Arch Soc Esp Oftalmol, 2000 Jun, 75(6), 377 - 82 {Effect of topical pranoprofen on the lipoxygenase metabolism of the arachidonic and in endotoxin-induced uveitis}; Torron C et al.; PURPOSE: To study the antiinflammatory effect of topical pranoprofen on the lipoxygenase metabolism of the arachidonic acid in albino rabbits . METHODS: Endotoxin-induced uveitis (EIU) was produced in albino rabbits by intravitreal injection in the right eye with 10 microg of Salmonella typhymurium lipopolysacharide A in 5 microl saline solution . We have used 5 groups of 12 animals each . Control group (G-I) was injected with 5 microl of saline solution and 5 microl of ET solution were injected in the remaining groups . Groups III, IV and V were treated with topical pranoprofen 2 hours before intravitreal injection, immediately after and every 6, 4 and 2 hours respectively . The animals were sacrificed 24 hours after the ET administration . Cellular and B4 leukotrien concentration in the aqueous humour was determined . RESULTS: The groups treated with pranoprofen showed a significant decrease in the cellular concentration in relation to the group of endotoxin (G-II) . We did not observe any difference in the B4 leukotriene concentration between ET group and topical pranoprofen groups . CONCLUSION: Topical pranoprofen has not increased the lipoxygenase metabolism of the arachidonic acid. Am J Nephrol, 2000 Nov-Dec, 20(6), 468 - 72 Cytomegalovirus colitis during mycophenolate mofetil therapy for Wegener's granulomatosis; Woywodt A et al.; Cytomegalovirus (CMV) infection of the gastrointestinal tract is an increasingly recognized cause of morbidity and mortality during the course of HIV infection and in association with immunosuppressive pharmacotherapy . Mycophenolate mofetil, a novel immunosuppressive drug, is currently used in renal transplant recipients and is under evaluation for a variety of disorders . There is preliminary evidence to suggest that CMV reactivation may be more common during treatment with mycophenolate than with other immunosuppressive drugs . We present the case of a 59-year-old male with Wegener's granulomatosis who received mycophenolate and presented with guaiac-positive diarrhea 8 weeks after recovery from Salmonella brandenburg infection . CMV serology and assays for CMV antigens were entirely negative . Colonoscopy demonstrated pancolitis and examination of the specimens disclosed CMV infection . Ganciclovir was administered and the patient made an uneventful recovery . We discuss aspects of gastrointestinal CMV infection with an emphasis on pitfalls in diagnosis and the association with mycophenolate mofetil treatment . We also speculate as to the potential role of previous Salmonella infection and proinflammatory cytokines in CMV reactivation . In summary, when using mycophenolate, clinicians should be more aware of CMV reactivation and disease. Pediatr Infect Dis J, 2000 Dec, 19(12), 1158 - 62 Factors associated with intestinal perforation in children's non-typhi Salmonella toxic megacolon; Chao HC et al.; BACKGROUND: To evaluate the risk factors for intestinal perforation in children with toxic megacolon caused by non-typhi Salmonella infection . METHODS: During an 11-year period we reviewed the records of children treated for non-typhi Salmonella infection . All of the subjects had positive stool culture for non-typhi Salmonella and were treated with intravenous ceftriaxone during hospitalization . Clinical data reviewed included demographic features, clinical manifestations, laboratory findings, radiologic findings, microbiology, therapeutic effect of hydration and rectal tube placement and the operative findings . Patients with toxic megacolon were defined as those having toxic appearance, diarrhea, high fever (>39 degrees C) and marked colon dilatation with maximal diameter > 1.5 times the width of the vertebra body of the first lumbar spine (L1-VB) . To define the risk factors for patients with toxic megacolon complicated by intestinal perforation, patients were divided into two groups for analysis: P group, those complicated with intestinal perforation; and NP group, those without intestinal perforation . Differences in age, sex, severity of diarrhea, duration of fever, hemogram and its differential, culture, stool analysis, serum C-reactive protein (CRP), electrolytes, maximal colon diameter, medical therapy and timing of rectal tube insertion between the two groups were analyzed . Statistical analyses were conducted with chi square tests and multiple logistic regression . RESULTS: A total of 75 patients (P group, 27 patients; NP group, 48 patients) ages 4 months to 6 years were evaluated . With chi square analysis 7 variables were found to be significantly associated with intestinal perforation: age >1 year; fever >5 days; ratio of immature to total neutrophils >20%; serum CRP >200 mg/l; colon diameter >2.5 times the width of L1-VB; inadequate early hydration; and delay in rectal tube insertion . With multivariate analysis age >1 year, serum CRP >200 mg/l and colon diameter >2.5 times of width of L1-VB, inadequate early hydration and delay in rectal tube insertion were the most significant factors associated with intestinal perforation . CONCLUSION: Identification of patients with toxic megacolon associated with non-typhi Salmonella infection at risk for further intestinal perforation is possible . Early effective fluid resuscitation and rectal tube insertion may be helpful to prevent the occurrence of intestinal perforation. Dtsch Tierarztl Wochenschr, 2000 Oct, 107(10), 402 - 8 {Administration of autochthonous intestinal microflora--a method to prevent Salmonella infections in poultry}; Methner U; Administration of autochthonous intestinal microflora to chicks during the early period after hatching (Competitive Exclusion) is a widely accepted prophylactic method to control Salmonella infections in poultry . The method of competitive exclusion consists in an administration of intestinal flora from healthy adult birds to chicks during the first hours or days of their life . Use of competitive exclusion cultures will considerably enhance resistance to all Salmonella serovars colonising the chicken intestine and reduce shedding of salmonellas by infected animals . However, sole use of this method does not completely prevent Salmonella colonisation of the animals nor elimination of the agents from poultry flocks . At present, only complex competitive exclusion cultures whose composition has not been defined are capable of inducing an adequately high and reproducible efficacy . Effective preparations with a defined composition have not yet been developed because knowledge of the mechanisms of action of the competitive exclusion cultures as well as the effective species of the various bacterial genera is still inadequate . Since in approval procedures, the competitive exclusion cultures with a non-defined composition can neither be classified as medicines nor feed additives nor vaccines, WHO has proposed to establish the product category "Normal Gut Flora" (WHO, 1994) . Basic prerequisites for an effective reduction of non-host-adapted Salmonella serovars in, or their elimination from poultry flocks are the performance and assurance of effective hygienic measures . Like the methods of immunisation using live or inactivated Salmonella vaccines in poultry, the method of competitive exclusion constitutes an additional prophylactic method that may be applied directly in the animal to enhance its resistance to Salmonella infection. Can J Microbiol, 2000 Dec, 46(12), 1149 - 52 The fliU and fliV genes are expressed as a single ORF in Salmonella choleraesuis; Ho KC et al.; A DNA fragment carrying flagellar genes was cloned from Salmonella choleraesuis . Compared to the corresponding DNA fragment of Salmonella muenchen, this fragment contained three ORFs instead of four shown in S . muenchen . The DNA sequence data showed that there was an insertion of nucleotide C in the ORF of the S . choleraesuis fliU gene, which resulted in the disappearance of a termination codon downstream . The recombinant plasmid pFU11 containing the coding region of the fliU gene made by PCR on S . choleraesuis genomic DNA was constructed and expressed in Escherichia coli in the presence of IPTG . As expected, a 45 kDa protein band was observed on a SDS-PAGE gel, in contrast to two with each having about a half of the molecular weight . These results demonstrated that the DNA sequence encoding one protein (FliU) in S . choleraesuis corresponded to the DNA sequence encoding two proteins (FliU and FliV) in S . muenchen . The protein encoded by this single ORF might carry out the functions of two separated proteins by folding in such a way that its conformation could function like two interdependent protein subunits. Rofo, 2000 Nov, 172(11), 934 - 9 {Possible mutagenic effects of magnetic fields}; Teichmann EM et al.; AIM: To assess the potential mutagenic effect of static magnetic fields of 1.5 T and 7 T, gradient fields and high frequency magnetic fields . METHOD: We used the Salmonella mutagenicity test (Ames test), which detects mutations in a gene of a histidine-requiring (his-) strain to produce a histidine-independent (his+) strain, Exposure to a static magnetic field of 1.5 T and 7.2 T, in a bipolar magnetic gradient and additionally in a high frequency field took place with and without known genotoxic chemicals . RESULTS: No differences in the number of revertants between the bacterial strains of exposed and control cells could be detected and the exposure with known genotoxic chemicals showed no significant difference in mutagenicity . CONCLUSION: In conclusion our data do not provide evidence that exposure to a static magnetic field exerts effects on the mutagenicity in our standard tester strains and whether the exposure took place in a diagnostic 1.5 T MR scanner which is used in the clinical routine or at 7.2 T which is a much stronger field made no difference . Also an exposure in a gradient field or in a high frequency field did not show any alteration in the number of revertants. Ann Ig, 2000 Jul-Aug, 12(4), 279 - 85 {Epidemiologic study and cost analysis of an Slamonella enteritidis epidemic}; Lopalco PL et al.; Salmonellosis is one of the most common forms of foodborne infection . An outbreak of gastroenteritidis associated with a wedding party was investigated, even to value the costs falling on individuals, the health services and society as a whole . One hundred and fifty nine wedding guests were interviewed by phone . Multivariate analysis was used to assess which food were significantly associated with infection . One hundred and thirteen cases were identified; ten stool samples were culture positive for Salmonella enteritidis . Handmade ice-cream and baba (a typical Italian pastry) were significantly associated with infection . The cost of a case was estimated to be between US $ 74 (for non hospitalised patients) and US $ 1,896 (for hospitalised patients) . The outbreak was caused by a strain of Salmonella enteritidis and the vehicle of infection were unpasteurised eggs used to prepare the ice-cream . The economic impact of this outbreak was considerable and mainly due to the hospitalisation. Int J Food Microbiol, 2000 Dec 5, 62(1-2), 161 - 4 Incidence of Listeria spp . and Salmonella spp . in horsemeat for human consumption; de Assis MA et al.; The incidence of Salmonella spp., Listeria spp . and Listeria monocytogenes in horsemeat for human consumption was investigated . One-hundred and twenty-one samples of frozen horsemeat collected from two Brazilian abattoirs were analysed over a period of 1 year . Twenty-two samples (18.2%) were positive for Listeria spp . with nine (7.4%) containing L . monocytogenes . None of the samples harbored Salmonella spp. Int J Food Microbiol, 2000 Dec 5, 62(1-2), 123 - 31 Survival and growth of Salmonella baildon in shredded lettuce and diced tomatoes, and effectiveness of chlorinated water as a sanitizer; Weissinger WR et al.; An outbreak of salmonellosis associated with diced tomatoes occurred in the United States in 1999 . Experiments were done to determine the efficacy of chlorine in killing Salmonella baildon, the causative serotype, inoculated onto shredded lettuce and diced tomatoes, and to determine survival characteristics of the organism on these produce items stored at 4 degrees C for up to 12 days and on tomatoes stored at 21 or 30 degrees C for up to 72 h . Populations of S . baildon in lettuce and tomatoes (pH 4.51 +/- 0.02) inoculated with 3.60 log10 and 3.86 log10 cfu/g, respectively, were reduced by less than 1 log when the produce was immersed for 40 s in a 120 or 200 microg/ml free chlorine solution . Produce inoculated with 0.60-0.86 log10 cfu/g was positive for the pathogen after treatment with 200 microg/ml chlorine . Initial populations of 3.28 and 3.40 log10 cfu/g of lettuce and tomatoes, respectively, decreased by about 2 log10 cfu/g during storage for 12 days at 4 degrees C . One of six samples of lettuce initially containing 0.28 log10 cfu of S . baildon per gram was positive after storage for 12 days, but the pathogen was not detected in tomatoes analyzed within 15 min of inoculation with 0.40 log10 cfu/g . While the number of viable cells decreased during storage at 4 degrees C, initial populations of 0.28 log10 cfu/g of shredded lettuce and 3.40 log10 cfu/g of diced tomatoes are not reduced to undetectable levels during storage at 4 degrees C for 12 days . Tolerance of S . baildon to an acidic pH (4.5) was not influenced by the pH (4.5, 5.8, or 7.2) of the medium in which it was grown, suggesting that this strain possesses unusual resistance to