WorldWideScience

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.

    Science.gov (United States)

    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.

    Science.gov (United States)

    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.

    Science.gov (United States)

    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.

    Science.gov (United States)

    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.

    Science.gov (United States)

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    KAUST Repository

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  14. 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.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:19376910

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

    Directory of Open Access Journals (Sweden)

    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

  2. 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.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  4. 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

    Institute of Scientific and Technical Information of China (English)

    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。

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

    Science.gov (United States)

    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.

  6. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  7. Determination of the invA gene of Salmonella using surface plasmon resonance along with streptavidin aptamer amplification

    International Nuclear Information System (INIS)

    We have developed a sensitive method for the determination of Salmonella by integrating a streptavidinylated aptamer (SA-aptamer) as a signal amplification unit along with a modified asymmetric polymerase chain reaction (PCR) technique into the surface of an SPR sensor chip. The gold film of the sensor was first modified with a thiolated probe, and the target sequence and SA-aptamer were then induced to form a sandwich structure. If SA is added, the SA-aptamer forms a complex with SA which will amplify the signal. Under optimal conditions, this sensing scheme has a linear response in the 50 pM to 200 nM range, and the lower detection limit is 20 pM (for a synthetic target sequence). This strategy was successfully applied to the determination of Salmonella bacteria at levels as low as 60 CFU mL−1. This biosensor is sensitive, selective and highly stable. These features make this strategy a promising and powerful screening tool to detect pathogens in food, and in clinical and environmental samples. (author)

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

    Science.gov (United States)

    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

    Institute of Scientific and Technical Information of China (English)

    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.

    Science.gov (United States)

    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. SPECIFIC CONTROL OF SALMONELLA IN POULTRY

    Directory of Open Access Journals (Sweden)

    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.

  12. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Directory of Open Access Journals (Sweden)

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Subcellular localization of rickettsial invasion protein, InvA.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

    Energy Technology Data Exchange (ETDEWEB)

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:26939645

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  3. Salmonella

    Science.gov (United States)

    ... Linked to Small Turtles More Reports, Publications, and Communication Materials Surveillance Salmonella Atlas MMWR Articles References Communication ... Infections Linked to Red and Black Pepper/Italian-Style Meats 2006 through 2009 Outbreaks Saintpaul Infections Linked ...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Salmonella

    Science.gov (United States)

    Salmonella are facultative anaerobic Gram-negative non-spore forming rods belonging to the family Enterobacteriaceae. Salmonellosis is a zoonotic and foodborne illness that is usually transmitted by the fecal-oral route estimated to be responsible for 1.4 million cases of human infections in 2009 in...

  7. 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.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Comparison of methods for specific depletion of ATP in Salmonella typhimurium.

    OpenAIRE

    Johnson, M. S.; Taylor, B L

    1993-01-01

    Three methods of ATP depletion in Salmonella typhimurium were compared. ATP concentrations were lowest after arsenate treatment. Arsenate or alpha-methylglucoside-plus-azide treatment nonspecifically lowered all nucleotide triphosphate levels. Histidine starvation in a hisF mutant was relatively specific for ATP depletion and therefore has potential in distinguishing ATP-dependent processes from processes dependent on other nucleotides.

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

    Science.gov (United States)

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

    2016-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  1. A Guerra Absoluta de Clausewitz nas Invasões Francesas

    OpenAIRE

    Gonçalves, Flávio, 1929-1988

    2015-01-01

    O presente trabalho, intitulado: “A Guerra Absoluta de Clausewitz nas Invasões Francesas”, tem como principal objetivo identificar os aspetos do conceito de Guerra Absoluta de Clausewitz que ocorreram durante o período das Invasões Francesas. Pretende-se esclarecer a importância do povo durante o período das Invasões Francesas, facto que deve ser de conhecimento público, de modo que exibam orgulho e tenham perfeita noção daquil...

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    DEFF Research Database (Denmark)

    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....

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

    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...

  13. Occurrence of Salmonella in retail beef and related meat products in Zaria, Nigeria

    DEFF Research Database (Denmark)

    Tafida, S.Y.; Kabir, J.; Kwaga, J.K.P.;

    2013-01-01

    serotyped. Confirmed isolates were evaluated in vitro for susceptibilities to 18 commonly used antimicrobial agents. Ten samples (2.3%) were positive for Salmonella. Raw beef samples had the highest isolation rates (2.43%). All the 10 Salmonella isolates were found to carry the invA gene. All the isolates...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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

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

    DEFF Research Database (Denmark)

    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 advancements...... amplification control (IAC) co-amplified with the invA gene of Salmonella to monitor potential PCR inhibitors and ensure successful amplification. The selectivity study involved 84 Salmonella and 44 non-Salmonella strains and the samples tested were represented by 60 artificially-contaminated samples of fish...

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

    Science.gov (United States)

    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.

  19. Designing of primers for detection of salmonella typhimirium and enteritidis by heminested PCR

    International Nuclear Information System (INIS)

    Salmonella are the main responsible agent for the frequent food borne gastrointestinal diseases. In Tunisia, this pathogen is considered one of the most important causes of toxiinfections and its detection using classical methods is laborious and requires a large amount of time for revelation. To solve this problem, we developed a rapid molecular technique for the detection of the invA virulence gene sequence which is found in the majority of Salmonella spp. This technique is a hemi nested PCR amplification using specific primers designed and by bioinformatics tools. The detection method consisted of pre-enrichment of the sample in buffered peptone water (BPW), followed by a total DNA extraction step prior to single tube hemi nested PCR amplification. This method was found highly specific and sensitive to detect low levels of salmonella typhimurium and salmonella enteritidis (1cfu/ 25g) in naturally contaminated spicy sausage (merguez) samples. These results can benefit the public health agencies concerning microbiological and quality aspects of the commercial and traditional merguez meat production in Tunisia. (Author)

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

    Science.gov (United States)

    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.

  1. Salmonella enterocolitis

    Science.gov (United States)

    Salmonellosis; Nontyphoidal salmonella; Food poisoning - salmonella; Gastroenteritis - salmonella ... Salmonella infection is one of the most common types of food poisoning . It occurs when you swallow ...

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

    Science.gov (United States)

    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. PMID:27000396

  3. Occurrence of Salmonella-specific bacteriophages in swine feces collected from commercial farms

    Science.gov (United States)

    Salmonella is one of the primary foodborne pathogens associated with swine production and represents a significant threat to human health. Bacteriophage are naturally-occurring viruses that prey on bacteria and have been suggested as a potential intervention strategy to reduce Salmonella in food an...

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

    NARCIS (Netherlands)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    NARCIS (Netherlands)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Isolation of scFv fragments specific to OmpD of Salmonella Typhimurium

    OpenAIRE

    2010-01-01

    Abstract Pork meat is one of the major sources for human infections with Salmonella enterica subspecies enterica serovars. Further, zoonoses caused by Salmonella enterica subspecies enterica serovars. are responsible for substantial economical losses in industrial countries. Quick and reliable detection of this infection is urgently needed to improve consumer security. Due to its capability to identify infections independent of the species, a competitive ELISA is the preferable met...

  9. Farm Specific Control of the Introduction and Spread of Salmonella at Finishing Pig Farms

    OpenAIRE

    Van der Gaag, M.A.; Enting, J.; Mul, Monique F.

    2003-01-01

    In The Netherlands, a system to control the prevalence of Salmonella in the pork supply chain is under development by the Product Boards of Livestock, Meat and Eggs. Therefore, the Animal Sciences Group-Applied Research has developed a tool to support pig-finishing farms to control Salmonella. This tool contains eight checklists. The checklists are based on the principles of the HACCP methodology. Important hazards and control measures were determined. Each checklist deals with a part of the ...

  10. 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.

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

    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...... of selectivity by using 364 strains showed that the inclusivity was 99.6% and the exclusivity was 100% for the invA primer set. To indicate possible PCR inhibitors derived from the sample DNA, an internal amplification control (IAC), which was coamplified with the invA target gene, was constructed...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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

    Institute of Scientific and Technical Information of China (English)

    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

  16. Heat resistance of Salmonella enterica is increased by pre-adaptation to peanut oil or sub-lethal heat exposure.

    Science.gov (United States)

    Fong, Karen; Wang, Siyun

    2016-09-01

    Cross-protection represents a considerable challenge in the food industry where hurdled interventions are often employed to reduce Salmonella contamination. The heat resistance of Salmonella strains from five serotypes (i.e., Typhimurium, Enteritidis, Tennessee, Thompson and Hartford) at 70 °C was determined by measurement of viable cell populations before and after adaptation to two common stresses employed in low-water activity food processing, desiccation and sub-lethal heat treatment. Survival of Salmonella at 70 °C significantly increased (p aw 0.52 ± 0.00) and/or the exposure to a sub-lethal heat treatment at 45 °C for 3 min. Quantitative PCR revealed upregulation of two desiccation stress-related genes, fadA and otsB, following the peanut oil incubation, whereas heat treatment induced upregulation of a heat-resistance gene, dnaK. Invasion gene invA and alternative sigma factor rpoE were downregulated following either of the treatments. Interestingly, different Salmonella strains yielded different transcriptional profiles. The strain-specific resistance phenotypes and transcriptional profiles provided further insights into the mechanisms employed to tolerate desiccation and heat stresses in the food industry. PMID:27217370

  17. 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.

    Institute of Scientific and Technical Information of China (English)

    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.

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

    NARCIS (Netherlands)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Molecular Detection of Salmonella Serovar Isolated from Eggs

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Phagocytic superoxide specifically damages an extracytoplasmic target to inhibit or kill Salmonella.

    Directory of Open Access Journals (Sweden)

    Maureen Craig

    Full Text Available BACKGROUND: The phagocytic oxidative burst is a primary effector of innate immunity that protects against bacterial infection. However, the mechanism by which reactive oxygen species (ROS kill or inhibit bacteria is not known. It is often assumed that DNA is a primary target of oxidative damage, consistent with known effects of endogenously produced ROS in the bacterial cytoplasm. But most studies fail to distinguish between effects of host derived ROS versus damage caused by endogenous bacterial sources. We took advantage of both the ability of Salmonella enterica serovar Typhimurium to survive in macrophages and the genetic tractability of the system to test the hypothesis that phagocytic superoxide damages cytoplasmic targets including DNA. METHODOLOGY/PRINCIPAL FINDINGS: SodCI is a periplasmic Cu-Zn superoxide dismutase (SOD that contributes to the survival of Salmonella Typhimurium in macrophages. Through competitive virulence assays, we asked if sodCI has a genetic interaction with various cytoplasmic systems. We found that SodCI acts independently of cytoplasmic SODs, SodA and SodB. In addition, SodCI acts independently of the base excision repair system and RuvAB, involved in DNA repair. Although sodCI did show genetic interaction with recA, this was apparently independent of recombination and is presumably due to the pleiotropic effects of a recA mutation. CONCLUSIONS/SIGNIFICANCE: Taken together, these results suggest that bacterial inhibition by phagocytic superoxide is primarily the result of damage to an extracytoplasmic target.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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. Salmonella Prevention

    Science.gov (United States)

    ... Salmonella Reading and Salmonella Abony Infections linked to Alfalfa Sprouts Advice to Consumers & Retailers Case Count Maps ... Signs & Symptoms Key Resources Salmonella Infections Linked to Alfalfa Sprouts from One Contaminated Seed Lot Advice to ...

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

    NARCIS (Netherlands)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  19. 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.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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.

    Science.gov (United States)

    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

  3. Chicken-Specific Kinome Array Reveals that Salmonella enterica Serovar Enteritidis Modulates Host Immune Signaling Pathways in the Cecum to Establish a Persistence Infection

    Science.gov (United States)

    Kogut, Michael H.; Swaggerty, Christina L.; Byrd, James Allen; Selvaraj, Ramesh; Arsenault, Ryan J.

    2016-01-01

    Non-typhoidal Salmonella enterica induces 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 underlying mechanisms that control this persistent colonization of the ceca of chickens by Salmonella are only beginning to be elucidated. We hypothesize that alteration of host signaling pathways mediate the induction of a tolerance response. Using chicken-specific kinomic immune peptide arrays and quantitative RT-PCR of infected cecal tissue, we have previously evaluated the development of disease tolerance in chickens infected with Salmonella enterica serovar Enteritidis (S. Enteritidis) in a persistent infection model (4–14 days post infection). Here, we have further outlined the induction of an tolerance defense strategy in the cecum of chickens infected with S. Enteritidis beginning around four days post-primary infection. The response is characterized by alterations in the activation of T cell signaling mediated by the dephosphorylation of phospholipase c-γ1 (PLCG1) that inhibits NF-κB signaling and activates nuclear factor of activated T-cells (NFAT) signaling and blockage of interferon-γ (IFN-γ) production through the disruption of the JAK-STAT signaling pathway (dephosphorylation of JAK2, JAK3, and STAT4). Further, we measured a significant down-regulation reduction in IFN-γ mRNA expression. These studies, combined with our previous findings, describe global phenotypic changes in the avian cecum of Salmonella Enteritidis-infected chickens that decreases the host responsiveness resulting in the establishment of persistent colonization. The identified tissue protein kinases also represent potential targets for future antimicrobial compounds for decreasing Salmonella loads in the intestines of food animals before going to market. PMID:27472318

  4. 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

    Institute of Scientific and Technical Information of China (English)

    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。

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

    Directory of Open Access Journals (Sweden)

    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

  6. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Salmonella: Salmonellosis

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  11. Ultrastructural Study of Salmonella typhimurium Treated with Membrane-Active Agents: Specific Reaction of Dansylchloride with Cell Envelope Components

    Science.gov (United States)

    Schindler, Peter R. G.; Teuber, Michael

    1978-01-01

    Amino groups of cell envelope proteins, lipids, and lipopolysaccharides cannot be labeled in intact cells of Salmonella typhimurium G 30 by using 5-dimethylaminonaphthalene-1-sulfonylchloride incorporated in lecithin-cholesterol vesicles. However, application of membrane-interacting agents like tris(hydroxymethyl)aminomethane (Tris)-hydrochloride, ethylenediaminetetraacetate (Na salt) (EDTA), divalent cations, and sublethal doses of the cationic antibacterial agents polymyxin B and chlorhexidine induced specific fluorescent labeling of envelope proteins and lipids but not of cytoplasmic compounds, with the exception of a soluble protein with a molecular weight of 46,000 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Treatment with Tris-hydrochloride buffer produced labeling of the heat-modifiable protein B/B+ and of proteins with molecular weights of 26,000, 22,000, and below 17,000. A combination of Tris-hydrochloride and EDTA induced additional dansylation of the major protein A and of proteins of molecular weights 80,000, 60,000, and 44,000. Polymyxin B and chlorhexidine caused similar labeling patterns. In every case, except with divalent cation treatment, protein B/B+ was the most prominently labeled species. Phosphatidylethanolamine was dansylated up to 30%. Lipopolysaccharide was not reactive under any condition or treatment. In addition, the peptidoglycan-bound lipoprotein did not react with dansylchloride in either intact or Tris-hydrochloride-treated cells. The results are discussed with regard to a possible localization of labeled and unlabeled compounds of the cell envelope on the basis of a model placing cell envelope amino groups into ion-ion interactions with anionic components of other envelope compounds like phosphate and carboxyl groups. Images PMID:97268

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

    Directory of Open Access Journals (Sweden)

    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.

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

    DEFF Research Database (Denmark)

    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...... an array of effectors into the host, relatively few host proteins have been identified as targets for their effects. Here we use stable isotope labeling with amino acids in cell culture (SILAC) and quantitative mass spectrometry-based proteomics to identify the host targets of the SPI-1 effector, Sop...

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

    Directory of Open Access Journals (Sweden)

    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

  15. [Salmonella pathogenicity islands].

    Science.gov (United States)

    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.

  16. Yersinia pestis pFra Shows Biovar-Specific Differences and Recent Common Ancestry with a Salmonella enterica Serovar Typhi Plasmid

    Science.gov (United States)

    Prentice, Michael B.; James, Keith D.; Parkhill, Julian; Baker, Stephen G.; Stevens, Kim; Simmonds, Mark N.; Mungall, Karen L.; Churcher, Carol; Oyston, Petra C. F.; Titball, Richard W.; Wren, Brendan W.; Wain, John; Pickard, Derek; Hien, Tran Tinh; Farrar, Jeremy J.; Dougan, Gordon

    2001-01-01

    Population genetic studies suggest that Yersinia pestis, the cause of plague, is a clonal pathogen that has recently emerged from Yersinia pseudotuberculosis. Plasmid acquisition is likely to have been a key element in this evolutionary leap from an enteric to a flea-transmitted systemic pathogen. However, the origin of Y. pestis-specific plasmids remains obscure. We demonstrate specific plasmid rearrangements in different Y. pestis strains which distinguish Y. pestis bv. Orientalis strains from other biovars. We also present evidence for plasmid-associated DNA exchange between Y. pestis and the exclusively human pathogen Salmonella enterica serovar Typhi. PMID:11274119

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

    Science.gov (United States)

    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.

  18. Serotype-specific and serotype-independent strategies for pre-harvest control of foodborne Salmonella in poultry.

    Science.gov (United States)

    Of more than 2500 identified Salmonella serotypes, only a small proportion are common in poultry flocks. However, there is an epidemiologically important connection between poultry products and human infections, as many of the serotypes that are most prevalent in humans (such as S. Typhimurium and S...

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

    NARCIS (Netherlands)

    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

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

    Science.gov (United States)

    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.

  1. Comparative Virulotyping of Salmonella typhi and Salmonella enteritidis.

    Science.gov (United States)

    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.

  2. Comparative Virulotyping of Salmonella typhi and Salmonella enteritidis.

    Science.gov (United States)

    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. PMID:24426144

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

    Science.gov (United States)

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

    2015-07-01

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

  4. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  7. Epidemiology of Non-Typhoidal Salmonella (NTS in Humans and Animals in the Gambia and Senegal

    Directory of Open Access Journals (Sweden)

    Dione, M.

    2010-01-01

    . However, one new clone of multi-resistant Salmonella Kentucky was found. This study provided us with new insights into the genetic diversity on NTS in Senegal. Molecular tools remain essential to study the epidemiology of NTS by tracking the sources of infection and/or contamination. These same techniques were used to study the animal to human transmission in The Gambia in the next chapter. In chapter 4, eight diarrheic children with confirmed salmonellosis and 6 healthy carriers were traced back to their compounds and Salmonella identified from the domestic animals (poultry, sheep and goat living in close contact in the same compound. The most common serotypes identified were Salmonella Colindale in humans (21.42% and Salmonella Poona in animals (14.28%. Among the animals, poultry carried the highest proportion of Salmonella (66.7%. In fact, poultry are considered as the most common asymptomatic carriers of Salmonella. However, serotypes in humans were different from those in animals except in one case where Salmonella Moualine was simultaneously found in chicken and a diarrheic child but in different compounds. After proceeding MLST on all isolates, we found that those two Salmonella Moualine were distinct but genetically very close because they differed at only one locus sucA. The similarity matrix of the strains revealed close genetic relatedness among Salmonella serotypes. There was at least 80% similarity and the majority varied between 98% and 100%. This showed the stability of Salmonella clones which are not subject to high genetic variability. There was therefore no indication of clonal groups which are adapted to a specific host because the genetic tree did reveal that all lineages contained isolates of mixed origin (human and animal. The association between salmonellosis and other diseases, most often malaria, in our study shows the role of opportunistic infections and malaria in NTS infections. Almost all serotypes were susceptible to all antibiotics tested

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  11. Immune Reaction and Survivability of Salmonella Typhimurium and Salmonella Infantis after Infection of Primary Avian Macrophages

    OpenAIRE

    Maria Braukmann; Ulrich Methner; Angela Berndt

    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.) Typhim...

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

    Science.gov (United States)

    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 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.

