Gram staining, growth on selective Bacteroides Bile Esculine medium as black colonies, and biochemical characteristics . PCR-mediated assessment of the presence of the B . fragilis enterotoxin (fragilysin) gene in all strains identified 12 so-called enterotoxin-positive B . fragilis (ETBF) strains (15%) among the Dutch strains and 16 ETBF among the Polish strains (13%) . NotI Pulsed Field Gel Electrophoresis (PFGE) analysis revealed that these strains are genetically heterogeneous . Among the Dutch strains an identical pair and a set of four indiscriminate strains were identified . This suggests that limited nosocomial spread of ETBF can be observed . However, there was no identity obeserved when strains from The Netherlands were compared to their Polish counterparts . The antimicrobial susceptibility testing revealed that one Polish strain isolated from a patient with antibiotic associated diarrhoeae (AAD) was simultaneously highly resistant to clindamycin and cefoxitin (MIC>256 mg/L) . Two other strains appeared to be clindamycin resistant . All resistant strains had different PFGE patterns, suggesting that resistance development occurred at independent occassions.

Infez Med, 2004 Mar, 12(1), 44 - 50
Efficacy of Telithromycin in the treatment of experimental Bacteroides fragilis intraabdominal abscess in the senescent mice; Thadepalli H et al.; The efficacy of telithromycin (HMR 3647), a new ketolide, in the treatment of experimental Bacteroides fragilis intraabdominal abscess in young and senescent mice was evaluated . Two different age groups of mice, young (2-3 months) and senescent (18-24 months) were used in this study . Telithromycin (50mg/kg/bid) was compared with clindamycin and metronidazole, both administered in 100 mg/kg/bid doses . Telithromycin cured the infection in 74% of the young and 67% of the old mice but this difference was not significant . Telithromycin efficacy was comparable to that of clindamycin which cured 82% of the young and 75% of the old, but was superior to the efficacy of metronidazole, which cured 61% of the young and 50% of the senescent mice . Young animals that were not cured by any of the three antibiotics showed decrease in the viable bacterial cell counts by two logs while the senescent mice had a one log difference . Serum, pus and tissue concentrations of telithromycin were five-fold higher in the old mice than in the young . Age by itself had no adverse effect on therapeutic outcome of any of the three antibiotics used.

Int Endod J, 2004 Sep, 37(9), 588 - 92
Induction of vascular endothelial growth factor expression in human pulp fibroblasts stimulated with black-pigmented Bacteroides; Yang LC et al.; AIM: To investigate the effect of black-pigmented Bacteroides on the expression of vascular endothelial growth factor (VEGF) gene in human pulp fibroblasts . METHODOLOGY: The supernatants of Porphyromonas endodontalis, Porphyromonas gingivalis and Prevotella intermedia were used to evaluate VEGF gene expression in human pulp fibroblasts . The levels of mRNAs were measured by the quantitative reverse-transcriptase polymerase chain reaction analysis . RESULTS: Black-pigmented Bacteroides induced significantly high levels of VEGF mRNA gene expression in human pulp fibroblasts (P < 0.05) . In addition, the expression of VEGF depended on the bacteria tested . CONCLUSIONS: Black-pigmented Bacteroides may be involved in developing pulpal disease through the stimulation of VEGF production that would lead to the expansion of the vascular network coincident to progression of the inflammation.

Res Microbiol, 2004 Sep, 155(7), 522 - 4
Non-toxigenic pattern II and III Bacteroides fragilis strains: coexistence in the same host; Antunes EN et al.; Diarrhoeic stool samples from 334 0-5-year-old children were analysed with respect to the incidence of Bacteroides fragilis as well as other enteropathogens . B . fragilis was recovered in 9.3% (31/334) of the samples, and 79 strains were examined for the presence of the bft gene or the BfPAI flanking region using polymerase chain reaction assays . No enterotoxigenic B . fragilis strains were detected . In 29% (9/31) of the samples the coexistence of both II and III non-toxigenic B . fragilis (NTBF) patterns could be seen . In 51.6% (16/31) of the samples there existed a pattern II NTBF only, and in 19.4% (6/31) only pattern III could be detected . Strains from the same patient representing different patterns were submitted to pulsed-field gel electrophoresis assays . Fingerprints obtained by this technique showed that there was strong heterogeneity among strains from different individuals . However, different patterns from the same individual shared 100% similarity.

Acta Crystallogr D Biol Crystallogr, 1997 Jul, 53(Pt 4), 485 - 7
Purification, crystallization and preliminary X-ray analysis of Bacteroides fragilis Zn(2+) beta-lactamase; Carfi A; The Zn(2+) beta-lactamase from Bacteroides fragilis (E.C . 3.5.2.6) was overexpressed in Escherichia coli using an isopropylthiogalactoside-inducible T7 RNA polymerase expression system . Crystallization trials by the hanging-drop vapour-diffusion method have yielded two different crystal forms from two slightly different conditions . Crystals of form I belong to the monoclinic space group C2 with unit-cell dimensions a = 56.03, b = 43.98, c = 105.32 A, beta = 112 degrees and diffracted only up to 4.0 A . Crystals of form II are orthorhombic, space group P2(1)2(1)2(1) with unit-cell dimensions a = 48.10, b = 98.05, c = 111.76 A, diffract to at least 2.0 A and are suitable for high-resolution structural analysis.

Hua Xi Kou Qiang Yi Xue Za Zhi, 2004 Jun, 22(3), 177 - 9
{Separation of Bacteroides forsythus ATCC43037 proteins by horizontal two-dimensional gel electrophoresis}; Huang DM et al.; OBJECTIVE: To set up a rapid, efficient, reliable and accurate method for separation of Bacteriodes forsythus proteins . METHODS: Bacteroides forsythus ATCC43037 cells were harvested by centrifugation, washed in Tris buffer to remove excess medium, and lysed by sonication . The sonicated lysis proteins were extracted step by step with ReadyPrep Sequential Extraction Kit (Bio-Rad) . The supernatant of B . forsythus proteins were used for two-dimensional gel electrophoresis . The first dimension IEF (isoelectric focusing) was run with Immobiline DryStrip (pH 3-10) and the second dimension SDS-PAGE was run with Excelgel SDS, gradient 8-18 precast gel and buffer strips . The separated proteins were stained with Coomassie Brilliant Blue and silver staining kit (Plusone Silver Staining Kit, Protein, Pharmacia Biotech) . RESULTS: 1 . The protein spots were clear when sample cups were used in the middle of IPG strip during IEF . 2 . B . forsythus proteins were separated clearly by horizontal two-dimensional electrophoresis and most of B . forsythus whole-cell proteins were acidic proteins (P13-7) . CONCLUSION: Horizontal two-dimension electrophoresis is a useful method for separating B . forsythus proteins.

Int J Antimicrob Agents, 2004 Aug, 24(2), 135 - 43
A Bacteroides thetaiotamicron porin that could take part in resistance to beta-lactams; Behra-Miellet J et al.; The aim of this study was to investigate porin absence or deficiency in two Bacteroides thetaiotaomicron strains resistant to amoxicillin combined with clavulanic acid . Their outer membrane protein (OMP) extracts and those of two susceptible strains were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and compared to detect differences between the strains . A protein band of interest at around 70 kDa electro-eluted for each strain, was tested in a liposome swelling assay . A decrease in initial absorbency was noted for the two susceptible strains but not for the two resistant strains . The liposome swelling of the two susceptible strains was directly visualized by photon microscopy and then photographed . This suggested a B . thetaiotaomicron porin of around 70 kDa could take part in resistance to beta-lactams.

Mem Inst Oswaldo Cruz, 2004 May, 99(3), 319 - 24 Epub 2004 Jul 19.
Survey of antimicrobial susceptibility patterns of the bacteria of the Bacteroides fragilis group isolated from the intestinal tract of children; Nakano V et al.; The bacteria of the Bacteroides fragilis group are considered important clinical pathogens and they are the most common anaerobes isolated from human endogenous infections . In this study, the susceptibility patterns to antibiotics and metals of 114 species of the B . fragilis group isolated from children with and without diarrhea were determined . Susceptibility was assayed by using an agar dilution method with Wilkins-Chalgren agar . All B . fragilis strains were resistant to lead and nickel, but susceptible to metronidazole and imipenem . beta-lactamase production was detected by using biological and nitrocefin methods, respectively, in 50% and 90.6% of the isolates of children with diarrhea and in 60% and 90% of the isolates of children without diarrhea . Our results show an increase of antibiotics and metals resistance in this microbial group, and a periodic evaluation of the antimicrobial susceptibility is needed . In Brazil, the contamination for antibiotics or metal ions is often observed, and it is suggested an increase the antimicrobial resistance surveillance of this microbial group, mainly those isolated from children's diarrhea.

Mem Inst Oswaldo Cruz, 2004 May, 99(3), 307 - 12 Epub 2004 Jul 19.
Virulence markers and antimicrobial susceptibility of bacteria of the Bacteroides fragilis group isolated from stool of children with diarrhea in São Paulo, Brazil; Nakano V et al.; Bacteroides fragilis has been isolated from several human and non-human monomicrobial and mixed infections . In this study, some virulence markers and the antimicrobial susceptibility of bacteria of the B . fragilis group isolated from children's stools were evaluated . All the 64 isolates showed the following characteristics: capsulated, beta-hemolytic, hydrophilic, and serum-resistant . Only, 24 (37.5%) strains were resistant at 60 masculine C, for 30 min, and among them, 12 (18.75%) were resistant at 60 masculine C, for 60 min . Also, none strain was resistant at 100 masculine C . Four strains were able to hemagglutinate erythrocytes and D-mannose, D-galactose, D-arabinose, and D-xylose inhibited hemagglutination in 2 B . fragilis strains (p76a, p76b) . The hemagglutination in the strain B . uniformis p3-2 was inhibited by D-xylose and D-galactose . The bft gene detection and the enterotoxin production were observed only in 13 EF-enterotoxigenic species . Fragilysin activity was confirmed on HT-29 cells . The antimicrobial determination confirmed that both imipenem and metronidazole were efficient against B . fragilis species; all the strains were resistant to lead and nickel . Plasmids of 2.9, 4.4, 4.8, and 8.9 kb were observed in 6 tested strains . These results show the values of the species identification from clinical infections, as well as of the periodic evaluation of the resistance patterns of the B . fragilis group at Brazilian medical institutions.

J Adolesc Health, 2004 Aug, 35(2), 156 - 8
Allergic symptoms and microflora in schoolchildren; Fukuda S et al.; We studied 867 junior high school children and administered a questionnaire documenting allergic symptoms and environmental variables, and measured Immunoglobulin E serum levels and the immunoglobulin G titers of serum antibody to microflora . A total of 716 subjects were ultimately used for statistics; those with at least two of the following allergic symptoms: asthma, rhinitis, eczema, or food allergy, showed significantly higher IgG titers to Bactroides vulgatus than other groups . This finding suggests that a species of the Bacteroides genus of the intestinal microflora tends to affect the gut issues, but further studies are needed to clarify this.

Microbiology, 2004 Jul, 150(Pt 7), 2125 - 34
Transcriptional regulation of the Bacteroides fragilis ferritin gene (ftnA) by redox stress; Rocha ER et al.; This study shows that the iron-storage protein ferritin is a component of the redox-stress response in the obligate anaerobe Bacteroides fragilis . It is up-regulated at transcriptional level under aerobic conditions but constitutively expressed at low levels under anaerobic conditions . Northern hybridization and primer extension analysis revealed that ftnA is transcribed as a monocistronic mRNA of approximately 600 nt . Under reduced anaerobic conditions, ftnA mRNA levels were not dependent on the iron content of the culture medium . Following oxygen exposure ftnA message increased about 10-fold in iron-replete medium compared to a fourfold increase under low-iron conditions . Addition of the oxidant potassium ferricyanide induced expression of ftnA mRNA anaerobically, suggesting that the oxidation of the medium affected expression of ftnA . Two transcription initiation start sites were identified . Both transcripts were expressed constitutively under anaerobic conditions but one promoter was induced by oxidative stress or the addition of the oxidant potassium ferricyanide . The effect of redox stress on ftnA expression was further investigated by addition of diamide, a thiol-oxidizing agent, which induced ftnA mRNA levels anaerobically, suggesting that an unbalanced cellular redox state also affects ftnA expression . Induction by hydrogen peroxide and oxygen was decreased in an oxyR deletion mutant but some oxygen induction still occurred . This strongly suggests that ftnA is regulated by both the peroxide response transcriptional activator, OxyR, and another unidentified oxygen-dependent regulator . Taken together, these data show that ftnA mRNA levels are controlled by both iron and oxidative stress; this coordinated regulation may be important for survival in an adverse aerobic environment.

Folia Microbiol (Praha), 2004, 49(2), 151 - 5
The effects of plant extracts on microbial community structure in a rumen-simulating continuous-culture system as revealed by molecular profiling; Ferme D et al.; An in vitro study in dual-flow continuous-culture fermentors was conducted with two different concentrations of monensin, cinnamaldehyde or garlic extract added to 1:1 forage-to-concentrate diet in order to determine their effects on selected rumen bacterial populations . Samples were subjected to total DNA extraction, restriction analysis of PCR amplified parts of 16S rRNA genes (ARDRA) and subsequent analysis of the restriction profiles by lab-on-chip technology with the Agilent's Bioanalyser 2100 . Eub338-BacPre primer pair was used to select for the bacteria from the genera Bacteroides, Porphyromonas and Prevotella, especially the latter representing the dominant Gram-negative bacterial population in the rumen . Preliminary results of HaeIII restriction analysis show that the effects of monensin, cinnamaldehyde and garlic extract on the BacPre targeted ruminal bacteria are somewhat different in regard to targeted populations and to the nature of the effect . Garlic extract was found to trigger the most intensive changes in the structure of the BacPre targeted population . Comparison of the in silico restriction analysis of BacPre sequences deposited in different DNA databanks and of the results of performed amplified ribosomal DNA restriction analysis showed differences between the predicted and obtained HaeIII restriction profiles, and suggested the presence of novel, still unknown Prevotella populations in studied samples.

Int J Antimicrob Agents, 2004 Jul, 24(1), 53 - 8
Determinants of resistance in Bacteroides fragilis strains according to recent Brazilian profiles of antimicrobial susceptibility; Paula GR et al.; Susceptibility profiles of 99 Bacteroides fragilis strains for 9 antimicrobial agents were defined by using an agar dilution method . The isolates were uniformly susceptible to imipenen and metronidazole . All isolates were resistant to ampicillin . The resistance rates to amoxicillin/clavulanate, cefoxitin, cefotaxime, chloramphenicol, clindamycin and tetracycline were 3.0, 12.1, 15.1, 1.0, 18.2 and 75.7%, respectively . Sixteen strains showed reduced susceptibility to metronidazole (MIC 2-4 mg/L) but none had nim genes using PCR . All strains were also investigated for the presence of cepA, cfiA, cfxA, ermF and tetQ genes by PCR methodology and 92.9, 4.9, 24.2, 2 and 64.6% of the strains were respectively found positive . These results reflect the importance of surveys of susceptibility profiles and the relevance of detecting major genetic determinants to monitor the dissemination of these genes.

J Chemother, 2004 Apr, 16(2), 151 - 5
Comparison of systemic flurithromycin therapy and clinical procedures in the treatment of periodontal diseases; Blandino G et al.; The purpose of the present investigation was to evaluate, in 20 periodontal patients, the microbial and clinical effects of flurithromycin therapy plus scaling and root planning (SRP) in comparison with SRP alone . Clinical assessments of plaque, bleeding on probing and pocket depth were made prior to SRP alone and SRP plus flurithromycin therapy (375 mg twice daily for 5 days) and after both treatments . Subgingival plaque samples (n . 180) were taken prior to and after both treatments and analyzed by conventional bacteriological procedures . Differences in pocket depth and prevalence of bacterial species were analyzed pre- and post-therapies using statistical analyses . A significant decrease (p<0.001) was seen for pocket depth post SRP alone and post SRP plus flurithromycin . After two treatments, Actinobacillus actinomycetemcomitans, Bacteroides forsythus and Prevotella melaninogenica were eradicated from all tested sites . If we compare the prevalence of the species isolated after SRP alone and after SRP plus flurithromycin statistically significant differences were detected for P . gingivalis and for Fusobacterium nucleatum (p<0.05 and p<0.01, respectively) . Flurithromycin can be considered a useful adjunct to mechanical periodontal treatment since it is more efficient in eliminating periodontal pathogens.

Lett Appl Microbiol, 2004, 38(4), 327 - 32
Fermentation of pectin and glucose, and activity of pectin-degrading enzymes in the rabbit caecal bacterium Bacteroides caccae; Sirotek K et al.; AIMS: To compare fermentation pattern in cultures of Bacteroides caccae supplied with pectin and glucose, and identify enzymes involved in metabolism of pectin . METHODS AND RESULTS: A strain KWN isolated from the rabbit caecum was used . Fermentation pattern, changes of viscosity and enzyme reactions products were determined . Cultures grown on pectin produced significantly more acetate and less formate, lactate, fumarate and succinate than cultures grown on glucose . Production of cell dry matter and protein per gram of substrate used was the same in pectin- and glucose-grown cultures . The principal enzymes that participated in the metabolism of pectin were extracellular exopectate hydrolase (EC 3.2.1.67), extracellular endopectate lyase (EC 4.2.2.2) and cell-associated 2-keto-3-deoxy-6-phosphogluconate (KDPG) aldolase (EC 4.1.2.14) . The latter enzyme is unique to the Entner-Doudoroff pathway . Activities of pectinolytic enzymes in cultures grown on glucose were low . Activity of KDPG aldolase was similar in pectin- and glucose-grown cells . CONCLUSIONS: Metabolites and activities of pectin-degrading enzymes differed in cultures of B . caccae KWN grown on pectin and glucose . Yields of dry matter and protein were the same on both substrates . SIGNIFICANCE AND IMPACT OF THE STUDY: Information on metabolism of pectin in animal strains of Bacteroides is incomplete . This study extends the knowledge on metabolism in bacteria from the rabbit caecum.

Eur J Immunol, 2004 Jul, 34(7), 2052 - 9
NOD2 mediates anti-inflammatory signals induced by TLR2 ligands: implications for Crohn's disease; Netea MG et al.; Mutations of the NOD2 gene have been associated with an increased susceptibility to Crohn's disease, but the pathogenetic mechanisms mediated by NOD2 remain elusive . In the present study, we demonstrate that the 3020insC frameshift-mutation in the NOD2 gene associated with Crohn's disease results in defective release of IL-10 from blood mononuclear cells after stimulation with the Toll-like receptor (TLR)2 ligands, peptidoglycan and Pam3Cys-KKKK, but not with bacterial LPS, a TLR4 ligand . The potential pathophysiological significance of this finding in patients with Crohn's disease and who are homozygous for this NOD2 mutation was substantiated by the finding of decreased anti-inflammatory cytokine release when cells from these patients were stimulated with different species of Bacteroides, an enteric microorganism implicated in the pathogenesis of Crohn's disease . In conclusion, defective NOD2 function results in a pro-inflammatory cytokine bias after stimulation of mononuclear cells with TLR2 stimuli, and this could contribute to the overwhelming inflammation seen in Crohn's disease.

Chemotherapy, 2004 Jun, 50(2), 76 - 80
Therapeutic efficacy of moxifloxacin, a new quinolone, in the treatment of experimental intra-abdominal abscesses induced by Bacteroides fragilis in mice; Thadepalli H et al.; Moxifloxacin, a new quinolone, is effective in vitro against several anaerobic bacteria including Bacteroides fragilis, but its in vivo activity against anaerobic infections is not known . In this study, we evaluated the in vivo activity of moxifloxacin in the treatment of experimentally induced intra-abdominal abscesses (IAA) caused by B . fragilis . For comparison, clindamycin, metronidazole, and levofloxacin were used, and saline for control . Absence of bacteria (sterile) in the abscess pus was required to call it a cure . Mice were intraperitoneally injected with B . fragilis plus sterile rat feces and barium sulfate . Animals were treated with moxifloxacin (40 mg/kg/b.i.d.), clindamycin (75 mg/kg/b.i.d.), levofloxacin (40 mg/kg/b.i.d.) or metronidazole (75 mg/kg/b.i.d.) for 10 days . The cure rate was 12% in controls on saline therapy, 57% on metronidazole, 67% on levofloxacin, 73% on moxifloxacin and 79% on clindamycin . The therapeutic efficacy of moxifloxacin in this B . fragilis infection was not significantly different from that observed with clindamycin . By virtue of its established efficacy on gram-negative aerobic bacteria and the observed in vivo efficacy on B . fragilis, moxifloxacin can be evaluated in the treatment of clinical anaerobic infections .

Eur J Biochem, 2004 Jul, 271(13), 2670 - 81
Molecular and biochemical characterization of D-phosphoglycerate dehydrogenase from Entamoeba histolytica . A unique enteric protozoan parasite that possesses both phosphorylated and nonphosphorylated serine metabolic pathways; Ali V et al.; A putative phosphoglycerate dehydrogenase (PGDH), which catalyzes the oxidation of d-phosphoglycerate to 3-phosphohydroxypyruvate in the so-called phosphorylated serine metabolic pathway, from the enteric protozoan parasite Entamoeba histolytica was characterized . The E . histolytica PGDH gene (EhPGDH) encodes a protein of 299 amino acids with a calculated molecular mass of 33.5 kDa and an isoelectric point of 8.11 . EhPGDH showed high homology to PGDH from bacteroides and another enteric protozoan ciliate, Entodinium caudatum . EhPGDH lacks both the carboxyl-terminal serine binding domain and the 13-14 amino acid regions containing the conserved Trp139 (of Escherichia coli PGDH) in the nucleotide binding domain shown to be crucial for tetramerization, which are present in other organisms including higher eukaryotes . EhPGDH catalyzed reduction of phosphohydroxypyruvate to phosphoglycerate utilizing NADH and, less efficiently, NADPH; EhPGDH did not utilize 2-oxoglutarate . Kinetic parameters of EhPGDH were similar to those of mammalian PGDH, for example the preference of NADH cofactor, substrate specificities and salt-reversible substrate inhibition . In contrast to PGDH from bacteria, plants and mammals, the EhPGDH protein is present as a homodimer as demonstrated by gel filtration chromatography . The E . histolytica lysate contained PGDH activity of 26 nmol NADH utilized per min per mg of lysate protein in the reverse direction, which consisted 0.2-0.4% of a total soluble protein . Altogether, this parasite represents a unique unicellular protist that possesses both phosphorylated and nonphosphorylated serine metabolic pathways, reinforcing the biological importance of serine metabolism in this organism . Amino acid sequence comparison and phylogenetic analysis of various PGDH sequences showed that E . histolytica forms a highly supported monophyletic group with another enteric protozoa, cilliate E . caudatum, and bacteroides.

J Biol Chem, 2004 Aug 20, 279(34), 36103 - 11 Epub 2004 Jun 15.
15-deoxy-delta12,14-prostaglandin J2-mediated ERK signaling inhibits gram-negative bacteria-induced RelA phosphorylation and interleukin-6 gene expression in intestinal epithelial cells through modulation of protein phosphatase 2A activity; Ruiz PA et al.; We have previously shown that non-pathogenic Gram-negative Bacteroides vulgatus induces transient RelA phosphorylation (Ser-536), NF-kappaB activity, and pro-inflammatory gene expression in native and intestinal epithelial cell (IEC) lines . We now demonstrate that 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) but not prostaglandin E(2) inhibits lipopolysaccharide (LPS) (B . vulgatus)/LPS (Escherichia coli)-induced RelA phosphorylation and interleukin-6 gene expression in the colonic epithelial cell line CMT-93 . This inhibitory effect of 15d-PGJ(2) was mediated independently of LPS-induced IkappaBalpha phosphorylation/degradation and RelA nuclear translocation as well as RelA DNA binding activity . Interestingly, although B . vulgatus induced nuclear expression of peroxisome proliferator-activated receptor gamma (PPARgamma) in native epithelium of monoassociated Fisher rats, PPARgamma-specific knock-down in CMT-93 cells using small interference RNA failed to reverse the inhibitory effects of PPARgamma agonist 15d-PGJ(2), suggesting PPARgamma-independent mechanisms . In addition, 15d-PGJ(2) but not the synthetic high affinity PPARgamma ligand rosiglitazone triggered ERK1/2 phosphorylation in IEC, and most importantly, MEK1 inhibitor PD98059 reversed the inhibitory effect of 15dPGJ(2) on LPS-induced RelA phosphorylation and interleukin-6 gene expression . Calyculin A, a specific phosphoserine/phospho-threonine phosphatase inhibitor increased the basal phosphorylation of RelA and reversed the inhibitory effect of 15d-PGJ(2) on LPS-induced RelA phosphorylation . We further demonstrated in co-immunoprecipitation experiments that 15d-PGJ(2) triggered protein phosphatase 2A activity, which directly dephosphorylated RelA in LPS-stimulated CMT-93 cells . We concluded that 15d-PGJ(2) may help to control NF-kappaB signaling and normal intestinal homeostasis to the enteric microflora by modulating RelA phosphorylation in IEC through altered protein phosphatase 2A activity.

J Antimicrob Chemother, 2004 Jul, 54(1), 109 - 16 Epub 2004 Jun 09.
Metronidazole resistance in Bacteroides spp . carrying nim genes and the selection of slow-growing metronidazole-resistant mutants; Gal M et al.; OBJECTIVES: Human clinical isolates of Bacteroides spp . originating from patients in the UK were investigated for the presence of metronidazole resistance determinants (nim genes) and their presence was related to the MIC of metronidazole for the isolates . METHODS: Isolates were screened for susceptibility to a metronidazole disc and had their MIC determined by the Etest method . They were investigated for the presence of nim genes by PCR . An experiment to determine the effect of prolonged exposure to metronidazole was applied to nim-positive isolates with MICs below the therapeutic breakpoint . RESULTS: Fifty of 206 isolates (24%) were found to possess nim genes and these had MICs of metronidazole ranging from 1.5 to >256 mg/L with 24 (11.6%) above the therapeutic breakpoint of 16 mg/L . The remaining 26 nim-gene-positive isolates had MICs that were still below the therapeutic breakpoint, ranging from 1.5 to 6.0 mg/L . nim genes were not found in 156 (76%) isolates, and all but seven of these were susceptible to a 5 microg disc of metronidazole . Ten members of the group for which the MICs were below the therapeutic level were found to have slow-growing sub-populations with metronidazole MICs ranging from 8.0 to >256 mg/L that became evident after prolonged exposure to metronidazole in vitro . This resistance selection process was sometimes reversible after passage in the absence of metronidazole; however, seven of the 10 slow-growing mutants converted to stable high-level resistance (MIC >256 mg/L) . CONCLUSIONS: Although the presence of nim genes per se does not always equate to therapeutic resistance, and other metronidazole resistance mechanisms may exist, this study has shown that prolonged exposure of nim-gene-carrying Bacteroides spp . to metronidazole can select for therapeutic resistance.

J Antimicrob Chemother, 2004 Jul, 54(1), 100 - 8 Epub 2004 May 18.
Differential gene expression in a Bacteroides fragilis metronidazole-resistant mutant; Diniz CG et al.; OBJECTIVES: The current work focused on molecular changes in a spontaneous Bacteroides fragilismutant selected by low concentrations of metronidazole as an adaptive response to the drug . METHODS: A metronidazole-resistant strain derived from B . fragilis ATCC 25285 was selected by passage in the presence of drug using 0-4 mg/L gradient plates . Using a combination of proteomics for identification of differentially expressed proteins by two-dimensional electrophoresis and selected mutational analyses by single cross-over insertion and an allelic exchange, we have identified genes involved in the adaptive response to metronidazole . RESULTS: There are significant changes in the protein profiles of resistant strains . These changes appeared to affect a wide range of metabolic proteins including lactate dehydrogenase (up-regulated) and flavodoxin (down-regulated), which may be involved in electron transfer reactions . Also, the enzymic activity of the pyruvate-ferredoxin oxidoreductase (PorA) complex was impaired . Mutant strains lacking the genes for flavodoxin and PorA were less susceptible to metronidazole than the sensitive parent, and a double flavodoxin/PorA mutant had even less susceptibility but none of the mutants were as resistant as the spontaneous metronidazole-resistant strain . CONCLUSIONS: Overall, the data indicated that there were global changes in the regulation of the physiology of the metronidazole-resistant strain . In addition, flavodoxin was identified as an important contributor to metronidazole sensitivity in B . fragilis.

Immunology, 2004 Jun, 112(2), 310 - 20
Differential effect of immune cells on non-pathogenic Gram-negative bacteria-induced nuclear factor-kappaB activation and pro-inflammatory gene expression in intestinal epithelial cells; Haller D et al.; We have previously shown that non-pathogenic Gram negative bacteria induce RelA phosphorylation, nuclear factor (NF)-kappaB transcriptional activity and pro-inflammatory gene expression in intestinal epithelial cells (IEC) in vivo and in vitro . In this study, we investigated the molecular mechanism of immune-epithelial cell cross-talk on Gram-negative enteric bacteria-induced NF-kappaB signalling and pro-inflammatory gene expression in IEC using HT-29/MTX as well as CaCO-2 transwell cultures Interestingly, while differentiated HT-29/MTX cells are unresponsive to non-pathogenic Gram negative bacterial stimulation, interleukin-8 (IL-8) mRNA accumulation is strongly induced in Escherichia coli- but not Bacteroides vulgatus-stimulated IEC cocultured with peripheral blood (PBMC) and lamina propria mononuclear cells (LPMC) . The presence of PBMC triggered both E . coli- and B . vulgatus-induced mRNA expression of the Toll-like receptor-4 accessory protein MD-2 as well as endogenous IkappaBalpha phosphorylation, demonstrating similar capabilities of these bacteria to induce proximal NF-kappaB signalling . However, B . vulgatus failed to trigger IkappaBalpha degradation and NF-kappaB transcriptional activity in the presence of PBMC . Interestingly, B . vulgatus- and E . coli-derived lipopolysaccharide-induced similar IL-8 mRNA expression in epithelial cells after basolateral stimulation of HT-29/PBMC cocultures . Although luminal enteric bacteria have adjuvant and antigenic properties in chronic intestinal inflammation, PBMC from patients with active ulcerative colitis and Crohn's disease differentially trigger epithelial cell activation in response to E . coli and E . coli-derived LPS . In conclusion, this study provides evidence for a differential regulation of non-pathogenic Gram-negative bacteria-induced NF-kappaB signalling and IL-8 gene expression in IEC cocultured with immune cells and suggests the presence of mechanisms that assure hyporesponsiveness of the intestinal epithelium to certain commensally enteric bacteria.

Gastroenterology, 2004 May, 126(5), 1358 - 73
DNA from probiotic bacteria modulates murine and human epithelial and immune function; Jijon H et al.; BACKGROUND & AIMS: The intestinal epithelium must discriminate between pathogenic and nonpathogenic bacteria and respond accordingly . The aim of this study was to examine whether bacterial DNA can serve as the molecular basis for bacterial recognition . METHODS: HT-29 monolayers were treated with various bacterial DNA and interleukin (IL)-8 secretion measured by enzyme-linked immunosorbent assay, nuclear factor kappaB activation by electrophoretic mobility shift assay and reporter assays, and IkappaB levels by Western blotting . Cytokine secretion in response to bacterial DNA was measured in murine colonic segments and splenocytes . IL-10-deficient mice were fed DNA from VSL probiotic compound daily for 2 weeks . Colons were removed and analyzed for cytokine production and inflammation . RESULTS: HT-29 cells responded with IL-8 secretion to bacterial DNA in a differential manner . In the presence of proinflammatory stimuli, VSL3 DNA inhibited IL-8 secretion, reduced p38 mitogen-activated protein kinase activation, delayed nuclear factor kappaB activation, stabilized levels of IkappaB, and inhibited proteasome function . VSL3 DNA inhibited colonic interferon (IFN)-gamma secretion in mouse colons and also attenuated a Bacteroides vulgatus-induced IFN-gamma release from murine splenocytes . In mice, VSL3 DNA attenuated a systemic release of tumor necrosis factor alpha in response to Escherichia coli DNA injection . Treatment of IL-10-deficient mice with oral VSL3 DNA resulted in a reduction in mucosal secretion of tumor necrosis factor alpha and IFN-gamma and an improvement in histologic disease . CONCLUSIONS: DNA from probiotic bacteria can limit epithelial proinflammatory responses in vivo and in vitro . Systemic and oral administration of VSL3 DNA ameliorates inflammatory responses.

J Clin Microbiol, 2004 May, 42(5), 2338 - 40
Brain abscess due to Gemella haemolysans; Lee MR et al.; We present a case of brain abscess due to Gemella haemolysans and Bacteroides species in a 60-year-old-immunocompetent man who underwent dental procedures . The patient completely recovered following intravenous therapy with ampicillin and metronidazole for 6 weeks.

J Antimicrob Chemother, 2004 Jun, 53(6), 1039 - 44 Epub 2004 May 05.
Surveillance of susceptibility patterns in 1297 European and US anaerobic and capnophilic isolates to co-amoxiclav and five other antimicrobial agents; Koeth LM et al.; In vitro susceptibility data were collected for co-amoxiclav and other antimicrobial agents against 1297 recent anaerobe isolates collected in Europe and the USA . The co-amoxiclav (amoxicillin/clavulanic acid) MIC(50/90)s (amoxicillin/clavulanic acid concentration in a ratio of 2:1, expressed in terms of amoxicillin concentration in mg/L) were 0.5/4 for Bacteroides fragilis, </=0.125/1 for Prevotella species, </=0.125/0.25 for Fusobacterium nucleatum, 0.5/1 for Eikenella corrodens, 0.25/8 for Peptostreptococcus anaerobius, </=0.125/0.5 for Micromonas (Peptostreptococcus) micros, </=0.25/0.5 for Fingoldia (Peptostreptococcus) magna, and </=0.125/0.125 for Porphyromonas species . The co-amoxiclav susceptibility rate for B . fragilis was 94.6%, for P . anaerobius 84.3% and for all other species tested 100% . These data indicate that co-amoxiclav remains an effective drug for the antimicrobial treatment and prophylaxis of many anaerobic infections . Among the comparator drugs, metronidazole was very active against all bacterial species (>96% susceptible) except E . corrodens (MIC(50/90) of >32/>64 mg/L), which is a capnophilic organism . Imipenem was also highly active against all species (>98% susceptible) . Levofloxacin and clindamycin were the least potent agents tested, particularly against Bacteroides, Prevotella and Peptostreptococcus (levofloxacin susceptibility rates: Bacteroides 72.7%, Prevotella 71.5%, F . magna 72.4%; clindamycin susceptibility rates: Bacteroides 79.5%, Prevotella 92.1%, F . magna 84.7%).

Appl Environ Microbiol, 2004 May, 70(5), 2867 - 79
Seasonal changes in an alpine soil bacterial community in the colorado rocky mountains; Lipson DA et al.; The period when the snowpack melts in late spring is a dynamic time for alpine ecosystems . The large winter microbial community begins to turn over rapidly, releasing nutrients to plants . Past studies have shown that the soil microbial community in alpine dry meadows of the Colorado Rocky Mountains changes in biomass, function, broad-level structure, and fungal diversity between winter and early summer . However, little specific information exists on the diversity of the alpine bacterial community or how it changes during this ecologically important period . We constructed clone libraries of 16S ribosomal DNA from alpine soil collected in winter, spring, and summer . We also cultivated bacteria from the alpine soil and measured the seasonal abundance of selected cultured isolates in hybridization experiments . The uncultured bacterial communities changed between seasons in diversity and abundance within taxa . The Acidobacterium division was most abundant in the spring . The winter community had the highest proportion of Actinobacteria and members of the Cytophaga/Flexibacter/Bacteroides (CFB) division . The summer community had the highest proportion of the Verrucomicrobium division and of beta-PROTEOBACTERIA: As a whole, alpha-Proteobacteria were equally abundant in all seasons, although seasonal changes may have occurred within this group . A number of sequences from currently uncultivated divisions were found, including two novel candidate divisions . The cultured isolates belonged to the alpha-, beta-, and gamma-Proteobacteria, the Actinobacteria, and the CFB groups . The only uncultured sequences that were closely related to the isolates were from winter and spring libraries . Hybridization experiments showed that actinobacterial and beta-proteobacterial isolates were most abundant during winter, while the alpha- and gamma-proteobacterial isolates tested did not vary significantly . While the cultures and clone libraries produced generally distinct groups of organisms, the two approaches gave consistent accounts of seasonal changes in microbial diversity.

Med Dosw Mikrobiol, 2003, 55(4), 365 - 70
{Biological activity of lipopolysaccharides from clinical Bacteroides fragilis strains isolated in Poland determined in reaction with limulus amoebocyte lysate}; Rokosz A et al.; The aim of this study was to determine a biological activity of lipopolysaccharides (LPS) from clinical Bacterioides fragilis strains isolated in Poland by means of quantitative, photometric BET (LAL) method with Limulus polyphemus amoebocyte lysate and chromogenic substrate S-2423 . Lipopolysaccharides were extracted from nine clinical B . fragilis strains by the procedure of Westphal and Jann (1965) . Crude LPS preparations were purified with ultracentrifugation . Biological activities of bacterial endotoxins were determined by quantitative BET method with chromogenic substrate S-2423 (ENDOCHROME kit) . Tests were performed according to the recommendations of the producer (Charles River Endosafe Ltd., USA) . E . coli O55:B5 LPS and LPS preparations from reference B . fragilis strains were applied to compare the results of examinations . Activities of endotoxins from clinical B . fragilis strains isolated in Poland determined in reaction with Limulus amoebocyte lysate were differentiated . Among endotoxins of clinical B . fragilis strains the most active was the preparation from strain cultured in the case of pancreatic ulcer (B . fragilis 80/81 LPS) . Lipopolysaccharides of examined B . fragilis strains were less active in BET test than E . coli O55:B5 LPS.

