Eur J Immunol, 2000 Mar, 30(3), 944 - 53 Dual role for macrophages in vivo in pathogenesis and control of murine Salmonella enterica var . Typhimurium infections; Wijburg OL et al.; Salmonella spp . are regarded as facultative intracellular bacterial pathogens which are found inside macrophages (Mphi) after i . v . infection . It is generally assumed that Mphi restrict the replication of the bacteria during infection . In this study we examined the in vivo activities of Mphi during experimental S . typhimurium infections, using a selective liposome-based Mphi elimination technique . Unexpectedly, elimination of Mphi prior to infection with virulent S . typhimurium decreased morbidity and mortality, suggesting that Mphi mediate the pathology caused by S . typhimurium . Removal of Mphi) during vaccination with attenuated S . typhimurium did not affect protection against challenge with virulent S . typhimurium, suggesting that Mphi are not required for the induction of protective immunity and that other cells must function as antigen-presenting cell to elicit T cell-mediated protection . However, Mphi appeared to be important effectors of protection against challenge infection since elimination of Mphi from vaccinated mice prior to challenge infection with virulent S . typhimurium significantly decreased protection . These results enhance our understanding of the control of S . typhimurium growth in vivo, and moreover suggest that Mphi play a major role in the pathology of virulent S . typhimurium infections . As such, these cells may present a novel target for therapeutic intervention. Eur J Immunol, 2000 Mar, 30(3), 768 - 77 Modulation of host immune responses stimulated by Salmonella vaccine carrier strains by using different promoters to drive the expression of the recombinant antigen; Medina E et al.; We evaluated whether immune responses stimulated by Salmonella vaccine carriers can be modulated by using different promoters to drive antigen expression . Mice were orally immunized with strains transfected with plasmids carrying beta-galactosidase (beta-gal) under the control of either a constitutive or an in vivo-activated promoter . While alpha-gal-reactive IgG1, IgG2a, IgG2b and IgG3 were detected in sera of mice immunized with Salmonella expressing constitutively beta-gal, higher titers dominated by IgG2a and IgG2b were detected in sera when the in vivo-activated promoter was used . beta-gal-specific proliferative responses of spleen-derived CD4+ T lymphocytes were similar in both groups . However, CD4+ T lymphocytes from mice immunized with the constitutive promoter secreted IL-4, IL-5, IL-6, IL-10 and IFN-gamma (Th1/Th2 pattern), whereas CD4+ cells mainly secreted IFN-gamma (Th1 pattern) when the second construct was used . The spleens of all immunized mice contained beta-gal-reactive CD8+ CTL precursors . The vaccine prototypes were tested for their capacity to control seeding and/or development within the lung of an intravenously delivered aggressive fibrosarcoma transfected with beta-gal . Reduced metastasis and significantly increased mean survival times were observed in all vaccinated mice . However, protection was improved when the carrier expressed beta-gal upon infection (80 % versus 50% survival, p < 0.05). Kansenshogaku Zasshi, 2000 Feb, 74(2), 143 - 9 Salmonella paratyphi A is more genetically homogeneous than Salmonella typhi, as indicated by pulsed-field gel electrophoresis; Matsumoto M et al.; We analyzed 18 Salmonella Paratyphi A and 12 Salmonella Typhi isolates from domestic and imported cases in Aichi, Japan, using pulsed-field gel electrophoresis . Paratyphoid fever cases have increased and outbreaks of Salmonella Paratyphi A occasionally occur in Japan, but S . Paratyphi A has not been extensively analyzed . Our study suggests significant genetic homogeneity among Salmonella Paratyphi A belonging to different phage types, which is in contrast to the genetic heterogeneity of Salmonella Typhi . These results suggest that a limited number of clones are responsible for paratyphoid fever. J Microbiol Methods, 2000 Mar, 40(1), 33 - 8 Differentiation of Salmonella enterica serotype gallinarum biotype pullorum from biotype gallinarum by analysis of phase 1 flagellin C gene (fliC); Kwon HJ et al.; Salmonella enterica serotype gallinarum biotype gallinarum and biotype pullorum are non-motile and pathogenic avian strains . Biotype gallinarum causes fowl typhoid and biotype pullorum is the cause of pullorum disease in chickens . The two biotypes could be differentiated based on biochemical characteristics . However, conventional culture and biochemical assays are time-consuming, laborious and need sterile laboratory practices . Although the two biotypes, gallinarum and pullorum are non-motile, they possess the phase 1 flagellin C gene . The variable regions of the flagellin C gene from 41 biotype pullorum and 52 biotype gallinarum were amplified by colony-PCR and analyzed by single strand conformational polymorphism (SSCP) method . Differences in SSCP electrophoretic patterns were confirmed by nucleotide sequencing . In addition, PCR-RFLP with Hinp1I was also successfully applied to differentiate the two biotypes . These results suggested that the variable regions of fliC could be used as a genetic marker to differentiate biotype gallinarum from biotype pullorum. Clin Orthop, 2000 Mar, (372), 250 - 3 Salmonella osteomyelitis secondary to iguana exposure; Nowinski RJ et al.; Salmonella osteomyelitis is a rare condition that has been associated with patients having hemoglobinopathies or immunosuppression . Healthy patients with no underlying medical history have been known to have Salmonella osteomyelitis develop . Salmonella infection secondary to reptile exposure is an increasing condition in the United States . Several manifestations of salmonellosis have been described in the literature, but no cases of reptile associated bone or joint infections have been reported . The authors present a case of a 7-month-old girl who contracted Salmonella osteomyelitis of her proximal humerus with septic arthritis of the glenohumeral joint secondary to iguana exposure. Proteins, 2000 Apr 1, 39(1), 89 - 101 Plasticity and steric strain in a parallel beta-helix: rational mutations in the P22 tailspike protein; Schuler B et al.; By means of genetic screens, a great number of mutations that affect the folding and stability of the tailspike protein from Salmonella phage P22 have been identified . Temperature-sensitive folding (tsf) mutations decrease folding yields at high temperature, but hardly affect thermal stability of the native trimeric structure when assembled at low temperature . Global suppressor (su) mutations mitigate this phenotype . Virtually all of these mutations are located in the central domain of tailspike, a large parallel beta-helix . We modified tailspike by rational single amino acid replacements at three sites in order to investigate the influence of mutations of two types: (1) mutations expected to cause a tsf phenotype by increasing the side-chain volume of a core residue, and (2) mutations in a similar structural context as two of the four known su mutations, which have been suggested to stabilize folding intermediates and the native structure by the release of backbone strain, an effect well known for residues that are primarily evolved for function and not for stability or folding of the protein . Analysis of folding yields, refolding kinetics and thermal denaturation kinetics in vitro show that the tsf phenotype can indeed be produced rationally by increasing the volume of side chains in the beta-helix core . The high-resolution crystal structure of mutant T326F proves that structural rearrangements only take place in the remarkably plastic lumen of the beta-helix, leaving the arrangement of the hydrogen-bonded backbone and thus the surface of the protein unaffected . This supports the notion that changes in the stability of an intermediate, in which the beta-helix domain is largely formed, are the essential mechanism by which tsf mutations affect tailspike folding . A rational design of su mutants, on the other hand, appears to be more difficult . The exchange of two residues in the active site expected to lead to a drastic release of steric strain neither enhanced the folding properties nor the stability of tailspike . Apparently, side-chain interactions in these cases overcompensate for backbone strain, illustrating the extreme optimization of the tailspike protein for conformational stability . The result exemplifies the view arising from the statistical analysis of the distribution of backbone dihedral angles in known three-dimensional protein structures that the adoption of straight phi/psi angles other than the most favorable ones is often caused by side-chain interactions . Proteins 2000;39:89-101 . Int J Infect Dis, 2000, 4(2), 96 - 9 Surveillance of bacterial pathogens associated with acute diarrhea in Lima, Peru; Seas C et al.; OBJECTIVES: A study was conducted in Lima, Peru, from January to April 1995, to determine the bacterial pathogens associated with acute diarrhea in adults, their susceptibility to common antimicrobials, the risk factors involved in cholera transmission, and the best clinical predictors of cholera . METHODS: A random sample of adult patients with acute diarrhea was studied . Epidemiologic and clinical data and risk factors to acquire diarrheal diseases were evaluated . Identification of bacteria and susceptibility to antimicrobials were determined . RESULTS: The study included 336 patients . Vibrio cholerae O1 (52.7%), Shigella spp . (4 . 8%), and Salmonella spp (2.7%) were the pathogens most commonly isolated . No resistance to antimicrobials was observed . Patients with cholera had less access to municipal water (P = 0.0018) and were less likely to have homes connected to a sewage system (P = 0 . 0003) or to have indoor toilet facilities (P = 0.0001) than those without cholera . Liquid stools (odds ratio {OR} = 16.51; confidence interval {CI} = 13.71-19.02; P = 0.003), severe dehydration (OR = 2 . 48; CI = 1.57-3.38; P = 0.0083), generalized cramps (OR = 4.63; CI = 3.10-6.17, P < 0.0001), and washerwoman's hands (OR = 2.45; CI = 1 . 55-3.34; P = 0.017) were the best clinical predictors of cholera in this setting . CONCLUSIONS: Cholera is still prevalent in Lima, and people living in environments with low sanitary conditions are especially at risk . Clinical signs of severe dehydration and liquid stools were the best predictors of cholera. J Nutr Sci Vitaminol (Tokyo), 1999 Dec, 45(6), 785 - 90 Antibacterial activity of garlic powder against Escherichia coli O-157; Sasaki J et al.; The antibacterial activity of garlic powder against O-157 was tested by using garlic bulbs post-harvested 1 y . O-157 at 10(6-7) cfu/mL perished after incubation for 24 h with a 1% solution of garlic powder . The use of powder from fresh garlic was more effective for antibacterial activity than that from old garlic; the 1% solution of fresh garlic powder eradicating the O-157 in 6 h . The antibacterial activity was resistant to heat treatment of 100 degrees C for 20 min . The water-soluble components of garlic powder were fractionated into three fractions (Fr . 1-3) by Sephadex G-100 column chromatography, among which Fr . 3 showed antibacterial activity against O-157 but the other fractions were scarce in activity . The antibacterial activity was also shown against other types of pathogenic bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), Salmonella enteritidis, and Candida albicans . Thus, the practical use of garlic powder is expected to prevent bacteria-caused food poisoning. Minerva Chir, 1999 Dec, 54(12), 851 - 4 {Perforation of the small intestine}; Buzio M et al.; BACKGROUND: Small bowel perforation is a major problem in abdominal typhi disease, but is seldom observed in Italy, as Salmonella typhi infections are rare in this Nation . The cause of perforation varies greatly . The reported mortality is high and varies from 23 up to 42% . A retrospective study has been performed in order to find how to improve the outcome . METHODS: A series spanning 10 years is reviewed, from January 1, 1987 to December 31, 1997, comprising 60 patients with small bowel perforation, operated in a urgency setting in the Operating Room of the Emergency Department of the Molinette Hospital in Torino . Resection and primary anastomosis were utilized in 33 patients, 27 underwent oversewing . In 3 patients a colostomy was felt necessary because of a concomitant damage of the colon . RESULTS: No leakages occurred . Hospital stay varies from 1 day to 76 days (24 days mean) . Mortality is consistent with literature: 20 patients (33%) but the cause is related to the primary diseases of the patients . Delay in diagnosis did not affect the patient's outcome . CONCLUSIONS: In conclusion, it is confirmed the one-time surgery as the choice treatment in small bowel perforations from causes other then S . typhi infection . Mortality is not directly related to the consequences of surgical repair. J Bacteriol, 2000 Apr, 182(8), 2341 - 4 Identification of SopE2, a Salmonella secreted protein which is highly homologous to SopE and involved in bacterial invasion of epithelial cells; Bakshi CS et al.; Type III secreted Sop protein effectors are delivered into target eukaryotic cells and elicit cellular responses underlying Salmonella pathogenicity . In this work, we have identified another secreted protein, SopE2, and showed that SopE2 is an important invasion-associated effector . SopE2 is encoded by the sopE2 gene which is present and conserved in pathogenic strains of Salmonella . SopE2 is highly homologous