  13. Simultaneous Detection of Listeria monocytogenes, Escherichia coli O157:H7, Bacillus cereus, Salmonella spp., and Staphylococcus aureus in Low-fatted Milk by Multiplex PCR

    Science.gov (United States)

    Kim, Ji-Hyun; Rhim, Seong-Ryul; Kim, Kee-Tae; Paik, Hyun-Dong

    2014-01-01

    A rapid and specific PCR assay for the simultaneous detection of Listeria monocytogenes, Escherichia coli O157:H7, Bacillus cereus, Salmonella spp., and Staphylococcus aureus in foods was developed to reduce the detection time and to increase sensitivity. Multiplex PCR developed in this study produced only actA, fliC, hbl, invA, ileS amplicons, but did not produce any non-specific amplicon. The primer sets successfully amplified the target genes in the multiplex PCR without any non-specific or additional bands on the other strains. The multiplex PCR assays also amplified some target genes from five pathogens, and multiplex amplification was obtained from as little as 1 pg of DNA. According to the results from the sensitivity evaluation, the multiplex PCR developed in this study detected 10 cells/mL of the pathogens inoculated in milk samples, respectively. The results suggested that multiplex PCR was an effective assay demonstrating high specificity for the simultaneous detection of five target pathogens in food system. PMID:26761507

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:26931537

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Salmonella Diagnosis and Treatment

    Science.gov (United States)

    ... Salmonella Reading and Salmonella Abony Infections linked to Alfalfa Sprouts Advice to Consumers & Retailers Case Count Maps ... Signs & Symptoms Key Resources Salmonella Infections Linked to Alfalfa Sprouts from One Contaminated Seed Lot Advice to ...

  3. Reptiles, Amphibians, and Salmonella

    Science.gov (United States)

    ... What's this? Submit Button Past Emails CDC Features Reptiles, Amphibians, and Salmonella Language: English Español (Spanish) Recommend ... live. How do people get Salmonella infections from reptiles and amphibians? Reptiles and amphibians might have Salmonella ...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

    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....

  13. Multiplex real-time PCR assay for the specific detection and quantification of Salmonella spp., Listeria monocytogenes, and Escherichia coli O157:H7 in ground pork samples

    Science.gov (United States)

    Salmonella spp., Listeria monocytogenes, and Escherichia coli O157:H7 are food borne-pathogens capable of causing serious gastrointestinal illness. We previously described simultaneous detection of these pathogens by multiplex PCR in 44 types of spiked food samples, including meat, produce, fish, an...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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.

  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

    Institute of Scientific and Technical Information of China (English)

    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. Mieloma múltiplo: invasão leptomeníngea difusa

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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. Multiplex T-RFLP Allows for Increased Target Number and Specificity: Detection of Salmonella enterica and Six Species of Listeria in a Single Test

    OpenAIRE

    Elliott, Geoffrey N.; Nadine Thomas; Marion Macrae; Campbell, Colin D.; Ogden, Iain D; Singh, Brajesh K.

    2012-01-01

    A multiplex T-RFLP test was developed to detect and identify Salmonella enterica and all six species of Listeria inoculated into milk at minimal levels. Extensive in silico analysis was used to design a fifteen-primer, six-amplimer methodology and in vitro application showed target organism DNA, when amplified individually, yielded the predicted terminal restriction fragments (TRFs) following digestion. Non-target organisms were either not-amplified or yielded TRFs which did not interfere wit...

  2. 78 FR 42526 - Salmonella

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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. PMID:25812224

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  6. A carbon nanotube immunosensor for Salmonella

    Directory of Open Access Journals (Sweden)

    Mitchell B. Lerner

    2011-12-01

    Full Text Available Antibody-functionalized carbon nanotube devices have been suggested for use as bacterial detectors for monitoring of food purity in transit from the farm to the kitchen. Here we report progress towards that goal by demonstrating specific detection of Salmonella in complex nutrient broth solutions using nanotube transistors functionalized with covalently-bound anti-Salmonella antibodies. The small size of the active device region makes them compatible with integration in large-scale arrays. We find that the on-state current of the transistor is sensitive specifically to the Salmonella concentration and saturates at low concentration (<1000 cfu/ml. In contrast, the carrier mobility is affected comparably by Salmonella and other bacteria types, with no sign of saturation even at much larger concentrations (108 cfu/ml.

  7. 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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  10. SALMATcor: microagglutination for Salmonella flagella serotyping.

    Science.gov (United States)

    Duarte Martínez, Francisco; Sánchez-Salazar, Luz Marina; Acuña-Calvo, María Teresa; Bolaños-Acuña, Hilda María; Dittel-Dittel, Isis; Campos-Chacón, Elena

    2010-08-01

    Salmonella is a complex bacterial group with more than 2400 serovars widely distributed in nature; they are considered zoonotic because they can infect a variety of animals and be transmitted to humans. Usually, they cause alimentary acquired diseases such as gastroenteritis, typhoid fever, and others that can lead to severe complications and death. Serotyping is useful to differentiate among Salmonella, because it shows an important correlation with their clinical and epidemiological patterns; consequently, it is of high value for public health, animal health, agriculture, and industry. To characterize all known Kauffmann-White Salmonella serovars, over 250 antisera are required. Due to this and to high prices antisera, many laboratories worldwide have limitations in establishing Salmonella surveillance. Therefore, we developed and validated a Salmonella flagella microagglutination test (SALMATcor) that significantly reduces laboratory requirements of antisera. SALMATcor is based on scaling down, by fivefold, the antigen:antiserum volumes actually required for the reference method: flagella standard tube agglutination technique (STAT). Antigen preparation, temperatures, and incubation periods remained as established for STAT. The SALMATcor was validated according to ISO/DIS 16140:1999 protocol, which included 1187 comparisons of flagella determinations conducted by SALMATcor and STAT, on 141 Salmonella isolates of 12 common serotypes and the use of antiserum recommended for STAT. SALMATcor concordance was excellent (Cohen's kappa index 0.9982), obtaining relative accuracy >99.9% and relative specificity >99.9%. Additionally, SALMATcor has been used by CNRB-INCIENSA since 2004 to respond to all 40 Salmonella proficiency testing strains, provided by World Health Organization-Global Salmonella Surveillance Network, obtaining 100% concordance on serovar identification. On the basis of the results achieved with SALMATcor and considering that it also significantly

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  13. The Salmonella enterica Pan-genome

    DEFF Research Database (Denmark)

    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. Seroincidence of non-typhoid Salmonella infections

    DEFF Research Database (Denmark)

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

    2016-01-01

    The incidence of reported infections of non-typhoid Salmonella is affected by biases inherent to passive laboratory surveillance, whereas analysis of blood sera may provide a less biased alternative to estimate the force of Salmonella transmission in humans. We developed a mathematical model...... 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...... of healthy individuals from 2006 to 2007 (n = 1780). The lowest antibody levels were measured in the samples from the community cohort and the highest in pregnant women. The annual Salmonella seroincidences were 319 infections/1000 pregnant women [90% credibility interval (CrI) 210-441], 182/1000 in blood...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  18. 40 CFR 79.68 - Salmonella typhimurium reverse mutation assay.

    Science.gov (United States)

    2010-07-01

    ... consulted. (1) 40 CFR 798.5265, The Salmonella typhimurium reverse mutation asay. (2) Ames, B.N., McCann, J... recommendations as specified under 40 CFR 79.60, the following specific information shall be reported: (i... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Salmonella typhimurium...

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

    Science.gov (United States)

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

    2016-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. A mannosyl transferase required for lipopolysaccharide inner core assembly in Rhizobium leguminosarum. Purification, substrate specificity, and expression in Salmonella waaC mutants.

    Science.gov (United States)

    Kanipes, Margaret I; Ribeiro, Anthony A; Lin, Shanhua; Cotter, Robert J; Raetz, Christian R H

    2003-05-01

    The lipopolysaccharide (LPS) core domain of Gram-negative bacteria plays an important role in outer membrane stability and host interactions. Little is known about the biochemical properties of the glycosyltransferases that assemble the LPS core. We now report the purification and characterization of the Rhizobium leguminosarum mannosyl transferase LpcC, which adds a mannose unit to the inner 3-deoxy-d-manno-octulosonic acid (Kdo) moiety of the LPS precursor, Kdo(2)-lipid IV(A). LpcC containing an N-terminal His(6) tag was assayed using GDP-mannose as the donor and Kdo(2)-[4'-(32)P]lipid IV(A) as the acceptor and was purified to near homogeneity. Sequencing of the N terminus confirmed that the purified enzyme is the lpcC gene product. Mild acid hydrolysis of the glycolipid generated in vitro by pure LpcC showed that the mannosylation occurs on the inner Kdo residue of Kdo(2)-[4'-(32)P]lipid IV(A). A lipid acceptor substrate containing two Kdo moieties is required by LpcC, since no activity is seen with lipid IV(A) or Kdo-lipid IV(A). The purified enzyme can use GDP-mannose or, to a lesser extent, ADP-mannose (both of which have the alpha-anomeric configuration) for the glycosylation of Kdo(2)-[4'-(32)P]lipid IV(A). Little or no activity is seen with ADP-glucose, UDP-glucose, UDP-GlcNAc, or UDP-galactose. A Salmonella typhimurium waaC mutant, which lacks the enzyme for incorporating the inner l-glycero-d-manno-heptose moiety of LPS, regains LPS with O-antigen when complemented with lpcC. An Escherichia coli heptose-less waaC-waaF deletion mutant expressing the R. leguminosarum lpcC gene likewise generates a hybrid LPS species consisting of Kdo(2)-lipid A plus a single mannose residue. Our results demonstrate that heterologous lpcC expression can be used to modify the structure of the Salmonella and E. coli LPS cores in living cells.

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

    Science.gov (United States)

    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.

  3. Genomics of Salmonella Species

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    Paião, F.G.; Arisitides, L.G.A.; Murate, L.S.; Vilas-Bôas, G.T.; Vilas-Boas, L.A.; Shimokomaki, M.

    2013-01-01

    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 °C 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. PMID:24159281

  7. Procalcitonin levels in salmonella infection

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  13. Unveiling ubiquitinome rearrangements induced by Salmonella infection

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  15. Detection of Salmonella and several common Salmonella serotypes in food by loop-mediated isothermal amplification method

    Directory of Open Access Journals (Sweden)

    Zhongqiang Chen

    2015-06-01

    Full Text Available Salmonella Choleraesuis, S. Enteritidis and S. Typhimurium are the main pathogens that contaminate animal products and cause human Salmonella food poisoning. To establish the loop-mediated isothermal amplification (LAMP method for the rapid detection of Salmonella and 3 common Salmonella serotypes, inner and outer primer sets targeting Salmonella invE gene and 3 serotype-specific genes fliC, lygD and STM4495 were designed. The LAMP reaction conditions were optimized. The specificity of LAMP primers was identified by testing 10 different bacterial strains including S. Choleraesuis, S. Enteritidis and S. Typhimurium. Take S. Choleraesuis as example, the detection limit of LAMP assay was 1.33 × 101 CFU/mL for bacteria culture and 2.0 × 101 CFU/mL for simulated pork sample. The results show that LAMP is a rapid, sensitive and specific method for Salmonella detection and can be used for the rapid detection of Salmonella in food.

  16. Antimicrobial Resistance Profiles of Salmonella spp. from Agricultural Environments in Fruit Production Systems.

    Science.gov (United States)

    Gomba, Annancietar; Chidamba, Lizyben; Korsten, Lise

    2016-09-01

    Foodborne disease outbreaks involving fresh produce have increased in recent years. The risk of infection from contaminated food is worsened by the increased prevalence of antibiotic-resistant strains. This study evaluated the prevalence of antibiotic resistance in Salmonella isolates (n = 263) from agricultural production systems through to the final packed product. Salmonella isolates were preliminarily identified by matrix-assisted laser desorption ionization-time-of-flight mass spectroscopy (MALDI-TOF MS) and API 20E and identities confirmed by invA gene polymerase chain reaction. Antimicrobial susceptibility was performed with 15 antimicrobial agents using the Kirby-Bauer disk diffusion test. Of the 263 Salmonella isolates assessed, 59.3% were resistant to one or more antimicrobials. The most frequently detected resistance was against chloramphenicol and kanamycin (46.7%), trimethoprim-sulfamethoxazole (28%), and streptomycin (14%), and the less frequently detected resistance was toward ampicillin (1.14%), amikacin (0.76%), and amoxicillin-clavulanic acid (0.38%). Multiple antimicrobial resistance (MAR) (resistance to ≥3 antibiotics) was found in 48.7% (76/156) isolates. The most common MAR phenotype was to chloramphenicol and trimethoprim/sulfamethoxazole-kanamycin (43.6%). Resistance to chloramphenicol, kanamycin, or trimethoprim/sulfamethoxazole was only observed in MAR phenotypes. All isolates were susceptible to ceftiofur, cefoxitin, ceftriaxone, ciprofloxacin, nalidixic acid, gentamicin, and tetracycline. This study confirms the importance of fresh produce production environments as potential reservoirs and fresh produce as carriers of antibiotic-resistant Salmonella spp. with significant clinical importance. Further studies to evaluate the actual level of health risk from these pathogens should include characterization of the antibiotic resistance determinant genes among the isolates. PMID:27294335

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Towards standardization of microarray-based genotyping of Salmonella

    DEFF Research Database (Denmark)

    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....

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  3. Salmonella enteritidis in Quail Eggs

    OpenAIRE

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Live attenuated vaccines for invasive Salmonella infections.

    Science.gov (United States)

    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.

  6. Salmonella radicidation of poultry carcasses

    International Nuclear Information System (INIS)

    This thesis reports investigations using gamma-radiation to decontaminate poultry carcasses. The application to foods of doses of ionizing radiation sufficient to reduce the number of viable specific non-sporeforming pathogenic microorganisms so that none is detectable in the treated food by any standard method is termed radicidation. The doses used in this study were at such a level that no undesirable or unfavourable side-effects occurred. The effects of these doses were studied on salmonellae and other microorganisms present in, or associated with poultry carcasses and in liquid and on solid culture media as well. Decimal reduction (D10) values were estimated. These represent the dose (kGy) required to achieve a reduction in initial colony count from N0 to 0.1 N0. Together with the estimation of the numbers of Salmonella present per carcass the data were used to predict the effect of an ionizing radiation treatment of poultry. Data on the effect of ionizing radiation on the total microflora of poultry carcasses were also collected. (Auth.)

  7. Cationic amino acid transporters and Salmonella Typhimurium ArgT collectively regulate arginine availability towards intracellular Salmonella growth.

    Directory of Open Access Journals (Sweden)

    Priyanka Das

    Full Text Available Cationic amino acid transporters (mCAT1 and mCAT2B regulate the arginine availability in macrophages. How in the infected cell a pathogen can alter the arginine metabolism of the host remains to be understood. We reveal here a novel mechanism by which Salmonella exploit mCAT1 and mCAT2B to acquire host arginine towards its own intracellular growth within antigen presenting cells. We demonstrate that Salmonella infected bone marrow derived macrophages and dendritic cells show enhanced arginine uptake and increased expression of mCAT1 and mCAT2B. We show that the mCAT1 transporter is in close proximity to Salmonella containing vacuole (SCV specifically by live intracellular Salmonella in order to access the macrophage cytosolic arginine pool. Further, Lysosome associated membrane protein 1, a marker of SCV, also was found to colocalize with mCAT1 in the Salmonella infected cell. The intra vacuolar Salmonella then acquire the host arginine via its own arginine transporter, ArgT for growth. The argT knockout strain was unable to acquire host arginine and was attenuated in growth in both macrophages and in mice model of infection. Together, these data reveal survival strategies by which virulent Salmonella adapt to the harsh conditions prevailing in the infected host cells.

  8. 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▿

    Science.gov (United States)

    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

  9. Specifications

    International Nuclear Information System (INIS)

    As part of the Danish RERTR Program, three fuel elements with LEU U3O8-Al fuel and three fuel elements with LEU U3Si2-Al fuel were manufactured by NUKEM for irradiation testing in the DR-3 reactor at the Risoe National Laboratory in Denmark. The specifications for the elements with U3O8-Al fuel are presented here as an illustration only. Specifications for the elements with U3Si2-Al fuel were very similar. In this example, materials, material numbers, documents numbers, and drawing numbers specific to a single fabricator have been deleted. (author)

  10. Cell lines and Salmonella

    NARCIS (Netherlands)

    Jonge R de; Hendriks H; Garssen J; Universteit Utrecht, afdeling; MGB; LPI

    2001-01-01

    In human gastrointestinal disease caused by Salmonella, transepithelial migration of neutrophils follows the attachment of bacteria to epithelial tissue. This migration of neutrophils is stimulated by the release of chemokines, including interleukin-8 (Il -8), from the epithelial cells. We have dev

  11. Iron ERRs with Salmonella

    OpenAIRE

    Fang, Ferric C.; Weiss, Günter

    2014-01-01

    The hormone hepcidin promotes iron sequestration by macrophages. A recent study by Kim et al (2014) implicates the orphan receptor ERRγ in the regulation of hepcidin production and suggests that targeting the ERRγ-hepcidin axis may be beneficial during infection with the facultative intracellular pathogen Salmonella.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

    Science.gov (United States)

    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. PMID:25811871

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

    Science.gov (United States)

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

    Directory of Open Access Journals (Sweden)

    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.

  17. RESTORATION OF PEROXISOME FORMATION IN 2 CONDITIONAL PEROXISOME-DEFICIENT MUTANTS OF HANSENULA-POLYMORPHA DURING GROWTH OF CELLS ON SPECIFIC ORGANIC NITROGEN-SOURCES

    NARCIS (Netherlands)

    TITORENKO, [No Value; EVERS, ME; VANDERKLEI, IJ; HARDER, W; VEENHUIS, M

    1995-01-01

    Expression of the peroxisome-deficient (Per(-)) phenotype by per mutants of Hansenula polymorpha is shown to be dependent on specific environmental conditions. Analysis of our collection of constitutive and conditional per mutants showed that, irrespective of the carbon source used, the mutants inva

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

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

    NARCIS (Netherlands)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Waardevermindering pluimveevlees besmet met Salmonella enteritidis en Salmonella typhymurium

    NARCIS (Netherlands)

    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

  3. Genetically Similar Isolates of Salmonella enterica Serotype Enteritidis Persistent in China for a Long-Term Period.

    Science.gov (United States)

    Song, Qifa; Shen, Xuanyi; Yang, Yuanbin; Zhang, Danyang; Gao, Hong

    2016-07-01

    Salmonella enterica serotype Enteritidis (S. Enteritidis) is an important causative agent of nontyphoidal salmonellosis in human populations. In this study, we collected 72 S. Enteritidis strains from 2004 to 2014 in Ningbo, mid-east China. Of the 72 strains, we identified a dominant clone of 58 strains recovered from patient's feces (n = 48), blood (n = 1), pleural effusion (n = 1), chickens (n = 3), and dessert cakes (n = 5) by pulsed-field gel electrophoresis (PFGE) and variable-number of tandem repeat analysis (MLVA). The profile arrangements of MLVA were SE1-SE2-SE3-SE5-SE6-SE8-SE9: 4-4-3-11-10-1-3. These dominant strains were susceptible to ampicillin, chloramphenicol, tetracycline, ciprofloxacin, gentamicin, cefotaxime and trimethoprim-sulfamethoxazole, and resistant to nalidixic acid. Additionally, all isolates harboured virulence genes invA, sipA, sopE, and spvB when tested by PCR. Our results reveal that genetically similar S. Enteritidis strains which accounted for several outbreaks as well as blood infection and pleural cavity infection are prevalent in China for a long-term period. This situation calls for further attention in the prevention and control of foodborne disease caused by Salmonella species. PMID:27228342

  4. Detection of Salmonella in Meat

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    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 < 0.05). PFGE allowed the identification of cross contamination and persistence of 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. PMID:27162388

  6. Estudo comparativo dos métodos de ultra-sonografia, tomografia computadorizada e ressonância magnética no estadiamento e invasão das estruturas adjacentes por tumores renais A comparative study of ultrasonography, computed tomography and magnetic resonance imaging in the staging and invasion of adjacent structures by renal tumors

    Directory of Open Access Journals (Sweden)

    S.M. RIBEIRO

    2001-09-01

    Full Text Available OBJETIVO: Comparamos os exames de ultra-som (US, tomografia computadorizada (TC e ressonância magnética (RM no estadiamento dos tumores renais, estudando as diferenças entre estes exames em relação a sua capacidade de detecção de adenomegalias, invasão vascular, metástases intra-abdominais à distância e particularmente invasão dos órgãos adjacentes. MÉTODOS: Foram estudados prospectivamente 31 pacientes portadores de massas renais sólidas ou complexas através dos exames de US, TC e RM. As discordâncias entre os resultados observados foram estudadas através do Teste G de Cochran e Teste de McNemar, além de se calcular a sensibilidade e especificidade de cada método diagnóstico utilizado, considerando-se como "regra de ouro" os achados cirúrgico e anatomopatológico. RESULTADOS: Destes 31 pacientes, 28 eram portadores de massas malignas e três de lesões benignas. Quanto à detecção de adenomegalia, o US mostrou sensibilidade de 63,6%, enquanto a TC e RM tiveram sensibilidade de 90,9%. Em relação à invasão vascular, o US mostrou sensibilidade de 42,8% enquanto que a TC e a RM tiveram a sensibilidade de 85,7%. Em relação à invasão de órgãos adjacentes, a sensibilidade foi respectivamente 28,5% (US, 85,7% (TC e 71,4% (RM. São critérios que sugerem a invasão das estruturas adjacentes: quando estas se encontram envolvidas/englobadas pelo tumor; a extensão do tumor para o seu interior com superfície de contato irregular; alterações na forma, tamanho e densidade da estrutura adjacente. Somente a perda do plano de gordura e o íntimo contato do tumor com a estrutura adjacente não indicam invasão. CONCLUSÕES: Houve diferenças significantes na capacidade de detecção do US em relação à TC e RM. Estas duas últimas não diferiram entre si. Somente em relação às metástases abdominais à distância todos os métodos se mostraram altamente sensíveis e específicos. Além da acurácia dos métodos, tanto

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

    OpenAIRE

    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...