J Med Microbiol, 2004 May, 53(Pt 5), 413 - 9
Molecular characterization of imipenem-resistant, cfiA-positive Bacteroides fragilis isolates from the USA, Hungary and Kuwait; Soki J et al.; Fifteen Bacteroides fragilis isolates from the USA, Hungary and Kuwait were examined for carbapenem resistance, for carbapenemase activity and, with the use of various PCR-based methods and nucleotide sequencing, for cfiA genes and activating insertion sequence (IS) elements . All the B . fragilis isolates were cfiA-positive, 10 of the cfiA genes being upregulated by IS elements that are already known . Of these 10, one was of a novel type (designated IS943) and two further ones (IS614B and IS614C) were suspected hybrids of IS612, IS614 and IS942 . There were five cfiA-positive imipenem-resistant B . fragilis isolates with elevated imipenem MICs (minimal inhibitory concentration) that harboured no IS insertion upstream of the cfiA gene, but produced carbapenemase; these isolates might possess a novel activation mechanism . On the basis of the available phenotypic and genotypic evidence, the present data suggest that there are at least two cfiA activation mechanisms among B . fragilis isolates.

Acta Microbiol Pol, 2003, 52(4), 361 - 72
Influence of clindamycin, metronidazole and polymyxin B on the expression of cell adhesion molecules stimulated by endotoxin and enterotoxin of Bacteroides fragilis; Meisel-Mikolajczyk F et al.; The aim of this study was to compare the influence of antimicrobials (clindamycin, metronidazole and polymyxin B) on the expression of adhesion molecules (VCAM-1, ICAM-1 and E-selectin) on the HMEC-1 cell line stimulated by LPS and enterotoxin of B . fragilis . LPS was extracted from two reference: ATCC 43858 and NCTC 11295 and one isolated in our laboratory (W2) enterotoxigenic strains, and one nonenterotoxigenic reference strain--IPL E 323 . Enterotoxin preparations (Tox 1 and Tox 2) were isolated from supematant of B . fragilis ATCC 43858 culture and purified . HMEC-1 cell line was stimulated with bacterial preparations at concentration of 10 mg/ml . For measuring the expression of adhesion molecules we used ELISA test . Clindamycin, metronidazole and polymyxin B supressed the ICAM-1 expression when endothelium was stimulated with B . fragilis LPS and augmented ICAM-1 expression by Tox 1 and Tox 2 . The expression of VCAM-1 was augmented by antimicrobials when endothelium was stimulated with LPS or enterotoxin preparations . The expression of E-selectin was differentiated.

J Bacteriol, 2004 May, 186(9), 2548 - 57
Regulation of a Bacteroides operon that controls excision and transfer of the conjugative transposon CTnDOT; Wang Y et al.; CTnDOT is a conjugative transposon (CTn) that is found in many Bacteroides strains . Transfer of CTnDOT is stimulated 100- to 1,000-fold if the cells are first exposed to tetracycline (TET) . Both excision and transfer of CTnDOT are stimulated by TET . An operon that contains a TET resistance gene, tetQ, and two regulatory genes, rteA and rteB, is essential for control of excision and transfer functions . At first, it appeared that RteA and RteB, which are members of a two-component regulatory system, might be directly responsible for the TET effect . We show here, however, that neither RteA nor RteB affected expression of the operon . TetQ, a ribosome protection type of TET resistance protein, actually reduced operon expression, possibly by interacting with ribosomes that are translating the tetQ message . Fusions of tetQ with a reporter gene, uidA, were only expressed at a high level when the fusion was cloned in frame with the first six codons of tetQ . However, out of frame fusions or fusions ending at the other five codons of tetQ showed much lower expression of the uidA gene . Moreover, reverse transcription-PCR amplification of tetQ mRNA revealed that despite the fact that the uidA gene product, beta-glucuronidase (GUS), was produced only when the cells were exposed to TET, tetQ mRNA was produced in both the presence and absence of TET . Computer analysis of the region upstream of the tetQ start codon predicted that the mRNA in this region could form a complex RNA hairpin structure that would prevent access of ribosomes to the ribosome binding site . Mutations that abolished base pairing in the stem that formed the base of this putative hairpin structure made GUS production as high in the absence of TET as in TET-stimulated cells . Compensatory mutations that restored the hairpin structure led to a return of regulated production of GUS . Thus, the tetQ-rteA-rteB operon appears to be regulated by a translational attenuation mechanism.

Ann Surg, 2004 May, 239(5), 733 - 8; discussion 738-40
Small intestinal submucosa for vascular reconstruction in the presence of gastrointestinal contamination; Jernigan TW et al.; INTRODUCTION: Surgical options for vascular reconstruction in a contaminated field are limited and include prosthetic reconstruction or ligation with extra-anatomic bypass . With prosthetic insertion, rates of graft infection and failures (pseudoaneurysms and thrombosis) are high . In the emergent situations, extra-anatomic bypass is time-consuming and complex, and it produces marginal long-term results . Small intestinal submucosa (SIS) is a cell-free collagen matrix derived from porcine small intestine . Preliminary studies have demonstrated its ability to be remodeled into host tissue . In this study, we compared SIS to polytetrafluoroethylene (PTFE) as a vascular patch for arterial repair in the presence of massive gastrointestinal contamination to evaluate graft patency, incorporation, infection, and aneurysm formation . METHODS: Adult mongrel pigs underwent general anesthesia with Isoflurane and were then randomized to 1 of 3 groups: control, contamination (colon puncture with stool contamination of the pelvis), or shock + contamination (40% blood volume for 1 hour, then resuscitation with shed blood and crystalloid, plus contamination) . All groups then underwent a left common iliac arteriotomy and further randomized to a 1 x 3-cm patch angioplasty with either SIS or PTFE . All received cefotetan for 24 hours . All animals were sacrificed between 2 and 4 weeks, and necropsy was performed . Grafts were cultured, and microscopic analysis with hematoxylin and eosin and trichrome was performed . Outcomes included pulse quality (normal or diminished) compared with opposite side, graft infection, and pseudoaneurysm; all were determined by a blinded investigator . RESULTS: Forty animals were randomized, and 1 died of abdominal sepsis . All control animals had normal distal pulses, no pseudoaneurysms, and no patch infections . The pseudoaneurysm rate for the contaminated PTFE patches was 25% compared with 0% in the SIS group (P = 0.09) . Patch infection occurred in 73% of all PTFE patches compared with 8% of SIS patches (P < 0.03) . Organisms present in the infected grafts included Escherichia coli, Bacteroides species, and other Gram-negative enterics . Histopathology demonstrated the presence of neointima in both SIS and PTFE . Only SIS was completely incorporated, with infiltration of collagen fibrils and lymphocytes . CONCLUSIONS: SIS was associated with improved graft patency, less infection, complete incorporation, and no false aneurysm formation when compared with PTFE . This may be due to its ability to provide a durable scaffold for cellularization and tissue remodeling . This material may offer a superior alternative to more complex vascular reconstruction techniques in contaminated fields.

Med Princ Pract, 2004 May-Jun, 13(3), 147 - 52
Molecular characterization of nitroimidazole resistance in metronidazole-resistant bacteroides species isolated from hospital patients in Kuwait; Jamal WY et al.; OBJECTIVES: The aim of this study was to screen for infections caused by metronidazole (MTZ)-resistant Bacteroides spp., and to characterize the genes that encode the MTZ resistance . MATERIALS AND METHODS: A total of 7 MTZ-resistant Bacteroides spp . were isolated from 5 patients with MTZ-resistant infections . These organisms were investigated for carriage of genes that encode MTZ resistance . The presence of these genes was investigated by PCR and the PCR products were subjected to PCR-RFLP analysis . RESULTS: The strains were MTZ-resistant with minimum inhibitory concentrations of > 32 microg/ml . The presence of nim genes was indicated by PCR in all 7 strains . PCR-RFLP analysis of the nim gene products demonstrated two of the five reported resistance genes, nimA-nimE . These two resistance genes were nimE in 5 of the 7 isolates and nimA in 2 strains . CONCLUSION: MTZ-resistant Bacteroides spp . have been isolated from patients in Kuwait . Nim genes, specifically nimE and nimA, mediate the drug resistance in these isolates . The methods used in detecting these genes are rapid, accurate and relatively inexpensive and could be adopted easily to help in monitoring emergence of MTZ resistance determinants in Kuwait .

J Clin Microbiol, 2004 Apr, 42(4), 1727 - 30
Identification of Bacteroides thetaiotaomicron on the basis of an unexpected specific amplicon of universal 16S ribosomal DNA PCR; Teng LJ et al.; We applied a set of commonly used universal primers (primers RW01 and DG74) to amplify partial fragments of 16S ribosomal DNA for bacterial identification and found an unexpected amplicon (547 bp), in addition to the expected 362-bp product, in samples containing Bacteroides thetaiotaomicron . It was demonstrated that the internal sequence (508 bp, excluding the primers) of the 547-bp amplicon was identical to the genomic sequence from nucleotide positions 165800 to 166307 of B . thetaiotaomicron type strain VPI-5482 by a BLAST search of the sequences in the GenBank database . The existence of this unexpected yet specific amplicon strongly indicated the presence of B . thetaiotaomicron in the sample, and it was found that it could be used to discriminate B . thetaiotaomicron from closely related species . Another set of PCR primers specific for B . thetaiotaomicron was developed on the basis of the sequence of this 547-bp genomic fragment . Both PCR-based assays showed the same sensitivity (88%) and specificity (100%).

Zhonghua Shao Shang Za Zhi, 2004 Feb, 20(1), 34 - 6
{Effects of succinic acid on the function of in vitro cultured human fibroblasts}; Ren LC et al.; OBJECTIVE: To explore the mechanism of injurious effect of succinic acid on human fibroblast and it's role in bacteroides fragilis infection . METHODS: In vitro cultured human fibroblasts were challenged by succinic acid in concentrations of 5, 10, 20 and 30 mmol/L (pH5.5), respectively . The cellular activity, apoptosis rate, the collagen synthesis in the supernatant of the cell culture, and the activity of caspase-3 were determined 24 hours after challenge . Isotonic saline challenged fibroblast were employed as control and the changes in the indices before and after succinic acid challenge were observed . RESULTS: Along with the increase in the concentration of succinic acid, the fibroblast proliferation rate was decreased and so was the collagen synthesis . But the apoptosis rate and caspase-3 activity were increased . The activity of caspase-3 was markedly higher than that in normal control when the succinic acid concentration was 10-30 mmol/L . The cellular activity and collagen synthesis were significantly lower and the apoptosis rate was obviously higher than those in control group when the succinic acid concentration was 20 or 30 mmol/L (P < 0.05) . CONCLUSION: The proliferation and collagen synthesis in fibroblast culture could be significantly inhibited and the cellular apoptosis could be promoted by succinic acid . The process of wound healing of the wounds infected by bacteroides fragilis would be delayed due to the production of succinic acid by the bacteria.

Shanghai Kou Qiang Yi Xue, 1999 Sep, 8(3), 129 - 31
{The chemical degradation of lipopolysaccharides from oral anaerobes}; Xie DY et al.; OBJECTIVE:To evaluate the effect of drug on chemical degradation of lipopolysaccharide (LPS) from oral anaerobes.METHODS:LPSs from porphyromonas gingivalis (Pg),bacteroides fragilis (Bf) and fusobacteria nucleatum (Fn) were extracted by the hot phenol-water method and purified by the phenol-chloroform-petroleum ether procedure.1.0 ml (200microg) various LPSs were incubated with 2.0 ml various drugs at 37degrees centigrade for 15 or 30 minutes in vitro,respectively.The chemical degradation of LPS was quantitated by limulus synthetic chromogenic substrated method after dialysis.RESULTS:The order of degradation was 30% hydrogen peroxide (H),50% citric acid (C),garlic guice (G),1:1 diluted G,25% C and 3% H,and their efffcts were dose dependent and were time dependent except H but the effect of lysozyme was minimal.CONCLUSION:The study may imply that the dose and the mechanism of various drugs on LPS degradation are different and remains to be elucidated.

Antimicrob Agents Chemother, 2004 Apr, 48(4), 1344 - 6
Role of topoisomerase mutations and efflux in fluoroquinolone resistance of Bacteroides fragilis clinical isolates and laboratory mutants; Ricci V et al.; Twelve laboratory mutants and 32 ciprofloxacin-resistant isolates of Bacteroides fragilis were examined for the mechanism(s) of fluoroquinolone resistance . Five mutants had mutations in gyrA . One mutant and two clinical isolates contained a mutation in gyrB . Eight mutants and five clinical isolates accumulated significantly less ciprofloxacin than did wild-type isolates; the mutants and clinical isolates were restored to wild-type characteristics when carbonyl cyanide m-chlorophenylhydrazone was used.

Clin Orthop, 2004 Jan, (418), 222 - 4
Infection of a total hip arthroplasty with Prevotella loeschii; Steingruber I et al.; Infection is a serious complication of total hip replacement . It has been proposed that 6% of all infections after total hip arthroplasty may be of dental origin through hematogenous spread . However, no conclusive evidence that the mouth is a definitive source for infection of a total hip replacement has been reported . In the current case, Prevotella loeschii, a pigmented bacteroides species was identified in a total hip replacement . Prevotella loeschii is an organism which exclusively inhabits the dental region . Hematogenous spread of Prevotella loeschii may occur after penetration of the mucosal barrier in cases of endodontic or periodontic lesions, pericoronitis, or complications of tooth extraction . The involvement of Prevotella loescheii in an infection in a patient who had a total hip arthroplasty is strong evidence for the mechanism of a hematogenous infection from a dental source.

J Virol Methods, 2004 Apr, 117(1), 19 - 25
Standardised evaluation of the performance of a simple membrane filtration-elution method to concentrate bacteriophages from drinking water; Mendez J et al.; The bacteriophage elution procedure described further after adsorption to acetate-nitrate cellulose membrane filters allows better recovery of phages concentrated from 1l of water than elution procedures used previously . The improvement is due to the combined effect of the eluent (3% (w/v) beef extract, 3% (v/v) Tween 80, 0.5M NaCl, pH 9.0) and the application of ultrasound instead of agitation or swirling . Average recovery of somatic coliphages, 82 +/- 7%, was the greatest, and that of phages infecting Bacteroides fragilis, 56 +/- 8%, the lowest, with intermediate values for F-specific and F-specific RNA bacteriophages . Thus, the method allowed recovery of over 56% for all the phages suggested as surrogate indicators . The method was then validated according to an International Standardisation Organisation validation standard procedure and implemented in routine laboratories, which obtained reproducible results.

Drugs Exp Clin Res, 2003, 29(4), 153 - 5
Characteristics of anaerobes from skin specimens; Higaki S et al.; Anaerobes isolated from skin specimens from 1999 to 2001 were examined . The most common type was Peptostreptococcus spp., especially P . magnus and P . assaccharolyticus and Bacteroides fragilis . Dominance was seen for P . magnus, P . acnes and P . prevotii . Peptostreptococcus spp . and P . acnes showed high susceptibility to four antimicrobial agents . Prevotella spp . and B . fragilis showed low or no susceptibility to ampicillin, while B . fragilis showed low susceptibility to ceftizoxime . Evaluation of anaerobes is important for the balance of skin flora as well as for the choice of antimicrobial agents, when the anaerobes are pathogenic.

J Clin Periodontol, 2004 Feb, 31(2), 141 - 8
Quadrant root planing versus same-day full-mouth root planing . II . Microbiological findings; Apatzidou DA et al.; OBJECTIVES: The aim of this study was to test the hypothesis that over a period of 6 months, same-day full-mouth scaling and root planing (FM-SRP) resulted in greater reductions in the detection frequency of five putative periodontal pathogens compared with quadrant scaling and root planing (Q-SRP) in chronic periodontitis patients . MATERIALS AND METHODS: Forty patients were recruited into this study . Subjects were randomised into two groups . The FM-SRP group received full-mouth scaling and root planing completed within the same day, while the Q-SRP group received quadrant root planing at 2-weekly intervals over four consecutive sessions . Selected-site analyses were performed on the deepest site in each quadrant before and after therapy, at approximately 3 and 6 months from baseline (R1 and R2) and clinical indices were recorded with an electronic pressure-sensitive probe . In addition, subgingival plaque samples were collected from these sites at baseline (BAS), at reassessment 1 (R1), approximately 6 weeks after the completion of therapy and at reassessment 2 (R2), 6 months from baseline . Polymerase chain reaction (PCR) was used to determine the presence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Treponema denticola and Bacteroides forsythus in plaque . RESULTS: Both therapies resulted in significant improvements in all clinical indices both at R1 and R2 . A marked reduction in the presence of all candidate periodontal pathogens was noted after both treatment modalities, reaching statistical significance for the majority of the test organisms . These improvements were maintained over a period of 6 months . When the two treatment groups were compared, a significantly higher percentage of Q-SRP patients was positive for P . intermedia at R1 compared with FM-SRP patients (p<0.05) . In addition, a greater reduction in the patient prevalence for T . denticola was found for the FM-SRP group than the Q-SRP group at R1 and R2 from baseline (p<0.005), but the significance of this is questionable given the skewed detection frequency of this organism at baseline between the two treatments (p<0.01) . CONCLUSION: This study failed to confirm that same-day FM-SRP resulted in greater microbiological improvements compared with Q-SRP at 2-weekly intervals over a 6-month period, as determined by PCR . Copyright Blackwell Munksgaard, 2004.

J Med Microbiol, 2004 Apr, 53(Pt 4), 273 - 80
Experimental swine dysentery: comparison between infection models; Jacobson M et al.; The aim of the present study was to develop a reproducible porcine infection model with Brachyspira hyodysenteriae . The influence of different factors was evaluated, namely, age, a diet containing large quantities of soybean meal, housing and administration of cortisol or antacids . Furthermore, the synergistic effect of additional bacteria (Escherichia coli O141, Bacteroides vulgatus or a mixture of Bacteroides fragilis, a field isolate of Bacteroides and Fusobacterium necrophorum) was studied . Experimental infection resulted in an increase in the serum concentrations of the acute-phase proteins serum amyloid A and haptoglobin and the percentages of neutrophils and monocytes . These alterations were specifically related to haemorrhagic diarrhoea . Inoculation combined with feeding of large quantities of soybean meal and group-housing induced swine dysentery in all experimental animals . If the pigs were fed soybean meal, kept in single pens and circulated between the pens, five out of nine developed disease.

J Clin Periodontol, 2004 Mar, 31(3), 166 - 72
Debridement and local application of tetracycline-loaded fibres in the management of persistent periodontitis: results after 12 months; Aimetti M et al.; BACKGROUNDS, AIMS: The aim of our study was to evaluate the clinical, radiological and microbiological response to the local delivery of tetracycline (TE) of sites with persistent periodontal lesions . MATERIALS AND METHODS: The study was conducted in a split-mouth design . Nineteen patients with at least four bilateral pockets 4-5 mm and bleeding on probing (BOP) were treated with scaling and root planing (SRP) plus TE fibres (test sites) or with SRP alone (control sites) . Clinical and radiological measurements were taken at baseline, 6 months and 12 months post-operatively . Subgingival plaque samples were collected at baseline, at fibres removal, 6 and 12 months following treatment and analysed by polymerase chain reaction . RESULTS: Both treatments yielded a statistically significant (p<0.05) reduction of probing depth (2.05 and 1.21 mm), gain of clinical attachment level (1.71 and 0.53 mm) and reduction of BOP scores (23.68% and 57.89%) for TE and SRP groups, respectively, when comparing 12-month data with baseline . The differences between two groups were significant . The prevalence of Treponema denticola and Bacteroides forsythus decreased after therapy in both groups but only in the test sites Actinobacillus actinomycetemcomitans and Prevotella intermedia were not yield detected . The pathogens could be eliminated from five periodontal pockets by SRP alone, while 21 TE sites were not recolonized at 12 months . CONCLUSIONS: SRP plus TE fibres gave the greatest advantage in the treatment of periodontal persistent lesions at least 12 months following treatment.

J Clin Periodontol, 2004 Mar, 31(3), 152 - 9
Quadrant root planing versus same-day full-mouth root planing; Apatzidou DA et al.; OBJECTIVES: The aim of this study was to determine whether same-day full-mouth scaling and root planing (FM-SRP) and quadrant scaling and root planing (Q-SRP) resulted in variations in the systemic humoral immune response dynamics (antibody titres and avidity) during active treatment and 3 and 6 months post-therapy . MATERIALS AND METHODS: Forty patients with chronic periodontitis were recruited into this study . Subjects were randomised into two groups and received either scaling and root planing quadrant by quadrant at 2-weekly intervals (Q-SRP group) or same-day full-mouth scaling and root planing (FM-SRP group) . Clinical measurements and serum samples were obtained at baseline and approximately 6 weeks after the last clinical intervention (R1) and 6 months after the initiation of therapy (R2) . Furthermore, serum samples were obtained from each patient undergoing therapy (Q-SRP and FM-SRP) at 3 bi-weekly instances so as to determine the short-term effects of each session of scaling and root planing on the dynamics of the humoral immune response . Serum antibody titre was assayed by enzyme-linked immunosorbent assay (ELISA) and antibody avidity was measured by thiocyanate dissociation against five putative periodontal pathogens: Porphyromonas gingivalis; Actinobacillus actinomycetemcomitans; Prevotella intermedia; Treponema denticola and Bacteroides forsythus . RESULTS: Both therapies resulted in similar antibody titre reductions against the majority of the organisms tested and although there was a distinct trend for antibody avidity to increase following therapy, this was not found to be statistically significant, reflecting marked inter-individual variation . In addition, no evidence emerged from this study to support increased antibody titres following the active phases of both treatment approaches due to an inoculation effect . Nevertheless, significant short-term increases in antibody avidity to most test bacteria were noted for both treatment strategies . CONCLUSION: Both therapies were associated with a reduction in antibody titres and an increase in the binding ability or avidity of antibodies, but there was a marked inter-subject variability and statistical significance was reached for only some of the test bacteria . No significant differences in the humoral antibody dynamics were found between the two treatment approaches.

Oral Dis, 2004 Mar, 10(2), 99 - 105
Evidence for local production of antibodies to auto and non-self antigens in periodontal disease; Rajapakse PS et al.; Autoimmune mechanisms may contribute to periodontal disease (PD) pathogenesis; autoantibody to collagen type 1 is produced at the periodontal site and local levels are found to be higher than in serum . OBJECTIVES: To find any evidence of autoimmune destruction in diseased periodontal tissues in patients with periodontitis . The study examines the relationship of antibodies to a self antigen collagen Type 1 and antigens from two periodontal pathogens namely Porphyromonas gingivalis (Pg), Actinobacillus actinomycetemcomitans (Aa) and a non-oral bacterium Bacteroides fragilis (Bf) in disease sites and in serum . MATERIALS AND METHODS: Granulomatous tissues from periodontally diseased sites and serum samples were obtained from 13 patients (15 sites) undergoing surgical therapy . Tissues were homogenized at 4 degrees C on Tris saline buffer {1 g (5 ml)-1}, homogenate was centrifuged and the resultant supernatants were used in assays . Antibody to collagen and Aa, Pg and Bf in tissue eluates and serum were determined by competitive enzyme linked immunosorbant assay (ELISA) and conventional ELISA respectively using an alkaline phosphatase/p-nitrophenyl phosphate enzyme-substrate system . Sera from age and sex matched healthy subjects and pooled human serum were used as controls . Antibody (Ab) levels in tissues and serum were standardized by concomitant albumin assay . RESULTS: Level of antibodies to collagen type 1 in tissue was significantly higher than in serum (P = 0.0001) . Antibody levels in tissue to Pg were significantly higher than in serum (P = 0.0271) . Ab levels to both Aa and Bf in tissues and serum were not significantly different from each other . CONCLUSIONS: These findings confirm the process of the local production of antibodies to autoantigen namely collagen type-1 and to bacterial antigens in the granulomatous tissues housed within the periodontal lesions in patients with periodontitis.

Rinsho Biseibutshu Jinsoku Shindan Kenkyukai Shi, 2003, 14(1), 17 - 23
{Recovery of facultatives and anaerobes from frozen specimens with a polymicrobial nature}; Kawamura C et al.; Microbiological examination of frozen specimens is sometimes carried out in clinical microbiology and the result is used as an aid of diagnosis and/or treatment of polymicrobial infections . The study was carried out to reevaluate the merit of freezing specimens in clinical microbiology . A total of 10 specimens with a polymicrobial nature were included in this study . Before and after freezing specimens, we isolated facultative and anaerobic bacteria using a set of primary isolation media, consisting of three aerobic agar plates (MacConkey agar, blood agar and chocolate agar) and four pre-reduced anaerobic agar plates (HK Blood agar, HK blood agar with paromomycin (PM) and vancomycin (VM), phenyl ethyl-alcohol (PEA) agar and Bacteroides bile esculin (BBE) agar) . All the procedures were done in a properly controlled anaerobic chamber . The number of isolates before and after freezing was 79 and 70, respectively . Among the strains isolated before freezing, 33 strains were recovered on the same kin of media artery freezing, without a remarkable decrease in the quantity . But 26 strains were not recovered and 2 strains were recovered with a remarkable decrease . Among 26 strains, 15 strains could be successfully backed up on the different kind of media . In conclusion, an anaerobic technique with an anaerobic chamber and a set of isolatin plates including blood agar, chocolate agar, HK blood agar, PEA blood agar, HK blood agar with PM and VM enable us to estimate the bacteriology before freezing from frozen specimens.

Antimicrob Agents Chemother, 2004 Mar, 48(3), 1034 - 6
In vitro activities of tigecycline against the Bacteroides fragilis group; Jacobus NV et al.; The in vitro activities of tigecycline were tested against 831 isolates of the Bacteroides fragilis group representing all of the species within the group . On a weight-to-weight basis (8 microg/ml), tigecycline was more active than clindamycin, minocycline, trovafloxacin, and cefoxitin and less active than imipenem or piperacillin-tazobactam against all isolates of the B . fragilis group . Tigecycline geometric mean MICs were statistically higher against B . distasonis than other Bacteroides species (P value of 0.0001).

Nippon Hinyokika Gakkai Zasshi, 2004 Jan, 95(1), 67 - 70
{A renocolic fistula due to colonic diverticulitis associated with polycystic kidney}; Ito H et al.; Renocolic fistulae caused by colonic diverticulitis are rare . We present a case of renocolic fistula caused by colonic diverticulitis associated with polycystic kidney . A 51-year-old male with polycystic kidney on hemodialysis presented with a lasting fever and left lower abdominal pain . Under the diagnosis of the infection of a cyst in a polycystic kidney, puncture of the cyst was performed . Nine hundred ml of turbid fluid, of which culture grew Bacteroides Fragilis, was discharged . Inflammation subsided after the puncture, but soon recurred . Moreover, pneumaturia was observed, and fecaloid fluid was drainaged . Barium enema demonstrated a fistula from the diverticulum of the descending colon into the punctured cyst . The patient underwent a nephrectomy combined with hemi-colectomy.

Infect Immun, 2004 Mar, 72(3), 1318 - 25
Biological activities of Bacteroides forsythus lipoproteins and their possible pathological roles in periodontal disease; Hasebe A et al.; Bacteroides forsythus is a gram-negative, anaerobic, fusiform bacterium and is considered to be an etiological agent in periodontal disease . A lipoprotein fraction prepared from B . forsythus cells by Triton X-114 phase separation (BfLP) activated human gingival fibroblasts and a human monocytic cell line, THP-1, to induce interleukin-6 production and tumor necrosis factor alpha production . BfLP was found to be capable of inducing nuclear factor-kappaB translocation in human gingival fibroblasts and THP-1 cells . By using Chinese hamster ovary K1 cells transfected with Toll-like receptor genes together with a nuclear factor-kappaB-dependent CD25 reporter plasmid, it was found that signaling by BfLP was mediated by Toll-like receptor 2 but not by CD14 or Toll-like receptor 4 . BfLP induced apoptotic cell death in human gingival fibroblasts, KB cells (an oral epithelial cell line), HL-60 cells (a human myeloid leukemia cell line), and THP-1 cells but not in MOLT4 cells (a T-cell leukemia cell line) . Caspase-8, an initiator caspase in apoptosis, was found to be activated in these cells in response to BfLP stimulation . Thus, this study suggested that BfLP plays some etiological roles in oral infections, especially periodontal disease, by induction of cell activation or apoptosis.

J Periodontol, 2003 Dec, 74(12), 1764 - 70
Associations between systemic status, periodontal status, serum cytokine levels, and delivery outcomes in pregnant women with a diagnosis of threatened premature labor; Hasegawa K et al.; BACKGROUND: Threatened premature labor (TPL) often results in preterm birth (PB) . The aim of the present study was to evaluate the associations of periodontal and general health conditions with TPL and PB in relation to serum cytokine levels and the composition of subgingival plaque . METHODS: Eighty-eight women were enrolled in the study . Systemic conditions were assessed, and subgingival plaque samples obtained for bacterial analysis . Periodontal examinations included assessments of plaque, gingivitis, clinical attachment level, probing depth, and bleeding on probing . Serum cytokine levels also were analyzed . Gestational age at delivery was recorded, and the mothers were divided into a TPL or non-TPL group, and into a non-TPL-TB (term birth), non-TPL-PB, TPL-TB, or TPL-PB group, accordingly . RESULTS: Forty subjects were classified as TPL and 18 as TPL-PB . There were significant differences between the TPL and non-TPL subjects in several of the systemic and periodontal parameters and serum cytokine levels . Significant differences were observed between the TPL-TB and TPL-PB groups in the percentage of Tannerella forsythensis (Tf, formerly Bacteroides forsythus), and the serum interleukin (IL)-8 and IL-1beta levels . Significant negative correlations between the gestational age at delivery and several periodontal parameters and serum IL-8 and IL-1beta levels, and significant positive correlations between periodontal status and serum IL-8 and IL-1beta levels, were observed . CONCLUSIONS: The TPL women revealed worsened periodontal conditions and elevated serum IL-8 and IL-1beta levels compared to the non-TPL women . The elevated levels of serum IL-8 and IL-1beta could have affected the maintenance of the proper uterine-fetus relationship, resulting in premature uterine contractions.

J Med Microbiol, 2004 Mar, 53(Pt 3), 213 - 21
Relationship between penicillin-binding protein patterns and beta-lactamases in clinical isolates of Bacteroides fragilis with different susceptibility to beta-lactam antibiotics; Piriz S et al.; This study examines the role of the penicillin-binding proteins (PBPs) of Bacteroides fragilis in the mechanism of resistance to different beta-lactam antibiotics . Six of the eight strains used were beta-lactamase-positive by the nitrocefin assay . These strains displayed reduced susceptibility to imipenem (MIC, 2-16 mg l(-1)) and some of them were resistant to the actions of ampicillin, cefuroxime, cephalexin, cefoxitin and piperacillin . When studying specific enzymic activity, the capacity to degrade cefuroxime was only detected in strains AK-4, R212 and 0423 and the capacity to degrade cephalexin was only detected in strains R212 and 2013E; no specific activity was detected on imipenem . Metallo-beta-lactamase activity was only detected in strains AK-2 and 119, despite the fact that the cfiA gene was identified in four strains (AK-2, 2013E, 119 and 7160) . The cepA gene was detected in six of the eight strains studied . Three high-molecular-mass PBPs were detected in all strains; however, in some cases, PBP2Bfr and/or PBP3Bfr appeared as a faint band . PBP4Bfr and PBP5Bfr were detected in six strains . PBP6Bfr only was detected in B . fragilis strains AK-2, 0423, 119 and 7160 . By analysis of the sequence of B . fragilis chromosomal DNA and comparison with genes that are known to encode PBPs in Escherichia coli, six genes that encode PBP-like proteins were detected in the former organism . The gene that encodes the PBP2 orthologue of E . coli (pbpABfr, PBP3Bfr) was sequenced in six of the eight strains and its implications for resistance were examined . Differences in the PBP3Bfr amino acid sequences of strains AK-2 and 119 and their production of beta-lactamases indicate that these differences are not involved in the mechanism of resistance to imipenem and/or cephalexin.

J Clin Microbiol, 2004 Feb, 42(2), 888 - 90
Genetic analysis of an ambler class A extended-spectrum beta-lactamase from Capnocytophaga ochracea; Jolivet-Gougeon A et al.; A beta-lactamase gene (cfxA3, 966 bp) was isolated from a beta-lactam-resistant Capnocytophaga ochracea clinical isolate and amplified using primers from the cfxA gene of Bacteroides vulgatus . The MICs of third-generation cephalosporins were much higher than those of the transconjugant Escherichia coli strain . The deduced protein sequence, by comparison with CfxA2 of Prevotella intermedia, had a Y239D substitution and possessed the characteristics of a class A, group 2e beta-lactamase.

J Bacteriol, 2004 Feb, 186(4), 968 - 77
Architecture of the Bacteroides cellulosolvens cellulosome: description of a cell surface-anchoring scaffoldin and a family 48 cellulase; Xu Q et al.; A large gene downstream of the primary Bacteroides cellulosolvens cellulosomal scaffoldin (cipBc, now renamed scaA) was sequenced . The gene, termed scaB, contained an N-terminal leader peptide followed by 10 type I cohesins, an "X" domain of unknown structure and function, and a C-terminal S-layer homology (SLH) surface-anchoring module . In addition, a previously identified gene in a different part of the genome, encoding for a dockerin-borne family 48 cellulosomal glycoside hydrolase (Cel48), was sequenced completely, and a putative cellulosome-related family 9 glycosyl hydrolase was detected . Recombinant fusion proteins, comprising dockerins derived from either the ScaA scaffoldin or Cel48, were overexpressed . Their interaction with ScaA and ScaB cohesins was examined by immunoassay . The results indicated that the ScaB type I cohesin of the new anchoring protein binds selectively to the ScaA dockerin, whereas the Cel48 dockerin binds specifically to the type II ScaA cohesin 5 . Thus, by virtue of the 11 type II ScaA cohesins and the 10 type I ScaB cohesins, the relatively simple two-component cellulosome-integrating complex would potentially incorporate 110 enzyme molecules onto the cell surface via the ScaB SLH module . Compared to previously described cellulosome systems, the apparent roles of the B . cellulosolvens cohesins are reversed, in that the type II cohesins are located on the enzyme-binding primary scaffoldin, whereas the type I cohesins are located on the anchoring scaffoldin . The results underscore the extensive diversity in the supramolecular architecture of cellulosome systems in nature.

Curr Microbiol, 2003 Dec, 47(6), 475 - 84
Cloning and characterization of the NAD-dependent 7alpha-Hydroxysteroid dehydrogenase from Bacteroides fragilis; Bennett MJ et al.; The NAD-linked 7alpha-hydroxysteroid dehydrogenase (7-HSDH) from Bacteroides fragilis ATCC 25285 was characterized and its gene cloned . The enzyme displayed optimal activities at pH 8.5 (NAD reduction) and 6.5 (NADH oxidation) . The lowest K(m) and highest V(max) values were observed with chenodeoxycholic acid and its conjugates . The protein had subunits of 27.4 kDa and a native size of 110 kDa, suggesting a homotetrameric composition . The enzyme was relatively thermostable, retaining 95% of initial activity after 1 h at 65 degrees C . A DNA probe based on the N-terminal amino acid sequence hybridized to a 2373-bp HindIII fragment of B . fragilis DNA . This fragment was cloned into E . coli and sequenced, revealing a 780-bp open reading frame . The predicted amino acid sequence of the ORF showed strong sequence similarity to three other bacterial 7-HSDHs, all in the short-chain dehydrogenase family . The regulation of expression of this gene is currently under investigation.

Acta Microbiol Immunol Hung, 2003, 50(4), 395 - 406
Molecular microbiology of gut bacteria: genetic diversity and community structure analysis; Peterka M et al.; Recently developed molecular biology approaches make possible the detailed genetic, taxonomic and ecological examination of microorganisms from various habitats . Animal gut represents one of the most complex microbial ecosystems with a large degree of microbial biodiversity present . Bacteria inhabiting the gut usually play important roles in metabolic transformations of substrates and sometimes, e.g . in ruminants, they make the basis for an obligate symbiosis with the host . Here we discuss molecular microbiology as a strategy for examination of gut bacteria, concentrating on a typical and in such environment dominant group of strictly anaerobic Gram-negative bacteria from the phylogenetic group Cytophaga/Flexibacter/Bacteroides . The bacteria from the genus Prevotella are the most abundant Gram-negative bacteria in the rumen and form a distinctive phylogenetic cluster, clearly separated from prevotellas isolated from other ecological niches . They may represent a good choice for a model organism in genetic manipulation experiments and for studies of gene transfer mechanisms taking place in the gut . The molecular tools for detection and monitoring of ruminal prevotellas are discussed.