acid pH . The pathogen grew in diced tomatoes (pH 4.40 +/- 0.01) from an initial population of 0.79 log10 cfu/g to 5.32 and 7.00 log10 cfu/g within 24 h at 21 and 30 degrees C, respectively. J Vasc Surg, 2001 Jan, 33(1), 106 - 13 Mycotic aneurysms of the thoracic and abdominal aorta and iliac arteries: experience with anatomic and extra-anatomic repair in 33 cases; Muller BT et al.; OBJECTIVE: A mycotic aneurysm of the aorta and adjacent arteries is a dreadful condition, threatening life, organs, and limbs . With regard to the aortic segment involved, repair by either in situ replacement or extra-anatomic reconstruction can be quite challenging . Even when surgery has been successful, the prognosis is described as very poor because of the weakened health status of the patient who has developed this type of aneurysm . The aim of our study was to find out whether any progress could be achieved in a single center over a long time period (18 years) through use of surgical techniques and antiseptic adjuncts . MATERIAL AND METHODS: From January 1983 to December 1999, a total of 2520 patients with aneurysms of the thoracic and abdominal aorta and iliac arteries underwent surgery for aortic or iliac replacement at our institution . During that period, 33 (1.31%) of these patients (mean age, 64.3 years) were treated for mycotic aneurysms of the lower descending and thoracoabdominal (n = 13), suprarenal (n = 4), and infrarenal (n = 10) aorta and iliac arteries (n = 6) . Twenty (61%) of these 33 patients had histories of various septic diseases; in the other 13 (39%), the etiology remained uncertain . Preoperative signs of infection, such as leukocytosis and elevated C-reactive protein, were found in 79% of the patients, and fever was apparent in 48%; 76% of the patients complained of pain . At the time of surgery, eight (24%) mycotic aneurysms were already ruptured, and 20 (61%) had penetrated into the periaortic tissues, forming a contained rupture . Five (15%) aneurysms were completely intact . The predominant microorganisms found in the aneurysm sac were Staphylococcus aureus and Salmonella species . Careful debridement of all infected tissue was essential . In the infrarenal aortic and iliac vascular bed, in situ reconstruction was performed only in cases of anticipated "low-grade" infection . Alternative revascularization with extra-anatomic procedures (axillobifemoral or femorofemoral crossover bypass graft) was carried out in eight of 16 cases . All four suprarenal and all 13 mycotic aneurysms of the thoracoabdominal aortic segment were repaired in situ . Antibiotics were administered perioperatively, and all patients were subsequently treated with long-term antibiotics . RESULTS: In-hospital mortality was 36% (n = 12) . Because of the smallness and heterogeneity of the sample, we could not demonstrate significant evidence for any influence of aneurysm location or type of reconstruction on patients' outcome . However, survival was clearly influenced by the status of rupture . During long-term follow-up (mean, 30 months; range, 1-139 months), 10 patients (48%) died-one (4.8%) probably as a consequence of the mycotic aneurysm, the others for unrelated reasons . Eleven patients (52%) are alive and well today, with no signs of persistent or recurrent infection . CONCLUSIONS: A mycotic aneurysm of the aortic iliac region remains a life-threatening condition, especially if the aneurysm has already ruptured by the time of surgery . Although the content of the aneurysm sac is considered septic, as was proved by positive cultures in 85% of our patients, in situ reconstruction is feasible and, surprisingly, was not more closely related to higher morbidity and mortality in our series than ligation and extra-anatomic reconstruction, although most of the aneurysms repaired in situ were located at the suprarenal and thoracoabdominal aorta . We assume that our operative mortality rate of 36%, which relates to a rupture rate of 85%, could be substantially lowered if the diagnosis of mycotic aneurysm were established before rupture. J Clin Microbiol, 2001 Jan, 39(1), 201 - 6 Fluorescent amplified-fragment length polymorphism subtyping of the Salmonella enterica serovar enteritidis phage type 4 clone complex; Desai M et al.; Fluorescent amplified-fragment length polymorphism (FAFLP) analysis, a high-resolution PCR-based genome fingerprinting method, was used to subtype Salmonella enterica serovar Enteritidis phage type 4 . This single phage type is responsible for the majority of salmonellosis in Europe . Twenty strains isolated from nine outbreaks, five isolates from sporadic cases of human infection, four strains of poultry origin, and one laboratory-derived strain were comparatively studied by pulsed-field gel electrophoresis (PFGE) and FAFLP analysis . Following macrorestriction with XbaI, PFGE classified 73% of PT4 strains as a single type . FAFLP analysis was carried out with the primer pair EcoRI+0 and MseI+C, by simultaneously sampling 170 to 190 loci throughout the PT4 genome . Twenty-three FAFLP profiles, with 1 to 61 amplified-fragment differences, were found among the 30 strains . The index of discriminatory power of FAFLP analysis was 0.98, compared to 0.47 for PFGE . FAFLP analysis assigned genotypes to each PT4 outbreak, as well as sporadic PT4 infections, a significant development for the epidemiology and control of this zoonotic enteric pathogen. J Clin Microbiol, 2001 Jan, 39(1), 154 - 61 Diversity of strains of Salmonella enterica serotype enteritidis from English poultry farms assessed by multiple genetic fingerprinting; Liebana E et al.; Reliable and sufficiently discriminative methods are needed for differentiating individual strains of Salmonella enterica serotype Enteritidis beyond the phenotypic level; however, a consensus has not been reached as to which molecular method is best suited for this purpose . In addition, data are lacking on the molecular fingerprinting of serotype Enteritidis from poultry environments in the United Kingdom . This study evaluated the combined use of classical methods (phage typing) with three well-established molecular methods (ribotyping, macrorestriction analysis of genomic DNA, and plasmid profiling) in the assessment of diversity within 104 isolates of serotype Enteritidis from eight unaffiliated poultry farms in England . The most sensitive technique for identifying polymorphism was PstI-SphI ribotyping, distinguishing a total of 22 patterns, 10 of which were found among phage type 4 isolates . Pulsed-field gel electrophoresis of XbaI-digested genomic DNA segregated the isolates into only six types with minor differences between them . In addition, 14 plasmid profiles were found among this population . When all of the typing methods were combined, 54 types of strains were differentiated, and most of the poultry farms presented a variety of strains, which suggests that serotype Enteritidis organisms representing different genomic groups are circulating in England . In conclusion, geographical and animal origins of Salmonella serotype Enteritidis isolates may have a considerable influence on selecting the best typing strategy for individual programs, and a single method cannot be relied on for discriminating between strains. Braz J Infect Dis, 2000 Dec, 4(6), 279 - 83 Seasonal and age distribution of rotavirus infection in Porto Alegre--Brazil; Bittencourt JA et al.; Diarrhea is one of the most important causes of morbidity and mortality in countries with inadequate water sanitation, crowding and poverty . In this study we evaluated the rotavirus infection profile in Porto Alegre, Brazil . We analyzed the results of 603 laboratory tests obtained from patients who attended a private laboratory to investigate gastroenteritis during a 2 year period (from July 1996 to June 1998) . Rotavirus was identified as the causative agent in 42/312 (13.4%) of patients during the first year, and in 55/291 (18.9%) during the second year . Coproculture for Salmonella and Shigela was positive in only 6.6% of the patients . The prevalence of rotavirus was significantly higher in the winter season and inversely related to the average temperature . Children 7 months to 18 months of age were the most common group infected with rotavirus . The presence of leukocytes in the feces did not correlate with the occurrence of this disease . These results agree with other studies concerning the age group, season, and overall prevalence of rotavirus . The results confirm the need for new approaches to the prevention, diagnoses and management of this disease. Braz J Infect Dis, 2000 Dec, 4(6), 275 - 8 Serial outbreaks of food-borne disease in Blumenau, Brazil, caused by Salmonella enteritidis; dos Santos SM et al.; This work describes the epidemic profile of outbreaks of food infection caused by Salmonella enteritidis, serogroup D, in the city of Blumenau, Federal State of Santa Catarina, Brazil, during the period between February, 1994, and June, 1997 . Ninety-six outbreaks were observed, and 79 (82%) were investigated, involving 7,802 people with signs and symptoms consistent with the infection . Most frequent symptoms were diarrhea (92%), abdominal pain (73%), fever (70%), vomiting (49%) and nausea (45%) . Mayonnaise was the food most frequently associated with the outbreaks, being the responsible vehicle in almost two thirds of the cases investigated . The outbreaks most frequently occurred at home (60%), but the largest number of infections resulted from industrial kitchens (78%) . The age group between 20 and 30 years was most affected . No relationships between the number of outbreaks and outside temperature or humidity were found . The attack rate showed no significant difference between men and women . Better attention to storage of food products at home and in industrial kitchens is needed to control this common gastrointestinal illness. Mol Microbiol, 2001 Jan, 39(2), 248 - 59 A Salmonella inositol polyphosphatase acts in conjunction with other bacterial effectors to promote host cell actin cytoskeleton rearrangements and bacterial internalization; Zhou D et al.; A central feature of Salmonella pathogenicity is the bacterium's ability to enter into non-phagocytic cells . Bacterial internalization is the consequence of cellular responses characterized by Cdc42- and Rac-dependent actin cytoskeleton rearrangements . These responses are triggered by the co-ordinated function of bacterial proteins delivered into the host cell by a specialized protein secretion system termed type III . We report here that SopB, a Salmonella inositol polyphosphatase delivered to the host cell by this secretion system, mediates actin cytoskeleton rearrangements and bacterial entry in a Cdc42-dependent manner . SopB exhibits overlapping functions with two other effectors of bacterial entry, the Rho family GTPase exchange factors SopE and SopE2 . Thus, Salmonella strains deficient in any one of these proteins can enter into cells at high efficiency, whereas a strain lacking all three effectors is completely defective for entry . Consistent with an important role for inositol phosphate metabolism in Salmonella-induced cellular responses, a catalytically defective mutant of SopB failed to stimulate actin cytoskeleton rearrangements and bacterial entry . Furthermore, bacterial infection of intestinal cells resulted in a marked increase in Ins(1,4,5,6)P4, a consumption of InsP5 and the activation of phospholipase C . In agreement with the in vivo findings, purified SopB specifically dephosphorylated InsP5 to Ins(1,4,5,6)P4 in vitro . Surprisingly, the inositol phosphate fluxes induced by Salmonella were not caused exclusively by SopB . We show that the SopB-independent inositol phosphate fluxes are the consequence of the SopE-dependent activation of an endogenous inositol phosphatase . The ability of Salmonella to stimulate Rho GTPases signalling and inositol phosphate metabolism through alternative mechanisms is an example of the remarkable ability of this bacterial pathogen to manipulate host cellular functions. J Clin Endocrinol Metab, 2000 Dec, 85(12), 4624 - 9 Changes in dehydroepiandrosterone (DHEA) and DHEA-sulfate plasma levels during experimental endotoxinemia in healthy volunteers; Schuld A et al.; Dehydroepiandrosterone (DHEA) and DHEA-sulfate (DHEA-S) have immunomodulatory effects in vitro and in vivo . Additionally, their plasma levels are altered during chronic infection and inflammation . However, it remains unknown whether these steroids are involved in early host responses to infection in humans . We examined DHEA and DHEA-S levels during experimental endotoxinemia, a well established pathophysiological model of bacterial infections in humans . Purified Salmonella abortus equi endotoxin (0.2, 0.4, or 0.8 ng/kg body weight) was injected in a single-blind, placebo-controlled experiment to 17 healthy male volunteers . During the following 12 h, rectal temperature and the plasma levels of ACTH, cortisol, DHEA, DHEA-S, interleukin 6, and tumor necrosis factor alpha were determined . Confirming earlier studies, temperature and cytokine levels showed monophasic, dose-dependent increases in response to endotoxin . In contrast, endocrinological effects of endotoxin showed a complex, biphasic pattern: cortisol levels were not affected by 0 . 2 ng/kg but significantly increased during the first 6 h following 0 . 