  8. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    NARCIS (Netherlands)

    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

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

    NARCIS (Netherlands)

    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

  11. Targeted Cancer Therapy Using Engineered Salmonella typhimurium

    Science.gov (United States)

    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

  12. Electrochemical immunosensors for Salmonella detection in food.

    Science.gov (United States)

    Melo, Airis Maria Araújo; Alexandre, Dalila L; Furtado, Roselayne F; Borges, Maria F; Figueiredo, Evânia Altina T; Biswas, Atanu; Cheng, Huai N; Alves, Carlúcio R

    2016-06-01

    Pathogen detection is a critical point for the identification and the prevention of problems related to food safety. Failures at detecting contaminations in food may cause outbreaks with drastic consequences to public health. In spite of the real need for obtaining analytical results in the shortest time possible, conventional methods may take several days to produce a diagnosis. Salmonella spp. is the major cause of foodborne diseases worldwide and its absence is a requirement of the health authorities. Biosensors are bioelectronic devices, comprising bioreceptor molecules and transducer elements, able to detect analytes (chemical and/or biological species) rapidly and quantitatively. Electrochemical immunosensors use antibody molecules as bioreceptors and an electrochemical transducer. These devices have been widely used for pathogen detection at low cost. There are four main techniques for electrochemical immunosensors: amperometric, impedimetric, conductometric, and potentiometric. Almost all types of immunosensors are applicable to Salmonella detection. This article reviews the developments and the applications of electrochemical immunosensors for Salmonella detection, particularly the advantages of each specific technique. Immunosensors serve as exciting alternatives to conventional methods, allowing "real-time" and multiple analyses that are essential characteristics for pathogen detection and much desired in health and safety control in the food industry. PMID:27138197

  13. Targeted Cancer Therapy Using Engineered Salmonella typhimurium.

    Science.gov (United States)

    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. PMID:27689027

  14. Targeted Cancer Therapy Using Engineered Salmonella typhimurium

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  18. CD4+ T Cells and Toll-Like Receptors Recognize Salmonella Antigens Expressed in Bacterial Surface Organelles

    OpenAIRE

    Bergman, Molly A.; Cummings, Lisa A.; Barrett, Sara L. Rassoulian; Smith, Kelly D.; Lara, J. Cano; Aderem, Alan; Cookson, Brad T.

    2005-01-01

    A better understanding of immunity to infection is revealed from the characteristics of microbial ligands recognized by host immune responses. Murine infection with the intracellular bacterium Salmonella generates CD4+ T cells that specifically recognize Salmonella proteins expressed in bacterial surface organelles such as flagella and membrane vesicles. These natural Salmonella antigens are also ligands for Toll-like receptors (TLRs) or avidly associated with TLR ligands such as lipopolysacc...

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Phylogenetic relationships of Salmonella based on rRNA sequences

    DEFF Research Database (Denmark)

    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 were...

  1. 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

    Institute of Scientific and Technical Information of China (English)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  6. Salmonella Control Programs in Denmark

    DEFF Research Database (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....

  7. Salmonella control programs in Denmark.

    Science.gov (United States)

    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.

  8. Salmonella in Sheep in Iceland

    Directory of Open Access Journals (Sweden)

    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.

  9. Prevalence of salmonella in captive reptiles from Croatia

    DEFF Research Database (Denmark)

    Lukac, Maja; Pedersen, Karl; Prukner-Radovcic, Estella

    2015-01-01

    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...

  10. Prevalence of Salmonella serovars from captive reptiles from Croatia

    DEFF Research Database (Denmark)

    Lukac, Maja; Pedersen, Karl; Prukner-Radovcic, Estella

    2015-01-01

    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...

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  13. Phosphorylation of the autophagy receptor optineurin restricts Salmonella growth

    DEFF Research Database (Denmark)

    Wild, Philipp; Farhan, Hesso; McEwan, David G;

    2011-01-01

    Selective autophagy can be mediated via receptor molecules that link specific cargoes to the autophagosomal membranes decorated by ubiquitin-like microtubule-associated protein light chain 3 (LC3) modifiers. Although several autophagy receptors have been identified, little is known about mechanisms...... controlling their functions in vivo. In this work, we found that phosphorylation of an autophagy receptor, optineurin, promoted selective autophagy of ubiquitin-coated cytosolic Salmonella enterica. The protein kinase TANK binding kinase 1 (TBK1) phosphorylated optineurin on serine-177, enhancing LC3 binding...... affinity and autophagic clearance of cytosolic Salmonella. Conversely, ubiquitin- or LC3-binding optineurin mutants and silencing of optineurin or TBK1 impaired Salmonella autophagy, resulting in increased intracellular bacterial proliferation. We propose that phosphorylation of autophagy receptors might...

  14. Osteomielitis por salmonella

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  17. EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on a review on the European Union Summary reports on trends and sources zoonoses, zoonotic agents and food-borne outbreaks in 2009 and 2010 – specifically for the data on Salmonella, Campylobacter, verotoxigenic Escherichia coli

    DEFF Research Database (Denmark)

    Hald, Tine

    -specific trends, the impact of sample sizes, weight of samples and methodologies should be considered, as these variables could otherwise lead to misinterpretation of the data. Incidence data alone do not provide a full picture of the public health burden of zoonotic diseases. Fatalities provide another important......The European Union (EU) Summary Reports on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2009 and 2010 – specifically for the data on Salmonella, Campylobacter, verotoxigenic Escherichia coli, Listeria monocytogenes and foodborne outbreaks was reviewed. The main...... conclusions and recommendations are reported. Comparison between EU Member States (MSs) was found to be difficult due to the differences of the methods used, sampling schemes and reporting systems. Methods, sampling schemes and reporting systems among MSs should therefore be harmonised. When comparing MS...

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

    Directory of Open Access Journals (Sweden)

    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

  19. 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

    Institute of Scientific and Technical Information of China (English)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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.

  1. Characterization of Virulence-Associated Genes, Antimicrobial Resistance Genes, and Class 1 Integrons in Salmonella enterica serovar Typhimurium Isolates from Chicken Meat and Humans in Egypt.

    Science.gov (United States)

    Ahmed, Heba A; El-Hofy, Fatma I; Shafik, Saleh M; Abdelrahman, Mahmoud A; Elsaid, Gamilat A

    2016-06-01

    Foodborne pathogens are leading causes of illness especially in developing countries. The current study aimed to characterize virulence-associated genes and antimicrobial resistance in 30 Salmonella Typhimurium isolates of chicken and human origin at Mansoura, Egypt. The results showed that invA, avrA, mgtC, stn, and bcfC genes were identified in all the examined isolates, while 96.7% and 6.7% were positive for sopB and pef genes, respectively. The highest resistance frequencies of the isolates were to chloramphenicol and trimethoprim-sulfamethoxazole (73.3%, each), followed by streptomycin (56.7%), tetracycline and ampicillin (53.3%, each), and gentamicin (30%). However, only 2.7% of the isolates were resistant to cefotaxime and ceftriaxone each. Different resistance-associated genes, including blaTEM, aadB, aadC, aadA1, aadA2, floR, tetA(A), tetA(B), and sul1, were identified in Salmonella Typhimurium isolates with the respective frequencies of 53.3%, 6.7%, 23.3%, 46.7%, 63.3%, 73.3%, 60%, 20%, and 96.7%. None of the isolates was positive for blaSHV, blaOXA, and blaCMY genes. The results showed that the intI1 gene was detected in 24 (80%) of the examined Salmonella Typhimurium isolates. Class 1 integrons were found in 19 (79.2%) isolates that were intI1 positive. Seven integron profiles (namely: P-I to P-VII) were identified with P-V (gene cassette dfrA15, aadA2), the most prevalent profile. To the best of our knowledge, this is the first study to characterize the unusual gene cassette array dfrA12-OrfF-aadA27 from Salmonella Typhimurium isolates in Egypt. PMID:26977940

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

    Directory of Open Access Journals (Sweden)

    Jorge Hernández

    2012-08-01

    Full Text Available 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 enterica serovar Pajala to this novel Salmonella.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Serologic reactions against Salmonella in samples from broiler parent stock with and without preceding colibacillosis: A case-control study

    DEFF Research Database (Denmark)

    Gradel, K.O.; Feld, Niels Christian; Andersen, J. S.

    2001-01-01

    . 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...

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

    DEFF Research Database (Denmark)

    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...

  6. Diagnostic Accuracy of Rectoanal Mucosal Swab of Feedlot Cattle for Detection and Enumeration of Salmonella enterica.

    Science.gov (United States)

    Agga, Getahun E; Arthur, Terrance M; Schmidt, John W; Wang, Rong; Brichta-Harhay, Dayna M

    2016-04-01

    Cattle are noted carriers of the foodborne pathogen Salmonella enterica. The perceived need to decrease the potential human health risk posed by excretion of this pathogen has resulted in numerous studies examining the factors that influence Salmonella shedding in cattle. Fecal grab (FG) samples have been the predominant method used to identify cattle colonized or infected with Salmonella; however, FG sampling can be impractical in certain situations, and rectoanal mucosal swabs (RAMS) are a more convenient sample type to collect. Despite a lack of studies comparing FG and RAMS for the detection and enumeration of Salmonella fecal shedding, RAMS is perceived as less sensitive because a smaller amount of feces is cultured. In a cross-sectional study to address these concerns, paired RAMS and FG samples were collected from 403 adult feedlot cattle approximately 90 days prior to harvest. Samples were processed for Salmonella enumeration (direct plating) and detection (enrichment and immunomagnetic separation). In all, 89.6% of RAMS and 98.8% of FG samples were positive for Salmonella, and concordant prevalence outcomes were observed for 90.8% of samples. Mean enumeration values were 3.01 and 3.12 log CFU/ml for RAMS and FG, respectively. The sensitivity and specificity of RAMS were 91% (95% confidence interval [CI]: 87.5 to 93%) and 100% (95% CI: 48 to 100%), respectively, for Salmonella detection. Furthermore, RAMS Salmonella enumeration was substantially concordant (ρc = 0.89; 95% CI: 0.86 to 0.91) with FG values. We conclude that RAMS are a reliable alternative to FG for assessing cattle Salmonella fecal shedding status, especially for cattle shedding high levels of Salmonella. PMID:27052855

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Screening for Salmonella in backyard chickens.

    Science.gov (United States)

    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.

  10. Screening for Salmonella in backyard chickens.

    Science.gov (United States)

    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. PMID:25899620

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Research and identification of pathogenic bacteria 'Salmonella and Listeria' in food

    International Nuclear Information System (INIS)

    The sums propose to evaluate the bacterial contamination of certain food taken randomly by two pathogenic bacteria (Salmonella and Listeria) considering the evolution of the diseases of food oignon. For that 78 food samples of different origins were analysed. 2 stocks of the Listeria kind and 3 stocks of the salmonella kind were insulated and identified by biochemical and molecular tests. The pathogenic isolates were identified by coloration gram, test catalase, insulation on specific culture media and Api (20 E for Salmonella and Api listeria. At the end, the PCR were realized to amplify the gene iap which codes for the protein p60 at listeria as well as a sequence clonee randomly specific of Salmonella.

  13. Application of bioinformatics on the detection of pathogens by Pcr

    International Nuclear Information System (INIS)

    Salmonellas are the main responsible agent for the frequent food-borne gastrointestinal diseases. Their detection using classical methods are laborious and their results take a lot of time to be revealed. In this context, we tried to set up a revealing technique of the invA virulence gene, found in the majority of Salmonella species. After amplification with PCR using specific primers created and verified by bioinformatics programs, two couples of primers were set up and they appeared to be very specific and sensitive for the detection of invA gene. (Author)

  14. Attenuated Salmonella typhimurium SV4089 as a potential carrier of oral DNA vaccine in chickens.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2014-08-01

    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. PMID:24975814

  16. The use of organic acids to combat Salmonella in poultry : a mechanistic explanation of the efficacy

    OpenAIRE

    Van Immerseel, Filip; Russell, James; Flythe, Michael; Gantois, Inne; Timbermont, Leen; Pasmans, Frank; Haesebrouck, Freddy; Ducatelle, Richard

    2006-01-01

    Abstract Salmonella is a human pathogen that is commonly found in poultry products. It is possible to decrease chicken carcass and egg contaminations by adding organic acids to the feed or drinking water at appropriate times. Medium chain fatty acids are be more antibacterial against Salmonella than short-chain fatty acids. The antibacterial effect of these acids is species specific. Bacteria that are unable to decrease intracellular pH accumulate organic acid anions in accordance...

  17. Salmonella impairs CD8 T cell response through PD-1: PD-L axis.

    Science.gov (United States)

    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.

  18. 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

    Directory of Open Access Journals (Sweden)

    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

  19. 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

    Directory of Open Access Journals (Sweden)

    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

  20. Salmonella Infection and Water Frogs

    Centers for Disease Control (CDC) Podcasts

    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.

  1. Salmonella radicidation of poultry carcasses

    NARCIS (Netherlands)

    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

  2. Cellulitis Due to Salmonella infantis.

    Directory of Open Access Journals (Sweden)

    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.

  3. 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

    Directory of Open Access Journals (Sweden)

    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

  4. Salmonella – A Brief Summary

    Directory of Open Access Journals (Sweden)

    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.

  5. Effects of drying temperature and surface characteristics of vegetable on the survival of salmonella.

    Science.gov (United States)

    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.

  6. Analysis of Hexanitrostilbene (HNS) and Dipicryethane (DPE) for Mutagenicity by the Ames/Salmonella Assay

    Energy Technology Data Exchange (ETDEWEB)

    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).

  7. Evaluation of a serological Salmonella Mix-ELISA for poultry used in a national surveillance programme

    DEFF Research Database (Denmark)

    Feld, Niels Christian; Ekeroth, Lars; Gradel, K.O.;

    2000-01-01

    by Mix-ELISA and by faecal culture, and in case of a positive result in either of these a repeated, serological testing was performed, and 60 animals were organ-cultured. If one of these samplings was positive, the flock was declared salmonella infected. In a period of 3 months, 35 flocks were found......A Mix-ELISA using lipopolysaccharide antigens from Salmonella enterica serotype Enteritidis and Typhimurium? was evaluated using samples collected over time in the Danish salmonella surveillance programme for poultry. Serological samples (n = 42813) taken from broiler-breeder flocks after a year...... of bacteriological monitoring with negative results were used for calculating the flock and individual test specificities, which were 0.997 and 0.999, respectively. Layer flocks from the table egg sector were used for calculation of positive predictive values. In the survey, flocks were examined for salmonella...

  8. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

  10. PIR-B-deficient mice are susceptible to Salmonella infection.

    Science.gov (United States)

    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.

  11. Co-enriching microflora associated with culture based methods to detect Salmonella from tomato phyllosphere.

    Science.gov (United States)

    Ottesen, Andrea R; Gonzalez, Antonio; Bell, Rebecca; Arce, Caroline; Rideout, Steven; Allard, Marc; Evans, Peter; Strain, Errol; Musser, Steven; Knight, Rob; Brown, Eric; Pettengill, James B

    2013-01-01

    The ability to detect a specific organism from a complex environment is vitally important to many fields of public health, including food safety. For example, tomatoes have been implicated numerous times as vehicles of foodborne outbreaks due to strains of Salmonella but few studies have ever recovered Salmonella from a tomato phyllosphere environment. Precision of culturing techniques that target agents associated with outbreaks depend on numerous factors. One important factor to better understand is which species co-enrich during enrichment procedures and how microbial dynamics may impede or enhance detection of target pathogens. We used a shotgun sequence approach to describe taxa associated with samples pre-enrichment and throughout the enrichment steps of the Bacteriological Analytical Manual's (BAM) protocol for detection of Salmonella from environmental tomato samples. Recent work has shown that during efforts to enrich Salmonella (Proteobacteria) from tomato field samples, Firmicute genera are also co-enriched and at least one co-enriching Firmicute genus (Paenibacillus sp.) can inhibit and even kills strains of Salmonella. Here we provide a baseline description of microflora that co-culture during detection efforts and the utility of a bioinformatic approach to detect specific taxa from metagenomic sequence data. We observed that uncultured samples clustered together with distinct taxonomic profiles relative to the three cultured treatments (Universal Pre-enrichment broth (UPB), Tetrathionate (TT), and Rappaport-Vassiliadis (RV)). There was little consistency among samples exposed to the same culturing medias, suggesting significant microbial differences in starting matrices or stochasticity associated with enrichment processes. Interestingly, Paenibacillus sp. (Salmonella inhibitor) was significantly enriched from uncultured to cultured (UPB) samples. Also of interest was the sequence based identification of a number of sequences as Salmonella despite

  12. Isolation and Evaluation Virulence Factors of Salmonella typhimurium and Salmonella enteritidis in Milk and Dairy Products

    Directory of Open Access Journals (Sweden)

    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. The StepOne real-time polymerase chain reaction detection of Salmonella sp., Salmonella enterica ser. typhimurium and enteritidis in milk and meat.

    Science.gov (United States)

    Pochop, Jaroslav; Kačániová, Miroslava; Hleba, Lukáš; Lejková, Jadža; Fikselová, Martina; Kunová, Simona; Kluz, Maciej

    2011-01-01

    The aim of this study was to follow contamination of ready to eat milk and meat products with Salmonella spp. by using the StepOne real-time polymerase chain reaction (PCR). Classical microbiological methods for detection of foodborne bacteria involve the use of pre-enrichment and/or specific enrichment, following isolation of bacteria in solid media and the final confirmation by biochemical and/or serological tests. We used the PrepSEQ Rapid Spin Sample Preparation Kit for isolation of DNA and MicroSEQ® Salmonella spp. Detection Kit for pursuance of the real-time PCR (Applied Biosystems). In samples without incubation we detected strain of Salmonella sp. in 5 out of 25 samples (swabs), as well as in the internal positive control (IPC), which was positive in all samples. This StepOne real-time PCR assay is extremely useful for any laboratory equipped by real-time PCR. It is a fast, reproducible, simple, specific and sensitive way to detect nucleic acids, which could be used in clinical diagnostic tests in the future. Our results indicated that real-time PCR assay developed in this study could sensitively detect Salmonella spp. in ready-to-eat food. This could prevent infection caused by Salmonella, and also could benefit food manufacturing companies by extending their product's shelf-life as well as saving the cost of warehousing their food products while awaiting pathogen testing results. PMID:21879831

  14. 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

    Directory of Open Access Journals (Sweden)

    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.