J Laryngol Otol, 2003 Dec, 117(12), 932 - 9
Management of lateral sinus thrombosis: update and literature review; Ooi EH et al.; The management of four cases of lateral sinus thrombosis (LST) over a four-year period at the Royal Darwin Hospital is presented in this retrospective review . The patients were aboriginal and presented with otalgia, otorrhoea and sepsis . Two cases had an associated complication of an otitic hydrocephalus and a subperiosteal abscess . Cholesteatoma was found in three cases . Computed tomography (CT) scan confirmed the LST in three cases . Three patients were anaemic and thrombocytopenic . All patients had positive blood cultures . The organisms were predominantly mixed anaerobes and Bacteroides species . Three patients were managed surgically as a two-stage procedure . One patient was managed as a single-stage procedure with a modified radical mastoidectomy . Therapeutic anticoagulation was utilized in one case . There were no deaths . The prognosis of LST is good if treatment is instituted early with broad-spectrum intravenous antibiotics and surgery . The role of clot removal at surgery and the use of anticoagulation are discussed in this paper.

J Immunol, 2004 Feb 1, 172(3), 1483 - 90
Zwitterionic polysaccharides stimulate T cells with no preferential V beta usage and promote anergy, resulting in protection against experimental abscess formation; Stingele F et al.; Zwitterionic polysaccharides (Zps) from pathogenic bacteria, such as Bacteroides fragilis, are virulence factors responsible for abscess formation associated with intra-abdominal sepsis . The underlying cellular mechanism for abscess formation requires T cell activation . Conversely, abscess formation can be prevented by prophylactic s.c . injection of purified Zps alone, a process also dependent on T cells . Hence, the modulatory role of T cells in abscess formation was investigated . We show that Zps interact directly with T cells with fast association/dissociation kinetics . Vbeta repertoire analysis using RT-PCR demonstrates that Zps have broad Vbeta usage . Zps-specific hybridomas responded to a variety of other Zps, but not to a nonzwitterionic polysaccharide, indicating cross-reactivity between different Zps . Furthermore, Zps-reactive T cell hybridomas could effectively transfer protection against abscess formation . Analysis of the proliferative capacity of T cells recovered from Zps-treated animals revealed that these T cells are anergic to subsequent stimulation by the different Zps or to alloantigens in an MLR . This anergic response was relieved by addition of IL-2 . Taken together, the data show that this class of polysaccharides interacts directly with T cells in a nonbiased manner to elicit an IL-2-dependent anergic response that confers protection against abscess formation.

J Gastroenterol Hepatol, 2004 Feb, 19(2), 200 - 4
Helicobacter pylori is a fragile bacteria when stored at low and ultra-low temperatures; Ohkusa T et al.; BACKGROUND AND AIM: Usually, bacteria are cryopreserved for short-term storage at low and ultra-low temperatures . There are no reports as to whether Helicobacter pylori is a fragile bacteria when stored at low and ultra-low temperatures as compared with other intestinal bacteria . A study was done on seven H . pylori strains and other intestinal bacteria to compare different temperatures for storage of organisms in saline solution . METHODS: Seven H . pylori strains, specifically American Type Culture Collection (ATCC) strains 43504 and TN2GF4, and five strains isolated from the present patients were grown on a modified Skirrow's agar for H . pylori . Escherichia coli and Bacteroides distasonis, both representing isolates from the present patients, were grown on trypticase soy blood agar for E . coli, and EG agar for B . distasonis . Culture was for 4-5 days under microaerobic, aerobic and anaerobic conditions at 37 degrees C . Cells were harvested by scraping growth from the solid medium and into sterile saline . The cells were adjusted to concentrations of 109 viable cells/mL in saline and preserved at 4 degrees C, -20 degrees C, or -80 degrees C for 3 weeks before reculture under microaerobic, aerobic and anaerobic conditions at 37 degrees C for 7 days . After incubation, morphologically distinct colonies were counted, isolated, and identified by standard bacteriologic techniques . The H . pylori were morphologically analyzed by electronic microscopy before and after preservation . Mongolian gerbils were inoculated with the cryopreserved H . pylori to evaluate the bacterial infectivity . RESULTS: Six of the seven H . pylori strains failed to culture after being preserved at 4 degrees C, -20 degrees C, or -80 degrees C . Only ATCC 43504 could be cultured after freezing at -80 degrees C . The number of H . pylori ATCC 43504 before preservation was 9.0 +/- 0.5 (log10 no . organisms/mL) and decreased to 5.7 +/- 0.6 after preservation . Morphologically, all H . pylori except ATCC 43504 strains transformed from a bacillary to a coccoid form after preservation . In addition, none of the H . pylori strains could infect Mongolian gerbils after preservation . Escherichia coli and B . distasonis were recovered . Titers before and after 4 degrees C, -20 degrees C, and -80 degrees C, respectively, were 9.1 +/- 0.2, 8.9 +/- 0.5, 8.6 +/- 0.3, and 8.7 +/- 0.3 for E . coli and 9.1 +/- 0.4, 8.7 +/- 0.6, 8.6 +/- 0.5, and 8.8 +/- 0.3 for B . distasonis . CONCLUSIONS: Helicobacter pylori is a fragile bacteria for storage at low and ultra-low temperatures in comparison with other intestinal bacteria.

J Antimicrob Chemother, 2004 Feb, 53(2), 318 - 24 Epub 2004 Jan 16.
Effect of moxifloxacin versus imipenem/cilastatin treatment on the mortality of mice infected intravenously with different strains of Bacteroides fragilis and Escherichia coli; Schaumann R et al.; OBJECTIVES: To study the effect of moxifloxacin versus imipenem/cilastatin (hereafter referred to as imipenem) treatment on the mortality of mice infected intravenously with different strains of Bacteroides fragilis and Escherichia coli . METHODS: Groups of 20 mice each were infected intravenously with different strains of B . fragilis {moxifloxacin and imipenem susceptible or resistant, and enterotoxin (ET) positive or negative} and E . coli (moxifloxacin and imipenem susceptible) . Twenty-four hours post-infection, intravenous therapy with either moxifloxacin (2.0 mg twice a day) or imipenem (2.4 mg three times a day) was started and continued for 3 days . Control groups were left untreated . Survival rates were recorded at day 7 post-infection . At that time, surviving mice were killed and numbers of bacteria in the liver and kidneys were determined . RESULTS: If compared with untreated animals, mice treated with either moxifloxacin or imipenem showed significantly improved survival (P < 0.001) . There was no significant difference (P = 0.97) in the survival rates comparing the two treatment regimens irrespective of the ET positivity or the susceptibility to moxifloxacin or imipenem of the infective B . fragilis strain . However, there was a tendency that B . fragilis was recovered more often from the liver and kidneys of mice infected with ET positive strains . CONCLUSIONS: The data show that moxifloxacin was as efficacious as imipenem in reducing the mortality rate of mice suffering from a severe systemic aerobic/anaerobic infection.

Int J Mol Med, 2004 Feb, 13(2), 221 - 7
Potential role of Helicobacter pylori in hepatocarcinogenesis; Ito K et al.; Helicobacter species can induce carcinoma in the liver of certain mice . Furthermore, Helicobacter pylori (H . pylori) exhibits hepatotoxicity in vitro . These reports indicate that H . pylori may play a role in hepatocarcinogenesis . The aim of this study was to assess the presence of H . pylori in human hepatocellular carcinoma (HCC) to determine if H . pylori may affect the development of this disease . Liver specimens from 15 HCC patients dissected into tumor and non-tumor tissues were examined for H . pylori by PCR using two sets of primers for 16S rRNA and urease B . DNA sequencing analysis was performed to confirm that PCR products with 16S rRNA primers were derived from H . pylori DNA . The specimens were also examined for H . pylori by immunohistochemistry using anti-H . pylori antibody . H . pylori was found in 13 of 15 tumor tissues, not in the non-tumor tissues . By contrast, Escherichia coli and Bacteroides fragilis, frequent colonizers of gut, were not detected by PCR in the HCC tumors . Ten cirrhotic liver tissue specimens and seven normal liver tissue specimens were also negative for H . pylori DNA by PCR . The nucleotide sequence of the amplified fragment shared 100% identity with the 16S rRNA gene of H . pylori . H . pylori was also detected in HCC tissue by immunohistochemical analysis . The presence of H . pylori in human HCC tissue was demonstrated by PCR and immunohistochemical analysis . These findings suggest that H . pylori might contribute to the development of HCC . Further study is needed to prove the pathogenetic role of H . pylori in the development of human HCC.

Med Dosw Mikrobiol, 2003, 55(3), 277 - 84
{The evaluation of prevalence and the impact of pathological microflora of the lower genital tract among women at early pregnancy on the risk of preterm delivery}; Kalinka J et al.; The main aim of this prospective study was to determine the prevalence and an association between pathological microflora of the lower genital tract diagnosed at early pregnancy and the risk of preterm delivery . The study group comprised 179 randomly selected pregnant women from Lodz region, between 8 and 16 week of pregnancy . For the qualitative and quantitative assessment of biocenosis of the lower genital tract vaginal and cervical swabs were collected from the pregnant women under study . The C . trachomatis antigen was detected by direct immunofluorescence assay . The vaginal swabs were tested for aerobic and anaerobic bacteria . Bacterial vaginosis was diagnosed by Gram stain according to Spiegel's criteria . To evaluate the risk factors odds ratios were calculated using EPI INFO software . 21 (11.7%) women delivered before 37th week of pregnancy . Bacterial vaginosis was diagnosed among 51 (28.5%) pregnant women while intermediate microflora was diagnosed by Gram stain in 62 (34.6%) women . The shortest mean gestational age at delivery was noted among women with BV . The rate of preterm delivery in BV group was 15.7% comparing to 9.1% among women with normal microflora . Among women with preterm delivery BV was diagnosed in 38.1% (OR = 1.86) . Based on culture results only 84 (46.9%) women had normal microflora at early pregnancy . The pathological culture was associated with slightly increased preterm delivery rate (12.6%) as compare to 10.7% in control group . Positive culture for Bacteroides and Mobiluncus was connected with nonstatistical rise in the risk of preterm delivery . No association between C . trachomatis infection at early pregnancy and elevated risk of preterm delivery was found . Early pregnancy diagnosis of bacterial vaginosis and its treatment should lower the rate of prematurity in Poland.

J Bacteriol, 2004 Jan, 186(2), 438 - 44
A multicomponent system is required for tetracycline-induced excision of Tn4555; Parker AC et al.; Bacteroides spp . are the predominant organisms in the intestinal tract, and they also are important opportunistic pathogens . Antibiotic therapy of Bacteroides infections often is complicated by the prevalence of drug-resistant organisms which acquire resistance genes from a variety of mobile genetic elements including conjugative transposons (CTns) and mobilizable transposons (MTns) . Tn4555 is an MTn that encodes beta-lactam resistance, and it is efficiently mobilized by the Bacteroides CTns via a tetracycline (TET)-inducible mechanism . In this study a model system with CTn341 and a Tn4555 minielement was used to examine Tn4555 excision from the chromosome . Using PCR and mobilization assays it was established that excision was stimulated by TET in the presence of CTn341 . In order to determine which Tn4555 genes were required for excision, int, tnpA, tnpC, xis, and mobA mutants were examined . The results indicated that int plus two additional genes, tnpC and xis, were required for optimal excision . In addition, there was no requirement for the mobA gene, as had been shown for another MTn, NBU1 . The Xis protein sequence is related to a family of plasmid excisionases, but the TnpC gene product did not match anything in the sequence databases . Evidence also was obtained that suggested that Xis is involved in the control of TET-induced excision and in control of mobilization by CTn341 . Overall, these results indicate that excision of MTns is a complex process that requires multiple gene products.

Trends Microbiol, 2004 Jan, 12(1), 21 - 8
Message from a human gut symbiont: sensitivity is a prerequisite for sharing; Xu J et al.; Microbial genome sequencing projects are beginning to provide insights about the molecular foundations of human-bacterial symbioses . The intestine contains our largest collection of symbionts, where members of Bacteroides comprise approximately 25% of the microbiota in adults . The recently defined proteome of a prominent human intestinal symbiont, Bacteroides thetaiotaomicron, contains an elaborate environmental-sensing apparatus . This apparatus includes an unprecedented number of extracytoplasmic function (ECF) sigma-factors, and a large collection of novel hybrid two-component systems composed of membrane-spanning periplasmic proteins with histidine kinase, phosphoacceptor, response regulator receiver and DNA-binding domains . These sensors are linked to the organism's large repertoire of genes involved in acquiring and processing dietary polysaccharides ('the glycobiome') . This arrangement illustrates how a successful symbiont has evolved strategies for detecting and responding to conditions in its niche so that it can sustain beneficial relationships with its microbial and human partners.

Nat Immunol, 2004 Jan, 5(1), 104 - 12 Epub 2003 Dec 21.
Commensal anaerobic gut bacteria attenuate inflammation by regulating nuclear-cytoplasmic shuttling of PPAR-gamma and RelA; Kelly D et al.; The human gut microflora is important in regulating host inflammatory responses and in maintaining immune homeostasis . The cellular and molecular bases of these actions are unknown . Here we describe a unique anti-inflammatory mechanism, activated by nonpathogenic bacteria, that selectively antagonizes transcription factor NF-kappaB . Bacteroides thetaiotaomicron targets transcriptionally active NF-kappaB subunit RelA, enhancing its nuclear export through a mechanism independent of nuclear export receptor Crm-1 . Peroxisome proliferator activated receptor-gamma (PPAR-gamma), in complex with nuclear RelA, also undergoes nucleocytoplasmic redistribution in response to B . thetaiotaomicron . A decrease in PPAR-gamma abolishes both the nuclear export of RelA and the anti-inflammatory activity of B . thetaiotaomicron . This PPAR-gamma-dependent anti-inflammatory mechanism defines new cellular targets for therapeutic drug design and interventions for the treatment of chronic inflammation.

J Pediatr (Rio J), 1995 May-Jun, 71(3), 158 - 62
{Proliferation of anaerobic flora in the small intestine of infants with acute and protracted diarrhea}; da Cruz AS et al.; Bacterial proliferation in the small intestine can induce the protraction of diarrhea due to malabsorption of the nutrients . We performed the culture of the small intestine juice for the aerobic and anaerobic flora in 40 infants with persistent and acute diarrhea . Bacterial proliferation was observed in 32 (80%) patients, being 30 (75%) due to the aerobic microflora and 17 (43%) due to the anaerobic microflora . There was no statistical difference in the bacterial growth between acute and persistent diarrhea.The aerobic bacteria most frequently isolated was E . coli in 23 patients, and Bacteroides sp was the most prevalent anaerobic bacteria, isolated in 9 cases . The transitory flora was significantly more abundant in patients with persistent diarrhea.

Environ Microbiol, 2004 Jan, 6(1), 45 - 54
Analysis and comparison of the microbial community structures of two enrichment cultures capable of reductively dechlorinating TCE and cis-DCE; Gu AZ et al.; In order to study the effect of different chloroethenes (electron acceptors) on the bacterial composition of dechlorinating communities, two reductive dechlorinating enrichment cultures were developed that were able to reduce trichloroethene (TCE) and cis-1,2-dichloroethene (cis-DCE) to ethene using hydrogen as electron donor, respectively . The inoculum for the cultures was material from a methanogenic fluidized bed reactor (FBR), which was originally seeded with digester sludge and showed a stable capacity for tetrachloroethene (PCE) reduction to ethene for over six years . Molecular methods were used to determine and compare the microbial communities of these two enrichment cultures . A clone library of bacterial 16S rRNA genes was generated for each enrichment . The clones were screened into different groups by restriction fragment length polymorphism (RFLP) analysis using two different four base pair recognition restriction enzymes . A total of 12 sequence types were identified by phylogenetic analysis of nearly complete 16S rDNA sequences ( approximately 1450 bp) . The sequences were affiliated with six recognized phyla of the domain Bacteria: Firmicutes (low G+C Gram-positives), Chloroflexi (green non-sulphur bacteria), Actinobacteria (high G+C Gram-positives), Bacteroidetes (Cytophaga-Flexibacter-Bacteroides), Nitrospira and Spirochaetes . The results led to the identification of an organism closely related to Dehalococcoides ethenogenes to be the presumptive dechlorinator in both enrichments . Different electron acceptors affected the bacterial diversity and the community profiles of the two enrichments . Most of the sequences identified in our dechlorinating enrichments shared high similarities with sequences previously obtained from other enriched dechlorinating cultures and chlorinated-compound-contaminated sediments or aquifers, suggesting these bacteria may have direct or indirect roles in reductive dechlorination.

Vasc Endovascular Surg, 2003 Nov-Dec, 37(6), 441 - 4
Allograft replacement of common iliac artery mycotic aneurysm caused by Bacteroides fragilis vertebral spondylitis--a case report; Tsuji Y et al.; Mycotic aneurysm secondary to vertebral spondylitis is a rare but life-threatening pathology with high mortality and morbidity . The authors describe a successfully treated case of mycotic aneurysm of the common iliac artery complicated with vertebral spondylitis in a 74-year-old man . Under midline laparotomy, complete debridement of the infected tissues, in-situ replacement of the common iliac artery with cryopreserved aortic allograft, and iliac bone autotransplantation and omentopexy to fill the debrided cavity were performed . The postoperative course was uneventful, and he remains well 3 years after his operation without persistent infection or allograft rejection.

Microbiology, 2003 Dec, 149(Pt 12), 3617 - 27
The surface (S-) layer is a virulence factor of Bacteroides forsythus; Sabet M et al.; Bacteroides forsythus has emerged as a crucial periodontal pathogen with possible implications for systemic disease . The aim of this study was to isolate the S-layer from B . forsythus and examine its virulence potential as a part of efforts to characterize virulence factors of B . forsythus . The role of the S-layer in the haemagglutinating and adherent/invasive activities was evaluated . It was observed that the S-layer alone was able to mediate haemagglutination . In adherent and invasive studies, transmission electron microscopy clearly revealed that B . forsythus cells were able to attach to and invade KB cells, showing the formation of a microvillus-like extension around adherent and intracellular bacteria . The quantitative analysis showed that five different B . forsythus strains exhibited attachment (1.9-2.3 %) and invasion (0.4-0.7 %) capabilities . It was also observed through antibody inhibition assays that adherent/invasive activities of B . forsythus are mediated by the S-layer . Furthermore, an in vivo immunization study adopting a murine abscess model was used to prove that the S-layer is involved in the infectious process of abscess formation . While mice immunized with purified S-layer and B . forsythus whole cells did not develop any abscesses when challenged with viable B . forsythus cells, unimmunized mice developed abscesses . Collectively, the data obtained from these studies indicate that the S-layer of B . forsythus is a virulence factor.

FEMS Microbiol Lett, 2003 Dec 5, 229(1), 23 - 30
Phylogenetic analysis of fiber-associated rumen bacterial community and PCR detection of uncultured bacteria; Koike S et al.; The fiber-associated rumen bacterial community was phylogenetically examined by analysis of 16S rRNA gene (16S rDNA) sequences . Hay stems of orchardgrass and alfalfa were incubated for 6 and 20 h, respectively in the rumen of two different sheep, and total DNA was extracted from the incubated stems to clone bacterial 16S rDNAs using polymerase chain reaction (PCR) . Of 91 such clones, 21 showed more than 97% sequence similarity with known isolates, 32 clones had 90-97% similarity with known sequences, and for the remaining 38 clones, the similarity was less than 90% . The majority of clones fell into the Cytophaga-Flavobacter-Bacteroides and low G+C Gram-positive bacterial phyla (43 and 44%, respectively) . Prevotella-related and Butyrivibrio fibrisolvens-related sequences formed large clusters in the phylogenetic tree . Unknown sequences were found to form three unique clusters, one of which was suggested by semi-quantitative PCR to be more prevalent in the rumen receiving a high alfalfa diet.

Int J Syst Evol Microbiol, 2003 Nov, 53(Pt 6), 2111 - 2
Proposal to conserve the adjectival form of the specific epithet in the reclassification of Bacteroides forsythus Tanner et al . 1986 to the genus Tannerella Sakamoto et al . 2002 as Tannerella forsythia corrig., gen . nov., comb . nov . Request for an Opinion; Maiden MF et al.; With reference to the first Principle of the International Code of Nomenclature of Bacteria, which emphasizes stability of names, it is proposed that the original adjectival form of the specific epithet be conserved in the reclassification of Bacteroides forsythus to the new genus Tannerella . Thus, Tannerella forsythensis Sakamoto et al . 2002 should be Tannerella forsythia Sakamoto et al . 2002 corrig., gen . nov., comb . nov., and we put forward a Request for an Opinion to the Judicial Commission regarding this correction.

Folia Morphol (Warsz), 2003 Nov, 62(4), 455 - 7
The influence of experimental Bacteroides fragilis infection on substance P and somatostatin-immunoreactive neural elements in the porcine ascending colon - a preliminary report; Gonkowski S et al.; The present study was aimed at disclosing the influence of Bacteroides fragilis (one of the most important bacterial agents causing colitis in children) experimental infection on the expression of substance P (SP) and somatostatin (SOM) in neurons and nerve fibres within the porcine ascending colon . Distinct differences in the distribution pattern of neural elements immunoreactive to the substances studied were observed between the experimental (Inflam) and control (Contr) pigs . In general, the number of SP-IR neurons and nerve terminals increased, while the expression of SOM decreased after Bacteroides fragilis-induced colitis (BFIC) . However, distinct differences in the intensity of these alterations were observed between particular compartments of the bowel segment studied . Thus, the present results suggest that SP- and SOM-immunoreactive (SOM-IR) elements of the enteric nervous system play a part in the control of colonic activity during BFIC.

Int Endod J, 2003 Nov, 36(11), 774 - 9
Induction of interleukin-8 gene expression by black-pigmented Bacteroides in human pulp fibroblasts and osteoblasts; Yang LC et al.; AIM: To investigate the effect of black-pigmented Bacteroides on the expression of interleukin (IL)-8 gene in human pulp fibroblasts and osteoblasts . METHODOLOGY: The supernatants of Porphyromonas endodontalis, P . gingivalis and Prevotella intermedia were used to evaluate IL-8 gene expression in human pulp fibroblasts and osteoblasts . The levels of mRNAs were measured by the quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis . RESULTS: Investigations of the time-dependence of IL-8 mRNA expression in black-pigmented Bacteroides-treated pulp fibroblasts and osteoblasts revealed a rapid accumulation of the transcript after 2 h of exposure, and remained elevated throughout the 24-h incubation period . In addition, IL-8 mRNA gene expression was also found in human osteoblasts stimulated with black-pigmented Bacteroides . However, black-pigmented Bacteroides was found to be more effective in the induction of IL-8 mRNA gene expression in osteoblasts than in pulp fibroblasts (P < 0.05) . CONCLUSIONS: Black-pigmented Bacteroides are capable of amplifying the local immune response and promoting pulpal/periapical tissue inflammation by stimulating pulp fibroblasts and osteoblasts to express IL-8.

J Oral Sci, 2003 Sep, 45(3), 127 - 37
The effects of extracts from periodontopathic bacteria on human periodontal fibroblasts stimulated with mineralization supplements; Marquez-San Miguel S et al.; Bacterial effects on in vitro mineralization of human periodontal fibroblasts (HPF) have not yet been examined in great detail . In our study, we investigated the effects of soluble extracts of the periodontopathic bacteria Porphyromonas gingivalis, Bacteroides forsythus and, Treponema denticola on cell proliferation, mineralization, as well as on osteoblastic markers present in HPF cultured in vitro, such as alkaline phosphatase (ALP) activity and collagen content . Periodontal fibroblasts stimulated by B-glycerophosphate, ascorbic acid and dexamethasone (BAD) or by dexamethasone and ascorbic acid (DA) were compared to unstimulated cells . During the cultivation period, the stimulation of HPF by combined dexamethasone and ascorbic acid (DA) had a strong inductive effect on proliferation, ALP activity and collagen formation . The extracts obtained from the periodontal pathogens had a suppressing effect on the proliferation rate of HPF . The extracts from P . gingivalis, B . forsythus and T . denticola caused a decrease in ALP activity within 24 h of application . While extracts obtained from P . gingivalis and B . forsythus induced a reduction in collagen content in BAD- and DA-stimulated HPF cells, T . denticola extracts led to an increase in collagen . Our data suggest that specific periodontopathic bacteria may suppress tissue regeneration in vivo not only by activating host defense mechanisms but also directly via a suppression of growth and differentiation of HPF and a reduction in the extracellular collagen matrix . For the process of pocket formation, not even the direct influence of viable bacteria seems to be necessary . Additionally, long-distance effects of bacteria harboured in periodontal pockets or in root canals may be of importance.

Jpn J Thorac Cardiovasc Surg, 2003 Oct, 51(10), 545 - 7
Acute type B aortic dissection complicated with a mycotic aortic arch aneurysm; Matsuyama K et al.; A successfully-treated case of acute type B aortic dissection associated with a mycotic aneurysm is reported . A 69-year-old man had a history of febrile illness and a high CRP level with increased enzyme activity of the hepatobiliary system before the onset . The culture of the abscess in the distal arch aneurysm revealed Bacteroides fragilis . A Dacron graft replacement between the distal arch and the proximal descending aorta was successfully performed with Teflon felt reinforcement, and the graft was covered with omental flap . The patient was discharged without recurrence of infection 2 months after the graft replacement.

J Med Microbiol, 2003 Dec, 52(Pt 12), 1101 - 7
Cloning of the Tannerella forsythensis (Bacteroides forsythus) siaHI gene and purification of the sialidase enzyme; Ishikura H et al.; Tannerella forsythensis (previously named Bacteroides forsythus) is a Gram-negative, anaerobic, fusiform bacterium that is a primary or secondary aetiological agent in periodontal disease in humans . T . forsythensis expresses several putative virulence factors, including a sialidase; however, there has been no molecular genetic characterization of this enzyme . A sialidase clone (pHI-1) was screened from a total of 455 recombinant clones of a genomic DNA library using the 2'- (4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid (MUNeuAc) filter-paper spot assay . The sialidase gene ORF (siaHI) consists of a 1395 bp coding sequence and encodes a protein with 465 amino acids with an overall molecular mass of 52 kDa . The sialidase does not have sequence similarity to any other bacterial sialidase . The entire sialidase ORF was expressed in Escherichia coli . Furthermore, the sialidase was purified from the type strain of T . forsythensis and from a recombinant clone, pHI-1 : 1, and was analysed using a non-denaturing gel, revealing that the enzyme preparations were respectively separated as two major bands and as a single band . Southern blot hybridization analysis revealed similar patterns of siaHI-hybridizing bands among clinical isolates of T . forsythensis from periodontitis patients . This is the first study on the cloning and expression of a T . forsythensis sialidase gene and the purification of the SiaHI enzyme from T . forsythensis ATCC 43037(T) and recombinant E . coli.

Am J Surg, 2003 Nov, 186(5), 519 - 25
Adrenomedullin is increased in the portal circulation during chronic sepsis in rats; Matheson PJ et al.; BACKGROUND: A clinical hallmark of sepsis is an early, hyperdynamic cardiac phase (increased cardiac output) that degrades to a hypodynamic phase, which results in poor gut perfusion and subsequent gastrointestinal (GI) hypoxemia, tissue ischemia, necrosis and loss of gut barrier function . Studies in rat cecal-ligation and puncture suggest that the potent vasodilator adrenomedullin (AM) might initiate or maintain the hypodynamic phase . We hypothesize that AM expression is increased in acute Escherichia coli bacteremia and chronic E coli-Bacteroides fragilis sepsis . METHODS: Acute bacteremia: male Sprague-Dawley rats were anesthetized (urethane/alpha-chloralose), tracheotomized, and cannulated for monitoring blood pressure (MABP) and heart rate (HR) and for infusion of E coli (10(9) colony-forming units {CFU} E coli per 1 mL normal saline) and blood sampling . Arterial blood was withdrawn for arterial blood gas (ABG) measurements every 60 minutes . After 6 hours, we harvested lung, liver, kidney, spleen, and small intestine tissue samples and drew arterial and portal blood for AM enzyme-linked immunosorbent assay (ELISA) . Chronic sepsis: a sterile gauze pad was implanted and animals recovered for 5 days . Twenty-four hours (10(9) CFU E coli and 10(9) CFU B fragilis per 1 mL normal saline; 1 injection) or 72 hours (2 injections) after the inoculation of the back sponge, rats were anesthetized, intubated, and cannulated as above . MABP, HR, and ABG were measured for 1 hour before tissue and serum harvest for AM ELISA . RESULTS: Sepsis increased HR and MABP in all groups . Acute sepsis caused a respiratory alkalosis and pH was also elevated in chronic sepsis . Serum AM levels were increased in all groups compared with baseline and remained elevated at every time point, but were not different between saline controls and septic animals at any time point, except for the portal serum from the 72-hour chronic sepsis, which was elevated . CONCLUSIONS: These data suggest that surgical manipulation alone is sufficient to stimulate AM secretion, most probably from endothelial cells . While the AM levels were decreasing at 72 hours compared with 6 hours or 24 hours in the arterial blood and the saline control portal blood, it remained elevated in the septic portal samples, suggesting that the sepsis-induced increase of AM was derived from the gut by a different mechanism than that which elevated arterial serum levels.

Eur J Clin Pharmacol, 2004 Jan, 59(11), 809 - 13 Epub 2003 Oct 29.
Perioperative penetration of metronidazole into muscle tissue: a microdialysis study; Karjagin J et al.; OBJECTIVE: To evaluate the concentration of metronidazole in muscle tissue using microdialysis and to compare it with plasma concentration and in vitro-defined MIC(90) (minimal inhibiting concentration) for the most frequent anaerobic bacteria isolated in our hospital . MATERIALS AND METHODS: Six female patients scheduled for elective gynaecological surgery were included . Exclusion criteria were active inflammatory process and being overweight (BMI more than 30) . Microdialysis catheters (CMA 60 catheters with 20 kDa cut-off membrane) were placed into the m . vastus lateralis . The microdialysis perfusion rate was 2 microl/min . To assess in vivo recovery of the drug, retrodialysis with a 5-mg/l solution of metronidazole was performed . Microdialysis and blood samples were collected simultaneously 10 h after metronidazole administration . MIC(90) data were obtained from the database of the microbiology laboratory of the local hospital . RESULTS: Data from five patients were included in analysis . The metronidazole concentration in blood achieved a value of 16.5+/-4.6 mg/l at 30 min (first available data), while in muscle a maximum level of 7.8+/-1.5 mg/l was achieved at 114 min . The mean MIC(90) for the Bacteroides fragilis group was 0.25+/-0.26 mg/l . Data from mean plasma concentrations were fitted into the two-compartmental model and time over MIC(90) and time over four times MIC(90) were calculated, which were 52.1+/-13.5 h and 33.2+/-8.7 h, respectively . The C(max)/MIC(90) ratio was 65.8+/-18.5 for plasma and 31.1+/-6.2 for muscle . CONCLUSION: The present data demonstrate that metronidazole penetrates well into muscle tissue . Muscle tissue concentrations reach values far greater than MIC(90) for the Bacteroides fragilis group and persist at such high levels for at least 10 h.

J Periodontol, 2003 Sep, 74(9), 1329 - 35
Distribution of periodontal pathogens in Korean aggressive periodontitis; Lee JW et al.; BACKGROUND: Microbial associations in aggressive periodontitis versus different ethnic origins are substantially unknown . We undertook this study to determine the prevalence of seven putative periodontopathogens in Korean patients and to evaluate microbial differences in localized and generalized aggressive periodontitis patients . METHODS: Thirty-nine aggressive periodontitis patients between 20 and 35 years old (24 males and 15 females; mean age 29.6 years) were selected according to clinical criteria . The patients were subclassified into 17 localized and 22 generalized aggressive periodontitis patients . In each of the 39 individuals, subgingival plaque samples were collected from four diseased teeth (> or = 6 mm probing depth, 156 sites) and one healthy site (< or = 3 mm probing depth, 39 sites) . Polymerase chain reaction (PCR) of the 16S ribosomal RNA gene fragments (about 530 bp) of plaque bacteria and their subsequent detection by dot-blot hybridization using specific oligonucleotide probes were performed to determine the presence of seven periodontopathogens . RESULTS: The prevalences were 75% for Actinobacillus actinomycetemcomitans, 94.2% for Tannerella forsythensis (formerly Bacteroides forsythus), 99.4% for Fusobacterium sp., 85.9% for Micromonas micros (formerly Peptostreptococcus micros), 96.8% for Porphyromonas gingivalis, 78.8% for Prevotella intermedia, and 96.8% for Treponema sp . The prevalences of these bacteria were significantly higher in diseased sites than in healthy sites . Logistic regression analysis showed that P . intermedia was more significantly associated with generalized aggressive periodontitis than the localized form, with an odds ratio of 3.28 (95% confidence interval 1.26-8.56, P = 0.015) . CONCLUSIONS: Our results demonstrate that the seven periodontal pathogens analyzed are strongly associated with Korean aggressive periodontitis . In particular, P . intermedia are more significantly associated with generalized aggressive periodontitis, a more severe and progressive form, than with localized aggressive periodontitis.

Med Dosw Mikrobiol, 2003, 55(2), 173 - 80
{Anaerobic bacteria in bronchoalveolar lavage fluid (BAL) after thoracic surgery}; Zajac-Lenczewska I et al.; Purpose of this study was to find out what kind of anaerobic bacteria were in lower respiratory tract and how often they were present there considering patients after thoracic surgery . Also, what is susceptibility of bacteria to antibiotics . Research covered 30 patients after operation . Material for research was bronchoalveolar lavage (BAL) taken during bronchoscopy . Collected sample was cultivated in anaerobic and aerobic conditions . Anaerobic bacteria were found in 28 samples (93%) . Totally there were 100 anaerobic bacteria strains . The most common Gram-negative rods were from genus Prevotella (24 strains, 24%) and Bacteroides (15 strains, 15%) . Gram-negative bacteria except Bacteroides characterised biggest susceptibility to imipenem, piperacillin/tazobactam, amoxicillin/clavulanate, ampicillin/sulbactam, piperacillin, clindamycin and metronidazol . Bacteroides were susceptible to imipenem, piperacillin/tazobactam and metronidazol . Among Gram-positive anaerobic bacteria mostly were isolated from cocci Peptostreptococcus (18 strains, 18%) and were susceptible to all antibiotics . Gram-positive rods were in most cases represented by Actinomyces (12 strains 12%) and were highly susceptible to all antibacterial means except metronidazol (100% is resistant).

Gene, 2003 Oct 16, 316, 167 - 75
Genetic analysis of an important oxidative stress locus in the anaerobe Bacteroides fragilis; Herren CD et al.; The obligate anaerobe, Bacteroides fragilis, is a highly aerotolerant intestinal tract organism that has evolved a complex oxidative stress response (OSR) . The redox regulator OxyR controls several OSR genes (katB, dps, and ahpC), but there is little else known about other genes it regulates . To identify additional genes in the OxyR regulon, two-dimensional gel electrophoresis was used to isolate proteins from a mutant that constitutively expresses genes in the regulon . The 28,500 Da protein thioredoxin peroxidase (Tpx) was identified . Two additional genes induced during oxidative stress were identified adjacent to tpx, a putative RNA-binding protein (rbpA) and a cytochrome-c peroxidase (ccp) . Transcriptional analyses showed that tpx and rbpA were transcribed as monocistronic mRNA species or as a bicistronic operon . Transcription of tpx was induced by exposure to air or H(2)O(2) from an OxyR-dependent promoter and to a lesser extent from a second OxyR-independent promoter . Expression of the rbpA gene during oxidative stress was regulated by the OxyR-dependent tpx promoter resulting in the bicistronic tpx/rbp mRNA . The ccp gene was expressed only as a monocistronic message and induction was only observed after exposure to H(2)O(2) in an OxyR-independent manner . Disruption of the tpx operon or ccp resulted in sensitivity to the organic peroxides cumene hydroperoxide (CHP) and t-butyl hydroperoxide (TBHP) but not to H(2)O(2) . This work brings the total of oxyR-controlled genes in B . fragilis to five and suggests the existence of a second peroxide response regulator that controls ccp expression.

Biotech Histochem, 2003 Apr, 78(2), 129 - 33
A morphological and immunolabeling study of freeze-substituted Bacteroides forsythus; Moriguchi K et al.; We used a rapid freezing and freeze-substitution technique without glutaraldehyde and OsO4 fixation for the electron microscopic immunocytochemical demonstration of the surface structure of Bacteroides forsythus, an anaerobic Gram-negative periodontopathogen . Cells were applied to pieces of filter paper and freeze-substituted by plunge-freezing in liquid propane, substituted in methanol containing 0.5% uranyl acetate, and infiltrated with LR White resin . The membrane ultrastructure of B . forsythus was preserved well, and the labeling density of the freeze-submitted cells was compared to a conventional processing method . Our results show the usefulness of the freeze-substitution method for immunohistochemical studies of B . forsythus.

Appl Environ Microbiol, 2003 Oct, 69(10), 6007 - 17
Phylogenetic diversity, abundance, and axial distribution of bacteria in the intestinal tract of two soil-feeding termites (Cubitermes spp.); Schmitt-Wagner D et al.; The hindgut of soil-feeding termites is highly compartmentalized and characterized by pronounced axial dynamics of the intestinal pH and microbial processes such as hydrogen production, methanogenesis, and reductive acetogenesis . Nothing is known about the bacterial diversity and the abundance or axial distribution of the major phylogenetic groups in the different gut compartments . In this study, we showed that the variety of physicochemical conditions is reflected in the diversity of the microbial communities in the different gut compartments of two Cubitermes species (TERMITIDAE: Termitinae) . 16S rRNA gene clones from the highly alkaline first proctodeal segment (P1) of Cubitermes orthognathus represented almost exclusively gram-positive bacteria with low G+C content (LGC bacteria) . In the posterior gut segments, their proportion decreased progressively, and the clone libraries comprised a variety of phyla, including the Cytophaga-Flexibacter-Bacteroides group, various subgroups of Proteobacteria, and the spirochetes . Phylogenetic analysis revealed that many of the clones clustered with sequences from the guts of other termites, and some even formed clusters containing only clones from C . orthognathus . The abundance and axial distribution of major phylogenetic groups in the gut of Cubitermes ugandensis were determined by fluorescence in situ hybridization with group-specific oligonucleotide probes . While the results were generally in good agreement with those of the clonal analysis, direct counts with probes specific for the Planctomycetales revealed a severe underestimation of representatives of this phylum in the clone libraries . Results obtained with newly designed FISH probes directed against two clusters of LGC clones from C . orthognathus indicated that the clones were restricted to specific gut regions . A molecular fingerprinting analysis published in a companion paper (D . Schmitt-Wagner, M . W . Friedrich, B . Wagner, and A . Brune, Appl . Environ . Microbiol . 69:6018-6024, 2003) corroborated the presence of compartment-specific bacterial communities in the gut of different Cubitermes species.