to SopE, a protein encoded by a gene within a temperate bacteriophage and present in only some pathogenic strains. J Bacteriol, 2000 Apr, 182(8), 2262 - 8 Complex function for SicA, a Salmonella enterica serovar typhimurium type III secretion-associated chaperone; Tucker SC et al.; Salmonella enterica encodes a type III secretion system within a pathogenicity island located at centisome 63 that is essential for virulence . All type III secretion systems require the function of a family of low-molecular-weight proteins that aid the secretion process by acting as partitioning factors and/or secretion pilots . One such protein is SicA, which is encoded immediately upstream of the type III secreted proteins SipB and SipC . We found that the absence of SicA results in the degradation of both SipB and SipC . Interestingly, in the absence of SipC, SipB was not only stable but also secreted at wild-type levels in a sicA mutant background, indicating that SicA is not required for SipB secretion . We also found that SicA is capable of binding both SipB and SipC . These results are consistent with a SicA role as a partitioning factor for SipB and SipC, thereby preventing their premature association and degradation . We also found that introduction of a sicA null mutation results in the lack of expression of SopE, another type III-secreted protein . Such an effect was shown to be transcriptional . Introduction of a loss-of-function sipC mutation into the sicA mutant background rescued sopE expression . These results indicate that the effect of sicA on sopE expression is indirect and most likely exerted through a regulatory factor(s) partitioned by SicA from SipC . These studies therefore describe a surprisingly complex function for the Salmonella enterica type III secretion-associated chaperone SicA. J Bacteriol, 2000 Apr, 182(8), 2245 - 52 OmpR regulates the stationary-phase acid tolerance response of Salmonella enterica serovar typhimurium; Bang IS et al.; Tolerance to acidic environments is an important property of free-living and pathogenic enteric bacteria . Salmonella enterica serovar Typhimurium possesses two general forms of inducible acid tolerance . One is evident in exponentially growing cells exposed to a sudden acid shock . The other is induced when stationary-phase cells are subjected to a similar shock . These log-phase and stationary-phase acid tolerance responses (ATRs) are distinct in that genes identified as participating in log-phase ATR have little to no effect on the stationary-phase ATR (I . S . Lee, J . L . Slouczewski, and J . W . Foster, J . Bacteriol . 176:1422-1426, 1994) . An insertion mutagenesis strategy designed to reveal genes associated with acid-inducible stationary-phase acid tolerance (stationary-phase ATR) yielded two insertions in the response regulator gene ompR . The ompR mutants were defective in stationary-phase ATR but not log-phase ATR . EnvZ, the known cognate sensor kinase, and the porin genes known to be controlled by OmpR, ompC and ompF, were not required for stationary-phase ATR . However, the alternate phosphodonor acetyl phosphate appears to play a crucial role in OmpR-mediated stationary-phase ATR and in the OmpR-dependent acid induction of ompC . This conclusion was based on finding that a mutant form of OmpR, which is active even though it cannot be phosphorylated, was able to suppress the acid-sensitive phenotype of an ack pta mutant lacking acetyl phosphate . The data also revealed that acid shock increases the level of ompR message and protein in stationary-phase cells . Thus, it appears that acid shock induces the production of OmpR, which in its phosphorylated state can trigger expression of genes needed for acid-induced stationary-phase acid tolerance. Poult Sci, 2000 Mar, 79(3), 331 - 5 Comparison of the effects of dietary selenium, zinc, and selenium and zinc supplementation on growth and immune response between chick groups that were inoculated with Salmonella and aflatoxin or Salmonella; Hegazy SM et al.; The effects of four diets (basal diet, Se, Zn, and Se- and Zn-enriched diets) fed to chicks that were administered one of three treatments {Salmonella and aflatoxin inoculation (T1), Salmonella inoculation (T2), or uninoculated (T3)} were investigated for growth and immune responses . We found a significant improvement in growth performance represented by relative body gain (RBG) and feed efficiency (FE), for the Zn- and Se + Zn-enriched diets fed to the T1 and T2 groups . The antibody immune response was significantly improved for the Se enrichment diet in the T1 and T2 groups . The weight of the bursa and thymus, which relate to the level of the immune response, showed significant decreases, whereas the spleen had a significantly increased relative weight (RW) in the T1 group . The variable dietary trace elements supplement increased the thymic RW in the T2 group. East Afr Med J, 1999 Nov, 76(11), 623 - 5 Antibody levels to Salmonella typhi and paratyphi in Nigerians; Tanyigna KB et al.; OBJECTIVE: To determine the antibody titre levels to typhoid/paratyphoid fever organisms among apparently healthy volunteers . DESIGN: Cross sectional study . SETTING: General community and University Teaching Hospital . PARTICIPANTS: Volunteer sample of 323 apparently healthy individuals with body temperatures < or = 37.8 degrees C . MAIN OUTCOME MEASURES: Questionnaire administration to classify volunteers into three socio-economic status (SES) . RESULTS: There were 35.29% of the apparently healthy population in Jos community with antibodies to typhoid/paratyphoid fever organisms . The presence of these antibodies were neither sex nor SES related . Normal antibody titres were up to 1:40 and 1:80 for O and H Salmonella antigens respectively . Contrary to the general belief, typhoid/paratyphoid fevers have not affected virtually everybody in Nigeria . The difference between those without previous history and those with previous history was significant (p < 0.05) with those in the former category having a higher percentage . CONCLUSION: For a single sero-diagnosis to have any diagnostic value in Jos community and its environs, only a four-fold rise to what has been found to be normal should be significant . This means that only titres of 1:160 and 1:320 and above for O and H antigens should be considered significant. Theriogenology, 1999 Jul 15, 52(2), 247 - 57 Risk factors for Neospora caninum-associated abortion storms in dairy herds in The Netherlands (1995 to 1997); Bartels CJ et al.; A 2 to 1 matched case control study design was used to analyze herd level risk factors for Neospora caninum-associated abortion storms in 47 dairy herds . Data were obtained using a questionnaire regarding the state of affairs at the farms over the 2 years prior to the abortion storm . The questionnaire included 120 variables considered to be potential risk factors for either introduction of infection or recrudescence of chronic infection . The relationship between risk factors and case control pairs was analyzed by conditional logistic regression using a three-steps procedure . In addition, cross sectional serology was used to assess the possible role of concomitant infections . The main factors that were significant in the analysis and that were considered to have potential biological relevance were the presence of dogs, the presence of poultry, and the feeding of moldy maize-silage during summer . For both the presence of dogs and the presence of poultry on the farms, a linear relationship was found between the number of animals and the assessed risk for an abortion storm . These findings suggest a possible role of these species in the transmission of N . caninum . Further evidence for such a role of dogs was the significant association between the presence of dogs and the presence of seropositive cattle in the control herds . The feeding of moldy fodder is considered to be a factor which may induce recrudescence of a latent N . caninum-infection by mycotoxins causing immune suppression . We also found some evidence for a possible influence of management practices around calving and a high prevalence of retained afterbirths . No significant association was found for herd level prevalence of antibodies to bovine viral diarrhea virus, bovine herpesvirus 1, Leptospira hardjo or Salmonella dublin. Int J Food Microbiol, 1999 Nov 15, 52(3), 123 - 53 Microbiological safety evaluations and recommendations on sprouted seeds . National Advisory Committee on Microbiological Criteria for Foods; A case of acute pancreatitis complicating Salmonella enteritis; Second Department of Internal Medicine, Kobe University School of Medicine, JapanWe report a case of acute pancreatitis complicating Salmonella enteritis . A 43-yr-old woman who was admitted to our department because of Salmonella enteritis developed clinical acute pancreatitis with laboratory and radiographic signs on the fourth hospital day . She was free from symptoms on the eighth hospital day, but her elevated serum amylase and lipase levels persisted for more than 2 m.o . In this case, clinical acute pancreatitis was a complication of bacterial enteritis caused by Salmonella enteritidis, and it was characterized by onset a few days after the onset of enteritis and by sustained elevation of serum pancreatic enzyme levels. Vet Microbiol, 2000 Apr 4, 73(1), 61 - 73 A critical assessment of antimicrobial treatment in uncomplicated Salmonella enteritis; van Duijkeren E et al.; The human and veterinary literature on the effect of antimicrobials on the clinical and bacteriological cure in uncomplicated Salmonella gastroenteritis is reviewed . Comparison of data on the efficacy of conventional antimicrobials (chloramphenicol, neomycin, ampicillin, amoxycillin, tetracycline, trimethoprim/sulfonamide combinations) and the newer fluoroquinolones indicate that quinolones may shorten the course of clinical disease in contrast to the conventional antimicrobials . Postconvalescent excretion of Salmonella was not affected by the conventional antimicrobials whereas the data on the fluoroquinolones in this respect are conflicting . The fluoroquinolones are the drugs of choice in human medicine for severe Salmonella infections and for the elimination of the carrier state . These drugs have not been evaluated in this respect in veterinary medicine . Well designed prospective placebo-controlled studies regarding the effect of antimicrobials, especially the fluoroquinolones, on the clinical cure and the postconvalescent shedding of Salmonella in animals are imperative to develop optimal therapeutic strategies. J Physiol Biochem, 1999 Dec, 55(4), 301 - 8 High hemoglobin affinity to oxygen and its relationships with lipid peroxidation during fever; Zinchuk V; The effects of high hemoglobin-oxygen affinity (HOA) on rectal temperature and lipid free radical oxidation were investigated in red blood cells, heart, liver and kidneys of male rats during fever . Fever was induced by intraperitoneal injection of Salmonella typhi lipopolysaccharide (LPS; 5.0 mg kg(-1)) . HOA was increased by addition of 0.5% sodium cyanate to drinking water for eight weeks . HOA modification (actual half-saturation oxygen pressure, P50act, decreased to 23.3+/-0.7 vs . 31.6+/-0.7 Torr in control; p < 0.001) weakened a febrile response: rise of temperature after 4 hours was 0.79+/-0.2 degrees C vs . 1.38+/-0.1 degrees C in rats with normal HOA (p < 0.05) . In red cells and tissues of rats with normal HOA, concentrations of conjugated dienes and Schiff bases increased during fever, and alpha-tocopherol level and catalase activity decreased . Rats with increased HOA had an inverse pattern of such changes . Changes in rectal temperature and markers of free radical oxidation correlated with a shift of oxyhemoglobin dissociation curve leftwards . The present results indicate that the intentional increment of HOA may substantially diminish lipid peroxidation activity, increase the body antioxidant content during fever and decrease the febrile response on LPS. Biol Neonate, 2000 Mar, 77(3), 191 - 5 Prophylactic treatment of endotoxic shock with monophosphoryl lipid A in newborn rats; Wy CA et al.; Mortality due to gram-negative septic shock remains high despite advances in medical care . Induction of endotoxin tolerance might be a new treatment strategy to prevent septic shock in the newborn . The present study was performed to show that an injection in pregnant rats of monophosphoryl lipid A (MPL), a nontoxic derivative of lipopolysaccharide (LPS), induces tolerance to Salmonella enteritidis LPS and tumor necrosis factor alpha (TNF-alpha) in their offspring . MPL at a dose of 2 mg/kg was injected into pregnant rats on the 19th day of gestation . Their 0-day-old offspring later received an intraperitoneal injection of S . enteritidis LPS or TNF-alpha . Newborn rats of MPL-treated dams exhibited a higher survival rate, absence of lactacidemia and lower plasma TNF-alpha concentration in response to S . enteritidis LPS when compared to the newborn rats of saline-treated dams . Newborn rats of MPL-treated dams were more tolerant to TNF-alpha than those of saline-treated dams . MPL injection into pregnant rats did not increase plasma endotoxin concentration in the fetuses, suggesting no placental passage took place, but it did increase plasma TNF-alpha concentration . We concluded that an injection of MPL into pregnant rats induced tolerance to LPS in their offspring, which might be due to TNF-alpha-induced TNF-alpha tolerance . Biol Neonate, 2000 Mar, 77(3), 174 - 80 The effect of cold stimulation to the face on the metabolic rate of the febrile piglet; Voss LJ et al.; Sudden infant death syndrome has been