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Sample records for salmonella serotype typhimurium

  1. Molecular detection assay of five Salmonella serotypes of public interest: Typhimurium, Enteritidis, Newport, Heidelberg, and Hadar.

    PubMed

    Bugarel, M; Tudor, A; Loneragan, G H; Nightingale, K K

    2017-03-01

    Foodborne illnesses due to Salmonella represent an important public-health concern worldwide. In the United States, a majority of Salmonella infections are associated with a small number of serotypes. Furthermore, some serotypes that are overrepresented among human disease are also associated with multi-drug resistance phenotypes. Rapid detection of serotypes of public-health concern might help reduce the burden of salmonellosis cases and limit exposure to multi-drug resistant Salmonella. We developed a two-step real-time PCR-based rapid method for the identification and detection of five Salmonella serotypes that are either overrepresented in human disease or frequently associated with multi-drug resistance, including serotypes Enteritidis, Typhimurium, Newport, Hadar, and Heidelberg. Two sets of four markers were developed to detect and differentiate the five serotypes. The first set of markers was developed as a screening step to detect the five serotypes; whereas, the second set was used to further distinguish serotypes Heidelberg, Newport and Hadar. The utilization of these markers on a two-step investigation strategy provides a diagnostic specificity of 97% for the detection of Typhimurium, Enteritidis, Heidelberg, Infantis, Newport and Hadar. The diagnostic sensitivity of the detection makers is >96%. The availability of this two-step rapid method will facilitate specific detection of Salmonella serotypes that contribute to a significant proportion of human disease and carry antimicrobial resistance.

  2. A comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice

    PubMed Central

    Sivula, Christine P; Bogomolnaya, Lydia M; Andrews-Polymenis, Helene L

    2008-01-01

    Background Salmonellosis is one of the most important bacterial food borne illnesses worldwide. A major source of infection for humans is consumption of chicken or egg products that have been contaminated with Salmonella enterica serotype Typhimurium, however our knowledge regarding colonization and persistence factors in the chicken is small. Results We compared intestinal and systemic colonization of 1-week-old White Leghorn chicks and Salmonella-resistant CBA/J mice during infection with Salmonella enterica serotype Typhimurium ATCC14028, one of the most commonly studied isolates. We also studied the distribution of wild type serotype Typhimurium ATCC14028 and an isogenic invA mutant during competitive infection in the cecum of 1-week-old White Leghorn chicks and 8-week-old CBA/J mice. We found that although the systemic levels of serotype Typhimurium in both infected animal models are low, infected mice have significant splenomegaly beginning at 15 days post infection. In the intestinal tract itself, the cecal contents are the major site for recovery of serotype Typhimurium in the cecum of 1-week-old chicks and Salmonella-resistant mice. Additionally we show that only a small minority of Salmonellae are intracellular in the cecal epithelium of both infected animal models, and while SPI-1 is important for successful infection in the murine model, it is important for association with the cecal epithelium of 1-week-old chicks. Finally, we show that in chicks infected with serotype Typhimurium at 1 week of age, the level of fecal shedding of this organism does not reflect the level of cecal colonization as it does in murine models. Conclusion In our study, we highlight important differences in systemic and intestinal colonization levels between chick and murine serotype Typhimurium infections, and provide evidence that suggests that the role of SPI-1 may not be the same during colonization of both animal models. PMID:18922185

  3. Salmonella enterica serotype Typhimurium fimbrial proteins serve as antigens during infection of mice.

    PubMed

    Humphries, Andrea; Deridder, Sandra; Bäumler, Andreas J

    2005-09-01

    The Salmonella enterica serotype Typhimurium genome contains 13 operons with homology to fimbrial gene sequences. Here we investigated the role of 11 serotype Typhimurium fimbrial proteins, including FimA, AgfA (CsgA), BcfA, StbA, SthA, LpfA, PefA, StdA, StcA, StiA, and StfA, as antigens during the infection of genetically resistant mice (CBA). Upon the growth of serotype Typhimurium in standard laboratory broth culture, only the expression of FimA could be detected by Western blot analysis. The infection of mice with serotype Typhimurium grown in broth culture, followed by at least one subsequent infection, resulted in seroconversion of animals to FimA, AgfA, BcfA, StbA, SthA, LpfA, PefA, StdA, StcA, StiA, and StfA positivity. Most animals seroconverted to only a subset of these fimbrial antigens. The immunization of mice with glutathione S-transferase (GST)-FimA, GST-AgfA, GST-BcfA, GST-StbA, GST-SthA, GST-LpfA, GST-PefA, GST-StdA, GST-StcA, GST-StiA, and GST-StfA fusion proteins resulted in reduced fecal shedding of serotype Typhimurium during a challenge compared to that by a control group immunized with purified GST protein. Collectively, these data suggest that the expression of serotype Typhimurium fimbrial antigens is induced during the infection of mice.

  4. Multiple Clones within Multidrug-Resistant Salmonella enterica Serotype Typhimurium Phage Type DT104

    PubMed Central

    Markogiannakis, Antonis; Tassios, Panayotis T.; Lambiri, Maria; Ward, Linda R.; Kourea-Kremastinou, Jenny; Legakis, Nicholas J.; Vatopoulos, Alkiviadis C.

    2000-01-01

    Six distinct clones were present among Greek multidrug-resistant Salmonella enterica serotype Typhimurium phage type DT104, since isolates belonging to resistance phenotypes including the ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline) core could be distinguished with respect to their pulsed-field gel electrophoresis patterns, int1 integron structures, and presence or absence of antibiotic resistance genes ant(3")-Ia, pse-1, and tem-1. PMID:10699039

  5. Contribution of Flagellin Pattern Recognition to Intestinal Inflammation during Salmonella enterica Serotype Typhimurium Infection▿

    PubMed Central

    Winter, Sebastian E.; Thiennimitr, Parameth; Nuccio, Sean-Paul; Haneda, Takeshi; Winter, Maria G.; Wilson, R. Paul; Russell, Joseph M.; Henry, Thomas; Tran, Quynh T.; Lawhon, Sara D.; Gomez, Gabriel; Bevins, Charles L.; Rüssmann, Holger; Monack, Denise M.; Adams, L. Garry; Bäumler, Andreas J.

    2009-01-01

    Salmonella enterica serotype Typhimurium causes acute inflammatory diarrhea in humans. Flagella contribute to intestinal inflammation, but the mechanism remains unclear since most mutations abrogating pattern recognition of flagellin also prevent motility and reduce bacterial invasion. To determine the contribution of flagellin pattern recognition to the generation of innate immune responses, we compared in two animal models a nonmotile, but flagellin-expressing and -secreting serotype Typhimurium strain (flgK mutant) to a nonmotile, non-flagellin-expressing strain (flgK fliC fljB mutant). In vitro, caspase-1 can be activated by cytosolic delivery of flagellin, resulting in release of the interferon gamma inducing factor interleukin-18 (IL-18). Experiments with streptomycin-pretreated caspase-1-deficient mice suggested that induction of gamma interferon expression in the murine cecum early (12 h) after serotype Typhimurium infection was caspase-1 dependent but independent of flagellin pattern recognition. In addition, mRNA levels of the CXC chemokines macrophage inflammatory protein 2 and keratinocyte-derived chemokine were markedly increased early after serotype Typhimurium infection of streptomycin-pretreated wild-type mice regardless of flagellin expression. In contrast, in bovine ligated ileal loops, flagellin pattern recognition contributed to increased mRNA levels of macrophage inflammatory protein 3α and more fluid accumulation at 2 h after infection. Collectively, our data suggest that pattern recognition of flagellin contributes to early innate host responses in the bovine ileal mucosa but not in the murine cecal mucosa. PMID:19237529

  6. Interaction of Salmonella enterica Serotype Typhimurium with Dendritic Cells Is Defined by Targeting to Compartments Lacking Lysosomal Membrane Glycoproteins

    PubMed Central

    García-Del Portillo, Francisco; Jungnitz, Heidrun; Rohde, Manfred; Guzmán, Carlos A.

    2000-01-01

    Dendritic cells (DCs) play a central role in the generation of acquired immunity to infections by pathogenic microorganisms. Salmonella enterica serotype Typhimurium is known to survive and proliferate intracellularly within macrophages and nonphagocytic cells, but no data exist on how this pathogen interacts with DCs. In this report, we show the capacity of serotype Typhimurium to survive within the established mouse DC line CB1. In contrast to the case for the macrophage model, the compartments of DCs containing serotype Typhimurium are devoid of lysosomal membrane glycoproteins and the PhoPQ two-component regulatory system is not essential for pathogen intracellular survival. PMID:10768999

  7. Characterization of blaCMY plasmids and their possible role in source attribution of salmonella enterica serotype typhimurium infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella is an important cause of foodborne illness; however, identifying the source of these infections can be difficult. This is especially true for Salmonella serotype Typhimurium, which is found in diverse agricultural niches. Cephalosporins are one of the primary treatment choices for complic...

  8. Novel determinants of intestinal colonization of Salmonella enterica serotype typhimurium identified in bovine enteric infection.

    PubMed

    Elfenbein, Johanna R; Endicott-Yazdani, Tiana; Porwollik, Steffen; Bogomolnaya, Lydia M; Cheng, Pui; Guo, Jinbai; Zheng, Yi; Yang, Hee-Jeong; Talamantes, Marissa; Shields, Christine; Maple, Aimee; Ragoza, Yury; DeAtley, Kimberly; Tatsch, Tyler; Cui, Ping; Andrews, Katharine D; McClelland, Michael; Lawhon, Sara D; Andrews-Polymenis, Helene

    2013-11-01

    Cattle are naturally infected with Salmonella enterica serotype Typhimurium and exhibit pathological features of enteric salmonellosis that closely resemble those in humans. Cattle are the most relevant model of gastrointestinal disease resulting from nontyphoidal Salmonella infection in an animal with an intact microbiota. We utilized this model to screen a library of targeted single-gene deletion mutants to identify novel genes of Salmonella Typhimurium required for survival during enteric infection. Fifty-four candidate mutants were strongly selected, including numerous mutations in genes known to be important for gastrointestinal survival of salmonellae. Three genes with previously unproven phenotypes in gastrointestinal infection were tested in bovine ligated ileal loops. Two of these mutants, STM3602 and STM3846, recapitulated the phenotype observed in the mutant pool. Complementation experiments successfully reversed the observed phenotypes, directly linking these genes to the colonization defects of the corresponding mutant strains. STM3602 encodes a putative transcriptional regulator that may be involved in phosphonate utilization, and STM3846 encodes a retron reverse transcriptase that produces a unique RNA-DNA hybrid molecule called multicopy single-stranded DNA. The genes identified in this study represent an exciting new class of virulence determinants for further mechanistic study to elucidate the strategies employed by Salmonella to survive within the small intestines of cattle.

  9. An outbreak of Salmonella serotype Typhimurium infections with an unusually long incubation period.

    PubMed

    Brooks, John T; Matyas, Bela T; Fontana, John; DeGroot, Mary Ann; Beuchat, Larry R; Hoekstra, Michael; Friedman, Cindy R

    2012-03-01

    A 1998 investigation of an outbreak of Salmonella serotype Typhimurium infections among children tasting unpasteurized milk during tours of a dairy farm demonstrated a distribution of unusually long incubation periods (median, 8 days; interquartile range [IQR], 6-14 days). Bacterial isolates were highly acid tolerant and contained genes associated with protection against destructive phagocytic reactive oxygen intermediates. We hypothesize that exposure to low-dose oral inoculum of a pathogen with these properties could have contributed to cases of non-typhoidal salmonellosis with the longest incubation period reported to the Centers for Disease Control and Prevention (CDC).

  10. transcriptional response of pigs to Salmonella infection: Comparison of responses to infection with Salmonella eimerica serotype Typhimurium as that observed in S. choleraesuis infection.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine responses to, and control of, Salmonella enterica serotype Typhimurium (ST) infection have been compared to S. enterica serotype Choleraesuis (SC) infection. Using subtractive suppression hybridization (SSH), long oligonucleotide Qiagen and Affymetrix porcine GeneChip® arrays, and real time ge...

  11. RosE represses Std fimbrial expression in Salmonella enterica serotype Typhimurium

    PubMed Central

    Chessa, Daniela; Winter, Maria G; Nuccio, Sean-Paul; Tükel, Çagla; Bäumler, Andreas J

    2008-01-01

    The Salmonella enterica serotype Typhimurium (S. typhimurium) genome contains a large repertoire of putative fimbrial operons that remain poorly characterized because they are not expressed in vitro. In this study, insertions that induced expression of the putative stdABCD fimbrial operon were identified from a random bank of transposon mutants by screening with immuno-magnetic particles for ligand expression (SIMPLE). Transposon insertions upstream of csgC and lrhA or within dam, setB and STM4463 (renamed rosE) resulted in expression of StdA and its assembly into fimbrial filaments on the cell surface. RosE is a novel negative regulator of Std fimbrial expression as indicated by its repression of a std::lacZ reporter construct and by binding of the purified protein to a DNA region upstream of the stdA start codon. Expression of Std fimbriae in the rosE mutant resulted in increased attachment of S. typhimurium to human colonic epithelial cell lines (T-84 and CaCo-2). A rosE mutant exhibited a reduced ability to compete with virulent S. typhimurium for colonization of murine organs, while no defect was observed when both competing strains carried a stdAB deletion. These data suggest that a tight control of Std fimbrial expression mediated by RosE is required during host pathogen interaction. PMID:18331470

  12. Identification of Novel Factors Involved in Modulating Motility of Salmonella enterica Serotype Typhimurium

    PubMed Central

    Bogomolnaya, Lydia M.; Aldrich, Lindsay; Ragoza, Yuri; Talamantes, Marissa; Andrews, Katharine D.; McClelland, Michael; Andrews-Polymenis, Helene L.

    2014-01-01

    Salmonella enterica serotype Typhimurium can move through liquid using swimming motility, and across a surface by swarming motility. We generated a library of targeted deletion mutants in Salmonella Typhimurium strain ATCC14028, primarily in genes specific to Salmonella, that we have previously described. In the work presented here, we screened each individual mutant from this library for the ability to move away from the site of inoculation on swimming and swarming motility agar. Mutants in genes previously described as important for motility, such as flgF, motA, cheY are do not move away from the site of inoculation on plates in our screens, validating our approach. Mutants in 130 genes, not previously known to be involved in motility, had altered movement of at least one type, 9 mutants were severely impaired for both types of motility, while 33 mutants appeared defective on swimming motility plates but not swarming motility plates, and 49 mutants had reduced ability to move on swarming agar but not swimming agar. Finally, 39 mutants were determined to be hypermotile in at least one of the types of motility tested. Both mutants that appeared non-motile and hypermotile on plates were assayed for expression levels of FliC and FljB on the bacterial surface and many of them had altered levels of these proteins. The phenotypes we report are the first phenotypes ever assigned to 74 of these open reading frames, as they are annotated as ‘hypothetical genes’ in the Typhimurium genome. PMID:25369209

  13. Genome Scanning for Conditionally Essential Genes in Salmonella enterica Serotype Typhimurium

    PubMed Central

    Khatiwara, Anita; Jiang, Tieshan; Sung, Sam-Sun; Dawoud, Turki; Kim, Jeong Nam; Bhattacharya, Dhruva; Kim, Hee-Bal; Ricke, Steven C.

    2012-01-01

    As more whole-genome sequences become available, there is an increasing demand for high-throughput methods that link genes to phenotypes, facilitating discovery of new gene functions. In this study, we describe a new version of the Tn-seq method involving a modified EZ:Tn5 transposon for genome-wide and quantitative mapping of all insertions in a complex mutant library utilizing massively parallel Illumina sequencing. This Tn-seq method was applied to a genome-saturating Salmonella enterica serotype Typhimurium mutant library recovered from selection under 3 different in vitro growth conditions (diluted Luria-Bertani [LB] medium, LB medium plus bile acid, and LB medium at 42°C), mimicking some aspects of host stressors. We identified an overlapping set of 105 protein-coding genes in S. Typhimurium that are conditionally essential under at least one of the above selective conditions. Competition assays using 4 deletion mutants (pyrD, glnL, recD, and STM14_5307) confirmed the phenotypes predicted by Tn-seq data, validating the utility of this approach in discovering new gene functions. With continuously increasing sequencing capacity of next generation sequencing technologies, this robust Tn-seq method will aid in revealing unexplored genetic determinants and the underlying mechanisms of various biological processes in Salmonella and the other approximately 70 bacterial species for which EZ:Tn5 mutagenesis has been established. PMID:22367088

  14. Development and evaluation of an experimental vaccination program using a live avirulent Salmonella typhimurium strain to protect immunized chickens against challenge with homologous and heterologous Salmonella serotypes.

    PubMed Central

    Hassan, J O; Curtiss, R

    1994-01-01

    A stable live avirulent, genetically modified delta cya delta crp Salmonella typhimurium vaccine strain, chi 3985, was used in several vaccination strategies to evaluate its use in the control of Salmonella infection in chickens. Oral vaccination of chickens at 1 and at 14 days of age with 10(8) CFU of chi 3985 protected against invasion of spleen, ovary, and bursa of Fabricius and colonization of the ileum and cecum in chickens challenged with 10(6) CFU of virulent homologous Salmonella strains from group B. Chickens challenged with heterologous Salmonella strains from groups C, D, and E were protected against visceral invasion of spleen and ovary, while invasion of the bursa of Fabricius and colonization of ileum and cecum was reduced in vaccinated chickens. Oral vaccination at 2 and at 4 weeks of age induced an excellent protection against challenge with virulent group B Salmonella serotypes and very good protection against challenge with group D or E Salmonella serotypes, while protection against challenge with group C Salmonella serotypes was marginal but significant. Vaccination at 2 and at 4 weeks of age also protected vaccinated chickens against challenge with 10(8) CFU of highly invasive S. typhimurium or S. enteritidis strains. The protection of chickens vaccinated with chi 3985 against challenge with homologous and heterologous Salmonella serotypes is outstanding, and the complete protection against ovarian invasion in chickens challenged with 10(8) CFU of highly invasive S. typhimurium or S. enteritidis strains suggests that vaccination of chickens with chi 3985 can complement the present hygiene- and sanitation-based Salmonella control measures. This paper reports a breakthrough in the use of live avirulent vaccine to control Salmonella carriers in chickens. PMID:7960134

  15. A colonisation-inhibition culture consisting of Salmonella Enteritidis and Typhimurium ΔhilAssrAfliG strains protects against infection by strains of both serotypes in broilers.

    PubMed

    De Cort, W; Mot, D; Haesebrouck, F; Ducatelle, R; Van Immerseel, F

    2014-08-06

    Consumption of contaminated poultry meat is still an important cause of Salmonella infections in humans and there is a need for control methods that protect broilers from day-of-hatch until slaughter age against infection with Salmonella. Colonisation-inhibition, a concept in which a live Salmonella strain is orally administered to day-old chickens and protects against subsequent challenge, can potentially be used as control method. In this study, the efficacy of a Salmonella Typhimurium ΔhilAssrAfliG strain as a colonisation-inhibition strain for protection of broilers against Salmonella Typhimurium was evaluated. Administration of a Salmonella Typhimurium ΔhilAssrAfliG strain to day-old broiler chickens decreased faecal shedding and strongly reduced caecal and internal organ colonisation of a Salmonella Typhimurium challenge strain administered one day later using a seeder bird model. In addition, it was verified whether a colonisation-inhibition culture could be developed that protects against both Salmonella Enteritidis and Typhimurium. Therefore, the Salmonella Typhimurium ΔhilAssrAfliG strain was orally administered simultaneously with a Salmonella Enteritidis ΔhilAssrAfliG strain to day-old broiler chickens, which resulted in a decreased caecal and internal organ colonisation for both a Salmonella Enteritidis and a Salmonella Typhimurium challenge strain short after hatching, using a seeder bird model. The combined culture was not protective against Salmonella Paratyphi B varietas Java challenge, indicating serotype-specific protection mechanisms. The data suggest that colonisation-inhibition can potentially be used as a versatile control method to protect poultry against several Salmonella serotypes.

  16. Ozone treatment for reduction of Escherichia coli 0157:H7 and Salmonella serotype typhimurium on beef carcass surfaces.

    PubMed

    Castillo, A; McKenzie, K S; Lucia, L M; Acuffi, G R

    2003-05-01

    The effectiveness of an aqueous ozone treatment in reducing Escherichia coli O157:H7 and Salmonella serotype Typhimurium on hot carcass surfaces was determined with the use of a model carcass spray cabinet. Carcass surface regions were removed from carcasses and inoculated with feces containing 10(6) to 10(7) CFU each of E. coli O157:H7 and Salmonella Typhimurium per g and were then exposed to a water wash or to a water wash followed by a sanitizing ozone treatment. Water washes were applied at 28 degrees C beginning at a pressure of 10 lb/in2 and gradually increasing to 400 lb/in2. Ozone treatment was carried out by spraying surfaces with an aqueous ozone solution (80 lb/in2 at 28 degrees C) containing 95 mg of ozone per liter. Pathogen reductions achieved with ozone treatment were not significantly different from those achieved with a water wash alone. In addition, ozone treatment did not reduce E. coli O157:H7 or Salmonella Typhimurium contamination that was spread over the carcass surface as a result of the water wash. Under the conditions of this study, the aqueous ozone treatment applied resulted in no significant improvement over a water wash in reducing pathogens on beef carcass surfaces.

  17. CTX-M-27 Producing Salmonella enterica Serotypes Typhimurium and Indiana Are Prevalent among Food-Producing Animals in China

    PubMed Central

    Zhang, Wen-Hui; Lin, Xiang-Yan; Xu, Liang; Gu, Xi-Xi; Yang, Ling; Li, Wan; Ren, Si-Qi; Liu, Ya-Hong; Zeng, Zhen-Ling; Jiang, Hong-Xia

    2016-01-01

    Salmonella spp. is one of the most important food-borne pathogens causing digestive tract and invasive infections in both humans and animals. Extended-spectrum β-lactamases (ESBLs) especially the CTX-M-type ESBLs are increasingly being reported worldwide and in China. These studies seldom focused on Salmonella isolates from food-producing animals. The aim of this study was to characterize the antimicrobial resistance profiles, serotypes and ESBLs and in particular, CTX-M producing Salmonella isolates from chickens and pigs in China. Salmonella isolates were identified by API20E system and polymerase chain reaction (PCR) assay; serotypes were determined using slide agglutination with hyperimmune sera; antimicrobial susceptibility was tested using the ager dilution method; the prevalence of ESBLs and PMQR genes were screened by PCR; CTX-M-producing isolates were further characterized by conjugation along with genetic relatedness and plasmid replicon type. In total, 159 Salmonella strains were identified, among which 95 strains were Salmonella enterica serovar Typhimurium, 63 strains were S. enterica serovar Indiana, and 1 strain was S. enterica serovar Enteritidis. All of these isolates presented multi-drug resistant phenotypes. Forty-five isolates carried blaCTX-M genes, the most common subtype was CTX-M-27(34), followed by CTX-M-65(7) and CTX-M-14(4). Most blaCTX-M genes were transmitted by non-typeable or IncN/IncFIB/IncP/IncA/C/IncHI2 plasmids with sizes ranging from 80 to 280 kb. In particular, all the 14 non-typeable plasmids were carrying blaCTX-M-27 gene and had a similar size. PFGE profiles indicated that CTX-M-positive isolates were clonally related among the same serotype, whilst the isolates of different serotypes were genetically divergent. This suggested that both clonal spread of resistant strains and horizontal transmission of the resistance plasmids contributed to the dissemination of blaCTX-M-9G-positive Salmonella isolates. The presence and spread

  18. CTX-M-27 Producing Salmonella enterica Serotypes Typhimurium and Indiana Are Prevalent among Food-Producing Animals in China.

    PubMed

    Zhang, Wen-Hui; Lin, Xiang-Yan; Xu, Liang; Gu, Xi-Xi; Yang, Ling; Li, Wan; Ren, Si-Qi; Liu, Ya-Hong; Zeng, Zhen-Ling; Jiang, Hong-Xia

    2016-01-01

    Salmonella spp. is one of the most important food-borne pathogens causing digestive tract and invasive infections in both humans and animals. Extended-spectrum β-lactamases (ESBLs) especially the CTX-M-type ESBLs are increasingly being reported worldwide and in China. These studies seldom focused on Salmonella isolates from food-producing animals. The aim of this study was to characterize the antimicrobial resistance profiles, serotypes and ESBLs and in particular, CTX-M producing Salmonella isolates from chickens and pigs in China. Salmonella isolates were identified by API20E system and polymerase chain reaction (PCR) assay; serotypes were determined using slide agglutination with hyperimmune sera; antimicrobial susceptibility was tested using the ager dilution method; the prevalence of ESBLs and PMQR genes were screened by PCR; CTX-M-producing isolates were further characterized by conjugation along with genetic relatedness and plasmid replicon type. In total, 159 Salmonella strains were identified, among which 95 strains were Salmonella enterica serovar Typhimurium, 63 strains were S. enterica serovar Indiana, and 1 strain was S. enterica serovar Enteritidis. All of these isolates presented multi-drug resistant phenotypes. Forty-five isolates carried bla CTX-M genes, the most common subtype was CTX-M-27(34), followed by CTX-M-65(7) and CTX-M-14(4). Most bla CTX-M genes were transmitted by non-typeable or IncN/IncFIB/IncP/IncA/C/IncHI2 plasmids with sizes ranging from 80 to 280 kb. In particular, all the 14 non-typeable plasmids were carrying bla CTX-M-27 gene and had a similar size. PFGE profiles indicated that CTX-M-positive isolates were clonally related among the same serotype, whilst the isolates of different serotypes were genetically divergent. This suggested that both clonal spread of resistant strains and horizontal transmission of the resistance plasmids contributed to the dissemination of bla CTX-M-9G-positive Salmonella isolates. The presence and

  19. Antibiotic resistance in Salmonella enterica serotypes Typhimurium, Enteritidis and Infantis from human infections, foodstuffs and farm animals in Italy.

    PubMed Central

    Busani, L.; Graziani, C.; Battisti, A.; Franco, A.; Ricci, A.; Vio, D.; Digiannatale, E.; Paterlini, F.; D'Incau, M.; Owczarek, S.; Caprioli, A.; Luzzi, I.

    2004-01-01

    The antimicrobial susceptibility of isolates of Salmonella enterica serotypes Typhimurium, Enteritidis, and Infantis isolated from humans, foodstuffs and farm animals in Italy between 1999 and 2001 was examined. All the isolates were susceptible to cefotaxime and ciprofloxacin, but high rates of resistance were observed for several other drugs, especially for S. Typhimurium. The rates of resistance and multiresistance were generally higher among animal and food isolates than in human strains; conversely, no significant difference was observed between animal and food isolates. Among S. Typhimurium, multiresistance was more common in bovine, poultry and rabbit strains than in swine isolates, and was rare in strains from pigeon. Resistance to trimethoprim sulphamethoxazole was mainly found in isolates of swine and human origin. This study confirms the role of livestock as a reservoir of drug-resistant Salmonella spp. and underlines the need for integrated surveillance systems of antibiotic resistance that consider isolates not only from human disease but also from the animal reservoirs and the food vehicles. PMID:15061499

  20. Characterization of blaCMY plasmids and their possible role in source attribution of Salmonella enterica serotype Typhimurium infections.

    PubMed

    Folster, Jason P; Tolar, Beth; Pecic, Gary; Sheehan, Deborah; Rickert, Regan; Hise, Kelley; Zhao, Shaohua; Fedorka-Cray, Paula J; McDermott, Patrick; Whichard, Jean M

    2014-04-01

    Salmonella is an important cause of foodborne illness; however, identifying the source of these infections can be difficult. This is especially true for Salmonella serotype Typhimurium, which is found in diverse agricultural niches. Extended-spectrum cephalosporins (ESC) are one of the primary treatment choices for complicated Salmonella infections. In Salmonella, ESC resistance in the United States is mainly mediated by blaCMY genes carried on various plasmids. In this study, we examined whether the characterization of blaCMY plasmids, along with additional information, can help us identify potential sources of infection by Salmonella, and used serotype Typhimurium as a model. In the United States, monitoring of retail meat, food animals, and ill persons for antimicrobial-resistant Salmonella is conducted by the National Antimicrobial Resistance Monitoring System. In 2008, 70 isolates (70/581; 12.0%) (34 isolates from retail meat, 23 food animal, and 13 human) were resistant to ceftriaxone and amoxicillin/clavulanic acid. All were polymerase chain reaction (PCR)-positive for blaCMY and 59/70 (84.3%) of these genes were plasmid encoded. PCR-based replicon typing identified 42/59 (71.2%) IncI1-blaCMY plasmids and 17/59 (28.8%) IncA/C-blaCMY plasmids. Isolates from chickens or chicken products with blaCMY plasmids primarily had IncI1-blaCMY plasmids (37/40; 92.5%), while all isolates from cattle had IncA/C-blaCMY plasmids. Isolates from humans had either IncA/C- blaCMY (n=8/12; [66.7%]) or IncI1- blaCMY (n=4/12 [33.3%]) plasmids. All of the IncI1-blaCMY plasmids were ST12 or were closely related to ST12. Antimicrobial susceptibility patterns (AST) and pulsed-field gel electrophoresis (PFGE) patterns of the isolates were also compared and differences were identified between isolate sources. When the source of a Typhimurium outbreak or sporadic illness is unknown, characterizing the outbreak isolate's blaCMY plasmids, AST, and PFGE patterns may help identify it.

  1. Complete closed genome sequences of Salmonella enterica subsp. enterica serotypes Anatum, Montevideo, Typhimurium and Newport, isolated from beef, cattle, and humans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella enterica are a versatile group of bacteria with a wide range in virulence potential. To facilitate genome comparisons across this virulence spectrum, we present eight complete closed genome sequences of four S. enterica serotypes (Anatum, Montevideo, Typhimurium, and Newport) isolated fro...

  2. Presence and persistence of Salmonella enterica serotype typhimurium in the phyllosphere and rhizosphere of spray-irrigated parsley.

    PubMed

    Kisluk, Guy; Yaron, Sima

    2012-06-01

    Salmonella enterica is one of the major food-borne pathogens associated with ready-to-eat fresh foods. Although polluted water might be a significant source of contamination in the field, factors that influence the transfer of Salmonella from water to the crops are not well understood, especially under conditions of low pathogen levels in water. The aim of this study was to investigate the short- and long-term (1 h to 28 days) persistence of Salmonella enterica serotype Typhimurium in the phyllosphere and the rhizosphere of parsley following spray irrigation with contaminated water. Plate counting and quantitative real-time PCR (qRT-PCR)-based methods were implemented for the quantification. By applying qRT-PCR with enrichment, we were able to show that even irrigation with water containing as little as ∼300 CFU/ml resulted in the persistence of S. Typhimurium on the plants for 48 h. Irrigation with water containing 8.5 log CFU/ml resulted in persistence of the bacteria in the phyllosphere and the rhizosphere for at least 4 weeks, but the population steadily declined with a major reduction in bacterial counts, of ∼2 log CFU/g, during the first 2 days. Higher levels of Salmonella were detected in the phyllosphere when plants were irrigated during the night compared to irrigation during the morning and during winter compared to the other seasons. Further elucidation of the mechanisms underlying the transfer of Salmonella from contaminated water to crops, as well as its persistence over time, will enable the implementation of effective irrigation and control strategies.

  3. Presence and Persistence of Salmonella enterica Serotype Typhimurium in the Phyllosphere and Rhizosphere of Spray-Irrigated Parsley

    PubMed Central

    Kisluk, Guy

    2012-01-01

    Salmonella enterica is one of the major food-borne pathogens associated with ready-to-eat fresh foods. Although polluted water might be a significant source of contamination in the field, factors that influence the transfer of Salmonella from water to the crops are not well understood, especially under conditions of low pathogen levels in water. The aim of this study was to investigate the short- and long-term (1 h to 28 days) persistence of Salmonella enterica serotype Typhimurium in the phyllosphere and the rhizosphere of parsley following spray irrigation with contaminated water. Plate counting and quantitative real-time PCR (qRT-PCR)-based methods were implemented for the quantification. By applying qRT-PCR with enrichment, we were able to show that even irrigation with water containing as little as ∼300 CFU/ml resulted in the persistence of S. Typhimurium on the plants for 48 h. Irrigation with water containing 8.5 log CFU/ml resulted in persistence of the bacteria in the phyllosphere and the rhizosphere for at least 4 weeks, but the population steadily declined with a major reduction in bacterial counts, of ∼2 log CFU/g, during the first 2 days. Higher levels of Salmonella were detected in the phyllosphere when plants were irrigated during the night compared to irrigation during the morning and during winter compared to the other seasons. Further elucidation of the mechanisms underlying the transfer of Salmonella from contaminated water to crops, as well as its persistence over time, will enable the implementation of effective irrigation and control strategies. PMID:22447598

  4. A multistate outbreak of Salmonella enterica serotype typhimurium infection linked to raw milk consumption--Ohio, 2003.

    PubMed

    Mazurek, Jacek; Salehi, Ellen; Propes, Dennis; Holt, Jo; Bannerman, Tammy; Nicholson, Lisa M; Bundesen, Mark; Duffy, Rosemary; Moolenaar, Ronald L

    2004-10-01

    In December 2002, the Ohio Department of Health was notified of two children with Salmonella infection. Both had a history of drinking raw milk from a combination dairy-restaurant-petting zoo (dairy). The dairy was the only establishment in Ohio licensed to sell raw milk and reported 1.35 million visitors annually. We investigated to determine the extent of the outbreak and identify illness risk factors. A case patient was any person with pulsed-field gel electrophoresis-matched Salmonella enterica serotype Typhimurium from 30 November 2002 to 18 February 2003. Sixty-two met the confirmed case definition. Forty dairy case patient patrons were included in a case-control study; 56 controls were their well meal companions. Consumption of raw milk was found to be associated with illness (odds ratio, 45.1; 95% confidence interval, 8.8 to 311.9). The dairy discontinued selling raw milk. Because 27 other states still allow the sale of raw milk, awareness of the hazards of its consumption should be raised and relevant regulations carefully reviewed.

  5. Identification of a Putative Salmonella enterica Serotype Typhimurium Host Range Factor with Homology to IpaH and YopM by Signature-Tagged Mutagenesis

    PubMed Central

    Tsolis, Renée M.; Townsend, Stacy M.; Miao, Edward A.; Miller, Samuel I.; Ficht, Thomas A.; Adams, L. Garry; Bäumler, Andreas J.

    1999-01-01

    The genetic basis for the host adaptation of Salmonella serotypes is currently unknown. We have explored a new strategy to identify Salmonella enterica serotype Typhimurium (S. typhimurium) genes involved in host adaptation, by comparing the virulence of 260 randomly generated signature-tagged mutants during the oral infection of mice and calves. This screen identified four mutants, which were defective for colonization of only one of the two host species tested. One mutant, which only displayed a colonization defect during the infection of mice, was further characterized. During competitive infection experiments performed with the S. typhimurium wild type, the mutant was defective for colonization of murine Peyer's patches but colonized bovine Peyer's patches at the wild-type level. No difference in virulence between wild type and mutant was observed when calves were infected orally with 1010 CFU/animal. In contrast, the mutant possessed a sixfold increase in 50% lethal morbidity dose when mice were infected orally. The transposon in this mutant was inserted in a 2.9-kb pathogenicity islet, which is located between uvrB and yphK on the S. typhimurium chromosome. This pathogenicity islet contained a single gene, termed slrP, with homology to ipaH of Shigella flexneri and yopM of Yersinia pestis. These data show that comparative screening of signature-tagged mutants in two animal species can be used for scanning the S. typhimurium genome for genes involved in host adaptation. PMID:10569754

  6. Identification and characterization of salmonella serotypes using DNA spectral characteristics by fourier transform infrared (FT-IR) spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Analysis of DNA samples of Salmonella serotypes (Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Infantis, Salmonella Heidelberg and Salmonella Kentucky) were performed using Fourier transform infrared spectroscopy (FT-IR) spectrometer by placing directly in contact with a diamond attenua...

  7. Multistate outbreak of Salmonella serotype typhimurium infections associated with drinking unpasteurized milk--Illinois, Indiana, Ohio, and Tennessee, 2002-2003.

    PubMed

    2003-07-04

    On December 10, 2002, the Clark County Combined Health District and the Ohio Department of Health (ODH) were notified of two hospitalized children infected with Salmonella Enterica serotype Typhimurium. Initial investigation implicated consumption of raw, unpasteurized milk purchased at a local combination dairy-restaurant (dairy) during November 27-December 13, 2002, as the cause. This report summarizes the subsequent investigation. Because 27 states still allow the sale of raw milk, and organizations continue their efforts to allow marketing and sale of raw milk to the public directly from the farm, consumer education about the hazards of raw milk and a careful review of existing policies are needed.

  8. Immediate Reduction of Salmonella enterica Serotype Typhimurium Viability via Membrane Destabilization following Exposure to Multiple-Hurdle Treatments with Heated, Acidified Organic Acid Salt Solutions▿†

    PubMed Central

    Milillo, S. R.; Martin, E.; Muthaiyan, A.; Ricke, S. C.

    2011-01-01

    The antimicrobial activity of organic acids in combination with nonchemical treatments was evaluated for inactivation of Salmonella enterica serotype Typhimurium within 1 min. It was observed that the effectiveness of the multiple-hurdle treatments was temperature (P ≤ 0.05) and pH (P ≤ 0.05) dependent and corresponded to the degree of organic acid lipophilicity (sodium acetate being least effective and sodium propionate being the most effective). This led to the hypothesis that the loss in viability was due at least in part to cell membrane disruption. Evaluation of osmotic response, potassium ion leakage, and transmission electron micrographs confirmed treatment effects on the cell membrane. Interestingly, all treatments, even those with no effect on viability, such as with sodium acetate, resulted in measurable cellular stress. Microarray experiments explored the specific response of S. Typhimurium to sodium acetate and sodium propionate, the most similar of the tested treatments in terms of pKa and ionic strength, and found little difference in the changes in gene expression following exposure to either, despite their very different effects on viability. Taken together, the results reported support our hypothesis that treatment with heated, acidified, organic acid salt solutions for 1 min causes loss of S. Typhimurium viability at least in part by membrane damage and that the degree of effectiveness can be correlated with lipophilicity of the organic acid. Overall, the data presented here indicate that a combined thermal, acidified sodium propionate treatment can provide an effective antimicrobial treatment against Salmonella. PMID:21478311

  9. Plane of nutrition influences the performance, innate leukocyte responses, and resistance to an oral Salmonella enterica serotype Typhimurium challenge in Jersey calves.

    PubMed

    Ballou, M A; Hanson, D L; Cobb, C J; Obeidat, B S; Sellers, M D; Pepper-Yowell, A R; Carroll, J A; Earleywine, T J; Lawhon, S D

    2015-03-01

    Two experiments investigated how plane of nutrition influences performance, leukocyte responses, and resistance to an oral Salmonella enterica serotype Typhimurium challenge. In experiment 1, 46 (2±1 d of age) calves were randomly assigned to 2 diets: a low (LPN; n=23) and high plane of nutrition (HPN; n=23). The LPN calves were fed 409 g/d of dry matter (DM) of a 20% crude protein and 20% fat milk replacer, whereas HPN calves were fed 610 and 735 g/d of DM of a 28% crude protein and 25% fat milk replacer during wk 1 and 2 to 6, respectively. In experiment 2, 20 bull calves (LPN; n=11 and HPN; n=9) were orally challenged on d 80 with 1.5×10(7) cfu of Salmonella Typhimurium (ATCC #14028). The HPN calves had a greater incidence (87.5 vs. 45.5%) and duration of days with high fecal scores (5.5 vs. 3.5 d). The LPN calves had greater neutrophil surface expression of L-selectin on d 7, 21, and 42. Following the Salmonella Typhimurium challenge, calf starter DM intake was greater among the HPN calves. The percentage of neutrophils producing an oxidative burst was also greater among HPN calves on d 1 to 5 after the challenge. Similarly, the intensity of the oxidative burst tended to be greater among the HPN calves on d 2 and 3 postchallenge. The secretion of tumor necrosis factor-α from whole-blood cultures stimulated with lipopolysaccharide tended to be greater on d 1 and was greater on d 5 and 6 among HPN calves. The median ranks of haptoglobin concentrations were greater and plasma zinc concentrations tended to be decreased among LPN calves. These data indicate that feeding a HPN to Jersey calves improved average daily gain and feed efficiency, but increased the incidence of high fecal scores during the first few weeks of life; however, the HPN Jersey calves may be more resistant to Salmonella Typhimurium after weaning.

  10. Differences in the carriage and the ability to utilize the serotype associated virulence plasmid in strains of Salmonella enterica serotype Typhimurium investigated by use of a self-transferable virulence plasmid, pOG669.

    PubMed

    Olsen, John E; Brown, Derek J; Thomsen, Line E; Platt, David J; Chadfield, Mark S

    2004-06-01

    Most strains of Salmonella enterica subspecies enterica serotype typhimurium (S. typhimurium) naturally harbour a virulence plasmid which carries the salmonella plasmid virulence (spv) genes. However, isolates belonging to certain phage types are generally found without the plasmid. We have utilized a self-transferable virulence plasmid, pOG669 to investigate the effect of introduction of spv genes into strains of such phage types. The use of the co-integrate plasmid, pOG669, was validated on a diverse collection of strains. pOG669 was transferred into strains of serotypes that are normally associated with the possession of virulence plasmids. All strains maintained the wild type level of virulence in a mouse model, except that introduction of pOG669 restored normal virulence levels in an avirulent, plasmid free strain of S. dublin and resulted in a decrease in virulence in a strain of S. dublin from clonal line Du3. S. gallinarum did not become virulent in mice, but pOG669 was functionally interchangeable with the wild type plasmid when strains were tested in a chicken model. Strains of serotypes not normally associated with the carriage of a virulence plasmid did not increase in virulence upon the introduction of pOG669. An IncX plasmid pOG670 that was included as control was incompatible with the virulence plasmid in a strain of S. dublin, demonstrating that the common virulence plasmid of this serotype is of a different incompatibility group than other virulence plasmids. Strains of S. typhimurium from phage types that do not normally carry a virulence plasmid responded differently to attempts to introduce pOG669. No transconjugants were observed with the strains of DT5 and DT21. The introduction of pOG669 did not alter the virulence of JEO3942(DT10), DT35 and JEO3949(DT66) significantly, while DT1 and DT27 became more virulent. DT27 became as virulent as wild type C5, while logVC(10) of DT1 only increased from 4.1 to 5.7. The ability to express spv-genes was

  11. In vitro anaerobic incubation of Salmonella enterica serotype Typhimurium and laying hen cecal bacteria in poultry feed substrates and a fructooligosaccharide prebiotic.

    PubMed

    Donalson, L M; Kim, Woo-Kyun; Chalova, V I; Herrera, P; Woodward, C L; McReynolds, J L; Kubena, L F; Nisbet, D J; Ricke, S C

    2007-01-01

    The objective of this study was to investigate the effect of combining a prebiotic with poultry feeds on the growth of Salmonella enterica serotype Typhimurium (ST) in an in vitro cecal fermentation system. Cecal contents from three laying hens were pooled and diluted to a 1:3000 concentration in an anaerobic dilution solution. The cecal dilution was added to sterile test tubes filled with alfalfa and layer ration with and without fructooligosaccharide (FOS). Two controls containing cecal dilutions and anaerobic dilution solution were used. The samples were processed in the anaerobic hood and incubated at 37 degrees C. Samples were inoculated with Salmonella at 0 and 24h after in vitro cecal fermentation and plated at 0 and 24h after inoculation with ST. Plates were incubated for 24h and colony forming units (CFU) enumerated. The samples immediately inoculated with ST without prior cecal fermentation did not significantly lower ST counts 24h later. However, samples pre-incubated for 24h with cecal microflora prior to ST inoculation exhibited reduced ST CFU by approximately 2 logarithms, with the most dramatic decreases seen in alfalfa and layer ration combined with FOS. The addition of FOS to feed substrate diets in combination with cecal contents acted in a synergistic manner to decrease ST growth only after ST was introduced to 24h cecal incubations.

  12. Probability of identifying different salmonella serotypes in poultry samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent work has called attention to the unequal competitive abilities of different Salmonella serotypes in standard broth culture and plating media. Such serotypes include Enteritidis and Typhimurium that are specifically targeted in some regulatory and certification programs because they cause a l...

  13. Proteome of Salmonella Enterica SerotypeTyphimurium Grown in a Low Mg2+/pH Medium

    SciTech Connect

    Shi, Liang; Ansong, Charles; Smallwood, Heather S.; Rommereim, Leah M.; McDermott, Jason E.; Brewer, Heather M.; Norbeck, Angela D.; Taylor, Ronald C.; Gustin, Jean K.; Heffron, Fred; Smith, Richard D.; Adkins, Joshua N.

    2009-09-01

    The facultative intracellular pathogen Salmonella enterica serovar Typhimurium (STM) must replicate within host macrophages in order to establish systemic infection in susceptible mice. In an effort to identify new STM proteins that help the bacterium colonize macrophages, we have cultured STM cells with a low pH/low magnesium medium (MgM) under two different conditions termed MgM-Shock and MgM-Dilution and investigated the impacts of these culturing conditions on the STM proteome by using liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics. LC-MS/MS results showed that alteration of culturing conditions affected a group of STM proteins differently. Compared to MgM-Shock, MgM-Dilution induced more proteins of the Salmonella-pathogenecity island 2-type III secretion system (SPI2-T3SS). The abundances of the proteins used for cobalamin biosynthesis increased under MgM-Shock condition but decreased under MgM-Dilution condition, while those proteins used for thiamine or biotin biosynthesis were not affected under the former condition but increased under the latter condition. Western-blot (WB) analysis confirmed the LC-MS/MS results. Because cobalamin, thiamine and biotin play different roles in STM metabolism, differential induction of the proteins involved in their biosyntheses suggests that the metabolic states of STM cells under these conditions differ considerably. WB analysis also showed that the abundances of SPI2-T3SS proteins SsaQ and SseE and biotin biosynthesis proteins BioB and BioD increased after STM infection of RAW 264.7 macrophages. Deletion of the gene encoding BioB reduced the ability of STM to replicate inside the macrophages, demonstrating for the first time the involvement of a biotin synthesis protein in STM colonization of macrophages.

  14. Detection and classification of salmonella serotypes using spectral signatures collected by fourier transform infrared (FT-IR) spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spectral signatures of Salmonella serotypes namely Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Infantis, Salmonella Heidelberg and Salmonella Kentucky were collected using Fourier transform infrared spectroscopy (FT-IR). About 5-10 µL of Salmonella suspensions with concentrations of 1...

  15. Salmonella serotype distribution in the Dutch broiler supply chain.

    PubMed

    van Asselt, E D; Thissen, J T N M; van der Fels-Klerx, H J

    2009-12-01

    Salmonella serotype distribution can give insight in contamination routes and persistence along a production chain. Therefore, it is important to determine not only Salmonella prevalence but also to specify the serotypes involved at the different stages of the supply chain. For this purpose, data from a national monitoring program in the Netherlands were used to estimate the serotype distribution and to determine whether this distribution differs for the available sampling points in the broiler supply chain. Data covered the period from 2002 to 2005, all slaughterhouses (n = 22), and the following 6 sampling points: departure from hatchery, arrival at the farm, departure from the farm, arrival at the slaughterhouse, departure from the slaughterhouse, and end of processing. Furthermore, retail data for 2005 were used for comparison with slaughterhouse data. The following serotypes were followed throughout the chain: Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Paratyphi B var. Java (Salmonella Java), Salmonella Infantis, Salmonella Virchow, and Salmonella Mbandaka. Results showed that serotype distribution varied significantly throughout the supply chain (P < 0.05). Main differences were found at the farm and at the slaughterhouse (within one stage), and least differences were found between departure from one stage and arrival at the next stage. The most prominent result was the increase of Salmonella Java at farm level. This serotype remained the most prominent pathogen throughout the broiler supply chain up to the retail phase.

  16. Plane of nutrition influences the performance, innate leukocyte responses, and resistance to an oral Salmonella enterica serotype Typhimurium challenge in Jersey calves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two experiments were conducted to determine the influence of plane of nutrition on performance, leukocyte responses, and the pathophysiological response to an oral Salmonella typhimurium challenge in Jersey calves. In experiment 1, forty-six (2 ± 1 days of age) calves were randomly assigned to 2 die...

  17. Effect of dietary mannanoligosaccharide and sodium chlorate on the growth performance, acute-phase response, and bacterial shedding of weaned pigs challenged with Salmonella enterica serotype Typhimurium.

    PubMed

    Burkey, T E; Dritz, S S; Nietfeld, J C; Johnson, B J; Minton, J E

    2004-02-01

    A 28-d experiment evaluated the growth, acute-phase response, and bacterial shedding patterns in pigs (n = 96; initially 6.8 +/- 1.3 kg) fed mannanoligosaccharides (MANNAN) and sodium chlorate (CHLORATE) before and after oral challenge with Salmonella enterica serotype Typhimurium (ST). The negative control diet contained no antimicrobial (CON), and the positive control contained carbadox (CARB; 55 ppm). Test diets contained (as-fed basis) MANNAN (1,500 ppm) or CHLORATE (800 ppm). Pigs were fed diets for 14 d and then given ST orally. Pigs fed CARB had greater ADG over the entire study than pigs from other treatments (P < 0.05). During wk 1 to 2, before ST challenge, feed intake (as-fed basis) was lower for pigs fed MANNAN and CHLORATE than pigs fed CARB (P < 0.05). During the final 2 wk, pigs fed CARB had greater feed intake than pigs on other treatments (P < 0.05). Gain/feed was greater for pigs fed CARB in the 2 wk before ST (P < 0.05); however, in wk 3 to 4 after ST, gain/feed was reduced for CON pigs compared to pigs on other treatments (P < 0.05). Serum IGF-I was decreased at 2 and 4 d after ST (P < 0.001), and, overall, IGF-I was greater in pigs fed CARB than CON or CHLORATE (P < 0.05). Serum haptoglobin concentrations were greater (P < 0.001) for all treatments at d 6 compared with d 13 after ST. Overall, haptoglobin was greater for MANNAN than for CARB and CHLORATE (P < 0.05) and tended to be increased (P < 0.06) relative to CON. Interleukin-6 was not affected by treatment or day post-ST challenge. Fecal shedding of salmonellae organisms was less for CHLORATE (P < 0.05) than all other treatments at 7 d after ST. Shedding scores decreased from d 7 to 14 after ST (P < 0.05) for the CON, CARB, and MANNAN treatments. We conclude that feeding MANNAN and CHLORATE before acute enteric disease challenge may support improved gut function as evidenced by improved gain/feed, and that CHLORATE may decrease bacterial shedding. But neither MANNAN nor CHLORATE enhanced

  18. Salmonella species and serotypes isolated from farm animals, animal feed, sewage, and sludge in Saudi Arabia*

    PubMed Central

    Nabbut, N. H.; Barbour, E. K.; Al-Nakhli, H. M.

    1982-01-01

    A total of 264 salmonellae representing 65 different species and serotypes were isolated for the first time in Saudi Arabia, from various animal species, animal feed, sewage, and sludge. The six most frequently isolated Salmonella species or serotypes were: livingstone, concord, “S. schottmuelleri” (invalid), lille, S. typhimurium, and cerro. PMID:6983931

  19. Salmonella enterica Serotype 4,5,12:i:−, an Emerging Salmonella Serotype That Represents Multiple Distinct Clones ▿ †

    PubMed Central

    Soyer, Y.; Moreno Switt, A.; Davis, M. A.; Maurer, J.; McDonough, P. L.; Schoonmaker-Bopp, D. J.; Dumas, N. B.; Root, T.; Warnick, L. D.; Gröhn, Y. T.; Wiedmann, M.

    2009-01-01

    The prevalence, among human clinical cases, of Salmonella enterica serotype 4,5,12:i:−, a serotype antigenically similar to Salmonella enterica serotype Typhimurium but lacking second-phase flagellar antigens, has increased considerably over the last 10 years. To probe the evolution and ecology of this emerging serotype, we characterized 190 Salmonella isolates initially classified as Salmonella serotypes 4,5,12:i:− (n = 90) and Typhimurium (n = 100) and obtained from various sources in the United States and Spain. These isolates were characterized into six sequence types (determined by multilocus sequence typing [MLST]) and 79 pulsed-field gel electrophoresis types. The majority of Salmonella serotype 4,5,12:i:− and Typhimurium isolates (85 and 84 isolates, respectively) represented a single MLST type. Existing genome information revealed different genome deletions (which included genes responsible for phase 2 flagellum expression) in four Spanish Salmonella serotype 4,5,12:i:− isolates and one U.S. Salmonella serotype 4,5,12:i:− isolate. Fifty-nine isolates of both serotypes, representing different sources and geographical locations as well as different molecular subtypes, were thus screened for the presence of six genes and one specific region, all of which were previously found to show variable presence among Salmonella serotype 4,5,12:i:− and Typhimurium strains. All Salmonella serotype 4,5,12:i:− isolates lacked the phase 2 flagella genes fljA and fljB, which were present in all Salmonella serotype Typhimurium isolates. While all Spanish Salmonella serotype 4,5,12:i:− isolates carried the same deletion surrounding fljAB, all but two U.S. isolates showed a different genomic deletion; the two atypical U.S. isolates represented the “Spanish” deletion genotype and a unique deletion genotype. Salmonella serotype 4,5,12:i:− thus appears to represent at least two common clones, which cannot easily be differentiated with standard diagnostic

  20. Quantitative comparison of intestinal invasion of zoonotic serotypes of Salmonella enterica in poultry.

    PubMed

    Aabo, S; Christensen, J P; Chadfield, M S; Carstensen, B; Olsen, J E; Bisgaard, M

    2002-02-01

    The aim of the present study was to compare the invasion of selected zoonotic Salmonella serotypes of poultry in an in vivo chicken intestinal loop model and also in vitro in epithelial cell cultures. Invasion was measured relative to a reference strain, Salmonella Typhimurium 4/74 invH201::TnphoA. Two serotypes demonstrated intracellular log(10) counts that differed significantly from all other serotypes tested: Salmonella Enteritidis PT4 being 1.5 log(10) colony forming units (CFU) (31-fold) higher, and Salmonella Tennessee being 0.7 log(10) CFU (fivefold) lower than the reference strain (P < or = 0.0001). A group of serotypes, which can be vertically transmitted, showed significantly higher intracellular counts (fourfold to eightfold) than the reference strain. The group included S. Typhimurium 4/74, S. Typhimurium DT104 (poultry and porcine isolates), S. Enteritidis PT1, S. Enteritidis PT6, S. Enteritidis PT8, and Salmonella Berta. The serotypes Salmonella Hadar, Salmonella Virchow, S. 4,12:b:-, S. Typhimurium DT41, and Salmonella Infantis, most of which are considered horizontally transmitted, did not show significantly different intracellular counts from the reference strain. Results from the cell culture invasion studies agreed with the in vivo data, with the exception of S. Berta and the poultry isolate of S. Typhimurium DT104.

  1. Oral administration of the Salmonella Typhimurium vaccine strain Nal2/Rif9/Rtt to laying hens at day of hatch reduces shedding and caecal colonization of Salmonella 4,12:i:-, the monophasic variant of Salmonella Typhimurium.

    PubMed

    Kilroy, Sofie; Raspoet, Ruth; Devloo, Rosalie; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip

    2015-06-01

    A new monophasic variant of Salmonella Typhimurium, Salmonella enterica serotype 4,12:i:-, is rapidly emerging. This serotype is now considered to be among the 10 most common serovars isolated from humans in many countries in Europe and in the United States. The public health risk posed by these emerging monophasic Salmonella Typhimurium strains is considered comparable to that of classical Salmonella Typhimurium strains. The serotype 4,12:i:- is frequently isolated from pigs but also poultry are carrying strains from this serotype. In the current study, we evaluated the efficacy of the Salmonella Typhimurium strain Nal2/Rif9/Rtt, a strain contained in the commercially available live vaccines AviPro Salmonella Duo and AviPro Salmonella VacT, against infection with the emerging monophasic variant in poultry. Three independent trials were conducted. In all trials, laying type chicks were orally vaccinated with the Salmonella Typhimurium strain Nal2/Rif9/Rtt at d hatch, while the birds were challenged the next d with a different infection dose in each trial (low, high, and intermediate). For the intermediate-dose study, a seeder bird model was used in which one out of 3 animals were infected while all individual birds were infected in the other trials. Data obtained from each independent trial show that oral administration of the Salmonella Typhimurium strain Nal2/Rif9/Rtt at d hatch reduced shedding, caecal, and internal organ colonization of Salmonella Typhimurium 4,12:i:-, administered at d 2 life. This indicates that Salmonella Typhimurium strain Nal2/Rif9/Rtt can help to control Salmonella 4,12:i:- infections in poultry.

  2. 9 CFR 113.120 - Salmonella Typhimurium Bacterin.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Salmonella Typhimurium Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.120 Salmonella Typhimurium Bacterin. Salmonella Typhimurium Bacterin shall be prepared from a culture of Salmonella typhimurium which has been inactivated and...

  3. 9 CFR 113.120 - Salmonella Typhimurium Bacterin.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Salmonella Typhimurium Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.120 Salmonella Typhimurium Bacterin. Salmonella Typhimurium Bacterin shall be prepared from a culture of Salmonella typhimurium which has been inactivated and...

  4. 9 CFR 113.120 - Salmonella Typhimurium Bacterin.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Salmonella Typhimurium Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.120 Salmonella Typhimurium Bacterin. Salmonella Typhimurium Bacterin shall be prepared from a culture of Salmonella typhimurium which has been inactivated and...

  5. 9 CFR 113.120 - Salmonella Typhimurium Bacterin.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Salmonella Typhimurium Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.120 Salmonella Typhimurium Bacterin. Salmonella Typhimurium Bacterin shall be prepared from a culture of Salmonella typhimurium which has been inactivated and...

  6. 9 CFR 113.120 - Salmonella Typhimurium Bacterin.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Salmonella Typhimurium Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.120 Salmonella Typhimurium Bacterin. Salmonella Typhimurium Bacterin shall be prepared from a culture of Salmonella typhimurium which has been inactivated and...

  7. Recognition of Salmonella typhimurium by immobilized phage P22 monolayers

    NASA Astrophysics Data System (ADS)

    Handa, Hitesh; Gurczynski, Stephen; Jackson, Matthew P.; Auner, Gregory; Walker, Jeremy; Mao, Guangzhao

    2008-04-01

    Phages are promising alternatives to antibodies as the biorecognition element in a variety of biosensing applications. In this study, a monolayer of bacteriophage P22 whose tailspike proteins specifically recognize Salmonella serotypes was covalently bound to glass substrates through a bifunctional cross linker 3-aminopropyltrimethoxysilane. The specific binding of Salmonella typhimurium to the phage monolayer was studied by enzyme-linked immunosorbent assay and atomic force microscopy. Escherichia coli and a Gram-positive bacterium Listeria monocytogenes were also studied as control bacteria. The P22 particles show strong binding affinity to S. typhimurium. In addition, the dried P22 monolayer maintained 50% binding capacity to S. typhimurium after a one-week storage time. This is a promising method to prepare phage monolayer coatings on surface plasmon resonance and acoustic biosensor substrates in order to utilize the nascent phage display technology.

  8. Development of a novel hexa-plex PCR method for identification and serotyping of Salmonella species.

    PubMed

    Li, Ruichao; Wang, Yang; Shen, Jianzhong; Wu, Congming

    2014-01-01

    Salmonella is one of the most important foodborne pathogens, which causes a huge economic burden worldwide. To detect Salmonella rapidly is very meaningful in preventing salmonellosis and decreasing economic losses. Currently, isolation of Salmonella is confirmed by biochemical and serobased serotyping methods, which are time consuming, labor intensive, and complicated. To solve this problem, a hexa-plex polymerase chain reaction (PCR) method was developed using comparative genomics analysis and multiplex PCR technology to detect Salmonella and Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Agona, Salmonella Choleraesuis, and Salmonella Pullorum simultaneously. The accuracy of this method was tested by a collection of 142 Salmonella. Furthermore, the strategy described in this article to mine serovar-specific fragments for Salmonella could be used to find specific fragments for other Salmonella serotypes and bacteria. The combination of this strategy and multiplex PCR is promising in the rapid identification of foodborne pathogens.

  9. Isolation of Salmonella typhimurium from outbreak-associated cake mix.

    PubMed

    Zhang, Guodong; Ma, Li; Patel, Nehal; Swaminathan, Bala; Wedel, Stephanie; Doyle, Michael P

    2007-04-01

    During May and June of 2005, 26 persons in several states were infected by a single strain (isolates indistinguishable by pulsed-field gel electrophoresis) of Salmonella enterica serotype Typhimurium after eating cake batter ice cream. The cake mix used to prepare the cake batter in the ice cream was implicated by epidemiologic investigation as the source of Salmonella contamination. Initial tests did not detect Salmonella in cake mix collected during the outbreak investigation. The objective of this study was to evaluate different procedures to isolate Salmonella from the implicated cake mix, cake, and ice cream. All outbreak-associated food samples (14 samples) were collected during the outbreak investigation by health departments of several of the states involved. Different combinations of Salmonella isolation procedures, including sample size, preenrichment broth, enrichment broth, enrichment temperature, and isolation medium, were used. Salmonella Typhimurium was isolated from two cake mix samples; the food isolates were indistinguishable from the outbreak pattern by pulsed-field gel electrophoresis subtyping. Universal preenrichment broth was substantially better than was lactose broth for preenrichment, and tetrathionate broth was better than was Rappaport-Vassiliadis broth for isolating Salmonella from the two positive cake mix samples. Although more typical Salmonella colonies were observed on plates from enrichment cultures grown at 35 degrees C, more confirmed Salmonella isolates were obtained from plates of enrichment cultures grown at 42 degrees C. Brilliant green agar, xylose lysine tergitol 4 agar, xylose lysine desoxycholate agar, Hektoen enteric agar, and bismuth sulfite agar plates were equally effective in isolating Salmonella from cake mix. The best combination of preenrichment-enrichment conditions for isolating the outbreak strain of Salmonella was preenrichment of cake mix samples in universal preenrichment broth at 35 degrees C for 24 h

  10. Outbreak-associated Salmonella enterica serotypes and food Commodities, United States, 1998-2008.

    PubMed

    Jackson, Brendan R; Griffin, Patricia M; Cole, Dana; Walsh, Kelly A; Chai, Shua J

    2013-08-01

    Salmonella enterica infections are transmitted not only by animal-derived foods but also by vegetables, fruits, and other plant products. To clarify links between Salmonella serotypes and specific foods, we examined the diversity and predominance of food commodities implicated in outbreaks of salmonellosis during 1998-2008. More than 80% of outbreaks caused by serotypes Enteritidis, Heidelberg, and Hadar were attributed to eggs or poultry, whereas >50% of outbreaks caused by serotypes Javiana, Litchfield, Mbandaka, Muenchen, Poona, and Senftenberg were attributed to plant commodities. Serotypes Typhimurium and Newport were associated with a wide variety of food commodities. Knowledge about these associations can help guide outbreak investigations and control measures.

  11. Prevalence and Characteristics of Salmonella Serotypes Isolated from Fresh Produce Marketed in the United States.

    PubMed

    Reddy, Shanker P; Wang, Hua; Adams, Jennifer K; Feng, Peter C H

    2016-01-01

    Salmonella continues to rank as one of the most costly foodborne pathogens, and more illnesses are now associated with the consumption of fresh produce. The U.S. Department of Agriculture Microbiological Data Program (MDP) sampled select commodities of fresh fruit and vegetables and tested them for Salmonella, pathogenic Escherichia coli, and Listeria. The Salmonella strains isolated were further characterized by serotype, antimicrobial resistance, and pulsed-field gel electrophoresis profile. This article summarizes the Salmonella data collected by the MDP between 2002 and 2012. The results show that the rates of Salmonella prevalence ranged from absent to 0.34% in cilantro. A total of 152 isolates consisting of over 50 different serotypes were isolated from the various produce types, and the top five were Salmonella enterica serotype Cubana, S. enterica subspecies arizonae (subsp. IIIa) and diarizonae (subsp. IIIb), and S. enterica serotypes Newport, Javiana, and Infantis. Among these, Salmonella serotypes Newport and Javiana are also listed among the top five Salmonella serotypes that caused most foodborne outbreaks. Other serotypes that are frequent causes of infection, such as S. enterica serotypes Typhimurium and Enteritidis, were also found in fresh produce but were not prevalent. About 25% of the MDP samples were imported produce, including 65% of green onions, 44% of tomatoes, 42% of hot peppers, and 41% of cantaloupes. However, imported produce did not show higher numbers of Salmonella-positive samples, and in some products, like cilantro, all of the Salmonella isolates were from domestic samples. About 6.5% of the Salmonella isolates were resistant to the antimicrobial compounds tested, but no single commodity or serotype was found to be the most common carrier of resistant strains or of resistance. The pulsed-field gel electrophoresis profiles of the produce isolates showed similarities with Salmonella isolates from meat samples and from outbreaks, but

  12. Subinhibitory concentrations of phloretin repress the virulence of Salmonella typhimurium and protect against Salmonella typhimurium infection.

    PubMed

    Shuai-Cheng, Wu; Ben-Dong, Fu; Xiu-Ling, Chu; Jian-Qing, Su; Yun-Xing, Fu; Zhen-Qiang, Cui; Dao-Xiu, Xu; Zong-Mei, Wu

    2016-11-01

    Phloretin, a natural component of many fruits, exhibits anti-virulence effects and provides a new alternative to counter bacterial infection. The aim of this study was to determine the effect of subinhibitory concentrations of phloretin on the virulence of Salmonella typhimurium. At concentrations where growth of Salmonella was not inhibited, phloretin significantly inhibited bacteria biofilm formation and motility. Subinhibitory concentrations of phloretin repressed eight genes involved in the Salmonella pathogenicity island 1 and 3 genes involved in flagella production. Furthermore, subinhibitory concentrations of phloretin inhibited the adhesion and invasion of Salmonella in IEC-6 cells and reduced the LDH levels of S. typhimurium-infected IEC-6 cells. Additionally, phloretin significantly decreased the cecum bacterial loads of the mice infected with live S. typhimurium containing subinhibitory concentrations of phloretin by gavage. These results suggested that subinhibitory concentrations of phloretin attenuate the virulence of S. typhimurium and protect against S. typhimurium infection.

  13. Characterization and Antimicrobial Resistance of Salmonella Typhimurium Isolates from Clinically Diseased Pigs in Korea.

    PubMed

    Oh, Sang-Ik; Kim, Jong Wan; Chae, Myeongju; Jung, Ji-A; So, Byungjae; Kim, Bumseok; Kim, Ha-Young

    2016-11-01

    This study investigated the prevalence of Salmonella enterica serovar and antimicrobial resistance in Salmonella Typhimurium isolates from clinically diseased pigs collected from 2008 to 2014 in Korea. Isolates were also characterized according to the presence of antimicrobial resistance genes and pulsed-field gel electrophoresis patterns. Among 94 Salmonella isolates, 81 (86.2%) were identified as being of the Salmonella Typhimurium serotype, followed by Salmonella Derby (6 of 94, 6.4%), Salmonella 4,[5],12:i:- (4 of 94, 4.3%), Salmonella Enteritidis (2 of 94, 2.1%), and Salmonella Brandenburg (1 of 94, 1.1%). The majority of Salmonella Typhimurium isolates were resistant to tetracycline (92.6%), followed by streptomycin (88.9%) and ampicillin (80.2%). Overall, 96.3% of Salmonella Typhimurium isolates showed multidrug-resistant phenotypes and commonly harbored the resistance genes blaTEM (64.9%), flo (32.8%), aadA (55.3%), strA (58.5%), strB (58.5%), sulII (53.2%), and tetA (61.7%). The pulsed-field gel electrophoresis analysis of 45 Salmonella Typhimurium isolates from individual farms revealed 27 distinct patterns that formed one major and two minor clusters in the dendrogram analysis, suggesting that most of the isolates (91.1%) from diseased pigs were genetically related. These findings can assist veterinarians in the selection of appropriate antimicrobial agents to combat Salmonella Typhimurium infections in pigs. Furthermore, they highlight the importance of continuous surveillance of antimicrobial resistance and genetic status in Salmonella Typhimurium for the detection of emerging resistance trends.

  14. Salmonella typhimurium mutants lacking NAD pyrophosphatase.

    PubMed Central

    Park, U E; Roth, J R; Olivera, B M

    1988-01-01

    NAD can serve as both a purine and a pyridine source for Salmonella typhimurium. Exogenous NAD is rapidly broken down into nicotinamide mononucleotide and AMP by an NAD pyrophosphatase, the first step in the pathway for the assimilation of exogenous NAD. We isolated and characterized mutants of S. typhimurium lacking NAD pyrophosphatase activity; such mutants were identified by their failure to use exogenous NAD as a purine source. These mutants carry mutations that map at a new locus, designated pnuE, between 86 and 87 min on the Salmonella chromosome. PMID:2841298

  15. Targeted Cancer Therapy Using Engineered Salmonella typhimurium

    PubMed Central

    Zheng, Jin Hai

    2016-01-01

    Obligate or facultative anaerobic bacteria such as Bifidobacterium, Clostridium, Salmonella, or Escherichia coli specifically colonize and proliferate inside tumor tissues and inhibit tumor growth. Among them, attenuated Salmonella typhimurium (S. typhimurium) has been widely studied in animal cancer models and Phase I clinical trials in human patients. S. typhimurium genes are easily manipulated; thus diverse attenuated strains of S. typhimurium have been designed and engineered as tumor-targeting therapeutics or drug delivery vehicles that show both an excellent safety profile and therapeutic efficacy in mouse models. An attenuated strain of S. typhimurium, VNP20009, successfully targeted human metastatic melanoma and squamous cell carcinoma in Phase I clinical trials; however, the efficacy requires further refinement. Along with the characteristics of self-targeting, proliferation, and deep tissue penetration, the ease of genetic manipulation allows for the production of more attenuated strains with greater safety profiles and vector systems that deliver designable cargo molecules for cancer diagnosis and/or therapy. Here, we discuss recent progress in the field of Salmonellae-mediated cancer therapy. PMID:27689027

  16. Targeted Cancer Therapy Using Engineered Salmonella typhimurium.

    PubMed

    Zheng, Jin Hai; Min, Jung-Joon

    2016-09-01

    Obligate or facultative anaerobic bacteria such as Bifidobacterium, Clostridium, Salmonella, or Escherichia coli specifically colonize and proliferate inside tumor tissues and inhibit tumor growth. Among them, attenuated Salmonella typhimurium (S. typhimurium) has been widely studied in animal cancer models and Phase I clinical trials in human patients. S. typhimurium genes are easily manipulated; thus diverse attenuated strains of S. typhimurium have been designed and engineered as tumor-targeting therapeutics or drug delivery vehicles that show both an excellent safety profile and therapeutic efficacy in mouse models. An attenuated strain of S. typhimurium, VNP20009, successfully targeted human metastatic melanoma and squamous cell carcinoma in Phase I clinical trials; however, the efficacy requires further refinement. Along with the characteristics of self-targeting, proliferation, and deep tissue penetration, the ease of genetic manipulation allows for the production of more attenuated strains with greater safety profiles and vector systems that deliver designable cargo molecules for cancer diagnosis and/or therapy. Here, we discuss recent progress in the field of Salmonellae-mediated cancer therapy.

  17. Identification of multidrug-resistant Salmonella enterica serovar typhimurium isolates that have an antibiotic-induced invasion phenotype

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multidrug-resistant (MDR) Salmonella is an important food safety issue in humans and animals. The National Antimicrobial Resistance Monitoring System (NARMS) has reported that 27.3% of Salmonella enterica serotype Typhimurium isolates in humans were resistant to three or more classes of antibiotics...

  18. Molecular Methods for Identification of Monophasic Salmonella Typhimurium Strains.

    PubMed

    Madajczak, Grzegorz; Dera-Tomaszewska, Bozena; Wasiak, Monika; Chróst, Anna; Szych, Jolanta

    2015-01-01

    Two molecular biology methods were used to differentiate Salmonella enterica 1,4,[5],12:i:- strains: "Salmonella Check&Trace microarray" (CT) and multiplex PCR (mPCR). For 92 strains in CT result "Salmonella 1,4,[5],12:i:-" were obtained. Those strains were confirmed in mPCR as monophasic fljB-lack Salmonella Typhimurium. For 17 strains, which in CT assay were recognized as Salmonella Typhimurium, the same identification was obtained in mPCR. Reference Salmonella strains: Lagos, Agama, Tsevie, Glocester and Tumodi in CT were recognized as Salmonella genovar, in mPCR--as Salmonella O:4, H:i other than Salmonella Typhimurium, the same like Salmonella Farsta, recognized incorrectly in CT as Salmonella Typhimurium.

  19. Dr. Cheryl Nickerson studies Salmonella Typhimurium

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Dr. Cheryl Nickerson of Tulane University is studying the effects of simulated low-g on a well-known pathogen, Salmonella typhimurium, a bacterium that causes two to four million cases of gastrointestinal illness in the United States each year. While most healthy people recover readily, S. typhimurium can kill people with weakened immune systems. Thus, a simple case of food poisoning could disrupt a space mission. Using the NASA rotating-wall bioreactor, Nickerson cultured S. typhimurium in modeled microgravity. Mice infected with the bacterium died an average of three days faster than the control mice, indicating that S. typhimurium's virulence was enhanced by the bioreactor. Earlier research showed that 3 percent of the genes were altered by exposure to the bioreactor. Nickerson's work earned her a 2001 Presidential Early Career Award for Scientists and Engineers.

  20. Rapid and early detection of salmonella serotypes with hyperspectral microscope and multivariate data analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to evaluate hyperspectral microscope images for early and rapid detection of Salmonella serotypes: S. Enteritidis, S. Heidelberg, S. Infantis, S. Kentucky, and S. Typhimurium at incubation times of 6, 8, 10, 12, and 24 hours. Images were collected by an acousto-optical tunab...

  1. Infection of chickens with antimicrobial-resistant Salmonella enterica Typhimurium DT193 and monophasic Salmonella Typhimurium-like variants: an emerging risk to the poultry industry?

    PubMed

    Parsons, B N; Crayford, G; Humphrey, T J; Wigley, P

    2013-01-01

    Antimicrobial-resistant Salmonella enterica poses a particular risk to public health, and in particular isolates belonging to clonal lineages such as Salmonella Typhimurium DT104 cause epidemics across species including poultry. In recent years, antimicrobial-resistant S. Typhimurium DT193 and specifically the monophasic S. Typhimurium-like variants of this phage type, serotypes 4,12:i:- and 4,5,12:i:-, have become an increasing risk to public health in Europe and the USA and now account for nearly one-half of human S. Typhimurium infections in the UK. Unlike S. Typhimurium that possesses two forms of flagella which can vary between phase 1 and phase 2 during infection, monophasic variants possess only phase 1 flagella. These monophasic antimicrobial-resistant variants have become a major problem in pig production but human cases have also been associated with poultry consumption and have been found in UK flocks through surveillance schemes since 2010. In this study we determined the ability of antimicrobial-resistant DT193 serotype 4,12:i:- and 4,5,12:i:- isolates from pigs to infect chickens. All isolates were found to colonize the caeca and liver. All but one isolate of serotype 4,5,12:i:- also infected the spleen. Levels of infection and pathology were comparable with those found with the virulent S. Typhimurium isolate 4/74. These findings indicate that both S. Typhimurium DT193 and monophasic variants of this phage type usually associated with pigs are capable of colonizing the chicken. This shows that both S. Typhimurium DT193 and monophasic variants represent a significant and potential emerging threat to poultry production from "spill-over" of these isolates from the pig industry or other sources.