  15. Genetic diversity of Salmonella pathogenicity islands SPI-5 and SPI-6 in Salmonella Newport.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  17. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  18. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  19. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  20. Ethanolamine utilization in Salmonella typhimurium.

    OpenAIRE

    Roof, D M; Roth, J R

    1988-01-01

    Ethanolamine can serve as the sole source of carbon and nitrogen for Salmonella typhimurium if vitamin B12 is present to serve as a cofactor. The pathway for ethanolamine utilization has been investigated in order to understand its regulation and determine whether the pathway is important to the selective forces that have maintained the ability to synthesize B12 in S. typhimurium. We isolated mutants that are defective in ethanolamine utilization (eut mutants). These mutants defined a cluster...

  1. Reiter's syndrome after salmonella infection

    Directory of Open Access Journals (Sweden)

    Čanović Predrag S.

    2004-01-01

    Full Text Available Two patients with Reiter's syndrome, after Salmonella infection were treated on the Infections disease ward at Clinical hospital center in Kragujevac. In the first patient, ten days after the onset of Salmonella infection, signs of edema and pain in the right ankle occurred, accompanied by expressed conjunctivitis. Within next two months consecutive metatarsophalanges changes joint of the right foot have appeared. In the second patient, two weeks after the onset of Salmonella infection, edema of the left hand joints and a week later edema of the right hand and right ankle joints appeared. In both patients inflammatory syndrome was expressed (high erythrocyte sedimentation rates, fibrinogen, C-reactive protein along with negative rheumatoid factors and positive antigen HLA-B27. Outcome of the disease in both cases was favorable upon receiving nonsteroid antirheumatic therapy. Signs of arthritis disappeared after three months. No signs of recurrent arthritis have been seen during the next four years in the first and next two years in the second patient.

  2. The Role of Biofilms and Curli in Salmonella Transport Through Porous Media

    Science.gov (United States)

    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.

  3. Multidrug-Resistant Salmonella Isolates from Swine in the Eastern Cape Province, South Africa.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-12-01

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

  5. Salmonella overcomes tumor immune tolerance by inhibition of tumor indoleamine 2, 3-dioxygenase 1 expression.

    Science.gov (United States)

    Kuan, Yu-Diao; Lee, Che-Hsin

    2016-01-01

    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.

  6. Modeling the long-term kinetics of Salmonella survival on dry pet food.

    Science.gov (United States)

    Lambertini, Elisabetta; Mishra, Abhinav; Guo, Miao; Cao, Huilin; Buchanan, Robert L; Pradhan, Abani K

    2016-09-01

    Due to multiple outbreaks and large-scale product recalls, Salmonella has emerged as a priority pathogen in dry pet food and treats. However, little data are available to quantify risks posed by these classes of products to both pets and their owners. Specifically, the kinetics of Salmonella survival on complex pet food matrices are not available. This study measured the long-term kinetics of Salmonella survival on a dry pet food under storage conditions commonly encountered during production, retail, and in households (aw < 0.60, 23 °C). A Salmonella enterica cocktail of 12 strains isolated from dry pet foods and treats was used to inoculate commercial dry dog food. Salmonella was enumerated on non-selective (BHI) and selective (XLD and BS) media. Results at 570 days indicated an initial relatively rapid decline (up to 54 days), followed by a much slower extended decline phase. The Weibull model provided a satisfactory fit for time series of Log-transformed Salmonella counts from all three media (δ: mean 4.65 day/Log (CFU/g); p: mean 0.364 on BHI). This study provides a survival model that can be applied in quantitative risk assessment models. PMID:27217351

  7. Multidrug-Resistant Salmonella Isolates from Swine in the Eastern Cape Province, South Africa.

    Science.gov (United States)

    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. PMID:27357044

  8. Occurrence of multidrug resistant Salmonella in antimicrobial-free (ABF) swine production systems.

    Science.gov (United States)

    Thakur, Siddhartha; Tadesse, Daniel A; Morrow, Morgan; Gebreyes, Wondwossen A

    2007-12-15

    This cross-sectional study was conducted to determine the prevalence and antimicrobial resistance of Salmonella species in swine reared in the intensive (indoor) and extensive (outdoor) ABF production systems at farm and slaughter in North Carolina, U.S.A. We sampled a total of 279 pigs at farm (extensive 107; intensive 172) and collected 274 carcass swabs (extensive 124; intensive 150) at slaughter. Salmonella species were tested for their susceptibility against 12 antimicrobial agents using the Kirby-Bauer disk diffusion method. Serogrouping was done using polyvalent and group specific antisera. A total of 400 salmonellae were isolated in this study with a significantly higher Salmonella prevalence from the intensive (30%) than the extensive farms (0.9%) (Pslaughter, significantly higher Salmonella was isolated at the pre- and post-evisceration stages from extensively (29% pre-evisceration and 33.3% post-evisceration) than the intensively (2% pre-evisceration and 6% post-evisceration) reared swine (Ppressure. In addition, it also highlights the possible role played by slaughterhouse and other environmental factors in the contamination and dissemination of antimicrobial resistant Salmonella in ABF production systems. PMID:17644277

  9. Prevalence and characterization of motile Salmonella in commercial layer poultry farms in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Himel Barua

    Full Text Available Salmonella is a globally widespread food-borne pathogen having major impact on public health. All motile serovars of Salmonella enterica of poultry origin are zoonotic, and contaminated meat and raw eggs are an important source to human infections. Information on the prevalence of Salmonella 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 isolates were randomly selected, from the ninety obtained from the survey, for serotyping and characterized further by plasmid profiling and pulsed-field gel electrophoresis (PFGE. Results of the survey showed that the prevalence of motile Salmonella at layer farm level was 18% (95% confidence interval 15-21%, and Salmonella Kentucky was identified to be the only serovar circulating in the study population. Plasmid analysis of the S. Kentucky and non-serotyped isolates revealed two distinct profiles with a variation of two different sizes (2.7 and 4.8 kb. PFGE of the 30 S. Kentucky and 30 non-serotyped isolates 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.

  10. A third mode of surface‐associated growth: immobilization of Salmonella enterica serovar Typhimurium modulates the RpoS‐directed transcriptional programme

    DEFF Research Database (Denmark)

    Knudsen, Gitte Maegaard; Nielsen, Maj‐Britt; Grassby, Terri;

    2012-01-01

    of Salmonella enterica serovar Typhimurium ST4/74 were compared during planktonic and immobilized growth, and a number of immobilization‐specific characteristics were identified. Immobilized S. Typhimurium did not express motility and chemotaxis genes, and electron microscopy revealed the absence of flagella...... that is distinct from the biofilm and swarming lifestyles of Salmonella....

  11. Development and comparison of a generic multiple-locus variable-number tandem repeat analysis with PFGE for typing of Salmonella entericasubsp. enterica

    DEFF Research Database (Denmark)

    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...

  12. Prevalence and characterization of multi-drug resistant Salmonella Enterica serovar Gallinarum biovar Pullorum and Gallinarum from chicken

    Directory of Open Access Journals (Sweden)

    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

  13. FAKTOR VIRULENSI Salmonella enterica SEROVAR TYPHI

    Directory of Open Access Journals (Sweden)

    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.

  14. Cephalosporin and Ciprofloxacin Resistance in Salmonella, Taiwan

    OpenAIRE

    Yan, Jing-Jou; Chiou, Chien-Shun; Lauderdale, Tsai-Ling Yang; Tsai, Shu-Huei; Wu, Jiunn-Jong

    2005-01-01

    We report the prevalence and characteristics of Salmonella strains resistant to ciprofloxacin and extended-spectrum cephalosporins in Taiwan from January to May 2004. All isolates resistant to extended-spectrum cephalosporins carried bla CMY-2, and all ciprofloxacin-resistant Salmonella enterica serotype Choleraesuis isolates were genetically related.

  15. Salmonella Typhimurium infection in the porcine intestine

    DEFF Research Database (Denmark)

    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...

  16. 9 CFR 113.120 - Salmonella Typhimurium Bacterin.

    Science.gov (United States)

    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...

  17. Significance of salmonella in pork production chain

    Directory of Open Access Journals (Sweden)

    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.

  18. Interactions of Salmonella with animals and plants

    Directory of Open Access Journals (Sweden)

    Agnès eWiedemann

    2015-01-01

    Full Text Available Salmonella enterica species is a Gram negative bacterium, which is 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 fruit 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 defence mechanisms ; and to point out similarities and differences between animal and plant infections.

  19. Pathogenesis of Salmonella-induced enteritis

    Directory of Open Access Journals (Sweden)

    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.

  20. Short communication: Determination of Salmonella clustered regularly interspaced short palindromic repeats (CRISPR) diversity on dairy farms in Wisconsin and Minnesota.

    Science.gov (United States)

    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.

  1. Prophylactic Administration of Vector-Encoded Porcine Granulocyte-Colony Stimulating Factor Reduces Salmonella Shedding, Tonsil Colonization, and Microbiota Alterations of the Gastrointestinal Tract in Salmonella-Challenged Swine

    Science.gov (United States)

    Bearson, Shawn M. D.; Bearson, Bradley L.; Loving, Crystal L.; Allen, Heather K.; Lee, InSoo; Madson, Darin; Kehrli, Marcus E.

    2016-01-01

    Salmonella colonization of food animals is a concern for animal health and public health as a food safety risk. Various obstacles impede the effort to reduce asymptomatic Salmonella carriage in food animals, including the existence of numerous serovars and the ubiquitous nature of Salmonella. To develop an intervention strategy that is non-specific yet effective against diverse Salmonella serovars, we explored the prophylactic use of a cytokine to decrease Salmonella in swine by boosting the host’s innate immune system. Granulocyte-colony stimulating factor (G-CSF) is the major cytokine regulating the production, differentiation, function, and survival of neutrophils. Neutrophils play a critical role in the response to Salmonella; therefore, we evaluated the vectored-delivery of porcine G-CSF as a prophylactic to reduce Salmonella in pigs. Crossbred pigs, 5 weeks of age, were intramuscularly injected with a replication-defective human adenovirus (Ad5) engineered to express porcine G-CSF (Ad5-G-CSF, n = 9). Control pigs received the same Ad5 vector lacking the gene encoding G-CSF (Ad5-empty, n = 7). Four days later, all pigs (n = 16) were intranasally inoculated with 1 × 107 colony forming unit (CFU) of Salmonella enterica serovar Typhimurium UK1. At 2 and 3 days post-challenge with Salmonella, Ad5-G-CSF-treated pigs shed significantly less Salmonella (~103 CFU/g) in their feces than Ad5-empty-treated pigs (~104–105 CFU/g; P structure of Salmonella-challenged pigs was less disturbed post-challenge in the Ad5-G-CSF-treated pigs than the Ad5-empty-treated pigs. This suggests that Ad5-G-CSF administration mitigated changes in the microbial community structure caused by Salmonella challenge. Collectively, these data suggest that delivery of a targeted immunostimulant to enhance neutropoiesis may be a strategy to reduce Salmonella colonization, potentially during periods of immunological stress. PMID:27610361

  2. Prophylactic Administration of Vector-Encoded Porcine Granulocyte-Colony Stimulating Factor Reduces Salmonella Shedding, Tonsil Colonization, and Microbiota Alterations of the Gastrointestinal Tract in Salmonella-Challenged Swine.

    Science.gov (United States)

    Bearson, Shawn M D; Bearson, Bradley L; Loving, Crystal L; Allen, Heather K; Lee, InSoo; Madson, Darin; Kehrli, Marcus E

    2016-01-01

    Salmonella colonization of food animals is a concern for animal health and public health as a food safety risk. Various obstacles impede the effort to reduce asymptomatic Salmonella carriage in food animals, including the existence of numerous serovars and the ubiquitous nature of Salmonella. To develop an intervention strategy that is non-specific yet effective against diverse Salmonella serovars, we explored the prophylactic use of a cytokine to decrease Salmonella in swine by boosting the host's innate immune system. Granulocyte-colony stimulating factor (G-CSF) is the major cytokine regulating the production, differentiation, function, and survival of neutrophils. Neutrophils play a critical role in the response to Salmonella; therefore, we evaluated the vectored-delivery of porcine G-CSF as a prophylactic to reduce Salmonella in pigs. Crossbred pigs, 5 weeks of age, were intramuscularly injected with a replication-defective human adenovirus (Ad5) engineered to express porcine G-CSF (Ad5-G-CSF, n = 9). Control pigs received the same Ad5 vector lacking the gene encoding G-CSF (Ad5-empty, n = 7). Four days later, all pigs (n = 16) were intranasally inoculated with 1 × 10(7) colony forming unit (CFU) of Salmonella enterica serovar Typhimurium UK1. At 2 and 3 days post-challenge with Salmonella, Ad5-G-CSF-treated pigs shed significantly less Salmonella (~10(3) CFU/g) in their feces than Ad5-empty-treated pigs (~10(4)-10(5) CFU/g; P Salmonella-challenged pigs was less disturbed post-challenge in the Ad5-G-CSF-treated pigs than the Ad5-empty-treated pigs. This suggests that Ad5-G-CSF administration mitigated changes in the microbial community structure caused by Salmonella challenge. Collectively, these data suggest that delivery of a targeted immunostimulant to enhance neutropoiesis may be a strategy to reduce Salmonella colonization, potentially during periods of immunological stress. PMID:27610361

  3. Protective effect of probiotics on Salmonella infectivity assessed with combined in vitro gut fermentation-cellular models

    Directory of Open Access Journals (Sweden)

    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.

  4. AOAC Official MethodSM Matrix Extension Validation Study of Assurance GDSTM for the Detection of Salmonella in Selected Spices.

    Science.gov (United States)

    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.

  5. Ultra-fast and sensitive detection of non-typhoidal Salmonella using microwave-accelerated metal-enhanced fluorescence ("MAMEF".

    Directory of Open Access Journals (Sweden)

    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.

  6. Outbreak of Salmonella Strathcona caused by datterino tomatoes, Denmark, 2011.

    Science.gov (United States)

    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.

  7. Optical immunosensors for detection of Listeria monocytogenes and Salmonella enteritidis from food

    Science.gov (United States)

    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 detection of foodborne L. monocytogenes and Salmonella Enteritidis.

  8. The capsular polysaccharide Vi from Salmonella Typhi is a B1b antigen

    Science.gov (United States)

    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

  9. The capsular polysaccharide Vi from Salmonella typhi is a B1b antigen.

    Science.gov (United States)

    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.

  10. Prediction of Salmonella carcass contamination by a comparative quantitative analysis of E. coli and Salmonella during pig slaughter

    DEFF Research Database (Denmark)

    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....

  11. Occurrence of Salmonella sp in laying hens

    Directory of Open Access Journals (Sweden)

    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. Liver dendritic cells present bacterial antigens and produce cytokines upon Salmonella encounter.

    Science.gov (United States)

    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.

  13. Virulent Salmonella enterica serovar typhimurium evades adaptive immunity by preventing dendritic cells from activating T cells.

    Science.gov (United States)

    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.

  14. Ex vivo perfusion of the isolated rat small intestine as a novel model of Salmonella enteritis.

    Science.gov (United States)

    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.

  15. Salmonella enterica serovar Typhimurium lacking hfq gene confers protective immunity against murine typhoid.

    Directory of Open Access Journals (Sweden)

    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.

  16. In vitro invasive capacity of Salmonella strains into sections of the layer hen oviduct.

    Science.gov (United States)

    McWhorter, Andrea R; Chousalkar, Kapil K

    2016-08-30

    Raw or undercooked eggs and egg products are frequently identified as the source of Salmonella following outbreaks of foodborne gastrointestinal disease. Some Salmonella serovars, such as Salmonella Enteriditis, have a high tropism for the oviduct of laying hens. Oviduct colonization with S. Enteriditis can result in both internal and external contamination of an egg. While oviduct invasion is not limited to S. Enteriditis, the invasive capacities of other serovars is not widely known. In this study, the in vitro invasive ability of eighteen Salmonella isolates of representative serovars into different segments of the oviduct was assessed. All Salmonella isolates tested were invasive and the highest bacterial invasion was observed in segments of the isthmus and vagina. S. Bredeney consistently exhibited the lowest invasion into all sections of the oviduct. Interestingly, the S. Typhimurium definitive types included in this study did not exhibit significantly greater invasion capacity than other serovars. In this study, the genomic capacity of the selected isolates of representative Salmonella serovars to colonize the layer hen oviduct was also investigated. Previous studies have identified several genes upregulated during oviduct colonization by S. Enteriditis. Single gene comparison of 107 genes from eleven Salmonella isolates was conducted to determine whether these oviduct colonization genes were present within each bacterial genome. The degree of homology with corresponding sequences in S. Enteriditis P125109 was also determined for each gene. Genes encoding the O-antigen as well as phage and virulence plasmid genes were among the most highly variable and may serve specific roles in oviduct invasion. PMID:27527775

  17. Pleural Empyema due to Group D Salmonella

    Directory of Open Access Journals (Sweden)

    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.

  18. Pleural Empyema due to Group D Salmonella

    Science.gov (United States)

    Kam, Jennifer C.; Abdul-Jawad, Sami; Modi, Chintan; Abdeen, Yazan; Asslo, Fady; Doraiswamy, Vikram; DePasquale, Joseph R.; Spira, Robert S.; Baddoura, Walid; Miller, Richard A.

    2012-01-01

    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. PMID:23056966

  19. Salmonella bongori provides insights into the evolution of the Salmonellae.

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  1. Evaluation of a CHROMagar Salmonella Medium for the Isolation of Salmonella Species

    Directory of Open Access Journals (Sweden)

    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.

  2. PREVALENCE OF SALMONELLA IN CAPTIVE REPTILES FROM CROATIA.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:26678129

  5. Establishment and Application of Multiple PCR for Diagnosing Proteus mirabilis, Salmonella and Listeria monocytogenes%多重PCR检测三种重要食源性致病菌方法的建立及应用

    Institute of Scientific and Technical Information of China (English)

    王慧; 朱瑞良; 谭燕玲; 魏凯; 王新建; 孙振红; 盛鹏程

    2011-01-01

    [Objective] The aim of this study is to establish a multiplex polymerase chain reaction (PCR) assay for simultaneous identification ofProteus mirabilis,Salmonella and Listeria monocytogenes. [ Method ] Based on the gene sequences of positive adjustment factor R gene of Urease (ureR) in Proteus mirabilis, conservative invasive antigen gene (invA) in Salmonella and the hly gene in Listeria monoytogenes, a three pairs of primer were designed. The specificity and sensitivity of PCR were analyzed for single gene. Multiple PCR method has been developed after analysis and optimization reaction condition by orthogonal experimental design L 16 (43). [ Result ] Aiming to Proteus mirabilis, Salmonella and Listeria monocytogenes, under the optimized conditions, the anticipated PCR products were 374 bp, 724 bp and 215 bp, respectively, and the specificity was high, and the minimum detection limit was 105 CFU/mL, which was a dilute degree lower in the sensitivity of single PCR. The results were stable in simulated examination and in marketing examination. [ Conclusion ] A rapid, specific and sensitive multiplex PCR system has been established and it is valuable for diagnosis and monitoring for Proteus mirabilis, Salmonella and Listeria monocytogenes.%[目的]建立快速检测奇异变形杆菌、沙门氏菌和单核细胞增生李斯特氏杆菌3种食源性致病菌的多重PCR方法.[方法]根据奇异变形杆菌尿素酶合成的正向调节因子R基因(ureR)、沙门氏菌侵袭性抗原保守基因(invA)和单核细胞增生李斯特氏杆菌编码溶血素0(LLO)的hlyA基因,分别设计3对特异性引物,对单基因PCR和单管多重PCR扩增的特异性、敏感性分析以及建立L16(43)正交试验对单管多重PCR扩增条件,如引物浓度、Tm值、模板量等的优化,建立快速检测奇异变形杆菌、沙门氏菌和单核细胞增生李斯特氏杆菌的稳定的单管多重PCR方法.[结果]针对奇异变形杆菌、沙门氏

  6. 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

    Directory of Open Access Journals (Sweden)

    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

  7. Inherent Variability of Growth Media Impacts the Ability of Salmonella Typhimurium to Interact with Host Cells.

    Science.gov (United States)

    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.

