Epidemiol Infect, 2004 Oct, 132(5), 889 - 95 Outbreak of Salmonella Livingstone infection in Norway and Sweden due to contaminated processed fish products; Guerin PJ et al.; In Europe, the number of reported sporadic human cases of Salmonella Livingstone infection is low, and outbreaks are rare . We report the largest S . Livingstone outbreak described in the literature having an identified source of infection . In February 2001, an increased incidence of infection caused by S . Livingstone was observed in Norway and Sweden . By July 2001, 44 cases were notified in Norway and 16 in Sweden . The median age was 63 years, and 40 were women . There were three deaths, and 22 patients were hospitalized . Based on standardized questionnaires and retrospective studies of S . Livingstone strains in Norway and Sweden, food items with egg powder were suspected, and S . Livingstone was subsequently recovered from a processed fish product at the retail level . Analysis by pulsed-field gel electrophoresis documented that isolates from the fish product belonged to the same clone as the outbreak strain. Epidemiol Infect, 2004 Oct, 132(5), 881 - 7 Outbreak of Salmonella Goldcoast infections linked to consumption of fermented sausage, Germany 2001; Bremer V et al.; Salmonella Goldcoast (SGC), an uncommon serotype in Germany, was identified in 25 isolates between 1 April and 7 May 2001 . To determine the cause of the outbreak, we conducted a matched case-control study including 24 cases and 51 controls . In a multivariable regression model, only consumption of a raw fermented sausage manufactured by a local company remained significant (adjusted odds ratio 20.0, 95 % confidence interval 2.7-302.5) . SGC isolated from case-patients shared an indistinguishable pulsed-field gel electrophoresis pattern . A part of the produced raw fermented sausage was sold after only 4 days of fermentation . Samples from the premises and products of the company were negative for SGC . However, short-time raw fermented sausage is more likely to contain pathogens . Irradiation of raw ingredients is not accepted by German consumers, thus strict adherence to good manufacturing practices, the use of HACCP programmes as well as on-farm programmes remain crucial to reduce Salmonella. Epidemiol Infect, 2004 Oct, 132(5), 873 - 9 Salmonella Enteritidis outbreak associated with a school-lunch dessert: cross-contamination and a long incubation period, Japan, 2001; Matsui T et al.; A Salmonella Enteritidis (SE) outbreak in Japan was investigated with an observational study, analytical epidemiology and bacteriological examination (including phage typing) . The outbreak occurred among 96 schoolchildren, and was caused by SE phage type 1 . The outbreak source was dessert buns served at a school lunch (RR 42.55, 95 % CI 5.93-305.11, P < 0.001) . The buns were probably cross-contaminated from eggs from a factory with a history of SE-contaminated products . The incubation period was longer than usual (3-16 days, median 8 days) . A low contaminating dose may account for the long incubation period and low attack rate . Outbreak detection was hampered by the absence of routine Salmonella surveillance in Japan . The investigation was complicated by concurrent illnesses from other SE phage types . It was successful, in part, because adequate food samples were available for microbiological testing. J Clin Microbiol, 2004 Oct, 42(10), 4885 - 8 Pediatric infection due to multiresistant Salmonella enterica serotype Infantis in Honduras; Liebana E et al.; We report the case of a pediatric patient with a Salmonella enterica serotype Infantis infection . Detailed microbiological investigation revealed that this isolate carries four beta-lactamase genes (bla(TEM-1b) variant, bla(SHV-5), bla(CTX-M-15), and bla(CMY-2)) conferring resistance to all beta-lactams but imipenem . This is the first report of a Salmonella isolate with CTX-M and AmpC enzymes on the American continent, the first report of bla(CMY-2) in Salmonella serotype Infantis, and the first report of bla(CTX-M-15) in the genus Salmonella. J Clin Microbiol, 2004 Oct, 42(10), 4843 - 5 Fluorescent amplified fragment length polymorphism subtyping of multiresistant Salmonella enterica serovar Typhimurium DT104; Lawson AJ et al.; Fluorescent amplified fragment length polymorphism (FAFLP) subtyping analysis was used to genotype multiresistant Salmonella enterica serovar Typhimurium definitive phage type 104 . Thirteen distinct FAFLP profiles were found among 85 isolates exhibiting identical pulsed-field gel electrophoresis (PFGE) profiles . A single FAFLP profile was shared by 93% of outbreak-associated isolates and 82% of sporadic isolates . This study demonstrates the value of FAFLP as a high-resolution tool for epidemiological investigation of Salmonella. J Clin Microbiol, 2004 Oct, 42(10), 4821 - 3 Rapid and economical method for biochemical screening of stool isolates for Salmonella and Shigella species; Wilson G; The LOUIS test is a screening protocol for Salmonella and Shigella that uses rapid enzyme tests . It had a sensitivity of 100% and a specificity of 94% and achieved presumptive reporting of Salmonella 3 h after colony isolation with savings of time and money compared to commercial identification systems. Indian J Pathol Microbiol, 2004 Jan, 47(1), 76 - 7 Infective endocarditis due to Salmonella typhi--a case report; Wani T et al.; Endocarditis is a rare complication of typhoid fever . We report a case in which Salmonella enterica serotype typhi was isolated from a case of endocarditis . The isolate was resistant to ampicillin, chloramphenicol and ciprofloxacin but sensitive to ceftriaxone, amikacin and gentamicin. Indian J Pathol Microbiol, 2004 Jan, 47(1), 75 - 6 Pleural empyema due to S . typhi: a case report; Mishra S et al.; In a 35 year old immunocompetent male, clinically diagnosed as a case of hydropneumothorax of left side, Salmonella typhi was isolated as the causative agent of pleural empyema. Mol Microbiol, 2004 Oct, 54(2), 386 - 95 Activation of the RcsC/YojN/RcsB phosphorelay system attenuates Salmonella virulence; Mouslim C et al.; Bacterial pathogens have the ability to sense their presence in host tissues and to promote expression of their virulence factors in a time- and location-dependent manner . However, little is known about those genes whose expression is detrimental and thus suppressed during infection . Here we report that constitutive activation of the RcsC/YojN/RcsB system resulting from a mutation in the rcsC sensor gene dramatically attenuates Salmonella virulence . Mutation of the cognate response regulator gene rcsB restored full virulence to the rcsC constitutive mutant, indicating that virulence attenuation results from aberrant expression of RcsB-regulated genes . The virulence attenuation phenotype was partially dependent on the regulatory gene rcsA, which is necessary for transcription of certain RcsB-regulated genes, and on the RcsB- and RcsA-dependent colanic acid capsule synthesis cps operon . The rcsC constitutive mutant was phagocytized less efficiently by macrophages and it was defective for invasion of non-phagocytic cells and survival within macrophages; but it could protect mice upon challenge with wild-type Salmonella . Our results suggest that a successful infection demands that pathogens turn off expression of products that might interfere with virulence functions. Mol Microbiol, 2004 Oct, 54(2), 287 - 90 Modulation of AraC family member activity by protein ligands; Plano GV; A number of AraC family transcriptional activators bind low-molecular-weight ligands that modulate the activity of these proteins . Recently, it has become clear that the activity of several virulence-related AraC family members is regulated through the direct interaction of protein ligands . These interactions, in general, function to activate or repress the transcription of virulence genes in response to specific extracellular stimuli . The identification and characterization of several protein ligands that modify the activity of AraC family members in Pseudomonas aeruginosa and Salmonella enterica are discussed herein. Cell Microbiol, 2004 Nov, 6(11), 1071 - 84 Salmonella enterica serovar Typhimurium interaction with dendritic cells: impact of the sifA gene; Petrovska L et al.; Salmonella enterica serovar Typhimurium (S . Typhimurium) and several mutant derivatives were able to enter efficiently murine bone marrow-derived dendritic cells using mechanisms predominantly independent of the Salmonella pathogenicity island 1 type III secretion system . The levels of intracellular bacteria did not increase significantly over many hours after invasion . Using fluid endocytic tracers and other markers, S . Typhimurium-containing vacuoles (SCVs) were physically distinguishable from early endocytic compartments . Fifty to eighty per cent of SCVs harbouring wild-type S . Typhimurium or aroA, invH and ssaV mutant derivatives were associated with late endosome markers . In contrast, S . Typhimurium sifA was shown to escape the SCVs into the cytosol of infected dendritic cells . S . Typhimurium aroC sifA was more efficient than S . Typhimurium aroC in delivering a eukaryotic promoter-driven green fluorescent protein reporter gene for expression in dendritic cells . In contrast, S . Typhimurium aroC sifA did not detectably increase the efficiency of MHC class I presentation of the model antigen ovalbumin to T cells compared to a similar aroC derivative . Mice infected with the S . Typhimurium aroC sifA expressing ovalbumin did not develop detectably enhanced levels of cytotoxic T cell or interferon-gamma production compared to S . Typhimurium aroC derivatives. Cell Microbiol, 2004 Nov, 6(11), 1041 - 55 Analysis of the mechanisms of Salmonella-induced actin assembly during invasion of host cells and intracellular replication; Unsworth KE et al.; Salmonella enterica serovar Typhimurium (S . typhimurium) induces actin assembly both during invasion of host cells and during the course of intracellular bacterial replication . In this study, we investigated the involvement in these processes of host cell signalling pathways that are frequently utilized by bacterial pathogens to manipulate the eukaryotic actin cytoskeleton . We confirmed that Cdc42, Rac, and Arp3 are involved in S . typhimurium invasion of HeLa cells, and found that N-WASP and Scar/WAVE also play a role in this process . However, we found no evidence for the involvement of these proteins in actin assembly during intracellular replication . Cortactin was recruited by Salmonella during both invasion and intracellular replication . However, RNA interference directed against cortactin did not inhibit either invasion or intracellular actin assembly, although it resulted in increased cell spreading and a greater number of lamellipodia . We also found no role for either the GTPase dynamin or the formin family member mDia1 in actin assembly by intracellular bacteria . Collectively, these data provide evidence that signalling pathways leading to Arp2/3-dependent actin nucleation play an important role in S . typhimurium invasion, but are not involved in intracellular Salmonella-induced actin assembly, and suggest that actin assembly by intracellular S . typhimurium may proceed by a novel mechanism. Cell Microbiol, 2004 Nov, 6(11), 1019 - 25 Salmonella-induced macrophage death: multiple mechanisms, different outcomes; Hueffer K et al.; The facultative intracellular pathogen Salmonella enterica triggers programmed cell death in macrophages . The close examination of this phenomenon has revealed an unusually complex picture involving diverse mechanisms that lead to different types of programmed cell death . It appears that the outcome of the interaction of salmonella with macrophages depends on the relative contribution of two type III protein secretion systems, in conjunction with the stimulation of innate immunity outputs through conserved determinants collectively known as 'pathogen-associated molecular patterns' (PAMPs) . These interactions result in a breakdown of the balance between survival and pro-apoptotic cellular pathways, which eventually leads to macrophage cell death . The relative significance for the infection process of the different types of macrophage cell death triggered by salmonella remains to be established. Dtsch Tierarztl Wochenschr, 2004 Aug, 111(8), 331 - 4 Risk assessment strategies for Europe: integrated safety strategy or final product control: Example of Listeria monocytogenes in processed products from pork meat industry; Salvat G et al.; The European regulation 2160/2003 of November 17th, 2003 clearly shows the European strategy of zoonosis monitoring and control as an integrated approach, including the entire food production chain with a first application to Salmonella control in different animal species . This regulation is the consequence of a risk assessment performed with a "farm to fork" philosophy . European strategy is scarcely different from the American strategy, despite the fact that both were achieved by a quantitative risk assessment, as for instance, in the USA the control of Salmonella in eggs is supposed to be completed by refrigeration . Nevertheless, the EU will still have a final product control approach towards future regulations on microbiological criteria for foodstuffs . The final production monitoring and control with HACCP (93/43/EC) and microbiological criteria is the only one available for L . monocytogenes in foodstuffs . The purpose of this paper is to discuss alternative control strategies for L . monocytogenes in pig production including integrated risk assessment . In France, most of the food-borne outbreaks associated with L . monocytogenes in delicatessen were due to one particular group of strains belonging to serovar 4b and presenting a particular RFLP/PFGE (Restriction Fragment Length Polymorphism/Pulsed Field Gel Electrophoresis) profile . The outbreak itself is always associated with the initial contamination of a RTE ("ready to eat") product and re-contamination by inappropriate handling after cooking . Consequently, in most cases the RTE product is subject to inadequate refrigeration during an excessive shelf-life . The responsibility of the food industry and the consumer is clearly engaged during this scenario of foodborne diseases . The question is how to avoid the introduction of this particular strain of L . monocytogenes in the food chain . In a study we tried to evaluate the risk of pig carcass contamination at slaughterhouse level and to identify the main risk factors associated with the infection of live pigs . In most cases inappropriate cleaning and disinfection of surfaces were associated with the contamination of raw meat, but in some cases the introduction of epidemic strains in the food chain was also associated with primary production . Feeding with soup in piggeries seemed to select a particular microbial ecology associated to L . monocytogenes contamination of live pigs . The possible strategies that may be used to control L . monocytogenes in live pig production are not yet developed sufficiently to be included in the EC regulation but should be discussed in more detail. Dtsch Tierarztl Wochenschr, 2004 Aug, 111(8), 324 - 6 {Up-to-date information from the German QS salmonella monitoring and reduction programme}; Blaha T; In the beginning, the history, objectives and basic principles of the samonella monitoring and reduction programme that has been developed and implemented since 2002 in the framework of the German cross-sectional quality management and assurance programme "QS" for the food chain are expained in detail . It is a semi-quantitative assessment of the intra-herd prevalence of animals (60 samples per slaughter pig herd and year) with antibodies against salmonella species . By means of this asessment, herds are assigned to one of three risk categories (I = low risk, II = medium risk, and III = high risk) in terms of the probability to introduce Salmonella spp . into the food chain via slaughter pigs . The assignment to the categories is the basis of salmonella-reducing intervention measures . The implementation of the programme is considerably behind the schedule by mid-2004 . The reasons for the delay are explained and conclusions for the further development of the programme are drawn. J Gene Med, 2004 Dec, 6(12), 1382 - 93 Endostatin gene therapy delivered by Salmonella choleraesuis in murine tumor models; Lee CH et al.; BACKGROUND: Some anaerobic and facultatively anaerobic bacteria have been used experimentally as anticancer agents because of their selective growth in tumors . In this study, we exploited attenuated Salmonella choleraesuis as a tumoricidal agent and a vector to deliver the endostatin gene for tumor-targeted gene therapy . METHODS: Attenuated S . choleraesuis carrying a eukaryotic expression plasmid encoding reporter gene was used to evaluate its abilities of tumor targeting and gene delivery in three syngeneic murine tumor models . Furthermore, S . choleraesuis carrying the endostatin expression vector was administered intraperitoneally into tumor-bearing mice, and its antitumor effect was evaluated . RESULTS: Systemically administered S . choleraesuis preferentially accumulated within tumors for at least 10 days, forming tumor-to-normal tissue ratios exceeding 1000-10 000 : 1 . Transgene expression via S . choleraesuis-mediated gene transfer also persisted for at least 10 days . Host immune responses and tumor hypoxia may influence tumor-targeting potential of S . choleraesuis . When systemically administered into mice bearing melanomas or bladder tumors, S . choleraesuis carrying the endostatin expression vector significantly inhibited tumor growth by 40-70% and prolonged survival of the mice . Furthermore, immunohistochemical studies in the tumors revealed decreased intratumoral microvessel density, reduced expression of vascular endothelial growth factor (VEGF), and increased infiltration of CD8(+) T cells . CONCLUSIONS: These results suggest that tumor-targeted gene therapy using S . choleraesuis carrying the endostatin expression vector, which exerts tumoricidal and antiangiogenic activities, represents a promising strategy for the treatment of solid tumors . Copyright (c) 2004 John Wiley & Sons, Ltd. J Bacteriol, 2004 Oct, 186(20), 6885 - 90 A pH-sensitive function and phenotype: evidence that EutH facilitates diffusion of uncharged ethanolamine in Salmonella enterica; Penrod JT et al.; The eutH gene is part of an operon that allows Salmonella enterica to use ethanolamine as a sole source of nitrogen, carbon, and energy . Although the sequence of EutH suggests a role in transport, eutH mutants use ethanolamine normally under standard conditions (pH 7.0) . These mutants fail to use ethanolamine at a low pH . Evidence is presented that protonated ethanolamine (Eth0) does not enter cells, while uncharged ethanolamine (Eth0) diffuses freely across the membrane . The external concentration of Eth0 varies with the pH (pK=9.5) . At pH 7.0, the standard ethanolamine concentration (41 mM) provides enough Eth0 for an influx rate that can support growth with or without EutH . When a lowered pH and/or ethanolamine concentration reduced the Eth0 concentration below 25 microM, EutH was needed to facilitate diffusion . EutH+ cells grew normally at Eth0 concentrations above 3 microM, close to the Km (9 microM) of the first degradative enzyme, ethanolamine ammonia lyase . It is suggested that EutH facilitates diffusion of Eth0 . As predicted for a transporter, EutH contributed to the toxicity of ethanolamine seen under some conditions; furthermore, fusion of EutH to fluorescent Yfp protein provided evidence that EutH is a membrane protein. J Wildl Dis, 2004 Jul, 40(3), 566 - 70 A comparison of Salmonella serotypes isolated from New Zealand sea lions and feral pigs on the Auckland Islands by pulsed-field gel electrophoresis; Fenwick SG et al.; The Salmonella serotypes S . Cerro and S . Newport were isolated from New Zealand sea lions (Phocarctos hookeri) and feral pigs on the Auckland Islands in the New Zealand subantarctic region . The isolates were typed by pulsed-field gel electrophoresis using Xba1 as the restriction enzyme . The isolates were indistinguishable, which suggests that Salmonella infection cycles between sea lions and pigs in this environment . Apart from a previous isolation from a single New Zealand fur seal (Arctocephalus forsteri), S . Newport has not been recorded in any animals from New Zealand, but it is associated with gastroenteritis in humans . Contamination of the marine environment by human waste is a possible source of infection for marine mammals and warrants further investigation. Toxicol In Vitro, 2004 Dec, 18(6), 895 - 900 Mutagenic activity in waste from an aluminum products factory in Salmonella/microsome assay; Varella SD et al.; The mutagenic activity of waste material originating from an aluminum products factory was determined by the Salmonella/microsome assay, using the bacterial strains TA100, TA98 and YG1024 . The material was obtained by sweeping the factory floor at the end of the work shift . Organic compounds were extracted by ultrasound for 30 min in dichloromethane or 70% ethanol . After evaporation of solvent, these extracts were dissolved in dimethylsulfoxide, and tested for the mutagenic activity at varying concentrations . All the extracts from the factory had mutagenic activity, especially in the YG1024 strain, suggesting the presence of aromatic amines, later confirmed by chemical analysis . The TA98 strain also showed mutagenic activity, though it did not exhibit the highest mutagenicity index observed with the YG1024 strain . In TA100, mutagenic activity was not observed . This study should serve as an alert to management and those who are occupationally exposed, and as a warning that this type of waste should not be discarded in the environment without any control. J Psychosom Res, 2004 Aug, 57(2), 189 - 94 Mild acute inflammatory stimulation induces transient negative mood; Strike PC et al.; OBJECTIVE: This study aims to assess the mood changes induced by mild acute inflammatory stimulation (typhoid vaccination) . METHODS: Using a double blind study design, 26 healthy volunteers underwent baseline assessments of mood, financial strain and work stress and were randomised to injection of Salmonella typhi vaccine or placebo injection . Mood, symptoms and body temperature was assessed by a modified version of the Profile of Mood States at 1, 2, 3, 4, 6 and 8 h post injection . RESULTS: Typhoid vaccination induces no increases in physical symptoms or temperature . Mood improved over the day in the placebo but not in the vaccine condition . Negative changes in mood following injection were correlated with chronic stress (financial strain) in the vaccination condition (r=-.65, P<.025) . CONCLUSION: A mild acute inflammatory stimulus induces transient negative mood, and responses were modulated by chronic stress . Implications for depressed mood in physical illness are discussed. Parasitol Today, 1991 Mar, 7(3), 42 - 5 Genetic control of innate resistance to mycobacterial infections; Schurr E et al.; The Mendelian segregation of resistance to infection in different strains of mice infected with mycobacteria, Salmonella and Leishmania spp, all of which live in macrophages, is currently under close scrutiny . Here, Erwin Schurr and colleagues review the nature and function of the Bcg gene in controlling innate resistance to mycobacterial infection in mice and speculate on the occurrence of a possible human equivalent. Parasitol Today, 1989 Feb, 5(2), 41 - 6 Adjuvants for anti-parasite vaccines; Bomford R; To date the most successful human vaccines use attenuated living pathogens, but the advent of techniques in genetic engineering has meant that pure antigen can be provided in quantity . This has allowed the development of combined vaccines that use only the parasite antigens that convey protective immunity . However, isolated antigens lose immunogenicity so to regain potency, living attenuated carriers like Vaccinia or Salmonella can be used . To avoid the attendant drawbacks of carriers as immunopotentiating agents, adjuvants are under investigation as alternatives for use in vaccines against parasitic infections . In this review, Robert Bomford describes the adjuvants currently being examined for use in vaccines for both protozoan and helminth infections including Leishmania, malaria and Schistosoma . He also points out the drawbacks of using adjuvants and the dilemma of needing to stimulate cell'-mediated immunity while avoiding the immunopathological consequences of doing so. Acta Clin Belg, 2004 May-Jun, 59(3), 152 - 60 Antimicrobial drug resistance in nontyphoid human Salmonella in Belgium: trends for the period 2000-2002; Wybot I et al.; In order to assess antimicrobial resistance in nontyphoid human Salmonella in Belgium, the six most important serovars, representing together more than 90% of laboratory confirmed cases, were randomly sampled . From June 2000 until December 2002, a total of 1756 isolates were screened for their antimicrobial resistance profile by the disc diffusion method . S . Hadar strains showed the highest level of antimicrobial resistance . Simultaneous resistance to ampicillin, nalidixic acid, tetracycline and streptomycin was observed in 81.5, 58 and 76.1% of these isolates in 2000, 2001 and 2002, respectively . All S . Hadar isolates resistant to nalidixic acid also displayed decreased susceptibility to ciprofloxacin (MIC50 values of 0.25 microg/mL in 2000-2001 and 0.19 microg/mL in 2002) . In 2000, 2001 and 2002, respectively 44.6, 46 and 36.5% of S . Typhimurium isolates were multiresistant (resistant to 4 or more antimicrobial agents) . These multiresistant isolates were preferably associated with a few phage types, such as DT104 . Complete resistance to ciprofloxacin was detected in three S . Typhimurium isolates and sequencing of the gyrA gene revealed for each isolate two mutations at codons corresponding to Ser-83 and Asp-87 . Multiresistance was also common in S . Virchow (7.7%, 15.9% and 29.7%, in 2000, 2001 and 2002, respectively) . Resistance to nalidixic acid in S . Virchow isolates increased from 46.2% in 2000 to 80.9% in 2002 and six S . Virchow isolates were detected as cefotaxime resistant . In contrast, the vast majority of S . Enteritidis, S . Brandenburg and S . Derby isolates remained sensitive to almost all antimicrobial agents tested. Bull Soc Pathol Exot, 2004 Aug, 97(3), 173 - 4 {Contribution of phage typing and ribotyping in investigating a typhoid fever outbreak in Tunisia}; Bouallegue O et al.; A study was carried out to investigate an outbreak of typhoid fever that occurred in Sousse city and in the vicinity of Sousse (Tunisia) during summer 1999 . Twenty four isolates of Salmonella enterica serotype Typhi were isolated in hospitalized patients with a typhoid fever in two hospitals (Farhat Hached Sousse and M'saken) and were studied with the help of two molecular typing methods: phage typing and automated ribotyping . Twenty one isolates with the Vi antigen had profile DVS (Degraded Vi Strain), one isolate with the Vi antigen belonged to phage type A and two isolates were non phage