  2. Antimicrobial resistance and serotype prevalence of Salmonella isolated from dairy cattle in the southwestern United States.

    PubMed

    Edrington, T S; Schultz, C L; Bischoff, K M; Callaway, T R; Looper, M L; Genovese, K J; Jung, Y S; McReynolds, J L; Anderson, R C; Nisbet, D J

    2004-01-01

    Mature dairy cattle were sampled over a 2-year period (2001-2002) on six farms in New Mexico and Texas. Fecal samples (n = 1560) were collected via rectal palpation and cultured for Salmonella, and one isolate from each positive sample was serotyped. Three isolates of each serotype, with the exception of Salmonella Newport (n = 12), were examined for susceptibility to 17 antimicrobial agents. Twenty-two different serotypes were identified from a total of 393 Salmonella isolates. Montevideo was the predominant serotype (27%) followed by Mbandaka (15%), Senftenberg (11.4%), Newport (6.4%), Anatum (4.8%), and Give (4.8%). Salmonella Typhimurium and Dublin, two frequently reported serotypes, accounted for only 1% of the observed serotypes in this study. Sixty-four percent of the serotypes were susceptible to all 17 antimicrobials, 14% were resistant to a single agent, and 22% were multiresistant (2-11 types of resistance). All isolates tested were susceptible to amikacin, apramycin, imipenem, ceftriaxone, nalidixic acid, and ciprofloxacin. The most frequent types of resistance were to sulfamethoxazole, tetracycline, streptomycin, kanamycin, chloramphenicol, and ampicillin (ranging from 8.9 to 22.4%). Serotypes demonstrating multiple resistance included Dublin and Give (resistant to three or more antibiotics), Typhimurium (resistant to five antibiotics), and Newport (four and two isolates resistant to six and nine antibiotics, respectively). Class 1 integrons were present in only two Salmonella Dublin isolates and one Salmonella Newport isolate. The most prevalent resistance patterns observed in this study were toward antimicrobial agents commonly used in cattle, while all Salmonella isolates were susceptible to ceftriaxone and ciprofloxacin, antibiotics used in human medicine.

  3. Use of a LightCycler gyrA Mutation Assay for Rapid Identification of Mutations Conferring Decreased Susceptibility to Ciprofloxacin in Multiresistant Salmonella enterica Serotype Typhimurium DT104 Isolates

    PubMed Central

    Walker, R. A.; Saunders, N.; Lawson, A. J.; Lindsay, E. A.; Dassama, M.; Ward, L. R.; Woodward, M. J.; Davies, R. H.; Liebana, E.; Threlfall, E. J.

    2001-01-01

    A LightCycler-based PCR-hybridization gyrA mutation assay (GAMA) was developed to rapidly detect gyrA point mutations in multiresistant (MR) Salmonella enterica serotype Typhimurium DT104 with decreased susceptibility to ciprofloxacin (MIC, 0.25 to 1.0 mg/liter). Ninety-two isolates (49 human, 43 animal) were tested with three individual oligonucleotide probes directed against an Asp-87-to-Asn (GAC→AAC) mutation, an Asp-87-to-Gly (GAC→GGC) mutation, and a Ser-83-to-Phe (TCC→TTC) mutation. Strains homologous to the probes could be distinguished from strains that had different mutations by their probe-target melting temperatures. Thirty-seven human and 30 animal isolates had an Asp-87-to-Asn substitution, 6 human and 6 animal isolates had a Ser-83-to-Phe substitution, and 5 human and 2 animal isolates had an Asp-87-to-Gly substitution. The remaining six strains all had mismatches with the three probes and therefore different gyrA mutations. The sequencing of gyrA from these six isolates showed that one human strain and two animal strains had an Asp-87-to-Tyr (GAC→TAC) substitution and two animal strains had a Ser-83-to-Tyr (TCC→TAC) substitution. One animal strain had no gyrA mutation, suggesting that this isolate had a different mechanism of resistance. Fifty-eight of the strains tested were indistinguishable by several different typing methods including antibiograms, pulsed-field gel gel electrophoresis, and plasmid profiling, although they could be further subdivided according to gyrA mutation. This study confirmed that MR DT104 with decreased susceptibility to ciprofloxacin from humans and food animals in England and Wales may have arisen independently against a background of clonal spread of MR DT104. PMID:11283069

  4. Requirement for cobalamin by Salmonella enterica serovars Typhimurium, Pullorum, Gallinarum and Enteritidis during infection in chickens

    PubMed Central

    Vaz, Jacqueline Boldrin; Penha Filho, Rafael Antonio Casarin; Junior, Angelo Berchieri; Lemos, Manoel Victor Franco

    2011-01-01

    Salmonella enterica serovar Typhimurium synthesizes cobalamin (vitamin B12) only during anaerobiosis. Two percent of the S. Typhimurium genome is devoted to the synthesis and uptake of vitamin B12 and to B12-dependent reactions. To understand the requirement for cobalamin synthesis better, we constructed mutants of Salmonella serovars Enteritidis and Pullorum that are double-defective in cobalamin biosynthesis (ΔcobSΔcbiA). We compared the virulence of these mutants to that of their respective wild type strains and found no impairment in their ability to cause disease in chickens. We then assessed B12 production in these mutants and their respective wild type strains, as well as in S. Typhimurium ΔcobSΔcbiA, Salmonella Gallinarum ΔcobSΔcbiA, and their respective wild type strains. None of the mutants was able to produce detectable B12. B12 was detectable in S. Enteritidis, S. Pullorum and S. Typhimurium wild type strains but not in S. Gallinarum. In conclusion, the production of vitamin B12in vitro differed across the tested Salmonella serotypes and the deletion of the cbiA and cobS genes resulted in different levels of alteration in the host parasite interaction according to Salmonella serotype tested. PMID:24031771

  5. Comparative analysis of twenty-four complete aenome aequences of Salmonella enterica Serotypes Anatum, Montevideo, Typhimurium and Newport isolated from ground beef or asymptomatic cattle on farm or at harvest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella enterica subsp. enterica are a versatile group of bacteria with a wide range of variation in virulence potential. Complete S. enterica genome sequences available to date are primarily of strains isolated from humans or of serotypes that commonly cause human disease. To facilitate genomic ...

  6. Salmonella typhimurium abscess of the chest wall

    PubMed Central

    Tonziello, Gilda; Valentinotti, Romina; Arbore, Enrico; Cassetti, Paolo; Luzzati, Roberto

    2013-01-01

    Patient: Male, 73 Final Diagnosis: Salmonella typhimurium abscess of the chest wall Symptoms: — Medication: Ciprofloxacin Clinical Procedure:— Specialty: Infectious Diseases Objective: Unusual clinical course Background: Non-typhoid Salmonella extra-intestinal infections usually develop in infants and in adult patients with pre-existing predisposing conditions. Blood stream infections and urinary tract infections are the most common clinical presentations, but other sites of infection may be involved as well. Case Report: We describe a case of invasive salmonellosis caused by Salmonella typhimurium involving the chest wall in a 73-year-old man. The patient had suffered from gastroenteritis followed by left basal pneumonia with pleural effusion 7 weeks before. The CT scan of the chest wall showed a pericostal abscess with shirt-stud morphology near the left last cartilaginous arch. The abscess was surgically drained and patient was cured after a 40-day ciprofloxacin treatment. Conclusions: A review of the literature on extra-intestinal non-typhoid salmonellosis shows that pleuropulmonary and soft-tissue infections are uncommon. We argue that non-typhoid Salmonella might be considered as a possible cause of chest wall abscess in individuals with recent history of gastroenteritis complicated by pneumonia and pleural effusion. PMID:24298305

  7. Serotypes and Antimicrobial Resistance of Human Nontyphoidal Isolates of Salmonella enterica from Crete, Greece.

    PubMed

    Maraki, Sofia; Papadakis, Ioannis S

    2014-01-01

    We report on the serotype distribution and the antimicrobial resistance patterns to 20 different antimicrobials of 150 Salmonella enterica strains isolated from stools of diarrhoeal patients on the island of Crete over the period January 2011-December 2012. Among the S. enterica serotypes recovered, Enteritidis was the most prevalent (37.3%), followed by Typhimurium (28.7%) and Newport (8.7%). No resistance was detected to extended-spectrum cephalosporins and carbapenems. Rates of resistance to ampicillin, amoxicillin/clavulanic acid, chloramphenicol, tetracycline, and cotrimoxazole were 9.3%, 4%, 2%, 15.3%, and 8.7%, respectively. Resistance to ≥4 antibiotics was primarily observed for serotypes Typhimurium and Hadar. Enteritidis remains the predominant serotype in Crete. Although low resistance to most antimicrobials was detected, continued surveillance of susceptibility is needed due to the risk of resistance.

  8. House Sparrows Do Not Constitute a Significant Salmonella Typhimurium Reservoir across Urban Gradients in Flanders, Belgium

    PubMed Central

    Rouffaer, Lieze Oscar; Lens, Luc; Haesendonck, Roel; Teyssier, Aimeric; Hudin, Noraine Salleh; Strubbe, Diederik; Haesebrouck, Freddy; Pasmans, Frank; Martel, An

    2016-01-01

    In recent decades major declines in urban house sparrow (Passer domesticus) populations have been observed in north-western European cities, whereas suburban and rural house sparrow populations have remained relatively stable or are recovering from previous declines. Differential exposure to avian pathogens known to cause epidemics in house sparrows may in part explain this spatial pattern of declines. Here we investigate the potential effect of urbanization on the development of a bacterial pathogen reservoir in free-ranging house sparrows. This was achieved by comparing the prevalence of Salmonella enterica subspecies enterica serotype Typhimurium in 364 apparently healthy house sparrows captured in urban, suburban and rural regions across Flanders, Belgium between September 2013 and March 2014. In addition 12 dead birds, received from bird rescue centers, were necropsied. The apparent absence of Salmonella Typhimurium in fecal samples of healthy birds, and the identification of only one house sparrow seropositive for Salmonella spp., suggests that during the winter of 2013–2014 these birds did not represent any considerable Salmonella Typhimurium reservoir in Belgium and thus may be considered naïve hosts, susceptible to clinical infection. This susceptibility is demonstrated by the isolation of two different Salmonella Typhimurium strains from two of the deceased house sparrows: one DT99, typically associated with disease in pigeons, and one DT195, previously associated with a passerine decline. The apparent absence (prevalence: <1.3%) of a reservoir in healthy house sparrows and the association of infection with clinical disease suggests that the impact of Salmonella Typhimurium on house sparrows is largely driven by the risk of exogenous exposure to pathogenic Salmonella Typhimurium strains. However, no inference could be made on a causal relationship between Salmonella infection and the observed house sparrow population declines. PMID:27168186

  9. Effect of probiotic-, bacteriophage-, or organic acid-supplemented feeds or fermented soybean meal on the growth performance, acute-phase response, and bacterial shedding of grower pigs challenged with Salmonella enterica serotype Typhimurium.

    PubMed

    Gebru, E; Lee, J S; Son, J C; Yang, S Y; Shin, S A; Kim, B; Kim, M K; Park, S C

    2010-12-01

    A 28-d experiment evaluated the growth performance, acute-phase response, and bacterial shedding patterns in pigs (n = 108; initially, 38.7 ± 6.7 kg) fed 6 treatment diets, including a control diet with no antimicrobial agents (CON), a positive control diet containing chlortetracycline, 100 mg/kg (CT), a diet containing anti-Salmonella Typhimurium bacteriophage, 3 × 10(9) plaque-forming units/kg of feed (ASB), Lactobacillus plantarum CJLP56, 6.5 × 10(8) cfu/kg of feed (LP), 0.2% microencapsulated organic acids (MOA), or 5% fermented soybean meal (FSM). Pigs were fed the diets for 2 wk before and 2 wk after challenging orally with Salmonella enterica serotype Typhimurium (SalT). Before bacterial challenge, ADFI was similar in all groups. After SalT challenge, ADFI of CON pigs was less (P < 0.05) than all other groups. Before challenge, pigs on MOA, FSM, and CT diets had greater (P < 0.05) ADG and G:F than CON pigs. After challenge (wk 3 to 4) and during the overall experimental period (wk 1 to 4), ADG of all treatment groups and G:F of all treatment groups except the LP group were greater (P < 0.05) than those of CON pigs. Relative to all other treatments, CON and LP pigs had greater (P < 0.05) bacterial shedding scores on d 7 after SalT challenge. At d 14 postchallenge, shedding scores declined (P < 0.05) in all treatment groups compared with CON pigs. Serum haptoglobin for all treatment groups increased from d 0 concentrations on d 6 postchallenge and declined to prechallenge concentrations on d 13 (P < 0.05). Circulating IGF-I concentrations declined from 2 to 6 d postchallenge and increased again by d 13 in ASB and LP groups, did not decline in FSM and CT groups, and continuously declined through d 13 in CON and LP groups (P < 0.05). However, in MOA group, IGF-I concentrations declined from preinfection concentrations on d 2, increased on d 4, and declined again until d 13 (P < 0.05). The serum concentrations of the cytokines IL-6 and IL-1β were not

  10. Salmonella newport and typhimurium colonization of fruit differs from leaves in various tomato cultivars.

    PubMed

    Han, Sanghyun; Micallef, Shirley Ann

    2014-11-01

    Several outbreaks of Salmonella enterica infections have been linked to tomatoes. One cost-effective way to complement on-farm preventive Good Agricultural Practices is to identify cultivars with inherent decreased susceptibility to Salmonella colonization. Fruit and leaves of 13 tomato cultivars with distinct phenotypes were screened to evaluate their susceptibility to Salmonella epiphytic colonization. Field-grown fruit or gnotobiotically grown seedling leaves were spot inoculated in replicate with either Salmonella Typhimurium LT2 or a tomato outbreak-associated strain of Salmonella Newport. Initial loads of the Salmonella inocula were 2.5 log CFU per fruit and 3.5 or 7.0 log CFU per seedling. Salmonella cells were retrieved and enumerated using direct plating after 24 h of incubation at room temperature for fruit and 72 h at 26°C during the day and 18°C at night for seedling leaves. Epiphytic colonization of fruit by S. enterica was cultivar-dependent and serotype-specific, but did not necessarily correlate with leaf colonization. Fruit of cultivar Heinz-1706 were the least colonized by Salmonella Newport, while the highest populations were retrieved from fruit of Nyagous. By contrast, seedling leaves supporting the lowest populations were Florida 91 VF and the highest were Virginia Sweets for Salmonella Newport. For Salmonella Typhimurium the lowest was Nyagous and the highest was Heinz-1706 and Moneymaker. The tomato outbreak strain of Salmonella Newport attained higher population densities on fruit than did Salmonella Typhimurium, suggesting better adaptation to tomato fruit colonization. Salmonella Newport populations were significantly lower on leaves, but not fruit of the near-isogenic line Movione, compared with the parent cultivar Moneymaker, suggesting the immunity conferring gene Pto could be responding to this outbreak strain. Susceptibility of tomato fruit to Salmonella colonization is highly variable and could be one criterion for cultivar

  11. Assessing risk profiles for Salmonella serotypes in breeding pig operations in Portugal using a Bayesian hierarchical model

    PubMed Central

    2012-01-01

    Background The EU Regulation No 2160/2003 imposes a reduction in the prevalence of Salmonella in pigs. The efficiency of control programmes for Salmonella in pigs, reported among the EU Member States, varies and definitive eradication seems very difficult. Control measures currently recommended for Salmonella are not serotype-specific. Is it possible that the risk factors for different Salmonella serotypes are different? The aim of this study was to investigate potential risk factors for two groups of Salmonella sp serotypes using pen faecal samples from breeding pig holdings representative of the Portuguese pig sector. Methods The data used come from the Baseline Survey for the Prevalence of Salmonella in breeding pigs in Portugal. A total of 1670 pen faecal samples from 167 herds were tested, and 170 samples were positive for Salmonella. The presence of Salmonella in each sample (outcome variable) was classified in three categories: i) no Salmonella, ii) Salmonella Typhimurium or S. Typhimurium-like strains with the antigenic formula: 1,4,5,12:i:-, , and iii) other serotypes. Along with the sample collection, a questionnaire concerning herd management and potential risk factors was utilised. The data have a “natural” hierarchical structure so a categorical multilevel analysis of the dataset was carried out using a Bayesian hierarchical model. The model was estimated using Markov Chain Monte Carlo methods, implemented in the software WinBUGS. Results The significant associations found (when compared to category “no Salmonella”), for category “serotype Typhimurium or S. Typhimurium-like strains with the antigenic formula: 1,4,5,12:i:-” were: age of breeding sows, size of the herd, number of pigs/pen and source of semen. For the category “other serotypes” the significant associations found were: control of rodents, region of the country, source of semen, breeding sector room and source of feed. Conclusions The risk factors significantly associated

  12. 40 CFR 798.5265 - The salmonella typhimurium reverse mutation assay.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false The salmonella typhimurium reverse....5265 The salmonella typhimurium reverse mutation assay. (a) Purpose. The Salmonella typhimurium.... (1) A reverse mutation assay in Salmonella typhimurium detects mutation in a gene of a...

  13. Study of Salmonella Typhimurium Infection in Laying Hens

    PubMed Central

    Pande, Vivek V.; Devon, Rebecca L.; Sharma, Pardeep; McWhorter, Andrea R.; Chousalkar, Kapil K.

    2016-01-01

    Members of Salmonella enterica are frequently involved in egg and egg product related human food poisoning outbreaks worldwide. In Australia, Salmonella Typhimurium is frequently involved in egg and egg product related foodborne illness and Salmonella Mbandaka has also been found to be a contaminant of the layer farm environment. The ability possessed by Salmonella Enteritidis to colonize reproductive organs and contaminate developing eggs has been well-described. However, there are few studies investigating this ability for Salmonella Typhimurium. The hypothesis of this study was that the Salmonella Typhimurium can colonize the gut for a prolonged period of time and that horizontal infection through feces is the main route of egg contamination. At 14 weeks of age hens were orally infected with either S. Typhimurium PT 9 or S. Typhimurium PT 9 and Salmonella Mbandaka. Salmonella shedding in feces and eggs was monitored for 15 weeks post-infection. Egg shell surface and internal contents of eggs laid by infected hens were cultured independently for detection of Salmonella spp. The mean Salmonella load in feces ranged from 1.54 to 63.35 and 0.31 to 98.38 most probable number/g (MPN/g) in the S. Typhimurium and S. Typhimurium + S. Mbandaka group, respectively. No correlation was found between mean fecal Salmonella load and frequency of egg shell contamination. Egg shell contamination was higher in S. Typhimurium + S. Mbandaka infected group (7.2% S. Typhimurium, 14.1% S. Mbandaka) compared to birds infected with S. Typhimurium (5.66%) however, co-infection had no significant impact on egg contamination by S. Typhimurium. Throughout the study Salmonella was not recovered from internal contents of eggs laid by hens. Salmonella was isolated from different segments of oviduct of hens from both the groups, however pathology was not observed on microscopic examination. This study investigated Salmonella shedding for up to 15 weeks p.i which is a longer period of time

  14. Study of Salmonella Typhimurium Infection in Laying Hens.

    PubMed

    Pande, Vivek V; Devon, Rebecca L; Sharma, Pardeep; McWhorter, Andrea R; Chousalkar, Kapil K

    2016-01-01

    Members of Salmonella enterica are frequently involved in egg and egg product related human food poisoning outbreaks worldwide. In Australia, Salmonella Typhimurium is frequently involved in egg and egg product related foodborne illness and Salmonella Mbandaka has also been found to be a contaminant of the layer farm environment. The ability possessed by Salmonella Enteritidis to colonize reproductive organs and contaminate developing eggs has been well-described. However, there are few studies investigating this ability for Salmonella Typhimurium. The hypothesis of this study was that the Salmonella Typhimurium can colonize the gut for a prolonged period of time and that horizontal infection through feces is the main route of egg contamination. At 14 weeks of age hens were orally infected with either S. Typhimurium PT 9 or S. Typhimurium PT 9 and Salmonella Mbandaka. Salmonella shedding in feces and eggs was monitored for 15 weeks post-infection. Egg shell surface and internal contents of eggs laid by infected hens were cultured independently for detection of Salmonella spp. The mean Salmonella load in feces ranged from 1.54 to 63.35 and 0.31 to 98.38 most probable number/g (MPN/g) in the S. Typhimurium and S. Typhimurium + S. Mbandaka group, respectively. No correlation was found between mean fecal Salmonella load and frequency of egg shell contamination. Egg shell contamination was higher in S. Typhimurium + S. Mbandaka infected group (7.2% S. Typhimurium, 14.1% S. Mbandaka) compared to birds infected with S. Typhimurium (5.66%) however, co-infection had no significant impact on egg contamination by S. Typhimurium. Throughout the study Salmonella was not recovered from internal contents of eggs laid by hens. Salmonella was isolated from different segments of oviduct of hens from both the groups, however pathology was not observed on microscopic examination. This study investigated Salmonella shedding for up to 15 weeks p.i which is a longer period of time

  15. Assessment of antibiotic resistance phenotype and integrons in Salmonella enterica serovar Typhimurium isolated from swine.

    PubMed

    Rayamajhi, Nabin; Kang, Sang Gyun; Kang, Mi Lan; Lee, Hee Soo; Park, Kyung Yoon; Yoo, Han Sang

    2008-10-01

    Salmonella enterica serovar Typhimurium (S. Typhimurium) isolated and identified from swine were subjected for the analysis of antibiotic resistance pattern and clinically important class 1 and 2 integrons. In addition, S. Typhimurium isolates exhibiting ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, tetracycline and florfenicol (ACSSuTF) resistance pattern as described in most Salmonella enterica serotype Typhimurium definitive type 104 (DT104) were characterized by polymerase chain reaction. All the isolates were resistant to more than four antibiotics and showed the highest resistance to streptomycin (94.1%), followed by tetracycline (90.1%), ampicillin (64.7%), chloramphenicol (56.8%) and gentamicin (54.9%). MIC value for the ten isolates ranged between 0.125-2 mug/ml for ciprofloxacin. Among the beta-lactams used, only one of the isolate exhibited resistance to ceftiofur (MIC 8 microg/ml). Sixty eight percent of these multi drug resistance (MDR) S. Typhimurium isolates carried clinically important class 1 integron with 1kb (aadA) and/or 2kb (dhfrXII-orfF-aadA2) resistance gene cassettes. This study reports the increasing trend of multi drug resistance (MDR) S. Typhimurium with clinically important class 1 integron in pigs. In addition, emergence of the ACSSuTF-type resistance in S. Typhimurium PT other than DT104 may limit the use of resistance gene markers in its detection methods by PCR.

  16. Strain differences among Salmonella serotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foodborne pathogens are constantly adapting to circumvent intervention strategies. The ability to detect and overcome these adaptations are critical to ensure a safe food supply. We determined genotypic and/or phenotypic differences between Salmonella recovered from broiler chicks after comingling w...

  17. Pathogenesis of Salmonellosis: Salmonella Exotoxins

    DTIC Science & Technology

    1982-03-08

    Newport; Sal. 9633 - serotype Newport; and Sal. 9186 - serotype Newport. Salmonella enteritidis serotype typhimurium strain 2000 was obtained from...7054 Table 1I CULTURE MEDIA SURVEY Salmonella enteritidis Salmonella typhimurium serotype Javiana #10016 SRlI Culture Media C H 0 Cell Factor C H 0 Cell...the pediatric bacteriology laboratory of the UTMB Children’s Hospital and previously reported to prs-’uce the heat labile toxin (9). Salmonella

  18. Salmonella Typhimurium infection primes a nutriprive mechanism in piglets.

    PubMed

    Miarelli, Maria; Drumo, Rosanna; Signorelli, Federica; Marchitelli, Cinzia; Pavone, Silvia; Pesciaroli, Michele; Ruggieri, Jessica; Chirullo, Barbara; Ammendola, Serena; Battistoni, Andrea; Alborali, Giovanni L; Manuali, Elisabetta; Pasquali, Paolo

    2016-04-15

    Salmonella enterica serovar Typhimurium (S. Typhimurium) is an important cause of acute food- borne zoonoses worldwide, typically carried by pigs. It is well known that Salmonella has evolved a wide array of strategies enabling it to invade the host, but little information is available on the specific host responses to Salmonella infections. In the present study, we used an in vivo approach (involving piglets infected with a virulent or an attenuated S. Typhimurium strain) coupled to histological and proteomic analysis of the cecum mucosa, to highlight the host pathways activated during S. Typhimurium infection. We confirm the complex host-pathogen interaction. Our data showed that the metabolic and the cytoskeleton organization functions were the most significantly altered. In particular, the modifications of energy metabolic pathway could suggest a "nutriprive" mechanism, in which the host reduce its metabolic and energetic status to limit Salmonella infection. This study could represent a preliminary approach, providing information useful to better understand the host-Salmonella interaction.

  19. Seroprevalence and antibiotic sensitivity of serotypes of Salmonella enterica in Greek pig herds.

    PubMed

    Grafanakis, E; Leontides, L; Genigeorgis, C

    2001-03-31

    Blood samples were taken from 50 pigs in each of 59 farrow-to-finish production herds and from 40 pigs in each of four of five registered multiplying herds. Samples of feed and faeces were also collected from 17 of the production herds and from the four multiplying herds. The sera were tested for antibodies to Salmonella enterica by the Danish mix-ELISA, and the organisms were isolated, serotyped and sensitivity tested by standard techniques. The average within-herd seroprevalence was 3.4 per cent and at least one pig tested seropositive in 21 of the 59 herds. In the multiplying herds, only a single seroreactor was detected. Salmonellae were isolated from only five of 95 feed samples, from two of the 17 herds sampled, Salmonella tennessee in four of five samples from one herd and an untypable strain in one of five samples from another. Four infected faecal samples were detected in four herds; they harboured Salmonella typhimurium, Salmonella bredeney or Salmonella london. No salmonellae were isolated from the samples of feed and faeces taken from the multiplying herds. The S london and S typhimurium had a low sensitivity to streptomycin, kanamycin and neomycin, and the S typhimurium also had low sensitivity to amoxycillin, ticarcillin, piperacillin, amoxycillin + clavulanic acid, cefalotin and cefoperazone. The other isolates were sensitive to all the antimicrobial agents tested.

  20. Molecular characterization of antibiotic resistant Salmonella Typhimurium and Salmonella Kentucky isolated from pre- and post-chill whole broilers carcasses.

    PubMed

    Mohamed, Tagelsir; Zhao, Shaohua; White, David G; Parveen, Salina

    2014-04-01

    There is conflicting data regarding whether commercial chilling has any effect on persistence of Salmonella serovars, including antibiotic resistant variants, on chicken carcasses. A total of 309 Salmonella Typhimurium and Salmonella Kentucky isolates recovered from pre- and post-chill whole broiler carcasses were characterized for genetic relatedness using Pulsed Field Gel Electrophoresis (PFGE) and for the presence of virulence factors (invA, pagC, spvC) by PCR and for aerobactin and colicin production by bioassays. A subset of these isolates (n = 218) displaying resistance to either sulfisoxazole and/or ceftiofur [S. Typhimurium (n = 66) and S. Kentucky (n = 152)] were further tested for the presence of associated antibiotic resistance elements (class-I integrons and blaCMY genes) by PCR. All 145 ceftiofur resistant S. Kentucky and S. Typhimurium isolates possessed blaCMY genes. Class-I integrons were only detected in 6.1% (n = 4/66) of sulfisoxazole resistant S. Typhimurium isolates. The PFGE analysis revealed the presence of genetically diverse populations within the recovered isolates but clusters were generally concordant with serotypes and antimicrobial resistance profiles. At a 100% pattern similarity index, thirty-six percent of the undistinguishable S. Typhimurium and 22% of the undistinguishable S. Kentucky isolates were recovered from the same chilling step. All isolates possessed the invA and pagC genes, but only 1.4%possessed spvC. Irrespective of the chilling step, there was a significant difference (P < 0.05) in the production of aerobactin and colicin between S. Typhimurium and S. Kentucky isolates. Taken together, these results indicate that chilling impacted the recovery of particular Salmonella clonal groups but had no effect on the presence of class-I integrons, blaCMY genes, and tested virulence factors.

  1. Epidemiology of virulence-associated plasmids and outer membrane protein patterns within seven common Salmonella serotypes.

    PubMed

    Helmuth, R; Stephan, R; Bunge, C; Hoog, B; Steinbeck, A; Bulling, E

    1985-04-01

    Antibiotic-sensitive Salmonella isolates belonging to seven common serotypes and originating from 29 different countries from all continents were investigated for their plasmid DNA content (337 isolates) and their outer membrane protein profiles (216 isolates). Of the S. typhimurium, S. enteritidis, S. dublin, and S. choleraesuis isolates, 90% or more carried a serotype-specific plasmid. The molecular sizes of the plasmids were 60 megadaltons (Md) for S. typhimurium, 37 Md for S. enteritidis, 56 Md for S. dublin, and 30 Md for S. choleraesuis. The outer membrane protein profiles were homogeneous within each of the seven serotypes, except that a minority of S. enteritidis and S. dublin strains were lacking one major outer membrane protein. Virulence studies were performed with 39 representative strains by measuring the 50% lethal doses (LD50S) after oral infection of mice. The LD50 values obtained for plasmid-positive strains of S. typhimurium, S. enteritidis, and S. dublin were up to 10(6)-fold lower than the values obtained for the plasmid-free strains of the same serotype. Only the plasmid-positive strains could invade the livers of orally infected mice, and only they were resistant to the bactericidal activity of 90% guinea pig serum. Strains of S. infantis were generally plasmid free, whereas S. panama and S. heidelberg isolates carried heterogeneous plasmid populations. The virulence properties of the latter three serotypes could not be correlated with the predominant plasmids found in these strains.

  2. Mutagenic potential of Mancozeb in Salmonella typhimurium.

    PubMed

    Shukla, Yogeshwer; Taneja, Pankaj; Arora, Annu; Sinha, Neeraj

    2004-01-01

    Mancozeb, a dithiocarbamate fungicide, was examined for its possible mutagenic activity using Salmonella typhimurium tester strains TA97a, TA98, TA100, and TA102. We found that Mancozeb exhibited toxic effects at the dose of 40 microg/plate and higher with all tester strains. Mancozeb showed dose-dependent increases in the number of revertants with and without metabolic activation when it was dissolved in DMSO or acetone with strain TA97a; however, the number of revertants at the highest dose was less than two-fold compared to control values. We postulate that the true mutagenic potential of Mancozeb may be masked by its toxic effect to the tester strain used.

  3. Salmonella serotypes in reptiles and humans, French Guiana.

    PubMed

    Gay, Noellie; Le Hello, Simon; Weill, François-Xavier; de Thoisy, Benoit; Berger, Franck

    2014-05-14

    In French Guiana, a French overseas territory located in the South American northern coast, nearly 50% of Salmonella serotypes isolated from human infections belong to serotypes rarely encountered in metropolitan France. A reptilian source of contamination has been investigated. Between April and June 2011, in the area around Cayenne, 151 reptiles were collected: 38 lizards, 37 snakes, 32 turtles, 23 green iguanas and 21 caimans. Cloacal swab samples were collected and cultured. Isolated Salmonella strains were identified biochemically and serotyped. The overall carriage frequency of carriage was 23.2% (95% confidence interval: 16.7-30.4) with 23 serotyped strains. The frequency of Salmonella carriage was significantly higher for wild reptiles. Near two-thirds of the Salmonella serotypes isolated from reptiles were also isolated from patients in French Guiana. Our results highlight the risk associated with the handling and consumption of reptiles and their role in the spread of Salmonella in the environment.

  4. Adaptive acidification tolerance response of Salmonella typhimurium.

    PubMed

    Foster, J W; Hall, H K

    1990-02-01

    Salmonella typhimurium can encounter a wide variety of environments during its life cycle. One component of the environment which will fluctuate widely is pH. In nature, S. typhimurium can experience and survive dramatic acid stresses that occur in diverse ecological niches ranging from pond water to phagolysosomes. However, in vitro the organism is very sensitive to acid. To provide an explanation for how this organism survives acid in natural environments, the adaptive ability of S. typhimurium to become acid tolerant was tested. Logarithmically grown cells (pH 7.6) shifted to mild acid (pH 5.8) for one doubling as an adaptive procedure were 100 to 1,000 times more resistant to subsequent strong acid challenge (pH 3.3) than were unadapted cells shifted directly from pH 7.6 to 3.3. This acidification tolerance response required protein synthesis and appears to be a specific defense mechanism for acid. No cross protection was noted for hydrogen peroxide, SOS, or heat shock. Two-dimensional polyacrylamide gel electrophoretic analysis of acid-regulated polypeptides revealed 18 proteins with altered expression, 6 of which were repressed while 12 were induced by mild acid shifts. An avirulent phoP mutant was 1,000-fold more sensitive to acid than its virulent phoP+ parent, suggesting a correlation between acid tolerance and virulence. The Mg2(+)-dependent proton-translocating ATPase was also found to play an important role in acid tolerance. Mutants (unc) lacking this activity were unable to mount an acid tolerance response and were extremely acid sensitive. In contrast to these acid-sensitive mutants, a constitutively acid-tolerant mutant (atr) was isolated from wild-type LT2 after prolonged acid exposure. This mutant overexpressed several acidification tolerance response polypeptides. The data presented reveal an important acidification defense modulon with broad significance toward survival in biologically hostile environments.

  5. Persistence of Salmonella typhimurium on Fabrics

    PubMed Central

    Wilkoff, Lee J.; Westbrook, Louise; Dixon, Glen J.

    1969-01-01

    The persistence of Salmonella typhimurium (V-31) on wool blanket, wool gabardine, cotton sheeting, cotton knit jersey, cotton terry cloth, and cotton wash-and-wear fabrics was studied. Three methods of exposure were employed to contaminate the fabrics: direct contact, aerosol, and a lyophilized mixture of bacteria and dust having a high content of textile fibers. After contamination, the fabrics were held in 35 or 78% relative humidity at 25 C. The persistence time of S. typhimurium on fabrics held in 35% relative humidity was substantially longer when the fabrics were contaminated by direct contact or by exposure to dust containing bacteria than when contaminated by exposure to aerosolized cultures. Viable bacterial populations persisted for 24 weeks at relatively high population densities on swatches of wool gabardine, cotton sheeting, cotton knit jersey, and cotton terry cloth exposed by direct contact and held in a humidity of 35%. In 78% humidity, bacterial populations persisted on the fabrics for relatively shorter periods of time regardless of the mode of contamination or fabric type. This organism retained its virulence for Swiss mice after being recovered from wool gabardine swatches held 8 weeks in humidities of 35 or 78% and from cotton terry cloth swatches held 6 weeks in the same humidities. Images PMID:4896883

  6. Proteome of Salmonella enterica serotype Tyhimurium Grown in Low Mg2+/pH Medium

    SciTech Connect

    Shi, Liang; Ansong, Charles; Smallwood, Heather S.; Rommereim, Leah M.; McDermott, Jason E.; Brewer, Heather M.; Norbeck, Angela D.; Taylor, Ronald C.; Gustin, Jean K.; Heffron, Fred; Smith, Richard D.; Adkins, Joshua N.

    2009-09-04

    To determine the impact of a low Mg2+/pH defined growth medium (MgM) on the proteome of Salmonella enterica serotype Typhimurium, we cultured S. Typhimurium cells in the medium under two different conditions termed MgM Shock and MgM Dilution and then comparatively analyzed the bacterial cells harvested from these conditions by a global proteomic approach. Proteomic results showed that MgM Shock and MgM Dilution differentially affected the S. Typhimurium proteome. MgM Shock induced a group of proteins whose induction usually occurred at low O2 level, while MgM Dilution induced those related to the type III secretion system (T3SS) of Salmonella Pathogenicity Island 2 (SPI2) and those involved in thiamine or biotin biosynthesis. The metabolic state of the S. Typhimurium cells grown under MgM Shock condition also differed significantly from that under MgM Dilution condition. Western blot analysis not only confirmed the proteomic results, but also showed that the abundances of SPI2-T3SS proteins SsaQ and SseE and biotin biosynthesis proteins BioB and BioD increased after S. Typhimurium infection of RAW 264.7 macrophages. Deletion of the gene encoding BioB reduced the bacterial ability to replicate inside the macrophages, suggesting a biotin-limited environment encountered by S. Typhimurium within RAW 264.7 macrophages.

  7. Genetic Manipulation of Pathogenicity Loci in Non-Typhimurium Salmonella

    PubMed Central

    Butela, Kristen; Lawrence, Jeffrey G.

    2012-01-01

    The traditional genetic tools used in Salmonella enterica serovar Typhimurium rely heavily on a high-transducing mutant of bacteriophage P22. P22 recognizes its hosts by the structure of their O-antigens, which vary among serovars of Salmonella; therefore, it cannot be used in most non-Typhimurium Salmonella, including the majority of those causing food-borne illnesses in both humans and livestock. Bacteriophage P1 infects a variety of enteric bacteria, including galE mutants of serovar Typhimurium; however, the degree to which the presence of coimmune prophages, the lack of required attachment sites or the lack of host factors act as barriers to using phage P1 in natural isolates of Salmonella is unknown. Here, we show that recombineering can be used to make virtually any serovar of Salmonella susceptible to P1 infection; as a result, P1 can be utilized for facile genetic manipulation of non-Typhimurium Salmonella, including movement of very large pathogenicity islands. A toolkit for easy manipulation of non-Typhimurium serovars of Salmonella is described. PMID:23041268

  8. Genetic map of Salmonella typhimurium, edition VIII.

    PubMed Central

    Sanderson, K E; Hessel, A; Rudd, K E

    1995-01-01

    We present edition VIII of the genetic map of Salmonella typhimurium LT2. We list a total of 1,159 genes, 1,080 of which have been located on the circular chromosome and 29 of which are on pSLT, the 90-kb plasmid usually found in LT2 lines. The remaining 50 genes are not yet mapped. The coordinate system used in this edition is neither minutes of transfer time in conjugation crosses nor units representing "phage lengths" of DNA of the transducing phage P22, as used in earlier editions, but centisomes and kilobases based on physical analysis of the lengths of DNA segments between genes. Some of these lengths have been determined by digestion of DNA by rare-cutting endonucleases and separation of fragments by pulsed-field gel electrophoresis. Other lengths have been determined by analysis of DNA sequences in GenBank. We have constructed StySeq1, which incorporates all Salmonella DNA sequence data known to us. StySeq1 comprises over 548 kb of nonredundant chromosomal genomic sequences, representing 11.4% of the chromosome, which is estimated to be just over 4,800 kb in length. Most of these sequences were assigned locations on the chromosome, in some cases by analogy with mapped Escherichia coli sequences. PMID:7603411

  9. Salmonella typhimurium Invasion Induces Apoptosis in Infected Macrophages

    NASA Astrophysics Data System (ADS)

    Monack, Denise M.; Raupach, Barbel; Hromockyj, Alexander E.; Falkow, Stanley

    1996-09-01

    Invasive Salmonella typhimurium induces dramatic cytoskeletal changes on the membrane surface of mammalian epithelial cells and RAW264.7 macrophages as part of its entry mechanism. Noninvasive S. typhimurium strains are unable to induce this membrane ruffling. Invasive S. typhimurium strains invade RAW264.7 macrophages in 2 h with 7- to 10-fold higher levels than noninvasive strains. Invasive S. typhimurium and Salmonella typhi, independent of their ability to replicate intracellularly, are cytotoxic to RAW264.7 macrophages and, to a greater degree, to murine bone marrow-derived macrophages. Here, we show that the macrophage cytotoxicity mediated by invasive Salmonella is apoptosis, as shown by nuclear morphology, cytoplasmic vacuolization, and host cell DNA fragmentation. S. typhimurium that enter cells causing ruffles but are mutant for subsequent intracellular replication also initiate host cell apoptosis. Mutant S. typhimurium that are incapable of inducing host cell membrane ruffling fail to induce apoptosis. The activation state of the macrophage plays a significant role in the response of macrophages to Salmonella invasion, perhaps indicating that the signal or receptor for initiating programmed cell death is upregulated in activated macrophages. The ability of Salmonella to promote apoptosis may be important for the initiation of infection, bacterial survival, and escape of the host immune response.

  10. Salmonella Typhimurium grown in a rotating wall bioreactor

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Salmonella typhimurium appears green in on human intestinal tissue (stained red) cultured in a NASA rotating wall bioreactor. Dr. Cheryl Nickerson of Tulane University is studying the effects of simulated low-g on a well-known pathogen, Salmonella typhimurium, a bacterium that causes two to four million cases of gastrointestinal illness in the United States each year. While most healthy people recover readily, S. typhimurium can kill people with weakened immune systems. Thus, a simple case of food poisoning could disrupt a space mission. Using the NASA rotating-wall bioreactor, Nickerson cultured S. typhimurium in modeled microgravity. Mice infected with the bacterium died an average of three days faster than the control mice, indicating that S. typhimurium's virulence was enhanced by the bioreactor. Earlier research showed that 3 percent of the genes were altered by exposure to the bioreactor. Nickerson's work earned her a 2001 Presidential Early Career Award for Scientists and Engineers.

  11. Investigation of Salmonella enterica in Sardinian slaughter pigs: prevalence, serotype and genotype characterization.

    PubMed

    Piras, Francesca; Brown, Derek J; Meloni, Domenico; Mureddu, Anna; Mazzette, Rina

    2011-12-02

    In order to improve the knowledge about the presence of Salmonella in pork meat in Sardinia (Italy), the prevalence and the sources of Salmonella at 5 pig slaughterhouses (slaughtered pigs and environment) were investigated and the isolates were characterised. A total of 462 samples were collected, 425 from pigs at slaughter and 41 from the slaughterhouse environment. Salmonella was isolated from 26/85 (30.5%) mesenteric lymph nodes, 14/85 (16.4%) colon contents, and from 12/85 (14.1%) carcasses and livers. Salmonella prevalence was 38% (8/21) in samples from surfaces not in contact with meat, and 35% (7/20) in those from surfaces in contact with meat. Thirty-one pigs were identified as carriers of Salmonella in lymph nodes and/or colon content, but of these, only 8 carcasses were positive. A total of 103 Salmonella isolates were serotyped and genotyped. Eight different serotypes were detected; the most common were S. Derby (44/103, 42.7%) and S. Typhimurium (24/103, 23.3%). The most prevalent S. Typhimurium phage type was DT193. Thirty-two isolates were found to be resistant to more than one antimicrobial (MDR). Pulse-field gel electrophoresis (PFGE) permitted the resolution of XbaI macrorestriction fragments of the Salmonella strains into 20 distinct pulsotypes. Combined application of a plasmid profiling assay (PPA) and PFGE gave useful additional information to assist in tracing the routes of Salmonella contamination in abattoirs. To reduce Salmonella prevalence some preventive measures should be encouraged: the origin of infected slaughter animals should be identified and direct and cross-contamination of carcasses should be avoided by adhering to HACCP principles in association with good hygiene procedures (GHP).

  12. Methods for Tumor Targeting with Salmonella typhimurium A1-R.

    PubMed

    Hoffman, Robert M; Zhao, Ming

    2016-01-01

    Salmonella typhimurium A1-R (S. typhimurium A1-R) has shown great preclinical promise as a broad-based anti-cancer therapeutic (please see Chapter 1 ). The present chapter describes materials and methods for the preclinical study of S. typhimurium A1-R in clinically-relevant mouse models. Establishment of orthotopic metastatic mouse models of the major cancer types is described, as well as other useful models, for efficacy studies of S. typhimurium A1-R or other tumor-targeting bacteria, as well. Imaging methods are described to visualize GFP-labeled S. typhimurium A1-R, as well as GFP- and/or RFP-labeled cancer cells in vitro and in vivo, which S. typhimurium A1-R targets. The mouse models include metastasis to major organs that are life-threatening to cancer patients including the liver, lung, bone, and brain and how to target these metastases with S. typhimurium A1-R. Various routes of administration of S. typhimurium A1-R are described with the advantages and disadvantages of each. Basic experiments to determine toxic effects of S. typhimurium A1-R are also described. Also described are methodologies for combining S. typhimurium A1-R and chemotherapy. The testing of S. typhimurium A1-R on patient tumors in patient-derived orthotopic xenograft (PDOX) mouse models is also described. The major methodologies described in this chapter should be translatable for clinical studies.

  13. Occurrence, serotype diversity, and antimicrobial resistance of salmonella in ground beef at retail stores in Jalisco state, Mexico.

    PubMed

    Cabrera-Diaz, Elisa; Barbosa-Cardenas, Claudia M; Perez-Montaño, Julia A; Gonzalez-Aguilar, Delia; Pacheco-Gallardo, Carlos; Barba, Jeannette

    2013-12-01

    The occurrence, serotype diversity, and antimicrobial resistance of Salmonella bacteria in commercial ground beef at retail establishments were investigated. Salmonella was isolated from 135 (56.7%) of 238 ground beef samples collected at the same number of butcher's shops located in three municipalities of Jalisco State, Mexico, during an 11-month period. The isolation frequency differed by municipality (P < 0.05) and was higher (P < 0.05) during the warm season (68.5%) than during the cold season (43.2%). Overall, 25 serotypes and 8 serogroups were identified among 135 Salmonella isolates; predominant were Salmonella group B (9.6%), Salmonella Anatum (8.9%), Salmonella Agona (6.7%), Salmonella Infantis (6.7%), and Salmonella Typhimurium (5.9%). All Salmonella isolates were tested for susceptibility to 11 antimicrobial drugs of human and veterinary use. Resistance to tetracycline was the most commonly observed (40.7%), followed by resistance to streptomycin (35.6%), trimethoprim-sulfamethoxazole (20.7%), and nalidixic acid (19.3%). Thirty-seven Salmonella isolates (27.4%) were multidrug resistant, and the majority corresponded to Salmonella Group B, Salmonella Anatum, and Salmonella Typhimurium. Three Salmonella isolates were resistant to seven different antimicrobials. The frequency of Salmonella in ground beef samples (56.7%) was higher than that observed in our previous investigation on beef carcasses (15.4%) at small abattoirs in the same region of Mexico. This may be a result of increasing contamination at these two points of the raw-beef production chain or may be an effect of the grinding process that facilitates a more-homogeneous pathogen distribution in the product. Poor hygiene, temperature abuse, and practices allowing cross-contamination during ground beef fabrication at these retail establishments increase the consumer's exposure to Salmonella.

  14. Prevalence, Enumeration, Serotypes, and Antimicrobial Resistance Phenotypes of Salmonella enterica Isolates from Carcasses at Two Large United States Pork Processing Plants

    PubMed Central

    Brichta-Harhay, Dayna M.; Kalchayanand, Norasak; Bosilevac, Joseph M.; Shackelford, Steven D.; Wheeler, Tommy L.; Koohmaraie, Mohammad

    2012-01-01

    The objective of this study was to characterize Salmonella enterica contamination on carcasses in two large U.S. commercial pork processing plants. The carcasses were sampled at three points, before scalding (prescald), after dehairing/polishing but before evisceration (preevisceration), and after chilling (chilled final). The overall prevalences of Salmonella on carcasses at these three sampling points, prescald, preevisceration, and after chilling, were 91.2%, 19.1%, and 3.7%, respectively. At one of the two plants, the prevalence of Salmonella was significantly higher (P < 0.01) for each of the carcass sampling points. The prevalences of carcasses with enumerable Salmonella at prescald, preevisceration, and after chilling were 37.7%, 4.8%, and 0.6%, respectively. A total of 294 prescald carcasses had Salmonella loads of >1.9 log CFU/100 cm2, but these carcasses were not equally distributed between the two plants, as 234 occurred at the plant with higher Salmonella prevalences. Forty-one serotypes were identified on prescald carcasses with Salmonella enterica serotypes Derby, Typhimurium, and Anatum predominating. S. enterica serotypes Typhimurium and London were the most common of the 24 serotypes isolated from preevisceration carcasses. The Salmonella serotypes Johannesburg and Typhimurium were the most frequently isolated serotypes of the 9 serotypes identified from chilled final carcasses. Antimicrobial susceptibility was determined for selected isolates from each carcass sampling point. Multiple drug resistance (MDR), defined as resistance to three or more classes of antimicrobial agents, was identified for 71.2%, 47.8%, and 77.5% of the tested isolates from prescald, preevisceration, and chilled final carcasses, respectively. The results of this study indicate that the interventions used by pork processing plants greatly reduce the prevalence of Salmonella on carcasses, but MDR Salmonella was isolated from 3.2% of the final carcasses sampled. PMID:22327585

  15. Blind comparison of traditional serotyping with three multiplex PCRs for the identification of Salmonella serotypes.

    PubMed

    Herrera-León, Silvia; Ramiro, Raquel; Arroyo, Margarita; Díez, Rosa; Usera, Miguel Angel; Echeita, Maria Aurora

    2007-03-01

    Salmonella serotypes are defined on the basis of somatic (O) antigens which define the serogroup and flagellar (H) factor antigens, both of which are present in the cell wall of Salmonella. Most Salmonella organisms alternatively express phase-1 or phase-2 flagellar antigens encoded by fliC and fljB genes, respectively. Our group previously published two multiplex PCRs for distinguishing the most common first- and second-phase antigens. In this paper we describe a third multiplex PCR to identify the most common serogroups (O:B; O:C1; O:C2; O:D and O:E). The combination of these three PCRs enabled us to completely serotype organisms belonging to the Salmonella species. This multiplex PCR includes 10 primers. A total of 67 Salmonella strains belonging to 32 different serotypes were tested. Each strain generated one serogroup-specific fragment ranging between 162 and 615bp. Twenty-eight strains belonging to 21 serotypes, with a serogroup different from those tested in this work, did not generate any fragments. To compare molecular serotyping with traditional serotyping, 500 strains, received according to the order of arrival in the laboratory, were serotyped using both methods. The three multiplex PCRs were able to serotype 84.6% of the tested strains. This method was found to be very helpful in our laboratory as an alternative method for typing strains causing outbreaks, and it can be used to supplement conventional serotyping, since it is also applicable to motionless and rough strains.

  16. Antimicrobial susceptibility and internalization of Salmonella Typhimurium in vacuum-tumbled marinated beef products.

    PubMed

    Pokharel, S; Brooks, J C; Martin, J N; Brashears, M M

    2016-12-01

    As the incidence of multidrug resistance (MDR) Salmonella enterica serotype Typhimurium is increasing, data regarding the antimicrobial interventions and pathogen internalization in marinated meat products are important. This study evaluated the antimicrobial intervention and internalization of Salm. Typhimurium in marinated beef sirloin steaks. Beef bottom sirloin flaps (IMPS #185A; USDA Select) inoculated (10(8)  log10  CFU ml(-1) ) with Salm. Typhimurium were sprayed (lactic acid (4%) and buffered vinegar (2%)) prior to vacuum-tumbled marination (0·35% sodium chloride and 0·45% sodium tripolyphosphate) for 30 min. Pathogen presence after antimicrobial spray, vacuum-tumbled marination, and translocation was determined by direct plating on Xylose Lysine Deoxycholate (XLD) agar with tryptic soy agar (TSA) overlay. The data imply varied internalization and antimicrobial susceptibility pattern of Salm. Typhimurium in marinated meat. Lactic acid (4%) spray (P < 0·0001) and buffered vinegar (2%; P < 0·0001) reduced surface populations of Salm. Typhimurium on inoculated beef sirloin flaps prior to vacuum marination. However, lactic acid treated sirloin flaps had greater reductions (~2 log10  CFU cm(-2) ) than buffered vinegar when compared with control prior to vacuum marination. However, the translocation of Salm. Typhimurium following vacuum marination was not influenced (P < 0·333) by the application of a surface organic acid spray prior to marination.

  17. Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in southern Brazil

    PubMed Central

    Pulido-Landínez, M; Sánchez-Ingunza, R; Guard, J; do Nascimento, V Pinheiro

    2013-01-01

    To assess diversity of Salmonella enterica serotypes present in poultry and their environment from southern Brazil, the Kauffmann–White–Le Minor (KWL) scheme was used to serotype a total of 155 isolates. Isolates were then re-examined with nested PCR and sequencing of the dkgB-linked intergenic sequence ribotyping (ISR) region that assesses single nucleotide polymorphisms occurring around a 5S ribosomal gene. Serotypes identified were Heidelberg (40·6%), Enteritidis (34·2%), Hadar (8·4%), Typhimurium (3·9%), Gallinarum (3·2%), Agona (1·3%), Cerro (1·3%), Livingstone (1·3%), Infantis (0·6%), Isangi (0·6%), Mbandaka (0·6%), Montevideo (0·6%) and Senftenberg (0·6%). Three unique ISRs were detected from four strains. Day old chicks yielded only S. Enteritidis, whereas S. Heidelberg was most often associated with poultry carcasses. Overall agreement between KWL and ISR was 85·2%, with disagreement possibly due to the ability of ISR to detect mixtures of serotypes in culture. Overall, ISR provided more information than did KWL about the ecology of Salm. enterica on-farm. The O-antigen group D Salm. enterica serovars such as Pullorum, Gallinarum and Enteritidis appear susceptible to overgrowth by other serotypes. Significance and Impact of the Study Single nucleotide polymorphisms found in a group of poultry-associated Salmonella isolates from southern Brazil provided evidence of mixtures of serovar group D serotypes on-farm and in single samples from birds. This finding suggests that co-infection and interserotype competition of Salmonella enterica in poultry could impact the incidence of disease in animals or humans. In addition, unique serotypes were identified on-farm that escaped characterization by antibody typing. Application of cost-efficient and highly discriminatory genomic methods for assigning serotype may alter concepts about the epidemiology of Salm. enterica on-farm and in foods. PMID:23734786

  18. Salmonella typhimurium peptidase active on carnosine.

    PubMed Central

    Kirsh, M; Dembinski, D R; Hartman, P E; Miller, C G

    1978-01-01

    Wild-type Salmonella typhimurium can use carnosine (beta-alanyl-L-histidine) as a source of histidine, but carnosine utilization is blocked in particular mutants defective in the constitutive enzyme peptidase D, the product of the pepD gene. Biochemical evidence for assigning carnosinase activity to peptidase D (a broad-specificity dipeptidase) includes: (i) coelution of carnosinase and dipeptidase activity from diethylaminoethyl-cellulose and Bio-Gel P-300 columns; (ii) coelectrophoresis of carnosinase and dipeptidase on polyacrylamide gels; and (iii) inactivation of carnosinase and dipeptidase activities at identical rates at both 4 and 42 degrees C. Genetic evidence indicates that mutations leading to loss of carnosinase activity map at pepD. Several independent pepD mutants have been isolated by different selection procedures, and the patterns of peptide utilization of strains carrying various pepD alleles have been studied. Many pepD mutations lead to the production of partially active peptidase D enzymes with substrate specificities that differ strikingly from those of the wild-type enzyme. The growth yields of carnosinase-deficient strains growing in Difco nutrient broth indicate that carnosine is the major utilizable source of histidine in this medium. PMID:26655

  19. HEPES-stabilized encapsulation of Salmonella typhimurium.

    PubMed

    Suo, Zhiyong; Yang, Xinghong; Avci, Recep; Kellerman, Laura; Pascual, David W; Fries, Marc; Steele, Andrew

    2007-01-30

    Most bacteria, planktonic and sessile, are encapsulated inside loosely bound extracellular polymeric substance (EPS) in their physiological environment. Imaging a bacterium with its capsule requires lengthy sample preparation to enhance the capsular contrast. In this study, Salmonella typhimurium was investigated using atomic force microscopy for a practical means of imaging an encapsulated bacterium in air. The investigation further aimed to determine the relation between the buffers used for preparing the bacterium and the preservation of the capsular material surrounding it. It was observed that rinsing bacteria with HEPES buffer could stabilize and promote capsule formation, while rinsing with PBS, Tris, or glycine removes most of the capsular EPS. For bacteria rinsed with HEPES and air-dried, the height images showed only the contour of the capsular material, while the phase and amplitude images presented the detailed structures of the bacterial surface, including the flagella encapsulated inside the capsular EPS. The encapsulation was attributed to the cross-linking of the acidic exopolysaccharides mediated by the piperazine moiety of HEPES through electrostatic attraction. This explanation is supported by encapsulated bacteria observed for samples rinsed with N,N'-bis(2-hydroxyethyl)-piperazine solution and by the presence of entrapped HEPES within the dry capsular EPS suggested by micro-Raman spectroscopy.

  20. Hydrophobic peptide auxotrophy in Salmonella typhimurium.

    PubMed Central

    Brãnes, L V; Somers, J M; Kay, W W

    1981-01-01

    The growth of a pleiotropic membrane mutant of Salmonella typhimurium with modified lipopolysaccharide composition was found to be strictly dependent on the peptone component of complex media. Nutritional Shiftdown into minimal media allowed growth for three to four generations. Of 20 commercial peptones, only enzymatic digests supported growth to varying degrees. Neither trace cations, amino acids, vitamins, carbohydrates, lipids, glutathione, polyamines, carbodimides, nor synthetic peptides stimulated growth; however, cells still metabolized carbohydrates, and amino acid transport systems were shown to be functional. A tryptic digest of casein was fractionated into four electrophoretically different peptide fractions of 1,000 to 1,200 molecular weight which supported growth to varying degrees. The best of these was further fractionated to two highly hydrophopic peptides. N-terminal modifications eliminated biological activity. Fluorescein-conjugated goat antibody to rabbit immunoglobulin G was used as a probe to detect antipeptide antibody-peptide complexes on membrane preparations. Cells grown on peptone distributed the peptide into both inner and outer membranes. The peptide could be removed with chaotropic agents, and cells had to be pregrown in peptone-containing media to bind the hydrophobic peptide. The gene (hyp) responsible for peptide auxotrophy was mapped at 44 to 45 units by conjugation. Images PMID:7024254

  1. Multistate outbreak of Salmonella typhimurium infections associated with eating ground beef--United States, 2004.

    PubMed

    2006-02-24

    Salmonella infections cause an estimated 1.4 million human illnesses and 400 deaths annually in the United States. Although the incidence of several other foodborne bacterial infections decreased substantially during 1996-2004, the incidence of Salmonella infections declined modestly. In September 2004, the New Mexico Department of Health received reports from the New Mexico Scientific Laboratory Division of eight Salmonella enterica serotype Typhimurium isolates that had indistinguishable pulsed-field gel electrophoresis (PFGE) patterns using XbaI and BlnI restriction enzymes. The patients were from three New Mexico counties and had onsets of illness during August 18-29. A review of PFGE patterns submitted to the National Molecular Subtyping Network for Foodborne Disease Surveillance (PulseNet) database for Salmonella revealed 31 indistinguishable patient isolates of S. Typhimurium from nine states (Colorado, Kansas, Minnesota, New Jersey, New Mexico, New York, Ohio, Tennessee, and Wisconsin) and the District of Columbia, with illness onset occurring during August 11-October 2, 2004. The S. Typhimurium isolates were susceptible to all antimicrobial agents tested. An investigation conducted by state health departments, CDC, and the U.S. Department of Agriculture Food Safety and Inspection Service (FSIS) identified ground beef purchased at a national chain of supermarkets as the source of S. Typhimurium infections. Traceback results indicated product originating from a common supplier; however, evaluators determined that plant practices conformed to FSIS production guidelines, and no product recalls were made. This report describes the investigation and underscores the risk for salmonellosis from contact with contaminated ground beef, despite regulatory directives to reduce Salmonella contamination in beef production. Reduced contamination and consumption of raw or undercooked meat and further education of the food service industry and consumers are critical to

  2. Salmonella typhimurium mediated delivery of Apoptin in human laryngeal cancer.

    PubMed

    Guan, Guo-fang; Zhao, Ming; Liu, Li-ming; Jin, Chun-shun; Sun, Kai; Zhang, De-jun; Yu, Duo-jiao; Cao, Hong-wei; Lu, Yan-qing; Wen, Lian-ji

    2013-01-01

    An effective cancer therapeutic should target tumours specifically with limited systemic toxicity. Here, we transformed an attenuated Salmonella typhimurium (S. typhimurium) with an Apoptin expressing plasmid into a human laryngeal carcinoma cell line. The expression of the inserted gene was measured using fluorescence and immunoblotting assays. The attenuated S. typhimurium-mediated Apoptin significantly decreased cytotoxicity and strongly increased cell apoptosis through the activation of caspase-3. The process was mediated by Bax, cytochrome c and caspase-9. A syngeneic nude murine tumour model was used to determine the anti-tumour effects of the recombinant bacteria in vivo. Systemic injection of the recombinant bacteria with and without re-dosing caused significant tumour growth delay and reduced tumour microvessel density, thereby extending host survival. Our findings indicated that the use of recombinant Salmonella typhimurium as an Apoptin expression vector has potential cancer therapeutic benefits.

  3. Identification of Virulence Properties in Salmonella Typhimurium DT104 Using Caenorhabditis elegans

    PubMed Central

    Sahu, Surasri N.; Anriany, Yuda; Grim, Christopher J.; Kim, Sungji; Chang, Zenas; Joseph, Sam W.; Cinar, Hediye N.

    2013-01-01

    Salmonella enterica serover Typhimurium definitive phage type DT104, resistant to multiple antibiotics, is one of the most widespread Salmonella species in human infection worldwide. Although several cohort studies indicate that DT104 carrying the multidrug resistance (MDR) locus on salmonella genomic island 1 is a possible hyper-virulent strain compared to DT104 strains without MDR, or other Salmonella enterica serotypes, existing experimental evidence regarding virulence properties associated with the MDR region is controversial. To address this question, we constructed an isogenic MDR deletion (∆MDR) mutant strain of DT104, SNS12, by allelic exchange and used Caenorhabditis elegans as a host model to assess differences in virulence between these two strains. SNS12 exhibited decreased virulence in C. elegans, and we observed increased colonization and proliferation of the intestine of C. elegans by DT104. The immune response against MDR-carrying DT104 appears to function through a non-canonical Unfolded Protein Response (UPR) pathway, namely prion-like-(QN-rich)-domain-bearing protein pathway (PQN), in a ced-1 dependent manner in C. elegans. Further, we also demonstrate that genes of the PQN pathway and antimicrobial peptide gene abf-2, are expressed at higher transcriptional levels in worms immediately following exposure to DT104, in comparison with worms exposed to SNS12. Altogether, our results suggest that the MDR region of Salmonella Typhimurium DT104 has a direct role in virulence against Caenorhabditis elegans. PMID:24124587

  4. Identification of virulence properties in Salmonella Typhimurium DT104 using Caenorhabditis elegans.

    PubMed

    Sahu, Surasri N; Anriany, Yuda; Grim, Christopher J; Kim, Sungji; Chang, Zenas; Joseph, Sam W; Cinar, Hediye N

    2013-01-01

    Salmonella enterica serover Typhimurium definitive phage type DT104, resistant to multiple antibiotics, is one of the most widespread Salmonella species in human infection worldwide. Although several cohort studies indicate that DT104 carrying the multidrug resistance (MDR) locus on salmonella genomic island 1 is a possible hyper-virulent strain compared to DT104 strains without MDR, or other Salmonella enterica serotypes, existing experimental evidence regarding virulence properties associated with the MDR region is controversial. To address this question, we constructed an isogenic MDR deletion (∆MDR) mutant strain of DT104, SNS12, by allelic exchange and used Caenorhabditis elegans as a host model to assess differences in virulence between these two strains. SNS12 exhibited decreased virulence in C. elegans, and we observed increased colonization and proliferation of the intestine of C. elegans by DT104. The immune response against MDR-carrying DT104 appears to function through a non-canonical Unfolded Protein Response (UPR) pathway, namely prion-like-(QN-rich)-domain-bearing protein pathway (PQN), in a ced-1 dependent manner in C. elegans. Further, we also demonstrate that genes of the PQN pathway and antimicrobial peptide gene abf-2, are expressed at higher transcriptional levels in worms immediately following exposure to DT104, in comparison with worms exposed to SNS12. Altogether, our results suggest that the MDR region of Salmonella Typhimurium DT104 has a direct role in virulence against Caenorhabditis elegans.

  5. Comparison of the environmental survival characteristics of Salmonella Dublin and Salmonella Typhimurium.

    PubMed

    Kirchner, Miranda J; Liebana, Ernesto; McLaren, Ian; Clifton-Hadley, Felicity A; Wales, Andrew D; Davies, Robert H

    2012-10-12

    To examine possible correlations in bovine Salmonella isolates between environmental survival and serovar-associated epidemiological patterns, bovine field isolates of Salmonella serovars Typhimurium and Dublin (two each) were inoculated into bovine faeces slurry and tested monthly by culture for survival during a six-month period of storage at a variable ambient temperature in a disused animal transporter. Low moisture conditions, where the slurry was dried onto wooden dowels, increased detectable survival of a low-level inoculum by up to five months, compared with wet slurry. A more modest increase of survival time was seen with storage of wet slurry under refrigeration at 4°C. Under both dry and wet conditions, the concentration of culturable Salmonella Typhimurium declined at a slower rate than did that of Salmonella Dublin. Salmonella that was naturally contaminating bovine faeces from farms with Salmonella Typhimurium did not show superior survival times compared with Salmonella Typhimurium that had been artificially inoculated into samples. The differing survival characteristics of the two serovars that was observed in environmental faeces may complement their different modes of infection in cattle. Salmonella Dublin, being a bovine host-adapted strain that establishes chronic infection in some animals, may have less need to survive for a prolonged period outside of its host than does Salmonella Typhimurium.

  6. [Annual distribution of serotypes of Salmonella, Shigella, and infantile enteropathogenic Escherichia coli in the Republic of Argentina, 1979-1981].

    PubMed

    Eiguer, T; Butta, N

    1983-01-01

    We report data of isolation of 3,665 strains of Salmonella, 1,855 of Shigella and 697 of E. coli infantile enteropathogenic (EPI) from different sources: human, animal, food and water, in Argentina during the triennium 1979-1981, considering their importance in the chain of transmission of enterobacteria. It appears that S. typhimurium is the most common among all the isolated serotypes of Salmonella, following in order of importance, S. oranienburg, S. derby, S. panama, S. agona, S. anatum, S. newport, S. bredeney and S. montevideo. It is important to emphasize the appearance of new Shigella serotypes in Argentina, particularly Sh. dysenteriae 2. We found that E. coli EPI 0111:B4 was the most frequent serotype and in 1981 the serotype 0112:B13 was also found.

  7. Specificity of Salmonella Typhimurium strain (ATCC 14028) growth responses to Salmonella serovar-generated spent media.

    PubMed

    Calo, Juliany Rivera; Park, Si Hong; Baker, Christopher A; Ricke, Steven C

    2015-01-01

    Salmonella enterica is one of the most prevalent pathogens responsible for foodborne illness worldwide. Numerous Salmonella serovars have been associated with the consumption of a variety of products, and limiting food-borne illness due to Salmonella serovars is a continuing problem for food producers and public health. The emergence and prevalence of Salmonella serovars has been studied but the predominant serovars have varied somewhat over the years. The aims of this research were to compare the aerobic growth responses of selected predominant foodborne Salmonella serovars, and evaluate how the spent media from different serovars affects the growth of a well-characterized Salmonella Typhimurium strain. Growth responses were similar for most strains in spent media except for S. Typhimurium (ATCC 14028), which exhibited a decrease in growth in the presence of Salmonella Heidelberg (ARI-14) spent media. This research will provide a better understanding of the growth differences among several Salmonella serovars in nutrient limited spent media.

  8. Assessment of attenuated Salmonella vaccine strains in controlling experimental Salmonella Typhimurium infection in chickens.

    PubMed

    Pei, Yanlong; Parreira, Valeria R; Roland, Kenneth L; Curtiss, Roy; Prescott, John F

    2014-01-01

    Salmonella hold considerable promise as vaccine delivery vectors for heterologous antigens in chickens. Such vaccines have the potential additional benefit of also controlling Salmonella infection in immunized birds. As a way of selecting attenuated strains with optimal immunogenic potential as antigen delivery vectors, this study screened 20 novel Salmonella Typhimurium vaccine strains, differing in mutations associated with delayed antigen synthesis and delayed attenuation, for their efficacy in controlling colonization by virulent Salmonella Typhimurium, as well as for their persistence in the intestine and the spleen. Marked differences were observed between strains in these characteristics, which provide the basis for selection for further study as vaccine vectors.

  9. Detection and characterization of Salmonella typhimurium from a dairy herd in North Dakota.

    PubMed

    Nolan, L K; Giddings, C W; Boland, E W; Steffen, D J; Brown, J; Misek, A

    1995-01-01

    Nasal secretions, faecal samples and buffy coats were obtained from 102 cattle from a North Dakota dairy herd with a history of calf scours. Treated buffy coats, faecal samples and nasal secretions were inoculated into tetrathionate broth (TB), incubated at 37 degrees C overnight, and plated onto brilliant green agar medium with novobiocin (BGAN). The TB was left at room temperature for 5 days and then used to inoculate fresh TB. The fresh TB was incubated at 37 degrees C over night and plated onto BGAN medium. All the plates were incubated at 37 degrees C over night and observed for Salmonella-like growth. Suspect colonies were further tested and Salmonella isolates were serotyped by the National Veterinary Services laboratory. Twenty-two of the 36 calves sampled harboured S. typhimurium in their faeces, but no samples from cows were positive. No Salmonella were isolated from the buffy coats, but 4 calves were shown to have Salmonella in their nasal secretions. Extended enrichment of the faecal cultures in TB resulted in a significant increase in Salmonella isolations, although 2 samples were positive following the initial enrichment period and not after secondary enrichment. The typical Salmonella isolate detected from this herd contained a transmissible R-plasmid encoding resistance to tetracycline, kanamycin, sulphisoxazole and ampicillin. This study confirmed that delayed secondary enrichment in TB is superior to primary enrichment for detection of Salmonella from cattle.

  10. Salmonella typhimurium infection in domesticated fowl in a children's zoo.

    PubMed

    Sato, Y; Fukui, S; Kurusu, H; Kitazawa, I; Kuwamoto, R; Aoyagi, T

    1999-01-01

    Salmonella typhimurium infection occurred in a children's zoo where 11 fowl and 85 mammals were kept. Initially, the guinea pigs were infected and transmitted the infection to the fowl and rabbits. These mammals responded to medication and cleared of the infection; however, the birds were judged to contain excreters despite four regimens of treatment with antibiotics. Cloacal swabs were taken from all the birds. One turkey was positive for Salmonella and was destroyed. Pooled fecal samples from the birds were again positive. All the birds were tested serologically, and two birds, a goose and a turkey, were positive with Salmonella pullorum-gallinarum antigen, which was assumed to be a cross reaction with S. typhimurium antigen. The two birds were destroyed and the goose yielded Salmonella. The infection was finally eradicated, and the serologic examination was considered to be the most useful procedure for detection of the excreters.

  11. The Cytolethal Distending Toxin Produced by Nontyphoidal Salmonella Serotypes Javiana, Montevideo, Oranienburg, and Mississippi Induces DNA Damage in a Manner Similar to That of Serotype Typhi

    PubMed Central

    Miller, Rachel A.

    2016-01-01

    ABSTRACT Select nontyphoidal Salmonella enterica (NTS) serotypes were recently found to encode the Salmonella cytolethal distending toxin (S-CDT), an important virulence factor for serotype Typhi, the causative agent of typhoid fever. Using a PCR-based assay, we determined that among 21 NTS serotypes causing the majority of food-borne salmonellosis cases in the United States, genes encoding S-CDT are conserved in isolates representing serotypes Javiana, Montevideo, and Oranienburg but that among serotype Mississippi isolates, the presence of S-CDT-encoding genes is clade associated. HeLa cells infected with representative strains of these S-CDT-positive serotypes had a significantly higher proportion of cells arrested in the G2/M phase than HeLa cells infected with representative strains of S-CDT-negative serotypes Typhimurium, Newport, and Enteritidis. The G2/M cell cycle arrest was dependent on CdtB, the active subunit of S-CDT, as infection with isogenic ΔcdtB mutants abolished their ability to induce a G2/M cell cycle arrest. Infection with S-CDT-encoding serotypes was significantly associated with activation of the host cell’s DNA damage response (DDR), a signaling cascade that is important for detecting and repairing damaged DNA. HeLa cell populations infected with S-CDT-positive serotypes had a significantly higher proportion of cells with DDR protein 53BP1 and γH2AX foci than cells infected with either S-CDT-negative serotypes or isogenic ΔcdtB strains. Intoxication with S-CDT occurred via autocrine and paracrine pathways, as uninfected HeLa cells among populations of infected cells also had an activated DDR. Overall, we show that S-CDT plays a significant role in the cellular outcome of infection with NTS serotypes. PMID:27999166

  12. Dissemination of clonal Salmonella enterica serovar Typhimurium isolates causing salmonellosis in Mauritius.

    PubMed

    Issack, Mohammad I; Garcia-Migura, Lourdes; Ramsamy, Veemala D; Svendsen, Christina A; Pornruangwong, Srirat; Pulsrikarn, Chaiwat; Hendriksen, Rene S

    2013-07-01

    Salmonella enterica serotype Typhimurium is one of the leading causes of salmonellosis in Mauritius, where it has also been associated with outbreaks of foodborne illness. However, little is known about its molecular epidemiology in the country. This study was therefore undertaken to investigate the clonality and source of Salmonella Typhimurium in Mauritius by studying human, food, and poultry isolates by pulsed-field gel electrophoresis (PFGE) and antibiotic minimum inhibitory concentration determination. Forty-nine isolates collected between 2008 and 2011 were analyzed, including 25 stool isolates from foodborne illness outbreaks and sporadic gastroenteritis cases, four blood isolates, one postmortem colon isolate, 14 food isolates, and five poultry isolates. All isolates were pansusceptible to the 16 antibiotics tested, except for two isolates that were resistant to sulfamethoxazole and trimethoprim. Overall characterization of the isolates by PFGE digested with XbaI and BlnI resulted in eight different patterns. The largest of the clusters in the composite dataset consisted of 20 isolates, including two raw chicken isolates, four poultry isolates, and nine human stool isolates from two outbreaks. A second cluster consisted of 18 isolates, of which 12 originated from human blood and stool samples from both sporadic and outbreak cases. Six food isolates were also found in this cluster, including isolates from raw and grilled chicken, marlin mousse, and cooked pork. One poultry isolate had a closely related PFGE pattern. The results indicate that one clone of Salmonella Typhimurium found in poultry has been causing outbreaks of foodborne illness in Mauritius and another clone that has caused many cases of gastrointestinal illness and bacteremia in humans could also be linked to poultry. Thus, poultry appears to be a major reservoir for Salmonella Typhimurium in Mauritius. Initiating on-farm control strategies and measures against future dissemination may

  13. Relative survival of four serotypes of Salmonella enterica in low-water activity whey protein powder held at 36 and 70°C at various water activity levels.