  8. Bacterial virulence, proinflammatory cytokines and host immunity: how to choose the appropriate Salmonella vaccine strain?

    Science.gov (United States)

    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.

  9. Genetic parameters for resistance to the Salmonella abortusovis vaccinal strain Rv6 in sheep

    Directory of Open Access Journals (Sweden)

    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.

  10. Anti-angiogenesis Effect on Glioma of Attenuated Salmonella Typhimurium Vaccine Strain with flk-1 Gene

    Institute of Scientific and Technical Information of China (English)

    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.

  11. Molecular modelling, docking and interaction studies of human-plasmogen and salmonella enolase with enolase inhibitors.

    Science.gov (United States)

    Chauhan, Digvijay Singh; Chandra, Sharat; Gupta, Arun; Singh, Tiratha Raj

    2012-01-01

    Salmonella enteric serovar Typhi Ty2 is a human specific pathogen and an etiological agent for typhoid fever. Most of Salmonella serotypes produce glycogen which has a comparatively minor role in virulence and colonization, but has a more significant role in survival. Enzymes present in glycolytic pathway of bacteria help bacteria to survive by activating other factors inside host. Numerous pathogenic bacteria species intervene with the plasminogen system, and this plasminogen-enolase association may play a critical role in the virulence of S. Typhi by causing direct damage to the host cell extracellular matrix, possibly by enzymic degradation of extracellular matrix proteins or other protein constituents. In this study, molecular modelling of enolase of Salmonella has been accomplished in silico by comparative modelling; we have then analyzed Human alpha enolase which is a homodimer and serves on epithelial cells with our model. Both Structures were docked by D-tartronate semialdehyde phosphate (TSP) and 3-aminoenolpyruvate phosphate (AEP) enolase inhibitors. Our study shows that salmonella enolase and human enolase have different active sites in their structure. This will help in development of new ligands, more suitable for inhibiting bacterial survival inside host as vaccines for typhoid fever are not fully protective. The study also confirmed that enolase Salmonella and Human Plasminogen suggested direct physical interaction between both of them as the activation loop of plasminogen residues showed conformational changes similar to the tissue type plasminogen activator. Various computational biology tools were used for our present study such as Modeller, Molegro Virtual Docker, Grommacs. PMID:22419838

  12. Acalculous cholecystitis due to Salmonella enteritidis

    Institute of Scientific and Technical Information of China (English)

    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.

  13. 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.)

    Institute of Scientific and Technical Information of China (English)

    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.

  14. lac repressor is an antivirulence factor of Salmonella enterica: its role in the evolution of virulence in Salmonella.

    Directory of Open Access Journals (Sweden)

    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 of Salmonella enterica and suggest that absence of lacI has facilitated the acquisition of virulence genes of Salmonella pathogenicity island 2 in Salmonella enterica making it a successful systemic pathogen.

  15. Salmonella typhimurium abscess of the chest wall

    OpenAIRE

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

    2013-01-01

    Patient: Male, 73 Final Diagnosis: Salmonella typhimurium abscess of the chest wall Symptoms: — Medication: Ciprofloxacin Clinical Procedure:— Specialty: Infectious Diseases Objective: Unusual clinical course Background: Non-typhoid Salmonella extra-intestinal infections usually develop in infants and in adult patients with pre-existing predisposing conditions. Blood stream infections and urinary tract infections are the most common clinical presentations, but other sites of infection may be ...

  16. Long term prognosis of reactive salmonella arthritis

    OpenAIRE

    Leirisalo-Repo, M; Helenius, P; Hannu, T; Lehtinen, A; Kreula, J; Taavitsainen, M; Koskimies, S

    1997-01-01

    OBJECTIVES—Reactive joint complications triggered by salmonella gastroenteritis are increasingly reported, but the outcome and long term prognosis of the patients is incompletely known. This study looked at the prognosis of salmonella arthritis in patients hospitalised in 1970-1986.
METHODS—Hospital records from two hospitals in southern Finland were screened for patients with the discharge diagnosis of salmonellosis or reactive, postinfectious arthritis or Reiter's disease. For the patients ...

  17. Salmonella in beef and produce from honduras.

    Science.gov (United States)

    Maradiaga, Martha; Miller, Mark F; Thompson, Leslie; Pond, Ansen; Gragg, Sara E; Echeverry, Alejandro; Garcia, Lyda G; Loneragan, Guy H; Brashears, Mindy M

    2015-03-01

    Salmonella continues to cause a considerable number of foodborne illnesses worldwide. The sources of outbreaks include contaminated meat and produce. The purpose of this study was to establish an initial investigation of the burden of Salmonella in produce and beef from Honduras by sampling retail markets and abattoirs. Retail produce samples (cantaloupes, cilantro, cucumbers, leafy greens, peppers, and tomatoes; n = 573) were purchased in three major cities of Honduras, and retail whole-muscle beef (n = 555) samples were also purchased in four major cities. Additionally, both hide and beef carcass (n = 141) samples were collected from two Honduran abattoirs. Whole-muscle beef samples were obtained using a sponge hydrated with buffered peptone water, and 10 ml of the buffered peptone water rinsate of each produce sample was collected with a dry sponge and placed in a bag to be transported back to the United States. Salmonella was detected using a commercially available, closeplatform PCR system, and positive samples were subjected to culture on selective media to obtain isolates. Overall, the prevalence of Salmonella-positive samples, based on PCR detection in Honduras (n = 555) retail beef was 10.1% (95% confidence interval = 7.8, 12.9), whereas 7.8% (n = 141) of beef carcass and hides samples were positive in both beef plants. The overall Salmonella prevalence for all produce samples (n = 573) collected was 2.1% (95% confidence interval = 1.2, 3.6). The most common serotypes identified in Honduras were Salmonella Typhimurium followed by Derby. These results provide an indication of Salmonella contamination of beef and produce in Honduras. Developing a Salmonella baseline for Latin America through an initial investigation like the one presented here contributes to a broader global understanding of the potential exposure through food, thus providing insight into the needs for control strategies. PMID:25719872

  18. Salmonella in beef and produce from honduras.

    Science.gov (United States)

    Maradiaga, Martha; Miller, Mark F; Thompson, Leslie; Pond, Ansen; Gragg, Sara E; Echeverry, Alejandro; Garcia, Lyda G; Loneragan, Guy H; Brashears, Mindy M

    2015-03-01

    Salmonella continues to cause a considerable number of foodborne illnesses worldwide. The sources of outbreaks include contaminated meat and produce. The purpose of this study was to establish an initial investigation of the burden of Salmonella in produce and beef from Honduras by sampling retail markets and abattoirs. Retail produce samples (cantaloupes, cilantro, cucumbers, leafy greens, peppers, and tomatoes; n = 573) were purchased in three major cities of Honduras, and retail whole-muscle beef (n = 555) samples were also purchased in four major cities. Additionally, both hide and beef carcass (n = 141) samples were collected from two Honduran abattoirs. Whole-muscle beef samples were obtained using a sponge hydrated with buffered peptone water, and 10 ml of the buffered peptone water rinsate of each produce sample was collected with a dry sponge and placed in a bag to be transported back to the United States. Salmonella was detected using a commercially available, closeplatform PCR system, and positive samples were subjected to culture on selective media to obtain isolates. Overall, the prevalence of Salmonella-positive samples, based on PCR detection in Honduras (n = 555) retail beef was 10.1% (95% confidence interval = 7.8, 12.9), whereas 7.8% (n = 141) of beef carcass and hides samples were positive in both beef plants. The overall Salmonella prevalence for all produce samples (n = 573) collected was 2.1% (95% confidence interval = 1.2, 3.6). The most common serotypes identified in Honduras were Salmonella Typhimurium followed by Derby. These results provide an indication of Salmonella contamination of beef and produce in Honduras. Developing a Salmonella baseline for Latin America through an initial investigation like the one presented here contributes to a broader global understanding of the potential exposure through food, thus providing insight into the needs for control strategies.

  19. Salmonellae and salmonellosis in captive reptiles.

    OpenAIRE

    Onderka, D K; Finlayson, M. C.

    1985-01-01

    In a survey of 150 pet reptiles submitted for necropsy, 51% of snakes, 48% of lizards and 7% of turtles were infected with Salmonella. About one third of the positive animals had died due to various manifestations of salmonellosis. Thirty-one Salmonella serotypes were identified including three isolates new to Canada. The public health implications are discussed in view of the restricted popularity of reptiles and their possible infection from domestic agricultural products.

  20. DETECTION OF FRNA COLIPHAGES IN GROUNDWATER: INTERFERENCE WITH THE ASSAY BY SOMATIC SALMONELLA BACTERIOPHAGES

    Science.gov (United States)

    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...

  1. Prevalence and characterization of motile Salmonella in commercial layer poultry farms in Bangladesh

    DEFF Research Database (Denmark)

    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....

  2. Salmonella spondylodiscitis of the thoracic vertebrae mimicking spine tuberculosis.

    Science.gov (United States)

    Muhamad Effendi, Ferdhany; Ibrahim, Mohd Ikraam; Mohd Miswan, Mohd Fairudz

    2016-01-01

    Extraintestinal Salmonella infection involving the thoracic spine is very rare. It commonly presents with non-specific chronic back pain and can occur with no gastrointestinal manifestation. Blood test results and imaging findings are often indistinguishable from more common chronic spine infections such as spine tuberculosis. Culture studies remain the key to establishing a definitive diagnosis and subsequently successful treatment. We report a case in which a patient presented with symptoms and signs suggestive of spine tuberculosis, yet the culture examination revealed otherwise. PMID:27381996

  3. Role of yqiC in the Pathogenicity of Salmonella and Innate Immune Responses of Human Intestinal Epithelium

    Science.gov (United States)

    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

  4. Toename Salmonella en Campylobacter bij slacht : Campylobacter in pluimveesector constant, Salmonella sterk gedaald

    NARCIS (Netherlands)

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

    2009-01-01

    In vrijwel alle schakels van de pluimveevleesketen is de besmetting met Salmonella in de periode van 2002 tot 2005 gedaald. Campylobacter werd in diezelfde periode juist vaker in slachthuizen aangetroffen. Tijdens het slachten nam de besmetting met beide pathogenen toe, voor Salmonella gold dit voor

  5. The sensitivity of real-time PCR amplification targeting invasive Salmonella serovars in biological specimens

    Directory of Open Access Journals (Sweden)

    Chau Tran

    2010-05-01

    Full Text Available Abstract Background PCR amplification for the detection of pathogens in biological material is generally considered a rapid and informative diagnostic technique. Invasive Salmonella serovars, which cause enteric fever, can be commonly cultured from the blood of infected patients. Yet, the isolation of invasive Salmonella serovars from blood is protracted and potentially insensitive. Methods We developed and optimised a novel multiplex three colour real-time PCR assay to detect specific target sequences in the genomes of Salmonella serovars Typhi and Paratyphi A. We performed the assay on DNA extracted from blood and bone marrow samples from culture positive and negative enteric fever patients. Results The assay was validated and demonstrated a high level of specificity and reproducibility under experimental conditions. All bone marrow samples tested positive for Salmonella, however, the sensitivity on blood samples was limited. The assay demonstrated an overall specificity of 100% (75/75 and sensitivity of 53.9% (69/128 on all biological samples. We then tested the PCR detection limit by performing bacterial counts after inoculation into blood culture bottles. Conclusions Our findings corroborate previous clinical findings, whereby the bacterial load of S. Typhi in peripheral blood is low, often below detection by culture and, consequently, below detection by PCR. Whilst the assay may be utilised for environmental sampling or on differing biological samples, our data suggest that PCR performed directly on blood samples may be an unsuitable methodology and a potentially unachievable target for the routine diagnosis of enteric fever.

  6. Use of TaqMan® real-time PCR for rapid detection of Salmonella enterica serovar Typhi.

    Science.gov (United States)

    Ranjbar, Reza; Naghoni, Ali; Farshad, Shohreh; Lashini, Hadi; Najafi, Ali; Sadeghifard, Nourkhoda; Mammina, Caterina

    2014-06-01

    We evaluated the performances of a newly designed real-time polymerase chain reaction (PCR) assay using TaqMan® probes to detect Salmonella Typhi. TaqMan® real-time PCR assays were performed by designed primers and probe based on the staG gene for detecting S. Typhi. The specificity of the assay was evaluated on 15 Salmonella serovars. The analytical specificity was evaluated on 20 non-Salmonella microorganisms. The analytical sensitivity was assessed using decreasing DNA quantities of S. Typhi ATCC 19430. Finally the detection capability of the TaqMan® real-time PCR assay on isolates recovered from patients with Salmonella infections was compared to the conventional PCR assay. Only S. Typhi strain had positive results when subjected to the assay using Typhi-specific real-time PCR. No amplification products were observed in real-time PCR with any of the non-Salmonella microorganisms tested. The TaqMan® real-time PCR was more sensitive than the conventional PCR. In conclusion, we found that the easy-to-use real-time PCR assays were faster than conventional PCR systems. The staG-based TaqMan® real-time PCR assay showed to be specific and sensitive method for the safe and rapid detection of the S. Typhi. PMID:24939681

  7. Enjoying Homemade Ice Cream without the Risk of Salmonella Infection

    Science.gov (United States)

    ... Contaminants Buy, Store & Serve Safe Food Enjoying Homemade Ice Cream without the Risk of Salmonella Infection Share Tweet ... it Email Print August 2004 Every year homemade ice cream causes several outbreaks of Salmonella infection with up ...

  8. Study on phenotypic characteristics of Salmonella gallinarum and Sallmonella pullorum isolates based on biochemical and antimicrobial susceptibility tests in Iran

    Directory of Open Access Journals (Sweden)

    Moradi Bidhendi, S

    2015-10-01

    Full Text Available Salmonellosis is a very important disease of avian species because of its huge economic impact, worldwide distribution and difficulty posed in its control. Fowl typhoid and pullorum disease, is caused by Salmonella enterica subsp enterica serovar Gallinarum biovar Gallinarum and Pullorum. The purpose of this study was to investigate the biochemical characteristics and antimicrobial susceptibility of Salmonella gallinarum and Salmonella pullorum. A total of 13 Salmonella isolates, identified by biochemical tests and specific antisera including Salmonella gallinarum (n=10 and Salmonella pullorum (n=3. All were found to be susceptible to gentamicin. Also 7 (53.8 %, 6 (46.1% and 5 (38.4% isolates were resistant to streptomycin, cephalexin and nalidixic acid respectively. Multidrug resistance to three or more antibiotics was observed in 6 (46.1% isolates and overall 9 antibiotic resistance patterns were recorded. The results showed that poultries as a source of antimicrobial resistance could pose a serious risk to public health via food chain transfer. Hence more epidemiological surveillance programs and antibiotic susceptibility investigations are advised.

  9. Salmonella enterica serovar Enteritidis enterocolitis during late stages of gestation induces an adverse pregnancy outcome in the murine model.

    Directory of Open Access Journals (Sweden)

    Mariángeles Noto Llana

    Full Text Available Foodborne diseases caused by Salmonella enterica serovar Enteritidis (S. Enteritidis are a significant health problem. Pregnancy, state of immunological tolerance, is a predisposing condition for the development of infections with intracellular pathogens. Salmonella species can cause pregnancy complications such as chorioamnionitis, transplacental fetal infection, pre term labor, abortions, neonatal and maternal septicemia. However, the specific mechanisms by which Salmonella infections trigger these alterations are not clear. In the present work, using a self-limiting enterocolitis murine model, we show that the ingestion of a low dose of S. Enteritidis at late stages of pregnancy (day 15 of gestation is sufficient to induce massive maternal infection. We found that Salmonella infection leads to 40% of pre term delivery, 33% of abortion and fetal growth restriction. Placental dysfunction during S. Enteritidis enterocolitis was confirmed through cellular infiltration and hypoxia markers (MPO activity and COX-1 and COX-2 expression, respectively. Apoptosis in placental tissue due to Salmonella infection was also evident at day 18 of gestation when investigated by morphometric procedure, DNA fragmentation and Fas/FasL expression. Also, the expression of IFN-γ, TNF-α, IL-17 and IL-10 was up regulated in response to Salmonella not only in placenta, but also in amniotic fluid and maternal serum. Altogether, our results demonstrate that S. Enteritidis enterocolitis during late stages of gestation causes detrimental effect on pregnancy outcome.

  10. A sandwich electrochemical immunosensor for Salmonella pullorum and Salmonella gallinarum based on a screen-printed carbon electrode modified with an ionic liquid and electrodeposited gold nanoparticles

    International Nuclear Information System (INIS)

    This article describes an electrochemical immunosensor for rapid determination of Salmonella pullorum and Salmonella gallinarum. The first step in the preparation of the immunosensor involves the electrodeposition of gold nanoparticles used for capturing antibody and enhancing signals. In order to generate a benign microenvironment for the antibody, the ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate was used to modify the surface of a screen-printed carbon electrode (SPCE). The single steps of modification were monitored via cyclic voltammetry and electrochemical impedance spectroscopy. Based on these findings, a sandwich immunoassay was worked out for the two Salmonella species by immobilizing the respective unlabeled antibodies on the SPCE. Following exposure to the analytes, secondary antibody (labeled with HRP) is added to form the sandwich. After adding hydrogen peroxide and thionine, the latter is oxidized and its signal measured via CV. A linear response to the Salmonella species is obtained in the 104 to 109 cfu · mL−1 concentration range, and the detection limits are 3.0 × 103 cfu · mL−1 for both species (at an SNR of 3). This assay is sensitive, highly specific, acceptably accurate and reproducible. Given its low detection limit, it represents a promising tool for the detection of S. pullorum, S. gallinarum, and - conceivably - of other food-borne pathogens by exchanging the antibody. (author)

  11. Test results of Salmonella typing by the National Reference Laboratories for Salmonella in the Member States of the European Union and the EnterNet Laboratories - Collaborative study VII on typing of Salmonella

    NARCIS (Netherlands)

    Korver H; Maas HME; Ward LR; Wannet WJB; Henken AM; MGB; LIS

    2003-01-01

    Het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) organiseerde in samenwerking met Public Health Laboratory Services (PHLS), London, Verenigd Koninkrijk een zevende ringonderzoek aangaande de typering van Salmonella. Zeventien Nationale Referentie L

  12. In vitro assessment of the susceptibility of planktonic and attached cells of foodborne pathogens to bacteriophage p22-mediated salmonella lysates.

