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Sample records for salmonella specific inva

  1. Amplification of an invA gene sequence of Salmonella typhimurium by polymerase chain reaction as a specific method of detection of Salmonella.

    Rahn, K; De Grandis, S A; Clarke, R C; McEwen, S A; Galán, J E; Ginocchio, C; Curtiss, R; Gyles, C L

    1992-08-01

    Amplification of nucleotide sequences within the invA gene of Salmonella typhimurium was evaluated as a means of detecting Salmonella. A collection of 630 strains of Salmonella comprising over 100 serovars, including the 20 most prevalent serovars isolated from animals and humans in Canada, was examined. Controls consisted of 142 non-Salmonella strains comprising 21 genera of bacteria. Cultures were screened by inoculating a single colony of bacteria directly into a polymerase chain reaction (PCR) mixture which contained a pair of primers specific for the invA gene. The specific PCR product was a 284 bp DNA fragment which was visualized in 2% agarose gels. With the exception of two S. litchfield and two S. senftenberg strains, all Salmonella strains were detected. In contrast, none of the non-Salmonella strains yielded the specific amplification product. Non-specific amplification of a few non-Salmonella strains resulted in a product that was distinctly different in size from the specific 284 bp product. Specificity of amplification was further confirmed by demonstration of hybridization of a 32P-labelled invA gene fragment only to the specific 284 bp product. The detection of 99.4% of Salmonella strains tested and the failure to specifically amplify DNA from non-Salmonella strains confirm that the invA gene contains sequences unique to Salmonella and demonstrate that this gene is a suitable PCR target, with potential diagnostic applications.

  2. Rapid identification of Salmonella serovars in feces by specific detection of virulence genes, invA and spvC, by an enrichment broth culture-multiplex PCR combination assay.

    Chiu, C H; Ou, J T

    1996-10-01

    In order to make a rapid and definite diagnosis of Salmonella enteritis in children, an enrichment broth culture-multiplex PCR combination assay was devised to identify Salmonella serovars directly from fecal samples. Two pairs of oligonucleotide primers were prepared according to the sequences of the chromosomal invA and plasmid spvC genes. PCR with these two primers would produce either one amplicon (from the invA gene) or two amplicons (from the invA and spvC genes), depending on whether or not the Salmonella bacteria contained a virulence plasmid. The fecal sample was diluted 10- to 20-fold into gram-negative enrichment broth and incubated to eliminate inhibitory compounds and also to allow selective enrichment of the bacteria. One or two amplicons were obtained, the expected result if Salmonella bacteria were present. The detection limit of this PCR was about 200 bacteria per reaction mixture. The primers were specific, as no amplification products were obtained with 18 species and 22 isolates of non-Salmonella bacteria tested which could be present in the feces or cause contamination. In contrast, when 23 commonly seen Salmonella serovars (38 isolates) were tested, all were shown to carry the invA gene and seven concomitantly harbored the spvC gene of the virulence plasmid. This assay was applied to the diagnosis of Salmonella enteritis in 57 children who were suffering from mucoid and/or bloody diarrhea. Of the 57 children, 38 were PCR positive and 22 were culture positive. There were two culture-positive samples that were not detected by PCR. Thus, this PCR assay showed an efficiency of 95% (38 of 40), which is much higher than the 60% (24 of 40) by culture alone. Not only is this method more sensitive, rapid, and efficient but it will cause only an incremental increase in the cost of stool processing, since enrichment cultivation of fecal samples from diarrheal patients using gram-negative enrichment broth is a routine practice for identification in many

  3. Comparison of API 20E and invA PCR for identification of Salmonella enterica isolates from swine production units.

    Nucera, Daniele M; Maddox, Carol W; Hoien-Dalen, Patricia; Weigel, Ronald M

    2006-09-01

    API 20E and invA PCR were evaluated for the identification of Salmonella enterica isolates from swine farms. API 20E had the highest agreement with other tests at the 99.9% likelihood level. Both tests had 100% sensitivity and 96% specificity compared to 16S rRNA sequencing. Compared to serotyping, both tests had 96% sensitivity; specificity was 86% for API 20E and 79% for invA PCR.

  4. Molecular and functional characterization of the Salmonella invasion gene invA: homology of InvA to members of a new protein family.

    Galán, J E; Ginocchio, C; Costeas, P

    1992-07-01

    One of the earliest steps in the pathogenic cycle of the facultative intracellular pathogen Salmonella spp. is the invasion of the cells of the intestinal epithelium. We have previously identified a genetic locus, inv, that allows Salmonella spp. to enter cultured epithelial cells. invA is a member of this locus, and it is the first gene of an operon consisting of at least two additional invasion genes. We have constructed strains carrying nonpolar mutations in invA and examined the individual contribution of this gene to the invasion phenotype of Salmonella typhimurium. Nonpolar S. typhimurium invA mutants were deficient in invasion of cultured epithelial cells although they were fully capable of attaching to the same cells. In addition, unlike wild-type S. typhimurium, invA mutants did not alter the normal architecture of the microvilli of polarized epithelial cells nor did they cause any alterations in the distribution of actin microfilaments of infected cells. The invasion phenotype of invA mutants was readily rescued by wild-type S. typhimurium when cultured epithelial cells were simultaneously infected with both strains. On the contrary, in a similar experiment, the adherent Escherichia coli strain RDEC-1 was not internalized into cultured cells when coinfected with wild-type S. typhimurium. The invA locus was found to be located at about 59 min on the Salmonella chromosome, 7% linked to mutS. The nucleotide sequence of invA showed an open reading frame capable of encoding a polypeptide of 686 amino acids with eight possible membrane-spanning regions and a predicted molecular weight of 75,974. A protein of this size was visualized when invA was expressed in a bacteriophage T7 RNA polymerase-based expression system. The predicted sequence of InvA was found to be homologous to Caulobacter crescentus FlbF, Yersinia LcrD, Shigella flexneri VirH, and E. coli FlhA proteins. These proteins may form part of a family of proteins with a common function, quite possibly

  5. Functional conservation among members of the Salmonella typhimurium InvA family of proteins.

    Ginocchio, C C; Galán, J E

    1995-02-01

    InvA, which is essential for Salmonella spp. to enter cultured epithelial cells, is a member of a family of proteins involved in either flagellar biosynthesis or the secretion of virulence determinants by a number of plant and mammalian pathogens. The predicted overall secondary structures of these proteins show significant similarities and indicate a modular construction with a hydrophobic amino-terminal half, consisting of six to eight potential transmembrane domains, and a hydrophilic carboxy terminus which is predicted to reside in the cytoplasm. These proteins can be aligned over the entire length of their polypeptide sequences, with the highest degree of homology found in the amino terminus and clusters of conserved residues in the carboxy terminus. We examined the functional conservation among members of this protein family by assessing the ability of MxiA of Shigella flexneri and LcrD of Yersinia pseudotuberculosis to restore invasiveness to an invA mutant of Salmonella typhimurium. We found that MxiA was able to complement the entry defect of the invA mutant strain of S. typhimurium. In contrast, LcrD failed to complement the same strain. However, a plasmid carrying a gene encoding a chimeric protein consisting of the amino terminus of LcrD and the carboxy terminus of InvA complemented the defect of the Salmonella invA mutant. These results indicate that the secretory systems in which these proteins participate are functionally similar and that the Salmonella and Shigella systems are very closely related. These data also suggest that determinants of specificity may be located at the carboxy termini of these proteins.

  6. Development of a Novel Quantum Dots and Graphene Oxide Based FRET Assay for Rapid Detection of invA Gene of Salmonella

    Guo, Jiubiao; Chan, Edward W. C.; Chen, Sheng; Zeng, Zhenling

    2017-01-01

    A novel, rapid and simple fluorescence resonance energy transfer (FRET) based Salmonella specific gene, invA, detection system was developed, in which quantum dots (QDs) and graphene oxide (GO) worked as fluorescent donor and quencher, respectively. By measuring the fluorescence intensity signal, the Salmonella specific invA gene could be sensitively and specifically detected with a limit of detection (LOD) of ∼4 nM of the invA gene in 20 min. The developed system has the potential to be used for Salmonella detection in food and environmental samples and further developed into a platform for detection of other bacterial pathogens. PMID:28144237

  7. Detection of Salmonella invA gene in shrimp enrichment culture by polymerase chain reaction.

    Upadhyay, Bishnu Prasad; Utrarachkij, Fuangfa; Thongshoob, Jarinee; Mahakunkijcharoen, Yuvadee; Wongchinda, Niracha; Suthienkul, Orasa; Khusmith, Srisin

    2010-03-01

    Contamination of seafood with salmonellae is a major public health concern. Detection of Salmonella by standard culture methods is time consuming. In this study, an enrichment culture step prior to polymerase chain reaction (PCR) was applied to detect 284 bp fragment of Salmonella invA in comparison with the conventional culture method in 100 shrimp samples collected from four different shrimp farms and fresh food markets around Bangkok. Samples were pre-enriched in non-selective lactose broth (LB) and selective tetrathionate broth (TTB). PCR detection limit was 10 pg and 10(4) cfu/ml of viable salmonellae with 100% specificity. PCR assay detected 19 different Salmonella serovars belonging to 8 serogroups (B, C1, C2-C3, D1, E1, E4 and K) commonly found in clinical and environmental samples in Thailand. The detection rate of PCR following TTB enrichment (24%) was higher than conventional culture method (19%). PCR following TTB, but not in LB enrichment allowed salmonella detection with 84% sensitivity, 90% specificity and 89% accuracy. Shrimp samples collected from fresh food markets had higher levels of contaminated salmonellae than those from shrimp farms. The results indicated that incorporation of an enrichment step prior to PCR has the potential to be applied for detection of naturally contaminated salmonellae in food, environment and clinical samples.

  8. Salmonella typhimurium InvA expression probed with a monoclonal antibody to the C-terminal peptide of InvA.

    Clark, C G; MacDonald, L A; Ginocchio, C C; Galán, J E; Johnson, R P

    1996-03-01

    The Salmonella typhimurium InvA protein is a component of a sec-independent secretion apparatus necessary for full virulence of the bacteria. We generated a monoclonal antibody to the C-terminal portion of the InvA protein that recognized proteins in S. typhimurium and weakly in Y. enterocolitica, but not in several other species of bacteria, including S. flexneri. S. typhimurium grown without agitation produced relatively constant amounts of membrane InvA throughout the growth cycle, whereas bacteria grown with agitation had a sharp increase in the amount of membrane InvA at late exponential phase. Levels of InvA present in Salmonella membranes under some growth conditions do not appear to correlate with levels of invasion under the same conditions.

  9. The distribution of invA, pagC and spvC genes among Salmonella isolates from animals.

    Nolan, L K; Giddings, C W; Brown, J

    1995-01-01

    New molecular diagnostic techniques often rely on hybridization or amplification of specific DNA regions to detect pathogenic bacteria. The choice of genes to be used as probes or as the targets of amplification techniques is critical to the success of these procedures. The genes so used might best be those associated with virulent isolates and having a wide distribution among such isolates. In this study three genes, invA, pagC and spvC, thought to be associated with the virulence of salmonellae, were labelled and used to probe the total DNA from 103 Salmonella isolates from animals in an attempt to determine whether these genes might be useful in diagnostic procedures. pagC was detected in 99% of the Salmonella tested, and invA was detected in 94.2% of the isolates. Both pagC and invA were detected with a significantly higher frequency than spvC in isolates from chickens and swine, but no significant difference in detection of these three genes occurred when bovine isolates were examined. Failure to detect any of these genes occurred in only one isolate. Isolates from apparently healthy or from clinically ill chickens and swine could not be distinguished by detecting these three genes. The genes were not detected in the non-Salmonella strains tested. These results suggest that, of these three genes, pagC may be the best choice for use as a probe or polymerase chain reaction target in future detection protocols.

  10. Detection of Salmonella species in chicken carcasses using genus specific primer belong to invA gene in Sohag city, Egypt

    Abdel-Aziz, Nahed Mahmoud

    2016-01-01

    Aim: This study aimed to detect Salmonella species found as contaminants in chicken carcass (thigh, breast, wings, liver, and gizzard). Materials and Methods: A total of 75 chicken samples including thigh, breast, wings, liver, and gizzard (15 of each) were collected from different markets in Sohag city for detection of Salmonella species by culture methods, biochemical tests, serology, and polymerase chain reaction. Results: The overall incidence of Salmonella contamination of 75 examined samples was found to be 6.6% with the higher percentage of Salmonella being isolated from liver samples (13.3%) followed by thigh, wings, gizzard (6.6%) while breast show negative result. Conclusion: Results in this study indicate that contamination of chicken carcass with Salmonella needs strict hygienic measures to prevent their transmission to human. PMID:27847423

  11. Detection of Salmonella species in chicken carcasses using genus specific primer belong to invA gene in Sohag city, Egypt

    Nahed Mahmoud Abdel-Aziz

    2016-10-01

    Full Text Available Aim: This study aimed to detect Salmonella species found as contaminants in chicken carcass (thigh, breast, wings, liver, and gizzard. Materials and Methods: A total of 75 chicken samples including thigh, breast, wings, liver, and gizzard (15 of each were collected from different markets in Sohag city for detection of Salmonella species by culture methods, biochemical tests, serology, and polymerase chain reaction. Results: The overall incidence of Salmonella contamination of 75 examined samples was found to be 6.6% with the higher percentage of Salmonella being isolated from liver samples (13.3% followed by thigh, wings, gizzard (6.6% while breast show negative result. Conclusion: Results in this study indicate that contamination of chicken carcass with Salmonella needs strict hygienic measures to prevent their transmission to human.

  12. Detection of Salmonella in Shellfish Using SYBR Green™ I-Based Real-Time Multiplexed PCR Assay Targeting invA and spvB

    Gangwar, Maulshree

    2012-09-23

    A SYBR Green™ I-based real-time multiplexed PCR assay was developed targeting invA and spvB for the detection of Salmonella strains in shellfish after both hns and invA genes were identified in all Salmonella strains. Simultaneously, the 16S rRNA gene was used as a PCR internal amplification control (IAC). All 89 Salmonella strains tested in this study exhibited amplification of invA, whereas only 21 (23. 6 %) were PCR positive for spvB. The sensitivity of detection of all three targeted genes was 1 ng, which is equivalent to approximately 105 colony-forming unit (CFU) of Salmonella enterica. The analysis showed specific PCR products that were identified by reproducible melt temperature profiles (invA, 84. 27 ± 1. 7 °C; spvB, 88. 76 ± 1. 0 °C; and 16S rRNA gene, 87. 16 ± 0. 8 °C). The sensitivity of detection was 10 pg purified DNA (invA) or 105 CFU in 1 mL pure culture of S. enterica ATCC 14028. The above molecular detection method for Salmonella strains was successfully applied to the oyster homogenates (food matrix). An initial inoculum of 106 and 102 CFU Salmonella in 1 ml seeded oyster tissue homogenate was detected by multiplexed PCR for all three genes after 5 and 24 h of enrichment, respectively. Natural oysters isolated from Gulf of Mexico during the winter months exhibited negative PCR amplification results suggesting the absence of Salmonella. In contrast to conventional PCR, real-time multiplex PCR assay developed in this study is rapid and sensitive and will help Interstate Shellfish Sanitation Conference undertake appropriate measures to monitor Salmonella in oysters, thereby preventing disease outbreaks and consequently protecting consumer health. © 2012 Springer Science+Business Media, LLC.

  13. Detection of Salmonella invA by isothermal and chimeric primer-initiated amplification of nucleic acids (ICAN) in Zambia.

    Isogai, Emiko; Makungu, Chitwambi; Yabe, John; Sinkala, Patson; Nambota, Andrew; Isogai, Hiroshi; Fukushi, Hideto; Silungwe, Manda; Mubita, Charles; Syakalima, Michelo; Hang'ombe, Bernard Mudenda; Kozaki, Shunji; Yasuda, Jun

    2005-01-01

    The isothermal and chimeric primer-initiated amplification of nucleic acids (ICAN) is a new isothermal DNA amplification method composed of exo Bca DNA polymerase, RNaseH and DNA-RNA chimeric primers. We detected invA of Salmonella from chicken carcasses, egg yolk and cattle fecal samples. Fifty-three of 59 isolates were invA-positive in ICAN-chromatostrip detection. The result was consistent with those obtained by standard PCR. Salmonella invA was detected in 12 of 14 carcass rinses by ICAN, while in 7 of 14 rinses by standard PCR. These results indicate that ICAN is an efficient, sensitive and simple system to detect invA of Salmonella species in developing countries such as Zambia.

  14. Real-time reverse-transcriptase polymerase chain reaction for the rapid detection of Salmonella using invA primers.

    D'Souza, Doris H; Critzer, Faith J; Golden, David A

    2009-11-01

    Recent outbreaks of Salmonella linked to fresh produce emphasize the need for rapid detection methods to help control the spread of disease. Reverse-transcriptase polymerase chain reaction (RT-PCR) can detect the presence of mRNA (shorter half-life than DNA) with greater potential for detecting viable pathogens. The chromosomally located invA gene required for host invasion by Salmonella is widely used for detection of this pathogen by PCR. Detection of Salmonella was undertaken by real-time RT-PCR (rt-RT-PCR) using newly designed invA gene primers to develop a sensitive and specific assay. Salmonella serovars Typhimurium and Enteritidis were grown (7.68 log(10) CFU/mL) in Luria-Bertani broth overnight at 37 degrees C, and RNA was extracted, followed by rt-RT-PCR with and without SYBR green I and agarose gel electrophoresis. All experiments were replicated at least thrice. Detection for both serovars using traditional RT-PCR was lower ( approximately 10(5) CFU/mL) than rt-RT-PCR (10(3) CFU/mL) by gel electrophoresis. Melt curve analysis showed melt temperatures at 87.5 degrees C with Ct values from 12 to 15 for up to 10(3) CFU/mL and improved to 10(2) CFU/mL after further optimization. Further, addition of RNA internal amplification control constructed using in vitro transcription with a T7 RNA polymerase promoter, to the RT-PCR assay also gave detection limits of 10(2) CFU/mL. Cross-reactivity was not observed against a panel of 21 non-Salmonella bacteria. Heat-inactivated (autoclaved) Salmonella showed faint or no detection by rt-RT-PCR or gel electrophoresis. This method has potential to be applied for the detection of Salmonella serovars in fresh produce and the simultaneous detection of foodborne viral (RNA viruses) and bacterial pathogens in a multiplex format.

  15. The use of a PCR-generated invA probe for the detection of Salmonella spp. in artificially and naturally contaminated foods.

    Bülte, M; Jakob, P

    1995-08-01

    Part of the invasion A gene (invA) of slamonellae (Rahn et al., 1992) was amplified and labelled simultaneously with digoxigenin by the polymerase chain reaction (PCR). This was used as gene probe for a colony hybridization assay which included nitrocellulose filter incubation on modified Rambach agar. 312 Salmonella and 268 non-Salmonella strains were hybridized with the invA probe. No false-negative or false-positive results were obtained. In 11 beef samples, which had been contaminated artificially with Salmonella, the test strain was recovered quantitatively with the invA probe. Salmonellae could be detected in 29 samples of 104 further foods of animal origin by means of the gene probe assay in contrast to 27 samples which were positive by the standard method. The invA probe assay allows for the quantitative estimation of Salmonella in fresh meat samples within 48 h. However, with frozen samples a pre-enrichment step is necessary.

  16. Distribution of the invA, -B, -C, and -D genes of Salmonella typhimurium among other Salmonella serovars: invA mutants of Salmonella typhi are deficient for entry into mammalian cells.

    Galán, J E; Curtiss, R

    1991-09-01

    Invasion of intestinal epithelial cells is an essential virulence factor of salmonellae. A group of genes, invABC and invD, that allow Salmonella typhimurium to penetrate cultured epithelial cells have previously been characterized (J. E. Galán and R. Curtiss III, Proc. Natl. Acad. Sci. USA 86:6383-6387, 1989). The distribution of these genes among Salmonella isolates belonging to 37 different species or serovars was investigated by Southern and colony blot hybridization analyses. Regions of high sequence similarity to the invABC genes were present in all Salonella isolates examined, while regions of sequence similarity to the invD gene were present in all but one (S. arizonae) of the isolates tested, with little restriction fragment length polymorphism. Sequences similar to these genes were not detected in strains of Escherichia coli, Yersinia spp., or Shigella spp. invA mutants (unable to express the invABC genes) of several Salmonella species or serovars, including S. typhi, were constructed and examined for their ability to penetrate Henle-407 cells. All mutants were deficient for entry into cultured epithelial cells, indicating that the invABC genes were not only present in these strains but also functional.

  17. Virulence determinants invA and spvC in salmonellae isolated from poultry products, wastewater, and human sources.

    Swamy, S C; Barnhart, H M; Lee, M D; Dreesen, D W

    1996-10-01

    The presence of two virulence foci, invA and spvC, in Salmonella isolates obtained from poultry, wastewater, and human sources was determined. All isolates (n = 245) were positive for the invA gene sequence. Differences in degree of invasiveness were apparent with the Madin Darby canine kidney cell line, as only 79 of 159 randomly selected isolates (49.7%) tested were invasive at > 0.1% of the inoculum. 25% were invasive between 0.1 and 1.0% of the inoculum, and 24.5% were invasive at > 1.0% of the inoculum. There was a significant correlation between degree of invasion and source from which the isolate was recovered but no correlation between geographic origin of poultry isolates and degree of invasion. Only 37 of 245 isolates (15.1%) hybridized with the spvC DNA probe. All isolates that were recovered from a commercial egg production environment and chicken eggs and whose sequences exhibited homology with the spvC gene sequence were determined to be either Salmonella enteritidis PT 23 or PT 13. The sequences of few isolates from ceca and none from wastewater or humans demonstrated homology with the spvC gene.

  18. Influence of temperature and predation on survival of Salmonella enterica serovar Typhimurium and expression of invA in soil and manure-amended soil.

    García, R; Baelum, J; Fredslund, L; Santorum, P; Jacobsen, C S

    2010-08-01

    The effects of three temperatures (5, 15, and 25 degrees C) on the survival of Salmonella enterica serovar Typhimurium in topsoil were investigated in small microcosms by three different techniques: plate counting, invA gene quantification, and invA mRNA quantification. Differences in survival were related to the effect of protozoan predation. Tetracycline-resistant Salmonella serovar Typhimurium was inoculated into soil and manure-amended soil at 1.5 x 10(8) cells g soil(-1). Population densities were determined by plate counting and by molecular methods and monitored for 42 days. Simultaneous extraction of RNA and DNA, followed by quantitative PCR, was used to investigate invA gene levels and expression. Analysis by these three techniques showed that Salmonella serovar Typhimurium survived better at 5 degrees C. Comparing DNA and CFU levels, significantly higher values were determined by DNA-based techniques. invA mRNA levels showed a fast decrease in activity, with no detectable mRNA after an incubation period of less than 4 days in any of the soil scenarios. A negative correlation was found between Salmonella serovar Typhimurium CFU levels and protozoan most probable numbers, and we propose the role of the predator-prey interaction as a factor to explain the die-off of the introduced strain by both culture- and DNA quantification-based methods. The results indicate that temperature, manure, and protozoan predation are important factors influencing the survival of Salmonella serovar Typhimurium in soil.

  19. Crystal structure of the C-terminal domain of the Salmonella type III secretion system export apparatus protein InvA.

    Worrall, Liam J; Vuckovic, Marija; Strynadka, Natalie C J

    2010-05-01

    InvA is a prominent inner-membrane component of the Salmonella type III secretion system (T3SS) apparatus, which is responsible for regulating virulence protein export in pathogenic bacteria. InvA is made up of an N-terminal integral membrane domain and a C-terminal cytoplasmic domain that is proposed to form part of a docking platform for the soluble export apparatus proteins notably the T3SS ATPase InvC. Here, we report the novel crystal structure of the C-terminal domain of Salmonella InvA which shows a compact structure composed of four subdomains. The overall structure is unique although the first and second subdomains exhibit structural similarity to the peripheral stalk of the A/V-type ATPase and a ring building motif found in other T3SS proteins respectively.

  20. Synergistic effect of mutations in invA and lpfC on the ability of Salmonella typhimurium to cause murine typhoid.

    Bäumler, A J; Tsolis, R M; Valentine, P J; Ficht, T A; Heffron, F

    1997-06-01

    Penetration of the intestinal mucosa at areas of Peyer's patches is an important first step for Salmonella typhimurium to produce lethal systemic disease in mice. However, mutations in genes that are important for intestinal invasion result in only moderately decreased virulence of S. typhimurium for mice. Here we report that combining mutations in invA and lpfC, two genes necessary for entry into Peyer's patches, results in a much stronger attenuation of S. typhimurium than inactivation of either of these genes alone. An S. typhimurium invA lpfC mutant was 150-fold attenuated by the oral route of infection but was fully virulent when the intestine was bypassed by intraperitoneal challenge of mice. During mixed-infection experiments, the S. typhimurium invA lpfC mutant showed a strong defect in colonizing Peyer's patches and mesenteric lymph nodes. These data suggest that mutations in invA and lpfC deactivate distinct pathways for intestinal penetration and colonization of Peyer's patches. While the inv-mediated pathway is widely distributed, the lpf operon is absent from many phylogenetic groups within the genus Salmonella. To investigate how acquisition of the lpf-mediated pathway for mucosal penetration contributed to evolution of virulence, we studied the relationship between the presence of the lpf operon and the pathogenicity for mice of 18 isolates representing 14 Salmonella serotypes. Only strains possessing the lpf operon were able to cause lethal infection in mice. These data show that both the invA- and lpfC-mediated pathways of intestinal perforation are conserved in mouse virulent Salmonella serotypes.

  1. Detection of live Salmonella sp. cells in produce by a TaqMan-based quantitative reverse transcriptase real-time PCR targeting invA mRNA.

    González-Escalona, Narjol; Hammack, Thomas S; Russell, Mindi; Jacobson, Andrew P; De Jesús, Antonio J; Brown, Eric W; Lampel, Keith A

    2009-06-01

    Salmonella enterica contamination in foods is a significant concern for public health. When DNA detection methods are used for analysis of foods, one of the major concerns is false-positive results from the detection of dead cells. To circumvent this crucial issue, a TaqMan quantitative real-time RT-PCR (qRT-PCR) assay with an RNA internal control was developed. invA RNA standards were used to determine the detection limit of this assay as well as to determine invA mRNA levels in mid-exponential-, late-exponential-, and stationary-phase cells. This assay has a detection limit of 40 copies of invA mRNA per reaction. The levels of invA mRNA in mid-exponential-, late-exponential-, and stationary-phase S. enterica cells was approximately 1 copy per 3 CFU, 1 copy per CFU, and 4 copies per 10(3) CFU, respectively. Spinach, tomatoes, jalapeno peppers, and serrano peppers were artificially contaminated with four different Salmonella serovars at levels of 10(5) and less than 10 CFU. These foods were analyzed with qRT-PCR and with the FDA's Bacteriological Analytical Manual Salmonella culture method (W. A. Andrews and T. S. Hammack, in G. J. Jackson et al., ed., Bacteriological analytical manual online, http://www.cfsan.fda.gov/ approximately ebam/bam-5.html, 2007). Comparable results were obtained by both methods. Only live Salmonella cells could be detected by this qRT-PCR assay, thus avoiding the dangers of false-positive results from nonviable cells. False negatives (inhibition of the PCR) were also ruled out through the use of an RNA internal control. This assay allows for the fast and accurate detection of viable Salmonella spp. in spinach, tomatoes, and in both jalapeno and serrano peppers.

  2. Inv A gene specific PCR for detection of Salmonella from broilers

    Thenmozhi Velayutham

    Full Text Available Poultry meat has been identified as one of the principal foodborne source of Salmonella. In this preliminary study the prevalence of Salmonella spp. contamination of broiler carcasses, were determined. Sixty samples were collected from poultry carcasses from the commercial broiler slaughtering facility in Namakkal, Tamil Nadu. The presence of Salmonella spp in collected samples was assessed by performing the pre-enrichment and enrichment culture, followed by PCR assay. The primers were selected from the invA gene specific for the detection of Salmonella spp. In this study 8.3% of poultry carcasses were found to be contaminated with Salmonella spp. In order to provide a more accurate profile of the prevalence of Salmonella spp in broiler carcasses, it is pertinent to use inv A gene specific PCR method that could be considered as an appropriate alternative to conventional culture method. [Vet. World 2011; 4(12.000: 562-564

  3. An evaluation of conventional culture, invA PCR, and the real-time PCR iQ-Check kit as detection tools for Salmonella in naturally contaminated premarket and retail turkey.

    Nde, Chantal W; Fakhr, Mohamed K; Doetkott, Curt; Logue, Catherine M

    2008-02-01

    This study was aimed at comparing the ability of conventional culture, the iQ-Check real-time PCR kit, and invA PCR to detect Salmonella in naturally contaminated premarket and retail turkey parts. Premarket (n = 120) turkey parts collected from a commercial turkey processing plant, and retail turkey parts (n = 138) were examined. Both PCR methods detected a significantly greater (P invA PCR for Salmonella detection in the premarket and retail parts, the indices of total agreement were 75.8% (95% CI: 67.2, 83.2) and 84.1% (95% CI: 76.9, 89.7), respectively. The rates of false positives (premarket: 31.9%, retail: 9.7%) and false negatives (premarket: 5.9%, retail: 9.7%) were determined between the culture method and the iQ-Check kit. When invA PCR was compared with the culture method, the rates of false positives (premarket: 37.7%, retail: 11.1%) and false negatives (premarket: 5.9%, retail: 18.3%) were obtained. The higher total agreement and the lower rates of both false positives and false negatives for the iQ-Check kit compared with invA PCR for both premarket and retail turkey parts corroborates the use of the iQ-Check kit as a screening tool for Salmonella in poultry meat.

  4. Comparison of DNA isolation methods and detection of Salmonella spp. from animal faeces and dust using invA real-time PCR.

    Braun, Sascha D; Methner, Ulrich

    2011-01-01

    There is a strong interest to reduce the expenditure for the detection of Salmonella spp. from animal faeces and environmental samples from primary production according to ISO 6579:2002 Annex D by including a rapid and effective method to detect Salmonella spp. already after pre-enrichment in BPW. It has been shown that real-time PCR methods are very effective to detect Salmonella organisms after pre-enrichment of foods. However, materials from primary animal production compose of much higher amounts of substances which might inhibit the sensitivity of real-time PCR. Different techniques of DNA isolation after pre-enrichment of artificially inoculated bovine faecal material were used to compare their detection limit and detection probability using an invA 5' nuclease real-time PCR approach. A detection probability of 100% was shown at 10(5) cfu/ml using the QIAamp DNA Stool Mini Kit (Qiagen, Germany), at 10(4) cfu/ml using the High Pure PCR Template Preparation Kit (Roche, Germany) and at 10(3) cfu/ml using thermal cell lysis or an in-house lab protocol, respectively. In comparison DNA isolation by thermal cell lysis revealed a very good detection limit, low costs and almost no risks of contamination. Furthermore, caecal contents from pigs were analysed by ISO 6579:2002 Annex D and the invA real-time PCR using thermal cell lysis for DNA extraction. As a result neither false positive nor false negative findings were obtained. Inclusion of the real-time PCR after pre-enrichment of samples in BPW followed by bacterial detection of Salmonella only with samples positive with real-time PCR might be a valuable tool to fulfil the international standard of ISO 6579:2002 Annex D but also to diminish the expenditures. However, it must be stated that the modification of an international standard method and its use in routine diagnostic requires the validation and registration of national and/or international competent authorities.

  5. 猪胆囊中沙门菌L型的分离培养与invA基因检测%Isolation and invA Gene Detection of Salmonella L-forms in pig gallbladder

    佘晓玲; 王涛; 丁文静; 吴文娟; 潘耀振; 汤可立; 王丹霓; 王和

    2015-01-01

    To understand the situation of Salmonella L-forms within pig gallbladder,the samples of 970 gallbladder tissues and bile were collected from the healthy pigs at the slaughter house in Guiyang city,and Salmonella spp.and the bacterial L-forms were isolated from the gallbladders by the routine bacteriologi-cal method and the non-high osmotic isolation technique.The L-forms derived from Salmonella spp.in the stable L-form isolates were identified by PCR with the primers of Salmonella specific gene invA,and the positive products of PCR were analyzed by DNA sequencing.The results showed that no any bacterial form of Salmonella spp.was isolated from 970 samples of the pig gallbladder,but the positive rate of the bacteri-al L-form was for 8.25% in the specimens.The positive rate of gene assay for Salmonella invA was for 5.15% in the 970 specimens or for 62.50% in the stable L-form positive isolates.This research provide the basic epidemiological data and inspection of Salmonella L-form infections in pig gallbladder.%为了解猪胆囊中沙门菌 L型携带情况,在贵阳市屠宰场采集970例健康生猪的胆囊组织与胆汁标本,用常规细菌学方法和非高渗分离培养法分离沙门菌及其细菌 L型,用 PCR和核酸序列分析方法对稳定L型纯培养物进行沙门菌的invA基因检测。结果显示,970例生猪胆囊标本未检出沙门菌细菌型,细菌L型检出率为8.25%;80例细菌L型分离物中有50例invA检测阳性,占5.15%;占细菌 L型阳性分离物62.50%。研究结果为生猪胆囊沙门菌 L型感染的流行病学及其检查提供了依据。

  6. Quinolone-resistance in Salmonella is associated with decreased mRNA expression of virulence genes invA and avrA, growth and intracellular invasion and survival.

    Wang, Yu-Ping; Li, Lin; Shen, Jian-Zhong; Yang, Fu-Jiang; Wu, Yong-Ning

    2009-02-01

    A variety of environmental factors, such as oxygen, pH, osmolarity and antimicrobial agents, modulate the expression of Salmonella pathogenicity islands (SPI) genes. This study investigated SPI-1 gene expression and the pathogenicity of quinolone-resistant Salmonella. mRNA expression levels of the invA and avrA genes, located in SPI-1, in quinolone-susceptible and quinolone-resistant Salmonella strains were determined using real-time fluorescent quantitative reverse transcription-polymerase chain reaction (RT-PCR). Twenty-five quinolone-resistant Salmonella mutants were derived from quinolone-susceptible strains by multiple-passage selection through increasing concentrations of ciprofloxacin in vitro, while an additional 15 strains were quinolone-resistant Salmonella clinical isolates. Sequence analysis showed no gene deletion or point mutations of nine SPI-1 genes (including invA and avrA) occurred in either the selected or clinical quinolone-resistant strains, while a single gyrA point mutation (S83F) was observed in all 40 quinolone-resistant strains. The mRNA expression levels of invA and avrA were significantly decreased (P<0.005) in quinolone-resistant strains (clinically acquired or experimentally selected in vitro), compared to the quinolone-susceptible strains. The resistant strains also had a slower growth rate combined with decreased epithelial cell invasion and intracellular replication in epithelial cells and macrophages. The results suggest that quinolone-resistance may be associated with lower virulence and pathogenicity than in quinolone-susceptible strains.

  7. 肉制品中沙门氏菌invA基因实时荧光定量PCR检测方法的建立%Establishment of real-time fluorescent PCR detection method of invA gene in salmonella

    杜雄伟; 李叶; 冮洁; 胡文忠; 武晓松

    2013-01-01

    针对沙门氏菌invA基因设计一对特异引物,建立SYBR Green实时荧光定量PCR检测方法,并进行特异性、敏感性、重复性检测.结果表明,所建立的沙门氏菌实时荧光定量PCR检测方法,特异性良好,组间组内重复性良好,沙门氏菌检测下线为101CFU/mL.本研究建立了沙门氏菌特异、敏感、快速的实时荧光定量PCR检测方法,为沙门氏菌的快速诊断奠定了基础.%A pair of specific primers was designed according to invA gene of salmonella.The SYBR Green realtime PCR method for detecting salmonella was established.The specificity,sensitivity and repeatability of this method was analyzed.The result showed that this method were good specificity and repeatability,the detection of salmonella minimum copy number was 1× 10CFU/mL.Therefore,the study established the salmonella specific,sensitive and rapid real-time fluorescence PCR detection method.

  8. Rapid and specific detection of Salmonella in water samples using real-time PCR and High Resolution Melt (HRM) curve analysis.

    van Blerk, G N; Leibach, L; Mabunda, A; Chapman, A; Louw, D

    2011-01-01

    A real-time PCR assay combined with a pre-enrichment step for the specific and rapid detection of Salmonella in water samples is described. Following amplification of the invA gene target, High Resolution Melt (HRM) curve analysis was used to discriminate between products formed and to positively identify invA amplification. The real-time PCR assay was evaluated for specificity and sensitivity. The assay displayed 100% specificity for Salmonella and combined with a 16-18 h non-selective pre-enrichment step, the assay proved to be highly sensitive with a detection limit of 1.0 CFU/ml for surface water samples. The detection assay also demonstrated a high intra-run and inter-run repeatability with very little variation in invA amplicon melting temperature. When applied to water samples received routinely by the laboratory, the assay showed the presence of Salmonella in particularly surface water and treated effluent samples. Using the HRM based assay, the time required for Salmonella detection was drastically shortened to less than 24 h compared to several days when using standard culturing methods. This assay provides a useful tool for routine water quality monitoring as well as for quick screening during disease outbreaks.

  9. Construction of recombinant plasmid of invA gene of Salmonella%沙门氏菌invA基因重组质粒标准的构建

    李正义; 梁成珠; 贾俊涛; 姜英辉; 孙涛; 王宇; 雷质文

    2014-01-01

    Objective To construct recombinant plasmid of invA gene as standard for the detection of Sal-monella by molecular biology methods. Methods The target segment was amplified by PCR and cloned into pMD 18-T vector, then transformed into Escherichia coli DH5α. The recombinant plasmid was identified by se-quencing. The value of standard plasmid was defined by PicoGreen DNA fluorescence quantitative method. Results The target segment was successfully recombined into pMD 18-T vector with correct sequences. The re-sults of the real-time quantitative PCR showed that the recombinant plasmid for the positive detection in Salmo-nella was validated. The concentration was 2.9μg/mL. Conclusion The recombinant plasmid of invA gene has been successfully constructed, which has established the foundation for the rapid detection of Salmonella.%目的:研制沙门氏菌 invA 基因重组质粒,为分子生物学方法快速检测沙门氏菌提供质粒标准。方法通过PCR扩增目的片段,连接至pMD 18-T载体,转化大肠杆菌DH5α,测序方法证实目的片段已成功重组,荧光定量 PCR方法定性检测分析,采用 PicoGreen DNA分子荧光定量方法对标准质粒分子进行定值。结果 invA基因目的片段成功重组至 pMD 18-T载体上,荧光定量 PCR结果显示制备重组质粒标准为沙门氏菌核酸标准,重组质粒标准的浓度为2.9μg/mL。结论成功构建沙门氏菌invA基因重组质粒,为快速检测沙门氏菌奠定了基础。

  10. Improvement of an invA-based PCR for the specific detection of Salmonella typhimurium in organs of pigs.

    Scholz, H C; Arnold, T; Marg, H; Rösler, U; Hensel, A

    2001-01-01

    The aim of this study was to investigate the suitability of the invA-based polymerase chain reaction (PCR) assay for the specific detection of Salmonella in organs of experimentally infected pigs and to compare these results to classical bacterial culture. While the PCR conditions specified in the "Deutsche Industrie Norm", DIN 10135 (section 35 LMBG, 1999), cutle based on the publication of Rahn et al. 1992, revealed various unspecific amplification products, modifications of the PCR conditions allowed the specific amplification of the invA fragment from inner organs. The modified PCR assay correlates exactly with cultivation results (as required by DIN Norm 6579) and enables the detection of Salmonella within 48 hours with equal sensitivity compared to routine cultivation.

  11. Effects of quinolones on the expressions of Salmonella pathogenicity genes hilA and invA mRNA%喹诺酮对沙门菌毒力基因hilA和invA的mRNA表达水平的影响

    王玉平; 沈建忠

    2012-01-01

    目的:研究喹诺酮对沙门菌毒力岛基因hilA和invA的mRNA表达水平的影响.方法:用多阶段诱导方式体外筛选耐喹诺酮沙门菌株,用荧光定量PCR方法测定喹诺酮敏感株和耐药株的hilA和invA基因的mRNA表达水平.结果:与喹诺酮敏感株相比,喹诺酮耐药株的hilA和invA的mRNA的表达水平显著降低(P<0.01).结论:喹诺酮可导致沙门菌毒力相关基因表达水平降低,这意味着喹诺酮耐药株毒力和致病性的降低.%Objective To investigate the effects of quinolones on the expressions of SPI-1 genes hilA and invA mRNA. Methods Quinolone-resistant Salmonella mutants were obtained from quinolone-susceptible strains by multiple-passage induction with increasing concentrations of ciprofloxacin in vitro. The expressions of hilA and invA genes mRNA were determined by real-time fluorescent quantitative RT-PCR in quinolone-susceptible and-resistant Salmonella strains. Results The expressions of hilA and invA gene mRNA were significantly decreased in quinolone-resistant strains (clinically acquired or drug-induced in vitro) than those in quinolone-susceptible strains (P < 0.01). Conclusion Suppressed expression of virulence-associated genes of quinolone-resistant salmonella strains suggests reduced virulence and pathogenicity of these bacteria.

  12. Subcellular localization of rickettsial invasion protein, InvA.

    Gaywee, Jariyanart; Sacci, John B; Radulovic, Suzana; Beier, Magda S; Azad, Abdu F

    2003-01-01

    To understand further the molecular basis of rickettsial host cell invasion, Rickettsia prowazekii invasion gene homolog (invA) has been characterized. Our previous experiments have shown that InvA is an Ap5A pyrophosphatase, a member of the Nudix hydrolase family, which is up-regulated during the internalization, early growth phase, and exit steps during rickettsial mammalian cell infection. In addition to the molecular characterization, subcellular localization of InvA was investigated. InvA-specific antibodies were raised in mice and used for immunoelectron microscopy. The generated antibodies were shown to recognize InvA and by immunogold labeling showed InvA in the cytoplasm of rickettsiae. A cytoplasmic location for InvA would allow for a rapid response to any internal substance and efficient functioning in hydrolysis of toxic metabolic by-products that are accumulated in the rickettsial cytoplasm during host cell invasion. Protecting bacteria from a hazardous environment could enhance their viability and allow them to remain metabolically active, which is a necessary step for the rickettsial obligate intracellular lifestyle.

  13. Rapid Detection of Salmonella in Food and Beverage Samples by Polymerase Chain Reaction

    Radji, M.

    2010-01-01

    Full Text Available Polymerase chain reaction (PCR assay had been used to detect Salmonella in food and beverage samples using suitable primers which are based on specific invA gene of Salmonella. Twenty nine samples were collected from street food counters and some canteens in Margonda Street, Depok, West Java, Indonesia. It was found that five of twenty nine samples were detected to contain Salmonella and showed the presence of the amplified product of the size 244 bp. The method of PCR demonstrated the specificity of invA primers for detection of Salmonella as confirmed by biochemical and serological assay. The results of this study revealed that PCR was a rapid and useful tool for detection of Salmonella in food and beverage samples.

  14. SPECIFIC CONTROL OF SALMONELLA IN POULTRY

    Pimenov N.V.

    2013-11-01

    Full Text Available Scientifically based and clinically validated new tools and methods to combat Salmonella infection in poultry, allowing to ensure the safety and health safety products - eggs and poultry meat. The method of selective decontamination involves the use of bivalent bacteriophage that is based on highly selected phages Phagum Salmonella typhimurium and Phagum Salmonella enteritidis, as well as probiotic laktobifadola. The developed tools and methods of selective decontamination followed by immunization with inactivated vaccine associated "Virosalm" allows you to eliminate salmonella infection in poultry.

  15. RAPID DETECTION OF Salmonella IN SHRIMP BY POLYMERASE CHAIN REACTION [Deteksi Cepat Salmonella pada Udang dengan Polymerase Chain Reaction

    Ulfah Amalia

    2014-06-01

    Full Text Available Shrimp is an important non-oil commodity for foreign trade in Indonesia. However, rejection of shrimp exports by the importing countries is still commonly encountered. In 2011, the USFDA recorded two cases of Salmonella spp. contamination in shrimp products from two shrimp processing companies in Indonesia. Analysis of Salmonella spp. in seafood is generally performed using a conventional method which takes at least 5 days. The objective of the study is to get a Salmonellae rapid detection method in shrimp by PCR. In this study, optimization of PCR protocol method to detect Salmonella invA gene was conducted using six different annealing temperatures (59, 59.5, 60.8, 62, 64 and 64.5°C. The results showed that 64°C was the optimum annealing temperature to detect the 284 bp fragment of Salmonella invA gene. The PCR based detection method has a DNA detection limit of 27.81ug/mL and 10°CFU/mL of viable salmonellae with 100% specificity. The PCR protocol is capable of detecting six different Salmonella serovars (S. Enteritidis, S. Hadar, S. Heidelberg, S. Kentucky, S. Paratyphi and S. Typhimurium but none of the non salmonellae isolates. Application of the PCR assay on Salmonella in shrimp after the selective enrichment step suggested that all 16 samples were positive for Salmonella. At the same time, the conventional method could only detected 3 samples for Salmonella positive.

  16. Virulence genes detection of Salmonella serovars isolated from pork and slaughterhouse environment in Ahmedabad, Gujarat

    J. H. Chaudhary

    2015-01-01

    Full Text Available Aim: The aim was to detect virulence gene associated with the Salmonella serovars isolated from pork and Slaughterhouse environment. Materials and Methods: Salmonella isolates (n=37 used in this study were isolated from 270 pork and slaughter house environmental samples collected from the Ahmedabad Municipal Corporation Slaughter House, Ahmedabad, Gujarat, India. Salmonella serovars were isolated and identified as per BAM USFDA method and serotyped at National Salmonella and Escherichia Centre, Central Research Institute, Kasauli (Himachal Pradesh, India. Polymerase chain reaction technique was used for detection of five genes, namely invA, spvR, spvC, fimA and stn among different serovars of Salmonella. Results: Out of a total of 270 samples, 37 (13.70% Salmonella were isolated with two serovars, namely Enteritidis and Typhimurium. All Salmonella serovars produced 284 bp invA gene, 84 bp fimA and 260 bp amplicon for enterotoxin (stn gene whereas 30 isolates possessed 310 bp spvR gene, but no isolate possessed spvC gene. Conclusion: Presence of invA, fimA and stn gene in all isolates shows that they are the specific targets for Salmonella identification and are capable of producing gastroenteric illness to humans, whereas 20 Typhimurium serovars and 10 Enteritidis serovars can able to produce systemic infection.

  17. Evaluation of different analysis and identification methods for Salmonella detection in surface drinking water sources

    Hsu, Bing-Mu, E-mail: bmhsu@ccu.edu.tw [Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC (China); Huang, Kuan-Hao; Huang, Shih-Wei [Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC (China); Tseng, Kuo-Chih [Department of Internal Medicine, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, ROC (China); Su, Ming-Jen [Department of Clinical Pathology, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, ROC (China); Lin, Wei-Chen; Ji, Dar-Der [Research and Diagnostic Center, Centers for Disease Control, Taipei, Taiwan, ROC (China); Shih, Feng-Cheng; Chen, Jyh-Larng [Department of Environmental Engineering and Health, Yuanpei University of Science and Technology, HsinChu, Taiwan, ROC (China); Kao, Po-Min [Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC (China)

    2011-09-15

    The standard method for detecting Salmonella generally analyzes food or fecal samples. Salmonella often occur in relatively low concentrations in environmental waters. Therefore, some form of concentration and proliferation may be needed. This study compares three Salmonella analysis methods and develops a new Salmonella detection procedure for use in environmental water samples. The new procedure for Salmonella detection include water concentration, nutrient broth enrichment, selection of Salmonella containing broth by PCR, isolation of Salmonella strains by selective culture plates, detection of possible Salmonella isolate by PCR, and biochemical testing. Serological assay and pulsed-field gel electrophoresis (PFGE) can be used to identify Salmonella serotype and genotype, respectively. This study analyzed 116 raw water samples taken from 18 water plants and belonging to 5 watersheds. Of these 116, 10 water samples (8.6%) taken from 7 water plants and belonging to 4 watersheds were positive for a Salmonella-specific polymerase chain reaction targeting the invA gene. Guided by serological assay results, this study identified 7 cultured Salmonella isolates as Salmonella enterica serovar: Alnaby, Enteritidis, Houten, Montevideo, Newport, Paratyphi B var. Java, and Victoria. These seven Salmonella serovars were identified in clinical cases for the same geographical areas, but only one of them was 100% homologous with clinical cases in the PFGE pattern. - Research highlights: {yields} A new Salmonella detecting procedure for environmental water is developed. {yields} Salmonella isolates are identified by serological assay and PFGE. {yields} A total of seven Salmonella serovars is isolated from environmental water.

  18. Transcriptional analysis of Rickettsia prowazekii invasion gene homolog (invA) during host cell infection.

    Gaywee, Jariyanart; Radulovic, Suzana; Higgins, James A; Azad, Abdu F

    2002-11-01

    An invasion gene homolog, invA, of Rickettsia prowazekii has recently been identified to encode a member of the Nudix hydrolase subfamily which acts specifically on dinucleoside oligophosphates (Np(n)N; n >/= 5), a group of cellular signaling molecules known as alarmones. InvA is thought to enhance intracellular survival by regulating stress-induced toxic nucleotide levels during rickettsial infection. To further characterize the physiological function of InvA, the gene expression pattern during various stages of rickettsial intracellular growth was investigated. Using semiquantitative reverse transcription-PCR (RT-PCR) and real-time fluorescent probe-based quantitative RT-PCR, a differential expression profile of invA during rickettsial host cell infection was examined. The invA transcript temporarily increased during the early period of infection. Expression of rickettsial groEL, a molecular indicator of cellular stresses, was also shown to be upregulated during the early period of infection. Furthermore, invA was cotranscribed in a polycistronic message with rrp, a gene encoding the response regulator protein homolog, which is a part of a two-component signal transduction system. These results support our earlier findings that under such stress conditions dinucleoside oligophosphate pyrophosphatase may function as a buffer, enhancing rickettsial survival within the cytoplasm of a eukaryotic cell. The expression of rickettsial dinucleoside oligophosphate pyrophosphatase may be regulated by a part of the two-component signal transduction system similar to that described for response regulators in other bacterial systems.

  19. Salmonella

    ... Count Maps Epi Curves Signs & Symptoms Key Resources Salmonella Enteritidis Infections Linked to Raw, Frozen, Stuffed Chicken Entrees ... Epi Curves Signs & Symptoms Key Resources Drug-Resistant Salmonella Enteritidis Infections Linked to Raw, Frozen, Stuffed Chicken Entrees ...

  20. Optimization of rapid Salmonella enterica detection in liquid whole eggs by SYBR green I-based real-time reverse transcriptase-polymerase chain reaction.

    Techathuvanan, Chayapa; D'Souza, Doris Helen

    2011-04-01

    Eggs and egg products have a high risk of Salmonella enterica serovar Enteritidis contamination leading to gastroenteritis outbreaks in humans. Thus, a rapid screening tool for viable Salmonella Enteritidis cells in the egg industry is needed. Our objective was to rapidly and sensitively detect viable Salmonella Enteritidis from spiked liquid whole eggs (LWEs) within 24 h using SYBR green I-based real-time reverse transcriptase-polymerase chain reaction (PCR) targeting the Salmonella specific invA gene along with an internal amplification control in a Bio-Rad iCycler. LWE was inoculated with Salmonella Enteritidis and mixed with tetrathionate broth, and 100 μL of serially diluted portions in phosphate-buffered saline was plated on Xylose Lysine Tergitol 4 agar or 5 mL were used for RNA extraction by the TRIzol method immediately or after enrichment of 6, 12, or 16 h at 37 °C. The real-time reverse transcriptase-PCR assay was carried out using previously described Salmonella invA gene primers. Melt temperature analysis of the PCR product was included to determine specific invA amplification. Without enrichment, the assay detection limit was 10(7) colony forming units (CFU)/25 mL LWE. After enrichment for 6 and 12 h, Salmonella Enteritidis could be detected from LWE up to 10(4) and 10(2) CFU/25 mL, respectively. Improved Salmonella Enteritidis detection up to 10(0) CFU/25 mL was obtained after 16-h enrichment. Even with 16-h enrichment, the results could be still be obtained within 24 h, which is much faster than by traditional cultural detection that takes several days. Therefore, this assay appears suitable for routine detection of Salmonella enterica contamination by the egg industry to help prevent the transmission of egg-associated Salmonella outbreaks and timely recall of contaminated products.

  1. Salmonella L-forms: formation in human bile in vitro and isolation culture from patients' gallbladder samples by a non-high osmotic isolation technique.

    Wang, D N; Wu, W J; Wang, T; Pan, Y Z; Tang, K L; She, X L; Ding, W J; Wang, H

    2015-05-01

    Bacterial L-forms have always been considered as osmotic-pressure-sensitive cell-wall-deficient bacteria and isolation culture of L-forms must use media with high osmotic pressure. However, isolation culture of stable L-forms formed in humans and animals is very difficult because they have adapted to the physiological osmotic pressure condition of the host. We use a non-high osmotic isolation technique to isolate stable L-forms of Salmonella Typhi and Salmonella Paratyphi A from bile-inducer cultures in vitro and from patients' gallbladder specimens. Multiplex PCR assay for Salmonella-specific genes and nucleotide sequencing are used to identify the Salmonella L-forms in stable L-form isolates. Using this method, we confirmed that Salmonella Paratyphi A and Salmonella Typhi cannot be isolated from bile-inducer cultures cultured for 6 h or 48 h, but the L-forms can be isolated from 1 h to 45 days. In the 524 gallbladder samples, the positive rate for bacterial forms was 19.7% and the positive rate for Salmonella spp. was 0.6% by routine bacteriological methods. The positive rate for bacterial L-forms was 75.4% using non-high osmotic isolation culture. In the L-form isolates, the positive rate of Salmonella invA gene was 3.1%. In these invA-positive L-form isolates, four were positive for the invA and flic-d genes of Salmonella Typhi, and ten were positive for the invA and flic-a genes of Salmonella Paratyphi A.

  2. Strain-Specific Survival of Salmonella enterica in Peanut Oil, Peanut Shell, and Chia Seeds.

    Fong, Karen; Wang, Siyun

    2016-03-01

    In North America, outbreaks of Salmonella have been linked to low-water activity (aw) foods, such as nuts and seeds. These outbreaks have implicated an assortment of Salmonella serotypes. Some Salmonella serotypes (e.g., Enteritidis and Typhimurium) cause high proportions of salmonellosis. Nevertheless, there has recently been an emergence of uncommon Salmonella serotypes and strains (e.g., Tennessee, Hartford, and Thompson) in low-aw foods. The aim of this study was to evaluate the survival characteristics of Salmonella serotypes Enteritidis, Typhimurium, Tennessee, Hartford, and Thompson in three low-aw food ingredients with varying aw: peanut oil (aw = 0.521 ± 0.003), peanut shell (aw = 0.321 ± 0.20), and chia seeds (aw = 0.585 ± 0.003). The survival of individual Salmonella strains on each food matrix was monitored for a maximum of 150 days by spreading the bacterial cells onto Luria-Bertani and/or xylose lysine deoxycholate agar. Overall, Salmonella survived for the longest periods of time in peanut oil (96 ± 8 days), followed by chia seeds (94 ± 46 days). The survival period was substantially reduced on the surface of peanut shell (42 ± 49 h), although PCR after 70 days of incubation revealed the presence of Salmonella cells. In addition, Salmonella exhibited a strain-specific response in the three low-aw foods tested. Salmonella Hartford was identified as highly persistent in all low-aw food matrices, whereas Salmonella Typhimurium was the least persistent. The current research emphasizes the adaptable nature of Salmonella to low-aw food ingredients. This may pose additional problems owing to the downstream production of various end products. Additionally, unique survival characteristics among Salmonella strains highlight the need for tailored mitigation strategies regarding high-risk Salmonella strains in the food industry.

  3. LOOP-MEDIATED ISOTHERMAL AMPLIFICATION (LAMP FOR THE DETECTION OF SALMONELLA SPP. ISOLATED FROM DIFFERENT FOOD TYPES

    Kostas Papanotas

    2012-08-01

    Full Text Available The objective of this study was the application and evaluation of a loop-mediated isothermal amplification (LAMP method for the detection of Salmonella spp. strains isolated from food samples. Salmonella specific invA gene sequences (50 strains, 15 serotypes were amplified at 65oC in 60 min. All of the strains of Salmonella subsp. Enterica were shown to be positive using the LAMP reaction assay, whereas, all other bacteria, virus and yeasts tested in this study were negative. LAMP products could be visually detected under day light or ultraviolet light, while the specific amplification of the DNA of Salmonella strains generated ladder-like pattern bands on agarose gel. LAMP is suitable for the sensitive, rapid, and inexpensive detection of Salmonella spp. in food analytical laboratories.

  4. InvA protein is a Nudix hydrolase required for infection by pathogenic Leptospira in cell lines and animals.

    Luo, Yihui; Liu, Yan; Sun, Dexter; Ojcius, David M; Zhao, Jinfang; Lin, Xuai; Wu, Dong; Zhang, Rongguang; Chen, Ming; Li, Lanjuan; Yan, Jie

    2011-10-21

    Leptospirosis caused by pathogenic species of the genus Leptospira is a re-emerging zoonotic disease, which affects a wide variety of host species and is transmitted by contaminated water. The genomes of several pathogenic Leptospira species contain a gene named invA, which contains a Nudix domain. However, the function of this gene has never been characterized. Here, we demonstrated that the invA gene was highly conserved in protein sequence and present in all tested pathogenic Leptospira species. The recombinant InvA protein of pathogenic L. interrogans strain Lai hydrolyzed several specific dinucleoside oligophosphate substrates, reflecting the enzymatic activity of Nudix in Leptospira species. Pathogenic leptospires did not express this protein in media but temporarily expressed it at early stages (within 60 min) of infection of macrophages and nephric epithelial cells. Comparing with the wild type, the invA-deficient mutant displayed much lower infectivity and a significantly reduced survival rate in macrophages and nephric epithelial cells. Moreover, the invA-deficient leptospires presented an attenuated virulence in hamsters, caused mild histopathological damage, and were transmitted in lower numbers in the urine, compared with the wild-type strain. The invA revertant, made by complementing the invA-deficient mutant with the invA gene, reacquired virulence similar to the wild type in vitro and in vivo. The LD(50) in hamsters was 1000-fold higher for the invA-deficient mutant than for the invA revertant and wild type. These results demonstrate that the InvA protein is a Nudix hydrolase, and the invA gene is essential for virulence in pathogenic Leptospira species.

  5. Multicenter validation of the analytical accuracy of Salmonella PCR: towards an international standard

    Malorny, B.; Hoorfar, Jeffrey; Bunge, C.

    2003-01-01

    Salmonella spp. and 47 non-Salmonella strains. The most selective primer set was found to be 139-141 (K. Rahn, S. A. De Grandis, R. C. Clarke, S. A. McEwen, J. E. Galan, C. Ginocchio, R. Curtiss 111, and C. L. Gyles, Mol. Cell. Probes 6:271-279, 1992), which targets the invA gene. An extended determination...... 16 participating laboratories. Analysis with 28 coded ("blind") DNA samples revealed an analytical accuracy of 98%. Thus, a simple PCR assay that is specific for Salmonella spp. and amplifies a chromosomal DNA fragment detected by gel electrophoresis was established through extensive validation......As part of a major international project for the validation and standardization of PCR for detection of five major food-borne pathogens, four primer sets specific for Salmonella species were evaluated in-house for their analytical accuracy (selectivity and detection limit) in identifying 43...

  6. Comparison of commercial RNA extraction kits for preparation of DNA-free total RNA from Salmonella cells

    Gonzalez-Escalona Narjol

    2010-07-01

    Full Text Available Abstract Background The isolation of DNA-free RNA is a crucial step in the reverse transcription PCR (RT-PCR. Every RNA extraction procedure results in RNA samples contaminated with genomic DNA, which can cause false-positive outcomes in highly sensitive applications, including a recently developed quantitative real-time PCR (RT-qPCR assay that targets invA mRNA for the detection of live Salmonella cells. The assay of this specific mRNA can be used to indicate the presence of live, as opposed to dead, cells of Salmonella enterica in a food matrix. Findings We evaluated the ability of five RNA extraction kits to produce RNA preparations from exponentially growing Salmonella cells. The acceptability of the preparations for use in downstream applications such as RT-qPCR was judged in terms of the total amount of RNA recovered, the integrity of the RNA molecules, and minimal content of DNA. The five kits produced RNA preparations that differed markedly in yield, integrity of the Salmonella RNA and the amount of contaminant DNA. The greatest RNA recovery was achieved with the MasterPure kit; however, the preparation contained high levels of genomic DNA. The UltraClean extraction kit gave a low level of RNA recovery with a poor level of integrity. The RNeasy Mini, RiboPure and PureLink extraction kits produced high-quality, DNA-free RNA suitable for Salmonella detection by RT-qPCR. Conclusions We showed that the RNeasy Mini and PureLink RNA extraction kits were the most suitable for the detection of Salmonella invA mRNA by RT-qPCR. The use of these two kits will greatly reduce the frequency of false-positive results and might allow fast RT-qPCR determination of invA mRNA produced by viable Salmonella in food samples.

  7. Detection of OmpA gene by PCR for specific detection of Salmonella serovars

    Joy. L. Kataria

    2013-10-01

    Full Text Available Aim: The study was carried out to determine the sensitivity and specificity of OmpA gene in Salmonella serovarsthrough PCR.Materials and Methods: Aset of primers were designed targeting the OmpAgene specific for the Salmonella and polymerasechain reaction was standardized using Salomonella Typhimurium as a positive control and as a negative control 4 nonsalmonella cultures such as Campylobacter coli, Arcobacter butzleri, Brucella abortus and E. coli. Sensitivity of the test wasdetermined by serial dilution of genomic DNAof standard S. Typhimurium. The PCR standardized was used for screening 68strains of different serovars of Salmonella.Results: The PCR developed targeting OmpA specific for Salmonella was highly specific in detection of the salmonellaserovar alone and sensitivity was upto 68.8 fg. Atotal of 68 virulent/ natural strains of different serovars of salmonella takenup for the study were positive by OmpAbased PCR.Conclusions: This study reports that, OmpAgene which is conserved among Salmonella serovars can be used for the detectionof Salmonella in food or clinical samples in further studies, with high sensitivity and specificity.

  8. Diagnostic performance and application of a real-time PCR assay for the detection of Salmonella in fecal samples collected from hospitalized horses with or without signs of gastrointestinal tract disease.

    Ekiri, A B; Long, M T; Hernandez, J A

    2016-02-01

    The main objective of this study was to assess the diagnostic performance of a real-time polymerase chain reaction (PCR) assay for the detection of Salmonella in fecal samples collected from hospitalized horses with or without signs of gastrointestinal (GI) tract disease. The PCR assay used primers and a probe that targeted the invA gene of Salmonella. Assuming a sensitivity of 100% and a specificity of 96.6%, and a disease prevalence of 2%, 5%, and 10-15% in study horses, the PCR assay had a high (100%) negative predictive value, and a positive predictive value that ranged from 37% in horses without signs of GI disease that tested Salmonella culture-negative, to 60% in horses with signs of GI disease that tested Salmonella culture-negative, to 76-83% in horses with signs of GI disease that tested Salmonella culture-positive. This study provides evidence that the real-time PCR that targets the Salmonella invA gene can be used as a screening test for the detection of Salmonella in feces of hospitalized horses with signs of GI disease. Horses that test PCR-positive can be tested in series using bacteriologic culture to reduce false positive results or to provide additional data (e.g., antibiogram and serotyping data) that can be used to identify potential nosocomial Salmonella infections.

  9. Label-free and high-sensitive detection of Salmonella using a surface plasmon resonance DNA-based biosensor.

    Zhang, Decai; Yan, Yurong; Li, Qing; Yu, Tianxiao; Cheng, Wei; Wang, Long; Ju, Huangxian; Ding, Shijia

    2012-08-31

    A method based on surface plasmon resonance (SPR) DNA biosensor has been developed for label-free and high-sensitive detection of Salmonella. A biotinylated single-stranded oligonucleotide probe was designed to target a specific sequence in the invA gene of Salmonella and then immobilized onto a streptavidin coated dextran sensor surface. The invA gene was isolated from bacterial cultures and amplified using a modified semi-nested asymmetric polymerase chain reaction (PCR) technique. In order to investigate the hybridization detection, experiments with different concentration of synthetic target DNA sequences have been performed. The calibration curve of synthetic target DNA had good linearity from 5 nM to 1000 nM with a detection limit of 0.5 nM. The proposed method was applied successfully to the detection of single-stranded invA amplicons from three serovars of Salmonella, i.e., Typhimurium, Enterica and Derby, and the responses to PCR products were related to different S. typhimurium concentrations in the range from 10(2) to 10(10) CFU mL(-1). While with this system to detect E. coli and S. aureus, no significant signal was observed, demonstrating good selectivity of the method. In addition, the hybridization can be completed within 15 min, and the excellent sensor surface regeneration allows at least 300 assay cycles without obvious loss of performance.

  10. Development of a quantitative fluorescence single primer isothermal amplification-based method for the detection of Salmonella.

    Wang, Jianchang; Li, Rui; Hu, Lianxia; Sun, Xiaoxia; Wang, Jinfeng; Li, Jing

    2016-02-16

    Food-borne disease caused by Salmonella has long been, and continues to be, an important global public health problem, necessitating rapid and accurate detection of Salmonella in food. Real time PCR is the most recently developed approach for Salmonella detection. Single primer isothermal amplification (SPIA), a novel gene amplification technique, has emerged as an attractive microbiological testing method. SPIA is performed under a constant temperature, eliminating the need for an expensive thermo-cycler. In addition, SPIA reactions can be accomplished in 30 min, faster than real time PCR that usually takes over 2h. We developed a quantitative fluorescence SPIA-based method for the detection of Salmonella. Using Salmonella Typhimurium genomic DNA as template and a primer targeting Salmonella invA gene, we showed the detection limit of SPIA was 2.0 × 10(1)fg DNA. Its successful amplification of different serotypic Salmonella genomic DNA but not non-Salmonella bacterial DNA demonstrated the specificity of SPIA. Furthermore, this method was validated with artificially contaminated beef. In conclusion, we showed high sensitivity and specificity of SPIA in the detection of Salmonella, comparable to real time PCR. In addition, SPIA is faster and more cost-effective (non-use of expensive cyclers), making it a potential alternative for field detection of Salmonella in resource-limited settings that are commonly encountered in developing countries.

  11. Selective culling of high avidity antigen-specific CD4+ T cells after virulent Salmonella infection.

    Ertelt, James M; Johanns, Tanner M; Mysz, Margaret A; Nanton, Minelva R; Rowe, Jared H; Aguilera, Marijo N; Way, Sing Sing

    2011-12-01

    Typhoid fever is a persistent infection caused by host-adapted Salmonella strains adept at circumventing immune-mediated host defences. Given the importance of T cells in protection, the culling of activated CD4+ T cells after primary infection has been proposed as a potential immune evasion strategy used by this pathogen. We demonstrate that the purging of activated antigen-specific CD4+ T cells after virulent Salmonella infection requires SPI-2 encoded virulence determinants, and is not restricted only to cells with specificity to Salmonella-expressed antigens, but extends to CD4+ T cells primed to expand by co-infection with recombinant Listeria monocytogenes. Unexpectedly, however, the loss of activated CD4+ T cells during Salmonella infection demonstrated using a monoclonal population of adoptively transferred CD4+ T cells was not reproduced among the endogenous repertoire of antigen-specific CD4+ T cells identified with MHC class II tetramer. Analysis of T-cell receptor variable segment usage revealed the selective loss and reciprocal enrichment of defined CD4+ T-cell subsets after Salmonella co-infection that is associated with the purging of antigen-specific cells with the highest intensity of tetramer staining. Hence, virulent Salmonella triggers the selective culling of high avidity activated CD4+ T-cell subsets, which re-shapes the repertoire of antigen-specific T cells that persist later after infection.

  12. Salmonella contamination of eggs of native Kohgiluyeh va Boyerahmad using PCR1 techniques and the evaluation of drug resistance

    M Monadi

    2014-05-01

    Full Text Available Abstract Background & aim:Foodborne disease, a major health and economic problem in industrialized and non-industrialized countries.The purpose of this study was to investigate Salmonella contamination of eggs by native province kohgiloyeh va Boyerahmad by PCR and evaluation of their drug resistance. Methods: This cross-sectional study-descriptive study of 210 eggs collected from native Kohgiluyeh va Boyerahmad done. Biochemical tests for identification of bacteria was isolated. Salmonella bacteria have suspected reactions were tested by PCR with specific primers invA genes were examined. Results: The results showed that 14 number of eggs (6/66 percent were contaminated with Salmonella genus. Dehdasht area of highest contamination and less pollution Charusa areas, Dyshmuk, Lndeh and was Basht And no significant correlation was found between the type and extent of contamination and the region.The antibiotic resistance of most resistance to penicillin (100% was observed.This study uses data from the nineteenth and application soft ware spss version microsofte office 2007-square test and Fisher were analyzed. Significant level of p>0/05 was considered. Conclusion: Microbial agents such as Salmonella can cause food spoilage and disease are. Resistance in Salmonellais recommended to avoid the in discriminate use of antibiotics in live stock and poultry should be avoided. Key words: Salmonella,Egg,drug resistance, invA, PCR.

  13. Solid tumors provide niche-specific conditions that lead to preferential growth of Salmonella

    Silva-Valenzuela, Cecilia A.; Desai, Prerak T.; Molina-Quiroz, Roberto C.; Pezoa, David; Zhang, Yong; Porwollik, Steffen; Zhao, Ming; Hoffman, Robert M.; Contreras, Inés; Santiviago, Carlos A.; McClelland, Michael

    2016-01-01

    Therapeutic attenuated strains of Salmonella Typhimurium target and eradicate tumors in mouse models. However, the mechanism of S. Typhimurium for tumor targeting is still poorly understood. We performed a high-throughput screening of single-gene deletion mutants of S. Typhimurium in an orthotopic, syngeneic murine mammary model of breast cancer. The mutants under selection in this system were classified into functional categories to identify bacterial processes involved in Salmonella accumulation within tumors. Niche-specific genes involved in preferential tumor colonization were identified and exemplars were confirmed by competitive infection assays. Our results show that the chemotaxis gene cheY and the motility genes motAB confer an advantage for colonization of Salmonella within orthotopic syngeneic breast tumors. In addition, eutC, a gene belonging to the ethanolamine metabolic pathway, also confers an advantage for Salmonella within tumors, perhaps by exploiting either ethanolamine or an alternative nutrient in the inflamed tumor environment. PMID:27145267

  14. Inflammatory Responses to Salmonella Infections Are Serotype-Specific

    Zhanna Ktsoyan

    2013-01-01

    Full Text Available The main purpose of this study was to investigate the profile of inflammatory response in patients with acute salmonellosis caused by two serotypes of Salmonella enterica, S. Enteritidis and S. Typhimurium, as well as in convalescent patients with previous acute disease caused by S. Enteritidis. Patients with acute disease showed significantly elevated levels of IL-1β, IL-17, IL-10, and calprotectin compared to healthy control subjects. In convalescent patients, these markers were also significantly elevated, with the exception of IL-1β. Multivariate statistical analyses with the use of these variables produced models with a good predictive accuracy resulting in excellent separation of the diseased and healthy cohorts studied. Overall, the results suggest that the profile of inflammatory response in this disease is determined, to a significant degree, by the serotype of Salmonella, and the profile of certain cytokines and calprotectin remains abnormal for a number of months following the acute disease stage.