    PubMed

    Farakos, S M Santillana; Hicks, J W; Frye, J G; Frank, J F

    2014-07-01

    Salmonella enterica is not able to grow at water activity (aw) levels below 0.94, but it can survive in low-aw foods for long periods of time. Temperature, aw, substrate, and serotype affect its persistence. The aim of this study was to evaluate the influence of temperature and aw on the relative persistence among four serotypes of Salmonella enterica in low-aw whey protein powder. Whey protein powder was equilibrated to aws 0.18 ± 0.02 and 0.54 ± 0.03, inoculated with a cocktail of Salmonella serovars (Agona, Tennessee, Montevideo, and Typhimurium), vacuum sealed, and stored at 36°C for 6 months and at 70°C for 48 h. Presumptive Salmonella colonies (30 to 32) were randomly picked from each plate at the end of each survival study. PCR multiplex serotyping was used to identify the isolates. A multinomial mixed logistic model with Salmonella Tennessee as a reference was used to test for significant differences in frequency distribution of the surviving serotypes. Salmonella Tennessee and Salmonella Agona were the most prevalent surviving serotypes, followed in decreasing order by Salmonella Montevideo and Salmonella Typhimurium. Statistical analysis indicated that temperature (P = 0.003) and aw (P = 0.012) influenced the relative prevalence of the Salmonella serotypes. If other environmental conditions are equal, Salmonella Tennessee is better able to survive than Salmonella Montevideo and Salmonella Typhimurium at higher temperatures and higher aw levels in low-aw whey protein powder held at 36 and 70°C. The relative prevalence of Salmonella Agona to Salmonella Tennessee did not change with increasing temperature (P = 0.211) or aw (P = 0.453). These results should be considered in risk assessment and when developing predictive models for survival of Salmonella in low-aw foods.

  14. Poor biofilm-forming ability and long-term survival of invasive Salmonella Typhimurium ST313.

    PubMed

    Ramachandran, Girish; Aheto, Komi; Shirtliff, Mark E; Tennant, Sharon M

    2016-07-01

    Salmonella enterica serovar Typhimurium, an enteric pathogen that causes a self-limiting gastroenteritis, forms biofilms on different surfaces. In sub-Saharan Africa, Salmonella Typhimurium of a novel sequence type (ST) 313 was identified and produces septicemia in the absence of gastroenteritis. No animal reservoir has been identified, and it is hypothesized that transmission occurs via human to human. In this study, we show that invasive Salmonella Typhimurium ST313 strains from Mali are poor biofilm producers compared to Salmonella Typhimurium ST19 strains, which are found worldwide and are known to be associated with gastroenteritis. We evaluated biofilms using crystal violet staining, examination of the red, dry and rough morphotype, pellicle formation and a continuous flow system. One month-old Salmonella Typhimurium ST19 colonies survived in the absence of exogenous nutrients and were highly resistant to sodium hypochlorite treatment compared to Salmonella Typhimurium ST313. This study for the first time demonstrates the comparative biofilm-forming ability and long-term survival of clinical Salmonella Typhimurium ST19 and ST313 isolates. Salmonella Typhimurium ST19 strains are strong biofilm producers and can survive desiccation compared to Salmonella Typhimurium ST313 that form weak biofilms and survive poorly following desiccation. Our data suggest that like Salmonella Typhi, Salmonella Typhimurium ST313 lack mechanisms that allow it to persist in the environment.

  15. Amperometric biosensor for Salmonella typhimurium detection in milk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reports an amperometric biosensor for rapid and sensitive Salmonella Typhimurium detection in milk. The biosensor was assembled from the self-assembled monolayers technique on a gold surface. In this device, polyclonal antibodies were oriented by protein A. The biosensor structure was cha...

  16. Micro amperometric immunosensor for the detection of salmonella typhimurium

    NASA Astrophysics Data System (ADS)

    Sun, Jizhou; Xia, Shanhong; Bian, Chao; Qu, Lan

    2008-12-01

    In this paper, a micro amperometric immunosensor based on Micro-Electro-Mechanical Systems technology for the detection of Salmonella typhimurium (S. typhimurium) was constructed by immobilizing a polyclonal antibody (the bio-molecular recognition element) onto the surface of polypyrrole(PPy) /staphylococcal protein A(SPA) modified Pt electrode. Pyrrole doped with SPA was co-electropolymerized onto the working electrode surface by cyclic voltammetry in 10 minutes for orientation-controlled immobilization of salmonella capture antibodies. S. typhimurium with the concentration of 102cfu/ml could be detected by this immunosensor with a controllable and convenient manipulation to effectively modify the sensing surface more rapidly with less consumption of reagent (10µL), which showed the good property of the sensor. It is potential to develop a micro biosensor that can be used for convenient, accurate, cost-effective and real-time sensing of pathogens in food products.

  17. International Salmonella Typhimurium DT104 Infections, 1992–2001

    PubMed Central

    Ethelberg, Steen; Mølbak, Kåre

    2005-01-01

    The incidence of multidrug-resistant (MDR) Salmonella Typhimurium infections in humans, and in particular MDR definitive phage type 104 (DT104), has increased substantially in many countries in the last 2 decades, often associated with increased illness. To examine the magnitude of this problem, a survey was conducted among countries with available antimicrobial resistance or phage typing surveillance data. A total of 29, primarily industrialized, countries participated in the survey, which covered the years 1992–2001. Overall, the incidence of MDR S. Typhimurium and DT104 increased continuously during this period, although the problem affected primarily Europe and North America. The increase appeared to have peaked in the United Kingdom but not in other countries. Also, the incidence of quinolone-resistant S. Typhimurium was increasing. This survey implies that MDR S. Typhimurium constitutes an increasing public health problem in large parts of the world and emphasizes the importance of surveillance and control programs. PMID:15963280

  18. Salmonella typhimurium intercepts Escherichia coli signaling to enhance antibiotic tolerance

    PubMed Central

    Vega, Nicole M.; Allison, Kyle R.; Samuels, Amanda N.; Klempner, Mark S.; Collins, James J.

    2013-01-01

    Bacterial communication plays an important role in many population-based phenotypes and interspecies interactions, including those in host environments. These interspecies interactions may prove critical to some infectious diseases, and it follows that communication between pathogenic bacteria and commensal bacteria is a subject of growing interest. Recent studies have shown that Escherichia coli uses the signaling molecule indole to increase antibiotic tolerance throughout its population. Here, we show that the intestinal pathogen Salmonella typhimurium increases its antibiotic tolerance in response to indole, even though S. typhimurium does not natively produce indole. Increased antibiotic tolerance can be induced in S. typhimurium by both exogenous indole added to clonal S. typhimurium populations and indole produced by E. coli in mixed-microbial communities. Our data show that indole-induced tolerance in S. typhimurium is mediated primarily by the oxidative stress response and, to a lesser extent, by the phage shock response, which were previously shown to mediate indole-induced tolerance in E. coli. Further, we find that indole signaling by E. coli induces S. typhimurium antibiotic tolerance in a Caenorhabditis elegans model for gastrointestinal infection. These results suggest that the intestinal pathogen S. typhimurium can intercept indole signaling from the commensal bacterium E. coli to enhance its antibiotic tolerance in the host intestine. PMID:23946425

  19. General regression neural network and Monte Carlo simulation model for survival and growth of Salmonella on raw chicken skin as a function of serotype, temperature and time for use in risk assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A general regression neural network and Monte Carlo simulation model for predicting survival and growth of Salmonella on raw chicken skin as a function of serotype (Typhimurium, Kentucky, Hadar), temperature (5 to 50C) and time (0 to 8 h) was developed. Poultry isolates of Salmonella with natural r...

  20. Nontyphoidal salmonella infection in children with acute gastroenteritis: prevalence, serotypes, and antimicrobial resistance in Shanghai, China.

    PubMed

    Li, Yuefang; Xie, Xinbao; Xu, Xuebing; Wang, Xiangshi; Chang, Hailing; Wang, Chuanqing; Wang, Aiming; He, Yanlei; Yu, Hui; Wang, Xiaohong; Zeng, Mei

    2014-03-01

    Information about nontyphoidal Salmonella (NTS) infection in children is limited in mainland China. The objective of this study was to investigate the prevalence, serotypes, and antibiotic resistance patterns of NTS infection in children in Shanghai. All cases with probable bacterial diarrhea were enrolled from the enteric clinic of a tertiary pediatric hospital between July 2010 and December 2011. Salmonella isolation, serotyping, and antimicrobial susceptibility testing were conducted by the microbiological laboratory. NTS were recovered from 316 (17.2%) of 1833 cases with isolation rate exceeding Campylobacter (7.1%) and Shigella (5.7%). NTS infection was prevalent year-round with a seasonal peak during summer and autumn. The median age of children with NTS gastroenteritis was 18 months. Fever and blood-in-stool were reported in 52.5% and 42.7% of cases, respectively. Salmonella Enteritidis (38.9%) and Salmonella Typhimurium (29.7%) were the most common serovars. Antimicrobial susceptibility showed 60.5% of isolates resistant to ≥1 clinically important antibiotics. Resistance to ciprofloxacin and the third-generation cephalosporins was detected in 5.5% and 7.1%-11.7% of isolates, respectively. NTS is a major enteropathogen responsible for bacterial gastroenteritis in children in Shanghai. Resistance to the current first-line antibiotics is of concern. Ongoing surveillance for NTS infection and antibiotic resistance is needed to control this pathogen in Shanghai.

  1. Serotypes and Antimicrobial Resistance in Salmonella enterica Recovered from Clinical Samples from Cattle and Swine in Minnesota, 2006 to 2015

    PubMed Central

    Hong, Samuel; Rovira, Albert; Davies, Peter; Ahlstrom, Christina; Muellner, Petra; Rendahl, Aaron; Olsen, Karen; Bender, Jeff B.; Wells, Scott; Perez, Andres

    2016-01-01

    Salmonellosis remains one of the leading causes of foodborne disease worldwide despite preventive efforts at various stages of the food production chain. The emergence of multi-drug resistant (MDR) non-typhoidal Salmonella enterica represents an additional challenge for public health authorities. Food animals are considered a major reservoir and potential source of foodborne salmonellosis; thus, monitoring of Salmonella strains in livestock may help to detect emergence of new serotypes/MDR phenotypes and to gain a better understanding of Salmonella epidemiology. For this reason, we analyzed trends over a nine-year period in serotypes, and antimicrobial resistance, of Salmonella isolates recovered at the Minnesota Veterinary Diagnostic Laboratory (MVDL) from swine (n = 2,537) and cattle (n = 1,028) samples. Prevalence of predominant serotypes changed over time; in swine, S. Typhimurium and S. Derby decreased and S. Agona and S. 4,5,12:i:- increased throughout the study period. In cattle, S. Dublin, S. Montevideo and S. Cerro increased and S. Muenster became less frequent. Median minimum inhibitory concentration (MIC) values and proportion of antibiotic resistant isolates were higher for those recovered from swine compared with cattle, and were particularly high for certain antibiotic-serotype combinations. The proportion of resistant swine isolates was also higher than observed in the NARMS data, probably due to the different cohort of animals represented in each dataset. Results provide insight into the dynamics of antimicrobial resistant Salmonella in livestock in Minnesota, and can help to monitor emerging trends in antimicrobial resistance. PMID:27936204

  2. Serotypes and Antimicrobial Resistance in Salmonella enterica Recovered from Clinical Samples from Cattle and Swine in Minnesota, 2006 to 2015.

    PubMed

    Hong, Samuel; Rovira, Albert; Davies, Peter; Ahlstrom, Christina; Muellner, Petra; Rendahl, Aaron; Olsen, Karen; Bender, Jeff B; Wells, Scott; Perez, Andres; Alvarez, Julio

    2016-01-01

    Salmonellosis remains one of the leading causes of foodborne disease worldwide despite preventive efforts at various stages of the food production chain. The emergence of multi-drug resistant (MDR) non-typhoidal Salmonella enterica represents an additional challenge for public health authorities. Food animals are considered a major reservoir and potential source of foodborne salmonellosis; thus, monitoring of Salmonella strains in livestock may help to detect emergence of new serotypes/MDR phenotypes and to gain a better understanding of Salmonella epidemiology. For this reason, we analyzed trends over a nine-year period in serotypes, and antimicrobial resistance, of Salmonella isolates recovered at the Minnesota Veterinary Diagnostic Laboratory (MVDL) from swine (n = 2,537) and cattle (n = 1,028) samples. Prevalence of predominant serotypes changed over time; in swine, S. Typhimurium and S. Derby decreased and S. Agona and S. 4,5,12:i:- increased throughout the study period. In cattle, S. Dublin, S. Montevideo and S. Cerro increased and S. Muenster became less frequent. Median minimum inhibitory concentration (MIC) values and proportion of antibiotic resistant isolates were higher for those recovered from swine compared with cattle, and were particularly high for certain antibiotic-serotype combinations. The proportion of resistant swine isolates was also higher than observed in the NARMS data, probably due to the different cohort of animals represented in each dataset. Results provide insight into the dynamics of antimicrobial resistant Salmonella in livestock in Minnesota, and can help to monitor emerging trends in antimicrobial resistance.

  3. Trends in Serotype Distribution and Antimicrobial Susceptibility in Salmonella enterica Isolates from Humans in Belgium, 2009 to 2013

    PubMed Central

    Ceyssens, Pieter-Jan; Mattheus, Wesley; Vanhoof, Raymond

    2014-01-01

    The Belgian National Reference Centre for Salmonella received 16,544 human isolates of Salmonella enterica between January 2009 and December 2013. Although 377 different serotypes were identified, the landscape is dominated by S. enterica serovars Typhimurium (55%) and Enteritidis (19%) in a ratio which is inverse to European Union averages. With outbreaks of Salmonella serotypes Ohio, Stanley, and Paratyphi B variant Java as prime examples, 20 serotypes displayed significant fluctuations in this 5-year period. Typhoid strains account for 1.2% of Belgian salmonellosis cases. Large-scale antibiotic susceptibility analyses (n = 4,561; panel of 12 antibiotics) showed declining resistance levels in S. Enteritis and Typhimurium isolates for 8 and 3 tested agents, respectively. Despite low overall resistance to ciprofloxacin (4.4%) and cefotaxime (1.6%), we identified clonal lineages of Salmonella serotypes Kentucky and Infantis displaying rising resistance against these clinically important drugs. Quinolone resistance is mainly mediated by serotype-specific mutations in GyrA residues Ser83 and Asp87 (92.2% not wild type), while an additional ParC_Ser80Ile mutation leads to ciprofloxacin resistance in 95.5% S. Kentucky isolates, which exceeds European averages. Plasmid-mediated quinolone resistance (PMQR) alleles qnrA1 (n = 1), qnrS (n = 9), qnrD1 (n = 4), and qnrB (n = 4) were found in only 3.0% of 533 isolates resistant to nalidixic acid. In cefotaxime-resistant isolates, we identified a broad range of Ambler class A and C β-lactamase genes (e.g., blaSHV-12, blaTEM-52, blaCTX-M-14, and blaCTX-M-15) commonly associated with members of the family Enterobacteriaceae. In conclusion, resistance to fluoroquinolones and cefotaxime remains rare in human S. enterica, but clonal resistant serotypes arise, and continued (inter)national surveillance is mandatory to understand the origin and routes of dissemination thereof. PMID:25385108

  4. [Serotypes of Salmonella in the Republic of Argentina isolated from human and non-human sources, 1979-1981].

    PubMed

    Eiguer, T; Butta, N; Picandet, A M

    1983-01-01

    A total of 49 serotypes were isolated in Argentina during the triennium 1979-1981, from 3,665 Salmonella strains isolated from different sources: human, animal, food and water. The degree of correlation among every one of them was analyzed in order to establish their influence in the cycles of transmission and human infection. S. typhimurium prevailed in human materials, being also isolated from water and animal, although in a smaller degree. Something similar occurred with S. oranienburg. It was observed that S. typhi retained its usual feature of endemic disease. Other serotypes of Salmonella were also found, particularly: S. paratyphi, S. panama, S. derby, S. agona, S. bredeney, S. newport, S. anatum and S. montevideo. From 3,665 Salmonella strains studied, 73.73% were isolated from human sources and the other 26.27% from non human sources, 5.40% corresponding to animal isolations, 15.39% from water and 5.48% from food.

  5. Ingress of Salmonella enterica Typhimurium into tomato leaves through hydathodes.

    PubMed

    Gu, Ganyu; Cevallos-Cevallos, Juan M; van Bruggen, Ariena H C

    2013-01-01

    Internal contamination of Salmonella in plants is attracting increasing attention for food safety reasons. In this study, three different tomato cultivars "Florida Lanai", "Crown Jewel", "Ailsa Craig" and the transgenic line Sp5 of "Ailsa Craig" were inoculated with 1 µl GFP-labeled Salmonella Typhimurium through guttation droplets at concentrations of 10(9) or 10(7) CFU/ml. Survival of Salmonella on/in tomato leaves was detected by both direct plating and enrichment methods. Salmonella cells survived best on/in the inoculated leaves of cultivar "Ailsa Craig" and decreased fastest on/in "Florida Lanai" leaves. Increased guttation in the abscisic acid over-expressing Sp5 plants may have facilitated the entrance of Salmonella into leaves and the colonization on the surface of tomato leaves. Internalization of Salmonella Typhimurium in tomato leaves through guttation drop inoculation was confirmed by confocal laser microscopy. For the first time, convincing evidence is presented that S. enterica can enter tomato leaves through hydathodes and move into the vascular system, which may result in the internal translocation of the bacteria inside plants.

  6. Ciprofloxacin-resistant Salmonella enterica Typhimurium and Choleraesuis from pigs to humans, Taiwan.

    PubMed

    Hsueh, Po-Ren; Teng, Lee-Jene; Tseng, Sung-Pin; Chang, Chao-Fu; Wan, Jen-Hsien; Yan, Jing-Jou; Lee, Chun-Ming; Chuang, Yin-Ching; Huang, Wen-Kuei; Yang, Dine; Shyr, Jainn-Ming; Yu, Kwok-Woon; Wang, Li-Shin; Lu, Jang-Jih; Ko, Wen-Chien; Wu, Jiunn-Jong; Chang, Feng-Yee; Yang, Yi-Chueh; Lau, Yeu-Jun; Liu, Yung-Ching; Liu, Cheng-Yi; Ho, Shen-Wu; Luh, Kwen-Tay

    2004-01-01

    We evaluated the disk susceptibility data of 671 nontyphoid Salmonella isolates collected from different parts of Taiwan from March 2001 to August 2001 and 1,261 nontyphoid Salmonella isolates from the National Taiwan University Hospital from 1996 to 2001. Overall, ciprofloxacin resistance was found in 2.7% (18/671) of all nontyphoid Salmonella isolates, in 1.4% (5/347) of Salmonella enterica serotype Typhimurium and in 7.5% (8/107) in S. enterica serotype Choleraesuis nationwide. MICs of six newer fluoroquinolones were determined for the following isolates: 37 isolates of ciprofloxacin-resistant (human) S. Typhimurium (N = 26) and Choleraesuis (N = 11), 10 isolates of ciprofloxacin-susceptible (MIC <1 mg/mL) (human) isolates of these two serotypes, and 15 swine isolates from S. Choleraesuis (N = 13) and Typhmurium (N = 2) with reduced susceptibility to ciprofloxacin (MIC >0.12 microg/mL). Sequence analysis of the gryA, gyrB, parC, parE, and acrR genes, ciprofloxacin accumulation, and genotypes generated by pulsed-field gel electrophoresis with three restriction enzymes (SpeI, XbaI, and BlnI) were performed. All 26 S. Typhimurium isolates from humans and pigs belonged to genotype I. For S. Choleraesuis isolates, 91% (10/11) of human isolates and 54% (7/13) of swine isolates belonged to genotype B. These two genotypes isolates from humans all exhibited a high-level of resistance to ciprofloxacin (MIC 16-64 mg/mL). They had two-base substitutions in the gyrA gene at codons 83 (Ser83Phe) and 87 (Asp87Gly or Asp87Asn) and in the parC gene at codon 80 (Ser80Arg, Ser80Ile, or Ser84Lys). Our investigation documented that not only did these two S. enterica isolates have a high prevalence of ciprofloxacin resistance nationwide but also that some closely related ciprofloxacin-resistant strains are disseminated from pigs to humans.

  7. [Serotype distribution and antimicrobial susceptibilities of Salmonella strains recovered from environmental samples between 2008-2014].

    PubMed

    Güleşen, Revasiye; Levent, Belkıs; Üvey, Mehmet; Bayrak, Hasan; Akgeyik, Mesut

    2016-07-01

    Despite the measures taken and control applications worldwide, Salmonella infections continue to threat the public health. Since these infections also cause significant economical loss, the salmonellas continue to be forefront globally. The determination of Salmonella serotypes and their sources is important for epidemiological point of view. In this study, serotype distribution and antimicrobial resistance of environmental isolates of Salmonella spp. recovered from the poultry farms, that were send for confirmation and serotyping between seven years period, 2008-2014, were evaluated. Strains isolated from environmental samples that were sent to Public Health Institute, Department of Microbiology Reference Laboratory, National Reference Laboratory for Enteric Pathogens, were inoculated onto Salmonella-Shigella and Xylose Lysine Desoxycholate agar and evaluated after 18-24 hours of incubation at 37°C. The identification of the strains was performed by using standard biochemical tests from the suspected colonies. Strains compatible with Salmonella spp. were serotyped using polyvalent and monovalent Salmonella O and H antisera by slide agglutination method. Antibiotic susceptibility tests were performed and evaluated according to CLSI recommendation using Kirby-Bauer disk diffusion method. In our study, a total of 2011 Salmonella strains were evaluated and 15 different serogroups and 75 different serotypes were identified. The most common Salmonella serotypes were S.Infantis (30.6%), followed by S.Enteritidis (21.8%), S.Typhimurium (6.5%), S.Kottbus (5.2%), S.Tennessee (4.3%), S.Mbandaka (4.1%), S.Indiana (3.9%), S.Kentucky (3%), S.Corvallis (2.5%), S.Paratyphi B (1.9%) and S.Hadar (1.7%). Among the isolates, 50.1% (1008/2011) were found susceptible to all of the tested antimicrobials. The rate of isolates that were resistant to only one drug was found to be 15.6%, whereas 30.9% of the strains showed multi-drug resistance (resistant to ≥ 3 antimicrobial drugs

  8. Glycerol elicits energy taxis of Escherichia coli and Salmonella typhimurium.

    PubMed

    Zhulin, I B; Rowsell, E H; Johnson, M S; Taylor, B L

    1997-05-01

    Escherichia coli and Salmonella typhimurium show positive chemotaxis to glycerol, a chemical previously reported to be a repellent for E. coli. The threshold of the attractant response in both species was 10(-6) M glycerol. Glycerol chemotaxis was energy dependent and coincident with an increase in membrane potential. Metabolism of glycerol was required for chemotaxis, and when lactate was present to maintain energy production in the absence of glycerol, the increases in membrane potential and chemotactic response upon addition of glycerol were abolished. Methylation of a chemotaxis receptor was not required for positive glycerol chemotaxis in E. coli or S. typhimurium but is involved in the negative chemotaxis of E. coli to high concentrations of glycerol. We propose that positive chemotaxis to glycerol in E. coli and S. typhimurium is an example of energy taxis mediated via a signal transduction pathway that responds to changes in the cellular energy level.

  9. Cloning of Salmonella typhimurium DNA encoding mutagenic DNA repair

    SciTech Connect

    Thomas, S.M.; Sedgwick, S.G. )

    1989-11-01

    Mutagenic DNA repair in Escherichia coli is encoded by the umuDC operon. Salmonella typhimurium DNA which has homology with E. coli umuC and is able to complement E. coli umuC122::Tn5 and umuC36 mutations has been cloned. Complementation of umuD44 mutants and hybridization with E. coli umuD also occurred, but these activities were much weaker than with umuC. Restriction enzyme mapping indicated that the composition of the cloned fragment is different from the E. coli umuDC operon. Therefore, a umu-like function of S. typhimurium has been found; the phenotype of this function is weaker than that of its E. coli counterpart, which is consistent with the weak mutagenic response of S. typhimurium to UV compared with the response in E. coli.

  10. Polyamines Are Required for Virulence in Salmonella enterica Serovar Typhimurium

    PubMed Central

    Jelsbak, Lotte; Thomsen, Line Elnif; Wallrodt, Inke; Jensen, Peter Ruhdal; Olsen, John Elmerdahl

    2012-01-01

    Sensing and responding to environmental cues is a fundamental characteristic of bacterial physiology and virulence. Here we identify polyamines as novel environmental signals essential for virulence of Salmonella enterica serovar Typhimurium, a major intracellular pathogen and a model organism for studying typhoid fever. Central to its virulence are two major virulence loci Salmonella Pathogenicity Island 1 and 2 (SPI1 and SPI2). SPI1 promotes invasion of epithelial cells, whereas SPI2 enables S. Typhimurium to survive and proliferate within specialized compartments inside host cells. In this study, we show that an S. Typhimurium polyamine mutant is defective for invasion, intracellular survival, killing of the nematode Caenorhabditis elegans and systemic infection of the mouse model of typhoid fever. Virulence of the mutant could be restored by genetic complementation, and invasion and intracellular survival could, as well, be complemented by the addition of exogenous putrescine and spermidine to the bacterial cultures prior to infection. Interestingly, intracellular survival of the polyamine mutant was significantly enhanced above the wild type level by the addition of exogenous putrescine and spermidine to the bacterial cultures prior to infection, indicating that these polyamines function as an environmental signal that primes S. Typhimurium for intracellular survival. Accordingly, experiments addressed at elucidating the roles of these polyamines in infection revealed that expression of genes from both of the major virulence loci SPI1 and SPI2 responded to exogenous polyamines and was reduced in the polyamine mutant. Together our data demonstrate that putrescine and spermidine play a critical role in controlling virulence in S. Typhimurium most likely through stimulation of expression of essential virulence loci. Moreover, our data implicate these polyamines as key signals in S. Typhimurium virulence. PMID:22558361

  11. Structural characterization of the Salmonella typhimurium LT2 umu operon

    SciTech Connect

    Thomas, S.M.; Crowne, H.M.; Pidsley, S.C.; Sedgwick, S.G. )

    1990-09-01

    The umuDC operon of Escherichia coli encodes functions required for mutagenesis induced by radiation and a wide variety of chemicals. The closely related organism Salmonella typhimurium is markedly less mutable than E. coli, but a umu homolog has recently been identified and cloned from the LT2 subline. In this study the nucleotide sequence and structure of the S. typhimurium LT2 umu operon have been determined and its gene products have been identified so that the molecular basis of umu activity might be understood more fully. S. typhimurium LT2 umu consists of a smaller 417-base-pair (bp) umuD gene ending 2 bp upstream of a larger 1,266-bp umuC gene. The only apparent structural difference between the two operons is the lack of gene overlap. An SOS box identical to that found in E. coli is present in the promoter region upstream of umuD. The calculated molecular masses of the umuD and umuC gene products were 15.3 and 47.8 kilodaltons, respectively, which agree with figures determined by transpositional disruption and maxicell analysis. The S. typhimurium and E. coli umuD sequences were 68% homologous and encoded products with 71% amino acid identity; the umuC sequences were 71% homologous and encoded products with 83% amino acid identity. Furthermore, the potential UmuD cleavage site and associated catalytic sites could be identified. Thus the very different mutagenic responses of S. typhimurium LT2 and E. coli cannot be accounted for by gross differences in operon structure or gene products. Rather, the ability of the cloned S. typhimurium umuD gene to give stronger complementation of E. coli umuD77 mutants in the absence of a functional umuC gene suggests that Salmonella UmuC protein normally constrains UmuD protein activity.

  12. The distribution of serotype-specific plasmids among different subgroups of strains of Salmonella enterica serotype Enteritidis: characterization of molecular variants by restriction enzyme fragmentation patterns.

    PubMed Central

    Rankin, S. C.; Benson, C. E.; Platt, D. J.

    1995-01-01

    Four hundred and thirty-four isolates of Salmonella enterica serotype Enteritidis were studied. They were grouped into five subsets defined by either the collection criteria or the parameter which formed the basis for subsequent analysis. Seventy-seven per cent harboured the serotype-specific plasmid (SSP). In 55% of the isolates this was the sole plasmid. Molecular variation in the SSP was detected in 17 (5%) of the isolates on the basis of restriction enzyme fragmentation pattern (REFP) analysis using Pst I and Sma I. The SSP variants were further characterized using additional restriction enzymes chosen to optimize the information content and analysed using a coefficient of similarity. A variant SSP designated pOG690 showed greater resemblance to the SSP of Salmonella enterica serotype Typhimurium than Enteritidis; 89% and 68% respectively for Pst I and 79% and 55% respectively for Sma I. In respect of the Pst I data pOG690 shared at least 55 kb of DNA with the Typhimurium SSP and 37 kb with the SSP of Enteritidis. This variant was associated with poultry (duck, goose, chicken) and all isolates belonged to phage type 9b. Other variants were associated with phage types 4, 6, 6a, 9a, 11, 15 and 24. The epidemiological implications of these results are discussed. Images Fig. 1 PMID:7867741

  13. Metabolism of Pyrimidines and Pyrimidine Nucleosides by Salmonella typhimurium

    PubMed Central

    Beck, Christoph F.; Ingraham, John L.; Neuhard, Jan; Thomassen, Elisabeth

    1972-01-01

    The pathways by which uracil, cytosine, uridine, cytidine, deoxyuridine, and deoxycytidine are metabolized by Salmonella typhimurium are established. The various 5-fluoropyrimidine analogues are shown to exert their toxic effects only after having been converted to the nucleotide level, and these conversions are shown to be catalyzed by the same enzymes which similarly convert the natural substrates. Methods for isolating mutant strains blocked in various steps of metabolism of pyrimidine bases and nucleosides are described. PMID:4259664

  14. Salmonella Typhimurium exploits inflammation to its own advantage in piglets

    PubMed Central

    Chirullo, Barbara; Pesciaroli, Michele; Drumo, Rosanna; Ruggeri, Jessica; Razzuoli, Elisabetta; Pistoia, Claudia; Petrucci, Paola; Martinelli, Nicola; Cucco, Lucilla; Moscati, Livia; Amadori, Massimo; Magistrali, Chiara F.; Alborali, Giovanni L.; Pasquali, Paolo

    2015-01-01

    Salmonella Typhimurium (S. Typhimurium) is responsible for foodborne zoonotic infections that, in humans, induce self-limiting gastroenteritis. The aim of this study was to evaluate whether the wild-type strain S. Typhimurium (STM14028) is able to exploit inflammation fostering an active infection. Due to the similarity between human and porcine diseases induced by S. Typhimurium, we used piglets as a model for salmonellosis and gastrointestinal research. This study showed that STM14028 is able to efficiently colonize in vitro porcine mono-macrophages and intestinal columnar epithelial (IPEC-J2) cells, and that the colonization significantly increases with LPS pre-treatment. This increase was then reversed by inhibiting the LPS stimulation through LPS antagonist, confirming an active role of LPS stimulation in STM14028-intracellular colonization. Moreover, LPS in vivo treatment increased cytokines blood level and body temperature at 4 h post infection, which is consistent with an acute inflammatory stimulus, capable to influence the colonization of STM14028 in different organs and tissues. The present study proves for the first time that in acute enteric salmonellosis, S. Typhimurium exploits inflammation for its benefit in piglets. PMID:26441914

  15. Salmonella Typhimurium and Multidirectional Communication in the Gut

    PubMed Central

    Gart, Elena V.; Suchodolski, Jan S.; Welsh, Thomas H.; Alaniz, Robert C.; Randel, Ronald D.; Lawhon, Sara D.

    2016-01-01

    The mammalian digestive tract is home to trillions of microbes, including bacteria, archaea, protozoa, fungi, and viruses. In monogastric mammals the stomach and small intestine harbor diverse bacterial populations but are typically less populated than the colon. The gut bacterial community (microbiota hereafter) varies widely among different host species and individuals within a species. It is influenced by season of the year, age of the host, stress and disease. Ideally, the host and microbiota benefit each other. The host provides nutrients to the microbiota and the microbiota assists the host with digestion and nutrient metabolism. The resident microbiota competes with pathogens for space and nutrients and, through this competition, protects the host in a phenomenon called colonization resistance. The microbiota participates in development of the host immune system, particularly regulation of autoimmunity and mucosal immune response. The microbiota also shapes gut–brain communication and host responses to stress; and, indeed, the microbiota is a newly recognized endocrine organ within mammalian hosts. Salmonella enterica serovar Typhimurium (S. Typhimurium hereafter) is a food-borne pathogen which adapts to and alters the gastrointestinal (GI) environment. In the GI tract, S. Typhimurium competes with the microbiota for nutrients and overcomes colonization resistance to establish infection. To do this, S. Typhimurium uses multiple defense mechanisms to resist environmental stressors, like the acidic pH of the stomach, and virulence mechanisms which allow it to invade the intestinal epithelium and disseminate throughout the host. To coordinate gene expression and disrupt signaling within the microbiota and between host and microbiota, S. Typhimurium employs its own chemical signaling and may regulate host hormone metabolism. This review will discuss the multidirectional interaction between S. Typhimurium, host and microbiota as well as mechanisms that allow S

  16. Identification of Salmonella serotypes isolated from cantaloupe and chile pepper production systems in Mexico by PCR-restriction fragment length polymorphism.

    PubMed

    Gallegos-Robles, Miguel A; Morales-Loredo, Alberto; Alvarez-Ojeda, Genoveva; Vega-P, Adrián; Chew-M, Yazmín; Velarde, Sixto; Fratamico, Pina

    2008-11-01

    A study was conducted in 2006 to determine the prevalence of Salmonella on three cantaloupe farms in Matamoros, Coahuila, Mexico, and on one farm that cultivates chile peppers var. Bell in Culiacán, Sinaloa, Mexico. Samples from cantaloupe farms consisted of cantaloupe rinses, irrigation water, water from furrows in the field, and workers' hands. Samples from the chile pepper farm consisted of rinses of chile peppers obtained at the field, pepper rinses obtained at the packing house, and irrigation water from the field. A total of 55 samples were obtained from both production systems. Twelve and 10 samples from the cantaloupe and chile pepper production systems, respectively, tested positive for Salmonella according to a traditional culture method. The difference between the proportion of Salmonella-positive samples from the cantaloupe production system (12 of 28 = 0.43) and the chile pepper production system (10 of 27 = 0.37) was not statistically significant (P > 0.05). A PCR-restriction fragment length polymorphism (RFLP) method based on the fliC gene was used to determine the serotype of the isolates. Salmonella Typhimurium was the only serotype found associated with the cantaloupe production system, whereas both Salmonella Typhimurium and Enteritidis serotypes were found associated with the chile pepper production system. Results showed that 91% (20 of 22) and 9% (2 of 22) of the isolates from both agricultural systems matched with the Salmonella Typhimurium and Salmonella Enteritidis reference strain restriction profiles, respectively. This study demonstrates the utility of the PCR-RFLP technique for determining the serotypes of Salmonella isolates obtained from cantaloupe and chile pepper production systems.

  17. Salmonella enterica serovar Typhimurium in Mauritius linked to consumption of marlin mousse.

    PubMed

    Issack, Mohammad I; Hendriksen, Rene S; Lun, Phimy Lan Keng; Lutchun, Ram K S; Aarestrup, Frank M

    2009-01-01

    We report the first outbreak of salmonellosis caused by consumption of contaminated marlin mousse. Between 29 October and 5 November 2008, at least 53 persons developed diarrheal illness, all with a history of eating marlin mousse. Salmonella spp. that did not produce gas from glucose was isolated from stools of 26 affected patients and blood culture from one patient. Salmonella sp. isolates with the same phenotype were isolated in three samples of marlin mousse manufactured on 27 October 2008. The constituents of the mousse were smoked marlin, raw eggs, bovine gelatin, oil, and cream. A laboratory investigation of one sample of marlin mousse manufactured 3 days later, and the individual ingredients sampled a week after production of the contaminated batch were all negative for Salmonella. Serotyping and minimum inhibitory concentration determination were performed on 12 patient isolates related to the outbreak and two mousse isolates. All isolates belonged to Salmonella serovar Typhimurium and were pansusceptible to all antimicrobials tested. Pulsed-field gel electrophoresis revealed that all the isolates were indistinguishable, thus implicating the mousse as the vehicle of the outbreak.

  18. Development of a rapid serotyping method for Salmonella enterica using serotype-specific single-nucleotide polymorphisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella enterica subsp. enterica serotype Enteriditis (S. Enteriditis) is the leading cause of salmonellosis worldwide, including the USA. Many S. enterica serotypes known to cause foodborne disease are associated with broiler meat contamination. While some serotypes are specific to birds (S. e...

  19. Persistence of salmonella Typhimurium in Nopal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Having documented information available on the capability of Salmonella to remain in the cladode tissue it is important to understand the role of nopal on the lifecycle of enteropathogenic bacteria in humans, as well as for management and control programs of theses pathogens in plants. Because of th...

  20. Persistence of salmonella typhimurium in nopal cladodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fresh produce associated outbreaks have increased in the last few years. E.coli O157:H7 and Salmonella have been causative agents of infection in these outbreaks. Fresh produce is consumed raw, and in the absence of terminal kill treatment, it is imperative to understand sources of contamination o...

  1. Immune reaction and survivability of salmonella typhimurium and salmonella infantis after infection of primary avian macrophages.

    PubMed

    Braukmann, Maria; Methner, Ulrich; Berndt, Angela

    2015-01-01

    Salmonella serovars are differentially able to infect chickens. The underlying causes are not yet fully understood. Aim of the present study was to elucidate the importance of Salmonella Pathogenicity Island 1 and 2 (SPI-1 and -2) for the virulence of two non-host-specific, but in-vivo differently invasive, Salmonella serovars in conjunction with the immune reaction of the host. Primary avian splenic macrophages were inoculated with Salmonella enterica sub-species enterica serovar (S.) Typhimurium and S. Infantis. The number and viability of intracellular bacteria and transcription of SPI-1 and -2 genes by the pathogens, as well as transcription of immune-related proteins, surface antigen expression and nitric oxide production by the macrophages, were compared at different times post inoculation. After infection, both of the Salmonella serovars were found inside the primary macrophages. Invasion-associated SPI-1 genes were significantly higher transcribed in S. Infantis- than S. Typhimurium-infected macrophages. The macrophages counteracted the S. Infantis and S. Typhimurium infection with elevated mRNA expression of inducible nitric oxide synthase (iNOS), interleukin (IL)-12, IL-18 and lipopolysaccharide-induced tumor necrosis factor alpha factor (LITAF) as well as with an increased synthesis of nitric oxide. Despite these host cell attacks, S. Typhimurium was better able than S. Infantis to survive within the macrophages and transcribed higher rates of the SPI-2 genes spiC, ssaV, sifA, and sseA. The results showed similar immune reactions of primary macrophages after infection with both of the Salmonella strains. The more rapid and stronger transcription of SPI-2-related genes by intracellular S. Typhimurium compared to S. Infantis might be responsible for its better survival in avian primary macrophages.

  2. Detoxification of Salmonella typhimurium Lipopolysaccharide by Ionizing Radiation1

    PubMed Central

    Previte, Joseph J.; Chang, Y.; El-Bisi, H. M.

    1967-01-01

    The efficiency of ionizing radiation in detoxifying the lethal determinant(s) of the lipopolysaccharide (LPS) of Salmonella typhimurium, S. enteritidis, and Escherichia coli in aqueous solution and associated with heat-killed S. typhimurium cells in suspension decreased with doses above 1 Mrad. The 50% end point of inactivation was more than 7.0 Mrad for heat-killed salmonellae and 4.8, 4.5, and 1.0 Mrad for the LPS of S. typhimurium, S. enteritidis, and E. coli, respectively. After exposure to 20 Mrad, S. typhimurium LPS retained a small portion of its lethal properties although the ld50 was much greater than 9.5 mg per 20-g mouse. However, at −184 C, no inactivation of the lethal determinant(s) occurred after exposure to as much as 20 Mrad. This demonstrated the significance of the indirect effect and the mobility and formation of free radicals. At 22 C, the optical density at 400 mμ increased and the pH decreased with increasing radiation dose, but no qualitative changes were observed in the infrared spectrum. No change was observed in the pyrogenicity of S. typhimurium LPS; a slight decrease in antigenicity was revealed when 6 days, but not when 1 day, elapsed between vaccination and challenge in the mouse protection test. The results were interpreted as evidence of the existence of two or more lethal and antigenic determinants. The differential effect of radiation on these properties and on the pyrogenic component(s) probably are indicative of separate functional sites for lethal, antigenic, and pyrogenic activities. PMID:5337846

  3. Serotype distribution and antibiotic resistance of Salmonella in food-producing animals in Shandong province of China, 2009 and 2012.

    PubMed

    Lai, Jing; Wu, Congming; Wu, Chenbin; Qi, Jing; Wang, Yang; Wang, Hongyu; Liu, Yuqing; Shen, Jianzhong

    2014-06-16

    The aims of this study were to investigate the serotype distribution, genetic relationships and antibiotic resistance of Salmonella from food-producing animals in Shandong province of China in 2009 and 2012. A total of 362 out of 1825 samples from chickens, 53 out of 445 samples from ducks, and 50 out of 692 samples from pigs were positive for Salmonella. Isolates were subjected to serotyping, antibiotic susceptibility testing (15 antibiotics) and pulsed-field gel electrophoresis (PFGE). The most common serotypes recovered in the chicken samples were Enteritidis (n=294, 81.2%) and Indiana (n=45, 12.4%). For ducks, Cremieu (n=25, 47.2%), Indiana (n=13, 24.5%) and Typhimurium (n=9, 17%) were frequently isolated. In the pig samples, Derby (n=29, 58%), Typhimurium (n=9, 18%), and Enteritidis (n=6, 12%) were the most common serovars. PFGE results indicated that clonal dissemination of each serovar was prevalent, and that the Salmonella found on the poultry carcasses was caused by cross-contamination in the abattoirs. More than 99% of the Salmonella isolates collected were resistant to at least one antibiotic. The Salmonella resistance rates for 15 antibiotics in 2012 were significantly higher than those in 2009. In 2012, the highest resistance was to nalidixic acid (95.9%), followed by sulphafurazole (78.2%) and ampicillin (72.3%); the lowest levels of resistance were to kanamycin (40.1%) and amikacin (38.7%). Additionally, 41.5% and 42.2% of the Salmonella were resistant to ciprofloxacin and ceftiofur, respectively. Noticeably, 25% of the serovar Enteritidis and all of the serovar Indiana were resistant to at least 10 antibiotics in 2012. The increasing trend of antibiotic resistance in Shandong province indicates the need for more careful use of antibiotics.

  4. Using a surface plasmon resonance biosensor for rapid detection of salmonella typhimurium in chicken carcass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chicken is one of the most popular meat products in the world. Salmonella Typhimurium is a common foodborne pathogens associated with the processing of poultry. An optical Surface Plasmon Resonance (SPR) biosensor was sensitive to the presence of Salmonella Typhimurium in chicken carcass. The Spr...

  5. Photonic plasmid stability of transformed Salmonella typhimurium: A comparison of three unique plasmids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acquiring a highly stable photonic plasmid in transformed Salmonella typhimurium for use in biophotonic studies of bacterial tracking in vivo is critical to experimental paradigm development. The objective of this study was to determine stability of transformed Salmonella typhimurium (S. typh-lux) u...

  6. Photonic Plasmid Stability of Transformed Salmonella Typhimurium: A Comparison of Three Unique Plasmids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Acquiring a highly stable photonic plasmid in transformed Salmonella Typhimurium for use in biophotonic studies of bacterial tracking in vivo is critical to experimental paradigm development. The objective of this study was to determine stability of transformed Salmonella Typhimurium (S....

  7. Influence of hard water ions on the growth rate of Salmonella Typhimurium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of magnesium and calcium ions in process water on the growth of Salmonella typhimurium was evaluated to address the concerns for food quality and safety. Salmonella typhimurium was exposed to media containing 500 ppm and 1000 ppm of magnesium and calcium ions for 45 minutes followed by...

  8. Detection of Salmonella typhimurium using polyclonal antibody immobilized magnetostrictive biosensors

    NASA Astrophysics Data System (ADS)

    Guntupalli, R.; Hu, Jing; Lakshmanan, Ramji S.; Wan, Jiehui; Huang, Shichu; Yang, Hong; Barbaree, James M.; Huang, T. S.; Chin, Bryan A.

    2006-05-01

    Novel mass-sensitive, magnetostrictive sensors have a characteristic resonant frequency that can be determined by monitoring the magnetic flux emitted by the sensor in response to an applied, time varying, magnetic field. This magnetostrictive platform has a unique advantage over conventional sensor platforms in that measurement is wireless or remote. These biosensors can thus be used in-situ for detecting pathogens and biological threat agents. In this work, we have used a magnetostrictive platform immobilized with a polyclonal antibody (the bio-molecular recognition element) to form a biosensor for the detection of Salmonella typhimurium. Upon exposure to solutions containing Salmonella typhimurium bacteria, the bacteria were bound to the sensor and the additional mass of the bound bacteria caused a shift in the sensor's resonant frequency. Responses of the sensors to different concentrations of S. typhimurium were recorded and the results correlated with those obtained from scanning electron microscopy (SEM) images of samples. Good agreement between the measured number of bound bacterial cells (attached mass) and frequency shifts were obtained. The longevity and specificity of the selected polyclonal antibody were also investigated and are reported.

  9. QCM-based aptamer selection and detection of Salmonella typhimurium.

    PubMed

    Wang, Lijun; Wang, Ronghui; Chen, Fang; Jiang, Tieshan; Wang, Hong; Slavik, Michael; Wei, Hua; Li, Yanbin

    2017-04-15

    In this study, quartz crystal microbalance (QCM) was used to select aptamers against Salmonella typhimurium. To increase the success rate of Systematic Evolution of Ligands Exponential Enrichment (SELEX), the affinity of DNA pool in each round was simultaneously tracked using QCM in order to avoid the loss of high-quality aptamers. When the frequency change reached a maximum value after several rounds of selection and counter-selection, the candidate pool was cloned and sequenced. Out of three aptamer candidates, aptamer B5 showed high specificity and binding affinity with dissociation constant (Kd value) of 58.5nM, and was chosen for further studies. Subsequently, a QCM-based aptasensor was developed to detect S. typhimurium. This aptasensor was able to detect 10(3)CFU/mL of S. typhimurium with less than 1h. This study demonstrated QCM-based selection could be more effective selection of aptamers and QCM-based aptasensor could be more sensitive in detecting S. typhimurium.

  10. Serotypes and antimicrobial susceptibility of Salmonella spp. isolated from farm animals in China.

    PubMed

    Kuang, Xiuhua; Hao, Haihong; Dai, Menghong; Wang, Yulian; Ahmad, Ijaz; Liu, Zhenli; Zonghui, Yuan

    2015-01-01

    Salmonella spp. can indirectly infect humans via transfer from animals and animal-derived food products, and thereby cause potentially fatal diseases. Therefore, gaining an understanding of Salmonella infection in farm animals is increasingly important. The aim of this study was to identify the distribution of serotypes in Salmonella samples isolated from chickens (n = 837), pigs (n = 930), and dairy cows (n = 418) in central China (Henan, Hubei, and Hunan provinces) in 2010-2011, and investigate the susceptibility of strains to antimicrobial agents. Salmonella isolates were identified by PCR amplification of the invA gene, serotypes were determined by using a slide agglutination test for O and H antigens, and susceptibility to 24 antimicrobials was tested using the agar dilution method. In total, 248 Salmonella strains were identified: 105, 105, and 38 from chickens, dairy cows, and pigs, respectively. Additionally, 209 strains were identified in diseased pigs from the Huazhong Agricultural University veterinary hospital. Among these 457 strains, the dominant serotypes were Typhimurium in serogroup B, IIIb in serogroup C, and Enteritidis in serogroup D. In antimicrobial susceptibility tests, 41.14% of Salmonella spp. were susceptible to all antimicrobial agents, 48.14% were resistant to at least one, and 34.72% were resistant to more than three classes. Strains were highly resistant to sulfamethoxazole-trimethoprim (39.61%), nalidixic acid (39.17%), doxycycline (28.22%), and tetracycline (27.58%). Resistance to cephalosporins and fluoroquinolones ranged from 5.25 to 7.44% and 19.04 to 24.51%, respectively. Among penicillin-resistant and cephalosporin-resistant strains, 25 isolates produced extended-spectrum β-lactamases (ESBLs). The multidrug-resistant and ESBL-producing Salmonella strains identified in healthy animals here will present a challenge for veterinary medicine and farm animal husbandry, and could also pose a threat to public health. The level of

  11. Dispersal of Salmonella Typhimurium by rain splash onto tomato plants.

    PubMed

    Cevallos-Cevallos, Juan M; Danyluk, Michelle D; Gu, Ganyu; Vallad, Gary E; van Bruggen, Ariena H C

    2012-03-01

    Outbreaks of Salmonella enterica have increasingly been associated with tomatoes and traced back to production areas, but the spread of Salmonella from a point source onto plants has not been described. Splash dispersal by rain could be one means of dissemination. Green fluorescent protein-labeled, kanamycin-resistant Salmonella enterica sv. Typhimurium dispensed on the surface of plastic mulch, organic mulch, or soil at 10⁸ CFU/cm² was used as the point source in the center of a rain simulator. Tomato plants in soil with and without plastic or organic mulch were placed around the point source, and rain intensities of 60 and 110 mm/h were applied for 5, 10, 20, and 30 min. Dispersal of Salmonella followed a negative exponential model with a half distance of 3 cm at 110 mm/h. Dispersed Salmonella survived for 3 days on tomato leaflets, with a total decline of 5 log and an initial decimal reduction time of 10 h. Recovery of dispersed Salmonella from plants at the maximum observed distance ranged from 3 CFU/g of leaflet after a rain episode of 110 mm/h for 10 min on soil to 117 CFU/g of leaflet on plastic mulch. Dispersal of Salmonella on plants with and without mulch was significantly enhanced by increasing rain duration from 0 to 10 min, but dispersal was reduced when rainfall duration increased from 10 to 30 min. Salmonella may be dispersed by rain to contaminate tomato plants in the field, especially during rain events of 10 min and when plastic mulch is used.

  12. Serotype Distribution of Salmonella Isolates from Turkey Ground Meat and Meat Parts

    PubMed Central

    Erol, Irfan; Goncuoglu, Muammer; Ayaz, Naim Deniz; Ellerbroek, Lüppo; Bilir Ormanci, Fatma Seda; Iseri Kangal, Ozlem

    2013-01-01

    The aim of the study was to find out the serotype distribution of 169 Salmonella colonies recovered from 112 Salmonella positive ground turkey (115 colonies) and 52 turkey meat parts (54 colonies). Out of 15 Salmonella serotypes: S. Corvallis, S. Kentucky, S. Bredeney, S. Virchow, S. Saintpaul and S. Agona were identified as the predominant serovars at the rates of 27%, 13%, 12%, 12%, 11%, and 10%, respectively. Other serotypes were below 6% of the total isolates. All S. Kentucky and S. Virchow and most of the S. Corvallis (39/46) and S. Heidelberg (9/9) serotypes were recovered from ground turkey. The results indicate that turkey ground meat and meat parts were contaminated with quite distinct Salmonella serotypes. This is the first study reporting Salmonella serotype distribution in turkey meat and S. Corvallis as predominant serotype in poultry meat in Turkey. PMID:23936785

  13. Serotype distribution of Salmonella isolates from turkey ground meat and meat parts.

    PubMed

    Erol, Irfan; Goncuoglu, Muammer; Ayaz, Naim Deniz; Ellerbroek, Lüppo; Ormanci, Fatma Seda Bilir; Kangal, Ozlem Iseri

    2013-01-01

    The aim of the study was to find out the serotype distribution of 169 Salmonella colonies recovered from 112 Salmonella positive ground turkey (115 colonies) and 52 turkey meat parts (54 colonies). Out of 15 Salmonella serotypes: S. Corvallis, S. Kentucky, S. Bredeney, S. Virchow, S. Saintpaul and S. Agona were identified as the predominant serovars at the rates of 27%, 13%, 12%, 12%, 11%, and 10%, respectively. Other serotypes were below 6% of the total isolates. All S. Kentucky and S. Virchow and most of the S. Corvallis (39/46) and S. Heidelberg (9/9) serotypes were recovered from ground turkey. The results indicate that turkey ground meat and meat parts were contaminated with quite distinct Salmonella serotypes. This is the first study reporting Salmonella serotype distribution in turkey meat and S. Corvallis as predominant serotype in poultry meat in Turkey.

  14. The effect of temperature on different Salmonella serotypes during warm seasons in a Mediterranean climate city, Adelaide, Australia.

    PubMed

    Milazzo, A; Giles, L C; Zhang, Y; Koehler, A P; Hiller, J E; Bi, P

    2016-04-01

    Changing trends in foodborne disease are influenced by many factors, including temperature. Globally and in Australia, warmer ambient temperatures are projected to rise if climate change continues. Salmonella spp. are a temperature-sensitive pathogen and rising temperature can have a substantial effect on disease burden affecting human health. We examined the relationship between temperature and Salmonella spp. and serotype notifications in Adelaide, Australia. Time-series Poisson regression models were fit to estimate the effect of temperature during warmer months on Salmonella spp. and serotype cases notified from 1990 to 2012. Long-term trends, seasonality, autocorrelation and lagged effects were included in the statistical models. Daily Salmonella spp. counts increased by 1·3% [incidence rate ratio (IRR) 1·013, 95% confidence interval (CI) 1·008-1·019] per 1 °C rise in temperature in the warm season with greater increases observed in specific serotype and phage-type cases ranging from 3·4% (IRR 1·034, 95% CI 1·008-1·061) to 4·4% (IRR 1·044, 95% CI 1·024-1·064). We observed increased cases of S. Typhimurium PT9 and S. Typhimurium PT108 notifications above a threshold of 39 °C. This study has identified the impact of warm season temperature on different Salmonella spp. strains and confirms higher temperature has a greater effect on phage-type notifications. The findings will contribute targeted information for public health policy interventions, including food safety programmes during warmer weather.

  15. HtpG contributes to Salmonella Typhimurium intestinal persistence in pigs.

    PubMed

    Verbrugghe, Elin; Van Parys, Alexander; Leyman, Bregje; Boyen, Filip; Haesebrouck, Freddy; Pasmans, Frank

    2015-10-14

    Salmonella enterica subspecies enterica serovar Typhimurium (Salmonella Typhimurium) contamination of pork, is one of the major sources of human salmonellosis. The bacterium is able to persist and hide in asymptomatic carrier animals, generating a reservoir for Salmonella transmission to other animals and humans. Mechanisms involved in Salmonella persistence in pigs remain poorly understood. In the present study, we demonstrate that the Salmonella htpG gene, encoding a homologue of the eukaryotic heat shock protein 90, contributes to Salmonella Typhimurium persistence in intestine-associated tissues of pigs, but not in the tonsils. HtpG does not seem to play an important role during the acute phase of infection. The contribution to persistence was shown to be associated with htpG-dependent Salmonella invasion and survival in porcine enterocytes and macrophages. These results reveal the role of HtpG as a virulence factor contributing to Salmonella persistence in pigs.

  16. Genetic characterization of Salmonella typhimurium LT2 ara mutations.

    PubMed

    Lee, J H; Nishitani, J; Wilcox, G

    1984-04-01

    Seventeen independently isolated L-arabinose utilization-deficient mutants of Salmonella typhimurium LT2 were characterized. Four complementation groups (araA, araB, araC, and araD) were identified and were equivalent to the same genes in the ara system in Escherichia coli. The order of the four genes was determined to be araD-araA-araB-araC-leu. Two transcription units were found: the araBAD operon was transcribed counterclockwise, and the araC gene was transcribed clockwise.

  17. Control of the receptor for galactose taxis in Salmonella typhimurium.

    PubMed

    Fahnestock, M; Koshland, D E

    1979-02-01

    The chemotactic response to galactose in wild-type Salmonella typhimurium is not inducible by galactose, but is inducible by fucose, a non-metabolizable analog. In a galactokinase mutant, however, the galactose receptor is inducible by galactose. These data indicate that the concentration of free galactose in the cell controls the levels of the galactose receptor. The intensities of the chemotactic responses were found to vary in proportion to the concentration of galactose receptors. In bacteria with higher levels of galactose receptors, the ribose response is inhibited by galactose. This supports the model in which the ribose and galactose receptors compete for a common component of the signaling system.

  18. [Various Salmonella serotypes isolated at a sewage purification plant in a large city over a one-year period].

    PubMed

    Sobotta, B; Schüsseler, G; Gerhardt, G G; Teitge, E; Gundermann, K O

    1986-04-01

    The paper offers the results of a one-year-survey of Salmonella-serotypes in a municipal sewage-purification plant with a capacity of roughly 70,000 m3 per day. Findings of a quantitative study had shown Salmonella-maxima in the activated-sludge-basin. This suggested specialized Salmonella-serotypes, resident in this part of the plant as a possible explanation which was to be verified by this study. On ten days samples were taken from the inlet, and the outlet of the primary-sedimentation-tank, the outlet of the activated-sludge-basin and the effluent of the final sedimentation-basin. A combination of membrane-filtration and MPN-Method with a fifefold enrichment in 2.5% tetrathionate was applied for salmonella isolation. Plating was done on malachit-green-chinablue-lactose-agar followed by serological typing. 1,587 strains representing 38 different serotypes (Table 1) were identified with S. typhi-murium (Fig. 1) accounting for 36% of the isolations followed by S. bovis-morbificans, S. hadar (Fig. 2) and S. panama. None of the serotypes found showed a preference of a special sampling point. The qualitative and quantitative distribution of Salmonella in the plant seems to depend on the Salmonella contents of the entering waste water mainly. The greatest variety of Salmonella-serotypes was located in the activated-sludge-basin (Table 2) where oxygen-enrichment seems to result in the best ecological conditions for Salmonella survival. 3.3% of 722 strains examined did not produce hydrogen-sulphide (Table 3) and some showed damaged flagella-antigens. As a possible explanation toxic influences in the sewage are discussed. The epidemiological links between findings of Salmonella in sewage and in man of the same area are established and results differing in some aspects explained by the high rate of unknown infections. The existence of an autochthonous Salmonella-population in the sewage plant could not be proved.

  19. Induction of seroconversion and persistence of Salmonella Typhimurium in pigs are strain dependent.

    PubMed

    Van Parys, Alexander; Boyen, Filip; Leyman, Bregje; Verbrugghe, Elin; Maes, Dominiek; Haesebrouck, Freddy; Pasmans, Frank

    2013-09-01

    Foodborne salmonellosis is one of the most important bacterial zoonotic diseases worldwide. Salmonella Typhimurium is the serovar most frequently isolated from persistently infected slaughter pigs in Europe. Salmonella Typhimurium pathogenesis is host species specific. In addition, differences in in vitro behaviour of Salmonella Typhimurium strains have also been described, which may be reflected by a different course of infection within a host species. We compared the course of a Salmonella Typhimurium infection in pigs, using two Salmonella Typhimurium strains that were able to interfere with MHC II expression on porcine macrophages to a different extent in vitro. After experimental inoculation, blood and faecal samples from all pigs were collected at regular time points. At 40 days post inoculation (pi), animals were euthanized and tissue samples were bacteriologically analysed. The proportion of serologically positive piglets at 33 days pi was significantly higher in pigs that were inoculated with the strain that did not downregulate MHC II expression in vitro. Furthermore, this strain was less frequently shed and isolated in lower numbers from tonsils and ileocaecal lymph nodes than the strain that was able to markedly downregulate MHC II expression in vitro. We thus found that the delayed onset of seroconversion after oral inoculation of piglets with a particular Salmonella Typhimurium strain coincided with higher faecal shedding and increased persistence. Strain specific differences in Salmonella pathogenesis might thus have repercussions on the serological detection of Salmonella Typhimurium infections in pigs.

  20. Characterization of Salmonella enterica serovar Typhimurium aconitase A.

    PubMed

    Baothman, Othman A S; Rolfe, Matthew D; Green, Jeffrey

    2013-06-01

    Aconitases (Acn) are iron-sulfur proteins that catalyse the reversible isomerization of citrate and isocitrate via the intermediate cis-aconitate in the Krebs cycle. Some Acn proteins are bi-functional and under conditions of iron starvation and oxidative stress lose their iron-sulfur clusters and become post-transcriptional regulators by binding specific mRNA targets. Many bacterial species possess two genetically distinct aconitase proteins, AcnA and AcnB. Current understanding of the regulation and functions of AcnA and AcnB in dual Acn bacteria is based on a model developed in Escherichia coli. Thus, AcnB is the major Krebs cycle enzyme expressed during exponential growth, whereas AcnA is a more stable, stationary phase and stress-induced enzyme, and both E. coli Acns are bi-functional. Here a second dual Acn bacterium, Salmonella enterica serovar Typhimurium (S. Typhimurium), has been analysed. Phenotypic traits of S. Typhimurium acn mutants were consistent with AcnB acting as the major Acn protein. Promoter fusion experiments indicated that acnB transcription was ~10-fold greater than that of acnA and that acnA expression was regulated by the cyclic-AMP receptor protein (CRP, glucose starvation), the fumarate nitrate reduction regulator (FNR, oxygen starvation), the ferric uptake regulator (Fur, iron starvation) and the superoxide response protein (SoxR, oxidative stress). In contrast to E. coli, S. Typhimurium acnA was not induced in the stationary phase. Furthermore, acnA expression was enhanced in an acnB mutant, presumably to partially compensate for the lack of AcnB activity. Isolated S. Typhimurium AcnA protein had kinetic and mRNA-binding properties similar to those described for E. coli AcnA. Thus, the work reported here provides a second example of the regulation and function of AcnA and AcnB proteins in a dual Acn bacterium.

  1. Salmonella enterica Infections in the United States and Assessment of Coefficients of Variation: A Novel Approach to Identify Epidemiologic Characteristics of Individual Serotypes, 1996–2011

    PubMed Central

    Boore, Amy L.; Hoekstra, R. Michael; Iwamoto, Martha; Fields, Patricia I.; Bishop, Richard D.; Swerdlow, David L.

    2015-01-01

    Background Despite control efforts, salmonellosis continues to cause an estimated 1.2 million infections in the United States (US) annually. We describe the incidence of salmonellosis in the US and introduce a novel approach to examine the epidemiologic similarities and differences of individual serotypes. Methods Cases of salmonellosis in humans reported to the laboratory-based National Salmonella Surveillance System during 1996–2011 from US states were included. Coefficients of variation were used to describe distribution of incidence rates of common Salmonella serotypes by geographic region, age group and sex of patient, and month of sample isolation. Results During 1996–2011, more than 600,000 Salmonella isolates from humans were reported, with an average annual incidence of 13.1 cases/100,000 persons. The annual reported rate of Salmonella infections did not decrease during the study period. The top five most commonly reported serotypes, Typhimurium, Enteritidis, Newport, Heidelberg, and Javiana, accounted for 62% of fully serotyped isolates. Coefficients of variation showed the most geographically concentrated serotypes were often clustered in Gulf Coast states and were also more frequently found to be increasing in incidence. Serotypes clustered in particular months, age groups, and sex were also identified and described. Conclusions Although overall incidence rates of Salmonella did not change over time, trends and epidemiological factors differed remarkably by serotype. A better understanding of Salmonella, facilitated by this comprehensive description of overall trends and unique characteristics of individual serotypes, will assist in responding to this disease and in planning and implementing prevention activities. PMID:26701276

  2. Comparison of a PCR serotyping assay, Check&Trace assay for Salmonella, and Luminex Salmonella serotyping assay for the characterization of Salmonella enterica identified from fresh and naturally contaminated cilantro.

    PubMed

    Jean-Gilles Beaubrun, J; Ewing, L; Jarvis, K; Dudley, K; Grim, C; Gopinath, G; Flamer, M-L; Auguste, W; Jayaram, A; Elmore, J; Lamont, M; McGrath, T; Hanes, D E

    2014-09-01

    Salmonella enterica isolated from fresh cilantro samples collected through the USDA/AMS Microbiological Data Program (MDP) were used to compare a PCR serotyping assay against the Check&Trace assay and the Luminex (BioPlex) Salmonella serotyping assay. The study was conducted to evaluate the effectiveness of the three methods for serotyping Salmonella from both enrichment broth cultures and pure Salmonella cultures. In this investigation, Salmonella spp. serotyping was conducted using 24 h enrichment broth cultures and pure Salmonella cultures from cilantro samples, with the PCR serotyping assay. Conversely, the Check&Trace and Luminex for Salmonella assays required pure cultures for Salmonella serotyping. The cilantro samples contained S. enterica serovar Montevideo, Newport, Saintpaul, and Tennessee, identified by the PCR serotyping assay and Check&Trace for Salmonella, but the Luminex assay only identified two of the four serotypes of the cilantro samples. The anticipated impact from this study is that the PCR serotyping assay provides a time- and cost-effective means for screening, identifying and serotyping Salmonella using DNA extracted from 24 h enrichment cilantro samples.

  3. Stress induced Salmonella Typhimurium recrudescence in pigs coincides with cortisol induced increased intracellular proliferation in macrophages.

    PubMed

    Verbrugghe, Elin; Boyen, Filip; Van Parys, Alexander; Van Deun, Kim; Croubels, Siska; Thompson, Arthur; Shearer, Neil; Leyman, Bregje; Haesebrouck, Freddy; Pasmans, Frank

    2011-12-07

    Salmonella Typhimurium infections in pigs often result in the development of carriers that intermittently excrete Salmonella in very low numbers. During periods of stress, for example transport to the slaughterhouse, recrudescence of Salmonella may occur, but the mechanism of this stress related recrudescence is poorly understood. Therefore, the aim of the present study was to determine the role of the stress hormone cortisol in Salmonella recrudescence by pigs. We showed that a 24 h feed withdrawal increases the intestinal Salmonella Typhimurium load in pigs, which is correlated with increased serum cortisol levels. A second in vivo trial demonstrated that stress related recrudescence of Salmonella Typhimurium in pigs can be induced by intramuscular injection of dexamethasone. Furthermore, we found that cortisol, but not epinephrine, norepinephrine and dopamine, promotes intracellular proliferation of Salmonella Typhimurium in primary porcine alveolar macrophages, but not in intestinal epithelial cells and a transformed cell line of porcine alveolar macrophages. A microarray based transcriptomic analysis revealed that cortisol did not directly affect the growth or the gene expression or Salmonella Typhimurium in a rich medium, which implies that the enhanced intracellular proliferation of the bacterium is probably caused by an indirect effect through the cell. These results highlight the role of cortisol in the recrudescence of Salmonella Typhimurium by pigs and they provide new evidence for the role of microbial endocrinology in host-pathogen interactions.

  4. Vaccination of pigs reduces Salmonella Typhimurium numbers in a model mimicking pre-slaughter stress.

    PubMed

    Leyman, Bregje; Boyen, Filip; Verbrugghe, Elin; Parys, Alexander Van; Haesebrouck, Freddy; Pasmans, Frank

    2012-11-01

    In pigs, infection with Salmonella Typhimurium often results in the development of carriers that re-excrete the organism during periods of stress. Previous studies have shown that cortisol plays a significant role in the recrudescence of Salmonella Typhimurium and that re-excretion can be induced by injections of dexamethasone. This study evaluated whether a commercially available Salmonella Typhimurium vaccine was able to reduce Salmonella excretion in a model mimicking pre-slaughter stress. Pigs were randomly assigned to either vaccination or a control group and, 5 weeks later, were infected with Salmonella Typhimurium. Twenty-three days post infection, pigs were injected with dexamethasone to induce recrudescence and Salmonella Typhimurium numbers were determined. Salmonella loads were significantly lower in the ileum and colon and in the contents of the ileum and caecum in vaccinated pigs than in non-vaccinated pigs. In addition, significantly more Salmonella positive tonsil and colon samples were found in non-vaccinated pigs. Vaccination with an attenuated vaccine reduced but did not eliminate Salmonella Typhimurium in pigs in conditions mimicking pre-slaughter stress.

  5. Stress induced Salmonella Typhimurium recrudescence in pigs coincides with cortisol induced increased intracellular proliferation in macrophages

    PubMed Central

    2011-01-01

    Salmonella Typhimurium infections in pigs often result in the development of carriers that intermittently excrete Salmonella in very low numbers. During periods of stress, for example transport to the slaughterhouse, recrudescence of Salmonella may occur, but the mechanism of this stress related recrudescence is poorly understood. Therefore, the aim of the present study was to determine the role of the stress hormone cortisol in Salmonella recrudescence by pigs. We showed that a 24 h feed withdrawal increases the intestinal Salmonella Typhimurium load in pigs, which is correlated with increased serum cortisol levels. A second in vivo trial demonstrated that stress related recrudescence of Salmonella Typhimurium in pigs can be induced by intramuscular injection of dexamethasone. Furthermore, we found that cortisol, but not epinephrine, norepinephrine and dopamine, promotes intracellular proliferation of Salmonella Typhimurium in primary porcine alveolar macrophages, but not in intestinal epithelial cells and a transformed cell line of porcine alveolar macrophages. A microarray based transcriptomic analysis revealed that cortisol did not directly affect the growth or the gene expression or Salmonella Typhimurium in a rich medium, which implies that the enhanced intracellular proliferation of the bacterium is probably caused by an indirect effect through the cell. These results highlight the role of cortisol in the recrudescence of Salmonella Typhimurium by pigs and they provide new evidence for the role of microbial endocrinology in host-pathogen interactions. PMID:22151081

  6. Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

    DOE PAGES

    Leekitcharoenphon, Pimlapas; Hendriksen, Rene S.; Le Hello, Simon; ...

    2016-03-04

    It has been 30 years since the initial emergence and subsequent rapid global spread of multidrug-resistant Salmonella enterica serovar Typhimurium DT104 (MDR DT104). Nonetheless, its origin and transmission route have never been revealed. In this paper, we used whole-genome sequencing (WGS) and temporally structured sequence analysis within a Bayesian framework to reconstruct temporal and spatial phylogenetic trees and estimate the rates of mutation and divergence times of 315 S. Typhimurium DT104 isolates sampled from 1969 to 2012 from 21 countries on six continents. DT104 was estimated to have emerged initially as antimicrobial susceptible in ~1948 (95% credible interval [CI], 1934more » to 1962) and later became MDR DT104 in ~1972 (95% CI, 1972 to 1988) through horizontal transfer of the 13-kb Salmonella genomic island 1 (SGI1) MDR region into susceptible strains already containing SGI1. This was followed by multiple transmission events, initially from central Europe and later between several European countries. An independent transmission to the United States and another to Japan occurred, and from there MDR DT104 was probably transmitted to Taiwan and Canada. An independent acquisition of resistance genes took place in Thailand in ~1975 (95% CI, 1975 to 1990). In Denmark, WGS analysis provided evidence for transmission of the organism between herds of animals. Interestingly, the demographic history of Danish MDR DT104 provided evidence for the success of the program to eradicate Salmonella from pig herds in Denmark from 1996 to 2000. Finally, the results from this study refute several hypotheses on the evolution of DT104 and suggest that WGS may be useful in monitoring emerging clones and devising strategies for prevention of Salmonella infections.« less

  7. Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

    SciTech Connect

    Leekitcharoenphon, Pimlapas; Hendriksen, Rene S.; Le Hello, Simon; Weill, François-Xavier; Baggesen, Dorte Lau; Jun, Se-Ran; Ussery, David W.; Lund, Ole; Crook, Derrick W.; Wilson, Daniel J.; Aarestrup, Frank M.

    2016-03-04

    It has been 30 years since the initial emergence and subsequent rapid global spread of multidrug-resistant Salmonella enterica serovar Typhimurium DT104 (MDR DT104). Nonetheless, its origin and transmission route have never been revealed. In this paper, we used whole-genome sequencing (WGS) and temporally structured sequence analysis within a Bayesian framework to reconstruct temporal and spatial phylogenetic trees and estimate the rates of mutation and divergence times of 315 S. Typhimurium DT104 isolates sampled from 1969 to 2012 from 21 countries on six continents. DT104 was estimated to have emerged initially as antimicrobial susceptible in ~1948 (95% credible interval [CI], 1934 to 1962) and later became MDR DT104 in ~1972 (95% CI, 1972 to 1988) through horizontal transfer of the 13-kb Salmonella genomic island 1 (SGI1) MDR region into susceptible strains already containing SGI1. This was followed by multiple transmission events, initially from central Europe and later between several European countries. An independent transmission to the United States and another to Japan occurred, and from there MDR DT104 was probably transmitted to Taiwan and Canada. An independent acquisition of resistance genes took place in Thailand in ~1975 (95% CI, 1975 to 1990). In Denmark, WGS analysis provided evidence for transmission of the organism between herds of animals. Interestingly, the demographic history of Danish MDR DT104 provided evidence for the success of the program to eradicate Salmonella from pig herds in Denmark from 1996 to 2000. Finally, the results from this study refute several hypotheses on the evolution of DT104 and suggest that WGS may be useful in monitoring emerging clones and devising strategies for prevention of Salmonella infections.

  8. Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

    PubMed Central

    Hendriksen, Rene S.; Le Hello, Simon; Weill, François-Xavier; Baggesen, Dorte Lau; Jun, Se-Ran; Lund, Ole; Crook, Derrick W.; Wilson, Daniel J.; Aarestrup, Frank M.

    2016-01-01

    It has been 30 years since the initial emergence and subsequent rapid global spread of multidrug-resistant Salmonella enterica serovar Typhimurium DT104 (MDR DT104). Nonetheless, its origin and transmission route have never been revealed. We used whole-genome sequencing (WGS) and temporally structured sequence analysis within a Bayesian framework to reconstruct temporal and spatial phylogenetic trees and estimate the rates of mutation and divergence times of 315 S. Typhimurium DT104 isolates sampled from 1969 to 2012 from 21 countries on six continents. DT104 was estimated to have emerged initially as antimicrobial susceptible in ∼1948 (95% credible interval [CI], 1934 to 1962) and later became MDR DT104 in ∼1972 (95% CI, 1972 to 1988) through horizontal transfer of the 13-kb Salmonella genomic island 1 (SGI1) MDR region into susceptible strains already containing SGI1. This was followed by multiple transmission events, initially from central Europe and later between several European countries. An independent transmission to the United States and another to Japan occurred, and from there MDR DT104 was probably transmitted to Taiwan and Canada. An independent acquisition of resistance genes took place in Thailand in ∼1975 (95% CI, 1975 to 1990). In Denmark, WGS analysis provided evidence for transmission of the organism between herds of animals. Interestingly, the demographic history of Danish MDR DT104 provided evidence for the success of the program to eradicate Salmonella from pig herds in Denmark from 1996 to 2000. The results from this study refute several hypotheses on the evolution of DT104 and suggest that WGS may be useful in monitoring emerging clones and devising strategies for prevention of Salmonella infections. PMID:26944846

  9. Intestinal invasion of Salmonella enterica serovar Typhimurium in the avian host is dose dependent and does not depend on motility and chemotaxis.