    Science.gov (United States)

    Ahn, Juhee; Kim, Songrae; Jung, Lae-Seung; Biswas, Debabrata

    2013-12-01

    This study was designed to evaluate the lytic activity of bacteriophage P22 against Salmonella Typhimurium ATCC 19585 (Salmonella Typhimurium P22(-)) at various multiplicities of infections (MOIs), the susceptibility of preattached Salmonella cells against bacteriophage P22, and the effect of P22-mediated bacterial lysates (extracellular DNA) on the attachment ability of Listeria monocytogenes ATCC 7644 and enterohemorrhagic Escherichia coli ATCC 700927 to surfaces. The numbers of attached Salmonella Typhimurium P22(-) cells were effectively reduced to below the detection limit (1 log CFU/ml) at the fixed inoculum levels of 3 × 10(-) CFU/ml (MOI = 3.12) and 3 × 10(3) CFU/ml (MOI = 4.12) by bacteriophage P22. The attached Salmonella Typhimurium P22(-) cells remained more than 2 log CFU/ml, with increasing inoculum levels from 3 × 10(4) to 3 × 10(7) CFU/ml infected with 4 × 10(8) PFU/ml of P22. The number of preattached Salmonella Typhimurium P22(-) cells was noticeably reduced by 2.72 log in the presence of P22. The highest specific attachment ability values for Salmonella Typhimurium P22(-), Salmonella Typhimurium ATCC 23555 carrying P22 prophage (Salmonella Typhimurium P22(+)), L. monocytogenes, and enterohemorrhagic E. coli were 2.09, 1.06, 1.86, and 1.08, respectively, in the bacteriophage-mediated cell-free supernatants (CFS) containing high amounts of extracellular DNA. These results suggest that bacteriophages could potentially be used to effectively eliminate planktonic and preattached Salmonella Typhimurium P22(-) cells with increasing MOI. However, further research is needed to understand the role of bacteriophage-induced lysates in bacterial attachment, which can provide useful information for the therapeutic use of bacteriophage in the food system.

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

    Science.gov (United States)

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

  14. Visualization of gold and platinum nanoparticles interacting with Salmonella Enteritidis and Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Ewa Sawosz

    2010-08-01

    Full Text Available Ewa Sawosz1, André Chwalibog2, Jacek Szeliga3, Filip Sawosz2, Marta Grodzik1, Marlena Rupiewicz1, Tomasz Niemiec1, Katarzyna Kacprzyk11Division of Biotechnology and Biochemistry of Nutrition, Warsaw University of Life Sciences, Warsaw, Poland; 2Department of Basic Animal and Veterinary Sciences, University of Copenhagen, Copenhagen, Denmark; 3Division of Microbiology of Analytical Centre, Warsaw University of Life Sciences, Warsaw, PolandPurpose: Rapid development of nanotechnology has recently brought significant attention to the extraordinary biological features of nanomaterials. The objective of the present ­investigation was to evaluate morphological characteristics of the assembles of gold and platinum nanoparticles (nano-Au and nano-Pt respectively, with Salmonella Enteritidis (Gram-negative and Listeria monocytogenes (Gram-positive, to reveal possibilities of constructing bacteria-nanoparticle vehicles.Methods: Hydrocolloids of nano-Au or nano-Pt were added to two bacteria suspensions in the following order: nano-Au + Salmonella Enteritidis; nano-Au + Listeria monocytogenes; nano-Pt + Salmonella Enteritidis; nano-Pt + Listeria monocytogenes. Samples were inspected by transmission electron microscope.Results: Visualization of morphological interaction between nano-Au and Salmonella Enteritidis and Listeria monocytogenes, showed that nano-Au were aggregated within flagella or biofilm network and did not penetrate the bacterial cell. The analysis of morphological effects of interaction of nano-Pt with bacteria revealed that nano-Pt entered cells of Listeria monocytogenes and were removed from the cells. In the case of Salmonella Enteritidis, nano-Pt were seen inside bacteria cells, probably bound to DNA and partly left bacterial cells. After washing and centrifugation, some of the nano-Pt-DNA complexes were observed within Salmonella Enteritidis.Conclusion: The results indicate that the bacteria could be used as a vehicle to deliver nano

  15. Functional Activity of Antibodies Directed towards Flagellin Proteins of Non-Typhoidal Salmonella.

    Science.gov (United States)

    Ramachandran, Girish; Tennant, Sharon M; Boyd, Mary A; Wang, Jin Y; Tulapurkar, Mohan E; Pasetti, Marcela F; Levine, Myron M; Simon, Raphael

    2016-01-01

    Non-typhoidal Salmonella (NTS) serovars Typhimurium and Enteritidis are major causes of invasive bacterial infections in children under 5 years old in sub-Saharan Africa, with case fatality rates of ~20%. There are no licensed NTS vaccines for humans. Vaccines that induce antibodies against a Salmonella Typhi surface antigen, Vi polysaccharide, significantly protect humans against typhoid fever, establishing that immune responses to Salmonella surface antigens can be protective. Flagella proteins, abundant surface antigens in Salmonella serovars that cause human disease, are also powerful immunogens, but the functional capacity of elicited anti-flagellar antibodies and their role in facilitating bacterial clearance has been unclear. We examined the ability of anti-flagellar antibodies to mediate microbial killing by immune system components in-vitro and assessed their role in protecting mice against invasive Salmonella infection. Polyclonal (hyperimmune sera) and monoclonal antibodies raised against phase 1 flagellin proteins of S. Enteritidis and S. Typhimurium facilitated bacterial uptake and killing of the homologous serovar pathogen by phagocytes. Polyclonal anti-flagellar antibodies accompanied by complement also achieved direct bacterial killing. Serum bactericidal activity was restricted to Salmonella serovars expressing the same flagellin used as immunogen. Notably, individual anti-flagellin monoclonal antibodies with complement were not bactericidal, but this biological activity was restored when different monoclonal anti-flagellin antibodies were combined. Passive transfer immunization with a monoclonal IgG antibody specific for phase 1 flagellin from S. Typhimurium protected mice against lethal challenge with a representative African invasive S. Typhimurium strain. These findings have relevance for the use of flagellin proteins in NTS vaccines, and confirm the role of anti-flagellin antibodies as mediators of protective immunity.

  16. Functional Activity of Antibodies Directed towards Flagellin Proteins of Non-Typhoidal Salmonella.

    Directory of Open Access Journals (Sweden)

    Girish Ramachandran

    Full Text Available Non-typhoidal Salmonella (NTS serovars Typhimurium and Enteritidis are major causes of invasive bacterial infections in children under 5 years old in sub-Saharan Africa, with case fatality rates of ~20%. There are no licensed NTS vaccines for humans. Vaccines that induce antibodies against a Salmonella Typhi surface antigen, Vi polysaccharide, significantly protect humans against typhoid fever, establishing that immune responses to Salmonella surface antigens can be protective. Flagella proteins, abundant surface antigens in Salmonella serovars that cause human disease, are also powerful immunogens, but the functional capacity of elicited anti-flagellar antibodies and their role in facilitating bacterial clearance has been unclear. We examined the ability of anti-flagellar antibodies to mediate microbial killing by immune system components in-vitro and assessed their role in protecting mice against invasive Salmonella infection. Polyclonal (hyperimmune sera and monoclonal antibodies raised against phase 1 flagellin proteins of S. Enteritidis and S. Typhimurium facilitated bacterial uptake and killing of the homologous serovar pathogen by phagocytes. Polyclonal anti-flagellar antibodies accompanied by complement also achieved direct bacterial killing. Serum bactericidal activity was restricted to Salmonella serovars expressing the same flagellin used as immunogen. Notably, individual anti-flagellin monoclonal antibodies with complement were not bactericidal, but this biological activity was restored when different monoclonal anti-flagellin antibodies were combined. Passive transfer immunization with a monoclonal IgG antibody specific for phase 1 flagellin from S. Typhimurium protected mice against lethal challenge with a representative African invasive S. Typhimurium strain. These findings have relevance for the use of flagellin proteins in NTS vaccines, and confirm the role of anti-flagellin antibodies as mediators of protective immunity.

  17. Salmonella enteritidis from a case of fever with thrombocytopenia

    Institute of Scientific and Technical Information of China (English)

    Shamma Arora; Naveen Gupta; Ashwani Kumar; IR Kaur

    2011-01-01

    Non typhoidalSalmonella species are thought to be potentially infectious to humans. We isolated Salmonella enteritidis from a 10-year-old boy with fever and thrombocytopenia. We reviewed the literature concerning infections caused bySalmonella but we could not find any such case report from India.

  18. 21 CFR 866.3550 - Salmonella spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Salmonella spp. serological reagents. 866.3550... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella spp. serological reagents. (a) Identification. Salmonella spp. serological reagents are devices...

  19. 9 CFR 113.30 - Detection of Salmonella contamination.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Detection of Salmonella contamination... REQUIREMENTS Standard Procedures § 113.30 Detection of Salmonella contamination. The test for detection of Salmonella contamination provided in this section shall be conducted when such a test is prescribed in...

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

    Science.gov (United States)

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

    2006-05-01

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

  1. Salmonella capture using orbiting magnetic microbeads

    Science.gov (United States)

    Owen, Drew; Ballard, Matthew; Mills, Zachary; Hanasoge, Srinivas; Hesketh, Peter; Alexeev, Alexander

    2014-11-01

    Using three-dimensional simulations and experiments, we examine capture of salmonella from a complex fluid sample flowing through a microfluidic channel. Capture is performed using orbiting magnetic microbeads, which can easily be extracted from the system for analysis after salmonella capture. Numerical simulations are used to model the dynamics of the system, which consists of a microchannel filled with a viscous fluid, model salmonella, magnetic microbeads and a series of angled parallel ridges lining the top of the microchannel. Simulations provide a statistical measure of the ability of the system to capture target salmonella. Our modeling findings guide the design of a lab-on-a-chip experimental device to be used for the detection of salmonella from complex food samples, allowing for the detection of the bacteria at the food source and preventing the consumption of contaminated food. Such a device can be used as a generic platform for the detection of a variety of biomaterials from complex fluids. This work is supported by a grant from the United States Department of Agriculture.

  2. Salmonella and Eggs: From Production to Plate

    Directory of Open Access Journals (Sweden)

    Harriet Whiley

    2015-02-01

    Full Text Available Salmonella contamination of eggs and egg shells has been identified as a public health concern worldwide. A recent shift in consumer preferences has impacted on the egg industry, with a push for cage-free egg production methods. There has also been an increased desire from consumers for raw and unprocessed foods, potentially increasing the risk of salmonellosis. In response to these changes, this review explores the current literature regarding Salmonella contamination of eggs during the production processing through to food handling protocols. The contamination of eggs with Salmonella during the production process is a complex issue, influenced by many variables including flock size, flock age, stress, feed, vaccination, and cleaning routines. Currently there is no consensus regarding the impact of caged, barn and free range egg production has on Salmonella contamination of eggs. The literature regarding the management and control strategies post-collection, during storage, transport and food handling is also reviewed. Pasteurisation and irradiation were identified as the only certain methods for controlling Salmonella and are essential for the protection of high risk groups, whereas control of temperature and pH were identified as potential control methods to minimise the risk for foods containing raw eggs; however, further research is required to provide more detailed control protocols and education programs to reduce the risk of salmonellosis from egg consumption.

  3. Invasão de áreas de savana intra-amazônicas por Digitonthophagus gazella (Fabricius, 1787 (Insecta: Coleoptera: Scarabaeidae Invasion of intra-Amazonian savannas by the dung beetle Digintonthophagus gazella (Fabricius, 1787 (Insecta: Coleoptera: Scarabaeidae

    Directory of Open Access Journals (Sweden)

    Rodrigo Augusto Matavelli

    2008-01-01

    Full Text Available Neste estudo, foi avaliada a invasão da comunidade de Scarabaeinae detritívoros de uma savana amazônica pela espécie africana Digitonthophagus gazella (Fabricius 1787. O estudo foi realizado nas proximidades da vila de Alter do Chão (2º 31' S e 55º 00' W, localizada a aproximadamente 36 km a sudoeste de Santarém, Pará, Brasil. Vinte e duas áreas de savanas de 3,75 ha (250 x 150 m distribuídas em 30.000 ha foram amostradas, no período de 21 de julho a 13 de agosto de 2003, utilizando 66 armadilhas de queda com três tipos de iscas (fezes bovinas, fezes humanas e carcaças. Foram encontrados indivíduos de D. gazella em quatro das vinte e duas áreas amostradas. Procurou-se explicar a presença da espécie nas áreas de savana através de análises de regressão logística, onde as variáveis explicativas foram: ocorrência de queimada nos últimos seis anos, diversidade e abundância total de Scarabaeidae nativos presentes na área, abundância de Canthon sp.1, (espécie de Scarabaeidae mais abundante na região. Exceto pela abundância total de indivíduos de Scarabaeidae nativos, nenhuma das variáveis bióticas e abióticas tiveram efeito estatisticamente significativo na presença do D. gazella. Estes resultados podem ser explicados por: (a algum fator ainda não analisado, relacionado à invasão da área pelo D. gazella; (b Não houve tempo para a dispersão e estabelecimento da espécie em todas as áreas; (c A comunidade nativa de Scarabaeinae apresenta resistência à invasão pelo D. gazella.This work aimed to verify the invasion of the dung beetles community from intra-Amazonian savanna by the African species Digitonthophagus gazella (Fabricius 1787. The research was carried out near Alter do Chão village (2º 31' S; 55º 00' W, 36 Km Southwest of Santarém, Pará, Brazil. Twenty two areas were sampled, from 21 July to 13 August 2003, using 66 baited pitfall traps (cattle dung, human faeces and carcass bait. D. gazella

  4. Test results of Salmonella serotyping in the Member States of the European Union. (Collaborative study III amongst the National Reference Laboratories for Salmonella)

    NARCIS (Netherlands)

    Voogt N; Maas HME; Leeuwen WJ van; Henken AM; MGB

    1998-01-01

    Het Communautair Referentie Laboratorium (CRL) voor Salmonella heeft een derde ringonderzoek voor de serotypering van Salmonella georganiseerd. Alle Nationale Referentie Laboratoria (NRLs) voor Salmonella van de Europese Unie deden aan het onderzoek mee. Het belangrijkste doel was het vergelijke

  5. Molecular characterization of Salmonella Paratyphi B dT+ and Salmonella Heidelberg from poultry and retail chicken meat in Colombia by pulsed-field gel electrophoresis

    Science.gov (United States)

    Salmonella Paratyphi B dT+ variant (also termed Salmonella Java) and Salmonella Heidelberg are human pathogens frequently isolated from poultry. As a step towards implementing the Colombian Integrated Program for Antimicrobial Resistant Surveillance (COIPARS), this study characterized molecular patt...

  6. Invasive Infections with Nontyphoidal Salmonella in Sub-Saharan Africa.

    Science.gov (United States)

    Mahon, Barbara E; Fields, Patricia I

    2016-06-01

    Invasive nontyphoidal Salmonella (NTS) infections in Africa cause an enormous burden of illness. These infections are often devastating, with mortality estimated at 20%, even with appropriate antimicrobial therapy. Two major groups-young children and HIV-infected adults-suffer the great majority of these infections. In children, younger age itself, as well as malaria, malnutrition, and HIV infection, are prominent risk factors. In adults, HIV infection is by far the most important risk factor. The most common serotypes in invasive infections are Salmonella enterica serotypes Typhimurium and Enteritidis. In recent years, a specific strain of Salmonella Typhimurium, multilocus sequence type 313, has caused epidemics of invasive disease. Little is known about risk factors for exposure to NTS, making the design of rational interventions to decrease exposure difficult. Antimicrobial therapy is critically important for treatment of invasive NTS infections. Thus, the emergence and spread of resistance to agents commonly used for treatment of invasive NTS infection, now including third-generation cephalosporins, is an ominous development. Already, many invasive NTS infections are essentially untreatable in many health care facilities in sub-Saharan Africa. Several candidate vaccines are in early development and, if safe and effective, could be promising. Interventions to prevent exposure to NTS (e.g., improved sanitation), to prevent the occurrence of disease if exposure does occur (e.g., vaccination, malaria control), and to prevent severe disease and death in those who become ill (e.g., preserving antimicrobial effectiveness) are all important in reducing the toll of invasive NTS disease in sub-Saharan Africa. PMID:27337467

  7. Invasive Infections with Nontyphoidal Salmonella in Sub-Saharan Africa.

    Science.gov (United States)

    Mahon, Barbara E; Fields, Patricia I

    2016-06-01

    Invasive nontyphoidal Salmonella (NTS) infections in Africa cause an enormous burden of illness. These infections are often devastating, with mortality estimated at 20%, even with appropriate antimicrobial therapy. Two major groups-young children and HIV-infected adults-suffer the great majority of these infections. In children, younger age itself, as well as malaria, malnutrition, and HIV infection, are prominent risk factors. In adults, HIV infection is by far the most important risk factor. The most common serotypes in invasive infections are Salmonella enterica serotypes Typhimurium and Enteritidis. In recent years, a specific strain of Salmonella Typhimurium, multilocus sequence type 313, has caused epidemics of invasive disease. Little is known about risk factors for exposure to NTS, making the design of rational interventions to decrease exposure difficult. Antimicrobial therapy is critically important for treatment of invasive NTS infections. Thus, the emergence and spread of resistance to agents commonly used for treatment of invasive NTS infection, now including third-generation cephalosporins, is an ominous development. Already, many invasive NTS infections are essentially untreatable in many health care facilities in sub-Saharan Africa. Several candidate vaccines are in early development and, if safe and effective, could be promising. Interventions to prevent exposure to NTS (e.g., improved sanitation), to prevent the occurrence of disease if exposure does occur (e.g., vaccination, malaria control), and to prevent severe disease and death in those who become ill (e.g., preserving antimicrobial effectiveness) are all important in reducing the toll of invasive NTS disease in sub-Saharan Africa.

  8. Rapid detection of Salmonella in foods using a combination of SPRINT TM,MSRV TM and Salmonella Latex TestTM Detecção rápida de Salmonella em alimentos empregando uma combinação de SPRINT®, MSRV® e Salmonella Latex Test®

    Directory of Open Access Journals (Sweden)

    Jane Maria Lafayette Neves Gelinski

    2002-09-01

    Full Text Available A new procedure for rapid detection of Salmonella in foods, based on the combination of SPRINT TM, MSRV TM and Salmonella Latex TestTM, was evaluated. SPRINT TM is a system to reduce the preenrichment and selective enrichment steps to 24 hours. MSRV TM is a semi-solid selective media for detection of motile Salmonella. Salmonella Latex TestTM is a rapid latex agglutination test for Salmonella. Using the three systems in combination, the total time for detection of Salmonella in a food sample is 48h. Evaluations were performed in artificially contaminated ready-to-eat baby-foods and raw Brazilian sausages (lingüiça containing no added microorganisms. The BAM conventional culture procedure was used as reference method. The study with baby foods indicated that the new procedure had good sensitivity (89% and specificity (100%, without cross-reactions with Enterobacteriaceae. However, when applied to naturally contaminated foods, the performance was poor: chi square (x² = 5.062, α> 0. 05 and Kappa-Cohen agreement (K = 0.171, p=0.089 indexes indicated that the differences between results given by the two procedures were significant and the correlation between them was low.Avaliou-se um novo procedimento para detecção rápida de Salmonella em alimentos, baseado na combinação entre SPRINT®, MSRV® e Salmonella Latex Test® . SPRINT® é um sistema para reduzir as etapas de pré-enriquecimento e enriquecimento seletivo para 24 h. MSRV® é um meio seletivo semi-sólido para detecção de salmonelas móveis. Salmonella Latex Test® é um teste rápido de aglutinação de látex. A combinação dos três sistemas permite que a detecção de Salmonella em alimentos possa ser feita em apenas 48 h. O procedimento foi avaliado em alimentos infantis prontos para consumo, experimentalmente contaminados com Salmonella exclusivamente e com uma mistura de Salmonella e várias espécies de Enterobacteriaceae e também em cem amostras de lingüiças de porco

  9. Salmonella enteritidis and other Salmonella in laying hens and eggs from flocks with Salmonella in their environment.

    OpenAIRE

    Poppe, C; Johnson, R. P.; Forsberg, C M; Irwin, R J

    1992-01-01

    Seven Canadian layer flocks with Salmonella enteritidis in their environment were investigated to determine the numbers of hens infected with S. enteritidis, the localization of S. enteritidis in organs of infected hens and the numbers of S. enteritidis-infected eggs produced by two affected flocks. By a microagglutination test (MAT) using S. pullorum antigens, these flocks had more seropositive hens (mean 51.9 +/- 16.9%) than two Salmonella-free flocks (mean 13.0 +/- 4.2%). Culture of tissue...