  15. Salmonella contamination, serovars and antimicrobial resistance profiles of cattle slaughtered in South Africa

    Evelyn Madoroba

    2016-03-01

    Full Text Available Antimicrobial resistant Salmonella are among the leading causes of foodborne infections. Our aim was to determine Salmonella contamination during cattle slaughter in South African rural abattoirs (n = 23 and environmental samples. Furthermore, antimicrobial resistance patterns of the Salmonella isolates were determined. Samples of cattle faeces (n = 400, carcass sponges (n = 100, intestinal contents (n = 62, hides (n = 67, and water from the abattoirs (n = 75 were investigated for Salmonella species using microbiological techniques and species-specific polymerase chain reaction targeting the invA gene. In total 92 Salmonella species isolates were recovered. The Salmonella mean frequency of occurrence on hides, carcasses, and intestinal contents was 35.37% (n = 81. Eleven faecal samples (2.75% tested positive for Salmonella. The predominant serovar was Salmonella Enteritidis. Diverse serovars that were identified on carcasses were not necessarily found on the hides and intestinal contents. The inconsistent occurrence of the diverse Salmonella serovars on hides, carcasses, and intestinal contents implies that in addition to carriage on hides and in intestinal contents, other external factors also play an important role regarding carcass contamination. The 92 Salmonella were serotyped and tested for susceptibility towards the following antimicrobials: ampicillin, cefotaxime, enrofloxacin, kanamycin, and oxytetracycline using the disk diffusion method. Most Salmonella (n = 66; 71.7% isolates were resistant to at least one antimicrobial with highest resistance observed towards oxytetracycline (51.90%, which highlights the need for strict hygiene during slaughter and prudent antimicrobial use during animal production. In conclusion, cattle slaughtered in South African rural abattoirs harbour diverse Salmonella serovars that are resistant to antimicrobials, which could be a public health risk. The findings should assist policymakers with improving

  16. Characterization and specificity of probiotics to prevent salmonella infection in mice

    Ana Andino

    2014-08-01

    Full Text Available Background: Probiotic strains of bacteria can prevent Salmonella from causing disease by preventing the pathogen from colonizing the intestines. Two strains of probiotics, Lactobacillus acidophilius and Pediococcus spp, that were obtained from poultry fecal samples have been shown to be efficacious in poultry. The objective of this study was to determine if these strains of probiotics could prevent salmonellosis in a mouse model. Methods: First, both strains of probiotics were evaluated for in vitro efficacy to inhibit the growth of and interfere with virulence gene regulation in Salmonella enterica. For in vivo efficacy, mice was used which models Typhoid illness. Mice were divided into 2 groups: Control and treatment, Lactobacillus and Pediococcus (LP; 108 Log CFU. Two experiments were conducted. In the first experiment, the mice were treated with LP in water for the first two days of the experiment and challenged with Salmonella at day three. In the second experiment, the LP treatment was given in the water for 10 days and challenge was performed on day 11. In both experiments, at day 20 post-challenge, all mice were sacrificed, intestinal tracts and organs removed and cultured for Salmonella. Results: The probiotic strains inhibited the growth of Salmonella and down-regulation of virulence genes was noted, but dependent on the strain of Salmonella being evaluated. For the in vivo experiment, the probiotics did not afford the mice protection from infection and increasing the length of time the probiotics were administered did not improve the efficacy of the probiotics. Conclusions: It appears that these strains of probiotic bacteria are effective against Salmonella in vitro. However, these isolates did not afford protection from Salmonella infection to mice which may be due to host specifity as these isolates were obtained from poultry

  17. Real-time reverse transcriptase PCR for the rapid and sensitive detection of Salmonella typhimurium from pork.

    Techathuvanan, Chayapa; Draughon, Frances Ann; D'Souza, Doris Helen

    2010-03-01

    Reverse transcriptase PCR (RT-PCR) detects the presence of mRNA and has a greater potential for detecting viable pathogens than do DNA-based PCR assays, with improved speed and sensitivity compared with traditional methods. Our objective was to rapidly and sensitively detect Salmonella Typhimurium from pork within two 8-h work shifts using a SYBR Green I real-time RT-PCR (rt-RT-PCR) assay. Pork chop and sausage samples (25 g) were inoculated with 10(8) to 10(0) CFU of Salmonella Typhimurium and stomached in 225 ml of tetrathionate broth. Serial dilutions were spread plated on xylose lysine Tergitol 4 agar either immediately or after 10 h of selective preenrichment or preenrichment followed by 12 h of selective enrichment (for stressed cells) at 37 degrees C for standard cultural enumeration. RNA was extracted using the TRIzol method. The rt-RT-PCR assay was carried out in a Bio-Rad iCycler using a SYBR Green I one-step RT-PCR kit and Salmonella specific invA gene primers with an internal amplification control (IAC). The PCR was followed by melting temperature (T(m)) analysis to determine specific Salmonella invA (T(m) = 87.5 degrees C) and IAC (T(m) = 82 degrees C) products. Improved Salmonella detection up to 10(1) CFU/25 g of pork and 10(0) CFU/25 g of sausages was obtained after 10 h of enrichment within approximately 24 h. Even without enrichment, Salmonella could be detected from both pork chop and sausage at 10(6) CFU/25 g within 1 day. This robust rt-RT-PCR detects and confirms Salmonella in pork within approximately 24 h and thus is significantly faster than traditional methods that take >/=1 week. This assay shows promise for routine testing and monitoring of Salmonella by the pork industry.

  18. Isolation and Molecular Identification of Salmonella typhimurium from Chicken Meat in Iraq

    Aseel A. Saeed

    2013-06-01

    Full Text Available This study was conducted to determine the prevalence of Salmonellae contamination of chicken meat imported from different origin to local markets in south of Iraq (Diwaniya. The bacteria were cultured, isolated and biochemically characterized by the analytical profiling index (API 20E system. The 16s rRNA and invA gene primers were selected specifically for the detection of Salmonella to amplify a 406 and 558 bp DNA fragments, respectively. The results of this study showed that 22 Salmonella isolates were detected by polymerase chain reaction (PCR from 100 chicken meats and only 7 isolates out of 22 were identified as S. typhimurium, the highest percent of isolates were 83.8 % for India origin and the lowest percent were 25% from Jordan origin.

  19. Salmonella contamination, serovars and antimicrobial resistance profiles of cattle slaughtered in South Africa.

    Madoroba, Evelyn; Kapeta, Daniel; Gelaw, Awoke K

    2016-05-26

    Antimicrobial resistant Salmonella are among the leading causes of foodborne infections. Our aim was to determine Salmonella contamination during cattle slaughter in South African rural abattoirs (n = 23) and environmental samples. Furthermore, antimicrobial resistance patterns of the Salmonella isolates were determined. Samples of cattle faeces (n = 400), carcass sponges (n = 100), intestinal contents (n = 62), hides (n = 67), and water from the abattoirs (n = 75) were investigated for Salmonella species using microbiological techniques and species-specific polymerase chain reaction targeting the invA gene. In total 92 Salmonella species isolates were recovered. The Salmonella mean frequency of occurrence on hides, carcasses, and intestinal contents was 35.37% (n = 81). Eleven faecal samples (2.75%) tested positive for Salmonella. The predominant serovar was Salmonella Enteritidis. Diverse serovars that were identified on carcasses were not necessarily found on the hides and intestinal contents. The inconsistent occurrence of the diverse Salmonella serovars on hides, carcasses, and intestinal contents implies that in addition to carriage on hides and in intestinal contents, other external factors also play an important role regarding carcass contamination. The 92 Salmonella were serotyped and tested for susceptibility towards the following antimicrobials: ampicillin, cefotaxime, enrofloxacin, kanamycin, and oxytetracycline using the disk diffusion method. Most Salmonella (n = 66; 71.7%) isolates were resistant to at least one antimicrobial with highest resistance observed towards oxytetracycline (51.90%), which highlights the need for strict hygiene during slaughter and prudent antimicrobial use during animal production. In conclusion, cattle slaughtered in South African rural abattoirs harbour diverse Salmonella serovars that are resistant to antimicrobials, which could be a public health risk. The findings should assist policymakers with improving implementation

  20. Molecular beacon-based real-time PCR detection of primary isolates of Salmonella Typhimurium and Salmonella Enteritidis in environmental and clinical samples

    Emmanuel Maria A

    2009-05-01

    Full Text Available Abstract Background A fast and simple two-step multiplex real-time PCR assay has been developed to replace the traditional, laborious Salmonella serotyping procedure. Molecular beacons were incorporated into the assay as probes for target DNA. Target sequences were regions of the invA, prot6E and fliC genes specific for Salmonella spp. Salmonella Enteritidis and Salmonella Typhimurium, respectively, the two most clinically relevant serotypes. An internal amplification positive control was included in the experiment to ensure the optimal functioning of the PCR and detect possible PCR inhibition. Three sets of primers were used for the amplification of the target sequences. The results were compared to those of the Kauffmann-White antigenic classification scheme. Results The assay was 100% sensitive and specific, correctly identifying all 44 Salmonella strains, all 21 samples of S. Enteritidis and all 17 samples of S. Typhimurium tested in this work. Therefore, the entire experiment had specificity and sensitivity of 100%. The detection limit was down to 10 copies of DNA target per 25 μl reaction. Conclusion The assay can amplify and analyse a large number of samples in approximately 8 hours, compared to the 4 to 5 days conventional identification takes, and is thus considered a very promising method for detecting the two major serotypes of Salmonella quickly and accurately from clinical and environmental samples.

  1. Interlaboratory diagnostic accuracy of a Salmonella specific PCR-based method

    Malorny, B.; Hoorfar, Jeffrey; Hugas, M.;

    2003-01-01

    A collaborative study involving four European laboratories was conducted to investigate the diagnostic accuracy of a Salmonella specific PCR-based method, which was evaluated within the European FOOD-PCR project (http://www.pcr.dk). Each laboratory analysed by the PCR a set of independent obtaine...

  2. Use of pooled samples for the detection of Salmonella in feces by polymerase chain reaction.

    Singer, Randall S; Cooke, Cara L; Maddox, Carol W; Isaacson, Richard E; Wallace, Richard L

    2006-07-01

    Many epidemiological studies of Salmonella rely on conventional bacteriological culture methods to detect Salmonella in fecal samples. These culture-based methods are inefficient for epidemiological studies in populations with a low prevalence of Salmonella. The objective of this study was to optimize a protocol that uses pooled Salmonella enrichment broth cultures of bovine feces and polymerase chain reaction (PCR) for the detection of the invA gene of Salmonella in feces. In one field trial, 196 animals were sampled, and all samples were tested by culture, invA PCR on individual samples, invA PCR on pools of 5 samples, and BAX PCR on individual samples. All assays showed a high agreement on individual samples (kappa > or = 0.75). The invA PCR was run on each of 40 pools and detected 19 of 22 culture-positive pools. In another field trial, 152 samples were taken from 4 dairies, and the invA PCR was performed on pools of 5 samples in addition to bacteriological culture of individual samples. Salmonella was detected in 5 of the 32 pools (7 total positive samples) by both PCR and culture. One pool was PCR-positive but culture-negative. Pooling did not dramatically affect the performance of the invA PCR; most of the culture-positive samples were detected, including all of the samples when there were 4 or more Salmonella colonies on the agar plate. Based on these field trials, invA PCR on pooled samples appears to be an efficient method of Salmonella detection as long as Salmonella loads are not extremely low.

  3. Specific Monoclonal Antibody Overcomes the Salmonella enterica Serovar Typhimurium's Adaptive Mechanisms of Intramacrophage Survival and Replication.

    Swarmistha Devi Aribam

    Full Text Available Salmonella-specific antibodies play an important role in host immunity; however, the mechanisms of Salmonella clearance by pathogen-specific antibodies remain to be completely elucidated since previous studies on antibody-mediated protection have yielded inconsistent results. These inconsistencies are at least partially attributable to the use of polyclonal antibodies against Salmonella antigens. Here, we developed a new monoclonal antibody (mAb-449 and identified its related immunogen that protected BALB/c mice from infection with Salmonella enterica serovar Typhimurium. In addition, these data indicate that the mAb-449 immunogen is likely a major protective antigen. Using in vitro infection studies, we also analyzed the mechanism by which mAb-449 conferred host protection. Notably, macrophages infected with mAb-449-treated S. Typhimurium showed enhanced pathogen uptake compared to counterparts infected with control IgG-treated bacteria. Moreover, these macrophages produced elevated levels of pro-inflammatory cytokine TNFα and nitric oxide, indicating that mAb-449 enhanced macrophage activation. Finally, the number of intracellular bacteria in mAb-449-activated macrophages decreased considerably, while the opposite was found in IgG-treated controls. Based on these findings, we suggest that, although S. Typhimurium has the potential to survive and replicate within macrophages, host production of a specific antibody can effectively mediate macrophage activation for clearance of intracellular bacteria.

  4. Comparison of multilocus sequence typing and pulsed-field gel electrophoresis for Salmonella spp. identification in surface water

    Kuo, Chun Wei; Hao Huang, Kuan; Hsu, Bing Mu; Tsai, Hsien Lung; Tseng, Shao Feng; Kao, Po Min; Shen, Shu Min; Chou Chiu, Yi; Chen, Jung Sheng

    2013-04-01

    Salmonella is one of the most important pathogens of waterborne diseases with outbreaks from contaminated water reported worldwide. In addition, Salmonella spp. can survive for long periods in aquatic environments. To realize genotypes and serovars of Salmonella in aquatic environments, we isolated the Salmonella strains by selective culture plates to identify the serovars of Salmonella by serological assay, and identify the genotypes by Multilocus sequence typing (MLST) based on the sequence data from University College Cork (UCC), respectively. The results show that 36 stream water samples (30.1%) and 18 drinking water samples (23.3%) were confirmed the existence of Salmonella using culture method combined PCR specific invA gene amplification. In this study, 24 cultured isolates of Salmonella from water samples were classified to fifteen Salmonella enterica serovars. In addition, we construct phylogenetic analysis using phylogenetic tree and Minimum spanning tree (MST) method to analyze the relationship of clinical, environmental, and geographical data. Phylogenetic tree showed that four main clusters and our strains can be distributed in all. The genotypes of isolates from stream water are more biodiversity while comparing the Salmonella strains genotypes from drinking water sources. According to MST data, we can found the positive correlation between serovars and genotypes of Salmonella. Previous studies revealed that the result of Pulsed field gel electrophoresis (PFGE) method can predict the serovars of Salmonella strain. Hence, we used the MLST data combined phylogenetic analysis to identify the serovars of Salmonella strain and achieved effectiveness. While using the geographical data combined phylogenetic analysis, the result showed that the dominant strains were existed in whole stream area in rainy season. Keywords: Salmonella spp., MLST, phylogenetic analysis, PFGE

  5. The Rickettsia prowazekii invasion gene homolog (invA) encodes a Nudix hydrolase active on adenosine (5')-pentaphospho-(5')-adenosine.

    Gaywee, Jariyanart; Xu, WenLian; Radulovic, Suzana; Bessman, Maurice J; Azad, Abdu F

    2002-03-01

    The genomic sequence of Rickettsia prowazekii, the obligate intracellular bacterium responsible for epidemic typhus, reveals an uncharacterized invasion gene homolog (invA). The deduced protein of 18,752 Da contains a Nudix signature, the specific motif found in the Nudix hydrolase family. To characterize the function of InvA, the gene was cloned and overexpressed in Escherichia coli. The expressed protein was purified to near homogeneity and subsequently tested for its enzymatic activity against a series of nucleoside diphosphate derivatives. The purified InvA exhibits hydrolytic activity toward dinucleoside oligophosphates (Np(n)N; n > or = 5), a group of cellular signaling molecules. At optimal pH 8.5, the enzyme actively degrades adenosine (5')-pentaphospho-(5')-adenosine into ATP and ADP with a K(m) of 0.1 mM and k(cat) of 1.9 s(-1). Guanosine (5')-pentaphospho-(5')-guanosine and adenosine-(5')-hexaphospho (5')-adenosine are also substrates. Similar to other Nudix hydrolases, InvA requires a divalent metal cation, Mg(2+) or Zn(2+), for optimal activity. These data suggest that the rickettsial invasion protein likely plays a role in controlling the concentration of stress-induced dinucleoside oligophosphates following bacterial invasion.

  6. Antigen-specific B cells reactivate an effective cytotoxic T cell response against phagocytosed Salmonella through cross-presentation.

    Jelle de Wit

    Full Text Available BACKGROUND: The eradication of facultative intracellular bacterial pathogens, like Salmonella typhi, requires the concerted action of both the humoral immune response and the cytotoxic CD8(+ T cell response. Dendritic cells (DCs are considered to orchestrate the cytotoxic CD8(+ T cell response via cross-presentation of bacterial antigens onto MHC class I molecules. Cross-presentation of Salmonella by DCs however, is accompanied by the induction of apoptosis in the DCs. Besides antibody production, B cells are required to clear Salmonella infection for other unknown reasons. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that Salmonella-specific B cells that phagocytose Salmonella upon BCR-ligation reactivate human memory CD8(+ T cells via cross-presentation yielding a Salmonella-specific cytotoxic T cell response. The reactivation of CD8(+ T cells is dependent on CD4(+ T cell help. Unlike the DCs, B cell-mediated cross-presentation of Salmonella does not coincide with apoptosis. CONCLUSIONS/SIGNIFICANCE: B cells form a new player in the activation of the cytotoxic effector arm of the immune response and the generation of effective adaptive immunity in Salmonella infection.

  7. A conserved domain in type III secretion links the cytoplasmic domain of InvA to elements of the basal body

    Lilic, Mirjana; Quezada, Cindy M.; Stebbins, C. Erec, E-mail: stebbins@rockefeller.edu [Laboratory of Structural Microbiology, The Rockefeller University, New York, NY 10065 (United States)

    2010-06-01

    The cytoplasmic domain of Salmonella InvA shares homology to a recurring scaffold in the membrane-spanning components of the type II and type III secretion systems. Protein type III secretion systems (T3SSs) are organic nanosyringes that achieve an energy-dependent translocation of bacterial proteins through the two membranes of Gram-negative organisms. Examples include the pathogenic systems of animals, plants and symbiotic bacteria that inject factors into eukaryotic cells, and the flagellar export system that secretes flagellin. T3SSs possess a core of several membrane-associated proteins that are conserved across all known bacterial species that use this system. The Salmonella protein InvA is one of the most highly conserved proteins of this core of critical T3SS components. The crystal structure of a C-terminal domain of InvA reveals an unexpected homology to domains that have been repeatedly found as building blocks of other elements of the T3SS apparatus. This suggests the surprising hypothesis that evolution has produced a significant component of the apparatus structure through a series of gene-duplication and gene-rearrangement events.

  8. Refining the LPS-Antigen in Salmonella Antibody Elisa for Poultry Enhanced Specificity without Impairing Sensitivity

    Lauritsen, Klara Tølbøl; Lind, Peter; Klausen, Joan;

    2014-01-01

    In the Danish serological surveillance for Salmonella in poultry (serum and egg yolk) a mix-ELISA is used, based on S. typhimurium and S. enteritidis antigens (Feld et al., 2000). When we evaluated results of the test retrospectively, over the years an unacceptably large fraction of seropositive...... findings could not be confirmed by the subsequent confirmatory bacteriological sampling in the herd. Therefore we tried to enhance specificity of the ELISA, without losing sensitivity, by refining the antigens used....

  9. Genome-Based Identification of Chromosomal Regions Specific for Salmonella spp.

    Hansen-Wester, Imke; Hensel, Michael

    2002-01-01

    Acquisition of genomic elements by horizontal gene transfer represents an important mechanism in the evolution of bacterial species. Pathogenicity islands are a subset of horizontally acquired elements present in various pathogens. These elements are frequently located adjacent to tRNA genes. We performed a comparative genome analysis of Salmonella enterica serovars Typhi and Typhimurium and Escherichia coli and scanned tRNA loci for the presence of species-specific, horizontally acquired gen...

  10. Determination of specific antibodies titre to salmonella enteritidis by elisa technique in several selected flocks of laying hens

    Velhner Maja

    2004-01-01

    Full Text Available In this paper, the antibody titre to Salmonella enteritidis (SE was examined by the ELISA method in two flocks of laying hens, where during routine bacteriological investigations Salmonellae was never isolated, and in one flock where Colysepticemia was diagnosed and Salmonella isolated accidentally. In the flocks were Salmonellae were not isolated, a titre with a high level of specific antibodies to SE was discovered (15 and 45%, while the flock with accidental findings of SE was poorly positive (5%. These results point to the necessity of introducing serological monitoring to SE so that the infection of salmonella may be discovered early and the prevalence in the flock determined, and also for the purpose of applying adequate measures that could reduce the possibility of secretion of SE through eggs.

  11. Direct visualization of endogenous Salmonella-specific B cells reveals a marked delay in clonal expansion and germinal center development.

    Nanton, Minelva R; Lee, Seung-Joo; Atif, Shaikh M; Nuccio, Sean-Paul; Taylor, Justin J; Bäumler, Andreas J; Way, Sing Sing; McSorley, Stephen J

    2015-02-01

    CD4(+) T cells and B cells are both essential for acquired immunity to Salmonella infection. It is well established that Salmonella inhibit host CD4(+) T-cell responses, but a corresponding inhibitory effect on B cells is less well defined. Here, we utilize an Ag tetramer and pull-down enrichment strategy to directly visualize OVA-specific B cells in mice, as they respond to infection with Salmonella-OVA. Surprisingly, OVA-specific B-cell expansion and germinal center formation was not detected until bacteria were cleared from the host. Furthermore, Salmonella infection also actively inhibited both B- and T-cell responses to the same coinjected Ag but this did not require the presence of iNOS. The Salmonella Pathogenicity Island 2 (SPI2) locus has been shown to be responsible for inhibition of Salmonella-specific CD4(+) T-cell responses, and an examination of SPI2-deficient bacteria demonstrated a recovery in B-cell expansion in infected mice. Together, these data suggest that Salmonella can simultaneously inhibit host B- and T-cell responses using SPI2-dependent mechanisms.

  12. Standardization of a quantification method for Salmonella spp. and Shigella spp. in specific liquid media

    Sandra Patricia Rivera

    2010-03-01

    Full Text Available Introduction: Chlorination is the most widely used disinfection process for drinking water production. The formation of chlorination carcinogenic by-products and chlorine intoxication by direct manipulation in small communities has motivated the study of alternative disinfection processes. In this sense, processes of advanced oxidation (PAOs have yielded promising results. Escherichia coli (E. coli is customarily used as faecal bacterial indicator to determine the efficiency of disinfection processes. However, it has been shown that E. coli is less resistant to disinfection than other enteric bacteria such as Shigella spp. and Salmonella spp. Additionally, the viable non-culturable (VNC state yields bacteria which are not detectable on many culture media.Objective: The main objective is to standardize a method for counting Salmonella spp. and Shigella spp. in specific liquid media to reliably quantify the bacteriological potential risk related to disinfection processes based on PAO.Methods: The study followed a randomized bi-factorial experimental design and the Duncan multiple comparison test. This design allowed the selection of specific liquid media to fittingly standardize the counting of Salmonella spp. and Shigella spp.Results: We found that the best broth for counting Salmonella typhimurium strain at different concentrations in pure and mixed cultures was the Rappaport broth RP, the EE broth also allowed growing the two bacterial species tested in this research. Nonetheless, the latter results suggest the use of additional tests for this particular broth.Discussion: There was a variation in the counting results when pure cultures were used compared to those obtained from mixtures of microorganisms. It was also noted that Salmonella typhimurium and Shigella sonnei, were recovered from minimal concentrations in both RP and EE broths, respectively. To some extent, this suggests an additional confirmative method when using the EE® broth

  13. Standardization of a quantification method for Salmonella spp. and Shigella spp. in specific liquid media

    Sandra Patricia Rivera

    2010-09-01

    Full Text Available Introduction: Chlorination is the most widely used disinfection process for drinking water production. The formation of chlorination carcinogenic by-products and chlorine intoxication by direct manipulation in small communities has motivated the study of alternative disinfection processes. In this sense, processes of advanced oxidation (PAOs have yielded promising results. Escherichia coli (E. coli is customarily used as faecal bacterial indicator to determine the efficiency of disinfection processes. However, it has been shown that E. coli is less resistant to disinfection than other enteric bacteria such as Shigella  spp. and Salmonella  spp. Additionally, the viable non-culturable (VNC state yields bacteria which are not detectable on many culture media. Objective: The main objective is to standardize a method for counting Salmonella  spp. and Shigella  spp. in specific liquid media to reliably quantify the bacteriological potential risk related to disinfection processes based on PAO. Methods: The study followed a randomized bi-factorial experimental design and the Duncan multiple comparison test. This design allowed the selection of specific liquid media to fittingly standardize the counting of Salmonella  spp. and Shigella  spp. Results: We found that the best broth for counting Salmonella typhimurium strain at different concentrations in pure and mixed cultures was the Rappaport broth RP, the EE broth also allowed growing the two bacterial species tested in this research. Nonetheless, the latter results suggest the use of additional tests for this particular broth. Discussion: There was a variation in the counting results when pure cultures were used compared to those obtained from mixtures of microorganisms. It was also noted that Salmonella typhimurium and Shigella sonnei, were recovered from minimal concentrations in both RP and EE broths, respectively. To some extent, this suggests an additional confirmative method when using the

  14. Isolation and identification of Salmonella spp. in drinking water, streams, and swine wastewater by molecular techniques in Taiwan

    Kuo, C.; Hsu, B.; Shen, T.; Tseng, S.; Tsai, J.; Huang, K.; Kao, P.; Chen, J.

    2013-12-01

    Salmonella spp. is a common water-borne pathogens and its genus comprises more than 2,500 serotypes. Major pathogenic genotypes which cause typhoid fever, enteritis and other intestinal-type diseases are S. Typhimurium, S. Enteritidis, S. Stanley, S. Agona, S.Albany, S. Schwarzengrund, S. Newport, S. Choleraesuis, and S. Derby. Hence, the identification of the serotypes of Salmonella spp. is important. In the present study, the analytical procedures include direct concentration method, non-selective pre-enrichment method and selective enrichment method of Salmonella spp.. Both selective enrichment method and cultured bacteria were detected with specific primers of Salmonella spp. by polymerase chain reaction (PCR). At last, the serotypes of Salmonella were confirmed by using MLST (multilocus sequence typing) with aroC, dnaN, hemD, hisD, purE, sucA, thrA housekeeping genes to identify the strains of positive samples. This study contains 121 samples from three different types of water sources including the drinking water (51), streams (45), and swine wastewater (25). Thirteen samples with positive invA gene are separated from culture method. The strains of these positive samples which identified from MLST method are S. Albany, S. Typhimurium, S. Newport, S. Bareilly, and S. Derby. Some of the serotypes, S. Albany, S. Typhimurium and S. Newport, are highly pathogenic which correlated to human diarrhea. In our results, MLST is a useful method to identify the strains of Salmonella spp.. Keywords: Salmonella, PCR, MLST.

  15. Recombinant plasmid-based quantitative Real-Time PCR analysis of Salmonella enterica serotypes and its application to milk samples.

    Gokduman, Kurtulus; Avsaroglu, M Dilek; Cakiris, Aris; Ustek, Duran; Gurakan, G Candan

    2016-03-01

    The aim of the current study was to develop, a new, rapid, sensitive and quantitative Salmonella detection method using a Real-Time PCR technique based on an inexpensive, easy to produce, convenient and standardized recombinant plasmid positive control. To achieve this, two recombinant plasmids were constructed as reference molecules by cloning the two most commonly used Salmonella-specific target gene regions, invA and ttrRSBC. The more rapid detection enabled by the developed method (21 h) compared to the traditional culture method (90 h) allows the quantitative evaluation of Salmonella (quantification limits of 10(1)CFU/ml and 10(0)CFU/ml for the invA target and the ttrRSBC target, respectively), as illustrated using milk samples. Three advantages illustrated by the current study demonstrate the potential of the newly developed method to be used in routine analyses in the medical, veterinary, food and water/environmental sectors: I--The method provides fast analyses including the simultaneous detection and determination of correct pathogen counts; II--The method is applicable to challenging samples, such as milk; III--The method's positive controls (recombinant plasmids) are reproducible in large quantities without the need to construct new calibration curves.

  16. A rapid and direct real time PCR-based method for identification of Salmonella spp

    Rodriguez-Lazaro, D.; Hernández, Marta; Esteve, T.

    2003-01-01

    The aim of this work was the validation of a rapid, real-time PCR assay based on TaqMan((R)) technology for the unequivocal identification of Salmonella spp. to be used directly on an agar-grown colony. A real-time PCR system targeting at the Salmonella spp. invA gene was optimized and validated ...

  17. Efficient and Specific Detection of Salmonella in Food Samples Using a stn-Based Loop-Mediated Isothermal Amplification Method

    Mevaree Srisawat

    2015-01-01

    Full Text Available The Salmonella enterotoxin (stn gene exhibits high homology among S. enterica serovars and S. bongori. A set of 6 specific primers targeting the stn gene were designed for detection of Salmonella spp. using the loop-mediated isothermal amplification (LAMP method. The primers amplified target sequences in all 102 strains of 87 serovars of Salmonella tested and no products were detected in 57 non-Salmonella strains. The detection limit in pure cultures was 5 fg DNA/reaction when amplified at 65°C for 25 min. The LAMP assay could detect Salmonella in artificially contaminated food samples as low as 220 cells/g of food without a preenrichment step. However, the sensitivity was increased 100-fold (~2 cells/g following 5 hr preenrichment at 35°C. The LAMP technique, with a preenrichment step for 5 and 16 hr, was shown to give 100% specificity with food samples compared to the reference culture method in which 67 out of 90 food samples gave positive results. Different food matrixes did not interfere with LAMP detection which employed a simple boiling method for DNA template preparation. The results indicate that the LAMP method, targeting the stn gene, has great potential for detection of Salmonella in food samples with both high specificity and high sensitivity.

  18. A novel multiplex PCR for the simultaneous detection of Salmonella enterica and Shigella species.

    Radhika, M; Saugata, Majumder; Murali, H S; Batra, H V

    2014-01-01

    Salmonella enterica and Shigella species are commonly associated with food and water borne infections leading to gastrointestinal diseases. The present work was undertaken to develop a sensitive and reliable PCR based detection system for simultaneous detection of Salmonella enterica and Shigella at species level. For this the conserved regions of specific genes namely ipaH1, ipaH, wbgZ, wzy and invA were targeted for detection of Shigella genus, S. flexneri, S. sonnei, S. boydii and Salmonella enterica respectively along with an internal amplification control (IAC). The results showed that twenty Salmonella and eleven Shigella spp., were accurately identified by the assay without showing non-specificity against closely related other Enterobacteriaceae organisms and also against other pathogens. Further evaluation of multiplex PCR was undertaken on 50 natural samples of chicken, eggs and poultry litter and results compared with conventional culture isolation and identification procedure. The multiplex PCR identified the presence of Salmonella and Shigella strains with a short pre-enrichment step of 5 h in peptone water and the same samples were processed by conventional procedures for comparison. Therefore, this reported multiplex PCR can serve as an alternative to the tedious time-consuming procedure of culture and identification in food safety laboratories.

  19. A novel multiplex PCR for the simultaneous detection of Salmonella enterica and Shigella species

    M. Radhika

    2014-06-01

    Full Text Available Salmonella enterica and Shigella species are commonly associated with food and water borne infections leading to gastrointestinal diseases. The present work was undertaken to develop a sensitive and reliable PCR based detection system for simultaneous detection of Salmonella enterica and Shigella at species level. For this the conserved regions of specific genes namely ipaH1, ipaH, wbgZ, wzy and invA were targeted for detection of Shigella genus, S. flexneri, S. sonnei, S. boydii and Salmonella enterica respectively along with an internal amplification control (IAC. The results showed that twenty Salmonella and eleven Shigella spp., were accurately identified by the assay without showing non-specificity against closely related other Enterobacteriaceae organisms and also against other pathogens. Further evaluation of multiplex PCR was undertaken on 50 natural samples of chicken, eggs and poultry litter and results compared with conventional culture isolation and identification procedure. The multiplex PCR identified the presence of Salmonella and Shigella strains with a short pre-enrichment step of 5 h in peptone water and the same samples were processed by conventional procedures for comparison. Therefore, this reported multiplex PCR can serve as an alternative to the tedious time-consuming procedure of culture and identification in food safety laboratories.

  20. Real-time PCR method combined with immunomagnetic separation for detecting healthy and heat-injured Salmonella Typhimurium on raw duck wings.

    Zheng, Qianwang; Mikš-Krajnik, Marta; Yang, Yishan; Xu, Wang; Yuk, Hyun-Gyun

    2014-09-01

    Conventional culture detection methods are time consuming and labor-intensive. For this reason, an alternative rapid method combining real-time PCR and immunomagnetic separation (IMS) was investigated in this study to detect both healthy and heat-injured Salmonella Typhimurium on raw duck wings. Firstly, the IMS method was optimized by determining the capture efficiency of Dynabeads(®) on Salmonella cells on raw duck wings with different bead incubation (10, 30 and 60 min) and magnetic separation (3, 10 and 30 min) times. Secondly, three Taqman primer sets, Sal, invA and ttr, were evaluated to optimize the real-time PCR protocol by comparing five parameters: inclusivity, exclusivity, PCR efficiency, detection probability and limit of detection (LOD). Thirdly, the optimized real-time PCR, in combination with IMS (PCR-IMS) assay, was compared with a standard ISO and a real-time PCR (PCR) method by analyzing artificially inoculated raw duck wings with healthy and heat-injured Salmonella cells at 10(1) and 10(0) CFU/25 g. Finally, the optimized PCR-IMS assay was validated for Salmonella detection in naturally contaminated raw duck wing samples. Under optimal IMS conditions (30 min bead incubation and 3 min magnetic separation times), approximately 85 and 64% of S. Typhimurium cells were captured by Dynabeads® from pure culture and inoculated raw duck wings, respectively. Although Sal and ttr primers exhibited 100% inclusivity and exclusivity for 16 Salmonella spp. and 36 non-Salmonella strains, the Sal primer showed lower LOD (10(3) CFU/ml) and higher PCR efficiency (94.1%) than the invA and ttr primers. Moreover, for Sal and invA primers, 100% detection probability on raw duck wings suspension was observed at 10(3) and 10(4) CFU/ml with and without IMS, respectively. Thus, the Sal primer was chosen for further experiments. The optimized PCR-IMS method was significantly (P=0.0011) better at detecting healthy Salmonella cells after 7-h enrichment than traditional PCR

  1. Development of multiplex loop-mediated isothermal amplification-RFLP (mLAMP-RFLP) to detect Salmonella spp. and Shigella spp. in milk.

    Shao, Yanchun; Zhu, Shengmei; Jin, Cuicui; Chen, Fusheng

    2011-08-02

    A multiplex loop-mediated isothermal amplification-RFLP (mLAMP-RFLP) was developed and validated for simultaneous detection of Salmonella strains and Shigella strains in milk. In this system, two sets of LAMP primers were designed to specifically target invA of Salmonella spp. and ipaH of Shigella spp. Under isothermal conditions at 63 °C, ladder pattern of DNA bands could be amplified within 60 min in the presence of genomic DNAs of Salmonella strains and Shigella strains, which could be distinguished between Salmonella spp. and Shigella spp. simultaneously based on the different ladder pattern of DNA bands and subsequent restriction enzyme analysis. The overall analysis time was approximately 20 h including the enrichment of the bacterial cells, which greatly saved detection time. The sensitivity of mLAMP was found to be 100 fg DNA/tube with genomic DNAs of Salmonella strains and Shigella strains, comparatively, multiplex PCR was 1 pg DNA/tube. The mLAMP allowed the detection of milk sample artificially contaminated by Salmonella strains and Shigella strains at initial inoculation levels of approximate 5CFU/10 mL. In conclusion, the mLAMP described here can potentially facilitate simultaneous monitoring of Salmonella and Shigella in a large number of food samples, which could be used as a primary screening method and as a supplement to classical detection method.

  2. SMM-system: A mining tool to identify specific markers in Salmonella enterica.

    Yu, Shuijing; Liu, Weibing; Shi, Chunlei; Wang, Dapeng; Dan, Xianlong; Li, Xiao; Shi, Xianming

    2011-03-01

    This report presents SMM-system, a software package that implements various personalized pre- and post-BLASTN tasks for mining specific markers of microbial pathogens. The main functionalities of SMM-system are summarized as follows: (i) converting multi-FASTA file, (ii) cutting interesting genomic sequence, (iii) automatic high-throughput BLASTN searches, and (iv) screening target sequences. The utility of SMM-system was demonstrated by using it to identify 214 Salmonella enterica-specific protein-coding sequences (CDSs). Eighteen primer pairs were designed based on eighteen S. enterica-specific CDSs, respectively. Seven of these primer pairs were validated with PCR assay, which showed 100% inclusivity for the 101 S. enterica genomes and 100% exclusivity of 30 non-S. enterica genomes. Three specific primer pairs were chosen to develop a multiplex PCR assay, which generated specific amplicons with a size of 180bp (SC1286), 238bp (SC1598) and 405bp (SC4361), respectively. This study demonstrates that SMM-system is a high-throughput specific marker generation tool that can be used to identify genus-, species-, serogroup- and even serovar-specific DNA sequences of microbial pathogens, which has a potential to be applied in food industries, diagnostics and taxonomic studies. SMM-system is freely available and can be downloaded from http://foodsafety.sjtu.edu.cn/SMM-system.html.

  3. Effects of gamma irradiation on the viability and phenotypic characteristics of Salmonella Enteritidis inoculated into specific-pathogen-free eggs.

    Rodrigues, Elizabeth C P; Souza, Mauro C L; Toledo, Sandro S; Barbosa, Celso G; Reis, Eliane M F; Rodrigues, Dalia P; Lázaro, Norma S

    2011-12-01

    The goal of this study was to determine the effects of various levels of gamma irradiation on the phenotypic characteristics of 20 strains of Salmonella Enteritidis inoculated separately into specific-pathogen-free shell eggs. Bacterial strains were inoculated into egg yolks and exposed to (60)Co radiation at doses of 0.49 to 5.0 kGy. The eggs were maintained at 25°C and analyzed for the presence of Salmonella on days 1, 2, 4, and 7, and the recovered Salmonella isolates were characterized biochemically. All strains were resistant to doses of 0.49, 0.54, 0.59, 0.8, and 1 kGy; colony counts were ≥10(5) CFU/ml of egg yolk except for one strain, which was detected at 96 h and at 7 days after irradiation at 1 kGy, with a population reduction of 2 log CFU/ml. For the other evaluated doses, 12 strains (60.0%) were resistant at 1.5 kGy and 7 strains (35.0%) were resistant at 3.0 kGy. Among all analyzed strains, 5.0 kGy was more effective for reducing and/or eliminating the inoculated bacteria; only two (10%) strains were resistant to this level of irradiation. Salmonella colony counts were significantly reduced (P Salmonella Enteritidis at 4 log CFU per egg is not sufficient for complete elimination of this pathogen from this food matrix.

  4. Isolation and characterization of Salmonella enterica in day-old ducklings in Egypt.

    Osman, Kamelia M; Marouf, Sherif H; Zolnikov, Tara R; AlAtfeehy, Nayerah

    2014-01-01

    Importing day-old ducklings (DOD) unknowingly infected with non-typhoid Salmonella (NTS) may be associated with disease risk. Domestic and international trade may enhance this risk. Salmonella enterica serovars, their virulence genes combinations and antibiotic resistance, garner attention for their potentiality to contribute to the adverse health effects on populations throughout the world. The aim of this study was to estimate the risk of imported versus domestic DOD as potential carriers of NTS. The results confirm the prevalence of salmonellosis in imported ducklings was 18·5% (25/135), whereas only 12% (9/75) of cases were determined in the domestic ducklings. Fourteen serovars (Salmonella enteritidis, Salmonella kisii, Salmonella typhimurium, Salmonella gaillac, Salmonella uno, Salmonella eingedi, Salmonella shubra, Salmonella bardo, Salmonella inganda, Salmonella kentucky, Salmonella stanley, Salmonella virchow, Salmonella haifa, and Salmonella anatum) were isolated from the imported ducklings, whereas only S. enteritidis, S. typhimurium, S. virchow, and S. shubra were isolated from the domestic ducklings. The isolated Salmonella serovars were 100% susceptible to only colistin sulphate and 100% resistant to lincomycin. The 14 Salmonella serovars were screened for 11 virulence genes (invA, avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, and bcfC) by PCR. The invA, sopB, and bcfC genes were detected in 100% of the Salmonella serovars; alternatively, the gipA gene was absent in all of the isolated Salmonella serovars. The 11 virulent genes were not detected in either of S. stanley or S. haifa serovars. The results confirm an association between antibiotic resistance and virulence of Salmonella in the DOD. This study confirms the need for a country adherence to strict public health and food safety regimes.

  5. Molecular characterization of Salmonella strains in individuals with acute diarrhea syndrome in the State of Sucre, Venezuela

    Hectorina Rodulfo

    2012-06-01

    Full Text Available INTRODUCTION:In Venezuela, acute diarrheic syndrome (ADS is a primary cause of morbi-mortality, often involving the Salmonella genus. Salmonella infections are associated with acute gastroenteritis, one of the most common alimentary intoxications, and caused by the consumption of contaminated water and food, especially meat. METHODS: Conventional and molecular methods were used to detect Salmonella strains from 330 fecal samples from individuals of different ages and both sexes with ADS. Polymerase chain reaction (PCR was used for the molecular characterization of Salmonella, using invA, sefA, and fliC genes for the identification of this genus and the serotypes Enteritidis and Typhimurium, respectively. RESULTS: The highest frequency of individuals with ADS was found in children 0-2 years old (39.4%, and the overall frequency of positive coprocultures was 76.9%. A total of 14 (4.2% strains were biochemically and immunologically identified as Salmonella enterica subsp. enterica, of which 7 were classified as belonging to the Enteritidis serotype, 4 to the Typhimurium serotype, and 3 to other serotypes. The S. enterica strains were distributed more frequently in the age groups 3-4 and 9-10 years old. CONCLUSIONS: The molecular characterization method used proved to be highly specific for the typing of S. enterica strains using DNA extracted from both the isolated colonies and selective enrichment broths directly inoculated with fecal samples, thus representing a complementary tool for the detection and identification of ADS-causing bacteria.

  6. Assessment of altered binding specificity of bacteriophage for ciprofloxacin-induced antibiotic-resistant Salmonella Typhimurium.

    Kim, Jeongjin; Jo, Ara; Ding, Tian; Lee, Hyeon-Yong; Ahn, Juhee

    2016-08-01

    This study describes a new effort toward understanding the interaction mechanisms between antibiotic-resistant Salmonella Typhimurium and phages. The antibiotic susceptibility, β-lactamase activity, bacterial motility, gene expression, and lytic activity were evaluated in ciprofloxacin-induced antibiotic-sensitive Salmonella Typhimurium (ASST(CIP)) and ciprofloxacin-induced antibiotic-resistant S. Typhimurium (ARST(CIP)), which were compared to the wild-type strains (ASST(WT) and ARST(WT)). The MIC values of ampicillin, norfloxacin, chloramphenicol, and tetracycline were significantly increased to > 512, 16, 16, and 256 μg/ml, respectively, in the ARST(CIP). The lowest and highest extracellular lactamase activities were observed in ASST(WT) (6.85 μmol/min/ml) and ARST(CIP) (48.83 μmol/min/ml), respectively. The acrA, lpfE, and hilA genes were significantly upregulated by more than tenfold in both ASST(CIP) and ARST(CIP). The induction of multiple antibiotic resistance resulted from the increased efflux pump activity (AcrAB-TolC). The highest phage adsorption rates were more than 95 % for ASST(WT), ASST(CIP), and ARST(WT), while the lowest adsorption rate was 52 % for ARST(CIP) at 15 min of infection. The least lytic activity of phage was 20 % against the ARST(CIP), followed by ASST(CIP) (30 %). The adsorption rate of phage against ARST(CIP) was 52 % at 15 min of infection, which resulted in the decrease in lytic activity (12 %). Understanding the interaction of phage and bacteria is essential for the practical application of phage to control and detect antibiotic-resistant bacteria. The results provide useful information for understanding the binding specificity of phages for multiple antibiotic-resistant pathogens.

  7. Salmonella serovar specific upregulation of porcine defensins 1 and 2 in a jejunal epithelial cell line

    Veldhuizen, E.J.A.; Koomen, I; Ultee, A.; van Dijk, A.; Haagsman, H.P.

    2009-01-01

    Defensins are important antimicrobial effector peptides of the innate immune system, which provides protection against bacterial infections in the intestine. Salmonella Choleraesuis and Salmonella Typhimurium are the most commonly isolated serovars in pig, but disease outcome is dependent on the Sal

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

    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...

  9. Structural and enzymatic characterization of a host-specificity determinant from Salmonella

    Kohler, Amanda C. [Rockefeller University, New York, NY 10065 (United States); Spanò, Stefania; Galán, Jorge E. [Yale University School of Medicine, New Haven, CT 06536 (United States); Stebbins, C. Erec, E-mail: stebbins@rockefeller.edu [Rockefeller University, New York, NY 10065 (United States)

    2014-02-01

    The Salmonella effector protein GtgE functions as a cysteine protease to cleave a subset of the Rab-family GTPases and to prevent delivery of antimicrobial agents to the Salmonella-containing vacuole. GtgE is an effector protein from Salmonella Typhimurium that modulates trafficking of the Salmonella-containing vacuole. It exerts its function by cleaving the Rab-family GTPases Rab29, Rab32 and Rab38, thereby preventing the delivery of antimicrobial factors to the bacteria-containing vacuole. Here, the crystal structure of GtgE at 1.65 Å resolution is presented, and structure-based mutagenesis and in vivo infection assays are used to identify its catalytic triad. A panel of cysteine protease inhibitors were examined and it was determined that N-ethylmaleimide, antipain and chymostatin inhibit GtgE activity in vitro. These findings provide the basis for the development of novel therapeutic strategies to combat Salmonella infections.

  10. Identification of novel Salmonella enterica Serovar Thyphimurium DT104-specific prophage and nonprophage chromosomal sequences among serovar Thyphimurium isolates by genomic subtractive hybridization

    Hermans, A.P.H.M.; Abee, T.; Zwietering, M.H.; Aarts, H.J.M.

    2005-01-01

    Genomic subtractive hybridization was performed between Salmonella enterica serovar Typhimurium LT2 and DT104 to search for novel Salmonella serovar Typhimurium DT104-specific sequences. The subtraction resulted mainly in the isolation of DNA fragments with sequence similarity to phages. Two fragmen

  11. Non-crosslinking gold nanoprobe-LAMP for simple, colorimetric, and specific detection of Salmonella typhi

    Bozorgmehr, Ali; Yazdanparast, Razieh; Mollasalehi, Hamidreza

    2016-12-01

    In this study, we developed a non-crosslinking gold nanoprobe loop-mediated isothermal amplification (LAMP) method for nanodiagnosis of bacterial typhoid fever source, Salmonella typhi. Therefore, a unique region in the S. typhi genomic DNA was targeted for LAMP amplification using a specific set of four precisely designed primers. Also, for specific colorimetric visualization of the amplicons, a thiolated oligonucleotide probe, complementary to the single-stranded loop region of the amplicons between F2 and F1C segments, was designed. The probe was bound to the surface of gold nanoparticles via covalent bonds. Increasing the salt concentration in the detection reaction medium led to aggregation of nanoprobes in the blank and the negative vessels in a time-dependent form. That was followed by a change in the surface plasmon resonance (SPR) leading to blue/black color that was observable by the naked eyes after about 5 min. Meanwhile, the original pink/red color was retained in the positive sample due to the large interparticle spaces and the stability against the ionic strength elevation which persisted for about 30 min. The whole process of DNA extraction, amplification, and detection took less than 2 h with a sensitivity of 20 CFU/ml. The developed gold nanoprobe-LAMP could serve as a simple, rapid, and cost-effective method for nanodiagnosis of S. typhi in point-of-need applications.

  12. Antimicrobial resistance and virulence-associated genes of Salmonella enterica subsp. enterica serotypes Muenster, Florian, Omuna, and Noya strains isolated from clinically diarrheic humans in Egypt.

    Osman, Kamelia M; Marouf, Sherif H; Alatfeehy, Nayerah

    2013-10-01

    Four serotypes recovered from clinically diarrheic human faecal samples (Salmonella Muenster, Salmonella Florian, Salmonella Omuna and Salmonella Noya) were investigated for the presence of 11 virulence genes (invA, avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, and bcfC) and their association with antibiotic resistance. The 4 Salmonella serotypes lacked virulence genes gipA and spvC. Resistance to 7 of the 14 antimicrobials was detected. The frequency of resistance, to lincomycin and streptomycin (100% of the Salmonella Muenster [2/5], Salmonella Florian [1/5], Salmonella Omuna [1/5], and Salmonella Noya [1/5] isolates), chloramphenicol (100% of the Salmonella Muenster [2/5] and Salmonella Florian [1/5] isolates) and trimethoprim-sulfamethoxazole (100% of the Salmonella Florian [1/5] and Salmonella Omuna [1/5] isolates) was an outstanding feature. With the rest of the antibiotics, the four Salmonella serotypes exhibited a great diversity in their resistance patterns. Overall, the four Salmonella serotypes were resistant to more than one antimicrobial. The antimicrobials to which the Salmonella Muenster, Salmonella Florian, and Salmonella Omuna isolates were resistant, contributed to five different antimicrobial resistance profiles. The virulence associated genes invA, ssaQ, siiD, sopB, and bcfC genes were 100% associated with certain antimicrobial resistance phenotypes (streptomycin and lincosamide) not recorded previously, and secondly, the presence of invA, avrA, ssaQ, mgtC, siiD, sopB, and bcfC was associated with resistance to chloramphenicol. The results of this study will help in understanding the spread of virulence genotypes and antibiotic resistance in Salmonella in the region of study.

  13. 鸡源致病性沙门菌多重 PCR 检测方法的建立及应用%Establishment and Application of a Multiplex PCR Assay for Detection of Pathogenic Salmonella from Chickens

    李凤梅; 施开创; 许心婷; 胡杰; 邹联斌; 钟诚

    2015-01-01

    To establish a rapid identification method for detection of pathogenic Salmonella in chickens,a multiplex PCR assay was established.In this assay,three pairs of primers were designed to specifically amplify 285 bp of invA gene from pathogenic Salmonella,600 bp of fliC gene from chicken Salmonella, 507 bp of spvR gene from virulence plasmid of Salmonella,respectively.The assay could only react with pathogenic chichen Salmonella,but not with E.coli,Pasteurella multocida ,Sh.dysenteriae and Proteus vulgaris.The detection limit of the method was as little as 4.0× 102 CFU/mL of Salmonella pullorum from cell culture and 1.67×103 copies/μL of recombinant plasmids.The established assay was successfully used to detect 223 clinical samples and 27 samples were positive for invA gene,of which 19 samples were positive for invA and spvR gene,2 samples were positive for invA and fliC genes,while 6 samples were positive for invA,fliC and spvR genes.The results showed that the multiple PCR assay could be used for differential detection and epidemiological investigation of pathogenic chichen Salmonella.%为建立鸡源致病性沙门菌的快速鉴别检测方法,设计3对特异性引物,第1对扩增沙门菌属特异性毒力基因 invA 285 bp 片段,第2对引物扩增沙门菌鸡宿主特异性基因 fliC 600 bp 片段,第3对引物扩增沙门菌质粒毒力基因 spvR 507 bp 片段,经过对反应条件的优化,建立了检测鸡源致病性沙门菌的多重PCR 方法。该方法可以特异扩增携带毒力质粒的致病性鸡沙门菌,而与大肠埃希菌、多杀性巴氏杆菌、痢疾志贺菌及普通变形杆菌均无交叉反应;对沙门菌菌液的检出下限为4.5×102 CFU/mL,对重组质粒标准品的检出下限为1.67×103拷贝/μL。应用所建立的方法对采集的223份临床疑似病料进行检测,结果检出invA 基因阳性27份,占12.11%,其中 invA+spvR 基因阳性19份,占8.52%;invA+fliC

  14. Variation in antigen-antibody affinity among serotypes of Salmonella O4 serogroup, determined using specific antisera.

    Aribam, Swarmistha Devi; Elsheimer-Matulova, Marta; Matsui, Hidenori; Hirota, Jiro; Shiraiwa, Kazumasa; Ogawa, Yohsuke; Hikono, Hirokazu; Shimoji, Yoshihiro; Eguchi, Masahiro

    2015-11-01

    Serotyping is widely used for typing Salmonella during surveillance, and depends on determining the lipopolysaccharide (LPS) O-antigen and the flagellar protein (H-antigens) components. As the O-antigen is highly variable, and structurally unique to each serotype, we investigated the binding affinities of LPS from Salmonella serotypes of O4 serogroup with specific anti-antigen serum via immunoblot and enzyme-linked immunosorbent assays. Since the serotypes from O4 serogroup also express the O-antigen factor 12, O12 antiserum was also used for the analysis. LPS from the different serotypes showed different binding affinities with the antisera. Therefore, based on the antigen-antibody affinity, a modified agglutination assay was carried out by using O4 and O12 antisera. Although serotypes from O4 serogroup have the common O-antigen factors 4 and 12, the analysis showed that the degree of agglutination reaction is different for each of the serotypes. We suggest that Salmonella serogroup O4 serotypes exhibit different binding affinities with specific antisera despite the presence of common O-antigen factors 4 and 12.

  15. Application of an Impedimetric Technique for the Detection of Lytic Infection of Salmonella spp. by Specific Phages

    Lara R. P. Amorim

    2009-01-01

    Full Text Available This study was performed to evaluate the adaption of the impedimetric method to detect the lytic infection by Salmonella-specific bacteriophages and to provide a higher selectivity to this rapid method in detecting Salmonella spp. by using specific agents. Three bacteriophages and twelve strains of Salmonella spp. were tested. Each of the twelve strains was used separately to inoculate TSB together with each one of the phages. The inoculum concentration was between 106 and 107 cfu/mL, at a cell: phage ratio of 1 : 100. From the sample analysis, based on conductance (G measurements (37°C, the infection could be detected, by observation of both detection-time delay and distinct curve trends. The main conclusions were that kinetic detection by impedance microbiology with phage typing constitutes a method of determining whether a test microorganism is sensitive to the bacteriophage and a method to evaluate whether a lytic bacteriophage is present in a sample, by affecting bacterial growth rate/metabolic change.

  16. 检测鸡蛋中沙门氏菌的LAMP方法的建立及初步应用%Loop-mediated isothermal amplification assay for rapid detection of Salmonella spp.

    唐梦君; 周生; 张小燕; 顾荣; 蒲俊华; 葛庆联; 高玉时

    2011-01-01

    Salmonella spp. is an important kind of food-borne pathogenic bacteria which can cause human and animal disease. Salmonella invA gene is known as a major virulence gene. According to published Salmonella invA gene sequence in GenBank, we designed one sets of specific loop-mediated isothermal amplification primers and developed a novel and highly specific loop-mediated isothermal amplification assay for the sensitive and rapid detection of Salmonella spp. The assay correctly identified Salmonella spp., but did not detect 7 non-Salmonella spp. strains. Sensitivity of the LAMP asssay for direct detection of Salmonella spp. in pure cultures was 1.04×102 cfu·mL-1. The results of LAMP detection of 100 eggs were consistent with the traditional method. The LAMP assay is a sensitive, rapid and simple tool for the detection of Salmonella spp. and will facilitate the surveillance for control of contamination of Salmonella spp. in egg.%根据GenBank上公布的沙门氏菌invA基因序列中的保守区域,设计一套环介导等温扩增(LAMP)引物,将其用于沙门氏菌的检测,结果成功地扩增出特异性的梯形条带.LAMP方法检测沙门氏菌纯培养的灵敏度为1.04×102 cfu·mL-1,对11株不同细菌进行LAMP检测,仅沙门氏菌获得阳性结果.应用该方法对扬州市场上销售的鸡蛋进行沙门氏菌检测,检测结果与传统培养方法相符合.因此,LAMP方法检测沙门氏菌具有灵敏度高,特异性强,耗时短,方法简便等特点,有望发展成为快速检测鸡蛋中沙门氏菌的有效手段.

  17. Structural and mutational studies on substrate specificity and catalysis of Salmonella typhimurium D-cysteine desulfhydrase.

    Sakshibeedu R Bharath

    Full Text Available Salmonella typhimurium DCyD (StDCyD is a fold type II pyridoxal 5' phosphate (PLP-dependent enzyme that catalyzes the degradation of D-Cys to H(2S and pyruvate. It also efficiently degrades β-chloro-D-alanine (βCDA. D-Ser is a poor substrate while the enzyme is inactive with respect to L-Ser and 1-amino-1-carboxy cyclopropane (ACC. Here, we report the X-ray crystal structures of StDCyD and of crystals obtained in the presence of D-Cys, βCDA, ACC, D-Ser, L-Ser, D-cycloserine (DCS and L-cycloserine (LCS at resolutions ranging from 1.7 to 2.6 Å. The polypeptide fold of StDCyD consisting of a small domain (residues 48-161 and a large domain (residues 1-47 and 162-328 resembles other fold type II PLP dependent enzymes. The structures obtained in the presence of D-Cys and βCDA show the product, pyruvate, bound at a site 4.0-6.0 Å away from the active site. ACC forms an external aldimine complex while D- and L-Ser bind non-covalently suggesting that the reaction with these ligands is arrested at Cα proton abstraction and transimination steps, respectively. In the active site of StDCyD cocrystallized with DCS or LCS, electron density for a pyridoxamine phosphate (PMP was observed. Crystals soaked in cocktail containing these ligands show density for PLP-cycloserine. Spectroscopic observations also suggest formation of PMP by the hydrolysis of cycloserines. Mutational studies suggest that Ser78 and Gln77 are key determinants of enzyme specificity and the phenolate of Tyr287 is responsible for Cα proton abstraction from D-Cys. Based on these studies, a probable mechanism for the degradation of D-Cys by StDCyD is proposed.

  18. A conserved domain in type III secretion links the cytoplasmic domain of InvA to elements of the basal body.

    Lilic, Mirjana; Quezada, Cindy M; Stebbins, C Erec

    2010-06-01

    Protein type III secretion systems (T3SSs) are organic nanosyringes that achieve an energy-dependent translocation of bacterial proteins through the two membranes of Gram-negative organisms. Examples include the pathogenic systems of animals, plants and symbiotic bacteria that inject factors into eukaryotic cells, and the flagellar export system that secretes flagellin. T3SSs possess a core of several membrane-associated proteins that are conserved across all known bacterial species that use this system. The Salmonella protein InvA is one of the most highly conserved proteins of this core of critical T3SS components. The crystal structure of a C-terminal domain of InvA reveals an unexpected homology to domains that have been repeatedly found as building blocks of other elements of the T3SS apparatus. This suggests the surprising hypothesis that evolution has produced a significant component of the apparatus structure through a series of gene-duplication and gene-rearrangement events.

  19. A Conserved Domain in Type III Secretion Links the Cytoplasmic Domain of InvA to Elements of the Basal Body

    Lilic, M.; Quezada, C; Stebbins, C

    2010-01-01

    Protein type III secretion systems (T3SSs) are organic nanosyringes that achieve an energy-dependent translocation of bacterial proteins through the two membranes of Gram-negative organisms. Examples include the pathogenic systems of animals, plants and symbiotic bacteria that inject factors into eukaryotic cells, and the flagellar export system that secretes flagellin. T3SSs possess a core of several membrane-associated proteins that are conserved across all known bacterial species that use this system. The Salmonella protein InvA is one of the most highly conserved proteins of this core of critical T3SS components. The crystal structure of a C-terminal domain of InvA reveals an unexpected homology to domains that have been repeatedly found as building blocks of other elements of the T3SS apparatus. This suggests the surprising hypothesis that evolution has produced a significant component of the apparatus structure through a series of gene-duplication and gene-rearrangement events.

  20. Detection of viable Salmonella in ice cream by TaqMan real-time polymerase chain reaction assay combining propidium monoazide

    Yuexia Wang

    2015-09-01

    Full Text Available Real-time polymerase chain reaction (PCR allows rapid detection of Salmonella in frozen dairy products, but it might cause a false positive detection result because it might amplify DNA from dead target cells as well. In this study, Salmonella-free frozen ice cream was initially inoculated with heat-killed Salmonella Typhimurium cells and stored at −18°C. Bacterial DNA extracted from the sample was amplified using TaqMan probe-based real-time PCR targeting the invA gene. Our results indicated that DNA from the dead cells remained stable in frozen ice cream for at least 20 days, and could produce fluorescence signal for real-time PCR as well. To overcome this limitation, propidium monoazide (PMA was combined with real-time PCR. PMA treatment can effectively prevent PCR amplification from heat-killed Salmonella cells in frozen ice cream. The PMA real-time PCR assay can selectively detect viable Salmonella at as low as 103 CFU/mL. Combining 18 hours of pre-enrichment with the assay allows for the detection of viable Salmonella at 100 CFU/mL and avoiding the false-positive result of dead cells. The PMA real-time PCR assay provides an alternative specifically for detection of viable Salmonella in ice cream. However, when the PMA real-time PCR assay was evaluated in ice cream subjected to frozen storage, it obviously underestimated the contamination situation of viable Salmonella, which might lead to a false negative result. According to this result, the use of enrichment prior to PMA real-time PCR analysis remains as the more appropriate approach.

  1. Active protection of mice against Salmonella typhi by immunization with strain-specific porins.

    Isibasi, A; Ortiz-Navarrete, V; Paniagua, J; Pelayo, R; González, C R; García, J A; Kumate, J

    1992-01-01

    NIH mice were immunized with between 2.5 and 30 micrograms of two highly purified porins, 34 kDa and 36 kDa, isolated from the virulent strain Salmonella typhi 9,12, Vi:d. Of mice immunized with 10 micrograms of porins, 90% were protected against a challenge with up to 500 LD50 (50% lethal doses) of S. typhi 9,12,Vi:d and only 30% protection was observed in mice immunized with the same dose of porins but challenged with the heterologous strain Salmonella typhimurium. These results demonstrate the utility of porins for the induction of a protective status against S. typhi in mice.

  2. Quantitative detection of Salmonella enterica and the specific interaction with Lactuca sativa

    Klerks, M.M.

    2007-01-01

    Salmonella is among the most commonly known bacterial pathogens to cause human illness. Often Salmonellosis is associated with the consumption of contaminated foods like meat, eggs or egg products. However, during the last decades an increase of outbreaks is recognized to be caused by human pathogen

  3. Biomagnetic separation of Salmonella Typhimurium with high affine and specific ligand peptides isolated by phage display technique

    Steingroewer, Juliane [Institute of Food Technology and Bioprocess Engineering, Technische Universitaet Dresden, D-01062 Dresden (Germany)]. E-mail: juliane.steingroewer@tu-dresden.de; Bley, Thomas [Institute of Food Technology and Bioprocess Engineering, Technische Universitaet Dresden, D-01062 Dresden (Germany); Bergemann, Christian [Chemicell GmbH, D-10823, Berlin (Germany); Boschke, Elke [Institute of Food Technology and Bioprocess Engineering, Technische Universitaet Dresden, D-01062 Dresden (Germany)

    2007-04-15

    Analyses of food-borne pathogens are of great importance in order to minimize the health risk for customers. Thus, very sensitive and rapid detection methods are required. Current conventional culture techniques are very time consuming. Modern immunoassays and biochemical analysis also require pre-enrichment steps resulting in a turnaround time of at least 24 h. Biomagnetic separation (BMS) is a promising more rapid method. In this study we describe the isolation of high affine and specific peptides from a phage-peptide library, which combined with BMS allows the detection of Salmonella spp. with a similar sensitivity as that of immunomagnetic separation using antibodies.

  4. Molecular Detection of Salmonella Serovar Isolated from Eggs

    Monadi, M. (MSc

    2015-05-01

    Full Text Available Background and Objective: Salmonellosis is the most common type of food poisoning in developed and developing countries that is caused by Salmonella serotype. Hence, we aimed to identify the Salmonella serovars in eggs obtained from Kohgiluyeh and Boyerahmad province and to evaluate antibiotic resistance of the isolated strains. Material and Methods: In this study, 210 eggs were collected from Kohgiluyeh and Boyerahmad Province. The bacteria were isolated and identified using biochemical tests. After extraction of genomic DNA, Salmonella gender, Salmonella enteritidis and Salmonella typhimurium were investigated by invA, fliC and sefA primers, respectively, using Multiplex PCR method. Results: Of 210, 14 (6.66% were contaminated with Salmonella. Of these, 12 (5.71% were Salmonella typhimurium and 2 (0.95% were related to Salmonella spp. None of the samples were contaminated with Salmonella enteritidis. The highest resistance was related to penicillin (100% and neomycin (78.57%. Conclusion: Salmonella typhimurium is the predominant serovar causing contamination in the eggs of this Province. Given the wide spread of antibiotic resistance in different serotypes of Salmonella, we recommend avoiding of indiscriminate use of antibiotics in livestock and poultry

  5. A kinesin, invA, plays an essential role in volvox morphogenesis.

    Nishii, Ichiro; Ogihara, Satoshi; Kirk, David L

    2003-06-13

    In Volvox carteri adults, reproductive cells called gonidia are enclosed within a spherical monolayer of biflagellate somatic cells. Embryos must "invert" (turn inside out) to achieve this configuration, however, because at the end of cleavage the gonidia are on the outside and the flagellar ends of all somatic cells point inward. Generation of a bend region adequate to turn the embryo inside out involves a dramatic change in cell shape, plus cell movements. Here, we cloned a gene called invA that is essential for inversion and found that it codes for a kinesin localized in the cytoplasmic bridges that link all cells to their neighbors. In invA null mutants, cells change shape normally, but are unable to move relative to the cytoplasmic bridges. A normal bend region cannot be formed and inversion stops. We conclude that the InvA kinesin provides the motile force that normally drives inversion to completion.

  6. Immuno-fluorescence based Vi capsular polysaccharide detection for specific recognition of Salmonella enterica serovar Typhi in clinical samples.

    Pandey, Satish K; Vinayaka, Aaydha C; Rishi, Dharam B; Rishi, Praveen; Suri, C Raman

    2014-09-01

    Typhoid fever is a life threatening bacterial infection that remains a major global health concern. This continued high burden associated with significant morbidity and mortality rate demands specific and rapid detection technique. This work reports a new sandwich type fluorescence immunoassay format using polymyxin B, a cationic receptor molecule, as a binder agent while anti-Vi antibody served as the capturing agent for specifically detecting Salmonella enterica serovar Typhi. Anti-Vi IgG antibody raised against Vi-BSA conjugate revealed affinity of 7.779nM(-1) signifying immunodominancy of O-acetyls groups in Vi polysaccharide. The detection limit of the developed assay was around 10(1) cellsmL(-1) of Vi expressing Salmonella enterica serovar Typhi with a correlation coefficient (R(2)) equal to 0.97. Positive response obtained for all the tested serovar Typhi clinical isolates as well as the pathogen spiked blood samples recommended specificity and accuracy of Vi antigen as a biomarker during typhoid fever. The intra- and inter-assay precision with Vi spiked samples were satisfactory revealing coefficient of variance (CV%) with a mean of 4.05% and 5.97% respectively. This may be the novel attempt and constructive report on the fluorescence based detection of Vi antigen of serovar Typhi in the epidemic as well as pandemic outbreaks.

  7. Compact disk (CD)-shaped device for single cell isolation and PCR of a specific gene in the isolated cell.

    Furutani, Shunsuke; Nagai, Hidenori; Takamura, Yuzuru; Kubo, Izumi

    2010-12-01

    For immediate discrimination among isolated cells we propose a novel device and technique for isolation of cells and sequential detection of specific gene(s) within them by polymerase chain reaction (PCR). In this study, we isolated Salmonella enterica cells and detected the Salmonella-specific invA gene from isolated cells by PCR on a compact disk (CD)-shaped device. This device enabled liquid flow by centrifugal force without a micro pump, and was fabricated from silicon wafer and glass to avoid evaporation of a small amount of reagent. One device has 24 microchannels, and 313 microchambers integrated on each microchannel. One microliter of PCR mixture containing cells was separated into microchambers on the device at 5000 rpm for 30 s. Each microchamber contained approximately 1.5 nL PCR mixture. A Poisson distribution of S. enterica cells was observed for different densities of cell suspension. At 200 cells μL(-1) of S. enterica or less, isolated single cells could be determined on the device by amplification of DNA of the invA gene; at 400 cells μL(-1), chambers containing no, one, two, or three cells could be determined on the device. Selective detection of S. enterica was achieved by PCR from a mixture of S. enterica and Escherichia coli on the CD-shaped device.

  8. Preparation and evaluation of immunogenic conjugates of Salmonella enterica serovar Typhi O-specific polysaccharides with diphtheria toxoid.

    Ali, Aamir; An, So Jung; Cui, Changfa; Haque, Abdul; Carbis, Rodney

    2012-02-01

    Typhoid fever, caused by Salmonella enterica serovar Typhi (S. Typhi), is a major health problem particularly in developing countries. The available vaccines have certain limitations regarding their efficacy, and inability to induce an immune response especially in individuals under 2 years of age. Conjugate vaccines which consist of a bacteria-specific polysaccharide chemically bound to a carrier protein overcome these problems by inducing a T-cell dependent immune response characterized by enhanced immunogenicity in all ages. In this study, O-specific polysaccharides (OSP) of S. Typhi were conjugated to diphtheria toxoid (DT) using adipic acid dihydrazide (ADH) as a linker. These conjugates (OSP-AH-DT) were then evaluated for their immunogenicity using mice as a model and showed significantly higher levels of IgG ELISA titers (P = 0.0241 and 0.0245) than lipopolysaccharides alone. Different immunization  schedules were compared and it was found that schedule-B (three injections with 4-weeks interval) induced higher immune responses than schedule-A (three injections with 2-weeks interval). We showed that diphtheria toxoid can be successfully employed as a carrier protein for conjugation with Salmonella OSP and play an important role in facilitating adequate immune response.

  9. Salmonella typhimurium's transthyretin-like protein is a host-specific factor important in fecal survival in chickens.

    Sarah C Hennebry

    Full Text Available The transthyretin-like protein (TLP from Salmonella enterica subspecies I is a periplasmic protein with high level structural similarity to a protein found in mammals and fish. In humans, the protein homologue, transthyretin, binds and carries retinol and thyroxine, and a series of other, unrelated aromatic compounds. Here we show that the amino acid sequence of the TLP from different species, subspecies and serovars of the Salmonella genus is highly conserved and demonstrate that the TLP gene is constitutively expressed in S. Typhimurium and that copper and other divalent metal ions severely inhibit enzyme activity of the TLP, a cyclic amidohydrolase that hydrolyses 5-hydroxyisourate (5-HIU. In order to determine the in vivo role of the S. Typhimurium TLP, we constructed a strain of mouse-virulent S. Typhimurium SL1344 bearing a mutation in the TLP gene (SL1344 ΔyedX. We assessed the virulence of this strain via oral inoculation of mice and chickens. Whilst SL1344 ΔyedX induced a systemic infection in both organisms, the bacterial load detected in the faeces of infected chickens was significantly reduced when compared to the load of S. Typhimurium SL1344. These data demonstrate that the TLP gene is required for survival of S. Typhimurium in a high uric acid environment such as chicken faeces, and that metabolic traits of Salmonellae in natural and contrived hosts may be fundamentally different. Our data also highlight the importance of using appropriate animal models for the study of bacterial pathogenesis especially where host-specific virulence factors or traits are the subject of the study.

  10. CRISPR is an optimal target for the design of specific PCR assays for salmonella enterica serotypes Typhi and Paratyphi A.

    Laetitia Fabre

    Full Text Available BACKGROUND: Serotype-specific PCR assays targeting Salmonella enterica serotypes Typhi and Paratyphi A, the causal agents of typhoid and paratyphoid fevers, are required to accelerate formal diagnosis and to overcome the lack of typing sera and, in some situations, the need for culture. However, the sensitivity and specificity of such assays must be demonstrated on large collections of strains representative of the targeted serotypes and all other bacterial populations producing similar clinical symptoms. METHODOLOGY: Using a new family of repeated DNA sequences, CRISPR (clustered regularly interspaced short palindromic repeats, as a serotype-specific target, we developed a conventional multiplex PCR assay for the detection and differentiation of serotypes Typhi and Paratyphi A from cultured isolates. We also developed EvaGreen-based real-time singleplex PCR assays with the same two sets of primers. PRINCIPAL FINDINGS: We achieved 100% sensitivity and specificity for each protocol after validation of the assays on 188 serotype Typhi and 74 serotype Paratyphi A strains from diverse genetic groups, geographic origins and time periods and on 70 strains of bacteria frequently encountered in bloodstream infections, including 29 other Salmonella serotypes and 42 strains from 38 other bacterial species. CONCLUSIONS: The performance and convenience of our serotype-specific PCR assays should facilitate the rapid and accurate identification of these two major serotypes in a large range of clinical and public health laboratories with access to PCR technology. These assays were developed for use with DNA from cultured isolates, but with modifications to the assay, the CRISPR targets could be used in the development of assays for use with clinical and other samples.

  11. A strand-specific RNA-Seq analysis of the transcriptome of the typhoid bacillus Salmonella typhi.

    Timothy T Perkins

    2009-07-01

    Full Text Available High-density, strand-specific cDNA sequencing (ssRNA-seq was used to analyze the transcriptome of Salmonella enterica serovar Typhi (S. Typhi. By mapping sequence data to the entire S. Typhi genome, we analyzed the transcriptome in a strand-specific manner and further defined transcribed regions encoded within prophages, pseudogenes, previously un-annotated, and 3'- or 5'-untranslated regions (UTR. An additional 40 novel candidate non-coding RNAs were identified beyond those previously annotated. Proteomic analysis was combined with transcriptome data to confirm and refine the annotation of a number of hpothetical genes. ssRNA-seq was also combined with microarray and proteome analysis to further define the S. Typhi OmpR regulon and identify novel OmpR regulated transcripts. Thus, ssRNA-seq provides a novel and powerful approach to the characterization of the bacterial transcriptome.

  12. Rapid discrimination of Salmonella isolates by single-strand conformation polymorphism analysis.

    Al-Adhami, Batol H; Huby-Chilton, Florence; Blais, Burton W; Martinez-Perez, Amalia; Chilton, Neil B; Gajadhar, Alvin A

    2008-10-01

    A molecular typing technique was developed for the differentiation of Salmonella isolates based on single-strand conformation polymorphism (SSCP) analysis of amplicons generated by PCR. Amplicons from parts of the fimA (both the 5' and 3' ends), mdh, invA, and atpD genes were generated separately from a panel of Salmonella strains representing Salmonella bongori, and four subspecies and 17 serovars of Salmonella enterica. These amplicons were subjected to SSCP analysis for differentiation of the salmonellae on the basis of different conformational forms arising due to nucleotide sequence variations in the target genes. Several distinct SSCP banding patterns (a maximum of 14 each for atpD and fimA 3' end) were observed with this panel of Salmonella strains for amplicons generated from each target gene. The best discrimination of Salmonella subspecies and serovar was achieved from the SSCP analysis of a combination of at least three gene targets: atpD, invA, and either mdh or fimA 3' end. This demonstrates the applicability of SSCP analysis as an important additional method to classical typing approaches for the differentiation of foodborne Salmonella isolates. SSCP is simple to perform and should be readily transferable to food microbiology laboratories with basic PCR capability.