    PubMed

    Olsen, John Elmerdahl; Hoegh-Andersen, Kirsten Hobolt; Rosenkrantz, Jesper Tjørnholt; Schroll, Casper; Casadesús, Josep; Aabo, Søren; Christensen, Jens Peter

    2013-08-30

    Salmonella enterica serotype Typhimurium (S. Typhimurium) can invade in the intestine of the avian host, and knowledge on the mechanisms that govern this is potentially important for prevention of disease. This study investigated the invasion of S. Typhimurium in the avian host and to which extent it depended on motility and chemotaxis. Wild type and previously well-characterized transposon mutants in flagella genes fliC and fljB and in chemotaxis genes cheA, cheB and cheR were used as challenge strains in intestinal loop experiments. Invasion was shown to be dose dependent, but did not require functional flagella or chemotaxis genes. In support of the results from intestinal loop experiments, flagella and chemotaxis genes were not significantly important to the outcome of an oral infection. The results showed that S. Typhimurium invasion in the avian host was dose dependent and was not affected by the loss of flagella and chemotaxis genes.

  10. An rfaH mutant of Salmonella enterica serovar typhimurium is attenuated in swine and reduces intestinal colonization, fecal shedding, and disease severity due to virulent Salmonella Typhimurium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine are often asymptomatic carriers of Salmonella spp., and interventions are needed to limit colonization of swine to enhance food safety and reduce environmental contamination. We evaluated the attenuation and potential vaccine use in pigs of a Salmonella enterica serovar Typhimurium mutant of r...

  11. Oxygen taxis and proton motive force in Salmonella typhimurium.

    PubMed

    Shioi, J; Taylor, B L

    1984-09-10

    The aerotactic response of Salmonella typhimurium SL3730 has been quantitatively correlated with a change in the proton motive force (delta p) as measured by a flow-dialysis technique. At pH 7.5, the membrane potential (delta psi) in S. typhimurium changed from -162 +/- 13 to -111 +/- 15 mV when cells grown aerobically were made anaerobic, and it returned to the original value when the cells were returned to aerobiosis. The delta pH across the membrane was zero. At pH 5.5, delta psi was -70 mV in aerobiosis and -20 mV in anaerobiosis, and delta pH was -118 and -56 mV for aerobic and anaerobic cells, respectively. A decrease in delta p resulted in increased tumbling, and an increase in delta p resulted in a smooth swimming response at either pH. Inhibition of aerotaxis at pH 7.5 by various concentrations of KCN correlated with a decreased delta p, due to a decreased delta psi in aerobiosis and little change in delta psi in anaerobiosis. At concentrations up to 100 mM, 2,4-dinitrophenol decreased delta psi, but did not inhibit aerotaxis because the difference between delta psi in aerobic and anaerobic cells remained constant. Considered as a whole, the results indicate that aerotaxis in S. typhimurium is mediated by delta p.

  12. Characterization of type 1 pili of Salmonella typhimurium LT2.

    PubMed Central

    Korhonen, T K; Lounatmaa, K; Ranta, H; Kuusi, N

    1980-01-01

    Type 1 pili from Salmonella typhimurium LT2 were purified and characterized. The pilus filaments were 6 nm in diameter and over 1 microns long. Estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the molecular weight of the pilin was 21,000. The isoelectric point of the filament was 4.1. Hydrophobic amino acids comprised 40.3% of the total amino acids of the pilin, which contained more proline, serine, and lysine than reported for the type 1 pilin of Escherichia coli. Purified pili agglutinated both horse and chicken erythrocytes and yeast cells but not bovine, sheep, or human erythrocytes. Horse erythrocyte agglutination was inhibited at lower concentrations by alpha-methyl-D-mannoside than by yeast mannane and D-fructose. Agglutination was not affected by D-galactose or sucrose. Results of the present study confirm the role of type 1 pili as Salmonella hemagglutinins and show chemical differences between the type 1 pili of S. typhimurium and E. coli. Images PMID:6107289

  13. Detection of Salmonella typhimurium using phage-based magnetostrictive sensor

    NASA Astrophysics Data System (ADS)

    Lakshmanan, Ramji S.; Hu, Jing; Guntupalli, Rajesh; Wan, Jiehui; Huang, Shichu; Yang, Hong; Petrenko, Valery A.; Barbaree, James M.; Chin, Bryan A.

    2006-05-01

    This article presents a contactless, remote sensing Salmonella typhimurium sensor based on the principle of magnetostriction. Magnetostrictive materials have been used widely for various types of sensor systems. In this work, the use of a magnetostrictive material for the detection of Salmonella typhimurium has been established. The mass of the bacteria attached to the sensor causes changes in the resonance frequency of the sensor. Filamentous bacteriophage was used as a probe order to ensure specific and selective binding of the bacteria onto the sensor surface. Thus changes in response of the sensor due to the mass added onto the sensor caused by specific attachment of bacteria can be monitored in absence of any contact to the sensor. The response of the sensor due to increasing concentrations (from 5x101 to 5x10 8 cfu/ml) of the bacteria was studied. A reduction in the physical dimensions enhances the sensitivity of these sensors and hence different dimensions of the sensor ribbons were studied. For a 2mm x 0.1mm x 0.02mm the detection limit was observed to be of the order of 10 4 cfu/mL and for a sensor of 1mm x 0.2mm x 0.02mm a reduced detection limit of 10 3 cfu/mL was achieved.

  14. Isolation of QseC-regulated genes in Salmonella enterica serovar Typhimurium by transposon mutgagenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-typhoidal Salmonella, a leading cause of U.S. foodborne disease and food-related deaths, often asymptomatically colonizes food-producing animals. In fact, >50% of U.S. swine production facilities test positive for Salmonella. The multidrug-resistant (MDR) Salmonella Typhimurium DT104 NCTC13348 c...

  15. Resistant mechanism study of benzalkonium chloride selected Salmonella Typhimurium mutants.

    PubMed

    Guo, Wei; Cui, Shenghui; Xu, Xiao; Wang, Haoyan

    2014-02-01

    Benzalkonium chloride is one of the invaluable biocides that is extensively used in healthcare settings as well as in the food processing industry. After exposing wild-type Salmonella Typhimurium 14028s or its AcrAB inactivation mutant to gradually increasing levels of benzalkonium chloride, resistance mutants S-41, S-150, S-AB-23, S-AB-38, and S-AB-73 were selected and these mutants also showed a 2-64-fold stable minimum inhibitory concentration (MIC) increase to chloramphenicol, ciprofloxacin, nalidixic acid, and tetracycline. In S-41 and S-150, the expression of acrB was increased 2.7- and 7.6-fold, and ΔtolC or ΔacrAB mutants of S-41 and S-150 showed the same MICs to all tested antimicrobials as the equivalent Salmonella Typhimurium 14028s mutants. However, in S-AB-23, S-AB-38, and S-AB-73, the expression of acrF was increased 96-, 230-, and 267-fold, respectively, and ΔtolC or ΔacrEF mutants of S-AB-23, S-AB-38, and S-AB-73 showed the similar MICs to all tested antimicrobials as the ΔtolC mutant of Salmonella Typhimurium 14028s. Our data showed that constitutively over-expressed AcrAB working through TolC was the main resistance mechanism in ST14028s benzalkonium chloride resistance mutants. However, after AcrAB had been inactivated, benzalkonium chloride-resistant mutants could still be selected and constitutively over-expressed, AcrEF became the dominant efflux pump working through TolC and being responsible for the increasing antimicrobial resistance. These data indicated that different mechanisms existed for acrB and acrF constitutive over-expression. Since exposure to benzalkonium chloride may lead to Salmonella mutants with a decreased susceptibility to quinolones, which is currently one of the drugs of choice for the treatment of life-threatening salmonelosis, research into the pathogenesis and epidemiology of the benzalkonium chloride resistance mutants will be of increasing importance.

  16. Aspartic Peptide Hydrolases in Salmonella enterica Serovar Typhimurium

    PubMed Central

    Larsen, Rachel A.; Knox, Tina M.; Miller, Charles G.

    2001-01-01

    Two well-characterized enzymes in Salmonella enterica serovar Typhimurium and Escherichia coli are able to hydrolyze N-terminal aspartyl (Asp) dipeptides: peptidase B, a broad-specificity aminopeptidase, and peptidase E, an Asp-specific dipeptidase. A serovar Typhimurium strain lacking both of these enzymes, however, can still utilize most N-terminal Asp dipeptides as sources of amino acids, and extracts of such a strain contain additional enzymatic activities able to hydrolyze Asp dipeptides. Here we report two such activities from extracts of pepB pepE mutant strains of serovar Typhimurium identified by their ability to hydrolyze Asp-Leu. Although each of these activities hydrolyzes Asp-Leu at a measurable rate, the preferred substrates for both are N-terminal isoAsp peptides. One of the activities is a previously characterized isoAsp dipeptidase from E. coli, the product of the iadA gene. The other is the product of the serovar Typhimurium homolog of E. coli ybiK, a gene of previously unknown function. This gene product is a member of the N-terminal nucleophile structural family of amidohydrolases. Like most other members of this family, the mature enzyme is generated from a precursor protein by proteolytic cleavage and the active enzyme is a heterotetramer. Based on its ability to hydrolyze an N-terminal isoAsp tripeptide as well as isoAsp dipeptides, the enzyme appears to be an isoAsp aminopeptidase, and we propose that the gene encoding it be designated iaaA (isoAsp aminopeptidase). A strain lacking both IadA and IaaA in addition to peptidase B and peptidase E has been constructed. This strain utilizes Asp-Leu as a leucine source, and extracts of this strain contain at least one additional, as-yet-uncharacterized, peptidase able to cleave Asp dipeptides. PMID:11325937

  17. Aspartic peptide hydrolases in Salmonella enterica serovar typhimurium.

    PubMed

    Larsen, R A; Knox, T M; Miller, C G

    2001-05-01

    Two well-characterized enzymes in Salmonella enterica serovar Typhimurium and Escherichia coli are able to hydrolyze N-terminal aspartyl (Asp) dipeptides: peptidase B, a broad-specificity aminopeptidase, and peptidase E, an Asp-specific dipeptidase. A serovar Typhimurium strain lacking both of these enzymes, however, can still utilize most N-terminal Asp dipeptides as sources of amino acids, and extracts of such a strain contain additional enzymatic activities able to hydrolyze Asp dipeptides. Here we report two such activities from extracts of pepB pepE mutant strains of serovar Typhimurium identified by their ability to hydrolyze Asp-Leu. Although each of these activities hydrolyzes Asp-Leu at a measurable rate, the preferred substrates for both are N-terminal isoAsp peptides. One of the activities is a previously characterized isoAsp dipeptidase from E. coli, the product of the iadA gene. The other is the product of the serovar Typhimurium homolog of E. coli ybiK, a gene of previously unknown function. This gene product is a member of the N-terminal nucleophile structural family of amidohydrolases. Like most other members of this family, the mature enzyme is generated from a precursor protein by proteolytic cleavage and the active enzyme is a heterotetramer. Based on its ability to hydrolyze an N-terminal isoAsp tripeptide as well as isoAsp dipeptides, the enzyme appears to be an isoAsp aminopeptidase, and we propose that the gene encoding it be designated iaaA (isoAsp aminopeptidase). A strain lacking both IadA and IaaA in addition to peptidase B and peptidase E has been constructed. This strain utilizes Asp-Leu as a leucine source, and extracts of this strain contain at least one additional, as-yet-uncharacterized, peptidase able to cleave Asp dipeptides.

  18. Aerotaxis in Salmonella typhimurium: role of electron transport.

    PubMed Central

    Laszlo, D J; Taylor, B L

    1981-01-01

    Sensory transduction in aerotaxis required electron transport, in contrast to chemotaxis, which is independent of electron transport. Assays for aerotaxis were developed by employing spatial and temporal oxygen gradients imposed independently of respiration. By varying the step increase in oxygen concentration in the temporal assay, the dose-response relationship was obtained for aerotaxis in Salmonella typhimurium. A half-maximal response at 0.4 microM oxygen and inhibition by 5 mM KCN suggested that the "receptor" for aerotaxis is cytochrome o. The response was independent of adenosine triphosphate formation via oxidative phosphorylation but did correlate with changes in membrane potential monitored with the fluorescent cyanine dye diS-C3-(5). Nitrate and fumarate, which are alternative electron acceptors for the respiratory chain in S. typhimurium, inhibited aerotaxis when nitrate reductase and fumarate reductase were induced. These results support the hypothesis that taxis to oxygen, nitrate, and fumarate is mediated by the electron transport system and by changes in the proton motive force. Aerotaxis was normal in Escherichia coli mutants that were defective in the tsr, tar, or trg genes; in S. typhimurium, oxygen did not stimulate methylation of the products of these genes. A cheC mutant which shows an inverse response to chemoattractants also gave an inverse response to oxygen. Therefore, aerotaxis is transduced by a distinct and unidentified signally protein but is focused into the common chemosensory pathway before the step involving the cheC product. When S. typhimurium became anaerobic, the decreased proton motive force from glycolysis supported slow swimming but not tumbling, indicating that a minimum proton motive force was required for tumbling. The bacteria rapidly adapted to the anaerobic condition and resumed tumbling after about 3 min. The adaptation period was much shorter when the bacteria had been previously grown anaerobically. Images PMID

  19. Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104.

    PubMed

    Leekitcharoenphon, Pimlapas; Hendriksen, Rene S; Le Hello, Simon; Weill, François-Xavier; Baggesen, Dorte Lau; Jun, Se-Ran; Ussery, David W; Lund, Ole; Crook, Derrick W; Wilson, Daniel J; Aarestrup, Frank M

    2016-04-01

    It has been 30 years since the initial emergence and subsequent rapid global spread of multidrug-resistant Salmonella entericaserovar Typhimurium DT104 (MDR DT104). Nonetheless, its origin and transmission route have never been revealed. We used whole-genome sequencing (WGS) and temporally structured sequence analysis within a Bayesian framework to reconstruct temporal and spatial phylogenetic trees and estimate the rates of mutation and divergence times of 315S Typhimurium DT104 isolates sampled from 1969 to 2012 from 21 countries on six continents. DT104 was estimated to have emerged initially as antimicrobial susceptible in ∼1948 (95% credible interval [CI], 1934 to 1962) and later became MDR DT104 in ∼1972 (95% CI, 1972 to 1988) through horizontal transfer of the 13-kb Salmonella genomic island 1 (SGI1) MDR region into susceptible strains already containing SGI1. This was followed by multiple transmission events, initially from central Europe and later between several European countries. An independent transmission to the United States and another to Japan occurred, and from there MDR DT104 was probably transmitted to Taiwan and Canada. An independent acquisition of resistance genes took place in Thailand in ∼1975 (95% CI, 1975 to 1990). In Denmark, WGS analysis provided evidence for transmission of the organism between herds of animals. Interestingly, the demographic history of Danish MDR DT104 provided evidence for the success of the program to eradicate Salmonellafrom pig herds in Denmark from 1996 to 2000. The results from this study refute several hypotheses on the evolution of DT104 and suggest that WGS may be useful in monitoring emerging clones and devising strategies for prevention of Salmonella infections.

  20. Protective immunity conferred by a DNA adenine methylase deficient Salmonella enterica serovar Typhimurium vaccine when delivered in-water to sheep challenged with Salmonella enterica serovar Typhimurium.

    PubMed

    Mohler, V L; Heithoff, D M; Mahan, M J; Walker, K H; Hornitzky, M A; Gabor, L; Thomson, P C; Thompson, A; House, J K

    2011-04-27

    Stimulation of acquired immunity to Salmonella in livestock is not feasible in neonates (which can be infected within 24h of birth) and is challenging in feedlots, which typically source animals from diverse locations and vendors. Induction of innate immune mechanisms through mass vaccination of animals upon arrival to feedlots is an alternative approach. Transport, environmental conditions, changes in social grouping, and further handling during feedlot assembly are significant stressors. These factors, as well as concurrent exposure to a diversity of pathogens, contribute to the risk of disease. We have shown that oral immunization of calves with a modified live Salmonella enterica serovar Typhimurium vaccine strain, which lacks the DNA adenine methylase gene (S. Typhimurium dam), attenuates the severity of clinical disease, reduces fecal shedding, and promotes clearance of salmonellae following virulent homologous and heterologous challenge. This study examines the safety and efficacy of a S. Typhimurium dam vaccine in sheep via oral delivery in drinking water (ad libitum), as a means to effectively vaccinate large groups of animals. Adult merino sheep were vaccinated in drinking water -28 days, -7 days and 24h pre and 24h post-virulent Salmonella Typhimurium challenge which was administered via the oral route. Significant attenuation of clinical disease (temperature, appetite, and attitude) and reduction in mortality and virulent Salmonella Typhimurium fecal shedding and tissue colonization was observed in animals that received the vaccine 28 and 7 days pre-challenge. Further, vaccination did not pose a risk to stock previously infected with virulent salmonellae as mortalities and clinical disease in sheep vaccinated prior to or following virulent challenge did not differ significantly from the non-vaccinated controls. The capacity of S. Typhimurium dam vaccines delivered in drinking water to protect livestock from virulent Salmonella challenge offers an

  1. Salmonella identification from foods in eight hours: A prototype study with Salmonella Typhimurium

    PubMed Central

    Koluman, A; Celik, G; Unlu, T

    2012-01-01

    Background and Objectives The significant rise in food borne infections is mainly caused by Campylobacter spp., Salmonella serovars and Verotoxigenic Escherichia coli. As the emerging food borne pathogens cause disease, more studies have been conducted for rapid detection of these pathogens. The combination of immunomagnetic separation and polymerase chain reaction (IMS-PCR) is the most accurate and rapid test preferred by almost every researcher. Fourier Transform Infrared Spectroscopy (FTIR) is preferred for being a new, user friendly and rapid technique in microbiological analyses. The main aim of this study is to detect application of IMS-FTIR for Salmonella identification from foods in a short time with a higher sensitivity. Materials and Methods Conventional Culture Technique (CC), IMS-CC, IMS-PCR and IMS-FTIR techniques were compared with each other for rapid detection in artificially contaminated minced beef with Salmonella Typhimurium, as of the 2nd, 4th and 8th hours of contamination. The method was evaluated in different food matrices and sensitivity, specifity and overall recovery was calculated. Results The results indicate that IMS-FTIR can detect S. Typhimurium as of the 8th hour with sensitivity of 95.6667, accuracy of 91.69329, false positive ratio of 0.04333 and overall recovery of 95.66%. Conclusion It can be suggested that the IMS-FTIR method is capable of detecting S.Typhimurium in a short time with lower cost. PMID:22783456

  2. Natural and experimental Salmonella Typhimurium infections in foxes (Vulpes vulpes).

    PubMed

    Handeland, Kjell; Nesse, Live L; Lillehaug, Atle; Vikøren, Turid; Djønne, Berit; Bergsjø, Bjarne

    2008-11-25

    The red fox (Vulpes vulpes) can be considered as a relevant indicator species for Salmonella in the local environment and Salmonella faecal carriage was investigated in 215 red foxes in Norway shot during the winters 2002/2003 and 2003/2004. Fourteen (6.5%) of the foxes carried Salmonella. Four isolates were determined as serovars Kottbus (n=2) and Hessarek (n=2) of Salmonella enterica subspecies enterica, and one as S. enterica subspecies IIIb:61:k:1,5,(7). The remaining nine isolates were S. enterica subspecies enterica serovar Typhimurium 4,12:i:1,2 and all displayed the same pulsed-field gel electrophoresis (PFGE) profile designated A2. This serovar regularly causes disease outbreaks amongst small passerine birds during winter and most of these outbreaks are associated with the PFGE profile A2. The results strongly indicated that the Salmonella Typhimurium infections in red foxes were primarily acquired through ingestion of infected small passerines. To investigate the capability of the A2 strain to establish a true intestinal infection in the fox an inoculation experiment with an A2 isolate from small passerines was carried out in farmed silver foxes (V. vulpes). The experiment also included one strain with an uncommonly occurring profile (X201) from small passerines. To highlight possible differences in capability of the two inoculation strains to pass the acid gastric juice in the fox, in vitro studies of their acid tolerance was carried out. Also their catalase activity and biofilm production were studied. All three foxes inoculated with the A2 strain developed sub-clinical intestinal infection of 2 weeks duration, whereas none of the three foxes inoculated with the X201 strain shed this bacterium. The X201 strain displayed a much lower capability, than the A2 strain, to survive at pH 3 in vitro. The low acid tolerance probably made it difficult for the X201 strain to pass the stomach and establish an intestinal infection in the experimental foxes. Reduced

  3. Methionine Sulfoxide Reductases Are Essential for Virulence of Salmonella Typhimurium

    PubMed Central

    Rouf, Syed Fazle; Kitowski, Vera; Böhm, Oliver M.; Rhen, Mikael; Jäger, Timo; Bange, Franz-Christoph

    2011-01-01

    Production of reactive oxygen species represents a fundamental innate defense against microbes in a diversity of host organisms. Oxidative stress, amongst others, converts peptidyl and free methionine to a mixture of methionine-S- (Met-S-SO) and methionine-R-sulfoxides (Met-R-SO). To cope with such oxidative damage, methionine sulfoxide reductases MsrA and MsrB are known to reduce MetSOs, the former being specific for the S-form and the latter being specific for the R-form. However, at present the role of methionine sulfoxide reductases in the pathogenesis of intracellular bacterial pathogens has not been fully detailed. Here we show that deletion of msrA in the facultative intracellular pathogen Salmonella (S.) enterica serovar Typhimurium increased susceptibility to exogenous H2O2, and reduced bacterial replication inside activated macrophages, and in mice. In contrast, a ΔmsrB mutant showed the wild type phenotype. Recombinant MsrA was active against free and peptidyl Met-S-SO, whereas recombinant MsrB was only weakly active and specific for peptidyl Met-R-SO. This raised the question of whether an additional Met-R-SO reductase could play a role in the oxidative stress response of S. Typhimurium. MsrC is a methionine sulfoxide reductase previously shown to be specific for free Met-R-SO in Escherichia (E.) coli. We tested a ΔmsrC single mutant and a ΔmsrBΔmsrC double mutant under various stress conditions, and found that MsrC is essential for survival of S. Typhimurium following exposure to H2O2, as well as for growth in macrophages, and in mice. Hence, this study demonstrates that all three methionine sulfoxide reductases, MsrA, MsrB and MsrC, facilitate growth of a canonical intracellular pathogen during infection. Interestingly MsrC is specific for the repair of free methionine sulfoxide, pointing to an important role of this pathway in the oxidative stress response of Salmonella Typhimurium. PMID:22073230

  4. Intracontinental spread of human invasive Salmonella Typhimurium pathovariants in sub-Saharan Africa.

    PubMed

    Okoro, Chinyere K; Kingsley, Robert A; Connor, Thomas R; Harris, Simon R; Parry, Christopher M; Al-Mashhadani, Manar N; Kariuki, Samuel; Msefula, Chisomo L; Gordon, Melita A; de Pinna, Elizabeth; Wain, John; Heyderman, Robert S; Obaro, Stephen; Alonso, Pedro L; Mandomando, Inacio; MacLennan, Calman A; Tapia, Milagritos D; Levine, Myron M; Tennant, Sharon M; Parkhill, Julian; Dougan, Gordon

    2012-11-01

    A highly invasive form of non-typhoidal Salmonella (iNTS) disease has recently been documented in many countries in sub-Saharan Africa. The most common Salmonella enterica serovar causing this disease is Typhimurium (Salmonella Typhimurium). We applied whole-genome sequence-based phylogenetic methods to define the population structure of sub-Saharan African invasive Salmonella Typhimurium isolates and compared these to global Salmonella Typhimurium populations. Notably, the vast majority of sub-Saharan invasive Salmonella Typhimurium isolates fell within two closely related, highly clustered phylogenetic lineages that we estimate emerged independently ∼52 and ∼35 years ago in close temporal association with the current HIV pandemic. Clonal replacement of isolates from lineage I by those from lineage II was potentially influenced by the use of chloramphenicol for the treatment of iNTS disease. Our analysis suggests that iNTS disease is in part an epidemic in sub-Saharan Africa caused by highly related Salmonella Typhimurium lineages that may have occupied new niches associated with a compromised human population and antibiotic treatment.

  5. Interaction of Salmonella enterica subspecies enterica serovar Typhimurium and mung bean (Phaseolus aureus) plants.

    PubMed

    Singh, Bhoj Raj; Chandra, Mudit; Agarwal, Ravikant

    2005-03-01

    The effect of Salmonella enterica subspecies enterica serovar Typhimurium, a zoonotic serovar, on mung bean (Phaseolus aureus) cultivar Pant Mung-3 plants was studied. Inoculation of mung bean seeds with Salmonella Typhimurium (7.2 x 10(5) CFU/ml) reduced sprouting rate (P < 0.07). This effect was more pronounced at higher levels of contamination. In the soil inoculated with Salmonella Typhimurium (7.2 x 10(6) CFU/g), germination was retarded and the number of defective sprouts was also significantly higher (P < 0.002). Salmonella Typhimurium grew inside germinating seeds and plant tissues and persisted in seedlings, adult plants, and harvested seedlings dried and stored at room temperature (30 degrees C) up to 45 days. Phaseolus aureus plants grown in sterile soil was resistant to Salmonella Typhimurium infection at 15 days of age and cleared Salmonella from all the aerial parts within 3 h of infection. However, Salmonella Typhimurium could be reisolated from the basal area of the stem and from soil even after 45 days of exposure to the pathogen.

  6. Predicting Salmonella enterica subsp. enterica Serotypes by Repetitive Extragenic Palindromic Sequence-Based PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The DiversiLabTM System, which employs repetitive extragenic palindromic sequence-based PCR (rep-PCR) to genotype microorganisms, was evaluated as a method to predict the serotype of Salmonella isolates. Two hundred and thirty-three Salmonella isolates belonging to 14 frequently isolated serotypes f...

  7. Innate immune control of Salmonella enterica serovar Typhimurium: mechanisms contributing to combating systemic Salmonella infection.

    PubMed

    Wick, Mary Jo

    2011-01-01

    Infections with Salmonella enterica serovars remain a serious problem worldwide. While serovar Typhi causes significant morbidity and mortality that is restricted to humans, serovar Typhimurium causes gastroenteritidis in humans and can also infect other animals. As mice with the susceptible Nramp1 locus get systemic infection with serovar Typhimurium, murine infection models using this serovar have been widely used to decipher the immune mechanisms required to survive systemic Salmonella infection. This review summarizes recent studies in murine infection models that have advanced our understanding of the events that occur during the first days after oral Salmonella infection. The pathways of bacterial penetration across the intestinal epithelium, bacterial spread to draining (mesenteric) lymph nodes and dissemination to systemic tissues is discussed. The response of myeloid cell populations, including dendritic cells, inflammatory monocytes and neutrophils, during the early stage of infection is also discussed. Finally, the mechanisms driving recruitment of myeloid cells to infected intestinal lymphoid tissues and what is known about Toll-like receptor signaling pathways in innate immunity to Salmonella infection is also discussed.

  8. Differential induction of total IgE by two Salmonella enterica serotypes

    PubMed Central

    Ktsoyan, Zhanna A.; Mkrtchyan, Mkhitar S.; Zakharyan, Magdalina K.; Mnatsakanyan, Armine A.; Arakelova, Karine A.; Gevorgyan, Zaruhi U.; Ktsoyan, Lusntag A.; Sedrakyan, Anahit Ì.; Hovhannisyan, Alvard I.; Ghazaryan1, Karine A.; Boyajyan, Anna S.; Aminov, Rustam I.

    2015-01-01

    The main goal of this study was to establish how the inflammation caused by infection with two different Salmonella enterica serotypes, S. Typhimurium and S. Enteritidis, may lead to the predisposition to allergy as measured by total IgE level in the blood. Infection by S. Typhimurium did not affect the systemic IgE concentration while in S. Enteritidis-infected patients there was a significant 3.5-fold increase. This effect was especially profound in patients >4 years old, with up to the 8-fold increase above the norm. The degree of dysbiosis in these two infections measured with the comparative counts of cultivated bacteria showed an inverse relationship with the IgE concentration. Earlier we reported the elevated level of IL-17 in patients infected by S. Enteritidis. In the current study a significant correlation was found between the concentrations of IL-17 and IgE suggesting a possible role played by this cytokine in triggering the production of IgE in response to S. Enteritidis infection. PMID:26075186

  9. Structural Genes for Ornithine Transcarbamylase in Salmonella typhimurium and Escherichia coli K-121

    PubMed Central

    Syvanen, J. Michael; Roth, John R.

    1972-01-01

    Mutations of Salmonella typhimurium affecting the structural gene for ornithine transcarbamylase (argl) have been isolated and mapped. The two ornithine transcarbamylase loci in Escherichia coli K-12 have been demonstrated by F′ episome transfer. PMID:4553006

  10. Salmonella in healthy pigs: prevalence, serotype diversity and antimicrobial resistance observed during 1998-1999 and 2004-2005 in Japan.

    PubMed

    Futagawa-Saito, K; Hiratsuka, S; Kamibeppu, M; Hirosawa, T; Oyabu, K; Fukuyasu, T

    2008-08-01

    To determine prevalence, serotype diversity and antimicrobial resistance of Salmonella in healthy pigs, faecal samples from 6771 pigs on 73 farms collected during 1998-1999 and 2004-2005 were examined. Salmonella isolates were serotyped and tested for susceptibility to 22 antimicrobials: benzylpenicillin, ampicillin, amoxicillin, cefazolin, cephaloridine, gentamicin, kanamycin, streptomycin, fradiomycin, colistin, tetracycline, chlortetracycline, oxytetracycline, chloramphenicol, thiamphenicol, sulfadimethoxine, sulfamethoxazole, sulfamethoxypyridazine, trimethoprim, sulfamethoxazole/trimethoprim, norfloxacin and ofloxacin. Farm-level and pig-level Salmonella prevalences were 35.5% and 2.2% in 1998-1999, and 35.7% and 3.3% in 2004-2005. Prevalence by growth stage was 2.4% for sows, 3.3% for weaned pigs, 2.7% for fattening pigs and 3.8% for finishing pigs. The predominant serotypes identified were Agona (28.4%), Typhimurium (17.9%) and Infantis (16.4%) in 1998-1999, and Typhimurium (32.5%), Anatum (24.6%) and Infantis (13.5%) in 2004-2005. Compared with the 1998-1999 isolates, the 2004-2005 isolates showed significantly higher rates of resistance to all the antimicrobials except tetracyclines (P<0.01 to P<0.05) and resistance to 2 antimicrobials [19.4% (13/67) vs. 39.7% (50/126), P<0.01]. This study provides national estimates of Salmonella prevalence in healthy pigs of different growth stages in Japan.

  11. Immunogenicity of a Bivalent Adjuvanted Glycoconjugate Vaccine against Salmonella Typhimurium and Salmonella Enteritidis

    PubMed Central

    Fiorino, Fabio; Rondini, Simona; Micoli, Francesca; Lanzilao, Luisa; Alfini, Renzo; Mancini, Francesca; MacLennan, Calman A.; Medaglini, Donata

    2017-01-01

    Salmonella enterica serovars Typhimurium and Enteritidis are the predominant causes of invasive non-typhoidal Salmonella (iNTS) disease. Considering the co-endemicity of S. Typhimurium and S. Enteritidis, a bivalent vaccine formulation against both pathogens is necessary for protection against iNTS disease, thus investigation of glycoconjugate combination is required. In the present work, we investigated the immune responses induced by S. Typhimurium and S. Enteritidis monovalent and bivalent glycoconjugate vaccines adjuvanted with aluminum hydroxide (alum) only or in combination with cytosine-phosphorothioate-guanine oligodeoxynucleotide (CpG). Humoral and cellular, systemic and local, immune responses were characterized in two different mouse strains. All conjugate vaccines elicited high levels of serum IgG against the respective O-antigens (OAg) with bactericidal activity. The bivalent conjugate vaccine induced systemic production of antibodies against both S. Typhimurium and S. Enteritidis OAg. The presence of alum or alum + CpG adjuvants in vaccine formulations significantly increased the serum antigen-specific antibody production. The alum + CpG bivalent vaccine formulation triggered the highest systemic anti-OAg antibodies and also a significant increase of anti-OAg IgG in intestinal washes and fecal samples, with a positive correlation with serum levels. These data demonstrate the ability of monovalent and bivalent conjugate vaccines against S. Typhimurium and S. Enteritidis to induce systemic and local immune responses in different mouse strains, and highlight the suitability of a bivalent glycoconjugate formulation, especially when adjuvanted with alum + CpG, as a promising candidate vaccine against iNTS disease. PMID:28289411

  12. Associations between host characteristics and antimicrobial resistance of Salmonella typhimurium.

    PubMed

    Ruddat, I; Tietze, E; Ziehm, D; Kreienbrock, L

    2014-10-01

    A collection of Salmonella Typhimurium isolates obtained from sporadic salmonellosis cases in humans from Lower Saxony, Germany between June 2008 and May 2010 was used to perform an exploratory risk-factor analysis on antimicrobial resistance (AMR) using comprehensive host information on sociodemographic attributes, medical history, food habits and animal contact. Multivariate resistance profiles of minimum inhibitory concentrations for 13 antimicrobial agents were analysed using a non-parametric approach with multifactorial models adjusted for phage types. Statistically significant associations were observed for consumption of antimicrobial agents, region type and three factors on egg-purchasing behaviour, indicating that besides antimicrobial use the proximity to other community members, health consciousness and other lifestyle-related attributes may play a role in the dissemination of resistances. Furthermore, a statistically significant increase in AMR from the first study year to the second year was observed.

  13. Electron microscopic visualization of trp operon expression in Salmonella typhimurium.

    PubMed

    French, S; Martin, K; Patterson, T; Bauerle, R; Miller, O L

    1985-07-01

    Transcriptional activity of plasmids carrying wild-type and mutant trp operons was visualized in cell lysates of Salmonella typhimurium. Plasmid and transcription-unit sizes varied with the size of the cloned operon. Following 3-(3-indolyl)acrylic acid derepression, all operons of a particular type exhibited the same high level of transcriptional activity. An estimated 11-14 transcripts must be initiated each minute to maintain the 190-base-pair spacing of RNA polymerases observed on the promoter-proximal half of the wild-type trp operon. A decline in RNA polymerase density was observed on promoter-distal portions of cloned trp operons, which may be attributable to premature transcription termination accompanying translation inhibition due to indolylacrylic acid's interference with normal tryptophanyl-tRNA synthetase activity.

  14. Radiation-induced mutagenicity and lethality in Salmonella typhimurium

    SciTech Connect

    Isildar, M.; Bakale, G.

    1983-01-01

    The mutagenic and lethal effects of ionizing radiation on histidine-deficient auxotrophs of Salmonella typhimurium were studied to improve the understanding of radiation damage to DNA. The auxotrophs were divided into two groups - one which is sensitive to base-pair substitutions and another sensitive to frameshifts. These groups were composed of parent-daughter pairs in which the chemical mutagenicity enhancing plasmid, pKM101, is absent in the parent strain and present in the daughter. Co-60 ..gamma..-radiation and 250 kV x-rays were used to irradiate the bacteria. Irradiation of the frameshift - sensitive strains which carry the pKm101 plasmid doubled the absolute number of induced revertants whereas irradiation of the base-pair substitution sensitive strain which also carries the pKm101 plasmid produced nearly no change in the number of induced revertants. A nearly negligible effect on the mutation rate was observed for all parent strains. (ACR)

  15. A locus affecting nucleoid segregation in Salmonella typhimurium.

    PubMed Central

    Schmid, M B

    1990-01-01

    Thirteen temperature-sensitive lethal mutations of Salmonella typhimurium map near metC at 65 min and form the clmF (conditional lethal mutation) locus. The mutations in this region were ordered by three-point transduction crosses. After a shift to the nonpermissive temperature, many of these clmF mutants failed to complete the segregation of nucleoids into daughter cells; daughter nucleoids appeared incompletely separated and asymmetrically positioned within cells. Some clmF mutants showed instability of F' episomes at permissive growth temperatures yet showed no detectable defect with smaller multicopy plasmids such as pSC101 or pBR322. In addition, many of the clmF mutants rapidly lost viability yet continued DNA replication at the nonpermissive temperature. These results suggest that the clmF locus encodes at least one indispensable gene product that is required for faithful partitioning of the bacterial nucleoid and F-plasmid replicons. Images PMID:2203751

  16. Flagella-independent surface motility in Salmonella enterica serovar Typhimurium

    PubMed Central

    Park, Sun-Yang; Pontes, Mauricio H.; Groisman, Eduardo A.

    2015-01-01

    Flagella are multiprotein complexes necessary for swimming and swarming motility. In Salmonella enterica serovar Typhimurium, flagella-mediated motility is repressed by the PhoP/PhoQ regulatory system. We now report that Salmonella can move on 0.3% agarose media in a flagella-independent manner when experiencing the PhoP/PhoQ-inducing signal low Mg2+. This motility requires the PhoP-activated mgtA, mgtC, and pagM genes, which specify a Mg2+ transporter, an inhibitor of Salmonella’s own F1Fo ATPase, and a small protein of unknown function, respectively. The MgtA and MgtC proteins are necessary for pagM expression because pagM mRNA levels were lower in mgtA and mgtC mutants than in wild-type Salmonella, and also because pagM expression from a heterologous promoter rescued motility in mgtA and mgtC mutants. PagM promotes group motility by a surface protein(s), as a pagM-expressing strain conferred motility upon a pagM null mutant, and proteinase K treatment eliminated motility. The pagM gene is rarely found outside subspecies I of S. enterica and often present in nonfunctional allelic forms in organisms lacking the identified motility. Deletion of the pagM gene reduced bacterial replication on 0.3% agarose low Mg2+ media but not in low Mg2+ liquid media. Our findings define a form of motility that allows Salmonella to scavenge nutrients and to escape toxic compounds in low Mg2+ semisolid environments. PMID:25624475

  17. Evaluation of Two Salmonella typhimurium Hybrids as Challenge Organisms in a System for the Assay of Typhoid Vaccines

    DTIC Science & Technology

    1982-03-02

    March 1982/Accepted 2 July 1982 ___A mouse-virulent Salmonella typhinturitim hybrid (H42), which expresses the -ac Salmonella typhi Vi antigen in addition... Salmonella typhi surface antigens as ments in which S. typhimurium hybrids, ex- challenge organisms in vaccinated Swiss-Web- pressing different... Salmonella typhi anti- ride-protein conjugates induce protection against infec- gens. Infect. Immun. 24:90-93. lion with Salmonella typhimurium. Infect. Immun

  18. Natural surface coating to inactivate Salmonella enterica Serovar Typhimurium and maintain quality of cherry tomatoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of the present study were to investigate the effectiveness of zein-based coatings in reducing populations of Salmonella enterica serovar Typhimurium and preserving quality of cherry tomatoes. Tomatoes were inoculated with a cocktail of S. Typhimurium LT2 plus three mutants on the smoo...

  19. Efficacy of myrtle oil against Salmonella Typhimurium on fresh produce.

    PubMed

    Gündüz, Gülten Tiryaki; Gönül, Sahika Aktuğ; Karapinar, Mehmet

    2009-03-31

    The antimicrobial activity of myrtle leaves (Myrtus communis) oil was tested against the nalidixic acid resistant strain of Salmonella Typhimurium ATCC 13311. An inoculum (100 microl, ca.10(8) cfu/ml) was deposited on the skin of whole tomatoes and 10 g of shredded iceberg lettuce, dried for 2 h at 22 degrees C and held for 22 h at 4 degrees C before treatments. Inoculated iceberg lettuce (3.51-3.99 log cfu/g) and tomatoes (3.47-4.86 log cfu/tomato) were treated with three different washing procedures for 5, 10, 15 and 20 min; washing with sterile distilled water (control), washing with three different concentrations of myrtle leaves oil and the last treatment was a combination of washing with myrtle leaves oil and then rinsing in sterile distilled water for 1 min. Washing with myrtle leaves oil with or without rinsing procedures caused significant reduction in S. Typhimurium population compared with the control after treatment for four different times (p<0.05). There is no significant difference between washing times in reduction of S. Typhimurium (p>0.05). The maximum logarithmic reductions of 1.66 cfu/g-1.89 cfu/tomato were respectively obtained on iceberg lettuce and tomatoes treated with 1000 ppm myrtle leaves oil without any rinsing treatment. The results suggest that the use of myrtle leaves oil is an innovative and useful tool as an alternative to the use of chlorine or other synthetic disinfectants in fruits and vegetables, especially for organic products.

  20. Fine structure analysis of Salmonella typhimurium glutamate synthase genes.

    PubMed Central

    Madonna, M J; Fuchs, R L; Brenchley, J E

    1985-01-01

    Glutamate synthase activity is required for the growth of Salmonella typhimurium on media containing a growth-rate-limiting nitrogen source. Mutations that alter glutamate synthase activity had been identified in the gltB gene, but it was not known which of the two nonidentical subunits of the enzyme was altered. To examine the gene-protein relationship of the glt region, two nonsense mutations were identified and used to demonstrate that gltB encodes the large subunit of the enzyme. Six strains with independent Mu cts d1 (lac bla) insertions were isolated, from which a collection of deletion mutations was obtained. The deletions were transduced with the nonsense mutations and 38 other glt point mutations to construct a fine-structure genetic map. Chromosome mobilization studies, mediated by Hfr derivatives of Mu cts d1 lysogens, showed that gltB is transcribed in a clockwise direction, as shown in the S. typhimurium linkage map. Studies of the polar effects of three Mu cts d1 insertions indicated that the gene for the small subunit maps clockwise to gltB and that the two genes are cotranscribed to form a glt operon. Images PMID:3881392

  1. Drug Resistance in Salmonella Typhimurium and its Implications*

    PubMed Central

    Anderson, E. S.

    1968-01-01

    A rise in Salmonella typhimurium infection was observed in calves in Britain during 1964–6, follwing the adoption of the intensive farming method. A single phage type of S. typhimurium, type 29, was incriminated as the major pathogen. Attempts to treat and control the disease with a range of antibiotics were ineffective, but resulted in the acquisition of transferable multiple drug resistance by type 29. The transmission of drug-resistant type 29, directly or indirectly, from bovines to man resulted in many human infections. Transferable drug resistance reaching man from enterobacteria of animal origin may ultimately enter specifically human pathogens. Infections such as that caused by type 29 can be eliminated, not by the massive use of antibiotics but by improvement in conditions of animal husbandry and reduction in the opportunities for the initiation and spread of the disease. A reappraisal is needed of the methods of using antibiotics to determine how these methods can be improved, in order to conserve the long-term efficacy of the antibiotics. PMID:4874171

  2. Resolution and purification of three periplasmic phosphatases of Salmonella typhimurium.

    PubMed Central

    Kier, L D; Weppelman, R; Ames, B N

    1977-01-01

    A survey of Salmonella typhimurium enzymes possessing phosphatase or phosphodiesterase activity was made using several different growth conditions. These studies revealed the presence of three major enzymes, all of which were subsequently purified: a cyclic 2' ,3'-nucleotide phosphodiesterase (EC 3.1.4.d), an acid hexose phosphatase (EC 3.1.3.2), and a nonspecific acid phosphatase (EC 3.1.3.2). A fourth enzyme hydrolyzed bis-(p-nitrophenyl)phosphate but none of the other substrates tested. No evidence was found for the existence of an alkaline phosphatase (EC 3.1.3.1) or a specific 5'-nucleotidase (EC 3.1.3.5) in S. typhimurium LT2. All three phosphatases could be measured efficiently in intact cells, which suggested a periplasmic location; however, they were not readily released by osmotic shock procedures. The nonspecific acid phosphatase, which was purified to apparent homogeneity, yielded a single polypeptide band on both sodium dodecyl sulfate and acidic urea gel electrophoretic systems. Images PMID:192712

  3. Hysteresis in myo-inositol utilization by Salmonella Typhimurium.

    PubMed

    Hellinckx, Jessica; Fuchs, Thilo M

    2016-12-27

    Growth of Salmonella enterica serovar Typhimurium strain 14028 with myo-inositol (MI) as the sole carbon and energy source is characterized by a bistable phenotype that manifests in a growth phenotype with an extraordinarily long and length-variable lag phase. However, in the presence of hydrogen carbonate, in the absence of IolR that represses the MI degradation pathway, or if cells are already adapted to minimal medium (MM) with MI, the lag phase is drastically shortened, and the bistable phenotype is abolished. We hypothesized that memory development or hysteresis is a further characteristic of MI degradation by S. Typhimurium; therefore, we investigated the transition from a short to a long lag phase in more detail. Growth experiments demonstrated that memory on the population level is successively lost within approximately 8 hr after cells, which had been adapted to MI utilization, were transferred to lysogeny broth (LB) medium. Flow cytometry (FC) analysis using a chromosomal fusion to PiolE , a promoter controlling the expression of the enzymatic genes iolE and iolG involved in MI degradation, indicated a gradual reversion within a few hours from a population in the "ON" status with respect to iolE transcription to one that is mainly in the "OFF" status. Growth and FC experiments revealed that IolR does not affect hysteresis.

  4. Roles of diet and the acid tolerance response in survival of common Salmonella serotypes in feces of finishing pigs.

    PubMed

    Rajtak, Ursula; Boland, Fiona; Leonard, Nola; Bolton, Declan; Fanning, Séamus

    2012-01-01

    The persistence of Salmonella in the environment is an important factor influencing the transmission of infection in pig production. This study evaluated the effects of acid tolerance response (ATR), organic acid supplementation, and physical properties of feed on the survival of a five-strain Salmonella mixture in porcine feces held at 4 and 22°C for 88 days. Acid-adapted or non-acid-adapted nalidixic acid-resistant Salmonella strains were used to inoculate feces of pigs fed four different diets, which consisted of a nonpelleted, finely ground meal feed or a finely ground, pelleted feed that was left unsupplemented or was supplemented with K-diformate. Organic acid supplementation and physical properties of feed markedly influenced Salmonella survival, but the effects were highly dependent on storage temperature; survival was unaffected by ATR. The most pronounced effects were observed at 22°C, a temperature similar to that of finishing pig houses. The supplementation of meal diets with K-diformate significantly reduced the duration of survival (P < 0.1) and increased rates of decline (P < 0.0001) of salmonellae in feces compared to survival in feces of pigs fed unsupplemented meal. The pelleting of feed, compared to feeding meal, significantly reduced (P < 0.1) the duration of survival in feces held at 22°C. Only minor effects of feed form and acid supplementation on survivor numbers were observed at 4°C. Differences in the fecal survival of Salmonella could not be related to diet-induced changes in fecal physiochemical parameters. The predominant survival of S. enterica serovar Typhimurium DT193 and serotype 4,[5],12:i:- in porcine feces demonstrates the superior ability of these serotypes to survive in this environment. Fecal survival and transmission of Salmonella in pig herds may be reduced by dietary approaches, but effects are highly dependent on environmental temperature.

  5. Outer membrane vesicles derived from Salmonella Typhimurium mutants with truncated LPS induce cross-protective immune responses against infection of Salmonella enterica serovars in the mouse model.

    PubMed

    Liu, Qiong; Liu, Qing; Yi, Jie; Liang, Kang; Liu, Tian; Roland, Kenneth L; Jiang, Yanlong; Kong, Qingke

    2016-12-01

    Salmonella enterica cause diarrheal and systemic diseases and are of considerable concern worldwide. Vaccines that are cross-protective against multiple serovars could provide effective control of Salmonella-mediated diseases. Bacteria-derived outer membrane vesicles (OMVs) are highly immunogenic and are capable of eliciting protective immune responses. Alterations in lipopolysaccharide (LPS) length can result in outer membrane remodeling and composition of outer membrane proteins (OMPs) changing. In this study, we investigated the impact of truncated LPS on both the production and immunogenicity of Salmonella OMVs, including the ability of OMVs to elicit cross-protection against challenge by heterologous Salmonella strains. We found that mutations in waaJ and rfbP enhanced vesiculation, while mutations in waaC, waaF and waaG inhibited this process. Animal experiments indicated that OMVs from waaC, rfaH and rfbP mutants induced stronger serum immune responses compared to OMVs from the parent strain, while all elicited protective responses against the wild-type S. Typhimurium challenge. Furthermore, intranasal or intraperitoneal immunization with OMVs derived from the waaC and rfbP mutants elicited significantly higher cross-reactive IgG responses and provided enhanced cross-protection against S. Choleraesuis and S. Enteritidis challenge than the wild-type OMVs. These results indicate that truncated-LPS OMVs are capable of conferring cross protection against multiple serotypes of Salmonella infection.

  6. Chlorine inactivation of nonresistant and antibiotic-resistant strains of salmonella typhimurium isolated from chicken carcasses.

    PubMed

    Oscar, T P; Tasmin, R; Parveen, S

    2013-06-01

    A study was conducted to test the hypothesis that strains of Salmonella Typhimurium that are resistant to antibiotics are more resistant to chlorine in chilled water than strains of Salmonella Typhimurium that are not resistant to antibiotics. To test this hypothesis, strains (n = 16) of Salmonella Typhimurium with four antibiotic resistance profiles were tested for their inactivation kinetics in chlorinated (30 ppm, pH 6) water at 4°C. The four antibiotic resistance profiles were (i) none; (ii) tetracycline-sulfisoxazole (T-Su); (iii) tetracycline-ampicillin-amoxicillin-cefoxitin-ceftiofur-sulfisoxazole (T-A-Am-C-Ce-Su); and (iv) tetracycline-ampicillin-amoxicillin-cefoxitin-ceftiofur-sulfisoxazole-kanamycin (T-A-Am-C-Ce-Su-K). Inactivation of Salmonella Typhimurium in chlorinated water displayed nonlinear kinetics with a concave downward curve that fit well (R(2) = 0.964) to the power law model, with a shape parameter of 1.37. The time for a single log reduction (D-value) of Salmonella Typhimurium from an initial concentration of 5.36 log/ml did not differ (P > 0.05) among the four antibiotic resistance groups and ranged from 3.8 to 4.3 min for n = 4 strains per group. Thus, the hypothesis was rejected, and it was concluded that expression of an antibiotic resistance phenotype does not confer cross-protection in Salmonella Typhimurium to chlorine inactivation in chilled water.

  7. The detection of Salmonella typhimurium on shell eggs using a phage-based biosensor

    NASA Astrophysics Data System (ADS)

    Chai, Yating; Li, Suiqiong; Horikawa, Shin; Shen, Wen; Park, Mi-Kyung; Vodyanoy, Vitaly J.; Chin, Bryan A.

    2011-06-01

    This paper presents the direct detection of Salmonella typhimurium on shell eggs using a phage-based magnetoelastic (ME) biosensor. The ME biosensor consists of a ME resonator as the sensor platform and E2 phage as the biorecognition element that is genetically engineered to specifically bind with Salmonella typhimurium. The ME biosensor, which is a wireless sensor, vibrates with a characteristic resonant frequency under an externally applied magnetic field. Multiple sensors can easily be remotely monitored. Multiple measurement and control sensors were placed on the shell eggs contaminated by Salmonella typhimurium solutions with different known concentrations. The resonant frequency of sensors before and after the exposure to the spiked shell eggs was measured. The frequency shift of the measurement sensors was significantly different than the control sensors indicating Salmonella contamination. Scanning electron microscopy was used to confirm binding of Salmonella to the sensor surface and the resulting frequency shift results.

  8. T-2 toxin induced Salmonella Typhimurium intoxication results in decreased Salmonella numbers in the cecum contents of pigs, despite marked effects on Salmonella-host cell interactions.

    PubMed

    Verbrugghe, Elin; Vandenbroucke, Virginie; Dhaenens, Maarten; Shearer, Neil; Goossens, Joline; De Saeger, Sarah; Eeckhout, Mia; D'Herde, Katharina; Thompson, Arthur; Deforce, Dieter; Boyen, Filip; Leyman, Bregje; Van Parys, Alexander; De Backer, Patrick; Haesebrouck, Freddy; Croubels, Siska; Pasmans, Frank

    2012-03-22

    The mycotoxin T-2 toxin and Salmonella Typhimurium infections pose a significant threat to human and animal health. Interactions between both agents may result in a different outcome of the infection. Therefore, the aim of the presented study was to investigate the effects of low and relevant concentrations of T-2 toxin on the course of a Salmonella Typhimurium infection in pigs. We showed that the presence of 15 and 83 μg T-2 toxin per kg feed significantly decreased the amount of Salmonella Typhimurium bacteria present in the cecum contents, and a tendency to a reduced colonization of the jejunum, ileum, cecum, colon and colon contents was noticed. In vitro, proteomic analysis of porcine enterocytes revealed that a very low concentration of T-2 toxin (5 ng/mL) affects the protein expression of mitochondrial, endoplasmatic reticulum and cytoskeleton associated proteins, proteins involved in protein synthesis and folding, RNA synthesis, mitogen-activated protein kinase signaling and regulatory processes. Similarly low concentrations (1-100 ng/mL) promoted the susceptibility of porcine macrophages and intestinal epithelial cells to Salmonella Typhimurium invasion, in a SPI-1 independent manner. Furthermore, T-2 toxin (1-5 ng/mL) promoted the translocation of Salmonella Typhimurium over an intestinal porcine epithelial cell monolayer. Although these findings may seem in favour of Salmonella Typhimurium, microarray analysis showed that T-2 toxin (5 ng/mL) causes an intoxication of Salmonella Typhimurium, represented by a reduced motility and a downregulation of metabolic and Salmonella Pathogenicity Island 1 genes. This study demonstrates marked interactions of T-2 toxin with Salmonella Typhimurium pathogenesis, resulting in bacterial intoxication.

  9. sn-Glycerol-3-phosphate transport in Salmonella typhimurium.

    PubMed Central

    Hengge, R; Larson, T J; Boos, W

    1983-01-01

    Salmonella typhimurium contains a transport system for sn-glycerol-3-phosphate that is inducible by growth on glycerol and sn-glycerol-3-phosphate. In fully induced cells, the system exhibited an apparent Km of 50 microM and a Vmax of 2.2 nmol/min . 10(8) cells. The corresponding system in Escherichia coli exhibits, under comparable conditions, a Km of 14 microM and a Vmax of 2.2 nmol/min . 10(8) cells. Transport-defective mutants were isolated by selecting for resistance against the antibiotic fosfomycin. They mapped in glpT at 47 min in the S. typhimurium linkage map, 37% cotransducible with gyrA. In addition to the glpT-dependent system, S. typhimurium LT2 contains, like E. coli, a second, ugp-dependent transport system for sn-glycerol-3-phosphate that was derepressed by phosphate starvation. A S. typhimurium DNA bank containing EcoRI restriction fragments in phage lambda gt7 was used to clone the glpT gene in E. coli. Lysogens that were fully active in the transport of sn-glycerol-3-phosphate with a Km of 33 microM and a Vmax of 2.0 nmol/min . 10(8) cells were isolated in a delta glpT mutant of E. coli. The EcoRI fragment harboring glpT was 3.5 kilobases long and carried only part of glpQ, a gene distal to glpT but on the same operon. The fragment was subcloned in multicopy plasmid pACYC184. Strains carrying this hybrid plasmid produced large amounts of cytoplasmic membrane protein with an apparent molecular weight of 33,000, which was identified as the sn-glycerol-3-phosphate permease. Its properties were similar to the corresponding E. coli permease. The presence of the multicopy glpT hybrid plasmid had a strong influence on the synthesis or assembly of other cell envelope proteins of E. coli. For instance, the periplasmic ribose-binding protein was nearly absent. On the other hand, the quantity of an unidentified E. coli outer membrane protein usually present only in small amounts increased. Images PMID:6408060

  10. Crystal Structure of the Salmonella Typhimurium Effector GtgE

    PubMed Central

    Wong, Kathy; Gehring, Kalle; Cygler, Miroslaw

    2016-01-01

    Salmonella Typhimurium GtgE is an effector protein contributing to the virulence of this pathogen. It was shown to possess highly selective proteolytic activity against a subset of Rab proteins that helps in evasion of Salmonella-containing vacuole (SCV) fusion with lysosomes. Cys45, His151 and Asp169 are essential for proteolytic activity. The structure of a C-terminal fragment GtgE(79–214) indicated the presence of a papain-like fold. Here, we present the structure of GtgE(17–214) containing the fully assembled active site. The design of a proteolytically active and crystallizable GtgE construct was aided by NMR spectroscopy. The protein indeed displays papain-like fold with an assembled Cys-His-Asp catalytic triad. Like the full-length GtgE, the crystallizable construct showed low activity in vitro for its known substrates, Rab32 and Rab29. NMR titration experiments showed at most very weak binding of GtgE to the peptide encompassing the Rab29 cleavage site. In view of the low in vitro activity and poor substrate binding, we postulate that the function of GtgE in vivo as a proteolytic enzyme is dependent on other factor(s), such as a protein partner or interactions with the SCV membrane, which stimulate(s) GtgE activity in vivo. PMID:27923041

  11. DNA ligase and the pyridine nucleotide cycle in Salmonella typhimurium.

    PubMed Central

    Park, U E; Olivera, B M; Hughes, K T; Roth, J R; Hillyard, D R

    1989-01-01

    Bacterial DNA ligases use NAD as an energy source. In this study we addressed two questions about these enzymes. First, what is the physiological consequence of completely removing the NAD-dependent enzyme and replacing it with an ATP-dependent DNA ligase? We constructed Salmonella typhimurium strains in which the endogenous NAD-dependent DNA ligase activity was inactivated by an insertion mutation and the ATP-dependent enzyme from bacteriophage T4 was provided by a cloned phage gene. Such strains were physiologically indistinguishable from the wild type, even under conditions of UV irradiation or treatment with alkylating agents. These results suggest that specific functional interactions between DNA ligase and other replication and repair enzymes may be unimportant under the conditions tested. Second, the importance of DNA ligation as the initiating event of the bacterial pyridine nucleotide cycle was critically assessed in these mutant strains. Surprisingly, our results indicate that DNA ligation makes a minimal contribution to the pyridine nucleotide cycle; the Salmonella strains with only an ATP-dependent ligase had the same NAD turnover rates as the wild-type strain with an NAD-dependent ligase. However, we found that NAD turnover was significantly decreased under anaerobic conditions. We suggest that most intracellular pyridine nucleotide breakdown occurs in a process that protects the cell against oxygen damage but involves a biochemical mechanism other than DNA ligation. Images PMID:2649488

  12. Detection of Multidrug-Resistant Salmonella enterica Serovar Typhimurium Phage Types DT102, DT104, and U302 by Multiplex PCR

    PubMed Central

    Chiu, Cheng-Hsun; Su, Lin-Hui; Chu, Chi-Hong; Wang, Mei-Hwei; Yeh, Chia-Ming; Weill, Francois-Xavier; Chu, Chishih

    2006-01-01

    Salmonella enterica serovar Typhimurium is a common cause of nontyphoidal salmonellosis in humans and animals. Multidrug-resistant serovar Typhimurium phage type DT104, which emerged in the 1990s, has become widely distributed in many countries. A total of 104 clinical isolates of Salmonella serogroup B were collected from three major hospitals in Taiwan during 1997 to 2003 and were examined by a multiplex PCR targeting the resistance genes and the spv gene of the virulence plasmid. A total of 51 isolates (49%) were resistant to all drugs (ACSSuT [resistance to ampicillin, chloramphenicol, streptomycin, sulfonamide, and tetracycline]), and all contained a 1.25-kb PCR fragment of integron that is part of the 43-kb Salmonella genomic island 1 (SGI1). The second group was resistant to SSu (28%), and the third was susceptible to all five drugs (13%). Fifty-nine isolates were serotyped to be serovar Typhimurium by the tube agglutination method using H antisera. The virulence plasmid was found in 54 (91.5%) of the 59 serovar Typhimurium isolates. A majority (94.1%) of the Salmonella serogroup B isolates with the ACSSuT resistance pattern harbored a virulence plasmid. Phage typing identified three major phage types: DT104, DT120, and U302. Analysis of the isolates by pulsed-field gel electrophoresis showed six genotypes. We found two genotypes in DT104 strains, two in DT120, and the other two in U302. The presence of a monophasic serovar (4,5,12:i:−) has added difficulty in the determination of the serovars of multidrug-resistant Salmonella serogroup B isolates. Nevertheless, the multiplex PCR devised in the present study appears to be efficient and useful in the rapid identification of ACSSuT-type serovar Typhimurium with SGI1, irrespective of their phage types. PMID:16825349

  13. Extensive Genetic Variability Linked to IS26 Insertions in the fljB Promoter Region of Atypical Monophasic Variants of Salmonella enterica Serovar Typhimurium

    PubMed Central

    Boland, Cécile; Bertrand, Sophie; Mattheus, Wesley; Dierick, Katelijne; Jasson, Vicky; Rosseel, Toon; Van Borm, Steven; Mahillon, Jacques

    2015-01-01

    Fifty-nine monophasic Salmonella enterica serovar Typhimurium isolates, collected in Belgium during the period from 2008 to 2011, have been serotyped as 4,[5]:i:− and shown to harbor an fljB coding sequence. The genetic differences between these strains and phenotypically biphasic Salmonella Typhimurium were analyzed through PCR and DNA sequencing. Genetic alterations in the fljB promoter region affecting expression of the phase 2 flagellin were observed in 53 isolates. Other genetic events in the invertible region carrying the fljB promoter were observed in 2 isolates. For the remaining 4 isolates, no molecular differences with a reference biphasic Salmonella Typhimurium strain could be observed. Next-generation sequencing of one representative isolate affected in the fljB promoter region revealed a 26-kb IS26 composite transposon insertion along with a local genomic rearrangement. Several other IS26 element-mediated alterations of this genomic region were observed. This group of monophasic Salmonella Typhimurium isolates was genetically heterogeneous, as revealed by multilocus variable-number tandem-repeat analysis (MLVA), PCR, and sequencing. Pigs and pork represented a major source of such monophasic isolates in Belgium, as reported in other countries. Three out of 5 isolates of human origin presented genetic profiles identical to those of food isolates, demonstrating the pathogenic potential of the newly characterized variants and potential dissemination along the food chain. This study highlighted the key role played by IS26 insertions in the loss of phase 2 flagellin expression and the subsequent generation of multiple monophasic variant lineages from biphasic Salmonella Typhimurium ancestors. PMID:25724958

  14. Around the World in 1,475 Salmonella Geo-serotypes

    PubMed Central

    Le Hello, Simon; de Jong, Birgitta; Rolfhamre, Per; Faensen, Daniel; Weill, François-Xavier; Giesecke, Johan

    2016-01-01

    It’s easy to remember Salmonella serotypes names, isn’t it? Surely, this is because the naming system of Salmonella serotypes is by far the most scientist friendly. Traditionally, most Salmonella serotypes have been named after geographic locations. We decided to explore the geographic locations to which Salmonella serotypes refer and describe some unexpected twists in the naming scheme. We found that 93% (n = 1,475) of the 1,585 serotypes could be categorized as geo-serotypes; that is, the name refers to a geographic location. The 3 countries with the most geo-serotypes are Germany, the United Kingdom, and the United States. Other serotype names refer to the name of a person, animal, tribe, or food item or are a composite of symptoms and host. The Salmonella serotypes naming scheme has had a valuable effect on public health microbiology, and in the current era of fast development of whole-genome sequencing, it should remain a reference.

  15. Identification of a umuDC locus in Salmonella typhimurium LT2

    SciTech Connect

    Smith, C.M.; Eisenstadt, E. )

    1989-07-01

    The umuDC operon of Escherichia coli is required for efficient mutagenesis by UV light and many other DNA-damaging agents. The existence of a umuDC analog in Salmonella typhimurium has been questioned. With DNA probes to the E. coli umuD and umuC genes, we detected, by Southern blot hybridization, sequences similar to both of these genes in S. typhimurium LT2. We also confirmed that the presence of cloned E. coli umuD enhances the UV mutability and resistance of S. typhimurium. Our data strongly suggest that S. typhimurium contains a functional umuDC operon.

  16. Antibiotics induce the expression of attachment genes in specific isolates of Salmonella enterica serovar Typhimurium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More than 27 percent of Salmonella enterica serovar Typhimurium isolates from humans in the United States are resistant to three or more antibiotics. This presents an important food safety concern as multidrug-resistant (MDR) Salmonella is associated with increased morbidity in humans. It has been...

  17. Tetracycline promotes the expression of ten fimbrial operons in specific Salmonella enterica serovar Typhimurium isolates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multidrug-resistant (MDR) Salmonella is associated with increased morbidity in humans and presents an important food safety concern. Antibiotic resistance among isolates of Salmonella enterica serovar Typhimurium has become especially prevalent as over 27 per cent of isolates from humans in the Unit...

  18. Hydrogen-Stimulated carbon acquisition and conservation in salmonella enterica serovar typhimurium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella enterica serovar Typhimurium can utilize molecular hydrogen for growth and amino acid transport during anaerobic growth. Via microarray we identified H2 gas-affected gene expression changes in Salmonella. Addition of H2 caused altered expression of 965 genes; 176 genes were H2-up-regulate...

  19. Genomic heterogeneity of Salmonella enterica serovar Typhimurium bacteriuria from chronic infection.

    PubMed

    Octavia, Sophie; Wang, Qinning; Tanaka, Mark M; Sintchenko, Vitali; Lan, Ruiting

    2017-03-07

    We sequenced the genomes of 14 sequential Salmonella enterica serovar Typhimurium isolates obtained over a five year period from a patient with persistent Salmonella bacteriuria. The isolates formed five distinct lineages; two of which co-existed over four years. We inferred that the observed within-patient variation resulted from mutation events.

  20. Signatures of Adaptation in Human Invasive Salmonella Typhimurium ST313 Populations from Sub-Saharan Africa

    PubMed Central

    Okoro, Chinyere K.; Barquist, Lars; Connor, Thomas R.; Harris, Simon R.; Clare, Simon; Stevens, Mark P.; Arends, Mark J.; Hale, Christine; Kane, Leanne; Pickard, Derek J.; Hill, Jennifer; Harcourt, Katherine; Parkhill, Julian; Dougan, Gordon; Kingsley, Robert A.

    2015-01-01

    Two lineages of Salmonella enterica serovar Typhimurium (S. Typhimurium) of multi-locus sequence type ST313 have been linked with the emergence of invasive Salmonella disease across sub-Saharan Africa. The expansion of these lineages has a temporal association with the HIV pandemic and antibiotic usage. We analysed the whole genome sequence of 129 ST313 isolates representative of the two lineages and found evidence of lineage-specific genome degradation, with some similarities to that observed in S. Typhi. Individual ST313 S. Typhimurium isolates exhibit a distinct metabolic signature and modified enteropathogenesis in both a murine and cattle model of colitis, compared to S. Typhimurium outside of the ST313 lineages. These data define phenotypes that distinguish ST313 isolates from other S. Typhimurium and may represent adaptation to a distinct pathogenesis and lifestyle linked to an-immuno-compromised human population. PMID:25803844

  1. Localization of viable Salmonella typhimurium internalized through the surface of green onion during preharvest.

    PubMed

    Ge, Chongtao; Lee, Cheonghoon; Lee, Jiyoung

    2013-04-01

    Internalization of pathogens poses a tremendous health risk in the consumption of raw fresh produce, because conventional washing cannot remove pathogens effectively after internalization occurs. We investigated (i) the pattern of Salmonella internalization in different parts of green onions when it was contaminated on their surfaces, and (ii) whether environmental factors (extreme weather) affect the extent of Salmonell a internalization. Green onions were surface contaminated with three different levels of Salmonella Typhimurium (1, 3, and 5 log CFU per green onion). Each contamination group was irrigated with three different water volumes to mimic water stress and to determine if Salmonella Typhimurium internalization was localized in different parts of the plant. The plants were collected 2 days after contamination, and surface bacteria were inactivated with ethanol and silver nitrate. The plants were then cut into two parts, upper and lower. The internalized Salmonella Typhimurium in each part was visualized and confirmed with a laser scanning confocal microscope and was quantified with the plate count method and real-time quantitative PCR (qPCR). The results indicate that Salmonella Typhimurium can be taken up through the plant surface and transported from the upper to the lower part of the plant. The level of viable internalized Salmonella Typhimurium (plate count) was higher in the lower part than the level in the upper leafy part, especially when the leaves were contaminated with a high concentration of Salmonella (5 log CFU, P < 0.05), whereas the total internalized Salmonella Typhimurium (by qPCR) was higher in the upper part (P < 0.05) at the same contamination level. The discrepancy between these results suggests that most internalized Salmonella lost viability in the upper part but survived in the lower part. Water stress did not significantly change the extent of internalization in either location of green onion, whether detected via plate count or q

  2. Quantitative proteomics and bioinformatic analysis provide new insight into the dynamic response of porcine intestine to Salmonella Typhimurium

    PubMed Central

    Collado-Romero, Melania; Aguilar, Carmen; Arce, Cristina; Lucena, Concepción; Codrea, Marius C.; Morera, Luis; Bendixen, Emoke; Moreno, Ángela; Garrido, Juan J.

    2015-01-01

    The enteropathogen Salmonella Typhimurium (S. Typhimurium) is the most commonly non-typhoideal serotype isolated in pig worldwide. Currently, one of the main sources of human infection is by consumption of pork meat. Therefore, prevention and control of salmonellosis in pigs is crucial for minimizing risks to public health. The aim of the present study was to use isobaric tags for relative and absolute quantification (iTRAQ) to explore differences in the response to Salmonella in two segment of the porcine gut (ileum and colon) along a time course of 1, 2, and 6 days post infection (dpi) with S. Typhimurium. A total of 298 proteins were identified in the infected ileum samples of which, 112 displayed significant expression differences due to Salmonella infection. In colon, 184 proteins were detected in the infected samples of which 46 resulted differentially expressed with respect to the controls. The higher number of changes in protein expression was quantified in ileum at 2 dpi. Further biological interpretation of proteomics data using bioinformatics tools demonstrated that the expression changes in colon were found in proteins involved in cell death and survival, tissue morphology or molecular transport at the early stages and tissue regeneration at 6 dpi. In ileum, however, changes in protein expression were mainly related to immunological and infection diseases, inflammatory response or connective tissue disorders at 1 and 2 dpi. iTRAQ has proved to be a proteomic robust approach allowing us to identify ileum as the earliest response focus upon S. Typhimurium in the porcine gut. In addition, new functions involved in the response to bacteria such as eIF2 signaling, free radical scavengers or antimicrobial peptides (AMP) expression have been identified. Finally, the impairment at of the enterohepatic circulation of bile acids and lipid metabolism by means the under regulation of FABP6 protein and FXR/RXR and LXR/RXR signaling pathway in ileum has been

  3. Interaction of Salmonella enterica Serovar Typhimurium with Intestinal Organoids Derived from Human Induced Pluripotent Stem Cells.

    PubMed

    Forbester, Jessica L; Goulding, David; Vallier, Ludovic; Hannan, Nicholas; Hale, Christine; Pickard, Derek; Mukhopadhyay, Subhankar; Dougan, Gordon

    2015-07-01

    The intestinal mucosa forms the first line of defense against infections mediated by enteric pathogens such as salmonellae. Here we exploited intestinal "organoids" (iHOs) generated from human induced pluripotent stem cells (hIPSCs) to explore the interaction of Salmonella enterica serovar Typhimurium with iHOs. Imaging and RNA sequencing were used to analyze these interactions, and clear changes in transcriptional signatures were detected, including altered patterns of cytokine expression after the exposure of iHOs to bacteria. S. Typhimurium microinjected into the lumen of iHOs was able to invade the epithelial barrier, with many bacteria residing within Salmonella-containing vacuoles. An S. Typhimurium invA mutant defective in the Salmonella pathogenicity island 1 invasion apparatus was less capable of invading the iHO epithelium. Hence, we provide evidence that hIPSC-derived organoids are a promising model of the intestinal epithelium for assessing interactions with enteric pathogens.

  4. Inactivation of Salmonella Senftenberg, Salmonella Typhimurium and Salmonella Tennessee in peanut butter by 915 MHz microwave heating.

    PubMed

    Song, Won-Jae; Kang, Dong-Hyun

    2016-02-01

    This study evaluated the efficacy of a 915 MHz microwave with 3 different levels to inactivate 3 serovars of Salmonella in peanut butter. Peanut butter inoculated with Salmonella enterica serovar Senftenberg, S. enterica serovar Typhimurium and S. enterica serovar Tennessee were treated with a 915 MHz microwave with 2, 4 and 6 kW and acid and peroxide values and color changes were determined after 5 min of microwave heating. Salmonella populations were reduced with increasing treatment time and treatment power. Six kW 915 MHz microwave treatment for 5 min reduced these three Salmonella serovars by 3.24-4.26 log CFU/g. Four and two kW 915 MHz microwave processing for 5 min reduced these Salmonella serovars by 1.14-1.48 and 0.15-0.42 log CFU/g, respectively. Microwave treatment did not affect acid, peroxide, or color values of peanut butter. These results demonstrate that 915 MHz microwave processing can be used as a control method for reducing Salmonella in peanut butter without producing quality deterioration.

  5. Heat Survival and Phenotype Microarray Profiling of Salmonella Typhimurium Mutants.

    PubMed

    Dawoud, Turki M; Khatiwara, Anita; Park, Si Hong; Davis, Morgan L; Baker, Christopher A; Ricke, Steven C; Kwon, Young Min

    2017-02-01

    Contamination of food products by pathogenic microorganisms continues to be a major public health and food industry concern. Non-typhoidal Salmonella species have led to numerous outbreaks associated with various foods. A wide variety of methods have been applied and introduced for treatment of fresh foods to eliminate pathogenic as well as spoilage microorganisms. Salmonella can become exposed to elevated temperatures while associated with hosts such as poultry. In addition, heat treatment is also applied at various stages of processing to retain the shelf life of food products. Despite this, these microorganisms may overcome exposure to such treatments through the efficient expression of stress response mechanisms and result in illness following consumption. Thermal stress induces a range of destructive exposures to bacterial cells such as protein damage and DNA damage caused by reactive oxygen species. In this study, we chose three genes (∆recD, ∆STM14_5307, and ∆aroD) associated with conditionally essential genes required for different aspects of optimal growth at 42 °C and evaluated the responses of wild type and mutant Salmonella Typhimurium strains to uncover potential mechanisms that may enable survival and resistance under thermal stress. The RecBCD complex that initiates repair of double-stranded DNA breaks through homologous recombination. STM14_5307 is a transcriptional regulator involved in stationary phase growth and inositol metabolism. The gene aroD is involved in metabolism and stationary phase growth. These strains were characterized via high throughput phenotypic profiling in response to two different growth temperatures (37 °C (human host temperature) and 42 °C (poultry host temperature)). The ∆aroD strain exhibited the highest sensitivity to the various temperatures followed by the ∆recD and ∆STM14_5307 strains, respectively. Achieving more understanding of the molecular mechanisms of heat survival may lead to the development

  6. Antimicrobial Resistance of Salmonella enterica Serovar Typhimurium in Shanghai, China

    PubMed Central

    Wang, Jinyan; Li, Yongrui; Xu, Xuebin; Liang, Beibei; Wu, Fuli; Yang, Xiaoxia; Ma, Qiuxia; Yang, Chaojie; Hu, Xiaofeng; Liu, Hongbo; Li, Hao; Sheng, Chunyu; Xie, Jing; Du, Xinying; Hao, Rongzhang; Qiu, Shaofu; Song, Hongbin

    2017-01-01

    We aimed to analyze the antimicrobial resistance phenotypes and to elucidate the molecular mechanisms underlying resistance to cephalosporins, ciprofloxacin, and azithromycin in Salmonella enterica serovar Typhimurium isolates identified from patients with diarrhea in Shanghai. The isolates showed high rates of resistance to traditional antimicrobials, and 20.6, 12.7, and 5.5% of them exhibited decreased susceptibility to cephalosporins, ciprofloxacin, and azithromycin, respectively. Notably, 473 (84.6%) isolates exhibited multidrug resistance (MDR), including 161 (28.8%) isolates that showed an ACSSuT profile. Twenty-two MDR isolates concurrently exhibited decreased susceptibility to cephalosporins and ciprofloxacin, and six of them were co-resistant to azithromycin. Of all the 71 isolates with decreased susceptibility to ciprofloxacin, 65 showed at least one mutation (D87Y, D87N, or D87G) in gyrA, among which seven isolates simultaneously had mutations of parC (S80R) (n = 6) or parC (T57S/S80R) (n = 1), while 49 isolates with either zero or one mutation in gyrA contained plasmid-mediated quinolone resistance (PMQR) genes including qnrB, qnrS, and aac(6′)-Ib-cr. Among the 115 cephalosporin-resistant isolates, the most common ESBL gene was blaCTX-M, followed by blaTEM-1, blaOXA-1, and blaSHV -12. Eight subtypes of blaCTX-M were identified and blaCTX-M-14 (n = 22) and blaCTX-M-55 (n = 31) were found to be dominant. To the best of our knowledge, this is the first report of the presence of blaCTX-M-123 and blaCTX-M-125 in S. Typhimurium. Besides, mphA gene was identified in 15 of the 31 azithromycin-resistant isolates. Among the 22 isolates with reduced susceptibility to cephalosporins and ciprofloxacin, 15 contained ESBL and PMQR genes. Coexistence of these genes lead to the emergence of MDR and the transmission of them will pose great difficulties in S. Typhimurium treatments. Therefore, surveillance for these MDR isolates should be enhanced.