4 and 0.8 ng/kg endotoxin, whereas ACTH and DHEA levels were significantly enhanced during the first 6 h following 0.8 ng/kg only . ACTH, DHEA, and cortisol secretion was blunted 6-12 h following 0.8 ng/kg . DHEA-S levels were unaffected during the first 6 h following all dosages, but between 6-12 h after injection they were significantly increased following 0.2 ng/kg, unaffected by 0.4 ng/kg, and significantly decreased following 0.8 ng/kg endotoxin . The present results suggest that similarly to glucocorticoids, the adrenal androgens DHEA and DHEA-S play an important role during early host responses to bacterial infections in humans. J Bacteriol, 2001 Jan, 183(2), 611 - 20 Characterization of grvA, an antivirulence gene on the gifsy-2 phage in Salmonella enterica serovar typhimurium; Ho TD et al.; The lambdoid phage Gifsy-2 contributes significantly to Salmonella enterica serovar Typhimurium virulence . The phage carries the periplasmic superoxide dismutase gene, sodCI, and other unidentified virulence factors . We have characterized the gene grvA, a single open reading frame inserted in the opposite orientation in the tail operon of the Gifsy-2 phage . Contrary to what is observed with classic virulence genes, grvA null mutants were more virulent than wild type as measured by intraperitoneal competition assays in mice . We have termed this effect antivirulence . Wild-type grvA in single copy complemented this phenotype . However, grvA(+) on a multicopy plasmid also conferred the antivirulence phenotype . Neither a grvA null mutation nor the grvA(+) plasmid conferred a growth advantage or disadvantage in laboratory media . The antivirulence phenotype conferred by the grvA null mutation and the grvA(+) plasmid required wild-type sodCI but was independent of other virulence factors encoded on Gifsy-2 . These results suggest that in a wild-type situation, GrvA decreases the pathogenicity of serovar Typhimurium in the host, most likely by affecting resistance to toxic oxygen species . These virulence phenotypes were independent of functional Gifsy-2 phage production . Our data suggest that the contribution of Gifsy-2 is a complicated sum of both positive virulence factors such as sodCI and antivirulence factors such as grvA. Appl Environ Microbiol, 2001 Jan, 67(1), 459 - 61 Application of rapid dot blot immunoassay for detection of Salmonella enterica serovar enteritidis in eggs, poultry, and other foods; Yoshimasu MA et al.; Salmonella enterica serovar Enteritidis was detected in artificially inoculated eggs within 24 h through a rapid monoclonal antibody-based dot blot immunoassay . Detection in poultry and other products required 28 h . Samples were directly enriched in homogenized egg without the need for pre- or postenrichment steps . Serovar Enteritidis was detected in the presence of other bacteria when outcompeted 1:400. Appl Environ Microbiol, 2001 Jan, 67(1), 445 - 8 Relative distribution and conservation of genes encoding aminoglycoside-modifying enzymes in Salmonella enterica serotype typhimurium phage type DT104; Frana TS et al.; PCR was used to identify genes encoding aminoglycoside-modifying enzymes in 422 veterinary isolates of Salmonella enterica serotype Typhimurium . The identities of extra-integron genes encoding resistance to streptomycin, gentamicin, kanamycin, and apramycin were evaluated . Gentamicin resistance was conferred by the aadB gene . Kanamycin resistance was encoded by either the aphA1-Iab gene or the Kn gene . Apramycin resistance was determined by the aacC4 gene . Analysis of gene distribution did not reveal significant differences with regard to phage type, host species, or region except for the Kn gene, which was found mostly in nonclinical isolates . The data from this study indicate that pentaresistant DT104 does not acquire extra-integron genes in species- or geography-related foci, which supports the hypothesis that clonal expansion is the method of spread of this organism. Appl Environ Microbiol, 2001 Jan, 67(1), 217 - 24 Development and optimization of a novel immunomagnetic separation- bacteriophage assay for detection of Salmonella enterica serovar enteritidis in broth; Favrin SJ et al.; Salmonella is the second-leading cause of food-borne illness in most developed countries, causing diarrhea, cramps, vomiting, and often fever . Many rapid methods are available for detection of Salmonella in foods, but these methods are often insensitive or expensive or require a high degree of technical ability to perform . In this paper we describe development and characterization of a novel assay that utilizes the normal infection cycle of bacteriophage SJ2 for detection of Salmonella enterica serovar Enteritidis in broth . The assay consists of four main stages: (i) capture and concentration of target cells by using immunomagnetic separation (IMS); (ii) infection of the target bacterium with phage; (iii) amplification and recovery of progeny phage; and (iv) assay of progeny phage on the basis of their effect on a healthy population of host cells (signal-amplifying cells) . The end point of the assay can be determined by using either fluorescence or optical density measurements . The detection limit of the assay in broth is less than 10(4) CFU/ml, and the assay can be performed in 4 to 5 h . The results of this study demonstrate that the IMS-bacteriophage assay is a rapid, simple, and sensitive technique for detection of Salmonella serovar Enteritidis in broth cultures which can be applied to preenriched food samples. Indian J Pediatr, 2000 Feb, 67(2 Suppl), S58 - 62 Recent advances in improved tuberculosis vaccines; McMurray DN; Tuberculosis continues to be a major infectious cause of global morbidity and mortality, both in children and adults, in spite of widespread vaccination of infants with Bacille Calmette-Guerin (BCG) and the availability of effective antibiotics . The failure of BCG to significantly affect disease incidence in adults in many endemic countries, combined with the growing HIV epidemic and the appearance of multidrug resistant strains of Mycobacterium tuberculosis, threatens to overwhelm current tuberculosis control strategies . This unfortunate state of affairs has driven an intensive search for better tuberculosis vaccines . This article reviews the various vaccine development strategies which are being used e.g., purification or synthesis of protein peptide and non-peptide antigens from M . tuberculosis, creation of rationally-attenuated mutants of BCG and M . tuberculosis, development of DNA vaccines based upon the published genome sequence, the cloning of mycobacterial genes into living vaccine carrier strains (e.g., attenuated Salmonella, vaccinia virus, etc), or the use of naturally attenuated mycobacterial species (e.g., M . vaccae, M . microti) . The animal models in which these vaccine candidates are being screened for protective efficacy (e.g., the mouse, guinea pig, rabbit, primate) will be discussed briefly . Finally, some of the challenges inherent in the eventual clinical evaluation of new tuberculosis vaccines are reviewed. J Vet Med Sci, 2000 Nov, 62(11), 1139 - 43 Induction of early immunopotentiation to Fimbriae of Salmonella Enteritidis (SE) by administering thymulin and zinc to SE-vaccinated chicken breeders: relationship to protection; Barbou EK et al.; The purpose of this study is to attempt the induction of early immunopotentiation of antibodies specific to fimbriae of Salmonella enterica serovar Enteritidis (SE), by administering thymulin and zinc to SE-vaccinated chicken breeders, and the improvement of protection against a controlled-live challenge by SE . The first two groups of breeders were administered subcutaneously at 15 and 19 weeks of age a killed SE vaccine . Breeders of the third and fourth groups were left unvaccinated . Breeders of the first group, immunopotentiated by thymulin and zinc, were able to induce the earliest antibodies in their pooled sera at 2 weeks post the first SE-vaccination, specific to fimbriae (approximately 21 KDa) of SE . However, the second group that was only vaccinated with the same SE-vaccine produced specific antibodies to fimbriae at 3 weeks following the second vaccination (22 weeks of age) . Breeders of the third group, that were neither SE-vaccinated nor immunopotentiated by thymulin and zinc, but were challenged by live SE at 22 weeks of age, were able to show specific antibodies to fimbriae at 3 weeks post challenge (25 weeks of age) . The fourth group that was deprived of SE-vaccination, immunopotentiators, and challenge didn't show any background antibodies specific to SE-fimbriae . The presence of the earliest antibody-immunopotentiation to fimbriae of SE in breeders of the first group, administered thymulin and zinc, was associated with the lowest frequency of SE-infected ceca (10%) among the challenged groups . In addition, breeders of the first group were the only challenged birds resulting in absence of SE infection in their cecal tonsils . The first group-vaccinated, immunopotentiated, and challenged, and the second group-vaccinated and challenged only resulted in breeders with absence of SE infection in their oviducts and spleens . In conclusion, immunopotentiation of chicken breeders by thymulin and zinc induces the earliest specific antibodies to fimbriae of SE associated with the lowest frequency of SE-infected ceca, and absence of SE infection from cecal tonsils, oviducts and spleens. J Clin Pathol, 2000 Nov, 53(11), 851 - 3 The serodiagnosis of infection with Salmonella typhi; Chart H et al.; BACKGROUND/AIMS: The serodiagnosis of infection with Salmonella typhi, using the Widal agglutination assay, relies on patients' antibodies to the O = 9,12 lipopolysaccharide (LPS) antigens, H = d flagellar antigens, and the Vi capsular antigens . A Vi agglutination titre of > 1/40 has traditionally been regarded as indicative of recent infection with S typhi . In this study, 91 sera were used to assess the reliability of the Widal agglutination assay based on antibodies to the Vi antigens . METHODS: The Widal agglutination assay was carried out using protocols established by the Central Public Health Laboratory, Colindale . Antibodies to the Vi capsular antigen were detected using a standard preparation of S typhi, ViI Bhatnagar variant strain (S typhi, ViI) . Sera used in the study comprised 73 from patients who were culture positive for S typhi, 10 from patients who were culture positive for other species of Salmonella not expressing a Vi antigen (namely, S javiana, S enteritidis, S typhimurium, S stanley, S saint paul, S bareilly, or S mbandaka), and eight from healthy blood donors . RESULTS: Agglutination titres of > or = 1/40 were detected to S typhi ViI in 69 of 73 sera from patients with typhoid, although 27 of these also agglutinated an unrelated control antigen . The Widal assay also detected significant amounts of agglutinating antibodies to S . typhi ViI in all eight control sera and seven sera from patients infected with S bareilly, S enteritidis, S javiana, S mbandaka, S saint paul, and S stanley . CONCLUSIONS: Agglutinating antibodies to the Vi antigen can be detected by the Widal assay, but even with the appropriate control antigens the results were unreliable . The serodiagnosis of infections with S typhi should be based on the detection of antibodies to both the O = 9,12 LPS antigen and the H = d flagellar antigen by immunoblotting, and should not use the Vi antigen-based Widal assay . Conclusions should be made in the light of patients' clinical details and any knowledge of previous immunisation for typhoid. Tumour Biol, 2001 Mar-Apr, 22(2), 67 - 71 Influence of AFP, CEA and PSA on the in vitro production of cytokines; Filella X et al.; Several studies have demonstrated a decreased cytokine production in patients with cancer . Likewise, there is some evidence showing that tumor markers may play a role in immunoregulation . In this work, we have studied the in vitro production of IL-1beta, IL-6 and TNF-alpha in whole-blood cell cultures of 10 healthy subjects after polyclonal activation with lipopolysaccharide of Salmonella enteridis and phytohemagglutinin in the presence or absence of three markers, AFP, CEA and PSA . Each sample was incubated for 48 h at 37 degrees C in a humidified atmosphere of 5% CO(2) . Subsequently, cytokine levels in the supernatant were determined . AFP did not significantly affect the production of the three cytokines compared to the basal value obtained on adding PBS . In contrast, CEA significantly increased the production of IL-6 (p <0.001) and TNF-alpha (p = 0.002), while PSA significantly decreased IL-1beta (p <0.001), IL-6 (p = 0.031) and TNF-alpha (p <0.0001) production . These results suggest a possible role of CEA and PSA in the production of these cytokines . Lett Appl Microbiol, 2000 Dec, 31(6), 443 - 8 Improvement in Salmonella detection in milk and dairy products: comparison between the ISO method and the Oxoid SPRINT Salmonella test; Richter J et al.; The Oxoid SPRINT Salmonella test was compared with the ISO method (ISO 6579: 1993) for the detection of Salmonella in milk and dairy products . Samples were artificially contaminated, in some cases with sublethally injured salmonellas . Experiments with raw milk, soft cheese made from heat-treated milk (mould-ripened and with smear) and soft cheese with smear made from raw milk showed no significant differences between the SPRINT and ISO methods . With dried milk products and mould-ripened soft cheese made from raw milk the reference method gave significantly more positive results . The addition of ferrioxamine E to pre-enrichment (ISO) or pre-enrichment/enrichment broth (SPRINT test) did not improve Salmonella detection. Antimicrob Agents Chemother, 2001 Jan, 45(1), 38 - 43 A soxRS-constitutive mutation contributing to antibiotic resistance in a clinical isolate of Salmonella enterica (Serovar typhimurium); Koutsolioutsou A et al.; The soxRS regulon is activated by redox-cycling drugs