  13. Salmonella Typhimurium-specific bacteriophage ΦSH19 and the origins of species specificity in the Vi01-like phage family

    Wilson Ray

    2011-11-01

    Full Text Available Abstract Background Whole genome sequencing of bacteriophages suitable for biocontrol of pathogens in food products is a pre-requisite to any phage-based intervention procedure. Trials involving the biosanitization of Salmonella Typhimurium in the pig production environment identified one such candidate, ΦSH19. Results This phage was sequenced and analysis of its 157,785 bp circular dsDNA genome revealed a number of interesting features. ΦSH19 constitutes another member of the recently-proposed Myoviridae Vi01-like family of phages, containing S. Typhi-specific Vi01 and Shigella-specific SboM-AG3. At the nucleotide level ΦSH19 is highly similar to phage Vi01 (80-98% pairwise identity over the length of the genome, with the major differences lying in the region associated with host-range determination. Analyses of the proteins encoded within this region by ΦSH19 revealed a cluster of three putative tail spikes. Of the three tail spikes, two have protein domains associated with the pectate lyase family of proteins (Tsp2 and P22 tail spike family (Tsp3 with the prospect that these enable Salmonella O antigen degradation. Tail spike proteins of Vi01 and SboM-AG3 are predicted to contain conserved right-handed parallel β-helical structures but the internal protein domains are varied allowing different host specificities. Conclusions The addition or exchange of tail spike protein modules is a major contributor to host range determination in the Vi01-like phage family.

  14. An oral recombinant Salmonella enterica serovar Typhimurium mutant elicits systemic antigen-specific CD8+ T cell cytokine responses in mice

    Chin'ombe Nyasha

    2009-04-01

    Full Text Available Abstract Background The induction of antigen-specific CD8+ T cell cytokine responses against an attenuated, oral recombinant Salmonella enterica serovar Typhimurium vaccine expressing a green fluorescent protein (GFP model antigen was investigated. A GFP expression plasmid was constructed in which the gfp gene was fused in-frame with the 5' domain of the Escherichia coli β-galactosidase α-gene fragment with expression under the lac promoter. Groups of mice were orally immunized three times with the bacteria and systemic CD8+ T cell cytokine responses were evaluated. Results High level of the GFP model antigen was expressed by the recombinant Salmonella vaccine vector. Systemic GFP-specific CD8+ T cell cytokine (IFN-γ and IL-4 immune responses were detected after mice were orally vaccinated with the bacteria. It was shown that 226 net IFN-γ and 132 net IL-4 GFP-specific SFUs/10e6 splenocytes were formed in an ELISPOT assay. The level of IFN-γ produced by GFP peptide-stimulated cells was 65.2-fold above background (p Conclusion These results suggested that a high expressing recombinant Salmonella vaccine given orally to mice would elicit antigen-specific CD8+ T cell responses in the spleen. Salmonella bacteria may, therefore, be used as potential mucosal vaccine vectors.

  15. Evidence for the Existence of a Channel in the Glucose-Specific Carrier EIIGlc of the Salmonella typhimurium Phosphoenolpyruvate-Dependent Phosphotransferase System

    Robillard, G.T.; Beechey, R.B.

    1986-01-01

    The effect of membrane-impermeable sulfhydryl reagents on glucose-specific enzyme II (EIIGlc) activity has been studied in Salmonella typhimurium whole cells and in properly sealed inverted cytoplasmic membrane vesicles. Glutathione N-hexylmaleimide and N-polymethylenecarboxymaleimides inactivate me

  16. Comparison of PCR-ELISA and LightCycler real-time PCR assays for detecting Salmonella spp. in milk and meat samples

    Perelle, Sylvie; Dilasser, Françoise; Malorny, Burkhard

    2004-01-01

    In a previous study, we reported the performance of a PCR assay amplifying 285-bp of the invA gene of Salmonella spp. through an international ring-trial involving four participating laboratories [Int. J. Food Microbiol. 89 (2003) 241]. Based on the validated set of primers and recent advancement...

  17. Detection of Salmonella enteritidis in pooled poultry environmental samples using a serotype-specific real-time-polymerase chain reaction assay.

    Adams, Derek R; Stensland, Wendy R; Wang, Chong H; O'Connor, Annette M; Trampel, Darrell W; Harmon, Karen M; Strait, Erin L; Frana, Timothy S

    2013-03-01

    While real-time-polymerase chain reaction (RT PCR) has been used as a rapid test for detection of Salmonella Enteritidis in recent years, little research has been done to assess the feasibility of pooling poultry environmental samples with a Salmonella Enteritidis-specific RT PCR assay. Therefore the objective of this study was to compare RT PCR Salmonella Enteritidis detection in individual and pooled (in groups of two, three, and four) poultry environmental drag swab samples to traditional cultural methods. The drag swabs were collected from poultry facilities previously confirmed positive for Salmonella Enteritidis and were cultured according to National Poultry Improvement Plan guidelines. Initial, Salmonella Enteritidis-specific RT PCR assay threshold cycle cutoff values of Salmonella Enteritidis was cultured in 7 of 208 environmental samples (3.4%). Individual samples were 99.0%, 100%, and 100% in agreement with the RT PCR at threshold cycle (C(t)) cutoff values of < or = 36, < or = 30, and < or = 28 respectively. The agreement for pooled samples also followed the same trend with highest agreement at C(t) < or = 28 (pool of 2 = 100.0%, pool of 3 = 100.0%, pool of 4 = 100.0%), midrange agreement at C(t) < or = 30 (pool of 2 = 99.0%, pool of 3 = 100.0%, pool of 4 = 100.0%), and lowest agreement at C(t) < or = 36 (pool of 2 = 98.1%, pool of 3 = 97.1%, pool of 4 = 98.1%). In conclusion, regardless of the level of pooling after tetrathionate enrichment, sensitivity was very good, and results would be comparable to what would have been found with individual culture or individual RT PCR at C(t) < or = 36.

  18. Antimicrobial resistance and virulence profiles of Salmonella isolated from butcher shops in Minas Gerais, Brazil.

    Cossi, Marcus Vinícius Coutinho; Burin, Raquel Cristina Konrad; Lopes, Danilo Augusto; Dias, Mariane Rezende; Castilho, Natalia Parma Augusto de; de Arruda Pinto, Paulo Sérgiode; Nero, Luís Augusto

    2013-09-01

    Salmonella can contaminate finished products of butcher shops, mainly through cross-contamination of utensils exposed to raw materials. To identify the main sources of contamination with this foodborne pathogen in four butcher shop environments, surface samples were obtained from employees' hands, cutting boards, knives, floor of the refrigeration room, meat grinders, and meat tenderizers (32 samples per area) and analyzed for Salmonella using the International Organization for Standardization method 6579, with modifications. Suspect isolates were identified by PCR (targeting ompC), and confirmed Salmonella isolates were subjected to pulsed-field gel electrophoresis (after treatment with restriction enzyme XbaI), analyzed for the presence of virulence genes (invA, sefA, and spvC), and screened for resistance to 12 antimicrobials. Salmonella isolates was identified only on cutting boards (five samples) from three butcher shops. Fifteen isolates were confirmed as Salmonella belonging to four pulse types (similarity of 71.1 to 100%). The invA gene was detected in 13 isolates, and the sefA was found in 8 isolates; no isolate carried spvC. All tested isolates were resistant to clindamycin and sensitive to amikacin and cefotaxine, and all isolates were resistant to at least 3 of the 12 antimicrobials tested. The results indicate the importance of cutting boards as a source of Salmonella contamination in butcher shops. The presence of multidrug-resistant Salmonella strains possessing virulence genes highlights the health risks for consumers.

  19. Electrochemical genosensing of Salmonella, Listeria and Escherichia coli on silica magnetic particles.

    Liébana, Susana; Brandão, Delfina; Cortés, Pilar; Campoy, Susana; Alegret, Salvador; Pividori, María Isabel

    2016-01-21

    A magneto-genosensing approach for the detection of the three most common pathogenic bacteria in food safety, such as Salmonella, Listeria and Escherichia coli is presented. The methodology is based on the detection of the tagged amplified DNA obtained by single-tagging PCR with a set of specific primers for each pathogen, followed by electrochemical magneto-genosensing on silica magnetic particles. A set of primers were selected for the amplification of the invA (278 bp), prfA (217 bp) and eaeA (151 bp) being one of the primers for each set tagged with fluorescein, biotin and digoxigenin coding for Salmonella enterica, Listeria monocytogenes and E. coli, respectively. The single-tagged amplicons were then immobilized on silica MPs based on the nucleic acid-binding properties of silica particles in the presence of the chaotropic agent as guanidinium thiocyanate. The assessment of the silica MPs as a platform for electrochemical magneto-genosensing is described, including the main parameters to selectively attach longer dsDNA fragments instead of shorter ssDNA primers based on their negative charge density of the sugar-phosphate backbone. This approach resulted to be a promising detection tool with sensing features of rapidity and sensitivity very suitable to be implemented on DNA biosensors and microfluidic platforms.

  20. Identification of cognate host targets and specific ubiquitylation sites on the Salmonella SPI-1 effector SopB/SigD

    Rogers, Lindsay D; Kristensen, Anders R; Boyle, Erin C;

    2008-01-01

    Salmonella enterica is a bacterial pathogen responsible for enteritis and typhoid fever. Virulence is linked to two Salmonella pathogenicity islands (SPI-1 and SPI-2) on the bacterial chromosome, each of which encodes a type III secretion system. While both the SPI-1 and SPI-2 systems secrete...

  1. Chimeric flagellin expressed by Salmonella typhimurium induces an ESAT-6-specific Th 1-type immune response and CTL effects following intranasal immunization

    Hui Zhang; Liu Liu; Ke Wen; Jinlin Huang; Shizhong Geng; Junsong Shen; Zhiming Pan; Xinan Jiao

    2011-01-01

    The flagellin component FliC of Salmonella typhimurium is capable of activating the innate immune system via specific interactions with TLR5 and can also act as a carrier of foreign antigen to elicit antigen-specific immune responses.Thus,we constructed an attenuated Salmonella strain SL5928(fliC/esat) expressing chimeric flagellin that contained the ESAT-6 antigen coding sequence of Mycobacterium tuberculosis inserted into the highly variable region of the Salmonella flagellin coding gene fliCi.The chimeric flagellin functioned normally,as demonstrated using a flagella swarming assay and electron microscopy.To analyze the effects of chimeric flagellin,the cell-mediated immune response and cytotoxic T lymphocyte (CTL) effects specific for ESAT-6antigen were tested after intranasal immunization of mice with flagellated Salmonella SL5928(fliC/esat).The results showed that SL5928(fliC/esat) intranasal immunization can strongly elicit an ESAT-6-specific T helper (Th) 1-type immune response in mucosal lymphoid tissues,such as nasopharynx-associated lymph nodes,lung and Peyer's patches,and a Th 1/Th2 response was elicited in spleen and mesenteric lymph nodes.Furthermore,intranasal immunization of SL5928(fliC/esat) produced efficient CTL effects,as demonstrated using a 5-and 6-carboxyfluorescein diacetate succinimidyl ester (CFSE) assay.Thus,our study revealed that Salmonella flagellin acts as a carrier for foreign antigen and triggers strong Th 1 and CTL responses during intranasal immunization.Chimeric flagellin is potentially an effective strategy for the development of novel vaccines against tuberculosis in humans and animals.

  2. Survival of Salmonella enterica in poultry feed is strain dependent.

    Andino, Ana; Pendleton, Sean; Zhang, Nan; Chen, Wei; Critzer, Faith; Hanning, Irene

    2014-02-01

    Feed components have low water activity, making bacterial survival difficult. The mechanisms of Salmonella survival in feed and subsequent colonization of poultry are unknown. The purpose of this research was to compare the ability of Salmonella serovars and strains to survive in broiler feed and to evaluate molecular mechanisms associated with survival and colonization by measuring the expression of genes associated with colonization (hilA, invA) and survival via fatty acid synthesis (cfa, fabA, fabB, fabD). Feed was inoculated with 1 of 15 strains of Salmonella enterica consisting of 11 serovars (Typhimurium, Enteriditis, Kentucky, Seftenburg, Heidelberg, Mbandanka, Newport, Bairely, Javiana, Montevideo, and Infantis). To inoculate feed, cultures were suspended in PBS and survival was evaluated by plating samples onto XLT4 agar plates at specific time points (0 h, 4 h, 8 h, 24 h, 4 d, and 7 d). To evaluate gene expression, RNA was extracted from the samples at the specific time points (0, 4, 8, and 24 h) and gene expression measured with real-time PCR. The largest reduction in Salmonella occurred at the first and third sampling time points (4 h and 4 d) with the average reductions being 1.9 and 1.6 log cfu per g, respectively. For the remaining time points (8 h, 24 h, and 7 d), the average reduction was less than 1 log cfu per g (0.6, 0.4, and 0.6, respectively). Most strains upregulated cfa (cyclopropane fatty acid synthesis) within 8 h, which would modify the fluidity of the cell wall to aid in survival. There was a weak negative correlation between survival and virulence gene expression indicating downregulation to focus energy on other gene expression efforts such as survival-related genes. These data indicate the ability of strains to survive over time in poultry feed was strain dependent and that upregulation of cyclopropane fatty acid synthesis and downregulation of virulence genes were associated with a response to desiccation stress.

  3. Quantification of mRNA in Salmonella sp. seeded soil and chicken manure using magnetic capture hybridization RT-PCR.

    Jacobsen, Carsten Suhr; Holben, William E

    2007-05-01

    Direct quantification of mRNA from Salmonella sp. seeded for 1 h to soil and chicken manure was accomplished using magnetic capture hybridization as a purification technique. This detection strategy targeted the invA gene present in Salmonella sp. After cell lysis, phenol/chloroform purification and isopropanol precipitation, the RNA extract was combined with the hybridization probe conjugated to paramagnetic beads. After hybridization, the captured nucleic acids were released by denaturation and purified of contaminating DNA using DNase. The resulting RNA was of high purity and there was no need for dilution of the samples prior to RT-PCR. The developed procedure was reproducibly used to quantify Salmonella sp. in high organic agricultural soil. The detection limit for mRNA using ordinary quantitative PCR (employing SYBRgreen-based detection) was 5 x 10(4)Salmonella sp. cells per gram of soil. Chicken manure amended into soil (1:4 w/w) did not reduce the ability to quantify Salmonella sp. mRNA in soil. Pasteurization (65 degrees C, 30 min) of chicken manure containing Salmonella sp. dramatically reduced the detection of invA mRNA (requiring 42 qPCR cycles for detection versus 26 cycles in unpasteurized manure), presumably due to degradation of the invA mRNA in Salmonella sp. cells killed by pasteurization. By contrast, DNA-based qPCR still detected Salmonella sp. in the pasteurized manure. Thus, in this case using samples seeded with fresh Salmonella sp. the mRNA-based detection appears to be superior to minimizing false-positive detection which was prevalent with DNA-based qPCR.

  4. Identification of Five Novel Salmonella Typhi-Specific Genes as Markers for Diagnosis of Typhoid Fever Using Single-Gene Target PCR Assays

    Yuan Xin Goay

    2016-01-01

    Full Text Available Salmonella Typhi (S. Typhi causes typhoid fever which is a disease characterised by high mortality and morbidity worldwide. In order to curtail the transmission of this highly infectious disease, identification of new markers that can detect the pathogen is needed for development of sensitive and specific diagnostic tests. In this study, genomic comparison of S. Typhi with other enteric pathogens was performed, and 6 S. Typhi genes, that is, STY0201, STY0307, STY0322, STY0326, STY2020, and STY2021, were found to be specific in silico. Six PCR assays each targeting a unique gene were developed to test the specificity of these genes in vitro. The diagnostic sensitivities and specificities of each assay were determined using 39 S. Typhi, 62 non-Typhi Salmonella, and 10 non-Salmonella clinical isolates. The results showed that 5 of these genes, that is, STY0307, STY0322, STY0326, STY2020, and STY2021, demonstrated 100% sensitivity (39/39 and 100% specificity (0/72. The detection limit of the 5 PCR assays was 32 pg for STY0322, 6.4 pg for STY0326, STY2020, and STY2021, and 1.28 pg for STY0307. In conclusion, 5 PCR assays using STY0307, STY0322, STY0326, STY2020, and STY2021 were developed and found to be highly specific at single-gene target resolution for diagnosis of typhoid fever.

  5. Identification of Five Novel Salmonella Typhi-Specific Genes as Markers for Diagnosis of Typhoid Fever Using Single-Gene Target PCR Assays.

    Goay, Yuan Xin; Chin, Kai Ling; Tan, Clarissa Ling Ling; Yeoh, Chiann Ying; Ja'afar, Ja'afar Nuhu; Zaidah, Abdul Rahman; Chinni, Suresh Venkata; Phua, Kia Kien

    2016-01-01

    Salmonella Typhi (S. Typhi) causes typhoid fever which is a disease characterised by high mortality and morbidity worldwide. In order to curtail the transmission of this highly infectious disease, identification of new markers that can detect the pathogen is needed for development of sensitive and specific diagnostic tests. In this study, genomic comparison of S. Typhi with other enteric pathogens was performed, and 6 S. Typhi genes, that is, STY0201, STY0307, STY0322, STY0326, STY2020, and STY2021, were found to be specific in silico. Six PCR assays each targeting a unique gene were developed to test the specificity of these genes in vitro. The diagnostic sensitivities and specificities of each assay were determined using 39 S. Typhi, 62 non-Typhi Salmonella, and 10 non-Salmonella clinical isolates. The results showed that 5 of these genes, that is, STY0307, STY0322, STY0326, STY2020, and STY2021, demonstrated 100% sensitivity (39/39) and 100% specificity (0/72). The detection limit of the 5 PCR assays was 32 pg for STY0322, 6.4 pg for STY0326, STY2020, and STY2021, and 1.28 pg for STY0307. In conclusion, 5 PCR assays using STY0307, STY0322, STY0326, STY2020, and STY2021 were developed and found to be highly specific at single-gene target resolution for diagnosis of typhoid fever.

  6. Phage-Based Fluorescent Biosensor Prototypes to Specifically Detect Enteric Bacteria Such as E. coli and Salmonella enterica Typhimurium.

    Manon Vinay

    Full Text Available Water safety is a major concern for public health and for natural environment preservation. We propose to use bacteriophages to develop biosensor tools able to detect human and animal pathogens present in water. For this purpose, we take advantage of the highly discriminating properties of the bacteriophages, which specifically infect their bacterial hosts. The challenge is to use a fluorescent reporter protein that will be synthesized, and thus detected, only once the specific recognition step between a genetically modified temperate bacteriophage and its bacterial host has occurred. To ensure the accuracy and the execution speed of our system, we developed a test that does not require bacterial growth, since a simple 1-hour infection step is required. To ensure a high sensitivity of our tool and in order to detect up to a single bacterium, fluorescence is measured using a portable flow cytometer, also allowing on-site detection. In this study, we have constructed and characterized several "phagosensor" prototypes using the HK620 bacteriophage and its host Escherichia coli TD2158 and we successfully adapted this method to Salmonella detection. We show that the method is fast, robust and sensitive, allowing the detection of as few as 10 bacteria per ml with no concentration nor enrichment step. Moreover, the test is functional in sea water and allows the detection of alive bacteria. Further development will aim to develop phagosensors adapted on demand to the detection of any human or animal pathogen that may be present in water.

  7. Multiplex PCR for the concurrent detection and differentiation of Salmonella spp., Salmonella Typhi and Salmonella Typhimurium

    Pui, Chai Fung; Wong, Woan Chwen; Chai, Lay Ching; Lee, Hai Yen; Noorlis, Ahmad; Zainazor, Tuan Chilek Tuan; Tang, John Yew Huat; Ghazali, Farinazleen Mohamad; Cheah, Yoke Kqueen; Nakaguchi, Yoshitsugu; Nishibuchi, Mitsuaki; Radu, Son

    2011-01-01

    Salmonellosis outbreaks involving typhoid fever and human gastroenteritis are important diseases in tropical countries where hygienic conditions are often not maintained. A rapid and sensitive method to detect Salmonella spp., Salmonella Typhi and Salmonella Typhimurium is needed to improve control and surveillance of typhoid fever and Salmonella gastroenteritis. Our objective was the concurrent detection and differentiation of these food-borne pathogens using a multiplex PCR. We therefore designed and optimized a multiplex PCR using three specific PCR primer pairs for the simultaneous detection of these pathogens. The concentration of each of the primer pairs, magnesium chloride concentration, and primer annealing temperature were optimized before verification of the specificity of the primer pairs. The target genes produced amplicons at 429 bp, 300 bp and 620 bp which were shown to be 100% specific to each target bacterium, Salmonella spp., Salmonella Typhi and Salmonella Typhimurium, respectively. PMID:22028607

  8. An oral Salmonella-based vaccine inhibits liver metastases by promoting tumor-specific T cell-mediated immunity in celiac & portal lymph nodes. A preclinical study.

    Alejandrina eVendrell

    2016-03-01

    Full Text Available Primary tumor excision is one of the therapies of cancer most widely used. However, the risk of metastases development still exists following tumor resection. The liver is a common site of metastatic disease for numerous cancers. Breast cancer is one of the most frequent source of metastases to the liver. The aim of this work was to evaluate the efficacy of the orally-administered Salmonella Typhi vaccine strain CVD 915 on the development of liver metastases in a mouse model of breast cancer. To this end, one group of BALB/c mice was immunized with CVD 915 via o.g. while another received PBS as a control. After 24 h, mice were injected with LM3 mammary adenocarcinoma cells into the spleen and subjected to splenectomy. This oral Salmonella-based vaccine produced an antitumor effect, leading to a decrease in the number and volume of liver metastases. Immunization with Salmonella induced an early cellular immune response in mice. This innate stimulation rendered a large production of IFN-γ by intrahepatic immune cells (IHIC detected within 24 h. An antitumor adaptive immunity was found in the liver and celiac & portal lymph nodes (LDLN 21 days after oral bacterial inoculation. The antitumor immune response inside the liver was associated with increased CD4+ and DC cell populations as well as with an inflammatory infiltrate located around liver metastatic nodules. Enlarged levels of inflammatory cytokines (IFN-γ and TNF were also detected in IHIC. Furthermore, a tumor-specific production of IFN-γ and TNF as well as tumor-specific IFN-γ-producing CD8 T cells (CD8+IFN-γ+ were found in the celiac & portal lymph nodes of Salmonella-treated mice. This study provides first evidence for the involvement of LDLN in the development of an efficient cellular immune response against hepatic tumors, which resulted in the elimination of liver metastases after oral Salmonella-based vaccination.

  9. An Oral Salmonella-Based Vaccine Inhibits Liver Metastases by Promoting Tumor-Specific T-Cell-Mediated Immunity in Celiac and Portal Lymph Nodes: A Preclinical Study.

    Vendrell, Alejandrina; Mongini, Claudia; Gravisaco, María José; Canellada, Andrea; Tesone, Agustina Inés; Goin, Juan Carlos; Waldner, Claudia Inés

    2016-01-01

    Primary tumor excision is one of the most widely used therapies of cancer. However, the risk of metastases development still exists following tumor resection. The liver is a common site of metastatic disease for numerous cancers. Breast cancer is one of the most frequent sources of metastases to the liver. The aim of this work was to evaluate the efficacy of the orally administered Salmonella Typhi vaccine strain CVD 915 on the development of liver metastases in a mouse model of breast cancer. To this end, one group of BALB/c mice was orogastrically immunized with CVD 915, while another received PBS as a control. After 24 h, mice were injected with LM3 mammary adenocarcinoma cells into the spleen and subjected to splenectomy. This oral Salmonella-based vaccine produced an antitumor effect, leading to a decrease in the number and volume of liver metastases. Immunization with Salmonella induced an early cellular immune response in mice. This innate stimulation rendered a large production of IFN-γ by intrahepatic immune cells (IHIC) detected within 24 h. An antitumor adaptive immunity was found in the liver and celiac and portal lymph nodes (LDLN) 21 days after oral bacterial inoculation. The antitumor immune response inside the liver was associated with increased CD4(+) and dendritic cell populations as well as with an inflammatory infiltrate located around liver metastatic nodules. Enlarged levels of inflammatory cytokines (IFN-γ and TNF) were also detected in IHIC. Furthermore, a tumor-specific production of IFN-γ and TNF as well as tumor-specific IFN-γ-producing CD8 T cells (CD8(+)IFN-γ(+)) were found in the celiac and portal lymph nodes of Salmonella-treated mice. This study provides first evidence for the involvement of LDLN in the development of an efficient cellular immune response against hepatic tumors, which resulted in the elimination of liver metastases after oral Salmonella-based vaccination.

  10. Impact of invA-PCR and culture detection methods on occurrence and survival of salmonella in the flesh, internal organs and lymphoid tissues of experimentally infected pigs.

    Arnold, T; Scholz, H C; Marg, H; Rösler, U; Hensel, A

    2004-12-01

    This study evaluated the suitability of invA gene amplification by PCR as an effective means of detecting Salmonella species in pigs experimentally infected with S. Typhimurium DT104. A controlled infection study using 24 pigs was performed in order to compare efficacy, precision and detection rates of the invA-based PCR method originally described by Rahn, K. De Grandis, S.A., Clarke, R.C., McEwan, S.A., Galan, J.E., Ginocchio, C., Curtiss, R. 3rd, C.L. Gyles, (Mol. Cell. Probes 1992; 6: 271-279) as a new in-house invA-based PCR method for the specific detection of Salmonella spp. in pork and different tissue samples of slaughter pigs. Finally, PCR results were compared with culture detection rates obtained by isolation procedures following the ISO 6579:2000, the 'gold standard'. After slaughtering, 14 different tissue samples of each pig were investigated to verify the usefulness of the two invA-based PCR methods in different matrices of slaughter pigs. The results demonstrate that the application of the widely used invA-based primer pair (139 + 141) may result in questionable products if samples gained from selective enrichment in the Rappaport-Vassiliadis medium were investigated. These questionable products can lead to false-positive results, if no additional hybridization procedure is attached or if unspecialized persons use this method in routine laboratory practice. The newly developed in-house PCR method used is based on the 3'-prime region of invA, especially designed and harmonized for the detection of Salmonella in different matrices of slaughtered pigs after bacterial enriched broth culture. In this study, this PCR revealed no questionable products and, furthermore, the specificity of the amplificate could be tested by means of the restriction enzyme NdeI. In comparison with the culture detection procedure, the new PCR method has a sensitivity of 100% and a specificity of 96%. Thus, this method might be used as a meaningful tool in eliminating

  11. Isolation and identification of Salmonella from diarrheagenic infants and young animals, sewage waste and fresh vegetables

    Amruta Nair

    2015-05-01

    Full Text Available Aim: This study was carried out to determine the prevalence, distribution, and identification of Salmonella serotypes in diarrheagenic infants and young animals, including sewage waste and fresh vegetables. Materials and Methods: A total of 550 samples were processed for the isolation of Salmonella spp., using standard microbiological and biochemical tests. Further polymerase chain reaction (PCR detection of Salmonella genus was carried out using self-designed primers targeting invA gene and thereafter identification of important serotypes namely Salmonella Enterica serovar Typhimurium, Salmonella Enterica serovar Enteritidis, Salmonella Enterica serovar Typhi was performed using published standardized multiplex PCR. Results: An overall low prevalence of 2.5% (14/550 was observed. The observed prevalence of Salmonella spp. in diarrheagenic infants was 1.2% (05/400, diarrheagenic young animals 4% (02/50, sewage waste 10% (05/50, and fresh vegetables 4% (02/50, respectively. In diarrheagenic infants, of the five Salmonella isolates identified, two were Salmonella Typhimurium, two Salmonella Enteritidis, and one was unidentified and hence designated as other Salmonella serovar. All the Salmonella isolates identified from diarrheagenic young animals and sewage waste belonged to other Salmonella serovar, whereas, of the two isolates recovered from fresh vegetables, one was identified as other Salmonella serovar, and one as Salmonella Typhimurium, respectively. Conclusion: Isolation of Salmonella spp. especially from sewage waste and fresh vegetable is a matter of great concern from public health point of view because these sources can accidentally serve as a potential vehicle for transmission of Salmonella spp. to animals and human beings.

  12. 空肠弯曲菌和沙门菌双重实时荧光定量 PCR 检测方法的建立%Duplex Real-time PCR for Simultaneous Detection of Campylobacter jejuni and Salmonella

    高瑞娟; 张凯; 吕嘉敏; 黄永兴; 罗开健

    2014-01-01

    This study aimed to establish a rapid detection of Campylobacter jejuni and Salmonella by duplex real-time PCR.The primers and Taq man probes were designed based on the invA gene of Salmonella and hipO gene of Campylobacter jejuni ,using FAM,JOE and TAMRA fluorescently labeled specific probes aimed at the conserved genes of target pathogens,respectively.We compared Tm values to fix these primers and probes,and optimize the reaction conditions to establish the duplex real-time PCR approach for the detection of Campylobacter jejuni and Salmonella.The sensitivity of the duplex real-time PCR was 10 CFU/mL,230 CFU/mL for Campylobacterjejuni and Salmonella.The duplex real-time PCR showed good specificity which was validated by testing various bacteria isolates.In this study,a duplex PCR with high specificity and sensitivity was developed and it would provide useful information for the simultaneous detection of Campylobacter jejuni and Salmonella in food.%为建立一种空肠弯曲菌和沙门菌的双重实时荧光定量 PCR 检测方法,根据空肠弯曲菌的保守基因 hipO 和沙门菌的保守基因 invA 分别设计合成引物和 TaqMan 探针,分别使用 FAM、JOE 作为探针报告基团,TAMRA 作为探针淬灭基团。优化反应体系及条件,建立适用于检测食品中空肠弯曲菌和沙门菌的双重实时荧光定量 PCR 方法。结果显示,该检测方法特异性强,灵敏度高,空肠弯曲菌检测限可达10 CFU/mL,沙门菌检测限达230 CFU/mL。表明建立的双重实时荧光定量 PCR 可为实现食品中空肠弯曲菌和沙门菌的同时检测提供新方法。

  13. Effect of operating conditions in production of diagnostic Salmonella Enteritidis O-antigen-specific monoclonal antibody in different bioreactor systems.

    Ayyildiz-Tamis, Duygu; Nalbantsoy, Ayse; Elibol, Murat; Deliloglu-Gurhan, Saime Ismet

    2014-01-01

    In this study, different cultivation systems such as roller bottles (RB), 5-L stirred-tank bioreactor (STR), and disposable bioreactors were used to cultivate hybridoma for lab-scale production of Salmonella Enteritidis O-antigen-specific monoclonal antibody (MAb). Hybridoma cell line was cultivated in either serum-containing or serum-free medium (SFM) culture conditions. In STR, MAb production scaled up to 4 L, and production capabilities of the cells were also evaluated in different featured production systems. Moreover, the growth parameters of the cells in all production systems such as glucose consumption, lactate and ammonia production, and also MAb productivities were determined. Collected supernatants from the reactors were concentrated by a cross-flow filtration system. In conclusion, cells were not adapted to SFM in RB and STR. Therefore, less MAb titer in both STR and RB systems with SFM was observed compared to the cultures containing fetal bovine serum-supplemented medium. A higher MAb titer was gained in the membrane-aerated system compared to those in STR and RB. Although the highest MAb titer was obtained in the static membrane bioreactor system, the highest productivity was obtained in STR operated in semicontinuous mode with overlay aeration.

  14. Expression, purification and immobilization of the intracellular invertase INVA, from Zymomonas mobilis on crystalline cellulose and Nylon-6.

    de Los Angeles Calixto-Romo, María; Santiago-Hernández, José Alejandro; Vallejo-Becerra, Vanessa; Amaya-Delgado, Lorena; del Carmen Montes-Horcasitas, María; Hidalgo-Lara, María Eugenia

    2008-11-01

    This paper presents two immobilization methods for the intracellular invertase (INVA), from Zymomonas mobilis. In the first method, a chimeric protein containing the invertase INVA, fused through its C-terminus to CBDCex from Cellulomonas fimi was expressed in Escherichia coli strain BL21 (DE3). INVA was purified and immobilized on crystalline cellulose (Avicel) by means of affinity, in a single step. No changes were detected in optimal pH and temperature when INVA-CBD was immobilized on Avicel, where values of 5.5 and 30 degrees C, respectively, were registered. The kinetic parameters of the INVA-CBD fusion protein were determined in both its free form and when immobilized on Avicel. Km and Vmax were affected with immobilization, since both showed an increase of up to threefold. Additionally, we found that subsequent to immobilization, the INVA-CBD fusion protein was 39% more susceptible to substrate inhibition than INVA-CBD in its free form. The second method of immobilization was achieved by the expression of a 6xHis-tagged invertase purified on Ni-NTA resin, which was then immobilized on Nylon-6 by covalent binding. An optimal pH of 5.5 and a temperature of 30 degrees C were maintained, subsequent to immobilization on Nylon-6 as well as with immobilization on crystalline cellulose. The kinetic parameters relating to Vmax increased up to 5.7-fold, following immobilization, whereas Km increased up to 1.7-fold. The two methods were compared showing that when invertase was immobilized on Nylon-6, its activity was 1.9 times that when immobilized on cellulose for substrate concentrations ranging from 30 to 390 mM of sucrose.

  15. Development of Loop-Mediate Isothermal Amplification Assay for Salmonella Detection in Food%食品中沙门氏菌LAMP快速检测方法的建立

    黄金海; 孙跃辉; 陈瑞; 庄世文; 刘莹; 王静思

    2012-01-01

    It is important to detect Salmonella in food or food materials in order to assure the food safety. A rapid sensitive loop-mediated isothermal amplification (LAMP) method assay for the food-borne pathogen Salmonella detection was developed. A set of primers were designed according to the nucleotide sequence of the target invA gene in Salmonella, 7 strains of Salmonella and 4 non--Salmonella bacteria were detected by LAMP, and meanwhile the mode of artificially contaminated food was constructed to evaluate the sensitivity of LAMP assay and bacterial cell counting method. The results showed that all the 7 Salmonella bacterial strains had specific amplification, but the 4 non-Salmonella bacterial strains submitted negative reactions. Sensitivity of LAMP assay for pure cell culture of Salmonella was 336 mL-1. However, an 8.25 g-1 detection limit was obtained for Salmonella artificially contaminated food following a bacterial culture enrichment process, while there was no amplification from the negative control. In conclusion, the LAMP assay developed in the present study is a specific, sensitive, simple and convenient method for the rapid detection of Salmonella in contaminated foods.%食品及其原料中沙门氏茵的快速、现场检测对食品安全控制具有重要意义.根据沙门氏茵invA基因核苷酸序列设计一组引物,应用环介导等温扩增技术(LAMP),分别对7种不同血清型沙门氏茵和4种非沙门氏茵进行扩增,同时建立沙门氏茵人工污染的食品模型,比较了LAMP法与活茵计数检测的敏感性.结果表明,该方法仅对沙门氏菌产生特异性扩增,灵敏度高达336mL-1,食品样品经细菌富集培养后,检测灵敏度高达8.25g-1.所建立的检测沙门氏茵方法具有较高的特异性与灵敏性,操作简单、快速,可用于沙门氏茵污染食品的快速检测.

  16. Detection of virulence genes in Salmonella Enteritidis isolated from different sources Detecção de genes de virulência in Salmonella Enteritidis isoladas de diferentes fontes

    Sílvia Dias de Oliveira

    2003-11-01

    Full Text Available The presence of three virulence genes, invA, spvR, and spvC, was determined in Salmonella Enteritidis isolated from poultry, pigs, humans and food. All isolates were positive for the invA gene, with 91.2% being positive for spvR and 90.2% for spvC. There was no significant difference in the prevalence of the virulence genes between isolates from different sources. The results indicate that there is a putative high virulence potential for the S. Enteritidis isolates characterized.A presença de três genes de virulência (invA, spvR e spvC foi determinada em Salmonella Enteritidis isoladas de aves, suínos, humanos e alimentos. Todos os isolados foram positivos para o gene invA, 91,2% também foram positivos para o spvR e 90,2% para o spvC. Não existiu diferença significativa na prevalência dos genes de virulência entre isolados de diferentes origens. Os resultados indicaram que, provavelmente, exista um alto potencial de virulência nos isolados de S. Enteritidis caracterizados.

  17. Acid environments affect biofilm formation and gene expression in isolates of Salmonella enterica Typhimurium DT104.

    O'Leary, Denis; McCabe, Evonne M; McCusker, Matthew P; Martins, Marta; Fanning, Séamus; Duffy, Geraldine

    2015-08-01

    The aim of this study was to examine the survival and potential virulence of biofilm-forming Salmonella Typhimurium DT104 under mild acid conditions. Salmonella Typhimurium DT104 employs an acid tolerance response (ATR) allowing it to adapt to acidic environments. The threat that these acid adapted cells pose to food safety could be enhanced if they also produce biofilms in acidic conditions. The cells were acid-adapted by culturing them in 1% glucose and their ability to form biofilms on stainless steel and on the surface of Luria Bertani (LB) broth at pH7 and pH5 was examined. Plate counts were performed to examine cell survival. RNA was isolated from cells to examine changes in the expression of genes associated with virulence, invasion, biofilm formation and global gene regulation in response to acid stress. Of the 4 isolates that were examined only one (1481) that produced a rigid biofilm in LB broth at pH7 also formed this same structure at pH5. This indicated that the lactic acid severely impeded the biofilm producing capabilities of the other isolates examined under these conditions. Isolate 1481 also had higher expression of genes associated with virulence (hilA) and invasion (invA) with a 24.34-fold and 13.68-fold increase in relative gene expression respectively at pH5 compared to pH7. Although genes associated with biofilm formation had increased expression in response to acid stress for all the isolates this only resulted in the formation of a biofilm by isolate 1481. This suggests that in addition to the range of genes associated with biofilm production at neutral pH, there are genes whose protein products specifically aid in biofilm production in acidic environments. Furthermore, it highlights the potential for the use of lactic acid for the inhibition of Salmonella biofilms.

  18. Electrochemical genosensing of Salmonella, Listeria and Escherichia coli on silica magnetic particles

    Liébana, Susana; Brandão, Delfina [Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès (Bellaterra) (Spain); Cortés, Pilar; Campoy, Susana [Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès (Bellaterra) (Spain); Alegret, Salvador [Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès (Bellaterra) (Spain); Pividori, María Isabel, E-mail: Isabel.Pividori@uab.cat [Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès (Bellaterra) (Spain)

    2016-01-21

    A magneto-genosensing approach for the detection of the three most common pathogenic bacteria in food safety, such as Salmonella, Listeria and Escherichia coli is presented. The methodology is based on the detection of the tagged amplified DNA obtained by single-tagging PCR with a set of specific primers for each pathogen, followed by electrochemical magneto-genosensing on silica magnetic particles. A set of primers were selected for the amplification of the invA (278 bp), prfA (217 bp) and eaeA (151 bp) being one of the primers for each set tagged with fluorescein, biotin and digoxigenin coding for Salmonella enterica, Listeria monocytogenes and E. coli, respectively. The single-tagged amplicons were then immobilized on silica MPs based on the nucleic acid-binding properties of silica particles in the presence of the chaotropic agent as guanidinium thiocyanate. The assessment of the silica MPs as a platform for electrochemical magneto-genosensing is described, including the main parameters to selectively attach longer dsDNA fragments instead of shorter ssDNA primers based on their negative charge density of the sugar-phosphate backbone. This approach resulted to be a promising detection tool with sensing features of rapidity and sensitivity very suitable to be implemented on DNA biosensors and microfluidic platforms. - Highlights: • Silica magnetic particles were used for the first time as carrier in electrochemical magneto-genosensing of single-tagged amplicons. • They demonstrated to be a robust platform for the electrochemical detection of PCR products. • Differential adsorption properties for longer dsDNA amplicon incorporating the tagging primers over shorter ssDNA tagged primers were observed due to the negative charge density. • Electrochemical magneto-genosensing of Salmonella enterica, Listeria monocytogenes and Escherichia coli was successfully performed.

  19. Specific responses of Salmonella enterica to tomato varieties and fruit ripeness identified by in vivo expression technology.

    Jason T Noel

    Full Text Available BACKGROUND: Recent outbreaks of vegetable-associated gastroenteritis suggest that enteric pathogens colonize, multiply and persist in plants for extended periods of time, eventually infecting people. Genetic and physiological pathways, by which enterics colonize plants, are still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: To better understand interactions between Salmonella enterica sv. Typhimurium and tomatoes, a gfp-tagged Salmonella promoter library was screened inside red ripe fruits. Fifty-one unique constructs that were potentially differentially regulated in tomato relative to in vitro growth were identified. The expression of a subset of these promoters was tested in planta using recombinase-based in vivo expression technology (RIVET and fitness of the corresponding mutants was tested. Gene expression in Salmonella was affected by fruit maturity and tomato cultivar. A putative fadH promoter was upregulated most strongly in immature tomatoes. Expression of the fadH construct depended on the presence of linoleic acid, which is consistent with the reduced accumulation of this compound in mature tomato fruits. The cysB construct was activated in the fruit of cv. Hawaii 7997 (resistant to a race of Ralstonia solanacearum more strongly than in the universally susceptible tomato cv. Bonny Best. Known Salmonella motility and animal virulence genes (hilA, flhDC, fliF and those encoded on the pSLT virulence plasmid did not contribute significantly to fitness of the bacteria inside tomatoes, even though deletions of sirA and motA modestly increased fitness of Salmonella inside tomatoes. CONCLUSIONS/SIGNIFICANCE: This study reveals the genetic basis of the interactions of Salmonella with plant hosts. Salmonella relies on a distinct set of metabolic and regulatory genes, which are differentially regulated in planta in response to host genotype and fruit maturity. This enteric pathogen colonizes tissues of tomatoes differently than plant

  20. Gastrointestinal tract distribution of Salmonella enteritidis in orally infected mice with a species-specific fluorescent quantitative polymerase chain reaction

    2007-01-01

    AIM: To identify and understand the regular distribution pattern and primary penetration site for Salmonella enteritidis (S. enteritidis) in the gastrointestinal tract.METHODS: Based on the species-specific DNA sequence of S. enteritidis from GenBank, a species-specific real-time, fluorescence-based quantitative polymerase chain reaction (FQ-PCR) was developed for the detection of S.enteritidis. We used this assay to detect genomic DNA of S. enteritidis in the gastrointestinal tract, including duodenum, jejunum, ileum, cecum, colon, rectum,esophagus and stomach, from mice after oral infection.RESULTS: S. enteritidis was consistently detected in all segments of the gastrointestinal tract. The jejunum and ileum were positive at 8 h post inoculation, and the final organ to show a positive result was the stomach at 18 h post inoculation. The copy number of S. enteritidis DNA in each tissue reached a peak at 24-36 h post inoculation,with the jejunum, ileum and cecum containing high concentrations of S. enteritidis, whereas the duodenum,colon, rectum, stomach and esophagus had low concentrations. S. enteritidis began to decrease and vanished at 2 d post inoculation, but it was still present up to 5 d post inoculation in the jejunum, ileum and cecum, without causing apparent symptoms. By 5 d post inoculation, the cecum had significantly higher numbers of S. enteritidis than any of the other areas (P < 0.01),and this appeared to reflect its function as a repository for S. enteritidis.CONCLUSION: The results provided significant data for clarifying the pathogenic mechanism of S. enteritidis in the gastrointestinal tract, and showed that the jejunum,ileum and cecum are the primary sites of invasion in normal mice after oral infection. This study will help to further understanding of the mechanisms of action of S.enteritidis.

  1. IDENTIFICATION AND ANTIMICROBIAL SUSCEPTIBILITY OF SALMONELLA GALLINARUM ISOLATED FROM FOWL TYPHOID OUTBREAK IN BACKYARD VANARAJA FOWL

    S. Dey

    2016-06-01

    Full Text Available From a disease outbreak among Vanaraja fowl, an indigenous Indian Breed reared by backyard system in Jhargram, West Bengal, Salmonella Gallinarum was isolated and characterised. The outbreak occurred among 6-8 day old chicks. A total of 150 birds died in a span of 5 days. Salmonella Gallinarum were identified and confirmed by standard bacteriological methods and presence of invasion ( invA gene was detected by PCR. The isolates were susceptible to 15 common antimicrobials in vitro. Although chemotherapy may be effective, outbreaks of fowl typhoid in backyard poultry warranted precise control policy

  2. Salmonella Prevention

    ... FDA) USDA Food Safety and Inspection Service Follow Salmonella RSS Prevention Recommend on Facebook Tweet Share Compartir Quick Tips for Preventing Salmonella Cook poultry, ground beef, and eggs thoroughly. Do ...

  3. Simplest identification, O-specific polysaccharide purification and antigenic evaluation of Salmonella enterica serovar Typhi Vi negative isolate.

    Salman, Muhammad; Ali, Aamir; Jabbar, Abdul; Sarwar, Yasra; Rahman, Moazur; Iqbal, Mazhar; Haque, Abdul

    2015-01-01

    Currently licensed typhoid vaccines are based on Vi capsular polysaccharides. Recent molecular reports from typhoid endemic countries state that Salmonella enterica serovar Typhi (S. Typhi) Vi negative strains occur naturally and cause typhoid fever which is indistinguishable from disease caused by Vi positive strains. Vaccine based on Vi polysaccharide may not protect patients if the invading S. Typhi are negative for Vi. The lipopolysaccharide (LPS) is an essential component of S. Typhi outer membrane in which O-specific polysaccharide (OSP) is a protective antigen and universal candidate for vaccine development. In this study, S. Typhi Vi negative isolates were discriminated from Vi positive isolates through a duplex PCR using primers of fliC-d (599bp) and tviA (495bp) genes. The LPS of S. Typhi Vi negative isolates was extracted by hot phenol method and OSP was purified by core hydrolysis. The yield of extracted LPS was 91 mg/L and that of purified OSP was 49.14 mg/L of culture broth. LPS showed ladder like appearance by zinc imidazole staining following SDS-PAGE. Whole cell challenged mice sera were used for in vitro antigenicity evaluation of the purified LPS and OSP. The antigenicity was found adequate by immunodiffusion assay. To our knowledge, this is the first report of purification and antigenic evaluation of LPS of a Vi negative S. Typhi isolate. The purified OSP from S. Typhi Vi negative isolate may be coupled with a carrier protein to produce universal low cost conjugate vaccine candidates for use in typhoid endemic regions.

  4. THE USE OF THE SPECIFIC ANTI-SALMONELLA POLYCLONAL ANTIBODIES ISOLATED FROM HEN EGGS, IN SALMONELLOSIS PROPHYLAXIS

    ADRIANA CRISTE

    2013-12-01

    Full Text Available The administration of increased doses of antibodies in groups experimentallyinfected with Salmonella gallinarum, in order to record the efficiency of theiradministration in salmonellosis prophylaxis was the aim of our research. When alow infection dose, 1x107 CFU Salmonella gallinarum, was used theadministration of IgY polyclonal antibodies as immunoglobulin extract, or evenyolk administration had a protective effect against germs invasion. This effect wasnot recorded when a 10 folds higher dose was administered (1x108 CFU. Theprophylactic effect of the administration of polyclonal antibodies is demonstrated.

  5. Antibiotic resistance and diversity of Salmonella enterica serovars associated with broiler chickens.

    Diarra, Moussa Sory; Delaquis, Pascal; Rempel, Heidi; Bach, Susan; Harlton, Colleen; Aslam, Mueen; Pritchard, Jane; Topp, Edward

    2014-01-01

    The objective of this study was to analyze the antibiotic resistance phenotype and genotype of Salmonella isolated from broiler production facilities. A total of 193 Salmonella isolates recovered from commercial farms in British Columbia, Canada, were evaluated. Susceptibility to antibiotics was determined with the Sensititre system. Virulence and antibiotic resistance genes were detected by PCR assay. Genetic diversity was determined by pulse-field gel electrophoresis (PFGE) typing. Seventeen serovars of Salmonella were identified. The most prevalent Salmonella serovars were Kentucky (29.0% of isolates), Typhimurium (23.8%), Enteritidis (13.5%), and Hadar (11.9%); serovars Heidelberg, Brandenburg, and Thompson were identified in 7.7, 4.1, and 3.6% of isolates, respectively. More than 43% of the isolates were simultaneously resistant to ampicillin, amoxicillin-clavulanic acid, ceftiofur, cefoxitim, and ceftriaxone. This β-lactam resistance pattern was observed in 33 (58.9%) of the Salmonella Kentucky isolates; 2 of these isolates were also resistant to chloramphenicol, streptomycin, sulfisoxazole, and tetracycline. Genes associated with resistance to aminoglycosides (aadA1, aadA2, and strA), β-lactams (blaCMY-2, blaSHV, and blaTEM), tetracycline (tetA and tetB), and sulfonamide (sul1) were detected among corresponding resistant isolates. The invasin gene (invA) and the Salmonella plasmid virulence gene (spvC) were found in 97.9 and 25.9% of the isolates, respectively, with 33 (71.7%) of the 46 Salmonella Typhimurium isolates and 17 (65.4%) of the 26 Salmonella Enteritidis isolates carrying both invA and spvC. PGFE typing revealed that the antibiotic-resistant serovars were genetically diverse. These data confirm that broiler chickens can be colonized by genetically diverse antibiotic-resistant Salmonella isolates harboring virulence determinants. The presence of such strains is highly relevant to food safety and public health.

  6. Salmonella: Salmonellosis

    Löfström, Charlotta; Hansen, Trine; Maurischat, Sven

    2015-01-01

    Salmonella remains one of the most important zoonotic pathogenic bacteria and is the causative agents of salmonellosis. The aim of this article is to give an overview of Salmonella and salmonellosis, starting by describing the characteristics of the microorganism Salmonella, including biochemical...

  7. PCR detection and microbiological isolation of Salmonella spp. from fresh beef and cantaloupes.

    Gallegos-Robles, M A; Morales-Loredo, A; Alvarez-Ojeda, G; Osuna-García, J A; Martínez, I O; Morales-Ramos, L H; Fratamico, P

    2009-01-01

    Species belonging to the genus Salmonella are an important cause of enteric fevers, gastroenteritis, and septicemia, and the pathogens are commonly transmitted through contaminated food. In this study, polymerase chain reaction (PCR) amplification of a 287-bp region of the invA gene was compared to a microbiological technique to determine the presence of Salmonella in retail beef and in cantaloupe rinse samples. Both methods showed the same level of sensitivity, detecting 1 CFU/25 g of meat after enrichment for 24 h at 42 degrees C. The presence of Salmonella was determined in 50 commercial top sirloin beef samples that were not artificially inoculated. Three samples were positive by the microbiological method, and these samples and an additional sample were positive by the PCR. Both methods were also used to test surface rinses of cantaloupes collected from 4 farms in Nayarit, Mexico. Salmonella was detected by the microbiological method in 9 of 20 samples (45%), whereas the pathogen was detected by the PCR in 11 samples (55%). This study demonstrates the utility of the PCR targeting the invA gene to determine the presence of Salmonella spp. in beef and cantaloupe samples.

  8. [Salmonella pathogenicity islands].

    Sırıken, Belgin

    2013-01-01

    Salmonella species are facultative intracellular pathogenic bacteria. They can invade macrophages, dendritic and epithelial cells. The responsible virulence genes for invasion, survival, and extraintestinal spread are located in Salmonella pathogenicity islands (SPIs). SPIs are thought to be acquired by horizontal gene transfer. Some of the SPIs are conserved throughout the Salmonella genus, and some of them are specific for certain serovars. There are differences between Salmonella serotypes in terms of adaptation to host cell, virulence factors and the resulting infection according to SPA presence and characteristics. The most important Salmonella virulence gene clusters are located in 12 pathogenicity islands. Virulence genes that are involved in the intestinal phase of infection are located in SPI-1 and SPI-2 and the remaining SPIs are required for intracellular survival, fimbrial expression, magnesium and iron uptake, multiple antibiotic resistance and the development of systemic infections. In addition SPIs, Sigma ss (RpoS) factors and adaptive acid tolerance response (ATR) are the other two important virulence factors. RpoS and ATR found in virulent Salmonella strains help the bacteria to survive under inappropriate conditions such as gastric acidity, bile salts, inadequate oxygen concentration, lack of nutrients, antimicrobial peptides, mucus and natural microbiota and also to live in phagosomes or phagolysosomes. This review article summarizes the data related to pathogenicity islands in Salmonella serotypes and some factors which play role in the regulation of virulence genes.

  9. Antigen-Specific B Cells Reactivate an Effective Cytotoxic T Cell Response against Phagocytosed Salmonella through Cross-Presentation

    de Wit, J.; Souwer, Y.; Jorritsma, T.; Bos, H.; ten Brinke, A.; Neefjes, J.; Ham, S.M.

    2010-01-01

    Background: The eradication of facultative intracellular bacterial pathogens, like Salmonella typhi, requires the concerted action of both the humoral immune response and the cytotoxic CD8(+) T cell response. Dendritic cells (DCs) are considered to orchestrate the cytotoxic CD8(+) T cell response vi

  10. Induction of feline immunodeficiency virus specific antibodies in cats with an attenuated Salmonella strain expressing the Gag protein.

    E.J. Tijhaar (Edwin); C.H.J. Siebelink (Kees); J.A. Karlas (Jos); M.C. Burger; F.R. Mooi (Frits); A.D.M.E. Osterhaus (Albert)

    1997-01-01

    textabstractSalmonella typhimurium aroA strains (SL3261), expressing high levels of the Gag protein of feline immunodeficiency virus (FIV) fused with maltose binding protein (SL3261-MFG), were constructed using an invertible promoter system that allows the stable expression of heterologous antigens

  11. Estimated Numbers of Community Cases of Illness Due to Salmonella, Campylobacter and Verotoxigenic Escherichia Coli: Pathogen-Specific Community Rates

    M Kate Thomas

    2006-01-01

    Full Text Available OBJECTIVE: To estimate the annual number of cases of illness due to verotoxigenic Escherichia coli (VTEC, Salmonella and Campylobacter in the Canadian population, using data from the National Notifiable Disease registry (NND, estimates of under-reporting derived from several National Studies on Acute Gastrointestinal Illness, and the literature.

  12. Development of RNA aptamers for detection of Salmonella Enteritidis.

    Hyeon, Ji-Yeon; Chon, Jung-Whan; Choi, In-Soo; Park, Chankyu; Kim, Dong-Eun; Seo, Kun-Ho

    2012-04-01

    We developed and evaluated RNA aptamers to analyze their potential for use in detecting Salmonella Enteritidis. The selected aptamer was observed to specifically bind to Salmonella Enteritidis without any cross-reactivity to other Salmonella serovars. Thus, this study suggests that aptamers specific to Salmonella Enteritidis have a high potential for use in presumptive presumptive screening methods or alternative serotyping methods.

  13. Establishment and application of Real- Time PCR with probe in detection of salmonella in food poisoning%Real - Time PCR探针法检测食物中毒中沙门菌方法建立及应用

    宋士利; 檀薇; 张丽

    2012-01-01

    Objective:To establish a real - time PCR method for direct amplification of the invA gene of Salmonella in food poisoning. Methods:A representative primer and probe were designed based on invA gene of Salnwnella spp. . Reaction condition was optimized constantly to test sensitivity and specificity for establishment of Real - Time PCR method. Results; With this PCR method, the sensitivity of salmonella detection in DNA and lysate were 56 fg/PCR system and 9 CFU/ml respectively, the specificity was 100%. 15 strains of salmonella were found in the detection of four food poisoning cases, 2000 swab anal and 80 food samples. Conclusion: This method had high sensitivity and specificity, which can be used for rapid detection of food poisoning caused by salmonella.%目的:建立食物中毒中沙门菌Real - Time PCR检测方法并将其应用.方法:选取沙门菌侵袭蛋白A基因(invA)进行引物和探针设计,并对反应条件不断优化,进行灵敏度和特异度测试,建立检测沙门菌的Real - Time PCR方法.结果:DNA灵敏度检测沙门菌达到56 fg/PCR体系,菌液灵敏度检测沙门菌达到9 CFU/ml,特异度100%.用建立的方法对四起食物中毒、2000份健康从业人员体检肛拭样品、80份食品监测样品进行了检测,共检出沙门菌15株.结论:该方法具有高灵敏性和高特异性的特点,可以应用在沙门菌引起的食物中毒的快速检测中.

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

    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.

  15. 应用Taqman荧光定量PCR快速检测宠物食品中的沙门氏菌%Taqman PCR-based Methods for Rapid Detection of Salmonella in Pet Food

    贾俊涛; 崔鹤; 马云; 曾静; 姜英辉; 李正义

    2012-01-01

    [目的]建立快速检测宠物食品中沙门氏菌(Salmonella)的荧光定量PCR方法.[方法]根据Genbank中登录的沙门氏菌吸附和侵袭上皮细胞表面蛋白invA基因序列设计合成引物和探针,检测该方法的特异性和敏感性.[结果]该方法具有良好的特异性,对沙门氏菌的检测灵敏度可达到17 CFU/反应(25 μl/反应).应用该方法检测人工污染宠物食品,样品经18 h增菌后,结果均为阳性.[结论]该研究建立的Taqman荧光定量PCR方法可以快速、准确地检测宠物食品中的沙门氏菌.%[ Objective ] To establish a Taqman real-time PCR for detection of Salmonella in pet food. [ Method ] A pair of primers and a probe were designed based on published nucleotide sequence of invA gene encoding the invasion protein of Salmonella enterica. [ Result] The assay detects Salmonella specifically. The detection limit of the real-time PCR was 17 CEU/test (25 μl/test) for the positive strain. This method was effective to detect artificially contaminated pet food. [ Conclusion ] The results showed that Taqman PCR assay was rapid and accure for detection of Salmonella from infected pet food.

  16. Comparative Virulotyping of Salmonella typhi and Salmonella enteritidis.

    Elemfareji, Omar Ismail; Thong, Kwai Lin

    2013-12-01

    Members of Salmonella enterica are important foodborne pathogens of significant public health concern worldwide. This study aimed to determine a range of virulence genes among typhoidal (S. typhi) and non-typhoidal (S. enteritidis) strains isolated from different geographical regions and different years. A total of 87 S. typhi and 94 S. enteritidis strains were tested for presence of 22 virulence genes by employing multiplex PCR and the genetic relatedness of these strains was further characterized by REP-PCR. In S. typhi, invA, prgH, sifA, spiC, sopB, iroN, sitC, misL, pipD, cdtB, and orfL were present in all the strains, while sopE, agfC, agfA, sefC, mgtC, and sefD were present in 98.8, 97.7, 90.8, 87.4, 87.4 and 17.2 %, of the strains, respectively. No lpfA, lpfC, pefA, spvB, or spvC was detected. Meanwhile, in S. enteritidis, 15 genes, agfA, agfC, invA, lpfA, lpfC, sefD, prgH, spiC, sopB, sopE, iroN, sitC, misL, pipD, and orfL were found in all S. enteritidis strains 100 %, followed by sifA and spvC 98.9 %, pefA, spvB and mgtC 97.8 %, and sefC 90.4 %. cdtB was absent from all S. enteritidis strains tested. REP-PCR subtyped S. typhi strains into 18 REP-types and concurred with the virulotyping results in grouping the strains, while in S. enteritidis, REP-PCR subtyped the strains into eight profiles and they were poorly distinguishable between human and animal origins. The study showed that S. typhi and S. enteritidis contain a range of virulence factors associated with pathogenesis. Virulotyping is a rapid screening method to identify and profile virulence genes in Salmonella strains, and improve an understanding of potential risk for human and animal infections.

  17. Risk of Illness with Salmonella due to Consumption of Raw Unwashed Vegetables Irrigated with Water from the Bogotá River.

    Henao-Herreño, Laura X; López-Tamayo, Ana M; Ramos-Bonilla, Juan P; Haas, Charles N; Husserl, Johana

    2016-06-27

    The Bogotá River receives untreated wastewater from the city of Bogotá and many other towns. Downstream from Bogotá, water from the river is used for irrigation of crops. Concentrations of indicator organisms in the river are high, which is consistent with fecal contamination. To investigate the probability of illness due to exposure to enteric pathogens from the river, specifically Salmonella, we took water samples from the Bogotá River at six sampling locations in an area where untreated water from the river is used for irrigation of lettuce, broccoli, and cabbage. Salmonella concentrations were quantified by direct isolation and qPCR. Concentrations differed, depending on the quantification technique used, ranging between 10(7.7) and 10(9.9) number of copies of gene invA per L and 10(5.3) and 10(8.4) CFU/L, for qPCR and direct isolation, respectively. A quantitative microbial risk assessment model that estimates the daily risk of illness with Salmonella resulting from consuming raw unwashed vegetables irrigated with water from the Bogotá River was constructed using the Salmonella concentration data. The daily probability of illness from eating raw unwashed vegetables ranged between 0.62 and 0.85, 0.64 and 0.86, and 0.64 and 0.85 based on concentrations estimated by qPCR (0.47-0.85, 0.47-0.86, and 0.41-0.85 based on concentrations estimated by direct isolation) for lettuce, cabbage, and broccoli, respectively, which are all above the commonly propounded benchmark of 10(-4) per year. Results obtained in this study highlight the necessity for appropriate wastewater treatment in the region, and emphasize the importance of postharvest practices, such as washing, disinfecting, and cooking.

  18. Prevalence of Salmonella Serovars Isolated from Turkey Carcasses and Giblets in Meknès-Morocco

    A. El Allaoui

    2013-12-01

    Full Text Available The present study was conducted to determine the prevalence and the serotypes involved the virulence gene (InvA and SpvC of Salmonella isolates recovered from the raw meat and giblets (liver and gizzard of the turkey in various outlets in the Moroccan market. From November 2011 to November 2012 a total of 192 samples of turkey meat (included 48 breasts, 48 legs, 48 gizzards and 48 livers were collected every ten days from retail outlets in Meknès. Of these, 48 were from popular market, 48 from artisanal slaughterhouses, 48 from poulterers’shops and 48 from a supermarket at Meknes, Morocco. Of the total of 192 samples examined, 24.5% (47/192 were contaminated with Salmonella. Out of the total 48 samples analysed from popular market, 19 (40.42% proved to be Salmonella positive whereas from 48 samples obtained from traditional slaughterhouses and 48 from poulterers’shops 14 (29.87% and 8 (17% contained Salmonella, respectively. Compared to other outlets, a low level of Salmonella contamination was found in samples obtained from Supermarket 6 (12.7%. Among the 47 Salmonella isolates, 6 different serotypes were identified of which S. Saintpaul (46.8% was the most frequent, followed by S. Agona (17% and S. Kentucky (17%, S. Typhimurium (8.5%, S. Infantis (6.3% and S. Bredeney (4.2%.The high level of contamination, especially in popular market and artisanal slaughterhouses of turkey meat and giblets with Salmonella observed in this paper indicates the need for an improvement in the microbiological quality of retail turkey. Examination of Salmonella for invA gene was detected in all the strains (n=47, only three isolates were positive for the gene SpvC: S. Agona, S. Kentucky and S. Infantis.

  19. Genetic susceptibility for Salmonella infections

    Amsterdam JGC van; Jong WH de; Jonge R de; Hoebee B; TOX

    2005-01-01

    The Salmonella species Typhimurium and Enteritidis form the most important causes of food poisoning. Immunity to Salmonellae requires innate and specific immune responses. Reported here are the genetic polymorphisms in the genes of Nramp1, Toll-like receptors and CD14 related to the innate immune re

  20. Isolation and molecular characterization of Salmonella spp. from chevon and chicken meat collected from different districts of Chhattisgarh, India

    V. K. Naik

    2015-06-01

    Full Text Available Aim: The aim was to assess the prevalence of Salmonella in raw chevon and chicken meat sold in the retail meat shops situated in and around Durg, Rajnandgaon, Dhamtari, Raipur, and Bilaspur districts of Chhattisgarh. Studies were also conducted to find out the antibiotic resistance in Salmonella isolates. Materials and Methods: A total of 400 samples comprising of 200 chevon meat and 200 chicken meat samples were processed for isolation of Salmonella and all isolates were further confirmed on the basis of cultural and biochemical characters and by targeting invA gene of Salmonella. All Salmonella isolates were also examined for their antimicrobial drug susceptibility/resistance pattern against commonly used antibiotics. Results: Out of 400 samples, the prevalence of Salmonella in chevon and chicken meat was found 9% and 7% respectively, with an overall prevalence of 8%. Polymerase chain reaction targeting invA gene of Salmonella showed positive result with 31 isolates. All 32 Salmonella isolates were found to be highly sensitive to ciprofloxacin while 96.87%, 96.87% and 93.75% were sensitive to gentamicin, imipenem, and ceftazidime, respectively. 93.75% and 59.37% isolates were resistant to erythromycin and oxytetracycline, respectively. Out of 32, 14 isolates had multiple antibiotic resistance index equal to or more than 0.2. Conclusion: Salmonella in chevon and chicken meat samples is prevailing in the areas of sampling due to poor hygienic conditions and also demonstrated the varied spectrum of antimicrobial resistance, including several multiple drug resistance phenotypes. Therefore, the present study emphasizes the need for continued surveillance of zoonotic foodborne pathogens including antimicrobial-resistant variants throughout the food production chain.

  1. Temporal analyses of the distribution and diversity of Salmonella in natural biofilms.

    Sha, Qiong; Gunathilake, Anuradha; Forstner, Michael R J; Hahn, Dittmar

    2011-07-01

    The diversity and distribution of salmonellae in freshwater biofilms were analyzed at a fine scale (i.e. in 20 locations from a 324 cm(2) area) for two sites in San Marcos, TX. A concrete storm water overflow channel (City Park) was sampled 4 times and a concrete surface in the spring-fed headwaters of the San Marcos River (Spring Lake) 5 times between April and September 2009, and each biofilm sample analyzed by a combination of traditional enrichment methods and molecular techniques. PCR detection of the invA gene, that encodes a protein of a type III secretion system present in salmonellae, after semi-selective enrichment of salmonellae was achieved in biofilms from all 20 locations at the City Park site, with locations generally being positive 2-3 times out of 4 sampling times for a total of 59% positive samples. InvA gene fragment detection in biofilms was less frequent for the 5 sampling times and 20 locations from the Spring Lake site (18% of all samples), with 1 sampling time being entirely negative and 8 locations remaining negative throughout the study. Rep-PCR fingerprinting of 491 Salmonella isolates obtained from both sites resulted in 30 distinct profiles, with 26 and 7 profiles retrieved from City Park and Spring Lake samples, respectively, and thus with 3 profiles present at both sites, and multiple strains frequently obtained from single locations at both sites. The composition of Salmonella strains in the area analyzed changed in time with large differences between early (April, June) and late sampling times (September) within and among sites, except for one strain (S12) that was present at almost all sampling times at both sites, though often at different locations within the area analyzed. These results demonstrate the presence of salmonellae in natural biofilms and a significant micro-heterogeneity with differences in diversity and persistence of salmonellae.

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

    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.

  3. Salmonella Osteomyelitis.

    McAnearney, S; McCall, D

    2015-10-01

    Salmonella infection can cause four predominant clinical syndromes: enteric fever, acute gastroenteritis, bacteraemia with or without metastatic infection, and the asymptomatic carrier state. Salmonella as an aetiological agent in osteomyelitis is essentially rare and salmonella osteomyelitis in itself is predominantly seen in patients with haemoglobinopathies such as sickle cell disease or thalassemia. There are very few cases reported in the literature in which salmonella osteomyelitis is seen in otherwise healthy individuals. We describe here a case of salmonella osteomyelitis in a young gentleman with no significant comorbidities who presented with fever and severe back pain, having returned from recent foreign travel. It is therefore important to consider uncommon pathogens in the differential diagnosis of travellers with prolonged fever and insidious symptoms.

  4. GolS controls the response to gold by the hierarchical induction of Salmonella-specific genes that include a CBA efflux-coding operon.

    Pontel, Lucas B; Audero, María E Pérez; Espariz, Martín; Checa, Susana K; Soncini, Fernando C

    2007-11-01

    Salmonella employs a specific set of proteins that allows it to detect the presence of gold salts in the environment and to mount the appropriate resistance response. This includes a P-type ATPase, GolT, and a small cytoplasmic metal binding protein, GolB. Their expression is controlled by a MerR-like sensor, GolS, which is highly selective for Au ions. Here, we identify a new GolS-controlled operon named gesABC which codes for a CBA efflux system, and establish its role in Au resistance. GesABC can also mediate drug resistance when induced by Au in a GolS-dependent manner, in a strain deleted in the main drug transporter acrAB. The GolS-controlled transcription of gesABC differs from the other GolS-regulated loci. It is activated by gold, but not induced by copper, even in a strain deleted of the main Cu transporter gene copA, which triggers a substantial GolS-dependent induction of golTS and golB. We demonstrate that the Au-dependent induction of gesABC transcription requires higher GolS levels than for the other members of the gol regulon. This correlates with a divergent GolS operator in the gesABC promoter. We propose that the hierarchical induction within the gol regulon allows Salmonella to cope with Au-contaminated environments.

  5. Salmonella Infection

    ... children, use an oral rehydration solution, such as Pedialyte, unless your doctor advises otherwise. Salmonella infection can ... can use an oral rehydration solution, such as Pedialyte, unless your doctor advises otherwise. The U.S. Department ...

  6. Development of ceftriaxone resistance affects the virulence properties of Salmonella enterica serotype Typhimurium strains.

    Li, Liang; Yang, Yu-Rong; Liao, Xiao-Ping; Lei, Chun-Yin; Sun, Jian; Li, Lu-Lu; Liu, Bao-Tao; Yang, Shou-Shen; Liu, Ya-Hong

    2013-01-01

    Development of antibiotic resistance may alter the virulence properties of bacterial organisms. In this study, nine clinical ceftriaxone-susceptible Salmonella enterica serotype Typhimurium strains were subjected to stepwise selection with increasing concentrations of ceftriaxone in culture media. Mutations in virulence-associated genes and antibiotic efflux genes were analyzed by polymerase chain reaction (PCR) and DNA sequencing. The expression levels of virulence genes invA and stn as well as efflux pump genes tolC, arcA, and arcB before and after the selection were measured by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The stepwise selection resulted in the development of Salmonella strains that were highly resistant to ceftriaxone. Sequence analysis did not reveal any mutations or deletions in the examined virulence genes and regulatory gene, but a silent mutation (T423C) in acrR (encoding a repressor for the efflux pump) was detected in most of the ceftriaxone-resistant strains. The qRT-PCR revealed increased expression of the AcrAB-TolC efflux pump and decreased expression of invA and stn in the ceftriaxone-resistant strains. Moreover, decreased invasion into cultured epithelial cells and reduced growth rates were observed with the resistant strains. These results suggest that acquisition of ceftriaxone resistance is associated with the overexpression of the AcrAB-TolC efflux pump and leads to reduced virulence in Salmonella Typhimurium.

  7. A study of Salmonella in pigs from birth to carcass: serotypes, genotypes, antibiotic resistance and virulence profiles.

    Bolton, Declan J; Ivory, Claire; McDowell, David

    2013-01-01

    A study was undertaken to investigate Salmonella in pigs at each step from birth to carcass. Environmental and/or pig samples were taken at birth, farrowing, 1st weaning, 2nd weaning, finishing, transport, lairage, bleeding and chilling of carcasses and tested for Salmonella. All isolates were characterised in terms of serotype, phage type (where relevant) and subtyping with pulsed field gel electrophosesis (PFGE). Isolates were tested for antibiotic resistance, resistance (intI1, bla(CIT), bla(Tem), bla(PSE-1), bla(OXA-1), floR, catA1, aadA1, aadA2, tetA, tetB, tetG, sul1and aphA1) and virulence (invA, rck, spvC and pefA) genes. PCR was also performed to test for the presence of the left junction, thdF-S001 and the right junction, S004-int2 or S004-yidY of Salmonella genomic island 1 (SGI1). Overall 4.3%, 27.5% and 5% of environmental, throat/rectal and carcass samples were Salmonella positive, respectively. S. Typhimurium DT193 was detected during production, while S. Typhimurium DT17 and U311 were present in lairage at the abattoir, where strain characterisation suggested cross contamination of the live animals occurred. The carcasses were also cross contaminated with S. Brandenburg during processing. PFGE grouped the isolates by serotype and/or phage type. The DT193 isolates displayed the ACSSuTTmMn/Gm resistance phenotype and carried the invA, spvC, rck, bla-tem, aadA2, tetA, strA virulence/antibiotic resistance markers; U311 showed an ASSuTMn resistance pattern and carried invA and tetB; DT17 was sensitive to all antibiotics tested but invA, spv and rck positive while S. Brandenburg displayed neither resistance nor virulence gene carriage. None of the isolates possessed class 1 integrons and all isolates were negative for the left and right junctions of SGI1. It was concluded that control activities should target improved biosecurity at farm level and better sanitation in lairage. This study also provides further evidence that multiple drug resistance may be

  8. Importância da invasão neural e linfática no prognóstico do adenocarcinoma colorretal

    Durante Antonio Paulo

    2004-01-01

    Full Text Available OBJETIVOS: A evolução paradoxal de um terço dos doentes com neoplasias colorretais catalogadas no estádio B e C de Dukes mostra ser desejável a adição de outras variáveis prognósticas. O principal objetivo deste trabalho foi o de estudar o papel prognóstico da invasão linfática e neural em uma série de doentes submetidos à cirurgia curativa e acompanhados por longo período. MÉTODOS: Foram estudados 320 doentes com câncer colorretal submetidos à extirpação curativa, com idade mediana de 58 anos, sendo 199 (62,8% do sexo feminino. A invasão neural foi caracterizada pela presença de células cancerosas, infiltrando o perineuro e/ou o fascículo neural. A linfática, pela presença de células neoplásicas no interior de espaço limitado por endotélio, desprovido de fibras musculares e elásticas. Essas variáveis foram associadas à classificação original de Dukes. RESULTADOS: A invasão neural foi observada em 15% das peças extirpadas e a linfática em 14,1%. Os índices de invasão cresceram do ceco ao reto, local preferencial das mesmas. A sobrevida de cinco anos dos portadores de neoplasias com invasão neural foi de 25% em oposição a 64% daqueles sem invasão (p<0,01. Para os com invasão linfática, a sobrevida foi de 26,7% e 63,3%, respectivamente (p<0,01. Independentemente do comprometimento ou não dos linfonodos, a sobrevida foi sempre pior na presença da invasão neural. Em portadores de linfonodos livres, a invasão linfática identificou subgrupo de doentes com pior prognóstico. A presença destas variáveis identificou nos portadores de tumores Dukes B, subgrupo de pior prognóstico. CONCLUSÃO: A presença de invasão neural e linfática no adenocarcinoma colorretal está associada a prognóstico desfavorável de seus portadores.