typable (no Vi antigen) . The same ribotype was found in 22 out of 24 isolates . The results suggested that ribotyping is more discriminative than phage typing in this case in distinguishing strains and the strains shared the same source of the contamination . Unfortunately the precise source of the contamination could not be determined. Commun Dis Intell, 2004, 28(2), 207 - 10 OzFoodNet: enhancing foodborne disease surveillance across Australia: quarterly report, January to March 2004; Crystal structure of an aminoimidazole riboside kinase from Salmonella enterica: implications for the evolution of the ribokinase superfamily; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USAThe crystal structures of a Salmonella enterica aminoimidazole riboside (AIRs) kinase, its complex with the substrate AIRs, and its complex with AIRs and an ATP analog were determined at 2.6 angstroms, 2.9 angstroms, and 2.7 angstroms, respectively . The product of the Salmonella-specific gene stm4066, AIRs kinase, is a homodimer with one active site per monomer . The core structure, consisting of an eight-stranded beta sheet flanked by eight alpha helices, indicates that AIRs kinase is a member of the ribokinase superfamily . Unlike ribokinase and adenosine kinase in this superfamily, AIRs kinase does not show significant conformational changes upon substrate binding . The active site is covered by a lid formed by residues 16-28 and 86-100 . A comparison of the structure of AIRs kinase with other ribokinase superfamily members suggests that the active site lid and conformational changes that occur upon substrate binding may be advanced features in the evolution of the ribokinase superfamily . J Am Vet Med Assoc, 2004 Sep 1, 225(5), 722 - 5, 699 Myonecrosis and cutaneous infarction associated with Salmonella serovar Infantum infection in a horse; Pellegrini-Masini A et al.; A 5-year-old Quarter Horse mare was referred for evaluation of oral ulcers, limb edema, weight loss, and weakness . There was marked diffuse swelling extending from the stifle region to the tarsal region of the left hind limb, and the horse had a left hind limb lameness . Firm swellings ranging from 2 to 15 cm in diameter and consisting of nodules, plaques, and discrete masses were palpated on both sides of the neck, over the right shoulder region, over the left elbow region, and over the left caudoventral aspect of the abdomen . Laboratory abnormalities included hypoproteinemia, neutrophilia, and hyperfibrinogenemia . Results of ultrasonographic examination of the left hind limb and masses were suggestive of muscle edema, necrosis, and hemorrhage . Histologic examination of a biopsy specimen from a subcutaneous mass revealed necrotizing, suppurative myositis . The horse's condition gradually deteriorated, and the horse was euthanatized . Necropsy revealed myonecrosis, cutaneous infarcts, hepatic abscesses, and cholangitis . Salmonella serovar Infantum was cultured from liver and muscle lesions, and a diagnosis of Salmonella myonecrosis was made. Mamm Genome, 2004 Aug, 15(8), 630 - 6 Quantitative trait loci in Chromosomes 3, 8, and 9 regulate antibody production against Salmonella flagellar antigens in the mouse; de Souza CM et al.; Two mouse lines were produced by bidirectional selection according to the high (HIII) or low (LIII) antibody responsiveness against Salmonella flagellar antigens (Selection III) . In the present work we conducted a genomewide scan to map the quantitative trait loci (QTL) involved in the antibody response regulation in these selected mice . HIII and LIII genomes were screened with microsatellite markers and those found polymorphic between the lines (146) were used for linkage analysis in F2 (HIII x LIII) intercross . Simple interval mapping analysis was performed using Mapmanager QTX software . Three highly significant QTL linked to antibody production against Salmonella flagellar antigens have been demonstrated in Chromosomes 3, 8, and 9 . HIII and LIII lines differ in the resistance to several diseases, therefore, the relevance of these QTL with the genetic factors involved in infections, autoimmunity, and neoplastic disease progression is discussed. Ned Tijdschr Geneeskd, 2004 Aug 14, 148(33), 1636 - 41 {Subcutaneous nodules with malignant presentation, but caused by infection}; Hermans SM et al.; Three patients, a woman aged 32, a boy aged 6.5 and a man aged 56 years, presented with a subcutaneous mass suggesting a malignancy: respectively a rubbery swelling, painful to the touch below the left scapula, a partly massive, partly soft swelling on the inside of the left upper leg, and a non-fluctuating mass near the right eighth rib, parasternally . Additional diagnostic investigation revealed an infectious cause: respectively Mycobacterium tuberculosis, Bartonella henselae and Salmonella typhi . Antimicrobial therapy was successful . Subcutaneous masses suspected of being a benign or malignant tumour are sometimes caused by an infection . The differential diagnosis is extensive . Sometimes the travel anamnesis yields helpful information . It is concluded that besides histopathological examination, microbiological investigation can play a major role in the evaluation of subcutaneous masses. Prev Vet Med, 2004 Aug 30, 65(1-2), 63 - 75 Risk factors for the herd-level bacteriologic prevalence of Salmonella in Belgian slaughter pigs; Nollet N et al.; Herd-level risk factors for salmonellosis in pigs were investigated in a cross-sectional study on 62 Belgian farrow-to-finish pig herds belonging to one slaughterhouse cooperative . Data concerning housing and ventilation, management, hygiene, biosecurity, production parameters, feeding, disease control and transport to the slaughterhouse were collected during a herd visit by means of a questionnaire . The percentage of positive animals in a slaughterhouse delivery, as determined by qualitative Salmonella isolation in the mesenteric lymph nodes taken from 30 slaughter pigs, was the outcome variable . All samples were taken in 4 different slaughterhouses . Variables first were submitted to a univariable analysis using a logistic mixed regression model, with herd as random effect . Variables which were related to the Salmonella prevalence (P < 0.05) were analysed further in a multivariable model . The clustering of Salmonella infection within a pen also was studied in a generalised mixed model with pen as random effect . Salmonella isolates were identified by serotype . In 57 (92%) of the herds, at least one sample was found positive for Salmonella . The median percentage of positive Salmonella samples per delivery was 64% (range: 0-100%) . In the multivariable model, only type of floor was related significantly to the prevalence: 100% (95% CI 88-100) for herds with <50% slatted floors to 54% (36-70) for herds with fully slatted floors . The results from the analysis should be interpreted with care because only 62 herds were included in the study . Clustering between pigs from the same pen could not be demonstrated (variance +/- S.D.: 0.11 +/- 0.16) . S . typhimurium (30%) and S . derby (20%) were most common among the 23 different serotypes that were found. Prev Vet Med, 2004 Aug 30, 65(1-2), 31 - 46 Predicted quantitative effect of logistic slaughter on microbial prevalence; Evers EG; Logistic slaughter is an intervention measure intended to reduce cross-contamination during slaughter by slaughtering contaminated units (=(groups of) animals) last . This paper describes a simple mathematical model which predicts the prevalences of contaminated units after logistic and random-order slaughter . The effect of logistic slaughter is the difference between these prevalences . The model assumes that uncontaminated units can become contaminated by contaminated units that were slaughtered before them; the contributions of contaminated units are independent . It also assumes that a slaughterhouse is uncontaminated at the start of the day and that a unit that is contaminated before slaughter also is contaminated after slaughter . The model was analysed using numerical simulations; for a selection of cases, analytical formulas can be derived and are presented . Contamination of broiler flocks with Salmonella was used as a case study . Even for this simple model, data availability is a problem leading to uncertain parameter estimates . An average cross-contamination scenario predicts that the beneficial effect of logistic slaughter is as low as 9.1%, which casts doubt on its usefulness as an intervention measure . The case study produced these general model results: the effect of logistic slaughter increases with the probability of cross-contamination between units; with the length of the slaughter queue; and with sensitivity (the probability of a positive test from a unit contaminated at the start of slaughter) . However, the effect is small if the prevalence of contaminated units before slaughter is low or high. J Food Prot, 2004 Sep, 67(9), 2024 - 32 Archiving of food samples from restaurants and caterers--quantitative profiling of outbreaks of foodborne salmonellosis in Japan; Kasuga F et al.; The Ministry of Health, Labor and Welfare (former MHW) of Japan issued a Directive in 1997 advising restaurants and caterers to freeze portions of both raw food and cooked dishes for at least 2 weeks . This system has been useful for determining vehicle foods at outbreaks . Enumeration of bacteria in samples of stored food provide data about pathogen concentrations in the implicated food . Data on Salmonella concentrations in vehicle foods associated with salmonellosis outbreaks were collected in Japan between 1989 and 1998 . The 39 outbreaks that occurred during this period were categorized by the settings where the outbreaks took place, and epidemiological data from each outbreak were summarized . Characteristics of outbreak groups were analyzed and compared . The effect of new food-storage system on determination of bacterial concentration was evaluated . Freezing and nonfreezing conditions prior to microbial examination were compared in the dose-response relationship . Data from outbreaks in which implicated foods had been kept frozen suggested apparent correlation between the Salmonella dose ingested and the disease rate . Combined with results of epidemiological investigation, quantitative data from the ingested pathogen could provide complete dose-response data sets. J Food Prot, 2004 Sep, 67(9), 2000 - 7 An epidemiologic critique of current microbial risk assessment practices: the importance of prevalence and test accuracy data; Gardner IA; Data deficiencies are impeding the development and validation of microbial risk assessment models . One such deficiency is the failure to adjust test-based (apparent) prevalence estimates to true prevalence estimates by correcting for the imperfect accuracy of tests that are used . Such adjustments will facilitate comparability of data from different populations and from the same population over time as tests change and the unbiased quantification of effects of mitigation strategies . True prevalence can be estimated from apparent prevalence using frequentist and Bayesian methods, but the latter are more flexible and can incorporate uncertainty in test accuracy and prior prevalence data . Both approaches can be used for single or multiple populations, but the Bayesian approach can better deal with clustered data, inferences for rare events, and uncertainty in multiple variables . Examples of prevalence inferences based on results of Salmonella culture are presented . The opportunity to adjust test-based prevalence estimates is predicated on the availability of sensitivity and specificity estimates . These estimates can be obtained from studies using archived gold standard (reference) samples, by screening with the new test and follow-up of test-positive and test-negative samples with a gold standard test, and by use of latent class methods, which make no assumptions about the true status of each sampling unit . Latent class analysis can be done with maximum likelihood and Bayesian methods, and an example of their use in the evaluation of tests for Toxoplasma gondii in pigs is presented . Guidelines are proposed for more transparent incorporation of test data into microbial risk assessments. J Food Prot, 2004 Sep, 67(9), 1953 - 6 Antibacterial effect of water-soluble arrowroot (Puerariae radix) tea extracts on foodborne pathogens in ground beef and mushroom soup; Kim S et al.; Antimicrobial activity of water-soluble arrowroot tea extract was evaluated against Escherichia coli O157:H7, Salmonella enterica Serotype Enteritidis, Listeria monocytogenes, and Staphylococcus aureus in ground beef and mushroom soup . The concentrations of arrowroot tea used were 0, 3, and 6% (wt/wt) for ground beef and 0, 1, 5, and 10% (wt/vol) for mushroom soup . Samples without tea extract were considered controls . Each sample was stored for 0, 1, 3, 5, and 7 days at 7 degrees C for ground beef and for 0, 1, 3, and 5 days at 35 degrees C for mushroom soup . On each sampling time, proper dilutions were spread plated on each pathogen-specific agar . Viable cell counts of each pathogen were performed after incubation at 35 degrees C for 24 to 48 h . For ground beef, Salmonella Enteritidis and L . monocytogenes were slightly suppressed by approximately 1.5 log, compared with the control, on day 7 at 3 and 6% arrowroot tea treatment . For mushroom soup, all test pathogens were suppressed by 6.5, 4.7, 3.4, and 4.3 log at 5% and 6.0, 4.7, 5.0, and 4.3 log at 10% against E . coli O157:H7, Salmonella Enteritidis, L . monocytogenes, and S . aureus, respectively, compared