associated with winter climates, infection, and overwrapping of babies . The hypothesis has been tested in this laboratory that two different causes of increased metabolic rate, high core temperature (via the van't Hoff or 'Q10' effect) and face-cooling, might synergistically induce hyperthermia . This proved not to be the case . We now report on a 'febrile' state adding Salmonella abortus equi pyrogens . The combination of face-cooling and pyrogen administration to 14 already hot piglets produced an increase in oxygen consumption of 47% in 6 of the animals (19% overall) . Face-cooling alone caused a 6.5% fall in oxygen consumption, and injection of pyrogens alone had no effect on oxygen consumption . We conclude that there may be a danger of life-threatening hyperthermia in the combination of a cold face and febrile state . J Med Assoc Thai, 1999 Nov, 82 Suppl 1, S144 - 8 Pulmonary involvement in childhood systemic lupus erythematosus; Chantarojanasiri T et al.; Twenty-four children (aged 6-15 years, M:F = 1:11) with systemic lupus erythematosus (SLE), who had respiratory symptoms, were retrospectively reviewed . Chest radiographs obtained from all patients revealed pleural effusion in 13, alveolar infiltration in 9, pericardial effusion and cardiomegaly in 6, interstitial infiltration in 4, hilar adenopathy in 3, lung abscess in 2 and pneumatocele with pneumothorax in 1 . Etiologic organisms were identified in 7 cases; (3 cases of nocardia isolated from pleural effusion and sputum, 2 cases of tuberculosis, 1 case with staphylococcus aureus septicemia and 1 case with salmonella septicemia) . All except one patient improved with medical treatment . One patient died from pneumonitis . Although pulmonary involvement is increasingly recognized in children with SLE, neither roentgenogram nor clinical findings were specific . The differentiation of pulmonary infiltrates caused by lupus lung disease from pulmonary infection should be carefully evaluated. Lett Appl Microbiol, 2000 Jan, 30(1), 75 - 9 An RNA transcription-based amplification technique (NASBA) for the detection of viable Salmonella enterica; Simpkins SA et al.; Possession of mRNA is indicative of cell viability . RTPCR is not appropriate for mRNA detection as it cannot unambiguously detect mRNA in a DNA background . The alternative amplification technique, NASBA, avoids the disadvantages of RTPCR . We have devised a method for detection of viable Salmonella enterica . This involves NASBA amplification of mRNA transcribed from the dnaK gene . Amplification of mRNA extracted from viable and heat-killed cells from the same population produced consistent and highly significant (P > 0.01) differences between the respective signals . The signal obtained from viable cells was completely eradicated by RNase treatment, while PCR amplification of treated and untreated samples was unaffected, indicating that NASBA was unaffected by background DNA. Eur J Biochem, 2000 Apr, 267(7), 2014 - 27 The structure of the linkage between the O-specific polysaccharide and the core region of the lipopolysaccharide from Salmonella enterica serovar Typhimurium revisited; Olsthoorn MM et al.; Salmonella enterica sv . Typhimurium strain 1135 possesses smooth(S)-form lipopolysaccharide (LPS) . Although the structures of the core region and the O-specific polysaccharide were investigated intensively between the 1960s and the 1980s, the structure of the linkage region between the O-chain and the core was not elucidated unequivocally . By using modern MS and high-field NMR spectroscopy for analysis of the isolated carbohydrate backbone of the LPS, it has been shown that it is a beta-D-Galp residue that links the first repeating unit of the O-specific polysaccharide to O-4 of the last D-Glcp residue of the core region . Interestingly, this particular D-Galp residue is alpha-linked in all following repeating units . The data are discussed with regard to the ligation of O-specific polysaccharide and core region during LPS biosynthesis. FEMS Immunol Med Microbiol, 2000 Apr, 27(4), 357 - 64 Recombinant live Salmonella spp . for human vaccination against heterologous pathogens; Bumann D et al.; Live attenuated Salmonella spp . are promising candidates as oral vaccine delivery systems for heterologous antigens . Clinical trials have demonstrated that this approach is feasible for human vaccinations but further optimisation is necessary to obtain a better efficacy . Here, we discuss how existing clinical and pre-clinical data can be used to guide such optimisation efforts. FEMS Immunol Med Microbiol, 2000 Apr, 27(4), 275 - 81 Kinetics of the mucosal antibody secreting cell response and evidence of specific lymphocyte migration to the lung after oral immunisation with attenuated S . enterica var . typhimurium; Allen JS et al.; The kinetic of mucosal secretory responses elicited by the vaccine vector Salmonella enterica var . typhimurium (S . typhimurium) was examined by enzyme linked immunospot (ELISPOT) and compared with serum responses . Mice immunised orally with BRD509, the aroA, aroD mutant of virulent S . typhimurium SL1344 expressing the C Fragment of tetanus toxin (TT), simultaneously developed an IgA antibody secreting cells (ASC) response in the gastrointestinal lamina propria, the spleen and the lung, against both S . typhimurium lipopolysaccharide (LPS) and TT . The magnitude of the ASC response was greatest in the gut, was boosted by a secondary immunisation at day 25, and the kinetic of the response did not correlate with the appearance of serum antibodies . This study suggests that S . typhimurium can engage the common mucosal immune system to effect mucosal secretory responses at distal sites, however, the magnitude of the responses is both greatest in the gut and antigen-specific . The ASC origin of the serum antibodies specific for S . typhimurium and antigens expressed by the bacterium is yet to be elucidated. Prev Vet Med, 2000 Mar 29, 44(1-2), 9 - 20 Risk factors for Salmonella persistence after cleansing and disinfection in French broiler-chicken houses; Rose N et al.; A prospective survey was carried out in 86 broiler houses in western France to identify risk factors for Salmonella persistence in French broiler houses . The Salmonella status of the house after cleansing and disinfection, was assessed from gauze-swab samples taken from the walls, feeders, ventilation system and bedding (analysed with classical bacteriological methods) . Thirty three (38%) houses had at least one contaminated sample and were classified as Salmonella-contaminated houses in the logistic regression . The absence of a terminal disinfection and a disinfection procedure performed by the farm staff rather than a contractor were positively related to the Salmonella contamination of the house after cleansing and disinfection . The risk for Salmonella persistence after decontamination was increased if rodents were observed by the farmer, if a large part of the access area to the house was accessible to trucks, and if a disease leading to a treatment occurred in the previous flock. Res Microbiol, 2000 Jan-Feb, 151(1), 63 - 5 Supplement 1998 (no . 42) to the Kauffmann-White scheme; Popoff MY et al.; This supplement reports the characterization of 14 new Salmonella serovars recognized in 1998 by the WHO Collaborating Centre for Reference and Research on Salmonella: 11 were assigned to S . enterica subsp . enterica, one to subspecies salamae, one to subspecies diarizonae, and one to subsp . indica . In addition, the antigenic factor H:z88 is described. Res Microbiol, 2000 Jan-Feb, 151(1), 37 - 42 Sequence variation of the 16S to 23S rRNA spacer region in Salmonella enterica; Christensen H et al.; The possibility for identification of Salmonella enterica serotypes by sequence analysis of the 16S to 23S rRNA internal transcribed spacer was investigated by direct sequencing of polymerase chain reaction-amplified DNA from all operons simultaneously in a collection of 25 strains of 18 different serotypes of S . enterica, and by sequencing individual cloned operons from a single strain . It was only possible to determine the first 117 bases upstream from the 23S rRNA gene by direct sequencing because of variation between the rrn operons . Comparison of sequences from this region allowed separation of only 15 out of the 18 serotypes investigated and was not specific even at the subspecies level of S . enterica . To determine the differences between internal transcribed spacers in more detail, the individual rrn operons of strain JEO 197, serotype IV 43:z4,z23:-, were cloned and sequenced . The strain contained four short internal transcribed spacer fragments of 382-384 bases in length, which were 98.4-99.7% similar to each other and three long fragments of 505 bases with 98.0-99.8% similarity . The study demonstrated a higher degree of interbacterial variation than intrabacterial variation between operons for serotypes of S . enterica. Infect Immun, 2000 Apr, 68(4), 2135 - 41 Pilot study of phoP/phoQ-deleted Salmonella enterica serovar typhimurium expressing Helicobacter pylori urease in adult volunteers; Angelakopoulos H et al.; Attenuated Salmonella enterica serovar Typhi has been studied as an oral vaccine vector . Despite success with attenuated S . enterica serovar Typhimurium vectors in animals, early clinical trials of S . enterica serovar Typhi expressing heterologous antigens have shown that few subjects have detectable immune responses to vectored antigens . A previous clinical study of phoP/phoQ-deleted S . enterica serovar Typhi expressing Helicobacter pylori urease from a multicopy plasmid showed that none of eight subjects had detectable immune responses to the vectored antigen . In an attempt to further define the variables important for engendering immune responses to vectored antigens in humans, six volunteers were inoculated with 5 x 10(7) to 8 x 10(7) CFU of phoP/phoQ-deleted S . enterica serovar Typhimurium expressing the same antigen . Two of the six volunteers had fever; none had diarrhea, bacteremia, or other serious side effects . The volunteers were more durably colonized than in previous studies of phoP/phoQ-deleted S . enterica serovar Typhi . Five of the six volunteers seroconverted to S . enterica serovar Typhimurium antigens and had strong evidence of anti-Salmonella mucosal immune responses by enzyme-linked immunospot studies . Three of six (three of five who seroconverted to Salmonella) had immune responses in the most sensitive assay of urease-specific immunoglobulin production by blood mononuclear cells in vitro . One of these had a fourfold or greater increase in end-point immunoglobulin titer in serum versus urease . Attenuated S . enterica serovar Typhimurium appears to be more effective than S . enterica serovar Typhi for engendering immune responses to urease . Data suggest that this may be related to a greater stability of antigen-expressing plasmid in S . enterica serovar Typhimurium and/or prolonged intestinal colonization . Specific factors unique to nontyphoidal salmonellae may also be important for stimulation of the gastrointestinal immune system. Epidemiol Infect, 2000 Feb, 124(1), 17 - 23 The antibiotic resistance patterns of Salmonella Typhi isolates in Italy, 1980-96 . The Italian SALM-NET Working Group . Salmonella Network; Scuderi G et al.; In this paper we report the distribution of Salmonella Typhi isolates in Italy and their resistance patterns to antibiotics . The data were collected by the Italian SALM-NET surveillance system in a pilot retrospective study of the period 1980-96 . Data on drug-resistance were available for 82 isolates out of 176 S . Typhi isolated in Italy . Of these 82 isolates, 32 (39%) were resistant or intermediate to 1 or more antibiotics . Eight isolates were resistant and 7 intermediate to streptomycin; 4 isolates were resistant to ampicillin alone or in association with other antibiotics; only 2 strains (1 isolated in Lombardia in 1993 and the other 1 in Lazio in 1994) were resistant to chloramphenicol, and 2 (isolated in Sardegna and Piemonte in 1995 and 1996, respectively) showed intermediate resistance to chloramphenicol . The strains showing resistance to 3 or more antibiotics were very scarce: 1 (with 5 complete resistances) was isolated in Lazio in 1994, and another 1 (with complete resistance to 10 antibiotics and intermediate resistance to 2 antibiotics) was isolated in Molise in 1988 . In conclusion, besides the routine activities to control typhoid fever, an accurate and continuous surveillance is necessary in order to quickly identify multidrug-resistant (MDR) S . Typhi strains and prevent their spread, even though their level, in our country, is still quite low. Epidemiol Infect, 2000 Feb, 124(1), 9 - 16 Characterization of multi-drug resistant Salmonella typhi isolated from Pakistan; Shanahan PM et al.; Thirty-nine strains of Salmonella typhi, isolated in 1995 from four Districts in Pakistan, Rawalpindi, Islamabad, Kharian and Jehlem, were catalogued and examined . Chromosomal DNA from each isolate was digested with XbaI restriction endonuclease and subjected to pulsed-field gel electrophoresis . Three clonal variants comprising of 17-19 DNA fragments were identified . Antibiotic susceptibility testing identified that 37 of the S . typhi were resistant to chloramphenicol, trimethoprim and ampicillin . These antibiotic resistance genes were found to be located on one of four plasmids belonging to incompatibility group IncHI1 and ranging in size from 150-175 Kb . The genes responsible for this resistance in each case were the chloramphenicol acetyltransferase (CAT) type I, the dihydrofolate reductase (DHFR) type VII and the beta-lactamase