such as paraquat and by nitric oxide . The >15 genes of this system provide resistance to both oxidants and multiple antibiotics . An association between clinical quinolone resistance and elevated expression of the soxRS regulon has been observed in Escherichia coli, but this association has not been explored for other enteropathogenic bacteria . Here we describe a soxRS-constitutive mutation in a clinical strain of Salmonella enterica (serovar Typhimurium) that arose with the development of resistance to quinolones during treatment . The elevated quinolone resistance in this strain derived from a point mutation in the soxR gene and could be suppressed in trans by multicopy wild-type soxRS . Multiple-antibiotic resistance was also transferred to a laboratory strain of S . enterica by introducing the cloned mutant soxR gene from the clinical strain . The results show that constitutive expression of soxRS can contribute to antibiotic resistance in clinically relevant S . enterica. J Immunol, 2000 Dec 15, 165(12), 7234 - 9 Up-regulation of the IL-12 receptor beta 2 chain in Crohn's disease; Parrello T et al.; Crohn' s disease (CD) is a chronic intestinal inflammatory disorder characterized by aberrant mucosal Th1 cell activation and production of IL-12, the major Th1-driving factor . The T cell response to IL-12 is dependent on the expression of a specific receptor composed of two subunits, termed IL-12Rbeta1 and IL-12Rbeta2 . The content of IL-12Rbeta2, as measured at the mRNA level, is crucial in regulating Th1 differentiation . In this study we therefore investigated IL-12Rbeta2 RNA transcripts in CD . IL-12Rbeta2 expression was increased in active CD as well as Helicobacter pylori (HP)-associated gastritis and Salmonella colitis compared with that in inactive CD, ulcerative colitis, noninflammatory controls, and celiac disease . In contrast, IL-12Rbeta1 transcripts were expressed at comparable levels in all samples . In CD, IL-12Rbeta2 expression strictly correlated with tyrosine phosphorylation of STAT4, a key component of the IL-12-dependent Th1 polarization . This was associated with a pronounced expression of IFN-gamma . Transcripts for IL-12/p40 were detected in CD, HP-positive, and Salmonella colitis patients, but not in celiac disease, indicating that IL-12Rbeta2 up-regulation occurs only in IL-12-associated Th1 gastrointestinal diseases . Finally, we showed that stimulation of lamina propria mononuclear cells with IL-12 enhanced IL-12Rbeta2, suggesting that IL-12 regulates IL-12Rbeta2 expression in human gastrointestinal mucosa . The data show that the signaling pathway used by IL-12 to induce Th1 differentiation is increased at the site of disease in CD, further supporting the view that IL-12/IL-12R signals contribute to the inflammatory response in this condition. J Surg Res, 2001 Jan, 95(1), 44 - 9 Use of rifampin-soaked gelatin-sealed polyester grafts for in situ treatment of primary aortic and vascular prosthetic infections; Bandyk DF et al.; BACKGROUND: In situ treatment of artery/graft infection has distinct advantages compared to vessel excision and extra-anatomic bypass procedures . Based on animal studies of a rifampin-soaked, gelatin-impregnated polyester graft that demonstrated prolonged in vivo antibacterial activity, this antibiotic-bonded graft was used selectively in patients for in situ treatment of low-grade Gram-positive prosthetic graft infections or primary aortic infections not amenable to excision and ex situ bypass . METHODS: In a 5-year period (1995-1999), 27 patients with prosthetic graft infection (aortofemoral, n = 18, femorofemoral, n = 3; axillofemoral, n = 1) or primary aortic infection (mycotic aneurysm, n = 3; infected AAA, n = 2) underwent excision of the infected vessel and in situ replacement with a rifampin soaked (45-60 mg/ml for 15 min) gelatin-impregnated polyester graft . All prosthetic graft infections were low grade in nature, caused Gram-positive bacteria (Staphylococcus epidermidis, 16; Staphylococcus aureus, 5; Streptococcus, 1), and were treated electively . Patients with mycotic aortic aneurysm presented with sepsis and underwent urgent or emergent surgery . RESULTS: Two (8%) patients died-1 as a result of a ruptured Salmonella mycotic aortic aneurysm and the other from methicillin-resistant S . aureus infection following deep vein replacement of an in situ replaced femorofemoral graft . No amputations or late deaths as the result of vascular infection occurred in the 25 surviving patients . Two patients developed recurrent infection caused by a rifampin-resistant S . epidermidis in a replaced aortofemoral graft limb and were successfully treated with graft excision and in situ autogenous vein replacement . Eighteen patients remain alive and clinically free of infection after a mean follow-up interval of 17 months . CONCLUSIONS: In situ replacement treatment using a rifampin-bonded prosthetic graft for low-grade staphylococcal arterial infection was safe, durable, and associated with eradication of clinical signs of infection . Failure of this therapy was the result of virulent and antibiotic-resistant bacterial strains . J Infect, 2000 Nov, 41(3), 256 - 9 Non-typhoidal Salmonella bacteraemia without gastroenteritis: a marker of underlying immunosuppression . Review Of cases at St . Thomas' Hospital 1970-1999; Brown M et al.; OBJECTIVES: To classify non-typhoidal salmonella bacteraemia according to clinical presentation, and to study how this correlates with the presence of underlying immunosuppression . METHODS: We analysed data collected prospectively for all 82 cases of non-typhoidal salmonella bacteraemia presenting to St . Thomas' Hospital between 1970 and 1999 . RESULTS: Patients presented with one of three syndromes: diarrhoea, an extra-intestinal focus of infection, or isolated fever with no focus . Only 18% of those with diarrhoea had underlying immunosuppression, compared with 80% of those with extra-intestinal focal infections (P= 0.001) and 80% of those with no focus (P= 0.0001) . There was no significant association between salmonella serotype and underlying immunosuppression . Salmonella enteritidis isolates, especially phage type 4, increased significantly during the last decade (P= 0.001) . The presentation of non-typhoidal salmonella bacteraemia in the absence of diarrhoea prompted the diagnosis of HIV in two patients . CONCLUSION: Underlying immunosuppression should be excluded in patients presenting with non-typhoidal salmonella bacteraemia in the absence of gastroenteritis . This may lead to an earlier diagnosis of HIV . Infect Immun, 2001 Jan, 69(1), 556 - 8 Immunity against Helicobacter pylori: significance of interleukin-4 receptor alpha chain status and gender of infected mice; Aebischer T et al.; Vaccination of interleukin-4 (IL-4) receptor alpha (IL-4Ralpha) chain-deficient BALB/c mice with Helicobacter pylori urease and cholera toxin or with urease-expressing, live attenuated Salmonella enterica serovar Typhimurium cells revealed that protection against H . pylori infection is independent of IL-4- or IL-13-mediated signals . A comparison of male and female mice suggests a sexual dimorphism in the extent of bacterial colonization that is particularly evident in the absence of the IL-4Ralpha chain. Infect Immun, 2001 Jan, 69(1), 547 - 50 Aromatic compound-dependent Brucella suis is attenuated in both cultured cells and mouse models; Foulongne V et al.; The aroC gene of the facultative intracellular pathogen Brucella suis was cloned and sequenced . The cloned aroC gene complements Escherichia coli and Salmonella enterica serovar Typhimurium aroC mutants . A B . suis aroC mutant was found to be unable to grow in a defined medium without aromatic compounds . The mutant was highly attenuated in tissue culture (THP1 macrophages and HeLa cells) and murine virulence models. Infect Immun, 2001 Jan, 69(1), 463 - 71 Improved innate immunity of endotoxin-tolerant mice increases resistance to Salmonella enterica serovar typhimurium infection despite attenuated cytokine response; Lehner MD et al.; During infection with gram-negative bacteria, exposure of immune cells to lipopolysaccharide (LPS) from the bacterial cell membrane induces a rapid cytokine response which is essential for the activation of host defenses against the invading pathogens . Administration of LPS to mice induces a state of hyporesponsiveness, or tolerance, characterized by reduced cytokine production upon subsequent LPS challenge . In the model of experimental Salmonella enterica serovar Typhimurium infection of mice, we assessed the question of whether complete LPS tolerance induced by repetitive doses of LPS interfered with cytokine production and host defense against gram-negative bacteria . Although production of various cytokines in response to serovar Typhimurium was attenuated by LPS pretreatment, LPS-tolerant mice showed improved antibacterial activity, evidenced by a prolongation of survival and a continuously lower bacterial load . We attribute this protective effect to three independent mechanisms . (i) Peritoneal accumulation of leukocytes in the course of LPS pretreatment accounted for enhanced defense against serovar Typhimurium during the first 6 h of infection but not for decreased bacterial load in late-stage infection . (ii) LPS-tolerant mice had an increased capacity to recruit neutrophilic granulocytes during infection . (iii) LPS-tolerant mice showed threefold-increased Kupffer cell numbers, enhanced phagocytic activity of the liver, and strongly improved clearance of blood-borne serovar Typhimurium . These results demonstrate that despite attenuated cytokine response, acquired LPS tolerance is associated with enhanced resistance to infections by gram-negative bacteria and that this effect is mainly mediated by improved effector functions of the innate immune system. Infect Immun, 2001 Jan, 69(1), 367 - 77 Salmonella pathogenicity island 2 influences both systemic salmonellosis and Salmonella-induced enteritis in calves; Bispham J et al.; We have used signature-tagged mutagenesis to identify mutants of the host-specific Salmonella enterica serotype Dublin which were avirulent in calves and/or BALB/c mice . A mutant with a transposon insertion in the sseD gene of Salmonella pathogenicity island 2 (SPI-2), which encodes a putative secreted effector protein, was identified . This mutant was recovered from the bovine host but not from the murine host following infection with a pool of serotype Dublin mutants . However, a pure inoculum of the sseD mutant was subsequently shown to be attenuated in calves following infection either by the intravenous route or by the oral route . The sseD mutant was fully invasive for bovine intestinal mucosa but was subsequently unable to proliferate to the same numbers as the parental strain in vivo . Both the sseD mutant and a second SPI-2 mutant, with a transposon insertion in the ssaT gene, induced significantly weaker secretory and inflammatory responses in bovine ligated ileal loops than did the parental strain . These results demonstrate that SPI-2 is required by serotype Dublin for the induction of both systemic and enteric salmonellosis in calves. Infect Immun, 2001 Jan, 69(1), 204 - 12 Salmonella enterica serotype typhimurium elicits cross-immunity against a Salmonella enterica serotype enteritidis strain expressing LP fimbriae from the lac promoter; Nicholson TL et al.; The biological significance of fimbrial phase variation in Salmonella serotypes is currently unknown . Exposure to long polar (LP) fimbriae of Salmonella enterica serotype Typhimurium results in selection against lpf phase ON cells of serotype Enteritidis during a subsequent challenge, suggesting that fimbrial phase variation may be a mechanism to evade cross-immunity between Salmonella serotypes . This notion was tested by assessing the effect of an immune response against serotype Typhimurium LP fimbriae on colonization of mice with a serotype Enteritidis mutant in which the lpf promoter region was replaced with the Escherichia coli lac promoter . During a challenge with a serotype Enteritidis mutant carrying the lac promoter in front of the lpf operon, significantly lower numbers were recovered from organs and feces of mice previously immunized with an lpf phase ON culture of serotype Typhimurium than from mice not previously exposed to LP fimbriae . Immunization with the lpf phase ON culture of serotype Typhimurium elicited antibodies that cross-reacted with a purified gluthathione-S-transferase-LpfA fusion protein of serotype Enteritidis . These data suggested that cross-immunity against LP fimbrial proteins cannot be evaded if phase variation on the transcriptional level is prevented by expressing the lpf operon from the lac promoter . These data hence support the idea that phase variation of LP fimbriae is a mechanism to evade cross-immunity between serotypes Enteritidis and Typhimurium. Vet Microbiol, 2001 Jan 5, 78(1), 61 - 77 Analysis of expression of flagella by Salmonella enterica serotype typhimurium by monoclonal antibodies recognising both phase specific and common epitopes; Sojka M et al.; Monoclonal antibodies specific for phase 1 ("i" antigen), phase 2 ("1,2" antigen) and common epitopes of the flagellins of Salmonella enterica serotype Typhimurium were raised . Having confirmed their specificity, the monoclonal antibodies were used to develop semi-quantitative ELISAs in order to assess the relative expression of the two phases by strains of Typhimurium . The majority of Typhimurium strains representative of a wide cross-section of definitive types from animal and environmental sources preferentially expressed phase 1 antigen