  9. Mangrove Ecosystems: An Adopted Habitat for Pathogenic Salmonella spp.

    Poharkar, Krupali V; Kerkar, Savita; D'Costa, Dilecta; Doijad, Swapnil; Barbuddhe, S B

    2016-03-01

    Mangroves are affected by industrial and anthropogenic factors. Although mangroves have been widely studied, investigations of pathogens that may affect public health significance are largely lacking even while incidences of diseases linked with the consumption of mangrove-associated food have increased. A total of 150 samples of water, sediment, and biota were collected from ten mangrove ecosystems in Goa, India. Total viable counts of pathogens such as E. coli, Listeria, Salmonella, and Vibrio spp. ranged from 1.25 to 3.9 × 10(3) cfu/ mL, which were above the relevant standards. Salmonella counts were the highest at 3.1 to 3.9 × 10(3)cfu/mL, with a prevalence of 40%. Considering its high prevalence, the virulence of Salmonella spp. was studied. The invA gene was detected in 35% of the Salmonella isolates by polymerase chain reaction (PCR). The findings suggested that pathogens adapt to this habitat, resulting in contamination of the indigenous fauna.

  10. Development of an Internal Amplification Control in the PCR Detection for Salmonella%添加扩增内标的沙门氏菌PCR检测方法

    杨晋; 曾庆梅; 张笛; 刘坤; 王琳; 张亚军

    2014-01-01

    通过构建人工扩增内标,建立可以有效指示沙门氏菌检测过程可能出现假阴性情况的PCR检测方法。本研究基于沙门氏菌invA基因设计特异性引物,复合法构建扩增内标,建立PCR检测体系。特异性引物LW,对33株沙门氏菌和6株非沙门氏菌标准株进行检测,结果显示,所有沙门氏菌均扩增出385 bp的目标片段,非沙门氏菌则只能扩增出484 bp的扩增内标片段,特异性良好。灵敏度实验表明,该检测体系的灵敏度可达6.35 fg/μL。人工污染实验表明,起始染菌量为3.2 CFU/25 mL时,仅需8 h增菌培养便可检出。大量食品样品检测证明,该检测体系确实可以有效的避免PCR检测过程出现的假阴性,提高检测准确性。%By constructing an internal amplification control(IAC), this study developed a PCR system for the detection of Salmonella, which could effectively indicate false-negative results. The specific primers were designed according to the conserved gene invA in Salmonella spp.. An IAC was constructed by the compound primer technology, and finally the PCR detection system was developed. The experiment indicated that the specific 385 bp DNA fragment was amplified against 33 reference strains of Salmonella spp., while 6 strains of non-Salmonella only showed the 484 bp amplified band of IAC. The detection limit of this PCR system forpurified genomic DNA was 6.35 fg/μL. The artificial contamination assays showed that Salmonella could be detected after eight hours enrichment when the original bacterial concentration was 3.2 CFU/25 mL. A large number of food samples were also tested, and the results demonstrated that the detection system could effectively avoid the false-negatives and improve the detection accuracy.

  11. Immunization with the conjugate vaccine Vi-CRM₁₉₇ against Salmonella typhi induces Vi-specific mucosal and systemic immune responses in mice.

    Fiorino, Fabio; Ciabattini, Annalisa; Rondini, Simona; Pozzi, Gianni; Martin, Laura B; Medaglini, Donata

    2012-09-21

    Typhoid fever is a public health problem, especially among young children in developing countries. To address this need, a glycoconjugate vaccine Vi-CRM₁₉₇, composed of the polysaccharide antigen Vi covalently conjugated to the non-toxic mutant of diphtheria toxin CRM₁₉₇, is under development. Here, we assessed the antibody and cellular responses, both local and systemic, following subcutaneous injection of Vi-CRM₁₉₇. The glycoconjugate elicited Vi-specific serum IgG titers significantly higher than unconjugated Vi, with prevalence of IgG1 that persisted for at least 60 days after immunization. Vi-specific IgG, but not IgA, were present in intestinal washes. Lymphocytes proliferation after restimulation with Vi-CRM₁₉₇ was observed in spleen and mesenteric lymph nodes. These data confirm the immunogenicity of Vi-CRM₁₉₇ and demonstrate that the vaccine-specific antibody and cellular immune responses are present also in the intestinal tract, thus strengthening the suitability of Vi-CRM₁₉₇ as a promising candidate vaccine against Salmonella Typhi.

  12. Salmonella enterica serotypes isolated from squabs reveal multidrug resistance and a distinct pathogenicity gene repertoire.

    Osman, K M; Marouf, S H; Mehana, O A; AlAtfeehy, N

    2014-12-01

    The consumption of squab (young unfledged pigeons) as part of the cuisine of many countries, together with the observation that squabs are vectors of zoonotic agents, may make them a public health risk. This study was designed to determine the serotypes, distribution of 11 virulence genes (invA, avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, bcfC) and the antimicrobial resistance profiles of salmonellae recovered from squabs. Six isolates were identified from among 45 (13.3%) squabs sampled. Three serotypes were identified according to the Kauffmann-White serotyping scheme: Salmonella Typhimurium (4/6; 66.7%), S. Braenderup (1/6; 16.7%) and S. Lomita (1/6; 16.7%). Polymerase chain reaction analyses revealed the presence of invA, sopB and bcfC in all six isolates, whereas sopE1 and gipA were absent. All six isolates were resistant to lincomycin and streptomycin, but all were susceptible to ciprofloxacin, colistin sulphate and gentamicin. Among the S. Typhimurium isolates, seven resistance profiles were identified: penicillins,aminoglycosides,fluoroquinolones, lincosamides,phenicols, tetracyclines and sulphonamides; four resistance profiles were identified in the isolates of S. Braenderup and S. Lomita: aminoglycosides, fluoroquinolones, lincosamides and polymyxin. Thus, the distribution of resistance to the antibiotics was largely dependent on serotype identity. The presence of invA, avrA, ssaQ, mgtC, siiD, sopB and bcfC was associated with resistance to chloramphenicol; invA, sopB and bcfC with resistance to streptomycin and lincosamide; and invA and sodC1 with resistance to trimethoprim-sulfamethoxazole. The identification of serotypes S. Typhimurium, S. Braenderup and S. Lomita in the squab samples has important implications because these serotypes are significant causes of food poisoning and enteric fever in humans.

  13. Use of Attenuated but Metabolically Competent Salmonella as a Probiotic To Prevent or Treat Salmonella Infection.

    Sabag-Daigle, Anice; Blunk, Henry M; Gonzalez, Juan F; Steidley, Brandi L; Boyaka, Prosper N; Ahmer, Brian M M

    2016-07-01

    Salmonella enterica is among the most burdensome of foodborne disease agents. There are over 2,600 serovars that cause a range of disease manifestations ranging from enterocolitis to typhoid fever. While there are two vaccines in use in humans to protect against typhoid fever, there are none that prevent enterocolitis. If vaccines preventing enterocolitis were to be developed, they would likely protect against only one or a few serovars. In this report, we tested the hypothesis that probiotic organisms could compete for the preferred nutrient sources of Salmonella and thus prevent or treat infection. To this end, we added the fra locus, which encodes a utilization pathway for the Salmonella-specific nutrient source fructose-asparagine (F-Asn), to the probiotic bacterium Escherichia coli Nissle 1917 (Nissle) to increase its ability to compete with Salmonella in mouse models. We also tested a metabolically competent, but avirulent, Salmonella enterica serovar Typhimurium mutant for its ability to compete with wild-type Salmonella The modified Nissle strain became more virulent and less able to protect against Salmonella in some instances. On the other hand, the modified Salmonella strain was safe and effective in preventing infection with wild-type Salmonella While we tested for efficacy only against Salmonella Typhimurium, the modified Salmonella strain may be able to compete metabolically with most, if not all, Salmonella serovars, representing a novel approach to control of this pathogen.

  14. Mieloma múltiplo: invasão leptomeníngea difusa

    N. O. Facure

    1971-03-01

    Full Text Available Registro de caso de paciente com infiltração leptomeníngea por metás-tase de mieloma múltiplo. A infiltração neoplásica ocorria nas leptomeninges da base do encéfalo e, em especial, nas do canal raqueano. O tecido tumoral formava manguito no espaço sub-aracnóideo que envolvia os segmentos cervical e torácico da medula espinhal. A partir dos segmentos lombares a medula se achava infiltrada pelo tumor; as raízes da cauda equina achavam-se também invadidas pelo tecido neoplásico. Não foi feito o diagnóstico em vida. O quadro clínico caracterizava-se por sinais de irritação meníngea e de sofrimento radículo-medular a partir dos segmentos lombares altos e o quadro liquórico, por reação inflamatória de tipo sub-agudo que determinava bloqueio do canal raqueano. Os autores chamam a atenção para a raridade da invasão leptomeníngea por mieloma múltiplo e para a dificuldade diagnostica do caso. Neste último sentido discutem os dados do quadro liquórico bem como salientam não ter sido possível completar o estudo histoquímico das células plasmocitárias.

  15. Prevalence and characterization of Salmonella isolated from chicken meat in Turkey.

    Siriken, Belgin; Türk, Haldun; Yildirim, Tuba; Durupinar, Belma; Erol, Irfan

    2015-05-01

    This study was conducted in a Turkish province to investigate the presence of Salmonella spp. in 150 chicken meat samples using 2 phenotyping techniques: classic culture technique (CCT) and immunomagnetic separation (IMS). For the confirmation of the isolates at molecular levels, invA gene was detected in these isolates. The presence of invA, class 1 (Cls1) integrons, and integrase (Int1) genes was demonstrated by PCR assay; and the resistance of the isolated Salmonella spp. strains to antibiotics was determined by disk diffusion test. All the cultural and PCR results were evaluated together; Salmonella spp. were detected in a total of 64 (42.66%) chicken meat samples. Contamination rate was higher in carcasses (53.33%, n = 75) than in meat pieces (32%, n = 75). When results of standard culture were compared with IMS technique, IMS (n = 54) showed a clear superiority over the CCT (n = 38). A very high resistance rate (≥ 89.28%) to vancomycin, tetracycline, streptomycin, or nalidixic acid was found. Trimethoprim-sulfamethoxazole resistance was present in 32.14%. Relatively lower incidence of resistance (≤ 8.33%) to gentamicin, chloramphenicol, ampicillin, and ceftriaxone was observed. Concurrent resistance to at least 4 antibiotics was detected in 92.85% of the isolates. Cls1 integrons and Int1 were positive in 80.95% and 95.23% of the isolates, respectively. However, Int1 alone was detected in 15.47% (n = 13). In conclusion, the high prevalence of Salmonella spp. in chicken meat may pose a potential public health risk, and the presence of antibiotic-resistant Salmonella spp. isolate together with Cls1 integron and/or integrase might play an important role in horizontal antibiotic gene transfer.

  16. Serotypes of Salmonella in Broiler Carcasses Marketed at Ibague, Colombia.

    JM Rodriguez

    2015-12-01

    Full Text Available ABSTRACT Salmonella enterica is a large group of Gram-negative bacteria responsible for a number of foodborne infections associated with the consumption of contaminated poultry products. The hygienic status of raw chicken meat marketed at Ibague, Tolima, Colombia, is currently unknown. To address this issue, a cross-sectional study was conducted to estimate the prevalence of Salmonella spp., in raw chicken marketed at different outlets in this city. Salmonella spp. was isolated by standard microbiological methods, followed by biochemical, serological, and molecular confirmation. Additionally, risk factors associated with the presence of the bacteria were identified. The prevalence of Salmonella in raw chicken was 17.41% (47/270, and 14 different serotypes were found, out of which S. Paratyphi B (36.17%, S. Hvittingfoss (19.15% and S. Muenster (10.64% were the most prevalent and represented 65.95% of all serotypes. Amplification of 284 bp of the invA gene was achieved by PCR in a number of randomly selected isolates. Raw chicken as the only type of meat sold at stores (odds ratio: 2,157, p<0.05, and stainless steel as a contact surface of chicken meat (odds ratio: 13,29, p<0.05, were found to be potential risk factors for the presence of Salmonella in chicken meat. This work serves as a reference about the current status of Salmonella in chicken meat marketed in Ibague, Tolima, Colombia, and indicates the need to establish appropriate control and contingency measures to minimize the presence of the bacteria in raw chicken to prevent its transmission to humans.

  17. Activation of Salmonella Typhi-specific regulatory T cells in typhoid disease in a wild-type S. Typhi challenge model.

    McArthur, Monica A; Fresnay, Stephanie; Magder, Laurence S; Darton, Thomas C; Jones, Claire; Waddington, Claire S; Blohmke, Christoph J; Dougan, Gordon; Angus, Brian; Levine, Myron M; Pollard, Andrew J; Sztein, Marcelo B

    2015-05-01

    Salmonella Typhi (S. Typhi), the causative agent of typhoid fever, causes significant morbidity and mortality worldwide. Currently available vaccines are moderately efficacious, and identification of immunological responses associated with protection or disease will facilitate the development of improved vaccines. We investigated S. Typhi-specific modulation of activation and homing potential of circulating regulatory T cells (Treg) by flow and mass cytometry using specimens obtained from a human challenge study. Peripheral blood mononuclear cells were obtained from volunteers pre- and at multiple time-points post-challenge with wild-type S. Typhi. We identified differing patterns of S. Typhi-specific modulation of the homing potential of circulating Treg between volunteers diagnosed with typhoid (TD) and those who were not (No TD). TD volunteers demonstrated up-regulation of the gut homing molecule integrin α4ß7 pre-challenge, followed by a significant down-regulation post-challenge consistent with Treg homing to the gut. Additionally, S. Typhi-specific Treg from TD volunteers exhibited up-regulation of activation molecules post-challenge (e.g., HLA-DR, LFA-1). We further demonstrate that depletion of Treg results in increased S. Typhi-specific cytokine production by CD8+ TEM in vitro. These results suggest that the tissue distribution of activated Treg, their characteristics and activation status may play a pivotal role in typhoid fever, possibly through suppression of S. Typhi-specific effector T cell responses. These studies provide important novel insights into the regulation of immune responses that are likely to be critical in protection against typhoid and other enteric infectious diseases.

  18. Activation of Salmonella Typhi-specific regulatory T cells in typhoid disease in a wild-type S. Typhi challenge model.

    Monica A McArthur

    2015-05-01

    Full Text Available Salmonella Typhi (S. Typhi, the causative agent of typhoid fever, causes significant morbidity and mortality worldwide. Currently available vaccines are moderately efficacious, and identification of immunological responses associated with protection or disease will facilitate the development of improved vaccines. We investigated S. Typhi-specific modulation of activation and homing potential of circulating regulatory T cells (Treg by flow and mass cytometry using specimens obtained from a human challenge study. Peripheral blood mononuclear cells were obtained from volunteers pre- and at multiple time-points post-challenge with wild-type S. Typhi. We identified differing patterns of S. Typhi-specific modulation of the homing potential of circulating Treg between volunteers diagnosed with typhoid (TD and those who were not (No TD. TD volunteers demonstrated up-regulation of the gut homing molecule integrin α4ß7 pre-challenge, followed by a significant down-regulation post-challenge consistent with Treg homing to the gut. Additionally, S. Typhi-specific Treg from TD volunteers exhibited up-regulation of activation molecules post-challenge (e.g., HLA-DR, LFA-1. We further demonstrate that depletion of Treg results in increased S. Typhi-specific cytokine production by CD8+ TEM in vitro. These results suggest that the tissue distribution of activated Treg, their characteristics and activation status may play a pivotal role in typhoid fever, possibly through suppression of S. Typhi-specific effector T cell responses. These studies provide important novel insights into the regulation of immune responses that are likely to be critical in protection against typhoid and other enteric infectious diseases.

  19. Prevalence of Salmonella and E. coli in neonatal diarrheic calves

    F.R. El-Seedy

    2016-03-01

    Full Text Available Neonatal calf diarrhea remains one of the most important problems faced by livestock, causing great economic losses. This study investigated the prevalence of Salmonella and Escherichia coli, especially enterotoxigenic E. coli (ETEC, in diarrheic calves. Fecal samples were collected from 127 diarrheic calves up to 3 months of age at 12 farms from different governorates in Egypt. 119 bacterial isolates (93.7% were recovered and the prevalences of Salmonella and E. coli in diarrheic calves were 18.1% and 75.6%, respectively. Serotyping of Salmonella isolates revealed that S. Enteritidis and S. Typhimurium were the most prevalent serotypes, representing 60.9% and 30.4%, respectively, while S. Dublin was 8.7%. Serogrouping of E. coli isolates showed that 10 O-serogroups were obtained where O26 and O103 were the most prevalent (17.7% of each. Salmonella serotypes showed positive results with PCR test using oligonucleotide primer amplifying 521 bp fragment of invA gene of Salmonella while 70% of E. coli serogroups possessed ETEC virulent gene (K99. The in-vitro antibiotic sensitivity test indicated that Salmonella serotypes showed high sensitivity against enrofloxacin, spectinomycin and neomycin while E. coli isolates showed high sensitivities against marbofloxacin, spectinomycin and neomycin only.

  20. Occurrence, genetic characterization and antimicrobial resistance of Salmonella isolated from chicken meat and giblets.

    Abd-Elghany, S M; Sallam, K I; Abd-Elkhalek, A; Tamura, T

    2015-04-01

    SUMMARY This study was undertaken to survey the presence of Salmonella in 200 chicken samples collected from Mansoura, Egypt. Salmonella was detected in 16% (8/50), 28% (14/50), 32% (16/50) and 60% (30/50) of whole chicken carcasses, drumsticks, livers and gizzards, respectively, with an overall prevalence of 34% (68/200) among all samples. One hundred and sixty-six isolates were identified biochemically as Salmonella, and confirmed genetically by PCR, based on the presence of invA and stn genes. The spvC gene, however, was detected in only 25.3% (42/166) of the isolates. Isolates were serotyped as Salmonella Enteritidis (37.3%), S. Typhimurium (30.1%), S. Kentucky (10.8%), S. Muenster (8.4%), S. Virchow (4.8%), S. Anatum (4.8%), S. Haifa (1.2%), and four were non-typable. Antimicrobial susceptibility tests of the Salmonella isolates revealed that 100% were resistant to each of erythromycin, penicillin, and amoxicillin, while 98.8%, 96.4%, 95.2%, and 91.6% were resistant to nalidixic acid, sulphamethoxazole, oxytetracycline, and ampicillin, respectively. Multidrug resistance was evident for 92.8% of the isolates. The high contamination level of chicken meat with multidrug-resistant Salmonella can constitute a problem for public health.

  1. Salmonellae interactions with host processes.

    LaRock, Doris L; Chaudhary, Anu; Miller, Samuel I

    2015-04-01

    Salmonellae invasion and intracellular replication within host cells result in a range of diseases, including gastroenteritis, bacteraemia, enteric fever and focal infections. In recent years, considerable progress has been made in our understanding of the molecular mechanisms that salmonellae use to alter host cell physiology; through the delivery of effector proteins with specific activities and through the modulation of defence and stress response pathways. In this Review, we summarize our current knowledge of the complex interplay between bacterial and host factors that leads to inflammation, disease and, in most cases, control of the infection by its animal hosts, with a particular focus on Salmonella enterica subsp. enterica serovar Typhimurium. We also highlight gaps in our knowledge of the contributions of salmonellae and the host to disease pathogenesis, and we suggest future avenues for further study.

  2. Salmonella Yoruba infection in white-tufted-ear marmoset (Callithrix jacchus

    Terezinha Knöbl

    2011-08-01

    Full Text Available The aim of this study was to describe a fatal salmonellosis case in a non-human female primate (Callithrix jacchus, found in the illegal pet trade in Brazil. The marmoset was sent to the quarantine section of the Guarulhos City Zoo and died in the sequence of an episode of profuse diarrhea. Necropsy findings included mucous enteritis, and liver enlargement and necrosis. Feces and liver fragments were collected for bacteriological tests, which indicated the presence of Salmonella sp.; it was subsequently characterized as pertaining to the Yoruba serotype. The susceptibility profile demonstrated resistance to tetracycline only. The strain was positive for genes that encoded the virulence factors investigated (invA, sefC, pefA and spvC. The results indicated the risk of introduction of Salmonella pathogenic serotypes in primates in captivity.

  3. Oral vaccination with a recombinant Salmonella vaccine vector provokes systemic HIV-1 subtype C Gag-specific CD4+ Th1 and Th2 cell immune responses in mice

    Williamson Anna-Lise

    2009-06-01

    Full Text Available Abstract Background Recombinant Salmonella vaccine vectors may potentially be used to induce specific CD4+ T cell responses against foreign viral antigens. Such immune responses are required features of vaccines against pathogens such as human immunodeficiency virus type 1 (HIV-1. The aim of this study was to investigate the induction of systemic HIV-1-specific CD4+ T helper (Th responses in mice after oral immunization with a live attenuated Salmonella vaccine vector that expressed HIV-1 subtype C Gag. Groups of BALB/c mice were vaccinated orally three times (4 weeks apart with this recombinant Salmonella. At sacrifice, 28 days after the last immunization, systemic CD4+ Th1 and Th2 cytokine responses were evaluated by enzyme-linked immunospot assay and cytometric bead array. HIV-1 Gag-specific IgG1 and IgG2a humoral responses in the serum were determined by enzyme-linked immunosorbent assay. Results Mice vaccinated with the recombinant Salmonella elicited both HIV-1-specific Th1 (interferon-gamma (IFN-γ and tumour necrosis factor-alpha (TNF-α and Th2 (interleukin-4 (IL-4 and interleukin-5 (IL-5 cytokine responses. The vaccine induced 70 (IFN-γ spot-forming units (SFUs/10e6 splenocytes and 238 IL-4 SFUs/10e6 splenocytes. Splenocytes from vaccinated mice also produced high levels of Th1 and Th2 cytokines upon stimulation with a Gag CD4 peptide. The levels of IFN-γ, TNF-α, IL-4 and IL-5 were 7.5-, 29.1-, 26.2- and 89.3-fold above the background, respectively. Both HIV-1 Gag-specific IgG1 and IgG2a antibodies were detected in the sera of vaccinated mice. Conclusion The study highlights the potential of orally-delivered attenuated Salmonella as mucosal vaccine vectors for HIV-1 Subtype C Gag to induce Gag-specific CD4+ Th1 and Th2 cellular immune responses and antibodies which may be important characteristics required for protection against HIV-1 infection.

  4. Salmonella typhi

    Mochammad, Hatta

    2008-01-01

    This manuscript could use as research on infectious diseases Multi-locus variable-number tandem repeat analysis differentiated 297 Salmonella enterica serovar Typhi blood culture isolates from Makassar in 76 genotypes and a single unique S. Typhi genotype was isolated from the cholecystectomy specimens of four patients with cholelithiasis. The high diversity in S. Typhi genotypes circulating in Makassar indicates that the number of carriers could be very large, which may complicat...

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

    Bogomolnaya Lydia M

    2008-10-01

    Full Text Available Abstract 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.

  6. Molecular typing, antibiotic resistance, virulence gene and biofilm formation of different Salmonella enterica serotypes.

    Turki, Yousra; Mehr, Ines; Ouzari, Hadda; Khessairi, Amel; Hassen, Abdennaceur

    2014-01-01

    Salmonella enterica isolates representing commonly isolated serotypes in Tunisia were analyzed using genotyping and phenotyping methods. ERIC and ITS-PCR applied to 48 Salmonella spp. isolates revealed the presence of 12 and 10 different profiles, respectively. The distribution of profiles among serotypes demonstrated the presence of strains showing an identical fingerprinting pattern. All Salmonella strains used in this study were positive for the sdiA gene. Three Salmonella isolates belonging to serotypes Anatum, Enteritidis and Amsterdam were negative for the invA gene. The spvC gene was detected in thirteen isolates belonging to serotypes Anatum, Typhimurium, Enteritidis, Gallinarum and Montevideo. Antibiotic resistance was frequent among the recovered Salmonella isolates belonging to serotypes Anatum, Typhimurium, Enteritidis, Zanzibar and Derby. The majority of these isolates exhibited resistance to at least two antibiotic families. Four multidrug-resistant isolates were recovered from food animals and poultry products. These isolates exhibited not only resistance to tetracycline, sulphonamides, and ampicillin, but also have shown resistance to fluoroquinolones. Common resistance to nalidixic acid, ciprofloxacin and ofloxacin in two S. Anatum and S. Zanzibar strains isolated from raw meat and poultry was also obtained. Furthermore, wastewater and human isolates exhibited frequent resistance to nalidixic acid and tetracycline. Of all isolates, 33.5% were able to form biofilm.

  7. A comparative study on the use of real time polymerase chain reaction (RT-PCR and standard isolation techniques for the detection of Salmonellae in broiler c

    Waleed A. Ibrahim

    2014-06-01

    Full Text Available This study was carried out to compare between conventional cultural isolation methods and real time polymerase chain reaction (RT-PCR technique for the detection of Salmonella in broiler chicks. About 120 livers and intestinal contents samples were collected from 1800 day-old imported and local broiler chicks. The incidence of Salmonellae among imported chicks was 11.67% compared to 21.67% among local chicks using conventional cultural isolation methods. Salmonella newport (S. newport showed the highest incidence rate in imported chicks, while Salmonella enteritidis and Salmonella typhimurium were frequently detected in local chicks. The RT-PCR results for detection of invA gene of Salmonella spp. were 58.33% and 66.67% positive samples in imported and local chicks, respectively. Results have confirmed that RT-PCR technique is rapid, robust, effective and reliable method for detection of Salmonella spp. in broiler chicken when compared to conventional cultural methods. However, RT-PCR should be performed parallel with conventional methods for more accurate detection results of different Salmonellae serovars.

  8. Salmonella Infections (For Parents)

    ... Old Feeding Your 1- to 2-Year-Old Salmonella Infections KidsHealth > For Parents > Salmonella Infections A A A What's in this article? Salmonella ... contaminated food (usually meat, poultry, eggs, or milk). Salmonella infections affect the intestines and cause vomiting, fever, and ...

  9. Influência da invasão tumoral da linha de anastomose na sobrevivência de pacientes com câncer de coto gástrico The influence of tumor invasion in anastomotic line on survival of patient with gastric stump cancer

    Ana Lúcia Granja Scarabel Nogueira Carrasco

    2008-06-01

    Full Text Available RACIONAL: O câncer do coto gástrico desenvolve- se no remanescente gástrico de gastrectomia realizada há pelo menos 5 anos por doença benigna e os sítios mais comuns de acometimento são próximo à anastomose e na pequena curvatura. Considera-se que o coto gástrico é estado pré-canceroso. OBJETIVOS: Identificar o padrão de disseminação de linfonodos acometidos, quantificar a invasão tumoral da linha de anastomose e correlacionar: a invasão da linha de anastomose com o comprometimento linfonodal e mesenterial, o acometimento linfonodal com sobrevivência e o acometimento da linha de anastomose com sobrevivência. MÉTODOS: Estudo retrospectivo com revisão de prontuários, peças cirúrgicas e exames anátomo-patológicos de 113 pacientes com diagnóstico de câncer de coto gástrico definido como adenocarcinoma desenvolvido no remanescente gástrico de gastrectomia realizada há pelo menos cinco anos por doença benigna. RESULTADOS: A disseminação linfonodal não se mostrou específica; 75% dos pacientes apresentaram invasão tumoral da linha de anastomose; em 66,7% dos casos ocorreu invasão da linha anastomótica e linfonodal concomitantes; menos de 10% dos casos exibiam invasão mesenterial; houve óbito em 86,5% dos casos com invasão linfonodal e 64,7% com invasão da linha de anastomose e em 100% com invasão mesenterial. CONCLUSÕES: 1 O câncer de coto gástrico não tem padrão de disseminação linfonodal específico; 2 a linha de anastomose sofre freqüente invasão tumoral; 3 apesar de freqüente a invasão da linha anastomótica, não apresenta correlação estatística significante com o comprometimento linfonodal regional ou mesenterial; 4 a presença de invasão linfonodal implica em sobrevida menor, em especial a de linfonodos do mesentério; 5 a presença de acometimento neoplásico da linha anastomótica não se correlaciona com pior resultado de sobrevivência.AIM: To identify the lymph node metastatic

  10. [A comparative study of the role of the yadA, invA, and psaA genes in the pathogenicity of Yersinia pseudotuberculosis].

    Karataev, G I; Markov, A R; Siniashina, L N; Miller, G G; Klitsunova, N V; Titova, I V; Semin, E G; Goncharova, N I; Pokrovskaia, M S; Amelina, I P; Amoako, K; Smirnov, G B

    2008-01-01

    The roles of yadA, invA, and psaA genes introduced into the genetic background of the Y. pseudotuberculosis strain possessing the large p VM82 plasmid in virulence and invasion capacity were studied. Isogenic single mutants as well as double and multiple mutants of these genes were constructed and used. LD50 was used as a measure of virulence and the estimation of the ability to invade mammalian cells and the effect of infection on the weight changes of infected mice were used as additional indicators of pathogenicity. It was shown that the YadA had a major effect on the bacterial virulence when compared with the effects of PsaA and InvA. InvA appears to mediate the main pathway of the cellular invasion. YadA is responsible for the weight loss after infection of mice with sublethal doses of Y. pseudotuberculosis. The effects of YadA on virulence and of InvA on bacterial invasion were independent of the expression of the other genes studied. To our knowledge, this study showed for the first time the direct involvement of YadA in the virulence of Y. pseudotuberculosis in mice. Further pathomorphological studies are required to reveal the differences in the pathogenesis of pseudotuberculosis caused by yadA mutants or yadA+ bacteria of Y. pseudotuberculosis.

  11. EMA与PCR结合检测沙门氏菌方法的研究%Research on Detection of Salmonella Combining EMA and PCR

    赵瑜; 李金磊; 董鹏; 狄元冉; 高延玲

    2013-01-01

    In order to establish a fast detection method for distinguishing dead bacteria and live bacteria of Salmonella from samples, EMA and PCR were combined, meanwhile invA gene of Salmonella was taken as target gene, and then amplification was carried out by taking pure culture cells of Salmonella as template, furthermore sensitivity, specificity, exposure time and EMA concentration test were carried out. Results showed that:the sensitivity was 14 CFU/mL;the optimal exposure time was 2 min;when the concentration of EMA was less than 18 μg/mL, EMA had no obvious inhibition to the amplification of live bacteria′target gene, while EMA at final concentration of 1μg/mL could effectively inhibit the amplification of dead bacteria at 1×108 CFU/mL. So EMA-PCR could effectively decrease false positive rate in the detection of Salmonella.%为了建立一种快速区分样品中沙门氏菌的死细菌与活细菌的检测方法,将叠氮溴化乙锭(EMA)与PCR技术相结合,以沙门氏菌的invA为靶基因,以沙门氏菌的纯培养细胞做模板进行扩增,并进行灵敏度、特异性、曝光时间及EMA浓度试验。结果显示,灵敏度为14 CFU/mL,最佳曝光时间为2 min,当EMA的浓度小于18μg/mL时,EMA对活菌靶基因的扩增没有明显的抑制,而终浓度为1μg/mL的EMA,能有效抑制1×108 CFU/mL沙门氏菌死菌的扩增。 EMA-PCR能有效降低沙门氏菌检测过程中的假阳性。

  12. Antimicrobial susceptibility and virulence characteristics of Salmonella enterica Typhimurium isolates from healthy and diseased pigs in Korea.

    Tamang, Migma Dorji; Gurung, Mamata; Nam, Hyang-Mi; Moon, Dong Chan; Jang, Geum-Chan; Jung, Suk-Chan; Lim, Suk-Kyung

    2014-09-01

    This study compared the antimicrobial susceptibility and prevalence of virulence genes in Salmonella enterica Typhimurium isolated from healthy and diseased pigs in Korea. A total of 456 Salmonella Typhimurium isolated from healthy (n = 238) and diseased (n = 218) pigs between 1998 and 2011 were investigated. In total, 93.4% of the Salmonella Typhimurium isolates were resistant to at least one antimicrobial agent tested. The isolates were most often resistant to tetracycline (85.7%), followed by streptomycin (83.6%), nalidixic acid (67.3%), ampicillin (49.3%), chloramphenicol (42.8%), and gentamicin (37.1%). Moreover, multidrug resistance phenotype and resistance to ampicillin, florfenicol, gentamicin, nalidixic acid, neomycin, streptomycin, and tetracycline were significantly higher (P invA, spiA, msgA, sipB, prgH, spaN, tolC, lpfC, sifA, sitC, and sopB virulence genes. The prevalence of orgA, pagC, and iroN were 50.2, 74.1, and 91.0%, respectively, whereas isolates carrying cdtB (1.5%), pefA (7.0%), and spvB (14.9%) were identified much less frequently. Furthermore, the prevalence of invA, lpfC, orgA, pagC, and iroN was significantly higher (P < 0.01) among the isolates from the diseased pigs than in isolates from the healthy pigs. Our results demonstrated that, among diseased pigs, there was significantly higher resistance to some antimicrobials and greater prevalence of some virulence genes than in healthy pigs, indicating the role these factors play in pathogenesis. Multidrug-resistant Salmonella isolates that carry virulence-associated genes are potentially more dangerous and constitute a public health concern. Thus, continuous surveillance of antimicrobial resistance and virulence characteristics in Salmonella is essential.

  13. Immediate differentiation of salmonella-resembling colonies on brilliant green agar

    Jensen, Annette Nygaard; Hoorfar, Jeffrey

    2000-01-01

    A rapid biochemical system (OBIS) based on immediate enzymatic differentiation of Citrobacter, Proteus, Providencia, Hafnia and Morganella spp. from Salmonella on brilliant green agar was evaluated A total of 96 field isolates from various Salmonella serotypes, 18 Citrobacter freundii and 25...... isolates of other Enterobacteriaceae were tested All Salmonella isolates were identified correctly by the kit, and none of the Enterobacteriaceae isolates were identified as Salmonella. The results indicate complete specificity for Salmonella colonies on brilliant green agar....

  14. USING BASE-SPECIFIC SALMONELLA TESTER STRAINS TO CHARACTERIZE THE TYPES OF MUTATION INDUCED BY BENZIDINE AND BENZIDINE CONGENERS AFTER REDUCTIVE METABOLISM

    Abstract Benzidine, 4-aminobiphenyl, 3,3'-dichlorobenzidine HCl, 3,3'-dimethylbenzidine, 3,3'- dimethoxybenzidine and benzidine congener-based dye trypan blue were mutagenic in Salmonella typhimurium TAl 00 only with metabolic activation. It was found that a hamster liver 89 ...

  15. Chicken-specific kinome array reveals that Salmonella enterica serovar Enteritidis modulates host immune signaling pathways in the cecum to establish a persistence infection

    Non-typhoidal Salmonella enterica induce an early, short-lived, pro-inflammatory response in chickens that is asymptomatic of clinical disease and results in a persistent colonization of the gastrointestinal (GI) tract that transmits infections to naïve hosts via fecal shedding of bacteria. The und...

  16. Quantitative studies of the regular distribution pattern for Salmonella enteritidis in the internal organs of mice after oral challenge by a specific real-time polymerase chain reaction

    Shu-Xuan Deng; An-Chun Cheng; Ming-Shu Wang; Ping Cao; Bin Yan; Nian-Chun Yin; Sheng-Yan Cao; Zhen-Hua Zhang

    2008-01-01

    AIM:To identify and understand the regular distribution pattern for Salmonella enteritidis (S.enteritidis) in the internal organs of mice after an oral challenge over a 3 wk period.METHODS:Assays based on the serovar-specific DNA sequence of S.enteritidis from GenBank,and a serovar-specific real-time,fluorescence-based quantitative polymerase chain reaction (FQ-PCR) were developed for the detection of S.enteritidis.We used this assay to detect genomic DNA of S.enteritidis in the blood and the internal organs,including heart,liver,spleen,kidney,pancreas,and gallbladder,from mice after oral challenge at different time points respectively.RESULTS:The results showed that the spleen was positive at 12 h post inoculation (PI),and the blood was at 14 h PI.The organism was detected in the liver and heart at 16 h PI,the pancreas was positive at 20 h PI,and the final organs to show positive results were the kidney and gallbladder at 22 h PI.The copy number of S.enteritidis DNA in each tissue reached a peak at 24-36 h PI,with the liver and spleen containing high concentrations of S.enteritidis,whereas the blood,heart,kidney,pancreas,and gallbladder had low concentrations.S.enteritidis populations began to decrease and were not detectable at 3 d PI,but were still present up to 12 d PI in the gallbladder,2 wk for the liver,and 3 wk for the spleen without causing apparent symptoms.CONCLUSION:The results provided significant data for understanding the life cycle of S.enteritidis in the internal organs,and showed that the liver and spleen may be the primary sites for setting itself up as a commensa over a long time after oral challenge.Interestingly,it may be the first time reported that the gallbladder is a site of carriage for S.enteritidis over a 12 d period.This study will help to understand the mechanisms of action of S.enteritidis infection in vivo.

  17. Detection of Salmonella spp. from chevon, mutton and its environment in retail meat shops in Anand city (Gujarat, India

    P. P. Makwana

    2015-03-01

    Full Text Available Aim: The aim of this study was (i To attempt isolation and identification of Salmonella species from samples. (ii Serotyping of Salmonella isolates. (iii Detection of virulence factor associated genes by polymerase chain reaction (PCR. Materials and Methods: A total of 284 samples comprised of chevon and mutton (112 samples each as well as 60 samples (20 each of retail meat shops environment samples viz. Butchers’ hands, knives and log swabs were collected from the retail meat shops in and around Anand City under aseptic precautions. Rappaport-vassiliadis soy bean meal broth and tetrathionate broth was used for the enrichment of all the samples and inoculation was done on brilliant green agar and xylose lysine deoxycholate agar. This was followed by the confirmation of isolates using biochemical tests. For the serotyping, isolates were sent to the National Salmonella and Escherichia Centre, Central Research Institute, Kasauli, Himachal Pradesh. Detection of virulence genes was performed by PCR technique using previously reported primer. Result: Of 284 meats and retail meat shops environment samples, 13 (4.58% samples were found positive for Salmonella. It was interesting to know that incidence of Salmonella was more in mutton (6.25% than chevon (3.57%. In case of meat shop environmental samples 1 (5.00% sample observed positive for Salmonella separately among the butchers’ hands and knives swabs (Each of 20 samples examined. Out of 13, eleven isolates detected as Salmonella Typhimurium, whereas only two isolates were detected as Salmonella Enteritidis. All Salmonella isolates possess invA and stn genes, whereas nine isolates had a presence of spvR gene while only five of the isolates revealed the presence of spvC gene as shown by in vitro detection of virulence genes by PCR. Conclusion: Therefore, might be suggested that the good hygiene practices and effective control measures should be taken to encourage clean meat production with

  18. Specific anti-tumor effect induced by attenuated Salmonella typhimurium vaccine expressing extracellular region of vascular endothelial growth factor receptor 2

    YANG Jun; DONG Jian; PU Ping; WANG ZhiQiang; HONG Min; CHEN MingQing

    2008-01-01

    The purposes of this research were to study the stable expression of exogenous gene encoding therapeutic protein in attenuated Salmonella typhimurium, observe the metabolism of oral gene vac-cine carried by attenuated Salmonella typhimurium in BALB/c mouse, and investigate the feasibility of prevention and treatment of tumors by the recombinant bacteria. Recombinant plasmid pcDNA3.1+ VEGFR2(n1-7) was transformed into competent attenuated Salmonella typhimurium SL3261 to develop oral DNA vaccine SL3261-pcDNA3.1+VEGFR2(n1-7). To observe whether the exogenous gene can be ex-pressed in the recombinant bacteria, PCR was performed to amplify the CMV promoter of the eu-karyotic expression vector as the proof of stable expression of exogenous protein; transmission elec-tron microscopy (TEM) was applied to observe the morphology of the recombinant bacteria to confirm that the exogenous gene has no impact on the growth of the bacteria, and then BALB/c mice were immunized with the gene vaccine. After inoculation of the gene vaccine, the recombinant bacteria SL3261 could be detected in the tissues such as small intestine, colon, liver and spleen. And then, mice in each group were challenged with tumor cells. The results of animal experiment showed that tumor growth of the mice in experimental group was inhibited and survival time of immunized mice was pro-longed compared with control groups. A higher lymphocyte infiltration in tumors from animals treated with DNA vaccine was observed. Immunohistochemical analysis of tumor samples revealed an en-hanced accumulation of CD8+ cytotoxic T lymphocytes, as well as an increase in CD4+ cells in the tu-mors of animals treated with the oral gene vaccine compared to tumors from control group mice. UI-trastructure of the tumor tissue showed that tumor cells in the samples of the immunized mice were well-differentiated. Our research confirmed that the exogenous gene can be stably expressed in the attenuated Salmonella typhimurium and has no

  19. Loop-Mediated Isothermal Amplification of the sefA Gene for Rapid Detection of Salmonella Enteritidis and Salmonella Gallinarum in Chickens.

    Gong, Jiansen; Zhuang, Linlin; Zhu, Chunhong; Shi, Shourong; Zhang, Di; Zhang, Linji; Yu, Yan; Dou, Xinhong; Xu, Bu; Wang, Chengming

    2016-04-01

    Salmonella spp. pose a threat to both human and animal health, with more than 2600 serovars having been reported to date. Salmonella serovars are usually identified by slide agglutination tests, which are labor intensive and time consuming. In an attempt to develop a more rapid screening method for the major poultry Salmonella serovars, we developed a loop-mediated isothermal amplification (LAMP) assay, which directly detected the sefA gene, a fimbrial operon gene existing in several specific serovars of Salmonella enterica including the major poultry serovars, namely Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) and Salmonella enterica serovar Gallinarum (Salmonella Gallinarum). With the 177 bacterial strains we tested, positive reactions were only observed with 85 strains of serovar Salmonella Enteritidis and Salmonella Gallinarum. The detection limit of the LAMP assay was 4 CFU/reaction with genomic DNAs of Salmonella Enteritidis (ATCC 13076) from pure culture and 400 CFU/ reaction with DNA extracted from spiked chicken feces. The LAMP assay was more sensitive than conventional culture, especially without enrichment, in detecting Salmonella Enteritidis (CMCC 50041) in the spiked fecal samples. The results show the sefA LAMP method is a rapid, sensitive, specific, and practical method for directly detection of Salmonella Enteritidis and Salmonella Gallinarum in chickens. The sefA LAMP assay can potentially serve as new on-site diagnostics in the poultry industry.

  20. Serotypes and Antimicrobial Susceptibility of Salmonella spp. Isolated from Farm Animals in China

    Yuan Zong Hui

    2015-06-01

    Full Text Available 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 unhealthy 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

  1. Salmonella enterica in imported and domestic day-old turkey poults in Egypt: repertoire of virulence genes and their antimicrobial resistance profiles.

    Osman, K M; Marouf, S H; Erfan, A M; AlAtfeehy, N

    2014-12-01

    Globalisation and international trade facilitate the rapid spread and transmission of foodborne pathogens. This study was designed to determine the serovars, distribution of virulence genes (invA, avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, bcfC) and antibiotic resistance profiles in salmonellae recovered from imported and domestic day-old turkey poults in Egypt. The prevalence of salmonellae in the imported poults was 4% (6/150): S. Enteritidis was the most frequent isolate (1.3%; 2/150), followed by Typhimurium, Virchow, Larochelle and a non-typeable strain, each with 0.7% (1/150) prevalence. The prevalence of salmonellae in the domestic poults was < 2% (2/150) and serotyping indicated a prevalence of 1.3% (1/150) for both Typhimurium and Altona. In polymerase chain reaction screening, the genes invA, sopB and bcfC were detected in all the Enteritidis, Typhimurium, Virchow, Larochelle, Altona and non-typeable isolates (100%); the gene gipA was absent from all isolates. Carriage of invA, sopB and bcfC among the Enteritidis, Typhimurium, Virchow, Larochelle, Altona and non-typeable isolates was associated with a core pattern of resistance to three antibiotics: streptomycin, nalidixic acid and chloramphenicol. The detection of S. Enteritidis, Typhimurium, Virchow, Larochelle, and Altona in turkey poults has important implications because these serovars are a significant cause of foodborne illness and enteric fever in humans.

  2. Molecular typing of Salmonella enterica subspecies enterica serovar Typhimurium isolated in Abruzzo region (Italy from 2008 to 2010

    Alessandra Alessiani

    2014-03-01

    Full Text Available In this study, 47 antibiotic-resistant strains of Salmonella enterica subspecies enterica serovar Typhimurium (ST were characterised, including 15 monophasic variants 1, 4, [5], 12:i:-, (STm isolated from different matrices. They were all selected from 389 Salmonella enterica subspecies enterica strains isolated during 2008-2010 in Abruzzo region (Italy. Thirty-seven strains showed to be resistant to more than 1 antibiotic. Among 47 isolates, phage type U311 and DT104 were identified. The ASSuT resistance pattern was predominant in mST strains and ACSSuT in ST DT104 and U302. A multiplex Polimerase Chain Reaction (PCR method was used to investigate 4 genes: fluorfenicol (floSt, virulence (spvC, invasine (invA and integrase (int. All ST the strain were positive for invA gene and 28,32% of strains were positive for spvC gene. PFGE analysis revealed a large number of small clonal populations, however not ascrivable to outbreaks.

  3. Molecular typing of Salmonella enterica subspecies enterica serovar Typhimurium isolated in Abruzzo region (Italy) from 2008 to 2010.

    Alessiani, Alessandra; Sacchini, Lorena; Pontieri, Eugenio; Gavini, Jacopo; Di Giannatale, Elisabetta

    2014-01-01

    In this study, 47 antibiotic-resistant strains of Salmonella enterica subspecies enterica serovar Typhimurium (ST) were characterised, including 15 monophasic variants 1, 4, [5], 12:i:-, (STm) isolated from different matrices. They were all selected from 389 Salmonella enterica subspecies enterica strains isolated during 2008-2010 in Abruzzo region (Italy). Thirty-seven strains showed to be resistant to more than 1 antibiotic. Among 47 isolates, phage type U311 and DT104 were identified. The ASSuT resistance pattern was predominant in mST strains and ACSSuT in ST DT104 and U302. A multiplex Polimerase Chain Reaction (PCR) method was used to investigate 4 genes: fluorfenicol (floSt), virulence (spvC), invasine (invA) and integrase (int). All ST the strain were positive for invA gene and 28,32% of strains were positive for spvC gene. PFGE analysis revealed a large number of small clonal populations, however not ascrivable to outbreaks.

  4. Salmonella Diagnosis and Treatment

    ... FDA) USDA Food Safety and Inspection Service Follow Salmonella RSS Diagnosis and Treatment Recommend on Facebook Tweet Share Compartir How Can Salmonella Infections Be Diagnosed? Diagnosing salmonellosis requires testing a ...

  5. Unveiling ubiquitinome rearrangements induced by Salmonella infection.

    Bionda, Tihana; Behrends, Christian

    2016-09-01

    Ubiquitination plays a critical role in the activation of host immune responses to infection and serves as a signal for pathogen delivery to phagophores along the xenophagy pathway. We recently performed systematic ubiquitination site profiling of epithelial cells infected with Salmonella Typhimurium. Our findings specifically highlight components of the NFKB, membrane trafficking pathways and RHO GTPase systems as ubiquitination hubs during infection. In addition, a broad spectrum of bacterial effectors and several outer membrane proteins are ubiquitinated in infected cells. This comprehensive resource of ubiquitinome dynamics during Salmonella infection enables further understanding of the complex host-pathogen interplay and may reveal novel targets for the inhibition of Salmonella invasion and inflammation.

  6. Prevalence of drug resistance and virulence features in Salmonella spp. isolated from foods associated or not with salmonellosis in Brazil.

    Rowlands, Ruth Estela Gravato; Ristori, Christiane Asturiano; Ikuno, Alice A; Barbosa, Maria Luisa; Jakabi, Miyoko; Franco, Bernadette Dora Gombossy de Melo

    2014-01-01

    Salmonella is the most common etiological agent of cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread of Salmonella spp., which has become multi-drug resistant and potentially more pathogenic, have increased the concern with this pathogen. In this study, 237 Salmonella spp., associated or not with foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis, were tested for antimicrobial susceptibility and the presence of the virulence genes spvC, invA, sefA and pefA. Of the isolates, 46.8% were sensitive to all antimicrobials and 51.9% were resistant to at least one antimicrobial agent. Resistance to more than one antimicrobial agent was observed in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%) and nalidixic acid (16.9%). No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxacin and imipenem. The invA gene was detected in all strains. Genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The gene sefA was detected in 31.6% of the strains and only among S. Enteritidis. Resistance and virulence determinants were detected in Salmonella strains belonging to several serotypes. The high rates of antibiotic-resistance in strains isolated from poultry products demonstrate the potential risk associated with the consumption of these products and the need to ensure good food hygiene practices from farm to table to reduce the spread of pathogens relevant to public health.

  7. PREVALENCE OF DRUG RESISTANCE AND VIRULENCE FEATURES IN Salmonella spp. ISOLATED FROM FOODS ASSOCIATED OR NOT WITH SALMONELLOSIS IN BRAZIL

    Ruth Estela Gravato Rowlands

    2014-12-01

    Full Text Available Salmonella is the most common etiological agent of cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread of Salmonella spp., which has become multi-drug resistant and potentially more pathogenic, have increased the concern with this pathogen. In this study, 237 Salmonella spp., associated or not with foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis, were tested for antimicrobial susceptibility and the presence of the virulence genes spvC, invA, sefA and pefA. Of the isolates, 46.8% were sensitive to all antimicrobials and 51.9% were resistant to at least one antimicrobial agent. Resistance to more than one antimicrobial agent was observed in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9% and nalidixic acid (16.9%. No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxacin and imipenem. The invA gene was detected in all strains. Genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The gene sefA was detected in 31.6% of the strains and only among S. Enteritidis. Resistance and virulence determinants were detected in Salmonella strains belonging to several serotypes. The high rates of antibiotic-resistance in strains isolated from poultry products demonstrate the potential risk associated with the consumption of these products and the need to ensure good food hygiene practices from farm to table to reduce the spread of pathogens relevant to public health.

  8. 78 FR 42526 - Salmonella

    2013-07-16

    ... HUMAN SERVICES Food and Drug Administration Salmonella Contamination of Dry Dog Food; Withdrawal of...) entitled ``Sec. 690.700 Salmonella Contamination of Dry Dog Food.'' This CPG is obsolete. DATES: The.... SUPPLEMENTARY INFORMATION: FDA issued the CGP entitled ``Sec. 690.700 Salmonella Contamination of Dry Dog...

  9. The invA gene of Brucella melitensis is involved in intracellular invasion and is required to establish infection in a mouse model.

    Alva-Pérez, Jorge; Arellano-Reynoso, Beatriz; Hernández-Castro, Rigoberto; Suárez-Güemes, Francisco

    2014-05-15

    Some of the mechanisms underlying the invasion and intracellular survival of B. melitensis are still unknown, including the role of a subfamily of NUDIX enzymes, which have been described in other bacterial species as invasins and are present in Brucella spp. We have generated a mutation in the coding gene of one of these proteins, the invA gene (BMEI0215) of B. melitensis strain 133, to understand its role in virulence. HeLa cell invasion results showed that mutant strain survival was decreased 5-fold compared with that of the parental strain at 2 h pi (Pgoat macrophage infection assay, mutant strain replication was 8-fold less than in the parental strain at 24 h pi (P<0.001); yet, at 48 h pi, no significant differences in intracellular replication were observed. Additionally, colocalization of the invA mutant with calregulin was significantly lower at 24 h pi compared with that of the parental strain. Furthermore, the mutant strain exhibited a low level of colocalization with cathepsin D, which was similar to the parental strain colocalization at 24 h pi. In vivo infection results demonstrated that spleen colonization was significantly lower with the mutant than with the parental strain. The immune response, measured in terms of antibody switching and IFN-γ transcription, was similar for Rev1 and infection with the mutant, although it was lower than the immune response elicited by the parental strain. Consequently, these results indicate that the invA gene is important during invasion but not for intracellular replication. Additionally, mutation of the invA gene results in in vivo attenuation.

  10. Prevalence of virulence and antimicrobial resistance genes in Salmonella spp. isolated from commercial chickens and human clinical isolates from South Africa and Brazil

    Oliver T. Zishiri

    2016-03-01

    Full Text Available Salmonellosis is a significant public health concern around the world. The injudicious use of antimicrobial agents in poultry production for treatment, growth promotion and prophylaxis has resulted in the emergence of drug resistant strains of Salmonella. The current study was conducted to investigate the prevalence of virulence and antimicrobial resistance genes from Salmonella isolated from South African and Brazilian broiler chickens as well as human clinical isolates. Out of a total of 200 chicken samples that were collected from South Africa 102 (51% tested positive for Salmonella using the InvA gene. Of the overall 146 Salmonella positive samples that were screened for the iroB gene most of them were confirmed to be Salmonella enterica with the following prevalence rates: 85% of human clinical samples, 68.6% of South African chicken isolates and 70.8% of Brazilian chicken samples. All Salmonella isolates obtained were subjected to antimicrobial susceptibility testing with 10 antibiotics. Salmonella isolates from South African chickens exhibited resistance to almost all antimicrobial agents used, such as tetracycline (93%, trimethoprim-sulfamthoxazole (84%, trimethoprim (78.4%, kanamycin (74%, gentamicin (48%, ampicillin (47%, amoxicillin (31%, chloramphenicol (31%, erythromycin (18% and streptomycin (12%. All samples were further subjected to PCR in order to screen some common antimicrobial and virulence genes of interest namely spiC, pipD, misL, orfL, pse-1, tet A, tet B, ant (3"-la, sul 1 and sul. All Salmonella positive isolates exhibited resistance to at least one antimicrobial agent; however, antimicrobial resistance patterns demonstrated that multiple drug resistance was prevalent. The findings provide evidence that broiler chickens are colonised by pathogenic Salmonella harbouring antimicrobial resistance genes. Therefore, it is evident that there is a need for prudent use of antimicrobial agents in poultry production systems in

  11. Salmonella infection inhibits intestinal biotin transport: cellular and molecular mechanisms.

    Ghosal, Abhisek; Jellbauer, Stefan; Kapadia, Rubina; Raffatellu, Manuela; Said, Hamid M

    2015-07-15

    Infection with the nontyphoidal Salmonella is a common cause of food-borne disease that leads to acute gastroenteritis/diarrhea. Severe/prolonged cases of Salmonella infection could also impact host nutritional status, but little is known about its effect on intestinal absorption of vitamins, including biotin. We examined the effect of Salmonella enterica serovar Typhimurium (S. typhimurium) infection on intestinal biotin uptake using in vivo (streptomycin-pretreated mice) and in vitro [mouse (YAMC) and human (NCM460) colonic epithelial cells, and human intestinal epithelial Caco-2 cells] models. The results showed that infecting mice with wild-type S. typhimurium, but not with its nonpathogenic isogenic invA spiB mutant, leads to a significant inhibition in jejunal/colonic biotin uptake and in level of expression of the biotin transporter, sodium-dependent multivitamin transporter. In contrast, infecting YAMC, NCM460, and Caco-2 cells with S. typhimurium did not affect biotin uptake. These findings suggest that the effect of S. typhimurium infection is indirect and is likely mediated by proinflammatory cytokines, the levels of which were markedly induced in the intestine of S. typhimurium-infected mice. Consistent with this hypothesis, exposure of NCM460 cells to the proinflammatory cytokines TNF-α and IFN-γ led to a significant inhibition of biotin uptake, sodium-dependent multivitamin transporter expression, and activity of the SLC5A6 promoter. The latter effects appear to be mediated, at least in part, via the NF-κB signaling pathway. These results demonstrate that S. typhimurium infection inhibits intestinal biotin uptake, and that the inhibition is mediated via the action of proinflammatory cytokines.

  12. PCR检测沙门氏菌invA基因的灵敏度%Sensitivity of PCR detection for the inva gene in salmonella

    江树勋; 吴圣静; 李寿崧; 饶静静; 江云

    2006-01-01

    沙门氏菌是一种重要的肠道致病菌,其invA基因编码吸附和侵袭上皮细胞表面蛋白,应用PCR扩增invA基因检测致病性沙门氏菌,并测定其PCR检测灵敏度.结果显示,扩增出的284bp大小的序列为目的条带,实验可检出的最小灵敏度为11.542pg.

  13. The Salmonella enterica Pan-genome

    Jacobsen, Annika; Hendriksen, Rene S.; Aarestrup, Frank Møller

    2011-01-01

    Salmonella enterica is divided into four subspecies containing a large number of different serovars, several of which are important zoonotic pathogens and some show a high degree of host specificity or host preference. We compare 45 sequenced S. enterica genomes that are publicly available (22......, and the core and pan-genome of Salmonella were estimated to be around 2,800 and 10,000 gene families, respectively. The constructed pan-genomic dendrograms suggest that gene content is often, but not uniformly correlated to serotype. Any given Salmonella strain has a large stable core, whilst...... there is an abundance of accessory genes, including the Salmonella pathogenicity islands (SPIs), transposable elements, phages, and plasmid DNA. We visualize conservation in the genomes in relation to chromosomal location and DNA structural features and find that variation in gene content is localized in a selection...

  14. Thermal inactivation of Salmonella spp. in pork burger patties.

    Gurman, P M; Ross, T; Holds, G L; Jarrett, R G; Kiermeier, A

    2016-02-16

    Predictive models, to estimate the reduction in Escherichia coli O157:H7 concentration in beef burgers, have been developed to inform risk management decisions; no analogous model exists for Salmonella spp. in pork burgers. In this study, "Extra Lean" and "Regular" fat pork minces were inoculated with Salmonella spp. (Salmonella 4,[5],12,i:-, Salmonella Senftenberg and Salmonella Typhimurium) and formed into pork burger patties. Patties were cooked on an electric skillet (to imitate home cooking) to one of seven internal temperatures (46, 49, 52, 55, 58, 61, 64 °C) and Salmonella enumerated. A generalised linear logistic regression model was used to develop a predictive model for the Salmonella concentration based on the internal endpoint temperature. It was estimated that in pork mince with a fat content of 6.1%, Salmonella survival will be decreased by -0.2407log10 CFU/g for a 1 °C increase in internal endpoint temperature, with a 5-log10 reduction in Salmonella concentration estimated to occur when the geometric centre temperature reaches 63 °C. The fat content influenced the rate of Salmonella inactivation (P=0.043), with Salmonella survival increasing as fat content increased, though this effect became negligible as the temperature approached 62 °C. Fat content increased the time required for patties to achieve a specified internal temperature (P=0.0106 and 0.0309 for linear and quadratic terms respectively), indicating that reduced fat pork mince may reduce the risk of salmonellosis from consumption of pork burgers. Salmonella serovar did not significantly affect the model intercepts (P=0.86) or slopes (P=0.10) of the fitted logistic curve. This predictive model can be applied to estimate the reduction in Salmonella in pork burgers after cooking to a specific endpoint temperature and hence to assess food safety risk.

  15. Bioinformatics analysis and mining serovar-specific genes of Salmonella enterica serovar Enteritidis%肠炎沙门氏菌血清型特异性基因挖掘及生物信息学分析

    余水静; 彭艳平; 邓扬悟; 郭燕华; 梁长利; 欧阳城添

    2014-01-01

    肠炎沙门氏菌(Salmonella enterica serovar Enteritidis)能引起畜禽的胃肠炎以及食物中毒,其血清型鉴定较为复杂。为了挖掘肠炎沙门氏菌血清型特异性基因,以44个已测序沙门氏菌基因组构建数据库,利用肠炎沙门氏菌所有蛋白编码序列为查询序列,通过BLASTN比对,挖掘出6个肠炎沙门氏菌血清型特异性基因(SEN1382, SEN1383, SEN1388, SEN1936, SEN1945和SEN1959),其中4个基因编码噬菌体相关蛋白。同时,研究分析了肠炎沙门氏菌血清型特异性基因的理化性质、二级结构、三级结构、亚细胞定位、信号肽和跨膜区等特征,结果表明肠炎沙门氏菌血清型特异性基因具有多样性特征。挖掘的血清型特异性基因可为鉴定肠炎沙门氏菌提供检测靶标。%Salmonella enterica serovar Enteritidis is one of the major causes of gastroenteritis and food poisoning in humans due to the consumption of poultry derivatives. To mine serovar-specific genes of S. enterica serovar Enteritidis, all CDSs of it were searched in a searching database of 44 other Salmonella genomic sequences using SMM-system tool. Six serovar-specific genes were identified including SEN1382, SEN1383, SEN1388, SEN1936, SEN1945, and SEN1959. Among them, four genes decoded phage-related proteins. The characteristics of these genes were analyzed including physicochemical properties, secondary structure, three-dimensional structure, signal peptide, transmembrane regions, and subcellular localization. The results indicated the diversification of these genes. These serovar-specific genes can be used as the targets for detecting and identifying S. enterica serovar Enteritidis.

  16. Prevalence of virulence and antimicrobial resistance genes in Salmonella spp. isolated from commercial chickens and human clinical isolates from South Africa and Brazil.

    Zishiri, Oliver T; Mkhize, Nelisiwe; Mukaratirwa, Samson

    2016-05-26

    Salmonellosis is a significant public health concern around the world. The injudicious use of antimicrobial agents in poultry production for treatment, growth promotion and prophylaxis has resulted in the emergence of drug resistant strains of Salmonella. The current study was conducted to investigate the prevalence of virulence and antimicrobial resistance genes from Salmonella isolated from South African and Brazilian broiler chickens as well as human clinical isolates. Out of a total of 200 chicken samples that were collected from South Africa 102 (51%) tested positive for Salmonella using the InvA gene. Of the overall 146 Salmonella positive samples that were screened for the iroB gene most of them were confirmed to be Salmonella enterica with the following prevalence rates: 85% of human clinical samples, 68.6% of South African chicken isolates and 70.8% of Brazilian chicken samples. All Salmonella isolates obtained were subjected to antimicrobial susceptibility testing with 10 antibiotics. Salmonella isolates from South African chickens exhibited resistance to almost all antimicrobial agents used, such as tetracycline (93%), trimethoprim-sulfamthoxazole (84%), trimethoprim (78.4%), kanamycin (74%), gentamicin (48%), ampicillin (47%), amoxicillin (31%), chloramphenicol (31%), erythromycin (18%) and streptomycin (12%). All samples were further subjected to PCR in order to screen some common antimicrobial and virulence genes of interest namely spiC, pipD, misL, orfL, pse-1, tet A, tet B, ant (3")-la, sul 1 and sul. All Salmonella positive isolates exhibited resistance to at least one antimicrobial agent; however, antimicrobial resistance patterns demonstrated that multiple drug resistance was prevalent. The findings provide evidence that broiler chickens are colonised by pathogenic Salmonella harbouring antimicrobial resistance genes. Therefore, it is evident that there is a need for prudent use of antimicrobial agents in poultry production systems in order to

  17. Performance of the chromID Salmonella Elite chromogenic agar in comparison with CHROMagar™ Salmonella, Oxoid™ Brilliance™ Salmonella and Hektoen agars for the isolation of Salmonella from stool specimens.

    Martiny, Delphine; Dediste, Anne; Anglade, Claire; Vlaes, Linda; Moens, Catherine; Mohamed, Souad; Vandenberg, Olivier

    2016-10-01

    chromID™ Salmonella Elite is compared with 3 culture media commonly used for Salmonella isolation from stool specimens. As results were equivalent to other chromogenic media (100% sensitivity, 98% specificity), only financial arguments should guide the choice for a medium with respect to another.

  18. Development of a real-time PCR melt curve assay for simultaneous detection of virulent and antibiotic resistant Salmonella.

    Singh, Prashant; Mustapha, Azlin

    2014-12-01

    Multiple drug resistance in Salmonella is an emerging problem in the area of food safety. Depending on the virulence and antibiotic resistance characteristics of the Salmonella strain, infections of varying severity could result. In this study, a multiplex melt curve real-time PCR assay for the detection of virulent and antibiotic resistance strains of Salmonella was developed with two primer sets. The first set targets the virulence gene, invasin (invA), and tetracycline (tetG), streptomycin (aadA2) and sulphonamide (sulI) antibiotic resistance genes, and the second set amplifies ampicillin (blaPSE,blaTEM) and chloramphenicol (floR) resistance genes. The multiplex assay was evaluated using 41 Salmonella strains and was further tested on eight different artificially inoculated food samples. The fluorescent DNA intercalating dye, SYTO9, generated high resolution melt curve peaks and, hence, was used for the development of the assay. This multiplex assay worked efficiently over a DNA concentration range of 20 ng-200 fg and showed a sensitivity of 290 CFU/mL with serially diluted broth cultures. The detection limit for un-enriched artificially inoculated food samples was 10(4) CFU/g, but an enrichment period of 6 h allowed for detection of 10 CFU/g of cells in the samples.

  19. Importância prognóstica da invasão neural no câncer colorretal: estudo imunoistoquímico com a proteína S-100 Prognostic importance of neural invasion in colorectal cancer: an immunohistochemical study with the S-100 protein

    José Vinícius Cruz

    2006-09-01

    Full Text Available Das variáveis anatomopatológicas relacionadas ao prognóstico de enfermos com câncer colorretal, a invasão neural ainda se encontra pouco estudada. OBJETIVO: Verificar se a invasão neural no câncer colorretal estádios B e C de Dukes pode ser considerada como fator prognóstico independente. MÉTODO: Foram estudados 97 doentes operados com intenção curativa e seguidos por período mínimo de cinco anos. Excluíram-se doentes que receberam tratamento adjuvante. Os espécimes cirúrgicos foram corados por hematoxilina-eosina e imunoistoquímica para pesquisa da proteína S-100, com o intuito de se comparar a fidedignidade das técnicas em detectar invasão neural, sendo analisadas comparativamente: acurácia, especificidade, sensibilidade e valores preditivos positivo e negativo. A comparação entre a incidência de invasão neural com relação à recidiva foi realizada, empregando-se o teste do qui-quadrado. A sobrevida e sobrevida livre de doença foram estudadas por análise univariada,. Estabeleceu-se nível de significância de 5% (p £ 0,05 para todos os testes adotados. RESULTADOS: A técnica da HE apresentou fraca habilidade em detectar a invasão neural, não sendo adequada para esta análise em doentes portadores de câncer colorretal. As curvas de sobrevida e sobrevida livre de doença dos enfermos portadores de invasão neural, pesquisada por meio da imunocoloração para proteína S-100 são significativamente piores, identificando aquela característica histológica como valor prognóstico independente (p = 0,0003 e p = 0,0002, respectivamente. A ocorrência de recidiva tumoral foi significativamente maior nos doentes que apresentavam invasão neural (p = 0,0010. CONCLUSÃO: Os resultados do presente estudo permitem concluir que, nos doentes portadores de câncer colorretal, a detecção da invasão neural pela pesquisa imunoistoquímica da proteína S-100 demonstrou ser variável independente, acrescentando informa

  20. Fructose-Asparagine Is a Primary Nutrient during Growth of Salmonella in the Inflamed Intestine

    Ali, Mohamed M.; Newsom, David L.; González, Juan F.; Sabag-Daigle, Anice; Stahl, Christopher; Steidley, Brandi; Dubena, Judith; Dyszel, Jessica L.; Smith, Jenee N.; Dieye, Yakhya; Arsenescu, Razvan; Boyaka, Prosper N.; Krakowka, Steven; Romeo, Tony; Behrman, Edward J.; White, Peter; Ahmer, Brian M. M.

    2014-01-01

    Salmonella enterica serovar Typhimurium (Salmonella) is one of the most significant food-borne pathogens affecting both humans and agriculture. We have determined that Salmonella encodes an uptake and utilization pathway specific for a novel nutrient, fructose-asparagine (F-Asn), which is essential for Salmonella fitness in the inflamed intestine (modeled using germ-free, streptomycin-treated, ex-germ-free with human microbiota, and IL10−/− mice). The locus encoding F-Asn utilization, fra, provides an advantage only if Salmonella can initiate inflammation and use tetrathionate as a terminal electron acceptor for anaerobic respiration (the fra phenotype is lost in Salmonella SPI1− SPI2− or ttrA mutants, respectively). The severe fitness defect of a Salmonella fra mutant suggests that F-Asn is the primary nutrient utilized by Salmonella in the inflamed intestine and that this system provides a valuable target for novel therapies. PMID:24967579

  1. Fructose-asparagine is a primary nutrient during growth of Salmonella in the inflamed intestine.

    Mohamed M Ali

    2014-06-01

    Full Text Available Salmonella enterica serovar Typhimurium (Salmonella is one of the most significant food-borne pathogens affecting both humans and agriculture. We have determined that Salmonella encodes an uptake and utilization pathway specific for a novel nutrient, fructose-asparagine (F-Asn, which is essential for Salmonella fitness in the inflamed intestine (modeled using germ-free, streptomycin-treated, ex-germ-free with human microbiota, and IL10-/- mice. The locus encoding F-Asn utilization, fra, provides an advantage only if Salmonella can initiate inflammation and use tetrathionate as a terminal electron acceptor for anaerobic respiration (the fra phenotype is lost in Salmonella SPI1- SPI2- or ttrA mutants, respectively. The severe fitness defect of a Salmonella fra mutant suggests that F-Asn is the primary nutrient utilized by Salmonella in the inflamed intestine and that this system provides a valuable target for novel therapies.

  2. Identification by PCR of non-typhoidal Salmonella enterica serovars associated with invasive infections among febrile patients in Mali.

    Sharon M Tennant

    Full Text Available BACKGROUND: In sub-Saharan Africa, non-typhoidal Salmonella (NTS are emerging as a prominent cause of invasive disease (bacteremia and focal infections such as meningitis in infants and young children. Importantly, including data from Mali, three serovars, Salmonella enterica serovar Typhimurium, Salmonella Enteritidis and Salmonella Dublin, account for the majority of non-typhoidal Salmonella isolated from these patients. METHODS: We have extended a previously developed series of polymerase chain reactions (PCRs based on O serogrouping and H typing to identify Salmonella Typhimurium and variants (mostly I 4,[5],12:i:-, Salmonella Enteritidis and Salmonella Dublin. We also designed primers to detect Salmonella Stanleyville, a serovar found in West Africa. Another PCR was used to differentiate diphasic Salmonella Typhimurium and monophasic Salmonella Typhimurium from other O serogroup B, H:i serovars. We used these PCRs to blind-test 327 Salmonella serogroup B and D isolates that were obtained from the blood cultures of febrile patients in Bamako, Mali. PRINCIPAL FINDINGS: We have shown that when used in conjunction with our previously described O-serogrouping PCR, our PCRs are 100% sensitive and specific in identifying Salmonella Typhimurium and variants, Salmonella Enteritidis, Salmonella Dublin and Salmonella Stanleyville. When we attempted to differentiate 171 Salmonella Typhimurium (I 4,[ 5],12:i:1,2 strains from 52 monophasic Salmonella Typhimurium (I 4,[5],12:i:- strains, we were able to correctly identify 170 of the Salmonella Typhimurium and 51 of the Salmonella I 4,[5],12:i:- strains. CONCLUSION: We have described a simple yet effective PCR method to support surveillance of the incidence of invasive disease caused by NTS in developing countries.

  3. Immunoblot detection of class-specific humoral immune response to outer membrane proteins isolated from Salmonella typhi in humans with typhoid fever.

    Ortiz, V; Isibasi, A; García-Ortigoza, E; Kumate, J

    1989-07-01

    The studies reported here were undertaken to assess the ability of the outer membrane proteins (OMPs) of Salmonella typhi to induce a humoral immune response in humans with typhoid fever. OMPs were isolated with the nonionic detergent Triton X-100 and were found to be contaminated with approximately 4% lipopolysaccharide. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns showed protein bands with molecular size ranges from 17 to 70 kilodaltons; the major groups of proteins were those that correspond to the porins and OmpA of gram-negative bacteria. Rabbit antiserum to OMPs or to S. typhi recognized OMPs after absorption with lipopolysaccharide. Sera from patients with typhoid fever contained immunoglobulin M antibodies which reacted with a protein of 28 kilodaltons and immunoglobulin G antibodies which reacted mainly with the porins, as determined by immunoblotting. These results indicate that the porins are the major immunogenic OMPs from S. typhi and that the immune response induced in the infection could be related to the protective status.

  4. Prevalence of Nontyphoidal Salmonella and Salmonella Strains with Conjugative Antimicrobial-Resistant Serovars Contaminating Animal Feed in Texas.