TEM-1 respectively. Epidemiol Infect, 2000 Feb, 124(1), 1 - 7 A community--wide outbreak of Salmonella enterica serotype Typhimurium infection associated with eating a raw milk soft cheese in France; De Valk H et al.; In 1997, a community-wide outbreak of Salmonella enterica serotype Typhimurium (S . typhimurium) infection occurred in France . The investigation included case searching and a case-control study . A case was defined as a resident of the Jura district with fever or diarrhoea between 12 May and 8 July 1997, from whom S . typhimurium was isolated in stool or blood . One hundred and thirteen cases were identified . Thirty-three (83 %) of 40 cases but only 23 (55 %) of 42 community controls, matched for age and area of residence, reported eating Morbier cheese (Odds ratio: 6.5; 95 % Confidence Interval: 1.4-28.8) . Morbier cheese samples taken from the refrigerators of two case-patients and one symptom-free neighbour cultured positive for S . typhimurium of the same phage type as the human isolates . The analysis of distribution channels incriminated one batch from a single processing plant . These findings show that an unpasteurized soft cheese is an effective vehicle of S . typhimurium transmission. J Korean Med Sci, 2000 Feb, 15(1), 83 - 7 NRAMP1 gene polymorphisms in patients with rheumatoid arthritis in Koreans; Yang YS et al.; Natural resistance-associated macrophage protein 1 (Nramp1) is a genetic locus associated with innate resistance or susceptibility of murine hosts to infection with intracellular pathogens such as Salmonella, Leishmania and Mycobacterium . The human homologue of the Nramp1 gene, designated NRAMP1, has been investigated as a candidate gene for genetic susceptibility to autoimmune diseases as well as infections . This study tries to determine whether NRAMP1 polymorphisms are associated with susceptibility to rheumatoid arthritis in Koreans . The nine NRAMP1 polymorphisms (1 microsatellite, 1 variation in 3' UTR, 5 silent substitution, 2 amino acid substitution) were typed by PCR-RFLP in 74 patients with rheumatoid arthritis (RA) and 53 healthy controls in Koreans . The distribution of allele and genotype frequencies were compared between patients and controls . Three NRAMP1 polymorphisms (823C/T, D543N and 1729+55del4) were significantly associated with RA . In addition, there were significant differences in the genotype frequencies for 823C/T, D543N and 1729+ 55del4 polymorphisms between RA patients and controls . Genotypes of A/A homozygote for D543N and TGTG deletion homozygote for 1729+55del4 were only detected in the patient group . These data indicate that genetic polymorphisms of NRAMP1 might be associated with the susceptibility to rheumatoid arthritis in Koreans. Int J Food Sci Nutr, 1999 Nov, 50(6), 451 - 5 Survival of some species of Salmonella and Shigella in mukumbi, a traditional Zimbabwean wine; Mugochi T et al.; Mukumbi is a traditional Zimbabwean wine prepared from a fruit called mapfura by the Shona people of Zimbabwe and amaganu by the Ndebele . The majority of people in Africa call the tree marula (Sclerocarya birrea subspecies caffra) . The survival of Salmonella group B, Salmonella enteritidis, Shigella sonnei and Shigella flexneri in unfermented and fermented mapfura (marula) juice (mukumbi) was investigated . It was found that within 30 min of inoculation, there were no longer any viable pathogens in the fermented mapfura juice whilst in the unfermented juice, more than 10(4) cfu/ml were still viable after 8 h . When lactic acid (0.25 mg/ml) was added to the unfermented mapfura juice, more than 10(4) cfu/ml were also still viable after 8 h but none were viable after 24 h . The fermented product, mukumbi, has a rapid antimicrobial effect against the pathogens as compared to the unfermented juice and is therefore safe from contamination with these pathogens . It appears thus that the death of the pathogens was due to other compounds besides the low levels of lactic acid. J Biomater Sci Polym Ed, 2000, 11(2), 187 - 96 In vitro toxicity of spiroorthocarbonate monomers designed for non-shrinking dental restoratives; Kostoryz EL et al.; In development of photopolymerized expanding monomers with epoxy resin systems, there is a need for reactive expanding monomers that exert a good biocompatibility profile . The objective of this study was to evaluate the in vitro toxicology of new spiroorthocarbonates designed to be expanding monomers . The expanding monomers investigated were: trans/trans-2,3,8,9-di(tetramethylene)-1,5,7,11-tetraoxaspiro{5,5} undecane (DTM-TOSU), 5,5-diethyl-19-oxadispiro-{1,3-dioxane-2,2'-1,3-dioxane-5',4'-bicy clo{4.1.0}heptane} (DECHE-TOSU); 3,9-diethyl-3,9-dipropionyloxy methyl-1,5,7,11-tetraoxaspiro{5.5}undecane (DEDPM-TOSU); and 3,9-diethyl-3,9-diacetoxy methyl-1,5,7,11-tetraoxaspiro{5.5}undecane (DAMDE-TOSU) . The in vitro toxicology of these monomers measured their cytotoxicity and mutagenicity potential . Succinic dehydrogenase (SDH) activity in the MTT assay was used to assess the toxic dose that kills 50% of cells (TC50) for all the monomers . Their mutagenic potential was measured in the Ames Salmonella assay with and without metabolic activation . Two solvents, DMSO and acetone, were used to validate effects . Appropriate controls included the solvents alone . All the expanding monomers in this study were less cytotoxic than BISGMA (p < 0.01), a commercial component of dental restoratives . The relative cytotoxicity of the expanding monomers in DMSO was defined in the following order: DTM-TOSU (more toxic) > DECHE-TOSU > DEDPM-TOSU > DAMDE-TOSU . Each was significantly different from the other (p < 0.05) . Overall, the TC50 values of all expanding monomers were significantly greater in DMSO than in acetone (p < 0.05) . However, for BISGMA this trend was opposite . For mutagenicity results, the expanding monomers were non-mutagenic and there was no solvent effect on this outcome . The non-mutagenicity and low cytotoxicity profile of these expanding monomers suggests their potential for development of biocompatible non-shrinking composites. Vaccine, 2000 Apr 28, 18(21), 2239 - 43 Granulocyte selected live Salmonella enteritidis vaccine is species specific; Kramer T et al.; Selection of Salmonellae from granulocytes may result in safe and effective vaccine strains . We demonstrated that the reduced virulence of such strains is limited to the species in which the selection was made . Repeated (sequential) selection of Salmonella enteritidis from chicken granulocytes yielded an avirulent strain for chickens . Repeated (sequential) selection of Salmonella enteritidis from pig granulocytes (neutrophils) yielded a strain that was comparable to the original wildtype strain. Ann Trop Med Parasitol, 1999 Oct, 93(7), 669 - 78 The host response in malaria and depression of defence against tuberculosis; Enwere GC et al.; Malaria causes significant morbidity and mortality world-wide . Both asymptomatic and symptomatic malarial infections cause immune depression, which predisposes the host to infection with other microorganisms . Specific clinical investigations have shown, for example, that those with malaria-attributable anaemia are particularly likely to have Salmonella septicaemia, and that asymptomatic malarial infection causes diminished response to polysaccharide vaccine . The results of clinical studies and experiments with animal models have revealed that malarial parasites can decrease their vertebrate host's effective humoral and cellular immune responses . In this review, the possible ways in which this malaria-induced immune impairment could affect the host's response to Mycobacterium tuberculosis infection are considered . Could malarial infection be one of the reasons for the persistence of tuberculosis in malaria-endemic regions? J Bacteriol, 2000 Apr, 182(7), 2026 - 32 Isolation and characterization of vicH, encoding a new pleiotropic regulator in Vibrio cholerae; Tendeng C et al.; During the last decade, the hns gene and its product, the H-NS protein, have been extensively studied in Escherichia coli . H-NS-like proteins seem to be widespread in gram-negative bacteria . However, unlike in E . coli and in Salmonella enterica serovar Typhimurium, little is known about their role in the physiology of those organisms . In this report, we describe the isolation of vicH, an hns-like gene in Vibrio cholerae, the etiological agent of cholera . This gene was isolated from a V . cholerae genomic library by complementation of different phenotypes associated with an hns mutation in E . coli . It encodes a 135-amino-acid protein showing approximately 50% identity with both H-NS and StpA in E . coli . Despite a low amino acid conservation in the N-terminal part, VicH is able to cross-react with anti-H-NS antibodies and to form oligomers in vitro . The vicH gene is expressed as a single gene from two promoters in tandem and is induced by cold shock . A V . cholerae wild-type strain expressing a vicHDelta92 gene lacking its 3' end shows pleiotropic alterations with regard to mucoidy and salicin metabolism . Moreover, this strain is unable to swarm on semisolid medium . Similarly, overexpression of the vicH wild-type gene results in an alteration of swarming behavior . This suggests that VicH could be involved in the virulence process in V . cholerae, in particular by affecting flagellum biosynthesis. J Bacteriol, 2000 Apr, 182(7), 1923 - 9 Distribution of intervening sequences in the genes for 23S rRNA and rRNA fragmentation among strains of the Salmonella reference collection B (SARB) and SARC sets; Pabbaraju K et al.; Intervening sequences (IVSs) occur sporadically in several bacterial genera in the genes for 23S rRNA at relatively conserved locations . They are cleaved after transcription and lead to the presence of fragmented rRNA, which is incorporated into the ribosomes without religation but is nevertheless functional . The fragmentation of rRNA and the number of IVSs in all 72 strains of the Salmonella Reference Collection B set and 16 strains of the Salmonella Reference Collection C set, which have been established on the basis of multilocus enzyme electrophoresis (MLEE), were analyzed in the present study . Fragmentation of 23S rRNA was restricted to conserved cleavage sites located at bp 550 (helix 25) and bp 1170 (helix 45), locations where IVSs have been reported . Random cleavage at sites where IVSs could not be detected was not seen . Uncleaved IVSs were not detected in any case; thus, the IVSs invariably led to rRNA fragmentation, indicating a strong selection for maintenance of RNase III cleavage sites . The distribution of the number of IVSs carried by the different strains in the seven rrl genes is diverse, and the pattern of IVS possession could not be related to the MLEE pattern among the various Salmonella strains tested; this indicates that the IVSs are frequently exchanged between strains by lateral transfer . All eight subspecies of the genus Salmonella, including subspecies V represented by Salmonella bongori, have IVSs in both helix 25 and helix 45; this indicates that IVSs entered the genus after its divergence from Escherichia coli (more than 100 million years ago) but before separation of the genus Salmonella into many forms or that they were in the ancestor but have been lost from Escherichia. J Bacteriol, 2000 Apr, 182(7), 1872 - 82 Multiple factors independently regulate hilA and invasion gene expression in Salmonella enterica serovar typhimurium; Lucas RL et al.; HilA activates the expression of Salmonella enterica serovar Typhimurium invasion genes . To learn more about regulation of hilA, we isolated Tn5 mutants exhibiting reduced hilA and/or invasion gene expression . In addition to expected mutations, we identified Tn5 insertions in pstS, fadD, flhD, flhC, and fliA . Analysis of the pstS mutant indicates that hilA and invasion genes are repressed by the response regulator PhoB in the absence of the Pst high-affinity inorganic phosphate uptake system . This system is required for negative control of the PhoR-PhoB two-component regulatory system, suggesting that hilA expression may be repressed by PhoR-PhoB under low extracellular inorganic phosphate conditions . FadD is required for uptake and degradation of long-chain fatty acids, and our analysis of the fadD mutant indicates that hilA is regulated by a FadD-dependent, FadR-independent mechanism . Thus, fatty acid derivatives may act as intracellular signals to regulate hilA expression . flhDC and fliA encode transcription factors required for flagellum production, motility, and chemotaxis . Complementation studies with flhC and fliA mutants indicate that FliZ, which is encoded in an operon with fliA, activates expression of hilA, linking regulation of hilA with motility . Finally, epistasis tests showed that PhoB, FadD, FliZ, SirA, and EnvZ act independently to regulate hilA expression and invasion . In summary, our screen has identified several distinct pathways that can modulate S . enterica serovar Typhimurium's ability to express hilA and invade host cells . Integration of signals from these different pathways may help restrict invasion gene expression during infection. Environ Mol Mutagen, 2000, 35(2), 106 - 13 Mutation spectra of the drinking water mutagen 3-chloro-4-methyl-5-hydroxy-2(5H)-furanone (MCF) in Salmonella TA100 and TA104: comparison to MX; Shaughnessy DT et al.; The chlorinated drinking water mutagen 3-chloro-4-methyl-5-hydroxy-2(5H)-furanone (MCF) occurs at concentrations similar to or greater than that of the related furanone 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) . MCF and MX differ structurally only by replacement of a 3-methyl in MCF with a 3-dichloromethyl in MX; yet, MCF is significantly less mutagenic than MX and produces different adducts when reacted with nucleosides or DNA . To explore further the effects that these structural differences might have on the biological activity of MCF and MX, we determined the mutation spectra of MCF in Salmonella strains TA100 and TA104 and of MX in strain TA104; the spectrum of MX in TA100 had been determined previously . In TA100, which presents only GC targets for mutagenesis, MCF induced primarily (75%) GC --> TA transversions, with most of the remaining revertants (20%) being GC --> AT transitions . This spectrum was not significantly different from that of MX in TA100 (P = 0.07) . In TA104, which presents both GC and AT targets, MCF induced a lower percentage (57%) of GC --> TA transversions, with most of the remaining revertants (33%) being AT --> TA transversions . In contrast, MX induced almost only (98%) GC --> TA transversions in TA104, with the remaining revertants (2%) being AT --> TA transversions . Thus, almost all (98%) of the MX mutations were targeted at GC sites in TA104, whereas only 63% of the MCF mutations were so targeted . These results are consistent with the published findings that MX: (1) forms an adduct on guanosine when reacted with guanosine, (2) induces apurinic sites in DNA, and (3) forms a minor adduct on adenosine when reacted with adenosine or DNA . The results are also consistent with evidence that MCF forms adenosine adducts when reacted with adenosine . Our results show that the replacement of the 4-methyl in MCF with a 4-dichloromethyl to form MX not only increases dramatically the mutagenic potency but also shifts significantly the mutagenic specificity from almost equal targeting of GC and AT sites by MCF to almost exclusive targeting of GC sites by MX . Environ . Mol . Mutagen . 