Bioessays, 2003 Oct, 25(10), 926 - 9
Bacteroides thetaiotaomicron: a dynamic, niche-adapted human symbiont; Comstock LE et al.; The coevolution of humans with their intestinal microflora has resulted in cooperative relationships that have shaped the biology and the genomes of these symbiotic partners . Bacteroides thetaiotaomicron is one such bacterial symbiont that is a dominant member of the intestinal microbiota of humans and other mammals . The recent report of the genome sequence of B . thetaiotaomicron is the first reported for an abundant Gram-negative organism of the human colonic microbiota and, as such, provides the first glimpse on a genomic scale of the genetic arsenal used by a Gram-negative symbiont to dominate in this ecosystem . The genome has revealed large expansions of many paralogous groups of genes that encode products essential to the organism's ability to successfully compete in this environment . Most noteable is the organism's abundant machinery for utilizing a large variety of complex polysaccharides as a source of carbon and energy . The proteome also reveals the organism's extensive ability to adapt and regulate expression of its genes in response to the changing ecosystem . These factors, as well as others highlighted below, suggest an incredibly flexible and adaptable organism that is exquisitely equipped to dominate in its challenging and competitive niche .

Rev Inst Med Trop Sao Paulo, 2003 Jul-Aug, 45(4), 225 - 7 Epub 2003 Sep 17.
Detection of non-enterotoxigenic and enterotoxigenic Bacteroides fragilis in stool samples from children in São Paulo, Brazil; Krzyzanowsky F et al.; Non-enterotoxigenic bacteria of the Bacteroides fragilis group and enterotoxigenic B . fragilis were identified from children with and without aqueous acute diarrhea . In this study, 170 stool samples from 96 children with and 74 without diarrhea were analyzed . Enterotoxin production and the toxin gene detection were detected by cytotoxicity assay on HT-29/C1 cells and by PCR, respectively . B . fragilis species was prevalent in both groups and enterotoxigenic B . fragilis strains were isolated from two children with diarrhea . More studies are important to evaluate the role of each bacteria of the B . fragilis group, including enterotoxigenic strains play in the diarrheal processes in children.

Pneumonol Alergol Pol, 2003, 71(1-2), 68 - 73
{Incidence of anaerobic bacteria in respiratory tract infections}; Kedzia A et al.; Anaerobic bacteria are predominant components of normal oral cavity, upper respiratory tract, gastrointestinal, genital and skin flora . They are involved in infections such as pneumonia, aspiration pneumonia, lung abscess and empyema . Laboratory diagnosis of anaerobic infections is based on recovering the etiological agents from clinical materials . Appropriatte specimens include: pus, purulent fluid, biopsy specimen of lung, transtracheal aspirates and bronchoalveolar lavage (BAL) . Lower respiratory infections are usually either polymicrobial or mixed anaerobic-aerobic infections . Peptostreptococcus, Fusobacterium, Prevotella and Bacteroides are the most common anaerobes . Anaerobic bacteria are susceptible to metronidazole, tinidazole (exception of Gram-positive rods), amoxicillin/clavulanate, ampicillin/sulbactam, piperacillin/tazobactam, imipenem and clindamycin . Treatment includes an antibiotics regimen with an agent active against anaerobic and aerobic bacteria (therapy with 2 or 3 antimicrobial drugs).

J Clin Microbiol, 2003 Sep, 41(9), 4428 - 30
Prevalence of fragilysin gene in Bacteroides fragilis isolates from blood and other extraintestinal samples; Foulon I et al.; Of 166 Bacteroides fragilis isolates, 26.2% of 103 isolates from blood and 20.6% of 63 extraintestinal isolates harbored the fragilysin gene (difference not statistically significant) . Clinical characteristics and evolution were comparable in patients with B . fragilis bacteremia with or without this enterotoxin . Fragilysin seems not to be an important virulence factor in B . fragilis disease.

J Antimicrob Chemother, 2003 Oct, 52(4), 605 - 9 Epub 2003 Sep 01.
Accumulation of garenoxacin by Bacteroides fragilis compared with that of five fluoroquinolones; Ricci V et al.; OBJECTIVES: Garenoxacin is a novel des-F(6)-quinolone with good anti-anaerobe activity . The accumulation of garenoxacin and five other quinolones in the presence and absence of a variety of efflux pump inhibitors, including carbonyl cyanide m-chlorophenyl hydrazone (CCCP: 100 microM), verapamil (25 microM), reserpine (20 mg/L), sodium orthovanadate (50 microM) and Phe-Arg-beta-naphthylamide (MC-207110) (20 mg/L) was investigated . METHODS: Bacteroides fragilis was grown in Wilkins Chalgren broth (Oxoid Ltd, UK) in a MKII anaerobic workstation (Don Whitley, Shipley, UK) . Susceptibility testing was performed, according to the agar doubling dilution method, using Wilkins Chalgren agar supplemented with 5% horse blood . A fluorometric assay was used to measure the accumulation of quinolones (10 mg/L) by B . fragilis . RESULTS: The activity of the agents for B . fragilis NCTC 9343/ATCC 25285 was clinafloxacin>garenoxacin>levofloxacin=gatifloxacin>moxifloxacin>ciprofloxacin . A weak correlation was observed between the molecular size of the free form and the MIC, the steady state concentration (SSC) and the initial rate of accumulation, but not for the hydrophobicity of each agent . In the presence of reserpine, the SSC of all agents increased . The addition of CCCP had no effect upon garenoxacin or clinafloxacin accumulation, but significantly increased the SSC of ciprofloxacin, moxifloxacin, gatifloxacin and levofloxacin . Verapamil increased the SSC of garenoxacin, whereas sodium orthovanadate had no effect on the concentration of accumulated garenoxacin . CONCLUSIONS: These data suggest that there is probably more than one type of efflux pump in B . fragilis that exports quinolones.

J Periodontal Res, 2003 Oct, 38(5), 465 - 70
Endpoint quantitative PCR assays for Bacteroides forsythus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans; Rudney JD et al.; BACKGROUND: Conventional polymerase chain reaction (PCR) assays for periodontal pathogens are so sensitive that they detect infections of no clinical significance . Quantitative PCR (qPCR) may provide a solution to this problem . However, most qPCR systems require expensive real-time thermal cyclers . OBJECTIVE: Our goal was to develop qPCR assays which would allow endpoint quantification . MATERIALS AND METHODS: 16S rRNA primers for Bacteroides forsythus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans were adapted to the Amplifluor qPCR system, which incorporates fluorescein into the PCR product so that endpoint fluorescence is proportional to the original amount of template . DNA dilutions representing known numbers of cells were used as standard curves . Pooled subgingival plaques from the four deepest pockets of 21 severe adult periodontitis patients were assayed . Buccal molar supragingival plaque from 35 dental students provided healthy controls . Endpoint fluorescence was measured with a microplate reader . RESULTS: Optimized standard curves were linear in log-log or semilog fits over a range of 100-10(6) cells . Countable B . forsythus was present in all patients, with counts (as logs) from 2.4 to 7.3 (mean = 5.0), and 11 controls with counts from 2.1 to 4.5 (mean = 3.0) . P . gingivalis was present in 11 patients and no controls, with counts from 2.2 to 4.7 (mean = 3.2) . A . actinomycetemcomitans was present in two patients, with counts of 1.5 and 3.5 . CONCLUSIONS: Amplifluor qPCR assays discriminated between plaque samples differing by one log or more, allowing major infections to be distinguished from minor ones . This approach allows high-throughput qPCR of plaque samples, using equipment available to many laboratories.

Oral Microbiol Immunol, 2003 Oct, 18(5), 309 - 12
Cloning and expression of alpha-D-glucosidase and N-acetyl-beta-glucosaminidase from the periodontal pathogen, Tannerella forsythensis (Bacteroides forsythus); Hughes CV et al.; Screening a genomic library of Tannerella forsythensis (Bacteroides forsythus), using synthetic substrates conjugated to a fluorogen, 4-methylumbelliferone identified two glycosidase genes, which encode alpha-D-glucosidase and N-acetyl-beta-D-glucosaminidase, respectively . The alpha-D-glucosidase has a Mr of 81,141 and is homologous to an alpha-D-glucosidase from Bacteroides thetaiotaomicron . The N-acetyl-beta-D-glucosaminidase has a Mr of 87,787 and is homologous to an N-acetyl-beta-D-glucosaminidase in Porphyromonas gingivalis W83.

Proc Natl Acad Sci U S A, 2003 Sep 2, 100(18), 10452 - 9 Epub 2003 Aug 15.
Inaugural Article: Honor thy symbionts; Xu J et al.; Our intestine is the site of an extraordinarily complex and dynamic environmentally transmitted consortial symbiosis . The molecular foundations of beneficial symbiotic host-bacterial relationships in the gut are being revealed in part from studies of simplified models of this ecosystem, where germ-free mice are colonized with specified members of the microbial community, and in part from comparisons of the genomes of members of the intestinal microbiota . The results emphasize the contributions of symbionts to postnatal gut development and host physiology, as well as the remarkable strategies these microorganisms have evolved to sustain their alliances . These points are illustrated by the human-Bacteroides thetaiotaomicron symbiosis . Interdisciplinary studies of the effects of the intestinal environment on genome structure and function should provide important new insights about how microbes and humans have coevolved mutually beneficial relationships and new perspectives about the foundations of our health.

J Antimicrob Chemother, 2003 Sep, 52(3), 481 - 4 Epub 2003 Aug 13.
Plasmid-mediated complementation of gyrA and gyrB in fluoroquinolone-resistant Bacteroides fragilis; Peterson ML et al.; OBJECTIVES: To identify whether mutations in gyrA and gyrB confer fluoroquinolone resistance in Bacteroides fragilis . METHODS: Eight fluoroquinolone-resistant (FQR) strains were complemented with plasmid-mediated B . fragilis wild-type gyrA (pMP1) and gyrB (pMP2), and MICs determined . Sequence analysis of the gyrA and gyrB quinolone resistance determining region (QRDR) was performed for all strains . RESULTS: MICs of fluoroquinolones were two- to 32-fold higher than wild-type for all mutants . Five mutants had a substitution in GyrA (Ser-82-->Phe), one mutant had a substitution in GyrA (Asp-81-->Gly), one mutant had a substitution in GyrB (Glu-478-->Lys), and one resistant strain did not contain mutations in the QRDR of gyrA or gyrB . Following complementation with pMP1 or pMP2, the MICs of fluoroquinolones were reduced two- to 32-fold for the mutants . CONCLUSION: These studies verify that substitutions in GyrA and GyrB confer resistance in B . fragilis . Other mechanisms are also responsible for resistance since not all resistant strains fully complemented to the wild-type phenotype.

Proc Natl Acad Sci U S A, 2003 Sep 2, 100(18), 10446 - 51 Epub 2003 Aug 12.
Mpi recombinase globally modulates the surface architecture of a human commensal bacterium; Coyne MJ et al.; The mammalian gut represents a complex and diverse ecosystem, consisting of unique interactions between the host and microbial residents . Bacterial surfaces serve as an interface that promotes and responds to this dynamic exchange, a process essential to the biology of both symbionts . The human intestinal microorganism, Bacteroides fragilis, is able to extensively modulate its surface . Analysis of the B . fragilis genomic sequence, together with genetic conservation analyses, cross-species cloning experiments, and mutational studies, revealed that this organism utilizes an endogenous DNA inversion factor to globally modulate the expression of its surface structures . This DNA invertase is necessary for the inversion of at least 13 regions located throughout the genome, including the promoter regions for seven of the capsular polysaccharide biosynthesis loci, an accessory polysaccharide biosynthesis locus, and five other regions containing consensus promoter sequences . Bacterial DNA invertases of the serine site-specific recombinase family are typically encoded by imported elements such as phage and plasmids, and act locally on a single region of the imported element . In contrast, the conservation and unique global regulatory nature of the process in B . fragilis suggest an evolutionarily ancient mechanism for surface adaptation to the changing intestinal milieu during commensalism.

J Biol Chem, 2003 Oct 17, 278(42), 41302 - 8 Epub 2003 Aug 06.
The phosphonopyruvate decarboxylase from Bacteroides fragilis; Zhang G et al.; The Bacteroides fragilis capsular polysaccharide complex is the major virulence factor for abscess formation in human hosts . Polysaccharide B of this complex contains a 2-aminoethylphosphonate functional group . This functional group is synthesized in three steps, one of which is catalyzed by phosphonopyruvate decarboxylase . In this paper, we report the cloning and overexpression of the B . fragilis phosphonopyruvate decarboxylase gene (aepY), purification of the phosphonopyruvate decarboxylase recombinant protein, and the extensive characterization of the reaction that it catalyzes . The homotrimeric (41,184-Da subunit) phosphonopyruvate decarboxylase catalyzes (kcat = 10.2 +/- 0.3 s-1) the decarboxylation of phosphonopyruvate (Km = 3.2 +/- 0.2 microm) to phosphonoacetaldehyde (Ki = 15 +/- 2 microm) and carbon dioxide at an optimal pH range of 7.0-7.5 . Thiamine pyrophosphate (Km = 13 +/- 2 microm) and certain divalent metal ions (Mg(II) Km = 82 +/- 8 microm; Mn(II) Km = 13 +/- 1 microm; Ca(II) Km = 78 +/- 6 microm) serve as cofactors . Phosphonopyruvate decarboxylase is a member of the alpha-ketodecarboxylase family that includes sulfopyruvate decarboxylase, acetohydroxy acid synthase/acetolactate synthase, benzoylformate decarboxylase, glyoxylate carboligase, indole pyruvate decarboxylase, pyruvate decarboxylase, the acetyl phosphate-producing pyruvate oxidase, and the acetate-producing pyruvate oxidase . The Mg(II) binding residue Asp-260, which is located within the thiamine pyrophosphate binding motif of the alpha-ketodecarboxylase family, was shown by site-directed mutagenesis to play an important role in catalysis . Pyruvate (kcat = 0.05 s-1, Km = 25 mm) and sulfopyruvate (kcat approximately 0.05 s-1; Ki = 200 +/- 20 microm) are slow substrates for the phosphonopyruvate decarboxylase, indicating that this enzyme is promiscuous.

Zhongguo Yi Xue Ke Xue Yuan Xue Bao, 2000 Dec, 22(6), 592 - 4
{Detection of bacterial DNA in blood with three pairs of primers}; Wen L et al.; OBJECTIVE: To develop a stable and sensitive method to detect gut-derived bacterial DNA present in the blood . METHODS: Blood culture and PCR were performed simultaneously when temperature of patients (n = 23) was higher than 38.5 degrees C after laparotomy . PCR was performed after DNA extraction, target genes being beta-lactosidase gene of Escherichia coli(E . coli), glutamine synthase gene of Bacteroides Fragilitas, and 16SrRNA gene of most pathogenic bacteria . DNA of standard strains of E . coli and Bacteroides Fragilitas served as positive controls, blank control as negative controls, and healthy volunteers (n = 20) served as normal controls . We performed PCR twice with part of the samples (n = 20) in order to test the repetition of this method . RESULTS: The repetition rate of PCR was 95% . Three of blood cultures were positive (13.0%, 3/23), the corresponding positive ratio of PCR was 43.5% (10/23) which was higher than that of the blood culture (P = 0.016) . CONCLUSION: PCR is more sensitive than blood culture in detection of bacteremia.

Int Urol Nephrol, 2002, 34(3), 387 - 92
A life-threatening infection: Fournier's gangrene; Atakan IH et al.; Fournier's gangrene is a life-threatening disorder in which infection of the perineum and scrotum spreads along fascial planes, causing soft tissue necrosis . If urgent surgery is delayed, the disease will soon result in septic shock, multiorgan failure, and death . In this study, we present 21 patients with Fournier's gangrene who were treated in period between 1994 and 2001 . Patients' charts were reviewed retrospectively and are discussed in the light of literature . All patients received aggressive surgical debridment . Penicillin or Ceftriaxone, aminoglicoside and metronidazole were administered intravenously . Of the 21 patients, 5 had scrotal carbuncle, 1 had urethral stricture, 1 had chronic indwelling urethral catheterization, 2 had perirectal abscess, and 1 had hemorrhoidectomy . In eleven patients we couldn't identify any cause . Twelve patients had diabetes mellitus, and two had chronic alcoholism . Escherichia coli was isolated in 12 purulent tissue cultures, and Bacteroides fragilis in eight . Seventeen patients survived, whereas four died . Fourier's gangrene is considered a surgical emergency . Early surgical intervention is essential, as the gangrene can spread rapidly at rates reaching 2 mm per hour . So that Fournier's gangrene is an abrupt, rapidly progressive, gangrenous infection of the external genitalia and perineum and is a real urologic emergency.

Ned Tijdschr Geneeskd, 2003 Jul 12, 147(28), 1337 - 40
{Two patients with fever, chills and pain in the right upper abdominal quadrant accompanied by hyperbilirubinaemia: pylephlebitis}; van den Berg MK et al.; Two male patients aged 55 and 77 years, respectively, presented to the casualty department with fever, chills and right abdominal upper quadrant tenderness . They also had hyperbilirubinaemia . Based on CT scan findings and blood cultures yielding Bacteroides fragilis, a diagnosis of pylephlebitis (septic thrombophlebitis of the mesenteric veins and/or the portal vein) was made . This is a condition with a mortality rate of 10-70% . Primary sources such as diverticulitis are often seen in patients with pylephlebitis, in which bacteria are drained by the mesenteric veins and cause a thrombus in the portal system . In the two patients no primary focus was detected . They were treated with intravenous antibiotic therapy followed by oral antibiotics, and were discharged in good health . Pylephlebitis can be complicated by liver abscesses . Treatment consists of broad-spectrum antibiotics which are adjusted based on the blood cultures results . The duration of treatment is between two and six weeks, depending on the presence of liver abscesses . In patients with abscesses that cannot be drained, longer treatment may be indicated.

J Periodontol, 2003 Jun, 74(6), 798 - 802
Detection of Tannerella forsythensis (Bacteroides forsythus) and porphyromonas gingivalis by polymerase chain reaction in subjects with different periodontal status; Klein MI et al.; BACKGROUND: The aim of this study was to determine the prevalence of Tannerella forsythensis (formerly Bacteroides forsythus) and Porphyromonas gingivalis in subgingival plaque samples by using polymerase chain reaction (PCR), and to assess the relationship of these bacteria with different categories of periodontal disease and health . METHODS: Subjects were distributed into 3 groups according to their periodontal diagnosis: group 1, periodontally healthy (N = 10); group 2, periodontitis with probing depth < or = 5 mm (N = 10); group 3, periodontitis with probing depth > 5 mm (N = 10) . The subjects in groups 2 and 3 had healthy and diseased periodontal sites . Subgingival plaque samples were obtained using paper points inserted into periodontal pockets (diseased sites) and into healthy gingival sulci (healthy sites) of the same subject . RESULTS: The distribution of bacteria differed in healthy and diseased sites . T . forsythensis (B . forsythus) was not detected in any sample from healthy sites in any group but was detected in 70% and 100% of diseased sites in groups 2 and 3, respectively . P . gingivalis was detected in only one sample from a healthy site (group 2), and in the diseased sites, its prevalence was 40% (group 2) and 90% (group 3) . In addition, T . forsythensis (B . forsythus) and P . gingivalis were both detected in 30% and 90% of the diseased sites in groups 2 and 3, respectively . CONCLUSION: These results indicate a possible association between periodontal disease and the presence of T . forsythensis (B . forsythus) and/or P . gingivalis.

J Dent Res, 2003 Aug, 82(8), 632 - 5
Accelerated alveolar bone loss in mice lacking interleukin-10; Al-Rasheed A et al.; Interleukin-10 regulates pro-inflammatory cytokines, including those implicated in alveolar bone resorption . We hypothesized that lack of interleukin-10 leads to increased alveolar bone resorption . Male interleukin-10(-/-) mice, on 129/SvEv and C57BL/6J background, were compared with age-, sex-, and strain-matched interleukin-10(+/+) controls for alveolar bone loss . Immunoblotting was used for analysis of serum reactivity against bacteria associated with colitis and periodontitis . Interleukin-10(-/-) mice had significantly greater alveolar bone loss than interleukin-10(+/+) mice (p = 0.006) . The 30-40% greater alveolar bone loss in interleukin-10(-/-) mice was evident in both strains, with C57BL/6J interleukin-10(-/-) mice exhibiting the most bone loss . Immunoblotting revealed distinct interleukin-10(-/-) serum reactivity against Bacteroides vulgatus, B . fragilis, Prevotella intermedia, and, to a lesser extent, against B . forsythus . The results of the present study suggest that lack of interleukin-10 leads to accelerated alveolar bone loss.

Appl Microbiol Biotechnol, 2003 Aug, 62(2-3), 191 - 201 Epub 2003 Mar 29.
Molecular, biochemical and ecological characterisation of a bio-catalytic calcification reactor; Hammes F et al.; Bio-catalytic calcification (BCC) reactors utilise microbial urea hydrolysis by autochthonous bacteria for the precipitation-removal of calcium, as calcite, from industrial wastewater . Due to the limited knowledge available concerning natural ureolytic microbial calcium carbonate (CaCO(3)) precipitation, the microbial ecology of BCC reactors has remained a black box to date . This paper characterises BCC reactor evolution from initialisation to optimisation over a 6-week period . Three key parameters were studied: (1) microbial evolution, (2) the (bio)chemical CaCO(3) precipitation pathway, and (3) crystal nucleation site development . Six weeks were required to establish optimal reactor performance, which coincided with an increase in urease activity from an initial 7 mg urea l(-1) reactor h(-1) to about 100 mg urea l(-1) reactor h(-1) . Urease activity in the optimal period was directly proportional to Ca(2+) removal, but urease gene diversity was seemingly limited to a single gene . Denaturing gradient gel electrophoresis of 16S rRNA genes revealed the dynamic evolution of the microbial community structure of the calcareous sludge, which was eventually dominated by a few species including Porphyromonas sp., Arcobacter sp . and Bacteroides sp . Epi-fluorescence and scanning electron microscopy showed that the calcareous sludge was colonised with living bacteria, as well as the calcified remains of organisms . It appears that the precipitation event is localised in a micro-environment, due to colonisation of crystal nucleation sites (calcareous sludge) by the precipitating organisms.

Scand J Infect Dis, 2003, 35(5), 318 - 21
Characteristics of brain abscess with isolation of anaerobic bacteria; Le Moal G et al.; In view of its localization, brain abscess (BA) usually requires medical and surgical care . A broad spectrum of bacteria is involved . Recent reports stress the increasing frequency of anaerobes, but their impact has not been well evaluated . A retrospective review was conducted of all episodes of documented BA admitted in a tertiary-care hospital over a 10 y period . BA due to anaerobic bacteria (group A) were compared with other cases (group B) to determine the frequency and eventual characteristics of BA with isolated anaerobic bacteria . Between 1991 and 2000, BA were diagnosed in 42 patients (28M, 14F, mean age 54.6 y) . No differences in clinical features and laboratory findings were found between patients with BA caused by anaerobic (n = 22) and only aerobic (n = 20) bacteria . Using appropriate microbiological techniques, 41 anaerobic bacteria strains were isolated in 22 of 42 patients (52.4%) with BA . Anaerobic bacteria were associated with aerobic strains in 5 patients (12%), whereas in 17 patients (40.5%) only anaerobic strains were isolated in cerebral puncture cultures . The most frequently isolated species were Fusobacterium nucleatum (n = 14), Prevotella sp . (n = 8), Actinomyces sp . (n = 6) and Bacteroides sp . (n = 4) . Compared with group B, group A had more cases of a single abscess (p = 0.03) and ear, nose and throat (ENT) as a source of infection (p = 0.04), and seemed to have a better outcome (p = 0.07) . These results emphasize the important role that anaerobic bacteria play in BA . The presence of such pathogens must be evoked when faced with a single abscess, an ENT infection, or both . Therapy should take into account this high frequency.

Eur J Biochem, 2003 Aug, 270(15), 3168 - 73
Purification and characterization of novel salt-active acharan sulfate lyase from Bacteroides stercoris HJ-15; Hong SW et al.; Salt-active acharan sulfate lyase (no EC number) has been purified from Bacteroides stercoris HJ-15, which was isolated from human intestinal bacteria with GAG degrading enzymes . The enzyme was purified to apparent homogeneity by a combination of QAE-cellulose, diethylaminoethyl (DEAE)-cellulose, CM-Sephadex C-50, HA ultrogel and phosphocellulose column chromatography with the final specific activity of 81.33 micro mol x min-1 x mg-1 . The purified salt-active acharan sulfate lyase was activated to 5.3-fold by salts (KCl and NaCl) . The molecular weight of salt-active acharan sulfate lyase was 94 kDa by SDS/PAGE and gel filtration . The salt-active acharan sulfate lyase showed optimal activity at pH 7.2 and 40 degrees C . Salt-active acharan sulfate lyase activity was potently inhibited by Cu2+, Ni2+ and Zn2+ . This enzyme was inhibited by some agents, butanediol and p-chloromercuric sulfonic acid, which modify arginine and cysteine residues . The purified Bacteroidal salt-active acharan sulfate lyase acted to the greatest extent on acharan sulfate, to a lesser extent on heparan sulfate and heparin . The biochemical properties of the purified salt-active acharan sulfate lyase are different from those of the previously purified heparin lyases . However, these findings suggest that the purified salt-active acharan sulfate lyase may belong to heparin lyase II.

Syst Appl Microbiol, 2003 Jun, 26(2), 182 - 8
Reclassification of Bacteroides putredinis (Weinberg et al., 1937) in a new genus Alistipes gen . nov., as Alistipes putredinis comb . nov., and description of Alistipes finegoldii sp . nov., from human sources; Rautio M et al.; During studies on the bacteriology of appendicitis in children, we often isolated from inflamed and non-inflamed tissue samples, an unusual bile-resistant pigment-producing strictly anaerobic gram-negative rod . Phenotypically this organism resembles members of Bacteroides fragilis group of species, as it is resistant to bile and exhibits a special-potency-disk pattern (resistance to vancomycin, kanamycin and colistin) typical for the B . fragilis group . However, the production of brown pigment on media containing haemolysed blood and a cellular fatty acid composition dominated by iso-C15:0, suggests that the organism most closely resembles species of the genus Porphyromonas . However, the unidentified organism differs from porphyromonads by being bile-resistant and by not producing butyrate as a metabolic end-product . Comparative 16S ribosomal RNA gene sequencing studies show the unidentified organism represents a distinct sub-line, associated with but distinct from, the miss-classified species Bacteroides putredinis . The clustering of the unidentified bacterium with Bacteroides putredinis was statistically significant, but they displayed > 4% sequence divergence with each other . Chromosomal DNA-DNA pairing studies further confirmed the separateness of the unidentified bacterium and Bacteroides putredinis . Based on phenotypic and phylogenetic considerations, it is proposed that Bacteroides putredinis and the unidentified bacterium from human sources be classified in a new genus Alistipes, as Alistipes putredinis comb . nov . and Alistipes finegoldii sp . nov., respectively . The type strain of Alistipes finegoldii is CCUG 46020(T) (= AHN243(T)).

J Antimicrob Chemother, 2003 Aug, 52(2), 208 - 13 Epub 2003 Jul 15.
Emergence of fluoroquinolone resistance among Bacteroides species; Golan Y et al.; BACKGROUND: Several newer generation fluoroquinolones have demonstrated good in vitro activity against Bacteroides species; particularly when first introduced . However, resistance of Bacteroides to quinolones appears to be increasing . MATERIALS AND METHODS: From 1994 to 2001, consecutive non-duplicated Bacteroides isolates from clinical specimens in 12 US hospitals were sent to the Tufts anaerobe laboratory for identification and susceptibility testing . NCCLS recommended methodology for testing was employed . Breakpoints of 8 mg/l for trovafloxacin and 4 mg/l for moxifloxacin were used to examine susceptibility trends . RESULTS: In total, 4434 isolates were analysed . The geometric mean MIC increased significantly for clinafloxacin, trovafloxacin and moxifloxacin . Resistance to trovafloxacin (breakpoint of 8 mg/l) and moxifloxacin (breakpoint of 4 mg/l) increased from 8% to 25% and from 30% to 43%, respectively . Increased resistance was observed for all Bacteroides species, for all sites of isolation, and in 11 of 12 participating hospitals . Bacteroides vulgatus and isolates from decubitus ulcers were associated with increased resistance . During 2001, trovafloxacin and moxifloxacin resistance among blood isolates was 27% and 52%, respectively . The association between increased resistance and year of isolation remained significant after adjustment for hospital, species and site of isolation . CONCLUSIONS: Fluoroquinolone resistance among Bacteroides isolated in the US has markedly increased during the years 1994 to 2001 . High rates of resistance among blood isolates are of particular concern.

J Laparoendosc Adv Surg Tech A, 2003 Jun, 13(3), 175 - 9
Effects of laparoscopic models on anaerobic bacterial growth with bacteroides fragilis in experimentally induced peritonitis; Sare M et al.; BACKGROUND: Previous reports of recurrent intra-abdominal abcess formation after the laparoscopic treatment of perforated acute appendicitis led us to investigate the possible effects of gas insufflation on the spread of infection . We previously showed that Escherichia coli counts were significantly higher in a laparoscopy group that underwent carbon dioxide (CO2) insufflation than in control and laparotomy groups . The aim of this study is to investigate the effects of intra-abdominal CO2 and nitrous oxide (N2O) insufflation on anaerobic bacterial growth in a rat model . METHODS: A standard strain of Bacteroides fragilis (ATCC 25285) was injected intraperitoneally (1 x 10(6) cfu/mL per kilogram) in 40 Wistar rats under sterile conditions . Forty rats with induced peritonitis were randomly divided into five groups: control, laparotomy, CO2 insufflation, N2O insufflation, and one group without pneumoperitoneum . Eight hours after the intraperitoneal injection of B . fragilis, peritoneal aspirates were obtained and inoculated onto Brucella agar . At the sixteenth hour of induced peritoneal infection (corresponding to hour 8 in the laparoscopy groups) all animals underwent laparotomy; peritoneal aspirates were obtained and inoculated into Brucella agar for bacterial counts . The colonies of B . fragilis were counted manually, and the results were expressed as the mean number of colony-forming units per milliliter . RESULTS: No significant differences in microorganism counts were noted between the study groups before the procedure (p>.05 for all comparisons) . We observed a significant increase in the number of bacteria (mean +/- SD) in the CO2 insufflation group between hour 8 and hour 16 of peritoneal contamination . CONCLUSION: The results suggest that CO2 insufflation may promote the growth of intra-abdominal anaerobic bacteria . Such bacterial growth may lead to intra-abdominal abcess formation or cause localized peritonitis to develop into generalized peritonitis . We suggest that laparoscopy without pneumoperitoneum may be preferred in patients with peritonitis.

Int J Tissue React, 2003, 25(1), 19 - 24
The benzoyl-DL arginine-naphthylamide (BANA) test and polymerase chain reaction measurement of pathogenic bacteria can assess the severity of periodontal disease; Takaishi Y et al.; The benzoyl-DL arginine-naphthylamide (BANA) test for detecting digesting peptidase and polymerase chain reaction (PCR) measurement of pathogenic bacteria were performed in 15 patients with periodontal disease . The number of Porphyromonas gingivalis, Bacteroides forsythus and Treponema denticola, which are the most potent accelerators of alveolar bone resorption, were determined . Attachment loss and the BANA test showed significant close correlations with the number of pathogenic bacteria as well as with the tooth mobility and pocket depth . In conclusion, the BANA test and PCR measurement of bacteria are useful methods for detecting pathogenic bacteria that promote alveolar tissue destruction.

Gastroenterology, 2003 Jul, 125(1), 162 - 77
Bacteroides vulgatus protects against Escherichia coli-induced colitis in gnotobiotic interleukin-2-deficient mice; Waidmann M et al.; BACKGROUND & AIMS: The microflora plays a crucial role in inflammatory bowel diseases (IBDs) . Specific pathogen-free (SPF), but not germ-free, interleukin (IL)-2-deficient (IL-2-/-) mice develop colitis . The colitogenicity of commensal bacteria was determined . METHODS: Gnotobiotic IL-2-/- and IL-2+/+ mice were colonized with Escherichia coli mpk, Bacteroides vulgatus mpk, or both bacterial strains, or with E . coli strain Nissle 1917 . DNA arrays were used to characterize E . coli mpk . Colitis was analyzed by histology and real-time reverse-transcription polymerase chain reaction (RT-PCR) for interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, IL-10, and CD14 messenger RNA (mRNA) expression . Bacterial numbers in feces and bacterial localization in the colon was determined by culture and fluorescence in situ hybridization (FISH) . RESULTS: IL-2-/- but not IL-2+/+ mice monocolonized with E . coli mpk developed colitis, whereas mono-association with B . vulgatus mpk, or E . coli Nissle, or co-colonization with E . coli mpk and B . vulgatus mpk, did not induce colitis . DNA array experiments and cellular studies revealed that E . coli mpk is a nonpathogenic strain . FISH and culture methods revealed that the anticolitogenic effect of B . vulgatus mpk on E . coli mpk cannot be explained by a significant reduction in numbers of E . coli in the colon . E . coli mpk-induced colitis was associated with increased IFN-gamma, TNF-alpha, CD14, and IL-10 mRNA expression in the colon . CONCLUSIONS: In IL-2-/- mice, B . vulgatus mpk protects against E . coli mpk-triggered colitis by an unknown mechanism . E . coli Nissle does not induce colitis . Various bacterial species common to the microflora differ in their ability to trigger IBD.

Clin Microbiol Infect, 2003 Jun, 9(6), 475 - 88
Antimicrobial susceptibility of Bacteroides fragilis group isolates in Europe; Hedberg M et al.; OBJECTIVE: To evaluate the activity of old and newer antianaerobic drugs against clinical isolates of Bacteroides fragilis group strains from different parts of Europe . METHODS: Bacteroides fragilis group isolates from 37 laboratories in 19 countries were biochemically characterized . The MICs of seven antimicrobial agents were determined by the agar dilution method as recommended by the NCCLS . Production of beta-lactamase was detected by nitrocefin . RESULTS: There were 1284 B . fragilis group isolates included in the study . Abdominal infections and wounds were the most common sources of isolation and B . fragilis was the dominating species . Ninety-nine percent of the strains were resistant to ampicillin (breakpoint 2 mg/L), 6% to cefoxitin (64 mg/L), 15% to clindamycin (8 mg/L) and 9% to moxifloxacin (8 mg/L) . Less than 1% were resistant to imipenem (16 mg/L), piperacillin-tazobactam (128 mg/L) and metronidazole (32 mg/L) . Ninety-six percent of the isolates were beta-lactamase producers . CONCLUSIONS: Antimicrobial resistance among the B . fragilis group is increasing.

Curr Womens Health Rep, 2003 Aug, 3(4), 274 - 9
Prevention and treatment of postpartum endometritis; French L; Postpartum endometritis is an important cause of maternal morbidity after cesarean section . Prophylactic antibiotic therapy reduces the risk by approximately 60% . The benefit of antibiotic therapy for laboring women has been established . For nonlaboring patients, there is still some uncertainty . Intravaginal metronidazole as surgical preparation and oral methylergometrine after delivery are two interventions that show promise as additional prophylactic interventions . The gold standard therapy, once endometritis has been diagnosed, is intravenous clindamycin and gentamicin . If an alternative regimen is chosen, it should have a similar spectrum, including good coverage for gram-positive anaerobes such as Bacteroides fragilis . Antibiotic therapy can be discontinued once the patient is afebrile without continued oral antibiotics . Treatment failure occurs in approximately 10% of cases and should trigger investigation of other infectious complications . Prolonged fever of undetermined etiology is not uncommon and requires prolonged antibiotic therapy, with or without heparin.

Inorg Chem, 2003 Jul 14, 42(14), 4245 - 7
Protonation state of Asp120 in the binuclear active site of the metallo-beta-lactamase from Bacteroides fragilis; Dal Peraro M et al.; The determination of the protonation state of enzyme active sites may be crucial for the investigation of their mechanism of action . In the bizinc beta-lactamase family of enzymes, no consensus has been reached on the protonation state of a fully conserved amino acid present in the active site, Asp120 . To address this issue, we carry out here density functional theory (DFT) calculations on large models (based on Bacteroides fragilis X-ray structure) which include the metal coordination polyhedron and groups interacting with it . Our calculations suggest that Asp120 is ionized . The relevance of this finding for site-directed mutagenesis experiments on the 120 position and on the mechanism of action is discussed.