  7. Functional and crystallographic characterization of Salmonella typhimurium Cu,Zn superoxide dismutase coded by the sodCI virulence gene.

    PubMed

    Pesce, A; Battistoni, A; Stroppolo, M E; Polizio, F; Nardini, M; Kroll, J S; Langford, P R; O'Neill, P; Sette, M; Desideri, A; Bolognesi, M

    2000-09-15

    The functional and three-dimensional structural features of Cu,Zn superoxide dismutase coded by the Salmonella typhimurium sodCI gene, have been characterized. Measurements of the catalytic rate indicate that this enzyme is the most efficient superoxide dismutase analyzed so far, a feature that may be related to the exclusive association of the sodCI gene with the most pathogenic Salmonella serotypes. The enzyme active-site copper ion is highly accessible to external probes, as indicated by quenching of the water proton relaxation rate upon addition of iodide. The shape of the electron paramagnetic resonance spectrum is dependent on the frozen or liquid state of the enzyme solution, suggesting relative flexibility of the copper ion environment. The crystal structure (R-factor 22.6%, at 2.3 A resolution) indicates that the dimeric enzyme adopts the quaternary assembly typical of prokaryotic Cu,Zn superoxide dismutases. However, when compared to the structures of the homologous enzymes from Photobacterium leiognathi and Actinobacillus pleuropneumoniae, the subunit interface of Salmonella Cu,Zn superoxide dismutase shows substitution of 11 out of 19 interface residues. As a consequence, the network of structural water molecules that fill the dimer interface cavity is structured differently from the other dimeric bacterial enzymes. The crystallographic and functional characterization of this Salmonella Cu,Zn superoxide dismutase indicates that structural variability and catalytic efficiency are higher in prokaryotic than in the eukaryotic homologous enzymes.

  8. Assessment of conjugal transfer of antibiotic resistance genes in Salmonella Typhimurium exposed to bile salts.

    PubMed

    He, Xinlong; Ahn, Juhee

    2014-08-01

    This study was designed to evaluate the transfer potential of antibiotic resistance genes in antibiotic-resistant Salmonella Typhimurium (S. Typhimurium(R)) in the presence of bile salts. The resistance of S. Typhimurium(R) to ampicillin, kanamycin, and tetracycline was increased by 64-, 64-, and 512-fold, respectively. The highest transfer frequency from S. Typhimurium(R) to Escherichia coli was observed at the bile salt concentration of 160 μg/ml (3.8 × 10(-3) transferrants/cells). The expression of traJ and traY was suppressed in S. Typhimurium(R) by bile salt. This study provides useful information for understanding the conjugative transfer of antibiotic resistance genes in S. Typhimurium under intestinal conditions.

  9. Outer membrane vesicles from flagellin-deficient Salmonella enterica serovar Typhimurium induce cross-reactive immunity and provide cross-protection against heterologous Salmonella challenge

    PubMed Central

    Liu, Qiong; Liu, Qing; Yi, Jie; Liang, Kang; Hu, Bo; Zhang, Xiangmin; Curtiss, Roy; Kong, Qingke

    2016-01-01

    Outer membrane vesicles (OMVs) isolated from Salmonella Typhimurium are potentially useful for developing subunit vaccines because of high immunogenicity and protective efficacy. However, flagella might remain in OMV pellets following OMV purification, resulting in non-essential immune responses and counteraction of bacterial protective immune responses when developing a vaccine against infection of multiple serotypes Salmonella. In this study, a flagellin-deficient S. Typhimurium mutant was constructed. Lipopolysaccharide profiles, protein profiles and cryo-electron microscopy revealed that there were no significant differences between the wild-type and mutant OMVs, with the exception of a large amount of flagellin in the wild-type OMVs. Neither the wild-type OMVs nor the non-flagellin OMVs were toxic to macrophages. Mice immunized with the non-flagellin OMVs produced high concentrations of IgG. The non-flagellin OMVs elicited strong mucosal antibody responses in mice when administered via the intranasal route in addition to provoking higher cross-reactive immune responses against OMPs isolated from S. Choleraesuis and S. Enteritidis. Both intranasal and intraperitoneal immunization with the non-flagellin OMVs provided efficient protection against heterologous S. Choleraesuis and S. Enteritidis challenge. Our results indicate that the flagellin-deficient OMVs may represent a new vaccine platform that could be exploited to facilitate the production of a broadly protective vaccine. PMID:27698383

  10. Antibiotic treatment selects for cooperative virulence of Salmonella typhimurium.

    PubMed

    Diard, Médéric; Sellin, Mikael E; Dolowschiak, Tamas; Arnoldini, Markus; Ackermann, Martin; Hardt, Wolf-Dietrich

    2014-09-08

    Antibiotics are powerful therapeutics but are not equally effective against all cells in bacterial populations. Bacteria that express an antibiotic-tolerant phenotype ("persisters") can evade treatment [1]. Persisters can cause relapses of the infection after the end of the therapy [2]. It is still poorly understood whether persistence affects the evolution of bacterial virulence. During infections, persisters have been found preferentially at particular sites within the host [3, 4]. If bacterial virulence factors are required to reach such sites, treatment with antibiotics could impose selection on the expression of virulence genes, in addition to their well-established effects on bacterial resistance. Here, we report that treatment with antibiotics selects for virulence and fosters transmissibility of Salmonella Typhimurium. In a mouse model for Salmonella diarrhea, treatment with the broad-spectrum antibiotic ciprofloxacin reverses the outcome of competition between wild-type bacteria and avirulent mutants that can spontaneously arise during within-host evolution [5]. While avirulent mutants take over the gut lumen and abolish disease transmission in untreated mice, ciprofloxacin tilts the balance in favor of virulent, wild-type bacteria. This is explained by the need for virulence factors to invade gut tissues and form a persistent reservoir. Avirulent mutants remain in the gut lumen and are eradicated. Upon cessation of antibiotic treatment, tissue-lodged wild-type pathogens reseed the gut lumen and thereby facilitate disease transmissibility to new hosts. Our results suggest a general principle by which antibiotic treatment can promote cooperative virulence during within-host evolution, increase duration of transmissibility, and thereby enhance the spread of an infectious disease.

  11. Effect of Chitosan on Salmonella Typhimurium in Broiler Chickens

    PubMed Central

    Menconi, Anita; Pumford, Neil R.; Morgan, Marion J.; Bielke, Lisa R.; Kallapura, Gopala; Latorre, Juan D.; Wolfenden, Amanda D.; Hernandez-Velasco, Xochitl; Hargis, Billy M.

    2014-01-01

    Abstract Public concern with the incidence of antibiotic-resistant bacteria, particularly among foodborne pathogens such as Salmonella, has been challenging the poultry industry to find alternative means of control. The purposes of the present study were to evaluate in vitro and in vivo effects of chitosan on Salmonella enterica serovar Typhimurium (ST) infection in broiler chicks. For in vitro crop assay experiments, tubes containing feed, water, and ST were treated with either saline as a control or 0.2% chitosan. The entire assay was repeated in three trials. In two independent in vivo trials, 40 broiler chicks were assigned to an untreated control diet or dietary treatment with 0.2% chitosan for 7 days (20 broiler chicks/treatment). At day 4, chicks were challenged with 2×105 colony-forming units (CFU) ST/bird. In a third in vivo trial, 100 broiler chicks were assigned to untreated control diet or dietary treatment with 0.2% chitosan for 10 days (50 broiler chicks/treatment) to evaluate ST horizontal transmission. At day 3, 10 birds were challenged with 105 CFU ST/bird, and the remaining nonchallenged birds (n=40) were kept in the same floor pen. In all three in vitro trials, 0.2% chitosan significantly reduced total CFU of ST at 0.5 and 6 h postinoculation compared with control (p<0.05). In two in vivo trials, at 7 days, dietary 0.2% chitosan significantly reduced total CFU of recovered ST in the ceca in both experiments. Dietary 0.2% chitosan significantly reduced total ST CFU recovered in the ceca of horizontally challenged birds in the third in vivo trial. Chitosan at 0.2% significantly reduced the CFU of recovered ST in vitro and in vivo, proving to be an alternative tool to reduce crop, ceca, and consequently carcass ST contamination as well as decreasing the amount of ST shed to the environment. PMID:24237042

  12. Evidence for two NAD kinases in Salmonella typhimurium.

    PubMed Central

    Cheng, W.; Roth, J. R.

    1994-01-01

    The electron-carrying cofactor NADP is formed by phosphorylation of NAD. A strategy for the isolation of NAD kinase mutants revealed two classes of temperature-sensitive mutations, nadF and nadG, mapping at min 13 and 72 of the Salmonella chromosome. Both mutant types grew on nutrient broth at both 30 and 42 degrees C but on minimal medium showed a temperature-sensitive growth defect which was not corrected by any of the single nutritional supplements tested. A nadF deletion mutant grew on nutrient broth but not on minimal medium. A double mutant with the nadF deletion and a nadG(Ts) mutation showed temperature-sensitive growth on all media. We propose that Salmonella typhimurium has two NAD kinases, one encoded by the nadF and one by the nadG gene. This is supported by the fact that temperature-sensitive mutants of both genes produce kinase activity with altered heat stability. Results suggest that either one of two NAD kinases is sufficient for growth on rich medium, but that both are needed for growth on minimal media. Enzyme assays show that the nadF gene is responsible for about 70% of total NAD kinase activity, and that the nadG gene dictates the remaining 30%. While testing nutritional phenotypes of nadF and nadG mutants, we found that the biosynthetic intermediate, quinolinic acid (QA) inhibited growth of nadF mutants on nutrient broth. This suggested that the NadG enzyme might be inhibited by QA. Enzyme assays demonstrated that QA inhibits the NadG but not the NadF enzyme. This suggests the existence of a regulatory mechanism which controls NADP levels. PMID:8021211

  13. Intracellular Voyeurism: Examining the Modulation of Host Cell Activities bySalmonella enterica Serovar Typhimurium.

    PubMed

    Szeto, Jason; Brumell, John H

    2005-11-01

    Salmonella spp. can infect host cells by gaining entry through phagocytosis or by inducing host cell membrane ruffling that facilitates bacterial uptake. With its wide host range, Salmonella enterica serovar Typhimurium has proven to be an important model organism for studying intracellular bacterial pathogenesis. Upon entry into host cells, serovar Typhimurium typically resides within a membrane-bound compartment termed the Salmonella-containing vacuole (SCV). From the SCV, serovar Typhimurium can inject several effector proteins that subvert many normal host cell systems, including endocytic trafficking, cytoskeletal rearrangements, lipid signaling and distribution, and innate and adaptive host defenses. The study of these intracellular events has been made possible through the use of various imaging techniques, ranging from classic methods of transmission electron microscopy to advanced livecell fluorescence confocal microscopy. In addition, DNA microarrays have now been used to provide a "snapshot" of global gene expression in serovar Typhimurium residing within the infected host cell. This review describes key aspects of Salmonella-induced subversion of host cell activities, providing examples of imaging that have been used to elucidate these events. Serovar Typhimurium engages specific host cell machinery from initial contact with the host cell to replication within the SCV. This continuous interaction with the host cell has likely contributed to the extensive arsenal that serovar Typhimurium now possesses, including two type III secretion systems, a range of ammunition in the form of TTSS effectors, and a complex genetic regulatory network that coordinates the expression of hundreds of virulence factors.

  14. Genomic Analysis of Salmonella enterica Serovar Typhimurium from Wild Passerines in England and Wales.

    PubMed

    Mather, Alison E; Lawson, Becki; de Pinna, Elizabeth; Wigley, Paul; Parkhill, Julian; Thomson, Nicholas R; Page, Andrew J; Holmes, Mark A; Paterson, Gavin K

    2016-11-15

    Passerine salmonellosis is a well-recognized disease of birds in the order Passeriformes, which includes common songbirds such as finches and sparrows, caused by infection with Salmonella enterica serovar Typhimurium. Previous research has suggested that some subtypes of S Typhimurium-definitive phage types (DTs) 40, 56 variant, and 160-are host adapted to passerines and that these birds may represent a reservoir of infection for humans and other animals. Here, we have used the whole-genome sequences of 11 isolates from British passerines, five isolates of similar DTs from humans and a domestic cat, and previously published S Typhimurium genomes that include similar DTs from other hosts to investigate the phylogenetic relatedness of passerine salmonellae to other S Typhimurium isolates and investigate possible genetic features of the distinct disease pathogenesis of S Typhimurium in passerines. Our results demonstrate that the 11 passerine isolates and 13 other isolates, including those from nonpasserine hosts, were genetically closely related, with a median pairwise single nucleotide polymorphism (SNP) difference of 130 SNPs. These 24 isolates did not carry antimicrobial resistance genetic determinants or the S Typhimurium virulence plasmid. Although our study does not provide evidence of Salmonella transmission from passerines to other hosts, our results are consistent with the hypothesis that wild birds represent a potential reservoir of these Salmonella subtypes, and thus, sensible personal hygiene precautions should be taken when feeding or handling garden birds.

  15. Production and characterization of monoclonal antibodies against the O-5 antigen of Salmonella typhimurium lipopolysaccharide.

    PubMed Central

    Jaradat, Z W; Zawistowski, J

    1996-01-01

    Three murine monoclonal antibodies (MAbs) were produced by fusion of P3X63-Ag8.653 myeloma cells and splenocytes of a mouse immunized with heat-attenuated (20 min, 80 degrees C) Salmonella typhimurium cells. MAbs 5A5 and 5B2 were of the immunoglobulin M (IgM) class, while MAb 4A8 was IgG2a. All possessed the kappa light chains. The MAbs were specific to the lipopolysaccharide (LPS) O-5 antigen of Salmonella B serogroup, as determined by electrophoresis followed by immunoblotting. All MAbs recognized the same epitope, as determined by an additive enzyme-linked immunosorbent assay (ELISA), although IgM MAbs exhibited higher avidity than the IgG MAb. ELISA analyses revealed that all three MAbs reacted with S. typhimurium (LPS O:1, 4, 5, and 12) while failing to recognize S. typhimurium var. copenhagen (LPS O:1, 4, and 12). The MAbs reacted equally with live and heat-attenuated Salmonella B serovars containing LPS O-5 antigen. The ability of the MAbs to detect live bacterial cells was further confirmed by transmission electron microscopy. Treatment of bacteria with cholic acid and extremely low pH did not affect antibody binding to S. typhimurium. However, when S. typhimurium cells were exposed to alkaline conditions prior to reaction with all three MAbs, no binding was observed. The use of MAbs to discriminate between S. typhimurium and S. typhimurium var. copenhagen in meat samples was investigated. PMID:8572685

  16. Detection and differentiation of Salmonella serotypes using Surface Enhanced Raman Scattering (SERS) technique.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface Enhanced Raman Scattering (SERS) can detect pathogens rapidly and accurately. The metal surface for the SERS spectroscopy was a silver nano-particle encapsulated biopolymer polyvinyl alcohol nano-colloid deposited on a stainless steel plate. Salmonella Typhimurium and Salmonella Enteritidis...

  17. Novel surface antigen based impedimetric immunosensor for detection of Salmonella typhimurium in water and juice samples.

    PubMed

    Mutreja, Ruchi; Jariyal, Monu; Pathania, Preeti; Sharma, Arunima; Sahoo, D K; Suri, C Raman

    2016-11-15

    A specific surface antigen, OmpD has been reported first time as a surface biomarker in the development of selective and sensitive immunosensor for detecting Salmonella typhimurium species. The OmpD surface antigen extraction was done from Salmonella typhimurium serovars, under the optimized growth conditions for its expression. Anti-OmpD antibodies were generated and used as detector probe in immunoassay format on graphene-graphene oxide (G-GO) modified screen printed carbon electrodes. The water samples were spiked with standard Salmonella typhimurium cells, and detection was done by measuring the change in impedimetric response of developed immunosensor to know the concentration of serovar Salmonella typhimurium. The developed immunosensor was able to specifically detect S. typhimurium in spiked water and juice samples with a sensitivity upto 10(1)CFUmL(-1), with high selectivity and very low cross-reactivity with other strains. This is the first report on the detection of Salmonella typhimurum species using a specific biomarker, OmpD. The developed technique could be very useful for the detection of nontyphoidal Salmonellosis and is also important from an epidemiological point of view.

  18. Oxidative stress responses in Escherichia coli and Salmonella typhimurium.

    PubMed Central

    Farr, S B; Kogoma, T

    1991-01-01

    Oxidative stress is strongly implicated in a number of diseases, such as rheumatoid arthritis, inflammatory bowel disorders, and atherosclerosis, and its emerging as one of the most important causative agents of mutagenesis, tumorigenesis, and aging. Recent progress on the genetics and molecular biology of the cellular responses to oxidative stress, primarily in Escherichia coli and Salmonella typhimurium, is summarized. Bacteria respond to oxidative stress by invoking two distinct stress responses, the peroxide stimulon and the superoxide stimulon, depending on whether the stress is mediated by peroxides or the superoxide anion. The two stimulons each contain a set of more than 30 genes. The expression of a subset of genes in each stimulon is under the control of a positive regulatory element; these genes constitute the OxyR and SoxRS regulons. The schemes of regulation of the two regulons by their respective regulators are reviewed in detail, and the overlaps of these regulons with other stress responses such as the heat shock and SOS responses are discussed. The products of Oxy-R- and SoxRS-regulated genes, such as catalases and superoxide dismutases, are involved in the prevention of oxidative damage, whereas others, such as endonuclease IV, play a role in the repair of oxidative damage. The potential roles of these and other gene products in the defense against oxidative damage in DNA, proteins, and membranes are discussed in detail. A brief discussion of the similarities and differences between oxidative stress responses in bacteria and eukaryotic organisms concludes this review. PMID:1779927

  19. Toxic effects of gold nanoparticles on Salmonella typhimurium bacteria

    PubMed Central

    Wang, Shuguang; Lawson, Rasheeda; Ray, Paresh C; Yu, Hongtao

    2013-01-01

    Nanometer-sized gold, due to its beautiful and bountiful color and unique optical properties, is a versatile material for many industrial and societal applications. We have studied the effect of gold nanoparticles on Salmonella typhimurium strain TA 102. The gold nanoparticles in solution prepared using the citrate reduction method is found not to be toxic or mutagenic but photomutagenic to the bacteria; however, careful control experiments indicate that the photomutagenicity is due to the co-existing citrate and Au3+ ions, not due to the gold nanoparticle itself. Au3+ is also found to be photomutagenic to the bacteria at concentrations lower than 1 µM, but toxic at higher concentrations. The toxicity of Au3+ is enhanced by light irradiation. The photomutagenicity of both citrate and Au3+ is likely due to the formation of free radicals, as a result of light-induced citrate decarboxylation or Au3+ oxidation of co-existing molecules. Both processes can generate free radicals that may cause DNA damage and mutation. Studies of the interaction of gold nanoparticles with the bacteria indicate that gold nanoparticles can be absorbed onto the bacteria surface but not able to penetrate the bacteria wall to enter the bacteria. PMID:21415096

  20. Regulatory implications of Ames' mutagenicity assay using Salmonella typhimurium

    SciTech Connect

    Jackson, B.A.; Pertel, R.

    1986-07-01

    Interpretive difficulties can be expected when molecular biology and modern genetics are applied to the safety evaluation of chemicals. Experience, in a regulatory setting, with evaluating the results of short term tests, such as Ames' mutagenicity assay using Salmonella typhimurium (Ames' assay), shows that the traditional toxicological paradigm for interpreting and evaluating the results of such tests is less than adequate. The considerable importance of a negative test outcome to the public health as well as to the course of the commercial development of a potentially useful chemical places special demands on both the investigator and the regulatory reviewer for an understanding of Ames' assay. The adequate design, conduct, interpretation, and evaluation of the outcomes of this assay require a knowledge of the chemical properties of the test agent, an understanding of the scientific basis of the test, and an appreciation of the extent to which modifications of the assay can alter the outcome. The investigator and the regulatory reviewer use the same considerations to determine the adequacy of the test design and of the test results. However, a fundamental difference exists between how they interpret results and how they view the outcome. Results from a study comparing activation systems from food animal and laboratory animal sources are used to illustrate the complexity of using safety data from a genetic test. A framework is developed to suggest how to accommodate the points of view of the investigator and the regulatory reviewer in evaluating these data.

  1. Chlorine inactivation of non-resistant and antibiotic resistant strains of Salmonella Typhimurium isolated from chicken carcasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to test the hypothesis that strains of Salmonella Typhimurium that are resistant to antibiotics are more resistant to chlorine than strains of S. Typhimurium that are not resistant to antibiotics. To test this hypothesis, strains (n = 16) of S. Typhimurium with four antibiotic...

  2. [The comparative characteristics of the Salmonella serotypes rarely encountered in the Maritime Territory].

    PubMed

    Koval'chuk, N I; Shubin, F N; Khoroshko, V A; Sheverdina, F N; Tarasenko, T T; Kosheleva, N G

    1997-01-01

    The results of the comparative study of the phenotypical properties and the plasmid profile of 63 strains of salmonellae, belonging to 44 serotypes of groups B, C1, C2, C3, D, E1, E4, F. The study revealed that strains of different serotypes had their individual plasmid profile. Strains of the same serotype of salmonellae isolated from similar sources had an identical plasmid profile, while strains isolated from different sources differed in their plasmid profiles, though they might have a similar phenotype. Plasmid analysis was shown to be an effective method for the intraspecific typing of rarely isolated Salmonella serotypes and suitable for use as the basis of the microbiological monitoring of salmonellae.

  3. Prevalence, serotype and antimicrobial resistance of salmonellae isolated from commercially processed broiler carcasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was undertaken to determine the prevalence, serotype and antimicrobial resistance profiles of Salmonella on broiler carcasses collected from commercial processing plants. Twenty US commercial processing plants representing eight integrators in thirteen states were included in the survey....

  4. Parenteral administration of attenuated Salmonella Typhimurium ΔznuABC is protective against salmonellosis in piglets.

    PubMed

    Ruggeri, J; Pesciaroli, M; Gaetarelli, B; Scaglione, F E; Pregel, P; Ammendola, S; Battistoni, A; Bollo, E; Alborali, G L; Pasquali, P

    2014-07-07

    A major cause of salmonellosis in humans is the contamination of pork products. Infection in pigs can be controlled using bio-security programs, but they are not sufficient in countries where a high level of infection is recorded. In this context, the use of vaccines can represent a valid supplementary method of control. Recently, we have demonstrated that an attenuated strain of Salmonella enterica serovar Typhimurium (Salmonella Typhimurium ΔznuABC) is protective against systemic and enteric salmonellosis in mouse and pig infection models, candidating this strain as an oral attenuated vaccine. In this study, we compared the efficacy of this attenuated Salmonella Typhimurium strain when administered orally or parenterally. Furthermore, in order to reproduce a pseudo-natural infection model, vaccinated pigs were allocated in the same pen with animals shedding virulent Salmonella Typhimurium. Animals were monitored weekly after vaccination and contact with infected piglets. Diarrhea and ataxia were recorded and Salmonella shedding was tested individually through bacterial culture. After four weeks of cohousing, piglets were euthanized, after which lymph nodes reactivity and gross lesions of the gut sections were scored at necropsy. Organs were submitted to microbiological and histological analyses. The data reported herein show that parenterally vaccinated animals do not shed the attenuated strain, and at the same time the absence of symptoms and decrease in virulent strain shedding in feces from day 6 after challenge demonstrated protection against infection induced by virulent Salmonella Typhimurium. In conclusion, our findings suggest that this is an alternative route of Salmonella Typhimurium ΔznuABC administration, without ignoring the advantages associated with oral vaccination.

  5. Differences in the motility phenotype of multidrug-resistant Salmonella enterica serovar Typhimurium exposed to various antibiotics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella enterica serovar Typhimurium (S. Typhimurium) is one of the most prevalent foodborne-associated bacteria in humans and livestock, and over 35 per cent of these isolates are resistant to three or more antibiotics. This is a concern as multidrug-resistant (MDR) Salmonella has been associat...

  6. Comparison of epidemiological marker methods for identification of Salmonella typhimurium isolates from an outbreak caused by contaminated chocolate.

    PubMed Central

    Kapperud, G; Lassen, J; Dommarsnes, K; Kristiansen, B E; Caugant, D A; Ask, E; Jahkola, M

    1989-01-01

    Plasmid profile analysis, restriction endonuclease analysis, and multilocus enzyme electrophoresis were used in conjunction with serotyping, bacteriophage typing, and biochemical fingerprinting to trace epidemiologically related isolates of Salmonella typhimurium from an outbreak caused by contaminated chocolate products in Norway and Finland. To evaluate the efficiency of the epidemiological marker methods, isolates from the outbreak were compared with five groups of control isolates not known to be associated with the outbreak. Both plasmid profile analysis and phage typing provided further discrimination over that produced by serotyping and biochemical fingerprinting. Plasmid profile analysis and phage typing were equally reliable in differentiating the outbreak isolates from the epidemiologically unrelated controls and were significantly more effective than multilocus enzyme electrophoresis and restriction enzyme analysis of total DNA. The greatest differentiation was achieved when plasmid profile analysis and phage typing were combined to complement serotyping and biochemical fingerprinting. However, none of the methods employed, including restriction enzyme analysis of plasmid DNA, were able to distinguish the outbreak isolates from five isolates recovered in Norway and Finland over a period of years from dead passerine birds and a calf. Images PMID:2674198

  7. The use of tannins to control Salmonella typhimurium infections in pigs.

    PubMed

    Van Parys, A; Boyen, F; Dewulf, J; Haesebrouck, F; Pasmans, F

    2010-09-01

    The aim of this study was to determine whether a hydrolysable tannin extract of sweet chestnut wood (Globatan(®)) has an inhibitory effect on Salmonella Typhimurium survival both in vitro and in vivo in pigs. In a first experiment, the minimal inhibitory concentration of Globatan(®) on 57 Salmonella Typhimurium isolates was determined. For all isolates, an MIC of 160-320 μg/ml was found. The second in vitro study revealed that Salmonella growth was strongly reduced using Globatan(®) concentrations of 25-50 μg/ml and nearly completely inhibited at a concentration of 100 μg/ml Globatan(®). In an in vivo trial, two groups of six piglets, each group receiving feed with or without the addition of Globatan(®) (3 g/kg), were orally inoculated with 10(7) colony forming units of a Salmonella Typhimurium strain. Globatan(®) had no effect on faecal excretion of Salmonella, and no differences in colonization of the intestines and internal organs were demonstrated in pigs euthanized at 4 days post-inoculation. In conclusion, the hydrolysable tannin extract used in this study showed strong action against Salmonella Typhimurium in vitro but not in vivo.

  8. [Various Salmonella serotypes isolated at a sewage purification plant in a smaller city over a one-year period].

    PubMed

    Schüsseler, G; Sobotta, B; Gerhardt, G G; Teitge, E; Gundermann, K O

    1986-04-01

    A one-year-study was carried out in the waste-water treatment plant of Plön (population equivalents 60,000), which has a mechanical and a biological purification and an additional chemical flocculation. Samples were taken at five different places in the plant and examined for Salmonella by use of membrane-filtration and MPN-method. 2,611 Salmonella-strains, representing 23 species, were isolated and serologically typed from samples taken at ten days. S. typhi-murium was found most frequently (Table 1, Fig. 1). The largest spectrum of different types was located in the activated sludge-basin and at the outlet of the chemical flocculation (Table 2). No correlation could be established between the qualitative findings and the Salmonella-counts or other parameter like temperatures. All the ten species that have been officially reported to cause salmonellosis in man were also isolated from the sewage (Table 5). Findings of other Salmonella-serotypes are attributed to unreported human infections and animals or other sources.

  9. Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in Southern Brazil.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To assess diversity of Salmonella enterica serotypes present in poultry and their environment from Southern Brazil, the Kauffman-White-LeMinor (KWL) scheme was used to serotype a total of 155 isolates. Isolates were then re-examined with nested PCR and sequencing of the dkgB-linked Intergenic Sequ...

  10. Ribosomal vaccines. I. Immunogenicity of ribosomal fractions isolated from Salmonella typhimurium and Yersinia pestis.

    PubMed

    Johnson, W

    1972-06-01

    The immunogenicity of ribosomes and ribosomal subfractions isolated from Yersina pestis and Salmonella typhimurium has been studied. Ribosomes and ribosomal protein isolated from S. typhimurium protected mice against lethal challenge. Ribosomal ribonucleic acid isolated by phenol extraction failed to induce any significant level of protection in mice. None of the ribosomes or ribosomal subfractions isolated from Y. pestis were effective in inducing immunity to lethal challenge. These results suggest that the immunogen of the ribosomal vaccine is protein.

  11. Salmonella typhimurium phage type 141 infections in Sheffield during 1984 and 1985: association with hens' eggs.

    PubMed Central

    Chapman, P. A.; Rhodes, P.; Rylands, W.

    1988-01-01

    Food poisoning due to Salmonella typhimurium phage type 141 was unusual in the Sheffield area before 1984. The sudden increase in incidence of this phage type during 1984 and 1985, and its causative role in several small outbreaks in this period have been investigated. Epidemiological and laboratory investigations suggested that hens' eggs were the most likely source of S. typhimurium phage type 141. PMID:3042440

  12. Antimicrobial activity of butyrate glycerides toward Salmonella Typhimurium and Clostridium perfringens.

    PubMed

    Namkung, H; Yu, H; Gong, J; Leeson, S

    2011-10-01

    The antimicrobial activities of n-butyric acid and its derivatives against Salmonella Typhimurium and Clostridium perfringens were studied. n-Butyric acid and its derivatives (monobutyrin and a mixture of mono-, di-, and tri-glycerides of butyric acid) were added at different concentrations (ranging from 250 to 7,000 mg/kg to a media inoculated with either Salmonella Typhimurium or C. perfringens. The antimicrobial activity of butyric acid against C. perfringens was measured at 2 bacterium concentrations and 2 inoculations involving ambient aerobic or anaerobic conditions. The most effective antimicrobial activity for Salmonella Typhimurium was observed with n-butyric acid, with 90% inhibition rate at a concentration of 1,500 mg/kg. Although minimal inhibition for Salmonella Typhimurium was observed with butyric acid glycerides, lipase addition to a mixture of mono-, di-, and triglycerides of butyric acid increased (P < 0.01) antimicrobial activity of these derivatives. Antimicrobial activity of butyric acid and its derivative against C. perfringens was higher when using a moderate initial inoculation concentration (10(5)) compared with a higher initial concentration (10(7)) of this bacterium. At a lower inoculation of C. perfringens (10(5)), >90% inhibition rate by all butyric acid glycerides was observed with prior aerobic inoculation at 2,000 mg/kg, whereas using anaerobic inoculation, only 50% monobutyrin maintained >90% inhibitory effect at 3,000 mg/kg. The antimicrobial effect of monobutyrin against C. perfringens was generally higher (P < 0.01) for 50% monobutyrin than for 100% monobutyrin. Either a mixture of butyric acid derivatives or 50% monobutyrin decreased (P < 0.01) C. perfringens in a media containing intestinal contents whereas only 50% monobutyrin decreased (P < 0.01) Salmonella Typhimurium within a media containing cecal contents from mature Leghorns. These results show that n-butyric acid and 50% monobutyrin could be used to control Salmonella

  13. Longevity of Salmonella typhimurium in Tilapia aurea and water from pools fertilized with swine waste.

    PubMed Central

    Baker, D A; Smitherman, R O; McCaskey, T A

    1983-01-01

    Salmonella typhimurium declined rapidly when inoculated into Tilapia aurea culture pools fertilized with fresh swine waste. Within the water column, a 95% decline of viable cells occurred during the first 6 h. Isolation of viable salmonellae was possible at 16 days post-inoculation, but not at 32 days. Similarly, salmonellae could be detected in the viscera and epithelium of T. aurea at 16 days, although not at 32 days. Salmonellae were not isolated from the fish flesh, nor was there evidence of septicemic infection. PMID:6347063

  14. Inducible pathway is required for mutagenesis in Salmonella typhimurium LT2

    SciTech Connect

    Orrego, C.; Eisenstadt, E.

    1987-06-01

    UV mutability of Salmonella typhimurium LT2 was eliminated in the presence of a multicopy plasmid carrying the Escherichia coli lexA/sup +/ gene. This result suggests that inducible, SOS-like functions are required for UV mutagenesis in S. typhimurium. S. typhimurium strains carrying either point or deletion mutations in topA had previously been shown to lose their mutability by UV or methyl methanesulfonate. Mitomycin C induction of the Phi(mucB'-lacZ') fusion (a DNA damage-inducible locus carried on plasmid pSE205) in S. typhimurium topA was normal, suggesting that RecA is activated in topA mutants. These observations lead the authors deduce that S. typhimurium has at least one DNA damage-inducible locus in addition to recA that is required for UV mutability.

  15. Intestinal autophagy activity is essential for host defense against Salmonella typhimurium infection in Caenorhabditis elegans.

    PubMed

    Curt, Alexander; Zhang, Jiuli; Minnerly, Justin; Jia, Kailiang

    2014-08-01

    Salmonella typhimurium infects both intestinal epithelial cells and macrophages. Autophagy is a lysosomal degradation pathway that is present in all eukaryotes. Autophagy has been reported to limit the Salmonella replication in Caenorhabditis elegans and in mammals. However, it is unknown whether intestinal autophagy activity plays a role in host defense against Salmonella infection in C. elegans. In this study, we inhibited the autophagy gene bec-1 in different C. elegans tissues and examined the survival of these animals following Salmonella infection. Here we show that inhibition of the bec-1 gene in the intestine but not in other tissues confers susceptibility to Salmonella infection, which is consistent with recent studies in mice showing that autophagy is involved in clearance of Salmonella in the intestinal epithelial cells. Therefore, the intestinal autophagy activity is essential for host defense against Salmonella infection from C. elegans to mice, perhaps also in humans.

  16. Survival, Deoxyribonucleic Acid Breakdown, and Synthesis in Salmonella typhimurium as Compared with Escherichia coli B Strains

    PubMed Central

    Hudnik-Plevnik, Tamara A.; Djordjević, Nadežda

    1970-01-01

    Salmonella typhimurium LT-2 was compared with radioresistant (B/r) and radiosensitive (Bs−2) strains of Escherichia coli in respect to the survival, deoxyribonucleic acid (DNA) breakdown, and DNA synthesis after X irradiation. It is shown that S. typhimurium LT-2 is about four times more sensitive than E. coli B/r but less sensitive than Bs−2. The DNA breakdown is in S. typhimurium LT-2 lower than the postirradiation breakdown of DNA in both E. coli strains and DNA synthesis proceeds in this bacterium in spite of a much lower survival, as in the radioresistant E. coli B/r. PMID:4916313

  17. The antimicrobial peptide cathelicidin-BF could be a potential therapeutic for Salmonella typhimurium infection.

    PubMed

    Xia, Xi; Zhang, Lin; Wang, Yizhen

    2015-02-01

    Resistance is increasing to several critical antimicrobials used to treat Salmonella typhimurium infection, urging people to search for new antimicrobial agents. In this work, we reported the possibility of a potent antimicrobial peptide cathelicidin-BF found in the venom of the snake Bungarus fasciatus in treating Salmonella typhimurium infection. We tested its activity in biological fluids and in vivo using a mouse model of Salmonella typhimurium infection, and examined the effect of cathelicidin-BF on Salmonella invasion to epithelial cells. In addition, the biodistribution of cathelicidin-BF was evaluated by using in vivo optical imaging. The results revealed that cathelicidin-BF was unstable in gastrointestinal tract, but retained substantially active in murine serum. Cathelicidin-BF attenuated the clinical symptoms of Salmonella infected-mice, significantly reduced the number of internalized Salmonella and attenuated Salmonella-induced decreases in TER in epithelial cells. Our results provide a first indication for the potential of cathelicidin-BF as a novel therapeutic option for salmonellosis.

  18. Activation and genetic modification of human monocyte-derived dendritic cells using attenuated Salmonella typhimurium.

    PubMed

    Michael, Agnieszka; John, Justin; Meyer, Brendan; Pandha, Hardev

    2010-03-05

    Live attenuated bacterial vectors, such as Salmonella typhimurium, have shown promise as delivery vehicles for DNA. We have examined two new strains of S. typhimurium and their impact on dendritic cell maturation (CD12-sifA/aroC mutant and WT05-ssaV/aroC, both in TML background). Strain WT05 matured dendritic cells in a more efficient way; caused higher release of cytokines TNF-alpha, IL-12, IL-1beta; and was efficient for gene transfer. These findings suggest that the genetic background of the attenuation can influence the pattern of inflammatory immune response to Salmonella infection.

  19. Quinolone-resistant Salmonella enterica serotype Enteritidis infections associated with international travel.

    PubMed

    O'Donnell, Allison T; Vieira, Antonio R; Huang, Jennifer Y; Whichard, Jean; Cole, Dana; Karp, Beth E

    2014-11-01

    We found a strong association between nalidixic acid-resistant Salmonella enterica serotype Enteritidis infections in the United States and recent international travel by linking Salmonella Enteritidis data from the National Antimicrobial Resistance Monitoring System and the Foodborne Diseases Active Surveillance Network.

  20. Classification of Salmonella Enterica serotypes with selective bands using visible/NIR hyperspectral imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Optical detection of foodborne bacteria such as Salmonella classifies bacteria by analyzing spectral data, and has potential for rapid detection. In this experiment hyperspectral microscopy is explored as a means for classifying five Salmonella serotypes. Initially, the microscope collects 89 spect...

  1. Transcriptional autoregulation of the Salmonella typhimurium phoPQ operon.

    PubMed

    Soncini, F C; Véscovi, E G; Groisman, E A

    1995-08-01

    The Salmonella typhimurium PhoP-PhoQ two-component regulatory system controls the expression of several genes, some of which are necessary for virulence. During a screening for PhoP-regulated genes, we identified the phoPQ operon as a PhoP-activated locus. beta-Galactosidase activity originating from phoPQ-lac transcriptional fusions required the presence of both the transcriptional regulator PhoP and its cognate sensor-kinase PhoQ. At low concentrations, PhoQ stimulated expression of phoPQ-lac transcriptional fusions. However, larger amounts of PhoQ protein without a concomitant increase in PhoP failed to activate phoPQ-lac fusions. Two different transcripts are produced from the phoPQ operon during exponential growth. These transcripts define two promoters: phoPp1, which requires both PhoP and PhoQ for activity and which is environmentally regulated, and phoPp2, which remains active in the absence of PhoP and PhoQ but which is slightly stimulated by these proteins. The pattern of transcriptional autoregulation was also observed at the protein level with anti-PhoP antibodies. In sum, autoregulation of the phoPQ operon provides several levels of control for the PhoP-PhoQ regulon. First, environmental signals would stimulate PhoQ to phosphorylate the PhoP protein that is produced at basal levels from the PhoP-PhoQ-independent promoter. Then, phospho-PhoP would activate transcription of phoPp1, resulting in larger amounts of PhoP and PhoQ and increased expression of PhoP-activated genes. A return to basal levels could be mediated by a posttranscriptional mechanism by which translation of the mRNA produced from phoPp1 is inhibited.

  2. Regulation of L-cystine transport in Salmonella typhimurium.

    PubMed Central

    Baptist, E W; Kredich, N M

    1977-01-01

    A kinetic analysis of L-cystine uptake in wild-type Salmonella typhimurium indicates the presence of at least two, and possibly three, separate transport systems. CTS-1 accounts for the majority of uptake at 20 muM L-cystine, with a Vmax of 9.5 nmol/min per mg and a Km of 2.0 muM; CTS-2 is a low-capacity, higher-affinity system with a Vmax of 0.22 nmol/min per mg and a Km of 0.05 muM; a third, nonsaturable process has been designated CTS-3. We find that wild-type CTS-1 levels are at least 11 times higher in sulfur-limited cells than in L-cystine-grown cells. Pleiotropic cysteine auxotrophs of the types cysE (lacking serine transacetylase) and cysB- (lacking a regulatory element of positive control) have very low levels of CTS-1 even when grown under conditions of sulfur limitation, which response is analogous to that previously observed for cysteine biosynthetic enzymes (N . M. Kredich, J. Biol. Chem. 246:3474-3484, 1971). CTS-1 is induced in cysE mutants by growth in the presence of O-acetyl-L-serine (the product of serine transacetylase), again paralleling the behavior of the cysteine biosynthetic pathway. Strain DW25, a prototrophic cysBc mutant, which is constitutive for cysteine biosynthesis, is also derepressed for CTS-1 when grown on L-cystine. Since CTS-1 is regulated by sulfur limitation, O-acetyl-L-serine, and the cysB gene product, the same three conditions controlling cysteine biosynthesis, we propose that this transport system is a part of the cysteine regulon. PMID:326753

  3. Human infections due to Salmonella Blockley, a rare serotype in South Africa: a case report

    PubMed Central

    2012-01-01

    Background Infections due to nontyphoidal Salmonella have increased worldwide over the last couple of decades. Salmonella enterica serotype Blockley (Salmonella Blockley) infections is associated with chickens and is a rarely isolated serotype in human infections in most countries. Case presentation We report a case of human infections due to Salmonella Blockley in KwaZulu-Natal, South Africa in 2011. Three African males (aged 4, 14 and 16) presented to a clinic with diarrhoea, stomach cramps and headache. They started experiencing signs of illness a day after they consumed a common meal, consisting of meat, rice and potatoes. Stool specimens from the patients cultured Salmonella Blockley. The strains showed an indistinguishable pulsed-field gel electrophoresis pattern. Conclusion This is the first recorded case of human infections due to Salmonella Blockley in South Africa. PMID:23050633

  4. Subtyping of Salmonella Food Isolates Suggests the Geographic Clustering of Serotype Telaviv.

    PubMed

    Durul, Bora; Acar, Sinem; Bulut, Ece; Kyere, Emmanuel O; Soyer, Yeşim

    2015-12-01

    Salmonella is commonly found in a variety of food products and is a major cause of bacterial foodborne illness throughout the world. In this study, we investigated the prevalence and diversity of Salmonella in eight different food types: sheep ground meat, cow ground meat, chicken meat, cow offal, traditional Sanliurfa cheese, unripened feta cheese, pistachios, and isot (a spice blend of dried red peppers specific to Sanliurfa), traditionally and commonly consumed in Turkey. Among 192 food samples, Salmonella was detected in 59 samples, with the highest prevalence in raw poultry parts (58%) and offal (58%) samples, while Salmonella was not detected in pistachios and dried red pepper. Resultant Salmonella isolates were characterized by serotyping, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Ten different serotypes represented 10 MLST sequence types (STs) with 1 novel ST and 17 PFGE types. Antimicrobial resistance profiling revealed that 30.5% of the isolates were resistant to two or more antimicrobials. Salmonella enterica subsp. enterica serotype Telaviv, which is rare throughout the world, was the second most common serotype isolated from food samples in this study, suggesting that this serotype might be one of the subtypes that is endemic to Turkey.

  5. Draft Genome Sequence of Salmonella enterica subsp. enterica Serotype Saintpaul Strain S-70, Isolated from an Aquatic Environment

    PubMed Central

    Estrada-Acosta, Mitzi; Medrano-Félix, Andrés; Jiménez, Maribel; Gómez-Gil, Bruno; León-Félix, Josefina; Amarillas, Luis

    2013-01-01

    Salmonella is a pathogen of worldwide importance, causing disease in a vast range of hosts, including humans. We report the genome sequence of Salmonella enterica subsp. enterica serotype Saintpaul strain S-70, isolated from an aquatic environment. PMID:24336367

  6. An rfaH Mutant of Salmonella enterica Serovar Typhimurium is Attenuated in Swine and Reduces Intestinal Colonization, Fecal Shedding, and Disease Severity Due to Virulent Salmonella Typhimurium

    PubMed Central

    Bearson, Bradley L.; Bearson, Shawn M. D.; Kich, Jalusa D.; Lee, In Soo

    2014-01-01

    Swine are often asymptomatic carriers of Salmonella spp., and interventions are needed to limit colonization of swine to enhance food safety and reduce environmental contamination. We evaluated the attenuation and potential vaccine use in pigs of a Salmonella enterica serovar Typhimurium mutant of rfaH, the gene encoding the RfaH antiterminator that prevents premature termination of long mRNA transcripts. Pigs inoculated with wild-type S. Typhimurium exhibited a significant elevation in average body temperature (fever) at 1 and 2 days post-inoculation; rfaH-inoculated pigs did not (n = 5/group). During the 7-day trial, a significant reduction of Salmonella in the feces, tonsils, and cecum were observed in the rfaH-inoculated pigs compared to wild-type inoculated pigs. To determine whether vaccination with the rfaH mutant could provide protection against wild-type S. Typhimurium challenge, two groups of pigs (n = 14/group) were intranasally inoculated with either the rfaH mutant or a PBS placebo at 6 and 8 weeks of age and challenged with the parental, wild-type S. Typhimurium at 11 weeks of age. The average body temperature was significantly elevated in the mock-vaccinated pigs at 1 and 2 days post-challenge, but not in the rfaH-vaccinated pigs. Fecal shedding at 2 and 3 days post-challenge and colonization of intestinal tract tissues at 7 days post-challenge by wild-type S. Typhimurium was significantly reduced in the rfaH-vaccinated pigs compared to mock-vaccinated pigs. Serological analysis using the IDEXX HerdChek Swine Salmonella Test Kit indicated that vaccination with the rfaH mutant did not stimulate an immune response against LPS. These results indicate that vaccination of swine with the attenuated rfaH mutant confers protection against challenge with virulent S. Typhimurium but does not interfere with herd level monitoring for Salmonella spp., thereby allowing for differentiation of infected from vaccinated animals (DIVA). PMID

  7. Use of an attenuated live Salmonella Typhimurium vaccine on three breeding pig units: A longitudinal observational field study.

    PubMed

    Davies, R; Gosling, R J; Wales, A D; Smith, R P

    2016-06-01

    The study examined the effects of a licensed live Salmonella Typhimurium vaccine, administered to sows and gilts on three commercial pig units experiencing clinical salmonellosis associated with S. Typhimurium or its monophasic variant. After vaccination, clinical salmonellosis resolved and shedding of S. Typhimurium declined markedly and persistently on all breeding or breeding-finishing units, during the one- to two-year monitoring period. On two finishing units supplied in part by one of the vaccinated herds, pigs from the vaccinated herd were less likely to shed Salmonella than those from non-vaccinating herds, and Salmonella counts in faeces were also lower from the vaccine-linked animals. Non-Typhimurium Salmonella serovars were isolated typically in fewer than 10% of samples, and showed no clear temporal changes in frequency. Vaccination of dams alone with S. Typhimurium was associated with reduced shedding of closely-related serovars among all age groups in this commercial setting.

  8. Inhibition of the virulence, antibiotic resistance, and fecal shedding of multiple antibiotic-resistant Salmonella Typhimurium in broilers fed Original XPC™.

    PubMed

    Feye, K M; Anderson, K L; Scott, M F; McIntyre, D R; Carlson, S A

    2016-12-01

    Salmonella carriage is an insidious problem for the poultry industry. While most Salmonella serotypes are avirulent in poultry, these bacteria can contaminate chicken meat during processing, leading to one of the most important food safety hazards. In this study, we examined the anti-Salmonella effects of Diamond V Original XPC(™) (XPC) included in the finisher diet fed to commercial broilers. On 3 occasions between day one (D1) and D20, broilers were experimentally infected with multiple antibiotic-resistant Salmonella Typhimurium. After confirming that the chicks were shedding Salmonella in the feces on D21, broiler chicks were fed a diet containing XPC (n = 57 birds; 1.25 kg/MT) or an XPC-free control diet (CON) (n = 57 birds) to D49. Fecal samples were obtained weekly and subjected to selective culture for enumerating and determining the antibiotic resistance of the Salmonella Salmonella isolates were then subjected to an in vitro virulence assay, which predicts the ability of Salmonella to cause illness in a mammalian host. Broilers were euthanized on D49 and a segment of the large intestine was removed and subjected to the same assays used for the fecal samples. When compared to the birds fed the CON diet, Salmonella fecal shedding, virulence (invasion and invasion gene expression), and antibiotic resistance were significantly decreased in birds fed XPC (5-fold, 7.5-fold, 6-fold, and 5.3-fold decreases, respectively). Birds fed XPC exhibited heavier body weight (BW) and greater BW gains than those fed the CON diet. The decrease in virulence was associated with a decreased expression of a genetic regulator of Salmonella invasion into cells (hilA), while the decrease in antibiotic resistance was due to a loss of an integron (SGI1) from the input strain. This study revealed that Original XPC(™) inhibits the shedding, downstream virulence, and antibiotic resistance of Salmonella residing in broilers.

  9. Inhibition of the virulence, antibiotic resistance, and fecal shedding of multiple antibiotic-resistant Salmonella Typhimurium in broilers fed Original XPC™

    PubMed Central

    Feye, K. M.; Anderson, K. L.; Scott, M. F.; McIntyre, D. R.; Carlson, S. A.

    2016-01-01

    Salmonella carriage is an insidious problem for the poultry industry. While most Salmonella serotypes are avirulent in poultry, these bacteria can contaminate chicken meat during processing, leading to one of the most important food safety hazards. In this study, we examined the anti-Salmonella effects of Diamond V Original XPC™ (XPC) included in the finisher diet fed to commercial broilers. On 3 occasions between day one (D1) and D20, broilers were experimentally infected with multiple antibiotic-resistant Salmonella Typhimurium. After confirming that the chicks were shedding Salmonella in the feces on D21, broiler chicks were fed a diet containing XPC (n = 57 birds; 1.25 kg/MT) or an XPC-free control diet (CON) (n = 57 birds) to D49. Fecal samples were obtained weekly and subjected to selective culture for enumerating and determining the antibiotic resistance of the Salmonella. Salmonella isolates were then subjected to an in vitro virulence assay, which predicts the ability of Salmonella to cause illness in a mammalian host. Broilers were euthanized on D49 and a segment of the large intestine was removed and subjected to the same assays used for the fecal samples. When compared to the birds fed the CON diet, Salmonella fecal shedding, virulence (invasion and invasion gene expression), and antibiotic resistance were significantly decreased in birds fed XPC (5-fold, 7.5-fold, 6-fold, and 5.3-fold decreases, respectively). Birds fed XPC exhibited heavier body weight (BW) and greater BW gains than those fed the CON diet. The decrease in virulence was associated with a decreased expression of a genetic regulator of Salmonella invasion into cells (hilA), while the decrease in antibiotic resistance was due to a loss of an integron (SGI1) from the input strain. This study revealed that Original XPC™ inhibits the shedding, downstream virulence, and antibiotic resistance of Salmonella residing in broilers. PMID:27566726

  10. Genetic Diversity of Clinical and Environmental Strains of Salmonella enterica Serotype Weltevreden Isolated in Malaysia

    PubMed Central

    Thong, K. L.; Goh, Y. L.; Radu, S.; Noorzaleha, S.; Yasin, R.; Koh, Y. T.; Lim, V. K. E.; Rusul, G.; Puthucheary, S. D.

    2002-01-01

    The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia. PMID:12089269

  11. The serological relationship between Brucella spp., Yersinia enterocolitica serotype IX and Salmonella serotypes of Kauffmann-White group N.

    PubMed

    Corbell, M J

    1975-08-01

    The serological relationship between Brucella spp., Yersinia enterocolitica IX, and the group N salmonella serotypes S. godesberg, S. landau, S. morehead, S. neusdorf, S. soerenga and S. urbana was examined using agglutination, antiglobulin, complement fixation, immunodiffusion and fluorescent antibody methods. Antisera to the group N salmonella serotypes all reacted to significant titres in agglutination and complement fixation, but not antiglobulin or immunodiffusion tests with smooth brucella antigens. These antisera also reacted in agglutination, but not antiglobulin, tests with Y. enterocolitica IX. They did not react significantly in any tests with rough brucella antigens. Conversely, antisera to smooth Brucella spp. agglutinated group N salmonellas to low titre and Y. enterocolitica IX to titres similar to those given against the homologous strain. Antiserum to Y. enterocolitica IX on the other hand reacted with smooth brucella antigens to high titre in agglutination, complement fixation and antiglobulin tests, and with the group N salmonella antigens to substantial titres in agglutination tests. In direct fluorescent antibody tests, smooth Brucella strains and Y. enterocolitica IX reacted strongly with FITC-labelled antibody to Br. abortus whereas the group N salmonella strains reacted weakly. In tests with monospecific antisera to the A and M determinants of Br. abortus and Br. melitensis respectively, Y. enterocolitica IX reacted only with the antiserum to the A determinant whereas group N salmonellas reacted to low titre with both A and M antisera. The results of cross-absorption tests confirmed this relationship and suggested that the O30 antigens of group N salmonella serotypes contained antigenic determinants similar to, but not identical with, the antigenic structure shared by smooth Brucella spp. and Y. enterocolitica IX.

  12. Role of T3SS-1 SipD Protein in Protecting Mice against Non-typhoidal Salmonella Typhimurium

    PubMed Central

    Jneid, Bakhos; Moreau, Karine; Plaisance, Marc; Rouaix, Audrey; Dano, Julie

    2016-01-01

    Background Salmonella enterica species are enteric pathogens that cause severe diseases ranging from self-limiting gastroenteritis to enteric fever and sepsis in humans. These infectious diseases are still the major cause of morbidity and mortality in low-income countries, especially in children younger than 5 years and immunocompromised adults. Vaccines targeting typhoidal diseases are already marketed, but none protect against non-typhoidal Salmonella. The existence of multiple non-typhoidal Salmonella serotypes as well as emerging antibiotic resistance highlight the need for development of a broad-spectrum protective vaccine. All Salmonella spp. utilize two type III Secretion Systems (T3SS 1 and 2) to initiate infection, allow replication in phagocytic cells and induce systemic disease. T3SS-1, which is essential to invade epithelial cells and cross the barrier, forms an extracellular needle and syringe necessary to inject effector proteins into the host cell. PrgI and SipD form, respectively, the T3SS-1 needle and the tip complex at the top of the needle. Because they are common and highly conserved in all virulent Salmonella spp., they might be ideal candidate antigens for a subunit-based, broad-spectrum vaccine. Principal Findings We investigated the immunogenicity and protective efficacy of PrgI and SipD administered by subcutaneous, intranasal and oral routes, alone or combined, in a mouse model of Salmonella intestinal challenge. Robust IgG (in all immunization routes) and IgA (in intranasal and oral immunization routes) antibody responses were induced against both proteins, particularly SipD. Mice orally immunized with SipD alone or SipD combined with PrgI were protected against lethal intestinal challenge with Salmonella Typhimurium (100 Lethal Dose 50%) depending on antigen, route and adjuvant. Conclusions and Significance Salmonella T3SS SipD is a promising antigen for the development of a protective Salmonella vaccine, and could be developed for

  13. Complete Genome Sequence of Salmonella enterica Serovar Typhimurium Strain YU15 (Sequence Type 19) Harboring the Salmonella Genomic Island 1 and Virulence Plasmid pSTV

    PubMed Central

    Calva, Edmundo; Puente, José L.; Zaidi, Mussaret B.

    2016-01-01

    The complete genome of Salmonella enterica subsp. enterica serovar Typhimurium sequence type 19 (ST19) strain YU15, isolated in Yucatán, Mexico, from a human baby stool culture, was determined using PacBio technology. The chromosome contains five intact prophages and the Salmonella genomic island 1 (SGI1). This strain carries the Salmonella virulence plasmid pSTV. PMID:27081132

  14. Active Suppression of Early Immune Response in Tobacco by the Human Pathogen Salmonella Typhimurium

    PubMed Central

    Shirron, Natali; Yaron, Sima

    2011-01-01

    The persistence of enteric pathogens on plants has been studied extensively, mainly due to the potential hazard of human pathogens such as Salmonella enterica being able to invade and survive in/on plants. Factors involved in the interactions between enteric bacteria and plants have been identified and consequently it was hypothesized that plants may be vectors or alternative hosts for enteric pathogens. To survive, endophytic bacteria have to escape the plant immune systems, which function at different levels through the plant-bacteria interactions. To understand how S. enterica survives endophyticaly we conducted a detailed analysis on its ability to elicit or evade the plant immune response. The models of this study were Nicotiana tabacum plants and cells suspension exposed to S. enterica serovar Typhimurium. The plant immune response was analyzed by looking at tissue damage and by testing oxidative burst and pH changes. It was found that S. Typhimurium did not promote disease symptoms in the contaminated plants. Live S. Typhimurium did not trigger the production of an oxidative burst and pH changes by the plant cells, while heat killed or chloramphenicol treated S. Typhimurium and purified LPS of Salmonella were significant elicitors, indicating that S. Typhimurium actively suppress the plant response. By looking at the plant response to mutants defective in virulence factors we showed that the suppression depends on secreted factors. Deletion of invA reduced the ability of S. Typhimurium to suppress oxidative burst and pH changes, indicating that a functional SPI1 TTSS is required for the suppression. This study demonstrates that plant colonization by S. Typhimurium is indeed an active process. S. Typhimurium utilizes adaptive strategies of altering innate plant perception systems to improve its fitness in the plant habitat. All together these results suggest a complex mechanism for perception of S. Typhimurium by plants. PMID:21541320

  15. Tumor-Targeting Salmonella typhimurium A1-R: An Overview.

    PubMed

    Hoffman, Robert M

    2016-01-01

    The present chapter reviews the development of the tumor-targeting amino-acid auxotrophic strain S. typhimurium A1 and the in vivo selection and characterization of the high-tumor-targeting strain S. typhimurium A1-R. Efficacy of S. typhimurium A1-R in nude-mouse models of prostate, breast, pancreatic, and ovarian cancer, as well as sarcoma and glioma in orthotopic mouse models is described. Also reviewed is efficacy of S. typhimurium A1-R targeting of primary bone tumor and lung metastasis of high-grade osteosarcoma, breast-cancer brain metastasis, and experimental breast-cancer bone metastasis in orthotopic mouse models. The efficacy of S. typhimurium A1-R on pancreatic cancer stem cells, on pancreatic cancer in combination with anti-angiogenic agents, as well as on cervical cancer, soft-tissue sarcoma, and pancreatic cancer patient-derived orthotopic xenograft (PDOX) mouse models, is also described.

  16. Analysis of the Salmonella typhimurium Proteome through Environmental Response toward Infectious Conditions

    SciTech Connect

    Adkins, Joshua N.; Mottaz, Heather M.; Norbeck, Angela D.; Gustin, Jean K.; Rue, Joanne; Clauss, Therese RW; Purvine, Samuel O.; Rodland, Karin D.; Heffron, Fred; Smith, Richard D.

    2006-08-01

    Salmonella enterica serovar Typhimurium (aka, S. typhimurium) is a facultative intracellular pathogen that causes ~40,000 reported cases of acute gastroenteritis and diarrhea a year in the United States. To develop a deeper understanding of the infectious state of S. typhimurium, liquid chromatography-mass spectrometry-based “bottom-up” proteomics was used to globally analyze the proteins present under specific growth conditions. Salmonella typhimurium LT2 strain cells were grown in contrasting culture conditions that mimicked both natural free-living conditions and an infectious state, i.e., logarithm phase, stationary phase and Mg-depleted medium growth. Initial comparisons of the LT2 strain protein abundances among cell culture conditions indicate that the majority of proteins do not change significantly. Not unexpectedly, cells grown in Mg-depleted medium conditions had a higher abundance of Mg2+ transport proteins than found in other growth conditions. A second more virulent Salmonella typhimurium strain (14028) was also studied with these growth conditions and used to directly compare to the LT2 strain. The strain comparison offers a unique opportunity to compare and contrast observations in these closely related bacteria. One particular protein family, propanediol utilization proteins, was drastically more abundant in the 14028 strain than in the LT2 strain, and may be a contributor to increased pathogenicity in the 14028 strain.

  17. Cross-protection against Salmonella Typhimurium infection conferred by a live attenuated Salmonella Enteritidis vaccine.

    PubMed

    Nandre, Rahul M; Lee, Dajeong; Lee, John Hwa

    2015-01-01

    In this study, a genetically engineered live attenuated Salmonella Enteritidis (SE) vaccine was evaluated for its ability to protect against Salmonella Typhimurium (ST) infection in chickens. The birds were orally primed with the vaccine on the 1st day of life and given an oral booster at 5 wk of age. Control birds were orally inoculated with phosphate-buffered saline. Both groups of birds were orally challenged with a virulent ST strain at 9 wk of age. Compared with the control chickens, the vaccinated chickens had significantly higher levels of systemic IgG and mucosal IgA against specific ST antigens and a significantly greater lymphoproliferative response to ST antigens. The excretion of ST into the feces was significantly lower in the vaccinated group than in the control group on days 9 and 13 d after challenge. In addition, the vaccinated group had significantly fewer pronounced gross lesions in the liver and spleen and lower bacterial counts in the internal organs than the control group after challenge. These data indicate that genetically engineered live attenuated SE may induce humoral and cellular immune responses against ST antigens and may confer protection against virulent ST challenge.

  18. Cross-protection against Salmonella Typhimurium infection conferred by a live attenuated Salmonella Enteritidis vaccine

    PubMed Central

    Nandre, Rahul M.; Lee, Dajeong; Lee, John Hwa

    2015-01-01

    In this study, a genetically engineered live attenuated Salmonella Enteritidis (SE) vaccine was evaluated for its ability to protect against Salmonella Typhimurium (ST) infection in chickens. The birds were orally primed with the vaccine on the 1st day of life and given an oral booster at 5 wk of age. Control birds were orally inoculated with phosphate-buffered saline. Both groups of birds were orally challenged with a virulent ST strain at 9 wk of age. Compared with the control chickens, the vaccinated chickens had significantly higher levels of systemic IgG and mucosal IgA against specific ST antigens and a significantly greater lymphoproliferative response to ST antigens. The excretion of ST into the feces was significantly lower in the vaccinated group than in the control group on days 9 and 13 d after challenge. In addition, the vaccinated group had significantly fewer pronounced gross lesions in the liver and spleen and lower bacterial counts in the internal organs than the control group after challenge. These data indicate that genetically engineered live attenuated SE may induce humoral and cellular immune responses against ST antigens and may confer protection against virulent ST challenge. PMID:25673904

  19. The agricultural antibiotic carbadox induces generalized transducing phage in multidrug-resistant Salmonella enterica serovar Typhimurium DT104

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-typhoidal Salmonella, a leading cause of U.S. foodborne disease and food-related deaths, often asymptomatically colonizes food-producing animals. In fact, >50% of U.S. swine production facilities test positive for Salmonella. The multidrug-resistant (MDR) Salmonella Typhimurium DT104 NCTC13348 c...

  20. Subversion of innate and adaptive immune activation induced by structurally modified lipopolysaccharide from Salmonella typhimurium.

    PubMed

    Pastelin-Palacios, Rodolfo; Gil-Cruz, Cristina; Pérez-Shibayama, Christian I; Moreno-Eutimio, Mario A; Cervantes-Barragán, Luisa; Arriaga-Pizano, Lourdes; Ludewig, Burkhard; Cunningham, Adam F; García-Zepeda, Eduardo A; Becker, Ingeborg; Alpuche-Aranda, Celia; Bonifaz, Laura; Gunn, John S; Isibasi, Armando; López-Macías, Constantino

    2011-08-01

    Salmonella are successful pathogens that infect millions of people every year. During infection, Salmonella typhimurium changes the structure of its lipopolysaccharide (LPS) in response to the host environment, rendering bacteria resistant to cationic peptide lysis in vitro. However, the role of these structural changes in LPS as in vivo virulence factors and their effects on immune responses and the generation of immunity are largely unknown. We report that modified LPS are less efficient than wild-type LPS at inducing pro-inflammatory responses. The impact of this LPS-mediated subversion of innate immune responses was demonstrated by increased mortality in mice infected with a non-lethal dose of an attenuated S. typhimurium strain mixed with the modified LPS moieties. Up-regulation of co-stimulatory molecules on antigen-presenting cells and CD4(+) T-cell activation were affected by these modified LPS. Strains of S. typhimurium carrying structurally modified LPS are markedly less efficient at inducing specific antibody responses. Immunization with modified LPS moiety preparations combined with experimental antigens, induced an impaired Toll-like receptor 4-mediated adjuvant effect. Strains of S. typhimurium carrying structurally modified LPS are markedly less efficient at inducing immunity against challenge with virulent S. typhimurium. Hence, changes in S. typhimurium LPS structure impact not only on innate immune responses but also on both humoral and cellular adaptive immune responses.

  1. Subversion of innate and adaptive immune activation induced by structurally modified lipopolysaccharide from Salmonella typhimurium

    PubMed Central

    Pastelin-Palacios, Rodolfo; Gil-Cruz, Cristina; Pérez-Shibayama, Christian I; Moreno-Eutimio, Mario A; Cervantes-Barragán, Luisa; Arriaga-Pizano, Lourdes; Ludewig, Burkhard; Cunningham, Adam F; García-Zepeda, Eduardo A; Becker, Ingeborg; Alpuche-Aranda, Celia; Bonifaz, Laura; Gunn, John S; Isibasi, Armando; López-Macías, Constantino

    2011-01-01

    Salmonella are successful pathogens that infect millions of people every year. During infection, Salmonella typhimurium changes the structure of its lipopolysaccharide (LPS) in response to the host environment, rendering bacteria resistant to cationic peptide lysis in vitro. However, the role of these structural changes in LPS as in vivo virulence factors and their effects on immune responses and the generation of immunity are largely unknown. We report that modified LPS are less efficient than wild-type LPS at inducing pro-inflammatory responses. The impact of this LPS-mediated subversion of innate immune responses was demonstrated by increased mortality in mice infected with a non-lethal dose of an attenuated S. typhimurium strain mixed with the modified LPS moieties. Up-regulation of co-stimulatory molecules on antigen-presenting cells and CD4+ T-cell activation were affected by these modified LPS. Strains of S. typhimurium carrying structurally modified LPS are markedly less efficient at inducing specific antibody responses. Immunization with modified LPS moiety preparations combined with experimental antigens, induced an impaired Toll-like receptor 4-mediated adjuvant effect. Strains of S. typhimurium carrying structurally modified LPS are markedly less efficient at inducing immunity against challenge with virulent S. typhimurium. Hence, changes in S. typhimurium LPS structure impact not only on innate immune responses but also on both humoral and cellular adaptive immune responses. PMID:21631497

  2. Swarm and swim motilities of Salmonella enterica serovar Typhimurium and role of osmoregulated periplasmic glucans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Salmonella enterica serovar Typhimurium strains synthesize osmoregulated periplasmic glucans (OPGs) under low osmolarity conditions (< 70 mos mol l-1). OPG synthesis is not observed when cells are grown in iso- or hyper-osmotic media (> 400 mos mol l-1). Mutation in OPG structural gene...

  3. Salmonella typhimurium contains an anion-selective outer membrane porin induced by phosphate starvation.

    PubMed Central

    Bauer, K; Benz, R; Brass, J; Boos, W

    1985-01-01

    A mutant of Salmonella typhimurium was selected that is constitutive for the pho regulon. It exhibited constitutive glycerol-3-phosphate transport activity and synthesized a new outer membrane porin. Upon measurement of porin activity in black lipid films, it exhibited anion selectivity. It therefore appears analogous to the Escherichia coli PhoE porin. Images PMID:2981826

  4. Influence of light exposure on horizontal transmission of Salmonella typhimurium in weaned pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of the following experiment was to examine the effect of light exposure on horizontal transmission of Salmonella typhimurium in weaned pigs. Twenty crossbred pigs (average BW = 15 kg) were housed in isolation rooms (10 pigs/room) and randomly assigned to one of two lighting regimes: ...

  5. Inhibition of Salmonella Typhimurium by Anaerobic Cecal Bacteria in Media Supplemented with Lactate and Succinate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of anaerobic cecal microflora of broilers to inhibit growth of Salmonella Typhimurium in media supplemented with lactate and succinate was examined. Cecal cultures were prepared by collecting ceca of processed broilers from a commercial processing facility, inoculating broth media with 1...

  6. Polynucleotide phosphorlyase (PNPase) is required for Salmonella enterica serovar Typhimurium colonization in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pnp gene encodes polynucleotide phosphorylase, an exoribonuclease involved in RNA degradation. A mutation in the pnp gene was previously identified by our group in a signature-tagged mutagenesis screen designed to search for Salmonella enterica serovar Typhimurium genes required for survival in...

  7. Transport of Escherichia coli, Salmonella typhimurium, and microspheres in biochar-amended soils with different textures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar amendment has been shown to affect bacterial transport in soils. The effect of soil texture on the transport of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in soils amended with 2 % poultry litter or pine chip biochars pyrolyzed under two temperatures (350 and 700 'C...

  8. Autoinducer AI-2 is involved in regulating a variety of cellular processes in Salmonella Typhimurium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    LuxS/AI-2 mediated cell signaling is a known strategy that modulates a variety of bacterial processes in prokaryotes. Salmonella Typhimurium is known to possess LuxS/AI-2 mediated cell signaling. Until now, the Lsr- ABC transporter system (LuxS- regulated) is the only known process controlled by t...

  9. Timeliness of Salmonella Typhimurium notifications after the introduction of routine MLVA typing in NSW.

    PubMed

    Heilbronn, Cherie; Munnoch, Sally; Butler, Michelle T; Merritt, Tony D; Durrheim, David N

    2014-06-01

    Salmonella Typhimurium is the most common bacterial cause of gastrointestinal disease in NSW. Regular review of surveillance procedures ensures system objectives are met and informs improvements in system utility and efficiency. This paper assesses the timeliness and data completeness of NSW Salmonella Typhimurium surveillance after the routine introduction of multilocus variable repeat analysis (MLVA), a rapid sub-typing technique. MLVA results were available significantly earlier than alternate sub-typing techniques over the 2 years of this review. Accordingly, from a timeliness perspective, MLVA offers a favourable Salmonella Typhimurium sub-typing option in NSW. Further opportunities to improve timeliness and data completeness are identified. This paper was produced as part of a review of Salmonella Typhimurium surveillance in NSW for the period 2008-2009 by members of OzFoodNet based at Hunter New England Population Health. OzFoodNet is a national network established by the then Commonwealth Department of Health and Ageing in 2000 to enhance foodborne disease surveillance in Australia.

  10. Animal-to-Human Transmission of Salmonella Typhimurium DT104A Variant

    PubMed Central

    Orsel, Karin; Wagenaar, Jaap A.; Miko, Angelika; van Duijkeren, Engeline

    2004-01-01

    Salmonella enterica serovar Typhimurium was isolated from a pig, a calf, and a child on a farm in the Netherlands. The isolates were indistinguishable by phenotyping and genotyping methods, which suggests nonfoodborne animal-to-animal and animal-to-human transmission. Persons in close contact with farm animals should be aware of this risk. PMID:15663868

  11. Inhibition of Salmonella Typhimurium by Cultures of Cecal Bacteria during Aerobic Incubation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two trials were conducted to examine the ability of cecal bacterial cultures from broilers to inhibit growth of Salmonella Typhimurium during aerobic incubation. Cecal broth media was inoculated with 10 µl of cecal contents from 6 week old broilers taken from 2 separate flocks. Cultures were incubat...

  12. A WATERBORNE SALMONELLA TYPHIMURIUM OUTBREAK IN GIDEON, MISSOURI: RESULTS FROM A FIELD INVESTIGATION

    EPA Science Inventory

    A waterborne disease outbreak associated with Salmonella typhimurium was identified in Gideon, Missouri (population 1104), a town in southeastern Missouri (USA) in December, 1993. It was estimated by the US Centers for Disease Control and Prevention (CDC) that approximately 44% o...

  13. Synergistic effect of thymol and carvacrol combined with chelators and organic acids against Salmonella Typhimurium.

    PubMed

    Zhou, Feng; Ji, Baoping; Zhang, Hong; Jiang, Hui; Yang, Zhiwei; Li, Jingjing; Li, Jihai; Ren, Yali; Yan, Wenjie

    2007-07-01

    To identify synergistic combinations of different food additives, the antimicrobial effects of thymol and carvacrol against Salmonella Typhimurium were assessed alone and in combination with various other preservatives including EDTA, acetic acid, lactic acid, and citric acid. Overall, growth of Salmonella Typhimurium was significantly inhibited in Mueller-Hinton broth containing thymol, carvacrol, EDTA, acetic acid, lactic acid, or citric acid at concentrations of 400 mg/liter, 400 microl/liter, 300 mg/liter, 0.2% (vol/vol), 0.2% (vol/vol), and 0.2% (wt/vol), respectively. The combination of different antimicrobials such as thymol or carvacrol with EDTA, thymol or carvacrol with acetic acid, and thymol or carvacrol with citric acid all resulted in significantly reduced populations of Salmonella Typhimurium. In samples treated with combinations, these antimicrobials had synergistic effects compared with samples treated with thymol, carvacrol, EDTA, acetic acid, or citric acid alone. However, the combined use of lactic acid with thymol or carvacrol did not produce a synergistic effect against Salmonella Typhimurium. Thus, some chelators or organic acids can be used as food preservatives in combination with thymol and carvacrol to reduce the concentrations needed to produce an adequate antimicrobial effect.

  14. Rice hull smoke extract inactivates Salmonella Typhimurium in laboratory media and protects infected mice against mortality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recently discovered and characterized rice hull liquid smoke extract was tested for bactericidal activity against Salmonella Typhimurium using the disc-agar method. The Minimum Inhibitory Concentration (MIC) value of rice hull smoke extract was found to be 0.822% (v/v). The in vivo antibacterial a...

  15. [Outbreak of Salmonella Typhimurium infections associated with consumption of chorizo in Bizkaia].