with the control on day 5 . Mushroom soup with 1% arrowroot tea also showed 2.3- and 2.7-log growth suppression of Salmonella Enteritidis and S . aureus, respectively, compared with the control on day 5 . This study showed that the use of arrowroot tea would effectively inhibit the microbial growth of both gram-negative and gram-positive foodborne pathogens in various foods, especially liquid foods. J Food Prot, 2004 Sep, 67(9), 1886 - 91 Effect of thermoultrasonication on Salmonella enterica serovar Enteritidis in distilled water and intact shell eggs; Cabeza MC et al.; The combined effects of simultaneous application of ultrasonic waves and heat treatment (thermoultrasonication) on the survival of a strain of Salmonella enterica Enteritidis was studied in both distilled water and intentionally contaminated intact eggs immersed in water . Although minor differences were observed between parameters obtained for thermoultrasonic treatment of bacteria suspended in water and those attached to the shell egg, the thermoultrasonication effects were considered to be of the same level in the range of temperatures assayed (52 to 58 degrees C) . This combined process presented a clearly higher killing effect than the heat treatment alone . It decreased the decimal reduction times (D-values) by 80 to 55%, respectively, in the range of temperatures for heat treatment when the organism was suspended in water, which means a 99.5% reduction (5D to >2D) of the original bacterial load versus a 90% reduction for the heat treatment alone . The practical implications of the phenomenon are discussed. J Food Prot, 2004 Sep, 67(9), 1876 - 85 Surface pasteurization of whole fresh cantaloupes inoculated with Salmonella poona or Escherichia coli; Annous BA et al.; Numerous outbreaks of salmonellosis by Salmonella Poona have been associated with the consumption of cantaloupe . Commercial washing processes for cantaloupe are limited in their ability to inactivate or remove this human pathogen . Our objective was to develop a commercial-scale surface pasteurization process to enhance the microbiological safety of cantaloupe . Populations of indigenous bacteria recovered from cantaloupes that were surface pasteurized at 96, 86, or 76 degrees C for 2 to 3 min were significantly (P < 0.05) lower than those of the controls . Whole cantaloupes, surface inoculated with Salmonella Poona RM 2350 or Escherichia coli ATCC 25922 to a final cell concentration of ca . 5 log CFU/cm2 were stored at 4 degrees C or room temperature (RT = 19+/-1 degrees C) for up to 72 h before processing . Treatments at 76 degrees C for 2 to 3 min at 24 h postinoculation resulted in a reduction in excess of 5 log CFU/cm2 of Salmonella Poona and E . coli populations . Cantaloupes that were surface pasteurized and stored at 4 degrees C for 21 days retained their firmness qualities and had no visible mold growth compared with the controls, which became soft and moldy . These results indicate that surface pasteurization will enhance the microbiological safety of cantaloupes and will extend the shelf life of this commodity as well . Storage of untreated inoculated cantaloupes at RT for 24 to 72 h postinoculation caused a significant (P < 0.05) increase in Salmonella Poona and E . coli populations compared with storage at 4 degrees C . This indicates that cantaloupes should be refrigerated as soon as possible following harvest to suppress the growth of any possible contaminant on the rind. Ned Tijdschr Geneeskd, 2004 Aug 21, 148(34), 1695 - 8 {Salmonella osteomyelitis in a child with sickle cell disease}; Juliana AE et al.; In an eight-months-old girl with sickle cell disease, osteomyelitis due to Salmonella arizona was diagnosed . Osteomyelitis caused by Salmonella species is rare in children . However, in patients with sickle cell disease it is the responsible pathogen in more than 50% of cases . The differentiation between, the much more common, bone crisis and osteomyelitis in sickle cell patients is often difficult . Ultrasound and bone marrow scans may be helpful . It is not known why Salmonella causes osteomyelitis in patients with sickle cell disease . What is clear, however, is that osteomyelitis usually occurs shortly after a preceding bone crisis . Empiric antibiotic treatment of osteomyelitis in patients with sickle cell disease should include coverage for Salmonella species . The patient described was initially treated with cefuroxime and gentamicin, but once the culture result was known this was switched to amoxicillin . As new infection foci later occurred in the bone the treatment was switched to ceftriaxone i.v . which was later substituted by ciprofloxacin orally . With this all of the skeletal abnormalities were fully corrected. J Mol Biol, 2004 Oct 15, 343(2), 457 - 66 Structural and functional analysis of the C-terminal cytoplasmic domain of FlhA, an integral membrane component of the type III flagellar protein export apparatus in Salmonella; Saijo-Hamano Y et al.; FlhA is an integral membrane component of the Salmonella type III flagellar protein export apparatus . It consists of 692 amino acid residues and has two domains: the N-terminal transmembrane domain consisting of the first 327 amino acid residues, and the C-terminal cytoplasmic domain (FlhAC) comprising the remainder . Here, we have investigated the structure and function of FlhAC . DNA sequence analysis revealed that temperature-sensitive flhA mutations, which abolish flagellar protein export at the restrictive temperature, lie in FlhAC, indicating that FlhAC plays an important role in the protein export process . Limited proteolysis of purified His-FlhAC by trypsin and V8 showed that only a small part of FlhAC near its N terminus (residues 328-351) is sensitive to proteolysis . FlhAC38K, the smallest fragment produced by V8 proteolysis, is monomeric and has a spherical shape as judged by analytical gel filtration chromatography and analytical ultracentrifugation . The far-UV CD spectrum of FlhAC38K showed that it contains considerable amounts of secondary structure . FlhA(Delta328-351) missing residues 328-351 failed to complement the flhA mutant, indicating that the proteolytically sensitive region of FlhA is important for its function . FlhA(Delta328-351) was inserted into the cytoplasmic membrane, and exerted a strong dominant negative effect on wild-type cells, suggesting that it retains the ability to interact with other export components within the cytoplasmic membrane . Overproduced FlhAC38K inhibited both motility and flagellar protein export of wild-type cells to some degree, suggesting that FlhAC38K is directly involved in the translocation reaction . Amino acid residues 328-351 of FlhA appear to be a relatively flexible linker between the transmembrane domain and FlhAC38K. FEMS Microbiol Lett, 2004 Oct 1, 239(1), 1 - 8 Chemotaxis in Vibrio cholerae; Boin MA et al.; The ability of motile bacteria to swim toward or away from specific environmental stimuli, such as nutrients, oxygen, or light provides cells with a survival advantage, especially under nutrient-limiting conditions . This behavior, called chemotaxis, is mediated by the bacteria changing direction by briefly reversing the direction of rotation of the flagellar motors . A sophisticated signal transduction system, consisting of signal transducer proteins, a histidine kinase, a response regulator, a coupling protein, and enzymes that mediate sensory adaptation, relates the input signal to the flagellar motor . Chemotaxis has been extensively studied in bacteria such as Escherichia coli and Salmonella enterica serovar Typhimurium, and depends on the activity of single copies of proteins in a linear pathway . However, growing evidence suggests that chemotaxis in other bacteria is more complex with many bacterial species having multiple paralogues of the various chemotaxis genes found in E . coli and, in most cases, the detailed functions of these potentially redundant genes have not been elucidated . Although the completed genome of Vibrio cholerae, the causative agent of cholera, predicted a multitude of genes with homology to known chemotaxis-related genes, little is known about their relative contribution to chemotaxis or other cellular functions . Furthermore, the role of chemotaxis during the environmental or infectious phases of this organism is not yet fully understood . This review will focus on the complex relationship between chemotaxis and virulence in V . cholerae. Mutat Res, 2004 Oct 4, 554(1-2), 335 - 50 Comparative mutagenicity of halomethanes and halonitromethanes in Salmonella TA100: structure-activity analysis and mutation spectra; Kundu B et al.; Halonitromethanes (HNMs) are a recently identified class of disinfection by-products (DPBs) in drinking water that are mutagenic in Salmonella and potent inducers of DNA strand breaks in mammalian cells . Here we compared the mutagenic potencies of the HNMs to those of their halomethane (HM) homologues by testing all nine HNMs and seven of the nine HMs (minus bromomethane and chloromethane) under the same conditions (the pre-incubation assay) in Salmonella TA100 +/- S9 . We also determined the mutation spectra for several DBPs . In the presence of S9, all nine HNMs, but only three HMs, dibromomethane (DBM), dichloromethane (DCM), and bromochloromethane (BCM), were mutagenic . Only two DBPs of each class were mutagenic in the absence of S9 . The HNMs were generally more potent mutagens than their HM homologues, and the brominated forms of both classes of DBPs were more mutagenic and cytotoxic than their chlorinated homologues . The HNMs were at least 10 times more cytotoxic than the HMs, and the cytotoxicity rankings in the presence of S9 were similar for the HNMs and the HMs . The addition of a nitro-group to BCM did not change the mutation spectra significantly, with both homologues inducing primarily (55-58%) GC --> AT transitions . The greater cytotoxic and mutagenic activities of the HNMs relative to the HMs are likely due to the greater intrinsic reactivity conferred by the nitro-group . Energy calculations predicted increased reactivity with increasing bromination and greater reactivity of the HNMs versus the HMs (Elumo values were approximately 20 kcal/mol lower for the HNMs compared to their HM homologues) . Given that the HNMs also are potent genotoxins in mammalian cells {Environ . Sci . Technol . 38 (2004) 62} and are more mutagenic and 10x more cytotoxic in Salmonella than the HMs, whose levels are regulated in drinking water, further study of their occurrence and potential health effects is warranted. Rev Esp Enferm Dig, 2004 Aug, 96(8), 559 - 62; 563-6 Abnormalities in liver enzyme levels during Salmonella enteritidis enterocolitis; Gonzalez-Quintela A et al.; OBJECTIVE: To evaluate the prevalence, associated factors, and time-course changes of abnormal liver enzyme serum levels in adult patients with Salmonella enteritidis enterocolitis . METHODS: The clinical records of 104 patients (age range 15-86 years, 46.2% males) admitted to hospital because of S . enteritidis enterocolitis were reviewed . The prevalence of abnormal liver enzyme levels was evaluated, as well as its possible relationship to data of systemic inflammatory response, severe sepsis, and bacteremia . In addition, time-course changes in serum levels of liver enzymes were studied in 16 cases with available follow-up after hospital discharge . RESULTS: In patients without a pre-existing cause for liver enzyme abnormalities (n = 84), the prevalence of serum AST elevation was 23.0% (95% CI 15.4-34.5%), of serum ALT elevation was 17.9% (95% CI 0.6-20.0%), and of GGT elevation was 19.0% (95% CI 11.6-29.3%) . The prevalence of abnormality for any of these enzymes (AST, ALT, or GGT) was 35.7% (95% CI 25.7-46.8%) . The prevalence of altered serum alkaline phosphatase was lower . Alteration in liver enzyme serum levels was moderate in the majority of cases, and was found in association with the presence of fever . Serum enzyme levels decreased during the convalescence period after hospital discharge . CONCLUSIONS: Abnormalities in liver enzyme levels are frequent during severe enterocolitis due to S . enteritidis in adult patients . These abnormalities are moderate and self-limited. Trop Anim Health Prod, 2004 Jul, 36(5), 451 - 8 Salmonella prevalence and distribution of serotypes in apparently healthy slaughtered camels (Camelus dromedarius) in Eastern Ethiopia; Molla B et al.; The present study was undertaken to determine the prevalence and distribution of Salmonella from apparently healthy slaughtered camels in Eastern Ethiopia . A total of 714 samples (faeces, mesenteric, lymph nodes, spleen, liver, abdominal and diaphragmatic muscles) from 119 slaughtered camels were analysed . Salmonellae were detected from 116 (16.2%) of the 714 samples examined . Eighteen (15.1%) faeces, 19 (15.9%) mesenteric lymph nodes, 14 (11.8%) livers and 17 (14.3%) spleen samples (n = 119 for each) were positive for Salmonella . Salmonellae were found in 20.1% of the abdominal and diaphragmatic muscles . A total of sixteen different serotypes were identified of which Salmonella saintpaul (38.8%) and S . braenderup (22.4%) were the most prevalent followed by S . muenchen (8.6%), S . kottbus (6.0%) and S . havana (5.2%) . Other serotypes, including S . typhimurium, S . heidelberg and S . enteritidis were also detected from Ethiopian camels. J Enzyme Inhib Med Chem, 2004 Apr, 19(2), 161 - 8 Antibacterial and antifugal mono- and di-substituted symmetrical and unsymmetrical triazine-derived Schiff-bases and their transition metal complexes; Chohan ZH et al.; A new series of antibacterial and