Int J Antimicrob Agents, 2003 Jul, 22(1), 28 - 34
Activity of linezolid against anaerobic bacteria; Behra-Miellet J et al.; Minimal inhibition concentrations (MICs) were determined for linezolid (LZD) and compared with those of reference antibiotics against 265 anaerobes . For the Bacteroides fragilis group, MIC range for LZD was 2-4 mg/l . Strains resistant to the other antibiotics were detected including one strain of B . fragilis showing high level resistance to metronidazole (64 mg/l) . LZD MIC(50) was 4 mg/l for prevotella and 1 mg/l for fusobacteria . LZD MICs were <1 mg/l for porphyromonas and veillonellae and </=4 mg/l for all Gram-positive anaerobes . For all anaerobes, resistance rates were 1, 2.4, 9.8 and 17% for imipenem, amoxycillin-clavulanic acid, metronidazole and clindamycin, respectively . As no strains resistant to LZD were detected, this antibiotic seems a promising candidate to treat infections caused by anaerobes.

Appl Environ Microbiol, 2003 Jul, 69(7), 4151 - 8
Identification of a new ribosomal protection type of tetracycline resistance gene, tet(36), from swine manure pits; Whittle G et al.; Previously, only one ribosome protection type of a tetracycline resistance gene, tetQ, had been identified in Bacteroides spp . During an investigation of anaerobic bacteria present in swine feces and manure storage pits, a tetracycline-resistant Bacteroides strain was isolated . Subsequent analysis showed that this new Bacteroides strain, Bacteroides sp . strain 139, did not contain tetQ but contained a previously unidentified tetracycline resistance gene . Sequence analysis showed that the tetracycline resistance gene from Bacteroides sp . strain 139 encoded a protein (designated Tet 36) that defines a new class of ribosome protection types of tetracycline resistance . Tet 36 has 60% amino acid identity over 640 aa to TetQ and between 31 and 49% amino acid identity to the nine other ribosome protection types of tetracycline resistance genes . The tet(36) region was not observed to transfer from Bacteroides sp . strain 139 to another Bacteroides sp . under laboratory conditions . Yet tet(36) was found in other genera of bacteria isolated from the same swine manure pits and from swine feces . Phylogenetic analysis of the tet(36)-containing isolates indicated that tet(36) was present not only in the Cytophaga-Flavobacter-Bacteroides group to which Bacteroides sp . strain 139 belongs but also in gram-positive genera and gram-negative proteobacteria, indicating that horizontal transfer of tet(36) is occurring between these divergent phylogenetic groups in the farm environment.

Res Microbiol, 2003 Jun, 154(5), 369 - 74
Presence of the cfxA gene in Bacteroides distasonis; Avelar KE et al.; In this study we investigated the presence of the cfxA gene (encoding a class A beta-lactamase) in 73 strains of the Bacteroides fragilis group belonging to the species B . distasonis (34), B . vulgatus (14), B . thetaiotaomicron (8), B . merdae (6), B . caccae (9) and B . ovatus (2) isolated from human intestinal microflora of healthy children and adults . Employing specific primers to the cfxA gene, a 312-bp amplified fragment was obtained in 2 strains of B . vulgatus and 9 strains, the majority from children, of B . distasonis . The expression of this enzyme was analysed by determining the MICs to cefoxitin and cefotaxime and values varied from 2 to >256 microg/ml of both cefoxitin and cefotaxime . Sequence analysis of the amplicons corresponding to the cfxA gene from B . distasonis and B . vulgatus revealed identical sequences between these isolates and high similarity with other beta-lactamase genes of anaerobes such as cfxA of B . vulgatus (99%) and cfxA2 of Prevotella intermedia (99%), both sequences of which deposited in Genbank under accession numbers U38243 and AF118110, respectively . However, a fragment obtained from a B . distasonis strain (EC17-4) showed a unique RFLP profile and 87% nucleotide similarity with cfxA and cfxA2 genes . These results seem to suggest a dissemination of these resistance determinants among Bacteroides species.

J Clin Periodontol, 2003 Jul, 30(7), 603 - 10
Effect of smoking and periodontal treatment on the subgingival microflora; Van der Velden U et al.; BACKGROUND: The effect of smoking on the prevalence of periodontal pathogens after periodontal treatment is still not clear . Some studies found no effect of the smoking status on the prevalence of periodontal pathogens after therapy, whereas others did . The aim of this retrospective study was to investigate the influence of smoking on the treatment of periodontitis and the composition of the subgingival microflora . METHOD: The study included 59 periodontitis patients (mean age 41.5 years): 30 smokers and 29 nonsmokers . The treatment consisted of initial periodontal therapy and, if necessary, surgery and/or antibiotics . Clinical and microbiological data were obtained before and after treatment at the deepest site in each quadrant . A pooled sample was analysed for the presence of Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotalla intermedia (Pi), Bacteroides forsythus (Bf), Fusobacterium nucleatum (Fn) and Peptostreptococcus micros (Pm) . RESULTS: For smokers and nonsmokers a significant improvement of the clinical condition was found after treatment . A decrease could be assessed for bleeding on probing (smokers: 0.46; nonsmokers: 0.52) and probing pocket depth (PPD) (smokers: 1.64 mm; nonsmokers: 2.09 mm) . Furthermore, both groups showed gain of attachment (smokers: 0.68 mm; nonsmokers: 1.46 mm) . No significant difference in bleeding on probing and PPD reduction was found between smokers and nonsmokers . In contrast, nonsmokers showed significantly more gain of attachment than smokers . The microbiological results revealed no differences in the prevalence of the various bacteria between smokers and nonsmokers before treatment . After treatment in nonsmokers, a significant decrease was found in the prevalence of Aa (11-3), Pg (17-7), Pi (27-11), Bf (27-11), Fn (28-20) and Pm (27-17) . In smokers, a significant decrease could be shown only for the prevalence of Pg (15-5) . CONCLUSIONS: Nonsmokers showed more gain of attachment and a greater decrease in the prevalence of periodontal bacteria as compared to smokers . The phenomenon that among smokers, more patients remain culture positive for periodontal pathogens after therapy, may contribute to the often observed unfavourable treatment results in smoker periodontitis patients.

J Periodontal Res, 2003 Aug, 38(4), 428 - 35
Lethal photosensitization of periodontal pathogens by a red-filtered Xenon lamp in vitro; Matevski D et al.; BACKGROUND: The ability of Helium-Neon (He-Ne) laser irradiation of a photosensitizer to induce localized phototoxic effects that kill periodontal pathogens is well documented and is termed photodynamic therapy (PDT) . OBJECTIVES: We investigated the potential of a conventional light source (red-filtered Xenon lamp) to activate toluidine blue O (TBO) in vitro and determined in vitro model parameters that may be used in future in vivo trials . MATERIALS AND METHODS: Porphyromonas gingivalis 381 was used as the primary test bacterium . RESULTS: Treatment with a 2.2 J/cm2 light dose and 50 micro g/ml TBO concentration resulted in a bacterial kill of 2.43 +/- 0.39 logs with the He-Ne laser control and 3.34 +/- 0.24 logs with the lamp, a near 10-fold increase (p = 0.028) . Increases in light intensity produced significantly higher killing (p = 0.012) that plateaued at 25 mW/cm2 . There was a linear relationship between light dose and bacterial killing (r2 = 0.916); as light dose was increased bacterial survival decreased . No such relationship was found for the drug concentrations tested . Addition of serum or blood at 50% v/v to the P . gingivalis suspension prior to irradiation diminished killing from approximately 5 logs to 3 logs at 10 J/cm2 . When serum was washed off, killing returned to 5 logs for all species tested except Bacteroides forsythus (3.92 +/- 0.68 logs kill) . CONCLUSIONS: The data indicate that PDT utilizing a conventional light source is at least as effective as laser-induced treatment in vitro . Furthermore, PDT achieves significant bactericidal activity in the presence of serum and blood when used with the set parameters of 10 J/cm2, 100 mW/cm2 and 12.5 micro g/ml TBO.

Protein Sci, 2003 Jul, 12(7), 1368 - 75
Role of a solvent-exposed tryptophan in the recognition and binding of antibiotic substrates for a metallo-beta-lactamase; Huntley JJ et al.; Numerous X-ray crystal structures of the metallo-beta-lactamase from Bacteroides fragilis and related organisms show a beta-hairpin loop immediately adjacent to the active-site zinc atom(s) . Both crystallographic and NMR information show that the end of this beta-hairpin loop, which contains a solvent exposed tryptophan residue, Trp49, is highly flexible in the absence of substrates or other ligands, giving rise in some of the X-ray structures to a lack of observable electron density in this region . We report an investigation of the role of this mobile, solvent-exposed tryptophan using site-directed mutagenesis, steady state kinetics measurements and characterization by NMR . Trp49 appears to have a role both in substrate binding and in promotion of catalysis . Substitution of this residue with a number of different side chains indicates that the binding interaction depends on the bulky hydrophobic and aromatic nature of the indole ring, which can provide relatively non-specific interactions with a variety of antibiotic substrates . In this way, the tryptophan at this position provides a large degree of the breadth of substrate specificity for the metallo-beta-lactamase . Previous studies established that the antibiotic binding site was sufficiently plastic that the derivatization of existing antibiotics is unlikely to result in the successful treatment of bacterial infections incorporating this resistance element . Rather, a more productive approach may be to design therapeutics directed towards this solvent-exposed tryptophan residue.

Oral Microbiol Immunol, 2003 Aug, 18(4), 208 - 14
Distribution of Bacteroides forsythus genotypes in a Japanese periodontitis population; Huang Y et al.; Bacteroides forsythus is an important pathogen in periodontal diseases and has been associated with advanced and refractory periodontitis . The difficulties associated with culturing this species have meant that the distribution and pathogenic mechanisms of B . forsythus remain unclear . In this study, the arbitrarily primed polymerase chain reaction (AP-PCR) method was used to investigate the genotype distribution of B . forsythus in a Japanese periodontitis population, as well as the relationship between AP-PCR genotypes and periodontal status . B . forsythus reference strain, ATCC 43037T and 137 clinical bacterial isolates from 64 subjects were separated into 11 distinct AP-PCR genotypes using a single randomly-sequenced primer, 5'-CCGGCGGCG-3' (A-05) . The majority (80.9%) of B . forsythus strains examined belonged to AP-PCR genotypes I, II, III and IV (accounting for 39.7%, 20.6%, 10.3% and 10.3%, respectively) . Types I and III primarily consisted of isolates from chronic periodontitis subjects (80.8% and 85.7%, respectively), while Types II and IV consisted mainly of isolates from aggressive periodontitis subjects (85.7% and 100%, respectively) . Except for three subjects who harbored two different B . forsythus genotypes in the oral cavity, all subjects only infected with one genotype intraindividually . These results demonstrate that the AP-PCR method is useful for genotypic analysis of B . forsythus . This species showed a genetic diversity among the investigated population . A clonal nature of B . forsythus infection is suggested . Furthermore, different AP-PCR genotypes of B . forsythus appear to be associated with different types of periodontitis.

J Endod, 2003 Jun, 29(6), 390 - 3
Bacteroides forsythus in primary endodontic infections as detected by nested PCR; Siqueira JF Jr et al.; The purpose of this study was to investigate the prevalence of Bacteroides forsythus in primary endodontic infections using a species-specific nested polymerase chain reaction assay . Samples were collected from 50 teeth having carious lesions, necrotic pulps, and different forms of periradicular diseases . DNA extracted from the samples was initially amplified using universal 16S rDNA primers . A second round of amplification used the first polymerase chain reaction products to detect a specific fragment of B . forsythus 16S rDNA . B . forsythus was detected in 13 of 22 asymptomatic cases (59.1%), 4 of 10 root canals associated with acute apical periodontitis (40%), and 9 of 18 cases diagnosed as acute periradicular abscesses (50%) . There was no relationship between the presence of B . forsythus and the occurrence of symptoms . In general, this bacterial species was detected in 26 of 50 samples of endodontic infections (52%) . The findings of this study support the assertion that this bacterial species is associated with infections of endodontic origin and suggest that B . forsythus may be involved in the pathogenesis of different forms of periradicular lesions.

Zhonghua Shao Shang Za Zhi, 2003 Apr, 19(2), 82 - 5
{The influence of the LPS from bacteroides fragilis on the secretion of IL-2 and IL-4 from the peripheral blood mononuclear cells of normal volunteers}; Zhou J et al.; OBJECTIVE: To investigate the influence of the LPS of Bacteroides fragilis on the secretion of IL-2 and IL-4 from the peripheral blood mononuclear cells of normal individuals, so as to elucidate the mechanism of the infection by Bacteroides fragilis . METHODS: LPS was obtained from both the strains isolated from patients and from standard NCTC9343 . Peripheral blood mononuclear cells (PBMCs) were treated with different concentrations of LPS thus obtained . The supernatants from the cell culture of the PBMCs were harvested at 24 PBHs and were subjected to the determination of the IL-2 and IL-4 contents by ELISA method . RESULTS The IL-2 secretion from the PBMCs of normal volunteers was obviously inhibited by the LPS from Bacteroides fragilis (P < 0.01), and the inhibitory effect was dose-dependent . Nevertheless, the IL-4 secretion from the PBMCs of normal volunteers was significantly stimulated by the LPS from Bacteroides Fragilis (P < 0.05), and it was not concentration dependent . There was no difference between the effects of the LPSs from patients and standard strains (P < 0.05) . CONCLUSION: The LPS from Bacteroides fragilis was inhibitory to the secretion of IL-2 from PBMCs and was stimulative to that of IL-4 from PBMCs of normal human persons.

Am J Med Sci, 2003 Jun, 325(6), 365 - 8
Thrombosis and infection: a case of transient anti-cardiolipin antibody associated with pylephlebitis; Liappis AP et al.; Infections with Bacteroides species have been noted to occur in association with cases of thrombophlebitis . This association has led to the speculation that the microorganisms themselves may contribute to the pathogenesis of thrombus formation through elaborated enzymes, including heparinases, or by interactions between the clotting cascade and the unique structure of the Bacteroides lipopolysaccharide . Anti-phospholipid antibodies have been linked with hypercoagulable states and thrombus formation . Although a number of infections have been associated with the transient production of anti-cardiolipin antibodies, the effect the antibodies may have in contributing to thrombus formation is not well understood . The occurrence of Bacteroides species infection with transient anti-cardiolipin antibody has not been previously reported.

J Appl Microbiol, 2003, 95(1), 29 - 37
Usefulness of different groups of bacteriophages as model micro-organisms for evaluating chlorination; Duran AE et al.; AIMS: To assess the usefulness of bacterial and viral indicators in chlorination processes and to collect quantitative information necessary for risk assessment analysis in water disinfection processes based on chlorination . METHODS AND RESULTS: Naturally occurring bacterial indicators, bacteriophages and enteroviruses were determined to evaluate the effect of chlorination in groundwater and secondary sewage effluents . Additionally, the effect of chlorinating on selected bacteriophages, enteroviruses and Escherichia coli was also tested in spiked samples of bottled water and sewage effluents . Results indicate that chlorination inactivates more efficiently bacteria than phages and enteroviruses . Among the human viruses, phages infecting Bacteroides fragilis and selected somatic coliphages belonging to the Siphoviridae family were the most persistent to chlorination . CONCLUSIONS: The three groups of bacteriophages studied were all more resistant to chlorination than bacteria and some of the phages were more resistant than enteroviruses . Results presented here indicate that it is very risky to generalize from information obtained with inactivation experiments done with single isolates of any phage or virus . If possible, inactivation studies should be done with naturally occurring populations . Phages offer a good opportunity for studying naturally occurring populations . Thus, the bacteriophages offer a range of resistance to chlorination that may represent most of the viruses that can be found in water . SIGNIFICANCE AND IMPACT OF THE STUDY: Data reported in this study support the inclusion of bacteriophages as additional indicators of the efficiency of water chlorination processes and water quality.

West Indian Med J, 2003 Mar, 52(1), 53 - 5
Acute haematogenous anaerobic osteomyelitis in sickle cell disease . A case report and review of the literature; Mansingh A et al.; Patients with sickle cell disease are more susceptible to acute anaerobic osteomyelitis due to focal gut mucosal ischaemia, translocation of bacteria, and seeding in infarcted bone marrow . Modulation of the immune system is also present . The isolation of anaerobic organisms requires a high index of suspicion, correct specimen collection procedures and meticulous specimen handling . Bacteroides is the predominant organism isolated . Intra-osseous gas in the bone may be seen within four days and radiographs are therefore useful earlier than with aerobic osteomyelitis . Surgical debridement and intravenous antibiotics are the mainstay of treatment with the erythrocyte sedimentation rate being relied on heavily to guide conversion to oral antibiotics . Coexistence of septic arthritis is more common with anaerobic osteomyelitis.

Appl Radiat Isot, 2003 Jun, 58(6), 651 - 6
Bacteriophages as viral indicators for radiation processing of water: a chemical approach; Gehringer P et al.; Inactivation of the bacteriophages PHI X 174 (somatic coliphage), MS2 (F-specific coliphage) and B40-8 (phage infecting Bacteroides fragilis) suspended in tap water was studied applying gamma and electron beam irradiation as well . PHI X 174 phage was found to be a suitable viral indicator for water disinfection by means of ionizing radiation . The nutrient broths introduced simultaneously with the bacteriophages into the water when it is spiked with the phages for the experiments did not significantly change the scavenging capacity of the water matrix . No dose rate effect was observed with MS2 and B40-8 phages but PHI X 174 phage showed a clear dose rate effect . It was found that in water MS2 phage is significantly more sensitive to ionizing radiation than Escherichia coli.

J Clin Periodontol, 2003 Jun, 30(6), 562 - 72
Five-year maintenance follow-up of early-onset periodontitis patients; Kamma JJ et al.; OBJECTIVES: The purpose of this study was to evaluate the clinical and microbiological status of patients with early-onset or aggressive periodontitis (EOP) who had received supportive periodontal care (SPC) every 3-6 months for a period of 5 years, following active periodontal treatment . MATERIAL AND METHODS: The study population consisted of 25 individuals with early-onset periodontitis . Clinical examination and recordings of probing pocket depth (PPD) and clinical attachment level (CAL) were performed at baseline prior to treatment (T0), 3 months following the termination of active periodontal treatment (T1) and annually at the SPC appointments (T2,T3,T4,T5) . Microbiological samples were obtained at the 5-year SPC (T5) . Subgingival plaque samples for each individual were collected from one deep pocket (>5 mm), based on pretreatment measurements, randomly selected in each quadrant . The levels of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis and Treponema denticola were determined using oligonucleotide probe hybridization . RESULTS: During the 5-year period, the mean of SPC/patient was 12.7 sessions . A significant improvement was observed in PPD, CAL, gingival bleeding index and suppuration following treatment . However, between T1 and T5, 134 sites in 20 patients deteriorated with a CAL loss of> or =2 mm . Out of these 134 sites showing disease progression, microbial samples were randomly obtained in 13 sites (9.7%) from 8 patients . Among other factors, smoking and stress were found to have significant predictive value on the future attachment loss . P . gingivalis, T . denticola and total bacterial load were statistically significantly higher in patients who experienced disease progression during the 5-year maintenance period . CONCLUSIONS: For most EOP patients, regular SPC was effective in maintaining clinical and microbiological improvements attained after active periodontal therapy . However, a small percentage of sites was identified as progressive in 20 patients . Variables found to be related to periodontal progression were the presence of as well as the high bacterial counts of P . gingivalis, T . denticola and total bacterial load, number of acute episodes, number of teeth lost, smoking and stress.

J Surg Res, 2003 Apr, 110(2), 352 - 9
Sepsis alters vessel contraction by adrenoceptor-induced nitric oxide and prostanoid; Kawabe T et al.; BACKGROUND: Alpha-adrenergic agents contract vascular smooth muscle (VSM) and stimulate endothelial release of secondary factors which modulate VSM contraction . Our study examined constrictor prostanoid (cPN) and nitric oxide (NO) as secondary factors which could alter alpha-1 adrenoceptor-mediated contraction during sepsis . METHODS: Sepsis was induced in rats by inoculation of an implanted sponge with Escherichia coli and Bacteroides fragilis . Aortic rings at 24 h from septic (n = 21) and control (n = 21) rats were suspended in physiological salt solution (PSS) with or without blockers to NO (N(G)-monomethylarginine), cPN (mefenamic acid, MFA), or thromboxane A2 (SQ29548) . Contraction dose-response curves were generated to determine maximal contraction force (F(max)) and pD2 (sensitivity) to phenylephrine in each experimental group . RESULTS: Sepsis increased F(max) to phenylephrine (PHE) (1.18 vs 0.90 g, SEM 0.0703) . COX inhibition reduced the F(max) in control (0.63 vs 0.90 g, SEM 0.0675) but not in septic animals (1.19 vs 1.18 g, SEM 0.0433) . TXA2 receptor inhibition did not alter F(max) in control (1.017 vs 0.973 g, SEM 0.0959) or septic animals (1.28 vs 1.12 g, SEM 0.0823) . NOS inhibition enhanced the F(max) in both nonseptic (2.03 vs 0.83 g, SEM 0.0523) and septic rats (1.96 vs 1.15 g, SEM 0.0526), but did less so in the septic animals . CONCLUSIONS: PHE-induced F(max) is determined by a balance between PHE-stimulated VSM alpha-adrenoceptor activity, and PHE-stimulated endothelial release of cPN and NO . Sepsis enhances total PHE-induced F(max) by increasing VSM alpha-adrenoceptor activity and reducing PHE-stimulated endothelial release of dilator NO . Sepsis abolishes the PHE-stimulated endothelial release of cPN . PHE-stimulated cPN is not thromboxane A2, but could be a nonprostanoid dilator in the lipoxygenase (HETE) or cytochrome P450 (EET) pathways.

Int J Pharm, 2003 Jun 18, 259(1-2), 47 - 55
Targeted retentive device for oro-dental infections: formulation and development; Ahuja A et al.; Fibers loaded with amoxycillin trihydrate were prepared for oro-dental infections using melt spinning technique . Ethylene vinyl acetate, a biocompatible polymer was used for providing controlled release effect over a period of several days . The fibers were evaluated for in vitro release in alkaline borate buffer pH 8.1 in a biological shaker which was rotated at 50 rpm at 37 degrees C . In situ studies were carried out in continuous flow through apparatus which simulated the conditions of periodontal pocket . Microbiological evaluation was carried out on strains commonly implicated in oro-dental infections namely S . aureus, S . mutans, and Bacteroides cereus . Results of in vitro release studies revealed that the effect was sustained over a period of 6 days and followed Fickian diffusion mechanism . In situ release study samples were well above the minimum inhibitory concentration of the drug . These samples were effective in inhibiting the growth of the above-mentioned strains . The optimized formulation was characterized for general appearance, content uniformity, and SEM . Stability studies carried out on the formulation showed the degradation rate constant value of 2.79 x 10(-4) per day . Retentive fibers were found to be very effective in controlled delivery of amoxycillin, and hence can be feasible alternative to systemic administration.

J Clin Periodontol, 2002, 29 Suppl 3, 22 - 36; discussion 37-8
Is periodontitis associated with an increased risk of coronary heart disease and preterm and/or low birth weight births?
Madianos PN, Bobetsis GA, Kinane DF.
The objective of this systematic review was to determine whether periodontal disease is associated with an increased risk for coronary heart disease (CHD) and preterm and/or low birth weight deliveries (PLBW) . A literature search was performed to identify cross-sectional, case-control, and cohort studies as well as clinical trials addressing different aspects of periodontal disease (clinical, microbial, immunological) and clinical outcomes of CHD or PLBW . The periodontitis-CHD association was evaluated in eight cohort, four case-control- and four cross-sectional studies . Meta-analysis was not performed due to the extensive heterogeneity of the studies, particularly with regard to periodontitis measures, which varied from full mouth probing assessments to questionnaires . Percentage-wise, 50% of the cohort studies (4/8), 75% of the case-control studies (3/4) and 50% of the cross-sectional studies (2/4) reported a significant association between clinical measures of periodontitis and CHD (excess risk ranged from 0 to 3.3-fold) . The periodontitis-PLBW association was evaluated in one cohort and two case-control studies . The cohort study as well as one of the two case-control studies reported a significant association between periodontitis and PLBW (odds ratios 4.4-7.9) . From two additional case-control studies microbiological data could be extracted . Bacteroides forsythus was found to be associated with PLBW in both studies . In conclusion, the evidence linking periodontitis with an increased risk for CHD and PLBW is limited . There is a clear need for new, well designed observational and intervention studies to confirm the thus far observed associations, explore the validity of the associations in diverse populations, establish whether they are causal in nature and determine potential benefits of periodontal intervention in reducing the risk for these conditions.

Microbiology, 2003 Jun, 149(Pt 6), 1551 - 8
The essential role of fumarate reductase in haem-dependent growth stimulation of Bacteroides fragilis; Baughn AD et al.; Haem is required for optimal growth of the bacterial anaerobe Bacteroides fragilis . Previous studies have shown that growth in the presence of haem is coincident with increased yields of ATP from glucose, expression of b-type cytochromes and expression of fumarate reductase activity . This paper describes the identification of the genes that encode the cytochrome, iron-sulfur cluster protein and flavoprotein of the B . fragilis fumarate reductase . These genes, frdC, frdA and frdB, respectively, are organized in an operon . Nonpolar, in-frame deletions of frdC and frdB were constructed in the B . fragilis chromosome . These mutant strains had no detectable fumarate reductase or succinate dehydrogenase activity . In addition, the frd mutant strains showed a threefold increase in generation time, relative to the wild-type strain . Growth of these mutant strains was fully restored to the wild-type rate by the introduction of a B . fragilis replicon containing the entire frd operon . Growth of the frd mutant strains was partially restored by supplementing the growth medium with succinate, indicating that the frd gene products function as a fumarate reductase . During growth on glucose, the frd mutant strains showed a threefold decrease in cell mass yield, relative to the wild-type strain . These data indicate that fumarate reductase is important for both energy metabolism and succinate biosynthesis in B . fragilis.

FEMS Microbiol Lett, 2003 May 16, 222(1), 9 - 16
Rapid identification of the species of the Bacteroides fragilis group by multiplex PCR assays using group- and species-specific primers; Liu C et al.; We report a rapid and reliable two-step multiplex polymerase chain reaction (PCR) assay to identify the 10 Bacteroides fragilis group species - Bacteroides caccae, B . distasonis, B . eggerthii, B . fragilis, B . merdae, B . ovatus, B . stercoris, B . thetaiotaomicron, B . uniformis and B . vulgatus . These 10 species were first divided into three subgroups by multiplex PCR-G, followed by three multiplex PCR assays with three species-specific primer mixtures for identification to the species level . The primers were designed from nucleotide sequences of the 16S rRNA, the 16S-23S rRNA intergenic spacer region and part of the 23S rRNA gene . The established two-step multiplex PCR identification scheme was applied to the identification of 155 clinical isolates of the B . fragilis group that were previously identified to the species level by phenotypic tests . The new scheme was more accurate than phenotypic identification, which was accurate only 84.5% of the time . The multiplex PCR scheme established in this study is a simple, rapid and reliable method for the identification of the B . fragilis group species . This will permit more accurate assessment of the role of various B . fragilis group members in infections and of the degree of antimicrobial resistance in each of the group members.

FEBS Lett, 2003 May 22, 543(1-3), 98 - 102
Chemical structure and immunobiological activity of lipid A from Prevotella intermedia ATCC 25611 lipopolysaccharide; Hashimoto M et al.; The novel chemical structure and immunobiological activities of Prevotella intermedia ATCC 25611 lipid A were investigated . A lipopolysaccharide (LPS) preparation of P . intermedia was extracted using a phenol-chloroform-petroleum ether method, after which its purified lipid A was prepared by weak acid hydrolysis followed by chromatographic separations . The lipid A structure was determined by mass spectrometry and nuclear magnetic resonance to be a diglucosamine backbone with a phosphate at the 4-position of the non-reducing side sugar, as well as five fatty acids containing branched long chains . It was similar to that of Bacteroides fragilis and Porphyromonas gingivalis, except for the phosphorylation site . P . intermedia lipid A induced weaker cytokine production and NF-kappaB activation in murine cells via Toll-like receptor (TLR) 4 as compared to Escherichia coli synthetic lipid A (compound 506) . Our results indicate that P . intermedia lipid A activates cells through a TLR4-dependent pathway similar to E . coli-type lipid A, even though these have structural differences.

Int Endod J, 2003 May, 36(5), 352 - 7
Induction of interleukin-6 gene expression by pro-inflammatory cytokines and black-pigmented Bacteroides in human pulp cell cultures; Yang LC et al.; AIM: To investigate the effect of pro-inflammatory cytokines and black-pigmented Bacteroides on the expression of IL-6 gene in human pulp fibroblasts . METHODOLOGY: IL-1alpha, tumour necrosis factor-alpha (TNF-alpha) and the supernatants of Porphyromonas endodontalis, P . gingivalis and Prevotella intermedia were used to evaluate IL-6 gene expression in human pulp fibroblasts . The levels of mRNAs were measured by the quantitative reverse-transcriptase polymerase chain reaction analysis . RESULTS: Investigations of the time dependence of IL-6 mRNA expression in pro-inflammatory cytokines-treated cells revealed a rapid accumulation of the transcript after 2 h of exposure and remained elevated throughout the 24-h incubation period . In addition, black-pigmented Bacteroides also induced IL-6 gene expression in human pulp fibroblasts . CONCLUSIONS: Pro-inflammatory cytokines and black-pigmented Bacteroides may be involved in developing pulpal inflammation through the stimulation of IL-6 production.

Clin Diagn Lab Immunol, 2003 May, 10(3), 383 - 7
Humoral immune responses to S-layer-like proteins of Bacteroides forsythus; Yoneda M et al.; Bacteroides forsythus is one of the important periodontopathic bacteria, and this microorganism is known to have an S-layer outside the outer membrane . The S-layer-like antigens were recently isolated from B . forsythus, and they were found to be 270- and 230-kDa proteins in the envelope fraction . In this study, these proteins were confirmed to be specific to B . forsythus by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and they were clearly recognized by sera from patients with adult and early-onset periodontitis in Western immmunoblot analysis . We compared the immunoglobulin G (IgG) responses against the purified S-layer-like antigen by enzyme-linked immunosorbent assay . IgG responses against this antigen were low in healthy control subjects, but they were significantly higher in subjects with adult and early-onset periodontitis . Together with the fact that the IgG responses against the crude extract of B . forsythus did not rise significantly in patients with periodontitis, S-layer-like proteins are considered to be specific antigens of B . forsythus and may play an important role in the progression of periodontitis.

J Mol Microbiol Biotechnol, 2003, 5(2), 123 - 32
Family of shuttle vectors for ruminal Bacteroides; Wong CM et al.; A family of shuttle plasmids was constructed for genetic transformation of Escherichia coli and of ruminal Bacteroides strains AR20 and AR29 . Plasmids were based on the replicon from Bacteroides plasmid pBI191 and were designed for studies of chromosomal integration (pBA), for the identification and study of Bacteroides gene promoters (pPPR) and for the expression of heterologous genes in Bacteroides (pBAC) . Electroporation efficiency of Bacteroides was up to 10(5) transformants/microg plasmid, depending on the source of the DNA . The largest plasmid, pBA, was maintained at approximately 8 copies per cell in AR20 and did not measurably alter in vitro growth of transformed cells . In the current work, pBA did not integrate into the chromosomes of AR20 or AR29 . The ability of plasmid pPPR to select promoter sequences was demonstrated by removal and replacement of promoters that activate the clindamycin resistance gene . The suitability of pBAC for expression of heterologous genes was demonstrated by expression of the Moraxella species fluoroacetate dehalogenase gene H1 to give intracellular activity of 7 nmol fluoride released/min/mg soluble protein in AR20 and 4 nmol/min/mg in AR29 . Spontaneous loss of pBAC under non-selective conditions was 0.11-0.165% per generation, significantly less than loss of the native Bacteroides plasmid pBI191, which was lost at 0.53% per generation .

Gastroenterology, 2003 May, 124(5), 1395 - 407
Enteric flora and lymphocyte-derived cytokines determine expression of heat shock proteins in mouse colonic epithelial cells; Kojima K et al.; BACKGROUND & AIMS: Inducible heat shock proteins (hsps), particularly hsp25 and hsp72, are expressed by surface colonocytes and may have a role in protecting intestinal epithelial cells against injury . This study is aimed at determining if enteric bacteria and/or immune signals regulate their physiologic expression . METHODS: Intestinal hsp25, hsp72, and constitutive hsc73 expression were studied in immunodeficient RAG-1(-/-) mice and in normal mice . Mucosal permeability was measured by mannitol flux and transepithelial resistance . Hsp expression in intestinal YAMC cells was assessed after incubation with recombinant cytokines, activated lamina propria lymphocytes (LPLs), or Bacteroides fragilis . RESULTS: Chronic metronidazole treatment decreases colonic mucosal hsp25 and hsp72 expression, an effect associated with increased susceptibility of mucosal barrier function to C . difficile toxin A . Hsp expression also was increased in YAMC cells incubated with B . fragilis, an effect mediated by lipopolysaccharide and other bacteria-derived factors . Colonic hsp72, but not hsp25 or hsc73, expression is decreased in RAG-1(-/-) mice . Recombinant IL-2 and other cytokines enhance YAMC hsp25 and/or hsp72 expression . Activated LPLs induce YAMC hsp expression, an effect blocked by IL-2 neutralizing antibody . CONCLUSIONS: Enteric flora and mucosal lymphocytes play a role in maintaining physiologic expression of colonocyte hsp25 and hsp72.

J Clin Periodontol, 2003 May, 30(5), 420 - 6
Herpesviral-bacterial interactions in aggressive periodontitis; Kamma JJ et al.; BACKGROUND: Human cytomegalovirus, Epstein-Barr virus and herpesvirus co-infections occur with significantly higher frequency in actively progressing than in stable periodontitis sites of adolescents and young adults . Also, periodontal presence of cytomegalovirus and Epstein-Barr virus is associated with increased occurrence of subgingival Porphyromonas gingivalis, Bacteroides forsythus, Dialister pneumosintes, Prevotella intermedia, Prevotella nigrescens, Treponema denticola and Actinobacillus actinomycetemcomitans . AIM: This article reviews the evidence linking herpesviruses to the development of aggressive periodontitis and suggests a potential mechanism for herpesviral acceleration of the periodontal disease process . CONCLUSIONS: It seems to be a reasonable supposition that the etiopathogenesis of various types of aggressive periodontitis includes the combined action of herpesviruses and specific bacterial species . New vaccines and vaccination technologies that are being developed against herpesviruses warrant testing for their ability to induce a protective immune response against destructive periodontal disease . Clearly, the importance of combined herpesviral-bacterial infections and associated host responses in the development of periodontitis needs to be studied further.

J Clin Periodontol, 2003 Jan, 30(1), 63 - 72
Ovine periodontitis as a potential model for periodontal studies . Cross-sectional analysis of clinical, microbiological, and serum immunological parameters; Duncan WJ et al.; OBJECTIVES: : To investigate infection and host immunity patterns in sheep with naturally occurring "broken-mouth" periodontitis . MATERIALS AND METHODS: : Eight periodontally healthy (HS) and eight periodontally diseased ewes (PDS) were selected . Subgingival plaque and sera were collected and examined for evidence of human periodontitis-associated pathogens . Serum IgG titers were measured by ELISA to multiple strains of Porphyromonas gingivalis, Bacteroides forsythus, Dichelobacter nodosus, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Fusobacterium nucleatum as well as several purified antigens (cysteine proteases, LPS, K, and fimbriae) . RESULTS: : Neither the organism Aa nor antigens to Aa were found in any animal . Most animals were positive for Pg, Bf, and Pi, but DNA probes detected no difference between HS and PDS relative to amounts of pathogens in subgingival plaque . PDS had significantly higher serum IgG titers to all Pg strains, to 50% of Bf strains, to the Pi and Fn strains, and to fimbriae and the two cysteine proteases (p-values ranging from 0.05 to 0.001) . Regression analysis demonstrated a significant association between number of teeth lost and serum IgG antibody titers to whole-cell sonicate antigens of P . gingivalis strains (p<0.01) and body weight (p<0.01) . CONCLUSIONS: : The presence of pathogens associated with periodontitis was reflected in differences in serum IgG titers between healthy and diseased sheep . This may have influenced animal body weight and might have systemic health and economic consequences . The data suggest that susceptible and non-susceptible sheep can be identified for periodontal research.

J Clin Periodontol, 2003 Jan, 30(1), 57 - 62
A rapid DNA probe test compared to culture methods for identification of subgingival plaque bacteria; Tsai CY et al.; There has been a significant amount of interest in developing a more rapid and cost-effective test to identify bacterial pathogens in plaque . DNA probe technology may meet both these objectives, it is more rapid and cost-effective when compared to culture methods . The purpose of this study was to compare an automated DNA probe test with classical culture methods for identifying Bacteroides forsythus and Porphyromonas gingivalis in subgingival plaque of patients with adult periodontitis . Subgingival plaque samples were collected from sites with moderate to severe periodontitis and divided into two aliquots for analysis by either DNA probe or culture methods . When the DNA probe method was compared with the culture method (gold standard), the sensitivity and specificity for B . forsythus were 92.0% (SE = 3.4%) and 50.5% (SE = 7.8%), respectively; for P . gingivalis they were 52.2% (SE = 8.7%) and 74.7% (SE = 5.9%), respectively . Detection of B . forsythus and P . gingivalis by DNA probe correlated with probing depth (P = 0.01 for B . forsythus and P = 0.03 for P . gingivalis) . It was concluded the DNA probe test was comparable to culture methods in detecting B . forsythus . In addition, when compared to the culture method, a better correlation was obtained with DNA probe detection of B . forsythus or P . gingivalis and clinical parameters.