35:106-113, 2000 Published 2000 Wiley-Liss, Inc. Mol Microbiol, 2000 Mar, 35(5), 1052 - 64 Interactions among components of the Salmonella flagellar export apparatus and its substrates; Minamino T et al.; We have examined the cytoplasmic components (FliH, FliI and FliJ) of the type III flagellar protein export apparatus, plus the cytoplasmic domains (FlhAC and FlhBC) of two of its six membrane components . FliH, FlhAC and FliJ, when overproduced, caused inhibition of motility of wild-type cells and inhibition of the export of substrates such as the hook protein FlgE . Co-overproduction of FliH and FliI substantially relieved the inhibition caused by FliH, suggesting that it is excess free FliH that is inhibitory and that FliH and FliI form a complex . We purified His-FLAG-tagged versions of: (i) export components FliH, FliI, FliJ, FlhAC and FlhBC; (ii) rod/hook-type export substrates FlgB (rod protein), FlgE (hook protein), FlgD (hook capping protein) and FliE (basal body protein); and (iii) filament-type export substrates FlgK and FlgL (hook-filament junction proteins) and FliC (flagellin) . We tested for protein-protein interactions by affinity blotting . In many cases, a given protein interacted with more than one other component, indicating that there are likely to be multiple dynamic interactions or interactions that involve more than two components . Interactions of FlhBC with rod/hook-type substrates were strong, whereas those with filament-type substrates were very weak; this may reflect the role of FlhB in substrate specificity switching . We propose a model for the flagellar export apparatus in which FlhA and FlhB and the other four integral membrane proteins of the apparatus form a complex at the base of the flagellar motor . A soluble complex of at least three proteins (FliH, FliI and FliJ) bind the protein to be exported and then interact with the complex at the motor to deliver the protein, which is then exported in an ATP-dependent process mediated by FliI. Mol Biol Evol, 2000 Feb, 17(2), 301 - 8 Solvent accessibility and purifying selection within proteins of Escherichia coli and Salmonella enterica; Bustamante CD et al.; The neutral theory of molecular evolution predicts that variation within species is inversely related to the strength of purifying selection, but the strength of purifying selection itself must be related to physical constraints imposed by protein folding and function . In this paper, we analyzed five enzymes for which polymorphic sequence variation within Escherichia coli and/or Salmonella enterica was available, along with a protein structure . Single and multivariate logistic regression models are presented that evaluate amino acid size, physicochemical properties, solvent accessibility, and secondary structure as predictors of polymorphism . A model that contains a positive coefficient of association between polymorphism and solvent accessibility and separate intercepts for each secondary-structure element is sufficient to explain the observed variation in polymorphism between sites . The model predicts an increase in the probability of amino acid polymorphism with increasing solvent accessibility for each protein regardless of physicochemical properties, secondary-structure element, or size of the amino acid . This result, when compared with the distribution of synonymous polymorphism, which shows no association with solvent accessibility, suggests a strong decrease in purifying selection with increasing solvent accessibility. Am J Gastroenterol, 2000 Mar, 95(3), 784 - 7 Typhoid carriers among patients with gallstones are at increased risk for carcinoma of the gallbladder; Dutta U et al.; OBJECTIVE: The aim of this study was to identify risk factors for carcinoma of the gallbladder (CaGB) among patients with gallstones (GS) with special reference to role of chronic Salmonella typhi carrier state . METHODS: A prospective case-control study was conducted in a tertiary care center in India . Cases were defined as consecutive patients with CaGB and GS, whereas controls were patients with GS alone . All were assessed clinically and their demographic data, diet, and smoking history recorded . Patients were detected to be typhoid carriers on the basis of Vi serology by enzyme linked immunosorbent assay . Cases (n = 37) and controls (n = 80) were compared by univariate and logistic regression analysis . RESULTS: The mean age of the cases and the controls were 53.4 +/- 11 yr and 43.5 +/- 14 yr, respectively . Among the cases, six (16%) patients were detected to be typhoid carriers, in contrast to two (2.5%) among controls (p = 0.01) . Compared to controls, cases were more often older (p = 0.0002), of a lower socioeconomic status (p = 0.0005), and smokers (p = 0.0002) . Stepwise logistic regression analysis identified typhoid carrier state (OR = 14; CI 2-92), age > or =47 yr (OR = 5; CI 2-14) and smoking (OR = 11; CI 2-71) as the three independent risk factors for development of CaGB among patients with GS . CONCLUSION: Chronic typhoid carrier state was the most important risk factor among patients with CaGB and gallstones. Vestn Ross Akad Med Nauk, 1999, (12), 32 - 4 {Temperature-dependent changes in immunochemical properties of lipopolysaccharides of yersinia pestis}; Gremiakova TA et al.; The preparations of pilopolysaccharides (LPS) of virulent and avirulent Y . pestis strains, which have a different composition, were cultivated at different temperatures . Despite the cultivation temperature of parental cells, all LPS preparation inhibited the passive hemagglutination reaction (PHR) of the red blood cells sensitized by LPS isolated from the cultures grown at 26 degrees C by using homologous antisera . In contrast, the homologous system consisting of the red blood cells sensitized by LPS from the EV NIIEG, cultured at 37 degrees C, and the antiserum to these cells proved to be more specific and it was inhibited only by the homologous LPS isolated from the strain EV NIIEG . The similar reaction of the interaction of the red blood cells sensitized by high temperature LPS agents from plasmid-free strains with the same serum was inhibited by all plague LPS preparations . The LPS preparations from the strains Y . pestis 1146 and Y . pseudotuberculosis 9532 obtained when cultivated at 37 degrees C . RHR of the red blood cells sensitized by these preparations was inhibited by homologous LPS irrespective of the temperature of cell cultivation . In all cases, the reaction was specific for Yersinia strains and it was inhibited by LPS from Ra-Rd2 cultures, variants of Salmonella and E . coli. Mutat Res, 2000 Feb 16, 465(1-2), 201 - 29 Modeling the mouse lymphoma forward mutational assay: the Gene-Tox program database; Grant SG et al.; An SAR model of the induction of mutations at the tk(+/-) locus of L5178Y mouse lymphoma cells (MLA, for mouse lymphoma assay) was derived based upon a re-evaluation of experimental results reported by a Gene-Tox (GT) working group {A.D . Mitchell, A.E . Auletta, D . Clive, P.E . Kirby, M.M . Moore, B.C . Myhr, The L5178Y/tk(+/-) mouse lymphoma specific gene and chromosomal mutation assay . A phase III report of the U.S . Environmental Protection Agency Gene-Tox Program, Mutation Res . 394 (1997) 177-303.} . The predictive performance of the GT MLA SAR model was similar to that of a Salmonella mutagenicity model containing the same number of chemicals . However, the structural determinants (biophores) derived from the GT MLA SAR model include both electrophilic as well as non-electrophilic moieties, suggesting that the induction of mutations in the MLA may occur by both direct interaction with DNA and by non-DNA-related mechanisms . This was confirmed by the observation that the set of biophores associated with MLA overlapped significantly with those associated with phenomena related to loss of heterozygosity, chromosomal rearrangements and aneuploidy . The MLA SAR model derived from the GT data evaluation was significantly more predictive than an SAR model previously derived from MLA data reported by the US National Toxicology Program {B . Henry, S.G . Grant, G . Klopman, H.S . Rosenkranz, Induction of forward mutations at the thymidine kinase locus of mouse lymphoma cells: evidence for electrophilic and non-electrophilic mechanisms, Mutation Res . 397 (1998) 331-335.} . Moreover, the latter model appeared to be more complex than the former, suggesting that the GT induction data was both simpler mechanistically and more homogeneous than that of the NTP. Mutat Res, 2000 Feb 16, 465(1-2), 191 - 200 Comparison of environmental tobacco smoke concentrations and mutagenicity for several indoor environments; Zhou R et al.; Environmental tobacco smoke (ETS) is a major source for indoor air pollution . Although ETS-caused indoor air pollution has been well studied in the developed countries, few studies have examined ETS indoor air pollution in China, which currently has the largest population of tobacco smokers . In this study, respirable-particulate (RP) from ETS-contaminated (RP-ETS) indoor air was collected and measured in 5 different indoor environments during the winter in the northwestern Liaoning Province, China . The extractable portion of RP-ETS (ERP-ETS) was obtained by dichloromethane extraction and used in the Salmonella mutagenicity assay in the presence of S9 using strains TA98, TA100, and TA1538 . The percentage of RP-ETS attributable to ETS (ETS-RP) and the percentage of ERP-ETS attributable to ETS (ETS-ERP) were estimated by measuring the concentration of solanesol, an ETS marker . Comparative results in 5 different indoor environments were: (1) the concentration of RP-ETS ranged from 197.3 to 1227.6 microg/m(3) and approximately 64.7 to 92 . 0% of the RP-ETS originated from ETS; (2) the concentration of ERP-ETS ranged 88.8 to 601.5 microg/m(3) and approximately 83.1 to 95.4% of the ERP-ETS originated from ETS; (3) the mutagenic potency (revertants/m(3)) of ERP-ETS ranged from 60.4 to 595.5 for TA98, from 33.7 to 312.8 for TA100, and from 49.7 to 475.2 for TA1538 . The data indicate that the extent of ETS pollution and the potential health hazards of ETS to humans in the five indoor environments are in the following increasing order: rural bedrooms, urban living rooms, office rooms, restaurants, and passenger cars in that area. Int J Immunopharmacol, 2000 May, 22(5), 355 - 64 Effect of Salmonella typhi wild type and O-antigen mutants on human natural killer cell activity; Puente J et al.; We investigated the effect of glutaraldehyde-fixed Salmonella typhi Ty2 (Vi(-)) wild-type (World Health Organization's vaccine strain) and mutant strains MEI028 (rough, O-antigen(-)) and MEI012 {smooth (O-antigen(+)95%), immunomagnetically isolated NK cell preparations . Incubation of PBMC with each and every one of the S . typhi strains studied consistently and significantly, increased this cellular immune function, as well as the supernatant level of the various cytokines tested e.g . IFN-gamma, TNF-alpha, IL-10 and IL-12 (ELISA) . In similar experiments, a significant increase in the cytolytic activity of HPNK cells was elicited by S . typhi Ty2 but not by mutant strain MEI028; neither of the cytokines assayed (IFN-gamma and TNF-alpha) was detected in the supernatant.Our results suggest that S . typhi O-antigen plays an essential role in a mechanism resulting in the direct activation of NK cell activity in HPNK cell preparations . However, the relative quantitative significance of this antigen in the direct stimulation of NK cell cytotoxicity expression in PBMC samples is less clear, as it appears that in this case bacterial-induced monocyte-released cytokines plays a most important role . Incubation with S . typhi Ty2 or MEI028 elicited significant expression of CD69, an early marker of NK cell activation, in PBMC but not in HPNK cell