antifungal triazine-derived mono- and di-substituted (symmetrical and unsymmetrical) Schiff-bases and their cobalt(II), copper(II), nickel(II) and zinc(II) metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments and IR and electronic spectral measurements . IR spectra indicated the ligands to act as tridentate towards divalent metal ions via a trazine-N, the azomethine-N and, indole-NH and deprotonated-O of salicylaldehyde . The magnetic moments and electronic spectral data suggest octahedral geometry for the Co(II), Ni(II) and Zn(II)complexes and square-pyramid for Cu(II) complexes . NMR spectral data of the ligands and their diamagnetic zinc(II) complexes well-define their proposed structures/geometries . Elemental analyses data of the ligands and metal complexes agree with their proposed structures/geometries . The synthesized ligands, along with their metal complexes were screened for their antibacterial activity against Escherichia coli, Bacillus subtillis, Shigella flexneri, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi and for antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata . The results of these studies show the metal complexes to be more antibacterial/ antifungal against two or more species as compared to the uncomplexed Schiff-base ligands. Lab Invest, 2004 Nov, 84(11), 1501 - 11 Control of Salmonella dissemination in vivo by macrophage inflammatory protein (MIP)-3alpha/CCL20; Fahy OL et al.; While chemokines are clearly important in the generation of protective immunity, the role of individual chemokines in the control of bacterial infection is still poorly understood . In this study, we investigated the role of macrophage inflammatory protein (MIP)-3alpha/CCL20, a chemokine that attracts activated T and B lymphocytes and immature dendritic cells, in host responses to bacterial infection . CCL20 production was induced in subcutaneous tissue in the BALB/c mouse in response to Salmonella enteritidis, Staphylococcus aureus and zymosan, with S . enteritidis being the most potent . S . enteritidis induced CCL20 production in the spleen following either oral administration or injection into the peritoneal cavity . In contrast, no increase was observed in the Peyer's patches . In this model, following intraperitoneal injection, dose-dependent colonization of the spleen and Peyer's patches by S . enteritidis, expression of IFNgamma and IL-4, and production of antibodies against the S . enteritidis surface antigen SefA were observed . Prior treatment with neutralizing antibodies against CCL20 enhanced bacterial dissemination to the spleen and Peyer's patches and strongly biased the IFNgamma/IL-4 ratio towards a type 2 profile in the spleen, while the humoral response was unaffected . In contrast, treatment with neutralizing anti-MIP-1alpha/CCL3 antibodies enhanced the bacterial burden in the Peyer's patches but not in the spleen, had no significant effect on the cytokine ratio, but significantly inhibited anti-SefA production . Together, these results demonstrate an important role for CCL20 in the control of bacterial infection and more specifically in the regulation of cell-mediated immunity against intracellular bacteria such as S . enteritidis. Am J Gastroenterol, 2004 Oct, 99(10), 2041 - 5 Association of Helicobacter pylori infection with Shigella gastroenteritis in young children; Shmuely H et al.; OBJECTIVE: Helicobacter pylori infection is acquired mainly in early childhood . Much is unknown about the mode of transmission . The organism can be cultivated from cathartic stools and vomitus and is potentially transmissible during episodes of gastrointestinal tract illness . Because Shigella and Salmonella are common pathogens in enteric infections in children, we examined the association of H . pylori with Shigella and Salmonella infections in pediatric patients . METHODS: The study population included consecutive children aged 2-72 months hospitalized with acute gastroenteritis who had culture-proven shigellosis (N = 78) or salmonellosis (N = 76) . Sixty-five healthy similarly aged children with culture-negative stools served as controls . Parents of cases were queried for personal and family characteristics and socioeconomic indicators . The stool specimens from all participants were tested for H . pylori antigen . RESULTS: On univariate analysis, Shigella gastroenteritis was significantly associated with H . pylori positivity (odds ratio, OR: 3.5, 95% confidence interval (CI): 1.5-8.8, p= 0.004) compared to controls . This association remained significant even after adjusting for living conditions, father's occupation, and father's education (OR = 3.38, 95% CI: 1.39-8.22, p= 0.007) . Salmonella gastroenteritis was not associated with H . pylori positivity (OR = 1.1; 95% CI: 0.4-3.0, p= 0.8) . CONCLUSION: H . pylori infection in young children is associated with Shigella gastroenteritis . This association warrants further investigation. J Pharm Sci, 2004 Nov, 93(11), 2718 - 23 TNFalpha measurement in rat and human whole blood as an in vitro method to assay pyrogens and its inhibition by dexamethasone and erythromycin; Martinez V et al.; To ensure the safety of potential drugs, pyrogen tests are traditionally performed in rabbits . New methods have been developed as alternatives to the test to reduce the use of experimental animals . Among these methods there are the Limulus amoebocyte lysate test and the determination of cytokine production by human leukocytes and whole blood . When exposed to a range of concentrations of endotoxins, human and rat whole blood release TNFalpha at amounts that are detectable by a commercially available enzyme-linked immunosorbent assay (ELISA) . Our results show that the sensitivity of human and rat blood to endotoxins from Salmonella abortus equi and Escherichia coli is similar . In rat blood, TNFalpha was detected after contact with the pyrogens only in fresh blood, collected on the same day of incubation with the pyrogenic substances . The measurement of TNFalpha production would be a reliable alternative to the rabbit pyrogen test . However, given that the addition of erythromycin and dexamethasone inhibited the production of this cytokine, this method is limited when parenteral formulations contain these two drugs . Similar inhibition has been observed in the rabbit test . Additional experiments will be necessary to demonstrate that the rat whole blood test system is useful and reliable for the pyrogens evaluation. Antimicrob Agents Chemother, 2004 Oct, 48(10), 4012 - 5 Prevalence of mutations within the quinolone resistance-determining region of gyrA, gyrB, parC, and parE and association with antibiotic resistance in quinolone-resistant Salmonella enterica; Eaves DJ et al.; Salmonella enterica isolates (n = 182) were examined for mutations in the quinolone resistance-determining region of gyrA, gyrB, parC, and parE . The frequency, location, and type of GyrA substitution varied with the serovar . Mutations were found in parC that encoded Thr57-Ser, Thr66-Ile, and Ser80-Arg substitutions . Mutations in the gyrB quinolone resistance-determining region were located at codon Tyr420-Cys or Arg437-Leu . Novel mutations were also found in parE encoding Glu453-Gly, His461-Tyr, Ala498-Thr, Val512-Gly, and Ser518-Cys . Although it is counterintuitive, isolates with a mutation in both gyrA and parC were more susceptible to ciprofloxacin than were isolates with a mutation in gyrA alone. Antimicrob Agents Chemother, 2004 Oct, 48(10), 3934 - 9 Mechanism of resistance to several antimicrobial agents in Salmonella Clinical isolates causing traveler's diarrhea; Cabrera R et al.; The evolution of antimicrobial resistance in Salmonella isolates causing traveler's diarrhea (TD) and their mechanisms of resistance to several antimicrobial agents were analyzed . From 1995 to 2002, a total of 62 Salmonella strains were isolated from stools of patients with TD . The antimicrobial susceptibility to 12 antibiotics was determined, and the molecular mechanisms of resistance to several of them were detected as well . The highest levels of resistance were found against tetracycline and ampicillin (21 and 19%, respectively), followed by resistance to nalidixic acid (16%), which was mainly detected from 2000 onward . Molecular mechanisms of resistance were analyzed in 16 isolates . In these isolates, which were resistant to ampicillin, two genes encoding beta-lactamases were detected: oxa-1 (one isolate) and tem-like (seven isolates {in one strain concomitantly with a carb-2}) . Resistance to tetracycline was mainly related to tetA (five cases) and to tetB and tetG (one case each) . Resistance to chloramphenicol was related to the presence of the floR and cmlA genes and to chloramphenicol acetyltransferase activity in one case each . Different genes encoding dihydrofolate-reductases (dfrA1, dfrA12, dfrA14, and dfrA17) were detected in trimethoprim-resistant isolates . Resistance to nalidixic acid was related to the presence of mutations in the amino acid codons 83 or 87 of the gyrA gene . Further surveillance of the Salmonella spp . causing TD is needed to detect trends in their resistance to antimicrobial agents, as we have shown in our study with nalidixic acid . Moreover, such studies will lead to better treatment and strategies to prevent and limit their spread. Antimicrob Agents Chemother, 2004 Oct, 48(10), 3877 - 83 Fusidic acid-resistant mutants of Salmonella enterica serovar typhimurium have low levels of heme and a reduced rate of respiration and are sensitive to oxidative stress; Macvanin M et al.; Mutations in the translation elongation factor G (EF-G) make Salmonella enterica serovar Typhimurium resistant to the antibiotic fusidic acid . Fus(r) mutants are hypersensitive to oxidative stress and rapidly lose viability in the presence of hydrogen peroxide . We show that this phenotype is associated with reduced activity of two catalase enzymes, HPI (a bifunctional catalase-hydroperoxidase) and HPII (a monofunctional catalase) . These catalases require the iron-binding cofactor heme for their activity . Fus(r) mutants have a reduced rate of transcription of hemA, a gene whose product catalyzes the first committed step in heme biosynthesis . Hypersensitivity of Fus(r) mutants to hydrogen peroxide is abolished by the presence of delta-aminolevulinic acid, the precursor of heme synthesis, in the growth media and by the addition of glutamate or glutamine, amino acids required for the first step in heme biosynthesis . Fluorescence measurements show that the level of heme in a Fus(r) mutant is significantly lower than it is in the wild type . Heme is also an essential cofactor of cytochromes in the electron transport chain of respiration . We found that the rate of respiration is reduced significantly in Fus(r) mutants . Sequestration of divalent iron in the growth media decreases the sensitivity of Fus(r) mutants to oxidative stress . Taken together, these results suggest that Fus(r) mutants are hypersensitive to oxidative stress because their low levels of heme reduce both catalase activity and respiration capacity . The sensitivity of Fus(r) mutants to oxidative stress could be associated with loss of viability due to iron-mediated DNA damage in the presence of hydrogen peroxide . We argue that understanding the specific nature of antibiotic resistance fitness costs in different environments may be a generally useful approach in identifying physiological processes that could serve as novel targets for antimicrobial agents. Antimicrob Agents Chemother, 2004 Oct, 48(10), 3806 - 12 Variant Salmonella genomic island 1 antibiotic resistance gene cluster containing a novel 3'-N-aminoglycoside acetyltransferase gene cassette, aac(3)-Id, in Salmonella enterica serovar newport; Doublet B et al.; Salmonella genomic island 1 (SGI1) harbors an antibiotic resistance gene cluster and was previously identified in the multidrug-resistant Salmonella enterica serovars Typhimurium DT104, Agona, Paratyphi B, and Albany . This antibiotic resistance gene cluster is a complex class 1 integron and most often confers resistance to ampicillin (Ap), chloramphenicol (Cm)/florfenicol (Ff), streptomycin (Sm)/spectinomycin (Sp), sulfonamides (Su), and tetracycline (Tc) (ApCmFfSmSpSuTc profile) . Recently, variant SGI1 antibiotic resistance gene clusters conferring different antibiotic resistance profiles have been identified in several S . enterica serovars and were classified as SGI1-A to -G . We identified a new variant SGI1 antibiotic resistance gene cluster in two multidrug-resistant S . enterica serovar Newport strains isolated from humans in France . In these strains, the Sm/Sp resistance gene cassette aadA2 inserted at the first attI1 site was replaced by two other aminoglycoside resistance gene cassettes . The first one contains a new resistance gene encoding an AAC(3)-I aminoglycoside 3-N-acetyltransferase that confers resistance to gentamicin (Gm) and sisomicin (Sc) . This gene has been named aac(3)-Id . The second one harbors the Sm/Sp resistance gene aadA7 . This gene cassette replacement in the SGI1 complex integron of serovar Newport strains constitutes a new variant SGI1 antibiotic resistance gene cluster named SGI1-H . The occurrence of SGI1 in different S . enterica serovars, now including serovar Newport, strengthens the hypothesis of horizontal transfer of SGI1. Antimicrob Agents Chemother, 2004 Oct, 48(10), 3789 - 93 Increasing prevalence of quinolone resistance in human nontyphoid Salmonella enterica isolates obtained in Spain from 1981 to 2003; Marimon JM et al.; From January 1981 to December 2003, susceptibility to nalidixic acid was tested in 