in vitro . DT40 strains were unique in expressing phase 2 preferentially . The ratio of phase 1 to phase 2 expressed by strains tended to be constant for any one strain when strains were grown on a number of conventional laboratory media . However, the ratio of phases was shown to be modulated by incubation at 42 degrees C and buffering media at pH values, notably 4.5, other than neutral . Selenite broth and Rambach media repressed flagellation. J Bacteriol, 2001 Jan, 183(1), 336 - 46 Methionine-to-cysteine recycling in Klebsiella aerogenes; Seiflein TA et al.; In the enteric bacteria Escherichia coli and Salmonella enterica, sulfate is reduced to sulfide and assimilated into the amino acid cysteine; in turn, cysteine provides the sulfur atom for other sulfur-bearing molecules in the cell, including methionine . These organisms cannot use methionine as a sole source of sulfur . Here we report that this constraint is not shared by many other enteric bacteria, which can use either cysteine or methionine as the sole source of sulfur . The enteric bacterium Klebsiella aerogenes appears to use at least two pathways to allow the reduced sulfur of methionine to be recycled into cysteine . In addition, the ability to recycle methionine on solid media, where cys mutants cannot use methionine as a sulfur source, appears to be different from that in liquid media, where they can . One pathway likely uses a cystathionine intermediate to convert homocysteine to cysteine and is induced under conditions of sulfur starvation, which is likely sensed by low levels of the sulfate reduction intermediate adenosine-5'-phosphosulfate . The CysB regulatory proteins appear to control activation of this pathway . A second pathway may use a methanesulfonate intermediate to convert methionine-derived methanethiol to sulfite . While the transsulfurylation pathway may be directed to recovery of methionine, the methanethiol pathway likely represents a general salvage mechanism for recovery of alkane sulfide and alkane sulfonates . Therefore, the relatively distinct biosyntheses of cysteine and methionine in E . coli and Salmonella appear to be more intertwined in Klebsiella. J Bacteriol, 2001 Jan, 183(1), 328 - 35 Alternative pathways for siroheme synthesis in Klebsiella aerogenes; Kolko MM et al.; Siroheme, the cofactor for sulfite and nitrite reductases, is formed by methylation, oxidation, and iron insertion into the tetrapyrrole uroporphyrinogen III (Uro-III) . The CysG protein performs all three steps of siroheme biosynthesis in the enteric bacteria Escherichia coli and Salmonella enterica . In either taxon, cysG mutants cannot reduce sulfite to sulfide and require a source of sulfide or cysteine for growth . In addition, CysG-mediated methylation of Uro-III is required for de novo synthesis of cobalamin (coenzyme B(12)) in S . enterica . We have determined that cysG mutants of the related enteric bacterium Klebsiella aerogenes have no defect in the reduction of sulfite to sulfide . These data suggest that an alternative enzyme allows for siroheme biosynthesis in CysG-deficient strains of Klebsiella . However, Klebsiella cysG mutants fail to synthesize coenzyme B(12), suggesting that the alternative siroheme biosynthetic pathway proceeds by a different route . Gene cysF, encoding an alternative siroheme synthase homologous to CysG, has been identified by genetic analysis and lies within the cysFDNC operon; the cysF gene is absent from the E . coli and S . enterica genomes . While CysG is coregulated with the siroheme-dependent nitrite reductase, the cysF gene is regulated by sulfur starvation . Models for alternative regulation of the CysF and CysG siroheme synthases in Klebsiella and for the loss of the cysF gene from the ancestor of E . coli and S . enterica are presented. J Bacteriol, 2001 Jan, 183(1), 77 - 85 Identification of residues involved in catalytic activity of the inverting glycosyl transferase WbbE from Salmonella enterica serovar borreze; Keenleyside WJ et al.; Synthesis of the O:54 O antigen of Salmonella enterica is initiated by the nonprocessive glycosyl transferase WbbE, assigned to family 2 of the glycosyl transferase enzymes (GT2) . GT2 enzymes possess a characteristic N-terminal domain, domain A . Based on structural data from the GT2 representative SpsA (S . J . Charnock and G . J . Davies, Biochemistry 38:6380-6385, 1999), this domain is responsible for nucleotide binding . It possesses two invariant Asp residues, the first forming a hydrogen bond to uracil and the second coordinating a Mn(2+) ion . Site-directed replacement of Asp41 (D41A) of WbbE, the analogue of the first Asp residue of SpsA, revealed that this is not required for activity . WbbE possesses three Asp residues near the position analogous to the second conserved residue . Whereas D95A reduced WbbE activity, activity in D93A and D96A mutants was abrogated, suggesting that either D93 or D96 may coordinate the Mn(2+) ion . Our studies also identified a C-terminal region of sequence conservation in 22 GT2 members, including WbbE . SpsA was not among these . This region is characterized by an ED(Y) motif . The Glu and Asp residues of this motif were individually replaced in WbbE . E180D in WbbE had greatly reduced activity, and an E180Q replacement completely abrogated activity; however, D181E had no effect . E180 is predicted to reside on a turn . Combined with the alignment of the motif with potential catalytic residues in the GT2 enzymes ExoM and SpsA, we speculate that E180 is the catalytic residue of WbbE . Sequence and predicted structural divergence in the catalytic region of GT2 members suggests that this is not a homogeneous family. Mutat Res, 2000 Nov 20, 455(1-2), 61 - 9 The bacterial tryptophan reverse mutation assay with Escherichia coli WP2; Mortelmans K et al.; The Escherichia coli WP2 tryptophan reverse mutation assay detects trp(-) to trp(+) reversion at a site blocking a step in the biosynthesis of tryptophan prior to the formation of anthranilic acid . The different WP2 strains all carry the same AT base pair at the critical mutation site within the trpE gene . The assay is currently used by many laboratories in conjunction with the Ames Salmonella assay for screening chemicals for mutagenic activity . In general the WP2 strains are used as a substitute for, or as an addition to Salmonella strain TA102 which also carries an AT base pair at the mutation site . The assay is also recommended together with the Ames assay for data submission to regulatory agencies . National and international guidelines have been established for performing these mutagenicity assays.The E . coli WP2 assay procedures are the same as those described elsewhere in this volume for the Ames Salmonella assay (Mortelmans and Zeiger, 2000) with the exception that limited tryptophan instead of limited histidine is used . This chapter is an addendum to the previous chapter and the reader should refer to the previous chapter for details regarding experimental procedures and assay design. Mutat Res, 2000 Nov 20, 455(1-2), 29 - 60 The Ames Salmonella/microsome mutagenicity assay; Mortelmans K et al.; The Ames Salmonella/microsome mutagenicity assay (Salmonella test; Ames test) is a short-term bacterial reverse mutation assay specifically designed to detect a wide range of chemical substances that can produce genetic damage that leads to gene mutations . The test employs several histidine dependent Salmonella strains each carrying different mutations in various genes in the histidine operon . These mutations act as hot spots for mutagens that cause DNA damage via different mechanisms . When the Salmonella tester strains are grown on a minimal media agar plate containing a trace of histidine, only those bacteria that revert to histidine independence (his(+)) are able to form colonies . The number of spontaneously induced revertant colonies per plate is relatively constant . However, when a mutagen is added to the plate, the number of revertant colonies per plate is increased, usually in a dose-related manner . The Ames test is used world-wide as an initial screen to determine the mutagenic potential of new chemicals and drugs . The test is also used for submission of data to regulatory agencies for registration or acceptance of many chemicals, including drugs and biocides . International guidelines have been developed for use by corporations and testing laboratories to ensure uniformity of testing procedures . This review provides historical aspects of how the Ames was developed and detailed procedures for performing the test, including the design and interpretation of results. Mutat Res, 2000 Nov 20, 455(1-2), 21 - 8 Practical aspects of mutagenicity testing strategy: an industrial perspective; Gollapudi BB et al.; Genetic toxicology studies play a central role in the development and marketing of new chemicals for pharmaceutical, agricultural, industrial, and consumer use . During the discovery phase of product development, rapid screening tests that require minimal amounts of test materials are used to assist in the design and prioritization of new molecules . At this stage, a modified Salmonella reverse mutation assay and an in vitro micronucleus test with mammalian cell culture are frequently used for screening . Regulatory genetic toxicology studies are conducted with a short list of compounds using protocols that conform to various international guidelines . A set of four assays usually constitutes the minimum test battery that satisfies global requirements . This set includes a bacterial reverse mutation assay, an in vitro cytogenetic test with mammalian cell culture, an in vitro gene mutation assay in mammalian cell cultures, and an in vivo rodent bone marrow micronucleus test . Supplementary studies are conducted in certain instances either as a follow-up to the findings from this initial testing battery and/or to satisfy a regulatory requirement . Currently available genetic toxicology assays have helped the scientific and industrial community over the past several decades in evaluating the mutagenic potential of chemical agents . The emerging field of toxicogenomics has the potential to redefine our ability to study the response of cells to genetic damage and hence our ability to study threshold phenomenon. Microbes Infect, 2000 Nov, 2(13), 1567 - 78 Diagnosis of defects in the type 1 cytokine pathway; Lammas DA et al.; Patients with inherited defects in the interleukin-12 (IL-12)-dependent, 'high-output' interferon-gamma (IFN-gamma) pathway exhibit selective susceptibility to poorly pathogenic mycobacterial and salmonella infections . This review summarises the extended clinical spectrum seen in this group of patients and indicates a strategy for the identification of putative defects in the type 1 cytokine pathway. Microbes Infect, 2000 Nov, 2(13), 1559 - 66 Human deficiencies in type 1 cytokine receptors reveal the essential role of type 1 cytokines in immunity to intracellular bacteria; Ottenhoff TH et al.; Studies on patients with idiopathic, severe infections due to poorly pathogenic mycobacteria and Salmonella have revealed that many of these patients are unable to produce or respond to interferon-gamma (IFN-gamma) . This inability results from causative, deleterious genetic mutations in either one of four different genes in the type 1 cytokine cascade, encoding interleukin-12Rbeta1 (IL-12Rbeta1), IL-12p40, IFN-gammaR1 or IFN-gammaR2 . The immunological phenotypes resulting from the seven groups of complete or partial deficiencies in type 1 cytokine (receptor) genes that have been distinguished thus far will be summarized and discussed, and placed in a broader context in relation to disease susceptibility. Dev Comp Immunol, 2001 Mar, 25(2), 159 - 68 Induction of the respiratory burst in turtle peritoneal macrophages by Salmonella muenchen; Pasmans F et al.; Peritoneal macrophages were collected from juvenile turtles 72h after intraperitoneal inoculation with a 3% Sephadex suspension . The macrophages were assayed for their chemiluminescent (CL) properties, reflecting their respiratory burst activity, after stimulation with Zymosan A, phorbol 12-myristate 13-acetate (PMA), N-formyl-methionyl-leucyl-phenylalanine (fMLP), and calcium ionophore A23187 . Except for fMLP, all triggering agents induced a marked CL response . Luminol was used as the chemiluminescent probe . When comparing CL responses in temperatures ranging from 15 to 35 degrees C, lower assay temperatures induced lower and slower CL responses . Stimulation with viable Salmonella muenchen resulted in a distinct response . Bacteria, inactivated by means of heat or acetone, induced a faster and stronger oxidative burst . Opsonization of either viable or heat-inactivated S . muenchen with non-inactivated anti-S . muenchen serum, prepared in turtles, induced faster and higher CL responses . On the other hand, opsonization of acetone-inactivated S . muenchen caused CL responses to be slower and weaker . S . muenchen, opsonized with heat-inactivated turtle anti S . muenchen serum, induced higher responses than non-opsonized bacteria, but slower and weaker responses than bacteria opsonized with native turtle antiserum . No response was recorded after stimulation with LPS and the supernatant of heat-inactivated bacteria. Int J Hyg Environ Health, 2000 Oct, 203(2), 117 - 26 GIS-supported investigation of a nosocomial Salmonella outbreak; Kistemann T et al.; Within an outbreak at a university hospital 102 persons (44 patients, 26 nursery school children and one relative as well as 31 employees) have been diagnosed to be infected by Salmonella enteritidis . Ninety-nine persons complied with the "primary