    Hsieh, Yi-Cheng; Poole, Toni L; Runyon, Mick; Hume, Michael; Herrman, Timothy J

    2016-02-01

    The objective of this study was to characterize 365 nontyphoidal Salmonella enterica isolates from animal feed. Among the 365 isolates, 78 serovars were identified. Twenty-four isolates (7.0%) were recovered from three of six medicated feed types. Three of these isolates derived from the medicated feed, Salmonella Newport, Salmonella Typhimurium var. O 5- (Copenhagen), and Salmonella Lexington var. 15+ (Manila), displayed antimicrobial resistance. Susceptibility testing revealed that only 3.0% (12) of the 365 isolates displayed resistance to any of the antimicrobial agents. These 12 isolates were recovered from unmedicated dry beef feed (n = 3), medicated dry beef feed (n = 3), cabbage culls (n = 2), animal protein products (n = 2), dry dairy cattle feed (n = 1), and fish meal (n = 1). Only Salmonella Newport and Salmonella Typhimurium var. O 5- (Copenhagen) were multidrug resistant. Both isolates possessed the IncA/C replicon and the blaCMY-2 gene associated with cephalosporin resistance. Plasmid replicons were amplified from 4 of 12 resistant isolates. Plasmids (40 kb) were Salmonella Montevideo and Salmonella Kentucky. Conjugation experiments were done using 7 of the 12 resistant isolates as donors. Only Salmonella Montevideo, possessing a plasmid and amplifying IncN, produced transconjugants. Transconjugants displayed the same antimicrobial resistance profile as did the donor isolate. Three isolates that amplified replicons corresponding to IncA/C or IncHI2 did not produce transconjugants at 30 or 37°C. The results of this study suggest that the prevalence of antimicrobial-resistant Salmonella contaminating animal feed is low in Texas. However, Salmonella was more prevalent in feed by-products; fish meal had the highest prevalence (84%) followed by animal protein products (48%). Ten of the 35 feed types had no Salmonella contamination. Further investigation is needed to understand the possible role of specific feed types in the dissemination of antimicrobial

  5. Development and Application of an IAC-PCR Kit for the Rapid Detection of Salmonella spp%沙门氏菌内标PCR快速检测试剂盒的研制与应用

    李小玲; 刘斌; 但现龙; 王大鹏; 周敏; 史贤明

    2011-01-01

    [Objective] The purpose of this study was to develop a rapid and accurate detection kit for Salmonella spp. Using polymerase chain reaction (PCR) with an internal amplification control (LAC). [Method] The specific primers and IAC were designed according to the conserved genes invA and stn in Salmonella spp. The optimization of the components and the evaluation of the parameters for the kit were carried out in this study. [Result] The experiment indicated that the specific 362 bp DNA fragment was amplified against 147 reference strains of Salmonella spp., while 28 strains of non-Salmonella only showed the 520 bp amplified band of IAC. The detection limit of the kit for purified genomic DNA was 8.0 fg/PCR. It was confirmed in artificial contamination assay that Salmonella spp. Could be detected by the kit after 8-10 h enrichment when 4-5 CFU germs were inoculated in 10 rnL milk. Thirty food samples were detected by the IAC-PCR kit in this study, and the experiments demonstrated that IAC could successfully indicate false-negative results. Besides, the kit worked well after being frozen-thawed for 60 times or stored at -20"C for one year. [Conclusion] The IAC-PCR detection kit developed in this study has good performances in specificity, sensitivity, stability and accuracy and is suitable for the rapid and accurate detection of Salmonella spp.%[目的] 研制一种能有效指示假阴性的PCR检测产品,用于沙门氏菌快速、准确、灵敏的检测.[方法] 针对沙门氏菌invA基因、stn基因序列分别设计引物与扩增内标,建立添加扩增内标的沙门氏菌PCR检测方法,组装试剂盒,并对试剂盒的各项性能进行评价.[结果] 试剂盒对147株沙门氏菌和28株非沙门氏菌的检测结果显示,所有沙门氏菌均能扩增出362 bp的目标条带,非沙门氏菌仅扩增出520 bp的内标条带.试剂盒检测沙门氏菌基因组DNA的检测限为8.0 fg/PCR,检测染菌量为4-5 CFU/10 mL的牛奶样品,增菌8-10 h即

  6. Detection of virulence-associated genes in Salmonella Enteritidis isolates from chicken in South of Brazil

    Karen A. Borges

    2013-12-01

    Full Text Available Salmonella spp. are considered the main agents of foodborne disease and Salmonella Enteritidis is one of the most frequently isolated serovars worldwide. The virulence of Salmonella spp. and their interaction with the host are complex processes involving virulence factors to overcome host defenses. The purpose of this study was to detect virulence genes in S. Enteritidis isolates from poultry in the South of Brazil. PCR-based assays were developed in order to detect nine genes (lpfA, agfA, sefA, invA, hilA, avrA, sopE, sivH and spvC associated with the virulence in eighty-four isolates of S. Enteritidis isolated from poultry. The invA, hilA, sivH, sefA and avrA genes were present in 100% of the isolates; lpfA and sopE were present in 99%; agfA was present in 96%; and the spvC gene was present in 92%. It was possible to characterize the isolates with four different genetic profiles (P1, P2, P3 and P4, as it follows: P1, positive for all genes; P2, negative only for spvC; P3, negative for agfA; and P4, negative for lpfA, spvC and sopE. The most prevalent profile was P1, which was present in 88% of the isolates. Although all isolates belong to the same serovar, it was possible to observe variations in the presence of these virulence-associated genes between different isolates. The characterization of the mechanisms of virulence circulating in the population of Salmonella Enteritidis is important for a better understanding of its biology and pathogenicity. The frequency of these genes and the establishment of genetic profiles can be used to determine patterns of virulence. These patterns, associated with in vivo studies, may help develop tools to predict the ability of virulence of different strains.

  7. Detection of Salmonella spp, Salmonella Enteritidis and Typhimurium in naturally infected broiler chickens by a multiplex PCR-based assay

    F.G. Paião

    2013-01-01

    Full Text Available The presence of Salmonella in the intestinal tract, on the chickens skin and among their feathers, may cause carcasses contamination during slaughtering and processing and possibly it is responsible by the introduction of this microorganism in the slaughterhouses. A rapid method to identify and monitor Salmonella and their sorovars in farm is becoming necessary. A pre-enriched multiplex polymerase chain reaction (m-PCR assay employing specific primers was developed and used to detect Salmonella at the genus level and to identify the Salmonella enterica serovar Enteritidis (S. Enteritidis and Salmonella enterica serovar Typhimurium (S. Typhimurium in broiler chicken swab samples. The method was validated by testing DNA extract from 90 fresh culture cloacal swab samples from poultry chicken cultured in phosphate buffer peptone water at 37 ºC for 18 h. The final results showed the presence of Salmonella spp. in 25% of samples, S. Enteritidis was present in 12% of the Salmonella-positive samples and S. Typhimurium in 3% of the samples. The m-PCR assay developed in this study is a specific and rapid alternative method for the identification of Salmonella spp. and allowed the observation of specific serovar contamination in the field conditions within the locations where these chickens are typically raised.

  8. Genomics of Salmonella Species

    Canals, Rocio; McClelland, Michael; Santiviago, Carlos A.; Andrews-Polymenis, Helene

    Progress in the study of Salmonella survival, colonization, and virulence has increased rapidly with the advent of complete genome sequencing and higher capacity assays for transcriptomic and proteomic analysis. Although many of these techniques have yet to be used to directly assay Salmonella growth on foods, these assays are currently in use to determine Salmonella factors necessary for growth in animal models including livestock animals and in in vitro conditions that mimic many different environments. As sequencing of the Salmonella genome and microarray analysis have revolutionized genomics and transcriptomics of salmonellae over the last decade, so are new high-throughput sequencing technologies currently accelerating the pace of our studies and allowing us to approach complex problems that were not previously experimentally tractable.

  9. Invasão tolteca em Chichén Itzá? Uma nova leitura da questão a partir da cultura material das Terras Maias Baixas do Norte

    Alexandre Guida Navarro

    2010-12-01

    Full Text Available Este artigo trata de uma das questões mais controversas da Arqueologia do México: uma possível invasão tolteca na cidade de Chichén Itzá. O assunto divide opiniões. Para um grupo de pesquisadores, Chichén Itzá é fruto da invasão dos habitantes de Tula, uma cidade do altiplano mexicano, a mais de 100 de distância dela. Já para outros pesquisadores, esta invasão não ocorreu e Chichén Itzá tem seu desenvolvimento dentro de uma tradição maia. Neste texto, mostramos algumas evidências arqueológicas em favor da segunda linha de pesquisa apresentada acima.

  10. Procalcitonin levels in salmonella infection

    Vikas Mishra

    2015-01-01

    Full Text Available Aim: Procalcitonin (PCT as a diagnostic marker for bacteremia and sepsis has been extensively studied. We aimed to study PCT levels in Salmonella infections whether they would serve as marker for early diagnosis in endemic areas to start empiric treatment while awaiting blood culture report. Materials and Methods: BACTEC blood culture was used to isolate Salmonella in suspected enteric fever patients. Serum PCT levels were estimated before starting treatment. Results: In 60 proven enteric fever patients, median value of serum PCT levels was 0.22 ng/ml, values ranging between 0.05 and 4 ng/ml. 95% of patients had near normal or mild increase (<0.5 ng/ml, only 5% of patients showed elevated levels. Notably, high PCT levels were found only in severe sepsis. Conclusion: PCT levels in Salmonella infections are near normal or minimally increased which differentiates it from other systemic Gram-negative infections. PCT cannot be used as a specific diagnostic marker of typhoid.

  11. Applications of microscopy in Salmonella research.

    Malt, Layla M; Perrett, Charlotte A; Humphrey, Suzanne; Jepson, Mark A

    2015-01-01

    Salmonella enterica is a Gram-negative enteropathogen that can cause localized infections, typically resulting in gastroenteritis, or systemic infection, e.g., typhoid fever, in humans and many other animals. Understanding the mechanisms by which Salmonella induces disease has been the focus of intensive research. This has revealed that Salmonella invasion requires dynamic cross-talk between the microbe and host cells, in which bacterial adherence rapidly leads to a complex sequence of cellular responses initiated by proteins translocated into the host cell by a type 3 secretion system. Once these Salmonella-induced responses have resulted in bacterial invasion, proteins translocated by a second type 3 secretion system initiate further modulation of cellular activities to enable survival and replication of the invading pathogen. Elucidation of the complex and highly dynamic pathogen-host interactions ultimately requires analysis at the level of single cells and single infection events. To achieve this goal, researchers have applied a diverse range of microscopy techniques to analyze Salmonella infection in models ranging from whole animal to isolated cells and simple eukaryotic organisms. For example, electron microscopy and high-resolution light microscopy techniques such as confocal microscopy can reveal the precise location of Salmonella and its relationship to cellular components. Widefield light microscopy is a simpler approach with which to study the interaction of bacteria with host cells and often has advantages for live cell imaging, enabling detailed analysis of the dynamics of infection and cellular responses. Here we review the use of imaging techniques in Salmonella research and compare the capabilities of different classes of microscope to address specific types of research question. We also provide protocols and notes on some microscopy techniques used routinely in our own research.

  12. Chronic effects of a Salmonella type III secretion effector protein AvrA in vivo.

    Rong Lu

    Full Text Available BACKGROUND: Salmonella infection is a common public health problem that can become chronic and increase the risk of inflammatory bowel diseases and cancer. AvrA is a Salmonella bacterial type III secretion effector protein. Increasing evidence demonstrates that AvrA is a multi-functional enzyme with critical roles in inhibiting inflammation, regulating apoptosis, and enhancing proliferation. However, the chronic effects of Salmonella and effector AvrA in vivo are still unknown. Moreover, alive, mutated, non-invasive Salmonella is used as a vector to specifically target cancer cells. However, studies are lacking on chronic infection with non-pathogenic or mutated Salmonella in the host. METHODS/PRINCIPAL FINDINGS: We infected mice with Salmonella Typhimurium for 27 weeks and investigated the physiological effects as well as the role of AvrA in intestinal inflammation. We found altered body weight, intestinal pathology, and bacterial translocation in spleen, liver, and gallbladder in chronically Salmonella-infected mice. Moreover, AvrA suppressed intestinal inflammation and inhibited the secretion of cytokines IL-12, IFN-gamma, and TNF-alpha. AvrA expression in Salmonella enhanced its invasion ability. Liver abscess and Salmonella translocation in the gallbladder were observed and may be associated with AvrA expression in Salmonella. CONCLUSION/SIGNIFICANCE: We created a mouse model with persistent Salmonella infection in vivo. Our study further emphasizes the importance of the Salmonella effector protein AvrA in intestinal inflammation, bacterial translocation, and chronic infection in vivo.

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

    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.

  14. Salmonella induces PD-L1 expression in B cells.

    Lopez-Medina, Marcela; Perez-Lopez, Araceli; Alpuche-Aranda, Celia; Ortiz-Navarrete, Vianney

    2015-10-01

    Salmonella persists for a long time in B cells; however, the mechanism(s) through which infected B cells avoid effector CD8 T cell responses has not been characterized. In this study, we show that Salmonella infects and survives within all B1 and B2 cell subpopulations. B cells are infected with a Salmonella typhimurium strain expressing an ovalbumin (OVA) peptide (SIINFEKL) to evaluate whether B cells process and present Salmonella antigens in the context of MHC-I molecules. Our data showed that OVA peptides are presented by MHC class I K(b)-restricted molecules and the presented antigen is generated through proteasomal degradation and vacuolar processing. In addition, Salmonella-infected B cells express co-stimulatory molecules such as CD40, CD80, and CD86 as well as inhibitory molecules such as PD-L1. Thus, the cross-presentation of Salmonella antigens and the expression of activation molecules suggest that infected B cells are able to prime and activate specific CD8(+) T cells. However, the Salmonella infection-stimulated expression of PD-L1 suggests that the PD-1/PD-L1 pathway may be involved in turning off the cytotoxic effector response during Salmonella persistent infection, thereby allowing B cells to become a reservoir for the bacteria.

  15. Meta-analysis of Chicken – Salmonella infection experiments

    te Pas Marinus FW

    2012-04-01

    Full Text Available Abstract Background Chicken meat and eggs can be a source of human zoonotic pathogens, especially Salmonella species. These food items contain a potential hazard for humans. Chickens lines differ in susceptibility for Salmonella and can harbor Salmonella pathogens without showing clinical signs of illness. Many investigations including genomic studies have examined the mechanisms how chickens react to infection. Apart from the innate immune response, many physiological mechanisms and pathways are reported to be involved in the chicken host response to Salmonella infection. The objective of this study was to perform a meta-analysis of diverse experiments to identify general and host specific mechanisms to the Salmonella challenge. Results Diverse chicken lines differing in susceptibility to Salmonella infection were challenged with different Salmonella serovars at several time points. Various tissues were sampled at different time points post-infection, and resulting host transcriptional differences investigated using different microarray platforms. The meta-analysis was performed with the R-package metaMA to create lists of differentially regulated genes. These gene lists showed many similarities for different chicken breeds and tissues, and also for different Salmonella serovars measured at different times post infection. Functional biological analysis of these differentially expressed gene lists revealed several common mechanisms for the chicken host response to Salmonella infection. The meta-analysis-specific genes (i.e. genes found differentially expressed only in the meta-analysis confirmed and expanded the biological functional mechanisms. Conclusions The meta-analysis combination of heterogeneous expression profiling data provided useful insights into the common metabolic pathways and functions of different chicken lines infected with different Salmonella serovars.

  16. Unveiling ubiquitinome rearrangements induced by Salmonella infection

    Bionda, Tihana; Behrends, Christian

    2016-01-01

    ABSTRACT Ubiquitination plays a critical role in the activation of host immune responses to infection and serves as a signal for pathogen delivery to phagophores along the xenophagy pathway. We recently performed systematic ubiquitination site profiling of epithelial cells infected with Salmonella Typhimurium. Our findings specifically highlight components of the NFKB, membrane trafficking pathways and RHO GTPase systems as ubiquitination hubs during infection. In addition, a broad spectrum of bacterial effectors and several outer membrane proteins are ubiquitinated in infected cells. This comprehensive resource of ubiquitinome dynamics during Salmonella infection enables further understanding of the complex host-pathogen interplay and may reveal novel targets for the inhibition of Salmonella invasion and inflammation. PMID:27467224

  17. Study on the Detaction of Shigella Spp., Salmonella Spp. and Proteus vulgaris by Multiplex PCR%多重PCR检测食品中志贺氏菌、沙门氏菌、变形杆菌方法的研究

    狄慧; 王羽; 张先舟; 马晓燕; 张伟

    2012-01-01

    To develop a rapid multiplex polymerase Chain reaction (m-PCR) assay for simultaneousdetection of Shigella spp., Salmonella spp. and Proteus vulgaris in food. The genomic alignment method was used to identify specific PCR target sequences. Design the three pairs of specific primers. IpaH gene of Shigella spp., invasive protein gene (invA) of Salmonella spp., and atpD gene of Proteus vulgaris Multiplex PCR was established by optimizing the reaction system. The specificity and sensitivity of the new multiplex PCR system were also evaluated. The result showed that the sensitivity of the multiplex PCR method was 102 CFU/mL, and the sensitivity of artificial pollution was 103 CFU/mL. The conclusions indicated that a triple PCR assay has been established for the simultaneous, sample, rapid and sensitive detection of Shigella spp., Salmonella spp. and Proteus vulgaris in food which also offers a convenient and rapid alternate microbiological tool for the detection and surveillance of sanitary inspection quarantine and food microbiological safety.%建立了同步快速检测食品中志贺氏菌、沙门氏菌、变形杆菌的多重聚合酶链式反应(multiplex polymerase chain reaction,mPCR)的方法。通过已报道基因和序列比对确定3种致病菌的特异性基因一志贺氏菌的ipaH~因、沙门氏菌的invA基因和变形杆菌的atpD基因并设计引物,优化反应条件,建立3种致病菌的多重PCR检测体系,测定方法特异性和灵敏度。结果表明,建立的多重PCR方法灵敏度为10。CFU/mL,人工模拟样品的灵敏度为10^3CFU/mL。初步建立了能同步、简便、快速、灵敏地检测食品中志贺氏菌、沙门氏菌、变形杆菌的三重PCR方法,可为卫生检验检疫、食品中致病菌的监测和监督提供较为实用的方法。

  18. Salmonella Questions and Answers

    ... Reduction; Hazard Analysis and Critical Control Point (PR/HACCP) Systems, Final Rule" in 1996. This rule sets Salmonella ... to reduce bacteria by means of the PR/HACCP system. [ Top of Page ] Q. How can consumers prevent ...

  19. Complete and Closed Genome Sequences of 10 Salmonella enterica subsp. enterica Serovar Anatum Isolates from Human and Bovine Sources

    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 an important pathogen transmitted by numerous vectors. Genomic comparisons of Salmonella strains from disparate hosts have the potential to further our understanding of mechanisms underlying host specificities and virulence. Here, we present the closed genome and plasmid sequences of 10 Salmonella enterica subsp. enterica serovar Anatum isolates from bovine and human sources. PMID:27257192

  20. Use of RapidChek® SELECT™ Salmonella to detect shedding of live attenuated Salmonella enterica serovar Typhi vaccine strains.

    Brenneman, Karen E; McDonald, Caitlin; Kelly-Aehle, Sandra M; Roland, Kenneth L; Curtiss, Roy

    2012-05-01

    Identification of individuals shedding Salmonella enterica serovar Typhi in stool is imperative during clinical trial safety evaluations. Recovery of live attenuated S. Typhi vaccine strains can be difficult because the mutations necessary for safety in humans often compromise survival in stringent selective enrichment media. RapidChek® SELECT™ Salmonella is a highly sensitive detection method for S. enterica species which utilizes a bacteriophage cocktail designed to reduce the growth of competitor microbes in mildly selective enrichment medium. Detection of Salmonella is enhanced by means of a Salmonella-specific antibody strip targeted to lipopolysaccharide. The RapidChek® SELECT™ Salmonella method was compared to conventional enrichment and plating methods to determine the most sensitive method for detecting attenuated S. Typhi strains in human stool samples. Although traditional enrichment strategies were more sensitive to the presence of wild-type S. Typhi, RapidChek® SELECT™ Salmonella was superior at detecting attenuated strains of S. Typhi. Strains containing a wide variety of attenuating mutations were detected with equal sensitivity as the wild type by RapidChek® SELECT™ Salmonella. The presence of Vi capsule or mutations which affected O-antigen synthesis (Δpmi, ΔgalE) did not decrease the sensitivity of the RapidChek® SELECT™ Salmonella assay.

  1. Rapid and sensitive detection of Shigella spp. and Salmonella spp. by multiple endonuclease restriction real-time loop-mediated isothermal amplification technique

    Yi eWang

    2015-12-01

    Full Text Available Shigella and Salmonella are frequently isolated from various food samples and can cause human gastroenteritis. Here, a novel multiple endonuclease restriction real-time loop-mediated isothermal amplification technology (MERT-LAMP were successfully established and validated for simultaneous detection of Shigella strains and Salmonella strains in only a single reaction. Two sets of MERT-LAMP primers for 2 kinds of pathogens were designed from ipaH gene of Shigella spp. and invA gene of Salmonella spp., respectively. Under the constant condition at 63˚C, the positive results were yielded in as short as 12 minutes with the genomic DNA extracted from the 19 Shigella strains and 14 Salmonella strains, and the target pathogens present in a sample could be simultaneously identified based on distinct fluorescence curves in real-time format. Accordingly, the multiplex detection assay significantly reduced effort, materials and reagents used, and amplification and differentiation were conducted at the same time, obviating the use of postdetection procedures. The analytical sensitivity of MERT-LAMP was found to be 62.5 fg and 125 fg DNA/reaction with genomic templates of Shigella strains and Salmonella strains, which was consist with normal LAMP assay, and at least 10- and 100-fold more sensitive than that of qPCR and conventional PCR approaches. The limit of detection of MERT-LAMP for Shigella strains and Salmonella strains detection in artificially contaminated milk samples was 5.8 CFU and 6.4 CFU per vessel. In conclusion, the MERT-LAMP methodology described here demonstrated a potential and valuable means for simultaneous screening of Shigella and Salmonella in a wide variety of samples.

  2. Rapid and Sensitive Detection of Shigella spp. and Salmonella spp. by Multiple Endonuclease Restriction Real-Time Loop-Mediated Isothermal Amplification Technique

    Wang, Yi; Wang, Yan; Luo, Lijuan; Liu, Dongxin; Luo, Xia; Xu, Yanmei; Hu, Shoukui; Niu, Lina; Xu, Jianguo; Ye, Changyun

    2015-01-01

    Shigella and Salmonella are frequently isolated from various food samples and can cause human gastroenteritis. Here, a novel multiple endonuclease restriction real-time loop-mediated isothermal amplification technology (MERT-LAMP) were successfully established and validated for simultaneous detection of Shigella strains and Salmonella strains in only a single reaction. Two sets of MERT-LAMP primers for 2 kinds of pathogens were designed from ipaH gene of Shigella spp. and invA gene of Salmonella spp., respectively. Under the constant condition at 63°C, the positive results were yielded in as short as 12 min with the genomic DNA extracted from the 19 Shigella strains and 14 Salmonella strains, and the target pathogens present in a sample could be simultaneously identified based on distinct fluorescence curves in real-time format. Accordingly, the multiplex detection assay significantly reduced effort, materials and reagents used, and amplification and differentiation were conducted at the same time, obviating the use of postdetection procedures. The analytical sensitivity of MERT-LAMP was found to be 62.5 and 125 fg DNA/reaction with genomic templates of Shigella strains and Salmonella strains, which was consist with normal LAMP assay, and at least 10- and 100-fold more sensitive than that of qPCR and conventional PCR approaches. The limit of detection of MERT-LAMP for Shigella strains and Salmonella strains detection in artificially contaminated milk samples was 5.8 and 6.4 CFU per vessel. In conclusion, the MERT-LAMP methodology described here demonstrated a potential and valuable means for simultaneous screening of Shigella and Salmonella in a wide variety of samples. PMID:26697000

  3. Transcriptional regulation of the assT-dsbL-dsbI gene cluster in Salmonella enterica serovar Typhi IMSS-1 depends on LeuO, H-NS, and specific growth conditions.

    Gallego-Hernández, A L; Hernández-Lucas, I; De la Cruz, M A; Olvera, L; Morett, E; Medina-Aparicio, L; Ramírez-Trujillo, J A; Vázquez, A; Fernández-Mora, M; Calva, E

    2012-05-01

    The assT gene encodes an arylsulfate sulfotransferase, an enzyme that catalyzes sulfuryl transfer from phenolic sulfate to a phenolic acceptor. In Salmonella enterica serovar Typhi IMSS-1, the assT gene is located upstream of the dsbL and dsbI genes, which are involved in a disulfide bond formation required for its activation. The assT-dsbL-dsbI gene cluster forms an operon transcribed by a LeuO-dependent promoter, in rich medium A (MA). Interestingly, in the absence of cloned leuO and in a ΔleuO background, two transcription start sites were detected for assT and two for dsbL-dsbI in minimal medium. The H-NS nucleoid protein repressed the expression of the assT-dsbL-dsbI LeuO-dependent operon, as well as of the assT transcriptional units. Thus, the expression of the assT-dsbL-dsbI gene cluster depends on the global regulatory proteins LeuO and H-NS, as well as on specific growth conditions.

  4. Relationship between genotype and phenotype of flagellin C in Salmonella

    Wan-Sheng Ji; Jia-Lu Hu; Jun-Wen Qiu; Bo-Rong Pan; Dao-Rong Peng; Bing-Long Shi; Shao-Juan Zhou; Kai-Chun Wu; Dai-Ming Fan

    2001-01-01

    AIM: To discover the relationship between the genotype and antigen serotype of flagellin C among Salmonella strains. METHODS: Fragment of Salmonella flagellin C in plasmid pLS408 was cloned, sequenced and compared with the corresponding sequence in other strains. Salmonella strains including two typhi strains, one paratyphoid strain, one enteritidis and one typhimurium strain were isolated from outpatients. Genome DNA was purified respectively from these clinical isolstes, then the corresponding flagellin C fragment was amplified by polymerase chain reaction, and the amplification products were analyzed by agarose gel electrophoreeis. RESULTS: The cloned fragment includes 582 nucleotides encoding the variable region and partial conservative region of Salmonella flagellin C in plasmid pLS408. With comparison to the corresponding sequences reported previously, there is only a little difference from other strains with the same flagellar serotype in both nucleotide and amino acid level. Specific PCR products were amplified in Salmonella strains with flagellar eerotype H-1-d including S. Muenchen, typhi and typhimurium, but not in S.paratyphoid C or S. Enteritidis strains. CONCLUSION: In this experiment, the specificity of nucleotide sequence could be found in flagellin C central variable regions as it exists in flagellar serotypes in Salmonella. It may be helpful to developing a rapid,sensitive, accurate and PCR-based method to detect Salmonella strains with serotype H-1-d.

  5. Salmonella typhi sternal wound infection.

    Sfeir, Maroun; Youssef, Pierre; Mokhbat, Jacques E

    2013-12-01

    Samonella typhi usually causes gastrointestinal infections. Few reports in the literature described skin and soft tissue infections related to Salmonella species, especially in immunocompetent patients. Our case exhibited sternal abscess growing Salmonella typhi.

  6. Study on the incidence of Salmonella enteritidis in Poultry and meat Samples by Cultural and PCR Methods

    Putturu Ramya

    Full Text Available Aim: To study the incidence of S.enteritidis in poultry and meat samples by cultural and PCR methods. Materials and Methods: A total of 130 samples (25 each of chicken, mutton, poultry faeces, cloacal samples and 10 each of liver, spleen and kidney collected from different sources were subjected to cultural and PCR methods for the presence of Salmonella and Salmonella enteritidis. Primers for invA and sefA gene were used for Salmonella and S.enteritidis respectively. Results: Out of 130 samples, 87 were positive for Salmonella spp. i.e. chicken-16(64%, mutton-12(48%, faeces-23(92%, cloacal swabs-23(92%, liver-5(50%, spleen and kidney samples-4(40% each by PCR methods, whereas 77 were positive by cultural method i.e. chicken-14(56%, mutton-10(40%, faeces-22(88%, cloacal swabs-21(84%, liver-4(40%, spleen and kidney-3(30% each. Out of 87 positive for Salmonella by PCR method, 59(chicken-12, mutton-7, faeces-17, cloacal swabs-15, liver-3, spleen-2, kidney-3 were positive for S.enteritidis. High incidence of S.enteritidis (68% in all the above samples are indicative of unhygienic conditions in poultry farms. Selective enrichment with Rappaport-Vassilidias (RV broths and Tetrathionate (TT broths were superior over Selenite-F (SF and Selenite cysteine (SC broths. Conclusions: High incidence of S.enteritidis was seen in most of poultry samples like chicken, kidney, liver and it's faeces than mutton, which was indicative of contamination of S.enteritidis is more prevalent in poultry farms. [Vet World 2012; 5(9.000: 541-545

  7. Application of Molecular Approaches for Understanding Foodborne Salmonella Establishment in Poultry Production

    Steven C. Ricke

    2014-01-01

    Full Text Available Salmonellosis in the United States is one of the most costly foodborne diseases. Given that Salmonella can originate from a wide variety of environments, reduction of this organism at all stages of poultry production is critical. Salmonella species can encounter various environmental stress conditions which can dramatically influence their survival and colonization. Current knowledge of Salmonella species metabolism and physiology in relation to colonization is traditionally based on studies conducted primarily with tissue culture and animal infection models. Consequently, while there is some information about environmental signals that control Salmonella growth and colonization, much still remains unknown. Genetic tools for comprehensive functional genomic analysis of Salmonella offer new opportunities for not only achieving a better understanding of Salmonella pathogens but also designing more effective intervention strategies. Now the function(s of each single gene in the Salmonella genome can be directly assessed and previously unknown genetic factors that are required for Salmonella growth and survival in the poultry production cycle can be elucidated. In particular, delineating the host-pathogen relationships involving Salmonella is becoming very helpful for identifying optimal targeted gene mutagenesis strategies to generate improved vaccine strains. This represents an opportunity for development of novel vaccine approaches for limiting Salmonella establishment in early phases of poultry production. In this review, an overview of Salmonella issues in poultry, a general description of functional genomic technologies, and their specific application to poultry vaccine developments are discussed.

  8. Growth and virulence properties of biofilm-forming Salmonella enterica serovar typhimurium under different acidic conditions.

    Xu, Hua; Lee, Hyeon-Yong; Ahn, Juhee

    2010-12-01

    This study was designed to characterize the viability and potential virulence of bofilm-forming Salmonella enterica serovar Typhimurium under different pH levels, ranging from 5 to 7. The plate count method and real-time reverse transcription-PCR (RT-PCR) were used to evaluate the survival of S. Typhimurium grown in Trypticase soy broth (TSB) adjusted to pH 5, 6, and 7 (TSB-5, TSB-6, and TSB-7, respectively) at 37°C for 10 days. In TSB-5 and TSB-6, the numbers of viable cells estimated by using the real-time RT-PCR were greater than the culturable counts enumerated by the plate count method. Reflectance micro-Fourier transform infrared (micro-FTIR) spectroscopy was used to evaluate the biochemical changes in biofilm cells. Considerable changes in chemical components were observed in the biofilm cells grown in TSB-5 and TSB-6 when compared to the cells grown in TSB-7. The enterotoxin production and invasive ability of planktonic and biofilm S. Typhimurium cells were inferred by the relative levels of expression of stn and invA. The levels of expression of stn and invA were significantly increased in biofilm S. Typhimurium cells grown in TSB-5 (1.9-fold and 3.2-fold) and TSB-6 (2.1-fold and 22.3-fold) after 10 days of incubation. These results suggest that the biofilm-forming S. Typhimurium under different pH levels might change the virulence production and stress response mechanisms.

  9. Towards standardization of microarray-based genotyping of Salmonella

    Löfström, Charlotta; Grønlund, Hugo Ahlm; Riber, Leise

    2010-01-01

    Genotyping is becoming an increasingly important tool to improve risk assessments of Salmonella. DNA microarray technology is a promising diagnostic tool that can provide high resolution genomic profile of many genes simultaneously. However, standardization of DNA microarray analysis is needed...... of Salmonella at two different laboratories. The low-density array contained 281 of 57-60-mer oligonucleotide probes for detecting a wide range of specific genomic markers associated with antibiotic resistance, cell envelope structures, mobile genetic elements and pathogenicity. Several test parameters...... for a decentralized and simple-to-implement DNA microarray as part of a pan-European source-attribution model for risk assessment of Salmonella....

  10. 基于SYBR Green Ⅰ荧光定量PCR建立生乳及乳制品沙门氏菌快速检测技术%SYBR Green Ⅰ real-time polymerase chain reaction for rapid detection of Salmonella spp.in raw milk and milk products

    张巧艳; 陈亭亭; 陈笑芸; 杨胜利; 缪青梅

    2012-01-01

    生乳易受沙门氏菌污染,并大量繁殖;经加工的乳制品细菌数大大减少,但仍存在沙门氏菌污染的风险.试验按生乳及乳制品沙门氏菌污染水平研究样品前处理方法,采用煮沸裂解法快速提取总DNA,针对沙门氏菌invA基因建立SYBR Green Ⅰ荧光定量PCR快速检测技术.建立的方法具有良好的特异性和较高的灵敏度,其中生乳沙门氏菌检出限为102 cfu· mL-1,方法的检测线性范围为102-108 cfu·mL-1,相关系数(R2)为0.999,扩增效率为103%;乳制品沙门氏菌经16 h增菌后检出限达到1 cfu·[25 g(mL)]-1.该技术可用于生乳中沙门氏菌的高效筛查及定量检测,检测一个样品仅需3 h;同时,可用于乳制品的准确定性检测,检测周期为1d;且方法重复性好、准确度高、操作简单,为乳制品企业快速检测沙门氏菌提供了有效的技术手段.%Raw milk was susceptible to Salmonella spp. , which was reproduced rapidly. Nevertheless, there was only the potential of very small amount of Salmonella spp. In milk products since sterilization and other treatments though the bacterial population decreased. In this paper, we studied the pretreatment methods of raw milk and milk products according to their contamination levels and optimized the extraction conditions of bacterial total DNA by the boiling lysis procedure. Furthermore, we set up a systemic detection technology for milk-borne Salmonella spp. , based on SYBR Green I real-time PCR targeting the invA. Gene. The developed methods possessed specificity for Salmonella spp. As far as raw milk was concerned, the limit of detection of the method was 102 cfu·mL-1 , the linear range of the standard curve was 102 - 108 cfu·mL-1 , correlation coefficient (R2 ) was 0.999, and amplification efficiency was 103%. For milk products, 1 cfu of Salmonella spp. Present in 25 g (mL) milk samples was shown detectable by this method with an enrichment step of 16 h. This technology could

  11. The age of production system and previous Salmonella infections on-farm are risk factors for low-level Salmonella infections in laying hen flocks.

    Van Hoorebeke, S; Van Immerseel, F; De Vylder, J; Ducatelle, R; Haesebrouck, F; Pasmans, F; de Kruif, A; Dewulf, J

    2010-06-01

    An explorative field study was carried out to determine risk factors for Salmonella infections in commercial laying hen flocks. For this purpose, 29 laying hen farms, including farms using conventional and alternative housing systems, were intensively sampled. An on-farm questionnaire was used to collect information on general management practices and specific characteristics of the sampled flock such as flock size, age of the hens, and age of the infrastructure. Salmonella was detected in laying hens from 6 of the 29 sampled farms. Using multivariate logistic regression with the Salmonella status of the flock as an outcome variable, a previous Salmonella contamination on the farm and the age of the production system were identified as risk factors for the presence of Salmonella in laying hens (P<0.05). The housing system did not have a significant influence on the prevalence of Salmonella in the current study.

  12. Epidemic increase in Salmonella bloodstream infection in children, Bwamanda, the Democratic Republic of Congo.

    Phoba, M-F; De Boeck, H; Ifeka, B B; Dawili, J; Lunguya, O; Vanhoof, R; Muyembe, J-J; Van Geet, C; Bertrand, S; Jacobs, J

    2014-01-01

    Salmonella enterica is the leading cause of bloodstream infection in children in sub-Saharan Africa, but few data are available from Central-Africa. We documented during the period November 2011 to May 2012 an epidemic increase in invasive Salmonella bloodstream infections in HGR Bwamanda, a referral hospital in Equateur Province, DR Congo. Salmonella spp. represented 90.4 % (103 out of 114) of clinically significant blood culture isolates and comprised Salmonella Typhimurium (54.4 %, 56 out of 103), Salmonella Enteritidis (28.2 %, 29 out of 103) and Salmonella Typhi (17.5 %, 18 out of 103), with Salmonella Enteritidis accounting for most of the increase. Most (82 out of 103, 79.6 %) isolates were obtained from children infected with Salmonella Typhimurium and Salmonella Enteritidis were 14 months (14 days to 64 years) and 19 months (3 months to 8 years) respectively. Clinical presentation was non-specific; the in-hospital case fatality rate was 11.1 %. More than two thirds (69.7 %, 53 out of 76) of children infection. Most (83/85, 97.6 %) non-typhoid Salmonella isolates as well as 6/18 (33.3 %) Salmonella Typhi isolates were multidrug resistant (i.e. resistant to the first-line oral antibiotics amoxicillin, trimethoprim-sulfamethoxazole and chloramphenicol), one (1.0 %) Salmonella Typhimurium had decreased ciprofloxacin susceptibility owing to a point mutation in the gyrA gene (Gly81Cys). Multilocus variable-number tandem-repeat (MLVA) analysis of the Salmonella Enteritidis isolates revealed closely related patterns comprising three major and four minor profiles, with differences limited to one out of five loci. These data show an epidemic increase in clonally related multidrug-resistant Salmonella bloodstream infection in children in DR Congo.

  13. Ubiquitination as an Efficient Molecular Strategy Employed in Salmonella Infection

    Narayanan, Lakshmi A.; Edelmann, Mariola J.

    2014-01-01

    The protein modification with ubiquitin has various functions in the host innate immune system in response to the bacterial infection. To counteract the host immunity, Salmonella can specifically target ubiquitinating or deubiquitinating enzymes by its effector proteins. In this review we describe the multiple facets of ubiquitin function during infection with Salmonella enterica Typhimurium and hypothesize how these studies on the host-pathogen interactions can help to understand the general...

  14. Ubiquitination as an efficient molecular strategy employed in salmonella infection.

    Narayanan, Lakshmi A; Edelmann, Mariola J

    2014-01-01

    The ubiquitin modification has various functions in the host innate immune system in response to the bacterial infection. To counteract the host immunity, Salmonella can specifically target ubiquitin pathways by its effector proteins. In this review, we describe the multiple facets of ubiquitin function during infection with Salmonella enterica Typhimurium and hypothesize how these studies on the host-pathogen interactions can help to understand the general function of the ubiquitination pathway in the host cell.

  15. Ubiquitination as an efficient molecular strategy employed in Salmonella infection

    Lakshmi A Narayanan

    2014-11-01

    Full Text Available The protein modification with ubiquitin has various functions in the host innate immune system in response to the bacterial infection. To counteract the host immunity, Salmonella can specifically target ubiquitinating or deubiquitinating enzymes by its effector proteins. In this review we describe the multiple facets of ubiquitin function during infection with Salmonella enterica Typhimurium and hypothesize how these studies on the host-pathogen interactions can help to understand the general function of the ubiquitination pathway in the host cell.

  16. Salmonella enteritidis in Quail Eggs

    ERDOĞRUL, Özlem Turgay

    2014-01-01

    The presence of Salmonella enteritidis was investigated in 123 liquid whole quail eggs. Salmonella strains were identified and sero-grouped by coagglutination test and slide agglutination test. Seven (5.69%) of 123 whole quail eggs were in group D1 and were sero-typed as Salmonella enteritidis. It was found that in phage-typing of Salmonella enteritidis, three of 7 strains were Salmonella enteritidis PT4 , two of them were PT1, one of them was PT7, and one of them was indefinite.

  17. Salmonella enteritidis in Quail Eggs

    ERDOĞRUL, Özlem Turgay

    2002-01-01

    The presence of Salmonella enteritidis was investigated in 123 liquid whole quail eggs. Salmonella strains were identified and sero-grouped by coagglutination test and slide agglutination test. Seven (5.69%) of 123 whole quail eggs were in group D1 and were sero-typed as Salmonella enteritidis. It was found that in phage-typing of Salmonella enteritidis, three of 7 strains were Salmonella enteritidis PT4 , two of them were PT1, one of them was PT7, and one of them was indefinite.

  18. Live attenuated vaccines for invasive Salmonella infections.

    Tennant, Sharon M; Levine, Myron M

    2015-06-19

    Salmonella enterica serovar Typhi produces significant morbidity and mortality worldwide despite the fact that there are licensed Salmonella Typhi vaccines available. This is primarily due to the fact that these vaccines are not used in the countries that most need them. There is growing recognition that an effective invasive Salmonella vaccine formulation must also prevent infection due to other Salmonella serovars. We anticipate that a multivalent vaccine that targets the following serovars will be needed to control invasive Salmonella infections worldwide: Salmonella Typhi, Salmonella Paratyphi A, Salmonella Paratyphi B (currently uncommon but may become dominant again), Salmonella Typhimurium, Salmonella Enteritidis and Salmonella Choleraesuis (as well as other Group C Salmonella). Live attenuated vaccines are an attractive vaccine formulation for use in developing as well as developed countries. Here, we describe the methods of attenuation that have been used to date to create live attenuated Salmonella vaccines and provide an update on the progress that has been made on these vaccines.

  19. Antibiotic susceptibility pattern of Salmonella enterica serovar typhi and Salmonella enterica serovar paratyphi A with special reference to quinolone resistance

    Shoorashetty Manohar Rudresh

    2015-01-01

    Full Text Available Background and Objectives: Typhoid fever is endemic in India. Extensive use of first-line antibiotics has led to the emergence of multi-drug resistant (MDR Salmonella typhi. Ciprofloxacin has become empirical therapy of choice against MDR salmonellae. Recent year′s emergence of low-level ciprofloxacin resistance in salmonellae resulted in delayed response and serious complications. Nalidixic acid (NA screen test is used as surrogate marker for detection low-level ciprofloxacin resistance. In this study, we evaluated prevalence of MDR and low-level ciprofloxacin resistant S. typhi and Salmonella paratyphi A. Materials and Methods: A total of 50 blood culture isolates of S. typhi and S. paratyphi A were tested for antibiotic susceptibility according to Clinical Laboratory Standards Institute (CLSI method. Minimal inhibitory concentration (MIC to ciprofloxacin was carried out by E-test and agar dilution method. Results: Among the 50 salmonella isolates, 80% were S. typhi and 20% were S. paratyphi A. MDR was found in 2% S. typhi. NA resistant salmonellae showed ciprofloxacin MIC ranging from 0.25 to 0.75 μg/ml. One isolate of S. typhi showed ciprofloxacin MIC of 32 μg/ml and was also resistant to ceftriaxone. NA screen test for low-level ciprofloxacin resistance was 100% sensitive and 97.9% specific. Interpretation and Conclusion: NA resistant isolates should be tested for ciprofloxacin MIC to decide therapeutic options. The current CLSI breakpoints may have to be re-evaluated for salmonellae.

  20. PCR Method To Identify Salmonella enterica Serovars Typhi, Paratyphi A, and Paratyphi B among Salmonella Isolates from the Blood of Patients with Clinical Enteric Fever▿

    Levy, Haim; Diallo, Souleymane; Tennant, Sharon M.; Livio, Sofie; Sow, Samba O.; Tapia, Milagritos; Fields, Patricia I.; Mikoleit, Matthew; Tamboura, Boubou; Kotloff, Karen L.; Lagos, Rosanna; Nataro, James P.; Galen, James E.; Levine, Myron M.

    2008-01-01

    PCR methodology was developed to identify Salmonella enterica serovars Typhi, Paratyphi A, and Paratyphi B. One multiplex PCR identifies serogroup D, A, and B and Vi-positive strains; another confirms flagellar antigen “d,” “a,” or “b.” Blinded testing of 664 Malian and Chilean Salmonella blood isolates demonstrated 100% sensitivity and specificity. PMID:18367574

  1. Stably Integrated luxCDABE for Assessment of Salmonella Invasion Kinetics

    Kelly N. Flentie

    2008-09-01

    Full Text Available Salmonella Typhimurium is a common cause of gastroenteritis in humans and also localizes to neoplastic tumors in animals. Invasion of specific eukaryotic cells is a key mechanism of Salmonella interactions with host tissues. Early stages of gastrointestinal cell invasion are mediated by a Salmonella type III secretion system, powered by the adenosine triphosphatase invC. The aim of this work was to characterize the invC dependence of invasion kinetics into disparate eukaryotic cells traditionally used as models of gut epithelium or neoplasms. Thus, a nondestructive real-time assay was developed to report eukaryotic cell invasion kinetics using lux+ Salmonella that contain chromosomally integrated luxCDABE genes. Bioluminescence-based invasion assays using lux+ Salmonella exhibited inoculum dose-response correlation, distinguished invasion-competent from invasion-incompetent Salmonella, and discriminated relative Salmonella invasiveness in accordance with environmental conditions that induce invasion gene expression. In standard gentamicin protection assays, bioluminescence from lux+ Salmonella correlated with recovery of colony-forming units of internalized bacteria and could be visualized by bioluminescence microscopy. Furthermore, this assay distinguished invasion-competent from invasion-incompetent bacteria independent of gentamicin treatment in real time. Bioluminescence reported Salmonella invasion of disparate eukaryotic cell lines, including neoplastic melanoma, colon adenocarcinoma, and glioma cell lines used in animal models of malignancy. In each case, Salmonella invasion of eukaryotic cells was invC dependent.

  2. Antimicrobial resistance in zoonotic nontyphoidal Salmonella: an alarming trend?

    Michael, G B; Schwarz, S

    2016-12-01

    Zoonotic bacteria of the genus Salmonella have acquired various antimicrobial resistance properties over the years. The corresponding resistance genes are commonly located on plasmids, transposons, gene cassettes, or variants of the Salmonella Genomic Islands SGI1 and SGI2. Human infections by nontyphoidal Salmonella isolates mainly result from ingestion of contaminated food. The two predominantly found Salmonella enterica subsp. enterica serovars in the USA and in Europe are S. Enteritidis and S. Typhimurium. Many other nontyphoidal Salmonella serovars have been implicated in foodborne Salmonella outbreaks. Summary reports of the antimicrobial susceptibility patterns of nontyphoidal Salmonella isolates over time suggest a moderate to low level of antimicrobial resistance and multidrug-resistance. However, serovar-specific analyses showed in part a steady state, a continuous decline, or a recent increase in resistance to certain antimicrobial agents. Resistance to critically important antimicrobial agents, e.g. third-generation cephalosporins and (fluoro)quinolones is part of many monitoring programmes and the corresponding results confirm that extended-spectrum β-lactamases are still rarely found in nontyphoidal Salmonella serovars, whereas resistance to (fluoro)quinolones is prevalent at variable frequencies among different serovars from humans and animals in different countries. Although it is likely that nontyphoidal Salmonella isolates from animals represent a reservoir for resistance determinants, it is mostly unknown where and when Salmonella isolates acquired resistance properties and which exchange processes have happened since then.

  3. LAMP-3 (Lysosome-Associated Membrane Protein 3) Promotes the Intracellular Proliferation of Salmonella typhimurium.

    Lee, Eun-Ju; Park, Kwan-Sik; Jeon, In-Sook; Choi, Jae-Woon; Lee, Sang-Jeon; Choy, Hyun E; Song, Ki-Duk; Lee, Hak-Kyo; Choi, Joong-Kook

    2016-07-01

    Lysosomes are cellular organelles containing diverse classes of catabolic enzymes that are implicated in diverse cellular processes including phagocytosis, autophagy, lipid transport, and aging. Lysosome-associated membrane proteins (LAMP-1 and LAMP-2) are major glycoproteins important for maintaining lysosomal integrity, pH, and catabolism. LAMP-1 and LAMP-2 are constitutively expressed in Salmonella-infected cells and are recruited to Salmonella-containing vacuoles (SCVs) as well as Salmonella-induced filaments (Sifs) that promote the survival and proliferation of the Salmonella. LAMP-3, also known as DC-LAMP/CD208, is a member of the LAMP family of proteins, but its role during Salmonella infection remains unclear. DNA microarray analysis identified LAMP-3 as one of the genes responding to LPS stimulation in THP-1 macrophage cells. Subsequent analyses reveal that LPS and Salmonella induced the expression of LAMP-3 at both the transcriptional and translational levels. Confocal Super resolution N-SIM imaging revealed that LAMP-3, like LAMP-2, shifts its localization from the cell surface to alongside Salmonella. Knockdown of LAMP-3 by specific siRNAs decreased the number of Salmonella recovered from the infected cells. Therefore, we conclude that LAMP-3 is induced by Salmonella infection and recruited to the Salmonella pathogen for intracellular proliferation.

  4. Effect of vaccinating breeder chickens with a killed Salmonella vaccine on Salmonella prevalences and loads in breeder and broiler chicken flocks.

    Berghaus, R D; Thayer, S G; Maurer, J J; Hofacre, C L

    2011-05-01

    The objective of this study was to evaluate the effect of vaccination of breeder chickens on Salmonella prevalences and loads in breeder and broiler chicken flocks. Chickens housed on six commercial breeder farms were vaccinated with a killed Salmonella vaccine containing Salmonella Typhimurium, Salmonella Enteritidis, and Salmonella Kentucky. Unvaccinated breeders placed on six additional farms served as controls. Eggs from vaccinated and unvaccinated breeder flocks were kept separately in the hatchery, and the resulting chicks were used to populate 58 commercial broiler flock houses by using a pair-matched design. Vaccinated breeder flocks had significantly higher Salmonella-specific antibody titers than did the unvaccinated breeder flocks, although they did not differ significantly with respect to environmental Salmonella prevalences or loads. Broiler flocks that were the progeny of vaccinated breeders had significantly lower Salmonella prevalences and loads than broiler flocks that were the progeny of unvaccinated breeders. After adjusting for sample type and clustering at the farm level, the odds of detecting Salmonella in samples collected from broiler flocks originating from vaccinated breeders were 62% lower (odds ratio [95% confidence interval] = 0.38 [0.21, 0.68]) than in flocks from unvaccinated breeders. In addition, the mean load of culture-positive samples was lower in broilers from vaccinated breeders by 0.30 log most probable number per sample (95% confidence interval of -0.51, -0.09; P = 0.004), corresponding to a 50% decrease in Salmonella loads. In summary, vaccination of broiler breeder pullets increased humoral immunity in the breeders and reduced Salmonella prevalences and loads in their broiler progeny, but did not significantly decrease Salmonella in the breeder farm environment.

  5. Salmonella pseudomembranous colitis.

    Beck, Andrew; McNeil, Candice; Abdelsayed, George; Chin-Lue, Roland; Kassis, Simon; Manthous, Constantine A

    2007-01-01

    Pseudomembranous colitis is most often associated with antibiotic use and caused most often by Clostridium difficile. Aclinical syndrome and pathology that is identical can be caused rarely by other organisms. We report a case of Salmonella enterica pseudomembranous colitis and briefly review the literature regarding rare causes of this syndrome.

  6. Salmonella from Baby Turtles

    2017-01-09

    Dr. Stacey Bosch, a veterinarian with CDC, discusses her article on Salmonella infections associated with baby turtles.  Created: 1/9/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 1/9/2017.

  7. Cell lines and Salmonella

    de Jonge R; Hendriks H; Garssen J; MGB; LPI

    2001-01-01

    Infectie met Salmonella kan gepaard gaan met de invasie van darmepitheelcellen. De aan de invasie voorafgaande aanhechting leidt reeds tot de transmigratie van witte bloedcellen (neutrofielen) vanuit de bloedbaan naar het epitheelweefsel. De migratie wordt gestimuleerd door de productie van chemok

  8. Foodborne Salmonella control

    Almost all of the paratyphoid Salmonella spp. are normal flora bacteria of the intestines of chickens and turkeys. They cohabit together and have a very comfortable living arrangement, causing little or no harm to one another and seldom attracting much attention from the birds’ defense systems. Th...

  9. Thermal inactivation of eight Salmonella serotypes on dry corn flour.

    Vancauwenberge, J E; Bothast, R J; Kwolek, W F

    1981-01-01

    Dry heat was used to inactivate Salmonella newington, Salmonella typhimurium, Salmonella anatum, Salmonella kentucky, Salmonella cubana, Salmonella seftenberg, Salmonella thompson, and Salmonella tennessee in corn flour at 10 and 15% moisture. The flour was spray inoculated at 10(5) Salmonella cells per g and then stored at 49 degrees C (120 degrees F); viable Salmonella cells were counted on Trypticase (BBL Microbiology Systems) soy agar plates every 30 min for the first 4 h and then at 4-h ...

  10. Prevalence, virulence and antibiotic susceptibility of Salmonella spp. strains, isolated from beef in Greater Tunis (Tunisia).

    Oueslati, Walid; Rjeibi, Mohamed Ridha; Mhadhbi, Moez; Jbeli, Mounir; Zrelli, Samia; Ettriqui, Abdelfettah

    2016-09-01

    The aim of this work was to investigate the presence of Salmonella spp. in 300 beef meat samples collected from cattle carcasses of different categories (young bulls, culled heifers and culled cows). The detection of Salmonella spp. was performed by the alternative VIDAS Easy Salmonella technique and confirmed by PCR using Salmonella specific primers. Salmonella serotypes were determined by slide agglutination tests. The resistance to 12 antibiotics was determined by the diffusion method on Mueller-Hinton agar antibiotic discs. The overall contamination rate of beef by Salmonella spp. was 5.7% (17/300). This rate varied from naught (0/100) in bulls' meat to 14% (14/100) in culled cows' meat (pinvA and negative for the virulence gene spvC. Only one isolate (S. Kentucky) harbored the h-li virulence gene.

  11. Invasão do nervo óptico por melanoma peripapilar: relato de caso Optic nerve invasion by juxtapapillary melanoma: case report

    Eduardo Ferrari Marback

    2003-06-01

    Full Text Available Tumores pigmentados localizados sobre o disco óptico são raros e representam desafio diagnóstico. Paciente masculino, 60 anos, apresenta baixa da acuidade visual no olho esquerdo devido à lesão pigmentada que cobre o disco óptico. Foi indicada a enucleação com recusa pelo paciente. O quadro evoluiu com descolamento de retina. Examinado em outro serviço teve indicação de vitrectomia também recusada. Retorna aos nossos cuidados; feita a enucleação o diagnóstico anatomopatológico revelou melanoma maligno da coróide com invasão pós-laminar do nervo óptico. A importância prognóstica da invasão do nervo óptico por melanoma da coróide ainda não está totalmente esclarecida. Embora raro, tumor pigmentado cobrindo o nervo óptico pode representar melanoma maligno. O diagnóstico diferencial destes casos é geralmente difícil, porém seu reconhecimento à ultra-sonografia ocular é patente e descolamento de retina associado é sinal de atividade tumoral. Os riscos de disseminação da doença exigem atenção na suspeita diagnóstica e conduta precisa.Small-pigmented lesions over the optic disc are very rare and may represent a diagnostic challenge. To report a case of a small malignant choroidal melanoma invading the optic nerve. A 60-year-old male presents with low vision in the left eye due to a small, pigmented lesion over the optic disc. At first the patient refused enucleation. One month later, after further drop in visual acuity, the patient was seen at another service, diagnosed as having a retinal detachment, and pars plana vitrectomy was proposed but also refused by the patient. Returning to our service, the eye was enucleated and a final diagnosis of choroidal melanoma with post-laminar optic nerve invasion was made. Although rare, pigmented lesions over the optic disc may represent a malignant melanoma. The prognostic significance of optic nerve invasion by choroidal melanoma is not clear yet. The differential

  12. A model of Salmonella colitis with features of diarrhea in SLC11A1 wild-type mice.

    Heungjeong Woo

    Full Text Available BACKGROUND: Mice do not get diarrhea when orally infected with S. enterica, but pre-treatment with oral aminoglycosides makes them susceptible to Salmonella colitis. However, genetically susceptible ItyS mice (Nramp1(G169D allele die from systemic infection before they develop diarrhea, so a new model is needed to study the pathogenesis of diarrhea. We pretreated ItyR mice (Nramp1(G169 with oral kanamycin prior to infecting them with virulent S. Typhimurium strain 14028s in order to study Salmonella-induced diarrhea. We used both a visual scoring system and the measurement of fecal water content to measure diarrhea. BALB/c.D2(Nramp1 congenic started losing weight 5 days post-infection and they began to die from colitis 10-14 days after infection. A SPI-1 (invA mutant caused cecal, but not colonic inflammation and did not cause diarrhea. A phoP- mutant did not cause manifestations of diarrhea in either normal or NADPH-deficient (gp91(phox mice. However, strain 14028s caused severe colitis and diarrhea in gp91(phox-deficient mice on an ItyR background. pmr A and F mutants, which are less virulent in orally infected BALB/c mice, were fully virulent in this model of colitis. CONCLUSIONS: S. enterica must be able to invade the colonic epithelium and to persist in the colon in order to cause colitis with manifestations of diarrhea. The NADPH oxidase is not required for diarrhea in Salmonella colitis. Furthermore, a Salmonella phoP mutant can be cleared from the colon by non-oxidative host defenses.

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

    Maria Braukmann

    Full Text Available 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.

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

    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.

  15. Salmonella Typhimurium induces SPI-1 and SPI-2 regulated and strain dependent downregulation of MHC II expression on porcine alveolar macrophages.

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

    2012-06-13

    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. Circumvention of the host's immune system by Salmonella might contribute to persistent infection of pigs. In the present study, we found that Salmonella Typhimurium strain 112910a specifically downregulated MHC II, but not MHC I, expression on porcine alveolar macrophages in a Salmonella pathogenicity island (SPI)-1 and SPI-2 dependent way. Salmonella induced downregulation of MHC II expression and intracellular proliferation of Salmonella in macrophages were significantly impaired after opsonization with Salmonella specific antibodies prior to inoculation. Furthermore, the capacity to downregulate MHC II expression on macrophages differed significantly among Salmonella strains, independently of strain specific differences in invasion capacity, Salmonella induced cytotoxicity and altered macrophage activation status. The fact that strain specific differences in MHC II downregulation did not correlate with the extent of in vitro SPI-1 or SPI-2 gene expression indicates that other factors are involved in MHC II downregulation as well. Since Salmonella strain dependent interference with the pig's immune response through downregulation of MHC II expression might indicate that certain Salmonella strains are more likely to escape serological detection, our findings are of major interest for Salmonella monitoring programs primarily based on serology.

  16. Salmonella Typhimurium induces SPI-1 and SPI-2 regulated and strain dependent downregulation of MHC II expression on porcine alveolar macrophages

    Van Parys Alexander

    2012-06-01

    Full Text Available Abstract 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. Circumvention of the host’s immune system by Salmonella might contribute to persistent infection of pigs. In the present study, we found that Salmonella Typhimurium strain 112910a specifically downregulated MHC II, but not MHC I, expression on porcine alveolar macrophages in a Salmonella pathogenicity island (SPI-1 and SPI-2 dependent way. Salmonella induced downregulation of MHC II expression and intracellular proliferation of Salmonella in macrophages were significantly impaired after opsonization with Salmonella specific antibodies prior to inoculation. Furthermore, the capacity to downregulate MHC II expression on macrophages differed significantly among Salmonella strains, independently of strain specific differences in invasion capacity, Salmonella induced cytotoxicity and altered macrophage activation status. The fact that strain specific differences in MHC II downregulation did not correlate with the extent of in vitro SPI-1 or SPI-2 gene expression indicates that other factors are involved in MHC II downregulation as well. Since Salmonella strain dependent interference with the pig’s immune response through downregulation of MHC II expression might indicate that certain Salmonella strains are more likely to escape serological detection, our findings are of major interest for Salmonella monitoring programs primarily based on serology.

  17. Salmonella enterica: Survival, Colonization, and Virulence Differences among Serovars

    A. Andino

    2015-01-01

    Full Text Available Data indicate that prevalence of specific serovars of Salmonella enterica in human foodborne illness is not correlated with their prevalence in feed. Given that feed is a suboptimal environment for S. enterica, it appears that survival in poultry feed may be an independent factor unrelated to virulence of specific serovars of Salmonella. Additionally, S. enterica serovars appear to have different host specificity and the ability to cause disease in those hosts is also serovar dependent. These differences among the serovars may be related to gene presence or absence and expression levels of those genes. With a better understanding of serovar specificity, mitigation methods can be implemented to control Salmonella at preharvest and postharvest levels.

  18. 问号钩端螺旋体毒力相关蛋白InvA转录和表达特征的研究%Transcription and expression characteristics of Leptospira virulence-associated protein InvA

    罗依惠; 陈铭; 李立伟; 钱景; 严杰

    2009-01-01

    objective To determine the existence of virulence-associated invA gene in different genospeeies of Leptospira interrogans reference strains in China.and to understand the alterations of invA gene transcription and expression of L.interrogans strain Lai before or after infecting cells.Methods PCR was applied to detect the invA gene of four L.interrogans strains belonging to four different genospecies and L.biflexa strain Patoc Ⅰ.The entire invA genes from the L.interrogans strains were cloned and then sequenced.The prokaryotic expression system of invA gene of L.interrogans serogroup Icterohaemorrhagiae serovar Lai strain Lai was constructed.Using Ni-NTA affinity chromatography,the target recombinant protein rInvA was extracted and purified.Rabbits were immunized with rInvA to obtain antiserum and the titer of antiserum was determined by immunodiffusion test.A model of L interrogans strain Lai infecting human embryo kidney cell line HEK293 was established to detect the alterations of invA gene transcription and expression of the leptospiral strain before or after infecting the host cells by real-time fluorescent quantitative RTPCR and western blot assay.Results All the four tested L.interrogans strains had invA gene whereas L.biflexa strain Patoc Ⅰ not.The similarity of nucleotide and putative amino acid sequences of invA genes from the four L.interrogans strains belonging four different genospecies were 99.33%-100%and 98.66%-100%,respectively.The constructed prokaryotic expression system could efficiently express rInvA and the immunodiffusion titer of rabbit anti-rInvA serum was 1:16.After L.interrogans strain Lai infecting HEK293 cells for 30 min or above,the microbe could adhere the surface of the cells.On the 30 min after the infection,the mRNA level of invA gene of L.interrogans strain Lai was remarkably upregulated,and on the 45 min after infection the mRNA level presented a peak value and then graduated decreased.On the 45 min or 60 min after L

  19. Increased susceptibility to Salmonella infection in signal regulatory protein α-deficient mice.

    Li, Lin-Xi; Atif, Shaikh M; Schmiel, Shirdi E; Lee, Seung-Joo; McSorley, Stephen J

    2012-09-01

    Recent studies have shed light on the connection between elevated erythropoetin production/spleen erythropoiesis and increased susceptibility to Salmonella infection. In this article, we provide another mouse model, the SIRPα-deficient (Sirpα⁻/⁻) mouse, that manifests increased erythropoiesis as well as heightened susceptibility to Salmonella infection. Sirpα⁻/⁻ mice succumbed to systemic infection with attenuated Salmonella, possessing significantly higher bacterial loads in both the spleen and the liver. Moreover, Salmonella-specific Ab production and Ag-specific CD4 T cells were reduced in Sirpα⁻/⁻ mice compared with wild-type controls. To further characterize the potential mechanism underlying SIRPα-dependent Ag-specific CD4 T cell priming, we demonstrate that lack of SIRPα expression on dendritic cells results in less efficient Ag processing and presentation in vitro. Collectively, these findings demonstrate an indispensable role of SIRPα for protective immunity to Salmonella infection.

  20. Bovine salmonellosis in Northeast of Iran: Frequency, genetic fingerprinting and antimicrobial resistance patterns of Salmonella spp.

    Hessam A. Halimi

    2014-01-01

    Conclusion: The emergence of multiple antibiotic-resistant strains of Salmonella Typhimurium should be of great concern to the public. No correlation between ERIC fingerprinting and resistance patterns of Salmonella isolates was found, which indicates resistance to antimicrobial agents was not related to specific genetic background.

  1. Farm and slaughterhouse characteristics affecting the occurrence of Salmonella and Campylobacter in the broiler supply chain

    Franz, E.; Fels, van der H.J.; Thissen, J.; Asselt, van E.D.

    2012-01-01

    Based on a data set on Campylobacter and Salmonella prevalence in the broiler supply chain, collected during the period 2002 through 2005 in the Netherlands, farm- and slaughterhouse-specific characteristics were tested for their effect on Campylobacter and Salmonella prevalence at different stages

  2. Evaluation of an indirect ELISA for the detection of Salmonella in chicken meat Avaliação de um ELISA indireto para detecção de Salmonella em carne de frango

    Andréa dos Santos Schneid

    2006-09-01

    Full Text Available In this work, an indirect ELISA based on a monoclonal antibody (MAb specific for an outer membrane protein of Salmonellaenterica serovar Enteritidis was used for detection of Salmonella in 154 samples of chicken meat. Its efficiency was determined through comparison with the results obtained from the conventional method. The prevalence of samples contaminated with Salmonella was 23% with the conventional culture method, and 26% with the ELISA. From thirty-five samples positive for Salmonella by the conventional method, 33 were also positive by ELISA. Seven other samples were only positive in the ELISA. Comparison of the results obtained in the two methods showed an ELISA sensitivity and specificity of 94%, and positive and negative predictive values of 82% and 98% respectively. The serotyping of the isolates revealed 31 Salmonella enterica serovar Enteritidis, 2 Salmonella enterica serovar Heidelberg, 1 Salmonella enterica serovar Choleraesuis and 1 Salmonella enterica sorovar 6,7:-:-.Neste trabalho, um ELISA indireto baseado em um anticorpo monoclonal (MAb especifico para proteína de membrane externa de Salmonellaenterica serovar Enteritidis foi usado para detecção de Salmonella em 154 amostras de carne de frango. Sua eficiência foi determinada através de comparação com os resultados obtidos pela metodologia convencional. A prevalência de amostras contaminadas com Salmonella foi de 23% pelo método de cultivo convencional, e 26% pelo ELISA. De 35 amostras positivas para Salmonella pela metodologia convencional, 32 também foram positivas no ELISA. Outras sete amostras foram positivas somente no ELISA. Comparando os resultados obtidos nos dois métodos, o ELISA demonstrou sensibilidade e especificidade de 94%, e valor preditivo positivo e negativo de 82% e 98% respectivamente. A sorotipagem dos isolados revelou 31 Salmonella enterica serovar Enteritidis, 2 Salmonella enterica serovar Heidelberg, 1 Salmonella enterica serovar Choleraesuis

  3. Evanescent Wave Fiber Optic Biosensor for Salmonella Detection in Food

    Arun K. Bhunia

    2009-07-01

    Full Text Available Salmonella enterica is a major food-borne pathogen of world-wide concern. Sensitive and rapid detection methods to assess product safety before retail distribution are highly desirable. Since Salmonella is most commonly associated with poultry products, an evanescent wave fiber-optic assay was developed to detect Salmonella in shell egg and chicken breast and data were compared with a time-resolved fluorescence (TRF assay. Anti-Salmonella polyclonal antibody was immobilized onto the surface of an optical fiber using biotin-avidin interactions to capture Salmonella. Alexa Fluor 647-conjugated antibody (MAb 2F-11 was used as the reporter. Detection occurred when an evanescent wave from a laser (635 nm excited the Alexa Fluor and the fluorescence was measured by a laser-spectrofluorometer at 710 nm. The biosensor was specific for Salmonella and the limit of detection was established to be 103 cfu/mL in pure culture and 104 cfu/mL with egg and chicken breast samples when spiked with 102 cfu/mL after 2–6 h of enrichment. The results indicate that the performance of the fiber-optic sensor is comparable to TRF, and can be completed in less than 8 h, providing an alternative to the current detection methods.

  4. Increasing Incidence of Salmonella in Australia, 2000-2013

    Glass, Kathryn; Veitch, Mark; Wardell, Rebecca; Polkinghorne, Ben; Dobbins, Timothy; Lal, Aparna; Kirk, Martyn D.

    2016-01-01

    Salmonella is a key cause of foodborne gastroenteritis in Australia and case numbers are increasing. We used negative binomial regression to analyze national surveillance data for 2000–2013, for Salmonella Typhimurium and non-Typhimurium Salmonella serovars. We estimated incidence rate ratios adjusted for sex and age to show trends over time. Almost all states and territories had significantly increasing trends of reported infection for S. Typhimurium, with states and territories reporting annual increases as high as 12% (95% confidence interval 10–14%) for S. Typhimurium in the Australian Capital Territory and 6% (95% CI 5–7%) for non-Typhimurium Salmonella in Victoria. S. Typhimurium notification rates were higher than non-Typhimurium Salmonella rates in most age groups in the south eastern states of Australia, while non-Typhimurium rates were higher in most age groups elsewhere. The S. Typhimurium notification rate peaked at 12–23 months of age and the non-Typhimurium Salmonella notification rate peaked at 0–11 months of age. The age-specific pattern of S. Typhimurium cases suggests a foodborne origin, while the age and geographic pattern for non-Typhimurium may indicate that other transmission routes play a key role for these serovars. PMID:27732615

  5. Waardevermindering pluimveevlees besmet met Salmonella enteritidis en Salmonella typhymurium

    Horne, van P.L.M.

    2011-01-01

    De doelstelling van het onderzoek is om de waardevermindering van met Salmonella enteritidis (S.e.) en Salmonella typhymurium (S.t.) besmet pluimveevlees van vleeskuikens te bepalen. Hoe hoog is de opbrengstenderving en hoe hoog zijn de extra kosten van maatregelen voor de slachterij of uitsnijderij

  6. Study on biological traits and molecular types of salmonella anatum from food poisoning%食物中毒鸭沙门菌的生物学特性及分子分型研究

    汪永禄; 沈荣柴; 王多春; 陶勇; 王利; 王艳; 刘力彰; 娄静; 闫梅英

    2013-01-01

    目的 对一起食物中毒分离的鸭沙门菌进行生物学特性和分子分型研究.方法 菌株分离、生化鉴定和血清型确定参照GB/T4789.4-2010方法进行,用VITEK-32全自动微生物鉴定系统检测菌株药物敏感性,鲎试验检测内毒素、PCR检测沙门菌侵袭相关基因invA和invE,用脉冲场凝胶电泳(pulsed field gel electrophoresis,PFGE)方法进行分子分型.结果 11份样品检出8株肠炎沙门菌;其中5株菌内毒素为阳性;所有菌株均携带侵袭相关基因invA和invE;该次食物中毒样品中分离得到的8株鸭沙门菌PFGE图谱完全相同,但有别于其它地区分离的鸭沙门菌.结论 PFGE可有效用于沙门菌食物中毒细菌同源性的分析.本次食物中毒有相同的鸭沙门菌克隆系来源.%Objective To study the biological traits and molecular types of salmonella anatin from a food poisoning.Method Do strains isolation,biochemical identification and serotypes according to GB/T4789.4-2010.Detect the drug sensitivity by VITEK-32 automated microbial identification system,detect endotoxin by limulus test,detect salmonella invasion-related gene invA and invE by PCR,and type the moleculars pulsedfield gel electrophoresis (PFGE) method.Results Eight salmonella were isolated from the 11 samples,among which,5 strains of bacteria endotoxin iwere positive,and all of them were salmonella anatis.All the strains carried invasion-related gene (invA and invE).The PFGE maps of the 8 strains were the same,but different from that of other regions.Conclusions PFGE could be effectively used for homology analysis of salmonella food poisoning.This food poisoning had the same salmonella anatis clone source system.

  7. Antibiotic susceptibility of Salmonella spp.: a comparison of two surveys with a 5 years interval

    Gordana Mijović

    2012-02-01

    Full Text Available Salmonella infections are one of the major global public health problems. During the last decade, antibiotic resistance and multiresistance of Salmonella spp. have increased a great deal, especially in developing countries with an increased and indiscriminate use of antibiotics in the treatment of humans and animals. This study aims to investigate and compare antimicrobial susceptibility patterns of Salmonella during 2005 and 2010.A total of 186 Salmonella strain during 2005 and 140 Salmonella strain during 2010 were isolated from stool specimens using standard methods. The isolates were confirmed as Salmonella by using a battery of biochemical reactions. Specific antisera were used for serologic characterization of Salmonella strain. Antimicrobial susceptibility testing was performed by standard disk diffusion method using ampicillin, trimethoprim-sulfamethoxasole, ceftriaxon, chloramphenicol, nalidixic acid and ciprofloxacin.One hundred eighty (96.8% of 186 isolated Salmonella strains in 2005, and 133 (95% of 140 isolated Salmonella strain in 2010 are recognized as Salmonella Enteritidis. Sensitivity of Salmonella isolates during 2005 and 2010 were 91.9% and 92.9% to ampicillin, 95.7% and 97.1% to trimethoprim-sulfamethoxasole, 99.5% and 100% to chloramphenicol, 99.5% and 100% to ciprofloxacin, 98.9% and 97.1% to ceftriaxon, 73.1% and 95.7% to nalidixic acid, respectively.Sensitivity of Salmonella isolates to all tested antimicrobial agents except to ceftriaxon was been slightly improved over testing period. Resistance rate to ceftriaxon was higher in 2010 than in 2005, and this fact deserves attention. Significantly increase susceptibility rate to nalidixic acid was observed between the two surveys

  8. Molecular tracking of Salmonella spp. in chicken meat chain: from slaughterhouse reception to end cuts.

    Dias, Mariane Rezende; Cavicchioli, Valéria Quintana; Camargo, Anderson Carlos; Lanna, Frederico Germano Piscitelli Alvarenga; Pinto, Paulo Sérgio de Arruda; Bersot, Luciano Dos Santos; Nero, Luís Augusto

    2016-02-01

    Due to the importance of Salmonella spp. in poultry products, this study aimed to track its main contamination routes since slaughtering reception to processing of chicken end cuts. Samples from different steps of slaughtering and processing (n = 277) were collected from two chicken slaughterhouses (Sl1 and Sl2) located in Minas Gerais state, Brazil, and subjected to Salmonella spp. detection. The obtained isolates were subjected to serological identification and tested by PCR for specific Salmonella spp. genes (ompC and sifB). Also, Salmonella spp. isolates were subjected to XbaI macrorestriction and pulsed-field gel electrophoresis (PFGE). Sixty-eight samples were positive for Salmonella spp. and 172 isolates were obtained. Sl1 and Sl2 presented similar frequencies of Salmonella spp. positive samples during reception, slaughtering and processing (p > 0.05), except for higher frequencies in Sl1 for chicken carcasses after de-feathering and evisceration (p Salmonella spp. strains in Sl1. The results highlighted the relevance of the initial steps of chicken slaughtering for Salmonella spp. contamination, and the pre-chilling of carcasses as an important controlling tool. In addition, the presence of Salmonella spp. in chicken end cuts samples represents a public health concern.

  9. Microencapsulated sorbic acid and nature-identical compounds reduced Salmonella Hadar and Salmonella Enteritidis colonization in experimentally infected chickens.