J Clin Periodontol, 2003 Jan, 30(1), 19 - 25
Guided tissue regeneration using a polylactic acid barrier . Part I: Environmental effects on bacterial colonization; Rudiger SG et al.; OBJECTIVES: The purpose of this study was to assess the dynamics of bacterial colonization in intra-osseous defects following guided tissue regeneration (GTR) therapy using a resorbable barrier . PATIENTS AND METHODS: In each of 30 patients, one intra-osseous defect was treated with GTR using a polylactic acid membrane (Guidor) . Plaque samples were taken from the defect site, other teeth and mucous membranes following initial therapy (baseline), and at 3, 6 and 12 months after periodontal surgery . Additionally, samples were taken from the defect sites at 1, 2 and 4 weeks . Actinobacillus actinomycetemcomitans (A.a.), Porphyromonas gingivalis (P.g.), and Bacteroides forsythus (B.f.) were detected by polymerase chain reaction (PCR) . Supportive periodontal therapy was performed at 3-month intervals . RESULTS: In the 29 patients completing the study, the assessed microflora was detected in 3 (A.a.), 13 (P.g.) and 14 (B.f.) defect sites at baseline, in 2 (A.a.), 2 (P.g.) and 2 (B.f.) following surgical debridement, and in 6 (A.a.), 10 (P.g.) and 22 (B.f.) at 12 months . Defect site colonization following GTR therapy was significantly correlated with presurgical colonization at other assessed teeth (A.a . and P.g.: tau = 0.45 and 0.66, respectively; P < 0.001), or on mucous membranes (B.f.: tau = 0.44, P < 0.001) . CONCLUSION: The colonization of periodontal pathogens at sites treated by GTR may correlate with the intra-oral presence of these pathogens before surgery . If colonization of GTR sites by periodontal pathogens is to be prevented, intra-oral suppression/eradication of these pathogens may be required before surgery.

J Endod, 2003 Apr, 29(4), 240 - 3
Induction of cyclooxygenase-2 mRNA and protein expression in human pulp cells stimulated with black-pigmented bacteroides; Chang YC et al.; Cyclooxygenase-2 (COX-2) is induced after the activation of cells by a variety of proinflammatory agents . Recently, evidence has shown that COX-2 may play a role in the pathogenesis of pulpal inflammation . However, little is known regarding the mechanism of pulpal inflammation at the site of bacterial infection . The purpose of this study was to determine the effects of the supernatants from black-pigmented Bacteroides (Porphyromonas endodontalis, Porphyromonas gingivalis, and Prevotella intermedia) on the COX-2 expression in primary human pulp cells in vitro . Investigations of the time dependence of COX-2 mRNA expression in black-pigmented Bacteroides-treated human pulp cells revealed a rapid accumulation of the transcript, a significant signal first detectable after 1 h of exposure . In addition, black-pigmented Bacteroides also up-regulated COX-2 protein expression in human pulp cells . Data from our in vitro experiment showed that black-pigmented Bacteroides were capable of stimulating COX-2 expression in human pulp cells . These results indicate that black-pigmented Bacteroides species may play an important role in the pathogenesis of pulpal inflammation . The activation of COX-2 may be one of the distinct host degradative pathways in the pathogenesis of microbial-induced pulpal/periapical inflammation.

J Antimicrob Chemother, 2003 May, 51(5), 1293 - 6 Epub 2003 Apr 14.
Sequence analysis of cfxA2-like beta-lactamases in Prevotella species; Giraud-Morin C et al.; Sixty-two strains of oral (32) and non-oral (30) Prevotella producing beta-lactamases were screened for cfxA by PCR, using an intragenic primer pair . All 62 were cfxA/cfxA2 positive . Fourteen of these strains, representing seven pigmented and seven non-pigmented Prevotella species were submitted to further PCR with specific primers that amplified the whole beta-lactamase structural gene (966 bp) . After cloning and sequencing, the deduced amino acid sequences were compared with that of Bacteroides vulgatus CfxA beta-lactamase . All 14 sequences possessed the E272K substitution characteristic of CfxA2 . CfxA sensu stricto was not observed in the present series . G83D, F/V189L, W193L and D239Y substitutions were observed more than once, without species specificity . This sequence analysis indicates that most oral and non-oral beta-lactamase-producing Prevotella isolates from French patients produce variants of the CfxA enzyme.

Surg Infect (Larchmt), 2002 Winter, 3(4), 303 - 14
Ertapenem versus piperacillin-tazobactam for treatment of mixed anaerobic complicated intra-abdominal, complicated skin and skin structure, and acute pelvic infections; Tellado J et al.; BACKGROUND: Anaerobes are an important component of many serious, deep tissue infections, especially complicated intra-abdominal (IAI), complicated skin and skin structure (SSSI), and acute pelvic (PI) infections . This study compares the efficacy of ertapenem, 1 g once a day, in the treatment of adults with anaerobic IAI, SSSI, and PI to piperacillin-tazobactam, 3.375 g every 6 hours . METHODS: Three randomized, double-blind trials comparing ertapenem to piperacillin-tazobactam for treatment of IAI, SSSI, and PI were conducted . This subgroup analysis included 623 patients, whose baseline culture grew one or more anaerobic pathogens, from these three studies . RESULTS: Anaerobes most commonly isolated were Bacteroides fragilis group (IAI) and peptostreptococci (SSSI and PI) . The median duration of ertapenem and piperacillin-tazobactam therapy, respectively, in these subgroups was 6 and 7 days for IAI, 7 and 8 days for SSSI, and 4 and 5 days for PI . Cure rates for all evaluable patients with anaerobic infection were 89.3% (242/271) for ertapenem and 85.9% (220/256) for piperacillin-tazobactam (95% CI for the difference, adjusting for infection, -2.6% to 9.3%), indicating that the two treatments were equivalent . Cure rates by infection, for ertapenem and piperacillin-tazobactam, respectively, were as follows: IAI, 86.4% (133/154) and 82.4% (117/142); SSSI, 84.4% (27/32) and 82.4% (28/34); PI, 96.5% (82/85) and 93.8% (75/80) . The frequency and severity of drug-related adverse experiences were comparable in both treatment groups . CONCLUSION: In this subgroup analysis, ertapenem was as effective as piperacillin-tazobactam for treatment of adults with moderate to severe anaerobic IAI, SSSI, and PI, was generally well tolerated, and had a similar safety profile.

J Clin Periodontol, 2003 Apr, 30(4), 364 - 7
Accumulation of methylglyoxal in the gingival crevicular fluid of chronic periodontitis patients; Kashket S et al.; BACKGROUND, AIMS: Methylglyoxal (MG), a toxic product of cellular metabolism, is elevated in tissues and fluids in a number of human diseases . A cross-sectional study was undertaken to determine whether MG accumulates in the gingival crevicular fluid (GCF) of chronic periodontitis patients . METHODS: GCF samples were collected for 30 s each from three teeth with pocket depths greater than 3 mm (DD sites), from 14 chronic periodontitis patients . Control samples were taken from three healthy sites (DH sites) in the same patients, as well as from seven subjects who were periodontally healthy (HH sites) . Fluid volumes were determined and the strips were placed in 0.5 N perchloric acid . Subsequently, samples were derivatized with o-phenylenediamine and the resulting methylquinoxaline was assayed by high-performance liquid chromatography on Lichrospher(R)-100 RP-18, with UV detection . RESULTS: Mean pocket depths were 5.7+/-0.7, 2.7+/-0.6 and 2.7+/-0.5 mm (mean+/-SD) for the DD, DH and HH sites, respectively . Mean MG levels were found to be 208.7+/-241.7 and 142.9+/-235.7 pmol/site in the GCF from DD and DH sites, respectively (p=0.0023), but only 11.5+/-4.4 pmol/site for the HH sites . Bacteroides forsythus has been found to accumulate high levels of MG in culture (unpublished data) and, consistent with this, the sampled diseased sites contained higher levels of B . forsythus than the corresponding healthy sites (2.7+/-4.2 x 10(5) versus 0.7+/-1.1 x 10(5), respectively; p=0.022) . Total "red complex" microorganisms were significantly elevated in the DD sites . CONCLUSIONS: In view of the known protein- and DNA-modifying effects of MG, the finding of elevated levels of MG in the GCF from chronic periodontitis patients supports the hypothesis that MG may contribute to destructive tissue damage in this disease.

Clin Neurol Neurosurg, 2003 Apr, 105(2), 128 - 31
A case of 'circling seizures' and an intratumoral abscess; Yeates KE et al.; We describe a case of a 38-year-old woman who presented with 'circling' seizures and was found to have an intracranial mass with features consistent with a meningioma . Three weeks prior to her presentation she underwent an uncomplicated vaginal hysterectomy . However, after discharge to home she developed a 4-day history of fever, chills and night sweats that eventually resolved . She underwent surgical removal of her intracranial mass without difficulty but intra-operative pathology showed features of acute cerebritis at the margins of the tumor . Further sectioning of the mass revealed evidence of an intratumoral abscess . Culture of the meningioma revealed heavy growth of Bacteroides fragilis . The patient was treated with intravenous antibiotics, discharged home in excellent health and has had no recurrence of seizures . In our case report we will review the historical literature on the incidence and features of intratumoral abscess . Although it is considered a rare event, our case demonstrates both common and unique features about this occurrence and highlights an unusual chain of events in the natural history of the patient's meningioma and the way in which it became clinically apparent.

J Biol Chem, 2003 Jun 27, 278(26), 23851 - 60 Epub 2003 Apr 02.
Transforming growth factor-beta 1 inhibits non-pathogenic Gram negative bacteria-induced NF-kappa B recruitment to the interleukin-6 gene promoter in intestinal epithelial cells through modulation of histone acetylation; Haller D et al.; We have shown that non-pathogenic enteric Gram-negative Bacteroides vulgatus induces RelA phosphorylation, NF-kappaB activation, and proinflammatory gene expression in primary and intestinal epithelial cell (IEC) lines . We now demonstrate the transient induction of nuclear phospho-RelA (day 3) followed by persistent activation of phospho-Smad2 (days 3 and 7) in IEC from mucosal tissue sections of B . vulgatus-monoassociated rats, indicating that both NF-kappaB and transforming growth factor-beta1 (TGF-beta1) signaling are induced in vivo following bacterial colonization . Interestingly, TGF-beta1 inhibited B . vulgatus- and lipopolysaccharide (LPS)-induced NF-kappaB transcriptional activity as well as interleukin-6 (IL-6) mRNA accumulation and protein secretion in IEC . The inhibitory effect of TGF-beta1 is mediated independently of B . vulgatus/LPS-induced IkappaBalpha, Akt, and RelA phosphorylation as well as NF-kappaB DNA binding activity . Moreover, the specific histone deacetylase inhibitor trichostatin A blocked B . vulgatus/LPS-induced histone acetylation/phosphorylation (Lys-9/Ser-10) and reversed TGF-beta1-mediated inhibition of IL-6 gene expression . Chromatin immunoprecipitation analysis revealed that B . vulgatus/LPS-induced RelA recruitment to the IL-6 promoter is inhibited by TGF-beta1 treatment . Adenoviral delivery of Smad7 and dominant negative Smad3 (SmadDelta3) reversed the TGF-beta1-mediated inhibition of NF-kappaB transcriptional activity and NF-kappaB recruitment to the IL-6 promoter . In addition, TGF-beta1 and Ad5Smad3/4 prevent B . vulgatus/LPS-induced CBP/p300 and p65 nuclear co-association . We concluded that the TGF-beta1/Smad signaling pathway helps maintain normal intestinal homeostasis to commensal luminal enteric bacteria by regulating NF-kappaB signaling in IEC through altered histone acetylation.

J Int Acad Periodontol, 2000 Apr, 2(2), 31 - 43
Vaccination and periodontitis: myth or reality; Page RC; In most industrialised countries approximately 15% of the population has enhanced risk for moderate to severe periodontitis . The disease is caused by infection by gram-negative, anaerobic bacteria including Porphyromonas gingivalis and Bacteroides forsythus . There is evidence that P . gingivalis is a key pathogen . Using ligature-induced periodontitis in the non-human primate Macaca fascicularis as a model, we immunised 10 animals using intact killed P . gingivalis and SAF-M adjuvant and 10 controls using adjuvant only . The vaccine, containing 250 microg protein/ml, was injected subcutaneously in the neck and into the deltoid muscle (0.5 ml each site) at baseline and weeks 3, 6, and 16, and the mandibular posterior teeth ligated at week 16 . At weeks 30 and 36 changes in alveolar bone, measured using digital subtraction radiography, were used as the outcome measure . Even though periodontitis in humans and in this animal model is a polymicrobial disease, immunisation with a vaccine containing a single bacterial species, P . gingivalis, induced protection . Of all the P . gingivalis components that have been studied, the cysteine proteases have the greatest potential as vaccine antigens . In a pilot study using the same protocol, we have shown that porphypain-2 purified from P . gingivalis is effective in inducing protection . Although opsonisation and bacterial cell killing may be involved in protection, other mechanisms such as antibody mediated reduction of levels of inflammatory mediators such as PGE2 and neutralisation of virulence factors may be important . In neither the whole cell vaccine nor the purified cysteine protease vaccine studies were signs of toxicity observed . In light of the increasing evidence that periodontitis significantly increases risk for potentially fatal diseases such as coronary heart disease, stroke and complications from diabetes mellitus a successful vaccine for periodontitis could have health benefits far exceeding the prevention of periodontitis.

Science, 2003 Mar 28, 299(5615), 2074 - 6
A genomic view of the human-Bacteroides thetaiotaomicron symbiosis; Xu J et al.; The human gut is colonized with a vast community of indigenous microorganisms that help shape our biology . Here, we present the complete genome sequence of the Gram-negative anaerobe Bacteroides thetaiotaomicron, a dominant member of our normal distal intestinal microbiota . Its 4779-member proteome includes an elaborate apparatus for acquiring and hydrolyzing otherwise indigestible dietary polysaccharides and an associated environment-sensing system consisting of a large repertoire of extracytoplasmic function sigma factors and one- and two-component signal transduction systems . These and other expanded paralogous groups shed light on the molecular mechanisms underlying symbiotic host-bacterial relationships in our intestine.

Med Dosw Mikrobiol, 2002, 54(4), 365 - 9
{Use of reactions with Limulus amoebocyte lysate (LAL) to determine biological activity of lipopolysaccharides from reference and clinical strains of the Bacteroides fragilis group}; Rokosz A et al.; The aim of this study was to determine and compare a biological activity of lipopolysaccharides (LPS) from reference and clinical strains of strictly anaerobic bacteria belonging to the Bacteroides fragilis group (BFG) by means of quantitative, photometric BET (LAL) method with Limulus polyphemus amoebocyte lysate and chromogenic substrate S-2423 . Lipopolysaccharides of five BFG species were extracted by Westphal and Jann method (1965) from eight reference and two clinical strains of B . fragilis group . Crude LPS preparations were purified according to the procedure described by Gmeiner (1975) with ultracentrifugation and nuclease treatment . Biological activities of bacterial endotoxins were determined by quantitative BET method with chromogenic substrate S-2423 (ENDOCHROME kit, Charles River Endosafe Ltd., USA) . Tests were performed according to the producer's recommendations . E . coli O55:B5 LPS was applied to compare its activity in reaction with LAL reagent with activities of LPS preparations from rods of the Bacteroides genus . Among examined bacterial compounds the most active in BET method was E . coli O55:B5 LPS . Activities of lipopolysaccharides from five species of BFG rods in reaction with Limulus amoebocyte lysate were differentiated . Greater ability to activate LAL proenzyme revealed lipopolysaccharides of these species of the Bacteroides genus, which are important from the clinical point of view--B . fragilis and B . thetaiotaomicron.

Med Dosw Mikrobiol, 2002, 54(3), 253 - 8
{Susceptibility to antimicrobial drugs of enterotoxin producing strains of Bacteroides fragilis isolated from different countries}; Obuch-Woszczatynski P et al.; Twenty two Bacteroides fragilis strains isolated from clinical samples in different countries (England, France, the Netherlands, Poland and USA) were used in the experiments . In all strains the presence of enterotoxin (fragilysin) gene was found by PCR with primers 404/407 . Drug susceptibility of B . fragilis strains was determined with Etest (MICs for penicillin G, ceftriaxone, amoxicillin/clavulanic acid, imipenem, clindamycin and metronidazole) . MICs were estimated in accordance to the NCCLS recommendations (1997) . All tested strains were susceptible to imipenem and metronidazole . Twenty one strains were susceptible and one was intermediate susceptible to amoxicillin/clavulanic acid . Fourteen strains were resistant to ceftriaxone and five were found highly resistant to clindamycin . All examined strains were resistant to penicillin G . Four tested strains were simultaneously resistant to penicillin G, ceftriaxone and clindamycin (three French human strains isolated from postoperative wound, peritoneal fluid and bone inflammation, and one strain isolated from a pig).

Med Dosw Mikrobiol, 2002, 54(3), 243 - 51
{Stimulation of adhesion molecule expression in human vascular endothelium by Bacteroides fragilis toxins--influence of polymyxin B}; Rokosz A et al.; The aim of this study was to examine the influence of polymyxin B on the level of expression of adhesion molecules E-selectin, ICAM-1, and VCAM-1 on human vascular endothelium activated with B . fragilis endotoxins or enterotoxin . Lipopolysaccharides were extracted by phenol-water method from one nonenterotoxigenic (NTBF) and three enterotoxigenic (ETBF) B . fragilis strains . LPS preparations were purified with nucleolytic enzymes and ultracentrifugation . Enteotoxin (BFT) was prepared from the supernatant of reference B . fragilis ATCC 43858 culture by precipitation with ammonium sulphate . BFT preparations were purified with the application of ion-exchange chromatography and hydrophobic chromatography . Adhesion molecule expression on the surface of human vascular endothelial cells (HMEC-1 cell line) was determined after simultaneous stimulation with bacterial compounds at the concentration of 10 micrograms/ml and polymyxin B at the concentration of 20 micrograms/ml . Endothelial cells were activated for 4 hours (E-selectin expression) or for 24 hours (ICAM-1 and VCAM-1 expression) . Adhesion molecules were detected in immunoenzymatic test (ELISA) with the use of mouse, monoclonal antibodies against human ICAM-1, VCAM-1, and E-selectin . The results of performed experiments suggest, that polymyxin B changes the level of adhesion molecule expression on human vascular endothelium . This antibiotic causes changes in the expression of endothelial ICAM-1, VCAM-1, and E-selectin during simultaneous stimulation of endothelium with B . fragilis endotoxins or enterotoxin . In the majority of cases the addition of polymyxin B leads to the up-regulation of examined adhesion molecules.

Appl Environ Microbiol, 2003 Mar, 69(3), 1457 - 64
Use of a packed-column bioreactor for isolation of diverse protease-producing bacteria from antarctic soil; Wery N et al.; Seventy-five aerobic heterotrophs have been isolated from a packed-column bioreactor inoculated with soil from Antarctica . The column was maintained at 10 degrees C and continuously fed with a casein-containing medium to enrich protease producers . Twenty-eight isolates were selected for further characterization on the basis of morphology and production of clearing zones on skim milk plates . Phenotypic tests indicated that the strains were mainly psychrotrophs and presented a high morphological and metabolical diversity . The extracellular protease activities tested were optimal at neutral pH and between 30 and 45 degrees C . 16S ribosomal DNA sequence analyses showed that the bioreactor was colonized by a wide variety of taxons, belonging to various bacterial divisions: alpha-, beta-, and gamma-Proteobacteria; the Flexibacter-Cytophaga-Bacteroides group; and high G+C gram-positive bacteria and low G+C gram-positive bacteria . Some strains represent candidates for new species of the genera Chryseobacterium and Massilia . This diversity demonstrates that the bioreactor is an efficient enrichment tool compared to traditional isolation strategies.

J Antimicrob Chemother, 2003 Mar, 51(3), 721 - 5
Faropenem, a new oral penem: antibacterial activity against selected anaerobic and fastidious periodontal isolates; Milazzo I et al.; The in vitro activity of faropenem, an oral penem, was compared with those of penicillin, co-amoxiclav, cefoxitin, clindamycin, erythromycin and metronidazole against 106 isolates of anaerobic pathogens involved in systemic infections . The organisms tested comprised Porphyromonas gingivalis (29), Prevotella spp . (eight), Prevotella melaninogenica (seven), Prevotella intermedia (five), Actinomyces spp . (25), Fusobacterium nucleatum (14), Peptostreptococcus spp . (11), Bacteroides ureolyticus (five) and Bacteroides forsythus (two) . The antimicrobial properties of faropenem were investigated by studying MICs, MBCs, time-kill kinetics and post-antibiotic effect (PAE) . Faropenem was highly active against all the anaerobes tested (MIC(90) < or = 0.5 mg/L) and was bactericidal against both beta-lactamase-positive and -negative anaerobes, with a maximum bactericidal effect at 10 x MIC at between 12 and 24 h . In addition, faropenem had an in vitro PAE on all the tested isolates and this was not influenced by beta-lactamase production . Faropenem may be useful for treating infections caused by periodontal bacteria or oral flora.

Inorg Chem, 2003 Mar 10, 42(5), 1604 - 15
Zinc-bound thiolate-disulfide exchange: a strategy for inhibiting metallo-beta-lactamases; Boerzel H et al.; The mononuclear zinc thiolate complexes {(Tp(PhMe))Zn(S-R)}, where Tp(PhMe) is hydrotris((3-methyl-5-phenyl)pyrazolyl)borate and (S-R) is benzyl thiolate, 4-nitrophenylthiolate, 4-trifluoromethylphenylthiolate, 4-chlorophenylthiolate, phenylthiolate, 2-methylphenylthiolate, 4-methylphenylthiolate, 4-methoxyphenylthiolate, or 4-hydroxyphenylthiolate, were synthesized . Representative members of the class were also characterized structurally . The benzyl thiolate complex undergoes a thiolate-disulfide exchange reaction with a variety of diphenyl and dipyridyl disulfides . Kinetic studies revealed that the reaction shows saturation behavior in both complex and disulfide for most of the disulfides studied . Combined with studies of the lability of the coordinated thiolate, a mechanism is proposed where the reactive species is the zinc-coordinated thiolate . When the free benzyl thiol was allowed to react with the same disulfides, the reaction was slower by a factor of 20-200 than that for the zinc-thiolate complex, depending on the particular disulfide employed . Since most metallo-beta-lactamases contain one or more cysteine residues, the one in the active site being coordinated to zinc, the present study was extended to examine whether disulfides can be used as inhibitors of these enzymes by selective oxidation of the metal-bound cysteine . Several disulfides allowed to react with metallo-beta-lactamase CcrA from Bacteroides fragilis were moderate to potent irreversible inhibitors of the enzyme.

Antimicrob Agents Chemother, 2003 Mar, 47(3), 979 - 85
New insertion sequence elements in the upstream region of cfiA in imipenem-resistant Bacteroides fragilis strains; Kato N et al.; The 747-bp cfiA gene, which encodes a metallo-beta-lactamase, and the regions flanking cfiA in six imipenem-resistant and four imipenem-susceptible Bacteroides fragilis strains isolated in Japan were analyzed by PCR and DNA sequencing . The nucleotide sequences of the cfiA genes (designated cfiA(1) to cfiA(10)) of all 10 strains tested varied from that of the standard cfiA gene from B . fragilis TAL2480 . However, putative proteins encoded by the cfiA variants contained conserved amino acid residues important for zinc binding and hairpin loop formation, suggesting that cfiA variants have the capability of producing metallo-beta-lactamases with full catalytic activities . PCR assay indicated that six metallo-beta-lactamase-producing, imipenem-resistant strains had an insertion mutation in the region immediately upstream of cfiA . Nucleotide sequencing of the PCR-amplified fragments along with the upstream region of cfiA revealed that there were five new kinds of insertion sequence (IS) elements (designated IS612, IS613, IS614, IS615, and IS616, with a size range of 1,594 to 1,691 bp), of which only IS616 was found to be almost identical to IS1188, one of the IS elements previously identified in the upstream region of cfiA . These elements had target site duplications of 4 or 5 bp in length, terminal inverted repeats (14, 15, or 17 bp in size), and a large open reading frame encoding a putative transposase which is required for the transcription of IS elements . Each element was inserted such that the transcriptional direction of the transposase was opposite to that of cfiA . A computer-aided homology search revealed that, based on the homology of their putative transposases, the sizes of their terminal inverted repeat sequences, and their target site duplications, IS612, IS613, IS614, and IS615 belong to the IS4 family, which includes IS942, previously found in some drug-resistant B . fragilis strains, but that IS616 belongs to the IS1380 family . All the IS elements appear to have putative promoter motif sequences (the -7 region's TAnnTTTG motif and the -33 region's TTG or TG) in their end regions, suggesting that the IS elements provide a promoter for the transcription of cfiA upon insertion . These data provide additional proof that various IS elements may exist to provide a promoter to express the cfiA gene.

Antimicrob Agents Chemother, 2003 Mar, 47(3), 910 - 6
Activities of garenoxacin (BMS-284756) and other agents against anaerobic clinical isolates; Hecht DW et al.; A total of 590 clinical isolates consisting of 33 species of both gram-positive and gram-negative anaerobes were collected from nine centers in the Chicago area in 1998-1999 . The largest number of isolates (330 isolates, 56%) belonged to the Bacteroides group . Isolates were tested by agar dilution against garenoxacin (BMS-284756, T-3811 ME), trovafloxacin, moxifloxacin, clindamycin, imipenem, piperacillin-tazobactam, and cefoxitin . All but one species (2% of Bacteroides vulgatus isolates) were fully susceptible to piperacillin-tazobactam and imipenem . A number of species were resistant to clindamycin . Among the fluoroquinolones, garenoxacin and trovafloxacin had an MIC at which 90% of the isolates tested were inhibited of <4 micro g/ml for all but two species (Fusobacterium mortiferum/varium and Peptostreptococcus anaerobius).

J Endod, 2003 Feb, 29(2), 118 - 20
Antibacterial effects of resinous retrograde root filling materials; Lai CC et al.; The effect of three resinous retrograde root filling materials on the growth of four obligate anaerobic bacteria associated with endodontic infections was determined by using the agar diffusion inhibitory test . Samples of the following resinous materials (resin-modified, glass-ionomer cement, Fuji II LC; compomer, Dyract; and composite resin, Spectrum) were incubated for 1 week with the following anaerobic bacteria: Fusobacterium nucleatum, Porphyromonas gingivalis, P . endodontalis, and Prevotella intermedia . The freshly mixed and set resinous materials were placed into the prepared wells of agar plates inoculated with the test microorganisms for 1 week . After the end of the incubation period, the zone of growth inhibition was observed and measured . Analysis of variance of the mean diameter of the zone of inhibition indicated no statistically significant overall differences in the response of the black-pigmented Bacteroides species (p > 0.05) . For F . nucleatum, Spectrum had more antibacterial effect against this bacteria than Dyract (p < 0.05) . Additionally, Fuji II LC was ineffective against F . nucleatum (p < 0.05) . However, positive control plates showed bacterial growth in all cases . Our data suggest that the antibacterial potency of polymerized materials varied considerably, depending on the type and the product tested.

Surg Infect (Larchmt), 2000, 1(1), 49 - 56
The consequences of suppression of anaerobic bacteria; Fry DE et al.; Anaerobic bacteria such as Bacteroides fragilis, Peptostreptococcus species, and Fusobacterium species, when accompanied by aerobic bacteria or in the presence of dead tissue, can cause severe infections . This article discusses the most common type of anaerobic infection, i.e., infection after colonic contamination of the abdominal cavity and soft tissues . Colonic anaerobes rarely cause infections as solitary pathogens . Mixed infections of aerobes and anaerobes are treated by source control, surgical drainage and debridement, and combination antibiotic therapy . Antimicrobial treatment should cover both anaerobes and aerobes; treatment of mixed infections with anti-anaerobic agents alone is likely to result in abscess formation . Recent trends toward cost cutting and the advent of antibiotics with good coverage of both aerobes and relevant pathogenic anaerobes have led to increased single-agent therapy with cefoxitin, cefotetan, ampicillin/sulbactam, imipenem/cilastatin, ticarcillin/clavulanate, trovafloxacin/alatrofloxacin, and piperacillin/tazobactam . In the past 15 years, research has begun to focus on the gut barrier, particularly on the beneficial effects of anaerobic microflora . Directing antibiotic therapy against the anaerobe when it is involved in clinical infection is important; however, the negative consequences of anti-anaerobic antibiotic therapy on the beneficial effects of normal distal gut colonization must also be considered.

Surg Infect (Larchmt), 2001 Summer, 2(2), 153 - 60; discussion 160-2
Relevance and utility of peritoneal cultures in patients with peritonitis; Nathens AB; BACKGROUND: The pathogenic organisms responsible for the manifestations of secondary peritonitis have been well characterized through almost 30 years of experimental and clinical studies . Enteric gram-negative organisms and anaerobes predominate, with Escherichia coli and Bacteroides fragilis, respectively, being the most frequent isolates . This flora is remarkably consistent across patients and institutions . As a result of this consistency and the availability of well-established effective empiric antimicrobial regimens, many surgeons believe that cultures of peritoneal exudates in patients with peritonitis offer no useful information and no clinical benefit . METHODS: Review of pertinent antibiotic and management trials in the management of intraabdominal infection . RESULTS: There is increasing evidence that identification of organisms resistant to the chosen empiric antibiotic regimen portends a higher likelihood of failure . What is not clear is whether postoperative changes in the regimen in accordance with sensitivity patterns of the isolates offers any clinical advantage . In most circumstances, the data provided allow for simplification of the antibiotic regimen . CONCLUSION: The potential for reducing antibiotic exposure and the value of information derived from surveillance of microbial sensitivity patterns support the routine performance of peritoneal cultures.

Microbes Infect, 2003 Jan, 5(1), 19 - 26
Enhanced pathogenicity of susceptible strains of the Bacteroides fragilis group subjected to low doses of metronidazole; Diniz CG et al.; Different concentrations of metronidazole are used widely to treat protozoan and fungal infections . As an antibacterial drug, metronidazole is mainly used against anaerobes, of which the Bacteroides fragilis group is the most important in terms of the frequency of recovery and antimicrobial resistance patterns . The objective of this study was to investigate (1) in vivo metronidazole-induced modifications in the B . fragilis group reflected by altered virulence, and (2) the interference of metronidazole in cellular viability of these samples when subjected in vitro to human polymorphonuclear leukocytes (PMNs) . Strains adapted to low metronidazole concentrations were observed to be more virulent, as demonstrated experimentally in mice by weight loss, quantitative evidence of tissue damage, hemorrhage and anatomopathology of spleen, liver and small intestine samples . A significant increase (P < 0.05) in mean bacterial viability rate of about 2.62-fold was observed for all the drug-adapted strains after contact with human PMNs . However, the level of this phenomenon was quite different among the tested species . These results draw attention to the risk that prolonged therapy, even with low concentrations of metronidazole, may affect the pathogenicity of Bacteroides strains, producing changes in host-bacteria relationships.

J Periodontol, 2003 Jan, 74(1), 129 - 34
High prevalence of Helicobacter pylori detected by PCR in the oral cavities of periodontitis patients; Umeda M et al.; BACKGROUND: Helicobacter pylori has been associated with the development of peptic ulcers and gastric cancer . Although it may be transmitted through the oral cavity, it is unknown whether the oral cavity acts as a permanent reservoir for this bacterium . The purpose of this study was to use nested polymerase chain reaction (PCR) to clarify whether the oral cavity acts as a reservoir for H . pylori . METHODS: The existence of H . pylori in the oral cavity was determined by nested PCR in 57 subjects and by culture method in 18 subjects . The presence of periodontopathic bacteria was also determined by 16S rRNA-based PCR method . RESULTS: Although H . pylori was rarely detected in the oral cavity by culture technique, it was frequently detected (35.1%) by nested PCR in the oral cavity, especially among periodontitis patients who had the bacterium in the gastrointestinal tract (46.4%) . Among the subjects who harbored H . pylori in the stomach or duodenum, 41.2% of patients with periodontal pockets > or = 4 mm and 9.1% of subjects without pockets showed H . pylori in dental plaque, although a statistically significant difference was not observed . One patient who had periodontal pockets retained H . pylori in the oral cavity even after eradication of the bacterium from the stomach and duodenum . Most (8/10) of the patients who had H . pylori in dental plaque harbored Bacteroides forsythus in their oral cavities . CONCLUSION: Close attention should be given to periodontitis patients who harbor H . pylori in the oral cavity.

Pathobiology, 2002-2003, 70(3), 131 - 8
Role of commensal bacteria in chronic experimental colitis: lessons from the HLA-B27 transgenic rat; Rath HC; Rats on Lewis or Fischer background, transgenic for human HLA-B27 and beta(2)-microglobulin genes spontaneously develop colitis, gastritis, arthritis, dermatitis, orchitis, epididymitis, carditis, alopecia and nail changes . Disease susceptibility correlates with the gene copy number and is influenced by the genetic background . The pathomechanism in this model is still not completely understood . Cell transfer experiments indicate an essential role of HLA-B27 expression in bone marrow-derived cells . On Fischer background the onset of colitis occurs at 2 months of age, peaks at 3 months of age, and plateaus . Histologic findings include inflammatory cell infiltration, mostly limited to the mucosa, crypt hyperplasia, reduction of goblet cells, occasionally crypt abscesses and early ulcers . There is evidence that normal luminal bacteria play an essential role in initiating and perpetuating chronic colitis and gastritis in HLA-B27 transgenic rats: Transgenic rats raised under germ-free conditions do not develop gastrointestinal disease, whereas transgenic littermates exposed to specific pathogen-free bacteria develop colitis and gastritis within 2-4 weeks . Obligate anaerobic bacteria, especially Bacteroides spp., may play a predominant role since metronidazole prevents colitis and transgenic germ-free rats contaminated with a cocktail of six obligate and facultative anaerobic bacteria develop colitis and gastritis only in the presence of Bacteroides vulgatus . Luminal bacteria may also be involved in trafficking and homing of inflammatory cells into remote organs, since varying cecal bacterial composition does not only alter local inflammation but also influences gastritis . Lymphocyte transfer experiments indicate a specific response to luminal bacteria . In summary, this animal model is suitable for investigating the influence of normal luminal bacteria on the cellular immune mechanism in chronic intestinal inflammation .

Cell Mol Life Sci, 2002 Dec, 59(12), 2044 - 54
The role of Bacteroides conjugative transposons in the dissemination of antibiotic resistance genes; Whittle G et al.; Investigations into the mechanisms of antibiotic resistance gene transfer utilized by Bacteroides species have led to a greater understanding of how bacteria transfer antibiotic resistance genes, and what environmental stimuli promote such horizontal transfer events . Although Bacteroides spp . harbor a variety of transmissible elements that are involved in the dissemination of antibiotic resistance genes, it is one particular class of elements, the conjugative transposons, that are responsible for most of the resistance gene transfer in Bacteroides . The potential for Bacteroides conjugative transposons to transfer antibiotic resistance genes extends beyond those genes carried by the conjugative transposon itself, because Bacteroides conjugative transposons are able to mobilize coresident plasmids in trans and in cis, and also stimulate the excision and transfer of unlinked integrated elements called mobilizable transposons . These characteristics of conjugative transposons alone have significant implications for the ecology and spread of antibiotic resistance genes, and in terms of biotechnology . A novel feature of the most widespread family of Bacteroides conjugative transposons, the CTnDOT/ERL family, is that their transfer is stimulated 100- to 1000-fold by low concentrations of tetracycline . This is significant because the use of antibiotics not only selects for resistant Bacteroides strains, but also stimulates their transfer . Other Bacteroides conjugative transposons do not require any induction to stimulate transfer, and hence appear to transfer constitutively . The constitutively transferring elements characterized so far appear to have a broader host range than the CTnDOT/ERL family of conjugative transposons, and the prevalence of these elements is on the increase . Since these constitutively transferring elements do not require induction by antibiotics to stimulate transfer, they have the potential to become as pervasive as the CTnDOT/ERL family of conjugative transposons.

Curr Microbiol, 2003 Mar, 46(3), 163 - 8
Homogeneity of the morphological groups of bacteriophages infecting Bacteroides fragilis strain HSP40 and strain RYC2056; Queralt N et al.; Bacteriophages infecting Bacteroides fragilis strains RYC2056 and HSP40 have been proposed as indicators of water quality . To accomplish this function, homogeneity of the group of phages detected by these strains is necessary to ensure that the final results are not due to the different kinetics of inactivation of the phages . To evaluate homogeneity, we observed by electron microscopy bacteriophages isolated from sewage with two Bacteroides fragilis strains (HSP40 and RYC2056) . A predominant group of phages was observed, Siphoviridae with slightly curved tails . Detection of other minority groups, which could be present in the sample, was done with neutralization experiments by using antiserum against the majority group and with host mutants resistant to infection with the predominant phage . Although two other minority groups were observed, results showed that bacteriophages infecting B . fragilis strain HSP40 and strain RYC2056 form a homogeneous group, Siphoviridae with slightly curved tails being the most predominant in sewage.