10,504 nontyphoid Salmonella enterica isolates from patients with acute enteric disease in Gipuzkoa, Spain . The prevalence of nalidixic acid resistance steadily increased from less than 0.5% before 1991 to 38.5% in 2003, mainly due to the increase in resistance among isolates of the most prevalent serovar, S . enterica serovar Enteritidis . For nalidixic acid-resistant isolates, the ciprofloxacin MIC was eightfold higher than that for susceptible isolates, and the nalidixic acid-resistant isolates contained a single point mutation in the gyrA gene (at codons for Ser83 or Asp87) . The same mutations were found in a sample of nalidixic acid-resistant nontyphoid Salmonella strains isolated between 1999 and 2003 from retail food for human consumption . In 2003, we identified five S . enterica serovar Typhimurium clinical isolates with high-level fluoroquinolone resistance (ciprofloxacin MIC, 16 microg/ml) with two point mutations in the gyrA gene (coding for Ser83-->Phe and Asp87-->Asn) and one point mutation in the parC gene (coding for Ser80-->Arg) . Strict sanitary controls are needed to avoid the spread of ciprofloxacin-resistant serovar Typhimurium isolates, and a more efficient veterinary policy must be adopted to decrease the large burden of Salmonella serovar Enteritidis infections in humans in our region. Antimicrob Agents Chemother, 2004 Oct, 48(10), 3729 - 35 AcrAB-TolC directs efflux-mediated multidrug resistance in Salmonella enterica serovar typhimurium DT104; Baucheron S et al.; Multidrug-resistant Salmonella enterica serovar Typhimurium definitive phage type 104 (DT104) strains harbor a genomic island, called Salmonella genomic island 1 (SGI1), which contains an antibiotic resistance gene cluster conferring resistance to ampicillin, chloramphenicol, florfenicol, streptomycin, sulfonamides, and tetracyclines . They may be additionally resistant to quinolones . Among the antibiotic resistance genes there are two, i.e., floR and tet(G), which code for efflux pumps of the major facilitator superfamily with 12 transmembrane segments that confer resistance to chloramphenicol-florfenicol and the tetracyclines, respectively . In the present study we determined, by constructing acrB and tolC mutants, the role of the AcrAB-TolC multidrug efflux system in the multidrug resistance of several DT104 strains displaying additional quinolone resistance or not displaying quinolone resistance . This study shows that the quinolone resistance and the decreased fluoroquinolone susceptibilities of the strains are highly dependent on the AcrAB-TolC efflux system and that single mutations in the quinolone resistance-determining region of gyrA are of little relevance in mediating this resistance . Overproduction of the AcrAB efflux pump, as determined by Western blotting with an anti-AcrA polyclonal antibody, appeared to be the major mechanism of resistance to quinolones . Moreover, chloramphenicol-florfenicol and tetracycline resistance also appeared to be highly dependent on the presence of AcrAB-TolC, since the introduction of mutations in the respective acrB and tolC genes resulted in a susceptible or intermediate resistance phenotype, according to clinical MIC breakpoints, despite the presence of the FloR and Tet(G) efflux pumps . Resistance to other antibiotics, ampicillin, streptomycin, and sulfonamides, was not affected in the acrB and tolC mutants of DT104 strains harboring SGI1 . Therefore, AcrAB-TolC appears to direct efflux-mediated resistance to quinolones, chloramphenicol-florfenicol, and tetracyclines in multidrug-resistant S . enterica serovar Typhimurium DT104 strains. Carbohydr Res, 2004 Oct 4, 339(14), 2441 - 3 The structure of the O-specific polysaccharide from Salmonella cerro (serogroup K, O:6,14,18); Vinogradov E et al.; The following structure of the Salmonella cerro LPS O-chain repeating unit has been determined using NMR and chemical methods: -->4)-alpha-D-Man(1-->2)-alpha-D-Man(1-->2)-beta-D-Man(1-->3)-alpha-D-GalNAc-(1-->. Mol Microbiol, 2004 Sep, 53(5), 1437 - 49 Repression of the RcsC-YojN-RcsB phosphorelay by the IgaA protein is a requisite for Salmonella virulence; Dominguez-Bernal G et al.; Bacterial pathogenesis relies on regulators that activate virulence genes . Some of them act, in addition, as repressors of specific genes . Intracellular-growth-attenuator-A (IgaA) is a Salmonella enterica membrane protein that prevents overactivation of the RcsC-YojN-RcsB regulatory system . This negative control is critical for growth because disruption of the igaA gene is only possible in rcsC, yojN or rcsB strains . In this work, we examined the contribution of this regulatory circuit to virulence . Viable igaA point mutant alleles were isolated and characterized . These alleles encode IgaA variants leading to different levels of activation of the RcsC-YojN-RcsB system . IgaA-mediated repression of the RcsB-YojN-RcsC system occurred at the post-translational level, as shown by chromosomal epitope tagging of the rcsC, yojN and rcsB genes . The activity of the RcsC-YojN-RcsB system, monitored with the product of a tagged gmd-3xFLAG gene (positively regulated by RcsC-YojN-RcsB), was totally abolished by wild-type bacteria in mouse target organs . Such tight repression occurred only in vivo and was mediated by IgaA . Shutdown of the RcsC-YojN-RcsB system is a requisite for Salmonella virulence since all igaA point mutant strains were highly attenuated . The degree of attenuation correlated to that of the activation status of RcsC-YojN-RcsB . In some cases, the attenuation recorded was unprecedented, with competitive index (CI) values as low as 10(-6) . Strikingly, IgaA is a protein absolutely dispensable for virulence in mutant strains having a non-functional RcsC-YojN-RcsB system . To our knowledge, IgaA exemplifies the first protein that contributes to virulence by exclusively acting as a negative regulator upon host colonization . Infect Immun, 2004 Oct, 72(10), 5824 - 31 Role of B7 costimulatory molecules in mediating systemic and mucosal antibody responses to attenuated Salmonella enterica serovar Typhimurium and its cloned antigen; Garcia CA et al.; The purpose of the present study was to evaluate the ability of an attenuated Salmonella enterica serovar Typhimurium vaccine strain to up-regulate B7-1 and B7-2 on antigen-presenting cells and to examine the functional roles these costimulatory molecules play in mediating immune responses to Salmonella and to an expressed cloned antigen, the saliva-binding region (SBR) of antigen I/II . In vitro stimulation of B cells (B220+), macrophages (CD11b+), and dendritic cells (CD11c+) with S . enterica serovar Typhimurium induced an up-regulation of B7-2 and, especially, B7-1 expression . The in vivo functional roles of B7-1, B7-2, and B7-1/2 were evaluated in BALB/c wild-type and B7-1, B7-2, and B7-1/2 knockout (KO) mice following intranasal immunization with the Salmonella expressing the cloned SBR . Differential requirements for B7-1 and B7-2 were observed upon primary and secondary immunizations . Compared to wild-type controls, B7-1 and B7-2 KO mice had reduced mucosal and systemic anti-Salmonella antibody responses after a single immunization, while only B7-1 KO mice exhibited suppressed anti-Salmonella antibody responses following the second immunization . Mucosal and systemic antibody responses to SBR were reduced following the primary immunization, whereas a compensatory role for either B7-1 or B7-2 was observed after the second immunization . B7-1/2 double KO mice failed to induce detectable levels of mucosal or systemic immunoglobulin A (IgA) or IgG antibody responses to either Salmonella or SBR . These findings demonstrate that B7-1 and B7-2 can play distinct as well as redundant roles for mediating mucosal and systemic antibody responses, which are likely dependent upon the nature of the antigen. Infect Immun, 2004 Oct, 72(10), 5613 - 21 Structural organization of the pFra virulence-associated plasmid of rhamnose-positive Yersinia pestis; Golubov A et al.; The 137,036-bp plasmid pG8786 from rhamnose-positive Yersinia pestis G8786 isolated from the high mountainous Caucasian plague focus in Georgia is an enlarged form of the pFra virulence-associated plasmid containing genes for synthesis of the antigen fraction 1 and phospholipase D . In addition to the completely conserved genes of the pFra backbone, pG8786 contains two large regions consisting of 4,642 and 32,617 bp, designated regions 1 and 2, respectively . Region 1 retains a larger part of Salmonella enterica serovar Typhi plasmid pHCM2 resembling the backbone of pFra replicons, while region 2 contains 25 open reading frames with high levels of similarity to the transfer genes of the F-like plasmids . Surprisingly, region 1 is also present in the pFra plasmid of avirulent Y . pestis strain 91001 isolated in Inner Mongolia, People's Republic of China . Despite the fact that some genes typically involved in conjugative transfer of the F-like replicons are missing in pG8786, we cannot exclude the possibility that pG8786 might be transmissive under certain conditions . pG8786 seems to be an ancient form of the pFra group of plasmids that were conserved due to the strict geographical isolation of rhamnose-positive Y . pestis strains in the high mountainous Caucasian plague locus. Poult Sci, 2004 Sep, 83(9), 1602 - 9 Phenotypic selection for residual feed intake and its effect on humoral immune responses in growing layer hens; Van Eerden E et al.; According to the resource allocation theory, animals have to make a trade-off between resource-demanding life traits to obtain maximal fitness . Artificial selection toward efficient producing farm animals, however, may have created animals that have an impaired ability to divert resources to maintenance processes, such as responding to immune challenges . Residual feed intake (RFI), defined as the difference between observed feed intake (FI) and expected feed intake based on metabolic BW and growth, was used as a measure for feed efficiency . Individual BW and FI of 352 pullets were recorded weekly from 4 until 14 wk of age to estimate RFI . The top 50 efficient R- and the top 50 nonefficient R+ birds were selected . BW and BW gain in both groups were similar . FI and RFI, however, were significantly higher in R+ birds . Thirty animals out of every group were randomly allocated to 1 of 3 treatments: immunization with keyhole limpet hemocyanin (KLH), Mycobacterium butyricum, or heat-inactivated Salmonella enteritidis bacteria . Antibody titers against KLH, M . butyricum, or Salmonella lipopolysaccharide did not differ between R+ and R- birds . The antibody titer against Salmonella protein was higher in R+ birds . We concluded that a population of chickens from a commercial breed shows considerable variation in RFI . Specific antibody production against KLH, M . butyricum, and S . enteritidis lipopolysaccharide, however, is not influenced by efficiency in terms of RFI . R+ animals may have a higher level of nonantigen specific antibodies, as indicated by the higher antibody response to Salmonella protein. Eur J Immunol, 2004 Nov, 34(11), 2986 - 95 Responses to the soluble flagellar protein FliC are Th2, while those to FliC on Salmonella are Th1; Cunningham AF et al.; Features of the Th1 or Th2 phenotype start to develop during CD4 T cell priming . This study of the response to the bacterial flagellar protein FliC shows that either Th1 or Th2 responses can be induced in mice depending upon how FliC is presented . This is shown by assessing the cytokine mRNA and class of FliC-specific plasma cells induced in situ . Soluble recombinant (r)FliC and polymerized FliC are strongly Th2 polarizing, inducing IL-4, NIP45 and c-Maf mRNA as well as epsilon and gamma1 switch transcripts and switching to IgG1 . CD28-requirement for this switching shows its T cell dependence . rFliC was unable to induce markers of Th1 activity including IL-12, T-bet and IFN-gamma . Conversely, when FliC is presented in its native context surface-bound on live, flagellated Salmonella, switching is predominantly to IgG2a (IgG2c in C57BL/6 mice), reflecting Th1 activity . The development of divergent FliC-specific polarization to either Th1 or Th2 indicates that the context in which this antigen is encountered rather than its intrinsic immunostimulatory properties determines the direction of Th polarization. Microbiol Immunol, 2004, 48(9), 639 - 45 Identification and characterization of class 1 integron resistance gene cassettes among Salmonella strains isolated from healthy humans in China; Zhang H et al.; Twenty-three strains of Salmonella spp . isolated from healthy humans in Guangdong, China, were examined for their susceptibility to ten common antibiotics and the presence of antibiotic resistance integrons . All the strains were resistant to at least one antibiotic, and 4 strains were positive for the intI1 gene . Polymerase chain reaction using in-F and in-B primers showed the existence of amplicons of 1,009 bp in two, 1,664 bp in one, and 1,009 bp and 1,664 bp in one of the intI1 -positive isolates, respectively . Sequence analysis revealed that the 1,009-bp amplicon harbored gene cassette aadA2, conferring resistance to spectinomycin, and the 1,664-bp amplicon harbored genes aadA5 and dfr17, conferring resistance to spectinomycin, streptomycin and trimethoprim . Meanwhile the experiments of plasmid conjugation and Southern hybridization with intI1 as the DNA probe indicated that all the integrons found in these strains were chromosomal . Because the strains carrying class 1 integrons were isolated from healthy humans, it suggests the need for all-round