samples (flow cytometry); in similar experiments, the expression of CD16/56 and activation marker CD25 remained essentially unchanged. J Immunol, 2000 Mar 15, 164(6), 3149 - 56 Salmonella-type heptaacylated lipid A is inactive and acts as an antagonist of lipopolysaccharide action on human line cells; Tanamoto K et al.; The stimulation of both THP-1 and U937 human-derived cells by Salmonella lipid A preparations from various strains, as assessed by TNF-alpha induction and NF-kappaB activation, was found to be very low (almost inactive) compared with Escherichia coli lipid A, but all of the lipid As exerted strong activity on mouse cells and on Limulus gelation activity . Experiments using chemically synthesized E . coli-type hexaacylated lipid A (506) and Salmonella-type heptaacylated lipid A (516) yielded clearer results . Both lipid A preparations strongly induced TNF-alpha release and activated NF-kappaB in mouse peritoneal macrophages and mouse macrophage-like cell line J774-1 and induced Limulus gelation activity, although the activity of the latter was slightly weaker than that of the former . However, 516 was completely inactive on both THP-1 and U937 cells in terms of both induction of TNF-alpha and NF-kappaB activation, whereas 506 displayed strong activity on both cells, the same as natural E . coli LPS . In contrast to the action of the lipid A preparations, all the Salmonella LPSs also exhibited full activity on human cells . However, the polysaccharide portion of the LPS neither exhibited TNF-alpha induction activity on the cells when administered alone or together with lipid A nor inhibited the activity of the LPS . These results suggest that the mechanism of activation by LPS or the recognition of lipid A structure by human and mouse cells may differ . In addition, both 516 and lipid A from Salmonella were found to antagonize the 506 and E . coli LPS action that induced TNF-alpha release and NF-kappaB activation in THP-1 cells. MMWR Morb Mortal Wkly Rep, 2000 Feb 4, 49(4), 73 - 9 Outbreaks of Salmonella serotype enteritidis infection associated with eating raw or undercooked shell eggs--United States, 1996-1998; Clinical application of a dot blot test for diagnosis of enteric fever due to Salmonella enterica serovar typhi in patients with typhoid fever from Colombia and Peru; Instituto Columbiano de Medicina Tropical, AA 52162 Medellin, Colombia . icmt@epm.net.co Clinical application of a dot blot test to detect immunoglobulin G (IgG) (88% sensitivity and specificity) and IgM (12.1% sensitivity and 97% specificity) against flagellar antigen from Salmonella enterica serovar Typhi was performed in Peruvian and Colombian patients with typhoid fever . This test can be used as a good predictor of serovar Typhi infection in regions lacking laboratory facilities and in field studies. Clin Diagn Lab Immunol, 2000 Mar, 7(2), 258 - 64 Improved repetitive-element PCR fingerprinting of Salmonella enterica with the use of extremely elevated annealing temperatures; Johnson JR et al.; Modified thermal cycling conditions were explored in an effort to improve the reproducibility and resolving power of repetitive-element PCR (rep-PCR) fingerprinting . Assay performance was rigorously evaluated under standard and modified cycling conditions, using as a test set 12 strains putatively representing 12 serovars of Salmonella enterica . For all three fingerprint types (ERIC2, BOXA1R, and composite fingerprints), the use of extremely elevated annealing temperatures plus an initial "touchdown" cycling routine yielded significant improvements in day-to-day reproducibility and discriminating power despite the somewhat sparser appearance of the fingerprints . Modified cycling conditions markedly reduced the variability of fingerprints between cyclers, allowing fingerprints from different cyclers to be analyzed together without the degradation of assay performance that occurred with between-cycler analyses under standard cycling conditions . With modified cycling, composite fingerprints exhibited the lowest reproducibility but the highest net discriminating power of the three fingerprint types . rep-PCR fingerprints led to the discovery of a serotyping error involving one of the 12 test strains . These data demonstrate that modified cycling regimens that incorporate elevated annealing temperatures (with or without an initial touchdown routine) may markedly improve the performance of rep-PCR fingerprinting as a bacterial typing tool. J Neurosurg, 2000 Mar, 92(3), 435 - 41 Induction of tolerance against ischemia/reperfusion injury in the rat brain by preconditioning with the endotoxin analog diphosphoryl lipid A; Toyoda T et al.; OBJECT: Inflammatory responses and oxygen free radicals have increasingly been implicated in the development of ischemic brain injury . In some cases, an attenuation of inflammation or free-radical injury can provide tissue protection . Diphosphoryl lipid A (DPL) is a detoxified derivative of a lipopolysaccharide (endotoxin) of Salmonella minnesota strain R595, which is capable of stimulating the immune system without eliciting direct toxic effects . In this study the authors examined the influence of preconditioning with DPL on ischemia/reperfusion injury in rats . METHODS: Sprague-Dawley rats were injected intravenously with either DPL or vehicle . Twenty-four hours later, some animals were tested for superoxide dismutase (SOD) activity . Others were subjected to a 3-hour period of focal cerebral ischemia and, after a reperfusion period of 24 hours, were killed . Infarction volume, SOD activity, and myeloperoxidase (MPO) activity were assayed in the postischemic animals . Pretreatment with DPL produced significant reductions in cerebral infarction and MPO activity in the ischemic penumbra . A significant enhancement of basal SOD activity was observed 24 hours after DPL treatment (that is, before ischemia), and a further enhancement of SOD activity was seen in the ischemic penumbra 24 hours after reperfusion . CONCLUSIONS: These data provide the first evidence of a neuroprotective effect of preconditioning with DPL in an in vivo model of cerebral ischemia . Although the precise mechanisms through which DPL exerts its neuroprotective influence remain to be established, an inhibition of the complex inflammatory response to ischemia and an enhancement of endogenous antioxidant activity are leading candidates. Indian J Med Res, 1999 Dec, 110, 183 - 5 Multi-drug resistant non-typhoidal Salmonella spp . associated with acute diarrhoeal disease; Niyogi SK et al.; The prevalence of different serotypes of non-typhoidal Salmonella spp . among patients suffering from acute diarrhoea admitted to the Infectious Diseases Hospital, Calcutta was investigated . The predominant serogroup was C and Salmonella infantis was the major serotype isolated followed by S . worthington, S . enteritidis, S . typhimurium, S . weltevereden and S . newport . All the Salmonella strains were isolated from adults . Multidrug resistance to various antimicrobial agents was observed in 37.5 per cent of the strains . All the strains were sensitive to ciprofloxacin, norfloxacin and gentamycin. Indian J Med Res, 1999 Dec, 110, 181 - 2 Copper resistance & its correlation to multiple drug resistance in Salmonella typhi isolates from south Karnataka; Ciraj AM et al.; A study was conducted to ascertain the prevalence of copper resistant Salmonella typhi isolates in south Karnataka . Of the 186 strains studied, 26 (13.97%) were found to be copper resistant . Among the copper resistant strains 19 (73.08%) were found multi drug resistant . All copper resistant strains remained uniformly sensitive to ceftriaxone, ciprofloxacin and norfloxacin . Multiple drug resistance was exclusively associated with E1 phage types. J Med Ethics, 2000 Feb, 26(1), 9 - 15 Ignorance is bliss? HIV and moral duties and legal duties to forewarn; Bennett R et al.; In 1997, a court in Cyprus jailed Pavlos Georgiou for fifteen months for knowingly infecting a British woman, Janet Pink, with HIV-1 through unprotected sexual intercourse . Pink met Georgiou in January 1994 whilst on holiday . She discovered that she had contracted the virus from him in October 1994 but continued the relationship until July 1996 when she developed AIDS . She returned to the UK for treatment and reported Georgiou to the Cypriot authorities . There have been a number of legal cases involving deliberate transmission of HIV, but most have involved forced exposure to infected bodily fluids for example, rape or biting, and have been dealt with using the existing legislation for rape or assault . While it is often difficult to prove responsibility for transmission in cases of forced exposure to HIV, it is even more contentious in cases like those of Janet Pink where an individual has consented to sex but claims that he/she was not forewarned of his/her partner's HIV-positive status . At present there is no specific criminal offence of having unprotected sexual intercourse without disclosing one's HIV-positive status but a prosecution could possibly be brought under any one of a number of existing offences . Perhaps a change of policy needs to be considered . The Home Office has issued a consultation document which outlines a proposal that will allow the criminalization of intentional transmission of diseases, like HIV, that are likely to cause serious harm . This revised legislation would cover all other potentially fatal diseases (including salmonella and legionnaire's disease, for instance) but seems primarily to be targeted at HIV transmission . Should transmission of HIV through consensual sex, without the HIV-positive status of the individual being disclosed, be an offence? This question, and that of whether there is a moral obligation to disclose a positive HIV status prior to having a sexual relationship is the subject of this paper. Arch Pediatr, 2000 Feb, 7(2), 154 - 7 {Acute Salmonella typhi meningitis in a 25-day-old newborn infant complicated by obstruction of the sylvian artery}; Kay's Kayemba S et al.; Acute Salmonella typhi meningitis is rare in neonates, mostly reported from developing countries with poor socioeconomic conditions . CASE REPORT: A male Caucasian newborn presented with acute Salmonella typhi meningitis at the age of 25 days . His parents had traveled across several African countries under rudimentary hygienic conditions a few months before his birth . Despite early and adapted antibiotic therapy (cefotaxime plus netilmycine), the child developed ischemia in the region of the left sylvian artery . CONCLUSION: Salmonella meningitis must be considered while dealing with a sick newborn whose mother has traveled across countries with endemic typhoid. Appl Environ Microbiol, 2000 Mar, 66(3), 1216 - 9 Development of a nonantibiotic dominant marker for positively selecting expression plasmids in multivalent Salmonella vaccines; McNeill HV et al.; We report the novel application of a herbicide-resistance-based dominant marker for the positive selection of expression plasmids in Salmonella serovar vaccines . The beta-lactamase gene of the plasmid pTETnir15, which expresses fragment C of tetanus toxin (TetC), has been replaced with the bar gene marker . The new plasmid pBAT1 can be positively selected in vitro within Salmonella serovars in the presence of the herbicide DL-phosphinothricin . The expression of TetC remains unaltered, and the Salmonella enterica serovar Typhimurium vaccine strain is stable and immunogenic in vivo. Surg Neurol, 2000 Jan, 53(1), 86 - 90 Multiple brain abscesses caused by Salmonella typhi: case report; Hanel RA et al.; BACKGROUND: Focal intracranial infections caused by Salmonella species are uncommon . The authors report a case of multiple brain abscesses caused by Salmonella typhi . CASE DESCRIPTION: A 2-month-old girl was admitted to the hospital because of diarrhea, vomiting, fever, and poor feeding . Neurological examination revealed cervical hyperextension and absence of sucking and Moro reflexes . During the next 20 hours she developed complex partial seizures with secondary generalization and alternated irritability with drowsiness . Investigation showed hemoglobin 6.3 g/dl; white blood cell count of 19500/mm3 with a marked shift to the left . The analysis of the cerebrospinal fluid revealed white cell count of 1695/mm3, lymphocytes 61%, protein 300 mg/dl and glucose 6 mg/dl . The patient was treated for acute gastroenterocolitis, sepsis, and meningitis . Blood culture taken on the day of admission showed gram-negative bacilli, later identified as S . typhi . Computed tomography scan demonstrated a lesion in the right parietal lobe compatible with a brain abscess . Follow-up computed tomography after 7 days showed several other lesions with the same features . Surgical drainage of the right parietal lesion was performed on the 13th day, through a burr hole . The patient was discharged 5 weeks after admission without neurological deficit . CONCLUSION: Bacteremia, sepsis, and meningitis are relatively common in children with Salmonella infection but intracranial abscesses are very rare . Surgical drainage combined with prolonged antibiotic therapy (drug of choice: chloramphenicol) is the best treatment for Salmonella brain abscesses . The possibility of intracranial infection should be considered in patients with Salmonellosis and neurological dysfunction. Can J Microbiol, 1999 Dec, 45(12), 988 - 94 Inhibition of pathogenic Salmonella enteritidis growth mediated by Escherichia coli microcin J25 producing strains; Portrait V et al.; For the first time, microcin-producing strains showing inhibitory activities against enteropathogen Salmonella enteritidis were