    PubMed

    Hernández Arricibita, Esther; Santamaria Zuazua, Rosaura; Ramos López, Gemma; Herrera-León, Silvia; Kárkamo Zuñeda, José Antonio; Muniozguren Agirre, Nerea

    2016-11-01

    A report is presented on an outbreak of Salmonella enterica serovar Typhimurium infection that affected six people. The epidemiological and laboratory investigation associated the outbreak with the consumption of homemade chorizo purchased at a local street market. The vendor and producer were informed that the sale of meat products without sanitary authorization is prohibited, and the product was withdrawn from sale.

  16. Effectiveness of radiation processing for elimination of Salmonella Typhimurium from minimally processed pineapple (Ananas comosus Merr.).

    PubMed

    Shashidhar, Ravindranath; Dhokane, Varsha S; Hajare, Sachin N; Sharma, Arun; Bandekar, Jayant R

    2007-04-01

    The microbiological quality of market samples of minimally processed (MP) pineapple was examined. The effectiveness of radiation treatment in eliminating Salmonella Typhimurium from laboratory inoculated ready-to-eat pineapple slices was also studied. Microbiological quality of minimally processed pineapple samples from Mumbai market was poor; 8.8% of the samples were positive for Salmonella. D(10) (the radiation dose required to reduce bacterial population by 90%) value for S. Typhimurium inoculated in pineapple was 0.242 kGy. Inoculated pack studies in minimally processed pineapple showed that the treatment with a 2-kGy dose of gamma radiation could eliminate 5 log CFU/g of S. Typhimurium. The pathogen was not detected from radiation-processed samples up to 12 d during storage at 4 and 10 degrees C. The processing of market samples with 1 and 2 kGy was effective in improving the microbiological quality of these products.

  17. Evaluating Chemical Mitigation of Salmonella Typhimurium ATCC 14028 in Animal Feed Ingredients.

    PubMed

    Cochrane, Roger A; Huss, Anne R; Aldrich, Gregory C; Stark, Charles R; Jones, Cassandra K

    2016-04-01

    Salmonella Typhimurium is a potential feed safety hazard in animal feed ingredients. Thermal mitigation of Salmonella spp. during rendering is effective but does not eliminate the potential for cross-contamination. Therefore, the objective of this experiment was to evaluate the effectiveness of chemicals to mitigate postrendering Salmonella Typhimurium ATCC 14028 contamination in rendered proteins over time. Treatments were arranged in a 6 × 4 factorial with six chemical treatments and four rendered protein meals. The chemical treatments included (i) control without chemical treatment, (ii) 0.3% commercial formaldehyde product, (iii) 2% essential oil blend, (iv) 2% medium chain fatty acid blend, (v) 3% organic acid blend, and (vi) 1% sodium bisulfate. The four rendered protein meals included (i) feather meal, (ii) blood meal, (iii) meat and bone meal, and (iv) poultry by-product meal. After matrices were chemically treated, they were inoculated with Salmonella Typhimurium ATCC 14028, stored at room temperature, and enumerated via plate counts on days 0, 1, 3, 7, 14, 21, and 42 postinoculation. The Salmonella concentration in ingredients treated with medium chain fatty acid and commercial formaldehyde were similar to one another (P = 0.23) but were 2 log lower than the control (P < 0.05). Ingredients treated with organic acids and essential oils also had lower Salmonella concentrations than the control (P < 0.05). Time also played a significant role in Salmonella mitigation, because all days except days 14 and 21 (P = 0.92) differed from one another. Rendered protein matrix also affected Salmonella stability, because concentrations in meat and bone meal and blood meal were similar to one another (P = 0.36) but were greater than levels in feather meal and poultry by-product meal (P < 0.05). In summary, chemical treatment and time both mitigated Salmonella Typhimurium ATCC 14028, but their effectiveness was matrix dependent. Time and chemical treatment with medium

  18. Salmonella typhimurium A1-R and Cell-Cycle Decoy Therapy of Cancer.

    PubMed

    Hoffman, Robert M; Yano, Shuya

    2016-01-01

    Cancer cells in G0/G1 are resistant to cytotoxic chemotherapy agents which kill only cycling cancer cells. Salmonella typhimurium A1-R (S. typhimurium A1-R) decoyed cancer cells in monolayer culture and in tumor spheres to cycle from G0/G1 to S/G2/M, as demonstrated by fluorescence ubiquitination-based cell cycle indicator (FUCCI) imaging. S. typhimurium A1-R targeted FUCCI-expressing subcutaneous tumors, and tumors growing on the liver, growing in nude mice and also decoyed quiescent cancer cells, which were the majority of the cells in the tumors, to cycle from G0/G1 to S/G2/M. The S. typhimurium A1-R-decoyed cancer cells became sensitive to cytotoxic agents.

  19. Luminex(®) multiplex bead suspension arrays for the detection and serotyping of Salmonella spp.

    PubMed

    Dunbar, Sherry A; Ritchie, Vivette Brown; Hoffmeyer, Michaela R; Rana, Gunjot S; Zhang, Hongwei

    2015-01-01

    In this chapter we describe two commercially available bead-based molecular assays for detection, identification and serotyping of Salmonella. The xTAG(®) Gastrointestinal Pathogen Panel (GPP) is a qualitative multiplex test for the simultaneous detection of nucleic acids from Salmonella plus 14 other gastroenteritis-causing bacteria, viruses, and parasites from stool specimens. xTAG GPP uses the Luminex(®) xTAG universal array technology for the identification of specific target sequences combined with the xMAP(®) bead multiplexing platform for detection of the targets that were present in the starting sample. The xMAP Salmonella Serotyping Assay (SSA) is a multiplex nucleic acid-based direct hybridization assay for molecular identification of the serotype of Salmonella isolates. In xMAP SSA, target sequences amplified from cultured Salmonella isolates are captured by hybridization to sequence-specific capture probes which have been coupled to the multiplexed bead sets. Herein we provide detailed protocols for each of these assays and present data which describe their performance characteristics for detection and serotyping Salmonella.

  20. Rapid molecular pathotyping of major salmonella enterica serotypes based on single-nucleotide polymorphisms (SNPs) in the adenylate cyclase (cyaA) gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Salmonella enterica subsp. enterica serotype Enteriditis (S. Enteriditis) is the leading cause of salmonellosis worldwide, including the USA. Many S. enterica serotypes known to cause foodborne disease are associated with broiler meat contamination. While some serotypes are specific...

  1. Inactivation of Salmonella enterica serovar Typhimurium on fresh produce by cold atmospheric gas plasma technology.

    PubMed

    Fernández, A; Noriega, E; Thompson, A

    2013-02-01

    Cold atmospheric gas plasma treatment (CAP) is an alternative approach for the decontamination of fresh and minimally processed food. In this study, the effects of growth phase, growth temperature and chemical treatment regime on the inactivation of Salmonella enterica serovar Typhimurium (S. Typhimurium) by Nitrogen CAP were examined. Furthermore, the efficacy of CAP treatment for decontaminating lettuce and strawberry surfaces and potato tissue inoculated with S. Typhimurium was evaluated. It was found that the rate of inactivation of S. Typhimurium was independent of the growth phase, growth temperature and chemical treatment regime. Under optimal conditions, a 2 min treatment resulted in a 2.71 log-reduction of S. Typhimurium viability on membrane filters whereas a 15 min treatment was necessary to achieve 2.72, 1.76 and 0.94 log-reductions of viability on lettuce, strawberry and potato, respectively. We suggest that the differing efficiency of CAP treatment on the inactivation of S. Typhimurium on these different types of fresh foods is a consequence of their surface features. Scanning electron microscopy of the surface structures of contaminated samples of lettuce, strawberry and potato revealed topographical features whereby S. Typhimurium cells could be protected from the active species generated by plasma.

  2. Isolation of Salmonella typhimurium from dead blue and gold macaws (Ara ararauna).

    PubMed

    Vigo, Germán B; Origlia, Javier; Gornatti, Daniel; Piscopo, Miguel; Salve, Angela; Caffer, María I; Pichel, Mariana; Binsztein, Norma; Leotta, Gerardo A

    2009-03-01

    Two blue and gold macaw (Ara ararauna) chicks died of fatal salmonellosis in Buenos Aires Province, Argentina. The birds were histopathologically and microbiologically examined. Salmonella enterica subspecies enterica serovar Typhimurium was isolated from the liver, spleen, heart, lung, kidney, and intestine of both birds. All strains were susceptible to ampicillin, cephalothin, cefotaxime, enrofloxacin, nalidixic acid, gentamicin, streptomycin, chloramphenicol, fosfomycin, tetracycline, nitrofurantoin, and trimethoprim-sulfamethoxazole. The XbaI-PFGE profile of the Salmonella Typhimurium isolated from the two animals, which shared the same cage, was identical and showed a unique pattern compared with 301 isolates included in the PulseNet national database of Salmonella pulsed-field gel electrophoresis patterns. This is the first report that describes fatal cases of salmonellosis from blue and gold macaws.

  3. Salmonella Enterica Serotype Enteritidis Vertebral Osteomyelitis and Epidural Abscess Complicated with Meningitis.

    PubMed

    Oki, Masayuki; Ueda, Akihiro; Tsuda, Ayumi; Yanagi, Hidetaka; Ozawa, Hideki; Takagi, Atsushi

    2016-09-20

    Infection with non-typhoidal Salmonella often results in a self-limited acute gastroenteritis. Extra-intestinal Salmonella infection is relatively rare and occurs predominantly in infants and adults with significant underlying conditions. We describe a 54-year-old Japanese man with a history of heavy alcohol consumption and daily contact with a dog, who developed bacteremia complicated by vertebral osteomyelitis, spinal epidural abscess, and meningitis, due to Salmonella enterica serotype Enteritidis. This case suggests that Salmonella should be considered as an etiologic pathogen in adult patients with perivertebral infection or meningitis.

  4. Development of a Rapid Multiplex PCR Technique for Determination of Salmonella enterica Serotypes Isolated from Pork and Poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: A multiplex PCR technique to discriminate Salmonella enterica serotypes was adapted to a high-throughput, automated assay. Methods: Fifteen target genes were chosen that varied in distribution among common Salmonella enterica serotypes isolated from various hosts. These targets were dete...

  5. A murine model to study the antibacterial effect of copper on infectivity of Salmonella enterica serovar Typhimurium.

    PubMed

    Sharan, Riti; Chhibber, Sanjay; Reed, Robert H

    2011-01-01

    This study investigated the effect of copper as an antibacterial agent on the infectivity of Salmonella enterica serovar Typhimurium. Mice were infected orally with a standardized dose of unstressed Salmonella Typhimurium and copper-stressed cells of Salmonella Typhimurium. Bacterial counts in ileum, blood, liver and spleen were observed up to 168 h under normal aerobic conditions. Serum sensitivity, phagocytosis, malondialdehyde levels and histopathology were studied for both set of animals. A decreased bacterial count in the organs with mild symptoms of infection and a complete recovery by 48 h was observed in mice infected with copper-stressed bacteria. Histopathological examination of ileum tissue demonstrated regeneration of damaged tissue post-infection with copper-stressed bacteria and no malondialdehyde levels were detected after 24 h in ileum, spleen and liver. Exposure to copper sensitized Salmonella Typhimurium to the lytic action of serum and intracellular killing by peritoneal macrophages. It can be concluded that copper stress confers a decrease in the infectivity of healthy Salmonella Typhimurium in normal mice. This study highlights the significance of use of copper as an antibacterial agent against Salmonella Typhimurium in reducing the risk of incidence of Salmonella infections from contaminated water.

  6. Molecular characterization of "inconsistent" variants of Salmonella Typhimurium isolated in Italy.

    PubMed

    Barco, Lisa; Longo, Alessandra; Lettini, Antonia Anna; Cortini, Enzo; Saccardin, Cristina; Minorello, Claudio; Olsen, John Elmerdahl; Ricci, Antonia

    2014-06-01

    Salmonella 4,[5],12:i:- is a variant of Salmonella Typhimurium, which lacks the expression of phase-2 flagellar antigen, generally associated with the deletion of the fljB gene. Additional mechanisms involving the fljAB operon ( fljA, fljB, and hin genes) lead to the lack of expression of phase-2 flagellar antigens also in Salmonella strains harboring the fljB gene. For 20 S. 4,[5],12:i:- strains, defined as "inconsistent" Salmonella Typhimurium variants since they had phenotypically behaved as monophasic, even though the fljB gene was conserved, the fljAB operon was characterized in order to explain the ineffective expression of the phase-2 flagellar antigen. The monophasic phenotype for a first group of strains (9) was likely due to the absence of the hin gene, leading to the inhibited switch between the expression of phase-1 and phase-2 flagellar genes. For a second group of strains (5), the monophasic phenotype could be attributed to nonconservative point mutations identified in fljA and hin genes, which could hamper the proper expression of invertase gene and the fljA, acting as repressor of the phase-1 flagellar gene. Finally, for a last group of inconsistent strains (6), a plausible reason for their monophasic phenotype was not found, since the genes involved in the expression of phase-2 flagellar antigen were fully conserved. Moreover, the collection of inconsistent Salmonella Typhimurium isolates investigated were characterized by distinct molecular profiles, as demonstrated by multiple-locus variable-number tandem repeat analysis, and phenotype variability, as demonstrated by phage-typing. This study highlights the usefulness of investigating the entire fljAB operon when a definitive identification of the monophasic or biphasic status of Salmonella Typhimurium strains is needed (for instance, in the context of epidemiological investigations aimed to identify the relatedness among strains).

  7. Invasive African Salmonella Typhimurium induces bactericidal antibodies against O-antigens.

    PubMed

    Rondini, Simona; Lanzilao, Luisa; Necchi, Francesca; O'Shaughnessy, Colette M; Micoli, Francesca; Saul, Allan; MacLennan, Calman A

    2013-10-01

    Nontyphoidal Salmonella are a major and emerging cause of fatal invasive disease in Africa, and are genetically distinct from those found elsewhere in the world. Understanding the targets of protective immunity to these African Salmonellae is key to vaccine development. We immunized mice and rabbits with heat-inactivated wild-type African invasive Salmonella Typhimurium D23580 and rough mutants lacking O-antigen. Wild-type Salmonella, unlike rough bacteria, induced a large bactericidal antibody response mainly against O-antigen. Bactericidal ability of anti-O-antigen antibodies was confirmed following purification by affinity chromatography. The current findings support the development of an O-antigen conjugate vaccine against invasive nontyphoidal Salmonellae for Africa.

  8. Evaluation of the respiratory route as a viable portal of entry for Salmonella in poultry via intratracheal challenge of Salmonella Enteritidis and Salmonella Typhimurium.

    PubMed

    Kallapura, G; Morgan, M J; Pumford, N R; Bielke, L R; Wolfenden, A D; Faulkner, O B; Latorre, J D; Menconi, A; Hernandez-Velasco, X; Kuttappan, V A; Hargis, B M; Tellez, G

    2014-02-01

    Experimental and epidemiological evidence suggests that primary infection of Salmonella is by the oral-fecal route for poultry. However, the airborne transmission of Salmonella and similar enteric zoonotic pathogens has been historically neglected. Increasing evidence of Salmonella bioaerosol generation in production facilities and studies suggesting the vulnerabilities of the avian respiratory architecture together have indicated the possibility of the respiratory system being a potential portal of entry for Salmonella in poultry. Presently, we evaluated this hypothesis through intratracheal (IT) administration of Salmonella Enteritidis and Salmonella Typhimurium, as separate challenges, in a total of 4 independent trials, followed by enumeration of cfu recovery in ceca-cecal tonsils and recovery incidence in liver and spleen. In all trials, both Salmonella Enteritidis and Salmonella Typhimurium, challenged IT colonized cecae to a similar or greater extent than oral administration at identical challenge levels. In most trials, chickens cultured for cfu enumeration from IT-challenged chicks at same dose as orally challenged, resulted in an increase of 1.5 log higher Salmonella Enteritidis from ceca-cecal tonsils and a much lower dose IT of Salmonella Enteritidis could colonize ceca to the same extent than a higher oral challenge. This trend of increased cecal colonization due to IT challenge was observed with all trails involving week-old birds (experiment 2 and 3), which are widely considered to be more difficult to infect via the oral route. Liver-spleen incidence data showed 33% of liver and spleen samples to be positive for Salmonella Enteritidis administered IT (10(6) cfu/chick), compared with 0% when administered orally (experiment 2, trial 1). Collectively, these data suggest that the respiratory tract may be a largely overlooked portal of entry for Salmonella infections in chickens.

  9. Evaluation of the respiratory route as a viable portal of entry for Salmonella in poultry via intratracheal challenge of Salmonella Enteritidis and Salmonella Typhimurium1

    PubMed Central

    Kallapura, G.; Morgan, M. J.; Pumford, N. R.; Bielke, L. R.; Wolfenden, A. D.; Faulkner, O. B.; Latorre, J. D.; Menconi, A.; Hernandez-Velasco, X.; Kuttappan, V. A.; Hargis, B. M.; Tellez, G.

    2014-01-01

    Experimental and epidemiological evidence suggests that primary infection of Salmonella is by the oral-fecal route for poultry. However, the airborne transmission of Salmonella and similar enteric zoonotic pathogens has been historically neglected. Increasing evidence of Salmonella bioaerosol generation in production facilities and studies suggesting the vulnerabilities of the avian respiratory architecture together have indicated the possibility of the respiratory system being a potential portal of entry for Salmonella in poultry. Presently, we evaluated this hypothesis through intratracheal (IT) administration of Salmonella Enteritidis and Salmonella Typhimurium, as separate challenges, in a total of 4 independent trials, followed by enumeration of cfu recovery in ceca-cecal tonsils and recovery incidence in liver and spleen. In all trials, both Salmonella Enteritidis and Salmonella Typhimurium, challenged IT colonized cecae to a similar or greater extent than oral administration at identical challenge levels. In most trials, chickens cultured for cfu enumeration from IT-challenged chicks at same dose as orally challenged, resulted in an increase of 1.5 log higher Salmonella Enteritidis from ceca-cecal tonsils and a much lower dose IT of Salmonella Enteritidis could colonize ceca to the same extent than a higher oral challenge. This trend of increased cecal colonization due to IT challenge was observed with all trails involving week-old birds (experiment 2 and 3), which are widely considered to be more difficult to infect via the oral route. Liver-spleen incidence data showed 33% of liver and spleen samples to be positive for Salmonella Enteritidis administered IT (106 cfu/chick), compared with 0% when administered orally (experiment 2, trial 1). Collectively, these data suggest that the respiratory tract may be a largely overlooked portal of entry for Salmonella infections in chickens. PMID:24570455

  10. A community effort towards a knowledge-base and mathematical model of the human pathogen Salmonella Typhimurium LT2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metabolic reconstructions (MRs) are common denominators in systems biology and represent biochemical, genetic, and genomic (BiGG) knowledge-bases for target organisms by capturing currently available information in a consistent, structured manner. Salmonella enterica subspecies I serovar Typhimurium...

  11. RNA-seq Brings New Insights to the Intra-Macrophage Transcriptome of Salmonella Typhimurium

    PubMed Central

    Hébrard, Magali; Colgan, Aoife; Owen, Siân V.; Sivasankaran, Sathesh K.; Cameron, Andrew D. S.; Hokamp, Karsten; Hinton, Jay C. D.

    2015-01-01

    Salmonella enterica serovar Typhimurium is arguably the world’s best-understood bacterial pathogen. However, crucial details about the genetic programs used by the bacterium to survive and replicate in macrophages have remained obscure because of the challenge of studying gene expression of intracellular pathogens during infection. Here, we report the use of deep sequencing (RNA-seq) to reveal the transcriptional architecture and gene activity of Salmonella during infection of murine macrophages, providing new insights into the strategies used by the pathogen to survive in a bactericidal immune cell. We characterized 3583 transcriptional start sites that are active within macrophages, and highlight 11 of these as candidates for the delivery of heterologous antigens from Salmonella vaccine strains. A majority (88%) of the 280 S. Typhimurium sRNAs were expressed inside macrophages, and SPI13 and SPI2 were the most highly expressed pathogenicity islands. We identified 31 S. Typhimurium genes that were strongly up-regulated inside macrophages but expressed at very low levels during in vitro growth. The SalComMac online resource allows the visualisation of every transcript expressed during bacterial replication within mammalian cells. This primary transcriptome of intra-macrophage S.-Typhimurium describes the transcriptional start sites and the transcripts responsible for virulence traits, and catalogues the sRNAs that may play a role in the regulation of gene expression during infection. PMID:26561851

  12. Coptidis rhizome and Si Jun Zi Tang can prevent Salmonella enterica serovar Typhimurium infection in mice.

    PubMed

    Chang, Chiung-Hung; Yu, Bi; Su, Chiu-Hsian; Chen, Daniel S; Hou, Yu-Chi; Chen, Yueh-Sheng; Hsu, Yuan-Man

    2014-01-01

    Salmonella, a common zoonotic pathogen, causes gastroenteritis in both humans and animals. Traditional Chinese Medicine (TCM) has been used to improve gastrointestinal dysfunction and to modify the immune response to inflammation for centuries. This study used six herbal plants and four TCM formulae to rate their efficacy in preventing S. Typhimurium infection via mouse model. Minimum bactericidal concentration (MBC) of Coptidis rhizome (CR) against the reference strain tallied 12.5 mg/ml and against clinical isolate ST21 was 25 mg/ml. MBCs of other herbal extracts and formulae on Salmonella Typhimurium strains were above 50 mg/ml. In the mice model, CR and Si Jun Zi Tang (SJZT) could significantly decrease the bacterial load in organs and blood after being challenged, along with body weight loss due to the infection. CR and SJZT alleviated infection-induced interferon-gamma levels in the serum and tissues, and tumor necrosis factor-alpha (TNF-α) levels in intestinal tissues. CR and SJZT serum metabolites could suppress S. Typhimurium invasion and TNF-α expression in RAW264.7 cells. The therapeutic activity of CR and SJZT may involve berberine, ginsenoside Rb1, and glycyrrhizin, interfering with Salmonella when invading macrophages. CR and SJZT has shown potential in preventing S. Typhimurium infection through the regulation of the immune response.

  13. Contact with cultured epithelial cells stimulates secretion of Salmonella typhimurium invasion protein InvJ.

    PubMed Central

    Zierler, M K; Galán, J E

    1995-01-01

    Contact of Salmonella typhimurium with cultured epithelial cells results in the assembly of surface appendages termed invasomes which are presumably required for the internalization of these organisms into host cells. The assembly of these structures requires the function of a dedicated protein secretion system encoded in the inv locus. We show in this report that contact of wild-type S. typhimurium with cultured Henle-407 cells stimulated the secretion of InvJ, a recently identified target of the inv-encoded type III protein secretion system. Stimulation of InvJ secretion also occurred upon bacterial contact with bovine calf serum-coated culture dishes but did not occur upon S. typhimurium contact with glutaraldehyde-fixed Henle-407 cells. The stimulation of InvJ secretion did not require de novo protein synthesis. Invasion-defective invC and invG mutants of S. typhimurium failed to secrete InvJ upon contact with live Henle-407 cells. In contrast, contact-dependent secretion of InvJ in S. typhimurium invE mutants occurred at levels equivalent to those of the wild type. These results indicate that the presence of Henle-407 cells and/or serum is capable of activating the type III secretion system encoded in the inv locus, further supporting the notion that Salmonella entry into cultured cells is the result of a biochemical cross-talk between the bacteria and the host cells. PMID:7558314

  14. Contribution of Salmonella typhimurium Virulence Factors to Diarrheal Disease in Calves

    PubMed Central

    Tsolis, Renée M.; Adams, L. Garry; Ficht, Thomas A.; Bäumler, Andreas J.

    1999-01-01

    Limited knowledge is available about the virulence mechanisms responsible for diarrheal disease caused by Salmonella typhimurium. To assess the contribution to diarrheal disease of virulence determinants identified in models of infection, we tested a collection of S. typhimurium mutants for their ability to cause enteritis in calves. S. typhimurium strains carrying mutations in the virulence plasmid (spvR), Salmonella pathogenicity island 2 (SPI-2) (spiB), or SPI-5 (sopB) caused mortality and acute diarrhea in calves. An S. typhimurium rfaJ mutant, which is defective for lipopolysaccharide outer core biosynthesis, was of intermediate virulence. Mutations in SPI-1 (hilA and prgH) or aroA markedly reduced virulence and the severity of diarrhea. Furthermore, histopathological examination of calves infected with SPI-1 or aroA mutants revealed a marked reduction or absence of intestinal lesions. These data suggest that virulence factors, such as SPI-1, which are required during intestinal colonization are more important for pathogenicity in calves than are genes required during the systemic phase of S. typhimurium infection, including SPI-2 or the spv operon. This is in contrast to the degree of attenuation caused by these mutations in the mouse. PMID:10456944

  15. Systemic responses of BALB/c mice to Salmonella typhimurium infection.

    PubMed

    Zhu, Xiaoyang; Lei, Hehua; Wu, Junfang; Li, Jia V; Tang, Huiru; Wang, Yulan

    2014-10-03

    Salmonella typhimurium is a bacterial pathogen that poses a great threat to humans and animals. In order to discover hosts' responses to S. typhimurium infection, we collected and analyzed biofluids and organ tissues from mice which had ingested S. typhimurium. We employed (1)H NMR spectroscopy coupled with multivariate data analysis and immunological techniques. The results indicate that infection leads to a severe impact on mice spleen and ileum, which are characterized by splenomegaly and edematous villi, respectively. We found that increased levels of itaconic acid were correlated with the presence of splenomegaly during infection and may play an important role in Salmonella-containing vacuole acidification. In addition, metabonomic analyses of urine displayed the development of salmonellosis in mice, which is characterized by dynamic changes in energy metabolism. Furthermore, we found that the presence of S. typhimurium activated an anti-oxidative response in infected mice. We also observed changes in the gut microbial co-metabolites (hippurate, TMAO, TMA, methylamine). This investigation sheds much needed light on the host-pathogen interactions of S. typhimurium, providing further information to deepen our understanding of the long co-evolution process between hosts and infective bacteria.

  16. Salmonella enterica Serovar Typhimurium Exploits Inflammation to Modify Swine Intestinal Microbiota

    PubMed Central

    Drumo, Rosanna; Pesciaroli, Michele; Ruggeri, Jessica; Tarantino, Michela; Chirullo, Barbara; Pistoia, Claudia; Petrucci, Paola; Martinelli, Nicola; Moscati, Livia; Manuali, Elisabetta; Pavone, Silvia; Picciolini, Matteo; Ammendola, Serena; Gabai, Gianfranco; Battistoni, Andrea; Pezzotti, Giovanni; Alborali, Giovanni L.; Napolioni, Valerio; Pasquali, Paolo; Magistrali, Chiara F.

    2016-01-01

    Salmonella enterica serovar Typhimurium is an important zoonotic gastrointestinal pathogen responsible for foodborne disease worldwide. It is a successful enteric pathogen because it has developed virulence strategies allowing it to survive in a highly inflamed intestinal environment exploiting inflammation to overcome colonization resistance provided by intestinal microbiota. In this study, we used piglets featuring an intact microbiota, which naturally develop gastroenteritis, as model for salmonellosis. We compared the effects on the intestinal microbiota induced by a wild type and an attenuated S. Typhimurium in order to evaluate whether the modifications are correlated with the virulence of the strain. This study showed that Salmonella alters microbiota in a virulence-dependent manner. We found that the wild type S. Typhimurium induced inflammation and a reduction of specific protecting microbiota species (SCFA-producing bacteria) normally involved in providing a barrier against pathogens. Both these effects could contribute to impair colonization resistance, increasing the host susceptibility to wild type S. Typhimurium colonization. In contrast, the attenuated S. Typhimurium, which is characterized by a reduced ability to colonize the intestine, and by a very mild inflammatory response, was unable to successfully sustain competition with the microbiota. PMID:26835435

  17. Complete, Closed Genome Sequences of 10 Salmonella enterica subsp. enterica Serovar Typhimurium Strains Isolated from Human and Bovine Sources

    PubMed Central

    Nguyen, Scott V.; Bono, James L.; Smith, Timothy P. L.; Fields, Patricia I.; Dinsmore, Blake A.; Santovenia, Monica; Kelley, Christy M.; Wang, Rong; Bosilevac, Joseph M.; Harhay, Gregory P.

    2016-01-01

    Salmonella enterica is a leading cause of enterocolitis for humans and animals. S. enterica subsp. enterica serovar Typhimurium infects a broad range of hosts. To facilitate genomic comparisons among isolates from different sources, we present the complete genome sequences of 10 S. Typhimurium strains, 5 each isolated from human and bovine sources. PMID:27811097

  18. Draft Genome Sequences of 40 Salmonella enterica Serovar Typhimurium Strains Isolated from Humans and Food in Brazil

    PubMed Central

    Almeida, Fernanda; Medeiros, Marta Inês Cazentini; Rodrigues, Dália Prazeres; Payne, Justin; Timme, Ruth E.

    2016-01-01

    Salmonellosis is an important health problem worldwide and Salmonella enterica serovar Typhimurium is one of the most common isolated serovars. Here, we reported the draft genomes of 40 S. Typhimurium strains isolated from humans and food in Brazil. These draft genomes will improve phylogenetic analysis and will help enhance our understanding of strains of this serovar isolated in Brazil. PMID:27660768

  19. Draft Genome Sequences of 40 Salmonella enterica Serovar Typhimurium Strains Isolated from Humans and Food in Brazil.

    PubMed

    Almeida, Fernanda; Medeiros, Marta Inês Cazentini; Rodrigues, Dália Prazeres; Payne, Justin; Timme, Ruth E; Allard, Marc W; Falcão, Juliana Pfrimer

    2016-09-22

    Salmonellosis is an important health problem worldwide and Salmonella enterica serovar Typhimurium is one of the most common isolated serovars. Here, we reported the draft genomes of 40 S Typhimurium strains isolated from humans and food in Brazil. These draft genomes will improve phylogenetic analysis and will help enhance our understanding of strains of this serovar isolated in Brazil.

  20. Complete, closed genome sequences of 10 Salmonella enterica subsp. enterica serovar Typhimurium strains isolated from human and bovine sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella enterica are a leading cause of enterocolitis for humans and animals. S. enterica serovar Typhimurium infects a broad range of hosts. To facilitate genomic comparisons among isolates from different sources, we present the complete genome sequences of ten S. Typhimurium strains, five each...

  1. Refined live attenuated Salmonella enterica serovar Typhimurium and Enteritidis vaccines mediate homologous and heterologous serogroup protection in mice.

    PubMed

    Tennant, Sharon M; Schmidlein, Patrick; Simon, Raphael; Pasetti, Marcela F; Galen, James E; Levine, Myron M

    2015-12-01

    Invasive nontyphoidal Salmonella (NTS) infections constitute a major health problem among infants and toddlers in sub-Saharan Africa; these infections also occur in infants and the elderly in developed countries. We genetically engineered a Salmonella enterica serovar Typhimurium strain of multilocus sequence type 313, the predominant genotype circulating in sub-Saharan Africa. We evaluated the capacities of S. Typhimurium and Salmonella enterica serovar Enteritidis ΔguaBA ΔclpX live oral vaccines to protect mice against a highly lethal challenge dose of the homologous serovar and determined protection against other group B and D serovars circulating in sub-Saharan Africa. The vaccines S. Typhimurium CVD 1931 and S. Enteritidis CVD 1944 were immunogenic and protected BALB/c mice against 10,000 50% lethal doses (LD50) of S. Typhimurium or S. Enteritidis, respectively. S. Typhimurium CVD 1931 protected mice against the group B serovar Salmonella enterica serovar Stanleyville (91% vaccine efficacy), and S. Enteritidis CVD 1944 protected mice against the group D serovar Salmonella enterica serovar Dublin (85% vaccine efficacy). High rates of survival were observed when mice were infected 12 weeks postimmunization, indicating that the vaccines elicited long-lived protective immunity. Whereas CVD 1931 did not protect against S. Enteritidis R11, CVD 1944 did mediate protection against S. Typhimurium D65 (81% efficacy). These findings suggest that a bivalent (S. Typhimurium and S. Enteritidis) vaccine would provide broad protection against the majority of invasive NTS infections in sub-Saharan Africa.

  2. Refined Live Attenuated Salmonella enterica Serovar Typhimurium and Enteritidis Vaccines Mediate Homologous and Heterologous Serogroup Protection in Mice

    PubMed Central

    Schmidlein, Patrick; Simon, Raphael; Pasetti, Marcela F.; Galen, James E.; Levine, Myron M.

    2015-01-01

    Invasive nontyphoidal Salmonella (NTS) infections constitute a major health problem among infants and toddlers in sub-Saharan Africa; these infections also occur in infants and the elderly in developed countries. We genetically engineered a Salmonella enterica serovar Typhimurium strain of multilocus sequence type 313, the predominant genotype circulating in sub-Saharan Africa. We evaluated the capacities of S. Typhimurium and Salmonella enterica serovar Enteritidis ΔguaBA ΔclpX live oral vaccines to protect mice against a highly lethal challenge dose of the homologous serovar and determined protection against other group B and D serovars circulating in sub-Saharan Africa. The vaccines S. Typhimurium CVD 1931 and S. Enteritidis CVD 1944 were immunogenic and protected BALB/c mice against 10,000 50% lethal doses (LD50) of S. Typhimurium or S. Enteritidis, respectively. S. Typhimurium CVD 1931 protected mice against the group B serovar Salmonella enterica serovar Stanleyville (91% vaccine efficacy), and S. Enteritidis CVD 1944 protected mice against the group D serovar Salmonella enterica serovar Dublin (85% vaccine efficacy). High rates of survival were observed when mice were infected 12 weeks postimmunization, indicating that the vaccines elicited long-lived protective immunity. Whereas CVD 1931 did not protect against S. Enteritidis R11, CVD 1944 did mediate protection against S. Typhimurium D65 (81% efficacy). These findings suggest that a bivalent (S. Typhimurium and S. Enteritidis) vaccine would provide broad protection against the majority of invasive NTS infections in sub-Saharan Africa. PMID:26351285

  3. Rapid detection of Escherichia coli and Salmonella typhimurium by surface-enhanced Raman scattering

    NASA Astrophysics Data System (ADS)

    Su, Lan; Zhang, Ping; Zheng, Da-wei; Wang, Yang-jun-qi; Zhong, Ru-gang

    2015-03-01

    In this paper, the surface-enhanced Raman scattering (SERS) is used as an analytical tool for the detection and identification of pathogenic bacteria of Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium). Compared with normal Raman signal, the intensity of SERS signal is greatly enhanced. After processing all SERS data, the obvious differences between the SERS spectra of two species are determined. And applying the chemometric tools of principal component analysis and hierarchical cluster analysis (PCA-HCA), the SERS spectra of two species are distinguished more accurately. The results indicate that SERS analysis can provide a rapid and sensitive method for the detection of pathogenic bacteria.

  4. Constraint-based analysis of metabolic capacity of Salmonella typhimurium during host-pathogen interaction

    PubMed Central

    Raghunathan, Anu; Reed, Jennifer; Shin, Sookil; Palsson, Bernhard; Daefler, Simon

    2009-01-01

    Background Infections with Salmonella cause significant morbidity and mortality worldwide. Replication of Salmonella typhimurium inside its host cell is a model system for studying the pathogenesis of intracellular bacterial infections. Genome-scale modeling of bacterial metabolic networks provides a powerful tool to identify and analyze pathways required for successful intracellular replication during host-pathogen interaction. Results We have developed and validated a genome-scale metabolic network of Salmonella typhimurium LT2 (iRR1083). This model accounts for 1,083 genes that encode proteins catalyzing 1,087 unique metabolic and transport reactions in the bacterium. We employed flux balance analysis and in silico gene essentiality analysis to investigate growth under a wide range of conditions that mimic in vitro and host cell environments. Gene expression profiling of S. typhimurium isolated from macrophage cell lines was used to constrain the model to predict metabolic pathways that are likely to be operational during infection. Conclusion Our analysis suggests that there is a robust minimal set of metabolic pathways that is required for successful replication of Salmonella inside the host cell. This model also serves as platform for the integration of high-throughput data. Its computational power allows identification of networked metabolic pathways and generation of hypotheses about metabolism during infection, which might be used for the rational design of novel antibiotics or vaccine strains. PMID:19356237

  5. Emergence of Clinical Salmonella enterica Serovar Typhimurium Isolates with Concurrent Resistance to Ciprofloxacin, Ceftriaxone, and Azithromycin

    PubMed Central

    Wong, Marcus Ho Yin; Yan, Meiying; Chan, Edward Wai Chi; Biao, Kan

    2014-01-01

    Salmonella infection is an important public health issue for which the needs of antimicrobial treatment are increasing. A total of 546 human clinical S. enterica serovar Typhimurium isolates were recovered from patients in hospitals in China during the period of 2005 to ∼2011. Twenty percent of the isolates exhibited resistance to ciprofloxacin, and 4% were resistant to ceftriaxone. Importantly, for the first time, 12 (2%) S. Typhimurium isolates resistant to both ciprofloxacin and ceftriaxone were recovered; among these 12 isolates, two were also resistant to azithromycin, and one was resistant to all other drugs tested. The combined effects of various transferrable extended-spectrum β-lactamase determinants and a novel efflux-based ciprofloxacin resistance mechanism encoded by the mobile efflux gene oqxAB were responsible for the emergence of these extremely (highly) drug-resistant (XDR) S. Typhimurium isolates. The dissemination of resistance genes, such as those encoding ESBLs and the OqxAB pump, among Salmonella organisms will speed up the selection of XDR Salmonella, posing a huge threat to public health and Salmonella infection control. PMID:24752251

  6. Inducible spy Transcription Acts as a Sensor for Envelope Stress of Salmonella typhimurium

    PubMed Central

    Kim, Jin Seok; Lee, Sang Dae

    2017-01-01

    Salmonella enterica infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target Salmonella envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for Salmonella envelope stress, we examined the transcription of the S. enterica serovar typhimurium spy gene, the ortholog of which in Escherichia coli encodes Spy (spheroplast protein y). Spy is a chaperone protein expressed and localized in the periplasm of E. coli during spheroplast formation, or by exposure to protein denaturing conditions. spy expression in S. typhimurium was examined by constructing a spy-gfp transcriptional fusion. S. typhimurium spy transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, spy induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring spy transcription may be useful to determine whether a molecule particularly cause envelope stress in Salmonella. PMID:28316480

  7. Quantitative evaluation of E. coli F4 and Salmonella Typhimurium binding capacity of yeast derivatives.

    PubMed

    Ganner, Anja; Stoiber, Christian; Uhlik, Jakob Tizian; Dohnal, Ilse; Schatzmayr, Gerd

    2013-10-22

    The target of the present study was to quantify the capacity of different commercially available yeast derivatives to bind E. coli F4 and Salmonella Typhimurium. In addition, a correlation analysis was performed for the obtained binding numbers and the mannan-, glucan- and protein contents of the products, respectively. In a subsequent experiment, different yeast strains were fermented and treated by autolysis or French press to obtain a concentrated yeast cell wall. The capacity of yeast cell wall products to bind E. coli F4 and Salmonella Typhimurium was assessed with a quantitative microbiological microplate-based assay by measuring the optical density (OD) as the growth parameter of adhering bacteria. Total mannan and glucan were determined by HPLC using an isocratic method and a Refractive Index (RI) Detector. Total protein was determined by Total Kjeldahl Nitrogen (TKN). Statistical analyses were performed with IBM SPSS V19 using Spearman correlation and Mann Whitney U Test.Different yeast derivatives show different binding numbers, which indicate differences in product quality.Interestingly, the binding numbers for Salmonella Typhimurium are consistently higher (between one and two orders of magnitude) than for E. coli F4.We could demonstrate some statistical significant correlations between the mannan- and glucan content of different yeast derivatives and pathogen binding numbers; however, for the different yeast strains fermented under standardized laboratory conditions, no statistically significant correlations between the mannan- and glucan content and the binding numbers for E. coli and Salmonella Typhimurium were found.Interestingly, we could demonstrate that the yeast autolysis had a statistically significant difference on E. coli binding in contrast to the French press treatment. Salmonella binding was independent of these two treatments.As such, we could not give a clear statement about the binding factors involved. We propose that many more factors

  8. Coated fatty acids alter virulence properties of Salmonella Typhimurium and decrease intestinal colonization of pigs.

    PubMed

    Boyen, F; Haesebrouck, F; Vanparys, A; Volf, J; Mahu, M; Van Immerseel, F; Rychlik, I; Dewulf, J; Ducatelle, R; Pasmans, F

    2008-12-10

    Salmonella Typhimurium infections in pigs are a major source of human foodborne salmonellosis. To reduce the number of infected pigs, acidification of feed or drinking water is a common practice. The aim of the present study was to determine whether some frequently used short- (SCFA) and medium-chain fatty acids (MCFA) are able to alter virulence gene expression and to decrease Salmonella Typhimurium colonization and shedding in pigs using well established and controlled in vitro and in vivo assays. Minimal inhibitory concentrations (MIC) of 4 SCFA (formic acid, acetic acid, propionic acid and butyric acid) and 2 MCFA (caproic and caprylic acid) were determined using 54 porcine Salmonella Typhimurium field strains. MIC values increased at increasing pH-values and were two to eight times lower for MCFA than for SCFA. Expression of virulence gene fimA was significantly lower when bacteria were grown in LB-broth supplemented with sub-MIC concentrations of caproic or caprylic acid (2 mM). Expression of hilA and invasion in porcine intestinal epithelial cells was significantly lower when bacteria were grown in LB-broth containing sub-MIC concentrations of butyric acid or propionic acid (10 mM) and caproic or caprylic acid (2 mM). When given as feed supplement to pigs experimentally infected with Salmonella Typhimurium, coated butyric acid decreased the levels of faecal shedding and intestinal colonization, but had no influence on the colonization of tonsils, spleen and liver. Uncoated fatty acids, however, did not influence fecal shedding, intestinal or tonsillar colonization in pigs. In conclusion, supplementing feed with certain coated fatty acids, such as butyric acid, may help to reduce the Salmonella load in pigs.

  9. The Molecular Epidemiological Characteristics and Genetic Diversity of Salmonella Typhimurium in Guangdong, China, 2007–2011

    PubMed Central

    Huang, Yanhui; He, Dongmei; Li, Xiaocui; Liang, Zhaoming; Ke, Changwen

    2014-01-01

    Background Salmonella enterica serovar Typhimurium is the most important serovar associated with human salmonellosis worldwide. Here we aimed to explore the molecular epidemiology and genetic characteristics of this serovar in Guangdong, China. Methodology We evaluated the molecular epidemiology and genetic characteristics of 294 endemic Salmonella Typhimurium clinical isolates which were collected from 1977 to 2011 in Guangdong, China, and compared them with a global set of isolates of this serovar using epidemiological data and Multilocus Sequence Typing (MLST) analysis. Principal Finding The 294 isolates were assigned to 13 Sequencing types (STs) by MLST, of which ST34 and ST19 were the most common in Guangdong. All the STs were further assigned to two eBurst Groups, eBG1 and eBG138. The eBG1 was the major group endemic in Guangdong. Nucleotide and amino acid variability were comparable for all seven MLST loci. Tajima’s D test suggested positive selection in hisD and thrA genes (p<0.01), but positive selection was rejected for the five other genes (p>0.05). In addition, The Tajima’s D test within each eBG using the global set of isolates showed positive selection in eBG1 and eBG138 (p<0.05), but was rejected in eBG243 (p>0.05). We also analyzed the phylogenetic structure of Salmonella Typhimurium from worldwide sources and found that certain STs are geographically restricted. ACSSuT was the predominant multidrug resistance pattern for this serovar. The resistant profiles ACSSuTTmNaG, ACSSuTTmNa and ACSuTTmNaG seem to be specific for ST34, and ASSuTNa for ST19. Conclusion Here we presented a genotypic characterization of Salmonella Typhimurium isolates using MLST and found two major STs are endemic in Guangdong. Our analyses indicate that genetic selection may have shaped the Salmonella Typhimurium populations. However, further evaluation with additional isolates from various sources will be essential to reveal the scope of the epidemiological characteristics

  10. Immunochromatographic strip assay for the rapid and sensitive detection of Salmonella Typhimurium in artificially contaminated tomato samples.

    PubMed

    Shukla, Shruti; Leem, Hyerim; Lee, Jong-Suk; Kim, Myunghee

    2014-06-01

    This study was designed to confirm the applicability of a liposome-based immunochromatographic assay for the rapid detection of Salmonella enterica subsp. enterica serovar Typhimurium (Salmonella Typhimurium) in artificially contaminated tomato samples. To determine the detection limit and pre-enrichment incubation time (10, 12, and 18 h pre-enrichment in 1% buffered peptone water), the tests were performed with different cell numbers of Salmonella Typhimurium (3 × 10(0), 3 × 10(1), 3 × 10(2), and 3 × 10(3) CFU·mL(-1)) inoculated into 25 g of crushed tomato samples. The assay was able to detect as few as 30 Salmonella Typhimurium cells per 25 g of tomato samples (1.2 cells·g(-1)) after 12 h pre-enrichment incubation. Moreover, when the developed assay was compared with traditional morphological and biochemical culture-based methods as well as colloidal gold nanoparticle-based commercial test strips, the developed assay yielded positive results for the detection of Salmonella Typhimurium within a shorter period time. These findings confirm that the developed assay may have practical application for the sensitive detection of Salmonella Typhimurium in various food samples, including raw vegetables, with a relatively low detection limit and shorter analysis time.

  11. Injury and death of various Salmonella serotypes under acidic conditions during pre-enrichment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A previous study showed that after incubation in commonly used pre-enrichment media, mixed feeds and feed ingredients reached a pH (4.0 to 5.0) capable of injuring or killing Salmonella. The objective of this study was to subject four (4) different Salmonella serotypes to pHs of 4.0, 4.5 and 5.0 fo...

  12. Genomic Variability of Serial Human Isolates of Salmonella enterica Serovar Typhimurium Associated with Prolonged Carriage.

    PubMed

    Octavia, Sophie; Wang, Qinning; Tanaka, Mark M; Sintchenko, Vitali; Lan, Ruiting

    2015-11-01

    Salmonella enterica serovar Typhimurium is an important foodborne human pathogen that often causes self-limiting but severe gastroenteritis. Prolonged excretion of S. Typhimurium after the infection can lead to secondary transmissions. However, little is known about within-host genomic variation in bacteria associated with asymptomatic shedding. Genomes of 35 longitudinal isolates of S. Typhimurium recovered from 11 patients (children and adults) with culture-confirmed gastroenteritis were sequenced. There were three or four isolates obtained from each patient. Single nucleotide polymorphisms (SNPs) were analyzed in these isolates, which were recovered between 1 and 279 days after the initial diagnosis. Limited genomic variation (5 SNPs or fewer) was associated with short- and long-term carriage of S. Typhimurium. None of the isolates was shown to be due to reinfection. SNPs occurred randomly, and the majority of the SNPs were nonsynonymous. Two nonsense mutations were observed. A nonsense mutation in flhC rendered the isolate nonmotile, whereas the significance of a nonsense mutation in yihV is unknown. The estimated mutation rate is 1.49 × 10(-6) substitution per site per year. S. Typhimurium isolates excreted in stools following acute gastroenteritis in children and adults demonstrated limited genomic variability over time, regardless of the duration of carriage. These findings have important implications for the detection of possible transmission events suspected by public health genomic surveillance of S. Typhimurium infections.

  13. The elimination of Salmonella typhimurium in sewage sludge by aerobic mesophilic stabilization and lime hydrated stabilization.

    PubMed

    Plachá, Iveta; Venglovský, Ján; Maková, Zuzana; Martinéz, José

    2008-07-01

    This study observed the effects of two methods, aerobic mesophilic stabilization and lime hydrated stabilization of sewage sludge upon the survival of Salmonella typhimurium. Raw (primary) sludges from the mechanical biological municipal sewage treatment plant were used. Aerobic stabilization and lime hydrated stabilization were carried out in a laboratory fermentor. Aerobic stabilization was carried out in the mesophilic temperature range (from 25.70+/-0.40 to 37.82+/-1.38 degrees C). Lime hydrated was used at an amount of 10 kg/m(3) for the stabilization. Sludge samples were inoculated with a broth culture of S. typhimurium. Quantitative and qualitative examinations of the presence of S. typhimurium were carried out. Aerobic mesophilic stabilization caused elimination S. typhimurium within 48 h. The T(90) value of S. typhimurium was 6.66+/-0.20 h. During the lime hydrated stabilization pH values significantly increased from 5.66+/-0.07 to 12.12+/-0.02 (P<0.01). S. typhimurium was inactivated within 1h and the T(90) value was 0.19+/-0.01 h. Our study confirmed that the treatment of sewage sludge with lime hydrated was significantly more effective than the aerobic mesophilic stabilization, (P<0.01).

  14. Halogenation and proteolysis of complement component C3 on Salmonella typhimurium during phagocytosis by human neutrophils

    SciTech Connect

    Joiner, K.A.; Schweinle, J.E.

    1989-05-01

    We examined the fate of C component C3 on the surface of Salmonella typhimurium during ingestion by human neutrophils. Initial experiments showed that C3 fragments and C3-acceptor complexes were the major serum ligands which were surface iodinated by canine myeloperoxidase on serum-incubated rough and smooth isolates of S. typhimurium. In contrast, labeled C3 was not identified when the same organisms were ingested by neutrophils in the presence of 125I-Na, a situation previously shown to iodinate particulate targets via the neutrophil myeloperoxidase-halide-H2O2 system. Pretreatment of neutrophils before phagocytosis with the lipid-soluble protease inhibitor diisopropylfluorophosphate (DFP), but not with other protease inhibitors (p-nitrophenylguanidinobenzoate, leupeptin, pepstatin), substantially blocked proteolysis of 125I-C3 on S. typhimurium strain RG108 during ingestion by neutrophils. Purification of neutrophil phagosomes containing S. typhimurium-bearing 125I-C3 showed that DFP but no other protease inhibitors blocked proteolysis of 125I-C3 within phagosomes. Iodinated C3-acceptor complexes were identified by immunoprecipitation from the detergent-insoluble fraction of phagosomes prepared from DFP-treated cells ingesting S. typhimurium in the presence of 125I-Na. These results show that C3 fragments on the surface of S. typhimurium are the major serum ligands which are halogenated and degraded by proteolysis during phagocytosis by human neutrophils, and suggest that the majority of proteolysis on the ingested target occurs within the neutrophil phagosome.

  15. Salmonella enterica serovar Typhimurium ΔmsbB Triggers Exacerbated Inflammation in Nod2 Deficient Mice

    PubMed Central

    Claes, Anne-Kathrin; Steck, Natalie; Schultz, Dorothee; Zähringer, Ulrich; Lipinski, Simone; Rosenstiel, Philip; Geddes, Kaoru; Philpott, Dana J.; Heine, Holger; Grassl, Guntram A.

    2014-01-01

    The intracellular pathogen Salmonella enterica serovar Typhimurium causes intestinal inflammation characterized by edema, neutrophil influx and increased pro-inflammatory cytokine expression. A major bacterial factor inducing pro-inflammatory host responses is lipopolysaccharide (LPS). S. Typhimurium ΔmsbB possesses a modified lipid A, has reduced virulence in mice, and is being considered as a potential anti-cancer vaccine strain. The lack of a late myristoyl transferase, encoded by MsbB leads to attenuated TLR4 stimulation. However, whether other host receptor pathways are also altered remains unclear. Nod1 and Nod2 are cytosolic pattern recognition receptors recognizing bacterial peptidoglycan. They play important roles in the host's immune response to enteric pathogens and in immune homeostasis. Here, we investigated how deletion of msbB affects Salmonella's interaction with Nod1 and Nod2. S. Typhimurium Δ msbB-induced inflammation was significantly exacerbated in Nod2−/− mice compared to C57Bl/6 mice. In addition, S. Typhimurium ΔmsbB maintained robust intestinal colonization in Nod2−/− mice from day 2 to day 7 p.i., whereas colonization levels significantly decreased in C57Bl/6 mice during this time. Similarly, infection of Nod1−/− and Nod1/Nod2 double-knockout mice revealed that both Nod1 and Nod2 play a protective role in S. Typhimurium ΔmsbB-induced colitis. To elucidate why S. Typhimurium ΔmsbB, but not wild-type S. Typhimurium, induced an exacerbated inflammatory response in Nod2−/− mice, we used HEK293 cells which were transiently transfected with pathogen recognition receptors. Stimulation of TLR2-transfected cells with S. Typhimurium ΔmsbB resulted in increased IL-8 production compared to wild-type S. Typhimurium. Our results indicate that S. Typhimurium ΔmsbB triggers exacerbated colitis in the absence of Nod1 and/or Nod2, which is likely due to increased TLR2 stimulation. How bacteria with “genetically detoxified” LPS

  16. Microgravity as a novel environmental signal affecting Salmonella enterica serovar Typhimurium virulence.

    PubMed

    Nickerson, C A; Ott, C M; Mister, S J; Morrow, B J; Burns-Keliher, L; Pierson, D L

    2000-06-01

    The effects of spaceflight on the infectious disease process have only been studied at the level of the host immune response and indicate a blunting of the immune mechanism in humans and animals. Accordingly, it is necessary to assess potential changes in microbial virulence associated with spaceflight which may impact the probability of in-flight infectious disease. In this study, we investigated the effect of altered gravitational vectors on Salmonella virulence in mice. Salmonella enterica serovar Typhimurium grown under modeled microgravity (MMG) were more virulent and were recovered in higher numbers from the murine spleen and liver following oral infection compared to organisms grown under normal gravity. Furthermore, MMG-grown salmonellae were more resistant to acid stress and macrophage killing and exhibited significant differences in protein synthesis than did normal-gravity-grown cells. Our results indicate that the environment created by simulated microgravity represents a novel environmental regulatory factor of Salmonella virulence.

  17. Isolation and immunological characterization of a 55-kilodalton surface protein from Salmonella typhimurium.

    PubMed Central

    Foulaki, K; Gruber, W; Schlecht, S

    1989-01-01

    Surface proteins of different Salmonella R mutants were labeled selectively by treating live bacteria with cycloheptaamylose-dansylchloride. The labeled proteins were extracted from the cells with 6 M urea and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. From the urea extract a 55-kilodalton protein common to numerous Salmonella strains could be isolated by ion-exchange chromatography and gel filtration free of lipopolysaccharide. Immunization of rabbits with isolated protein led to the formation of specific antibodies. Such antiprotein antisera could be employed in Western blots for the specific identification of the 55-kilodalton protein in bacterial extracts containing mixtures of different Salmonella proteins. The importance of this antigen is emphasized by antisera against acetone-killed Salmonella bacteria, showing a preferential interaction with the 55-kilodalton protein in Western blots. Active immunization of mice with the 55-kilodalton protein afforded significant protection against experimental infection with S. typhimurium. Images PMID:2651306

  18. Distinct innate responses are induced by attenuated Salmonella enterica serovar Typhimurium mutants.

    PubMed

    Powell, Daniel A; Roberts, Lydia M; Ledvina, Hannah E; Sempowski, Gregory D; Curtiss, Roy; Frelinger, Jeffrey A

    2016-01-01

    Upon bacterial infection the host cells generate a wide variety of cytokines. Genetic attenuation of bacterial physiological pathogens can be accomplished not only by disruption of normal bacterial processes, but also by the loss of the ability to redirect the host immune system. We examined nine attenuated Salmonella Typhimurium mutants for their ability to replicate as well as the cytokines produced after infection of Bone Marrow Derived Macrophages (BMDM). Infection of BMDM with attenuated Salmonella mutants led to host cytokine patterns distinct from those that followed WT infection. Surprisingly, each bacterial mutant had a unique cytokine signature. Because some of the mutants induced an IL-10 response not seen in WT, we examined the role of IL-10 on Salmonella replication. Surprisingly, addition of IL-10 before or concurrent with infection restricted growth of WT Salmonella in BMDM. Bacterial attenuation is not a single process and results in attenuated host responses, which result in unique patterns for each attenuated mutants.

  19. Distinct Innate Responses are Induced by Attenuated Salmonella enterica serovar Typhimurium Mutants

    PubMed Central

    Powell, Daniel A.; Roberts, Lydia M.; Ledvina, Hannah E.; Sempowski, Gregory D.; Curtiss, Roy; Frelinger, Jeffrey A.

    2015-01-01

    Upon bacterial infection the host cells generate a wide variety of cytokines. Genetic attenuation of bacterial physiological pathogens can be accomplished not only by disruption of normal bacterial processes, but also by the loss of the ability to redirect the host immune system. We examined nine attenuated Salmonella Typhimurium mutants for their ability to replicate as well as the cytokines produced after infection of Bone Marrow Derived Macrophages (BMDM). Infection of BMDM with attenuated Salmonella mutants led to host cytokine patterns distinct from those that followed WT infection. Surprisingly, each bacterial mutant had a unique cytokine signature. Because some of the mutants induced an IL-10 response not seen in WT, we examined the role of IL-10 on Salmonella replication. Surprisingly, addition of IL-10 before or concurrent with infection restricted growth of WT Salmonella in BMDM. Bacterial attenuation is not a single process and results in attenuated host responses, which result in unique patterns for each attenuated mutants. PMID:26546408

  20. Microgravity as a novel environmental signal affecting Salmonella enterica serovar Typhimurium virulence

    NASA Technical Reports Server (NTRS)

    Nickerson, C. A.; Ott, C. M.; Mister, S. J.; Morrow, B. J.; Burns-Keliher, L.; Pierson, D. L.

    2000-01-01

    The effects of spaceflight on the infectious disease process have only been studied at the level of the host immune response and indicate a blunting of the immune mechanism in humans and animals. Accordingly, it is necessary to assess potential changes in microbial virulence associated with spaceflight which may impact the probability of in-flight infectious disease. In this study, we investigated the effect of altered gravitational vectors on Salmonella virulence in mice. Salmonella enterica serovar Typhimurium grown under modeled microgravity (MMG) were more virulent and were recovered in higher numbers from the murine spleen and liver following oral infection compared to organisms grown under normal gravity. Furthermore, MMG-grown salmonellae were more resistant to acid stress and macrophage killing and exhibited significant differences in protein synthesis than did normal-gravity-grown cells. Our results indicate that the environment created by simulated microgravity represents a novel environmental regulatory factor of Salmonella virulence.

  1. Draft Genome Sequence of Salmonella enterica subsp. enterica Serotype Oranienburg Strain S-76, Isolated from an Aquatic Environment

    PubMed Central

    Medrano-Félix, Andrés; Estrada-Acosta, Mitzi; Jiménez, Maribel; Gómez-Gil, Bruno; León-Félix, Josefina; Amarillas, Luis

    2013-01-01

    Salmonella is a widespread microorganism and a common causative agent of food-borne illnesses. Salmonella enterica subsp. enterica serotype Oranienburg is highly prevalent in surface water from tropical ecosystems and is not commonly related to illnesses. Here, we report the first genome sequence of Salmonella Oranienburg strain S-76, isolated from an aquatic environment. PMID:24336368

  2. In vitro quantitative analysis of Salmonella typhimurium preference for amino acids secreted by human breast tumor

    NASA Astrophysics Data System (ADS)

    Choi, Eunpyo; Maeng, Bohee; Lee, Jae-hun; Chang, Hyung-kwan; Park, Jungyul

    2016-12-01

    Bacterial therapies have been paid significant attentions by their ability to penetrate deep into the solid tumor tissue and its propensity to naturally accumulate in tumors of living animals. Understanding the actual mechanism for bacteria to target the tumor is therapeutically crucial but is poorly understood. We hypothesized that amino acids released from the specific tumors induced bacteria to those tumors and the experiments for chemotactic response of bacteria toward the cancer secreting amino acids was then performed by using the diffusion based multiple chemical gradient generator constructed by in situ self-assembly of microspheres. The quantitative analysis was carried out by comparison of intensity using green fluorescent protein (GFP) tagged Salmonella typhimurium ( S. typhimurium) in the gradient generator, which showed the clear preference to the released amino acids, especially from breast cancer patients. The understanding chemotaxis toward the cancer secreting amino acids is essential for controlling S. typhimurium targeting in tumors and will allow for the development of bacterial therapies.

  3. Microevolution of Monophasic Salmonella Typhimurium during Epidemic, United Kingdom, 2005–2010

    PubMed Central

    Petrovska, Liljana; Mather, Alison E.; AbuOun, Manal; Branchu, Priscilla; Harris, Simon R.; Connor, Thomas; Hopkins, K.L.; Underwood, A.; Lettini, Antonia A.; Page, Andrew; Bagnall, Mary; Wain, John; Parkhill, Julian; Dougan, Gordon; Davies, Robert

    2016-01-01

    Microevolution associated with emergence and expansion of new epidemic clones of bacterial pathogens holds the key to epidemiologic success. To determine microevolution associated with monophasic Salmonella Typhimurium during an epidemic, we performed comparative whole-genome sequencing and phylogenomic analysis of isolates from the United Kingdom and Italy during 2005–2012. These isolates formed a single clade distinct from recent monophasic epidemic clones previously described from North America and Spain. The UK monophasic epidemic clones showed a novel genomic island encoding resistance to heavy metals and a composite transposon encoding antimicrobial drug resistance genes not present in other Salmonella Typhimurium isolates, which may have contributed to epidemiologic success. A remarkable amount of genotypic variation accumulated during clonal expansion that occurred during the epidemic, including multiple independent acquisitions of a novel prophage carrying the sopE gene and multiple deletion events affecting the phase II flagellin locus. This high level of microevolution may affect antigenicity, pathogenicity, and transmission. PMID:26982594

  4. Microevolution of Monophasic Salmonella Typhimurium during Epidemic, United Kingdom, 2005-2010.

    PubMed

    Petrovska, Liljana; Mather, Alison E; AbuOun, Manal; Branchu, Priscilla; Harris, Simon R; Connor, Thomas; Hopkins, K L; Underwood, A; Lettini, Antonia A; Page, Andrew; Bagnall, Mary; Wain, John; Parkhill, Julian; Dougan, Gordon; Davies, Robert; Kingsley, Robert A

    2016-04-01

    Microevolution associated with emergence and expansion of new epidemic clones of bacterial pathogens holds the key to epidemiologic success. To determine microevolution associated with monophasic Salmonella Typhimurium during an epidemic, we performed comparative whole-genome sequencing and phylogenomic analysis of isolates from the United Kingdom and Italy during 2005-2012. These isolates formed a single clade distinct from recent monophasic epidemic clones previously described from North America and Spain. The UK monophasic epidemic clones showed a novel genomic island encoding resistance to heavy metals and a composite transposon encoding antimicrobial drug resistance genes not present in other Salmonella Typhimurium isolates, which may have contributed to epidemiologic success. A remarkable amount of genotypic variation accumulated during clonal expansion that occurred during the epidemic, including multiple independent acquisitions of a novel prophage carrying the sopE gene and multiple deletion events affecting the phase II flagellin locus. This high level of microevolution may affect antigenicity, pathogenicity, and transmission.

  5. Spraying chicken skin with selected chemicals to reduce attached Salmonella typhimurium.

    PubMed

    Xiong, H; Li, Y; Slavik, M F; Walker, J T

    1998-03-01

    Aqueous solutions of 5% and 10% trisodium phosphate (TSP), 0.1% and 0.5% cetylpyridinium chloride (CPC), 1% and 2% lactic acid (LA), and 0.1% and 0.5% grapefruit seed extract (DF-100) were evaluated in prechill spraying for reducing Salmonella typhimurium attached on chicken skins. Chicken skins were inoculated with S. typhimurium and then sprayed with the selected chemical solutions for 30 sec at 206 kPa and 20 degrees C. After chemical spraying, the skins were rinsed by spraying tap water for 30 sec. Each skin was stomached in buffered peptone water (BPW) for 1 min. The stomaching water was then diluted serially, inoculated onto both xylose lysine tergitol (XLT4) agar and Aerobic Plate Count (APC) Petrifilm, and incubated for 24 hr at 37 degrees C. The results showed that the numbers of Salmonella on the chicken skins after the chemical spraying were significantly lower than those without spray (P < 0.05). The CPC reduced Salmonella by 1.5 to 1.9 log10. TSP resulted in a 2.1 to 2.2 log10 reduction of Salmonella and DF-100 produced a 1.6 to 1.8 log10 reduction of Salmonella. The LA had a number of Salmonella with a 2.2 log10 reduction. The 0.5% CPC resulted a significantly greater reduction in Salmonella than 0.1% CPC. There were no significant differences in Salmonella reduction between different concentrations of the other three chemicals.

  6. Activation of inflammasome by attenuated Salmonella typhimurium in bacteria-mediated cancer therapy.

    PubMed

    Phan, Thuy Xuan; Nguyen, Vu Hong; Duong, Mai Thi-Quynh; Hong, Yeongjin; Choy, Hyon E; Min, Jung-Joon

    2015-11-01

    Escherichia coli and attenuated Salmonella both naturally accumulate in a tumor mass, yet have distinct therapeutic efficacy: the E. coli K-12 strain (MG1655) cannot induce as significant a tumor suppression as attenuated Salmonella typhimurium, despite similar levels of accumulation in the tumor. To elucidate the mechanism of the robust antitumor effect of S. typhimurium, the cytokine profiles elicited by bacterial colonization in tumors were analyzed. C57BL/6 mice bearing MC38 tumors were injected with Salmonella or MG1655 in the tail vein. Tumors were collected 3 days post-infection and homogenized. Inflammasome-related signals were measured by real-time PCR, ELISA and western blot analysis. Only attenuated Salmonella triggered significant levels of the inflammatory cytokine IL-1β in the tumor, whereas tumor growth was significantly suppressed. In addition, transcript levels of the core molecules of inflammasome signaling, IPAF, NLRP3 and P2X7, were significantly elevated only in Salmonella-treated tumors. Upon direct interaction between Salmonella and BMDM, BMDM expressed inflammasome-related proteins such as NLRP3, IPAF and caspase-1 p10, and secreted a significant amount of IL-1β in supernatants. Coincubation assays with BMDM and Salmonella-treated MC38 cells (damaged cancer cells) revealed secretion of IL-1β only when TLR4 and inflammasome were activated by both LPS and damaged cancer cells. ATP released from damaged cancer cells was also identified as a mechanism of NLRP3 activation. In conclusion, Salmonella activate the inflammasome pathway using damage signals released from cancer cells and through direct interaction with macrophages.

  7. Lipocalin-2 ensures host defense against Salmonella Typhimurium by controlling macrophage iron homeostasis and immune response.

    PubMed

    Nairz, Manfred; Schroll, Andrea; Haschka, David; Dichtl, Stefanie; Sonnweber, Thomas; Theurl, Igor; Theurl, Milan; Lindner, Ewald; Demetz, Egon; Aßhoff, Malte; Bellmann-Weiler, Rosa; Müller, Raphael; Gerner, Romana R; Moschen, Alexander R; Baumgartner, Nadja; Moser, Patrizia L; Talasz, Heribert; Tilg, Herbert; Fang, Ferric C; Weiss, Günter

    2015-11-01

    Lipocalin-2 (Lcn2) is an innate immune peptide with pleiotropic effects. Lcn2 binds iron-laden bacterial siderophores, chemo-attracts neutrophils and has immunomodulatory and apoptosis-regulating effects. In this study, we show that upon infection with Salmonella enterica serovar Typhimurium, Lcn2 promotes iron export from Salmonella-infected macrophages, which reduces cellular iron content and enhances the generation of pro-inflammatory cytokines. Lcn2 represses IL-10 production while augmenting Nos2, TNF-α, and IL-6 expression. Lcn2(-/-) macrophages have elevated IL-10 levels as a consequence of increased iron content. The crucial role of Lcn-2/IL-10 interactions was further demonstrated by the greater ability of Lcn2(-/-) IL-10(-/-) macrophages and mice to control intracellular Salmonella proliferation in comparison to Lcn2(-/-) counterparts. Overexpression of the iron exporter ferroportin-1 in Lcn2(-/-) macrophages represses IL-10 and restores TNF-α and IL-6 production to the levels found in wild-type macrophages, so that killing and clearance of intracellular Salmonella is promoted. Our observations suggest that Lcn2 promotes host resistance to Salmonella Typhimurium infection by binding bacterial siderophores and suppressing IL-10 production, and that both functions are linked to its ability to shuttle iron from macrophages.

  8. Lipocalin-2 ensures host defense against Salmonella Typhimurium by controlling macrophage iron homeostasis and immune response

    PubMed Central

    Nairz, Manfred; Schroll, Andrea; Haschka, David; Dichtl, Stefanie; Sonnweber, Thomas; Theurl, Igor; Theurl, Milan; Lindner, Ewald; Demetz, Egon; Aβhoff, Malte; Bellmann-Weiler, Rosa; Müller, Raphael; Gerner, Romana R.; Moschen, Alexander R.; Baumgartner, Nadja; Moser, Patrizia L.; Talasz, Heribert; Tilg, Herbert; Fang, Ferric C.; Weiss, Günter

    2015-01-01

    Lipocalin-2 (Lcn2) is an innate immune peptide with pleiotropic effects. Lcn2 binds iron-laden bacterial siderophores, chemo-attracts neutrophils and has immunomodulatory and apoptosis-regulating effects. In this study we show that upon infection with Salmonella enterica serovar Typhimurium, Lcn2 promotes iron export from Salmonella-infected macrophages, which reduces cellular iron content and enhances the generation of pro-inflammatory cytokines. Lcn2 represses IL-10 production while augmenting Nos2, TNF-α and IL-6 expression. Lcn2-/- macrophages have elevated IL-10 levels as a consequence of increased iron content. The crucial role of Lcn-2/IL-10 interactions was further demonstrated by the greater ability of Lcn2-/- IL-10-/- macrophages and mice to control intracellular Salmonella proliferation in comparison to Lcn2-/- counterparts. Over-expression of the iron exporter ferroportin-1 in Lcn2-/- macrophages represses IL-10 and restores TNF-α and IL-6 production to the levels found in wild-type macrophages, so that killing and clearance of intracellular Salmonella is promoted. Our observations suggest that Lcn2 promotes host resistance to Salmonella Typhimurium infection by binding bacterial siderophores and suppressing IL-10 production, and that both functions are linked to its ability to shuttle iron from macrophages. PMID:26332507

  9. High prevalence of Salmonella in tegu lizards (Tupinambis merianae), and susceptibility of the serotypes to antibiotics.

    PubMed

    Maciel, B M; Argôlo Filho, R C; Nogueira, S S C; Dias, J C T; Rezende, R P

    2010-12-01

    Species of tegu (Tupinambis) are the largest lizards in South America. Large numbers of these lizards are hunted; there is a vigorous trade in their skins and the meat is consumed by rural and native peoples. The animals are also bred in captivity, an economic activity for rural populations which can help in the animals' conservation. Faecal samples from 30 captive-born tegus were analysed for the presence of Salmonella in two separate samplings. In the first analysis, samples from 26 animals (87%) yielded Salmonella enterica of which 23% were of Rubislaw serotype; 20% Carrau and Agona serotypes; 7% Infantis and Saint-Paul serotypes; 3% Panama and Brandenburg serotypes; 10% were S. enterica subsp. enterica and 7% were rough form. In the second analysis, four tegus (13%) which had been negative in the first sampling were positive, thus, 100% of the animals studied carried the bacterium. Antibiotic susceptibility showed resistance to sulfonamide in 82% of the isolates, streptomycin in 64%, tetracycline in 6% and Chloramphenicol in 20%. Two animals carried strains of the same serotype with different patterns of antibiotic susceptibility. Although it is well known that reptiles are a significant source of Salmonella, to our knowledge, its prevalence in tegu has not been studied previously.

  10. Identification and characterization of Salmonella serotypes using DNA spectral characteristics by fourier transform infrared

    NASA Astrophysics Data System (ADS)

    Sundaram, Jaya; Park, Bosoon; Hinton, Arthur; Yoon, Seung Chul; Lawrence, Kurt C.

    2012-05-01

    Analysis of DNA samples of Salmonella serotypes were performed using FT-IR spectrometer by placing directly in contact with a diamond attenuated total reflection (ATR) crystal. Spectra were recorded from 4000 cm-1 to 525 cm-1 wavenumber with the resolution of 4 cm-1 and data spacing of 1.928 cm-1. Collected spectra were subtracted from the background spectra of empty diamond crystal surface. Principal Component Analysis (PCA) was conducted at four different spectral regions to differentiate the different serotypes of Salmonella on the basis of difference in their spectral features of DNA structure macromolecules. PCA was used to show the natural clusters in the data set and to describe the difference between the sample clusters. At the region 1800 - 1200 cm-1, PC1 distinguished 93 % and PC2 distinguished 7 % of the serotypes. Therefore, maximum classification of 100 % in total was obtained at this region. For all the Salmonella serotypes, the frequency between 1000-1150 cm-1 and 1170 -1280 cm-1 had higher loading values which showed their significant contribution in the serotype classification.

  11. Salmonella typhimurium Suppresses Tumor Growth via the Pro-Inflammatory Cytokine Interleukin-1β.

    PubMed

    Kim, Jung-Eun; Phan, Thuy Xuan; Nguyen, Vu Hong; Dinh-Vu, Hong-Van; Zheng, Jin Hai; Yun, Misun; Park, Sung-Gyoo; Hong, Yeongjin; Choy, Hyon E; Szardenings, Michael; Hwang, Won; Park, Jin-A; Park, SunHee; Im, Sin-Hyeog; Min, Jung-Joon

    2015-01-01

    Although strains of attenuated Salmonella typhimurium and wild-type Escherichia coli show similar tumor-targeting capacities, only S. typhimurium significantly suppresses tumor growth in mice. The aim of the present study was to examine bacteria-mediated immune responses by conducting comparative analyses of the cytokine profiles and immune cell populations within tumor tissues colonized by E. coli or attenuated Salmonellae. CT26 tumor-bearing mice were treated with two different bacterial strains: S. typhimurium defective in ppGpp synthesis (ΔppGpp Salmonellae) or wild-type E. coli MG1655. Cytokine profiles and immune cell populations in tumor tissue colonized by these two bacterial strains were examined at two time points based on the pattern of tumor growth after ΔppGpp Salmonellae treatment: 1) when tumor growth was suppressed ('suppression stage') and 2) when they began to re-grow ('re-growing stage'). The levels of IL-1β and TNF-α were markedly increased in tumors colonized by ΔppGpp Salmonellae. This increase was associated with tumor regression; the levels of both IL-1β and TNF-α returned to normal level when the tumors started to re-grow. To identify the immune cells primarily responsible for Salmonellae-mediated tumor suppression, we examined the major cell types that produce IL-1β and TNF-α. We found that macrophages and dendritic cells were the main producers of TNF-α and IL-1β. Inhibiting IL-1β production in Salmonellae-treated mice restored tumor growth, whereas tumor growth was suppressed for longer by local administration of recombinant IL-1β or TNF-α in conjunction with Salmonella therapy. These findings suggested that IL-1β and TNF-α play important roles in Salmonella-mediated cancer therapy. A better understanding of host immune responses in Salmonella therapy may increase the success of a given drug, particularly when various strategies are combined with bacteriotherapy.