surveillance of the antibiotic resistance of pathogens. RNA, 2004 Oct, 10(10), 1662 - 73 The modified wobble nucleoside uridine-5-oxyacetic acid in tRNAPro(cmo5UGG) promotes reading of all four proline codons in vivo; Nasvall SJ et al.; In Salmonella enterica serovar Typhimurium five of the eight family codon boxes are decoded by a tRNA having the modified nucleoside uridine-5-oxyacetic acid (cmo5U) as a wobble nucleoside present in position 34 of the tRNA . In the proline family codon box, one (tRNAProcmo5UGG) of the three tRNAs that reads the four proline codons has cmo5U34 . According to theoretical predictions and several results obtained in vitro, cmo5U34 should base pair with A, G, and U in the third position of the codon but not with C . To analyze the function of cmo5U34 in tRNAProcmo5UGG in vivo, we first identified two genes (cmoA and cmoB) involved in the synthesis of cmo5U34 . The null mutation cmoB2 results in tRNA having 5-hydroxyuridine (ho5U34) instead of cmo5U34, whereas the null mutation cmoA1 results in the accumulation of 5-methoxyuridine (mo5U34) and ho5U34 in tRNA . The results suggest that the synthesis of cmo5U34 occurs as follows: U34 -->(?) ho5U -->(CmoB) mo5U -->(CmoA?) cmo5U . We introduced the cmoA1 or the cmoB2 null mutations into a strain that only had tRNAProcmo5UGG and thus lacked the other two proline-specific tRNAs normally present in the cell . From analysis of growth rates of various strains and of the frequency of +1 frameshifting at a CCC-U site we conclude: (1) unexpectedly, tRNAProcmo5UGG is able to read all four proline codons; (2) the presence of ho5U34 instead of cmo5U34 in this tRNA reduces the efficiency with which it reads all four codons; and (3) the fully modified nucleoside is especially important for reading proline codons ending with U or C . J Biol Chem, 2004 Nov 26, 279(48), 49804 - 15 Epub 2004 Nov 26. Expression and secretion of Salmonella pathogenicity island-2 virulence genes in response to acidification exhibit differential requirements of a functional type III secretion apparatus and SsaL; Coombes BK et al.; Salmonella pathogenicity island (SPI)-2 is pivotal to the intracellular survival of Salmonella and for virulence in mammals . SPI-2 encodes virulence factors (called effectors) that are translocated into the host cell, a type III secretion apparatus and a two-component regulatory system that regulates intracellular expression of SPI-2 . Salmonella SPI-2 secretion activity appears to be induced in response to acidification of the vacuole in which it replicates . Here we show that the expression of the SPI-2 proteins, SseB and SseD (filament and pore forming components of the secretion apparatus, respectively) in response to acidification requires an intact secretion system and SsaL, a Salmonella homologue of SepL, a regulator required for type III-dependent secretion of translocators but not effectors in attaching and effacing gastrointestinal pathogens . We show that the expression of SPI-2-encoded effectors is acid-regulated but can be uncoupled from the expression of filament and translocon components, thus showing a differential requirement of SsaL for expression . The secretion and translocation of SPI-2-encoded effectors requires SsaL, but SsaL is dispensable for the secretion of SPI-2 effectors encoded in other pathogenicity loci, suggesting a secretion regulation function for SsaL . Further, we demonstrate that the differential expression of adjacent genes within the sseA operon (sseD and sseE) occurs at the transcriptional level . These data indicate that a Salmonella SPI-2 activation state is achieved by an acidregulated response that requires SsaL . These data also suggest the existence of a previously unrecognized regulatory element within SPI-2 for the "effector operon" region downstream of sseD that might demarcate the expression of translocators and effectors. Vet Microbiol, 2004 Oct 5, 103(1-2), 71 - 6 Phage types, ribotypes and tetracycline resistance genes of Salmonella enterica subsp . enterica serovar Typhimurium strains isolated from different origins in Italy; Pasquali F et al.; The tetracycline resistance (tet) gene patterns of 52 tetracycline resistant Salmonella enterica subsp . enterica (S.) serovar Typhimurium isolates collected from animals, food of animal origin, and humans in Italy, were investigated to evaluate whether the tet gene patterns could be used for strain differentiation in addition to phage typing and ribotyping . The detection of tet genes was performed by specific PCR assays . Ribotyping was performed automatically using PvuII as restriction enzyme . Ten different ribotyping patterns were detected . All isolates were positive for at least one of the tet genes studied and six different tet gene patterns were observed . Ribotyping and tet gene patterns showed discriminatory indices of 0.741 and 0.812, respectively . Multiple tet genes were commonly found among tetracycline resistant S . typhimurium isolates from various sources . The resulting tet gene patterns allowed further discrimination of strains which were otherwise indistinguishable by their phage type, ribotype and origin . Thus, the analysis of tet gene patterns might represent an additional tool for the differentiation of S . typhimurium isolates. Int J Antimicrob Agents, 2004 Oct, 24(4), 327 - 33 Detection of integrons and antibiotic-resistance genes in Salmonella enterica serovar Typhimurium isolates with resistance to ampicillin and variable susceptibility to amoxicillin-clavulanate; Guerri ML et al.; We characterized 29 antimicrobial-resistant Salmonella enterica serovar Typhimurium strains, including four belonging to the monophasic variant 4,5,12:i:-, mostly isolated from infants . They were selected from 3230 strains isolated in the years 1990-2001 on the basis of resistance to ampicillin and variable susceptibility to the amoxicillin-clavulanate combination . Twenty-three strains were resistant to more than four antibiotics . All the strains carried the bla(TEM) gene and most were able to transfer this gene by conjugation . Sequencing of the gene from one of the amoxicillin-clavulanate-resistant strains allowed identification of the encoded beta-lactamase as TEM-1; all of these strains carried a second gene encoding beta-lactamase production, either pse-1 or oxa1 . However, the association of bla(TEM) plus pse-1 genes did not always confer resistance to amoxicillin-clavulanate . The pse-1 gene, found in 17 strains, was located in the Salmonella Genomic Island-1 (SGI1), which carries two integrons and encodes multiple drug-resistance . None of the oxa1-bearing strains had the SGI1, yet this gene was found as part of an integron that also carried the aadA1 gene and was not plasmid-associated . Thirteen of the strains harbouring SGI1 belonged to the definitive phage type (DT) 104, and most of those remaining to DT104b and U302; particularly, strains carrying the oxa1-aadA1 integron belonged to the last two phage types . Pulsed field electrophoresis confirmed the clonal organization of DT104 strains, whereas U302 strains fell into different groups, depending on their resistance determinants. Chem Biol, 2004 Sep, 11(9), 1307 - 16 Dual effects of MLS antibiotics: transcriptional modulation and interactions on the ribosome; Tsui WH et al.; The macrolide-lincosamide-streptogramin (MLS) antibiotics are an important group of translation inhibitors that act on the 50S ribosome . We show that, at subinhibitory concentrations, members of the MLS group modulate specific groups of bacterial promoters, as detected by screening a library of promoter-luxCDABE reporter clones of Salmonella enterica serovar Typhimurium . The patterns of transcription permit identification of classes of promoters having differential responses to antibiotics of related structure and mode-of-action; studies of antibiotic synergy or antagonism showed that eukaryotic translation inhibitors may act on the 50S ribosome . The mechanism of transcriptional modulation is not known but may involve bacterial stress responses and/or the disturbance and subsequent compensation of metabolic networks as a result of subtle interference with ribosome function . Transcriptional patterns detected with promoter-lux clones provide a novel approach to antibiotic discovery and mode-of-action studies. BMC Infect Dis . 2004 Sep 20;4(1):36. Suboptimal clinical response to ciprofloxacin in patients with enteric fever due to Salmonella spp . with reduced fluoroquinolone susceptibility: a case series; Slinger R et al.; BACKGROUND: Salmonella spp . with reduced susceptibility to fluoroquinolones have higher than usual MICs to these agents but are still considered "susceptible" by NCCLS criteria . Delayed treatment response to fluoroquinolones has been noted, especially in cases of enteric fever due to such strains . We reviewed the ciprofloxacin susceptibility and clinical outcome of our recent enteric fever cases . METHODS: Salmonella enterica Serotype Typhi (S . Typhi) and Serotype Paratyphi (S . Paratyphi) blood culture isolates (1998-2002) were tested against nalidixic acid by disk diffusion (DD) and agar dilution (AD) and to ciprofloxacin by AD using NCCLS methods and interpretive criteria . Reduced fluoroquinolone susceptibility was defined as a ciprofloxacin MIC of 0.125-1.0 mg/L . The clinical records of patients treated with ciprofloxacin for isolates with reduced fluoroquinolone susceptibility were reviewed . RESULTS: Seven of 21 (33%) S . Typhi and S . Paratyphi isolates had reduced susceptibility to fluoroquinolones (MIC range 0.125-0.5 mg/L) . All 7 were nalidixic acid resistant by DD (no zone) and by AD (MIC 128- >512 mg/L) . The other 14 isolates were nalidixic acid susceptible and fully susceptible to ciprofloxacin (MIC range 0.015-0.03 mg/L).Five of the 7 cases were treated initially with oral ciprofloxacin . One patient remained febrile on IV ciprofloxacin until cefotaxime was added, with fever recurrence when cefotaxime was discontinued . Two continued on oral or IV ciprofloxacin alone but had prolonged fevers of 9-10 days duration, one was switched to IV beta-lactam therapy after remaining febrile for 3 days on oral/IV ciprofloxacin and one was treated successfully with oral ciprofloxacin . Four of the 5 required hospitalization . CONCLUSIONS: Our cases provide further evidence that reduced fluoroquinolone susceptibility of S . Typhi and S . Paratyphi is clinically significant . Laboratories should test extra-intestinal Salmonella spp . for reduced fluoroquinolone susceptibility. Biochemistry, 2004 Sep 28, 43(38), 11998 - 2008 solution structure, backbone dynamics, and interaction with Cdc42 of Salmonella guanine nucleotide exchange factor SopE2; Williams C et al.; SopE and SopE2 are delivered by the Salmonella type III secretion system into eukaryotic cells to promote cell invasion . SopE and SopE2 are potent guanine nucleotide exchange factors (GEFs) for Rho GTPases Cdc42 and Rac1 and constitute a novel class of Rho GEFs . Although the sequence of SopE-like GEFs is not at all homologous to those of the Dbl homology domain-containing eukaryotic GEFs, the mechanism of nucleotide release seems to have significant similarities . We have determined the solution structure of the catalytic domain (residues 69-240) of SopE2, showing that SopE2(69-240) comprises two three-helix bundles (alpha1alpha4alpha5 and alpha2alpha3alpha6) arranged in a Lambda shape . Compared to the crystal structure of SopE(78-240) in complex with Cdc42, SopE2(69-240) exhibits a less open Lambda shape due to movement of SopE(78-240) helices alpha2 and alpha5 to accommodate binding to the Cdc42 switch regions . In an NMR titration to investigate the SopE2(69-240)-Cdc42 interaction, the SopE2(69-240) residues affected by binding Cdc42 were very similar to the SopE(78-240) residues that contact Cdc42 in the SopE(78-240)-Cdc42 complex . Analysis of the backbone (15)N dynamics of SopE2(69-240) revealed flexibility in residues that link the two three-helix bundles, including the alpha3-alpha4 linker that incorporates a beta-hairpin and the catalytic loop, and the alpha5-alpha6 loop, and flexibility in residues involved in interaction with Cdc42 . Together, these observations provide experimental evidence of a previously proposed mechanism of GEF-mediated nucleotide exchange based on the Rac1-Tiam1 complex structure, with SopE/E2 flexibility, particularly in the interbundle loops, enabling conformational rearrangements of the nucleotide binding region of Cdc42 through an induced fit type of binding . Such flexibility in SopE/E2 may also facilitate interaction through adaptive binding with alternative target proteins such as Rab5, allograft inflammatory factor 1, and apolipoprotein A-1. Cancer Gene Ther . 