    Grilli, E; Tugnoli, B; Formigoni, A; Massi, P; Fantinati, P; Tosi, G; Piva, A

    2011-08-01

    The reduction of Salmonella prevalence in broilers is a priority in European Union agricultural policies because treatment with antibiotics is forbidden by Regulation (EC) 2160/2003. Two trials were conducted to evaluate the efficacy of a microencapsulated blend of sorbic acid and nature-identical compounds (i.e., chemically synthesized botanicals; SAB) on the reduction of the cecal prevalence and contents of Salmonella enterica serovars Hadar and Enteritidis in experimentally infected chickens. In the first trial, 125 one-day-old Lohmann specific-pathogen-free chickens were assigned to one of the following treatments: negative control (not challenged and not treated), positive control (challenged and not treated), SAB0.3, SAB1, or SAB5 (challenged and treated with the microencapsulated blend included in the feed at 0.03, 0.1, or 0.5%, respectively). At 30 d of age, birds were infected with 10(6) cfu of Salmonella Hadar, and after 5, 10, or 20 d postinfection, 5, 10, and 10 birds per treatment, respectively, were killed and the cecal contents and liver and spleen samples were analyzed for Salmonella Hadar. In the second trial, 100 one-day-old Ross 708 chickens were assigned to 1 of 5 treatments: control (not treated), SAB0.3, SAB1, SAB2, or SAB5 (treated with the blend included in the feed at 0.03, 0.1, 0.2, or 0.5%, respectively). At 7 d of age, the birds were challenged with 10(5) cfu of Salmonella Enteritidis, and after 7, 14, or 24 d after challenge, 5, 5, and 10 birds per treatment, respectively, were killed and cecal contents were analyzed for Salmonella Enteritidis. Results showed that in the early stage of infection Salmonella prevalence was high in both studies, whereas at the end of the observation periods, the blends at 0.03, 0.1, and 0.5 in the challenge with Salmonella Hadar and at 0.2 and 0.5% in the challenge with Salmonella Enteritidis significantly reduced (by 2 log(10) cfu) the cecal content of Salmonella. This study showed that intestinal

  10. Distribution of virulence genes sefC, pefA and spvC in Salmonella Enteritidis phage type 4 strains isolated in Brazil Distribuição de genes de virulência sefC, pefA e spvC em cepas de Salmonella Enteritidis fago tipo 4 isoladas no Brasil

    Karina Salvagni Castilla

    2006-06-01

    Full Text Available The distribution of virulence genes, sefC, pefA and spvC, was investigated in 110 Salmonella Enteritidis phage type 4 strains by polymerase chain reaction. Their influence in the caecal colonization and invasion of liver and spleen of one-day-old chickens was studied. Eight isolates were negative for the spvC gene, three for the pefA gene and one, for the sefC gene. These results allowed grouping the strains into four genotypes. Presence of these genes did not influence bacteria invasion in the liver and spleen of the chickens ten days after infection, although the presence of more than one fimbrial gene can be related to caecal colonization.A distribuição dos genes de virulência sefC, pefA e spvC foi investigada em 110 amostras de Salmonella Enteritidis pertencentes ao fagotipo 4 através da reação em cadeia da polimerase. A influência destes genes na colonização do ceco e invasão do fígado e baço em pintinhos de um dia de idade foi avaliada. Oito amostras foram negativas para o gene spvC, três para o gene pefA e uma amostra para o gene sefC. Estes resultados permitiram a classificação das amostras em quatro genótipos. A presença destes genes não influenciou a invasão da bactéria no fígado e baço das aves dez dias após a infecção, entretanto, a presença de mais de um gene fimbrial pode ter relação com a colonização cecal.

  11. Detection of Salmonella in Meat

    Löfström, Charlotta; Hansen, Flemming; Mansdal, Susanne

    2012-01-01

    Cost-effective and rapid monitoring of Salmonella in the meat production chain can contribute to food safety. The objective of this study was to validate an easy-to-use pre-PCR sample preparation method based on a simple boiling protocol for screening of Salmonella in meat and carcass swab samples...

  12. RapidChek SELECT Salmonella enteritidis test system for the detection of Salmonella enteritidis in poultry house drag swabs, shell egg pools, and chicken carcass rinsates.

    Muldoon, Mark T; Gonzalez, Verapaz; Sutzko, Meredith I; Allen, Ann-Christine Olsson; Creamer, Samantha; Onisk, Dale V; Lindpaintner, Klaus

    2011-01-01

    The RapidChek SELECT Salmonella Enteritidis Test System was validated for the detection of Salmonella Enteritidis (SE) in poultry house drag swabs, shell egg pools, and chicken carcass rinsates. The method utilizes RapidChek SELECT Salmonella (AOAC PTM License No. 080601) proprietary primary and secondary enrichment media. Following enrichment, an immunochromatographic test strip is inserted into the tube containing the secondary enrichment broth, developed for 10 min, and interpreted. Salmonella Enteritidis-inoculated samples (1-5 CFU SE/analytical unit) were tested by the test method as well as the appropriate cultural reference method U.S. Food and Drug Administration-Bacteriological Analytical Manual (drag swabs and egg pools) or U.S. Department of Agriculture-Food Safety and Inspection Service (chicken carcass rinsates). A total of 80 samples were tested by both methods in the study. Fifty-two samples were positive by the RapidChek SELECT Salmonella Enteritidis method and 38 were found positive by the respective reference method. The sensitivity of the method was 100% and the specificity was 100%. The accuracy of the test method was 137%, indicating that the method was more sensitive than the reference method. The RapidChek SELECT Salmonella Enteritidis method was tested with 82 Salmonella Group D1 strains including 63 Salmonella Enteritidis strains as well as 32 non-Salmonella Group D1 strains representing 10 bacteria genera. The test method detected all 82 Group D1 strains (100% sensitivity). None of the non-Salmonella Group D1 or other genera of bacteria were detected, indicating a specificity of 100%. The method was shown to be highly robust and stable under control and accelerated stability conditions.

  13. Contribution of Salmonella Enteritidis virulence factors to intestinal colonization and systemic dissemination in 1-day-old chickens.

    Addwebi, Tarek M; Call, Douglas R; Shah, Devendra H

    2014-04-01

    Salmonella enterica serovar Enteritidis is one of the most common serovars associated with poultry and poultry product contamination in the United States. We previously identified 14 mutant strains of Salmonella Enteritidis phage type 4 (PT4) with significantly reduced invasiveness in human intestinal epithelial cells (Caco-2), chicken macrophages (HD-11), and chicken hepatocellular epithelial cells (LMH). These included Salmonella Enteritidis mutants with transposon insertions in 6 newly identified Salmonella Enteritidis-specific genes (pegD and SEN1393), and genes or genomic islands common to most other Salmonella serovars (SEN0803, SEN0034, SEN2278, and SEN3503) along with 8 genes previously known to contribute to enteric infection (hilA, pipA, fliH, fljB, csgB, spvR, and rfbMN). We hypothesized that Salmonella Enteritidis employs both common Salmonella enterica colonization factors and Salmonella Enteritidis-specific traits to establish infection in chickens. Four Salmonella Enteritidis mutants (SEN0034::Tn5, fliH::Tn5, SEN1393::Tn5, and spvR::Tn5) were indistinguishable from the isogenic wild-type strain when orally inoculated in 1-d-old chickens, whereas 2 mutants (CsgB::Tn5 and PegD::Tn5) were defective for intestinal colonization (P Salmonella Enteritidis pathogenesis, and the target genes identified here could potentially serve as targets for the development of live-attenuated or subunit vaccine.

  14. A novel Salmonella serovar isolated from Peregrine Falcon (Falco peregrinus) nestlings in Sweden: Salmonella enterica enterica serovar Pajala (Salmonella Pajala)

    Hernandez, Jorge; Lindberg, Peter; Waldenström, Jonas; Drobni, Mirva; Olsen, Björn

    2012-01-01

    A novel Salmonella serovar was isolated from Peregrine falcon (Falco peregrinus) nestlings in northern Sweden in 2006. Three isolates of the same clone was retrieved from three falcon siblings and characterized as Salmonella enterica sub-species enterica: O-phase 13, 23:-: e, n, z 15 and the H-phase was not present. We propose the geographical name Salmonella enterica, sub-species entericaserovar Pajala to this novel Salmonella.Keywords: Salmonella; epidemiology; ecology; peregrine falcon; no...

  15. Characterization of an unusual Salmonella phage type DT7a and report of a foodborne outbreak of salmonellosis.

    Lettini, A A; Saccardin, C; Ramon, E; Longo, A; Cortini, E; Dalla Pozza, M C; Barco, L; Guerra, B; Luzzi, I; Ricci, A

    2014-10-17

    Salmonella enterica subsp. enterica serovar 4,[5],12,i:- is a monophasic variant of Salmonella Typhimurium and its occurrence has markedly increased in several European countries in the last ten years. In June 2011, an outbreak of Salmonella 4,[5],12,i:- was reported among attendees of a wedding reception in the North-East of Italy. The source of this outbreak was identified as a cooked pork product served during the wedding reception. All Salmonella isolates from humans and the contaminated pork products were identified as Salmonella 4,[5],12,i:- and phage typed as DT7a. Afterwards, the farm where the pigs were raised was identified and sampled, and Salmonella Typhimurium was isolated from swine fecal samples. Despite the difference in serovar, these Salmonella Typhimurium isolates were also phage typed as DT7a. In the present study, Salmonella isolates from animals, humans and pork products during the outbreak investigation were subtyped by pulsed-field gel electrophoresis (PFGE), Multiple-Locus Variable number tandem repeats Analysis (MLVA), and resistance patterns, aiming to identify the most suitable subtyping methods to characterize isolates associated with this outbreak. In addition, a collection of epidemiologically unrelated strains of Salmonella 4,[5],12,i:- and Salmonella Typhimurium sharing the same phage type (DT7a) was similarly characterized in order to investigate their genetic relationship. This study provides a first snapshot of a rare Salmonella phage type, DT7a, associated with both Salmonella 4,[5],12,i:- and Salmonella Typhimurium. Moreover, the study demonstrated that in this specific context MLVA could be a reliable tool to support outbreak investigations as well as to assess the genetic relatedness among Salmonella isolates.

  16. Prevalence of Salmonella in Australian reptiles.

    Scheelings, T Franciscus; Lightfoot, Dianne; Holz, Peter

    2011-01-01

    From January 2007 until June 2008, 504 reptiles of four families and 57 species were examined for Salmonella by using cloacal or intestinal swabs. Salmonella was identified in 139 (28%) of the 504 animals tested. Of the 504 reptiles examined, 210 were captive and 294 were wild. Ninety-eight (47%) of the captive reptiles were shedding Salmonella at the time of sampling. In contrast, only 41 (14%) of the wild reptiles were shedding Salmonella. The higher prevalence of Salmonella in captive reptiles was statistically significant (Preptiles in Australia are not natural carriers of Salmonella and that diet and captivity may influence Salmonella excretion in other species.

  17. Distribution and Genetic Diversity of Salmonella enterica in the Upper Suwannee River

    Masoumeh Rajabi

    2011-01-01

    Full Text Available The Suwannee River spans the Florida/Georgia border to the Gulf of Mexico, and contributes to regional irrigation and recreational activities. Association of Salmonella enterica with these resources may result in the contamination of produce and disease outbreaks. Therefore, surface water was examined for the distribution of S. enterica at multiple time points from 4 sites on the upper Suwannee River. Isolates were confirmed by detection of the invA gene, and 96% of all samples were positive for the bacterium. Most probable number enumeration ranged from 60% similarity and distributed into 16 rep-PCR genogroups. Most (74% of the Suwannee River isolates were clustered into two genogroups that were comprised almost exclusively (97% of just these isolates. Conversely, 85% of the clinical reference strains clustered into other genogroups. However, some Suwannee River isolates (12% were clustered with these primarily clinically-associated genogroups, supporting the hypothesis that river water can serve as a disease reservoir and that pathogenic strains may persist or possibly originate from environmental sources.

  18. Tenth CRL-Salmonella interlaboratory comparison study on typing of Salmonella spp.

    Korver H; Maas HME; Ward LR; Mevius DJ; Mooijman KA; MGB

    2006-01-01

    Het tiende ringonderzoek voor de typering van Salmonella werd in maart 2005 georganiseerd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) in samenwerking met de Health Protection Agency (HPA, Londen, Verenigd Koninkrijk) en het Centraal Instituut

  19. Eleventh CRL-Salmonella interlaboratory comparison study on typing of Salmonella spp.

    Berk PA; Maas HME; de Pinna E; Mooijman KA; MGB

    2010-01-01

    Het elfde ringonderzoek voor de typering van Salmonella werd in maart 2006 georganiseerd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) in samenwerking met de Health Protection Agency (HPA, Londen, Verenigd Koninkrijk). 26 Nationale Referentie L

  20. Eleventh CRL-Salmonella interlaboratory comparison study on typing of Salmonella spp.

    Berk PA; Maas HME; de Pinna E; Mooijman KA; MGB

    2006-01-01

    Het elfde ringonderzoek voor de typering van Salmonella werd in maart 2006 georganiseerd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) in samenwerking met de Health Protection Agency (HPA, Londen, Verenigd Koninkrijk). 26 Nationale Referentie L

  1. FECAL EXCRETION OF Salmonella Enteritidis IN BROILER LINES ROSS AND ISA LABEL EXCREÇÃO FECAL de Salmonella Enteritidis EM DUAS LINHAGENS DE FRANGOS DE CORTE

    Adson Santa Cruz Oliveira

    2007-12-01

    Full Text Available

    The invasive capacity and persistence of this pathogen, crop and ceca in apparently healthy birds of two broiler lines raised without growth promoter antibiotics in ration and originated from eggs inoculated eggshell and in allantoidal cavity with Salmonella Enteritidis. Histological and bacteriological exams from cecal and crop were performed with one, seven, 14 and 21 days of age after hatch in broilers of fast and slow growing rate. Bacterio-logical exams were performed fecal excretion with one, eigth, 22 and 35 days. The Salmonella Enteritidis invaded and colonizated the gastrointestinal tract of the two lines tested, but the the infection reduced with age, and was more persistant in Ross broilers. The results were different for two lines. The pathogen was excreted from just one chick of ISA Label at 22 days of age and four Ross chicks until 35 days of age. In order, Salmonella was detected in 87.5% (14/16 and 38,1% (5/16 of ceca; in 81.2% (13/16 and 12.5% (2/16 of crops; in fast and slow growing rate lines, respectively. In apparent healthy organs, excepted the crop, an inflammatory process with predominance of macrophage and lymphocytes. The slow growing rate line was effective to eliminate bacteria in the organism.

    Key-words: Ceca, crop, fecal excretion, inflammation.

    Avaliaram-se, neste estudo, a capacidade inva-siva, a persistência e a freqüência de excreção fecal da Salmonella Enteritidis em aves aparentemente saudáveis de duas linhagens de frango de corte, criadas sem antibióticos promotores de crescimento na ração e oriundas de ovos inoculados na casca ou na cavidade alantóide com Salmonella Enteritidis fagotipo 4. Realizaram-se exames bacteriológicos das excretas com um, oito, 22 e 35 dias, e histológicos e bacteriológicos do inglúvio e ceco, com um, sete, quatorze e 21 dias pós-eclosão em frangos de crescimento rápido e lento. Salmonella

  2. Isolation, serotype diversity and antibiogram of Salmonella enterica isolated from different species of poultry in India

    Irfan Ahmad Mir; Sudhir Kumar Kashyap; Sunil Maherchandani

    2015-01-01

    Objective:To study the occurrence and serotype diversity of Salmonella isolates in different species of poultry (chicken, emu and duck) and determine their resistance pattern against various antibiotics of different classes. Methods:About 507 samples comprising 202 caecal contents and 305 fecal samples from chicken, emu and duck were processed for isolation of Salmonella enterica. Salmonellae were isolated and detected by standard protocol of ISO 6579 Amendment 1:Annex D. Genetic confirmation was also made by using 16S rRNA genus specific PCR. Serotype specific PCR was also done to detect the most common serovars viz. Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Gallinarum. All obtained isolates were subjected to a set of 25 antibiotics to study their antibiogram by using Baeur-Kirby disk diffusion method. Results:Out of 507 samples processed, 32 isolates of Salmonella enterica (18 from caecal contents and 14 from faecal samples) were obtained, of which 24 belonged to 6 different serovars, 6 were untypeable and 2 were rough strains. Salmonella Enteritidis was the most predominant serotype (9), followed by Salmonella Typhimurium (5), Salmonella Virchow (4), Salmonella Gallinarum (3), Salmonella Reading (2) and Salmonella Altona (1). Antibiotic resistance pattern was maximum (100%) to oxacillin, penicillin and clindamycin, followed by ampicillin (68.75%), tetracycline (65.62%), nalidixic acid (56.25%) and colistin (46.87%). High sensitivity of isolates was recorded for chloramphenicol (96.87%) followed by meropenem (84.37%). Conclusions:Occurrence of high proportion of serovars in our study which can cause serious gastroenteritis in humans is a matter of concern. Salmonella Altona has been detected for the first time in India from poultry. This serotype is known to cause serious outbreaks of gastroenteritis in humans. Multidrug resistant isolates were recovered at high percentage which can be attributed to non-judicious use of antibiotics both in

  3. Isolation, serotype diversity and antibiogram of Salmonella enterica isolated from different species of poultry in India

    Irfan; Ahmad; Mir; Sudhir; Kumar; Kashyap; Sunil; Maherchandani

    2015-01-01

    Objective: To study the occurrence and serotype diversity of Salmonella isolates in different species of poultry(chicken, emu and duck) and determine their resistance pattern against various antibiotics of different classes.Methods: About 507 samples comprising 202 caecal contents and 305 fecal samples from chicken, emu and duck were processed for isolation of Salmonella enterica. Salmonellae were isolated and detected by standard protocol of ISO 6579 Amendment 1: Annex D. Genetic confirmation was also made by using 16 S r RNA genus specific PCR. Serotype specific PCR was also done to detect the most common serovars viz. Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Gallinarum. All obtained isolates were subjected to a set of 25 antibiotics to study their antibiogram by using Baeur-Kirby disk diffusion method.Results: Out of 507 samples processed, 32 isolates of Salmonella enterica(18 from caecal contents and 14 from faecal samples) were obtained, of which 24 belonged to 6 different serovars, 6 were untypeable and 2 were rough strains. Salmonella Enteritidis was the most predominant serotype(9), followed by Salmonella Typhimurium(5), Salmonella Virchow(4), Salmonella Gallinarum(3), Salmonella Reading(2) and Salmonella Altona(1). Antibiotic resistance pattern was maximum(100%) to oxacillin, penicillin and clindamycin, followed by ampicillin(68.75%), tetracycline(65.62%), nalidixic acid(56.25%) and colistin(46.87%). High sensitivity of isolates was recorded for chloramphenicol(96.87%) followed by meropenem(84.37%). Conclusions: Occurrence of high proportion of serovars in our study which can cause serious gastroenteritis in humans is a matter of concern. Salmonella Altona has been detected for the first time in India from poultry. This serotype is known to cause serious outbreaks of gastroenteritis in humans. Multidrug resistant isolates were recovered at high percentage which can be attributed to non-judicious use of antibiotics both in prophylaxis

  4. Targeted Cancer Therapy Using Engineered Salmonella typhimurium.

    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.

  5. Targeted Cancer Therapy Using Engineered Salmonella typhimurium

    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

  6. Rauid simultaneous detections of Salmonella and Listeria monocytogenes by multiulex real-time PCR%多重实时荧光PCR快速检测沙门菌和单增李斯特菌

    吴晓芳; 韩建康; 纪蕾; 徐德顺; 陈莉萍; 沈月华; 查赘峰

    2011-01-01

    目的 建立可同时检测沙门菌、单增李斯特菌的双重实时荧光PCR快速检测方法,并应用于食品样品的检测.方法 根据GenBank上下载的沙门菌invA基因、单增李斯特菌hlyA基因的保守区序列分别设计特异性引物和TaqMan探针,建立并优化双重实时荧光PCR反应体系.对该方法的特异性、敏感性和稳定性进行评估,并应用于食品标本的检测.结果 实验结果表明,该检测方法特异性强,对大肠埃希菌、志贺菌、副溶血性弧菌等其他病原菌进行检测均未产生交叉反应.对沙门菌和单增李斯特菌纯培养物的最低检出限分别可达10 cfu/ml和100cfu/ml;并且重复性好,变异系数均小于5%;对80份食品标本同时采用本文建立的双重荧光PCR方法和单重荧光PCR方法以及传统的分离培养方法进行检测,结果显示本文建立的双重荧光PCR方法对两种病原菌的检测效果明显优于单重荧光PCR方法以及传统的分离培养法,整个检测过程可在10 h内完成,包括前增菌所用的6 h.结论 本研究建立的多重实时荧光PCR方法能同时对沙门菌和单增李斯特菌进行快速检测,并且灵敏度高、特异性好,可为食源性疾病的病原学快速检测提供新的手段.%Objective To establish a TaqMan-based multiplex real-time PCR assay for the detections of Salmonella and Listeria monocytogenes and conduct Salmonella and Listeria monocytogenes detections in food samples. Methods The specific primers and probes were designed in the conserved region of the invA gene for Salmonella and in the hlyA gene for Listeria monocytogenes, respectively. The reaction conditions were optimized, and the sensitivity, specificity and the stability of the assay were evaluated. The food samples collected from the supermarket were detected by this assay. Results The results showed that the assay had high specificity for the detections of Salmonella and Listeria monocytogenes without any

  7. Molecular Characterisation of Salmonella enterica Serovar Typhi Isolated from Typhoidial Humans

    Arunava Das

    2012-09-01

    Full Text Available Aims: Salmonella enterica serovar Typhi is the major causative agent for typhoidial fever around the globe among human population reported till date. Present research work was carried out for detection and molecular characterisation of Salmonella enterica serovar Typhi isolated from humans with Typhoidial fever by biochemical, phenotypical and virulence gene based polymerase chain reaction (PCR techniques. The isolated strains were also investigated for antibiotic susceptibility patterns as a control measure. Methodology and Results: A total of 16 clinical samples were collected from the same numbers of patients (7 males and 9 females from Coimbatore, Erode and Salem districts of Tamil Nadu and were processed via broth enrichment methods for isolation and identification of the causative agent S. enterica serovar Typhi. Microbiological and biochemical investigations revealed the presence of S. Typhi from 16 samples. The biotyping of the isolates showed that all the isolates belonged to biotype IV. The PCR analysis confirmed the presence of invA (Invasion gene, 244bp, tyv (Tyveloseepimerase gene, 615 bp, fliC-d (Phage-1 flagellin gene for d-antigen, 750 bp and viaB (Vi antigen gene, 439bp in all 16 clinical samples. The antibiotic susceptibility test that was carried out among the isolates against 12 antimicrobial agents, showed 100 % resistance to only ampicillin and 100 % sensitivity to carbenicillin, chloramphenicol, clindamycin, gentamycin, kanamycin and tetracycline.Conclusion, significance and impact of study: This study confirmed the association of virulent strains of S. enterica serovar Typhi from Typhoidial fever among human population and suggested that PCR based diagnostic could be very useful for the rapid detection of S. Typhi isolates. Present study emphasized the use of antibiotic like chloramphenicol or in combination with other antibiotics for the effective control of S. Typhi.

  8. Active suppression of early immune response in tobacco by the human pathogen Salmonella Typhimurium.

    Natali Shirron

    Full Text Available 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.

  9. The infectious intracellular lifestyle of Salmonella enterica relies on the adaptation to nutritional conditions within the Salmonella-containing vacuole.

    Diacovich, Lautaro; Lorenzi, Lucía; Tomassetti, Mauro; Méresse, Stéphane; Gramajo, Hugo

    2016-12-09

    Salmonella enterica serovar Typhimurium (S. Typhimurium) is a Gram-negative pathogen that causes various host-specific diseases. During their life cycle, Salmonellae survive frequent exposures to a variety of environmental stresses, e.g. carbon-source starvation. The virulence of this pathogen relies on its ability to establish a replicative niche, named Salmonella-containing vacuole, inside host cells. However, the microenvironment of the SCV and the bacterial metabolic pathways required during infection are largely undefined. In this work we developed different biological probes whose expression is modulated by the environment and the physiological state of the bacterium. We constructed transcriptional reporters by fusing promoter regions to the gfpmut3a gene to monitor the expression profile of genes involved in glucose utilization and lipid catabolism. The induction of these probes by a specific metabolic change was first tested in vitro, and then during different conditions of infection in macrophages. We were able to determine that Entner-Doudoroff is the main metabolic pathway utilized by Salmonella during infection in mouse macrophages. Furthermore, we found sub-populations of bacteria expressing genes involved in pathways for the utilization of different sources of carbon. These populations are modified in presence of different metabolizable substrates, suggesting the coexistence of Salmonella with diverse metabolic states during the infection.

  10. Transcriptional Regulation of the assT-dsbL-dsbI Gene Cluster in Salmonella enterica Serovar Typhi IMSS-1 Depends on LeuO, H-NS, and Specific Growth Conditions

    Gallego-Hernández, A. L.; Hernández-Lucas, I.; De la Cruz, M. A.; Olvera, L.; Morett, E; Medina-Aparicio, L.; Ramírez-Trujillo, J. A.; Vázquez, A.; Fernández-Mora, M.; Calva, E

    2012-01-01

    The assT gene encodes an arylsulfate sulfotransferase, an enzyme that catalyzes sulfuryl transfer from phenolic sulfate to a phenolic acceptor. In Salmonella enterica serovar Typhi IMSS-1, the assT gene is located upstream of the dsbL and dsbI genes, which are involved in a disulfide bond formation required for its activation. The assT-dsbL-dsbI gene cluster forms an operon transcribed by a LeuO-dependent promoter, in rich medium A (MA). Interestingly, in the absence of cloned leuO and in a Δ...

  11. EU Collaborative study VI on bacteriological detection of Salmonella spp.

    Korver H; Mooijman KA; Nagelkerke NJD; van de Giessen AW; Henken AM; MGB; IMA

    2003-01-01

    Het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) organiseerde in 2002 een zesde bacteriologisch ringonderzoek. Zeventien Nationale Referentie Laboratoria voor Salmonella (NRLs-Salmonella) namen deel aan deze studie. Referentie materialen in combinatie

  12. Phylogenetic relationships of Salmonella based on rRNA sequences

    Christensen, H.; Nordentoft, Steen; Olsen, J.E.

    1998-01-01

    To establish the phylogenetic relationships between the subspecies of Salmonella enterica (official name Salmonella choleraesuis), Salmonella bongori and related members of Enterobacteriaceae, sequence comparison of rRNA was performed by maximum-likelihood analysis. The two Salmonella species wer...

  13. Protection of epithelial cells from Salmonella enterica serovar Enteritidis invasion by antibodies against the SPI-1 type III secretion system.

    Desin, Taseen S; Mickael, Claudia S; Lam, Po-King S; Potter, Andrew A; Köster, Wolfgang

    2010-06-01

    Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) is one of the major causes of bacterial food-borne illness in humans. During the course of infection, Salmonella Enteritidis uses 2 type III secretion systems (T3SS), one of which is encoded on Salmonella pathogenicity island 1 (SPI-1). SPI-1 plays a major role in the invasion process. In the present study, we evaluated the effect of sera against the SPI-1 T3SS components on invasion in vitro using polarized human intestinal epithelial cells (Caco-2). Antisera to SipD protected Caco-2 cells against entry of wild-type Salmonella Enteritidis. On the other hand, sera against InvG, PrgI, SipA, SipC, SopB, SopE, and SopE2 did not affect Salmonella Enteritidis entry. To illustrate the specificity of anti-SipD mediated inhibition, SipD-specific antibodies were depleted from the serum. Antiserum depleted of SipD-specific antibodies lost its capacity to inhibit Salmonella Enteritidis entry. Thus, we demonstrate for the first time that antibodies against the SPI-1 needle tip protein (SipD) inhibit Salmonella Enteritidis invasion and that the SipD protein may be an important target in blocking SPI-1 mediated virulence of Salmonella Enteritidis.

  14. First Case of Lung Abscess due to Salmonella enterica Serovar Abony in an Immunocompetent Adult Patient

    Vassiliki Pitiriga

    2016-01-01

    Full Text Available In healthy individuals, nontyphoidal Salmonella species predominantly cause a self-limited form of gastroenteritis, while they infrequently invade or cause fatal disease. Extraintestinal manifestations of nontyphoidal Salmonella infections are not common and mainly occur among individuals with specific risk factors; among them, focal lung infection is a rare complication caused by nontyphoidal Salmonella strains typically occurring in immunocompromised patients with prior lung disease. We describe the first case of a localized lung abscess formation in an immunocompetent healthy female adult due to Salmonella enterica serovar Abony. The patient underwent lobectomy and was discharged after full clinical recovery. This case report highlights nontyphoidal Salmonellae infections as a potential causative agent of pleuropulmonary infections even in immunocompetent healthy adults.

  15. Assessment of administrative claims data for public health reporting of Salmonella in Tennessee.

    Marder, Ellyn; Garman, Katie; Jones, Timothy F; Dunn, John; Jones, Stephen

    2015-04-01

    In the USA, approximately 4% of the estimated 1 million Salmonella infections occurring annually are reported to public health. Administrative claims data from large health insurance companies capture disease-specific data which could potentially enhance public health surveillance. To determine the utility of medical claims data for public health reporting of Salmonella, we assessed medical claims data from BlueCross BlueShield of Tennessee (BCBST) members compared to Tennessee Department of Health (TDH) surveillance data. BCBST Salmonella cases diagnosed during 2007-2011 were matched to TDH Salmonella cases reported during the same time period. Matches and non-matches were validated using medical records. Of the 450 BCBST cases identified, 72% matched TDH cases. All culture-confirmed BCBST cases were reported to TDH. Non-matched BCBST cases included clinical diagnoses which were culture negative or not tested. Our findings indicate administrative claims data are not currently a viable mechanism for enhancing routine reporting of Salmonella infections.

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

    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.

  17. Salmonella Infection Drives Promiscuous B Cell Activation Followed by Extrafollicular Affinity Maturation.

    Di Niro, Roberto; Lee, Seung-Joo; Vander Heiden, Jason A; Elsner, Rebecca A; Trivedi, Nikita; Bannock, Jason M; Gupta, Namita T; Kleinstein, Steven H; Vigneault, Francois; Gilbert, Tamara J; Meffre, Eric; McSorley, Stephen J; Shlomchik, Mark J

    2015-07-21

    The B cell response to Salmonella typhimurium (STm) occurs massively at extrafollicular sites, without notable germinal centers (GCs). Little is known in terms of its specificity. To expand the knowledge of antigen targets, we screened plasmablast (PB)-derived monoclonal antibodies (mAbs) for Salmonella specificity, using ELISA, flow cytometry, and antigen microarray. Only a small fraction (0.5%-2%) of the response appeared to be Salmonella-specific. Yet, infection of mice with limited B cell receptor (BCR) repertoires impaired the response, suggesting that BCR specificity was important. We showed, using laser microdissection, that somatic hypermutation (SHM) occurred efficiently at extrafollicular sites leading to affinity maturation that in turn led to detectable STm Ag-binding. These results suggest a revised vision of how clonal selection and affinity maturation operate in response to Salmonella. Clonal selection initially is promiscuous, activating cells with virtually undetectable affinity, yet SHM and selection occur during the extrafollicular response yielding higher affinity, detectable antibodies.

  18. Serum Bactericidal Assay: New Role in Salmonella Detection.

    Chen, Yu; Wu, Da; Sun, Min; Deng, Mingjun; Cui, Shuhua; Liang, Chengzhu; Geng, Juan; Sun, Tao; Long, Ling; Xiao, Xizhi

    2016-01-01

    While inspecting animal feed for Salmonella contamination, we routinely observed bacterial colonies on selective agars that were similar in appearance to those formed by Salmonella. These were identified as Citrobacter freundii, Proteus mirabilis, and Serratia fonticola using biochemical and serological techniques. Because the presence of these bacterial species confounds identification of Salmonella, we refer to them as "interference bacteria." Polyvalent antisera against these interference bacteria were prepared by immunizing rabbits with a mixture of all three organisms. To minimize or eliminate interference by these bacteria, the polyvalent antisera were introduced between the steps of selective enrichment and Salmonella-selective plating. The antisera raised against the interference bacteria, when combined with neonatal rabbit complement, exhibited specific bactericidal activity against C. freundii, P. mirabilis, and S. fonticola. The respective serum bactericidal assay titers were 2(9), 2(8), and 2(10). In selective broth, polyvalent antisera could also kill the target bacterial cells effectively. We tested 526 samples (186 white fishmeal, 97 red fishmeal, and 243 cattle bone powder) using the polyvalent antisera and found that the rates of contamination of each species of the three respective foods decreased by 58.8, 100, and 83%. Our data indicates that polyvalent sera against C. freundii, P. mirabilis, and S. fonticola can be used as inhibitors to increase the accuracy of Salmonella detection.

  19. Isolation, characterization, and application of bacteriophages for Salmonella spp. biocontrol in pigs.

    Albino, Luiz A A; Rostagno, Marcos H; Húngaro, Humberto M; Mendonça, Regina C S

    2014-08-01

    Foodborne illness due to Salmonella-contaminated pork products is an important public health problem, causing significant economic losses worldwide. The use of bacteriophages is a potential intervention tool that has attracted interest for the control of foodborne pathogens. The objective of this study was to detect the presence of Salmonella in commercial pig farms and to isolate specific autochthonous bacteriophages against Salmonella Typhimurium, to characterize them and to evaluate their lytic capacity against Salmonella Typhimurium in vivo and in vitro. Salmonella was isolated on 50% (4/8) of the farms, with serotype Typhimurium being the most prevalent, detected in 48.2% of samples (13/27). The isolated Salmonella Typhimurium bacteriophages belong to the Podoviridae family, were active against serotypes Abony, Enteritidis, Typhi, and Typhimurium, but not against serotypes Arizonae, Cholerasuis, Gallinarum, and Pullorum. In in vitro tests, bacteriophage at 10(7) PFU/mL and 10(9) PFU/mL significantly reduced (pbacteriophages, Salmonella was identified in 93.3% (28/30) of the fecal samples from the pigs inoculated with 10(6) CFU/mL, and only in 56.6% (17/30) after the treatment consisting of oral administration of the pool of the bacteriophages after the fasting period, simulating a common preslaughter practice. These results indicate that the pool of bacteriophages administered was capable of reducing the colonization of Salmonella in pigs.

  20. Comparison of Six Culture Methods for Salmonella Isolation from Poultry Fecal Samples

    Morshed, R. (PhD

    2014-06-01

    Full Text Available Background and Objective: Salmonellosis is one of the most important food-borne bacterial zoonotic diseases worldwide, and poultry and its products are the major sources for salmonella transmission to human. Isolation of Salmonella enterica from poultry needs bacteriologic enrichment and selected cultures of fecal samples. In this study, different culture methods for the isolation of salmonella from fecal samples were compared. Material and Methods: Forty- five positive samples from infected farms and 45 negative samples from normal farms were processed using enrichment media including tetrathionate broth, selenite cistine and Rappaport-Vassiliadis. Then the samples were incubated in selective cultures, and after 24 h, their results were compared with standard method. Results: Specificity of all methods for salmonella isolation was 100%, and salmonella was not isolated from the negative samples. The highest susceptibility was related to the method in which the sample first in Selenite cistine and later in Rappaport-Vassiliadis was enriched (100%. Enrichment in Rappaport-Vassiliadis could isolate 41 salmonella from 45 positive samples (91% while the result of enrichment in tetrathionate was 6 isolates (13.3%. Conclusion: This study shows that enrichment in selenite cistine and then in Rappaport-Vassiliadis is currently the best method for isolating salmonella from fecal samples of poultry. Key words: Salmonella; Bacteriologic Culture; Diagnosis; Isolation; Enrichment; Poultry

  1. Seroincidence of non-typhoid Salmonella infections

    Emborg, H-D; Simonsen, J; Jørgensen, C S

    2016-01-01

    that enabled a back-calculation of the annual seroincidence of Salmonella based on measurements of specific antibodies. The aim of the present study was to determine the seroincidence in two convenience samples from 2012 (Danish blood donors, n = 500, and pregnant women, n = 637) and a community-based sample...

  2. Ubiquitination as an efficient molecular strategy employed in salmonella infection

    The ubiquitin modification has various functions in the host innate immune system in response to the bacterial infection. To counteract the host immunity, Salmonella can specifically target ubiquitin pathways by its effector proteins. In this review, we describe the multiple facets of ubiquitin func...

  3. Probability of identifying different salmonella serotypes in poultry samples

    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...

  4. Type III effector-mediated processes in Salmonella infection.

    van der Heijden, Joris; Finlay, B Brett

    2012-06-01

    Salmonella is one of the most successful bacterial pathogens that infect humans in both developed and developing countries. In order to cause infection, Salmonella uses type III secretion systems to inject bacterial effector proteins into host cells. In the age of antibiotic resistance, researchers have been looking for new strategies to reduce Salmonella infection. To understand infection and to analyze type III secretion as a potential therapeutic target, research has focused on identification of effectors, characterization of effector functions and how they contribute to disease. Many effector-mediated processes have been identified that contribute to infection but thus far no specific treatment has been found. In this perspective we discuss our current understanding of effector-mediated processes and discuss new techniques and approaches that may help us to find a solution to this worldwide problem.

  5. Animal salmonelloses: a brief review of “host adaptation and host specificity” of Salmonella spp.

    Grammato Evangelopoulou

    2013-07-01

    Full Text Available Salmonella enterica, the most pathogenic species of the genusSalmonella, includes more than 2,500 serovars, many of which are of great veterinary and medical significance. The emergence of food-borne pathogens, such as Salmonella spp., has increased knowledge about the mechanisms helping microorganisms to persist and spread within new host populations. It has also increased information about the properties they acquire for adapting in the biological environment of a new host. Thedifferences observed between serovars in their host preference and clinical manifestations are referred to as “serovar-host specificity” or “serovar-host adaptation”. The genus Salmonella, highly adaptive to vertebrate hosts, has many pathogenic serovars showing host specificity. Serovar Salmonella Typhi, causing disease to man and higher primates, is a good example of host specificity. Thus, understanding the mechanisms that Salmonella serovars use to overcome animal species' barriers or adapt to new hosts is also important for understanding the origins of any other infectious diseases or the emergence of new pathogens. In addition, molecular methods used to study the virulence determinants of Salmonella serovars, could also be used to model ways of studying the virulence determinants used by bacteria in general, when causing disease to a specific animal species

  6. Produção e purificação de anticorpos policlonais para Salmonella Enteritidis (Enterobacteriaceae Production and purification of polyclonal antibodies for Salmonella Enteritidis (Enterobacteriaceae

    Mario Augusto Ono

    2002-04-01

    Full Text Available O objetivo deste trabalho foi produzir e purificar anticorpos policlonais específicos para Salmonella Enteritidis (Enterobacteriaceae. O anti-soro foi produzido em coelhos, empregando-se flagelina purificada. O título e a especificidade foram determinados através do ensaio imunoenzimático - ELISA e a purificação por cromatografia de afinidade com sepharose Proteína A. As suspensões bacterianas foram cultivadas em cinco diferentes meios de cultura (infusão de cérebro coração - BHI, caldo tripticase soja, caldo lactosado, caldo nutriente - CN e água peptonada. Observou-se que dependendo do meio o título do anti-soro pode variar e os melhores resultados foram obtidos com BHI e CN. O anti-soro foi específico para Salmonella Enteritidis, apresentando porcentagens de reações cruzadas com Salmonella Typhimurium, Salmonella Infantis e Salmonella Newport de 16,0, 11,9 e 6,4%, respectivamente. Menores porcentagens foram obtidas com outras enterobactérias testadas. Esses resultados indicam a possibilidade da utilização desses anticorpos na padronização de ensaios imunológicos para a detecção de Salmonella EnteritidisThe purpose of this study was to produce and to purify specific polyclonal antibodies for Salmonella Enteritidis (Enterobacteriaceae. The anti-serum was raised in rabbits using purified flagelin. Anti-serum titer and specificity were determined by an immunoassay - ELISA and its purification was performed by sepharose protein A affinity chromatography. The bacteria suspensions were cultivated in five different media (brain heart infusion - BHI, tripticase soy broth, nutrient broth - NB, peptone water. Results have showed that anti-serum titers varied depending on which media type was used and BHI and NB media yielded the most significant results. The anti-serum produced was specific for Salmonella Enteritidis. Its cross-reactivity with Salmonella Thyphimurium, Salmonella Infantis and Salmonella Newport were 16.0, 11

  7. Salmonella in Sheep in Iceland

    Gunnarsson E

    2002-03-01

    Full Text Available In 1995 several outbreaks of food poisoning in humans occurred in Iceland, that were traced to salmonella contamination of singed sheep heads. This prompted us to study the prevalence of salmonella infection in sheep and to trace where and how infection might have occurred. Faecal, intestinal contents and tonsillar samples were collected in the spring and autumn from sheep on 50 farms in the southwestern part of the country, where salmonellosis had been detected and from 5 farms in the northwestern part of the country. All faecal samples from the southwest were negative, whereas samples from 3 farms obtained in the autumn in the northwest were positive. Tonsillae taken in the autumn were positive in sheep from 3 farms in the southwest and 2 in the northwest. Our results show that salmonella infection is rare in Icelandic sheep but healthy carriers may harbour the bacteria in tonsillae. Salmonella was not detected in drainage from slaughterhouses nor in singed sheep heads.

  8. EPA Method 1682: Salmonella spp.

    Method 1682 describes procedures for analysis of solid samples (biosolids) and may be adapted for assessment of water, liquid, particulate and aerosol samples contaminated with Salmonella spp. using culture and immunoassay.

  9. Salmonella control programs in Denmark.

    Wegener, Henrik C; Hald, Tine; Lo Fo Wong, Danilo; Madsen, Mogens; Korsgaard, Helle; Bager, Flemming; Gerner-Smidt, Peter; Mølbak, Kåre

    2003-07-01

    We describe Salmonella control programs of broiler chickens, layer hens, and pigs in Denmark. Major reductions in the incidence of foodborne human salmonellosis have occurred by integrated control of farms and food processing plants. Disease control has been achieved by monitoring the herds and flocks, eliminating infected animals, and diversifying animals (animals and products are processed differently depending on Salmonella status) and animal food products according to the determined risk. In 2001, the Danish society saved U.S.$25.5 million by controlling Salmonella. The total annual Salmonella control costs in year 2001 were U.S.$14.1 million (U.S.$0.075/kg of pork and U.S.$0.02/kg of broiler or egg). These costs are paid almost exclusively by the industry. The control principles described are applicable to most industrialized countries with modern intensive farming systems.

  10. Salmonella Control Programs in Denmark

    Wegener, Henrik Caspar; Hald, Tine; Wong, Danilo Lo Fo

    2003-01-01

    We describe Salmonella control programs of broiler chickens, layer hens, and pigs in Denmark. Major reductions in the incidence of foodborne human salmonellosis have occurred by integrated control of farms and food processing plants. Disease control has been achieved by monitoring the herds...... and flocks, eliminating infected animals, and diversifying animals (animals and products are processed differently depending on Salmonella status) and animal food products according to the determined risk. In 2001, the Danish society saved U.S.$25.5 million by controlling Salmonella. The total annual...... Salmonella control costs in year 2001 were U.S.$14.1 million (U.S.$0.075/kg of pork and U.S.$0.02/kg of broiler or egg). These costs are paid almost exclusively by the industry. The control principles described are applicable to most industrialized countries with modern intensive farming systems....

  11. Protective host immune responses to Salmonella infection.

    Pham, Oanh H; McSorley, Stephen J

    2015-01-01

    Salmonella enterica serovars Typhi and Paratyphi are the causative agents of human typhoid fever. Current typhoid vaccines are ineffective and are not widely used in endemic areas. Greater understanding of host-pathogen interactions during Salmonella infection should facilitate the development of improved vaccines to combat typhoid and nontyphoidal Salmonellosis. This review will focus on our current understanding of Salmonella pathogenesis and the major host immune components that participate in immunity to Salmonella infection. In addition, recent findings regarding host immune mechanisms in response to Salmonella infection will be also discussed, providing a new perspective on the utility of improved tools to study the immune response to Salmonella infections.

  12. Effect of Low Dose of Fumonisins on Pig Health: Immune Status, Intestinal Microbiota and Sensitivity to Salmonella

    Philippe Fravalo

    2013-04-01

    Full Text Available The objective of this study was to measure the effects of chronic exposure to fumonisins via the ingestion of feed containing naturally contaminated corn in growing pigs infected or not with Salmonella spp. This exposure to a moderate dietary concentration of fumonisins (11.8 ppm was sufficient to induce a biological effect in pigs (Sa/So ratio, but no mortality or pathology was observed over 63 days of exposure. No mortality or related clinical signs, even in cases of inoculation with Salmonella (5 × 104 CFU, were observed either. Fumonisins, at these concentrations, did not affect the ability of lymphocytes to proliferate in the presence of mitogens, but after seven days post-inoculation they led to inhibition of the ability of specific Salmonella lymphocytes to proliferate following exposure to a specific Salmonella antigen. However, the ingestion of fumonisins had no impact on Salmonella translocation or seroconversion in inoculated pigs. The inoculation of Salmonella did not affect faecal microbiota profiles, but exposure to moderate concentrations of fumonisins transiently affected the digestive microbiota balance. In cases of co-infection with fumonisins and Salmonella, the microbiota profiles were rapidly and clearly modified as early as 48 h post-Salmonella inoculation. Therefore under these experimental conditions, exposure to an average concentration of fumonisins in naturally contaminated feed had no effect on pig health but did affect the digestive microbiota balance, with Salmonella exposure amplifying this phenomenon.

  13. Phenotypic and genotypic characterization of locally isolated Salmonella strains used in preparation of Salmonella antigens in Egypt

    Hazem Mohammed Ibrahim; Dalia Ahmed Mohammed Abd El-moaty; Hanan Ali Ahmed; Mona Ibrahim El-Enbaawy

    2016-01-01

    Aim: This work was conducted to study the phenotypic and genotypic characterization of locally isolated Salmonella strains (Salmonella Pullorum, Salmonella Enteritidis, and Salmonella Typhimurium) from poultry used in the preparation of Salmonella antigens in Egypt. Materials and Methods: The phenotypic characterization of Salmonella strains was done using standard microbiological, biochemical, and serological techniques. Molecular identification was done using different sets of primers on...

  14. Bovine salmonellosis in Northeast of Iran:Frequency, genetic fingerprinting and antimicrobial resistance patterns of Salmonella spp.

    Hessam A Halimi; Hesam A Seifi; Mehrnaz Rad

    2014-01-01

    Objective:To evaluate serovar and antimicrobial resistance patterns of Salmonella spp isolated from healthy, diseased and necropsied cows and calves in this observational study. Methods:Nineteen isolates recovered from feces and tissues of salmonellosis-affected animals of two commercial farms in north-east of Iran. In second part of the study, the two farms were sampled 4 times with an interval of 2 month. The samples included calves’ feces, adult cows’ feces, feeds, water, milk filters, and milk fed to calves. Five Salmonella were isolated from 332 fecal samples collected from calves and peri-parturient cows. No Salmonella was recovered from water, feed, milk filers and milk fed to calves. Results:Salmonella Typhimurium was the most frequently isolate among all sero-groups. S. Dublin was only accounted for 8%(two out of 24) of isolates. Isolated Salmonella strains were used for the ERIC PCR DNA fingerprinting assay. Our results grouped Salmonella isolates into 3 clusters, suggesting that specific genotypes were responsible for each sero-group of Salmonella. The results also revealed diversity among Salmonella isolates in cluster III (sero-group B). Eighteen out of 19 Salmonella spp. were resistant to oxytetracycline. Five isolates out of 19 showed more than one drug resistance. Multi-drug resistance was seen only among Salmonella Typhimurium isolates. Enrofloxacin was the most susceptible antibiotic against all isolates in this study. Conclusion:The emergence of multiple antibiotic-resistant strains of Salmonella Typhimurium should be of great concern to the public. No correlation between ERIC fingerprinting and resistance patterns of Salmonella isolates was found, which indicates resistance to antimicrobial agents was not related to specific genetic background.

  15. Mieloma múltiplo: invasão leptomeníngea difusa Diffuse leptomeningeal involvement in multiple myelomatosis: a case report

    N. O. Facure

    1971-03-01

    Full Text Available Registro de caso de paciente com infiltração leptomeníngea por metás-tase de mieloma múltiplo. A infiltração neoplásica ocorria nas leptomeninges da base do encéfalo e, em especial, nas do canal raqueano. O tecido tumoral formava manguito no espaço sub-aracnóideo que envolvia os segmentos cervical e torácico da medula espinhal. A partir dos segmentos lombares a medula se achava infiltrada pelo tumor; as raízes da cauda equina achavam-se também invadidas pelo tecido neoplásico. Não foi feito o diagnóstico em vida. O quadro clínico caracterizava-se por sinais de irritação meníngea e de sofrimento radículo-medular a partir dos segmentos lombares altos e o quadro liquórico, por reação inflamatória de tipo sub-agudo que determinava bloqueio do canal raqueano. Os autores chamam a atenção para a raridade da invasão leptomeníngea por mieloma múltiplo e para a dificuldade diagnostica do caso. Neste último sentido discutem os dados do quadro liquórico bem como salientam não ter sido possível completar o estudo histoquímico das células plasmocitárias.A case of a patient with multiple myelomatosis that presented diffuse leptomeningeal involvement by metastatic tissue is reported. The diagnosis was based upon necroscopic examination. The leptomeninges were infiltrated by neoplastic cells, the infiltration being more evident in the leptomeninges of the spinal canal. In this region the subarachnoid space was filled by neoplastic tissue that surrounded the spinal cord and cauda equina. The lumbal and sacral portions of spinal cord were invaded by tumor cells. Fever, congestion of left eye and signs of leptomeningeal irritation appeared at first and were followed by crural paraplegia about two months later. At this occasion a CSF examination showed changes proper to subacute inflammatory process and the manometric test of Stookey suggested the occurence of blockage in the spinal canal. The unusual leptomeningeal involvement

  16. Osteomielitis por salmonella

    Alicia Velázquez Pérez

    2014-08-01

    Full Text Available Se presenta el caso de una paciente femenina de color blanco y dos años de edad, con diagnóstico prenatal de sicklemia, que desde edades tempranas tiene problemas de la enfermedad. Ingresó en esta ocasión por una de las complicaciones infecciosas que ocasiona este padecimiento, una osteomielitis del húmero izquierdo, aislándose el germen en el hemocultivo realizado, una salmonella. Necesitó de tratamiento enérgico y prolongado; se obtuvo un resultado satisfactorio en la evolución de la enfermedad y se sigue sistemáticamente por consulta externa en la actualidad

  17. Genes de virulência e diversidade genética em Salmonella spp. isoladas de amostras de origem suína

    M.S. Moura

    2014-10-01

    Full Text Available A diversificação da produção industrial de alimentos de origem suína e o intercâmbio comercial de animais e seus derivados destinados ao consumo humano podem ser importantes disseminadores de sorovares de Salmonella spp. na cadeia alimentar. Objetivou-se avaliar em 86 cepas de Salmonella spp., isoladas em granja de terminação e no abate de suínos, a ocorrência de três genes de virulência (invA, agfA e lpfA, bem como a similaridade genética entre elas. A ocorrência do gene invA foi verificada em 100% das amostras. O gene lpfA foi detectado em 80,23% (69/86 das cepas, não foi detectado em S. Panama e estava presente em todas as cepas de S. Infantis. O gene agfA foi detectado em 63,95% (55/86 das amostras. S. Agona apresentou positividade para todos os genes de virulência estudados. A análise de homologia entre as cepas agrupou os diferentes sorovares em clusters. A similaridade foi independente do local de isolamento, o que demonstra a presença de clones ao longo da cadeia de produção e a existência de multiplicidade de fontes para a infecção dos animais, como a ração, e a contaminação cruzada das carcaças. A pesquisa de genes de virulência e a avaliação da proximidade gênica permitem a caracterização e um maior entendimento sobre cepas de Salmonella circulantes na cadeia produtiva de suínos e, assim, podem subsidiar medidas de controle durante o processo produtivo com o objetivo de garantir a saúde do consumidor.

  18. Use of muscle fluid as a source of antibodies for serologic detection of Salmonella infection in slaughter pig herds

    Nielsen, B.; Ekeroth, Lars; Bager, F.

    1998-01-01

    Fluid drained from a muscle tissue sample was used as an alternative to serum for the detection of specific anti-Salmonella antibodies in an indirect LPS enzyme-linked immunosorbent assay (ELISA). In the first study, serum and muscle fluid from 3 pigs experimentally infected with Salmonella typhi...

  19. Complete and closed genome sequences of 10 Salmonella enterica subsp. enterica serovar Anatum isolated from human and bovine sources

    Salmonella enterica is an important pathogen transmitted by numerous vectors. Genomic comparisons of Salmonella from disparate hosts have the potential to further our understanding of mechanisms underlying host specificities and virulence. Here, we present closed genome and plasmid sequences of 10...

  20. Diversification of the Salmonella fimbriae: a model of macro- and microevolution.

    Min Yue

    Full Text Available Bacteria of the genus Salmonella comprise a large and evolutionary related population of zoonotic pathogens that can infect mammals, including humans and domestic animals, birds, reptiles and amphibians. Salmonella carries a plethora of virulence genes, including fimbrial adhesins, some of them known to participate in mammalian or avian host colonization. Each type of fimbria has its structural subunit and biogenesis genes encoded by one fimbrial gene cluster (FGC. The accumulation of new genomic information offered a timely opportunity to better evaluate the number and types of FGCs in the Salmonella pangenome, to test the use of current classifications based on phylogeny, and to infer potential correlations between FGC evolution in various Salmonella serovars and host niches. This study focused on the FGCs of the currently deciphered 90 genomes and 60 plasmids of Salmonella. The analysis highlighted a fimbriome consisting of 35 different FGCs, of which 16 were new, each strain carrying between 5 and 14 FGCs. The Salmonella fimbriome was extremely diverse with FGC representatives in 8 out of 9 previously categorized fimbrial clades and subclades. Phylogenetic analysis of Salmonella suggested macroevolutionary shifts detectable by extensive FGC deletion and acquisition. In addition, microevolutionary drifts were best depicted by the high level of allelic variation in predicted or known adhesins, such as the type 1 fimbrial adhesin FimH for which 67 different natural alleles were identified in S. enterica subsp. I. Together with strain-specific collections of FGCs, allelic variation among adhesins attested to the pathoadaptive evolution of Salmonella towards specific hosts and tissues, potentially modulating host range, strain virulence, disease progression, and transmission efficiency. Further understanding of how each Salmonella strain utilizes its panel of FGCs and specific adhesin alleles for survival and infection will support the

  1. Sodium alginate oligosaccharides from brown algae inhibit Salmonella Enteritidis colonization in broiler chickens.

    Yan, G L; Guo, Y M; Yuan, J M; Liu, D; Zhang, B K

    2011-07-01

    The effects of sodium alginate oligosaccharides (sAO) on growth performance, cecal microbiota, Salmonella translocation to internal organs, and mucosal immune responses to challenge with Salmonella enterica serovar Enteritidis in broiler chickens were investigated. We designed an experiment with a 2 × 3 factorial arrangement, in which 3 feed treatments with supplementation of sAO at 0 (controls), 0.04, or 0.2% were provided in the diet for birds not challenged or challenged with Salmonella Enteritidis. There were 5 randomly placed replicate pens for each treatment. At 8 to 12 d of age, one-half the poults were orally gavaged with 10(8) cfu of Salmonella Enteritidis and the nonchallenged groups were inoculated with sterile PBS. Body weight loss and mortality resulting from Salmonella infection were mitigated by the addition of sAO. Supplementation of sAO at 0.2% was the most effective concentration for reducing Salmonella colonization and increasing the number of lactic acid bacteria in the cecum of chickens challenged with Salmonella Enteritidis. Cecal Salmonella Enteritidis-specific IgA production was significantly increased by sAO at 0.2% at 5 d postchallenge compared with the other treatments and was maintained at higher levels at the 2 dosages of sAO at 10 d postchallenge. With Salmonella Enteritidis challenge, sAO at 0.04% showed an anti-inflammatory effect through upregulation of interleukin (IL)-10 expression in the cecal tonsils. The supplementation level of 0.2% showed dramatic immunostimulatory activity by inducing interferon-γ, IL-10, and IL-1β mRNA expression in cecal tonsils of nonchallenged birds. However, the high level of sAO induced a robust mucosal immune response in the absence of a challenge, and this may have led to a decline in BW. These findings suggest that dietary sAO can decrease Salmonella colonization and improve intestinal barrier function and performance of chickens.

  2. Salmonella enteritidis deposition in eggs after experimental infection of laying hens with different oral doses.

    Gast, Richard K; Guraya, Rupa; Guard, Jean

    2013-01-01

    The continuing attribution of human Salmonella Enteritidis infections to internally contaminated eggs has necessitated the commitment of substantial public and private resources to Salmonella Enteritidis testing and control programs in commercial laying flocks. Cost-effective risk-reduction requires a detailed and comprehensive understanding of how Salmonella Enteritidis infections in hens result in deposition of the pathogen inside eggs. The present study sought to resolve some incompletely defined aspects of the relationship between Salmonella Enteritidis oral-exposure dose levels in experimentally infected laying hens and the frequency and location of subsequent egg contamination. In two trials, groups of specific-pathogen-free hens were experimentally inoculated with oral doses of 10(4), 10(6), or 10(8) CFU of a phage type 4 Salmonella Enteritidis strain. Eggs were collected 5 to 23 days postinoculation, and the yolk and albumen of each egg were cultured separately to detect Salmonella Enteritidis contamination. Larger oral doses of Salmonella Enteritidis administered to hens were associated with significant increases in the frequencies of both yolk and albumen contamination. Moreover, Salmonella Enteritidis was found in the albumen of a far-higher proportion of contaminated eggs from hens given the largest dose than from the other two groups. Salmonella Enteritidis contamination was detected in 0.7% of yolk and 0.2% of albumen samples after inoculation of hens with 10(4) CFU, 4.0% of yolk and 1.7% of albumen samples after inoculation with 10(6) CFU, and 6.5% of yolk and 10.8% of albumen samples after inoculation with 10(8) CFU. These results demonstrate that oral-exposure doses of Salmonella Enteritidis for laying hens can significantly affect both the frequency and location of deposition of this pathogen inside eggs.

  3. Duplex PCR for detection of Salmonella and Shigella spp in cockle samples.

    Senachai, Pachara; Chomvarin, Chariya; Wongboot, Warawan; Boonyanugomol, Wongwarut; Tangkanakul, Waraluk

    2013-09-01

    Salmonella and Shigella spp are important causative agents of foodborne diseases. A sensitive, specific and rapid method is essential for detection of these pathogens. In this study, a duplex PCR method was developed for simultaneous detection of Salmonella and Shigella spp in cockle samples and compared with the traditional culture method. Enrichment broths for Salmonella spp recovery were also compared. Sensitivity of the duplex PCR for simultaneous detection of Salmonella and Shigella spp from pure culture was 10(3) CFU/ml (40 CFU/PCR reaction), and that of sterile cockle samples spiked with these two pathogens was 1 CFU/10 g of cockle tissue after 9 hours enrichment [3 hours in buffered peptone water (BPW), followed by 6 hours in Rappaport Vasiliadis (RV) broth or tetrathionate (TT) broth for Salmonella spp and 6 hours enrichment in Shigella broth (SB) for Shigella spp]. There was no significant difference in detection sensitivity between enrichment in RV and TT broths. Salmonella spp detected in cockles in Khon Kaen, Thailand by duplex PCR and culture method was 17% and 13%, respectively but Shigella spp was not detected. The duplex PCR technique developed for simultaneous detection of Salmonella and Shigella spp in cockle samples was highly sensitive, specific and rapid and could serve as a suitable method for food safety assessment.

  4. Farm and slaughterhouse characteristics affecting the occurrence of Salmonella and Campylobacter in the broiler supply chain.

    Franz, E; van der Fels-Klerx, H J; Thissen, J; van Asselt, E D

    2012-09-01

    Based on a data set on Campylobacter and Salmonella prevalence in the broiler supply chain, collected during the period 2002 through 2005 in the Netherlands, farm- and slaughterhouse-specific characteristics were tested for their effect on Campylobacter and Salmonella prevalence at different stages of the broiler supply chain. Three different sampling points were considered: departure from the farm, arrival at the slaughterhouse, and the end of the slaughterline. Strong associations were found between Salmonella and Campylobacter prevalence at a particular sampling point and their prevalence at the preceding point of the chain. Statistical analyses showed that the country of origin of the broiler farm had a significant effect on the prevalence of Salmonella and Campylobacter at slaughterhouse arrival. The feeding company delivering to the farm also showed a significant effect on the occurrence of both pathogens at departure from the broiler farm. The prevalence of Campylobacter decreased with an increasing number of birds per flock, whereas the prevalence of Salmonella increased with an increasing number of birds per flock. The number of flocks processed within a specific slaughterhouse was not associated with an increased or decreased prevalence of Campylobacter and Salmonella. The results provide more insight into factors related to the occurrence of both pathogens and in understanding their epidemiology. The results can be supportive in decision making on measures to reduce the contamination of broiler products with Salmonella and Campylobacter.

  5. Inhibitory Effects of Several Essential Oils towards Salmonella typhimurium, Salmonella paratyphi A and Salmonella paratyphi B

    S.F. Mazhar

    2014-09-01

    Full Text Available Plant essential oils are natural products extracted from plants and because of their antimicrobial properties can be used as natural additives in foods. They are also useful for decontamination of food-borne pathogens and can be a safe additive in foods. The antimicrobial activities of essential oils belonging to Saturiea hortensis, Thymus vulgaris, Mentha polegium, Cuminum cyminum, Lavandula officinalis and Mentha viridis L. (spearmint were investigated at different concentrations (0.1, 0.3, 0.5, 1, 2, 5 and 10%v/v against Salmonella typhimurium, Salmonella paratyphi A and Salmonella paratyphi B by using the agar well diffusion method. Essential oils showed inhibitory effect on Salmonella spp. in the agar well diffusion assay. In addition, the capability of essential oils for decontamination of minced row beef, ground beef, minced raw chicken and minced raw fish inoculated with Salmonella spp. at 0.1 and 0.5%v/v were assessed. Reduction of the Salmonella spp. population was observed following the inoculation of the cultures with 0.1 and 0.5%v/v essential oils.

  6. Sampling and detection of Salmonella in eggs

    The detection of Salmonella in the edible internal contents of shell eggs provides the most incontrovertible and epidemiologically relevant evidence that laying flocks might threaten consumers. Accordingly, dependable tests for Salmonella in eggs remain essential for achieving public health objectiv...

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

    A Koluman

    2012-03-01

    Full Text Available 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.

  8. Salmonella Typhimurium and Salmonella Sofia: Growth in and Persistence on Eggs under Production and Retail Conditions

    Catherine M. McAuley

    2015-01-01

    Full Text Available Salmonellosis in Australia has been linked to eggs and egg products with specific serotypes associated with outbreaks. We compared attachment to and survival on egg shells and growth in eggs of two Salmonella serotypes, an egg outbreak associated Salmonella Typhimurium and a non-egg-associated Salmonella enterica ssp. II 1,4,12,27:b:[e,n,x] (S. Sofia. Experiments were conducted at combinations of 4, 15, 22, 37 and 42°C. No significant differences occurred between the serotypes in maximum growth rates, which were significantly greater (P<0.001 in egg yolk (0.427 log10 CFU/mL/h compared to whole egg (0.312 log10 CFU/mL/h and egg white (0.029 log10 CFU/mL/h. Attachment to egg shells varied by time (1 or 20 min and temperature (4, 22 and 42°C, with S. Typhimurium isolates attaching at higher levels (P<0.05 than S. Sofia after 1 min at 4°C and S. Typhimurium ATCC 14028 attaching at higher (P<0.05 levels at 22°C. Survival on egg shells was not significantly different across isolates. Salmonella serotypes behaved similarly regarding growth in egg contents, attachment to egg shells and survival on eggs, indicating that other factors more likely contributed to reasons for S. Typhimurium being implicated in multiple egg-associated outbreaks.

  9. Salmonella Typhimurium and Salmonella Sofia: Growth in and Persistence on Eggs under Production and Retail Conditions

    McAuley, Catherine M.; Duffy, Lesley L.; Subasinghe, Nela; Hogg, Geoff; Coventry, John; Fegan, Narelle

    2015-01-01

    Salmonellosis in Australia has been linked to eggs and egg products with specific serotypes associated with outbreaks. We compared attachment to and survival on egg shells and growth in eggs of two Salmonella serotypes, an egg outbreak associated Salmonella Typhimurium and a non-egg-associated Salmonella enterica ssp. II 1,4,12,27:b:[e,n,x] (S. Sofia). Experiments were conducted at combinations of 4, 15, 22, 37 and 42°C. No significant differences occurred between the serotypes in maximum growth rates, which were significantly greater (P < 0.001) in egg yolk (0.427 log10 CFU/mL/h) compared to whole egg (0.312 log10 CFU/mL/h) and egg white (0.029 log10 CFU/mL/h). Attachment to egg shells varied by time (1 or 20 min) and temperature (4, 22 and 42°C), with S. Typhimurium isolates attaching at higher levels (P < 0.05) than S. Sofia after 1 min at 4°C and S. Typhimurium ATCC 14028 attaching at higher (P < 0.05) levels at 22°C. Survival on egg shells was not significantly different across isolates. Salmonella serotypes behaved similarly regarding growth in egg contents, attachment to egg shells and survival on eggs, indicating that other factors more likely contributed to reasons for S. Typhimurium being implicated in multiple egg-associated outbreaks. PMID:26539536

  10. Detection of the Salmonella invasion gene invA using molecular beacon probe%分子信标探针技术检测沙门菌invA基因

    万成松; 李俊艾; 罗军

    2004-01-01

    目的研究沙门菌的分子信标基因检测方法.方法在PCR反应体系中加入分子信标探针,探针的5′端标记6-fluorescine(6-FAM),3′端标记4-(dimethylaminophenylazo)benzoicacid(DABCYL),对沙门菌invA基因PCR产物进行荧光检测.结果肠炎沙门菌、甲型副伤寒沙门菌、乙型副伤寒沙门菌、伤寒沙门菌"H"、伤寒沙门菌和肠侵袭型大肠杆菌的荧光值分别为161.6、104.5、85.9、83.1、94.8、46.1,Ax值(样本荧光值-空白对照荧光值)分别为121.3、64.2、45.6、42.8、54.5、5.8,沙门菌的Ax值均大于21,结果阳性,与琼脂糖电泳分析结果一致.结论分子信标探针技术可以准确、快速、简便进行沙门菌invA基因检测.

  11. Establishment and preliminary application of LAMP invA gene assay for rapid detection of Salmonella%沙门菌invA基因LAMP快速检测法的建立和初步应用

    王敏雅; 徐明汉; 潘宏伟; 王志刚

    2008-01-01

    目的:建立适合基层检验部门使用的快速检测沙门菌LAMP法.方法:在65℃普通恒温水浴中、60 min扩增沙门菌invA基因片段,目测或电泳快速检测沙门菌.分别对环介导等温扩增(LAMP)反应影响较大的温度、Betaine浓度等进行优化,并对实验室保存的28种沙门菌不同血清型共34株和其他9种肠杆菌科细菌进行检测;对部分沙门菌进行污染血清直接LAMP模拟检测.结果:28种不同血清型的沙门菌LAMP检测都呈阳性,其它9种肠杆菌科细菌均为阴性;血清模拟实验与菌株直接DNA提取LAMP检测结果一致.结论:LAMP法能够快速、特异地检测沙门菌,且不需要昂贵的仪器,适合基层检验部门使用.

  12. DNA sequence analysis and molecular detection of invA gene from salmonella spp%沙门氏菌的invA基因序列分析与分子检测

    陈金顶; 索青利; 廖明; 辛朝安

    2004-01-01

    目的采用聚合酶链反应和DNA序列分析,了解沙门氏菌侵袭蛋白A(invasion protein A,invA)基因核苷酸序列有何差异,建立沙门氏菌的分子快速检测方法.方法根据沙门氏菌的invA基因核苷酸序列设计一对引物,应用聚合酶链反应技术,分别对3种沙门氏菌标准菌株的invA基因及6种非沙门氏菌株进行PCR扩增,并将扩增的片段进行克隆及序列分析.结果 3种沙门氏菌标准菌株PCR均扩增出283 bp的特异条带,非沙门氏菌皆无特异带扩增;DNA序列分析证实,沙门氏菌的invA基因核苷酸序列比较保守.结论本研究建立的检测沙门氏菌方法具有较高的特异性与灵敏性,invA基因的序列分析为进一步研究沙门氏菌不同分离株的流行病学、遗传学与分子致病机理奠定了基础.

  13. Mixed salmonella infection - A case report

    Joshi S

    2002-01-01

    Full Text Available Mixed infection with multiple Salmonella serotypes in the same patient is an unusual finding. We present a case of enteric fever in which the blood culture was sterile and Widal test was negative. The culture of the bone marrow yielded Salmonella typhi and Salmonella paratyphi A.

  14. Screening for Salmonella in backyard chickens.

    Manning, Johanna; Gole, Vaibhav; Chousalkar, Kapil

    2015-06-15

    Salmonellosis is a significant zoonotic disease which has a considerable economic impact on the egg layer industry. There is limited information about the prevalence of Salmonella spp. in backyard chickens. The current study was conducted to determine the prevalence of Salmonella in backyard chickens, and the associated virulence of any serovars identified. Hundred and fifteen pooled samples from 30 backyard flocks in South Australia were screened. Four flocks tested positive for Salmonella spp. The overall Salmonella isolation rate in the current study was 10.4%. The estimated prevalence at individual bird level was 0.02% (95% CI 0.025-0.975). The serovars isolated were Salmonella Agona, Salmonella subsp 2 ser 21:z10:z6 (Wandsbek) and Salmonella Bovismorbificans. All Salmonella isolates tested positive for the prgH, orfL and spiC genes. The Salmonella subsp 2 ser 21:z10:z6 (Wandsbek) had the most antibiotic resistance, being resistant to ampicillin and cephalothin and having intermediate resistance to florphenicol. All of the Salmonella Agona had intermediate resistance to the ampicillin, while the Salmonella Bovismorbificans were susceptible to all antibiotics tested. With the increased interest of keeping backyard chickens, the current study highlights the zoonotic risk from Salmonella spp. associated with home flocks.

  15. Splenic abscess due to Salmonella enteritidis

    Hatice Çabadak

    2012-02-01

    Full Text Available Splenic abscess is a very rare complication of non-typhoidal Salmonella infections. We report a case of splenic abscess caused by Salmonella enteritidis. The patient is a 63-year-old woman with diabetes mellitus and underwent splenectomy. This case suggests that the patients with comorbities are at increased risk for invasive infections in non-typhoidal Salmonella infections.

  16. Early eradication of persistent Salmonella infection primes antibody-mediated protective immunity to recurrent infection.

    Johanns, Tanner M; Law, Calvin Y; Kalekar, Lokeshchandra A; O'Donnell, Hope; Ertelt, James M; Rowe, Jared H; Way, Sing Sing

    2011-04-01

    Typhoid fever is a systemic, persistent infection caused by host-specific strains of Salmonella. Although the use of antibiotics has reduced the complications associated with primary infection, recurrent infection remains an important cause of ongoing human morbidity and mortality. Herein, we investigated the impacts of antibiotic eradication of primary infection on protection against secondary recurrent infection. Using a murine model of persistent Salmonella infection, we demonstrate protection against recurrent infection is sustained despite early eradication of primary infection. In this model, protection is not mediated by CD4(+) or CD8(+) T cells because depletion of these cells either alone or in combination prior to rechallenge does not abrogate protection. Instead, infection followed by antibiotic-mediated clearance primes robust levels of Salmonella-specific antibody that can adoptively transfer protection to naïve mice. Thus, eradication of persistent Salmonella infection primes antibody-mediated protective immunity to recurrent infection.

  17. Acute diarrhea associated with Salmonella enterica in Belo Horizonte-MG: prevalence and characterization of isolates Diarreia aguda associada a Salmonella enterica em Belo Horizonte-MG: prevalência e caracterização das amostras isoladas

    Mireille Ângela Bernardes Sousa

    2013-02-01

    Full Text Available Introduction: Acute infectious diarrhea is still regarded as a public health problem associated with a wide range of etiologic agents, from which Salmonella enterica is particularly worth mentioning inasmuch as it is a major cause of inflammatory diarrhea in both developed and developing countries. Objective: To assess the distribution of S. enterica among children with acute diarrhea in Belo Horizonte and to characterize bacterium isolates. Material and methods: The study group comprised a total of 157 children from low socioeconomic background. Stool samples were collected for leukocyte analysis and Salmonella bacterial culture. The isolates were serotyped and evaluated as to antimicrobial susceptibility profile, extended-spectrum β-lactamases (ESBL production, and presence of virulence markers (invA, iroB, and spvC. RESULTS: A total of 5/3.2% children were infected by S. enterica, 3/60% by S. enterica Typhimurium, 1/20% by S. enterica Enteritidis and 1/20% S. enterica subsp. enterica serotype 8.20:z4,z23:-. Fecal leucocytes were detected in two out of five fecal specimens positive for S. enterica. Isolates from three children were resistant to nalidixic acid, nalidixic acid + chloramphenicol, and nalidixic acid + chloramphenicol + ampicillin. ESBL production was not detected. All samples presented invA and iroB genes. spvC marker was observed in isolates from two children infected by S. Typhimurium and S. Enteritidis. Conclusion: The results demonstrate that S. enterica infection is uncommon among children from our region. Furthermore, they indicate the need for periodic monitoring of bacterial antimicrobial susceptibility profile in order to establish suitable antimicrobial therapy when required.INTRODUÇÃO: A diarreia infecciosa aguda é considerada um problema de saúde pública associado a uma ampla gama de agentes etiológicos, entre os quais destaca-se Salmonella enterica, causa importante de diarreia inflamatória em pa

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

    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.