  10. Development of a novel cross-streaking method for isolation, confirmation, and enumeration of Salmonella from irrigation ponds.

    Science.gov (United States)

    Luo, Zhiyao; Gu, Ganyu; Giurcanu, Mihai C; Adams, Paige; Vellidis, George; van Bruggen, Ariena H C; Wright, Anita C

    2014-06-01

    The 2013 Produce Safety Rules in Food Safety Modernization Act (FSMA) require regular testing for generic Escherichia coli in agricultural water intended for pre-harvest contact with the edible portion of fresh produce. However, the use of fecal contamination indicators frequently does not correctly reflect distribution of foodborne pathogens such as Salmonella enterica, and ensuring food safety may require direct detection and enumeration of pathogens in agricultural settings. Herein we report the evaluation of different cost-effective methods for quantification, isolation, and confirmation of Salmonella in irrigation pond water and sediment samples. A most probably number (MPN) dual enrichment culture method was used in combination with differential and selective agars, XLT4 and CHROMagar™ Salmonella plus (CSP). The necessity for PCR confirmation was evaluated, and methods were compared by cost and performance measures (i.e., sensitivity, specificity, positive predictive value, and negative predictive value). Statistical analyses showed that using XLT4 as the initial selective agar to isolate Salmonella colonies improved recovery compared to CSP agar; however, PCR confirmation was required to avoid false positive results on either agar. Therefore, a novel cross-streaking method utilizing CHROMagar™ agar for individual colony confirmation of Salmonella presence/absence on XLT4 was developed. This method classifies the colony as positive if typical Salmonella appearance is observed on both agars. Statistical analysis showed that this method was as effective as PCR for species confirmation of pure individual strains isolated from enrichment cultures (sensitivity=0.99, specificity=1.00, relative to PCR). This method offers a cost-effective alternative to PCR that would increase the capacity and sensitivity of Salmonella evaluation. PMID:24732066

  11. Inactivation of Salmonellae in Frozen Catfish by Gamma Irradiation

    International Nuclear Information System (INIS)

    The effect of gamma irradiation on salmonellae viability in frozen catfish was investigated using fresh cut of catfish artificially contaminated with stationary phase cells of salmonellae, frozen at-18 οC and irradiated with does ranging from 0.0 to 2.4 kGy. The D10 values for ten serovars of salmonellae ranged from 0.47 to 0.77 kGy. Salmonella Enteritidis was the most resistant serovars found in frozen catfish. Dosage at 2.5 kGy would be sufficient to kill 103.2 Salmonella Enteritidis that may occasionally present in frozen catfish

  12. Septic arthritis of the ankle due to Salmonella enteritidis.

    LENUS (Irish Health Repository)

    Dineen, Patrick F

    2011-06-01

    Salmonella septic arthritis in healthy, immunocompetent patients is extremely rare. We present the case of a 70-year-old man who presented with a one-day history of painful swelling of his ankle from which was aspirated pus which subsequently grew Salmonella enteritidis. There was no history of trauma or symptoms consistent with Salmonella enterocolitis. Our patient recovered fully after two weeks on intravenous ceftriaxone and six weeks on oral ciprofloxacin. Salmonella is a notifiable disease in the European Union and the United States of America, and is associated with outbreaks as a result of food contamination. The nature of Salmonella arthritis and its appropriate management are outlined.

  13. Occurrence of Salmonella sp in laying hens

    OpenAIRE

    Gama NMSQ; Berchieri Jr A; SA Fernandes

    2003-01-01

    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. Salmo...

  14. PREVALENCE AND ANTIMICROBIAL RESISTANCE OF SALMONELLA ISOLATED FROM CARCASSES, PROCESSING FACILITIES AND THE ENVIRONMENT SURROUNDING SMALL SCALE POULTRY SLAUGHTERHOUSES IN THAILAND.

    Science.gov (United States)

    Chotinun, Suwit; Rojanasthien, Suvichai; Unger, Fred; Tadee, Pakpoom; Patchanee, Prapas

    2014-11-01

    Salmonella is a major food-borne pathogen worldwide, including Thai- land, and poultry meat plays a role as a vehicle for the spread of the disease from animals to humans. The prevalence and characteristics of Salmonella isolated from 41 small scale poultry slaughterhouses in Chiang Mai, Thailand were determined during July 2011 through May 2012. Salmonella's prevalence in live poultry, car- casses, waste water, and soil around processing plants were 3.2%, 7.3%, 22.0% and 29.0%, respectively. Eighteen different serotypes were identified, the most common being Corvallis (15.2%), followed by Rissen (13.9%), Hadar (12.7%), Enteritidis (10.1%), [I. 4,5,12:i:-] (8.8%), Stanley (8.8%), and Weltevreden (8.8%). Antimicrobial susceptibility tests revealed that 68.4% of the Salmonella spp were resistant to at least one antimicrobial while 50.6% showed multiple drug resis- tance (MDR). Specifically, 44.3% of Salmonella were resistant to nalidixic acid, followed by streptomycin (41.8%), ampicillin (34.2%), tetracycline (34.2%), and sulfamethoxazole/trimethoprim (20.3%). Salmonella contamination was found in processing lines, carcasses, and in the environment around the processing sta- tions. These findings indicate that improving hygiene management in small scale poultry slaughterhouses as well as prudent use of antimicrobial drugs is urgently needed if Salmonella contamination is to be reduced.

  15. The Progress of the Vector Construction of Attenuated Salmonella%减毒沙门氏菌载体构建策略研究进展

    Institute of Scientific and Technical Information of China (English)

    刘明荣; 朱良全

    2014-01-01

    Attenuated Salmonella can induce mucosal, humoral and cellular immune responses. Salmonella can present antigen, stimulate specific humoral and cellular immune response against both Salmonella and heterologous antigen. So that Salmonella is considered as prospective vaccine vector. In this review, the strategy for constructions of attenuated Salmonella vector is described, including the attenuated Salmonella strains, high level expression of heterologous antigen, etc. At the end, it is prospected about the problems to be solved during the application of attenuated Salmonella vector.%减毒沙门氏菌能诱导粘膜、体液及细胞免疫,不仅其自身能够产生免疫效应,而且还能携带外源基因诱导宿主特异性应答,是具有广泛应用前景的疫苗载体。本文从减毒致弱菌株构建、外源基因高效表达等方面综述了减毒沙门氏菌载体构建策略的新进展,进而对减毒沙门氏菌活载体应用中待解决的科学问题进行了归纳。

  16. Cloning and sequencing of hfq (host factor required for synthesis of bacteriophage Q beta RNA gene of Salmonella Typhimurium isolated from poultry

    Directory of Open Access Journals (Sweden)

    Parthasarathi Behera

    2015-05-01

    Full Text Available Aim: The aim was to clone and sequence hfq gene of Salmonella Typhimurium strain PM-45 and compare its sequence with hfq gene of other serovar of Salmonella. Materials and Methods: Salmonella Typhimurium strain PM-45 was procured from the G. B. Pant University of Agriculture and Technology, Pantnagar, India. The genomic DNA was isolated from Salmonella Typhimurium. Hfq gene was polymerase chain reaction (PCR amplified from the DNA using specific primers, which was subsequently cloned into pET32a vector and transformed into Escherichia coli BL21 pLys cells. The recombinant plasmid was isolated and subjected to restriction enzyme digestion as well as PCR. The clone was then sequenced. The sequence was analyzed and submitted in GenBank. Results: PCR produced an amplicon of 309 bp. Restriction digestion of the recombinant plasmid released the desired insert. The hfq sequence shows 100% homology with similar sequences from other Salmonella Typhimurium isolates. Both nucleotide and amino acid sequences are highly conserved. The submitted sequence is having Genbank accession no KM998764. Conclusion: Hfq, the hexameric RNA binding protein is one of the most important post-transcriptional regulator of bacteria. The sequence of hfq gene of Salmonella Typhimurium is highly conserved within and between Salmonella enterica serovars. This gene sequence is probably under heavy selection pressure to maintain the conformational integrity of its product in spite of its being not a survival gene.

  17. Salmonella in broiler flocks in the republic of Ireland.

    Science.gov (United States)

    Gutierrez, Montserrat; Fanning, June; Murphy, Anne; Murray, Gerardine; Griffin, Margaret; Flack, Alma; Leonard, Nola; Egan, John

    2009-01-01

    In order to obtain an estimation of the prevalence of Salmonella spp. in flocks of broilers in the Republic of Ireland, a study was conducted in 2006 in a total of 362 broiler flocks associated with four integrated companies. Salmonella spp. was isolated from 27.3% of flocks, and eight Salmonella serovars were identified, none of which were Salmonella Enteritidis or Salmonella Typhimurium. The most prevalent serovar was Salmonella Mbandaka, followed by Salmonella Kentucky, which respectively accounted for 61.6% and 27.0% of positive samples. Notable differences were observed among the flocks associated with different integrated companies, both in the Salmonella spp. prevalence and in the serovar distribution. Results from routine official Salmonella testing in broiler production in 2006 showed similar serovar distribution within each integrated company from the associated hatchery and factory samples. In our study, differences in the prevalence of Salmonella at farm level did not correlate with differences in the percentages of positive chicken carcasses officially tested, which were low, for all the four companies investigated. Given the high prevalence of Salmonella Mbandaka, all human isolates obtained in the Republic of Ireland from 2003 to 2006 were compared to a subset of poultry isolates by pulsed-field gel electrophoresis, but an epidemiological link between the animal and the human strains could not be established. Finally the antimicrobial resistance analysis indicated a low proportion of resistant strains among the broiler flock isolates. PMID:19061369

  18. Source attribution of human Salmonella cases in Sweden

    DEFF Research Database (Denmark)

    Wahlström, H.; Andersson, Y.; Plym-Forshell, L.;

    2010-01-01

    The aim of this study was to identify the sources of sporadic domestic Salmonella cases in Sweden and to evaluate the usefulness of a source-attribution model in a country in which food animals are virtually free from Salmonella. The model allocates human sporadic domestic Salmonella cases...... to different sources according to distribution of Salmonella subtypes in the different sources. Sporadic domestic human Salmonella cases (n=1086) reported between July 2004 and June 2006 were attributed to nine food-animal and wildlife sources. Of all Salmonella cases, 82% were acquired abroad and 2.9% were...... associated with outbreaks. We estimated that 6.4% were associated with imported food, 0.5% with food-producing animals, and 0.6% with wildlife. Overall, 7.7% could not be attributed to any source. We concluded that domestic food-producing animals are not an important source for Salmonella in humans in Sweden...

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

    Science.gov (United States)

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

    2006-05-01

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

  20. Intracellular demography and the dynamics of Salmonella enterica infections.

    Directory of Open Access Journals (Sweden)

    Sam P Brown

    2006-10-01

    Full Text Available An understanding of within-host dynamics of pathogen interactions with eukaryotic cells can shape the development of effective preventive measures and drug regimes. Such investigations have been hampered by the difficulty of identifying and observing directly, within live tissues, the multiple key variables that underlay infection processes. Fluorescence microscopy data on intracellular distributions of Salmonella enterica serovar Typhimurium (S. Typhimurium show that, while the number of infected cells increases with time, the distribution of bacteria between cells is stationary (though highly skewed. Here, we report a simple model framework for the intensity of intracellular infection that links the quasi-stationary distribution of bacteria to bacterial and cellular demography. This enables us to reject the hypothesis that the skewed distribution is generated by intrinsic cellular heterogeneities, and to derive specific predictions on the within-cell dynamics of Salmonella division and host-cell lysis. For within-cell pathogens in general, we show that within-cell dynamics have implications across pathogen dynamics, evolution, and control, and we develop novel generic guidelines for the design of antibacterial combination therapies and the management of antibiotic resistance.

  1. Salmonella Typhi shdA: pseudogene or allelic variant?

    Science.gov (United States)

    Urrutia, I M; Fuentes, J A; Valenzuela, L M; Ortega, A P; Hidalgo, A A; Mora, G C

    2014-08-01

    ShdA from Salmonella Typhimurium (ShdASTm) is a large outer membrane protein that specifically recognizes and binds to fibronectin. ShdASTm is involved in the colonization of the cecum and the Peyer's patches of terminal ileum in mice. On the other hand, shdA gene from Salmonella Typhi (shdASTy) has been considered a pseudogene (i.e. a nonfunctional sequence of genomic DNA) due to the presence of deletions and mutations that gave rise to premature stop codons. In this work we show that, despite the deletions and mutations, shdASTy is fully functional. S. Typhi ΔshdA mutants presented an impaired adherence and invasion of HEp-2 pre-treated with TGF-β1, an inducer of fibronectin production. Moreover, shdA from S. Typhi and S. Typhimurium seem to be equivalent since shdASTm restored the adherence and invasion of S. Typhi ΔshdA mutant to wild type levels. In addition, anti-FLAG mAbs interfered with the adherence and invasion of the S. Typhi shdA-3xFLAG strain. Finally, shdASTy encodes a detectable protein when heterologously expressed in Escherichia coli DH5α. The data presented here show that shdASTy is not a pseudogene, but a different functional allele compared with shdASTm. PMID:24859062

  2. Global burden of invasive nontyphoidal Salmonella disease, 2010(1).

    Science.gov (United States)

    Ao, Trong T; Feasey, Nicholas A; Gordon, Melita A; Keddy, Karen H; Angulo, Frederick J; Crump, John A

    2015-06-01

    Nontyphoidal Salmonella is a major cause of bloodstream infections worldwide, and HIV-infected persons and malaria-infected children are at increased risk for the disease. We conducted a systematic literature review to obtain age group-specific, population-based invasive nontyphoidal Salmonella (iNTS) incidence data. Data were categorized by HIV and malaria prevalence and then extrapolated by using 2010 population data. The case-fatality ratio (CFR) was determined by expert opinion consensus. We estimated that 3.4 (range 2.1-6.5) million cases of iNTS disease occur annually (overall incidence 49 cases [range 30-94] per 100,000 population). Africa, where infants, young children, and young adults are most affected, has the highest incidence (227 cases [range 152-341] per 100,000 population) and number of cases (1.9 [range 1.3-2.9] million cases). An iNTS CFR of 20% yielded 681,316 (range 415,164-1,301,520) deaths annually. iNTS disease is a major cause of illness and death globally, particularly in Africa. Improved understanding of the epidemiology of iNTS is needed.

  3. Report on the seventh workshop organised by CRL-Salmonella. Ploufragan (France), 28 May 2002

    NARCIS (Netherlands)

    Korver H; Raamsdonk EC van; Henken AM; MGB

    2002-01-01

    At 28 May 2002 a workshop was organised by the Community Reference Laboratory for Salmonella (CRL-Salmonella) in Ploufragan, France. All National Reference Laboratories for Salmonella (NRLs-Salmonella) of the EU Member States, with the exception of the Greek and the Northern-Ireland NRLs-Salmonella,

  4. Paradigm Diagnostics Salmonella Indicator Broth (PDX-SIB) for detection of Salmonella on selected environmental surfaces.

    Science.gov (United States)

    Olstein, Alan; Griffith, Leena; Feirtag, Joellen; Pearson, Nicole

    2013-01-01

    The Paradigm Diagnostics Salmonella Indicator Broth (PDX-SIB) is intended as a single-step selective enrichment indicator broth to be used as a simple screening test for the presence of Salmonella spp. in environmental samples. This method permits the end user to avoid multistep sample processing to identify presumptively positive samples, as exemplified by standard U.S. reference methods. PDX-SIB permits the outgrowth of Salmonella while inhibiting the growth of competitive Gram-negative and -positive microflora. Growth of Salmonella-positive cultures results in a visual color change of the medium from purple to yellow when the sample is grown at 37 +/- 1 degree C. Performance of PDX-SIB has been evaluated in five different categories: inclusivity-exclusivity, methods comparison, ruggedness, lot-to-lot variability, and shelf stability. The inclusivity panel included 100 different Salmonella serovars, 98 of which were SIB-positive during the 30 to 48 h incubation period. The exclusivity panel included 33 different non-Salmonella microorganisms, 31 of which were SIB-negative during the incubation period. Methods comparison studies included four different surfaces: S. Newport on plastic, S. Anatum on sealed concrete, S. Abaetetuba on ceramic tile, and S. Typhimurium in the presence of 1 log excess of Citrobacter freundii. Results of the methods comparison studies demonstrated no statistical difference between the SIB method and the U.S. Food and Drug Administration-Bacteriological Analytical Manual reference method, as measured by the Mantel-Haenszel Chi-square test. Ruggedness studies demonstrated little variation in test results when SIB incubation temperatures were varied over a 34-40 degrees C range. Lot-to-lot consistency results suggest no detectable differences in manufactured goods using two reference Salmonella serovars and one non-Salmonella microorganism.

  5. Low-oxygen tensions found in Salmonella-infected gut tissue boost Salmonella replication in macrophages by impairing antimicrobial activity and augmenting Salmonella virulence.

    Science.gov (United States)

    Jennewein, Jonas; Matuszak, Jasmin; Walter, Steffi; Felmy, Boas; Gendera, Kathrin; Schatz, Valentin; Nowottny, Monika; Liebsch, Gregor; Hensel, Michael; Hardt, Wolf-Dietrich; Gerlach, Roman G; Jantsch, Jonathan

    2015-12-01

    In Salmonella infection, the Salmonella pathogenicity island-2 (SPI-2)-encoded type three secretion system (T3SS2) is of key importance for systemic disease and survival in host cells. For instance, in the streptomycin-pretreated mouse model SPI-2-dependent Salmonella replication in lamina propria CD11c(-)CXCR1(-) monocytic phagocytes/macrophages (MΦ) is required for the development of colitis. In addition, containment of intracellular Salmonella in the gut critically depends on the antimicrobial effects of the phagocyte NADPH oxidase (PHOX), and possibly type 2 nitric oxide synthase (NOS2). For both antimicrobial enzyme complexes, oxygen is an essential substrate. However, the amount of available oxygen upon enteroinvasive Salmonella infection in the gut tissue and its impact on Salmonella-MΦ interactions was unknown. Therefore, we measured the gut tissue oxygen levels in a model of Salmonella enterocolitis using luminescence two-dimensional in vivo oxygen imaging. We found that gut tissue oxygen levels dropped from ∼78 Torr (∼11% O2) to values of ∼16 Torr (∼2% O2) during infection. Because in vivo virulence of Salmonella depends on the Salmonella survival in MΦ, Salmonella-MΦ interaction was analysed under such low oxygen values. These experiments revealed an increased intracellular replication and survival of wild-type and t3ss2 non-expressing Salmonella. These findings were paralleled by blunted nitric oxide and reactive oxygen species (ROS) production and reduced Salmonella ROS perception. In addition, hypoxia enhanced SPI-2 transcription and translocation of SPI-2-encoded virulence protein. Neither pharmacological blockade of PHOX and NOS2 nor impairment of T3SS2 virulence function alone mimicked the effect of hypoxia on Salmonella replication under normoxic conditions. However, if t3ss2 non-expressing Salmonella were used, hypoxia did not further enhance Salmonella recovery in a PHOX and NOS2-deficient situation. Hence, these data suggest that

  6. Fis is required for proper regulation of ssaG expression in Salmonella enterica serovar Typhimurium.

    Science.gov (United States)

    Lim, Sangyong; Kim, Byeongkwan; Choi, Hyun-Sook; Lee, Younghoon; Ryu, Sangryeol

    2006-07-01

    Salmonella pathogenicity island 2 (SPI2) encodes a type III secretion system (TTSS) necessary for bacterial survival and replication in intracellular environment of host cells. SPI2 genes are transcribed preferentially after Salmonella enters the host cells. Transcriptional regulation of ssaG encoding the component of SPI2-TTSS apparatus was studied in vivo and in vitro. Fis, one of the major components of bacterial nucleoid, activated the stationary phase-specific expression of ssaG when Salmonella was grown in LB media. Gel-shift and footprinting analysis showed Fis bound to four distinct sites of the ssaG promoter region with different affinities. All four Fis-binding sites were required for timely transcription activation of ssaG after Salmonella entered macrophage cells. Gentamicin protection experiments using bacteria grown to stationary phase prior to infection showed that the ability of the fis mutant strain to replicate within the RAW264.7 macrophage cells was lower than the wild type. These observations confirm that Fis plays an important role in regulations of SPI2 as well as SPI1 for an efficient regulation of the virulence genes.