case"-definition . The source of infection could not be detected in retrospect by hygienic-microbiological methods due to missing food samples . But GIS (Geographical Information System)-supported epidemiological investigation and analysis of food production showed that most likely vanilla pudding had been the vehicle of infection . Contamination of the pudding could be put down to the fact that its production took place in direct spatial and temporal association with the preparation of turkey . Probably further infections caused by this primary source were avoided by immediate measures . The making out of an HACCP-concept as well as structural and technical short-term redevelopment measures proved to be decisive factors to decrease the risk of further infections . From these experiences, some recommendations could be derived for the investigation of food-borne outbreaks in hospitals. Int Microbiol, 1999 Jun, 2(2), 115 - 7 A rapid procedure for the isolation of plasmid DNA from environmental bacteria; Ferrus MA et al.; The INSTA-MINI-PREP method, a rapid protocol for plasmid DNA extraction, was originally developed to prepare plasmid DNA from 1 to 3 ml miniprep Escherichia coli cultures . Direct extraction of plasmid DNA is achieved by a two-phase solution which is separated by centrifugation in the presence of the INSTA-PREP gel barrier material . This method has been successfully tested on various environmental Salmonella strains, although it was not suitable for Pseudomonas aeruginosa and enterococci strains . The INSTA-MINI-PREP method is a new alternative procedure to screen plasmid contents of Salmonella and E . coli strains rapidly and easily. Int Microbiol, 1998 Sep, 1(3), 197 - 204 Molecular mechanisms of Salmonella invasion: the type III secretion system of the pathogenicity island 1; Suarez M et al.; Salmonella spp . are facultative intracellular pathogens which are able to enter into non-phagocytic cells as an essential step in their pathogenic life cycle . The majority of the molecular determinants involved in this entry process are encoded in a pathogenicity island located at the centisome 63 of the bacterial chromosome, and belong to a specialized protein secretion system termed "type III" or "contact-dependent" . This secretion system is used by Salmonella spp . and several other bacterial pathogens to translocate bacterial effector proteins into the eukaryotic cell . Thus, a bidirectional biochemical cross-talk with the host cell is initiated, which leads to several responses such as membrane ruffling, bacterial internalization and the activation of various transcription factors. Mutat Res, 2000 Dec 20, 457(1-2), 41 - 55 Mutagenicity in lung of big Blue((R)) mice and induction of tandem-base substitutions in Salmonella by the air pollutant peroxyacetyl nitrate (PAN): predicted formation of intrastrand cross-links; DeMarini DM et al.; Peroxyacetyl nitrate (PAN) is a ubiquitous air pollutant formed from NO(2) reacting with acetoxy radicals generated from ambient aldehydes in the presence of sunlight and ozone . It contributes to eye irritation associated with photochemical smog and is present in most urban air . PAN was generated in a chamber containing open petri dishes of Salmonella TA100 (gas-phase exposure) . After subtraction of the background mutation spectrum, the spectrum of PAN-induced mutants selected at 3.1-fold above the background mutant yield was 59% GC-->TA, 29% GC-->AT, 2% GC-->CG, and 10% multiple mutations - primarily GG-->TT tandem-base substitutions . Using computational molecular modeling methods, a mechanism was developed for producing this unusual tandem-base substitution . The mechanism depends on the protonation of PAN near the polyanionic DNA to release NO(2)(+) resulting in intrastrand dimer formation . Insertion of AA opposite the dimerized GG would account for the tandem GG-->TT transversions . Nose-only exposure of Big Blue((R)) mice to PAN at 78ppm (near the MTD) was mutagenic at the lacI gene in the lung (mutant frequency +/-S.E . of 6.16+/-0.58/10(5) for controls versus 8.24+/-0.30/10(5) for PAN, P=0.016) . No tandem-base mutations were detected among the 40 lacI mutants sequenced . Dosimetry with 3H-PAN showed that 24h after exposure, 3.9% of the radiolabel was in the nasal tissue, and only 0.3% was in the lung . However, based on the molecular modeling considerations, the labeled portion of the molecule would not have been expected to have been bound covalently to DNA . Our results indicate that PAN is weakly mutagenic in the lungs of mice and in Salmonella and that PAN produces a unique signature mutation (a tandem GG-->TT transversion) in Salmonella that is likely due to a GG intrastrand cross-link . Thus, PAN may pose a mutagenic and possible carcinogenic risk to humans, especially at the high concentrations at which it is present in some urban environments. Mutat Res, 2000 Dec 20, 457(1-2), 15 - 30 Induction of chromosome aberrations in vitro by phenolphthalein: mechanistic studies; Armstrong MJ et al.; Phenolphthalein induces tumors in rodents but because it is negative in assays for mutation in Salmonella and in mammalian cells, for DNA adducts and for DNA strand breaks, its primary mechanism does not seem to be DNA damage . Chromosome aberration (Ab) induction by phenolphthalein in vitro is associated with marked cytotoxicity . At very high doses, phenolphthalein induces weak increases in micronuclei (MN) in mouse bone marrow; a larger response is seen with chronic treatment . All this suggests genotoxicity is a secondary effect that may not occur at lower doses . In heterozygous TSG-p53((R)) mice, phenolphthalein induces lymphomas and also MN, many with kinetochores (K), implying chromosome loss . Induction of aneuploidy would be compatible with the loss of the normal p53 gene seen in the lymphomas.Here we address some of the postulated mechanisms of genotoxicity in vitro, including metabolic activation, inhibition of thymidylate synthetase, cytotoxicity, oxidative stress, DNA damage and aneuploidy . We show clearly that phenolphthalein does not require metabolic activation by S9 to induce Abs . Inhibition of thymidylate synthetase is an unlikely mechanism, since thymidine did not prevent Ab induction by phenolphthalein . Phenolphthalein dramatically inhibited DNA synthesis, in common with many non-DNA reactive chemicals that induce Abs at cytotoxic doses . Phenolphthalein strongly enhances levels of intracellular oxygen radicals (ROS) . The radical scavenger DMSO suppresses phenolphthalein-induced toxicity and Abs whereas H(2)O(2) potentiates them, suggesting a role for peroxidative activation . Phenolphthalein did not produce DNA strand breaks in rat hepatocytes or DNA adducts in Chinese hamster ovary (CHO) cells . All the evidence points to an indirect mechanism for Abs that is unlikely to operate at low doses of phenolphthalein . We also found that phenolphthalein induces mitotic abnormalities and MN with kinetochores in vitro . These are also enhanced by H(2)O(2) and suppressed by DMSO . Our findings suggest that induction of Abs in vitro is a high-dose effect in oxidatively stressed cells and may thus have a threshold . There may be more than one mechanism operating in vitro and in vivo, possibly indirect genotoxicity at high doses and also chromosome loss, both of which would likely have a threshold. Microbiol Mol Biol Rev, 2000 Dec, 64(4), 694 - 708 Coupling of flagellar gene expression to flagellar assembly in Salmonella enterica serovar typhimurium and Escherichia coli; Chilcott GS et al.; How do organisms assess the degree of completion of a large structure, especially an extracellular structure such as a flagellum? Bacteria can do this . Mutants that lack key components needed early in assembly fail to express proteins that would normally be added at later assembly stages . In some cases, the regulatory circuitry is able to sense completion of structures beyond the cell surface, such as completion of the external hook structure . In Salmonella and Escherichia coli, regulation occurs at both transcriptional and posttranscriptional levels . One transcriptional regulatory mechanism involves a regulatory protein, FlgM, that escapes from the cell (and thus can no longer act) through a complete flagellum and is held inside when the structure has not reached a later stage of completion . FlgM prevents late flagellar gene transcription by binding the flagellum-specific transcription factor sigma(28) . FlgM is itself regulated in response to the assembly of an incomplete flagellum known as the hook-basal body intermediate structure . Upon completion of the hook-basal body structure, FlgM is exported through this structure out of the cell . Inhibition of sigma(28)-dependent transcription is relieved, and genes required for the later assembly stages are expressed, allowing completion of the flagellar organelle . Distinct posttranscriptional regulatory mechanisms occur in response to assembly of the flagellar type III secretion apparatus and of ring structures in the peptidoglycan and lipopolysaccharide layers . The entire flagellar regulatory pathway is regulated in response to environmental cues . Cell cycle control and flagellar development are codependent . We discuss how all these levels of regulation ensure efficient assembly of the flagellum in response to environmental stimuli. MedGenMed . 1999 Jun 10;:E16. Primary Psoas Abscess Due to Salmonella typhi; Baccaro FG; Typhoid fever is a febrile illness caused by Salmonella typhi . The usual symptoms include fever, malaise, and compromise of the gut such as diarrhea and abdominal pain . Occasionally, an extraintestinal involvement can be seen and it may be accompanied by severe complications like bowel perforation or massive hemorrhage . The general manifestations are always present in the extraintestinal compromise, and can be preponderant . However, nonintestinal involvement without the general symptoms that this case reports is so rare that no related records can be found in the MEDLINE database. J Dairy Sci, 2000 Nov, 83(11), 2441 - 7 A cross-sectional study on the prevalence of Listeria monocytogenes and Salmonella in New York dairy herds; Hassan L et al.; As part of our long-term objective of assessing risk for Listeria monocytogenes and Salmonella spp . in dairy herds, we carried out a cross-sectional study to determine the prevalence of the two organisms . The study population consisted of a sample of dairy herds enrolled in the Quality Milk Promotion Services at Cornell during the period of April 1998 to March 1999 . The sample was stratified by geographical region to assure representation . Four hundred and four dairy farms were enrolled in the study . In-line milk filters were collected from each farm for bacteriological examination of L . monocytogenes and Salmonella spp . Four hypothesized risk factors were evaluated for their association with the likelihood of the presence of each of the two organisms using logistic regression analysis . Listeria monocytogenes was isolated from 51 (12.6%) of the milk filters . We found region-specific differences in the rate of farms with positive milk filters for this pathogen . Salmonella spp . were isolated from 6 (1.5%) milk filters . One isolate was confirmed as Salmonella enterica Serotype Typhimurium DT 104 . There was no significant association between any of the hypothetical risk factors and the likelihood of Salmonella spp . isolation . Our study demonstrated that both L . monocytogenes and Salmonella spp . were prevalent in milk filters in New York dairy herds and that Salmonella was isolated at a significantly lower rate then L . monocytogenes. J Antimicrob Chemother, 2000 Dec, 46(6), 965 - 71 Antibiotic resistance in salmonellae isolated from humans and animals in France: comparative data from 1994 and 1997; Breuil J et al.; Among 25526 recorded isolates of salmonellae, 5086 isolated from humans and 20440 from animals in 1994 and 1997 in France, the antibiotic resistance phenotype was determined for all human and 5336 animal isolates . In Salmonella enterica serovar typhimurium, one of the two most frequently isolated serovars from humans as well as animals, resistance to ampicillin was observed in 61% of both human and animal isolates in 1994 and in 73% of human and 53% of animal isolates in 1997 . During these periods, resistance to co-amoxiclav was between 45% and 66% for both types of isolate . Resistance to ampicillin was associated with resistance to streptomycin, spectinomycin, sulphonamide, tetracycline and chloramphenicol in over 70% of isolates . Resistance to ampicillin as well as co-amoxiclav never exceeded 7% in Salmonella enteritidis . While Salmonella hadar was practically absent among the human isolates in 1994, this serovar was the third most frequent in 1997, and at that time 92% were resistant to nalidixic acid . Among the animal S . hadar isolates, the prevalence of resistance to nalidixic acid increased from 3% in 1994 to 72% in 1997 . None of these isolates manifested high-level resistance to ofloxacin . The levels of resistance to aminoglycosides (< or =3%) and trimethoprim-suphamethoxazole (< or =14%) remained practically unchanged in all three serovars . The resistance markers of 463 ampicillin-resistant S . typhimurium isolated in 1997 were determined . Among the 24 phenotypes observed, six multiresistance phenotypes, representing 82% of these isolates (as compared with 80% in 1994), were associated with the PSE-1 gene typically found in the lysotype DT104 of this serovar. Microbiology, 2000 Dec, 146 Pt 12, 3227 - 35 Invasiveness in chickens, stress resistance and RpoS status of wild-type Salmonella enterica