Gastroenterology, 2003 Feb, 124(2), 392 - 400
Bacteroides fragilis enterotoxin induces c-Myc expression and cellular proliferation; Wu S et al.; BACKGROUND & AIMS: Enterotoxigenic Bacteroides fragilis that secrete a zinc-dependent metalloprotease toxin termed the B . fragilis toxin (BFT) have been associated with acute diarrheal disease . BFT rapidly cleaves the extracellular domain of E-cadherin, leading to the complete degradation of the E-cadherin protein . E-cadherin is the primary intercellular adhesion protein of the zonula adherens, and its cytoplasmic domain associates with the nuclear signaling protein beta-catenin . The goal of this study was to examine if BFT triggers beta-catenin nuclear signaling in intestinal epithelial cells . METHODS: Cell biologic and biochemical techniques were combined to address beta-catenin nuclear signaling stimulated by BFT . RESULTS: Loss of membrane-associated E-cadherin after BFT treatment of human colonic epithelial cells (HT29/C1 clone) triggers beta-catenin nuclear localization within 3 hours . Subsequently, c-myc transcription and translation are induced and persistent cellular proliferation ensues, mediated in part by beta-catenin/T-cell factor-dependent transcriptional activation . Cellular proliferation is stimulated by as little as 5 x 10(-10) mol/L BFT . CONCLUSIONS: To our knowledge, BFT is the first bacterial toxin reported to activate T-cell factor-dependent beta-catenin nuclear signaling in intestinal epithelial cells . These results suggest that genetic evolution of this common colonic commensal has rendered an organism with the potential to contribute to oncogenic transformation in the colon.

Eur J Intern Med, 2003 Feb, 14(1), 63 - 64
Hematogenous anaerobic vertebral osteomyelitis due to Bacteroides fragilis in a diabetic patient; Boutoille D et al.; We report the case of a 70-year-old diabetic man with spontaneous vertebral osteomyelitis due to Bacteroides fragilis . Diagnosis was obtained on positive blood cultures . The port of entry remained unknown despite extensive investigation . A combination of metronidazole and clindamycin led to a clinical cure with no need for surgical debridement and no relapse after 9 months of follow-up.

Nat Immunol, 2003 Mar, 4(3), 269 - 73 Epub 2003 Jan 27.
Angiogenins: a new class of microbicidal proteins involved in innate immunity; Hooper LV et al.; Although angiogenins have been implicated in tumor-associated angiogenesis, their normal physiologic function remains unclear . We show that a previously uncharacterized angiogenin, Ang4, is produced by mouse Paneth cells, is secreted into the gut lumen and has bactericidal activity against intestinal microbes . Ang4 expression is induced by Bacteroides thetaiotaomicron, a predominant member of the gut microflora, revealing a mechanism whereby intestinal commensal bacteria influence gut microbial ecology and shape innate immunity . Furthermore, mouse Ang1 and human angiogenin, circulating proteins induced during inflammation, exhibit microbicidal activity against systemic bacterial and fungal pathogens, suggesting that they contribute to systemic responses to infection . These results establish angiogenins as a family of endogenous antimicrobial proteins.

J Microbiol Immunol Infect, 2002 Dec, 35(4), 255 - 8
Bacteroides fragilis bacteremia associated with portal vein and superior mesentery vein thrombosis secondary to antithrombin III and protein C deficiency: a case report; Ni YH et al.; Hypercoagulability is one of the causes of portal vein and superior mesentery vein thrombosis . We report a case of Bacteroides fragilis bacteremia associated with portal vein and superior mesentery vein thrombosis secondary to antithrombin III and protein C deficiency . The patient presented with high fever for more than 3 weeks . Abdominal sonography revealed a liver cyst of 1.7 cm in diameter over segment 4 and a renal stone of 0.7 cm in size over the lower portion of the right kidney but no evidence of hydronephrosis . Elevation of liver enzymes was also noted . Intermittent fever was noted despite treatment with ceftriaxone and doxycycline . On Day 15 of hospitalization, blood culture revealed B . fragilis, which prompted further investigation of the source of intraabdominal and pelvic infection . Abdominal computed tomography revealed portal vein and superior mesentery vein thrombosis . Endoscopic studies of the gastrointestinal tract showed no tumor or diverticulum . Study of coagulation factors disclosed deficiency of antithrombin III and protein C . Clinicians should remain aware of the need to promptly search for a portal or mesentery vein thrombosis in cases of Bacteroides bacteremia of unknown origin.

Astrobiology, 2002 Fall, 2(3), 255 - 70
A culture-independent survey of the bacterial community in a radon hot spring; Anitori RP et al.; Paralana is an active, radon-containing hot spring situated in a region of South Australia's Flinders Ranges with a long history of hydrothermal activity . Our aim was to determine the bacterial composition of Paralana using a culture-independent, 16S rRNA-based technique . The presence of a diverse bacterial community was strongly suggested by the large number (approximately 180) of different ribotypes obtained upon analysis of nine hot spring samples . DNA sequencing of Paralana 16S rRNA genes corroborated this observation, identifying representatives of seven confirmed and two candidate divisions of the domain Bacteria . These included Cyanobacteria, Proteobacteria (both beta and delta subdivisions), the Cytophaga-Flexibacter-Bacteroides group, Low G + C Gram-positives, Nitrospira, green non-sulfur bacteria, green sulfur bacteria, OP8, and OP12 . No known ionizing radiation-resistant Bacteria were identified . Only one Paralana 16S rRNA sequence type (recombinant B5D) was homologous to a sequence previously identified from a radioactive environment.

Int J Syst Evol Microbiol, 2002 Nov, 52(Pt 6), 2061 - 3
Runella zeae sp . nov., a novel gram-negative bacterium from the stems of surface-sterilized Zea mays; Chelius MK et al.; A Gram-negative bacterium, designated NS12(T), was previously isolated from duplicate treatments of surface-sterilized Zea mays stems . The plants were grown in synthetic soil under greenhouse conditions and watered with fertilizer containing no nitrogen . Strain NS12(T) was not isolated from plants watered with the standard level or 20% (w/v) of the standard level of nitrogen . Cells were bent rods that formed chains of irregular shapes in R2A broth . Unlike its closest described relative Runella slithyformis, strain NS12(T) fermented glucose and sucrose . The G+C content was 49 mol% . Phylogenetic analysis of the 16S rRNA gene showed that the strain was a member of the domain Bacteria and is most closely related to R . slithyformis, a member of the Flexibacter group within the Cytophaga-Flexibacter-Bacteroides phylum . Phenotypic and genotypic analyses indicated that strain NS12(T) could not be assigned to any recognized species; therefore a new species designated Runella zeae sp . nov . is proposed, for which NS12(T) ( = ATCC BAA-293(T) = LMG 21438(T)) is the type strain.

Int J Oral Maxillofac Implants, 2002 Nov-Dec, 17(6), 829 - 38
Microbiota around root-form endosseous implants: a review of the literature; Heydenrijk K et al.; Although high success rates for root-form endosseous implants have been reported, failures occasionally occur, and these implants must be removed . At least 10% of the failures have been suggested to be the result of peri-implantitis . There is some evidence that periodontal pathogens, mainly those belonging to the group of gram-negative anaerobic rods, play a role in the etiology of peri-implantitis . This article provides an overview of the literature associated with common peri-implant microbiology and an assessment as to whether bacteria associated with periodontitis exert a possible risk for peri-implant tissue breakdown . The peri-implant area is colonized by a large variety of oral microbial complexes . The microflora of the oral cavity prior to implant placement determines the composition of the microflora in the peri-implant area . Implants involved in peri-implantitis are colonized with large amounts of gram-negative anaerobic bacteria, including Fusobacteria, spirochetes, Bacteroides forsythus, and "black-pigmented bacteria" such as Prevotella intermedia, Prevotella nigrescens, and Porphyromonas gingivalis . Also, Actinobacillus actinomycetemcomitans can be isolated from these lesions . Thus, the microflora of peri-implantitis lesions resembles that of adult or refractory periodontitis . However, the presence of periodontal pathogens does not always lead to a destructive process . Therefore, the etiologic role of specific microorganisms in implant failure related to infection is still not resolved . Controversy remains as to whether organisms recovered from the original microflora cause the failure (and if so to what extent) or merely result from the infection . Nevertheless, there is accumulating evidence that bacteria cause the disease, while the individual's genetic makeup and environmental influences determine the severity of the disease.

Antimicrob Agents Chemother, 2003 Jan, 47(1), 148 - 53
Bacteremia due to Bacteroides fragilis group: distribution of species, beta-lactamase production, and antimicrobial susceptibility patterns; Aldridge KE et al.; A retrospective analysis of susceptibility data on 542 blood isolates of the Bacteroides fragilis group tested from 1987 to 1999 by the same NCCLS-recommended broth microdilution method throughout is presented . Metronidazole, beta-lactam-beta-lactamase inhibitor combinations, carbapenems, and trovafloxacin were the most active agents (susceptibility of >or=93%) . Among the cephalosporin-cephamycins, the order of activity was cefoxitin > ceftizoxime > cefotetan = cefotaxime = cefmetazole > ceftriaxone . All isolates were resistant to penicillin G, and 22% were resistant to clindamycin . The susceptibility rates to piperacillin-tazobactam, imipenem, and meropenem were affected least among isolates resistant to cefoxitin or clindamycin . Except for piperacillin-tazobactam, imipenem, and meropenem, the B . fragilis species was more susceptible than were the non-B . fragilis species . These data underscore the importance of susceptibility testing of the B . fragilis group and can serve as a guide in the choice of empirical antimicrobial therapy.

Acta Vet Hung, 2002, 50(4), 445 - 57
Effect of double nursing on some anatomical and physiological properties of the digestive tract of rabbits between 23 and 44 days of age; Zomborszky-Kovacs M et al.; Anatomical and physiological properties of the digestive tract were examined and compared in young rabbits nursed either by one (SS) or by two does (DD) daily up to the age of 35 days . At the age of 23, 30, 37 and 44 days, 8 young per treatment were euthanised . Double suckling and the subsequent higher level of solid feed intake after weaning were found to exert a stronger influence on the weight of the entire gastrointestinal tract and that of its individual parts (the stomach, small intestine, caecum and colon) than on its length . The quantity of the gastric content was found to rise with advancing age in both groups (from 36 to 70 g and from 37.5 to 79 g) . In both groups the pH of the stomach was higher during the suckling period (4.5-5.3) than subsequent to weaning (1.6-2.4) . The quantity of the caecal content also increased with age (from 4 or 8 g), but on the 37th day significantly higher quantities of caecal content were recorded in DD rabbits (50.5 g compared with 35 g) . The pH of the caecal content decreased more slowly from an initial high value (6.0 and 6.5 in SS and DD rabbits, respectively), and by the 37th day had settled at a low value (5.7-5.8) in both groups . The dry matter content of the caecal content decreased from 270-273 g to 188-207 g in both groups . Total volatile fatty acid (tVFA) and acetic acid (C2) concentration, which amounted to 66-88% of tVFA, rose; in SS rabbits they were at higher levels by the 30th day (53.6 and 42.2 mmol/L, respectively), and remained at an increased level until the 44th day (P < 0.05) . The ratio of C3: C4 was high on the 23rd day (2.5 and 2.4), but dropped at the age of 30 days (0.5 in SS and 1.7 in DD, P < 0.05) and, further, by the 37th day (0.2 in SS) . In SS rabbits coliform count proved significantly lower (10(5)) on the 23rd day than in DD rabbits (10(6)) . By the 37th day this count had decreased in both groups and subsequently remained at a low level (< 10(4)) . By the 23rd day Bacteroides were present in large quantities (10(8)) in the caecum and showed no change with advancing age or feeding regime.

J Periodontol, 2002 Nov, 73(11), 1338 - 42
The relationship of oral malodor in patients with or without periodontal disease; Figueiredo LC et al.; BACKGROUND: Halitosis has been correlated with the concentration of volatile sulfur compounds (VSC) produced in the oral cavity by metabolic activity of bacteria colonizing the periodontal area and the dorsum of the tongue . The aim of this study was to determine whether there is some relationship between the presence of N-benzoyl-DL-arginine-2-napthylamide (BANA)-positive species Treponema denticola, Porphyromonas gingivalis, and Bacteroides forsythus and clinical and oral malodor parameters . METHODS: Twenty-one subjects (21 to 59 years old) with probing depths (PD) > 3.0 mm and 20 subjects (21 to 63 years old) with PD < or = 3.0 mm (controls) participated . The quality of the mouth air was assessed organoleptically, and a portable sulfide monitor was used to measure the concentration of VSC . Clinical parameters, plaque index (PI) and gingival index (GI), were obtained from 6 teeth . Samples for BANA test were taken from the dorsal surface of the tongue, saliva, and the 6 reference teeth . RESULTS: The scores of PI, GI, subgingival samples that tested positive for BANA hydrolyzing species, organoleptic ratings, and VSC values were significantly higher in the subjects with PD > 3.0 mm (P < 0.01, Mann-Whitney U test) . There was a correlation between BANA hydrolysis by subgingival plaque bacteria and VSC values (r = 0.55, P < 0.01), and between GI and VSC values (r = 0.48, P < 0.05) in patients with PD > 3.0 mm . There was no significant correlation between these parameters in the control group . CONCLUSION: These results confirm that the BANA hydrolyzing bacteria in the subgingival plaque are an important source of malodor production in the oral cavity.

J Periodontol, 2002 Nov, 73(11), 1253 - 9
Microbiological markers for prediction and assessment of treatment outcome following non-surgical periodontal therapy; Fujise O et al.; BACKGROUND: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus are considered major putative periodontal pathogens . However, it remains unclear what combinations or what levels of these bacteria influence treatment outcome . The purpose of the present study was to establish useful pathogenic markers for prediction and assessment of treatment outcome following scaling and root planing (SRP) . METHODS: A total of 1,149 sites in 104 chronic periodontitis patients were clinically examined at baseline . Three months after SRP, 606 sites in 56 of these patients were reexamined . Subgingival plaque samples taken from the examined sites at baseline and 3 months were analyzed for the detection and quantification of A . actinomycetemcomitans, P . gingivalis, and B . forsythus using a colorimetric polymerase chain reaction technique . RESULTS: At baseline, high levels and a combination of P . gingivalis and B . forsythus were frequently detected in diseased sites (74%) . SRP reduced the levels and the coexistence of P . gingivalis and B . forsythus (from 75% to 43%) . However, in treated sites where there was less reduction of probing depth (<2 mm), or where bleeding on probing (BOP) or suppuration was detected, residual coexistence of P . gingivalis and B . forsythus and a high level of P . gingivalis after SRP were significantly more frequent . Furthermore, SRP did not improve BOP at sites exhibiting initially high levels of A . actinomycetemcomitans . CONCLUSIONS: These results suggest that the combination of P . gingivalis and B . forsythus, as well as the level of P . gingivalis, is useful in assessing treatment outcome . Furthermore, the high level of A . actinomycetemcomitans before SRP is a possible valuable predictor of treatment outcome.

Water Sci Technol, 2002, 46(10), 189 - 94
Evaluation of bacteriophages during the treatment of sludge; Mignotte-Cadiergues B et al.; The aim of this work was to determine the effect of liming and composting on the fate of three bacteriophages (somatic coliphages, F-RNA phages, Bacteroides fragilis phages) considered as potential indicators of viral contamination . It was shown that the three bacteriophages studied exhibited variable densities in sludge . Somatic coliphages were most abundant (10(4) to 10(5) x 10 g(-1) DM) then F-RNA bacteriophages (10(2) to 10(4) x 10 g(-1) DM) and Bacteroides fragilis phages (10(1) to 10(2) x 10 g(-1) DM) . The efficacy of liming was found to be pH dependent but also sludge dependent . The pH allowing 99% elimination of somatic coliphage is close to 9 for solid sludges and close to 13.5 for liquid sludges . For composting, our findings clearly demonstrated that phage inactivation is very clearly temperature-dependent . For temperatures reaching 70 degrees, there is a 5 log reduction in somatic coliphages while for temperature in the 50-55 degrees C range, the drop off is only 2 log . Considering the efficacy of the treatment methods, it is clear that the well-established industrial procedures that reach temperatures in the 60-70 degrees C range totally inactivate all 3 phages tested and present in sludge before composting.

Mikrobiyol Bul, 2002 Jan, 36(1), 99 - 103
{Enterotoxigenic Bacteroides fragilis as a factor in diarrhea}; Durmaz B; The etiology of almost half of the diarrheal diseases has not been cleared yet, in spite of modern diagnostic methods . Bacteroides fragilis strains which secrete an enterotoxin are termed as enterotoxigenic B.fragilis (ETBF) . These strains are associated with diarrheal diseases in children above 1 year of age and in adults . B . fragilis toxin (BFT) stimulates intestinal secretion and in-vitro cytotoxic response in HT29/C1 cells . Recent studies suggest that BFT is related to inflammatory bowel disease and colon cancer by triggering nuclear activation with potential oncogene expression . In this review, the molecular pathogenesis, epidemiology and laboratory diagnosis of ETBF have been reviewed to focus on ETBF as a diarrheal agent.

J Clin Periodontol, 2002 Nov, 29(11), 1023 - 8
Porphyromonas gingivalis, Bacteroides forsythus and other putative periodontal pathogens in subjects with and without periodontal destruction; van Winkelhoff AJ et al.; BACKGROUND AND AIMS: Bacteria play an essential role in the pathogenesis of destructive periodontal disease . It has been suggested that not all bacteria associated with periodontitis may be normal inhabitants of a periodontally healthy dentition . In particular, Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans have been isolated infrequently from subjects without periodontitis . The aim of the present study was to compare prevalence and proportions of a number of periodontal bacteria in periodontitis patients and control subjects . MATERIAL AND METHODS: In all, 116 consecutive subjects diagnosed with moderate to severe periodontitis (mean age 42.4) and 94 subjects without radiographic evidence of alveolar bone loss (mean age 40.4) were recruited for the study . The gingival condition in the control group varied between gingival health and various degrees of gingivitis . In patients, the deepest pocket in each quadrant was selected for microbiological sampling . In control subjects all mesial and distal sites of all first molars were selected for sampling . All paper points from a patient were pooled and processed for anaerobic cultivation within 6 h after sampling . Clinical variables of sampled sites included bleeding index, probing pocket depth and clinical attachment level . RESULTS: A . actinomycetemcomitans, P . gingivalis, Prevotella intermedia, Bacteroides forsythus, Fusobacterium nucleatum and Peptostreptococcus micros were significantly more often prevalent in patients than in controls . The highest odds ratios were found for P . gingivalis and B . forsythus (12.3 and 10.4 resp.) . Other odds ratios varied from 3.1 to 7.7 for A . actinomycetemcomitans and P . micros, respectively . Absolute numbers of target bacteria were all higher in patients, but only the mean percentage of B . forsythus was significantly higher in patients in comparison to controls (P < 0.001) . CONCLUSIONS:A . actinomycetemcomitans, P . gingivalis, P . intermedia, B . forsythus, F . nucleatum and P . micros are all significant markers for destructive periodontal disease in adult subjects . Based on calculated odds ratios, B . forsythus and P . gingivalis are the strongest bacterial markers for this disease and are infrequently cultured from subjects without periodontal bone loss.

J Med Microbiol, 2002 Dec, 51(12), 1090 - 6
Comparison of 16S rDNA-based PCR and checkerboard DNA-DNA hybridisation for detection of selected endodontic pathogens; Siqueira JF et al.; Molecular methods have been used recently to investigate the bacteria encountered in human endodontic infections . The aim of the present study was to compare the ability of a 16S rDNA-based PCR assay and checkerboard DNA-DNA hybridisation in detecting Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Peptostreptococcus micros, Porphyromonas endodontalis, Por . gingivalis and Treponema denticola directly from clinical samples . Specimens were obtained from 50 cases of endodontic infections and the presence of the target species was investigated by whole genomic DNA probes and checkerboard DNA-DNA hybridisation or taxon-specific oligonucleotides with PCR assay . Prevalence of the target species was based on data obtained by each method . The sensitivity and specificity of each molecular method was compared with the data generated by the other method as the reference--a value of 1.0 representing total agreement with the chosen standard . The methods were also compared with regard to the prevalence values for each target species . Regardless of the detection method used, T . denticola, Por . gingivalis, Por . endodontalis and B . forsythus were the most prevalent species . If the checkerboard data for these four species were used as the reference, PCR detection sensitivities ranged from 0.53 to 1.0, and specificities from 0.5 to 0.88, depending on the target bacterial species . When PCR data for the same species were used as the reference, the detection sensitivities for the checkerboard method ranged from 0.17 to 0.73, and specificities from 0.75 to 1.0 . Accuracy values ranged from 0.6 to 0.74 . On the whole, matching results between the two molecular methods ranged from 60% to 97.5%, depending on the target species . The major discrepancies between the methods comprised a number of PCR-positive but checkerboard-negative results . Significantly higher prevalence figures for Por . endodontalis and T . denticola were observed after PCR assessment . There was no further significant difference between the methods with regard to detection of the other target species.

J Clin Microbiol, 2002 Dec, 40(12), 4423 - 7
Quantification of bacteria adherent to gastrointestinal mucosa by real-time PCR; Huijsdens XW et al.; The use of real-time quantitative PCR (5' nuclease PCR assay) as a tool to study the gastrointestinal microflora that adheres to the colonic mucosa was evaluated . We developed primers and probes based on the 16S ribosomal DNA gene sequences for the detection of Escherichia coli and Bacteroides vulgatus . DNA was isolated from pure cultures and from gut biopsy specimens and quantified by the 5' nuclease PCR assay . The assay showed a very high sensitivity: as little as 1 CFU of E . coli and 9 CFU of B . vulgatus could be detected . The specificities of the primer-probe combinations were evaluated with samples that were spiked with the species most closely related to E . coli and B . vulgatus and with eight other gut microflora species . Mucosal samples spiked with known amounts of E . coli or B . vulgatus DNA showed no PCR inhibition . We conclude that the 5' nuclease PCR assay may be a useful alternative to conventional culture techniques to study the actual in vivo composition of a complex microbial community like the gut microflora.

Mol Microbiol, 2002 Dec, 46(5), 1239 - 46
Characterization of Exc, a novel protein required for the excision of Bacteroides conjugative transposon; Sutanto Y et al.; Conjugative transposons are integrated elements that excise from the chromosome, then transfer by conjugation to a recipient in which they integrate once again . Recently, a gene, designated exc, was shown to be essential for excision of the Bacteroides conjugative transposon (CTnDOT) from the chromosome . The deduced amino acid sequence of Exc had low amino acid sequence similarity to DNA topoisomerase III, an enzyme that relaxes DNA supercoils . This similarity raised the question of whether Exc protein was a topoisomerase and, if so, whether topoisomerase activity might contribute to the excision process . Here, we demonstrate that Exc does have topoisomerase activity in vitro . Exc relaxed supercoiled DNA, had a conserved tyrosine as its active site and required magnesium ions for its relaxation activity . However, although mutation of the catalytic tyrosine of Exc to phenylalanine abolished the ability of the enzyme to relax DNA supercoils in vitro, the mutation did not abolish the ability of the protein to mediate excision in vivo . This surprising result suggests that CTnDOT excision does not rely on the topoisomerase activity of Exc in vivo.

Appl Environ Microbiol, 2002 Dec, 68(12), 6421 - 4
Competitive PCR for quantitation of a Cytophaga-Flexibacter-Bacteroides phylum bacterium associated with the Tuber borchii Vittad . mycelium; Barbieri E et al.; An uncultured bacterium associated with the ectomycorrhizal fungus Tuber borchii Vittad . was identified as a novel member of the Cytophaga-Flexibacter-Bacteroides group . Utilizing a quantitative PCR targeting the 16S rRNA gene, we relatively quantified this bacterium in the host . The estimated number of bacteria was found to be approximately 10(6) cells per 30-day-old T . borchii mycelium culture . This represents the first molecular attempt to enumerate an uncultured bacterium associated with a mycorrhizal fungus.

Antimicrob Agents Chemother, 2002 Dec, 46(12), 3712 - 8
Effect of a single percutaneous abscess drainage puncture and imipenem therapy, alone or in combination, in treatment of mixed-infection abscesses in mice; Stearne LE et al.; The importance of supplementary imipenem therapy after a single percutaneous abscess drainage puncture was studied in a mouse model of established mixed-infection abscesses . Animals were treated for 3 days with daily dosing regimens of 384 to 1,536 mg/kg of body weight that took into account the short half-life of this antibiotic in mice . Imipenem therapy in conjunction with abscess drainage was significantly better than drainage alone in reducing the Escherichia coli and Bacteroides fragilis counts in the mixed infections . Furthermore, the killing of B . fragilis by the combination of imipenem therapy and abscess drainage was significantly better than that by imipenem treatment alone . The maximum reductions in E . coli and B . fragilis counts were 1.1 and 2.2 log(10) CFU/abscess, respectively . In contrast, the in vitro activity of imipenem was significantly better (maximum reduction, > or =6.2 log(10) CFU/ml) against mixed cultures of the same strains even when bacterial numbers similar to those found in the abscesses were used . Comparable in vivo activity was achieved only when treatment was started 30 min before inoculation (reduction for both strains, > or =6.1 log(10) CFU/abscess), but this killing was significantly diminished if the start of treatment was delayed until > or =12 h after inoculation . Imipenem concentrations in abscess tissue reached levels above the MIC for E . coli for >60% of the dosing interval . Possible reasons for the reduced activity of imipenem in vivo are discussed, and we conclude that standard susceptibility tests overestimate the efficacy of this antibiotic against the organisms present in these abscesses.

Proc Natl Acad Sci U S A, 2002 Nov 26, 99(24), 15451 - 5 Epub 2002 Nov 13.
Developmental regulation of intestinal angiogenesis by indigenous microbes via Paneth cells; Stappenbeck TS et al.; The adult mouse intestine contains an intricate vascular network . The factors that control development of this network are poorly understood . Quantitative three-dimensional imaging studies revealed that a plexus of branched interconnected vessels developed in small intestinal villi during the period of postnatal development that coincides with assembly of a complex society of indigenous gut microorganisms (microbiota) . To investigate the impact of this environmental transition on vascular development, we compared the capillary networks of germ-free mice with those of ex-germ-free animals colonized during or after completion of postnatal gut development . Adult germ-free mice had arrested capillary network formation . The developmental program can be restarted and completed within 10 days after colonization with a complete microbiota harvested from conventionally raised mice, or with Bacteroides thetaiotaomicron, a prominent inhabitant of the normal mouse/human gut . Paneth cells in the intestinal epithelium secrete antibacterial peptides that affect luminal microbial ecology . Comparisons of germ-free and B . thetaiotaomicron-colonized transgenic mice lacking Paneth cells established that microbial regulation of angiogenesis depends on this lineage . These findings reveal a previously unappreciated mechanism of postnatal animal development, where microbes colonizing a mucosal surface are assigned responsibility for regulating elaboration of the underlying microvasculature by signaling through a bacteria-sensing epithelial cell.

Int J Antimicrob Agents, 2002 Nov, 20(5), 366 - 74
Antianaerobic activity of moxifloxacin compared with that of ofloxacin, ciprofloxacin, clindamycin, metronidazole and beta-lactams; Behra-Miellet J et al.; Minimal inhibitory concentrations of moxifloxacin were compared with those of ofloxacin, ciprofloxacin, clindamycin, metronidazole and six beta-lactams for 159 anaerobes isolated from human clinical samples . Unlike other fluoroquinolones, moxifloxacin demonstrated high activity against the 76 strains of the Bacteroides fragilis group as the minimal inhibitory concentration(50) was 0.5 mg/l . Porphyromonas, Prevotella, Fusobacterium and Gram-positive anaerobic cocci were inhibited by 1 mg/l or less of moxifloxacin . It inhibited 93.7, 94.9 and 98% of the 159 strains investigated at concentrations of 1, 2 and 4 mg/l, respectively . Moxifloxacin was more potent than ofloxacin and ciprofloxacin against Gram-positive rods and anaerobic cocci . Its broad anaerobic spectrum in vitro is promising for the treatment of intra-abdominal and respiratory infections.

Syst Appl Microbiol, 2002 Oct, 25(3), 416 - 22
Persistence and functional impact of a microbial inoculant on native microbial community structure, nutrient digestion and fermentation characteristics in a rumen model; Ziemer CJ et al.; Small sub-unit (SSU) rRNA-targeted oligonucleotide probes were used to monitor the persistence of a genetically engineered bacterium inoculated in model rumens . Eight dual flow continuous culture fermenters were operated with either standard artificial saliva buffer or buffer with chondroitin sulfate (0.5 g/l) added . After 168 h of operation, fermenters were inoculated with Bacteroides thetaiotaomicron BTX (BTX), at approximately 1% of total bacteria . B . thetaiotaomicron was quantified using a species-specific probe and shown to persist in fermenters 144 h after inoculation (relative abundance 0.48% and 1.42% of total SSU rRNA with standard and chondroitin sulfate buffers, respectively) . No B . thetaiotaomicron SSU rRNA was detected in fermenter samples prior to inoculation with strain BTX . Relative abundances of Bacteria, Eucarya and Archaea were not affected by either inoculation or buffer type . Fiber digestion, in particular the hemicellulose fraction, increased after strain BTX addition . Chondroitin sulfate addition to the buffer increased bacterial nitrogen flow in fermenters, but did not alter fiber digestion . Neither inoculum nor buffer type altered total short chain fatty acid (VFA) concentrations but proportions of individual VFA differed . In model rumens, B . thetaiotaomicron BTX increased fiber digestion when added to mixed ruminal microbes, independent of chondroitin sulfate addition; but further study is needed to determine effects on other fiber-digesting bacteria.

J Med Liban, 2001 Jul-Aug, 49(4), 228 - 30
Isolated septic arthritis of a lumbar facet joint; Abi Karam G et al.; This is a report of an isolated septic arthritis of a lumbar facet joint where the infectious agent was Bacteroides sp . and where an early diagnosis was made using MRI.

J Clin Microbiol, 2002 Nov, 40(11), 4349 - 52
In vitro susceptibilities of the Bacteroides fragilis group species: change in isolation rates significantly affects overall susceptibility data; Aldridge KE et al.; A comparison of antimicrobial susceptibility data of species of the Bacteroides fragilis group for 1989-1990 and 1998-1999 studies showed statistically significant increases or decreases in in vitro activity . Overall significant increases in resistance were noted for ampicillin-sulbactam and clindamycin, while significant decreases in resistance were noted for ertapenem and cefoxitin . Susceptibilities to piperacillin-tazobactam, imipenem, meropenem, and trovafloxacin remained virtually the same for the two studies . Importantly, a change in the rates of isolation of the various species showed the B . fragilis species comprised 58% of the isolates in 1989 to 1990 and 45% of the isolates in 1998 to 1999 . This change in rates of isolation of B . fragilis versus non-B . fragilis species had an overall effect on susceptibility data.

J Comput Chem, 2002 Dec, 23(16), 1587 - 600
Molecular dynamics simulations of the dinuclear zinc-beta-lactamase from Bacteroides fragilis complexed with imipenem; Suarez D et al.; Herein, we present results from MD simulations of the Michaelis complex formed between the dizinc beta-lactamase from B . fragilis and imipenem . We considered two catalytically important configurations, which differ in the presence or absence of a hydroxide bridge connecting the two zinc ions in the active site . The structural and dynamical effects induced by substrate binding, the specific roles of the conserved residues and the zinc-bound water molecules, the near attack conformers of the Michaelis complex, and so forth, are discussed in detail . The relative stability of the two configurations was estimated from QM linear scaling calculations on the enzyme-substrate complex combined with Poisson-Boltzmann electrostatic calculations and normal mode calculations . Importantly, we find that the two configurations have similar energies, indicating that these two structures could readily be interchanged, thereby facilitating catalysis . The configuration with the hydroxide bound to the two zinc ions is predicted to be the resting form of the enzyme, while the configuration without the bridge is the reactive form that was found to place the hydroxide in position to attack the carbonyl of the beta-lactam ring . Thus, we propose that the enzyme initiates catalysis by converting from the hydroxide bridge form into the configuration that lacks the hydroxide bridge . This interconversion increases the nucleophilicity of the hydroxide ion and exposes it to the beta-lactam carbonyl, which ultimately facilitates nucleophilic attack . The implications of the observed modes of binding, the possible influence of mutating the Lys184 and Asn193 residues on substrate binding, and the reaction mechanism are also discussed in detail .

J Virol Methods, 2002 Dec, 106(2), 215 - 24
Conservation of phage reference materials and water samples containing bacteriophages of enteric bacteria; Mendez J et al.; The survival was determined in different conservation conditions of: somatic coliphages, F-specific RNA bacteriophages and phages infecting Bacteroides fragilis proposed as model micro-organisms for water quality control . Titres of phages of all groups either in pure culture phage suspensions or in naturally occurring phage suspensions were stable at (-70+/-10) degrees C and at (-20+/-5) degrees C when protected with glycerol . Moreover, phage analysis of stored suspensions demonstrated that their numbers were homogeneous, both between vials and within vials, and consequently they can be used as reference materials . Furthermore, changes in the storage temperature of the vials cause unpredictable changes in the numbers of bacteriophages . Consequently, phage reference materials and samples containing a quantitative number of phages must be maintained and dispatched at a constant temperature . Consequently, the results indicate that bacteriophages should be packed in dry ice during transport and storage . Finally, the number of phages in water samples stored at (5+/-3) degrees C in the dark does not decrease significantly during the first 72 h of storage . In addition, phage concentrates from natural samples obtained by adsorption-elution to cellulose nitrate filters and mixed with 10% glycerol were stable at least for 2 months at (-70+/-10) degrees C and at (-20+/-5) degrees C .

Obstet Gynecol, 2002 Oct, 100(4), 759 - 64
A multiplex polymerase chain reaction-based diagnostic method for bacterial vaginosis; Obata-Yasuoka M et al.; OBJECTIVE: To develop a polymerase chain reaction (PCR)-based diagnostic method for bacterial vaginosis using bacterial vaginosis-associated anaerobes . METHODS: A multiple PCR assay was developed using primers specific to 16S ribosomal deoxyribonucleic acid (DNA) (Mobiluncus mulieris and Mobiluncus curtisii), nanH (Bacteroides fragilis), and an internal spacer region of ribosomal DNA (Gardnerella vaginalis) . The vaginal swabs from pregnant and nonpregnant women were examined by Gram stain-based Nugent scoring system . One hundred seventy-two samples of 853 Gram stain-interpretable samples were randomly selected and subjected to multiplex PCR assay . RESULTS: The sensitivity of the PCR assay ranged from 10 to 10 colony-forming units per vaginal swab . The prevalence of the bacterial vaginosis, intermediate, and normal categories was found by Nugent scoring system to be 21.6% (184/853), 26.0% (222/853), and 52.4% (447/853), respectively . By the multiplex PCR-based diagnostic method, 20.3% (35/172) of the samples were identified as bacterial vaginosis . The diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of multiplex PCR in comparison with Gram stain examination were 78.4% (95% confidence interval {CI} 65.1%, 91.6%), 95.6% (95% CI 92.1%, 99.0%), 82.9% (95% CI 70.4%, 95.4%), and 94.2% (95% CI 90.3%, 98.1%), respectively . CONCLUSION: This multiplex PCR can be used as a diagnostic or screening test for bacterial vaginosis.

Int J Oral Maxillofac Implants, 2002 Sep-Oct, 17(5), 696 - 702
Transmission of periodontal disease-associated bacteria from teeth to osseointegrated implant regions; Sumida S et al.; PURPOSE: The presence of periodontopathic bacteria is a risk factor for peri-implantitis . The present study examined colonization by periodontopathic bacteria and their transmission from periodontal pockets to osseointegrated implant sulcus . MATERIALS AND METHODS: Plaque samples were collected from 105 sites in the 15 patients who participated in the study . Colonization by these bacteria was examined by polymerase chain reaction (PCR) and culture . The transmission of periodontopathic bacteria from periodontal sites of natural teeth to the implant sulcus was analyzed by pulsed field gel electrophoresis (PFGE) . RESULTS: The PCR detection rates of Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, and Treponema denticola were 80.0%, 53.3%, 46.7%, 60.0% and 40.0%, respectively . Colonizations by P gingivalis and A actinomycetemcomitans were statistically correlated with periodontal pockets and implant sulcus regions (P < .01) . The PFGE patterns of the P gingivalis strains isolated from each patient were identical, but differed from those from other patients . The PFGE patterns of P intermedia strains were identical in 2 out of 3 patients . DISCUSSION: These analyses indicated that there appeared to be transmission of P gingivalis and P intermedia from the periodontal pocket to the peri-implant region . CONCLUSION: Elimination of these periodontal pathogens from the patient's oral cavity before administering dental implant treatment may inhibit colonization by these pathogens and reduce the risk of peri-implantitis.

Appl Environ Microbiol, 2002 Oct, 68(10), 5142 - 50
Succession of bacterial community structure along the Changjiang River determined by denaturing gradient gel electrophoresis and clone library analysis; Sekiguchi H et al.; Bacterial community structure along the Changjiang River (which is more than 2,500 km long) was studied by using denaturing gradient gel electrophoresis (DGGE) and clone library analysis of PCR-amplified 16S ribosomal DNA (rDNA) with universal bacterial primer sets . DGGE profiles and principal-component analysis (PCA) demonstrated that the bacterial community gradually changed from upstream to downstream in both 1998 and 1999 . Bacterial diversity, as determined by the Shannon index (H'), gradually decreased from upstream to downstream . The PCA plots revealed that the differences in the bacterial communities among riverine stations were not appreciable compared with the differences in two adjacent lakes, Lake Dongting and Lake Poyang . The relative stability of the bacterial communities at the riverine stations was probably due to the buffering action of the large amount of water flowing down the river . Clone library analysis of 16S rDNA revealed that the dominant bacterial groups changed from beta-proteobacteria and the Cytophaga-Flexibacter-Bacteroides group upstream to high-G+C-content gram-positive bacteria downstream and also that the bacterial community structure differed among the stations in the river and the lakes . The results obtained in this study should provide a reference for future changes caused by construction of the Three Gorges Dam.