isolated from poultry intestinal contents . Among the numerous strains isolated, two strains of Escherichia coli, named J02 and J03, showing the greatest activities against S . enteritidis, were studied . Biochemical tests and purification identified the main antagonist compound produced as microcin J25 . In order to evaluate the protective potential of E . coli J02 and J03 against S . enteritidis infection, the ability of these strains to inhibit growth of S . enteritidis was investigated in mixed culture . A strong antagonist activity was obtained with a preculture phase of the active strain in minimal medium before incubation with S . enteritidis . In a bioreactor experiment simulating the chicken gastric and intestinal tract environment, a mixture of the two strains E . coli J02 and J03, provided an enhanced inhibitory effect . Microcinogenic strain activities were not affected by bile, pancreatic enzymes addition, or acidic conditions . These results suggest the relevant role of microcin-producing microorganisms in microbial intestinal ecology . To conclude, this study shows that microcin J25 strains could exert a beneficial protective effect against S . enteritidis growth in situ. J Biol Chem, 2000 Mar 10, 275(10), 7013 - 20 The RcsAB box . Characterization of a new operator essential for the regulation of exopolysaccharide biosynthesis in enteric bacteria; Wehland M et al.; The interaction of the two transcriptional regulators RcsA and RcsB with a specific operator is a common mechanism in the activation of capsule biosynthesis in enteric bacteria . We describe RcsAB binding sites in the wza promoter of the operon for colanic acid biosynthesis in Escherichia coli K-12, in the galF promoter of the operon for K2 antigen biosynthesis in Klebsiella pneumoniae, and in the tviA (vipR) promoter of the operon for Vi antigen biosynthesis in Salmonella typhi . We further show the interaction of RcsAB with the rcsA promoters of various species, indicating that rcsA autoregulation also depends on the presence of both proteins . The compilation of all identified RcsAB binding sites revealed the conserved core sequence TaAGaatatTCctA, which we propose to be termed RcsAB box . The RcsAB box is also part of Bordetella pertussis BvgA binding sites and may represent a more distributed recognition motif within the LuxR superfamily of transcriptional regulators . The RcsAB box is essential for the induction of Rcs-regulated promoters . Site-specific mutations of conserved nucleotides in the RcsAB boxes of the E . coli wza and rcsA promoters resulted in an exopolysaccharide-negative phenotype and in the reduction of reporter gene expression. J Clin Microbiol, 2000 Mar, 38(3), 1269 - 71 Multiple clones within multidrug-resistant Salmonella enterica serotype Typhimurium phage type DT104 . The Greek Nontyphoidal Salmonella Study Group; Markogiannakis A et al.; Six distinct clones were present among Greek multidrug-resistant Salmonella enterica serotype Typhimurium phage type DT104, since isolates belonging to resistance phenotypes including the ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline) core could be distinguished with respect to their pulsed-field gel electrophoresis patterns, int1 integron structures, and presence or absence of antibiotic resistance genes ant(3'')-Ia, pse-1, and tem-1. J Clin Microbiol, 2000 Mar, 38(3), 1221 - 6 Diagnostic and public health dilemma of lactose-fermenting Salmonella enterica serotype Typhimurium in cattle in the Northeastern United States; McDonough PL et al.; The presence of lactose-fermenting Salmonella strains in clinical case materials presented to microbiology laboratories presents problems in detection and identification . Failure to detect these strains also presents a public health problem . The laboratory methods used in detecting lactose-fermenting Salmonella enterica serotype Typhimurium from six outbreaks of salmonellosis in veal calves are described . Each outbreak was caused by a multiply-resistant and lactose-fermenting strain of S . enterica serotype Typhimurium . The use of Levine eosin-methylene blue agar in combination with screening of suspect colonies for C8 esterase enzyme and inoculation of colonies into sulfide-indole-motility medium for hydrogen sulfide production was particularly effective for their detection . A hypothesis for the creation of lactose-fermenting salmonellae in the environment is presented . It is proposed that the environment and husbandry practices of veal-raising barns provide a unique niche in which lactose-fermenting salmonellae may arise. Am Surg, 2000 Feb, 66(2), 219 - 22 Intestinal perforation secondary to Salmonella typhi: case report and review of the literature; Stoner MC et al.; The case of a young woman presenting with fever, abdominal distention, and diarrhea is presented . While hospitalized, she developed peritonitis, and a laparotomy was performed emergently . Intraoperative and pathologic examinations are highly suggestive of Salmonella typhi as an etiology for her symptoms and eventual perforation . Salmonella enteritis can be a difficult diagnosis to make, but in most cases it is a self-limited disease process . In a minority of cases, multidrug antibiotic therapy may be required secondary to an increasing prevalence of resistant strains . Patients who perforate require prompt operation to limit morbidity and mortality . Outcome is significantly improved in those patients by directed resection of the affected segment of bowel and by aggressive perioperative care. Epidemiol Infect, 1999 Dec, 123(3), 431 - 6 Electronic network for monitoring travellers' diarrhoea and detection of an outbreak caused by Salmonella enteritidis among overseas travellers; Osaka K et al.; The Traveller's Diarrhoea Network, by which the Infectious Disease Surveillance Center is electronically connected with two major airport quarantine stations and three infectious disease hospitals, was launched in February 1988 in Japan . The data on travellers' diarrhoea detected is reported weekly by e-mail . Two clusters of infection among travellers returning from Italy were reported by two airport quarantine stations at the end of September 1998 . A total of 12 salmonella isolates from 2 clusters were examined . All were identified as Salmonella enteritidis, phage type 4 and showed identical banding patterns on pulsed-field gel electrophoresis . A case-control study showed that the scrambled eggs served at the hotel restaurant in Rome were the likely source of this outbreak . This outbreak could not have been detected promptly and investigated easily without the e-mail network . International exchange of data on travellers' diarrhoea is important for preventing and controlling food-borne illnesses infected abroad. Epidemiol Infect, 1999 Dec, 123(3), 423 - 30 Levels of virulence are not determined by genomic lineage of Salmonella enterica serotype Enteritidis strains; Olsen JE et al.; Mouse virulence and the ability to adhere to, and invade cultured MDCK cells were investigated in 38 phage type reference strains of Salmonella enterica serotype Enteritidis and correlated with genomic lineage . The genomic lineage of 11 of the strains was determined in the present study; one IS200 and one ribotype pattern that had not been reported previously were observed . Log c.f.u . in the spleen 10 days post intraperitoneal (i.p.) infection with 3x10(3) bacteria (logVC10) varied between 2.9 and 8.7 . The reference strains of PT7 and PT23 were found to be semi-rough and were of low virulence . All other strains possessed smooth LPS . Within each of the two major clonal lines, as well as among phage types outside these, both highly virulent and moderate to low virulent strains were present . While all strains of PT1, PT2 and PT8 were highly virulent, low virulent strains were detected in PT4 and PT13 . The ability to adhere to, and invade MDCK cells varied between phage types (adherence between 13 and 61% of the inocula and invasion between 4 and 151% of the adherent cells) . The results of the cell culture experiments did not correlate with the results of mouse virulence tests . No correlation between clonal lineage and virulence was found within S . Enteritidis . It seems most likely that some strains have lost some of the essential factors enabling this serotype to cause successful systemic infection. J Perinatol, 2000 Jan-Feb, 20(1), 54 - 6 Fatal neonatal Salmonella enteritidis sepsis; Pumberger W et al.; A case history of a fatal neonatal infection caused by Salmonella enteritidis group D is reported . The baby deteriorated rapidly at 24 hours after birth with clinical signs and symptoms of an acute abdomen . Bloody diarrhea led to a tentative diagnosis of midgut volvulus or necrotizing enterocolitis . Autopsy and bacteriologic investigation revealed sepsis by S . enteritidis group D . The same organism was found in cultures taken from stool and vaginal swabs from the mother . This clearly confirmed transmission of the infection during delivery. J Bacteriol, 2000 Mar, 182(6), 1558 - 63 ssrA (tmRNA) plays a role in Salmonella enterica serovar Typhimurium pathogenesis; Julio SM et al.; Escherichia coli ssrA encodes a small stable RNA molecule, tmRNA, that has many diverse functions, including tagging abnormal proteins for degradation, supporting phage growth, and modulating the activity of DNA binding proteins . Here we show that ssrA plays a role in Salmonella enterica serovar Typhimurium pathogenesis and in the expression of several genes known to be induced during infection . Moreover, the phage-like attachment site, attL, encoded within ssrA, serves as the site of integration of a region of Salmonella-specific sequence; adjacent to the 5' end of ssrA is another region of Salmonella-specific sequence with extensive homology to predicted proteins encoded within the unlinked Salmonella pathogenicity island SPI4 . S . enterica serovar Typhimurium ssrA mutants fail to support the growth of phage P22 and are delayed in their ability to form viable phage particles following induction of a phage P22 lysogen . These data indicate that ssrA plays a role in the pathogenesis of Salmonella, serves as an attachment site for Salmonella-specific sequences, and is required for the growth of phage P22. J Vet Diagn Invest, 2000 Jan, 12(1), 83 - 7 Improved plating media for the detection of Salmonella species with typical and atypical hydrogen sulfide production; Mallinson ET et al.; The Salmonella detection ability of 2 surfactant-supplemental media, xylose-lysine-tergitol (Nia-proof) 4 (XLT4) and Miller-Mallinson (MM) agar, was compared against that of several commonly used plating media . XLT4 and MM appeared to be the most efficient in detecting Salmonella in meat products and food animal environments . MM was superior to XLT4 in detecting those increasingly more prevalent strains of Salmonella possessing weak to ultraweak H2S production characteristics. Antibiot Khimioter, 2000, 45(1), 21 - 4 {A comparative analysis of the properties of bacteria in the genus Salmonella isolated from children in Latvia}; Grope I et al.; Since social and economic changes in Latvia in 1991 the incidence of salmonellosis dramatically increased: more than 500 pediatric cases are registered every year . Specification of the properties of the Salmonella strains isolated in Latvia was undertaken . The study demonstrated that acute salmonellosis in pediatric inpatients was mainly due to S.typhimurium (78 per cent) and only in 22 per cent of the patients it was due to S.enteritidis . All the S.typhimurium isolates showed high antibiotic resistance defined by specific extended spectrum beta-lactamase (CTX-M-5). J Travel Med, 2000 Jan, 7(1), 19 - 24 Typhoid fever in group travelers: opportunity for studying vaccine efficacy; Cobelens FG et al.; BACKGROUND: Typhoid fever (TF) is a rare disease among travelers to endemic areas, and little is known about its travel-related epidemiology . In addition, efficacy data on TF vaccines in travelers is scanty . During 3 months of 1994/95, six cases of TF were reported in The Netherlands among participants of four package tours to Indonesia provided by the same operator . The present study was designed to describe the epidemiology of TF in these groups, and to assess whether travel groups can be used for studying the efficacy of TF vaccines in travelers . METHOD: Questionnaire-based historical cohort study of participants of 4 groups that stayed in the same hotels along their tours (n=156) . TF was defined as blood culture-confirmed Salmonella typhi infection . Submitted isolates were typed by antigen and phage typing . Immunization status was considered documented if ascertained by written records . RESULTS: Among 110 participants (71%), six cases of TF were identified (group specific attack rate AR 5.4%), three of which were from one travel group (AR 12.0%) . There were no significant differences by age or sex . Three submitted S . typhi isolates showed three different types, two of which were in the same group . Eighty-three percent of respondents reported documented TF vaccination in the preceding 3 years . All cases occurred in recipients of the oral Ty21a vaccine (AR 10.2%, 95% CI 3.8-20.8%), but differences with nonvaccinees and recipients of the heat-inactivated whole cell or Vi-antigen polysaccharide vaccines were not significant . CONCLUSIONS: Although TF is rare in travelers, infections with different strains of S . typhi can occur in one travel group . Travel groups offer an opportunity for retrospective assessment of vaccine efficacy, provided that equal chance of exposure is largely guaranteed; case ascertainment is maximally specific and similar in the vaccine