subsp . enterica serovar typhimurium definitive type 104 and serovar enteritidis phage type 4 strains; Jorgensen F et al.; The heat and acid resistance and the ability to survive airdrying on commonly used kitchen surfaces were assessed for clinical and environmental strains of Salmonella enterica subsp . enterica serovar Typhimurium, definitive type (DT) 104 . Three out of thirty-eight strains of DT 104 were found to be more sensitive in stationary phase to the stresses examined than the other strains . This compares to a previous study by the authors which showed that seven out of forty serovar Enteritidis phage type (PT) 4 strains were more sensitive . RpoS activity was examined indirectly in selected strains of DT 104 and PT 4 . In those with normal stress resistance a 100-fold induction of an RpoS-dependent spvR/A:'::luxCDABE fusion was observed upon entry into stationary phase . The sensitive strains examined showed either no induction or a reduced level of spvR/A:'::luxCDABE expression . The rpoS gene was sequenced from these strains and three were found to harbour mutations including one deletion, one base-pair substitution resulting in a nonsense codon, and one insertion causing a frameshift resulting in an early stop codon . Strains with negligible or reduced spvR/A:'::luxCDABE expression had low stress resistance . All strains of DT 104 could be recovered from liver and spleen tissues of infected hens 14 d post-infection, but one with no induction of spvR/A:'::luxCDABE expression was significantly less likely to be recovered from chicken reproductive tissues, liver or spleen than the majority of other strains, including one with reduced spvR/A:'::luxCDABE expression . This work has demonstrated that clinical and environmental strains of DT 104 and PT 4 not infrequently harbour mutations in the rpoS allele . It is possible that the rpoS mutations may have occurred during the initial isolation of the strains . The ability of a strain to cause infection, however, also depends on factors such as host susceptibility and dose. J Clin Microbiol, 2000 Dec, 38(12), 4676 - 8 Salmonella enterica serovar virchow with CTX-M-like beta-lactamase in Spain; Simarro E et al.; Four Salmonella enterica serovar Virchow strains resistant to broad-spectrum cephalosporins were isolated from patients with gastroenteritis in 1997 and 1998 in Murcia and Barcelona, Spain . The isolates expressed a beta-lactamase with a pI of about 8 and a positive PCR when specific primers for CTX-M-9 were used . These results suggest the presence of a CTX-M-9 beta-lactamase in these strains. J Clin Microbiol, 2000 Dec, 38(12), 4633 - 6 Antimicrobial resistance of Salmonella isolates from swine; Gebreyes WA et al.; We examined the antimicrobial resistance of 1,257 isolates of 30 serovars of Salmonella enterica subsp . enterica isolated from swine . Serovars Typhimurium and Typhimurium var . Copenhagen were widespread and were frequently multidrug resistant, with distinct resistance to ampicillin, kanamycin, streptomycin, sulfamethoxazole, and tetracycline and to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline, respectively. J Clin Microbiol, 2000 Dec, 38(12), 4459 - 62 Diarrhea in children under 5 years of age from Ifakara, Tanzania: a case-control study; Gascon J et al.; A matched case-control study was conducted in the Maternal and Child Health Clinic (MCH) in Ifakara, Tanzania, during the rainy season in order to elucidate the risk factors for and etiology of diarrheal diseases in children under 5 years of age . Cases (103) and controls (206) were matched for sex and age group . Precoded questionnaires with demographic details, clinical history, and physical signs were completed . Stools samples were collected for bacterial, parasitological, and viral studies . A high number of siblings (odds ratio {OR}, 0.86; P = 0.027), the number of siblings surviving (OR, 0.82; P = 0.007), the birth order (OR, 0.85; P = 0.018) and the distance from the house to the water source (OR, 0.33; P = 0.011) were associated with the risk of diarrhea . There were high rates of enteropathogen isolates in stool samples from children without diarrhea (52.23%) . Shigella species were the only enteropathogen statistically related with diarrhea (OR, 2.90; P < 0.029) . Enterotoxigenic, enteropathogenic, and enteroaggregative strains of Escherichia coli were not related with diarrhea, and neither were Giardia lamblia or Salmonella species. J Clin Microbiol, 2000 Dec, 38(12), 4425 - 9 Prevalence of diarrheagenic Escherichia coli in finns with or without diarrhea during a round-the-world trip; Keskimaki M et al.; The incidence of diarrhea and the prevalence of bacterial enteropathogens, viruses, and parasites in feces of subjects with and without diarrhea were evaluated in 204 Finns traveling round the world (from Finland to China, Malaysia, Australia, Fiji, Chile, and Brazil and back to Finland) . Special emphasis was placed on the finding of diarrheagenic Escherichia coli (enterotoxigenic, enteropathogenic, Shiga toxin-producing, and enteroaggregative strains) by PCR from growth on primary culture plates . From the PCR-positive samples, corresponding strains were isolated, confirmed as E . coli, and O serotyped . Of all the subjects, 37% experienced a total of 90 episodes of diarrhea . No adenoviruses or rotaviruses were detected, and findings of parasites were insignificant . In contrast, enteropathogenic bacteria were present in 62% of the 65 diarrheal and in 33% of the 127 nondiarrheal samples (P < 0.001); diarrheagenic E . coli strains were found in 35 and 26% of these, respectively (not statistically significant) . As a single pathogen, E . coli was found in 20 and 24% of samples (not significant) . Of all diarrheagenic E . coli strains, enteropathogenic strains were the most commonly found independently of the clinical picture of the subjects, whereas Salmonella enterica as a single pathogen was the most common non-E . coli organism found in diarrheal samples . Multiple bacterial pathogens were found 10 times more commonly in diarrheal than in nondiarrheal samples (20 versus 2%; P < 0.001). Appl Environ Microbiol, 2000 Dec, 66(12), 5472 - 6 Simultaneous detection of Salmonella strains and Escherichia coli O157:H7 with fluorogenic PCR and single-enrichment-broth culture; Sharma VK et al.; A multiplex fluorogenic PCR assay for simultaneous detection of pathogenic Salmonella strains and Escherichia coli O157:H7 was developed and evaluated for use in detecting very low levels of these pathogens in meat and feces . Two sets of primers were used to amplify a junctional segment of virulence genes sipB and sipC of Salmonella and an intragenic segment of gene eae of E . coli O157:H7 . Fluorogenic reporter probes were included in the PCR assay for automated and specific detection of amplified products . The assay could detect <10 CFU of Salmonella enterica serovar Typhimurium or E . coli O157:H7 per g of meat or feces artificially inoculated with these pathogens and cultured for 6 to 18 h in a single enrichment broth . Detection of amplification products could be completed in </=4 h after enrichment. Appl Environ Microbiol, 2000 Dec, 66(12), 5406 - 9 Long-term shifts in patterns of antibiotic resistance in enteric bacteria; Houndt T et al.; Several mechanisms are responsible for the ability of microorganisms to tolerate antibiotics, and the incidence of resistance to these compounds within bacterial species has increased since the commercial use of antibiotics became widespread . To establish the extent of and changes in the diversity of antibiotic resistance patterns in natural populations, we determined the MICs of five antibiotics for collections of enteric bacteria isolated from diverse hosts and geographic locations and during periods before and after commercial application of antibiotics began . All of the pre-antibiotic era strains were susceptible to high levels of these antibiotics, whereas 20% of strains from contemporary populations of Escherichia coli and Salmonella enterica displayed high-level resistance to at least one of the antibiotics . In addition to the increase in the frequency of high-level resistance, background levels, conferred by genes providing nonspecific low-level resistance to multiple antibiotics, were significantly higher among contemporary strains . Changes in the incidence and levels of antibiotic resistance are not confined to particular segments of the bacterial population and reflect responses to the increased exposure of bacteria to antimicrobial compounds over the past several decades. Appl Environ Microbiol, 2000 Dec, 66(12), 5273 - 81 Suitability of PCR fingerprinting, infrequent-restriction-site PCR, and pulsed-field gel electrophoresis, combined with computerized gel analysis, in library typing of Salmonella enterica serovar enteritidis; Garaizar J et al.; Strains of Salmonella enterica (n = 212) of different serovars and phage types were used to establish a library typing computerized system for serovar Enteritidis on the basis of PCR fingerprinting, infrequent-restriction-site PCR (IRS-PCR), or pulsed-field gel electrophoresis (PFGE) . The rate of PCR fingerprinting interassay and intercenter reproducibility was low and was only increased when DNA samples were extracted at the same time and amplified with the same reaction mixtures . Reproducibility of IRS-PCR technique reached 100%, but discrimination was low (D = 0.52) . The PFGE procedure showed an intercenter reproducibility value of 93.3% . The high reproducibility of PFGE combined with the previously determined high discrimination directed its use for library typing . The use of PFGE with enzymes XbaI, BlnI, and SpeI for library typing of serovar Enteritidis was assessed with GelCompar 4.0 software . Three computer libraries of PFGE DNA profiles were constructed, and their ability to recognize new DNA profiles was analyzed . The results obtained pointed out that the combination of PFGE with computerized analysis could be suitable in long-term epidemiological comparison and surveillance of Salmonella serovar Enteritidis, specially if the prevalence of genetic events that could be responsible for changes in PFGE profiles in this serovar was low. Appl Environ Microbiol, 2000 Dec, 66(12), 5248 - 52 PCR detection of Salmonella enterica serotype Montevideo in and on raw tomatoes using primers derived from hilA; Guo X et al.; Salmonellae have been some of the most frequently reported etiological agents in fresh-produce-associated outbreaks of human infections in recent years . PCR assays using four innovative pairs of primers derived from hilA and sirA, positive regulators of Salmonella invasive genes, were developed to identify Salmonella enterica serotype Montevideo on and in tomatoes . Based on examination of 83 Salmonella strains and 22 non-Salmonella strains, we concluded that a pair of hilA primers detects Salmonella specifically . The detection limits of the PCR assay were 10(1) and 10(0) CFU/ml after enrichment at 37 degrees C for 6 and 9 h, respectively . When the assay was validated by detecting S . enterica serotype Montevideo in and on artificially inoculated tomatoes, 10(2) and 10(1) CFU/g were detected, respectively, after enrichment for 6 h at 37 degrees C . Our results suggest that the hilA-based PCR assay is sensitive and specific, and can be used for rapid detection of Salmonellae in or on fresh produce. Eur J Cancer, 2000 Dec, 36(18), 2397 - 402 Antitumour effects of genetically engineered Salmonella in combination with radiation; Platt J et al.; The antitumour efficacy of lipid A mutant Salmonella was evaluated alone and in combination with X-rays in mice bearing B16F10 or Cloudman S91 melanomas . Each treatment alone slowed tumour growth and prolonged survival, and the combined treatments produced supra-additive antitumour effects . That is, in dose-response studies with single doses of Salmonella and increasing doses of radiation, the two agents together caused suppression of tumour growth that was greater than that calculated for additivity . The results suggest that the combination of these genetically engineered Salmonella with radiotherapy could be a new and beneficial treatment for solid tumours. Biol Neonate, 2000 Nov, 78(4), 308 - 14 Sublethal endotoxemia promotes pulmonary cytokine-induced neutrophil chemoattractant expression and neutrophil recruitment but not overt lung injury in neonatal rats; Tillema MS et al.; Gram-negative sepsis and septic shock remain major causes of morbidity and mortality in the newborn . Respiratory failure is a common feature in neonatal sepsis regardless of the presence or absence of associated pneumonia . In adult animal models, cytokine-induced neutrophil chemoattractant (CINC) is a potent chemoattractant for neutrophils and believed to play a role in endotoxin-induced lung injury . We examined this in a neonatal model . Ten-day-old Sprague-Dawley rats were injected with Salmonella enteritidis endotoxin (ETX) 0.03 mg/kg i.p . and sacrificed at baseline, 30 min, 1, 2, 4, 8 and 16 h post-ETX . Blood was collected by cardiac puncture . After bronchoalveolar lavage, lung tissue was collected and evaluated for neutrophil (polymorphonuclear leukocyte) recruitment by myeloperoxidase assay (MPO) . Lung CINC expression was measured by Northern blot and ELISA . Peripheral blood leukocytosis was noted at 1 h (p < 0.001) with counts below baseline at 2 and 4 h . Differential counts revealed neutrophilia at 8 h (p < 0.001) . MPO revealed pulmonary PMN recruitment peaking at 1 h (p < 0.05) and CINC RNA and protein expression peaked slightly later at 2 h (p < 0 . 