  12. Salmonella typhimurium Suppresses Tumor Growth via the Pro-Inflammatory Cytokine Interleukin-1β

    PubMed Central

    Kim, Jung-Eun; Phan, Thuy Xuan; Nguyen, Vu Hong; Dinh-Vu, Hong-Van; Zheng, Jin Hai; Yun, Misun; Park, Sung-Gyoo; Hong, Yeongjin; Choy, Hyon E.; Szardenings, Michael; Hwang, Won; Park, Jin-A; Park, SunHee; Im, Sin-Hyeog; Min, Jung-Joon

    2015-01-01

    Although strains of attenuated Salmonella typhimurium and wild-type Escherichia coli show similar tumor-targeting capacities, only S. typhimurium significantly suppresses tumor growth in mice. The aim of the present study was to examine bacteria-mediated immune responses by conducting comparative analyses of the cytokine profiles and immune cell populations within tumor tissues colonized by E. coli or attenuated Salmonellae. CT26 tumor-bearing mice were treated with two different bacterial strains: S. typhimurium defective in ppGpp synthesis (ΔppGpp Salmonellae) or wild-type E. coli MG1655. Cytokine profiles and immune cell populations in tumor tissue colonized by these two bacterial strains were examined at two time points based on the pattern of tumor growth after ΔppGpp Salmonellae treatment: 1) when tumor growth was suppressed ('suppression stage') and 2) when they began to re-grow ('re-growing stage'). The levels of IL-1β and TNF-α were markedly increased in tumors colonized by ΔppGpp Salmonellae. This increase was associated with tumor regression; the levels of both IL-1β and TNF-α returned to normal level when the tumors started to re-grow. To identify the immune cells primarily responsible for Salmonellae-mediated tumor suppression, we examined the major cell types that produce IL-1β and TNF-α. We found that macrophages and dendritic cells were the main producers of TNF-α and IL-1β. Inhibiting IL-1β production in Salmonellae-treated mice restored tumor growth, whereas tumor growth was suppressed for longer by local administration of recombinant IL-1β or TNF-α in conjunction with Salmonella therapy. These findings suggested that IL-1β and TNF-α play important roles in Salmonella-mediated cancer therapy. A better understanding of host immune responses in Salmonella therapy may increase the success of a given drug, particularly when various strategies are combined with bacteriotherapy. PMID:26516371

  13. A live attenuated Salmonella enterica serovar Typhimurium vaccine provides cross-protection against Salmonella serovars to reduce disease severity and pathogen transmission

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A live attenuated Salmonella enterica serovar Typhimurium vaccine was developed to confer broad protection against multiple Salmonella serovars to prevent disease and reduce pathogen colonization and shedding. Two vaccine trials were performed in swine to determine the protection afforded by the vac...

  14. Rapid Molecular Determination of Serotype from Clinical Isolates of Salmonella Enterica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: The conventional serotyping of Salmonella Enterica is time consuming, costly, and requires highly skilled staff. In the present study, we report a multiplex PCR typing method using capillary electrophoresis for fragment analysis that allows for the identification of the 30 most common h...

  15. Prevalence of ColE1-like plasmids and kanamycinr resistance genes in Salmonella enterica serotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multi-antibiotic resistant Salmonella enterica serotypes are increasing in prevalence and concern in human and animal health. Many strains carry resistance determinants on plasmids; current practices focus heavily on large plasmids, and the role that small plasmids play in resistance gene transfer ...

  16. Salmonella enterica serotype enteritidis in French Polynesia, South Pacific, 2008-2013.

    PubMed

    Le Hello, Simon; Maillard, Fiona; Mallet, Henri-Pierre; Daudens, Elise; Levy, Marc; Roy, Valérie; Branaa, Philippe; Bertrand, Sophie; Fabre, Laetitia; Weill, François-Xavier

    2015-06-01

    Outbreaks of Salmonella enterica serotype Enteritidis infections associated with eggs occurred in French Polynesia during 2008-2013. Molecular analysis of isolates by using clustered regularly interspaced short palindromic repeat polymorphisms and multilocus variable-number tandem-repeat analysis was performed. This subtyping made defining the epidemic strain, finding the source, and decontaminating affected poultry flocks possible.

  17. Genomic epidemiology of Salmonella enterica serotype Enteritidis based on population structure of prevalent lineages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella enterica serotype Enteritidis (SE) is one of the most commonly reported causes of human salmonellosis. The low genetic diversity of SE measured by fingerprinting methods has made subtyping a challenge. In this study, we used whole genome sequencing to characterize a total of 125 SE and Sa...

  18. Epidemiology of a Salmonella enterica subsp. enterica serovar Typhimurium strain associated with a songbird outbreak.

    PubMed

    Hernandez, Sonia M; Keel, Kevin; Sanchez, Susan; Trees, Eija; Gerner-Smidt, Peter; Adams, Jennifer K; Cheng, Ying; Ray, Al; Martin, Gordon; Presotto, Andrea; Ruder, Mark G; Brown, Justin; Blehert, David S; Cottrell, Walter; Maurer, John J

    2012-10-01

    Salmonella enterica subsp. enterica serovar Typhimurium is responsible for the majority of salmonellosis cases worldwide. This Salmonella serovar is also responsible for die-offs in songbird populations. In 2009, there was an S. Typhimurium epizootic reported in pine siskins in the eastern United States. At the time, there was also a human outbreak with this serovar that was associated with contaminated peanuts. As peanuts are also used in wild-bird food, it was hypothesized that the pine siskin epizootic was related to this human outbreak. A comparison of songbird and human S. Typhimurium pulsed-field gel electrophoresis (PFGE) patterns revealed that the epizootic was attributed not to the peanut-associated strain but, rather, to a songbird strain first characterized from an American goldfinch in 1998. This same S. Typhimurium strain (PFGE type A3) was also identified in the PulseNet USA database, accounting for 137 of 77,941 total S. Typhimurium PFGE entries. A second molecular typing method, multiple-locus variable-number tandem-repeat analysis (MLVA), confirmed that the same strain was responsible for the pine siskin epizootic in the eastern United States but was distinct from a genetically related strain isolated from pine siskins in Minnesota. The pine siskin A3 strain was first encountered in May 2008 in an American goldfinch and later in a northern cardinal at the start of the pine siskin epizootic. MLVA also confirmed the clonal nature of S. Typhimurium in songbirds and established that the pine siskin epizootic strain was unique to the finch family. For 2009, the distribution of PFGE type A3 in passerines and humans mirrored the highest population density of pine siskins for the East Coast.

  19. Epidemiology of a Salmonella enterica subsp. enterica Serovar Typhimurium Strain Associated with a Songbird Outbreak

    PubMed Central

    Hernandez, Sonia M.; Keel, Kevin; Sanchez, Susan; Trees, Eija; Gerner-Smidt, Peter; Adams, Jennifer K.; Cheng, Ying; Ray, Al; Martin, Gordon; Presotto, Andrea; Ruder, Mark G.; Brown, Justin; Blehert, David S.; Cottrell, Walter

    2012-01-01

    Salmonella enterica subsp. enterica serovar Typhimurium is responsible for the majority of salmonellosis cases worldwide. This Salmonella serovar is also responsible for die-offs in songbird populations. In 2009, there was an S. Typhimurium epizootic reported in pine siskins in the eastern United States. At the time, there was also a human outbreak with this serovar that was associated with contaminated peanuts. As peanuts are also used in wild-bird food, it was hypothesized that the pine siskin epizootic was related to this human outbreak. A comparison of songbird and human S. Typhimurium pulsed-field gel electrophoresis (PFGE) patterns revealed that the epizootic was attributed not to the peanut-associated strain but, rather, to a songbird strain first characterized from an American goldfinch in 1998. This same S. Typhimurium strain (PFGE type A3) was also identified in the PulseNet USA database, accounting for 137 of 77,941 total S. Typhimurium PFGE entries. A second molecular typing method, multiple-locus variable-number tandem-repeat analysis (MLVA), confirmed that the same strain was responsible for the pine siskin epizootic in the eastern United States but was distinct from a genetically related strain isolated from pine siskins in Minnesota. The pine siskin A3 strain was first encountered in May 2008 in an American goldfinch and later in a northern cardinal at the start of the pine siskin epizootic. MLVA also confirmed the clonal nature of S. Typhimurium in songbirds and established that the pine siskin epizootic strain was unique to the finch family. For 2009, the distribution of PFGE type A3 in passerines and humans mirrored the highest population density of pine siskins for the East Coast. PMID:22885752

  20. Use of acetic and citric acids to control Salmonella Typhimurium in tahini (sesame paste).

    PubMed

    Al-Nabulsi, Anas A; Olaimat, Amin N; Osaili, Tareq M; Shaker, Reyad R; Zein Elabedeen, Noor; Jaradat, Ziad W; Abushelaibi, Aisha; Holley, Richard A

    2014-09-01

    Since tahini and its products have been linked to Salmonella illness outbreaks and product recalls in recent years, this study assessed the ability of Salmonella Typhimurium to survive or grow in commercial tahini and when hydrated (10% w/v in water), treated with 0.1%-0.5% acetic or citric acids, and stored at 37, 21 and 10 °C for 28 d. S. Typhimurium survived in commercial tahini up to 28 d but was reduced in numbers from 1.7 to 3.3 log10 CFU/ml. However, in the moist or hydrated tahini, significant growth of S. Typhimurium occurred at the tested temperatures. Acetic and citric acids at ≤0.5% reduced S. Typhimurium by 2.7-4.8 log10 CFU/ml and 2.5-3.8 log10 CFU/ml, respectively, in commercial tahini at 28 d. In hydrated tahini the organic acids were more effective. S. Typhimurium cells were not detected in the presence of 0.5% acetic acid after 7 d or with 0.5% citric acid after 21 d at the tested temperatures. The ability of S. Typhimurium to grow or survive in commercial tahini and products containing hydrated tahini may contribute to salmonellosis outbreaks; however, use of acetic and citric acids in ready-to-eat foods prepared from tahini can significantly minimize the risk associated with this pathogen.

  1. Impact of phytopathogen infection and extreme weather stress on internalization of Salmonella Typhimurium in lettuce.

    PubMed

    Ge, Chongtao; Lee, Cheonghoon; Nangle, Ed; Li, Jianrong; Gardner, David; Kleinhenz, Matthew; Lee, Jiyoung

    2014-01-03

    Internalization of human pathogens, common in many types of fresh produce, is a threat to human health since the internalized pathogens cannot be fully inactivated/removed by washing with water or sanitizers. Given that pathogen internalization can be affected by many environmental factors, this study was conducted to investigate the influence of two types of plant stress on the internalization of Salmonella Typhimurium in iceberg lettuce during pre-harvest. The stresses were: abiotic (water stress induced by extreme weather events) and biotic (phytopathogen infection by lettuce mosaic virus [LMV]). Lettuce with and without LMV infection were purposefully contaminated with green fluorescence protein-labeled S. Typhimurium on the leaf surfaces. Lettuce was also subjected to water stress conditions (drought and storm) which were simulated by irrigating with different amounts of water. The internalized S. Typhimurium in the different parts of the lettuce were quantified by plate count and real-time quantitative PCR and confirmed with a laser scanning confocal microscope. Salmonella internalization occurred under the conditions outlined above; however internalization levels were not significantly affected by water stress alone. In contrast, the extent of culturable S. Typhimurium internalized in the leafy part of the lettuce decreased when infected with LMV under water stress conditions and contaminated with high levels of S. Typhimurium. On the other hand, LMV-infected lettuce showed a significant increase in the levels of culturable bacteria in the roots. In conclusion, internalization was observed under all experimental conditions when the lettuce surface was contaminated with S. Typhimurium. However, the extent of internalization was only affected by water stress when lettuce was infected with LMV.

  2. Epidemiology of a Salmonella enterica subsp. Enterica serovar Typhimurium strain associated with a songbird outbreak.

    USGS Publications Warehouse

    Blehert, David S.; Hernandez, Sonia M.; Keel, Kevin; Sanchez, Susan; Trees, Eija; ,

    2012-01-01

    Salmonella enterica subsp. enterica serovar Typhimurium is responsible for the majority of salmonellosis cases worldwide. This Salmonella serovar is also responsible for die-offs in songbird populations. In 2009, there was an S. Typhimurium epizootic reported in pine siskins in the eastern United States. At the time, there was also a human outbreak with this serovar that was associated with contaminated peanuts. As peanuts are also used in wild-bird food, it was hypothesized that the pine siskin epizootic was related to this human outbreak. A comparison of songbird and human S. Typhimurium pulsed-field gel electrophoresis (PFGE) patterns revealed that the epizootic was attributed not to the peanut-associated strain but, rather, to a songbird strain first characterized from an American goldfinch in 1998. This same S. Typhimurium strain (PFGE type A3) was also identified in the PulseNet USA database, accounting for 137 of 77,941 total S. Typhimurium PFGE entries. A second molecular typing method, multiple-locus variable-number tandem-repeat analysis (MLVA), confirmed that the same strain was responsible for the pine siskin epizootic in the eastern United States but was distinct from a genetically related strain isolated from pine siskins in Minnesota. The pine siskin A3 strain was first encountered in May 2008 in an American goldfinch and later in a northern cardinal at the start of the pine siskin epizootic. MLVA also confirmed the clonal nature of S. Typhimurium in songbirds and established that the pine siskin epizootic strain was unique to the finch family. For 2009, the distribution of PFGE type A3 in passerines and humans mirrored the highest population density of pine siskins for the East Coast.

  3. Evaluation of alternariol and alternariol methyl ether for mutagenic activity in Salmonella typhimurium

    SciTech Connect

    Davis, V.M.; Stack, M.E. )

    1994-10-01

    Alternariol and alternariol methyl ether were tested in the Ames Salmonella typhimurium assay, and both were shown, with and without metabolic activation, to be nonmutagenic to strains TA98 and TA100. The finding of other investigators that alternariol methyl ether is weakly mutagenic to Ta98 without metabolic activation could have resulted from the presence of a small amount of one of the highly mutagenic altertoxins in the alternariol methyl ether originally tested. 9 refs., 3 figs., 1 tab.

  4. Draft Genome Sequence of the Tumor-Targeting Salmonella enterica Serovar Typhimurium Strain SL7207

    PubMed Central

    Johnson, Síle A.; Ormsby, Michael J.

    2017-01-01

    ABSTRACT Salmonella enterica serovar Typhimurium strain SL7207 is a genetically modified derivative of strain SL1344, which preferentially accumulates in tumors and can be used as a vehicle for tissue-specific gene delivery in vivo. Here, we report the draft genome sequence of SL7207, confirming a purported aroA deletion and four single-nucleotide polymorphisms compared to SL1344. PMID:28153911

  5. Evidence for regulation of gluconeogenesis by the fructose phosphotransferase system in Salmonella typhimurium.

    PubMed Central

    Chin, A M; Feucht, B U; Saier, M H

    1987-01-01

    A genetic locus designated fruR, previously mapped to min 3 on the Salmonella typhimurium chromosome, gave rise to constitutive expression of the fructose (fru) regulon and pleiotropically prevented growth on all Krebs cycle intermediates. Regulatory effects of fruR were independent of cyclic AMP and its receptor protein and did not prevent uptake of Krebs cycle intermediates. Instead, the phosphotransferase system appeared to regulate gluconeogenesis by controlling the activities of phosphoenolpyruvate carboxykinase and phosphoenolpyruvate synthase. PMID:3542978

  6. Therapeutic targeting of tumors with imageable GFP-expressing Salmonella typhimurium auxotrophic mutants

    NASA Astrophysics Data System (ADS)

    Hoffman, Robert M.; Hayashi, Katsuhiro; Zhao, Ming

    2008-02-01

    Tumor targeting Salmonella typhimurium has been developed. These bacteria were mutagenized and a strain auxotrophic for leucine and arguine was selected. This strain was also engineered to express GFP. This train, termed A1, could target prostate tumors in nude mouse models and inhibit their growth. A1 was passaged through a tumor and re-isolated and termed A1-R. A1-R had greater antitumor efficacy and could cure breast, prostate, pancreatic, and lung tumors in nude mouse models.

  7. Cd/sup 2 +/ tolerance in Escherichia coli and Salmonella typhimurium

    SciTech Connect

    Hartman, P.E.; Kuo, D.C.

    1987-01-01

    Relative tolerance of Escherichia coli strains to Cd/sup 2 +/ is induced by prior growth in medium containing low levels of either Cd/sup 2 +/ or Hg/sup 2 +/, and maximal induction appears to be dependent upon recA/sup +/ function. Biosynthesis of glutathione is not required for induction or for expression of induced resistance. Salmonella typhimurium strains are relatively resistant to Cd/sup 2 +/, and this resistance is essentially constitutive.

  8. LUMO energies and hydrophobicity as determinants of mutagenicity by nitroaromatic compounds in Salmonella typhimurium

    SciTech Connect

    Lopez de Compadre, R.L.; Debnath, A.K.; Hansch, C. ); Shusterman, A.J. )

    1990-01-01

    Quantitative structure-activity relationships have been derived for the mutagenic activity of 47 nitroaromatic compounds acting on Salmonella typhimurium (TA100) and 66 acting on TA98. The mutagenicity is linearly dependent on the energy of the lowest occupied molecular orbital and bilinearly dependent on the hydrophobicity (octanol/water log P) of the mutagens. The mechanism of action is considered in the light of these findings.

  9. Draft Genome Sequences of Salmonella enterica subsp. enterica Serovars Typhimurium and Nottingham Isolated from Food Products

    PubMed Central

    Zheng, Jie; Ayers, Sherry; Melka, David C.; Curry, Phillip E.; Payne, Justin S.; Laasri, Anna; Wang, Charles; Hammack, Thomas S.; Brown, Eric W.

    2016-01-01

    A quantitative real-time PCR (qPCR) designed to detect Salmonella enterica subsp. enterica serovar Enteritidis, targeting the sdf gene, generated positive results for S. enterica subsp. enterica serovar Typhimurium (CFSAN033950) and S. enterica subsp. enterica serovar Nottingham (CFSAN006803) isolated from food samples. Both strains show pulsed-field gel electrophoresis (PFGE) patterns distinct from those of S. Enteritidis. Here, we report the genome sequences of these two strains. PMID:27445384

  10. mcr-1−Harboring Salmonella enterica Serovar Typhimurium Sequence Type 34 in Pigs, China

    PubMed Central

    Yi, Linxian; Wang, Jing; Gao, Yanling; Liu, Yiyun; Doi, Yohei; Wu, Renjie; Zeng, Zhenling; Liang, Zisen

    2017-01-01

    We detected the mcr-1 gene in 21 (14.8%) Salmonella isolates from pigs at slaughter; 19 were serovar Typhimurium sequence type 34. The gene was located on IncHI2-like plasmids that also harbored IncF replicons and lacked a conjugative transfer region. These findings highlight the need to prevent further spread of colistin resistance in animals and humans. PMID:28098547

  11. Anti-infective mechanisms induced by a probiotic Lactobacillus strain against Salmonella enterica serovar Typhimurium infection.

    PubMed

    de LeBlanc, Alejandra de Moreno; Castillo, Natalia A; Perdigon, Gabriela

    2010-04-15

    The prevention of pathogen infections is one of the most extensively studied effects of probiotics. L. casei CRL 431 is a probiotic bacterium and its effects on the gut immune cells have been extensively studied. The aim of the present study was to determine, using a mouse model, the preventive and therapeutic effect of L. casei CRL 431 to achieve protection against Salmonella enteritidis serovar Typhimurium infection. In both previous and continuous (previous and post-infection) probiotic administration, the mechanisms induced by this lactic acid bacteria on the first line of intestinal defense (non-specific barrier and the innate immune cells associated to the gut), as a way to understand some of the mechanisms involved in the protection against Salmonella enteritidis serovar Typhimurium, were analyzed. The results obtained demonstrated that 7 days L. casei CRL 431 administration before infection decreased the severity of the infection with Salmonella enteritidis serovar Typhimurium, demonstrating that the continuous administration (even after infection) had the best effect. This continuous administration diminished the counts of the pathogen in the intestine as well as its spread outside this organ. Several mechanisms and cells are involved in this protective effect against Salmonella enteritidis serovar Typhimurium. L. casei CRL 431 acted on cells of the innate and adaptive immune response. The probiotic administration decreased the neutrophil infiltration with the consequent diminution of intestinal inflammation; activated the macrophage phagocytic activity in different sites such as Peyer's patches, spleen and peritoneum; and increased the number of IgA+cells in the lamina propria of the small intestine which was correlated with increased release of s-IgA specific against the pathogen in the intestinal fluids. The mechanism of the inhibition of cellular apoptosis was not involved.

  12. Direct ROS Scavenging Activity of CueP from Salmonella enterica serovar Typhimurium

    PubMed Central

    Yoon, Bo-Young; Yeom, Ji-Hyun; Kim, Jin-Sik; Um, Si-Hyeon; Jo, Inseong; Lee, Kangseok; Kim, Yong-Hak; Ha, Nam-Chul

    2014-01-01

    Salmonella enterica serovar Typhimurium (S. Typhimurium) is an intracellular pathogen that has evolved to survive in the phagosome of macrophages. The periplasmic copper-binding protein CueP was initially known to confer copper resistance to S. Typhimurium. Crystal structure and biochemical studies on CueP revealed a putative copper binding site surrounded by the conserved cysteine and histidine residues. A recent study reported that CueP supplies copper ions to periplasmic Cu, Zn-superoxide dismutase (SodCII) at a low copper concentration and thus enables the sustained SodCII activity in the periplasm. In this study, we investigated the role of CueP in copper resistance at a high copper concentration. We observed that the survival of a cueP-deleted strain of Salmonella in macrophage phagosome was significantly reduced. Subsequent biochemical experiments revealed that CueP specifically mediates the reduction of copper ion using electrons released during the formation of the disulfide bond. We observed that the copper ion-mediated Fenton reaction in the presence of hydrogen peroxide was blocked by CueP. This study provides insight into how CueP confers copper resistance to S. Typhimurium in copper-rich environments such as the phagosome of macrophages. PMID:24598994

  13. Rapid detection of Salmonella typhimurium on fresh spinach leaves using phage-immobilized magnetoelastic biosensors

    NASA Astrophysics Data System (ADS)

    Horikawa, Shin; Li, Suiqiong; Chai, Yating; Park, Mi-Kyung; Shen, Wen; Barbaree, James M.; Vodyanoy, Vitaly J.; Chin, Bryan A.

    2011-06-01

    This paper presents an investigation into the use of magnetoelastic biosensors for the rapid detection of Salmonella typhimurium on fresh spinach leaves. The biosensors used in this investigation were comprised of a strip-shaped, goldcoated sensor platform (2 mm-long) diced from a ferromagnetic, amorphous alloy and a filamentous fd-tet phage which specifically binds with S. typhimurium. After surface blocking with bovine serum albumin, these biosensors were, without any preceding sample preparation, directly placed on wet spinach leaves inoculated with various concentrations of S. typhimurium. Upon contact with cells, the phage binds S. typhimurium to the sensor thereby increasing the total mass of the sensor. This change in mass causes a corresponding decrease in the sensor's resonant frequency. After 25 min, the sensors were collected from the leaf surface and measurements of the resonant frequency were performed immediately. The total assay time was less than 30 min. The frequency changes for measurement sensors (i.e., phageimmobilized) were found to be statistically different from those for control sensors (sensors without phage), down to 5 × 106 cells/ml. The detection limit may be improved by using smaller, micron-sized sensors that will have a higher probability of contacting Salmonella on the rough surfaces of spinach leaves.

  14. PREDICTIVE MODEL FOR SURVIVAL AND GROWTH OF SALMONELLA TYPHIMURIUM DT104 ON CHICKEN SKIN DURING TEMPERATURE ABUSE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To better predict risk of Salmonella infection from chicken subjected to temperature abuse, a study was undertaken to develop a predictive model for survival and growth of Salmonella Typhimurium DT104 on chicken skin with native micro flora. For model development, chicken skin portions were inocula...

  15. Postmortem photonic imaging of lux-modified Salmonella typhimurium within the gastrointestinal tract of swine following oral inoculation in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study objective was to monitor Salmonella progression by photonic detection through segments of the gastrointestinal tract following oral inoculation. Pigs (~ 80 kg) were inoculated orally with 3.1 or 4.1×10*10 colony forming units (cfu) of Salmonella typhimurium transformed with plasmid pAK1-lu...

  16. Tetracycline accelerates the temporally-regulated invasion response in specific isolates of multidrug-resistant Salmonella enterica serovar Typhimurium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background Multidrug-resistant (MDR) Salmonella is associated with increased morbidity compared to antibiotic-sensitive strains and is an important health and safety concern in both humans and animals. Salmonella enterica serovar Typhimurium is a prevalent cause of foodborne disease, and a consider...

  17. Live-cell imaging of Salmonella Typhimurium interaction with zebrafish larvae after injection and immersion delivery methods.

    PubMed

    Varas, Macarena; Fariña, Alonso; Díaz-Pascual, Francisco; Ortíz-Severín, Javiera; Marcoleta, Andrés E; Allende, Miguel L; Santiviago, Carlos A; Chávez, Francisco P

    2017-04-01

    The zebrafish model has been used to determine the role of vertebrate innate immunity during bacterial infections. Here, we compare the in vivo immune response induced by GFP-tagged Salmonella Typhimurium inoculated by immersion and microinjection in transgenic zebrafish larvae. Our novel infection protocols in zebrafish allow live-cell imaging of Salmonella colonization.

  18. Correlating Blood Immune Parameters and a CCT7 Genetic Variant with the Shedding of Salmonella enterica Serovar Typhimurium in Swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the current study, 40 crossbred pigs were intranasally inoculated with Salmonella enterica serovar Typhimurium and monitored for Salmonella fecal shedding and blood immune parameters at 2, 7, 14 and 20 days post-inoculation (dpi). Using a multivariate permutation test, a positive correlation was...

  19. Persistence of contamination of hens' egg albumen in vitro with Salmonella serotypes.

    PubMed Central

    Lock, J. L.; Board, R. G.

    1992-01-01

    A study was made of the persistence of different Salmonella serotypes in hens' egg albumin in vitro at 4, 20 and 30 degrees C. The majority of serotypes remained viable but did not increase in numbers at 20 and 30 degrees C for 42 days. At 4 degrees C many of the serotypes died out. The addition of ferric ammonium citrate on the 42nd day of incubation induced multiplication of organisms incubated at 20 and 30 degrees C, but not at 4 degrees C. The pH and glucose concentration of the albumen diminished only when heavy growth occurred. Salmonella enteritidis remained viable on the air cell membrane in vitro for 17 days at 4, 20 and 30 degrees C. Thirty percent of the organisms also remained motile in albumen for 42 days at 25 degrees C and up to 5% of the cells remained motile for up to 20 days at 4 degrees C. PMID:1601073

  20. Structural and Functional Characterization of Three DsbA Paralogues from Salmonella enterica Serovar Typhimurium*

    PubMed Central

    Heras, Begoña; Totsika, Makrina; Jarrott, Russell; Shouldice, Stephen R.; Gunčar, Gregor; Achard, Maud E. S.; Wells, Timothy J.; Argente, M. Pilar; McEwan, Alastair G.; Schembri, Mark A.

    2010-01-01

    In prototypic Escherichia coli K-12 the introduction of disulfide bonds into folding proteins is mediated by the Dsb family of enzymes, primarily through the actions of the highly oxidizing protein EcDsbA. Homologues of the Dsb catalysts are found in most bacteria. Interestingly, pathogens have developed distinct Dsb machineries that play a pivotal role in the biogenesis of virulence factors, hence contributing to their pathogenicity. Salmonella enterica serovar (sv.) Typhimurium encodes an extended number of sulfhydryl oxidases, namely SeDsbA, SeDsbL, and SeSrgA. Here we report a comprehensive analysis of the sv. Typhimurium thiol oxidative system through the structural and functional characterization of the three Salmonella DsbA paralogues. The three proteins share low sequence identity, which results in several unique three-dimensional characteristics, principally in areas involved in substrate binding and disulfide catalysis. Furthermore, the Salmonella DsbA-like proteins also have different redox properties. Whereas functional characterization revealed some degree of redundancy, the properties of SeDsbA, SeDsbL, and SeSrgA and their expression pattern in sv. Typhimurium indicate a diverse role for these enzymes in virulence. PMID:20233716

  1. Curcumin increases the pathogenicity of Salmonella enterica serovar Typhimurium in murine model.

    PubMed

    Marathe, Sandhya A; Ray, Seemun; Chakravortty, Dipshikha

    2010-07-09

    Curcumin has gained immense importance for its vast therapeutic and prophylactic applications. Contrary to this, our study reveals that it regulates the defense pathways of Salmonella enterica serovar Typhimurium (S. Typhimurium) to enhance its pathogenicity. In a murine model of typhoid fever, we observed higher bacterial load in Peyer's patches, mesenteric lymph node, spleen and liver, when infected with curcumin-treated Salmonella. Curcumin increased the resistance of S. Typhimurium against antimicrobial agents like antimicrobial peptides, reactive oxygen and nitrogen species. This increased tolerance might be attributed to the up-regulation of genes involved in resistance against antimicrobial peptides--pmrD and pmrHFIJKLM and genes with antioxidant function--mntH, sodA and sitA. We implicate that iron chelation property of curcumin have a role in regulating mntH and sitA. Interestingly, we see that the curcumin-mediated modulation of pmr genes is through the PhoPQ regulatory system. Curcumin downregulates SPI1 genes, required for entry into epithelial cells and upregulates SPI2 genes required to intracellular survival. Since it is known that the SPI1 and SPI2 system can be regulated by the PhoPQ system, this common regulator could explain curcumin's mode of action. This data urges us to rethink the indiscriminate use of curcumin especially during Salmonella outbreaks.

  2. Pyruvate kinase deficiency confers susceptibility to Salmonella typhimurium infection in mice

    PubMed Central

    Roy, Marie-France; Riendeau, Noémie; Bédard, Christian; Hélie, Pierre; Min-Oo, Gundula; Turcotte, Karine; Gros, Philippe; Canonne-Hergaux, François; Malo, Danielle

    2007-01-01

    The mouse response to acute Salmonella typhimurium infection is complex, and it is under the influence of several genes, as well as environmental factors. In a previous study, we identified two novel Salmonella susceptibility loci, Ity4 and Ity5, in a (AcB61 × 129S6)F2 cross. The peak logarithm of odds score associated with Ity4 maps to the region of the liver and red blood cell (RBC)–specific pyruvate kinase (Pklr) gene, which was previously shown to be mutated in AcB61. During Plasmodium chabaudi infection, the Pklr mutation protects the mice against this parasite, as indicated by improved survival and lower peak parasitemia. Given that RBC defects have previously been associated with resistance to malaria and susceptibility to Salmonella, we hypothesized that Pklr is the gene underlying Ity4 and that it confers susceptibility to acute S. typhimurium infection in mice. Using a fine mapping approach combined with complementation studies, comparative studies, and functional analysis, we show that Pklr is the gene underlying Ity4 and that it confers susceptibility to acute S. typhimurium infection in mice through its effect on the RBC turnover and iron metabolism. PMID:17998386

  3. Thermal inactivation D- and z-values of Salmonella serotypes and listeria innocua in chicken patties, chicken tenders, franks, beef patties, and blended beef and turkey patties.

    PubMed

    Murphy, R Y; Duncan, L K; Johnson, E R; Davis, M D; Smith, J N

    2002-01-01

    Commercially formulated meat products, including chicken patties, chicken tenders, franks, beef patties, and blended beef and turkey patties, were obtained from processors. Each product was inoculated with 7 to 8 logs of Salmonella (Senftenberg, Typhimurium, Heidelberg, Mission, Montevideo, and California) or Listeria innocua. The inoculated meat samples were heat treated at 55 to 70 degrees C. At each temperature, the decimal reduction time (D) was obtained by linear regression of survival curves. Values of D and the temperature difference required for the thermal inactivation curve to drop a logarithmic cycle (z) were determined for the Salmonella serotypes and L. innocua in each product. At 55 to 70 degrees C. for the five tested products, the D-values for the Salmonella serotypes and L. innocua were 26.97 to 0.25 min and 191.94 to 0.18 min, respectively, and their z-values were 7.60 to 9.83 degrees C and 4.86 to 8.67 degrees C, respectively. Significant differences were found for the D- and z-values among the five products. This study will better enable processors to determine the process lethality of pathogens in commercial meat products.

  4. Colonization of internal organs by Salmonella serovars Heidelberg and Typhimurium in experimentally infected laying hens housed in enriched colony cages at different stocking densities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contaminated eggs produced by infected commercial laying flocks are often implicated as sources of human infections with Salmonella Enteritidis, but Salmonella serovars Heidelberg and Typhimurium have also been significantly associated with egg-transmitted illness. Contamination of the edible conten...

  5. A high affinity phage-displayed peptide as a recognition probe for the detection of Salmonella Typhimurium.

    PubMed

    Agrawal, Shailaja; Kulabhusan, Prabir Kumar; Joshi, Manali; Bodas, Dhananjay; Paknikar, Kishore M

    2016-08-10

    Salmonellosis is one of the most common and widely distributed foodborne diseases. A sensitive and robust detection method of Salmonella Typhimurium (S. Typhimurium) in food can critically prevent a disease outbreak. In this work, the use of phage displayed peptides was explored for the detection of S. Typhimurium. A phage-displayed random dodecapeptide library was subjected to biopanning against lipopolysaccharide (LPS) of S. Typhimurium. The peptide NFMESLPRLGMH (pep49) derived from biopanning displayed a high affinity (25.8nM) for the LPS of S. Typhimurium and low cross-reactivity with other strains of Salmonella and related Gram-negative bacteria. Molecular insights into the interaction of pep49 with the LPS of S. Typhimurium was gleaned using atomistic molecular dynamics simulations and docking. It was deduced that the specificity of pep49 with S. Typhimurium LPS originated from the interactions of pep49 with abequose that is found only in the O-antigen of S. Typhimurium. Further, pep49 was able to detect S. Typhimurium at a LOD of 10(3) CFU/mL using ELISA, and may be a potential cost efficient alternative to antibodies.

  6. Immunogenicity of transmissible gastroenteritis virus (TGEV) M gene delivered by attenuated Salmonella typhimurium in mice.

    PubMed

    Qing, Ying; Liu, Jiawen; Huang, Xiaobo; Li, Yaqing; Zhang, Yudi; Chen, Jie; Wen, Xintian; Cao, Sanjie; Wen, Yiping; Wu, Rui; Yan, Qigui; Ma, Xiaoping

    2016-04-01

    Attenuated Salmonella typhimurium (S. typhimurium) was selected as a transgenic vehicle for the development of live mucosal vaccines against transmissible gastroenteritis virus (TGEV) based on the M gene. An approximate 1.0 kb DNA fragment, encoding for glycoprotein M, was amplified by RT-PCR and cloned into eukaryotic expression vector pVAX1. The recombinant plasmid pVAX-M was transformed by electroporation into attenuated S. typhimurium SL7207, and the expression and translation of the pVAX-M delivered by recombinant S. typhimurium SL7207 (pVAX-M) was detected both in vitro and in vivo. BALB/c mice were inoculated orally with SL7207 (pVAX-M) at different dosages to evaluate safety of the vaccines. The bacterium was safe to mice at a dosage of 2 × 10(9) CFU, almost eliminated from the spleen and liver at week 4 post-immunization and eventually cleared at week 6. Mice immunized with 1 × 10(9) CFU of SL7207 (pVAX-M) elicited specific anti-TGEV local mucosal and humoral responses including levels of IgA, IgG, IL-4, and IFN-γ as measured by indirect ELISA assay. Moreover, the control groups (pVAX group, PBS group) maintained at a normal level during week 4-8 post-immunization. The results indicated that attenuated S. typhimurium could be used as a delivery vector for oral immunization of TGEV M gene vaccine.

  7. A new wireless detection device for the in-situ identification of Salmonella Typhimurium

    NASA Astrophysics Data System (ADS)

    Chai, Yating; Wikle, Howard C.; Park, Mi-kyung; Horikawa, Shin; Hong, Xie; Chin, Bryan A.

    2013-05-01

    This paper presents a new device and method for the in-situ detection of Salmonella Typhimurium on tomato surfaces. This real-time in-situ detection was accomplished with phage-based magnetoelastic (ME) biosensors on fresh food surfaces. The E2 phage from a landscape phage library serves as the bio-recognition element that has the capability of binding specifically with S. Typhimurium. This mass-sensitive ME biosensor is wirelessly actuated into mechanical resonance by an externally applied time-varying magnetic field. When the biosensor binds with S. Typhimurium, the mass of the sensor increases, resulting in a decrease in the sensor's resonant frequency. Until now, ME sensors had to be collected from the tomato surface where they are exposed to S. Typhimurium and inserted into a measurement coil for the detection of the bacterium. In contrast, the newly designed test device allows the whole detection process to take place directly on the tomato. Changes in resonant frequency over time due to the accumulation of S. Typhimurium on the sensor were measured and are presented. Real-time in-situ detection of 20 minutes was achieved. In addition, this new methodology effectively decreases the measurement error and enables the simultaneous detection of multiple pathogens.

  8. Salmonella typhimurium and Escherichia coli dissimilarity: Closely related bacteria with distinct metabolic profiles.

    PubMed

    Sargo, Cintia R; Campani, Gilson; Silva, Gabriel G; Giordano, Roberto C; Da Silva, Adilson J; Zangirolami, Teresa C; Correia, Daniela M; Ferreira, Eugénio C; Rocha, Isabel

    2015-01-01

    Live attenuated strains of Salmonella typhimurium have been extensively investigated as vaccines for a number of infectious diseases. However, there is still little information available concerning aspects of their metabolism. S. typhimurium and Escherichia coli show a high degree of similarity in terms of their genome contents and metabolic networks. However, this work presents experimental evidence showing that significant differences exist in their abilities to direct carbon fluxes to biomass and energy production. It is important to study the metabolism of Salmonella to elucidate the formation of acetate and other metabolites involved in optimizing the production of biomass, essential for the development of recombinant vaccines. The metabolism of Salmonella under aerobic conditions was assessed using continuous cultures performed at dilution rates ranging from 0.1 to 0.67 h(-1), with glucose as main substrate. Acetate assimilation and glucose metabolism under anaerobic conditions were also investigated using batch cultures. Chemostat cultivations showed deviation of carbon towards acetate formation, starting at dilution rates above 0.1 h(-1). This differed from previous findings for E. coli, where acetate accumulation was only detected at dilution rates exceeding 0.4 h(-1), and was due to the lower rate of acetate assimilation by S. typhimurium under aerobic conditions. Under anaerobic conditions, both microorganisms mainly produced ethanol, acetate, and formate. A genome-scale metabolic model, reconstructed for Salmonella based on an E. coli model, provided a poor description of the mixed fermentation pattern observed during Salmonella cultures, reinforcing the different patterns of carbon utilization exhibited by these closely related bacteria.

  9. Immuno-capture and in situ detection of Salmonella typhimurium on a novel microfluidic chip.

    PubMed

    Wang, Renjie; Ni, Yanan; Xu, Yi; Jiang, Yan; Dong, Chunyan; Chuan, Na

    2015-01-01

    The new method presented in this article achieved the goal of capturing Salmonella typhimurium via immunoreaction and rapid in situ detection of the CdSe/ZnS quantum dots (QDs) labeled S. typhimurium by self-assembly light-emitting diode-induced fluorescence detection (LIF) microsystem on a specially designed multichannel microfluidic chip. CdSe/ZnS QDs were used as fluorescent markers improving detection sensitivity. The microfluidic chip developed in this study was composed of 12 sample channels, 3 mixing zones, and 6 immune reaction zones, which also acted as fluorescence detection zones. QDs-IgG-primary antibody complexes were generated by mixing CdSe/ZnS QDs conjugated secondary antibody (QDs-IgG) and S. typhimurium antibody (primary antibody) in mixing zones. Then, the complexes went into immune reaction zones to label previously captured S. typhimurium in the sandwich mode. The capture rate of S. typhimurium in each detection zone was up to 70%. The enriched QDs-labeled S. typhimurium was detected using a self-assembly LIF microsystem. A good linear relationship was obtained in the range from 3.7×10 to 3.7×10(5) cfu mL(-1) using the equation I=0.1739 log (C)-0.1889 with R(2)=0.9907, and the detection limit was down to 37 cfu mL(-1). The proposed method of online immunolabeling with QDs for in situ fluorescence detection on the designed multichannel microfluidic chip had been successfully used to detect S. typhimurium in pork sample, and it has shown potential advantages in practice.

  10. Serotyping of Salmonella Isolates from Broiler Vertical Integrations in Colombia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study analyzed 106 Salmonella isolates from different points in broiler vertical integrations of two important poultry areas of Colombia. It was possible to identify the presence of Salmonella in five categories: breeder farm (17.9%), hatchery (6.6 %), broiler farm (38.7 %), processing plant (9...

  11. Salmonella-positive broiler carcasses contaminated by multiple serotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many laboratories that routinely sample broiler carcasses for Salmonella are primarily interested only in determining the presence or absence of Salmonella, so only one colony-forming unit may be selected. The objective of this study was to select several colonies from each of four selective plates...

  12. Salmonella serotype shift during an endemic dairy infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dairy farms are known reservoirs for Salmonella spp. and control of this organism is challenging. Salmonellae have been shown to be endemic in herds in part because they are easily spread between animals and throughout the farm environment. The impact of the infection on the herd is variable and dep...

  13. Identification of PhoP-PhoQ activated genes within a duplicated region of the Salmonella typhimurium chromosome.

    PubMed

    Gunn, J S; Belden, W J; Miller, S I

    1998-08-01

    Salmonellae virulence requires the PhoP-PhoQ two-component regulatory system. PhoP-PhoQ activate the transcription of genes following phagocytosis by macrophages which are necessary for survival within the phagosome environment. Thirteen previously undefined PhoP-activated gene fusions generated by MudJ and TnphoA (pag A, and E-P, respectively) were cloned and sequenced. Most pag products show no similarity to proteins in the database, while others are predicted to encode: a UDP-glucose dehydrogenase (pagA); a protein with similarity to the product of an E. coli aluminium-induced gene (pagH); a protein encoded within a Salmonella-unique region adjacent to the sinR gene (pagN); a protein similar to a product of the Yersinia virulence plasmid (pagO); and a protein with similarity to CrcA which is necessary for resistance of E. coli to camphor (pagP). Of the pag characterized, only pagK, M and O were closely linked. pagJ and pagK were shown to be unlinked but nearly identical in DNA sequence, as each was located within a 1.6 kb DNA duplication. The translations of sequences surrounding pagJ and pagK show similarity to proteins from extrachromosomal elements as well as those involved in DNA transposition and rearrangement, suggesting that this region may have been or is a mobile element. The transcriptional start sites of pagK, M, and J were determined; however, comparison to other known pag gene promoters failed to reveal a consensus sequence for PhoP-regulated activation. DNA sequences hybridizing to a Salmonella typhimurium pagK specific probe were found in S. enteritidis but absent in other Salmonella serotypes and Enterobacteriaceae tested, suggesting that these genes are specific for broad host range Salmonellae that cause diarrhoea in humans. Cumulatively, these data further demonstrate: (1) that PhoP-PhoQ is a global regulator of the production of diverse envelope or secreted proteins; (2) that PhoP-PhoQ regulate the production of proteins of redundant function

  14. Detection of Salmonella Typhimurium on Spinach Using Phage-Based Magnetoelastic Biosensors.

    PubMed

    Wang, Fengen; Horikawa, Shin; Hu, Jiajia; Wikle, Howard C; Chen, I-Hsuan; Du, Songtao; Liu, Yuzhe; Chin, Bryan A

    2017-02-16

    Phage-based magnetoelastic (ME) biosensors have been studied as an in-situ, real-time, wireless, direct detection method of foodborne pathogens in recent years. This paper investigates an ME biosensor method for the detection of Salmonella Typhimurium on fresh spinach leaves. A procedure to obtain a concentrated suspension of Salmonella from contaminated spinach leaves is described that is based on methods outlined in the U.S. FDA Bacteriological Analytical Manual for the detection of Salmonella on leafy green vegetables. The effects of an alternative pre-enrichment broth (LB broth vs. lactose broth), incubation time on the detection performance and negative control were investigated. In addition, different blocking agents (BSA, Casein, and Superblock) were evaluated to minimize the effect of nonspecific binding. None of the blocking agents was found to be superior to the others, or even better than none. Unblocked ME biosensors were placed directly in a concentrated suspension and allowed to bind with Salmonella cells for 30 min before measuring the resonant frequency using a surface-scanning coil detector. It was found that 7 h incubation at 37 °C in LB broth was necessary to detect an initial spike of 100 cfu/25 g S. Typhimurium on spinach leaves with a confidence level of difference greater than 95% (p < 0.05). Thus, the ME biosensor method, on both partly and fully detection, was demonstrated to be a robust and competitive method for foodborne pathogens on fresh products.

  15. Salmonella typhimurium is pathogenic for Dictyostelium cells and subverts the starvation response.

    PubMed

    Sillo, Alessio; Matthias, Jan; Konertz, Roman; Bozzaro, Salvatore; Eichinger, Ludwig

    2011-11-01

    In unicellular amoebae, such as Dictyostelium discoideum, bacterial phagocytosis is a food hunting device, while in higher organisms it is the first defence barrier against microbial infection. In both cases, pathogenic bacteria exploit phagocytosis to enter the cell and multiply intracellularly. Salmonella typhimurium, the agent of food-borne gastroenteritis, is phagocytosed by both macrophages and Dictyostelium cells. By using cell biological assays and global transcriptional analysis with DNA microarrays covering the Dictyostelium genome, we show here that S. typhimurium is pathogenic for Dictyostelium cells. Depending on the degree of virulence, which in turn depended on bacterial growth conditions, Salmonella could kill Dictyostelium cells or inhibit their growth and development. In the early phase of infection in non-nutrient buffer, the ingested bacteria escaped degradation, induced a starvation-like transcriptional response but inhibited selectively genes required for chemotaxis and aggregation. This way differentiation of the host cells into spore and stalk cells was blocked or delayed, which in turn is likely to be favourable for the establishment of a replicative niche for Salmonella. Inhibition of the aggregation competence and chemotactic streaming of aggregation-competent cells in the presence of Salmonella suggests interference with cAMP signalling.

  16. Stress-induced prophage DNA replication in Salmonella enterica serovar Typhimurium.

    PubMed

    Garcia-Russell, Nathalie; Elrod, Brandon; Dominguez, Katrina

    2009-09-01

    Salmonella Typhimurium, a foodborne pathogen, is the cause of new outbreaks every year. The virulence of new pathogens is determined by their virulence genes, many of them carried on transferable elements, such as prophages. In bacteria harboring multiple prophages such as Salmonella, the reassortment of these genes plays a major role in the emergence of new pathogens and consequently new epidemics. This gene transfer depends on prophage induction and the initiation of the phage lytic cycle. In the present study we have tested the effects of bacterial extracytoplasmic stress on prophage induction. We developed a quantitative real-time PCR assay to quantify variations in phage genes copy number, representative of phage DNA replication associated with the initiation of the lytic cycle. The induction of the four Salmonella enterica serovar Typhimurium LT2 prophages (Fels-1, Fels-2, Gifsy-1 and Gifsy-2) was measured during exponential growth, stationary phase, starvation, as well as after treatment with Mitomycin C, Ampicillin or heat. Our results show that the four prophages respond differently to each treatment. Gifsy-2 showed constant low level of induction independently of the extracytoplasmic stress, Fels-1 was strongly induced after DNA damage, Fels-2 showed spontaneous induction only during optimal bacterial growth, and Gifsy-1 was repressed in all conditions. These findings show that the transfer of virulence genes can respond to and depend on variations of the bacterial surrounding conditions, and help to explain the appearance of new Salmonella outbreaks.

  17. Detection of Salmonella Typhimurium on Spinach Using Phage-Based Magnetoelastic Biosensors

    PubMed Central

    Wang, Fengen; Horikawa, Shin; Hu, Jiajia; Wikle, Howard C.; Chen, I-Hsuan; Du, Songtao; Liu, Yuzhe; Chin, Bryan A.

    2017-01-01

    Phage-based magnetoelastic (ME) biosensors have been studied as an in-situ, real-time, wireless, direct detection method of foodborne pathogens in recent years. This paper investigates an ME biosensor method for the detection of Salmonella Typhimurium on fresh spinach leaves. A procedure to obtain a concentrated suspension of Salmonella from contaminated spinach leaves is described that is based on methods outlined in the U.S. FDA Bacteriological Analytical Manual for the detection of Salmonella on leafy green vegetables. The effects of an alternative pre-enrichment broth (LB broth vs. lactose broth), incubation time on the detection performance and negative control were investigated. In addition, different blocking agents (BSA, Casein, and Superblock) were evaluated to minimize the effect of nonspecific binding. None of the blocking agents was found to be superior to the others, or even better than none. Unblocked ME biosensors were placed directly in a concentrated suspension and allowed to bind with Salmonella cells for 30 min before measuring the resonant frequency using a surface-scanning coil detector. It was found that 7 h incubation at 37 °C in LB broth was necessary to detect an initial spike of 100 cfu/25 g S. Typhimurium on spinach leaves with a confidence level of difference greater than 95% (p < 0.05). Thus, the ME biosensor method, on both partly and fully detection, was demonstrated to be a robust and competitive method for foodborne pathogens on fresh products. PMID:28212322

  18. Inhibition and inactivation of Salmonella typhimurium biofilms from polystyrene and stainless steel surfaces by essential oils and phenolic constituent carvacrol.

    PubMed

    Soni, Kamlesh A; Oladunjoye, Ademola; Nannapaneni, Ramakrishna; Schilling, M Wes; Silva, Juan L; Mikel, Benjy; Bailey, R Hartford

    2013-02-01

    Persistence of Salmonella biofilms within food processing environments is an important source of Salmonella contamination in the food chain. In this study, essential oils of thyme and oregano and their antimicrobial phenolic constituent carvacrol were evaluated for their ability to inhibit biofilm formation and inactivate preformed Salmonella biofilms. A crystal violet staining assay and CFU measurements were utilized to quantify biofilm cell mass, with evaluating factors such as strain variation, essential oil type, their concentrations, exposure time, as well as biofilm formation surface. Of the three Salmonella strains, Salmonella Typhimurium ATCC 23564 and Salmonella Typhimurium ATCC 19585 produced stronger biofilms than Salmonella Typhimurium ATCC 14028. Biofilm formation by different Salmonella strains was 1.5- to 2-fold higher at 22°C than at 30 or 37°C. The presence of nonbiocidal concentrations of thyme oil, oregano oil, and phenolic carvacrol at 0.006 to 0.012% suppressed Salmonella spp. biofilm formation 2- to 4-fold, but could not completely eliminate biofilm formation. There was high correlation in terms of biofilm inactivation, as determined by the crystal violet-stained optical density (at a 562-nm wavelength) readings and the viable CFU counts. Reduction of biofilm cell mass was dependent on antimicrobial concentration. A minimum concentration of 0.05 to 0.1% of these antimicrobial agents was needed to reduce a 7-log CFU biofilm mass to a nondetectable level on both polystyrene and stainless steel surfaces within 1 h of exposure time.

  19. Only one of the two type VI secretion systems encoded in the Salmonella enterica serotype Dublin genome is involved in colonization of the avian and murine hosts.

    PubMed

    Pezoa, David; Blondel, Carlos J; Silva, Cecilia A; Yang, Hee-Jeong; Andrews-Polymenis, Helene; Santiviago, Carlos A; Contreras, Inés

    2014-01-09

    The type VI secretion system (T6SS) is a virulence factor for many Gram-negative bacteria. Salmonella genus harbors five phylogenetically distinct T6SS loci encoded in Salmonella Pathogenicity Islands (SPIs) SPI-6, SPI-19, SPI-20, SPI-21 and SPI-22, which are differentially distributed among serotypes. The T6SSs encoded in SPI-6 and SPI-19 contribute to pathogenesis of serotypes Typhimurium and Gallinarum in mice and chickens, respectively. Salmonella Dublin is a pathogen restricted to cattle where it causes a systemic disease. Also, it can colonize other hosts such as chickens and mice, which can act as reservoirs of this serotype. Salmonella Dublin harbors the genes for both T6SS(SPI-6) and T6SS(SPI-19). This study has determined the contribution of T6SS(SPI-6) and T6SS(SPI-19) to host-colonization by Salmonella Dublin using avian and murine models of infection. Competitive index experiments showed that, a mutant strain lacking both T6SSs (∆T6SS(SPI-6)/∆T6SS(SPI-19)) presents a strong colonization defect in cecum of chickens, similar to the defect observed for the ∆T6SS(SPI-6) mutant, suggesting that this serotype requires a functional T6SS(SPI-6) for efficient colonization of the avian gastrointestinal tract. Colonization of mice was also defective, although to a lesser extent than in chickens. In contrast, the T6SS(SPI-19) was not necessary for colonization of either chickens or mice. Transfer of T6SS(SPI-6), but not T6SS(SPI-19), restored the ability of the double mutant to colonize both animal hosts. Our data indicate that Salmonella Dublin requires only the T6SS(SPI-6) for efficient colonization of mice and chickens, and that the T6SS(SPI-6) and T6SS(SPI-19) are not functionally redundant.

  20. Natural surface coating to inactivate Salmonella enterica serovar Typhimurium and maintain quality of cherry tomatoes.

    PubMed

    Yun, Juan; Fan, Xuetong; Li, Xihong; Jin, Tony Z; Jia, Xiaoyu; Mattheis, James P

    2015-01-16

    The objective of the present study was to investigate the effectiveness of zein-based coatings in reducing populations of Salmonella enterica serovar Typhimurium and preserving quality of cherry tomatoes. Tomatoes were inoculated with a cocktail of S. Typhimurium LT2 plus three attenuated strains on the smooth skin surface and stem scar area. The zein-based coatings with and without cinnamon (up to 20%) and mustard essential oil or a commercial wax formulation were applied onto tomatoes and the treated fruits were stored at 10 °C for up to 3 weeks. Populations of S. Typhimurium decreased with increased essential oil concentration and storage duration. S. Typhimurium populations on the smooth skin surface were reduced by 4.6 and 2.8 log colony forming units(CFU)/g by the zein coatings with 20% cinnamon and 20% mustard oil, respectively, 5h after coating. The same coating reduced populations of S. Typhimurium to levels below detection limit (1.0 log CFU/g) on the stem scar area of tomato during 7 days of storage at 10 °C. Salmonella populations were not reduced on fruit coated with the commercial wax. All of the coatings resulted in reduced weight loss compared with uncoated control. Compared with the control, loss of firmness and ascorbic acid during storage was prevented by all of the coatings except the zein coating with 20% mustard oil which enhanced softening. Color was not consistently affected by any of the coating treatments during 21 days of storage at 10°C. The results suggest that the zein-based coating containing cinnamon oil might be used to enhance microbial safety and quality of tomato.

  1. Immunoregulatory role of intestinal surfactant-like particles during Salmonella typhimurium infection

    PubMed Central

    Sofi, M. Hanief; Bhatnagar, Archana; Sapra, Saveeta; Mahmood, Akhtar; Majumdar, Sidhartha

    2007-01-01

    Surfactants like particles (SLP) are secreted by Intestinal epithelium. These particles have the ability to lower surface tension of intestinal epithelial cells and contain small amounts of surfactant specific proteins A, B, and D. In the intestinal lumen they are known to function as lubricants and/or as a vehicle to deliver digestive enzymes to the luminal fluid. These particles have been found to have the ability in binding of uropathogenic E.coli. But their immunological function is not known. The present study was designed to assess the role of the SLP in the regulation of immune response during Salmonella (S) typhimurium infection using a rat an enteric model. The animals were divided in four different groups including control (PBS), rats fed fat diet (corn oil), rats fed fat diet followed with S. typhimurium infection and rats with S. typhimurium infection alone. The Peyer's patches (PP), intraepithelial (IE) and lamina propria (LP) mononuclear cells were isolated from the above-mentioned groups. These mononuclear cells were then incubated in presence of S. typhimurium lysate alone, SLP alone and S. typhimurium lysate and SLP together. T cell markers CD4 and CD8, cytokines mainly pro-inflammatory ones including IFN-γ, TNF-α, IL-12 etc were studied under such conditions. In addition histological studies were also carried out under these conditions. We report in this study that SLP plays an important role in modulating the cytokine level during infection. The pro-inflammatory cytokines were found significantly reduced in SLP induced diet along with the infection group compared to the infection group alone. Histopathological studies revealed the breakdown of duodenal villi after infection while only broadening of villi was observed in rats given corn oil induced SLP along with infection. These results suggested an important immuno-modulatory role for SLP during Salmonella infection. PMID:18026566

  2. A Genome-Scale Modeling Approach to Quantify Biofilm Component Growth of Salmonella Typhimurium.

    PubMed

    Ribaudo, Nicholas; Li, Xianhua; Davis, Brett; Wood, Thomas K; Huang, Zuyi Jacky

    2017-01-01

    Salmonella typhimurium (S. typhimurium) is an extremely dangerous foodborne bacterium that infects both animal and human subjects, causing fatal diseases around the world. Salmonella's robust virulence, antibiotic-resistant nature, and capacity to survive under harsh conditions are largely due to its ability to form resilient biofilms. Multiple genome-scale metabolic models have been developed to study the complex and diverse nature of this organism's metabolism; however, none of these models fully integrated the reactions and mechanisms required to study the influence of biofilm formation. This work developed a systems-level approach to study the adjustment of intracellular metabolism of S. typhimurium during biofilm formation. The most advanced metabolic reconstruction currently available, STM_v1.0, was 1st extended to include the formation of the extracellular biofilm matrix. Flux balance analysis was then employed to study the influence of biofilm formation on cellular growth rate and the production rates of biofilm components. With biofilm formation present, biomass growth was examined under nutrient rich and nutrient deficient conditions, resulting in overall growth rates of 0.8675 and 0.6238 h(-1) respectively. Investigation of intracellular flux variation during biofilm formation resulted in the elucidation of 32 crucial reactions, and associated genes, whose fluxes most significantly adapt during the physiological response. Experimental data were found in the literature to validate the importance of these genes for the biofilm formation of S. typhimurium. This preliminary investigation on the adjustment of intracellular metabolism of S. typhimurium during biofilm formation will serve as a platform to generate hypotheses for further experimental study on the biofilm formation of this virulent bacterium.

  3. Effect of acid shock with hydrochloric, citric, and lactic acids on the survival and growth of Salmonella typhi and Salmonella typhimurium in acidified media.

    PubMed

    Arvizu-Medrano, Sofía M; Escartín, Eduardo F

    2005-10-01

    The effect of acid shock with hydrochloric, citric, or lactic acid on the survival and growth of Salmonella Typhi and Salmonella Typhimurium in acidified broth was evaluated. Salmonella serovars were acid shocked (1 h at 35 degrees C) in Trypticase soy broth acidified with hydrochloric, citric, or lactic acid at pH 5.5. Unshocked cells were exposed to the same media that had been neutralized before use to pH 7.0. Shocked and unshocked cells were inoculated into broth acidified with hydrochloric acid (pH 3.0), citric acid (pH 3.0), or lactic acid (pH 3.8), and growth and survival ability were evaluated. The acid shock conferred protection to Salmonella against the lethal effects of low pH and organic acids. The adaptive response was not specific to the anion used for adaptation. The biggest difference in reduction of survival between shocked and unshocked strains (approximately 2 log CFU/ml) was observed when the microorganisms were shocked with lactic acid and then challenged with citric acid. Salmonella Typhi was more tolerant of citric acid than was Salmonella Typhimurium, but Salmonella Typhimurium had higher acid tolerance in response to acid shock than did Salmonella Typhi. The acid shock decreased the extension of the lag phase and enhanced the physiological state values of Salmonella Typhi and Salmonella Typhimurium when the pH of growth was 4.5. This increased ability to tolerate acidity may have an important impact on food safety, especially in the case of Salmonella Typhi, given the very low infectious dose of this pathogen.

  4. The role of flagella and chemotaxis genes in host pathogen interaction of the host adapted Salmonella enterica serovar Dublin compared to the broad host range serovar S. Typhimurium

    PubMed Central

    2013-01-01

    Background The importance of flagella and chemotaxis genes in host pathogen interaction in Salmonella enterica is mainly based on studies of the broad host range serovar, S. Typhimurium, while little is known on the importance in host specific and host adapted serovars, such as S. Dublin. In the current study we have used previously characterized insertion mutants in flagella and chemotaxis genes to investigate this and possible differences in the importance between the two serovars. Results fliC (encoding the structural protein of the flagella) was essential for adhesion and fliC and cheB (CheB restores the chemotaxis system to pre-stimulus conformation) were essential for invasion of S. Dublin into epithelial Int407 cells. In S. Typhimurium, both lack of flagella (fliC/fljB double mutant) and cheB influenced adhesion, and invasion was influenced by lack of both cheA (the histidine-kinase of the chemotaxis system), fliC/fljB and cheB mutation. Uptake in J774A.1 macrophage cells was significantly reduced in cheA, cheB and fliC mutants of S. Dublin, while cheA was dispensable in S. Typhimurium. Removal of flagella in both serotypes caused an increased ability to propagate intracellular in J774 macrophage cells and decreased cytotoxicity toward these cells. Flagella and chemotaxis genes were found not to influence the oxidative response. The induction of IL-6 from J774A-1 cells depended on the presence of flagella in S. Typhimurium, whilst this was not the case following challenge with S. Dublin. Addition of fliC from S. Typhimurium in trans to a fliC mutant of S. Dublin increased cytotoxicity but it did not increase the IL-6 production. Flagella were demonstrated to contribute to the outcome of infection following oral challenge of mice in S. Dublin, while an S. Typhimurium fliC/fljB mutant showed increased virulence following intra peritoneal challenge. Conclusions The results showed that flagella and chemotaxis genes differed in their role in host pathogen

  5. Development of classification models to detect salmonella enteritidis and salmonella typhimurium found in poultry carcass rinses by visible-near infrared hyperspectral imaging.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella is a major cause of foodborne disease outbreaks resulting from the consumption of contaminated food products in the United States. This paper reports the development of a hyperspectral imaging technique for detecting and differentiating two of the most common Salmonella serotypes, Salmone...

  6. The ferric enterobactin transporter Fep is required for persistent Salmonella enterica serovar typhimurium infection.

    PubMed

    Nagy, Toni A; Moreland, Sarah M; Andrews-Polymenis, Helene; Detweiler, Corrella S

    2013-11-01

    Most bacterial pathogens require iron to grow and colonize host tissues. The Gram-negative bacterium Salmonella enterica serovar Typhimurium causes a natural systemic infection of mice that models acute and chronic human typhoid fever. S. Typhimurium resides in tissues within cells of the monocyte lineage, which limit pathogen access to iron, a mechanism of nutritional immunity. The primary ferric iron import system encoded by Salmonella is the siderophore ABC transporter FepBDGC. The Fep system has a known role in acute infection, but it is unclear whether ferric iron uptake or the ferric iron binding siderophores enterobactin and salmochelin are required for persistent infection. We defined the role of the Fep iron transporter and siderophores in the replication of Salmonella in macrophages and in mice that develop acute followed by persistent infections. Replication of wild-type and iron transporter mutant Salmonella strains was quantified in cultured macrophages, fecal pellets, and host tissues in mixed- and single-infection experiments. We show that deletion of fepB attenuated Salmonella replication and colonization within macrophages and mice. Additionally, the genes required to produce and transport enterobactin and salmochelin across the outer membrane receptors, fepA and iroN, are needed for colonization of all tissues examined. However, salmochelin appears to be more important than enterobactin in the colonization of the spleen and liver, both sites of dissemination. Thus, the FepBDGC ferric iron transporter and the siderophores enterobactin and salmochelin are required by Salmonella to evade nutritional immunity in macrophages and cause persistent infection in mice.

  7. Identification and Characterization of Multidrug-Resistant Salmonella enterica Serotype Albert Isolates in the United States

    PubMed Central

    Campbell, Davina; Grass, Julian; Brown, Allison C.; Bicknese, Amelia; Tolar, Beth; Joseph, Lavin A.; Plumblee, Jodie R.; Walker, Carrie; Fedorka-Cray, Paula J.; Whichard, Jean M.

    2015-01-01

    Salmonella enterica is one of the most common causes of bacterial foodborne illness in the United States. Although most Salmonella infections are self-limiting, antimicrobial treatment of invasive salmonellosis is critical. The primary antimicrobial treatment options include fluoroquinolones or extended-spectrum cephalosporins, and resistance to these antimicrobial drugs may complicate treatment. At present, S. enterica is composed of more than 2,600 unique serotypes, which vary greatly in geographic prevalence, ecological niche, and the ability to cause human disease, and it is important to understand and mitigate the source of human infection, particularly when antimicrobial resistance is found. In this study, we identified and characterized 19 S. enterica serotype Albert isolates collected from food animals, retail meat, and humans in the United States during 2005 to 2013. All five isolates from nonhuman sources were obtained from turkeys or ground turkey, and epidemiologic data suggest poultry consumption or live-poultry exposure as the probable source of infection. S. enterica serotype Albert also appears to be geographically localized to the midwestern United States. All 19 isolates displayed multidrug resistance, including decreased susceptibility to fluoroquinolones and resistance to extended-spectrum cephalosporins. Turkeys are a likely source of multidrug-resistant S. enterica serotype Albert, and circulation of resistance plasmids, as opposed to the expansion of a single resistant strain, is playing a role. More work is needed to understand why these resistance plasmids spread and how their presence and the serotype they reside in contribute to human disease. PMID:25733501

  8. Identification and characterization of multidrug-resistant Salmonella enterica serotype Albert isolates in the United States.

    PubMed

    Folster, Jason P; Campbell, Davina; Grass, Julian; Brown, Allison C; Bicknese, Amelia; Tolar, Beth; Joseph, Lavin A; Plumblee, Jodie R; Walker, Carrie; Fedorka-Cray, Paula J; Whichard, Jean M

    2015-05-01

    Salmonella enterica is one of the most common causes of bacterial foodborne illness in the United States. Although most Salmonella infections are self-limiting, antimicrobial treatment of invasive salmonellosis is critical. The primary antimicrobial treatment options include fluoroquinolones or extended-spectrum cephalosporins, and resistance to these antimicrobial drugs may complicate treatment. At present, S. enterica is composed of more than 2,600 unique serotypes, which vary greatly in geographic prevalence, ecological niche, and the ability to cause human disease, and it is important to understand and mitigate the source of human infection, particularly when antimicrobial resistance is found. In this study, we identified and characterized 19 S. enterica serotype Albert isolates collected from food animals, retail meat, and humans in the United States during 2005 to 2013. All five isolates from nonhuman sources were obtained from turkeys or ground turkey, and epidemiologic data suggest poultry consumption or live-poultry exposure as the probable source of infection. S. enterica serotype Albert also appears to be geographically localized to the midwestern United States. All 19 isolates displayed multidrug resistance, including decreased susceptibility to fluoroquinolones and resistance to extended-spectrum cephalosporins. Turkeys are a likely source of multidrug-resistant S. enterica serotype Albert, and circulation of resistance plasmids, as opposed to the expansion of a single resistant strain, is playing a role. More work is needed to understand why these resistance plasmids spread and how their presence and the serotype they reside in contribute to human disease.

  9. Unusual Enterobacteriaceae: lactose-positive Salmonella typhimurium which is endemic in São Paulo, Brazil.

    PubMed Central

    Falcão, D P; Trabulsi, L R; Hickman, F W; Farmer, J J

    1975-01-01

    Since 1971 a lactose-positive (lac+) Salmonella typhimurium variety Copenhagen has been endemic in the city of Sao Paulo. The strain is a strong lactose fermenter and resembles Escherichia coli on primary plating media and in triple sugar iron agar. Although most isolates of the strain have uniform properties, some have slightly different antigens, antibiograms, phage types, or fermentation patterns. Most isolates have come from stools of infants under 1 year of age and are probably hospital acquired; however, other isolates are probably community acquired. Eighteen other lac+ Salmonella isolated in the United States were also studied. Most of these strains resembled E. coli on primary plates and triple sugar iron agar; thus their identification would pose a problem for most clinical laboratories. A simple procedure for detecting lac+ Salmonella mixed with lac+ E. coli consists of touching 12 colonies in succession with a straight wire and then inoculating a peptone iron agar tube. H2S production is apparent from lac+ Salmonella even if 11 E. coli and one Salmonella colony are picked. If a positive peptone iron agar tube is observed, then individual colonies are tested to rule out other strong H2S producers. The true incidence of lac+ Salmonella is unknown because they are not isolated and identified in most laboratories. Images PMID:1102562

  10. Multidrug-resistant Salmonella enterica Serovar Typhimurium Monophasic Variant 4,12:i:- Isolated from Asymptomatic Wildlife in a Catalonian Wildlife Rehabilitation Center, Spain.

    PubMed

    Molina-López, Rafael A; Vidal, Anna; Obón, Elena; Martín, Marga; Darwich, Laila

    2015-07-01

    Wildlife can act as long-term asymptomatic reservoirs for zoonotic bacteria, such as Salmonella. The prevalence and antimicrobial-susceptibility profiles of Salmonella spp. were assessed in 263 cases in wildlife from 22 animal orders from a wildlife rehabilitation center in Catalonia (NE Spain), September 2013-May 2014. Eleven of 263 tested animals were positive for Salmonella spp., representing an overall prevalence of 4.2%. Prevalences by taxonomic categories were 2% in mammals, 4.7% in birds, and 4.5% in reptiles. By species, one each of European hedgehog (Erinaceus europeus; from a sample of n = 26), Eurasian Eagle Owl (Bubo bubo; n = 2), Barn Owl (Tyto alba; n = 3), Tawny Owl (Strix aluco; n = 20), Egyptian Vulture (Neophron percnopterus; n = 1), Griffon Vulture (Gyps fulvus; n = 1), and Hoopoe (Upupa epops; n = 2), and two each Common Kestrels (Falco tinnunculus; n = 16) and pond sliders (Trachemys scripta; n = 25) were positive for Salmonella. By serotyping, seven of eleven isolates were classified as S. enterica subsp. enterica serovar Typhimurium, and five of seven belonged to the monophasic variant 4,12:i:-. All the monophasic variants were isolated from birds (4/5 in raptors) and showed a multidrug-resistance (MDR) profile to at least ampicillin, streptomycin, sulfonamide, and tetracycline (R-type ASSuT), and up to 12 antibiotics. The large proportion of S. Typhimurium monophasic MDR strains detected in wildlife never treated with antibiotics, especially in raptors, adds more complexity to the epidemiologic control of one of the most frequent serovars involved in human and livestock infection.

  11. Genome Sequence of Bacteriophage GG32, Which Can Infect both Salmonella enterica Serovar Typhimurium and Escherichia coli O157:H7

    PubMed Central

    Chae, Su-Jin; Kwon, Taesoo; Lee, Sunjin; Kang, Yeon Ho; Chung, Gyung Tae

    2016-01-01

    We report here a new virulent Salmonella enterica serovar Typhimurium (S. Typhimurium) bacteriophage, GG32, which was isolated from the Guem River in the Republic of Korea. The strain can infect both S. Typhimurium and Escherichia coli (E. coli) O157:H7 and may be a good candidate for a bio-control agent. PMID:27932635

  12. Chloramphenicol and tetracycline decrease motility and increase invasion and attachment gene expression in specific isolates of multidrug-resistant Salmonella enterica serovar Typhimurium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella enterica serovar Typhimurium (S. Typhimurium) is one of the most common serovars isolated from humans and livestock, and over 35 percent of these isolates are resistant to three or more antibiotics. Multidrug-resistant (MDR) Salmonella is a public health concern as it is associated with i...

  13. Iron regulated genes of Salmonella enterica serovar Typhimurium in response to norepinephrine and the requirement of fepCDG for norepinephrine-enhanced growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence of catecholamines in vivo may stimulate enteric bacteria including the foodborne pathogen Salmonella enterica serovar Typhimurium by two mechanisms, acting as a quorum sensing signal and providing iron in the presence of serum. To identify genes of Salmonella Typhimurium that participa...

  14. Fatty acid modulation of autoinducer (AI-2) influenced growth and macrophage invasion by Salmonella Typhimurium.

    PubMed

    Widmer, Kenneth W; Jesudhasan, Palmy; Pillai, Suresh D

    2012-03-01

    Autoinducer-2 (AI-2) is a small molecule that is involved in bacterial cell-to-cell signaling whose precursor formation is mediated by luxS. A luxS mutant of Salmonella Typhimurium PJ002 (ΔluxS) was grown in glucose-containing M-9 minimal medium supplemented with varying concentrations (1×, 10×, and 100×) of long-chain fatty acids (linoleic acid, oleic acid, palmitic acid, and stearic acid) to study the influence of fatty acids on growth rate and macrophage invasion. Additionally, in vitro synthesized AI-2 was added to this medium to identify the influence of AI-2 on S. Typhimurium PJ002 (ΔluxS) growth rate and macrophage invasion. The growth rate constant (k) for each experimental treatment was determined based on OD₆₀₀ values recorded during 12 h of incubation. There was a significant (p=0.01) increase in the growth rate of S. Typhimurium PJ002 (ΔluxS) in the presence of AI-2 when compared to the phosphate-buffered saline (PBS) control. However, fatty acids either singly or in a mixture were unable to influence AI-2's effect on growth rate. The presence of AI-2 significantly (p=0.02) decreased the invasiveness of S. Typhimurium PJ002 (ΔluxS) towards the murine macrophage cell line, RAW 264.7. However, the fatty acid mixture was able to reverse this reduction and restore invasiveness to background levels. These results suggest that, while AI-2 may enhance the growth rate and reduce macrophage invasion by the luxS mutant S. Typhimurium PJ002 (ΔluxS), fatty acids may influence the virulence in S. Typhimurium (PJ002) by modulating AI-2 activity.

  15. Beneficial Effects of Sodium Phenylbutyrate Administration during Infection with Salmonella enterica Serovar Typhimurium

    PubMed Central

    Jellbauer, Stefan; Perez Lopez, Araceli; Behnsen, Judith; Gao, Nina; Nguyen, Thao; Murphy, Clodagh; Edwards, Robert A.