  19. Attenuated Salmonella typhimurium SV4089 as a potential carrier of oral DNA vaccine in chickens.

    Jazayeri, Seyed Davoud; Ideris, Aini; Zakaria, Zunita; Omar, Abdul Rahman

    2012-01-01

    Attenuated Salmonella has been used as a carrier for DNA vaccine. However, in vitro and in vivo studies on the bacteria following transfection of plasmid DNA were poorly studied. In this paper, eukaryotic expression plasmids encoding avian influenza virus (AIV) subtype H5N1 genes, pcDNA3.1/HA, NA, and NP, were transfected into an attenuated Salmonella enteric typhimurium SV4089. In vitro stability of the transfected plasmids into Salmonella were over 90% after 100 generations. The attenuated Salmonella were able to invade MCF-7 (1.2%) and MCF-10A (0.5%) human breast cancer cells. Newly hatched specific-pathogen-free (SPF) chicks were inoculated once by oral gavage with 10(9) colony-forming unit (CFU) of the attenuated Salmonella. No abnormal clinical signs or deaths were recorded after inoculation. Viable bacteria were detected 3 days after inoculation by plating from spleen, liver, and cecum. Fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR) were carried out for confirmation. Salmonella was not detected in blood cultures although serum antibody immune responses to Salmonella O antiserum group D1 factor 1, 9, and 12 antigens were observed in all the inoculated chickens after 7 days up to 35 days. Our results showed that live attenuated S. typhimurium SV4089 harboring pcDNA3.1/HA, NA, and NP may provide a unique alternative as a carrier for DNA oral vaccine in chickens.

  20. Outbreak-associated Salmonella enterica Serotypes and Food Commodities, United States, 1998–2008

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

    2013-01-01

    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...

  1. MÉTODOS DE EXTRAÇÃO DE DNA PARA A DETECÇÃO DE Salmonella EM OVOS DE GALINHAS, COM E SEM CASCA, ATRAVÉS DA REAÇÃO EM CADEIA PELA POLIMERASE DNA EXTRACTION METHODS FOR Salmonella DETECTION IN CHICKEN EGGS, INSHELL AND OUTSHELL, BY POLIMERASE CHAIN REACTION

    Maristela Lovato Flôres

    2001-04-01

    Full Text Available O diagnóstico microbiológico de Salmonella sp em amostras de alimentos é demorado, com cinco diferentes etapas, levando cerca de 120 horas até o resultado final. A utilização da técnica da Reação em Cadeia pela Polimerase (PCR pode diminuir esse período, porém sofre influência de substâncias presentes na amostra que afetam a reação. O objetivo deste trabalho foi comparar dois métodos de extração de DNA, a extração por tratamento térmico e a pelo fenol-clorofórmio, em amostras de 100 ovos de galinhas domésticas artificialmente contaminados com uma cepa de Salmonella enterica sorovar typhimurium em fase estacionária. O material obtido com as extrações foi submetido à PCR, utilizando-se um par de iniciadores que amplificam um fragmento de 284pb do gene InvA de Salmonella sp. Comparando os métodos de extração, observou-se uma diferença na capacidade de detecção de 12% a favor do método do fenol-clorofórmio, quando a extração foi realizada a partir do ovo com casca. No momento em que a mesma metodologia foi usada apenas com a parte interna dos ovos, essa diferença subiu para 26% o que foi significativo (PThe Salmonella sp detection in feed samples is time consuming, it has five stages and requires 120 hours for final results. The use of polimerase chain reaction technique can reduce this time considerably, however it can be affected by substances from the sample. This study had the objective of comparing two methods of DNA extraction, by heating process and by phenol-chloroform in samples of 100 chicken eggs experimentally infected with a sample of Salmonella enterica sorovar typhimurium in stationary phase. After the two extraction methods a PCR was done using a pair of oligonucleotides that amplifies a fragment of 284pb in the InvA gene de Salmonella sp. Comparing the extraction methods it was noted a difference of 12% favorably to the phenol-chloroform method when the extraction was done from eggs with shell

  2. Antimicrobial resistance in typhoidal salmonellae

    B N Harish

    2011-01-01

    Full Text Available Infections with Salmonella are an important public health problem worldwide. On a global scale, it has been appraised that Salmonella is responsible for an estimated 3 billion human infections each year. The World Health Organization (WHO has estimated that annually typhoid fever accounts for 21.7 million illnesses (217,000 deaths and paratyphoid fever accounts for 5.4 million of these cases. Infants, children, and adolescents in south-central and South-eastern Asia experience the greatest burden of illness. In cases of enteric fever, including infections with S. Typhi and S. Paratyphi A and B, it is often necessary to commence treatment before the results of laboratory sensitivity tests are available. Hence, it is important to be aware of options and possible problems before beginning treatment. Ciprofloxacin has become the first-line drug of choice since the widespread emergence and spread of strains resistant to chloramphenicol, ampicillin, and trimethoprim. There is increase in the occurrence of strains resistant to ciprofloxacin. Reports of typhoidal salmonellae with increasing minimum inhibitory concentration (MIC and resistance to newer quinolones raise the fear of potential treatment failures and necessitate the need for new, alternative antimicrobials. Extended-spectrum cephalosporins and azithromycin are the options available for the treatment of enteric fever. The emergence of broad spectrum β-lactamases in typhoidal salmonellae constitutes a new challenge. Already there are rare reports of azithromycin resistance in typhoidal salmonellae leading to treatment failure. This review is based on published research from our centre and literature from elsewhere in the world. This brief review tries to summarize the history and recent trends in antimicrobial resistance in typhoidal salmonellae.

  3. Antipathogenic activity of probiotics against Salmonella Typhimurium and Clostridium difficile in anaerobic batch culture systems: is it due to synergies in probiotic mixtures or the specificity of single strains?

    Tejero-Sariñena, Sandra; Barlow, Janine; Costabile, Adele; Gibson, Glenn R; Rowland, Ian

    2013-12-01

    Probiotics are currently being investigated for prevention of infections caused by enteric pathogens. The aim of this in vitro study was to evaluate the influence of three single probiotics: Lactobacillus casei NCIMB 30185 (PXN 37), Lactobacillus acidophilus NCIMB 30184 (PXN 35), Bifidobacterium breve NCIMB 30180 (PXN 25) and a probiotic mixture containing the above strains plus twelve other strains belonging to the Lactobacillus, Bifidobacterium, Lactococcus, Streptococcus and Bacillus genera on the survival of Salmonella Typhimurium and Clostridium difficile using pH-controlled anaerobic batch cultures containing mixed faecal bacteria. Changes in relevant bacterial groups and effects of probiotic addition on survival of the two pathogens were assessed over 24 h. Quantitative analysis of bacterial populations revealed that there was a significant increase in lactobacilli and/or bifidobacteria numbers, depending on probiotic addition, compared with the control (no added probiotic). There was also a significant reduction in S. Typhimurium and C. difficile numbers in the presence of certain probiotics compared with controls. Of the probiotic treatments, two single strains namely L. casei NCIMB 30185 (PXN 37), and B. breve NCIMB 30180 (PXN 25) were the most potent in reducing the numbers of S. Typhimurium and C. difficile. In addition, the supplementation with probiotics into the systems influenced some fermentations parameters. Acetate was found in the largest concentrations in all vessels and lactate and formate were generally detected in higher amounts in vessels with probiotic addition compared to controls.

  4. Salmonella impairs CD8 T cell response through PD-1: PD-L axis.

    López-Medina, Marcela; Carrillo-Martín, Ismael; Leyva-Rangel, Jessica; Alpuche-Aranda, Celia; Ortiz-Navarrete, Vianney

    2015-12-01

    We have shown that Salmonella remains for a long period of time within B cells, plasma cells, and bone marrow B cell precursors, which might allow persistence and dissemination of infection. Nonetheless, how infected cells evade CD8 T cell response has not been characterized. Evidence indicates that some pathogens exploit the PD-1: PD-L (PD-L1 and PD-L2) interaction to inhibit CD8 T cells response to contribute the chronicity of the infection. To determine whether the PD-1: PD-L axis plays a role during Salmonella infection; we evaluated PD-1 expression in antigen-specific CD8 T cells and PD-1 ligands in Salmonella-infected cells. Our results show that infected B cells and macrophages express continuously co-stimulatory (CD40, CD80, and CD86) and inhibitory molecules (PD-L1 and PD-L2) in early and late stages of chronic Salmonella infection, while antigen-specific CD8 T cells express in a sustained manner PD-1 in the late stages of infection. Blocking this axis restores the ability of the CD8 T cells to proliferate and eliminate primary infected APCs. Therefore, a continuous PD-1: PDL interaction might be a mechanism employed by Salmonella to negatively regulate Salmonella-specific CD8 T cell cytotoxic response in order to remain within the host for a long period of time.

  5. Development and comparison of a generic multiple-locus variable-number tandem repeat analysis with PFGE for typing of Salmonella entericasubsp. enterica

    Kjeldsen, Marianne Kirstine; Torpdahl, Mia; Pedersen, Karl

    2015-01-01

    Aims Salmonella enterica subsp. enterica causes salmonellosis in humans and animals. Serovar specific multiple-locus variable-number tandem repeat analysis (MLVA) is widely used for Salmonella surveillance; however, isolates have to be serotyped prior to MLVA typing and only the most common serov...... inexpensive and fast surveillance for laboratories without resources for both serotyping and molecular typing, e.g. PFGE or sequence-based methods, and thereby improve the effectiveness of epidemiological investigations of Salmonella infections globally....

  6. Bayesian estimation of true between-herd and within-herd prevalence of Salmonella in Danish veal calves

    Nielsen, Torben Dahl; Nielsen, Liza Rosenbaum; Toft, Nils

    2011-01-01

    Specialised veal producers that purchase and raise calves from several dairy herds are potentially at high risk of delivering Salmonella-infected animals to slaughter. However, the true prevalence of Salmonella infected veal producing herds and the prevalence of infected calves delivered...... six of 68 herds obtaining posterior probability of being infected less than 10%. Furthermore, this study indicated that serology is sufficiently sensitive and specific to be used for estimating the prevalence of Salmonella-infected specialised veal producing herds....

  7. PERFIL SOROLÓGICO E DE ISOLAMENTO DE Salmonella sp. EM SUÍNOS NO INÍCIO DA TERMINAÇÃO E AO ABATE SEROLOGY AND ISOLATION OF SALMONELLA SP. IN PIGS AT THE FINISHING SITE AND AT SLAUGHTER

    Monika Müller

    2009-09-01

    Full Text Available Estudos que elucidem a cadeia de transmissão de Salmonella enterica nos sistemas de produção de suínos são importantes para que seja possível implementar programas de controle da infecção. O objetivo deste estudo foi comparar o índice de animais positivos para Salmonella sp. no início da fase de terminação e ao abate e identificar possíveis fontes de contaminação no período. Em três granjas terminadoras, coletaram-se: suabes de superfície nas baias e nos silos durante o vazio sanitário; amostras de fezes e sangue dos animais no dia do alojamento; alíquotas de todos os lotes de ração e amostras de sangue, linfonodos mesentéricos (LM e conteúdo intestinal (CI ao abate. As amostras de sangue foram submetidas a teste de ELISA-LPS para Salmonella Typhimurium. Nas demais amostras, pesquisou-se a presença de Salmonella sp. As amostras de ração foram adicionalmente submetidas à técnica da Reação em Cadeia da Polimerase (PCR amplificando o gene invA. Todos os animais foram negativos para presença de Salmonella sp. nas fezes no início da terminação; entretanto, em duas granjas havia animais soropositivos (12% e 28%, respectivamente. Em duas granjas havia contaminação residual no ambiente e na terceira granja, em um dos lotes de ração, detectou-se a presença de Salmonella sp. pela PCR. Ao abate, acima de 90% dos animais foram positivos no teste de ELISA-LPS, sendo que em todos os lotes encontrou-se um número variável (12-92% de portadores em LM e CI. A partir disso, concluiu-se que a terminação foi a fase crítica para a amplificação da infecção por Salmonella sp., sendo a presença residual do microrganismo na granja e o fornecimento de ração contaminada fontes prováveis de infecção.

    PALAVRAS-CHAVES: Abate, isolamento, Salmonella, sorologia, suíno, terminação.
    Studies assessing the Salmonella transmission chain in pig herds are the first step to start a control program.  The aims

  8. Prevalence, concentrations, and antibiotic sensitivities of Salmonella serovars in poultry from retail establishments in Seattle, Washington.

    Mazengia, E; Samadpour, M; Hill, H W; Greeson, K; Tenney, K; Liao, G; Huang, X; Meschke, J S

    2014-06-01

    Poultry have been identified as one of the major sources of salmonellosis, with estimates ranging from 10 to 22% of total cases. Despite several advances in the industry and new performance standards, the incidence of salmonellosis in the population has not declined over the last 15 years. Salmonella is pervasive in a wide variety of foods, and thus, estimating its burden resulting from specific food categories has been challenging and plagued with uncertainty due to critical data gaps. The objective of this study was to conduct a year-long market survey (1,322 samples) to help bridge the data gaps on the contamination rates and levels of Salmonella on raw poultry by product type (i.e., breast, thighs, drums, wings, and split breast) and production method (conventional versus organic). The isolates recovered were serotyped and tested for antibiotic sensitivities. A PCR method was utilized for initial screening of samples after an overnight enrichment in tryptic soy broth. Three-tube most-probable-number (MPN) assays and anti-Salmonella immunomagnetic separation methods were utilized to determine the levels of Salmonella and aid with the recovery of Salmonella species, respectively. Eleven percent of the samples were positive for Salmonella. Significant differences in percent positive rates by product type included up to a 4-fold difference in percent positive rates between establishments, ranging from 7 to 31%. Of the samples positive for Salmonella species, 94% had <30 MPN/100 g. Production methods identified as organic or as not using antibiotics had significantly higher rates of recovery of Salmonella. On the other hand, all of the Salmonella isolates that were resistant to two or more antibiotics originated from conventional processing establishments where antibiotics were utilized. In addition, a significant proportion of isolates from conventionally processed products were serotypes clinically relevant to humans.

  9. Evaluation of virulence and antimicrobial resistance in Salmonella enterica serovar Enteritidis isolates from humans and chicken- and egg-associated sources.

    Han, Jing; Gokulan, Kuppan; Barnette, Dustyn; Khare, Sangeeta; Rooney, Anthony W; Deck, Joanna; Nayak, Rajesh; Stefanova, Rossina; Hart, Mark E; Foley, Steven L

    2013-12-01

    Salmonella enterica serovar Enteritidis is a leading cause of salmonellosis throughout the world and is most commonly associated with the consumption of contaminated poultry and egg products. Salmonella Enteritidis has enhanced ability to colonize and persist in extraintestinal sites within chickens. In this study, 54 Salmonella Enteritidis isolates from human patients (n=28), retail chicken (n=9), broiler farms (n=9), and egg production facilities (n=8) were characterized by antimicrobial susceptibility testing, plasmid analysis, genetic relatedness using XbaI and AvrII pulsed-field gel electrophoresis (PFGE), and the presence of putative virulence genes. Nine isolates were evaluated for their abilities to invade and survive in intestinal epithelial and macrophage cell lines. Overall, 56% (n=30) of isolates were resistant to at least one antimicrobial agent tested, yet no isolates showed resistance to more than three antimicrobials. All isolates carried a common ∼55-kb plasmid, with some strains containing additional plasmids ranging from 3 to 50 kb. PFGE analysis revealed five XbaI and AvrII clusters. There were significant overlaps in the PFGE patterns of the isolates from human, chicken, and egg houses. All isolates tested PCR positive for iacP, purR, ttrB, spi4H, rmbA, sopE, invA, sopB, spvB, pagC, msgA, spaN, orgA, tolC, and sifA, and negative for iss, virB4, and sipB. Of the isolates selected for virulence testing, those containing the iron acquisition genes, iutA, sitA, and iucA, and ∼50-kb plasmids demonstrated among the highest levels of macrophage and epithelial cell invasion, which may indicate their importance in pathogenesis.

  10. 食品中沙门菌特异性二重聚合酶链反应检测方法的研究%Study on a dulplex specific detection of Salmonella spp. in foods by a dulplex PCR

    徐晓可; 吴清平; 张菊梅; 周艳红; 邓梅清

    2008-01-01

    目的 建立二重聚合酶链反应(PCR)方法快速检测食品中的沙门菌(Salmonella spp.).方法 以沙门菌特异性基因invA、hilA为靶基因,选择2对引物对16株沙门菌和24株非沙门菌进行扩增,验证二重PCR的特异性.梯度稀释DNA,以不同稀释度的DNA PCR扩增.在猪肉中以不同菌量人工污染,不同增菌时问培养,提取DNA进行PCR扩增.应用该方法检测实际样品.结果 以invA、hilA为靶基因的两对引物对沙门菌的检出均有很好的特异性,PCR能检出0.1332pg的沙门菌DNA,人工污染猪肉的检测限为2.5cfu/ml.本研究共检测了53份食品样品,有21份检出了沙门菌.结论 建立了适用于肉类、水产品及蛋糕等食品中的沙门菌检测的快速、灵敏、特异的二重PCR方法.

  11. Analysis of Hexanitrostilbene (HNS) and Dipicryethane (DPE) for Mutagenicity by the Ames/Salmonella Assay

    Wu, R; Felton, J

    2007-10-12

    The Ames/Salmonella assay, developed by Professor Bruce Ames at the University of California, Berkeley, is a rapid and sensitive assay for detecting mutagenicity of various chemical compounds (Maron and Ames, 1983). It is a widely accepted short-term assay for detecting chemicals that induce mutations in the histidine (his) gene of Salmonella typhimurium. This is a reverse mutation assay that detects the mutational reversion of his-dependent Salmonella to the his-independent counterpart. Thereby, mutagenic compounds will increase the frequency of occurrence of his-independent bacterial colonies. The assay utilizes the specific genetically constructed strains of bacteria either with or without mammalian metabolic activation enzymes (S9), Aroclor induced rat liver homogenate to assess the mutagenicity of different compounds. In this study, we will use the Ames/Salmonella assay to investigate the mutagenicity of Hexanitrostilbene (HNS) from both Bofors and Pantex, and Dipicryethane (DPE).

  12. A Rab32-dependent pathway contributes to Salmonella typhi host restriction.

    Spanò, Stefania; Galán, Jorge E

    2012-11-16

    Unlike other Salmonellae, the intracellular bacterial human pathogen Salmonella Typhi exhibits strict host specificity. The molecular bases for this restriction are unknown. Here we found that the expression of a single type III secretion system effector protein from broad-host Salmonella Typhimurium allowed Salmonella Typhi to survive and replicate within macrophages and tissues from mice, a nonpermissive host. This effector proteolytically targeted Rab32, which controls traffic to lysosome-related organelles in conjunction with components of the biogenesis of lysosome-related organelle complexes (BLOCs). RNA interference-mediated depletion of Rab32 or of an essential component of a BLOC complex was sufficient to allow S. Typhi to survive within mouse macrophages. Furthermore, S. Typhi was able to survive in macrophages from mice defective in BLOC components.

  13. Expanding the genetic code of Salmonella with non-canonical amino acids

    Gan, Qinglei; Lehman, Brent P.; Bobik, Thomas A.; Fan, Chenguang

    2016-01-01

    The diversity of non-canonical amino acids (ncAAs) endows proteins with new features for a variety of biological studies and biotechnological applications. The genetic code expansion strategy, which co-translationally incorporates ncAAs into specific sites of target proteins, has been applied in many organisms. However, there have been only few studies on pathogens using genetic code expansion. Here, we introduce this technique into the human pathogen Salmonella by incorporating p-azido-phenylalanine, benzoyl-phenylalanine, acetyl-lysine, and phosphoserine into selected Salmonella proteins including a microcompartment shell protein (PduA), a type III secretion effector protein (SteA), and a metabolic enzyme (malate dehydrogenase), and demonstrate practical applications of genetic code expansion in protein labeling, photocrosslinking, and post-translational modification studies in Salmonella. This work will provide powerful tools for a wide range of studies on Salmonella. PMID:28008993

  14. An immunoproteomic approach for characterization of the outer membrane proteins of Salmonella Gallinarum.

    Cho, Youngjae; Sun, Jisun; Han, Jang Hyuck; Jang, Joo Hyun; Kang, Zheng Wu; Hahn, Tae-Wook

    2014-03-01

    Salmonella enterica serovar Gallinarum (SG) is an important pathogen that causes fowl typhoid in chickens. In order to investigate SG outer membrane proteins (OMPs) as potential vaccine candidate proteins, we established a proteomic map and database of antigenic SG-OMPs. A total of 174 spots were detected by 2DE. Twenty-two antigen-reactive spots were identified as nine specific proteins using PMF. OmpA was the most abundant protein among all of the identified OMPs, and it exhibited seven protein species. We conducted Western blot analysis for the SG-OMPs in order to determine which proteins were cross-reactive to the serovars Salmonella Enteritidis, Salmonella Typhimurium, and SG. Our results indicated that OmpA was considered to be an antigenic cross-reactive protein among the three serovars. This study sheds new light on our understanding of cross-protection among Salmonella serovars.

  15. Effects of drying temperature and surface characteristics of vegetable on the survival of salmonella.

    Hawaree, N; Chiewchan, N; Devahastin, S

    2009-01-01

    The heat resistance of Salmonella Anatum inoculated on the surface of a model vegetable as affected by hot-air drying temperature (50 to 70 degrees C) and surface characteristics was determined in this study. Cabbage was selected as a model vegetable to demonstrate the effect of topographical feature of vegetable surface on the Salmonella attachment ability. An image analysis technique was developed to monitor the change of cabbage surface during drying and the specific surface characteristics were described in terms of the roughness factor (R). It was found that the water activity of the vegetable decreased while R-value increased with longer drying time and higher drying temperature. However, the changes of both parameters during drying did not show a significant effect on the susceptibility of Salmonella attached on the cabbage surface. Drying temperature was found to be a major factor influencing the heat resistance of Salmonella during drying.

  16. Serologic reactions against Salmonella in samples from broiler parent stock with and without preceding colibacillosis: A case-control study

    Gradel, K.O.; Feld, Niels Christian; Andersen, J. S.

    2001-01-01

    response is measured in percentage optical density (OD%) of a strong positive reaction, and the cutoff value has been determined to be 40 OD%. Two or more reactors above 40 OD% will place the parent flock under suspicion. There has been concern about possible cross-reactions between Salmonella spp......In the Danish Salmonella Control Program, eggs from broiler parent flocks are surveyed by serologic analysis every 4 wk for antibodies against Salmonella lipopolysaccharide O-antigens 1, 4, 5, 9, and 12 (Mix-enzyme-linked immunosorbent assay [ELISA]) and 6 and 7 (Infantis-ELISA). The antibody....... and other Enterobacteriaceae, e.g., Escherichia coli, because a high specificity of a Salmonella antibody test is desirable. Moreover, false-positive Salmonella results have economic consequences and impede planning the production. A case-control study based on cases of clinical E. coli infections...

  17. Salmonella spp. contamination in commercial layer hen farms using different types of samples and detection methods.

    Soria, M C; Soria, M A; Bueno, D J; Godano, E I; Gómez, S C; ViaButron, I A; Padin, V M; Rogé, A D

    2017-03-31

    The performance of detection methods (culture methods and polymerase chain reaction assay) and plating media used in the same type of samples were determined as well as the specificity of PCR primers to detected Salmonella spp. contamination in layer hen farms. Also, the association of farm characteristics with Salmonella presence was evaluated. Environmental samples (feces, feed, drinking water, air, boot-swabs) and eggs were taken from 40 layer hen houses. Salmonella spp. was most detected in boot-swabs taken around the houses (30% and 35% by isolation and PCR, respectively) follow by fecal samples (15.2% and 13.6% by isolation and PCR, respectively). Eggs, drinking water, and air samples were negative for Salmonella detection. Salmonella Schwarzengrund and S. Enteritidis were the most isolated serotypes. For plating media, relative specificity was 1, and the relative sensitivity was greater for EF-18 agar than XLDT agar in feed and fecal samples. However, relative sensitivity was greater in XLDT agar than EF-18 agar for boot-swab samples. Agreement was between fair to good depending on the sample, and it was good between isolation and PCR (feces and boot-swabs), without agreement for feed samples. Salmonella spp. PCR was positive for all strains, while S. Typhimurium PCR was negative. Salmonella Enteritidis PCR used was not specific. Based in the multiple logistic regression analyses, categorization by counties was significant for Salmonella spp. presence (P-value = 0.010). This study shows the importance of considering different types of samples, plating media and detection methods during a Salmonella spp. monitoring study. In addition, it is important to incorporate the sampling of floors around the layer hen houses to learn if biosecurity measures should be strengthened to minimize the entry and spread of Salmonella in the houses. Also, the performance of some PCR methods and S. Enteritidis PCR should be improved, and biosecurity measures in hen farms must be

  18. Salmonella-secreted Virulence Factors

    Heffron, Fred; Niemann, George; Yoon, Hyunjin; Kidwai, Afshan S.; Brown, Roslyn N.; McDermott, Jason E.; Smith, Richard D.; Adkins, Joshua N.

    2011-05-01

    In this short review we discuss secreted virulence factors of Salmonella, which directly affect Salmonella interaction with its host. Salmonella secretes protein to subvert host defenses but also, as discussed, to reduce virulence thereby permitting the bacteria to persist longer and more successfully disperse. The type III secretion system (TTSS) is the best known and well studied of the mechanisms that enable secretion from the bacterial cytoplasm to the host cell cytoplasm. Other secretion systems include outer membrane vesicles, which are present in all Gram-negative bacteria examined to date, two-partner secretion, and type VI secretion will also be addressed. Excellent reviews of Salmonella secreted effectors have focused on themes such as actin rearrangements, vesicular trafficking, ubiquitination, and the activities of the virulence factors themselves. This short review is based on S. Typhimurium infection of mice because it is a model of typhoid like disease in humans. We have organized effectors in terms of events that happen during the infection cycle and how secreted effectors may be involved.

  19. Salmonella radicidation of poultry carcasses

    Mulder, R.W.A.W.

    1982-01-01

    Validity of methodsExperiments were carried out In which it was assessed which Salmonella isolation method is the most productive one In the examination of broiler carcasses. Refrigerated, refrigerated and radiated (2.50 kGy), frozen and frozen and radiated (2.50 kGy) samples of broile

  20. Cellulitis Due to Salmonella infantis.

    Satish R Patil

    2013-01-01

    Full Text Available Bacteria of the genus Salmonella are highly adapted for the growth in both humans and animals and cause a wide spectrum of disease. The growth of Serotypes S. typhi and S. paratyphi is restricted to human hosts, in whom these organisms cause enteric (typhoid fever. The remaining Serotypes (non typhoidal Salmonella or NTS can colonize the gastrointestinal tracts of the broad range of animals, including mammals, reptiles, birds and insects. The usual clinical presentation of non-typhoidal salmonellae (NTS infection is self limited gastroenteritis; however bacteremia and focal extra intestinal infection may occur. However salmonella localization to the skin presenting as cutaneous ulceration is regarded as a rare event. Rates of morbidity and mortality associated with NTS are highest among the elderly, infants, and immunocompromised individuals, including those with hemoglobinopathies, HIV infection, or infections that cause blockade of the reticuloendothelial system. We isolated S.infantis in 50 years old man with left leg cellulitis. The serotype was confirmed at Central Research Institute, Kasauli.

  1. Salmonella Infection and Water Frogs

    2010-01-12

    This podcast, featuring lead investigator Shauna Mettee, discusses the first known outbreak of Salmonella in people due to contact with water frogs.  Created: 1/12/2010 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 1/12/2010.

  2. Carcinoma do esôfago com invasão do canal medular: relato de caso e revisão da literatura Esophageal carcinoma extending into the spinal canal: case report and review of the literature

    Linei A.B.D. Urban

    2002-06-01

    Full Text Available Os autores apresentam o caso de paciente do sexo masculino, 62 anos de idade, com emagrecimento há quatro meses e diminuição da força muscular associada a parestesias em membros inferiores há dois dias. Foi submetido a mielotomografia, que demonstrou massa no mediastino posterior com destruição dos corpos vertebrais e invasão do canal medular, além de espessamento irregular das paredes do esôfago. Na evolução, foi submetido a estudo contrastado do esôfago, que demonstrou falha de enchimento irregular. A biópsia confirmou a presença de carcinoma de células escamosas. Este é o primeiro relato na literatura latino-americana (Lilacs de carcinoma de esôfago com invasão de canal medular e manifestação inicial de síndrome de compressão medular.The authors report the case of a 62-year-old male with a 4 month history of weight loss and a 2 day complaint of weakness and paresthesia on the lower limbs. A computed tomography myelogram revealed a mass in the posterior mediastinum associated with destruction of the vertebral body, spinal canal extension and irregular esophageal wall thickening. The patient was later submitted to a barium esophagogram that showed an irregular filling defect. A biopsy confirmed the presence of a squamous cell carcinoma. This is the first report in the Latin-American literature (Lilacs of a patient with an esophageal carcinoma with spinal canal extension and spinal cord compression syndrome at initial presentation.

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

    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.

  4. 75 FR 48973 - Draft Guidance for Industry: Prevention of Salmonella

    2010-08-12

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry: Prevention of Salmonella... availability of a draft guidance entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During... ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation''...

  5. Salmonella – A Brief Summary

    Nurmi Esko

    2002-03-01

    Full Text Available Abstract Salmonellosis is the main cause of human bacterial gastroenteritis in most European countries. Infections with Salmonella is usually subclinical, whereas clinical cases show symptoms with a wide range of severity. Infection is most commonly associated with the consumption of meat, especially poultry or pork, and eggs and their products. Salmonella can enter the food chain at any point throughout its length. The principal reservoir of Salmonellae is the gastrointestinal tract of mammals and birds, but Salmonellae are able to survive and even multiply in many external environments. In Norway, Sweden and Finland cost effective prevention methods have been used for several years to prevent and control Salmonellea infections. In addition, competitive exclusion (CE and vaccination might be relevant as biological methods to prevent colonisation of bird intestines by enteropathogens, especially Salmonella. Antibiotic drug resistance has been a problem since the start of the antibiotic era. The cause for anxiety is that more and more bacteria are becoming resistant, often to a whole range of antibiotics. The debate on the use of antimicrobials in veterinary medicine and animal production dates back almost as long as the use itself. There is a clear evidence to show that antibacterial agents given to animals for growth promotion, prophylactic purposes or treatment induce a rise in the number of antibiotic resistant strains isolated from the animals. These bacteria may be transmitted to humans by several possible routes. There are thus strong arguments for preventive efforts which have to be directed towards identifying real critical control points (HACCP throughout the whole food chain, which starts from the farm and ends at the consumer's table.

  6. New Salmonella serotype: Salmonella enteritidis serotype Grandhaven (30(1):r:1,2).

    McDougal, D L; Treleaven, B E; Renshaw, E C

    1982-01-01

    A new Salmonella serotype, Salmonella enteritidis serotype Grandhaven (30(1):r:1,2), was isolated from the stool of a 35-year-old man with mild gastroenteritis. He had just returned from Sudan, Africa.

  7. PIR-B-deficient mice are susceptible to Salmonella infection.

    Torii, Ikuko; Oka, Satoshi; Hotomi, Muneki; Benjamin, William H; Takai, Toshiyuki; Kearney, John F; Briles, David E; Kubagawa, Hiromi

    2008-09-15

    Paired Ig-like receptors of activating (PIR-A) and inhibitory (PIR-B) isoforms are expressed by many hematopoietic cells, including B lymphocytes and myeloid cells. To determine the functional roles of PIR-A and PIR-B in primary bacterial infection, PIR-B-deficient (PIR-B(-/-)) and wild-type (WT) control mice were injected i.v. with an attenuated strain of Salmonella enterica Typhimurium (WB335). PIR-B(-/-) mice were found to be more susceptible to Salmonella infection than WT mice, as evidenced by high mortality rate, high bacterial loads in the liver and spleen, and a failure to clear bacteria from the circulation. Although blood levels of major cytokines and Salmonella-specific Abs were mostly comparable in the two groups of mice, distinct patterns of inflammatory lesions were found in their livers at 7-14 days postinfection: diffuse spreading along the sinusoids in PIR-B(-/-) mice vs nodular restricted localization in WT mice. PIR-B(-/-) mice have more inflammatory cells in the liver but fewer B cells and CD8(+) T cells in the spleen than WT mice at 14 days postinfection. PIR-B(-/-) bone marrow-derived macrophages (BMMphi) failed to control intracellular replication of Salmonella in vitro, in part due to inefficient phagosomal oxidant production, when compared with WT BMMphi. PIR-B(-/-) BMMphi also produced more nitrite and TNF-alpha upon exposure to Salmonella than WT BMMphi did. These findings suggest that the disruption of PIR-A and PIR-B balance affects their regulatory roles in host defense to bacterial infection.

  8. Development of a Multiplex PCR Technique for Detection and Epidemiological Typing of Salmonella in Human Clinical Samples

    Alvarez, Juan; Sota, Mertxe; Vivanco, Ana Belén; Perales, Ildefonso; Cisterna, Ramón; Rementeria, Aitor; Garaizar, Javier

    2004-01-01

    We have developed a multiplex PCR assay for Salmonella detection and epidemiological typing. Six sets of primers were designed to detect the major Salmonella serotypes and phage types in Spain. An internal amplification control was designed in order to detect PCR inhibition. The different amplification profiles obtained allowed us to detect Salmonella bacteria and to distinguish the clinically prevalent Salmonella enterica serotypes Enteritidis, Typhimurium and subspecies I serotype 4,5,12:i:−. Using this method, we could detect a specific band for DT104 and U302 phage types in Salmonella serotype Typhimurium. Salmonella enterica serotype Hadar and other C2 serogroup strains showed two specific band profiles. In the validation stage, the assay was reproducible for all serotypes studied, apart from some C2 serogroup strains. When the technique was applied to clinical stool specimens, the prevalent serotypes Enteritidis and Typhimurium were detected with a sensitivity of 93%, specificity of 100%, and efficiency of 98%. Also, a low PCR inhibition rate (8%) was obtained. The overall agreement of the multiplex PCR with conventional culture-based techniques was 95% for Salmonella typing using Cohen's kappa index. PMID:15071035

  9. CLINICAL AND ANATOMOHISTOPATOLOGICAL ASPECTS OF TWO BROILER ORIGINATED FROM EXPERIMENTALLY INOCULATED EGGS WITH Salmonella Enteritidis FAGOTIPO 4 ASPECTOS CLÍNICOS E ANATOMOHISTOPATOLÓGICOS DE PINTOS DE CORTE ORIUNDOS DE OVOS INOCULADOS EXPERIMENTALMENTE COM Salmonella Enteritidis FAGOTIPO 4

    Maria Auxiliadora Andrade

    2009-09-01

    linhagem ISA Label (crescimento lento. Nos dois experimentos, 1,5 X 102 UFC/0,1mL de Salmonella Enteritidis fagotipo 4 foram inoculadas na casca e no albume de ovos férteis no momento da incubação, para averiguar os sinais clínicos, as lesões macro e microscópicas e a mortalidade até a terceira semana de vida dos pintos. A Salmonella Enteritidis invadiu e colonizou o trato gastrintestinal das duas linhagens determinando alterações clínicas aliadas à disfunção intestinal, as quais foram mais pronunciadas nas aves Ross. A mortalidade observada foi de 25,0% (15/60 na linhagem Ross, e de apenas 1,7% (1/60 nas aves de crescimento lento até 21 dias de idade. Onfalite, enterite, pericardite e peri-hepatite constituíram as principais lesões macroscópicas da linhagem de crescimento rápido. No exame histopatológico observou-se processo inflamatório com infiltrados de células mononucleares com predominância de macrófagos e linfócitos no coração, fígado, duodeno, jejuno, íleo e ceco. Salmonella Enteritidis colonizou o trato gastrintestinal, invadiu os órgãos de ambas as linhagens, porém aves ISA Label foram mais resistentes à infecção do que aves da linhagem Ross.

    PALAVRAS-CHAVES: Colonização intestinal, infecção, invasão, órgãos, resistência genética.

  10. Transcription analysis of TIMP-1 and NM23-h1 genes in glioma cell invasion Análise transcricional dos genes TIMP-1 e NM23-H1 na invasão celular em astrocitoma difuso e glioblastoma multiforme

    José Augusto Nasser

    2006-09-01

    Full Text Available PURPOSE: To evaluate using transcription analysis the presence and importance of two genes: NM23-H1 and TIMP-1 on control of tumor cell invasion in diffuse astrocytomas (WHO II and glioblastoma multiforme (WHO IV. METHOD: Northern blot analysis of NM23-H1 and TIMP-1 was performed. Eight diffuse astrocytomas and 19 glioblastomas (WHO IV were analyzed to determine if TIMP-1 and NM23-H1 were candidates to inhibition of tumor cell invasion quantitated RNA levels. The samples were collected directly from operating room. Total cellular RNA was extracted from frozen tissue samples using guanidinium-isothiocyanate and cesium chloride gradients. Total RNA (10 mg per sample from tumor tissue were size fractionated through 1% agarose-formaldehyde gel and transferred to nylon filters and then hybridized to 32P-labeled DNA probes and placed for autoradiography. Levels of specific RNAs were determined by computer-assisted laser densitometry. Blot filters were sequentially hybridized to nm23 and TIMP-1 probes in addition to GAPDH, as a control. Statistical analyses were carried out according to t-test for equality of means. RESULTS: NM23-H1 were detected in each sample, however it did not correlate with malignancy and invasiveness. On the other side TIMP-1 gene expression showed a clear correlation between low expression and invasiveness. CONCLUSION: The data suggest that TIMP-1 is an inhibitor of high grade gliomas invasion. NM23-H1 was present in the entire gliomas sample, but it did not vary in diffuse astrocytomas and glioblastomas.OBJETIVO: Comparar através da análise da expressão dos níveis de RNA, a presença e a relevância dos genes NM23-H1 e TIMP-1 no controle da invasão celular tumoral dentro do tecido cerebral normal em: astrocitoma difuso (OMS II e glioblastoma multiforme (OMS:IV. MÉTODO: Análise em "Northern blot" dos genes NM23-H1 e TIMP-1. Oito astrocitomas fibrilares difusos (OMS II e 19 glioblastomas multiformes foram analisados para

  11. Minimization of Salmonella contamination on raw poultry.

    Cox, N A; Cason, J A; Richardson, L J

    2011-01-01

    Many reviews have discussed Salmonella in poultry and suggested best practices to minimize this organism on raw poultry meat. Despite years of research and conscientious control efforts by industry and regulatory agencies, human salmonellosis rates have declined only modestly and Salmonella is still found on raw poultry. Expert committees have repeatedly emphasized the importance of controlling risk, but information about Salmonella in poultry is often limited to prevalence, with inadequate information about testing methods or strains of Salmonella that are detected by these methods and no information about any impact on the degree of risk. This review examines some assumptions behind the discussion of Salmonella in poultry: the relationships between sampling and cultural methodology, prevalence and numbers of cells, and the implications of serotype and subtype issues. Minimizing Salmonella contamination of poultry is not likely to reduce human salmonellosis acquired from exposure to contaminated chicken until these issues are confronted more systematically.

  12. Isolation and Evaluation Virulence Factors of Salmonella typhimurium and Salmonella enteritidis in Milk and Dairy Products

    Shima Shaigan nia

    2014-06-01

    Conclusions: To our best knowledge the present study is the first prevalence report of Salmonella spp., Salmonella enteritidis and Salmonella typhimurium in raw sheep and goat samples in Iran. Consumption of pasteurized milk and dairy products can reduce the risk of salmonellosis.

  13. Ninth CRL-Salmonella interlaboratory comparison study on typing of Salmonella spp

    Korver H; Maas HME; Ward LR; Mevius DJ; Wannet WJB; Mooijman KA; MGB; LIS; HPA (London); CIDC

    2005-01-01

    Het negende ringonderzoek voor de typering van Salmonella werd in de lente van 2004 georganiseerd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) in samenwerking met Health Protection Agency (HPA, Londen, Verenigd Koninkrijk) en het Centraal Insti

  14. Ninth CRL-Salmonella interlaboratory comparison study on typing of Salmonella spp

    Korver H; Maas HME; Ward LR; Mevius DJ; Wannet WJB; Mooijman KA; MGB; LIS; HPA (London); CIDC

    2005-01-01

    The ninth interlaboratory comparison study on the typing of Salmonella was organised by the Community Reference Laboratory for Salmonella (CRL-Salmonella, Bilthoven, the Netherlands) in collaboration with the Health Protection Agency (HPA, London, United Kingdom) and the Central Institute for Animal

  15. Protective host immune responses to Salmonella infection

    Pham, Oanh H.; McSorley, Stephen J.

    2015-01-01

    Salmonella enterica serovars Typhi and Paratyphi are the causative agents of human typhoid fever. Current typhoid vaccines are ineffective and are not widely used in endemic areas. Greater understanding of host–pathogen interactions during Salmonella infection should facilitate the development of improved vaccines to combat typhoid and nontyphoidal Salmonellosis. This review will focus on our current understanding of Salmonella pathogenesis and the major host immune components that participat...

  16. Salmonella Typhimurium infection in the porcine intestine

    Schauser, Kirsten; Olsen, John Elmerdahl; Larsson, Lars-Inge

    2005-01-01

    The normal intestinal epithelium is renewed with a turnover rate of 3-5 days. During Salmonella infection increased cell loss is observed, possibly as a result of programmed cell death (PCD). We have, therefore, studied the effects of Salmonella Typhimurium infection on three elements involved...... in scattered epithelial cells and the number of positive cells increased with increasing times of exposure to Salmonella (P

  17. Genetic diversity of Salmonella pathogenicity islands SPI-5 and SPI-6 in Salmonella Newport.

    Cao, Guojie; Allard, Marc; Strain, Errol; Stones, Robert; Zhao, Shaohua; Brown, Eric; Meng, Jianghong

    2014-10-01

    Salmonella enterica subspecies enterica serotype Newport is one of the common serotypes causing foodborne salmonellosis outbreaks in the United States. Salmonella Newport consists of three lineages exhibiting extensive genetic diversity. Due to the importance of Salmonella pathogenicity islands 5 and 6 (SPI-5 and SPI-6) in virulence of pathogenic Salmonella, the genetic diversity of these two SPIs may relate to different potentials of Salmonella Newport pathogenicity. Most Salmonella Newport strains from North America belong to Salmonella Newport lineages II and III. A total 28 Salmonella Newport strains of lineages II and III from diverse sources and geographic locations were analyzed, and 11 additional Salmonella genomes were used as outgroup in phylogenetic analyses. SPI-5 was identified in all Salmonella Newport strains and 146 single nucleotide polymorphisms (SNPs) were detected. Thirty-nine lineage-defining SNPs were identified, including 18 nonsynonymous SNPs. Two 40-kb genomic islands (SPI5-GI1 and SPI5-GI2) encoding bacteriophage genes were found between tRNA-ser and pipA. SPI5-GI1 was only present in Salmonella Newport multidrug-resistant strains of lineage II. SPI-6 was found in all strains but three Asian strains in Salmonella Newport lineage II, whereas the three Asian strains carried genomic island SPI6-GI1 at the same locus as SPI-6 in other Salmonella. SPI-6 exhibited 937 SNPs, and phylogenetic analysis demonstrated that clustering of Salmonella Newport isolates was a reflection of their geographic origins. The sequence diversity within SPI-5 and SPI-6 suggests possible recombination events and different virulence potentials of Salmonella Newport. The SNPs could be used as biomarkers during epidemiological investigations.

  18. Application of a novel biopolymer for removal of Salmonella from poultry wastewater.

    Ghosh, Moushumi; Ganguli, Abhijit; Pathak, Santosh

    2009-04-01

    This study evaluated the potential of an extracellular, novel biopolymeric flocculant produced by a strain of Klebsiella terrigena for removal of Salmonella, a potent pathogen prevalent in poultry wastewater. The purified biopolymer was applied to poultry wastewater containing 3 log CFU cells of Salmonella. An optimized dosage of 2 mg L(-1) of the purified bioflocculant was sufficient to remove 80.3% Salmonella spp. within 30 min, at ambient temperature. Also this bioflocculant showed high flocculating activity (90%) against kaolin particles and proved to be far more effective than the other synthetic flocculants used in this study. Fluorescent in situ hybridization (FISH) with the genus specific Sal3 probe hybridized with the Salmonella present in the agglomerated matrix of the bioflocculant. Confocal laser scanning micrographs (CLSM) allowed a clear visualization of the spatial distribution of the total flocculated bacterial population (with DAPI and Eub338 probe) as well as Salmonella (with the Sal3 probe), indicating that the removed Salmonella remained bound and embedded within the flocculant matrix. Scanning electron microscopic (SEM) analysis exhibited a porous surface morphology. The bioflocculant was characterized to be a polysaccharide by FTIR, HPLC, CHN and chemical analysis. A viable alternative treatment technology of poultry wastewater using this novel bioflocculant is suggested.

  19. Salmonella overcomes tumor immune tolerance by inhibition of tumor indoleamine 2, 3-dioxygenase 1 expression.

    Kuan, Yu-Diao; Lee, Che-Hsin

    2016-01-05

    Over the past decades, Salmonella has been proven capable of inhibiting tumor growth. It can specifically target tumors and due to its facultative anaerobic property, can be more penetrative than other drug therapies. However, the molecular mechanism by which Salmonella inhibits tumor growth is still incompletely known. The antitumor therapeutic effect mediated by Salmonella is associated with an inflammatory immune response at the tumor site and a T cell-dependent immune response. Many tumors have been proven to have a high expression of indoleamine 2, 3-dioxygenase 1 (IDO), which is a rate-limiting enzyme that catalyzes tryptophan to kynurenine, thus causing immune tolerance within the tumor microenvironment. With decreased expression of IDO, increased immune response can be observed, which might be helpful when developing cancer immunotherapy. The expression of IDO was decreased after tumor cells were infected with Salmonella. In addition, Western blot analysis showed that the expression levels of phospho-protein kinase B (P-AKT), phospho-mammalian targets of rapamycin (P-mTOR), and phospho-p70 ribosomal s6 kinase (P-p70s6K) in tumor cells were decreased after Salmonella infection. In conclusion, our results indicate that Salmonella inhibits IDO expression and plays a crucial role in anti-tumor therapy, which might be a promising strategy combined with other cancer treatments.

  20. Multidrug-Resistant Salmonella Isolates from Swine in the Eastern Cape Province, South Africa.

    Iwu, Chinwe Juliana; Iweriebor, Benson Chuks; Obi, Larry Chikwelu; Basson, Albertus Kotze; Okoh, Anthony Ifeanyi

    2016-07-01

    The exposure of farm animals to antimicrobials for treatment, prophylaxis, or growth promotion can select for resistant bacteria that can be transmitted to humans, and Salmonella as an important zoonotic pathogen can act as a potential reservoir of antimicrobial resistance determinants. We assessed the antibiogram profiles of Salmonella species isolated from pig herds in two commercial farms in South Africa. Two hundred fifty-eight presumptive Salmonella isolates were recovered from the fecal samples of 500 adult pigs. Specific primers targeting Salmonella serogroups A, B, C1, C2, and D were used to determine the prevalence of different serogroups. Only serogroup A (n = 48) was detected, while others were not. Antimicrobial susceptibility of the confirmed Salmonella serogroup A isolates was performed by using the disk diffusion method against a panel of 18 antibiotics. All the 48 isolates were resistant to tetracycline and oxytetracycline, while 75% were resistant to ampicillin, sulphamethoxazole-trimethoprim, nalidixic acid, and streptomycin. All the isolates exhibited multidrug resistance, with the predominant phenotype being against 11 antibiotics, and multiple antibiotic resistance index ranged between 0.3 and 0.6. The incidence of genes encoding resistance against ampicillin (ampC), tetracycline (tetA), and streptomycin (strA) were 54, 61, and 44%, respectively. We conclude that healthy pigs are potential reservoirs of multidrug-resistant Salmonella that could be transmitted to humans through the food chain and, hence, a significant public health threat.

  1. The Role of Biofilms and Curli in Salmonella Transport Through Porous Media

    Salvucci, A. E.; Zhang, W.; Morales, V. L.; Cakmak, M. E.; Hay, A. G.; Steenhuis, T. S.

    2008-12-01

    Microbial pathogens, such as Salmonella and E. coli, are continually deposited in the environment and have been shown to contaminate the groundwater by leaching through the vadose zone. Therefore, understanding the mechanisms controlling the transport of these microbial pathogens through porous media is critical to protecting drinking water supplies. As previous research has shown, retention of microbial pathogens in porous media can be influenced by numerous biological factors. Consequently, this experiment specifically investigated the role of biofilm formation and curli production on the transport of environmental Salmonella through porous media. Environmental Salmonella strains used in the experiment were isolated from tile drains on dairy farms. In addition, two well-characterized E. coli strains with known high and low biofilm and curli producing capabilities were tested as controls alongside the Salmonella isolates throughout the experiment. The isolates were first assayed for their ability to form biofilms and produce curli, and then a subset of these isolates, representing range of high and low biofilm and curli formation capabilities, were simultaneously examined for transport characteristics through packed sand columns. Transport characteristics were tested for correlation with biofilm and curli-forming capabilities. Unlike the E. coli strains in which column retention correlated with biofilm formation and curli production, no obvious correlation between Salmonella phenotypes was observed. The results indicate that while transport of well-characterized laboratory E. coli strains can often be hindered by the presence of curli and biofilms, such assumptions are not fully representative of the behavior exhibited by environmental isolates of Salmonella.

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

    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.

  3. Blood heat shock proteins evoked by some Salmonella strains infection in ducks.

    Osman, Kamelia; Ibrahim, Ihab; Yousef, Ashgan; Nabil, Tanios; Nayerah, Alatfeehy

    2012-05-01

    Bacterial heat-shock response is a global regulatory system required for effective adaptation to changes (stress) in the environment. An in vitro study was conducted to investigate the impact of a sublethal temperature (42°C) on heat shock protein (HSP) expression in 6 Salmonella strains (Salmonella Enteritidis, S. Typhimurium, S. Virchow, S. Shubra, S. Haifa and S. Eingedi). The 6 Salmonella strains were isolated from the tissues of ducklings that had died from avian salmonellosis. To determine the induction of HSP in the 6 Salmonella strains, they were exposed to the selected temperature level for 24 h and further kept for 48 h at culturing condition of 42°C. Growth under a sublethal temperature of 42°C increased the expression of several proteins of Salmonella, including a 63 kDa protein in addition to the generation and/or overexpression of 143 proteins which were specific to heat shock, concurrent to this acquired thermotolerance. The 6 Salmonella strains responded to 24 h of thermal stress at an elevated temperature 42°C by synthesizing different heat shock proteins (HSP) with molecular weights ranging between 13.62 and 96.61 kDa. At 48 h, the 6 Salmonella strains synthesized different HSPs with molecular weights ranging between 14.53 and 103.43 kDa. It follows that salmonellae would produce HSPs during the course of the infectious process. Salmonellosis produced several proteins after 24 and 48 h of infection. Seven of these proteins (100, 80, 60, 40, 30, 20 and 10 kDa) were recognized in the serum obtained from the ducklings infected with S. Enteritidis, S. Typhimurium, S. Virchow, S. Shubra, S. Haifa and S. Eingedi after 24 h of infection. After 48 h, the 1-7 kDa HSP became more evident and indicated their de novo generation.

  4. Prevalence and characterization of multi-drug resistant Salmonella Enterica serovar Gallinarum biovar Pullorum and Gallinarum from chicken

    Md. Shafiullah Parvej

    2016-01-01

    Full Text Available Aim: Salmonella is an important zoonotic pathogen responsible for animal and human diseases. The aim of the present study was to determine the prevalence and stereotyping of Salmonella isolates isolated from apparently healthy poultry. Furthermore, the clonal relatedness among the isolated Salmonella serovars was assessed. Materials and Methods: A total of 150 cloacal swab samples from apparently healthy chickens were collected, and were subjected for the isolation and identification of associated Salmonella organisms. The isolated colonies were identified and characterized on the basis of morphology, cultural characters, biochemical tests, slide agglutination test, polymerase chain reaction, and pulsed-field gel electrophoresis (PFGE. Antibiotic sensitivity patterns were also investigated using commonly used antibiotics. Results: Of the 150 samples, 11 (7.33% produced characteristics pink colony with black center on XLD agar medium, and all were culturally and biochemically confirmed to be Salmonella. All possessed serovar-specific gene SpeF and reacted uniformly with group D antisera, suggesting that all of the isolates were Salmonella Enterica serovar Gallinarum, biovar Pullorum and/or Gallinarum. Antimicrobial susceptibility testing revealed that 54.54% of the isolated Salmonella Enterica serovars were highly sensitive to ciprofloxacin, whereas the 81.81% isolates were resistant to amoxycillin, doxycycline, kanamycin, gentamycin, and tetracycline. Pulsed-field gel electrophoresis of the XbaI-digested genomic DNA exhibited identical banding patterns, suggesting that the multidrug resistant Salmonella Enterica serovars occurring in commercial layers are highly clonal in Bangladesh. Conclusion: The present study was conducted to find out the prevalence of poultry Salmonella in layer chicken and to find out the clonal relationship among them. The data in this study suggest the prevalence of Salmonella Enterica, which is multidrug resistant and

  5. Sensitivity and specificity of leukocyte count in feces as a predictor of stool culture positivity for S amonella or Shigella Sensibilidad y especificidad del recuento de leucocitos en las materias fecales para predecir la presencia de Salmonella o Shigella en pacientes con enfermedad diarreica aguda

    John Jairo Zuleta Tobón

    2008-01-01

    Full Text Available

    In most studies of fecal leukocyte counts as predictors of the result of stool cultures the sensitivity and specificity were not determined.

    Objective: to evaluate fecal leukocyte counts as a predictor of the presence of Salmonella and Shigella.

    Design: a descriptive, cross section study was carried out in 905 stool cultures at a university hospital in Medellín, Colombia. Results for Salmonella and Shigella were taken as the gold standard to evaluate the sensitivity and specificity of fecal leukocyte counts.

    Results: sensitivity and specificity, according to the level of the count, were, respectively: 1-5 leukocytes: 89.2% and 57.1%; 6-10 leukocytes: 86.2% and 52.8%;11-20 leukocytes: 77.7% and 62.7%; 21-30 leukocytes: 63.9% and 76.3%; 31-50 leukocytes: 45.2% and 85.5%; more than 50 leukocytes: 28.3% and 90.9%. The area under the curve was 0.7699 (CI 95%: 0.7275-0.8123.

    Conclusions: Diversity and antimicrobial susceptibility of Salmonella enterica serovars isolated from pig farms in Ibadan, Nigeria

    Fashae, Kayode; Hendriksen, Rene S.

    2014-01-01

    reaction. The 229 Salmonella isolates were made of 50 serovars predominated by rare serovars Salmonella Give (n = 36; 15.7 %), Salmonella Brancaster (n = 17; 7.4 %), Salmonella Colindale (n = 15; 6.6 %), Salmonella Elisaberthville (n = 13; 5.7 %), Salmonella Hillingdon (n = 13; 5.7 %), and Salmonella...

  6. [Breast abscess with Salmonella typhi and review of the literature].

    Delori, M; Abgueguen, P; Chennebault, J-M; Pichard, E; Fanello, S

    2007-11-01

    We report the case of a 54-year-old woman who presented with breast abscess, which appeared through a common alimentary toxi-infection with Salmonella Typhi, infection, which implied twelve patients having attended the same restaurant. With around hundred native cases a year in France, typhoid fever is not a very frequent toxi-infection. Among the known extra-intestinal manifestations of Salmonella infections, the breast abscess remains rare and the literature revealed less than ten published cases, including some revealed the disease. In our observation, the imputability of S. Typhi was retained based on the chronology of the clinical signs, specific treatments, and the successful outcome under antibiotherapy, in spite of the negativity of the breast abscess bacteriological samples. We also analyze rare cases of breast abscess due to S. Typhi found in the literature.

  7. FAKTOR VIRULENSI Salmonella enterica SEROVAR TYPHI

    Marvy Khrisna Pranamartha

    2015-09-01

    Full Text Available ABSTRAK Demam tifoid disebabkan oleh bakteri Salmonella typhi, dengan gejala umum berupa demam tinggi dan nyeri perut. Tifoid adalah penyakit infeksi yang disebabkan oleh bakteri Salmonella typhi, yang masuk ke dalam tubuh melalui mulut dan saluran cerna.1 Untuk bisa memahami patogenesis dari demam tifoid sampai ke tingkat selular dan molekular, ada 5 hal penting yang harus digaris bawahi, yaitu: 1.\tTipe 3 Sistem Sekresi (T3SS 2.\tVirulence Genes dari Salmonella yang mengkode 5 SIP (Salmonella Invasion Protein SIP A, B, C, D, dan E. 3.\tToll R2 dan toll R3 yang merupakan lapisan luar dari makrofag. 4.\tSistem imun lumen usus sampai ke organ dalam 5.\tFungsi endotelial sel dalam inflamasi. Infeksi Salmonella dapat berakibat fatal kepada bayi, balita, ibu hamil dan kandungannya serta orang lanjut usia. Hal ini disebabkan karena kekebalan tubuh mereka yang menurun. Virulensi salmonella tidak lepas dari peranan SPI, yang terletak di dalam kromosom dan plasmid bakteri. Dimana SPI 1 dan SPI 2 telah dikaji cukup mendalam karena keterkaitannya dengan T3SS, dan berperan sangat penting pada invasi awal serta siklus hidup intrasel dari bakteri Salmonella. Kontaminasi Salmonella dapat dicegah dengan mencuci tangan dan menjaga kebersihan makanan yang dikonsumsi. Selalu menjaga kebersihan lingkungan hidup kita agar terhindar dari kontaminasi dengan bakteri Salmonella typhi. Agar mewaspadai sejak dini pencegahan dan pengobatan penyakit typhus. Studi mendalam perlu dilakukan agar kita mampu lebih memahami proses kompleks antara patogen dan sel inang. Mengingat dari 15 SPI yang sudah diketahui, hanya SPI 1 dan SPI 2 yang sudah dikaji secara mendalam. Kata Kunci: Salmonella, Salmonella Invasion Protein, Typhi.

  8. The incidence of Salmonella in random-source cats purchased for use in research.

    Fox, J G; Beaucage, C M

    1979-03-01

    In research facilities, cats are routinely ignored as a potential source of salmonella infection. Over a period of 18 months, 142 cats received from commercial vendors for use in research were screened for enteric Salmonella. Salmonella was isolated from 15 animals, an incidence of 10.6%. Five (29%) of the 17 shipments contained animals that were positive for Salmonella. The serotypes isolated were Salmonella derby, Salmonella typhimurium, Salmonella anatum, Salmonella enteritidis, and Salmonella bredeney.

  9. Antimicrobial susceptibility of Salmonella Gallinarum and Salmonella Pullorum isolated from ill poultry in Brazil

    Rafael Antonio Casarin Penha Filho

    2016-03-01

    Full Text Available ABSTRACT: Salmonella Gallinarum (S. Gallinarum and Salmonella Pullorum (S. Pullorum are poultry host-specific, agents of fowl typhoid and pullorum disease, respectively. These biovars cause septicemic infections, resulting in high mortality. Outbreaks are frequently reported worldwide, causing losses due to the elimination of infected flocks and treatments. The use of antimicrobial agents is frequent in poultry farms to prevent or treat gastrointestinal infections. In the present research it was evaluated the antimicrobial susceptibility of 50 S. Gallinarum and S. Pullorum isolates, from outbreaks that occurred between 1987 to 1991 and 2006 to 2013. The comparison of the susceptibility profiles showed that all isolates were susceptible to β-lactams. All isolates from 1987-1991 were susceptible to all antibiotics tested except NAL and CIP (78%. The susceptibility profile of S. Gallinarum (2006 - 2013 period was the following NAL (58%, CIP (63%, ENR (67%, TET (92%, FFC (96% and SXT (96%. S. Pullorum isolates (2006 - 2013 period showed the following susceptibility rates to NAL (65%, CIP (71%, ENR (94% and TET (94%. All isolates were susceptible to β-lactams tested, however, resistance to quinolones and fluoroquinolones increased over time. Furthermore, low levels of resistance to other antibiotics were found in recent isolates, such as tetracyclines.

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

    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.

  11. Salmonella Typhi and Salmonella Paratyphi A elaborate distinct systemic metabolite signatures during enteric fever.

    Näsström, Elin; Vu Thieu, Nga Tran; Dongol, Sabina; Karkey, Abhilasha; Voong Vinh, Phat; Ha Thanh, Tuyen; Johansson, Anders; Arjyal, Amit; Thwaites, Guy; Dolecek, Christiane; Basnyat, Buddha; Baker, Stephen; Antti, Henrik

    2014-06-05

    The host-pathogen interactions induced by Salmonella Typhi and Salmonella Paratyphi A during enteric fever are poorly understood. This knowledge gap, and the human restricted nature of these bacteria, limit our understanding of the disease and impede the development of new diagnostic approaches. To investigate metabolite signals associated with enteric fever we performed two dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC/TOFMS) on plasma from patients with S. Typhi and S. Paratyphi A infections and asymptomatic controls, identifying 695 individual metabolite peaks. Applying supervised pattern recognition, we found highly significant and reproducible metabolite profiles separating S. Typhi cases, S. Paratyphi A cases, and controls, calculating that a combination of six metabolites could accurately define the etiological agent. For the first time we show that reproducible and serovar specific systemic biomarkers can be detected during enteric fever. Our work defines several biologically plausible metabolites that can be used to detect enteric fever, and unlocks the potential of this method in diagnosing other systemic bacterial infections.

  12. Salmonella fecal shedding and immune responses are dose- and serotype- dependent in pigs.

    Renata Ivanek

    Full Text Available Despite the public health importance of Salmonella infection in pigs, little is known about the associated dynamics of fecal shedding and immunity. In this study, we investigated the transitions of pigs through the states of Salmonella fecal shedding and immune response post-Salmonella inoculation as affected by the challenge dose and serotype. Continuous-time multistate Markov models were developed using published experimental data. The model for shedding had four transient states, of which two were shedding (continuous and intermittent shedding and two non-shedding (latency and intermittent non-shedding, and one absorbing state representing permanent cessation of shedding. The immune response model had two transient states representing responses below and above the seroconversion level. The effects of two doses [low (0.65×10(6 CFU/pig and high (0.65×10(9 CFU/pig] and four serotypes (Salmonella Yoruba, Salmonella Cubana, Salmonella Typhimurium, and Salmonella Derby on the models' transition intensities were evaluated using a proportional intensities model. Results indicated statistically significant effects of the challenge dose and serotype on the dynamics of shedding and immune response. The time spent in the specific states was also estimated. Continuous shedding was on average 10-26 days longer, while intermittent non-shedding was 2-4 days shorter, in pigs challenged with the high compared to low dose. Interestingly, among pigs challenged with the high dose, the continuous and intermittent shedding states were on average up to 10-17 and 3-4 days longer, respectively, in pigs infected with S. Cubana compared to the other three serotypes. Pigs challenged with the high dose of S. Typhimurium or S. Derby seroconverted on average up to 8-11 days faster compared to the low dose. These findings highlight that Salmonella fecal shedding and immune response following Salmonella challenge are dose- and serotype-dependent and that the detection of

  13. Short communication: Determination of Salmonella clustered regularly interspaced short palindromic repeats (CRISPR) diversity on dairy farms in Wisconsin and Minnesota.

    Wehnes, C A; Rehberger, T G; Barrangou, R; Smith, A H

    2014-10-01

    Salmonella enterica ssp. enterica is a foodborne pathogen able to cause disease in both humans and animals. Diverse serovars of this pathogen exist, some of which are host specific, causing a range of clinical symptoms from asymptomatic infection through morbidity and mortality. According to a 2007 survey by the USDA National Animal Health Monitoring System, fecal shedding of Salmonella from healthy cows occurs on 39.7% of dairy farms in the United States. Certain serovars are frequently isolated from dairy farms and the majority of isolates from the National Animal Health Monitoring System study were represented by 5 serovars; however, genotypic diversity was not examined. The objective of this study was to determine the diversity of clustered regularly interspaced short palindromic repeats (CRISPR) loci in Salmonella collected from 8 dairy farms with a previous history of salmonellosis. None of the cows or calves sampled on 2 of the 8 dairy farms were shedding Salmonella, although Salmonella was detected in a cow bedding sample on 1 of these farms. Salmonella populations were discrete on each farm, according to CRISPR typing, with the exception of an Anatum var. 15+ type on farms 5 and 6 and the Montevideo type on farms 1 and 2. One to 4 distinct CRISPR genotypes were identified per farm. The CRISPR typing differed within serovars, as Montevideo, Anatum var. 15+, and Muenster serovars had no overlap of spacer content, even on the same farm, reflecting between- and within-serovar genetic diversity. The dynamic nature of Salmonella populations was shown in a farm that was sampled longitudinally over 13.5 mo. Changes in serovar from 3,19:-:z27 to Montevideo was observed between the first sampling time and 8 mo later, with concomitant change in CRISPR alleles. The results indicate that Salmonella strains present in smaller dairy herds (<500 head) are specific to that farm and new Salmonella strains may emerge over time.

  14. Direct PCR - A rapid method for multiplexed detection of different serotypes of Salmonella in enriched pork meat samples

    Chin, Wai Hoe; Sun, Yi; Høgberg, Jonas

    2017-01-01

    Salmonellosis, an infectious disease caused by Salmonella spp., is one of the most common foodborne diseases. Isolation and identification of Salmonella by conventional bacterial culture method is time consuming. In response to the demand for rapid on line or at site detection of pathogens...... of newly designed primers targeting Salmonella spp. at subtype level were incorporated in the multiplex Direct PCR. To maximize the efficiency of the Direct PCR, the ratio between sample and dilution buffer was optimized. The sensitivity and specificity of the multiplex Direct PCR were tested using...... naturally contaminated pork meat samples for detecting and subtyping of Salmonella spp. Conventional bacterial culture methods were used as reference to evaluate the performance of the multiplex Direct PCR. Relative accuracy, sensitivity and specificity of 98.8%; 97.6% and 100%, respectively, were achieved...

  15. Adaptation to bile in salmonella enterica

    Hernández Piñero, Sara Belén

    2013-01-01

    Las bacterias pertenecientes al género Salmonella son patógenos Gramnegativos capaces de infectar una gran variedad de animales. En humanos, la infección por Salmonella suele comenzar con la ingestión de agua o alimentos contaminados, y puede dar lugar a

  16. Anaerobiosis induced virulence of Salmonella typhi

    Kapoor, Sarika; Singh, R D; Sharma, P C

    2002-01-01

    , we examined the effect of anaerobiosis on the virulence of Salmonella Typhi, a Gram negative bacteria which invades through the gut mucosa and is responsible for typhoid fever. METHODS: Salmonella Typhi (ty2) was cultured in aerobic and anaerobic conditions to compare its virulence by rabbit ileal...

  17. 9 CFR 113.122 - Salmonella Choleraesuis Bacterin.

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Salmonella Choleraesuis Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.122 Salmonella Choleraesuis Bacterin. Salmonella Choleraesuis Bacterin shall be prepared from a culture of Salmonella choleraesuis which has been inactivated and...

  18. 9 CFR 113.120 - Salmonella Typhimurium Bacterin.

    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...

  19. 9 CFR 113.123 - Salmonella Dublin Bacterin.

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Salmonella Dublin Bacterin. 113.123... Inactivated Bacterial Products § 113.123 Salmonella Dublin Bacterin. Salmonella Dublin Bacterin shall be prepared from a culture of Salmonella dublin which has been inactivated and is nontoxic. Each serial...

  1. Salmonella - at home in the host cell.

    Preeti eMalik Kale

    2011-06-01

    Full Text Available The Gram-negative bacterium Salmonella enterica has developed an array of sophisticated tools to manipulate the host cell and establish an intracellular niche, for successful propagation as a facultative intracellular pathogen. While Salmonella exerts diverse effects on its host cell, only the cell biology of the classic trigger-mediated invasion process and the subsequent development of the Salmonella-containing vacuole have been investigated extensively. These processes are dependent on cohorts of effector proteins translocated into host cells by two type III secretion systems (T3SS, although T3SS-independent mechanisms of entry may be important for invasion of certain host cell-types. Recent studies into the intracellular lifestyle of Salmonella have provided new insights into the mechanisms used by this pathogen to modulate its intracellular environment. Here we discuss current knowledge of Salmonella-host interactions including invasion and establishment of an intracellular niche within the host.

  2. Interaction between Salmonella and Schistosomiasis: A Review

    Hsiao, Amber; Toy, Trevor; Marks, Florian

    2016-01-01

    The interaction between schistosomiasis and Salmonella is a particularly important issue in Africa, where dual infection by the parasite and the bacterium are likely common. In this review, the ways in which schistosomiasis affects human biology as it relates to Salmonella are described. Those who are infected by both organisms experience reduced immunological functioning, exhibit irreversible organ damage due to prolonged schistosomiasis infection, and become latent carriers of Salmonella enterica serotypes Typhi and Paratyphi and S. Typhimurium. The sequestration of the bacteria in the parasite leads to ineffective antibiotic treatment because the bacteria cannot be completely killed, and lingering infection may then lead to antimicrobial resistance. These manifestations are likely not just for those dually infected but also for those first infected with schistosomes and, later, Salmonella. More data are needed to better understand dual infection, particularly as it may impact treatment and prevention of schistosomiasis and Salmonella in sub-Saharan Africa. PMID:27907208

  3. Pathogenesis of Salmonella-induced enteritis

    R.L. Santos

    2003-01-01

    Full Text Available Infections with Salmonella serotypes are a major cause of food-borne diseases worldwide. Animal models other than the mouse have been employed for the study of nontyphoidal Salmonella infections because the murine model is not suitable for the study of Salmonella-induced diarrhea. The microbe has developed mechanisms to exploit the host cell machinery to its own purpose. Bacterial proteins delivered directly into the host cell cytosol cause cytoskeletal changes and interfere with host cell signaling pathways, which ultimately enhance disease manifestation. Recently, marked advances have been made in our understanding of the molecular interactions between Salmonella serotypes and their hosts. Here, we discuss the molecular basis of the pathogenesis of Salmonella-induced enteritis.

  4. Interactions of Salmonella with animals and plants

    Wiedemann, Agnès; Virlogeux-Payant, Isabelle; Chaussé, Anne-Marie; Schikora, Adam; Velge, Philippe

    2015-01-01

    Salmonella enterica species are Gram-negative bacteria, which are responsible for a wide range of food- and water-borne diseases in both humans and animals, thereby posing a major threat to public health. Recently, there has been an increasing number of reports, linking Salmonella contaminated raw vegetables and fruits with food poisoning. Many studies have shown that an essential feature of the pathogenicity of Salmonella is its capacity to cross a number of barriers requiring invasion of a large variety of cells and that the extent of internalization may be influenced by numerous factors. However, it is poorly understood how Salmonella successfully infects hosts as diversified as animals or plants. The aim of this review is to describe the different stages required for Salmonella interaction with its hosts: (i) attachment to host surfaces; (ii) entry processes; (iii) multiplication; (iv) suppression of host defense mechanisms; and to point out similarities and differences between animal and plant infections. PMID:25653644

  5. Significance of salmonella in pork production chain

    Karabasil Neđeljko

    2008-01-01

    Full Text Available Animals, feed, meat and meat products are often transported across long distances, being an important part of international trade, which enables a dissemination of salmonella, including even of some resistant strains. Pigs are animals which are difficult to manipulate because of their temperament, build, sharp teeth, irritability, good sense of smell, bad sight and their sensitivity to stress. Animals coming from different farms should be separated in stock yards to prevent both contamination with pathogens such as salmonella and their irritation and aggressiveness caused by contacts with other pigs. These animals are usually a significant reservoir of salmonella which are 'inside' the gastrointestinal tract and gut associated lymph tissue. In contrast to our country, in the EU, even countries which have always had low salmonella prevalence, e.g. Finland, have a control program. The program has to be based on a guarantee that all relevant factors will participate in the prevention of salmonella contamination.

  6. Protective effect of probiotics on Salmonella infectivity assessed with combined in vitro gut fermentation-cellular models

    Zihler Annina

    2011-12-01

    epithelial integrity compared to previous E. coli L1000 periods, as reflected by a significant mean increase of TER by 58% in all reactors. Inulin addition enhanced Salmonella growth and invasion when tested with distal and proximal reactor samples, respectively, but induced a limited decrease of TER (minus 18% in all reactors. Conclusions Our results highlight the benefits of combining suitable cellular and colonic fermentation models to assess strain-specific first-level host protection properties of probiotics during Salmonella infection, providing an efficient system biology tool for preclinical development of new antimicrobials.

  7. AOAC Official MethodSM Matrix Extension Validation Study of Assurance GDSTM for the Detection of Salmonella in Selected Spices.

    Feldsine, Philip; Kaur, Mandeep; Shah, Khyati; Immerman, Amy; Jucker, Markus; Lienau, Andrew

    2015-01-01

    Assurance GDSTM for Salmonella Tq has been validated according to the AOAC INTERNATIONAL Methods Committee Guidelines for Validation of Microbiological Methods for Food and Environmental Surfaces for the detection of selected foods and environmental surfaces (Official Method of AnalysisSM 2009.03, Performance Tested MethodSM No. 050602). The method also completed AFNOR validation (following the ISO 16140 standard) compared to the reference method EN ISO 6579. For AFNOR, GDS was given a scope covering all human food, animal feed stuff, and environmental surfaces (Certificate No. TRA02/12-01/09). Results showed that Assurance GDS for Salmonella (GDS) has high sensitivity and is equivalent to the reference culture methods for the detection of motile and non-motile Salmonella. As part of the aforementioned validations, inclusivity and exclusivity studies, stability, and ruggedness studies were also conducted. Assurance GDS has 100% inclusivity and exclusivity among the 100 Salmonella serovars and 35 non-Salmonella organisms analyzed. To add to the scope of the Assurance GDS for Salmonella method, a matrix extension study was conducted, following the AOAC guidelines, to validate the application of the method for selected spices, specifically curry powder, cumin powder, and chili powder, for the detection of Salmonella.