Clin Exp Immunol, 2002 Oct, 130(1), 59 - 66
Nuclear factor-kappa B activation pathway in intestinal epithelial cells is a major regulator of chemokine gene expression and neutrophil migration induced by Bacteroides fragilis enterotoxin; Kim JM et al.; Although intestinal epithelial cells are known to up-regulate the expression of several chemokine genes in response to the stimulation with B . fragilis enterotoxin (BFT), there has been little understanding on the cellular mechanisms of BFT-induced mucosal inflammation . To test whether nuclear transcriptional factor-kappa B (NF-kappaB) is involved in the process, we stimulated intestinal epithelial cells with BFT, and evaluated the signalling NF-kappaB pathways . BFT increased signals of NF-kappaB in HT-29 and T84 epithelial cell lines as well as primary human colon epithelial cells . NF-kappaB molecules activated by BFT stimulation were composed of p65 and p50 heterodimers . In contrast, BFT decreased the signals of IkappaBalpha and IkappaB epsilon, as assessed by immunoblot . Super-repressors of IkappaBalpha, IkappaB kinase (IKK)beta, and NF-kappaB inducing kinase (NIK) inhibited an up-regulated transcription of downstream target gene (CXCL8) of NF-kappaB . Moreover, blocking the activation of NF-kappaB by MG-132 or antisense p50 oligonucleotide transfection resulted in down-regulated expression of chemokines such as CXCL1, CXCL8, and CCL2 in BFT-stimulated HT-29 cells . In addition, NF-kappaB inhibition suppressed the BFT-induced neutrophil transepithelial migration in T84 cells . These results indicate that NF-kappaB can be a central regulator of chemokine gene expression in BFT-stimulated intestinal epithelial cells and may be an important regulator of neutrophil migration.

Invest Med Int, 1985, 11(4), 211 - 4
{Open comparative study between the combination clyndamicin/gentamycin and penicillin/gentamycin in septic abortion}; French AR et al.; PIP: Septic abortion is not uncommon in countries where abortion is illegal, and antibiotics are second only to uterine evacuation in the treatment of such cases . Although the combination of penicillin and gentamycin has given excellent results, the high incidence of Bacteroides fragilis and other anerobics in septic abortion prompted a comparison of penicillin and gentamycin with clindamycin and gentamycin at the Hospital Santo Tomas in Panama City, Panama, beginning in May 1984 . Among 30 febrile patients with diagnoses of septic abortion, 14 were treated with penicillin/gentamycin and 16 with clindamycin/gentamycin . The penicillin group ranged in age from 17-29 with an average age of 21.9, while the clindamycin group ranged from 18-32 years with an average of 24.3 . The average gestational ages were 10.2 weeks for the penicillin group and 10.7 for the clindamycin group . The average body temperature of both groups was 38.9 degrees Celsius . 1 patient had a blood pressure of 80/60 without clinical evidence of shock . The average duration of fever was 43 hours in the penicillin group and 40.6 hours in the clindamycin group . The hospital stay ranged from 3-7 days with an average of 5.4 in the penicillin group and from 3-6 days with an average of 4.2 in the clindamycin group . Patients recovered rapidly after uterine curettage and initiation of antibiotic therapy . Bacteremia was not detected in any patient . Tolerance to the drugs was similar in both groups .

Spec Care Dentist, 2002 May-Jun, 22(3), 115 - 20
Clinical and microbiological analysis of periodontally diseased sites after renal transplant; Vieira ML et al.; This study compared the clinical and microbiological status of periodontally diseased sites in 42 patients who had a renal transplant and were undergoing immunosuppressive therapy (21 taking azathioprin and corticosteroids {Az-C} and 21 taking cyclosporin-A {Cy-A} with those of 21 systemically healthy matched controls . Probing pocket depth (PPD), bleeding on probing (BOP) and gingival hyperplasia (GH) were measured at 339 sites . Subgingival plaque samples were analyzed for the presence of Porphyromonas gingivalis, Treponema denticola and/or Bacteroides forsythus using the BANA test . Our findings suggest that immunosuppressed patients showed significantly less inflammation and fewer putative anaerobic pathogens using the BANA test, and that patients undergoing therapy with cyclosporin-A have a higher frequency of sites with gingival hyperplasia when compared with patients medicated with azathioprin or corticosteroids.

Res Microbiol, 2002 Jul-Aug, 153(6), 333 - 8
Limited selection of sodium channel blocking toxin-producing bacteria from paralytic shellfish toxin-contaminated mussels (Aulacomya ater); Vasquez M et al.; Paralytic shellfish toxins (PSTs) are sodium channel blocking (SCB) toxins, produced by cyanobacteria, as well as by marine dinoflagellates and their associated bacteria, and cause serious health and economic concern worldwide . In a previous study, approximately 70% of the bacteria enriched from PST-contaminated shellfish tissue and isolated on marine agar medium were observed to produce SCB toxins . In the study reported here, the high percentage of cultivable toxigenic bacteria is demonstrated to be obtained through a marked selection on marine agar medium . The cultivable as well as the total bacterial diversity associated with PST-contaminated shellfish collected from the Magallanes region in the south of Chile has been analysed . Approximately 80% of bacterial isolates, analysed by restriction analysis of PCR amplified ribosomal DNA (i.e., ARDRA fingerprinting), were limited to only two genotypic OTUs (operational taxonomic unit) . Sequence determination and analysis of the 16S rDNA from representative isolates of both OTUs established them to be closely related to species of the Psychrobacter genus of the gamma-subclass of the Proteobacteria . The total bacterial diversity in the shellfish was further analysed, using a cultivation-independent strategy of extraction of total DNA from contaminated tissue, PCR-amplification of bacterial 16S rRNA genes, cloning of the PCR products and analysis of the cloned 16S rDNA sequence types by fingerprinting and sequencing . Only 2% of the cloned sequence types corresponded to species of the Psychrobacter genus . The 16S rDNA sequence types detected clustered with species of the y-Proteobacteria subclass, the Cytophaga-Flexibacter-Bacteroides (CFB), the Fusobacteria and the Firmicutes phyla . The level of diversity observed within the libraries of cloned 16S rDNA was markedly greater than that observed among isolates obtained through marine agar enrichment cultures from the same shellfish tissue . Additionally the predominant cloned 16S rDNA sequence types detected from samples of the surrounding seawater demonstrated no correlation with those observed in the PST-contaminated mussels.

Antimicrob Agents Chemother, 2002 Oct, 46(10), 3276 - 9
In vitro activities of newer quinolones against bacteroides group organisms; Snydman DR et al.; The activities of BMS-284576, clinafloxacin, moxifloxacin, sitafloxacin, trovafloxacin, imipenem, cefoxitin, and clindamycin against 589 Bacteroides fragilis group isolates were determined . The activity of BMS-284576 was comparable to that of trovafloxacin . Sitafloxacin and clinafloxacin were the most active quinolones, and moxifloxacin was the least active . B . fragilis was the most susceptible of the species, and Bacteroides vulgatus was the most resistant . Association of specific antibiotic resistance with Bacteroides species was noted for all quinolones.

J Microbiol Methods, 2002 Nov, 51(3), 273 - 82
Evaluation of methods to solubilize and analyze cell-associated ectoenzymes; Konopka A et al.; To quantify the functional diversity of microbes that use hydrolytic ectoenzymes, the feasibility of separating cell-associated proteins on polyacrylamide gels and detecting enzyme activity via fluorescent substrate analogs for aminopeptidases, glucosidases, and esterases was determined . More than 87% of aminopeptidase activity was associated with particulate cell material in all of the 10 Gram-negative bacterial strains that were investigated . Although 7-amino-4-methylcoumarin-leucine (AMC-leucine) provided high activities after incubation with eight strains from the Cytophaga-Flexibacter-Bacteroides group, very poor responses were noted with two gamma Proteobacteria that grew well on protein . Therefore, this molecule was not a universal substrate for aminopeptidases . Methods of increasing stringency were evaluated to release enzyme activity from particulate material . Some methods (treatment with 0.1% Triton X-100) gave good results with some but not all strains . Cell lysis by shearing produced the most consistent results . Ectoenzyme activities could be localized on polyacrylamide gels using fluorescent substrate analogs . However, some activities were located in high molecular weight complexes, and methods that disrupted these complexes (such as treatment with sodium dodecyl sulfate at elevated temperature) destroyed enzyme activity . In addition, the enzymes from different strains showed the same electrophoretic mobility . Therefore, the analysis of functional diversity by this approach is limited by the difficulty in solubilizing particulate enzymes under conditions where they retain activity .

Antimicrob Agents Chemother, 2002 Sep, 46(9), 2908 - 13
High incidence of cefoxitin and clindamycin resistance among anaerobes in Taiwan; Teng LJ et al.; Susceptibilities to 16 antimicrobial agents were determined by measurement of MICs for 344 isolates of anaerobic bacteria recovered from patients with significant infections . Resistance rates varied among antimicrobial agents and the species tested . The beta-lactams were more active in gram-positive than in gram-negative anaerobes . Resistance to meropenem was low (<1%) . For beta-lactam-beta-lactamase inhibitors, piperacillin-tazobactam was most active for all species (resistance, <6%) . The rates of resistance to cefoxitin (31 to 65%) and clindamycin (50 to 70%) for non-Bacteroides fragilis species of the B . fragilis group were higher than those for B . fragilis (4% resistant to cefoxitin and 33% resistant to clindamycin) . Among members of B . fragilis group, Bacteroides thetaiotaomicron was the most resistant to clindamycin (70%) and cefoxitin (65%) . Rates of susceptibility to imipenem and metronidazole for B . fragilis continue to be high compared to those from a previous study 10 years ago . However, resistance to metronidazole was found recently in five strains of B . fragilis . We analyzed the genetic relationships among the metronidazole-resistant B . fragilis strains by pulsed-field gel electrophoresis . The metronidazole-resistant B . fragilis strains showed genotypic heterogeneity, excluding the dissemination of a single clone.

Mol Microbiol, 2002 Aug, 45(4), 1067 - 77
Modulation of bft expression by the Bacteroides fragilis pathogenicity island and its flanking region; Franco AA et al.; To establish a recombinant system for high-level expression of biologically active Bacteroides fragilis toxin (BFT), we studied the expression of bft in non-toxigenic B . fragilis (NTBF) strains . The bft gene and the B . fragilis pathogenicity island (BfPAI) were cloned into NTBF strains with two distinct genetic patterns: (i) pattern II, strains lacking the BfPAI and its flanking region; and (ii) pattern III, strains lacking the BfPAI but containing its flanking region . Analysis of BFT activity of these recombinant strains on HT29/C1 cells showed that both the BfPAI and its flanking regions are important to optimal BFT activity . Reverse transcription polymerase chain reaction (RT-PCR) analysis indicated that the BfPAI and its flanking regions modulate bft expression . Further experiments demonstrated that the approximately 700 bp region upstream of bft is the BfPAI region critical for optimal bft expression . We conclude that both the region flanking the BfPAI and approximately 700 bp region upstream of bft are crucial to maximal BFT production by ETBF strains.

Clin Oral Implants Res, 2002 Aug, 13(4), 349 - 58
Microbiological findings and host response in patients with peri-implantitis; Hultin M et al.; The aim of the present study was to characterise microbiota and inflammatory host response around implants and teeth in patients with peri-implantitis . We included 17 partly edentulous patients with a total of 98 implants, of which 45 showed marginal bone loss of more than three fixture threads after the first year of loading . Nineteen subjects with stable marginal tissue conditions served as controls . Oral hygiene, gingival inflammation, and probing pocket depth were evaluated clinically at teeth and implants . Microbiological and crevicular fluid samples were collected from five categories of sites: 1) implants with peri-implantitis (PI), 2) stable implants (SI) in patients with both stable and peri-implantitis implants, 3) control implants (CI) in patients with stable implants alone, 4) teeth in patients (TP) and 5) controls (TC) . Crevicular fluid from teeth and implants was analysed for elastase activity, lactoferrin and IL-1 beta concentrations . Elastase activity was higher at PI than at CI in controls . Lactoferrin concentration was higher at PI than at SI in patients with peri-implantitis . Higher levels of both lactoferrin and elastase activity were found at PI than at teeth in patients . The concentrations of IL-1 beta were about the same in the various sites . Microbiological DNA-probe analysis revealed a putative periodontal microflora at teeth and implants in patients and controls . Patients with peri-implantitis harboured high levels of periodontal pathogens, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus and Treponema denticola . These findings indicate a site-specific inflammation rather than a patient-associated specific host response.

New Microbiol, 2002 Jul, 25(3), 345 - 50
Peritoneal infection: a possible redox disease; Goldner M et al.; In a recent report, pertaining to Bacteroidesfragilis peritonitis, the influence of oxidation-reduction (redox) potential provided experimental evidence for B . fragilis penetration into Hela cell monolayers (using 3D imaging techniques) . Bacteria grown under oxidizing conditions (+mV redox) penetrated into tissue cells unlike that of reducing conditions (-mV redox) . The present results emphasise the significance of the level of redox potential during infection with an interpretation based on anaerobe/aerobe environmental flux, triggering the invasive mechanism.

Clin Infect Dis, 2002 Sep 1, 35(Suppl 1), S126 - 34
National survey on the susceptibility of Bacteroides Fragilis Group: report and analysis of trends for 1997-2000; Snydman DR et al.; The results of a multicenter US survey using the National Committee for Clinical Laboratory Standards currently recommended methodology for measuring in vitro susceptibility of 2673 isolates of Bacteroides fragilis group species were compared from 1997 to 2000 . The test panel consisted of 14 antibiotics: 3 carbapenems, 3 beta-lactam-beta-lactamase inhibitors, 3 cephamycins, 2 fluoroquinolones, clindamycin, chloramphenicol, and metronidazole . Declines in the geometric mean minimum inhibitory concentrations were seen with imipenem, meropenem, ampicillin-sulbactam, and the cephamycins . Increased geometric means were observed with the fluoroquinolones and were usually accompanied by an increase in resistance rates . Bacteroides distasonis shows the highest resistance rates among beta-lactam antibiotics, whereas Bacteroides vulgatus shows the highest resistance levels among fluoroquinolones . B . fragilis shows the lowest resistance rates for all antibiotics . All strains were susceptible to chloramphenicol and metronidazole concentrations <8 microgram/mL . The data underscore the need for species identification and continued surveillance to monitor resistance patterns.

Clin Infect Dis, 2002 Sep 1, 35(Suppl 1), S112 - 8
Anaerobic infections in the surgical patient: microbial etiology and therapy; Edmiston CE Jr et al.; Anaerobic infections occur in surgical patients in part because of structural or functional defects in the host that (1) cause a breech in the normal mucosal barriers, (2) create localized vascular insufficiencies, or (3) produce an obstruction . Any or all of these events may compromise the oxidation-reduction potential within the tissues, encouraging rapid anaerobic growth . Although diverse anaerobic populations are spread throughout the gastrointestinal tract, a relatively limited number of organisms are responsible for clinical infection in the surgical patient . Many of these offending organisms express overt virulence factors that enhance microbial adherence, tissue destruction, and, in the case of Bacteroides fragilis, facilitate abscess formation . The selection of an appropriate perioperative or therapeutic agent requires a fundamental knowledge of the microbial ecology of this microbial population . The failure to consider the anaerobic flora as a component in the etiology of mixed surgical infections is associated with a high rate of perioperative and therapeutic failures.

Clin Infect Dis, 2002 Sep 1, 35(Suppl 1), S106 - 11
Intra-abdominal anaerobic infections: bacteriology and therapeutic potential of newer antimicrobial carbapenem, fluoroquinolone, and desfluoroquinolone therapeutic agents; Goldstein EJ; Intra-abdominal infections are biphasic, synergistic processes with early peritonitis and bacteremia due to aerobes and a later abscess component due to anaerobes . Although Bacteroides fragilis is the most commonly recognized pathogen, other anaerobes, including other members of the B . fragilis-group species, are major components of infection . Anaerobic bacteremia is often associated with an intra-abdominal source . New antimicrobial agents with anaerobic activity are in various stages of development for the therapy of intra-abdominal infections . The in vitro activity and the currently available sparse clinical data are reviewed for a new carbapenem (ertapenem), several fluoroquinolones (trovafloxacin, moxifloxacin, and gemifloxacin), and a desfluoroquinolone (BMS-284756).

Clin Infect Dis, 2002 Sep 1, 35(Suppl 1), S65 - 71
Outer-membrane pore-forming proteins in gram-negative anaerobic bacteria; Wexler HM; The outer-membrane proteins (OMPs) of bacteria function as the dynamic interface between the bacterium and its surroundings and are involved in maintenance of cell structure, binding a variety of substances, adhesion to other cells, and regulation of transport of both nutrients and bactericidal agents . There is a vast amount of information about aerobic OMPs and their roles in immunogenicity, virulence, and antimicrobial resistance . Knowledge about OMPs in anaerobic bacteria is much sparser . Genetic data present in data banks regarding aerobic porins are not readily helpful in identifying or analyzing anaerobic porins because of the large phylogenetic distance between the aerobic and anaerobic organisms . We recently identified and sequenced the genes for both a porin protein complex and an OmpA protein in Bacteroides fragilis, and the data are summarized here . Also, recent information is presented about similar OMPs found in other gram-negative anaerobic bacteria, including Bacteroides thetaiotaomicron, Bacteroides distasonis, Porphyromonas, and Fusobacterium.

Clin Infect Dis, 2002 Sep 1, 35(Suppl 1), S47 - 53
Selection of cefoxitin-resistant bacteroides thetaiotaomicron mutants and mechanisms involved in beta-lactam resistance; Fang H et al.; The beta-lactam antibiotics are the most widely used of all the groups of antimicrobials, but beta-lactam resistance is increasingly common among members of the Bacteroides fragilis group . Three major mechanisms are involved in beta-lactam resistance, and they act together in certain instances . In the present study, 2 resistant mutants (238m and 1186m) of Bacteroides thetaiotaomicron, obtained from clinical isolates (238 and 1186) by selection with increasing concentrations of cefoxitin, showed decreased susceptibilities to cefoxitin and other beta-lactam antibiotics . Alterations in both penicillin-binding proteins (PBPs) and outer-membrane proteins (OMPs) were observed in the mutants in comparison with their parent strains . The similar alteration in OMPs was also observed in clinical isolates . In conclusion, the beta-lactam-resistant mutants of B . thetaiotaomicron with deficiency in both PBPs and OMPs can be selected for by exposure to cefoxitin, and several mechanisms are involved in the beta-lactam resistance in the strains investigated.

J Bacteriol, 2002 Sep, 184(17), 4829 - 37
Development of an in vitro integration assay for the Bacteroides conjugative transposon CTnDOT; Cheng Q et al.; Integrated self-transmissible elements called conjugative transposons (CTns) are responsible for the transfer of antibiotic resistance genes in many different species of bacteria . One of the best characterized of these newly recognized elements is the Bacteroides CTn, CTnDOT . CTnDOT is thought to have a circular transfer intermediate that transfers to and integrates into the genome of the recipient cell . Previous investigations of the mechanism of CTnDOT integration have been hindered by the lack of an in vitro system for checking this model of integration and determining whether the CTnDOT integrase alone was sufficient to catalyze the integration reaction or whether host factors might be involved . We report here the development of an in vitro system in which a plasmid containing the joined ends of CTnDOT integrates into a plasmid carrying a CTnDOT target site . To develop this in vitro system, a His-tagged version of the integrase gene of CTnDOT was cloned and shown to be active in vivo . The protein produced by this construct was partially purified and then added to a reaction mixture that contained the joined ends of the circular form of CTnDOT and a plasmid carrying one of the CTnDOT target sites . Integration was demonstrated by using a fairly simple mixture of components, but integration was stimulated by a Bacteroides extract or by purified Escherichia coli integration host factor . The results of this study demonstrate both that the circular form of CTnDOT is the form that integrates into the target site and that host factors are involved in the integration process.

J Gastroenterol, 2002, 37(7), 509 - 16
Quantitative analysis of bacterial DNA from Mycobacteria spp., Bacteroides vulgatus, and Escherichia coli in tissue samples from patients with inflammatory bowel diseases; Fujita H et al.; BACKGROUND: The etiology of inflammatory bowel diseases is unknown . Mycobacteria spp., Bacteroides vulgatus, and Escherichia coli have been suspected to be involved . The aim of the present study was to examine the possible relationship between inflammatory bowel diseases and these microbes . METHODS: We studied 45 patients; 16 with Crohn's disease, 11 with ulcerative colitis, and 18 with colon cancer as controls . We used a real-time quantitative polymerase chain reaction to detect and estimate numbers of bacterial genomes in formalin-fixed, paraffin-embedded tissue samples from the subjects . The bacteria studied were Mycobacterium tuberculosis, M . avium, M . paratuberculosis, B . vulgatus, and E . coli . Immunohistochemical staining was done to locate B . vulgatus and E . coli in tissue samples . RESULTS: The three Mycobacterium species were not detected . B . vulgatus and E . coli were detected more frequently and in greater numbers in samples from patients with inflammatory bowel diseases than in samples from control patients with colon cancer . The frequency and numbers were not related to the severity of the disease . Many bacteria of these species were found within the mucous layer, underneath erosions, in necrotic ulcer bed tissues, and in abscesses . E . coli cells were found in perivascular areas in the proper muscle layer and in germinal centers of lymph follicles . CONCLUSIONS: Our results suggest that Mycobacteria spp . are not involved in the etiology of Crohn's disease and that mucosa-associated B . vulgatus and E . coli are not a direct cause of inflammatory bowel diseases, although they may contribute to the diseases by preventing or delaying remission.

Eur J Biochem, 2002 Aug, 269(15), 3715 - 21
Structural study on lipid A and the O-specific polysaccharide of the lipopolysaccharide from a clinical isolate of Bacteroides vulgatus from a patient with Crohn's disease; Hashimoto M et al.; Bacteroides vulgatus has been shown to be involved in the aggravation of colitis . Previously, we separated two potent virulence factors, capsular polysaccharide (CPS) and lipopolysaccharide (LPS), from a clinical isolate of B . vulgatus and characterized the structure of CPS . In this study, we elucidated the structures of O-antigen polysaccharide (OPS) and lipid A in the LPS . LPS was subjected to weak acid hydrolysis to produce the lipid A fraction and polysaccharide fraction . Lipid A was isolated by preparative TLC, and its structure determined by MS and NMR to be similar to that of Bacteroides fragilis except for the number of fatty acids . The polysaccharide fraction was subjected to gel-filtration chromatography to give an OPS-rich fraction . The structure of OPS was determined by chemical analysis and NMR spectroscopy to be a polysaccharide composed of the following repeating unit: {-->4)alpha-L-Rhap(1-->3)beta-D-Manp(1-->}.

Chirurg, 2002 Jun, 73(6), 585 - 91
{Detection of periodontal pathogenic microorganisms in atheromatous plaque . Preliminary results}; Mastragelopulos N et al.; INTRODUCTION: Recent studies suggest that chronic infections, including those associated with periodontitis, increase the risk for coronary vascular disease . We hypothesize that oral microorganisms including periodontal bacterial pathogens enter the blood stream during transient bacteremias where they may play a role in the development and progression of atherosclerosis . MATERIALS AND METHODS: To test this hypothesis, 34 human specimens obtained during carotid endarterectomy or bypass procedures were examined by use of specific oligonucleotide primers for Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans and Bacteroides forsythus in polymerase chain reaction (PCR) assays . RESULTS: Twenty (59%) of the 34 specimens tested positive for bacterial 16S rDNA . Subsequent hybridization of the bacterial 16S rDNA positive specimens with species-specific oligonucleotide probes revealed that 32.4% of the 34 atheromas tested positive for at least one of the target periodontal pathogens . Further analysis of the results in the bacterial positive group (n = 20) shows that 55% of the atheromas tested positive for at least one of the target periodontal pathogens . CONCLUSION: These findings indicate that periodontal pathogens are present in atherosclerotic plaques, where they may play a role in the development and progression of atherosclerosis leading to coronary vascular disease and other clinical sequelae.

J Clin Microbiol, 2002 Aug, 40(8), 3032 - 4
Cross-infection due to imipenem-resistant Bacteroides fragilis associated with a totally implantable venous port; Arpin C et al.; Four patients in an oncology ward developed Bacteroides fragilis bacteremia over a 12-day period . Cross-infection between two of them, due to an imipenem-resistant strain, was demonstrated by epidemiological investigation and genotypic typing methods (arbitrarily primed PCR fingerprinting and nucleotide sequencing of the cfiA genes and upstream IS1186/IS1168 elements).

Nucleic Acids Res, 2002 Aug 1, 30(15), 3481 - 9
PRIMROSE: a computer program for generating and estimating the phylogenetic range of 16S rRNA oligonucleotide probes and primers in conjunction with the RDP-II database; Ashelford KE et al.; We describe PRIMROSE, a computer program for identifying 16S rRNA probes and PCR primers for use as phylogenetic and ecological tools in the identification and enumeration of bacteria . PRIMROSE is designed to use data from the Ribosomal Database Project (RDP) to find potentially useful oligonucleotides with up to two degenerate positions . The taxonomic range of these, and other existing oligonucleotides, can then be explored, allowing for the rapid identification of suitable oligonucleotides . PRIMROSE includes features to allow user-defined sequence databases to be used . An in silico trial of the program using the RDP database identified oligonucleotides that described their target taxa with a degree of accuracy far greater than that of equivalent currently used oligonucleotides . We identify oligonucleotides for subdivisions of the Proteobacteria and for the Cytophaga-Flexibacter-Bacteroides (CFB) division . These oligonucleotides describe up to 94.7% of their target taxon with fewer than 50 non-target hits, and the authors recommend that they be investigated further . A comparison with PROBE DESIGN within the ARB software package shows that PRIMROSE is capable of identifying oligonucleotides with a higher specificity . PRIMROSE has an intuitive graphical user interface and runs on the Microsoft Windows 95/NT/2000 operating systems . It is open source and is freely available from the authors.

J Biol Chem, 2002 Oct 11, 277(41), 38168 - 78 Epub 2002 Jul 24.
IKK beta and phosphatidylinositol 3-kinase/Akt participate in non-pathogenic Gram-negative enteric bacteria-induced RelA phosphorylation and NF-kappa B activation in both primary and intestinal epithelial cell lines; Haller D et al.; Pathogenic and enteroinvasive bacteria have been shown to trigger the I kappa B/NF-kappa B transcriptional system and proinflammatory gene expression in epithelial cells . In this study, we investigated the molecular mechanism of the commensal Gram-negative Bacteroides vulgatus-induced NF-kappa B signal transduction in intestinal epithelial cells (IEC) . We report that B . vulgatus induced interleukin-1 receptor-associated kinase-1 degradation, I kappa B alpha phosphorylation/degradation, RelA and Akt phosphorylation, as well as NF-kappa B DNA binding and NF-kappa B transcriptional activity in rat non-transformed IEC-6 cells . B . vulgatus- but not interleukin-1 beta-mediated NF-kappa B transcriptional activity was inhibited by dominant negative (dn) toll-like receptor 4 . Of importance, B . vulgatus induced I kappa B alpha phosphorylation/degradation and IKK alpha/beta and RelA phosphorylation in primary IEC derived from germ-free or mono-associated HLA-B27 transgenic and wild type rats, demonstrating the physiological relevance of non-pathogenic bacterial signaling in IEC . Adenoviral delivery of dn IKK beta or treatment with wortmannin inhibited B . vulgatus-induced endogenous RelA Ser-536 and GST-p65TAD (Ser-529/Ser-536) phosphorylation as well as NF-kappa B transcriptional activity in IEC-6 cells, suggesting a critical role of IKK beta and phosphatidylinositol 3-kinase/Akt in bacteria-induced RelA phosphorylation and NF-kappa B activation . Interestingly, B . vulgatus-induced I kappa B alpha degradation and NF-kappa B transcriptional activity in IEC transwell cultures were inhibited in the presence of lymphocytes . We propose that non-pathogenic B . vulgatus activates the NF-kappa B signaling pathway through both I kappa B degradation and RelA phosphorylation but that immune cells mediate tolerance of IEC to this commensal bacteria.

J Orthop Surg (Hong Kong), 2001 Dec, 9(2), 41 - 45
Septic arthritis of the hip joint in cervical cancer patients after radiotherapy: Three case reports; Yang SH et al.; Cervical cancer patients may experience hip problems related to the cancer itself or therapeutic management for the cancer . Septic arthritis should be one of the possibilities but there have been no reports on this . Here we present three patients who developed hip problems more than two years after radiotherapy with or without a radical operation . One patient was managed as septic arthritis because of significant inflammatory signs around the affected hip joint even though the causative organism was not confirmed . Succeeding total hip arthroplasty functioned well and had no recurrence of infection . The hip problems of the other two patients were diagnosed as radiation osteonecrosis of the femoral head initially . However, Bacteroides fragilis infection was found several months after total hip arthroplasties . Radiotherapy to the pelvis may damage the hip joint and compromise host-defense mechanisms of the pelvic region . Both factors may increase the possibility of infection of hip joints . Further clinical evidence is needed to understand whether subacute or chronic anaerobic infection could also be one of the causes leading to progressive destruction of the femoral head.

J Infect Chemother, 2002 Jun, 8(2), 190 - 3
In-vitro activity of ciprofloxacin combined with flomoxef against Bacteroides fragilis, compared with that of ciprofloxacin combined with clindamycin; Kato K et al.; Using checkerboard and time-kill assays, the in-vitro activity of ciprofloxacin alone and in combination with flomoxef against clinical Bacteroides fragilis strains was evaluated . In addition, the microbiological efficacy of this combination was compared with that of ciprofloxacin plus clindamycin . In 88% of the 25 strains tested, the combination of ciprofloxacin plus flomoxef exhibited a synergistic or an additive effect, whereas only 56% of the 25 strains ( P< 0.01, chi(2) test) tested with the combination of ciprofloxacin plus clindamycin exhibited similar effects . In a time-kill study using 7 clinical strains, a synergistic or additive effect of the combination of ciprofloxacin plus flomoxef was observed in all 7 strains . In conclusion, the combination of ciprofloxacin plus flomoxef is very active against B . fragilis, suggesting that this combination may be very useful in the treatment of aerobic and B . fragilis mixed infections, because ciprofloxacin has an expanded spectrum against aerobes.

J Mol Biol, 2002 Jul 19, 320(4), 899 - 908
Crystal structure of a transcarbamylase-like protein from the anaerobic bacterium Bacteroides fragilis at 2.0 A resolution; Shi D et al.; A transcarbamylase-like protein essential for arginine biosynthesis in the anaerobic bacterium Bacteroides fragilis has been purified and crystallized in space group P4(3)2(1)2 (a=b=153.4 A, c=94.8 A) . The structure was solved using a single isomorphous replacement with anomalous scattering (SIRAS) and was refined at 2.0 A resolution to an R-factor of 20.6% (R-free=25.2%) . The molecular model is trimeric and comprises 960 amino acid residues, two phosphate groups and 422 water molecules . The monomer has the consensus transcarbamylase fold with two structural domains linked by two long interdomain helices: the putative carbamoyl phosphate-binding domain and a binding domain for the second substrate . Each domain has a central parallel beta-sheet surrounded by alpha-helices and loops with alpha/beta topology . The putative carbamoyl phosphate-binding site is similar to those in ornithine transcarbamylases (OTCases) and aspartate transcarbamylases (ATCases); however, the second substrate-binding site is strikingly different . This site has several insertions and deletions, and residues critical to substrate binding and catalysis in other known transcarbamylases are not conserved . The three-dimensional structure and the fact that this protein is essential for arginine biosynthesis suggest strongly that it is a new member of the transcarbamylase family . A similar protein has been found in Xylella fastidiosa, a bacterium that infects grapes, citrus and other plants.

Int Dent J, 2002 Jun, 52 Suppl 3, 212 - 6
The relationship between the presence of periodontopathogenic bacteria in saliva and halitosis; Awano S et al.; OBJECTIVE: To evaluate the association between the presence of periodontal pathogenic bacteria in saliva and halitosis in mouth air . DESIGN: Cross-sectional microbiological and clinical oral examination of adult patients . SUBJECTS: 101 adult patients (25 males, 76 females) who attended the Preventive Dentistry and Breath Odour Clinic of Kyushu Dental College . Their average age was 50.0+/-13.5 years old (mean +/- SD) . SETTING: The subjects were classified into three groups: halitosis subjects with a probing depth (PD) > or = 4mm (P group), halitosis subjects without PD > or = 4mm (H group), and non-halitosis subjects without PD > or = 4mm (C group) . METHODS: All subjects received a periodontal examination . Volatile sulphur compounds (VSC: hydrogen sulphide and methyl mercaptan) were measured using gas chromatography . The presence of Bacteroides forsythus, Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Prevotella intermedia in the saliva was detected by polymerase chain reaction . RESULTS AND CONCLUSION: The presence of B . forsythus, P . gingivalis and P . intermedia influenced the production of VSC . Specifically, the presence of B . forsythus in subjects with periodontitis was strongly correlated to the concentration of VSC in mouth air.

J Bacteriol, 2002 Jul, 184(14), 3839 - 47
Characterization of genes involved in modulation of conjugal transfer of the Bacteroides conjugative transposon CTnDOT; Whittle G et al.; In previous studies we identified an 18-kb region of the Bacteroides conjugative transposon CTnDOT that was sufficient for mobilization of coresident plasmids and unlinked integrated elements, as well as self-transfer from Bacteroides to Escherichia coli . When this 18-kb region was cloned on a plasmid (pLYL72), the plasmid transferred itself constitutively in the absence of a coresident conjugative transposon . However, when this plasmid was present in a Bacteroides strain containing a coresident conjugative transposon, conjugal transfer was repressed in the absence of tetracycline and enhanced in the presence of tetracycline . These results suggested that a negative and a positive regulator of conjugal transfer were encoded outside the transfer region of the CTnDOT element . In this work, a minimal and inducible transfer system was constructed and used in transfer and Western blot analyses to identify the differentially regulated genes from CTnDOT responsible for the enhancement and repression of pLYL72 conjugal transfer . Both of these regulatory functions have been localized to a region of the CTnDOT element that is essential for CTn excision . In the presence of tetracycline, the regulatory protein RteC activates the expression of a putative topoisomerase gene, exc, which in turn results in an increase in transfer protein expression and a concomitant 100- to 1,000-fold increase in the frequency of pLYL72 transfer . Our results also suggest that since exc alone cannot result in enhancement of transfer, other factors encoded upstream of exc are also required . Conversely, in the absence of tetracycline, a gene located near the 3' end of exc is responsible for the repression of transfer protein expression and also results in a 100- to 1,000-fold decrease in the frequency of pLYL72 transfer.

Eur J Biochem, 2002 Jun, 269(12), 2934 - 40
Purification and characterization of novel chondroitin ABC and AC lyases from Bacteroides stercoris HJ-15, a human intestinal anaerobic bacterium; Hong SW et al.; Two novel chondroitinases, chondroitin ABC lyase (EC 4.2.2.4) and chondroitin AC lyase (EC 4.2.2.5), have been purified from Bacteroides stercoris HJ-15, which was isolated from human intestinal bacteria with glycosaminoglycan degrading enzymes . Chondroitin ABC lyase was purified to apparent homogeneity by a combination of QAE-cellulose, CM-Sephadex C-50, hydroxyapatite and Sephacryl S-300 column chromatography with a final specific activity of 45.7 micromol.min-1.mg-1 . Chondroitin AC lyase was purified to apparent homogeneity by a combination of QAE-cellulose, CM-Sephadex C-50, hydroxyapatite and phosphocellulose column chromatography with a final specific activity of 57.03 micromol.min-1.mg-1 . Chondroitin ABC lyase is a single subunit of 116 kDa by SDS/PAGE and gel filtration . Chondroitin AC lyase is composed of two identical subunits of 84 kDa by SDS/PAGE and gel filtration . Chondroitin ABC and AC lyases showed optimal activity at pH 7.0 and 40 degrees C, and 5.7-6.0 and 45-50 degrees C, respectively . Both chondroitin lyases were potently inhibited by Cu2+, Zn2+, and p-chloromercuriphenyl sulfonic acid . The purified Bacteroidal chondroitin ABC lyase acted to the greatest extent on chondroitin sulfate A (chondroitin 4-sulfate), to a lesser extent on chondroitin sulfate B (dermatan sulfate) and C (chondroitin 6-sulfate) . The purified chondroitin AC lyase acted to the greatest extent on chondroitin sulfate A, and to a lesser extent on chondroitin C and hyaluronic acid . They did not act on heparin and heparan sulfate . These findings suggest that the biochemical properties of these purified chondroitin lyases are different from those of the previously purified chondroitin lyases.

Int J Hyg Environ Health, 2002 May, 205(4), 325 - 8
Bacteroides fragilis and Escherichia coli bacteriophages in human faeces; Gantzer C et al.; Some bacteriophages found in human faeces are being evaluated as possible indicators of viral contamination of water . These bacteriophages include somatic coliphages and Bacteroides fragilis phages . The aims of this study were to determine the occurrence and concentrations of somatic coliphages and Bacteroides fragilis phages in the stools of a human population residing in eastern France (n = 193) . Somatic coliphages were detected in 68% of the stools at a mean concentration of 4.3 x 10(3) PFU.g-1 and Bacteroides fragilis phages were detected in 11% of the stools at a mean concentration of 7 x 10(1) PFU.g-1 . Statistical analysis showed no correlation between the phage concentration and the age or sex of the human subject.

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