2004 Sep 17; {Epub ahead of print} Systemic administration of attenuated Salmonella choleraesuis carrying thrombospondin-1 gene leads to tumor-specific transgene expression, delayed tumor growth and prolonged survival in the murine melanoma model; Lee CH et al.; Some anaerobic and facultative anaerobic bacteria have been used experimentally as anticancer agents because of their selective growth in the hypoxia regions of solid tumors after systemic administration . We have previously shown the feasibility of using attenuated Salmonella choleraesuis as a gene delivery vector . In this study, we exploited S . choleraesuis carrying thrombospondin-1 (TSP-1) gene for treating primary melanoma and experimental pulmonary metastasis in the syngeneic murine B16F10 melanoma model . Systemic administration of S . choleraesuis allowed targeted gene delivery to tumors . The bacteria accumulated preferentially in tumors over livers and spleens at ratios ranging from 1000:1 to 10,000:1 . The level of transgene expression via S . choleraesuis-mediated gene transfer in tumors could reach more than 1800-fold higher than in livers and spleens . Notably, bacterial accumulation was also observed in the lungs with metastatic nodules, but not in healthy lungs . When administered into mice bearing subcutaneous or pulmonary metastatic melanomas, S . choleraesuis carrying TSP-1 gene significantly inhibited tumor growth and enhanced survival of the mice . Immunohistochemical studies in the tumors from these mice displayed decreased intratumoral microvessel density . Taken together, these findings suggest that TSP-1 gene therapy delivered by S . choleraesuis may be effective for the treatment of primary as well as metastatic melanomas.Cancer Gene Therapy advance online publication, 17 September 2004; doi:10.1038/sj.cgt.7700777 Nat Rev Microbiol, 2004 Sep, 2(9), 747 - 65 Persistent bacterial infections: the interface of the pathogen and the host immune system; Monack DM et al.; Persistent bacterial infections involving Mycobacterium tuberculosis, Salmonella enterica serovar Typhi (S . typhi) and Helicobacter pylori pose significant public-health problems . Multidrug-resistant strains of M . tuberculosis and S . typhi are on the increase, and M . tuberculosis and S . typhi infections are often associated with HIV infection . This review discusses the strategies used by these bacteria during persistent infections that allow them to colonize specific sites in the host and evade immune surveillance . The nature of the host immune response to this type of infection and the balance between clearance of the pathogen and avoidance of damage to host tissues are also discussed. Genes Dev, 2004 Sep 15, 18(18), 2302 - 13 Connecting two-component regulatory systems by a protein that protects a response regulator from dephosphorylation by its cognate sensor; Kato A et al.; A fundamental question in signal transduction is how an organism integrates multiple signals into a cellular response . Here we report the mechanism by which the Salmonella PmrA/PmrB two-component system responds to the signal controlling the PhoP/PhoQ two-component system . We establish that the PhoP-activated PmrD protein binds to the phosphorylated form of the response regulator PmrA, preventing both its intrinsic dephosphorylation and that promoted by its cognate sensor kinase PmrB . This results in PmrA-mediated transcription because phosphorylated PmrA exhibits higher affinity for its target promoters than unphosphorylated PmrA . A PmrD-independent form of the PmrA protein was resistant to PmrB-catalyzed dephosphorylation and promoted transcription of PmrA-activated genes in the absence of inducing signals . This is the first example of a protein that enables a two-component system to respond to the signal governing a different two-component system by protecting the phosphorylated form of a response regulator. J Toxicol Environ Health A, 2004 Oct 22-Nov 26, 67(20-22), 1643 - 53 Bacterial pathogens in rural water supplies in Southern Alberta, Canada; Gannon VP et al.; Raw river and irrigation water in the Oldman River Basin in southern Alberta was tested for the presence of two bacterial pathogens, Escherichia coli O157:H7 and Salmonella spp., over the last 2 yr (2000-2001) . The number of E . coli O157:H7 and Salmonella spp . isolated from raw water peaked during the summer months . While E . coli O157:H7 was only isolated from 11/802 (1.35%) of raw water samples over the entire sampling season in 2000 and from 16/806 (2.05%) of the samples in 2001, the pathogen was isolated one or more times from 10/35 (28.55%) sampling sites in 2000 and from 13/40 (32.55%) sampling sites in 2001 . Salmonella was isolated from 44/802 (5.55%) of raw water samples in 2000 and from 122/822 (14.95%) of the samples in 2001; the pathogen was isolated one or more times from 25/35 (71.45%) sampling sites in 2000 and from 29/40 (72.55%) sampling sites in 2001 . Certain sites had multiple pathogen isolations in the same year and from year to year . Salmonella Rublislaw was the most common Salmonella serovar isolated in both years, accounting for 52.45% of isolates. Scand J Infect Dis, 2004, 36(8), 547 - 51 Salmonella bacteraemia in a tertiary children's hospital; Papaevangelou V et al.; A retrospective study was conducted between July 1990 and July 2002 to investigate the epidemiology, clinical characteristics, and the outcome of Salmonella bacteraemia in children . A total of 148 episodes of bacteraemia were identified in 144 children . The annual incidence ranged from 1.6 to 8.3 cases per 100,000 children < or = 14 y of age, and higher numbers of cases occurred in summer than in winter months . In 22 children the bacteraemia was caused by S . typhi and in 122 by S . non-typhi . S . enteritidis was the most common serotype isolated . Resistance to ampicillin was exhibited by 28.5% of Salmonella isolates, whereas all S . typhi isolates were susceptible to commonly used antibiotics . The mean age was 40.3 months (range 50 d to 14 y) . Children with S . typhi bacteraemia were significantly older than children with S . non-typhi bacteraemia (7.8 vs 2.4 y, p < 0.01) . 11 children were immunosuppressed . The immunosuppressed children had longer duration of fever, longer hospitalization stay, and higher relapse rates compared to normal children (p < 0.05) . Four children developed complications and 1 died . Although the incidence of S . typhi bacteraemia is decreasing, the non-typhi species continue to cause significant morbidity in our geographical region. SAR QSAR Environ Res, 2004 Aug, 15(4), 251 - 63 Searching for an enhanced predictive tool for mutagenicity; Klopman G et al.; The Multiple Computer Automated Structure Evaluation (MCASE) program was used to evaluate the mutagenic potential of organic compounds . The experimental Ames test mutagenic activities for 2513 chemicals were collected from various literature sources . All chemicals have experimental results in one or more Salmonella tester strains . A general mutagenicity data set and fifteen individual Salmonella test strain data sets were compiled . Analysis of the learning sets by the MCASE program resulted in the derivation of good correlations between chemical structure and mutagenic activity . Significant improvement was obtained as more data was added to the learning databases when compared with the results of our previous reports . Several biophores were identified as being responsible for the mutagenic activity of the majority of active chemicals in each individual mutagenicity module . It was shown that the multiple-database mutagenicity model showed a clear advantage over normally used single-database models . The expertise produced by this analysis can be used to predict the mutagenic potential of new compounds. J Microbiol Methods, 2004 Nov, 59(2), 163 - 72 Multiple-locus variable-number tandem-repeats analysis of Salmonella enterica subsp . enterica serovar Typhimurium using PCR multiplexing and multicolor capillary electrophoresis; Lindstedt BA et al.; The multiple-locus variable-number tandem-repeats analysis (MLVA) method is currently being used as the primary typing tool for Salmonella enterica subsp . enterica serovar Typhimurium (S . Typhimurium) isolates in our laboratory . Our published initial MLVA was performed using a single fluorescent dye and the different patterns were assigned from gel images . Here we present a new and significantly improved assay using multiple dye colors, enhanced PCR multiplexing and the introduction of two new loci for better adaptation to capillary electrophoresis with increased speed . The different MLVA patterns are now based on allele sizes entered as character values, thus removing the uncertainties introduced when analyzing band patterns from gel images . We additionally propose an easy numbering scheme for the identification of separate isolates that will facilitate exchange of typing data . A total of 106 human, bird, animal and food isolates of S . Typhimurium, including 16 with definite type (DT) 104, were used for the development of the improved MLVA . The method is based on capillary separation of multiplexed PCR products from five VNTR loci in the S . Typhimurium genome labeled with multiple fluorescent dyes . The different alleles at each locus were then assigned allele numbers, which were used for strain comparison. BMC Infect Dis . 2004 Sep 14;4(1):35. Nosocomial outbreak of neonatal Salmonella enterica serotype Enteritidis meningitis in a rural hospital in northern Tanzania; Vaagland H et al.; BACKGROUND: Clinicians at Haydom Lutheran Hospital, a rural hospital in northern Tanzania noted an unusually high case-fatality rate of pediatric meningitis and suspected an outbreak of an unknown agent or an organism resistant to the empirical therapy . METHODS: We established a provisional microbiology laboratory to investigate the suspected outbreak . Blood and spinal fluid specimens were taken from children below the age of seven years with suspected meningitis . The blood and spinal fluid specimens were inoculated in commercial blood culture bottles and locally prepared Thayer-Martin medium in slanted tubes, respectively . The bacterial isolates were sent to Norway for further investigation, including susceptibility testing and pulsed-field gel-electrophoresis (PFGE) . RESULTS: Among 24 children with suspected meningitis and/or septicemia, five neonates had meningitis caused by Salmonella enterica serotype Enteritidis, all of whom died . Two children had S . Enteritidis septicemia without meningitis and both survived . Genotyping with PFGE suggested a clonal outbreak . The salmonella strain was resistant to ampicillin and sensitive to gentamicin, the two drugs commonly used to treat neonatal meningitis at the hospital . CONCLUSION: The investigation reminds us that nontyphoidal salmonellae can cause meningitis associated with very high case-fatality rates . Resistance to multiple antimicrobial agents increases the risk of treatment failure and may have contributed to the fatal outcome in all of the five patients with salmonella meningitis . The investigation indicated that the outbreak was nosocomial and the outbreak subsided after hygienic measures were instituted . Establishing a provisional microbiological laboratory is a valuable and affordable tool to investigate and control outbreaks even in remote rural areas. J Agric Food Chem, 2004 Sep 22, 52(19), 6042 - 8 Antibacterial activities of plant essential oils and their components against Escherichia coli O157:H7 and Salmonella enterica in apple juice; Friedman M et al.; We evaluated 17 plant essential oils and nine oil compounds for antibacterial activity against the foodborne pathogens Escherichia coli O157:H7 and Salmonella enterica in apple juices in a bactericidal assay in terms of % of the sample that resulted in a 50% decrease in the number of bacteria (BA(50)) . The 10 compounds most active against E . coli (60 min BA(50) range in clear juice, 0.018-0.093%) were carvacrol, oregano oil, geraniol, eugenol, cinnamon leaf oil, citral, clove bud oil, lemongrass oil, cinnamon bark oil, and lemon oil . The corresponding compounds against S . enterica (BA(50) range, 0.0044-0.011%) were Melissa oil, carvacrol, oregano oil, terpeineol, geraniol, lemon oil, citral, lemongrass oil, cinnamon leaf oil, and linalool . The activity (i) was greater for S . enterica than for E . coli, (ii) increased with incubation temperature and storage time, and (iii) was not affected by the acidity of the juices . The antibacterial agents could be divided into two classes: fast-acting and slow-acting . High-performance liquid chromatography analysis showed that the bactericidal results are related to the composition of the oils . These studies provide information about new ways to protect apple juice and other foods against human pathogens. J Pak Med Assoc, 2004 Jun, 54(6), 295 - 301 Fluroquinolone resistance in typhoidal Salmonella and its detection by nalidixic acid disc diffusion; Anjum P et al.; OBJECTIVE: To determine the presence of fluoroquinolone resistance in Typhoidal salmonellae at Rawalpindi and the role of nalidixic acid in predicting the resistance against fluoroquinolones in Microbiology Laboratory, Department of Pathology, Army Medical College, Rawalpindi . METHODS: One hundred consecutive clinical isolates of Typhoidal salmonellae isolated from blood culture samples were studied . The organisms were identified biochemically and serologically by standard technique . Sensitivity testing was carried out against nalidixic acid and ciprofloxacin by modified Kirby bauer disc diffusion method and minimum inhibitory concentration (MICs) were determined by E-test . RESULTS: Seventeen percent of the isolates were resistant to nalidixic acid . Nalidixic acid disc diffusion and MIC estimation by E-test were 100% comparable . All isolates were sensitive to ciprofloxacin but the isolates which were resistant to nalidixic acid had raised MIC values against ciprofloxacin . CONCLUSION: Typhoidal salmonellae have not shown an overt in vitro resistance against fluoroquinolones in our set up but a significant population has emerged with raised MIC values . Nalidixic acid susceptibility test can be used an indirect evidence of resistance to quinolones. Clin Chem, 2004 Nov, 50(11), 2136 - 40 Epub 2004 Sep 13. Genetic predisposition of the interleukin-6 response to inflammation: implications for a variety of major diseases? Bennermo M, Held C, Stemme S, Ericsson CG, Silveira A, Green F, Tornvall P. BACKGROUND: A single-nu