  8. Ultra-fast and sensitive detection of non-typhoidal Salmonella using microwave-accelerated metal-enhanced fluorescence ("MAMEF".

    Sharon M Tennant

    Full Text Available Certain serovars of Salmonella enterica subsp. enterica cause invasive disease (e.g., enteric fever, bacteremia, septicemia, meningitis, etc. in humans and constitute a global public health problem. A rapid, sensitive diagnostic test is needed to allow prompt initiation of therapy in individual patients and for measuring disease burden at the population level. An innovative and promising new rapid diagnostic technique is microwave-accelerated metal-enhanced fluorescence (MAMEF. We have adapted this assay platform to detect the chromosomal oriC locus common to all Salmonella enterica subsp. enterica serovars. We have shown efficient lysis of biologically relevant concentrations of Salmonella spp. suspended in bacteriological media using microwave-induced lysis. Following lysis and DNA release, as little as 1 CFU of Salmonella in 1 ml of medium can be detected in <30 seconds. Furthermore the assay is sensitive and specific: it can detect oriC from Salmonella serovars Typhi, Paratyphi A, Paratyphi B, Paratyphi C, Typhimurium, Enteritidis and Choleraesuis but does not detect Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, Haemophilus influenzae or Acinetobacter baumanii. We have also performed preliminary experiments using a synthetic Salmonella oriC oligonucleotide suspended in whole human blood and observed rapid detection when the sample was diluted 1:1 with PBS. These pre-clinical data encourage progress to the next step to detect Salmonella in blood (and other ordinarily sterile, clinically relevant body fluids.

  9. Salmonella enterica Typhimurium infection causes metabolic changes in chicken muscle involving AMPK, fatty acid and insulin/mTOR signaling

    Arsenault, Ryan J.; Napper, Scott; Kogut, Michael H.

    2013-01-01

    Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) infection of chickens that are more than a few days old results in asymptomatic cecal colonization with persistent shedding of bacteria. We hypothesized that while the bacterium colonizes and persists locally in the cecum it has systemic effects, including changes to metabolic pathways of skeletal muscle, influencing the physiology of the avian host. Using species-specific peptide arrays to perform kinome analysis on metabolic s...

  10. Factors influencing phagocytosis of Salmonella typhimurium by macrophages in murine schistosomiasis

    Muniz-Junqueira Maria Imaculada

    1997-01-01

    Full Text Available We investigated the influence of Salmonella typhimurium load and specific antibodies on phagocytosis in schistosomiasis. Macrophages from Schistosoma mansoni-infected mice showed depressed capacity to increase the phagocytosis in the presence of a high bacterial load, due to a reduced involvement of these cells in phagocytosis and to a deficient ability to increase the number of phagocytosed bacteria. Normal and Salmonella-infected mice increased their phagocytic capacity when exposed to a high bacterial load. Antibody to Salmonella increased the phagocytic capacity of macrophages from Schistosoma-infected mice due to an increase in the number of bacteria phagocytosed but caused no modification in the number of macrophages engaged in phagocytosis. Our data indicate that macrophages from Schistosoma-infected mice work close to their functional limit, since no increase in phagocytosis was observed after increasing the bacterial load. Specific antibodies can improve their phagocytic capacity and, therefore, could help clearing concurrent infection.

  11. Multiplex PCR-Based Serogrouping and Serotyping of Salmonella enterica from Tonsil and Jejunum with Jejunal Lymph Nodes of Slaughtered Swine in Metro Manila, Philippines.

    Ng, Kamela Charmaine S; Rivera, Windell L

    2015-05-01

    Food poisoning outbreaks and livestock mortalities caused by Salmonella enterica are widespread in the Philippines, with hogs being the most commonly recognized carriers of the pathogen. To prevent and control the occurrence of S. enterica infection in the country, methods were used in this study to isolate and rapidly detect, differentiate, and characterize S. enterica in tonsils and jejuna with jejunal lymph nodes of swine slaughtered in four locally registered meat establishments (LRMEs) and four meat establishments accredited by the National Meat Inspection Services in Metro Manila. A total of 480 samples were collected from 240 animals (120 pigs from each type of meat establishment). A significantly higher proportion of pigs were positive for S. enterica in LRMEs (60 of 120) compared with meat establishments accredited by the National Meat Inspection Services (38 of 120). More S. enterica-positive samples were found in tonsils compared with jejuna with jejunal lymph nodes in LRMEs, but this difference was not significant. A PCR assay targeting the invA gene had sensitivity that was statistically similar to that of the culture method, detecting 93 of 98 culture-confirmed samples. Multiplex PCR-based O-serogrouping and H/Sdf I typing revealed four S. enterica serogroups (B, C1, D, and E) and six serotypes (Agona, Choleraesuis, Enteritidis, Heidelberg, Typhimurium, and Weltevreden), respectively, which was confirmed by DNA sequencing of the PCR products. This study was the first to report detection of S. enterica serotype Agona in the country.

  12. The capsular polysaccharide Vi from Salmonella Typhi is a B1b antigen

    Marshall, Jennifer L.; Flores-Langarica, Adriana; Kingsley, Robert A.; Hitchcock, Jessica R.; Ross, Ewan A.; Lopez-Macias, Constantino; Lakey, Jeremy; Martin, Laura B.; Toellner, Kai-Michael; MacLennan, Calman A.; MacLennan, Ian C; Henderson, Ian R.; Dougan, Gordon; Cunningham, Adam F.

    2012-01-01

    Vaccination with purified capsular polysaccharide Vi antigen from Salmonella Typhi can protect against typhoid fever, although the mechanism for its efficacy is not clearly established. Here, we have characterised the B cell response to this vaccine in wild-type and T cell-deficient mice. We show that immunization with Typhim Vi rapidly induces proliferation in B1b peritoneal cells, but not in B1a cells or marginal zone (MZ) B cells. This induction of B1b proliferation is concomitant with the detection of splenic Vi-specific antibody secreting cells and protective antibody and Rag1-deficient B1b cell chimeras generated by adoptive transfer induced specific antibody after Vi immunization. Furthermore, antibody derived from peritoneal B cells is sufficient to confer protection against Salmonella that express Vi antigen. Expression of Vi by Salmonella during infection did not inhibit the development of early antibody responses to non-Vi antigens. Despite this, the protection conferred by immunization of mice with porin proteins from Salmonella, which induce antibody-mediated protection, was reduced after infection with Vi-expressing Salmonella, although protection was not totally abrogated. This work therefore suggests that in mice, B1b cells contribute to the protection induced by Vi antigen and targeting non-Vi antigens as sub-unit vaccines may offer an attractive strategy to augment current Vi-based vaccine strategies. PMID:23162127

  13. The capsular polysaccharide Vi from Salmonella typhi is a B1b antigen.

    Marshall, Jennifer L; Flores-Langarica, Adriana; Kingsley, Robert A; Hitchcock, Jessica R; Ross, Ewan A; López-Macías, Constantino; Lakey, Jeremy; Martin, Laura B; Toellner, Kai-Michael; MacLennan, Calman A; MacLennan, Ian C; Henderson, Ian R; Dougan, Gordon; Cunningham, Adam F

    2012-12-15

    Vaccination with purified capsular polysaccharide Vi Ag from Salmonella typhi can protect against typhoid fever, although the mechanism for its efficacy is not clearly established. In this study, we have characterized the B cell response to this vaccine in wild-type and T cell-deficient mice. We show that immunization with typhoid Vi polysaccharide vaccine rapidly induces proliferation in B1b peritoneal cells, but not in B1a cells or marginal zone B cells. This induction of B1b proliferation is concomitant with the detection of splenic Vi-specific Ab-secreting cells and protective Ab in Rag1-deficient B1b cell chimeras generated by adoptive transfer-induced specific Ab after Vi immunization. Furthermore, Ab derived from peritoneal B cells is sufficient to confer protection against Salmonella that express Vi Ag. Expression of Vi by Salmonella during infection did not inhibit the development of early Ab responses to non-Vi Ags. Despite this, the protection conferred by immunization of mice with porin proteins from Salmonella, which induce Ab-mediated protection, was reduced postinfection with Vi-expressing Salmonella, although protection was not totally abrogated. This work therefore suggests that, in mice, B1b cells contribute to the protection induced by Vi Ag, and targeting non-Vi Ags as subunit vaccines may offer an attractive strategy to augment current Vi-based vaccine strategies.

  14. Determination of viable Salmonellae from potable and source water through PMA assisted qPCR.

    Singh, Gulshan; Vajpayee, Poornima; Bhatti, Saurabh; Ronnie, Nirmala; Shah, Nimish; McClure, Peter; Shanker, Rishi

    2013-07-01

    Resource constrained countries identified as endemic zones for pathogenicity of Salmonella bear an economic burden due to recurring expenditure on medical treatment. qPCR used for Salmonella detection could not discriminate between viable and nonviable cells. Propidium monoazide (PMA) that selectively penetrates nonviable cells to cross-link their DNA, was coupled with ttr gene specific qPCR for quantifying viable salmonellae in source/potable waters collected from a north Indian city. Source water (raw water for urban potable water supply) and urban potable water exhibited viable salmonellae in the range of 2.1×10(4)-2.6×10(6) and 2-7160CFU/100mL, respectively. Potable water at water works exhibited DNA from dead cells but no viable cells were detected. PMA assisted qPCR could specifically detect low numbers of live salmonellae in Source and potable waters. This strategy can be used in surveillance of urban potable water distribution networks to map contamination points for better microbial risk management.

  15. Optical immunosensors for detection of Listeria monocytogenes and Salmonella enteritidis from food

    Bhunia, Arun K.; Geng, Tao; Lathrop, Amanda; Valadez, Angela; Morgan, Mark T.

    2004-03-01

    Listeria monocytogenes and Salmonella are two major foodborne pathogens of significant concern. Two optical evanescent wave immunosensors were evaluated for detection: Antibody-coupled fiber-optic biosensor and a surface plasmon resonant (SPR) immunosensor. In the fiber-optic sensor, polyclonal antibodies for the test organisms were immobilized on polystyrene fiber wave -guides using streptavidin - biotin chemistry. Cyanine 5 -labeled monoclonal antibodies C11E9 (for L. monocytogenes) and SF-11 (for Salmonella Enteritidis) were used to generate a specific fluorescent signal. Signal acquisition was performed by launching a laser-light (635 nm) from an Analyte-2000. This immunosensor was able to detect 103 - 109 cfu/ml of L. monocytogenes or 106-109 cfu/ml of Salmonella Enteritidis and the assays were conducted at near real-time with results obtained within one hour of sampling. The assays were specific and showed signal even in the presence of other microorganisms such as E. coli, Enterococcus faecalis or Salmonella Typhimurium. In the SPR system, IAsys instrument (resonant mirror sensor) was used. Monoclonal antibody-C11E9 was directly immobilized onto a carboxylate cuvette. Whole Listeria cells at various concentrations did not yield any signal while surface protein extracts did. Crude protein extracts from L. monocytogenes and L. innocua had average binding responses of around 150 arc sec (0.25 ng/mm2), which was significantly different from L. grayi, L. ivanovii, or L. welshimeri with average responses of Salmonella Enteritidis.

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

    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.

  17. Outbreak of Salmonella Strathcona caused by datterino tomatoes, Denmark, 2011.

    Müller, L; Kjelsø, C; Frank, C; Jensen, T; Torpdahl, M; Søborg, B; Dorleans, F; Rabsch, W; Prager, R; Gossner, C M; Ethelberg, S

    2016-10-01

    In September 2011, a patient cluster with a rare Salmonella serotype - Strathcona - was identified in Denmark. An outbreak investigation was initiated to reveal the source in order to stop the outbreak. In addition to hypothesis-generating interviews, comparable analyses of patients' household shopping receipts were conducted. A matched case-control study with 25 cases and 56 population register controls was conducted to test the findings of the hypothesis-generating investigation. In total, 43 cases of Salmonella Strathcona were reported in Denmark. Additionally, 28 cases were reported from Germany, Italy, Austria and Belgium. The results of the investigation in Denmark showed that 8/10 cases had bought datterino tomatoes prior to disease onset. Illness was associated with a specific supermarket chain [matched odds ratio (mOR) 16·9, 95% confidence interval (CI) 2·2-130], and having consumed elongated small tomatoes (OR 28·1, 95% CI 2·6-302). Traceback investigation showed that the tomatoes came from an Italian producer. This outbreak, linked to tomatoes, underpins the growing recognition of the broad source range of Salmonella and the ability of fresh produce to cause multi-country outbreaks. It is important to strengthen the international cooperation between public-health and food-safety authorities in the European Union to investigate future multi-country outbreaks in order to prevent illness from ready-to-eat produce.

  18. Ulcerative Colitis and Its Association with Salmonella Species

    Manish Kumar Tripathi

    2016-01-01

    Full Text Available Ulcerative colitis (UC is characterized by presence of ulcer in colon and bloody diarrhea. The present study explores the possibility of association between Salmonella and ulcerative colitis. The present study comprised 59 cases of UC, 28 of colon cancer (CC, 127 of irritable bowel syndrome (IBS, and 190 of healthy control. The serological study was done by Widal and Indirect Haemagglutination Assay (IHA for ViAb. Nested PCR was performed targeting fliC, staA, and stkG gene for Typhi and Paratyphi A, respectively. A total of 15.3% patients were positive for Salmonella “O” antigen among them 18.6% UC, 35.5% CC, 12.6% IBS, and 15.3% healthy control. A total of 36.9% patients were positive for “H” antigen including 39.0%, 57.1%, and 67.7% UC, CC, and IBS, respectively. About 1.73% show positive agglutination for AH antigen including 3.4%, 3.6%, and 1.6%, UC, CC, and IBS. A total of 10.89% were positive for ViAb. While 6.8% of UC, 10.7% of CC, 11.0% of IBS, and 12.1% of healthy subjects were positive for the antibody, the PCR positivity rates for Salmonella specific sequences were 79.7% in UC, 53.6% in CC, 66.1% in IBS, and 16.3% in healthy controls. The present study suggested that higher prevalence of Salmonella might play important role in etiopathogenesis of UC, IBS, and CC.

  19. Ulcerative Colitis and Its Association with Salmonella Species

    Tripathi, Manish Kumar; Pratap, Chandra Bhan; Dixit, Vinod K.; Singh, Tej Bali; Shukla, Sunit K.; Jain, Ashok K.; Nath, Gopal

    2016-01-01

    Ulcerative colitis (UC) is characterized by presence of ulcer in colon and bloody diarrhea. The present study explores the possibility of association between Salmonella and ulcerative colitis. The present study comprised 59 cases of UC, 28 of colon cancer (CC), 127 of irritable bowel syndrome (IBS), and 190 of healthy control. The serological study was done by Widal and Indirect Haemagglutination Assay (IHA) for ViAb. Nested PCR was performed targeting fliC, staA, and stkG gene for Typhi and Paratyphi A, respectively. A total of 15.3% patients were positive for Salmonella “O” antigen among them 18.6% UC, 35.5% CC, 12.6% IBS, and 15.3% healthy control. A total of 36.9% patients were positive for “H” antigen including 39.0%, 57.1%, and 67.7% UC, CC, and IBS, respectively. About 1.73% show positive agglutination for AH antigen including 3.4%, 3.6%, and 1.6%, UC, CC, and IBS. A total of 10.89% were positive for ViAb. While 6.8% of UC, 10.7% of CC, 11.0% of IBS, and 12.1% of healthy subjects were positive for the antibody, the PCR positivity rates for Salmonella specific sequences were 79.7% in UC, 53.6% in CC, 66.1% in IBS, and 16.3% in healthy controls. The present study suggested that higher prevalence of Salmonella might play important role in etiopathogenesis of UC, IBS, and CC. PMID:26904116

  20. Serodiversity and serological as well as cultural distribution of Salmonella on farms and in abattoirs in Lower Saxony, Germany.

    Visscher, C F; Klein, G; Verspohl, J; Beyerbach, M; Stratmann-Selke, J; Kamphues, J

    2011-03-15

    In this study fattening pigs were monitored on farms and in the abattoir for Salmonella prevalence. The samples with the highest prevalence at slaughter should be identified with special attention to the distribution of Salmonella serovars on farms in comparison to those in slaughtered pigs. Another aim was to monitor whether high serological antibody responses in pigs are in accordance with the specific Salmonella serovars in tissues. From 3418 farm faecal samples, 191 were Salmonella positive (5.58%), whereas from slaughtered pigs 330 out of 2494 analysed samples were Salmonella positive (13.2%) with the highest prevalence in the caecal content (124/499=24.9%). The chi-square test for homogeneity between the serovars found on farms and in the different types of samples at slaughter was in most cases negative (pmeat juice (cut off 40) and cultural detection of Salmonella spp. in ileocaecal lymph nodes, as well as between meat juice samples (cut off 20) and caecal content did not differ significantly. The Kappa indices only showed signs of weak concordance according to positive test results (Kappa ≤ 0.4) between different sample types on an animal basis. Pigs harbouring S. Typhimurium 1,4,12:i:1,2; DT104L in tonsils or S. Typhimurium 1,4,12:i:1,2 DT 104B low in caecal content or ileocaecal lymph nodes had the highest optical densities in meat juice. Apart from the different Salmonella prevalences between farms and slaughterhouses and in most cases non-existing concordance in Salmonella serovar distribution on farms and at slaughter, also in future farm intervention strategies to control Salmonella in the food chain are not dispensable. This is because once introduced into a slaughterhouse via swine the serovars seem to maintain the resident slaughterhouse flora and add to it.

  1. Surveillance and cross contamination of salmonella spp., in pork, with profiles of nalidixic acid resistance in salmonella

    Dillon, Colm

    2010-01-01

    peer-reviewed Salmonella is a major foodborne pathogen and porcine products are an important source. With this in mind, pork sausages were surveyed for Salmonella prevalence. Sausages were sampled during August-December 2008, none of which were positive for Salmonella. As an alternative porcine source of salmonella, 102 pig ear pet treats were surveyed from October 2008 to September 2009. Salmonella was detected in 24.5% of treats using a culture detection method and 28.4% u...

  2. Prediction of Salmonella carcass contamination by a comparative quantitative analysis of E. coli and Salmonella during pig slaughter

    Nauta, Maarten; Barfod, Kristen; Hald, Tine;

    2013-01-01

    carcass contamination with Salmonella, when the distribution of Salmonella concentrations in faeces is known. Paired pig sample data (faecal samples and carcass swabs) were obtained from five slaughterhouses and analysed for prevalence and concentrations of E. coli and Salmonella. A simple model...... extensive data set showed that other factors than the observed faecal carriage of Salmonella by the individual animals brought to slaughter, play a more important role in the Salmonella carcass contamination of pork....

  3. An Efficient Multiplex PCR-Based Assay as a Novel Tool for Accurate Inter-Serovar Discrimination of Salmonella Enteritidis, S. Pullorum/Gallinarum and S. Dublin

    Xiong, Dan; Song, Li; Tao, Jing; Zheng, Huijuan; Zhou, Zihao; Geng, Shizhong; Pan, Zhiming; Jiao, Xinan

    2017-01-01

    Salmonella enterica serovars Enteritidis, Pullorum/Gallinarum, and Dublin are infectious pathogens causing serious problems for pig, chicken, and cattle production, respectively. Traditional serotyping for Salmonella is costly and labor-intensive. Here, we established a rapid multiplex PCR method to simultaneously identify three prevalent Salmonella serovars Enteritidis, Pullorum/Gallinarum, and Dublin individually for the first time. The multiplex PCR-based assay focuses on three genes tcpS, lygD, and flhB. Gene tcpS exists only in the three Salmonella serovars, and lygD exists only in S. Enteritidis, while a truncated region of flhB gene is only found in S. Pullorum/Gallinarum. The sensitivity and specificity of the multiplex PCR assay using three pairs of specific primers for these genes were evaluated. The results showed that this multiplex PCR method could accurately identify Salmonella Enteritidis, Pullorum/Gallinarum, and Dublin from eight non-Salmonella species and 27 Salmonella serovars. The least concentration of genomic DNA that could be detected was 58.5 pg/μL and the least number of cells was 100 CFU. Subsequently, this developed method was used to analyze clinical Salmonella isolates from one pig farm, one chicken farm, and one cattle farm. The results showed that blinded PCR testing of Salmonella isolates from the three farms were in concordance with the traditional serotyping tests, indicating the newly developed multiplex PCR system could be used as a novel tool to accurately distinguish the three specific Salmonella serovars individually, which is useful, especially in high-throughput screening.

  4. Angiogenesis in advanced colorectal adenocarcinoma with special reference to tumoral invasion Angiogênese no adenocarcinoma colorretal avançado com especial referência à invasão tumoral

    Cláudio TARTA

    2002-03-01

    , apresenta valor prognóstico em muitas neoplasias malignas e, recentemente, tem sido avaliada em tumores gastrointestinais. Objetivos - Avaliar a significância prognóstica da contagem microvascular no carcinoma colorretal, estudando sua associação com metástases hematogênicas, sobrevida e variáveis clinicopatológicas, tais como tamanho, diferenciação histológica e profundidade de invasão tumoral. Pacientes/Métodos - Foram incluídos 48 pacientes com adenocarcinoma colorretal. Secções histológicas contendo a margem tumoral invasiva (4 mm foram analisadas e os microvasos foram identificados através de imunohistoquímica utilizando o anticorpo monoclonal anti-FVIII (Von Willebrand Factor - mouse. A contagem microvascular foi realizada através da identificação de áreas com maior densidade microvascular - hot spots - e resulta da média entre cinco destas áreas. Resultados - A contagem microvascular mediana foi de 14 microvasos/0,785 mm², dividindo a amostra em grupos hipo e hipervascular. Enquanto 2/8 (25% tumores com invasão da muscular própria foram classificados como hipervasculares, 11/15 (73% tumores com invasão da serosa ou tecidos peri-colônicos foram classificados como hipervasculares. No entanto, associação não significativa foi encontrada entre a quantificação angiogênica e metástases hematogênicas, sobrevida e variáveis clinicopatológicas, tais como o tamanho tumoral e diferenciação histológica. Conclusões - O achado de aumento significativo na contagem microvascular em conformidade com a maior profundidade de invasão tumoral suporta a teoria que a progressão tumoral possa estar relacionada à angiogênese. Embora a angiogênese seja etapa importante no crescimento tumoral e durante a metastatização à distância, outros fatores podem estar implicados em tais processos.

  5. Ex vivo perfusion of the isolated rat small intestine as a novel model of Salmonella enteritis.

    Boyle, Erin C; Dombrowsky, Heike; Sarau, Jürgen; Braun, Janin; Aepfelbacher, Martin; Lautenschläger, Ingmar; Grassl, Guntram A

    2016-01-15

    Using an ex vivo perfused rat small intestinal model, we examined pathological changes to the tissue, inflammation induction, as well as dynamic changes to smooth muscle activity, metabolic competence, and luminal fluid accumulation during short-term infection with the enteropathogenic bacteria Salmonella enterica serovar Typhimurium and Yersinia enterocolitica. Although few effects were seen upon Yersinia infection, this system accurately modeled key aspects associated with Salmonella enteritis. Our results confirmed the importance of the Salmonella Pathogenicity Island 1 (SPI1)-encoded type 3 secretion system (T3SS) in pathology, tissue invasion, inflammation induction, and fluid secretion. Novel physiological consequences of Salmonella infection of the small intestine were also identified, namely, SPI-1-dependent vasoconstriction and SPI-1-independent reduction in the digestive and absorptive functions of the epithelium. Importantly, this is the first small animal model that allows for the study of Salmonella-induced fluid secretion. Another major advantage of this model is that one can specifically determine the contribution of resident cell populations. Accordingly, we can conclude that recruited cell populations were not involved in the pathological damage, inflammation induction, fluid accumulation, nutrient absorption deficiency, and vasoconstriction observed. Although fluid loss induced by Salmonella infection is hypothesized to be due to damage caused by recruited neutrophils, our data suggest that bacterial invasion and inflammation induction in resident cell populations are sufficient for fluid loss into the lumen. In summary, this model is a novel and useful tool that allows for detailed examination of the early physiopathological effects of Salmonella infection on the small intestine.

  6. Salmonella enterica serovar Typhimurium lacking hfq gene confers protective immunity against murine typhoid.

    Uday Shankar Allam

    Full Text Available Salmonella enterica is an important enteric pathogen and its various serovars are involved in causing both systemic and intestinal diseases in humans and domestic animals. The emergence of multidrug-resistant strains of Salmonella leading to increased morbidity and mortality has further complicated its management. Live attenuated vaccines have been proven superior over killed or subunit vaccines due to their ability to induce protective immunity. Of the various strategies used for the generation of live attenuated vaccine strains, focus has gradually shifted towards manipulation of virulence regulator genes. Hfq is a RNA chaperon which mediates the binding of small RNAs to the mRNA and assists in post-transcriptional gene regulation in bacteria. In this study, we evaluated the efficacy of the Salmonella Typhimurium Δhfq strain as a candidate for live oral vaccine in murine model of typhoid fever. Salmonella hfq deletion mutant is highly attenuated in cell culture and animal model implying a significant role of Hfq in bacterial virulence. Oral immunization with the Salmonella hfq deletion mutant efficiently protects mice against subsequent oral challenge with virulent strain of Salmonella Typhimurium. Moreover, protection was induced upon both multiple as well as single dose of immunizations. The vaccine strain appears to be safe for use in pregnant mice and the protection is mediated by the increase in the number of CD4(+ T lymphocytes upon vaccination. The levels of serum IgG and secretory-IgA in intestinal washes specific to lipopolysaccharide and outer membrane protein were significantly increased upon vaccination. Furthermore, hfq deletion mutant showed enhanced antigen presentation by dendritic cells compared to the wild type strain. Taken together, the studies in murine immunization model suggest that the Salmonella hfq deletion mutant can be a novel live oral vaccine candidate.

  7. Liver dendritic cells present bacterial antigens and produce cytokines upon Salmonella encounter.

    Johansson, Cecilia; Wick, Mary Jo

    2004-02-15

    The capacity of murine liver dendritic cells (DC) to present bacterial Ags and produce cytokines after encounter with Salmonella was studied. Freshly isolated, nonparenchymal liver CD11c(+) cells had heterogeneous expression of MHC class II and CD11b and a low level of CD40 and CD86 expression. Characterization of liver DC subsets revealed that CD8alpha(-)CD4(-) double negative cells constituted the majority of liver CD11c(+) ( approximately 85%) with few cells expressing CD8alpha or CD4. Flow cytometry analysis of freshly isolated CD11c(+) cells enriched from the liver and cocultured with Salmonella expressing green fluorescent protein (GFP) showed that CD11c(+) MHC class II(high) cells had a greater capacity to internalize Salmonella relative to CD11c(+) MHC class II(low) cells. Moreover, both CD8alpha(-) and CD8alpha(+) liver DC internalized bacteria with similar efficiency after both in vitro and in vivo infection. CD11c(+) cells enriched from the liver could also process Salmonella for peptide presentation on MHC class I and class II to primary, Ag-specific T cells after internalization requiring actin cytoskeletal rearrangements. Flow cytometry analysis of liver CD11c(+) cells infected with Salmonella expressing GFP showed that both CD8alpha(-) and CD8alpha(+) DC produced IL-12p40 and TNF-alpha. The majority of cytokine-positive cells did not contain bacteria (GFP(-)) whereas only a minor fraction of cytokine-positive cells were GFP(+). Furthermore, only approximately 30-50% of liver DC containing bacteria (GFP(+)) produced cytokines. Thus, liver DC can internalize and process Salmonella for peptide presentation to CD4(+) and CD8(+) T cells and elicit proinflammatory cytokine production upon Salmonella encounter, suggesting that DC in the liver may contribute to immunity against hepatotropic bacteria.

  8. Virulent Salmonella enterica serovar typhimurium evades adaptive immunity by preventing dendritic cells from activating T cells.

    Tobar, Jaime A; Carreño, Leandro J; Bueno, Susan M; González, Pablo A; Mora, Jorge E; Quezada, Sergio A; Kalergis, Alexis M

    2006-11-01

    Dendritic cells (DCs) constitute the link between innate and adaptive immunity by directly recognizing pathogen-associated molecular patterns (PAMPs) in bacteria and by presenting bacterial antigens to T cells. Recognition of PAMPs renders DCs as professional antigen-presenting cells able to prime naïve T cells and initiate adaptive immunity against bacteria. Therefore, interfering with DC function would promote bacterial survival and dissemination. Understanding the molecular mechanisms that have evolved in virulent bacteria to evade activation of adaptive immunity requires the characterization of virulence factors that interfere with DC function. Salmonella enterica serovar Typhimurium, the causative agent of typhoid-like disease in the mouse, can prevent antigen presentation to T cells by avoiding lysosomal degradation in DCs. Here, we show that this feature of virulent Salmonella applies in vivo to prevent activation of adaptive immunity. In addition, this attribute of virulent Salmonella requires functional expression of a type three secretion system (TTSS) and effector proteins encoded within the Salmonella pathogenicity island 2 (SPI-2). In contrast to wild-type virulent Salmonella, mutant strains carrying specific deletions of SPI-2 genes encoding TTSS components or effectors proteins are targeted to lysosomes and are no longer able to prevent DCs from activating T cells in vitro or in vivo. SPI-2 mutant strains are attenuated in vivo, showing reduced tissue colonization and enhanced T-cell activation, which confers protection against a challenge with wild-type virulent Salmonella. Our data suggest that impairment of DC function by the activity of SPI-2 gene products is crucial for Salmonella pathogenesis.

  9. Salmonella typhimurium peptidase active on carnosine.

    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

  10. EU Interlaboratory comparison study VIII on bacteriological detection of Salmonella spp.

    Korver H; Heisterkamp SH; Veenman C; Mooijman KA; MGB

    2006-01-01

    In 2004 werd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) het achtste bacteriologische ringonderzoek georganiseerd. Deelnemers van de studie waren de Nationale Referentie Laboratoria voor Salmonella (NRL's-Salmonella) van de EU lidstaten

  11. Occurrence of Salmonella sp in laying hens

    Gama NMSQ

    2003-01-01

    Full Text Available This study was carried out to investigate the presence of Salmonella sp in flocks of white laying hens. In different farms, the transport boxes of twelve flocks were inspected at arrival for the presence of Salmonella. Four positive (A, B, L and M and one negative (I flocks were monitored at each four weeks using bacteriological examination of cecal fresh feces up to 52 weeks. Birds were also evaluated at 52 weeks, when 500 eggs were taken randomly, and at 76 weeks, after forced molt. Salmonella enterica serovar Enteritidis and S. enterica rough strain were isolated from the transport boxes of the four positive flocks (flocks A, B, L and M. Salmonella sp was not isolated from the transport boxes or from the feces after 76 weeks-old in flock I. Salmonella sp was isolated in the 1st, 11th, 34th, 42nd and 76th weeks from flock A; in the 1st, 4th, 11th and 76th weeks from flock B; in the first week and in the 17th to 52nd weeks from flock L; and in the 1st and 76th weeks from flock M. S. Enteritidis, S. enterica rough strain and Salmonella enterica serovar Infantis were isolated from the four positive flocks. Besides, Salmonella enterica serovar Javiana was isolated from flocks B and L, and Salmonella enterica serovar Mbandaka was isolated from flock L. Eggs produced by flock A and by flock L were contaminated with S. Enteritidis and S. enterica rough strain. According to these results, Salmonella-infected flocks may produce contaminated eggs.

  12. Survival of Salmonella Newport on Whole and Fresh-Cut Cucumbers Treated with Lytic Bacteriophages.

    Sharma, Manan; Dashiell, Gwendolyn; Handy, Eric T; East, Cheryl; Reynnells, Russell; White, Chanelle; Nyarko, Esmond; Micallef, Shirley; Hashem, Fawzy; Millner, Patricia D

    2017-04-01

    Salmonella enterica associated with consumption of cucumbers ( Cucumis sativus ) has led to foodborne outbreaks in the United States. Whole and fresh-cut cucumbers are susceptible to S. enterica contamination during growing, harvesting, and postharvest handling. The application of lytic bacteriophages specific for S. enterica was evaluated to reduce Salmonella populations on cucumbers. Unwaxed cucumbers ('Lisboa' variety, or mini-cucumbers purchased at retail) were inoculated with Salmonella Newport (5 log CFU per cucumber) and were sprayed with 3.2 mL of phosphate-buffered saline (control) or 10 log PFU/ml of SalmoFresh, a Salmonella-specific bacteriophage preparation (phage), to deliver 4.76 × 10(7) PFU/cm(2). Cucumbers were stored at 10 or 22°C for 7 days. Inoculated mini-cucumbers were sliced with a sterile knife to investigate Salmonella transfer to mesocarp, and cut pieces were stored at 4°C for 2 days. Populations (log CFU per cucumber) of Salmonella Newport on phage-treated whole cucumbers were significantly (P cucumbers (4.27 ± 0.37) on day 0. Populations on phage-treated cucumbers stored at 10°C were 1.72 ± 0.77 and 1.56 ± 0.46, which were significantly lower than those on control-treated cucumbers (3.20 ± 0.48 and 2.33 ± 0.25) on days 1 and 4, respectively. Between days 0 and 1, populations on control-treated cucumbers stored at 10 and 22°C declined by 1.07 and 2.47 log CFU per cucumber, respectively. At 22°C, Salmonella Newport populations declined by 2.37 log CFU per cucumber between days 0 and 1. Phage application to whole cucumbers before slicing did not reduce the transfer of Salmonella Newport to fresh-cut slices. Lytic phage application may be a potential intervention to reduce Salmonella populations on whole cucumbers.

  13. Bilateral amaurosis caused by Salmonella enteritidis infection.

    Cerovski, Branimir; Barisić, Nina; Vidović, Tomislav; Petricek, Igor; Cerovski, Jasenka

    2004-12-01

    The aim of this paper was to show the potential of Salmonella enteritidis infection to eventually result in visual impairment. A case of salmonellosis in a 6-year-old boy, caused by intake of a cake made from eggs infected with Salmonella enteritidis, is presented. Prolonged duration of the disease was followed by complete remission of neurologic complications and persistent amaurosis with bilateral optic nerve atrophy. A severe form of Salmonella enterocolitis with neurologic involvement can lead to optic nerve lesion with consequential loss of vision.

  14. Pleural Empyema due to Group D Salmonella

    Jennifer C. Kam

    2012-01-01

    Full Text Available Non-typhi Salmonella normally presents as a bacteremia, enterocolitis, and endovascular infection but rarely manifests as pleuropulmonary disease. We present a case of a 66-year-old female with underlying pulmonary pathology, secondary to an extensive smoking history, who presented with a left-sided pleural effusion. The causative agent was identified as being group D Salmonella. Decortication of the lung was performed and the patient was discharged on antibiotics with resolution of her symptoms. This case helps to support the inclusion of Salmonella group D as a possible etiological agent of infection in the differential causes of exudative pleural effusions.

  15. Salmonella source attribution based on microbial subtyping

    Barco, Lisa; Barrucci, Federica; Olsen, John Elmerdahl

    2013-01-01

    Source attribution of cases of food-borne disease represents a valuable tool for identifying and prioritizing effective food-safety interventions. Microbial subtyping is one of the most common methods to infer potential sources of human food-borne infections. So far, Salmonella microbial subtyping...... source attribution models have been implemented by using serotyping and phage-typing data. Molecular-based methods may prove to be similarly valuable in the future, as already demonstrated for other food-borne pathogens like Campylobacter. This review assesses the state of the art concerning Salmonella...... in the context of their potential applicability for Salmonella source attribution studies....

  16. Antimicrobial resistance and molecular epidemiology of Salmonella Rissen from animals, food products, and patients in Thailand and Denmark

    Hendriksen, Rene S.; Bangtrakulnonth, Aroon; Pulsrikarn, Chaiwat

    2008-01-01

    Recently we reported increases in both the number of Salmonella infections due to Salmonella Rissen in Thailand and the isolation of this serovar from pork products in Thailand. The objectives of the present study were to determine the genetic diversity and antimicrobial resistance of Salmonella...... Rissen isolates recovered from humans, food products, and animals in Denmark and Thailand. Additionally, risk factors due to travel and consumption of specific food products were analyzed and evaluated. A total of 112 Salmonella Rissen isolates were included in this study from Thailand and Denmark. Thai...... isolates were recovered from humans, uncooked food, and ready-to-eat food. Danish isolates were obtained from humans (with and without a history of travel to Thailand prior to the infection), Danish pig or pork products, imported pig or pork products, turkeys, and animal feed. A total of 63 unique Xba...

  17. Prevention of egg contamination by Salmonella Enteritidis after oral vaccination of laying hens with Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC mutants.

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

    2016-08-12

    Vaccination of laying hens has been successfully used to reduce egg contamination by Salmonella Enteritidis, decreasing human salmonellosis cases worldwide. Currently used vaccines for layers are either inactivated vaccines or live attenuated strains produced by mutagenesis. Targeted gene deletion mutants hold promise for future vaccines, because specific bacterial functions can be removed that may improve safety and allow differentiation from field strains. In this study, the efficacy of Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC strains in laying hens as live vaccines was evaluated. The mutants are deficient in either the membrane channel TolC (ΔtolC) or the multi-drug efflux systems acrAB, acrEF and mdtABC (ΔacrABacrEFmdtABC). These strains have a decreased ability for gut and tissue colonization and are unable to survive in egg white, the latter preventing transmission of the vaccine strains to humans. Two groups of 30 laying hens were orally inoculated at day 1, 6 weeks and 16 weeks of age with 10(8) cfu of either vaccine strain, while a third group was left unvaccinated. At 24 weeks of age, the birds were intravenously challenged with 5 × 10(7) cfu Salmonella Enteritidis PT4 S1400/94. The vaccine strains were not shed or detected in the gut, internal organs or eggs, 2 weeks after the third vaccination. The strains significantly protected against gut and internal organ colonization, and completely prevented egg contamination by Salmonella Enteritidis under the conditions of this study. This indicates that Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC strains might be valuable strains for vaccination of layers against Salmonella Enteritidis.

  18. Diversity and Persistence of Salmonella enterica Strains in Rural Landscapes in the Southeastern United States.

    John J Maurer

    Full Text Available Salmonellosis cases in the in the United States show distinct geographical trends, with the southeast reporting among the highest rates of illness. In the state of Georgia, USA, non-outbreak associated salmonellosis is especially high in the southern low-lying coastal plain. Here we examined the distribution of Salmonella enterica in environmental waters and associated wildlife in two distinct watersheds, one in the Atlantic Coastal Plain (a high case rate rural area physiographic province and one in the Piedmont (a lower case rate rural area. Salmonella were isolated from the two regions and compared for serovar and strain diversity, as well as distribution, between the two study areas, using both a retrospective and prospective design. Thirty-seven unique serovars and 204 unique strain types were identified by pulsed-field gel electrophoresis (PFGE. Salmonella serovars Braenderup, Give, Hartford, and Muenchen were dominant in both watersheds. Two serovars, specifically S. Muenchen and S. Rubislaw, were consistently isolated from both systems, including water and small mammals. Conversely, 24 serovars tended to be site-specific (64.8%, n = 37. Compared to the other Salmonella serovars isolated from these sites, S. Muenchen and S. Rubislaw exhibited significant genetic diversity. Among a subset of PFGE patterns, approximately half of the environmental strain types matched entries in the USA PulseNet database of human cases. Ninety percent of S. Muenchen strains from the Little River basin (the high case rate area matched PFGE entries in PulseNet compared to 33.33% of S. Muenchen strains from the North Oconee River region (the lower case rate area. Underlying the diversity and turnover of Salmonella strains observed for these two watersheds is the persistence of specific Salmonella serovars and strain types that may be adapted to these watersheds and landscapes.

  19. Study on Salmonella Typhi occurrence in gallbladder of patients suffering from chronic cholelithiasis-a predisposing factor for carcinoma of gallbladder.

    Walawalkar, Yogesh D; Gaind, Rajni; Nayak, Vijayashree

    2013-09-01

    Cholelithiasis is frequently associated with carcinoma of gallbladder, and the presence of Salmonella Typhi in gallbladder of patients suffering from cholelithiasis is implicated as a predisposing factor for carcinogenesis. This study was conducted on patients suffering from chronic cholelithiasis from a region in North India-endemic area for enteric fever with high incidence of gallstones and gallbladder cancer. Since culture studies rarely reveal the chronic Salmonella Typhi persistence, we use PCR assay to specifically amplify the H1-d flagellin gene sequence homologous with Salmonella Typhi. Seven cases (17.5%), none of which were positive for culture, showed positive PCR results for Salmonella Typhi, 4 (10%) of which were tissue, 2 bile (5%), and 1 gallstone (2.5%). The chronic existence of Salmonella Typhi in gallbladder disease was confirmed. Thus, the study would indicate the importance of vaccination so as to prevent chronic infection and need for early diagnostic tools to prevent any further complications.

  20. Evaluation of a CHROMagar Salmonella Medium for the Isolation of Salmonella Species

    yesim cekin

    2014-03-01

    Full Text Available Aim: Salmonella infections are the leading cause of food-borne infections and can cause gastroenteritis outbreaks worldwide. Salmonella species is defined as inability to lactose fermentation, using citrate as a carbon source, using lysine as nitrate source and forming Hydrogen sulfide (H2S in TSI agar. However, confirmation of false positive results is time consuming and lead to increased costs. The aim of this study is to evaluate the performance of CHROMagar Salmonella (CHROMagar Microbiology, France which is developed for isolation and detection of Salmonella species. Material and Method: For this purpose, among a total of 148 isolates which were isolated from various clinical specimens and stocked at the Central Laboratory of Akdeniz University Hospital, 65 were Salmonella spp., 10 were Pseudomonas aeruginosa, 10 were E. coli, 10 were Acinetobacter baumannii, 10 were Klebsiella pneumoniae, 18 were Morganella morganii, 11 were Citrobacter spp., 5 were Providencia spp., 4 were Aeromonas spp., 5 were Proteus spp. were included in this study. All of the 65 Salmonella spp. isolates apperared with mauve colonies at the CHROMagar Salmonella. Results: E. coli and Klebsiella pnemoniae species were seen as blue, Providencia species were seen as pale-blue; Morganella morganii species were seen as pale-pink, mauve; and Pseudomonas aeruginosa species were seen as pale. Acinebacter baumannii and Aeromonas spp. species were also seen as mauve colonies. Dicussion: CHROMagar Salmonella medium can detect Salmonella species with %100 sensitivity, however there is a need to biochemical or serological confirmation.

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

    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.

  2. Salmonella bongori provides insights into the evolution of the Salmonellae.

    Maria Fookes

    2011-08-01

    Full Text Available The genus Salmonella contains two species, S. bongori and S. enterica. Compared to the well-studied S. enterica there is a marked lack of information regarding the genetic makeup and diversity of S. bongori. S. bongori has been found predominantly associated with cold-blooded animals, but it can infect humans. To define the phylogeny of this species, and compare it to S. enterica, we have sequenced 28 isolates representing most of the known diversity of S. bongori. This cross-species analysis allowed us to confidently differentiate ancestral functions from those acquired following speciation, which include both metabolic and virulence-associated capacities. We show that, although S. bongori inherited a basic set of Salmonella common virulence functions, it has subsequently elaborated on this in a different direction to S. enterica. It is an established feature of S. enterica evolution that the acquisition of the type III secretion systems (T3SS-1 and T3SS-2 has been followed by the sequential acquisition of genes encoding secreted targets, termed effectors proteins. We show that this is also true of S. bongori, which has acquired an array of novel effector proteins (sboA-L. All but two of these effectors have no significant S. enterica homologues and instead are highly similar to those found in enteropathogenic Escherichia coli (EPEC. Remarkably, SboH is found to be a chimeric effector protein, encoded by a fusion of the T3SS-1 effector gene sopA and a gene highly similar to the EPEC effector nleH from enteropathogenic E. coli. We demonstrate that representatives of these new effectors are translocated and that SboH, similarly to NleH, blocks intrinsic apoptotic pathways while being targeted to the mitochondria by the SopA part of the fusion. This work suggests that S. bongori has inherited the ancestral Salmonella virulence gene set, but has adapted by incorporating virulence determinants that resemble those employed by EPEC.

  3. PREVALENCE OF SALMONELLA IN CAPTIVE REPTILES FROM CROATIA.

    Lukac, Maja; Pedersen, Karl; Prukner-Radovcic, Estella

    2015-06-01

    Salmonellosis transmitted by pet reptiles is an increasing public health issue worldwide. The aim of this study was to investigate the prevalence of Salmonella strains from captive reptiles in Croatia. From November 2009 to November 2011 a total of 292 skin, pharyngeal, cloacal, and fecal samples from 200 apparently healthy reptiles were tested for Salmonella excretions by bacteriologic culture and serotyping. These 200 individual reptiles included 31 lizards, 79 chelonians, and 90 snakes belonging to private owners or housed at the Zagreb Zoo, Croatia. Salmonella was detected in a total of 13% of the animals, among them 48.4% lizards, 8.9% snakes, and 3.8% turtles. Representatives of five of the six Salmonella enterica subspecies were identified with the following proportions in the total number of isolates: Salmonella enterica enterica 34.6%, Salmonella enterica houtenae 23.1%, Salmonella enterica arizonae 23.1%, Salmonella enterica diarizonae 15.4%, and Salmonella enterica salamae 3.8%. The 14 different serovars isolated included several rarely occurring serovars such as Salmonella Apapa, Salmonella Halle, Salmonella Kisarawe, and Salmonella Potengi. These findings confirm that the prevalence of Salmonella is considerable in captive reptiles in Croatia, indicating that these animals may harbor serovars not commonly seen in veterinary or human microbiologic practice. This should be addressed in the prevention and diagnostics of human reptile-transmitted infections.

  4. Role of yqiC in the Pathogenicity of Salmonella and Innate Immune Responses of Human Intestinal Epithelium

    Wang, Ke-Chuan; Huang, Chih-Hung; Ding, Shih-Min; Chen, Ching-Kuo; Fang, Hsu-Wei; Huang, Ming-Te; Fang, Shiuh-Bin

    2016-01-01

    The yqiC gene of Salmonella enterica serovar Typhimurium (S. Typhimurium) regulates bacterial growth at different temperatures and mice survival after infection. However, the role of yqiC in bacterial colonization and host immunity remains unknown. We infected human LS174T, Caco-2, HeLa, and THP-1 cells with S. Typhimurium wild-type SL1344, its yqiC mutant, and its complemented strain. Bacterial colonization and internalization in the four cell lines significantly reduced on yqiC depletion. Post-infection production of interleukin-8 and human β-defensin-3 in LS174T cells significantly reduced because of yqiC deleted in S. Typhimurium. The phenotype of yqiC mutant exhibited few and short flagella, fimbriae on the cell surface, enhanced biofilm formation, upregulated type-1 fimbriae expression, and reduced bacterial motility. Type-1 fimbriae, flagella, SPI-1, and SPI-2 gene expression was quantified using real-time PCR. The data show that deletion of yqiC upregulated fimA and fimZ expression and downregulated flhD, fliZ, invA, and sseB expression. Furthermore, thin-layer chromatography and high-performance liquid chromatography revealed the absence of menaquinone in the yqiC mutant, thus validating the importance of yqiC in the bacterial electron transport chain. Therefore, YqiC can negatively regulate FimZ for type-1 fimbriae expression and manipulate the functions of its downstream virulence factors including flagella, SPI-1, and SPI-2 effectors. PMID:27777572

  5. Bacterial clearance reverses a skewed T-cell repertoire induced by Salmonella infection.

    Leyva-Rangel, Jessica P; de Los Angeles Hernández-Cueto, Maria; Galan-Enriquez, Carlos-Samuel; López-Medina, Marcela; Ortiz-Navarrete, Vianney

    2015-09-01

    Salmonella typhimurium invades the spleen, liver, and peripheral lymph nodes and has recently been detected in the bone marrow and thymus, resulting in a reduced thymic size and a decline in the total number of thymic cells. A specific deletion of the double-positive cell subset has been characterized, yet the export of mature T cells to the periphery remains normal. We analyzed Salmonella pathogenesis regarding thymic structure and the T-cell maturation process. We demonstrate that, despite alterations in the thymic structure, T-cell development is maintained during Salmonella infection, allowing the selection of single-positive T-cell clones expressing particular T-cell receptor beta chains (TCR-Vβ). Moreover, the treatment of infected mice with an antibiotic restored the normal thymic architecture and thymocyte subset distribution. Additionally, the frequency of TCR-Vβ usage after treatment was comparable to that in non-infected mice. However, bacteria were still recovered from the thymus after 1 month of treatment. Our data reveal that a skewed T-cell developmental process is present in the Salmonella-infected thymus that alters the TCR-Vβ usage frequency. Likewise, the post-treatment persistence of Salmonella reveals a novel function of the thymus as a potential reservoir for this infectious agent.

  6. Salmonella Protein AvrA Activates the STAT3 Signaling Pathway in Colon Cancer

    Rong Lu

    2016-05-01

    Full Text Available Salmonella infection in humans can become chronic, which leads to low-grade persistent inflammation. These chronic infections increase the risk of several gastrointestinal diseases, including cancer. Salmonella AvrA is a multifunctional protein that influences eukaryotic cell pathways by regulating ubiquitination and acetylation. In an animal model, we have demonstrated that infection with AvrA-expressing Salmonella induces beta-catenin signals and enhances colonic tumorigenesis. Beta-catenin signaling is a key player in intestinal proliferation and tumorigenesis. The relative contributions of AvrA-induced proliferation and inflammation on tumorigenesis, however, are unknown. STAT3 is activated in chronically inflamed intestines in human inflammatory bowel diseases and in colitis-associated colon cancer. In the current study, mice were colonized with Salmonella AvrA-sufficient or AvrA-deficient bacterial strains. Then, inflammation-associated colon cancer was induced through the use of azoxymethane/dextran sulfate sodium. We determined that AvrA-expressing bacteria activated the STAT3 pathway, which is predicted to enhance proliferation and promote tumorigenesis. Transcriptional activity of STAT3 and its target genes were upregulated by Salmonella expressing AvrA, thus promoting proliferation and intestinal tumorigenesis. Our findings provide new insights regarding a STAT3-dependent mechanism by which the specific bacterial product AvrA enhances the development of infection-associated colon cancer. These insights might suggest future biomarkers to risk assessment and early detection of infection-related cancer.

  7. Genetic parameters for resistance to the Salmonella abortusovis vaccinal strain Rv6 in sheep

    Bouix Jacques

    2003-03-01

    Full Text Available Abstract An experimental population (1216 lambs from 30 sires of the Inra401 sheep was created in an Inra flock to allow QTL detection for susceptibility to Salmonella infection, wool and carcass traits. The Inra401 is a sheep composite line developed from two breeds: Berrichon du Cher and Romanov. At 113 days of age on average, the lambs were inoculated intravenously with 108 Salmonella abortusovis Rv6 (vaccinal strain. They were slaughtered 10 days after the inoculation. Several traits were measured at inoculation and/or slaughtering to estimate the genetic resistance of the lambs to Salmonella infection: specific IgM and IgG1 antibody titres, body weight loss, spleen and pre-scapular node weights and counts of viable Salmonella persisting in these organs. This paper presents a quantitative analysis of the genetic variability of the traits related to salmonellosis susceptibility. The heritabilities of the traits varied between 0.10 and 0.64 (significantly different from zero. Thus, in sheep as well as in other species, the determinism of resistance to Salmonella infection is under genetic control. Moreover, the correlations between the traits are in agreement with the known immune mechanisms. The genetic variability observed should help QTL detection.

  8. Myeloperoxidase targets oxidative host attacks to Salmonella and prevents collateral tissue damage.

    Schürmann, Nura; Forrer, Pascal; Casse, Olivier; Li, Jiagui; Felmy, Boas; Burgener, Anne-Valérie; Ehrenfeuchter, Nikolaus; Hardt, Wolf-Dietrich; Recher, Mike; Hess, Christoph; Tschan-Plessl, Astrid; Khanna, Nina; Bumann, Dirk

    2017-01-23

    Host control of infections crucially depends on the capability to kill pathogens with reactive oxygen species (ROS). However, these toxic molecules can also readily damage host components and cause severe immunopathology. Here, we show that neutrophils use their most abundant granule protein, myeloperoxidase, to target ROS specifically to pathogens while minimizing collateral tissue damage. A computational model predicted that myeloperoxidase efficiently scavenges diffusible H2O2 at the surface of phagosomal Salmonella and converts it into highly reactive HOCl (bleach), which rapidly damages biomolecules within a radius of less than 0.1 μm. Myeloperoxidase-deficient neutrophils were predicted to accumulate large quantities of H2O2 that still effectively kill Salmonella, but most H2O2 would leak from the phagosome. Salmonella stimulation of neutrophils from normal and myeloperoxidase-deficient human donors experimentally confirmed an inverse relationship between myeloperoxidase activity and extracellular H2O2 release. Myeloperoxidase-deficient mice infected with Salmonella had elevated hydrogen peroxide tissue levels and exacerbated oxidative damage of host lipids and DNA, despite almost normal Salmonella control. These data show that myeloperoxidase has a major function in mitigating collateral tissue damage during antimicrobial oxidative bursts, by converting diffusible long-lived H2O2 into highly reactive, microbicidal and locally confined HOCl at pathogen surfaces.

  9. Detection of Yersinia spp and Salmonella spp. in apparently healthy cats and dogs in Tehran, Iran

    shabnam hashemi

    2016-03-01

    Full Text Available Introduction: Companion animals, such as cat and dog, are potential sources of transmissible diseases to humans, especially children. They harbor zoonotic agents in gastrointestinal tracts as carriers which are capable of infecting their owners. Salmonella and Yersinia bacteria are considered as frequent causes of illness in children. This study was aimed at finding out the prevalence rate of infection in apparently healthy dogs and cats in Tehran, Iran. Materials and methods: A total of 100 rectal swabs from dogs and cats were analyzed by a multiplex PCR method with specific primers for detection of Yersinia and Salmonella species. Results: Fifteen samples (4 cats and 11 dogs were positive for Yersinia and 20 samples (9 cats and 11 dogs were positive for Salmonella. So the prevalence rate of Yersinia was 8% in cats and 22% in dogs and the prevalence rates of Salmonella were 18 and 22% in cats and dogs respectively. Discussion and conclusion: According to the results, Yersinia and Salmonella were detected in 8- 22% of pet animals without any clinical signs. The contaminated animal foods may be the main source of infection. These results may be useful in planning control and preventive programs. 

  10. Identification of immunogenic proteins and generation of antibodies against Salmonella Typhimurium using phage display

    Meyer Torsten

    2012-06-01

    Full Text Available Abstract Background Solely in Europoe, Salmonella Typhimurium causes more than 100,000 infections per year. Improved detection of livestock colonised with S. Typhimurium is necessary to prevent foodborne diseases. Currently, commercially available ELISA assays are based on a mixture of O-antigens (LPS or total cell lysate of Salmonella and are hampered by cross-reaction. The identification of novel immunogenic proteins would be useful to develop ELISA based diagnostic assays with a higher specificity. Results A phage display library of the entire Salmonella Typhimurium genome was constructed and 47 immunogenic oligopeptides were identified using a pool of convalescent sera from pigs infected with Salmonella Typhimurium. The corresponding complete genes of seven of the identified oligopeptids were cloned. Five of them were produced in E. coli. The immunogenic character of these antigens was validated with sera from pigs infeced with S. Tyhimurium and control sera from non-infected animals. Finally, human antibody fragments (scFv against these five antigens were selected using antibody phage display and characterised. Conclusion In this work, we identified novel immunogenic proteins of Salmonella Typhimurium and generated antibody fragments against these antigens completely based on phage display. Five immunogenic proteins were validated using a panel of positive and negative sera for prospective applications in diagnostics of Salmonela Typhimurium.

  11. Inherent Variability of Growth Media Impacts the Ability of Salmonella Typhimurium to Interact with Host Cells.

    Sridhar, Sushmita; Steele-Mortimer, Olivia

    2016-01-01

    Efficient invasion of non-phagocytic cells, such as intestinal epithelial cells, by Salmonella Typhimurium is dependent on the Salmonella Pathogenicity Island 1 (SPI-1)-encoded Type Three Secretion System. The environmental cues involved in SPI-1 induction are not well understood. In vitro, various conditions are used to induce SPI-1 and the invasive phenotype. Although lysogeny broth (LB) is widely used, multiple formulations exist, and variation can arise due to intrinsic differences in complex components. Minimal media are also susceptible to variation. Still, the impact of these inconsistencies on Salmonella virulence gene expression has not been well studied. The goal of this project is to identify growth conditions in LB and minimal medium that affect SPI-1 induction in vitro using both whole population and single cell analysis. Here we show, using a fluorescent reporter of the SPI-1 gene prgH, that growth of Salmonella in LB yields variable induction. Deliberate modification of media components can influence the invasive profile. Finally, we demonstrate that changes in SPI-1 inducing conditions can affect the ability of Salmonella to replicate intracellularly. These data indicate that the specific media growth conditions impact how the bacteria interact with host cells.

  12. Bacterial virulence, proinflammatory cytokines and host immunity: how to choose the appropriate Salmonella vaccine strain?

    Raupach, B; Kaufmann, S H

    2001-01-01

    Salmonella infection in its mammalian host can be dissected into two main components. The co-ordinate expression of bacterial virulence genes which are designed to evade, subvert or circumvent the host response on the one hand, and the host defence mechanisms which are designed to restrict bacterial survival and replication on the other hand. The outcome of infection is determined by the one which succeeds in disturbing this equilibrium more efficiently. This delicate balance between Salmonella virulence and host immunity/inflammation has important implications for vaccine development or therapeutic intervention. Novel Salmonella vaccine candidates and live carriers for heterologous antigens are attenuated strains with defined genetic modifications of metabolic or virulence functions. Although genetic defects of different gene loci can lead to similar degrees of attenuation, effects on the course of infection may vary, thereby altering the quality of the elicited immune response. Studies with gene-deficient animals indicate that Salmonella typhimurium strains with mutations in aroA, phoP/phoQ or ssrA/ssrB invoke different immune responses and that a differential repertoire of pro-inflammatory cytokines is required for clearance. Consequently, Salmonella mutants defective in distinct virulence functions offer the potential to specifically modulate the immune response for defined medical applications.

  13. Anti-angiogenesis Effect on Glioma of Attenuated Salmonella Typhimurium Vaccine Strain with flk-1 Gene

    冯珂珂; 赵洪洋; 陈剑; 姚东晓; 姜小兵; 周伟

    2004-01-01

    To investigate the anti-vasculature effects and the anti-glioma effects of attenuated Salmonella typhimurium vaccine strain expressing VEGFR2 (flk-1) gene, plasmid pcDNA3. 1-flk1 was constructed and electro-transfected into live attenuated Salmonella typhimurium strain SL7207. Mouse models of intracranial Gl261 glioblastoma were treated with an orally administered attenuated Salmonella typhimurium expressing flk-1 gene. The survival period was recorded and vessel density was observed by immunofluorescence. CTLs activity was measured by MTT assay.Our results showed that attenuated Salmonella typhimurium vaccine strain expressing flk-1 gene could significantly inhibit glioblastoma growth, reduce vessel density, prolong the survival period and improve the survival rate in these mice. The flk-1 specific CTLs activity was increased obviously after the vaccination. Our study showed that attenuated Salmonella typhimurium vaccine strain expressing flk-1 gene could break peripheral immune tolerance a in glioma gainst this self-antigen and kill endothelial cells by the orally administered vaccine and can be used for both prophylactic and therapeutic purposes.

  14. Isolation and identification of Salmonella from curry samples and its sensitivity to commercial antibiotics and aqueous extracts of Camelia sinensis (L.) and Trachyspermum ammi (L.)

    Thanes Gunasegaran; Xavier Rathinam; Marimuthu Kasi; Kathiresan Sathasivam; Sasidharan Sreenivasan; Sreeramanan Subramaniam

    2011-01-01

    Objective: To isolate Salmonella from curry samples and to evaluate the drug sensitivity of the food-borne Salmonella and its susceptibility to specific plant extracts. Methods: Salmonella was isolated from the curry samples by standard microbiological methods and was confirmed by biochemical tests. The antibiotic susceptibility test was conducted by disc diffusion method using commercially available antibiotics such as ampicillin, tetracycline, chloramphenicol, kanamycin, and penicillin. In addition, the susceptibility of the food-borne Salmonella was also evaluated against the aqueous extracts of Camelia sinensis (L.) Theaceae (tea leaves) and the Trachyspermum ammi (L.) Apiaceae ( ajwain or omum seeds). Results: Out of fifty curry samples, only seven samples were identified to have Salmonella contamination. The Salmonella isolates showed a significant drug resistance pattern except for kanamycin. The plant extracts showed a considerable antibacterial activity against the isolates, indicating the presence of antimicrobial principle which can be exploited after complete pharmacological investigations. Conclusions:The present study demonstrates the occurrence of Salmonella in the curry samples, and shows significant drug resistance against most of the commercially available antibiotics, except kanamycin. Antimicrobial effect of the plant extracts against the food-bone Salmonella suggests that dietary including medicinal herbs would be one strategy to manage food borne pathogens.

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

    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.

  16. Bug on the back: vertebral osteomyelitis secondary to fluoroquinolone resistant Salmonella typhi in an immunocompetent patient.

    Shrestha, Pragya; Mohan, Sachin; Roy, Satyajeet

    2015-11-27

    Although Salmonella osteomyelitis is commonly seen in immunocompromised patients, it may occasionally affect an immunocompetent host. Symptoms are usually non-specific, such as fever, abdominal or back pain; hence it should be considered in the differential diagnosis of patients with a history of travel to endemic regions. Fluoroquinolone resistance is rising and non-responsive patients should be treated with ampicillin, trimethoprim-sulfamethoxazole and ceftriaxone. We present a case of acute T8-T11 osteomyelitis with cord compression caused by a fluoroquinolone resistant strain of Salmonella typhi.

  17. Retlig beskyttelse mod salmonella i et EU- og WTO-retligt perspektiv

    2011-01-01

    This article addresses the legal approach to the risk of salmonella infections on the complex interaction between EU Law and international law. It is examined how the latitude of individual states to adopt national food safety measures is restricted by both EU Law and WTO Law. The specific issue...

  18. Yeast β-d-glucans induced antimicrobial peptide expressions against Salmonella infection in broiler chickens.

    Shao, Yujing; Wang, Zhong; Tian, Xiangyu; Guo, Yuming; Zhang, Haibo

    2016-04-01

    The present study was designed to investigate the effects of yeast β-d-glucans (YG) on gene expression of endogenous β-defensins (AvBDs), cathelicidins (Cath) and liver-expressed antimicrobial peptide-2 (LEAP-2) in broilers challenged with Salmonella enteritidis (SE). 240 day-old Cobb male broilers were randomly assigned to 2×2 factorial arrangements of treatments with two levels of dietary YG (0 or 200mg/kg in diet) and two levels of SE challenge (0 or 1×10(9) SE at 7-9 days of age). The results showed SE infection reduced growth performance,and increased salmonella cecal colonization and internal organs invasion, increased concentration of intestinal specific IgA and serum specific IgG antibody, as compared to uninfected birds. SE challenge differentially regulated AvBDs, Caths and LEAP-2 gene expression in the jejunum and spleen of broiler chickens during the infection period. However, YG supplementation inhibited the growth depression by SE challenge, and further increased level of serum specific IgG and intestinal specific IgA antibody. Higher level of salmonella colonization and internal organs invasion in the SE-infected birds were reduced by YG. SE-induced differentially expression patterns of AMPs genes was inhibited or changed by YG. Results indicated YG enhance chicken's resistance to salmonella infection.

  19. The Role of the st313-td Gene in Virulence of Salmonella Typhimurium ST313

    Herrero-Fresno, Ana; Wallrodt, Inke; Leekitcharoenphon, Pimlapas;

    2014-01-01

    Multidrug-resistant Salmonella enterica serovar Typhimurium ST313 has emerged in sub-Saharan Africa causing severe infections in humans. Therefore, it has been speculated that this specific sequence type, ST313, carries factors associated with increased pathogenicity. We assessed the role in viru...

  20. Characterization of putative multidrug resistance transporters of the major facilitator-superfamily expressed in Salmonella Typhi

    Shaheen, Aqsa; Ismat, Fouzia; Iqbal, Mazhar

    2015-01-01

    of this study was to gain insight into the substrate specificity of previously uncharacterized transporters of Salmonella Typhi to identify their role in the development of multidrug resistance. S. Typhi genes encoding putative members of the major facilitator superfamily were cloned and expressed in the drug...

  1. DETECTION OF FRNA COLIPHAGES IN GROUNDWATER: INTERFERENCE WITH THE ASSAY BY SOMATIC SALMONELLA BACTERIOPHAGES

    Groundwater samples from two sites in Alabama, USA were plaque assayed for F-specific RNA (FRNA) coliphages using Salmonella typhimurium WG49 as the host bacterium. While numerous plaques were detected with WG49 (a strain possessing Escherichia coli F pili), plaques were also obs...

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

    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.

  3. Study of 163 children with invasive Salmonella infection in pediatric medical center1

    Khotaeei Gh

    2000-07-01

    Full Text Available Invasive salmonellosis is common in tropical areas. This study examines the performance of a clinical definition for its recognition among children ages 1 to 14 years admitting to a referral pediatric hospital in Tehran. 60 children were enrolled into the study during a period of 51 months. To facilitate analysis, cases were divided into 5 categories according to the likelihood of invasive salmonellosis with category A representing microbiologically confirmed salmonella bacteremia 17 (28.3% and 6 (10% with positive bone marrow cultures. And category D representing those cases in which an alternative diagnosis was firmly established. Salmonella serology supported invasive salmonellosis as the diagnosis in 17 (28% of the nonbacteremic children (category B and C. Salmonella serology suggested that invasive salmonellosis without detectable bacteremia was common. Blood culture proved and serologically diagnosed cases shows that the definition has a specificity of at least 60%.

  4. Prevalence and characterization of motile Salmonella in commercial layer poultry farms in Bangladesh

    Barua, Himel; Biswas, Paritosh K.; Olsen, Katharina E. P.;

    2012-01-01

    at farm/holding level, and the zoonotic serovars circulating in layer poultry in the South and South-East Asian countries including Bangladesh, where small-scale commercial farms are predominant, is limited. To investigate the prevalence of Salmonella at layer farm level, and to identify the prevalent...... serovars we conducted a cross-sectional survey by randomly selecting 500 commercial layer poultry farms in Bangladesh. Faecal samples from the selected farms were collected following standard procedure, and examined for the presence of Salmonella using conventional bacteriological procedures. Thirty...... showed that all of them were clonally related because only one genotype and three subtypes were determined based on the variation in two or three bands. This is also the first report on the presence of any specific serovar of Salmonella enterica in poultry in Bangladesh....

  5. Typhoid toxin provides a window into typhoid fever and the biology of Salmonella Typhi.

    Galán, Jorge E

    2016-06-07

    Salmonella Typhi is the cause of typhoid fever, a disease that has challenged humans throughout history and continues to be a major public health concern. Unlike infections with most other Salmonellae, which result in self-limiting gastroenteritis, typhoid fever is a life-threatening systemic disease. Furthermore, in contrast to most Salmonellae, which can infect a broad range of hosts, S. Typhi is a strict human pathogen. The unique features of S. Typhi pathogenesis and its stringent host specificity have been a long-standing puzzle. The discovery of typhoid toxin not only has provided major insight into these questions but also has offered unique opportunities to develop novel therapeutic and prevention strategies to combat typhoid fever.

  6. Risk assessment of Salmonella in Danish meatballs produced in the catering sector

    Møller, Cleide Oliveira de Almeida; Nauta, Maarten; Schaffner, Donald W.

    2015-01-01

    A modular process risk model approach was used to assess health risks associated with Salmonella spp. after consumption of the Danish meatball product (frikadeller) produced with fresh pork in a catering unit. Meatball production and consumption were described as a series of processes (modules...... observational data and models that were specific for Salmonella spp. in meatballs produced in the catering sector. Danish meatballs are often pan-fried followed by baking in an oven before consumption, in order to reach the core temperature of 75 degrees C recommended by the Danish Food Safety Authority...... of meatballs to core temperatures higher than 70 degrees C, and subsequent holding at room temperatures lower than 20 degrees C, for no longer than 3.5 h, were very effective in Salmonella control. The current Danish Food Safety Authority recommendation of cooking to an internal temperature of 75 degrees C...

  7. Cooperation of Adhesin Alleles in Salmonella-Host Tropism

    De Masi, Leon; Yue, Min; Hu, Changmin; Rakov, Alexey V.; Rankin, Shelley C.

    2017-01-01

    ABSTRACT Allelic combinations and host specificities for three fimbrial adhesins, FimH, BcfD, and StfH, were compared for 262 strains of Salmonella enterica serovar Newport, a frequent human and livestock pathogen. Like FimH, BcfD had two major alleles (designated A and B), whereas StfH had two allelic groups, each with two alleles (subgroup A1 and A2 and subgroup B1 and B2). The most prevalent combinations of FimH/BcfD/StfH alleles in S. Newport were A/A/A1 and B/B/B1. The former set was most frequently found in bovine and porcine strains, whereas the latter combination was most frequently found in environmental and human isolates. Bacteria genetically engineered to express Fim, Bcf, or Stf fimbriae on their surface were tested with the different alleles for binding to human, porcine, and bovine intestinal epithelial cells. The major allelic combinations with bovine and porcine strains (A/A/A1) or with human isolates (B/B/B1) provided at least two alleles capable of binding significantly better than the other alleles to an intestinal epithelial cell line from the respective host(s). However, each combination of alleles kept at least one allele mediating binding to an intestinal epithelial cell from another host. These findings indicated that allelic variation in multiple adhesins of S. Newport contributes to bacterial adaptation to certain preferential hosts without losing the capacity to maintain a broad host range. IMPORTANCE Salmonella enterica remains a leading foodborne bacterial pathogen in the United States; infected livestock serve often as the source of contaminated food products. A study estimated that over a billion Salmonella gastroenteritis cases and up to 33 million typhoid cases occur annually worldwide, with 3.5 million deaths. Although many Salmonella strains with a broad host range present preferential associations with certain host species, it is not clear what determines the various levels of host adaptation. Here, causal properties of host

  8. Acalculous cholecystitis due to Salmonella enteritidis

    Ruiz-Rebollo, Maria Lourdes; Sánchez-Antolín, Gloria; García-Pajares, Félix; Vallecillo-Sande, Maria Antonia; Fernández-Orcajo, Pilar; Velicia-Llames, Rosario; Caro-Patón, Agustín

    2008-01-01

    Acute acalculous cholecystitis (AAC) is defined as an acute inflammation of the gallbladder in the absence of stones. We herein report a case of a young man who developed AAC after a Salmonella enteritidis gastrointestinal infection.

  9. Whole Genome Epidemiological Typing of Salmonella

    Leekitcharoenphon, Pimlapas

    Salmonella is one of the most common foodborne pathogens worldwide. In the US alone, salmonellosis was estimated to cause 1.4 million cases effecting 17,000 hospitalization and almost 600 deaths each year. Particularly, Salmonella enterica is a common cause of minor and large food borne outbreaks....... Technological advances and effective price in high throughput genome sequencing are making whole genome sequencing (WGS) available as a routine tool for bacterial typing. Typing of Salmonella, especially sub-typing within the same serotype or even the same clone, the genetic variation of the target genes being...... available Salmonella enterica genomes (accessed in April 2011). A consensus tree based on variation of the core genes gives better resolution than 16S rRNA and MLST that rarely provide separation between closely related strains. The performance of the pan-genome tree which is based on the presence...

  10. Acalculous cholecystitis due to Salmonella enteritidis

    Maria Lourdes Ruiz-Rebollo; Gloria Sánchez-Antolín; Félix García-Pajares; Maria Antonia Vallecillo-Sande; Pilar Fernández-Orcajo; Rosario Velicia-Uames; Agustín Caro-Patón

    2008-01-01

    Acute acalculous cholecystitis (AAC) is defined as an acute inflammation of the gallbladder in the absence of stones. We herein report a case of a young man who developed AAC after a Salmonella enteritidis gastroin-testinal infection.

  11. lac repressor is an antivirulence factor of Salmonella enterica: its role in the evolution of virulence in Salmonella.

    Sandeepa M Eswarappa

    Full Text Available The genus Salmonella includes many pathogens of great medical and veterinary importance. Bacteria belonging to this genus are very closely related to those belonging to the genus Escherichia. lacZYA operon and lacI are present in Escherichia coli, but not in Salmonella enterica. It has been proposed that Salmonella has lost lacZYA operon and lacI during evolution. In this study, we have investigated the physiological and evolutionary significance of the absence of lacI in Salmonella enterica. Using murine model of typhoid fever, we show that the expression of LacI causes a remarkable reduction in the virulence of Salmonella enterica. LacI also suppresses the ability of Salmonella enterica to proliferate inside murine macrophages. Microarray analysis revealed that LacI interferes with the expression of virulence genes of Salmonella pathogenicity island 2. This effect was confirmed by RT-PCR and Western blot analysis. Interestingly, we found that SBG0326 of Salmonella bongori is homologous to lacI of Escherichia coli. Salmonella bongori is the only other species of the genus Salmonella and it lacks the virulence genes of Salmonella pathogenicity island 2. Overall, our results demonstrate that LacI is an antivirulence factor o