groups; vaccine status is ascertained accurately; and prior immunity by previous exposures to and use of antibiotics effective against the infection are excluded from, or controlled for in, the analysis. J Travel Med, 2000 Jan, 7(1), 15 - 8 Etiology of travelers' diarrhea on a Caribbean island; Paredes P et al.; BACKGROUND: Between December 6, 1994 and March 10, 1996, a study of the etiology of diarrhea was carried out among 332 travelers to five all-inclusive hotels in Negril, Jamaica . METHODS: Stool specimens were collected and sent to Montego Bay for laboratory analysis . Escherichia coli strains isolated at the Jamaican laboratory were sent to Houston for toxin testing . RESULTS: A recognized enteropathogen was found in 118 of the 332 (35.5%) cases . Enterotoxigenic E . coli (ETEC) were the most commonly identified pathogen (87/332; 26.2%) followed by Salmonella (4.2%) and Shigella (4.2%) . Clustering of etiologically defined cases was studied at each hotel . A cluster was defined as 2 or more cases with the same pathogen identified in the same hotel within 7 days . In the 3 hotels with the highest number of cases of diarrhea, enteropathogens were part of a cluster in 65 of 99 cases (65.7%) of diarrhea of which an etiologic agent was identified . In the other 2 hotels, only 4 of 20 cases (20%) occurred in clusters . CONCLUSIONS: A total of 25 clusters of travelers' diarrhea cases was detected at the five hotels during the study period . Seventeen of 25 (68%) ETEC isolations occurred as part of a clustering of diarrhea cases . The largest outbreak of pathogen-identified diarrhea consisted of 7 cases of ETEC producing both heat-stable and heat-labile enterotoxins . In the Jamaican hotels with all inclusive meal packages most diarrhea cases occurred as small clusters, presumably as the result of foodborne outbreaks. Am J Infect Control, 2000 Feb, 28(1), 54 - 7 Direct costs associated with a nosocomial outbreak of Salmonella infection: an ounce of prevention is worth a pound of cure; Spearing NM et al.; BACKGROUND: Nosocomial outbreaks of Salmonella infections in Australia are an infrequent but significant source of morbidity and mortality . Such an outbreak results in direct, measurable expenses for acute care management, as well as numerous indirect (and less quantifiable) costs to those affected, the hospital, and the wider community . This article describes the significant direct costs incurred as a result of a nosocomial outbreak of Salmonella infection involving patients and staff . METHOD: Information on costs incurred by the hospital was gathered from a number of sources . The data were grouped into 4 sections (medical costs, investigative costs, lost productivity costs, and miscellaneous) with use of an existing tool for calculating the economic impact of foodborne illness . RESULTS: The outbreak cost the hospital more than AU $120, 000 . (US $95,000) . This amount is independent of more substantial indirect costs . CONCLUSION: Salmonella infections are preventable . Measures to aid the prevention of costly outbreaks of nosocomial salmonellosis, although available, require an investment of both time and money . We suggest that dedication of limited resources toward such preventive strategies as education is a practical and cost-effective option for health care facilities. Infect Immun, 2000 Mar, 68(3), 1549 - 56 Construction and characterization of a Salmonella enterica serovar typhimurium clone expressing a salivary adhesin of Streptococcus mutans under control of the anaerobically inducible nirB promoter; Huang Y et al.; Attenuated Salmonella enterica serovar Typhimurium has been used for targeted delivery of recombinant antigens to the gut-associated lymphoid tissues . One potential problem associated with this vaccine approach is the likelihood of in vivo instability of the plasmid constructs caused by constitutive hyperexpression of the heterologous immunogen . The aim of this study was to generate and characterize an expression system encoding the saliva-binding region (SBR) of Streptococcus mutans antigen I/II adhesin, either alone or linked with the mucosal adjuvant cholera toxin A2/B subunits (CTA2/B), under the control of the inducible nirB promoter . This promoter is activated in an anaerobic environment and within macrophages, which are the primary antigen-presenting cells involved in phagocytosis and processing of Salmonella . The gene encoding the chimeric SBR-CTA2/B was amplified by PCR using primers containing appropriate restriction sites for subcloning into pTETnirB, which contains the nirB promoter . The resulting plasmid was introduced into serovar Typhimurium by electroporation . Production of the SBR-CTA2/B chimeric protein under anaerobic conditions was verified by enzyme-linked immunosorbent assay of whole-cell lysates on plates coated with G(M1) ganglioside and developed with antibodies to SBR . Similar procedures were followed for cloning the gene encoding SBR in serovar Typhimurium under nirB control . Anaerobic expression of SBR was confirmed by Western blotting of whole-cell lysates probed with anti-SBR antibodies . The resulting serovar Typhimurium strains were administered by either the oral or the intranasal route to mice, and colonization was assessed by microbiologic analysis of dissociated spleens, Peyer's patches (PP), and nasal tissues . High numbers of the recombinant strains persisted in PP and spleen for at least 21 days following oral challenge . A single intranasal administration of the Salmonella clones to mice also resulted in the colonization of the nasal tissues by the recombinant bacteria . Salmonellae were recovered from nasal lymphoid tissues, superficial lymph nodes, internal jugular lymph nodes, PP, and spleens of mice for at least 21 days after challenge . This study provides quantitative evidence for colonization by Salmonella strains expressing a recombinant protein under the control of the inducible nirB promoter in PP or nasal tissues following a single oral or nasal administration of the bacteria, respectively. Infect Immun, 2000 Mar, 68(3), 1529 - 34 Phase 1 and phase 2 studies of Salmonella enterica serovar paratyphi A O-specific polysaccharide-tetanus toxoid conjugates in adults, teenagers, and 2- to 4-year-old children in Vietnam; Konadu EY et al.; Salmonella enterica serovar Paratyphi A O-specific polysaccharide (O-SP) was activated with 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) and bound to tetanus toxoid (TT) with adipic acid dihydrazide as a linker (SPA-TT(1)) or directly (SPA-TT(2)) . In mice, these two conjugates elicited high levels of immunoglobulin G (IgG) anti-lipopolysaccharide (LPS) in serum with bactericidal activity (E . Konadu, J . Shiloach, D . A . Bryla, J . B . Robbins, and S . C . Szu, Infect . Immun . 64:2709-2715, 1996) . The safety and immunogenicity of the two conjugates were then evaluated sequentially in Vietnamese adults, teenagers, and 2- to 4-year-old children . None of the vaccinees experienced significant side effects, and all had preexisting LPS antibodies . At 4 weeks after injection, there were significant increases of the geometric mean IgG and IgM anti-LPS levels in the adults and teenagers: both conjugates elicited a greater than fourfold rise in the IgG anti-LPS level in serum in >/=80% of the volunteers . SPA-TT(2) elicited slightly higher, though not statistically significantly, levels of IgG anti-LPS than did SPA-TT(1) in these age groups . Accordingly, only SPA-TT(2) was evaluated in the 2- to 4-year-old children . On a random basis, one or two injections were administered 6 weeks apart to the children . No significant side effects were observed, and the levels of preexisting anti-LPS in serum were similar in children of all ages . A significant rise in the IgG anti-LPS titer was elicited by the first injection (P = 0.0001); a second injection did not elicit a booster response . Representative sera from all groups had bactericidal activity that could be adsorbed by S . enterica serovar Paratyphi A LPS. Infect Immun, 2000 Mar, 68(3), 1196 - 201 Phase 2 clinical trial of attenuated Salmonella enterica serovar typhi oral live vector vaccine CVD 908-htrA in U.S . volunteers; Tacket CO et al.; Salmonella enterica serovar Typhi strain CVD 908-htrA is a live attenuated strain which may be useful as an improved oral typhoid vaccine and as a vector for cloned genes of other pathogens . We conducted a phase 2 trial in which 80 healthy adults received one of two dosage levels of CVD 908-htrA in a double-blind, placebo-controlled, crossover study . There were no differences in the rates of side effects among volunteers who received high-dose vaccine (4.5 x 10(8) CFU), lower-dose vaccine (5 x 10(7) CFU), or placebo in the 21 days after vaccination, although recipients of high-dose vaccine (8%) had more frequent diarrhea than placebo recipients (0%) in the first 7 days . Seventy-seven percent and 46% of recipients of high- and lower-dose vaccines, respectively, briefly excreted vaccine organisms in their stools . All blood cultures were negative . Antibody-secreting cells producing antilipopolysaccharide (LPS) immunoglobulin A (IgA) were detected in 100 and 92% of recipients of high- and lower-dose vaccines, respectively . Almost half the volunteers developed serum anti-LPS IgG . Lymphocyte proliferation and gamma interferon production against serovar Typhi antigens occurred in a significant proportion of vaccinees . This phase 2 study supports the further development of CVD 908-htrA as a single-dose vaccine against typhoid fever and as a possible live vector for oral delivery of other vaccine antigens. Infect Immun, 2000 Mar, 68(3), 1109 - 15 Salmonella enterica serovar typhimurium surA mutants are attenuated and effective live oral vaccines; Sydenham M et al.; A previously described attenuated TnphoA mutant (BRD441) of Salmonella enterica serovar Typhimurium C5 (I . Miller, D . Maskell, C . Hormaeche, K . Johnson, D . Pickard, and G . Dougan, Infect . Immun . 57:2758-2763, 1989) was characterized, and the transposon was shown to be inserted in surA, a gene which encodes a peptidylprolyl-cis, trans-isomerase . A defined surA deletion mutation was introduced into S . enterica serovar Typhimurium C5 and the mutant strain, named S . enterica serovar Typhimurium BRD1115, was extensively characterized both in vitro and in vivo . S . enterica serovar Typhimurium BRD1115 was found to be defective in the ability to adhere to and invade eukaryotic cells . Furthermore, S . enterica serovar Typhimurium BRD1115 was attenuated by at least 3 log units when administered orally or intravenously to BALB/c mice . Complementation of the mutation with a plasmid carrying the intact surA gene almost completely restored the virulence of BRD1115 . In addition, S . enterica serovar Typhimurium BRD1115 demonstrated potential as a vaccine candidate, since mice immunized with BRD1115 were protected against subsequent challenge with S . enterica serovar Typhimurium C5 . S . enterica serovar Typhimurium BRD1115 also showed potential as a vehicle for the effective delivery of heterologous antigens, such as the nontoxic, protective fragment C domain of tetanus toxin, to the murine immune system. Infect Immun, 2000 Mar, 68(3), 1086 - 93 Cloning of porcine NRAMP1 and its induction by lipopolysaccharide, tumor necrosis factor alpha, and interleukin-1beta: role of CD14 and mitogen-activated protein kinases; Zhang G et al.; The gene for natural resistance-associated macrophage protein 1 (NRAMP1) plays a dominant role in controlling the resistance of inbred mice to infection with intracellular bacteria, such as Mycobacteria, Salmonella, and Leishmania . NRAMP1 is a membrane protein with a consensus transport motif present in one of the intracellular loops . Although its functions remain unclear, recent clues suggest that NRAMP1 protein plays a potential role in ion transport, which presumably accounts for the ability of this single protein to regulate the intraphagosomal replication of several species of antigenically unrelated intracellular pathogens . Expression of NRAMP1 in mice can be induced by lipopolysaccharide (LPS) or bacterial infection; however, little is known about the mechanisms of induction . Here, we report the cloning of the full-length cDNA for porcine NRAMP1, which had over 85% identity in amino acid sequence to its congeners from humans, mice, cattle, and sheep . As for its mammalian congeners, expression of porcine NRAMP1 mRNA was cell and tissue specific and was highest in macrophages . Investigation of the molecular mechanisms by which NRAMP1 is induced showed that LPS-induced expression in macrophages, neutrophils, and peripheral blood mononuclear cells was time and dose dependent and was mediated primarily through CD14 . Induction of NRAMP1 required de novo protein synthesis, and mitogen-activated protein kinases (MAPK) were essential . Blockage of either p38 or p42/44 MAPK pathways suppressed the expression of NRAMP1 to basal levels . These findings suggest that bacterial infection and proinflammatory mediators induce NRAMP1 expression via activation of MAPK pathways. Infect Immun, 2000 Mar, 68(3), 1005 - 13 Differential bacterial survival, replication, and apoptosis-inducing ability of Salmonella serovars within human and murine macrophages; Schwan WR et al.; Salmonella serovars are associated with human diseases that range from mild gastroenteritis to host-disseminated enteric fever . Human infections by Salmonella enterica serovar Typhi can lead to typhoid fever, but this serovar does not typically cause disease in mice or other animals . In contrast, S . enterica serovar Typhimurium and S . enterica serovar Enteritidis, which