001) . No overt lung injury was noted by bronchoalveolar lavage cell counts or by histology . Therefore, pulmonary CINC expression and neutrophil recruitment follows LPS exposure in neonatal rats . This may represent priming of the lung tissue and a secondary event may be necessary for injury to occur. Poult Sci, 2000 Nov, 79(11), 1571 - 4 Salmonella penetration of egg shells and proliferation in broiler hatching eggs--a review; Cox NA et al.; The presence of salmonellae in fertile broiler hatching eggs has been clearly identified as a critical control point in the salmonellae contamination of broiler chickens . This paper reviews the published research studies on a) the penetration and proliferation of salmonellae in hatching eggs, b) the consequences of this contamination on the contamination of the final product, and c) the egg's defenses against invading salmonellae . A better understanding of the material in this review paper will assist poultry researchers and the poultry industry in continuing to make progress in reducing and eliminating salmonellae from fertile hatching eggs, hatcheries, and breeder flocks. Poult Sci, 2000 Nov, 79(11), 1557 - 61 Characterization of the contribution of water activity and moisture content to the population distribution of Salmonella spp . in commercial poultry houses; Hayes JR et al.; Because Salmonella spp . can be spread from the production environment to the consumer, strategies are required to control Salmonella . One such intervention involves control of the distribution of the organism in poultry litter . In this regard, we have attempted to determine whether Salmonella spp . are uniformly distributed throughout the litter of commercial poultry houses, or if they are unevenly localized to "hot spots" associated with high surface litter water activity (Aw) and high total moisture levels . Of the 86 houses sampled, 48 (55.8%) were positive for Salmonella spp . using a combination of the drag swab and targeted litter culturing methods . Data are presented that show that elevated Aw and percentage moisture content values representative of targeted litter samples or whole-house moisture status are not statistically predictive of Salmonella contamination, using either drag swab or targeted litter culture results as indicators of contamination . This study suggests that favorable environmental conditions for the growth of Salmonella are unequally dispersed in poultry houses . Because there is not equivalent distribution of salmonellae in the surface litter, the drag swab technique is apparently necessary to adequately survey for Salmonella spp . contamination . The findings further suggest that the development of a methodology to detect areas within houses that possess risk factors favorable for Salmonella growth must also include elevated Aw and percentage moisture content levels . This capability may enable a grower to detect and intervene in these targeted areas with neutralizing procedures, agents, or other substances to provide significant reduction of Salmonella or other poultry-associated food-borne pathogens. Int J Antimicrob Agents, 2000 Nov, 16(3), 347 - 8 Ciprofloxacin versus chloramphenicol in the treatment of salmonella infection; Liberti A et al.; Strains of Salmonella typhi resistant to chloramphenicol and ampicillin have been isolated in several countries . This study compares treatment of Salmonella infection using ciprofloxacin (500 mg twice daily) for 10 days with chloramphenicol (50 mg/kg per day divided into four doses) for 14 days . The pathogen eradication rates for patients receiving ciprofloxacin was 18/20 (90%), compared with 25/28 (89%) for those who received chloramphenicol . Signs and symptoms in patients receiving chloramphenicol lasted longer and sometimes twice as long as patients treated with ciprofloxacin . In this study, ciprofloxacin was superior to cloramphenicol in the treatment of S . typhi infection and also had fewer side-effects and the convenience of a twice-a-day dosing Int J Antimicrob Agents, 2000 Nov, 16(3), 249 - 51 Decrease of antibiotic resistance in Salmonella typhi isolated from patients attending hospitals of Dhaka City over a 3 year period; Zahurul Haque Asna SM et al.; Salmonella typhi is an important cause of enteric fever in Bangladesh . Resistance to commonly used antibiotics like cotrimoxazole and ampicillin has led to the introduction of third generation cephalosporins and fluoroquinolones for the treatment of enteric fever . Prescription patterns for enteric fevers and for other infections have been changing and so we looked at the antibiotic resistance of S . typhi isolated from patients in and around Dhaka City from 1996-1998 . The study showed a gradual change in resistance to ampicillin and cotrimoxazole among S . typhi in our area . The rate of resistance to cotrimoxazole, ampicillin and chloramphenicol decreased from 59.6 to 5.6% in S . typhi over a 3 year period . The extensive use of third generation cephalosporins and fluoroquinolones, in place of conventional antibiotics, has probably influenced the change in resistance pattern in S . typhi. Int J Antimicrob Agents, 2000 Nov, 16(3), 211 - 7 Natural antibiotic susceptibility of Salmonella enterica strains; Stock I et al.; The susceptibility of 100 Salmonella enterica strains belonging to S . enterica subsp . enterica (n=90) and S . enterica subsp . arizonae (n=10) was examined to 71 antibiotics . Within S . enterica subsp . enterica, strains of different serovars (typhimurium (n=17), enteritidis (n=17), dublin (n=10), typhi (n=16), paratyphi A (n=6), others (n=24)) were studied . MICs were determined using a microdilution procedure and apart from fosfomycin there were no significant differences in susceptibility between the subspecies and serovars of S . enterica . All salmonellae were sensitive or intermediately resistant to tetracyclines, aminoglycosides, most beta-lactam antibiotics, quinolones, co-trimoxazole group antibiotics, chloramphenicol, nitrofurantoin and azithromycin . S . enterica strains were intrinsically resistant to benzylpenicillin, oxacillin, most macrolides, rifampicin, lincosamides, streptogramins, glycopeptides and fusidic acid . Apart from some slight differences in antibiotic susceptibility between strains of S . enterica subsp . enterica and S . enterica subsp . arizonae, only the susceptibility to fosfomycin varied among the taxa studied . Whereas 'enteric' salmonellae including S . enterica subsp . arizonae were sensitive to fosfomycin, 'typhoid' salmonellae were intrinsically resistant . A database of the antibiotic susceptibility of S . enterica was set up . It may be of use to validate antibiotic susceptibility test results of these bacteria. J Biomol Struct Dyn, 2000 Oct, 18(2), 261 - 71 Homology model of surface antigen OmpC from Salmonella typhi and its functional implications; Arockiasamy A et al.; Homology based 3D structural model of the immunodominant major surface antigen OmpC from Salmonella typhi, an obligatory human pathogen, was built to understand the possible unique conformational features of its antigenic loops with respect to other immunologically cross reacting porins . The homology model was built based on the known crystal structures of the E . coli porins OmpF and PhoE . Structure based sequence alignment helped to define the structurally conserved regions (SCRs) . The SCR regions of OmpC were modelled using the coordinates of corresponding regions from reference proteins . Surface exposed variable regions were modelled based on the sequence similarity and loop search in PDB . Structural refinement based on symmetry restrained energy minimization resulted in an agreeable model for the trimer of OmpC . The resulting model was compared with other porin structures, having b-barrel fold with 16 transmembrane beta-strands, and found that the variable regions are unique in terms of sequence and structure . A ranking of the loops taking into account the antigenic index, the sequence variability, the surface accessibility in the context of the trimer, and the structural variability suggests that loop 4 (151-172), loop 5 (194-218) and loop 6 (237-264) are the best ranked B-cell epitopes . The model provides possible explanations for the functional and unique immunological properties associated with the surface exposed regions and outlines the implications for structure based experimental design. J Exp Med, 2000 Nov 20, 192(10), 1415 - 24 Severe lung lesions caused by Salmonella are prevented by inhibition of the contact system; Persson K et al.; Vascular damage induced by trauma, inflammation, or infection results in an alteration of the endothelium from a nonactivated to a procoagulant, vasoconstrictive, and proinflammatory state, and can lead to life-threatening complications . Here we report that activation of the contact system by Salmonella leads to massive infiltration of red blood cells and fibrin deposition in the lungs of infected rats . These pulmonary lesions were prevented when the infected animals were treated with H-D-Pro-Phe-Arg-chloromethylketone, an inhibitor of coagulation factor XII and plasma kallikrein, suggesting that inhibition of contact system activation could be used therapeutically in severe infectious disease. Vet Clin North Am Food Anim Pract, 2000 Nov, 16(3), 559 - 97 The concentration of swine production . Effects on swine health, productivity, human health, and the environment; Donham KJ; The concern about environmental issues centering around CAFOs is appropriate . The veterinary profession can be an important force in meeting these challenges by broadening its scope of knowledge and practice into the broader environmental field . Although animal agriculture's contribution to environmental concerns is the focus of this article, it is only one of several sectors that contributes to environmental degradation . Crop production, as well as livestock production industries, contribute to pollution . Manufacturing industries, municipalities, private individuals, our consumptive lifestyles, and agriculture all contribute to the degradation of our environment . One must keep in mind the huge importance of our agricultural industry and not single it out to the detriment of its progress . We have an abundance of high-quality foods at the lowest cost to the individual of any industrialized nation . We export over 40 billion dollars in agricultural products yearly . Agriculture sustains our rural economies and provides opportunities for over 2 million private enterprises scattered across the country; however, there is a goal that we have a sustainable agriculture . A big part of that depends on development and enhancement of an agriculture that does not pollute, that sustains its farm operators and workers, and that does not make the area residents ill or degrade their quality of life; however, the current situation is not promising . Much remains to be learned about the actual acute and long-term health consequences of animal agricultural pollution . Many health concerns are speculative, even though based on sound facts . We know that many surface waters have excess N and P that leads to eutrophication and possibly enhanced growth of undesirable organisms such as Pfiesteria piscicida . We know that other animal pathogens, such as cryptosporidia, have caused large community outbreaks . There are other potential pathogens, such as Salmonella sp, for which we do not know the hazard . We know that our soils may become excessively laden with P, Cu, and Zn, which retard plant growth and create toxic conditions for grazing animals . There are concerns about air pollution . Odors have negative sensory and physical health consequences . H2S and dust may cause toxic effects on neighbors . NH3 vaporizing from manure sources may be carried with precipitation to cause eutrophication in lakes or altered ecosystems in natural areas . CH4 escaping from degrading manure contributes to greenhouse gases . Workers in confined livestock structures have high risk for a variety of chronic respiratory conditions . They also are at risk for acute poisoning from H2S in operations where liquid manure is stored in confined spaces . There have been numerous health complaints in recent years from community neighbors of large-scale livestock operations . One study showed adverse altered mood states, and another showed evidence of respiratory illness similar to what workers experience . Although it has not been possible to objectively measure conditions and know toxic levels of substances causing these illnesses, there are so-called extratoxic mechanisms, such as inherent aversion to putrefactive odors and exacerbation of preexisting conditions that lower the tolerance threshold . Environmental concerns regarding livestock production are not new . In the early and mid-1970s, there were many conferences and publications regarding odors and water contamination from livestock operations . Although most of what is known in this area has been known for 20 years, relatively little effective efforts have been made to correct the concerns . In fact, trends over this past decade have increased the concerns . This past decade has seen a tremendous acceleration in the concentration and consolidation of agriculture, capping a slow trend over the past 50 years toward larger, fewer, and more-specialized farms . This trend has gone against the old saying that "dilution is the solution to pollution. Trop Gastroenterol, 2000 Jul-Sep, 21(3), 121 - 3 Role of molecular typing in an outbreak of Salmonella paratyphi A; Chandel DS et al.; During the post monsoon season of 1996 an outbreak of human Salmonellosis caused by Salmonella serovar-paratyphi A occurred in New Delhi and had continued for over 2 month