    2016-01-01

    Sodium phenylbutyrate (PBA) is a derivative of the short-chain fatty acid butyrate and is approved for treatment of urea cycle disorders and progressive familial intrahepatic cholestasis type 2. Previously known functions include histone deacetylase inhibitor, endoplasmic reticulum stress inhibitor, ammonia sink, and chemical chaperone. Here, we show that PBA has a previously undiscovered protective role in host mucosal defense during infection. Administration of PBA to Taconic mice resulted in the increase of intestinal Lactobacillales and segmented filamentous bacteria (SFB), as well as an increase of interleukin 17 (IL-17) production by intestinal cells. This effect was not observed in Jackson Laboratory mice, which are not colonized with SFB. Because previous studies showed that IL-17 plays a protective role during infection with mucosal pathogens, we hypothesized that Taconic mice treated with PBA would be more resistant to infection with Salmonella enterica serovar Typhimurium (S. Typhimurium). By using the streptomycin-treated mouse model, we found that Taconic mice treated with PBA exhibited significantly lower S. Typhimurium intestinal colonization and dissemination to the reticuloendothelial system, as well as lower levels of inflammation. The lower levels of S. Typhimurium gut colonization and intestinal inflammation were not observed in Jackson Laboratory mice. Although PBA had no direct effect on bacterial replication, its administration reduced S. Typhimurium epithelial cell invasion and lowered the induction of the proinflammatory cytokine IL-23 in macrophage-like cells. These effects likely contributed to the better outcome of infection in PBA-treated mice. Overall, our results suggest that PBA induces changes in the microbiota and in the mucosal immune response that can be beneficial to the host during infection with S. Typhimurium and possibly other enteric pathogens. PMID:27382022

  16. Salmonella enterica serovars Typhimurium and Typhi as model organisms

    PubMed Central

    Garai, Preeti; Gnanadhas, Divya Prakash; Chakravortty, Dipshikha

    2012-01-01

    The lifestyle of intracellular pathogens has always questioned the skill of a microbiologist in the context of finding the permanent cure to the diseases caused by them. The best tool utilized by these pathogens is their ability to reside inside the host cell, which enables them to easily bypass the humoral immunity of the host, such as the complement system. They further escape from the intracellular immunity, such as lysosome and inflammasome, mostly by forming a protective vacuole-bound niche derived from the host itself. Some of the most dreadful diseases are caused by these vacuolar pathogens, for example, tuberculosis by Mycobacterium or typhoid fever by Salmonella. To deal with such successful pathogens therapeutically, the knowledge of a host-pathogen interaction system becomes primarily essential, which further depends on the use of a model system. A well characterized pathogen, namely Salmonella, suits the role of a model for this purpose, which can infect a wide array of hosts causing a variety of diseases. This review focuses on various such aspects of research on Salmonella which are useful for studying the pathogenesis of other intracellular pathogens. PMID:22722237

  17. Amino acid substitutions in GyrA affect quinolone susceptibility in Salmonella typhimurium.

    PubMed

    Kongsoi, Siriporn; Changkwanyeun, Ruchirada; Yokoyama, Kazumasa; Nakajima, Chie; Changkaew, Kanjana; Suthienkul, Orasa; Suzuki, Yasuhiko

    2016-10-01

    The prevalence of quinolone-resistant Salmonella has become a public health concern. Amino acid substitutions have generally been found within the quinolone resistance-determining region in subunit A of DNA gyrase (GyrA) of Salmonella Typhimurium. However, direct evidence of the contribution of these substitutions to quinolone resistance remains to be shown. To investigate the significance of amino acid substitutions in S. Typhimurium GyrA to quinolone resistance, we expressed recombinant wild-type (WT) and five mutant DNA gyrases in Escherichia coli and characterized them in vitro. WT and mutant DNA gyrases were reconstituted in vitro by mixing recombinant subunits A and B of DNA gyrase. The correlation between the amino acid substitutions and resistance to quinolones ciprofloxacin, levofloxacin, nalidixic acid, and sitafloxacin was assessed by quinolone-inhibited supercoiling assays. All mutant DNA gyrases showed reduced susceptibility to all quinolones when compared with WT DNA gyrases. DNA gyrase with a double amino acid substitution in GyrA, serine to phenylalanine at codon 83 and aspartic acid to asparagine at 87 (GyrA-S83F-D87N), exhibited the lowest quinolone susceptibility amongst all mutant DNA gyrases. The effectiveness of sitafloxacin was shown by the low inhibitory concentration required for mutant DNA gyrases, including the DNA gyrase with GyrA-S83F-D87N. We suggest sitafloxacin as a candidate drug for the treatment of salmonellosis caused by ciprofloxacin-resistant S. Typhimurium. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Phage shock protein G, a novel ethanol-induced stress protein in Salmonella typhimurium.

    PubMed

    Shoae Hassani, Alireza; Malekzadeh, Feridon; Amirmozafari, Nour; Hamdi, Kasra; Ordouzadeh, Negar; Ghaemi, Amir

    2009-03-01

    Exposure to ethanol is a stress condition that Salmonella typhimurium often encounters during its life cycle. Food, beverage, drugs, and cosmetics have a long history of using alcohols to control pathogens. Ethanol is also commonly used for disinfecting medical instruments. This study was conducted to evaluate the ethanol stress variations on the protein profile, cell structure, and serologic features of S. typhimurium. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the phage shock protein G (pspG), a new ethanol-induced stress protein in cells adapted to 10% ethanol. The result was confirmed by liquid chromatography-mass spectrometry. The maximum quantity of this 9.02-kDa protein was produced in 12.5% (v/v) of ethanol-treated cultures. Scanning electron microscopy has demonstrated new phenotypic characteristics in bacterial structure. The cells were unable to undergo binary fission. This phenomenon explains the tight attachment of bacteria in a colony. Overall, ethanol extreme stress induced expression of new proteins like PspG and repression of some other proteins in S. typhimurium. These induction and repression processes have inflicted dramatic changes on Salmonella behaviors.

  19. Dietary Bifidobacterium lactis (HN019) enhances resistance to oral Salmonella typhimurium infection in mice.

    PubMed

    Shu, Q; Lin, H; Rutherfurd, K J; Fenwick, S G; Prasad, J; Gopal, P K; Gill, H S

    2000-01-01

    The ability of a newly identified probiotic lactic acid bacterial strain, Bifidobacterium lactis (HN019), to confer protection against Salmonella typhimurium was investigated in BALB/c mice. Feeding mice with B. lactis conferred a significant degree of protection against single or multiple oral challenge with virulent S. typhimurium, in comparison to control mice that did not receive B. lactis. Protection included a ten-fold increase in survival rate, significantly higher post-challenge food intake and weight gain, and reduced pathogen translocation to visceral tissues (spleen and liver). Furthermore, the degree of pathogen translocation showed a significant inverse correlation with splenic lymphocyte proliferative responses to mitogens, blood and peritoneal cell phagocytic activity and intestinal mucosal anti-S. typhimurium antibody titers in infected mice; all of these immune parameters were enhanced in mice fed B. lactis. Together, these results suggest that dietary B. lactis can provide a significant degree of protection against Salmonella infection by enhancing various parameters of immune function that are relevant to the immunological control of salmonellosis. Thus dietary supplementation with B. lactis provides a unique opportunity for developing immune-enhancing probiotic dairy food products with proven health benefits.

  20. The inositol phosphatase SHIP controls Salmonella enterica serovar Typhimurium infection in vivo.

    PubMed

    Bishop, Jennifer L; Sly, Laura M; Krystal, Gerald; Finlay, B Brett

    2008-07-01

    The SH2 domain-containing inositol 5'-phosphatase, SHIP, negatively regulates various hematopoietic cell functions and is critical for maintaining immune homeostasis. However, whether SHIP plays a role in controlling bacterial infections in vivo remains unknown. Salmonella enterica causes human salmonellosis, a disease that ranges in severity from mild gastroenteritis to severe systemic illness, resulting in significant morbidity and mortality worldwide. The susceptibility of ship(+/+) and ship(-/-) mice and bone marrow-derived macrophages to S. enterica serovar Typhimurium infection was compared. ship(-/-) mice displayed an increased susceptibility to both oral and intraperitoneal serovar Typhimurium infection and had significantly higher bacterial loads in intestinal and systemic sites than ship(+/+) mice, indicating a role for SHIP in the gut-associated and systemic pathogenesis of serovar Typhimurium in vivo. Cytokine analysis of serum from orally infected mice showed that ship(-/-) mice produce lower levels of Th1 cytokines than do ship(+/+) animals at 2 days postinfection, and in vitro analysis of supernatants taken from infected bone marrow-derived macrophages derived to mimic the in vivo ship(-/-) alternatively activated (M2) macrophage phenotype correlated with these data. M2 macrophages were the predominant population in vivo in both oral and intraperitoneal infections, since tissue macrophages within the small intestine and peritoneal macrophages from ship(-/-) mice showed elevated levels of the M2 macrophage markers Ym1 and Arginase 1 compared to ship(+/+) cells. Based on these data, we propose that M2 macrophage skewing in ship(-/-) mice contributes to ineffective clearance of Salmonella in vivo.

  1. Salmonella enterica prevalence and serotype distribution in swine at slaughter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this cross-sectional study was to analyze data available from multiple studies conducted by our research team estimating the prevalence of S. enterica, and the serotype distribution in swine at slaughter, based on different sample types. A total of 1,110 pigs from three large capaci...

  2. Effect of coffee filtrate, methylglyoxal, glyoxal, and caffeine on Salmonella typhimurium and S. enteritidis survival in ground chicken breasts.

    PubMed

    Maletta, Anne B; Were, Lilian M

    2012-02-01

    The antimicrobial effect of roasted coffee filtrate (CF) and dicarbonyls on Salmonella Typhimurium and Salmonella Enteritidis in raw ground chicken breast meat (GCB) was investigated. Coffee was brewed and filtered before addition to GCB. Coffee filtrate with and without added caffeine, methylglyoxal, and/or glyoxal was added to GCB and then inoculated with Salmonella Typhimurium and Salmonella Enteritidis. Ground chicken samples were stomached with peptone water at days 1, 3, 5, and 7, plated on XLD agar with a TSA overlay, and Salmonella survivors were enumerated. CF alone gave less than a 1 Log reduction in all runs compared to control GCB with no treatment. Methylglyoxal (2.28 mg/g GCB) had the greatest antimicrobial effect against Salmonella Typhimurium and Salmonella Enteritidis in GCB with average Log reductions of 2.27 to 3.23, respectively, over the 7 d duration of the experiment compared to control GCB with no treatment. A 1 Log reduction was observed in GCB with CF, 0.93 mg glyoxal, and 1 mg caffeine/g chicken compared to the control and GCB with only CF. Heat-produced coffee compounds could potentially reduce Salmonella in retail ground chicken and chicken products.

  3. Foodborne outbreak and nonmotile Salmonella enterica variant, France.

    PubMed

    Le Hello, Simon; Brisabois, Anne; Accou-Demartin, Marie; Josse, Adeline; Marault, Muriel; Francart, Sylvie; Da Silva, Nathalie Jourdan; Weill, François-Xavier

    2012-01-01

    We report a food-related outbreak of salmonellosis in humans caused by a nonmotile variant of Salmonella enterica serotype Typhimurium in France in 2009. This nonmotile variant had been circulating in laying hens but was not considered as Typhimurium and consequently escaped European poultry flock regulations.

  4. Development of classification models to detect Salmonella Enteritidis and Salmonella Typhimurium found in poultry carcass rinses by visible-near infrared hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Seo, Young Wook; Yoon, Seung Chul; Park, Bosoon; Hinton, Arthur; Windham, William R.; Lawrence, Kurt C.

    2013-05-01

    Salmonella is a major cause of foodborne disease outbreaks resulting from the consumption of contaminated food products in the United States. This paper reports the development of a hyperspectral imaging technique for detecting and differentiating two of the most common Salmonella serotypes, Salmonella Enteritidis (SE) and Salmonella Typhimurium (ST), from background microflora that are often found in poultry carcass rinse. Presumptive positive screening of colonies with a traditional direct plating method is a labor intensive and time consuming task. Thus, this paper is concerned with the detection of differences in spectral characteristics among the pure SE, ST, and background microflora grown on brilliant green sulfa (BGS) and xylose lysine tergitol 4 (XLT4) agar media with a spread plating technique. Visible near-infrared hyperspectral imaging, providing the spectral and spatial information unique to each microorganism, was utilized to differentiate SE and ST from the background microflora. A total of 10 classification models, including five machine learning algorithms, each without and with principal component analysis (PCA), were validated and compared to find the best model in classification accuracy. The five machine learning (classification) algorithms used in this study were Mahalanobis distance (MD), k-nearest neighbor (kNN), linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), and support vector machine (SVM). The average classification accuracy of all 10 models on a calibration (or training) set of the pure cultures on BGS agar plates was 98% (Kappa coefficient = 0.95) in determining the presence of SE and/or ST although it was difficult to differentiate between SE and ST. The average classification accuracy of all 10 models on a training set for ST detection on XLT4 agar was over 99% (Kappa coefficient = 0.99) although SE colonies on XLT4 agar were difficult to differentiate from background microflora. The average classification

  5. Cloning and properties of the Salmonella typhimurium tricarboxylate transport operon in Escherichia coli

    SciTech Connect

    Widenhorn, K.A.; Boos, W.; Somers, J.M.; Kay, W.W.

    1988-02-01

    The tricarboxylate transport operon (tctI) was cloned in Escherichia coli as a 12-kilobase (kb) fragment from an EcoRI library of the Salmonella typhimurium chromosome in lambdagtWES. It was further subcloned as a 12-kb fragment into pACYC184 and as an 8-kb fragment into pBR322. By insertional mutagenesis mediated by lambdaTn5, restriction mapping, and phenotypic testing, the tctI operon was localized to a 4.5-kb region. The tctC gene which encodes a periplasmic binding protein (C-protein) was located near the center of the insert. E. coli/tctI clones on either multicopy or single-copy vectors grew on the same tricarboxylates as S. typhimurium, although unusually long growth lags were observed. E. coli/tctI clones exhibited similar (/sup 14/C) fluorocitrate transport kinetics to those of S. typhimurium, whereas E. coli alone was virtually impermeable to (/sup 14/C) fluorocitrate. The periplasmic C proteins (C1 and C2 isoelectric forms) were produced in prodigious quantities from the cloned strains. Motile E. coli/tctI clones were not chemotactic toward citrate, whereas tctI deletion mutants of S. typhimurium were. Taken together, these observations indicate that tctI is not an operon involved in chemotaxis.

  6. Bioprobes Based on Aptamer and Silica Fluorescent Nanoparticles for Bacteria Salmonella typhimurium Detection

    NASA Astrophysics Data System (ADS)

    Wang, Qiu-Yue; Kang, Yan-Jun

    2016-03-01

    In this study, we have developed an efficient method based on single-stranded DNA (ssDNA) aptamers along with silica fluorescence nanoparticles for bacteria Salmonella typhimurium detection. Carboxyl-modified Tris(2,2'-bipyridyl)dichlororuthenium(II) hexahydrate (RuBPY)-doped silica nanoparticles (COOH-FSiNPs) were prepared using reverse microemulsion method, and the streptavidin was conjugated to the surface of the prepared COOH-FSiNPs. The bacteria S. typhimurium was incubated with a specific ssDNA biotin-labeled aptamer, and then the aptamer-bacteria conjugates were treated with the synthetic streptavidin-conjugated silica fluorescence nanoprobes (SA-FSiNPs). The results under fluorescence microscopy show that SA-FSiNPs can be applied effectively for the labeling of bacteria S. typhimurium with great photostable property. To further verify the specificity of SA-FSiNPs out of multiple bacterial conditions, variant concentrations of bacteria mixtures composed of bacteria S. typhimurium, Escherichia coli, and Bacillus subtilis were treated with SA-FSiNPs.

  7. tRNA modified bases and oxidative stress in Salmonella typhimurium

    SciTech Connect

    Kramer, G.F.

    1987-01-01

    The mechanisms of toxicity of two different environmental stresses have been characterized in Salmonella typhimurium. The toxicity of near-UV (NUV) light (300-400 nm) appeared to be mediated by oxidative mechanisms. The overproduction of NUV-absorbing proteins sensitized the cells to killing by NUV. Selenium also appeared to be toxic to S. typhimurium by oxidative mechanisms. At low concentrations, the main target for this toxicity appeared to be intracellular thiols. At higher concentrations, selenite toxicity appeared to have been mediated by oxygen radicals which we have shown to be produced by the reactions of selenite with sulfhydryl groups. Such radicals may also have been involved in the selenite mutagenicity we have observed in S. typhimurium. The function of two different modified bases with respect to such oxidative stress has been characterized. The isolation of mutants lacking these bases has facilitated this investigation. S. typhimurium contained a single seleno-modified base, 5-methylaminomethyl-2-selenouridine (mnm{sup 5}Se{sup 2}U). Mutants which were unable to incorporate selenium into their tRNA (selA) were isolated based on a pleiotropic defect in selenium metabolism.

  8. Regulation of fucose and 1,2-propanediol utilization by Salmonella enterica serovar Typhimurium.

    PubMed

    Staib, Lena; Fuchs, Thilo M

    2015-01-01

    After ingestion, Salmonella enterica serovar Typhimurium (S. Typhimurium) encounters a densely populated, competitive environment in the gastrointestinal tract. To escape nutrient limitation caused by the intestinal microbiota, this pathogen has acquired specific metabolic traits to use compounds that are not metabolized by the commensal bacteria. For example, the utilization of 1,2-propanediol (1,2-PD), a product of the fermentation of L-fucose, which is present in foods of herbal origin and is also a terminal sugar of gut mucins. Under anaerobic conditions and in the presence of tetrathionate, 1,2-PD can serve as an energy source for S. Typhimurium. Comprehensive database analysis revealed that the 1,2-PD and fucose utilization operons are present in all S. enterica serovars sequenced thus far. The operon, consisting of 21 genes, is expressed as a single polycistronic mRNA. As demonstrated here, 1,2-PD was formed and further used when S. Typhimurium strain 14028 was grown with L-fucose, and the gene fucA encoding L-fuculose-1-phosphate aldolase was required for this growth. Using promoter fusions, we monitored the expression of the propanediol utilization operon that was induced at very low concentrations of 1,2-PD and was inhibited by the presence of D-glucose.

  9. Characterization of the invasiveness of monophasic and aphasic Salmonella Typhimurium strains in 1-day-old and point-of-lay chickens.

    PubMed

    Martelli, Francesca; Gosling, Rebecca; Kennedy, Emma; Rabie, André; Reeves, Hannah; Clifton-Hadley, Felicity; Davies, Rob; La Ragione, Roberto

    2014-01-01

    Egg-related outbreaks of salmonellosis are a significant health concern. Although Salmonella Enteritidis (SE) is the major egg-associated serotype, Salmonella Typhimurium (ST) can also infect the hen's reproductive tract and contaminate eggs. Recently, monophasic and aphasic variants of ST have been reported with increased frequency in Europe, and the isolation of these variants from laying flocks triggers the same legislative restrictions associated with biphasic ST strains. However, little is known about the colonization, invasiveness and persistence of monophasic and aphasic ST strains in laying hens. In this study, seven groups of 1-day-old and point-of-lay commercial Hy-line chicken layers were separately challenged with four different strains of monophasic ST, one aphasic ST, one biphasic ST and one egg-invasive SE strain. Tissue samples and cloacal swabs (point-of-lay chickens only) were collected at regular intervals post challenge in order to recover the Salmonella challenge strains. In 1-day-old chicks, only the aphasic ST strain and the SE strain were recovered after direct plating, suggesting that the number of salmonellas colonizing the tissues of the chicks infected with the other strains was likely to be low. Interestingly, all of the strains colonized well in the point-of-lay chickens, and there was no statistical difference in the overall number of positive samples or Salmonella counts between the seven strains. Salmonella was recovered from the point-of-lay birds to the end of the study (20 days after challenge). Monophasic and aphasic ST strains colonized point-of-lay birds as efficiently as biphasic ST and SE strains. Further studies are necessary to estimate the invasiveness of these strains in naturally-infected vaccinated laying hens, and to assess the impact of natural infection on egg contamination.

  10. Transmission Dynamics of a Multidrug-Resistant Salmonella Typhimurium Outbreak in a Dairy Farm

    PubMed Central

    Warnick, Lorin D.; James, Karen L.; Wright, Emily M.; Wiedmann, Martin; Gröhn, Yrjo T.

    2010-01-01

    Abstract Cattle are recognized as an important source of foodborne Salmonella causing human illness, particularly for antimicrobial-resistant strains. The transmission dynamics of multidrug-resistant (MDR) Salmonella after the onset of a clinical outbreak in a dairy farm has been rarely monitored. The early transmission of a pathogen influences the outbreak size and persistence of the pathogen at the farm level and, therefore, how long the herd represents a risk for Salmonella zoonotic transmission. The objective of this study was to describe the transmission dynamics of MDR Salmonella Typhimurium after the onset of a clinical outbreak in a dairy herd. For that purpose, fecal shedding and serological response to MDR Salmonella were monitored in a longitudinal study conducted in a dairy herd after a few cases of salmonellosis, and a stochastic transmission model was developed to predict Salmonella persistence at the pen level. The outbreak was limited to five clinical cases, and only 18 animals out of 500 cows shed Salmonella in feces. The longest shedder was culture-positive for Salmonella for at least 68 days. The isolates (n = 27) were represented by four pulsed-field gel electrophoresis patterns; three patterns were similar. With one exception, isolates were resistant to nine or more antimicrobial drugs. Simulations of the transmission model indicated that approximately 50% of the outbreaks were likely to die out within 20 days after the first animal was infected. The simulation studies indicated that salmonellosis outbreaks with few clinical cases were likely due to the extinction of the pathogen in the premises in the early phase of the outbreaks. Small population size and group structure within the farm decrease the on-farm persistence of the pathogen. PMID:19919288

  11. Isolation and characterization of mutants of Salmonella typhimurium with a disturbed process of generation of nonculturable forms

    SciTech Connect

    Romanova, Y.M.; Terekhov, A.A.; Gintsburg, A.L.

    1995-08-01

    A laboratory model of the induction of nonculturable forms in Salmonella typhimurium has been developed. Mutants of S. typhimurium were obtained using insertion mutagenesis via the TnPhoA transposon. These mutants were impaired in the cell transition from the vegetative to the nonculturable state assayed in this model. Mutants have various phenotypes and are located in different regions of the chromosome, as shown by the data obtained using pulsed-field electrophoresis of genomic DNA. 11 refs., 3 figs., 1 tab.

  12. Tackling the issue of environmental survival of live Salmonella Typhimurium vaccines: deletion of the lon gene.

    PubMed

    Leyman, Bregje; Boyen, Filip; Van Parys, Alexander; Verbrugghe, Elin; Haesebrouck, Freddy; Pasmans, Frank

    2012-12-01

    Vaccination is an important measure to control Salmonella contamination in the meat production chain. A previous study showed that both the ΔrfaJ and ΔrfaL strains are suitable markers and allow serological differentiation of infected and vaccinated animals. The aim of this study was to verify whether deletion of the lon gene in a Salmonella Typhimurium ΔrfaJ marker strain resulted in decreased environmental survival. Our results indicate that deletion of the lon gene in the ΔrfaJ strain did not affect invasiveness in IPEC-J2 cells and resulted in an increased susceptibility to UV, disinfectants (such as hydrogen peroxide and tosylchloramide sodium) and citric acid. Immunization of pigs with inactivated ΔrfaJ or ΔlonΔrfaJ vaccines allowed differentiation of infected and vaccinated pigs. Furthermore, deletion of the lon gene did not reduce the protection conferred by live wild type or ΔrfaJ vaccines against subsequent challenge with a virulent Salmonella Typhimurium strain in BALB/c mice. Based on our results in mice, we conclude that deletion of lon in ΔrfaJ contributes to environmental safety of the ΔrfaJ DIVA strain.

  13. Development and application of novel SNP-based serotyping assays in targeting Salmonella enterica within the poultry production and processing continuum.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella enterica subsp. enterica serotype Enteriditis (S. Enteriditis) is the leading cause of salmonellosis worldwide. While some S. enterica serotypes are specific to birds, many represent human zoonotic pathogens, thus their presence and survival throughout the continuum of poultry production...

  14. Biological activity of Pityrosporum. I. Enhancement of resistance in mice stimulated by Pityrosporum against Salmonella typhimurium.

    PubMed Central

    Takahashi, M; Ushijima, T; Ozaki, Y

    1984-01-01

    The effect of administration with Pityrosporum (P. orbiculare, P. ovale, P. pachydermatis and Pityrosporum sp.) on susceptibility of mice to Salmonella typhimurium infection was studied. Pretreatment of mice with 50 mg (wet weight) of killed Pityrosporum 4 days prior to the intraperitoneal (i.p.) challenge of 4 X 10(5) (10 LD50) S. typhimurium elicited resistance comparable to that induced by 500 micrograms (dry weight) of killed Propionibacterium acnes and over 30% of the infected mice survived. Among the species tested, P. pachydermatis was slightly less effective. The challenged organisms were not detected from the blood of mice treated with Pityrosporum but were present in the liver and spleen in approximately level amounts (10(4)-10(5)/organ) during the course of testing. These results suggest that the increased resistance in mice is the result of stimulation of the reticuloendothelial system by Pityrosporum. PMID:6368372

  15. The Acetic Acid Tolerance Response induces cross-protection to salt stress in Salmonella typhimurium.

    PubMed

    Greenacre, E J; Brocklehurst, T F

    2006-10-15

    Salmonella typhimurium induces an Acid Tolerance Response (ATR) upon exposure to mildly acidic conditions in order to protect itself against severe acid shock. This response can also induce cross-protection to other stresses such as heat and salt. We investigated whether both the acetic acid induced and lactic acid induced ATR in S. typhimurium provided cross-protection to a salt stress at 20 degrees C. Acid-adapted cells were challenged with both a sodium chloride (NaCl) and potassium chloride (KCl) shock and their ability to survive ascertained. Acetic acid adaptation provided cells with protection against both NaCl and KCl stress. However, lactic acid adaptation did not protect against either osmotic stressor and rendered cells hypersensitive to NaCl. These results have implications for the food industry where hurdle technology means multiple sub-lethal stresses such as mild pH and low salt are commonly used in the preservation of products.

  16. The Salmonella typhimurium mar locus: molecular and genetic analyses and assessment of its role in virulence.

    PubMed Central

    Sulavik, M C; Dazer, M; Miller, P F

    1997-01-01

    The marRAB operon is a regulatory locus that controls multiple drug resistance in Escherichia coli. marA encodes a positive regulator of the antibiotic resistance response, acting by altering the expression of unlinked genes. marR encodes a repressor of marRAB transcription and controls the production of MarA in response to environmental signals. A molecular and genetic study of the homologous operon in Salmonella typhimurium was undertaken, and the role of marA in virulence in a murine model was assessed. Expression of E. coli marA (marAEC) present on a multicopy plasmid in S. typhimurium resulted in a multiple antibiotic resistance (Mar) phenotype, suggesting that a similar regulon exists in this organism. A genomic plasmid library containing S. typhimurium chromosomal sequences was introduced into an E. coli strain that was deleted for the mar locus and contained a single-copy marR'-'lacZ translational fusion. Plasmid clones that contained both S. typhimurium marR (marRSt) and marA (marASt) genes were identified as those that were capable of repressing expression of the fusion and which resulted in a Mar phenotype. The predicted amino acid sequences of MarRSt, MarASt, and MarBSt were 91, 86, and 42% identical, respectively, to the same genes from E. coli, while the operator/promoter region of the operon was 86% identical to the same 98-nucleotide-upstream region in E. coli. The marRAB transcriptional start sites for both organisms were determined by primer extension, and a marRABSt transcript of approximately 1.1 kb was identified by Northern blot analysis. Its accumulation was shown to be inducible by sodium salicylate. Open reading frames flanking the marRAB operon were also conserved. An S. typhimurium marA disruption strain was constructed by an allelic exchange method and compared to the wild-type strain for virulence in a murine BALB/c infection model. No effect on virulence was noted. The endogenous S. typhimurium plasmid that is associated with virulence

  17. Bacteriophages with potential to inactivate Salmonella Typhimurium: Use of single phage suspensions and phage cocktails.

    PubMed

    Pereira, Carla; Moreirinha, Catarina; Lewicka, Magdalena; Almeida, Paulo; Clemente, Carla; Cunha, Ângela; Delgadillo, Ivonne; Romalde, Jésus L; Nunes, Maria L; Almeida, Adelaide

    2016-07-15

    The aim of this study was to compare the dynamics of three previously isolated bacteriophages (or phages) individually (phSE-1, phSE-2 and phSE-5) or combined in cocktails of two or three phages (phSE-1/phSE-2, phSE-1/phSE-5, phSE-2/phSE-5 and phSE-1/phSE-2/phSE-5) to control Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) in order to evaluate their potential application during depuration. Phages were assigned to the family Siphoviridae and revealed identical restriction digest profiles, although they showed a different phage adsorption, host range, burst size, explosion time and survival in seawater. The three phages were effective against S. Typhimurium (reduction of ∼2.0 log CFU/mL after 4h treatment). The use of cocktails was not significantly more effective than the use of single phages. A big fraction of the remained bacteria are phage-resistant mutants (frequency of phage-resistant mutants 9.19×10(-5)-5.11×10(-4)) but phage- resistant bacterial mutants was lower for the cocktail phages than for the single phage suspensions and the phage phSE-1 presented the highest rate of resistance and phage phSE-5 the lowest one. The spectral changes of S. Typhimurium resistant and phage-sensitive cells were compared and revealed relevant differences for peaks associated to amide I (1620cm(-1)) and amide II (1515cm(-1)) from proteins and from carbohydrates and phosphates region (1080-1000cm(-1)). Despite the similar efficiency of individual phages, the development of lower resistance indicates that phage cocktails might be the most promising choice to be used during the bivalve depuration to control the transmission of salmonellosis.

  18. Evolution of Variable Number Tandem Repeats and Its Relationship with Genomic Diversity in Salmonella Typhimurium

    PubMed Central

    Fu, Songzhe; Octavia, Sophie; Wang, Qinning; Tanaka, Mark M.; Tay, Chin Yen; Sintchenko, Vitali; Lan, Ruiting

    2016-01-01

    Salmonella enterica serovar Typhimurium is the most common Salmonella serovar causing human infections in Australia and many other countries. A total of 12,112 S. Typhimurium isolates from New South Wales were analyzed by multi-locus variable number of tandem repeat (VNTR) analysis (MLVA) using five VNTRs from 2007 to 2014. We found that mid ranges of repeat units of 8–14 in VNTR locus STTR5, 6–13 in STTR6, and 9–12 in STTR10 were always predominant in the population (>50%). In vitro passaging experiments using MLVA type carrying extreme length alleles found that the majority of long length alleles mutated to short ones and short length alleles mutated to longer ones. Both data suggest directional mutability of VNTRs toward mid-range repeats. Sequencing of 28 isolates from a newly emerged MLVA type and its five single locus variants revealed that single nucleotide variation between isolates with up to two MLVA differences ranged from 0 to 12 single nucleotide polymorphisms (SNPs). However, there was no relationship between SNP and VNTR differences. A population genetic model of the joint distribution of VNTRs and SNPs variations was used to estimate the mutation rates of the two markers, yielding a ratio of 1 VNTR change to 6.9 SNP changes. When only one VNTR repeat difference was considered, the majority of pairwise SNP difference between isolates were 4 SNPs or fewer. Based on this observation and our previous findings of SNP differences of outbreak isolates, we suggest that investigation of S. Typhimurium community outbreaks should include cases of 1 repeat difference to increase sensitivity. This study offers new insights into the short-term VNTR evolution of S. Typhimurium and its application for epidemiological typing. PMID:28082952

  19. Correlates of protection induced by live Aro- Salmonella typhimurium vaccines in the murine typhoid model.

    PubMed Central

    Harrison, J A; Villarreal-Ramos, B; Mastroeni, P; Demarco de Hormaeche, R; Hormaeche, C E

    1997-01-01

    Live attenuated salmonella vaccines generally confer better protection than killed vaccines. The immune responses in BALB/c mice elicited by immunization with a live attenuated Aro Salmonella typhimurium vaccine given orally, intravenously or subcutaneously were compared with those elicited by killed whole-cell vaccines (acetone or heat-treated) given subcutaneously. Live vaccines given by all routes elicited higher interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) responses in spleen cells against an alkali-treated whole-cell salmonella lysate than did killed vaccines. Live and killed vaccines elicited high total antibody levels to smooth lipopolysaccharide (LPS) (enzyme-linked immunosorbent assay), but all live vaccine regimes elicited higher IgG2a, suggesting a Th1 response. Oral and intravenous vaccination with live organisms elicited IgA against smooth LPS which subcutaneous vaccination with live or killed salmonellae failed to evoke. Western blots using rough whole-cell lysates showed that all vaccines elicited a varied anti-protein response; however, all groups immunized with live organisms recognized three unidentified bands of MW 52,000, 46,000 and 18,000 which were consistently absent in groups immunized with killed organisms. The results indicate that immunization with live aroA salmonellae elicited a Th1 type of response, including bystander T-cell help to LPS, and a response to proteins not seen in mice that received killed vaccines. Images Figure 6 PMID:9176117

  20. Impedance characterization of a piezoelectric immunosensor part II: Salmonella typhimurium detection using magnetic enhancement.

    PubMed

    Kim, Gi Ho; Rand, A Garth; Letcher, Stephen V

    2003-01-01

    This study investigated the usefulness and characteristics of a 5-MHz quartz crystal resonator as a sensor of biological pathogens such as Salmonella typhimurium. An impedance analyzer measured the impedance behavior of the oscillating quartz crystal exposed to various concentrations of Salmonella (10(2)-10(8) cells per ml). The Salmonella cells were captured by antibody-coated paramagnetic microspheres, and then these complexes were moved magnetically to the sensing quartz and were captured by antibodies immobilized on the crystal surface. The response of the crystal was expressed in terms of equivalent circuit parameters. The motional inductance and the motional resistance increased as a function of the concentration of Salmonella. The viscous damping was the main contributor to the resistance and the inductance in a liquid environment. The load resistance was the most effective and sensitive circuit parameter. A magnetic force was a useful method to collect the complexes of Salmonella-microspheres on the crystal surface and enhance the response of the sensor. In this system, the detection limit, based on resistance monitoring, was about 10(3) cells per ml.

  1. Experimental annotation of post-translational features and translated coding regions in the pathogen Salmonella Typhimurium

    PubMed Central

    2011-01-01

    Background Complete and accurate genome annotation is crucial for comprehensive and systematic studies of biological systems. However, determining protein-coding genes for most new genomes is almost completely performed by inference using computational predictions with significant documented error rates (> 15%). Furthermore, gene prediction programs provide no information on biologically important post-translational processing events critical for protein function. Results We experimentally annotated the bacterial pathogen Salmonella Typhimurium 14028, using "shotgun" proteomics to accurately uncover the translational landscape and post-translational features. The data provide protein-level experimental validation for approximately half of the predicted protein-coding genes in Salmonella and suggest revisions to several genes that appear to have incorrectly assigned translational start sites, including a potential novel alternate start codon. Additionally, we uncovered 12 non-annotated genes missed by gene prediction programs, as well as evidence suggesting a role for one of these novel ORFs in Salmonella pathogenesis. We also characterized post-translational features in the Salmonella genome, including chemical modifications and proteolytic cleavages. We find that bacteria have a much larger and more complex repertoire of chemical modifications than previously thought including several novel modifications. Our in vivo proteolysis data identified more than 130 signal peptide and N-terminal methionine cleavage events critical for protein function. Conclusion This work highlights several ways in which application of proteomics data can improve the quality of genome annotations to facilitate novel biological insights and provides a comprehensive proteome map of Salmonella as a resource for systems analysis. PMID:21867535

  2. Effect of the Escherichia coli EMO strain on experimental infection by Salmonella enterica serovar Typhimurium in gnotobiotic mice.

    PubMed

    Lima-Filho, J V M; Vieira, L Q; Arantes, R M E; Nicoli, J R

    2004-07-01

    An experimental infection with Salmonella enterica subsp. enterica serovar Typhimurium was evaluated in gnotobiotic mice previously exposed to a plasmid-free non-pathogenic Escherichia coli (EMO strain). Mice were exposed to EMO (experimental) or not (control) 10 days before challenge with Salmonella Typhimurium (10(2) colony forming units (CFU)/mouse). Survival after challenge was higher (P < 0.05) in the experimental group (16%) than in the control animals (0%). Histopathological examination of the colon and ileum mucosa of the experimental group showed less extensive lesions such as edema, cell inflammatory infiltration and hyperemia. The epithelial cells of the mucosal surface and the production of the mucous layer were also better preserved in the experimental group. The population levels of Salmonella Typhimurium in the feces were initially 10-fold lower (P < 0.05) in the experimental groups. However, 3 days after challenge both experimental and control groups showed similar population levels ranging from 10(8) to 10(9) CFU/g of feces. The intestinal contents of total and anti-Salmonella Typhimurium sIgA were higher in the experimental groups 10 days after inoculation of E. coli EMO strain. Translocation of Salmonella Typhimurium to the spleen was 10-fold lower (P < 0.05) in the experimental group only on day 3 after infection. This was not related to an increase in the bacterial blood clearance of the animals, as shown by experimental venous challenge with E. coli B41. In conclusion, treatment of mice with E. coli EMO strain promoted a relative protection against experimental infection with Salmonella Typhimurium. This protection was not due to the reduction of the population of pathogens in the intestine but was probably related to stimulation of the immune response.

  3. Tumor-targeting Salmonella typhimurium A1-R inhibits human prostate cancer experimental bone metastasis in mouse models.

    PubMed

    Toneri, Makoto; Miwa, Shinji; Zhang, Yong; Hu, Cameron; Yano, Shuya; Matsumoto, Yasunori; Bouvet, Michael; Nakanishi, Hayao; Hoffman, Robert M; Zhao, Ming

    2015-10-13

    Bone metastasis is a frequent occurrence in prostate cancer patients and often is lethal. Zoledronic acid (ZOL) is often used for bone metastasis with limited efficacy. More effective models and treatment methods are required to improve the outcome of prostate cancer patients. In the present study, the effects of tumor-targeting Salmonella typhimurium A1-R were analyzed in vitro and in vivo on prostate cancer cells and experimental bone metastasis. Both ZOL and S. typhimurium A1-R inhibited the growth of PC-3 cells expressing red fluorescent protien in vitro. To investigate the efficacy of S. typhimurium A1-R on prostate cancer experimental bone metastasis, we established models of both early and advanced stage bone metastasis. The mice were treated with ZOL, S. typhimurium A1-R, and combination therapy of both ZOL and S. typhimurium A1-R. ZOL and S. typhimurium A1-R inhibited the growth of solitary bone metastases. S. typhimurium A1-R treatment significantly decreased bone metastasis and delayed the appearance of PC-3 bone metastases of multiple mouse models. Additionally, S. typhimurium A1-R treatment significantly improved the overall survival of the mice with multiple bone metastases. The results of the present study indicate that S. typhimurium A1-R is useful to prevent and inhibit prostate cancer bone metastasis and has potential for future clinical use in the adjuvant setting.

  4. Salmonella enterica Serotype Typhi Bacteremia Complicating Pregnancy in the Third Trimester

    PubMed Central

    Patel, Krunal; Gittens-Williams, Lisa; Apuzzio, Joseph J.; Martimucci, Kristina; Williams, Shauna F.

    2017-01-01

    Background. Salmonella enterica serotype Typhi (S. Typhi) is an anaerobic gram-negative enteric rod that causes infection when contaminated food or water is ingested and may cause illness in pregnancy. Case. This is a patient who presented at 31 weeks' gestation with abdominal pain and fever and was diagnosed with S. Typhi bacteremia. Conclusion. S. Typhi should be considered in febrile patients with recent travel presenting with abdominal discomfort with or without elevated liver enzymes. PMID:28203469

  5. Prevalence and Diversity of Salmonella Serotypes in Ecuadorian Broilers at Slaughter Age

    PubMed Central

    Cevallos, María; Ron-Garrido, Lenin; Bertrand, Sophie; De Zutter, Lieven

    2016-01-01

    Salmonella is frequently found in poultry and represent an important source for human gastrointestinal infections worldwide. The aim of this study was to investigate the prevalence, genotypes and antimicrobial resistance of Salmonella serotypes in broilers from Ecuador. Caeca content from 388 at random selected broiler batches were collected in 6 slaughterhouses during 1 year and analyzed by the ISO 6579/Amd1 protocol for the isolation for Salmonella. Isolates were serotyped and genotypic variation was acceded by pulsed field gel electrophoresis. MIC values for sulfamethoxazole, gentamicin, ciprofloxacin, ampicillin, cefotaxime, ceftazidime, tetracycline, streptomycin, trimethropim, chloramphenicol, colistin, florfenicol, kanamycin and nalidixic acid were obtained. Presence of blaCTX-M, blaTEM, blaSHV and blaCMY; and mcr-1 plasmid genes was investigated in resistant strains to cefotaxime and colistin respectively. Prevalence at batch level was 16.0%. The most common serotype was S. Infantis (83.9%) followed by S. Enteritidis (14.5%) and S. Corvallis (1.6%). The pulsed field gel electrophoresis analysis showed that S. Corvallis, S. Enteritidis and S. Infantis isolates belonged to 1, 2 and 12 genotypes respectively. S. Infantis isolates showed high resistance rates to 12 antibiotics ranging from 57.7% (kanamycin) up to 98.1% (nalidixic acid and sulfamethoxazole). All S. Enteritidis isolates showed resistance to colistin. High multiresistant patterns were found for all the serotypes. The blaCTX-M gene was present in 33 S. Infantis isolates while mcr-1 was negative in 10 colistin resistant isolates. This study provides the first set of scientific data on prevalence and multidrug-resistant Salmonella coming from commercial poultry in Ecuador. PMID:27414038

  6. PMQR genes oqxAB and aac(6')Ib-cr accelerate the development of fluoroquinolone resistance in Salmonella typhimurium.

    PubMed

    Wong, Marcus H; Chan, Edward W; Liu, Li Z; Chen, Sheng

    2014-01-01

    Emergence of multidrug-resistant Salmonella typhimurium strains, especially the ACSSuT and nalidixic acid R types, has significantly compromised the effectiveness of current strategies to control Salmonella infections, resulting in increased morbidity and mortality. Clinical S. typhimurium isolates recovered in Hong Kong during the period of 2005-2011 were increasingly resistant to ciprofloxacin (CIP) and antibiotics of the ACSSuT group. Our data revealed that oqxAB and aac(6')Ib-cr were encoded on plasmids of various sizes and the presence of these two elements together with a single gyrA mutation in S. typhimurium were sufficient to mediate resistance to CIP. Acquisition of the oqxAB and aac(6')Ib-cr encoding plasmids by S. typhimurium caused a fourfold increase in CIP minimal inhibitory concentration. Furthermore, the presence of oqxAB and aac(6')Ib-cr in Salmonella dramatically increased the mutation prevention concentration of CIP which may due to mutational changes in the drug target genes. In conclusion, possession of oqxAB and aac(6')Ib-cr encoding plasmid facilitate the selection of CIP resistant S. typhimurium, thereby causing a remarkable increase of CIP resistance among clinical Salmonella strains in Hong Kong.

  7. A comparative study of thermal and acid inactivation kinetics in fruit juices of Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Senftenberg grown at acidic conditions.

    PubMed

    Alvarez-Ordóñez, Avelino; Fernández, Ana; Bernardo, Ana; López, Mercedes

    2009-11-01

    Acid and heat inactivation in orange and apple juices of Salmonella enterica serovar Typhimurium Colección Española de Cultivos Tipo (i.e., Spanish Type Culture Collection) 443 (CECT 443) (Salmonella Typhimurium) and S. enterica serovar Senftenberg CECT 4384 (Salmonella Senftenberg) grown in buffered brain heart infusion (pH 7.0) and acidified brain heart infusion up to pH 4.5 with acetic, citric, lactic, and hydrochloric acids was evaluated. Acid adaptation induced an adaptive response that increased the subsequent resistance to extreme pH conditions (pH 2.5) and to heat, although the magnitude of these responses differed between the two isolates and fruit juices. The acid resistance in orange juice for acid-adapted cells (D-values of 28.3-34.5 min for Salmonella Senftenberg and 30.0-39.2 min for Salmonella Typhimurium) resulted to be about two to three times higher than that corresponding to non-acid-adapted cells. In apple juice, acid-adapted Salmonella Senftenberg cells survived better than those of Salmonella Typhimurium, obtaining mean D-values of 114.8 +/- 12.3 and 41.9 +/- 2.5 min, respectively. The thermotolerance of non-acid-adapted Salmonella Typhimurium in orange (D(58)-value: 0.028 min) and apple juices (D(58)-value: 0.10 min) was approximately double for acid-adapted cells. This cross-protection to heat was more strongly expressed in Salmonella Senftenberg. D(58)-values obtained for non-acid-adapted cells in orange (0.11 min) and apple juices (0.19 min) increased approximately 10 and 5 times, respectively, after their growth in acidified media. The conditions prevailing during bacterial growth and heat treatment did not significantly influence the z-values observed (6.0 +/- 0.3 degrees C for Salmonella Typhimurium and 7.0 +/- 0.3 degrees C for Salmonella Senftenberg). The enhanced acid resistance found for both isolates could enable them to survive for prolonged time periods in the gastrointestinal tract, increasing the risk of illness. Further, it

  8. Chromosomal Rearrangements in Salmonella enterica Serotype Typhi Affecting Molecular Typing in Outbreak Investigations

    PubMed Central

    Echeita, M. A.; Usera, M. A.

    1998-01-01

    Salmonella enterica serotype Typhi strains belonging to eight different outbreaks of typhoid fever that occurred in Spain between 1989 and 1994 were analyzed by ribotyping and pulsed-field gel electrophoresis. For three outbreaks, two different patterns were detected for each outbreak. The partial digestion analysis by the intron-encoded endonuclease I-CeuI of the two different strains from each outbreak provided an excellent tool for examining the organization of the genomes of epidemiologically related strains. S. enterica serotype Typhi seems to be more susceptible than other serotypes to genetic rearrangements produced by homologous recombinations between rrn operons; these rearrangements do not substantially alter the stability or survival of the bacterium. We conclude that genetic rearrangements can occur during the emergence of an outbreak. PMID:9650981

  9. Influence of Natural Organic Matter on Attachment Kinetics of Salmonella Typhimurium

    NASA Astrophysics Data System (ADS)

    Chowdhury, I.; Zorlu, O.; Hill, J. E.; Walker, S. L.

    2011-12-01

    Salmonella enterica serovar Typhimurium is one of the most common and virulent bacterial pathogens, usually found in food and water. This waterborne pathogen has been attributed to causing gastroenteritis and typhoid fever, leading to 16 million cases and over half a million deaths worldwide each year. Natural organic matter (NOM) is ubiquitous in environment and previous work has shown NOM to enhance the stability and transport of bacteria cells; hence NOM will certainly interact with Salmonella and affect its transport in environment. The objective of this study was to investigate the influence of NOM (Suwannee River humic acid standard II, SRHA) on the attachment kinetics of a model Salmonella (Salmonella enterica serovar Typhimurium SA5983) to glass. The transport study was conducted in a parallel plate flow chamber using fluorescent microscope to visualize the bacterial cells, which were tagged with green fluorescent protein (GFP). The solution pH was unadjusted, and the flow rate through parallel plate channel was 0.1 mL/min to simulate groundwater conditions. Parameters varied in this study were NOM presence, ion valence (K+, Ca2+) as well as cell growth phase (mid-exponential and late-exponential growth phases). These parameters were chosen because ion valence may alter the NOM conformation and capacity for bridging, as well growth phase impacts the cellular surface chemistry. Extensive characterization of the bacterial cells was conducted including measurements of electrophoretic mobility, hydrophobicity, acidity, surface charge density and extracellular polymeric substance content. Additionally, electrokintic characterization was conducted for the glass. Preliminary results demonstrated the sensitivity of cell attachment to ionic valence and cell growth phase. Also the addition of NOM reduced the attachment of the Salmonella cells significantly under all of these conditions. Without NOM, attachment efficiencies (α) in KCl were similar at both growth

  10. Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium in powdered weaning food by electron-beam irradiation

    NASA Astrophysics Data System (ADS)

    Hong, Yun-Hee; Park, Ji-Yong; Park, Jong-Hyun; Chung, Myong-Soo; Kwon, Ki-Sung; Chung, Kyungsook; Won, Misun; Song, Kyung-Bin

    2008-09-01

    Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium were evaluated in powdered weaning food using electron-beam irradiation. E. sakazakii, B. cereus, and S. typhimurium were eliminated by irradiation at 16, 8, and 8 kGy, respectively. The D10-vlaues of E. sakazakii, B. cereus, and S. typhimurium inoculated on powdered weaning food were 4.83, 1.22, and 0.98 kGy, respectively. The results suggest that electron-beam irradiation should inhibit the growth of pathogenic bacteria on baby food without impairing qualities.

  11. Use of electron beam radiation for the reduction of Salmonella enterica serovars typhimurium and Tennessee in peanut butter.

    PubMed

    Hvizdzak, A L; Beamer, S; Jaczynski, J; Matak, K E

    2010-02-01

    Peanut butter and peanut paste products were implicated as the vehicle of contamination in an outbreak of Salmonella Typhimurium, which began in September 2008, and in the November 2006 outbreak of Salmonella Tennessee. Therefore, this study evaluated the effectiveness of electron beam (e-beam) radiation for the reduction of Salmonella serovars Tennessee (ATCC 10722) and Typhimurium (ATCC 14028) in creamy peanut butter. Each strain was studied independently. Peanut butter samples were inoculated with approximately 8.0 log CFU/g of Salmonella, and exposed to e-beam doses ranging from 0 to 3.1 kGy. Doses were confirmed with film dosimetry. Survivors were enumerated by standard spread plating on nonselective tryptic soy agar (TSA) and selective xylose-lysine-desoxycholate agar (XLD) media. Salmonella Tennessee was more susceptible to e-beam radiation, with 5.00- and 6.75-log reduction of cells on TSA and XLD, respectively, at the approximate e-beam dose of 3.0 kGy. Salmonella Typhimurium was reduced by 4.19 and 4.85 log on TSA and XLD, respectively, at the approximate e-beam dose of 3.0 kGy. D(10)-values show that Salmonella Typhimurium was more resistant (0.82 +/- 0.02 and 0.73 +/- 0.01 kGy on TSA and XLD, respectively) than was Salmonella Tennessee (0.72 +/- 0.02 and 0.60 +/- 0.01 kGy on TSA and XLD, respectively) to e-beam radiation (P < 0.05). The recovery on growth and selective media were different (P < 0.05), indicating cell injury. The results of this study demonstrate that e-beam radiation may be an effective processing step for the nonthermal inactivation of Salmonella in peanut butter.

  12. Thermal inactivation D- and z-values of multidrug-resistant and non-multidrug-resistant Salmonella serotypes and survival in ground beef exposed to consumer-style cooking.

    PubMed

    Stopforth, J D; Suhalim, R; Kottapalli, B; Hill, W E; Samadpour, M

    2008-03-01

    There has been speculation that multidrug-resistant (MDR) strains are generated by subtherapeutic antibiotic use in food animals and that such strains result in increased resistance to lethality by food processes such as heat and irradiation. The objective of this study was to evaluate the heat resistance of 20 strains, namely an MDR and a non-multidrug-resistant (NMDR) strain of each of 10 Salmonella serotypes isolated from cattle or cattle environments. MDR and NMDR Salmonella serotypes studied included Montevideo, Typhimurium, Anatum, Muenster, Newport, Mbandaka, Dublin, Reading, Agona, and Give. For phase I, stationary-phase cultures of the strains were aliquoted into sterile capillary tubes and immersed in a temperature-controlled water bath at 55, 60, 65, and 70 degrees C for appropriate times. Survivor curves were plotted for each temperature, and a best-fit linear regression was derived for each temperature. D-values (decimal reduction times) and z-values (changes in temperature required to change the D-values) were calculated for each strain. Although there was no overall significant difference in the heat resistance of MDR and NMDR serotypes, NMDR serotypes generally appeared to have slightly higher heat resistance than NMDR serotypes, especially at 55 and 60 degrees C. The highest relative heat resistance (highest z-values) was exhibited by Salmonella Anatum. Notably, the relative heat resistance of NMDR Salmonella Agona was similar to that of NMDR Salmonella Anatum and had the highest D-values at all four temperatures. For phase II, three serotypes (regardless of resistance profile) with the highest relative heat resistance and their drug-resistant counterparts were selected for thermal inactivation in ground beef patties cooked to endpoint temperatures. Salmonella Agona was able to survive in ground beef cooked to an internal temperature of 71 degrees C. Results of these studies suggest drug resistance does not affect the heat resistance of Salmonella

  13. Utilization of a molecular serotyping method for Salmonella enterica in a routine laboratory in Alberta Canada.

    PubMed

    Ferrato, Christina; Chui, Linda; King, Robin; Louie, Marie

    2017-04-01

    Salmonella is one of the most common enteric pathogens related to foodborne illness. Alberta's Provincial Laboratory for Public Health (ProvLab) provides Outbreak and Surveillance support by performing serotyping. The Check&Trace Salmonella™ (CTS) assay (Check-Points, Netherlands), a commercial DNA microarray system, can determine the serotype designation of a Salmonella isolate with automated interpretation. Here we evaluate 1028 Salmonella isolates of human clinical or environmental sources in Alberta, Canada with the CTS assay. CTS was able to assign a serovar to 98.7% of the most frequently occurring human clinical strains in Alberta (82.5% overall), and 71.7% of isolates which were inconclusive by conventional methods. There was 99.7% concordance in environmental isolates. The CTS database has potential to expand to identify rare serovars. With the anticipated shift to molecular methods for identification, CTS provides an easy transition and demonstrates ease-of-use and reduces the turn-around-time of a reported result significantly compared to classical serotyping.

  14. Detection of Salmonella typhimurium in dairy products with flow cytometry and monoclonal antibodies.

    PubMed Central

    McClelland, R G; Pinder, A C

    1994-01-01

    Flow cytometry, combined with fluorescently labelled monoclonal antibodies, offers advantages of speed and sensitivity for the detection of specific pathogenic bacteria in foods. We investigated the detection of Salmonella typhimurium in eggs and milk. Using a sample clearing procedure, we determined that the detection limit was on the order of 10(3) cells per ml after a total analysis time of 40 min. After 6 h of nonselective enrichment, the detection limits were 10 cells per ml for milk and 1 cell per ml for eggs, even in the presence of a 10,000-fold excess of Escherichia coli cells. Images PMID:7811064

  15. [A ruptured mycotic aneurysm of the femoral artery due to Salmonella typhimurium].

    PubMed

    Calvo Cascallo, J; Mundi Salvadó, N; Cardona Fontanet, M

    1993-01-01

    Mycotic aneurysms of the femoral artery is rare. We report a new case with a mycotic aneurysm of the femoral artery by "Salmonella typhimurium". The surgical operation was performed as surgical emergence for ruptured aneurysm. We did not know the aneurysm infection origin. The treatment of lesions was resection and femoro-femoral bypass with PTFE. The microbiological examination discovered infection material. A posterior bypass infection required a exeresis bypass and new revascularization with iliofemoral saphenous vein bypass by obturator foramen, and antibiotic treatment prolonged.

  16. Transcriptional organization of the rfaGBIJ locus of Salmonella typhimurium.

    PubMed

    Brazas, R; Davie, E; Farewell, A; Rothfield, L I

    1991-10-01

    The transcriptional organization of the rfaGBIJ gene cluster of Salmonella typhimurium was studied by using lacZ and cat transcriptional probes. The results indicated that the leftward end of the gene cluster (rfaG-rfaB-rfaI) is an operon that is transcribed from one or more promoters that lie upstream of rfaG. The results further indicated that the product of the rfaH (sfrB) gene acts as a positive regulator of transcription of the entire rfaGBIJ cluster. At least one site required for the RfaH-mediated transcriptional regulation lies within or very close to the upstream promoter.

  17. Inactivation of encephalomyocarditis virus and salmonella typhimurium by using a visible femtosecond laser

    NASA Astrophysics Data System (ADS)

    Tsen, Shaw-Wei D.; Tsen, K. T.

    2011-03-01

    We report inactivation of encephalomyocarditis virus and salmonella typhimurium by a visible femtosecond laser. Our results show that inactivation of virus and bacterium by an ultrashort pulsed laser light might involve completely different mechanisms. Inactivation of viruses by an ultrashort pulsed laser might involve disruption of their protein coat through laser-induced excitation of large-amplitude acoustic vibrations. On the other hand, inactivation of bacteria is most likely related to the disruption of their metabolism by the DNA relaxation process caused by irradiation of ultrashort pulsed lasers.

  18. Characterization of Salmonella Typhimurium DNA gyrase as a target of quinolones.

    PubMed

    Kongsoi, Siriporn; Yokoyama, Kazumasa; Suprasert, Apinun; Utrarachkij, Fuangfa; Nakajima, Chie; Suthienkul, Orasa; Suzuki, Yasuhiko

    2015-08-01

    Quinolones exhibit good antibacterial activity against Salmonella spp. isolates and are often the choice of treatment for life-threatening salmonellosis due to multi-drug resistant strains. To assess the properties of quinolones, we performed an in vitro assay to study the antibacterial activities of quinolones against recombinant DNA gyrase. We expressed the S. Typhimurium DNA gyrase A (GyrA) and B (GyrB) subunits in Escherichia coli. GyrA and GyrB were obtained at high purity (>95%) by nickel-nitrilotriacetic acid agarose resin column chromatography as His-tagged 97-kDa and 89-kDa proteins, respectively. Both subunits were shown to reconstitute an ATP-dependent DNA supercoiling activity. Drug concentrations that suppressed DNA supercoiling by 50% (IC50 s) or generated DNA cleavage by 25% (CC25 s) demonstrated that quinolones highly active against S. Typhimurium DNA gyrase share a fluorine atom at C-6. The relationships between the minimum inhibitory concentrations (MICs), IC50 s and CC25 s were assessed by estimating a linear regression between two components. MICs measured against S. Typhimurium NBRC 13245 correlated better with IC50 s (R = 0.9988) than CC25 s (R = 0.9685). These findings suggest that the DNA supercoiling inhibition assay may be a useful screening test to identify quinolones with promising activity against S. Typhimurium. The quinolone structure-activity relationship demonstrated here shows that C-8, the C-7 ring, the C-6 fluorine, and N-1 cyclopropyl substituents are desirable structural features in targeting S. Typhimurium gyrase.

  19. [Mortality in free living siskins (Spinus spinus Linnaeus, 1758) due to Salmonella typhimurium, phage type DT104 and DT013].

    PubMed

    Krüger, Alexandra; Redmann, Thomas; Sommer, Dagmar; Antakli, Ali; Kaleta, Erhard F

    2009-09-01

    This report deals with an enzootic due to Salmonella Typhimurium in two free living Eurasian siskins (Spinus spinus Linnaeus, 1758). Other birds in the vicinity of the siskins were not affected. Clinical signs consisted of non-specific symptoms such as ruffled plumage, apathy and reduced food intake. During necropsy, gross lesions were enlarged livers with focal necrosis, pale spleens, enlarged kidneys, pneumonia and enteritis. Salmonella Typhimurium was isolated from internal organs in pure culture. Using the polymerase chain reaction, the detection of Salmonella according to EN ISO 6579:2002 was confirmed. The detailed characterisation of both isolates in the Federal Institute for Risk Assessment and in the Robert Koch Institute yielded for the first siskin Salmonella Typhimurium, 4, 5, 12: i : 1, 2, LT DT104, BT a and for the second siskin Salmonella Typhimurium, 4,12 i : 1, 2, LT DT013, BT c. These phage types were identified for the first time in siskins. The detected phage types have importance as causes of disease not only for free living siskins but also as infectious and zoonotic agents for domestic poultry and poultry products.

  20. Integrative analysis of Salmonellosis in Israel reveals association of Salmonella enterica Serovar 9,12:l,v:- with extraintestinal infections, dissemination of endemic S. enterica Serovar Typhimurium DT104 biotypes, and severe underreporting of outbreaks.

    PubMed

    Marzel, Alex; Desai, Prerak T; Nissan, Israel; Schorr, Yosef Ilan; Suez, Jotham; Valinsky, Lea; Reisfeld, Abraham; Agmon, Vered; Guard, Jean; McClelland, Michael; Rahav, Galia; Gal-Mor, Ohad

    2014-06-01

    Salmonella enterica is the leading etiologic agent of bacterial food-borne outbreaks worldwide. This ubiquitous species contains more than 2,600 serovars that may differ in their host specificity, clinical manifestations, and epidemiology. To characterize salmonellosis epidemiology in Israel and to study the association of nontyphoidal Salmonella (NTS) serovars with invasive infections, 48,345 Salmonella cases reported and serotyped at the National Salmonella Reference Center between 1995 and 2012 were analyzed. A quasi-Poisson regression was used to identify irregular clusters of illness, and pulsed-field gel electrophoresis in conjunction with whole-genome sequencing was applied to molecularly characterize strains of interest. Three hundred twenty-nine human salmonellosis clusters were identified, representing an annual average of 23 (95% confidence interval [CI], 20 to 26) potential outbreaks. We show that the previously unsequenced S. enterica serovar 9,12:l,v:- belongs to the B clade of Salmonella enterica subspecies enterica, and we show its frequent association with extraintestinal infections, compared to other NTS serovars. Furthermore, we identified the dissemination of two prevalent Salmonella enterica serovar Typhimurium DT104 clones in Israel, which are genetically distinct from other global DT104 isolates. Accumulatively, these findings indicate a severe underreporting of Salmonella outbreaks in Israel and provide insights into the epidemiology and genomics of prevalent serovars, responsible for recurring illness.

  1. Method for studying the mutagenicity of some gaseous compounds in Salmonella typhimurium

    SciTech Connect

    Victorin, K.; Stahlberg, M.

    1988-01-01

    A dynamic flow-through exposure system was designed for mutagenicity studies of gaseous compounds in Salmonella. Salmonella typhimurium strain TA100 was the primary tester strain. The dose ranges were 0.5-20% of vinyl chloride, ethene, propene, and 1,3-butadiene, 1-200 ppm of ethylene oxide, 0.5-20 ppm of nitrogen dioxide, and 0.1-3.5 ppm of ozone. The gas flow rate was 250, 500, or 1000 ml/min, and the exposure time was 6 or 7 hours. Of the tested gases, vinyl chloride, ethylene oxide, and nitrogen dioxide were mutagenic. Ethene, propene, and 1,3-butadiene were not mutagenic in this system. Ozone is bacteriotoxic, and no mutagenic effect could be demonstrated in the nontoxic dose range. The exposure system was considered suitable for studies on gaseous chemicals.

  2. Genetic Characterization of the Galactitol Utilization Pathway of Salmonella enterica Serovar Typhimurium.

    PubMed

    Nolle, Nicoletta; Felsl, Angela; Heermann, Ralf; Fuchs, Thilo M

    2017-02-15

    Galactitol degradation by salmonellae remains underinvestigated, although this metabolic capability contributes to growth in animals (R. R. Chaudhuri et al., PLoS Genet 9:e1003456, 2013, https://doi.org/10.1371/journal.pgen.1003456). The genes responsible for this metabolic capability are part of a 9.6-kb gene cluster that spans from gatY to gatR (STM3253 to STM3262) and encodes a phosphotransferase system, four enzymes, and a transporter of the major facilitator superfamily. Genome comparison revealed the presence of this genetic determinant in nearly all Salmonella strains. The generation time of Salmonella enterica serovar Typhimurium strain ST4/74 was higher in minimal medium with galactitol than with glucose. Knockout of STM3254 and gatC resulted in a growth-deficient phenotype of S Typhimurium, with galactitol as the sole carbon source. Partial deletion of gatR strongly reduced the lag phase of growth with galactitol, whereas strains overproducing GatR exhibited a near-zero growth phenotype. Luciferase reporter assays demonstrated strong induction of the gatY and gatZ promoters, which control all genes of this cluster except gatR, in the presence of galactitol but not glucose. Purified GatR bound to these two main gat gene cluster promoters as well as to its own promoter, demonstrating that this autoregulated repressor controls galactitol degradation. Surface plasmon resonance spectroscopy revealed distinct binding properties of GatR toward the three promoters, resulting in a model of differential gat gene expression. The cyclic AMP receptor protein (CRP) bound these promoters with similarly high affinities, and a mutant lacking crp showed severe growth attenuation, demonstrating that galactitol utilization is subject to catabolite repression. Here, we provide the first genetic characterization of galactitol degradation in Salmonella, revealing novel insights into the regulation of this dissimilatory pathway.

  3. Magnetic focusing immunosensor for the detection of Salmonella typhimurium in foods

    NASA Astrophysics Data System (ADS)

    Pivarnik, Philip E.; Cao, He; Letcher, Stephen V.; Pierson, Arthur H.; Rand, Arthur G.

    1999-01-01

    From 1988 through 1992 Salmonellosis accounted for 27% of the total reported foodborne disease outbreaks and 57% of the outbreaks in which the pathogen was identified. The prevalence of Salmonellosis and the new requirements to monitor the organism as a marker in pathogen reduction programs will drive the need for rapid, on-site testing. A compact fiber optic fluorometer using a red diode laser as an excitation source and fiber probes for analyte detection has been constructed and used to measure Salmonella. The organisms were isolated with anti-Salmonella magnetic beads and were labeled with a secondary antibody conjugated to a red fluorescent dye. The response of the system was proportional to the concentration of Salmonella typhimurium from 3.2 X 105 colony forming units (CFU)/ml to 1.6 X 107 CFU/ml. The system was developed to utilize a fiber-optic magnetic focusing problem that attracted the magnetic microspheres to the surface of a sample chamber directly in front of the excitation and emission fibers. The signal obtained from a homogenous suspension of fluorescent magnetic microspheres was 9 to 10 picowatts. After focusing, the signal from the fluorescent labeled magnetic microspheres increased to 200 picowatts, approximately 20 times greater than the homogeneous suspension. The magnetic focusing assay detected 1.59 X 105 colony forming units/ml of Salmonella typhimurium cultured in growth media. The process of magnetic focusing in front of the fibers has the potential to reduce the background fluorescence from unbound secondary antibodies, eliminating several rinsing steps, resulting in a simple rapid assay.

  4. Multistate Outbreak of Human Salmonella Typhimurium Infections Linked to Pet Hedgehogs - United States, 2011-2013.

    PubMed

    Anderson, T C; Marsden-Haug, N; Morris, J F; Culpepper, W; Bessette, N; Adams, J K; Bidol, S; Meyer, S; Schmitz, J; Erdman, M M; Gomez, T M; Barton Behravesh, C

    2016-10-13

    Zoonotic Salmonella infections cause approximately 130 000 illnesses annually in the United States. Of 72.9 million US households owning at least one pet, five million own small mammals; 3000 hedgehogs were documented by USDA in USDA-licensed breeding facilities and pet stores in 2012. State health department collaborators and PulseNet, the national bacterial subtyping network, identified human infections of a Salmonella Typhimurium outbreak strain, which were investigated by CDC, USDA-APHIS and state public and animal health officials. A case was defined as an illness in a person infected with the outbreak strain identified between 1 December 2011 and 3 June 2013. Investigators collected information on patient exposures, cultured animal and environmental specimens for Salmonella, and conducted traceback investigations of USDA-licensed hedgehog facilities. There were 26 cases in 12 states. Illness onset dates ranged from 26 December 2011 to 8 April 2013. The median patient age was 15 years (range = <1-91 years); 58% were female. Among 23 persons with available information, 8 (35%) were hospitalized and one outbreak strain-associated death was reported. Of 25 patients with available information, 20 (80%) reported pet hedgehog contact in the week before illness onset. The outbreak strain was isolated from animal and environmental samples collected from three ill persons' homes in three states. Hedgehogs were purchased in geographically distant states from USDA-licensed breeders (10/17, 59%); a USDA-licensed pet store (1/17, 6%); unlicensed or unknown status breeders (3/17, 18%); and private individuals (3/17, 18%). Traceback investigations of USDA-licensed facilities did not reveal a single source of infection. Public and animal health collaboration linked pet hedgehog contact to human infections of Salmonella Typhimurium, highlighting the importance of a One Health investigative approach to zoonotic salmonellosis outbreaks. More efforts are needed to increase

  5. THE EFFECT OF ANTIBODY ON INTRACELLULAR PARASITISM OF SALMONELLA TYPHIMURIUM IN MONONUCLEAR PHAGOCYTES IN VITRO

    PubMed Central

    Gelzer, Justus; Suter, Emanuel

    1959-01-01

    The effect of antibody on the fate of Salmonella typhimurium within mononuclear phagocytes (MN) of rabbits was studied in vitro. Monocytes and bacteria were incubated either in absence or presence of antibody. After 45 minutes during which phagocytosis occurred infected cells were washed to remove extracellular bacilli and free antibody. The cells were then reincubated in a medium without addition of antibody, and the interaction between the MN and bacteria was followed, correlating bacterial viability and the morphology of the mixture. The following results were obtained. The anti-Salmonella antibody was not bactericidal even in presence of complement and did not enhance phagocytosis. Regardless of whether antibody was present or absent during phagocytosis, the bacteria appeared to multiply within the cells. When no antibody was present during phagocytosis the infected cells were severely damaged within a few hours of incubation, and extensive extracellular multiplication was dominating. When antibody was present during phagocytosis MN packed with bacteria persisted for a long time. Little or no extracellular growth occurred. It was possible to demonstrate the presence of the antibody within the infected MN, using the fluorescent antibody technique. The antibody appeared as a coat around the bacteria. Antibody entered the cells only during phagocytosis, presumably attached to the bacteria. The active factor of the immune serum was found in the gamma globulin fraction and reacted specifically with the somatic antigen of Salmonella typhimurium. The antiflagellar portion of the antiserum was not involved in the phenomenon described. It is concluded that this antibody protects monocytes against the effect of intracellularly located Salmonella. PMID:13827241

  6. Salmonella in raccoons (Procyon lotor) in southern Ontario, Canada.

    PubMed

    Jardine, Claire; Reid-Smith, Richard J; Janecko, Nicol; Allan, Mike; McEwen, Scott A

    2011-04-01

    Numerous serotypes of Salmonella have been detected in a variety of wild animals, including raccoons (Procyon lotor). Raccoons are common, mid-size omnivores that live in close association with people in urban and rural areas in Ontario. Although raccoons are known to shed Salmonella, little is known about their potential long-term role in maintaining Salmonella infections. We sampled feces from raccoons in three areas of Ontario: one primarily urban site around Niagara, one primarily rural site north of Guelph, and the grounds of the Toronto Zoo, in 2007 to identify which serotypes of Salmonella were commonly shed by raccoons in southern Ontario. In addition, we conducted a longitudinal study at the Toronto Zoo site to determine if raccoons remain persistently infected with Salmonella. Salmonella was found in 45% of samples. The prevalence of Salmonella in raccoon feces ranged from 27% at the rural site to 65% at the urban site. We detected 16 serotypes of Salmonella in 83 positive samples. The most common serotype detected in raccoons from the rural and zoo sites was Salmonella enterica serotype Typhimurium, whereas Salmonella Newport was detected most commonly in the urban site. Only one raccoon of 11 that were captured in four or more consecutive trapping sessions shed the same Salmonella serotype for two consecutive months, suggesting that raccoons regularly acquire new Salmonella serotypes from the environment.

  7. International spread of an epidemic population of Salmonella enterica serotype Kentucky ST198 resistant to ciprofloxacin.

    PubMed

    Le Hello, Simon; Hendriksen, Rene S; Doublet, Benoît; Fisher, Ian; Nielsen, Eva Møller; Whichard, Jean M; Bouchrif, Brahim; Fashae, Kayode; Granier, Sophie A; Jourdan-Da Silva, Nathalie; Cloeckaert, Axel; Threlfall, E John; Angulo, Frederick J; Aarestrup, Frank M; Wain, John; Weill, François-Xavier

    2011-09-01

    National Salmonella surveillance systems from France, England and Wales, Denmark, and the United States identified the recent emergence of multidrug-resistant isolates of Salmonella enterica serotype Kentucky displaying high-level resistance to ciprofloxacin. A total of 489 human cases were identified during the period from 2002 (3 cases) to 2008 (174 cases). These isolates belonged to a single clone defined by the multilocus sequence type ST198, the XbaI-pulsed-field gel electrophoresis cluster X1, and the presence of the Salmonella genomic island 1 variant SGI1-K. This clone was probably selected in 3 steps in Egypt during the 1990s and the early 2000s and has now spread to several countries in Africa and, more recently, in the Middle East. Poultry has been identified as a potential major vehicle for infection by this clone. Continued surveillance and appropriate control measures should be implemented by national and international authorities to limit the spread of this strain.

  8. Mutagenicity of rubber vulcanization gases in Salmonella typhimurium.

    PubMed

    Hedenstedt, A; Ramel, C; Wachtmeister, C A

    1981-01-01

    Gases formed by rubber and rubber additives in the vulcanization process were collected with a laboratory-scale glass apparatus. Mutagenicity testing of the vulcanization gases by the Salmonella/microsome test was conducted with strains TA1535, TA1538, TA98, and TA100 in the absence and presence of a metabolizing system from rat liver homogenates. The mutagenicity of gases derived by heating chloroprene rubber and ethylene propylene rubber was established with both base substitution- and frameshift-sensitive strains and that of a styrene-butadiene rubber was established with the base substitution-sensitive stain TA100. Tests on pyrolysis gases from a butadiene acrylonitrile rubber revealed only toxic effects. Curing systems, additives, and filling materials from various sources were represented in the material. Gases were collected at temperature levels corresponding to both mixing and curing of these particular rubbers in the industrial operations. Attempts were made to correlate the mutagenicity of the gases to the presence of mutagenic components in the rubber mixtures.

  9. Mapping the Regulatory Network for Salmonella enterica Serovar Typhimurium Invasion

    PubMed Central

    Smith, Carol; Stringer, Anne M.; Mao, Chunhong; Palumbo, Michael J.

    2016-01-01

    ABSTRACT Salmonella enterica pathogenicity island 1 (SPI-1) encodes proteins required for invasion of gut epithelial cells. The timing of invasion is tightly controlled by a complex regulatory network. The transcription factor (TF) HilD is the master regulator of this process and senses environmental signals associated with invasion. HilD activates transcription of genes within and outside SPI-1, including six other TFs. Thus, the transcriptional program associated with host cell invasion is controlled by at least 7 TFs. However, very few of the regulatory targets are known for these TFs, and the extent of the regulatory network is unclear. In this study, we used complementary genomic approaches to map the direct regulatory targets of all 7 TFs. Our data reveal a highly complex and interconnected network that includes many previously undescribed regulatory targets. Moreover, the network extends well beyond the 7 TFs, due to the inclusion of many additional TFs and noncoding RNAs. By comparing gene expression profiles of regulatory targets for the 7 TFs, we identified many uncharacterized genes that are likely to play direct roles in invasion. We also uncovered cross talk between SPI-1 regulation and other regulatory pathways, which, in turn, identified gene clusters that likely share related functions. Our data are freely available through an intuitive online browser and represent a valuable resource for the bacterial research community. PMID:27601571

  10. Use of Caenorhabditis elegans for preselecting Lactobacillus isolates to control Salmonella Typhimurium.

    PubMed

    Wang, Chunyang; Wang, Jinquan; Gong, Joshua; Yu, Hai; Pacan, Jennifer C; Niu, Zhongxiang; Si, Weiduo; Sabour, Parviz M

    2011-01-01

    Host-specific probiotics have been used to control enteric pathogens, including foodborne pathogens, in food animal production. However, evaluation of the efficacy of these probiotics requires costly in vivo assays in the target animal. The nematode Caenorhabditis elegans has been used for prescreening of antimicrobial agents and for studies of host-pathogen interactions. In the present study, 17 Lactobacillus isolates from chicken and pig intestines were tested with C. elegans, and the ability of these isolates to prevent death from Salmonella infection was variable. Two Lactobacillus isolates (S64, which gave full protection, and CL11, which gave no protection) were further studied. Both isolates exhibited a similar colonization profile in the C. elegans intestine. Although different culture fractions of CL11 were not protective, both live and heat-killed S64 cells provided full or partial protection of C. elegans from death caused by Salmonella infection. In contrast, different culture fractions from both isolates had similar effects on the colonization of the nematode intestine by Salmonella