  7. Seroincidence of non-typhoid Salmonella infections: convenience vs. random community-based sampling.

    Science.gov (United States)

    Emborg, H-D; Simonsen, J; Jørgensen, C S; Harritshøj, L H; Krogfelt, K A; Linneberg, A; Mølbak, K

    2016-01-01

    The incidence of reported infections of non-typhoid Salmonella is affected by biases inherent to passive laboratory surveillance, whereas analysis of blood sera may provide a less biased alternative to estimate the force of Salmonella transmission in humans. We developed a mathematical model 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 of healthy individuals from 2006 to 2007 (n = 1780). The lowest antibody levels were measured in the samples from the community cohort and the highest in pregnant women. The annual Salmonella seroincidences were 319 infections/1000 pregnant women [90% credibility interval (CrI) 210-441], 182/1000 in blood donors (90% CrI 85-298) and 77/1000 in the community cohort (90% CrI 45-114). Although the differences between study populations decreased when accounting for different age distributions the estimates depend on the study population. It is important to be aware of this issue and define a certain population under surveillance in order to obtain consistent results in an application of serological measures for public health purposes.

  8. An Immuno-Magnetic Nanobead Probe Competitive Assay for Rapid Detection of Salmonella choleraesuis.

    Science.gov (United States)

    Liu, Daofeng; Yu, Zhibiao; Huang, Yanmei; Wang, Shuying; Wang, Jingyun; Guo, Qi; Xu, Chaolian; Xia, Shiqi; Lai, Weihua

    2016-03-01

    A competitive lateral flow assay for the rapid detection of Salmonella choleraesuis was developed. Immuno-magnetic nanobeads were produced by covalently coupling anti-Salmonella choleraesuis antibody to magnetic nanobeads. These immuno-magnetic nanobeads were used as visually detected probes in the subsequent assay. Compared with the traditional sandwich assay, which is used for detecting macro-molecules, this new method was developed based on the competitive relationship between S. choleraesuis in the inspected sample and the outer membrane protein immobilized on the T line. Thus, only one antibody was necessary in the new assay, whereas a pair of rigorously selected antibodies were required in the sandwich assay. The sensitivity of the competitive assay for S. choleraesuis was 1.2 x 10(7) cfu/mL. In addition, no cross reactions were found in the 17 common non-Salmonella bacteria strains and in the 4 Salmonella strains of other serotypes. Thus, with satisfactory sensitivity and specificity, the assay can be applied for the rapid detection of pre-enriched culture that may contain S. choleraesuis. PMID:27455631

  9. An Immuno-Magnetic Nanobead Probe Competitive Assay for Rapid Detection of Salmonella choleraesuis.

    Science.gov (United States)

    Liu, Daofeng; Yu, Zhibiao; Huang, Yanmei; Wang, Shuying; Wang, Jingyun; Guo, Qi; Xu, Chaolian; Xia, Shiqi; Lai, Weihua

    2016-03-01

    A competitive lateral flow assay for the rapid detection of Salmonella choleraesuis was developed. Immuno-magnetic nanobeads were produced by covalently coupling anti-Salmonella choleraesuis antibody to magnetic nanobeads. These immuno-magnetic nanobeads were used as visually detected probes in the subsequent assay. Compared with the traditional sandwich assay, which is used for detecting macro-molecules, this new method was developed based on the competitive relationship between S. choleraesuis in the inspected sample and the outer membrane protein immobilized on the T line. Thus, only one antibody was necessary in the new assay, whereas a pair of rigorously selected antibodies were required in the sandwich assay. The sensitivity of the competitive assay for S. choleraesuis was 1.2 x 10(7) cfu/mL. In addition, no cross reactions were found in the 17 common non-Salmonella bacteria strains and in the 4 Salmonella strains of other serotypes. Thus, with satisfactory sensitivity and specificity, the assay can be applied for the rapid detection of pre-enriched culture that may contain S. choleraesuis.

  10. Oral Delivery of a Novel Attenuated Salmonella Vaccine Expressing Influenza A Virus Proteins Protects Mice against H5N1 and H1N1 Viral Infection.

    Directory of Open Access Journals (Sweden)

    Zenglin Pei

    Full Text Available Attenuated strains of invasive enteric bacteria, such as Salmonella, represent promising gene delivery agents for nucleic acid-based vaccines as they can be administrated orally. In this study, we constructed a novel attenuated strain of Salmonella for the delivery and expression of the hemagglutinin (HA and neuraminidase (NA of a highly pathogenic H5N1 influenza virus. We showed that the constructed Salmonella strain exhibited efficient gene transfer activity for HA and NA expression and little cytotoxicity and pathogenicity in mice. Using BALB/c mice as the model, we evaluated the immune responses and protection induced by the constructed Salmonella-based vaccine. Our study showed that the Salmonella-based vaccine induced significant production of anti-HA serum IgG and mucosal IgA, and of anti-HA interferon-γ producing T cells in orally vaccinated mice. Furthermore, mice orally vaccinated with the Salmonella vaccine expressing viral HA and NA proteins were completely protected from lethal challenge of highly pathogenic H5N1 as well as H1N1 influenza viruses while none of the animals treated with the Salmonella vaccine carrying the empty expression vector with no viral antigen expression was protected. These results suggest that the Salmonella-based vaccine elicits strong antigen-specific humoral and cellular immune responses and provides effective immune protection against multiple strains of influenza viruses. Furthermore, our study demonstrates the feasibility of developing novel attenuated Salmonella strains as new oral vaccine vectors against influenza viruses.

  11. Prevalence and Characterization of Salmonella enterica and Salmonella Bacteriophages Recovered from Beef Cattle Feedlots in South Texas.

    Science.gov (United States)

    Xie, Yicheng; Savell, Jeffrey W; Arnold, Ashley N; Gehring, Kerri B; Gill, Jason J; Taylor, T Matthew

    2016-08-01

    Asymptomatic Salmonella carriage in beef cattle is a food safety concern, and the beef feedlot environment may function as a reservoir of this pathogen. The goal of this study was to identify and isolate Salmonella and Salmonella bacteriophages from beef cattle feedlot environments in order to better understand the microbial ecology of Salmonella and identify phages that might be useful as anti-Salmonella beef safety interventions. Three feedlots in south Texas were visited, and 27 distinct samples from each source were collected from dropped feces, feed from feed bunks, drinking water from troughs, and soil in cattle pens (n = 108 samples). Preenrichment, selective enrichment, and selective/differential isolation of Salmonella were performed on each sample. A representative subset of presumptive Salmonella isolates was prepared for biochemical identification and serotyping. Samples were pooled by feedlot and sample type to create 36 samples and enriched to recover phages. Recovered phages were tested for host range against two panels of Salmonella hosts. Salmonella bacteria were identified in 20 (18.5%) of 108 samples by biochemical and/or serological testing. The serovars recovered included Salmonella enterica serovars Anatum, Muenchen, Altona, Kralingen, Kentucky, and Montevideo; Salmonella Anatum was the most frequently recovered serotype. Phage-positive samples were distributed evenly over the three feedlots, suggesting that phage prevalence is not strongly correlated with the presence of culturable Salmonella. Phages were found more frequently in soil and feces than in feed and water samples. The recovery of bacteriophages in the Salmonella-free feedlot suggests that phages might play a role in suppressing the Salmonella population in a feedlot environment.

  12. Water Frogs, Aquariums, and Salmonella -- Oh My!

    Centers for Disease Control (CDC) Podcasts

    2009-12-09

    This CDC Kidtastics podcast discusses how people can get Salmonella from water frogs and aquariums.  Created: 12/9/2009 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 12/9/2009.

  13. Serovars of Salmonella from captive reptiles

    DEFF Research Database (Denmark)

    Pedersen, Karl; Lassen-Nielsen, Anne Marie; Nordentoft, Steen;

    2009-01-01

    The distribution on serovars of 60 Salmonella isolates from reptiles kept in captivity in Denmark during the period 1995–2006 was investigated. The isolates were all recovered from clinical specimens submitted to the National Veterinary Institute. A majority of the samples were from reptiles...

  14. Salmonella typhi time to change empiric treatment

    DEFF Research Database (Denmark)

    Gade, C.; Engberg, J.; Weis, N.

    2008-01-01

    In the present case series report we describe seven recent cases of typhoid fever. All the patients were travellers returning from Pakistan, where typhoid is endemic. Salmonella typhi isolated from the patients by blood culture were reported as intermediary susceptible to fluoroquinolones in six...

  15. Colicinogeny in Salmonella serovars isolated in Brazil

    Directory of Open Access Journals (Sweden)

    Leila Carvalho Campos

    1988-06-01

    Full Text Available A study of colicinogeny was made in 748 strains of Salmonella (97 serovars isolated from different sources; human (291, animal (119, environmental (141, food (102 and animal feed (95. Colicin production was detected in 64 strains (8.6%, particularly isolated from foods (30.4%. Col. E1 (53 and Ia (44 were the most frequently observed, especially in S. agona for environment and food sources. Col V production was identified in 5 strains of S. typhimurium within 8 producer cultures isolated from humans. Its relationship with the sources and serovars of Salmonella are discussed.Investigou-se a produção de colicina em 748 amostras de Salmonella (97 sorovares advindas de díferentes fontes: humana (291, animal (119, ambiental (141, de alimentos (102 e rações (95. Detectaram-se 64 amostras (8,6% colicinogênicas, particularmente isoladas de alimentos (30,4%. ColE1 (53 e Ia (44 foram as mais freqüentes, especialmente no sorovar S, agona, de origem ambiental e de alimentos. Identificou-se também a produção de col V em 5 amostras de S. typhimurium dentre 8 culturas produtoras de origem humana. Discute-se a relação entre a capacidade colicinogênica e as fontes e sorovares de Salmonella.

  16. Attachment of Salmonella spp. to pork meat

    DEFF Research Database (Denmark)

    Hansen, Trine; Riber, Leise; Löfström, Charlotta;

    2011-01-01

    Five strains of Salmonella, one wildtype and four knock-out mutants (the prg, flhDC, yhjH and fliC genes) were investigated based on their probability to attach and subsequently detach from a surface of pork fillet. The attachment followed by detachment was measured and modelled for two different...

  17. Experimental Salmonella typhimurium infections in rats. I

    DEFF Research Database (Denmark)

    Hougen, H P; Jensen, E T; Klausen, B

    1989-01-01

    The course of experimentally induced Salmonella typhimurium infection was studied in three groups of inbred LEW rats: homozygous +/+, athymic rnu/rnu and isogeneic thymus-grafted rnu/rnu rats. In the first experiment the animals were inoculated intraperitoneally with 10(8) bacteria and all animals...

  18. Virulence factors of Salmonella enterica serovar Enteritidis

    NARCIS (Netherlands)

    Zhao, Y.

    2002-01-01

    Salmonella enterica serovar Enteritidis is one of the major etiologic agents of human food-borne gastrointestinal infections. Efforts to control the number of serovar Enteritidis infections have had a limited success, in part because of the lack of knowledge of the molecular mechanisms that contribu

  19. Persistence of salmonella typhimurium in nopal cladodes

    Science.gov (United States)

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

  20. Persistence of salmonella Typhimurium in Nopal

    Science.gov (United States)

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

  1. Identification of genes to differentiate closely related Salmonella lineages.

    Directory of Open Access Journals (Sweden)

    Qing-Hua Zou

    Full Text Available BACKGROUND: Salmonella are important human and animal pathogens. Though highly related, the Salmonella lineages may be strictly adapted to different hosts or cause different diseases, from mild local illness like gastroenteritis to fatal systemic infections like typhoid. Therefore, rapid and accurate identification of Salmonella is essential for timely and correct diagnosis of Salmonella infections. The current identification methods such as 16S rRNA sequencing and multilocus sequence typing are expensive and time consuming. Additionally, these methods often do not have sufficient distinguishing resolution among the Salmonella lineages. METHODOLOGIES/PRINCIPAL FINDINGS: We compared 27 completely sequenced Salmonella genomes to identify possible genomic features that could be used for differentiation of individual lineages. We concatenated 2372 core genes in each of the 27 genomes and constructed a neighbor-joining tree. On the tree, strains of each serotype were clustered tightly together and different serotypes were unambiguously separated with clear genetic distances, demonstrating systematic genomic divergence among the Salmonella lineages. We made detailed comparisons among the 27 genomes and identified distinct sets of genomic differences, including nucleotide variations and genomic islands (GIs, among the Salmonella lineages. Two core genes STM4261 and entF together could unambiguously distinguish all Salmonella lineages compared in this study. Additionally, strains of a lineage have a common set of GIs and closely related lineages have similar sets of GIs. CONCLUSIONS: Salmonella lineages have accumulated distinct sets of mutations and laterally acquired DNA (e.g., GIs in evolution. Two genes entF and STM4261 have diverged sufficiently among the Salmonella lineages to be used for their differentiation. Further investigation of the distinct sets of mutations and GIs will lead to novel insights into genomic evolution of Salmonella and

  2. ESTABELECIMENTO DE UM PROTOCOLO DE SOROAGLUTINAÇÃO RÁPIDA (SAR PARA DETECÇÃO DE ANTICORPOS PARA Salmonella Typhimurium EM SUÍNOS

    Directory of Open Access Journals (Sweden)

    Rosecler Alves Pereirara

    2010-10-01

    Full Text Available Salmonella Typhimurium is an important agent isolated from cases of human food poisoning in Brazil. Animal-origin products are the main source of infection, and pork has been implicated in Salmonella transmission to humans. Programs to salmonella monitoring in swine have been carried out, using bacteriologicaland serological tests like ELISA. However, these tests are time-consuming and expensive. The rapid agglutination test (RAT is cheaper, faster and easier. Aiming to standardize RAT to detect anti-salmonella antibodies in swine serum, 60 samples of swine serum were tested. They had previously displayed positive (30 or negative (30 results in the ELISA test. The results showed that RAT had sensitivity, specificity, predictive positive value and predictive negative value equal to 96.7% when non-diluted serum was tested. Thus, this test can be applied to detect antibodies against S. Typhimurium in swine serum.

  3. [Increase in antimicrobial resistance of Salmonella from food to fluoroquinolones and cephalosporins--a review of data from ten years].

    Science.gov (United States)

    Tenhagen, Bernd-Alois; Schroeter, Andreas; Szabo, Istvan; Dorn, Christina; Appel, Bernd; Helmuth, Reiner; Käsbohrer, Annemarie

    2014-01-01

    Animal derived food is a relevant source of human infections with Salmonella enterica. In this paper we analyse the presence of Salmonella in meat with respect to the observed serovars and their resistance to the fluoroquinolone ciprofloxacin and 3rd generation cephalosporins in the years 2003 to 2012. Data originated from 8176 isolates that were isolated from meat, characterized in the National Reference Laboratory for Salmonella and tested for antimicrobial resistance in the National Reference Laboratory for antimicrobial resistance in this time period. The analysis reveals substantial differences in resistance patterns between isolates from different types of meat and different serovars. Frequent serovars were mostly associated with one type of meat, suggesting an additional influence of specific characteristics of the serovars besides the effect of selection pressure excerted by antimicrobial treatments. Results show a clear increase in resistance to fluoroquinolones and 3rd generation cephalosporins that was most prominent in isolates from poultry meat. Although the number of human infections with Salmonella in Germany decreased sharply in recent years, results indicate a substantial exposure of consumers to Salmonella that are resistant to important antimicrobials via meat.

  4. Sampling by sponge wipe or skin excision for recovery of inoculated Salmonella and Campylobacter from defeathered broiler carcasses.

    Science.gov (United States)

    Berrang, Mark E; Cox, Nelson A; Oakley, Brian B

    2014-05-01

    Broilers may carry Salmonella and Campylobacter on inner and outer surfaces upon arrival at the slaughter plant, and carcasses can be further contaminated during commercial processing. A sensitive, nondestructive, repeatable sampling method would be useful to test carcasses for levels of bacteria before and after specific processing steps to measure either contamination or efficacy of intervention techniques. Blending of excised skin is accepted as an effective sampling method but requires damage to the carcass; this makes repeated measurements on the same carcass difficult. Herein we compare sponge sampling to skin excision to recover inoculated Salmonella and Campylobacter from broiler carcasses. In each of three replications, broiler carcass breast skin was inoculated with approximately 6.0 log antimicrobial-resistant Salmonella and Campylobacter, allowed to dry for 60 s, and sampled by either sponge, skin excision, or sponge followed by skin excision. Antimicrobial-resistant Salmonella and Campylobacter were enumerated from all samples. Skin excision allowed recovery of 0.1 to 0.2 log more inoculated bacteria than did sponge sampling. When excision was used on the same skin previously sampled by sponging, the combination of both methods did not significantly improve recovery compared with sponging alone. Skin excision is slightly more sensitive than sponge sampling; however, for repeated nondestructive sampling of broiler carcasses during processing, sponge sampling may be preferable to recover Salmonella and Campylobacter within 60 s of a contamination event.

  5. Effect of natural microbiota on growth of Salmonella spp. in fresh pork--a predictive microbiology approach.

    Science.gov (United States)

    Møller, C O A; Ilg, Y; Aabo, S; Christensen, B B; Dalgaard, P; Hansen, T B

    2013-06-01

    This study was undertaken to model and predict growth of Salmonella and the dominating natural microbiota, and their interaction in ground pork. Growth of Salmonella in sterile ground pork at constant temperatures between 4 °C and 38 °C was quantified and used for developing predictive models for lag time, max. specific growth rate and max. population density. Data from literature were used to develop growth models for the natural pork microbiota. Challenge tests at temperatures from 9.4 to 24.1 °C and with Salmonella inoculated in ground pork were used for evaluation of interaction models. The existing Jameson-effect and Lotka-Volterra species interaction models and a new expanded Jameson-effect model were evaluated. F-test indicated lack-of-fit for the classical Jameson-effect model at all of the tested temperatures and at 14.1-20.2 °C this was caused by continued growth of Salmonella after the natural microbiota had reached their max. population density. The new expanded Jameson-effect model and the Lotka-Volterra model performed better and appropriately described the continued but reduced growth of Salmonella after the natural microbiota had reached their max. population density. The expanded Jameson-effect model is a new and simple species interaction model, which performed as well as the more complex Lotka-Volterra model.

  6. Comparing human-Salmonella with plant-Salmonella protein-protein interaction predictions

    Directory of Open Access Journals (Sweden)

    Sylvia eSchleker

    2015-01-01

    Full Text Available Salmonellosis is the most frequent food-borne disease world-wide and can be transmitted to humans by a variety of routes, especially via animal and plant products. Salmonella bacteria are believed to use not only animal and human but also plant hosts despite their evolutionary distance. This raises the question if Salmonella employs similar mechanisms in infection of these diverse hosts. Given that most of our understanding comes from its interaction with human hosts, we investigate here to what degree knowledge of Salmonella-human interactions can be transferred to the Salmonella-plant system. Reviewed are recent publications on analysis and prediction of Salmonella-host interactomes. Putative protein-protein interactions (PPIs between Salmonella and its human and Arabidopsis hosts were retrieved utilizing purely interolog-based approaches in which predictions were inferred based on available sequence and domain information of known PPIs, and machine learning approaches that integrate a larger set of useful information from different sources. Transfer learning is an especially suitable machine learning technique to predict plant host targets from the knowledge of human host targets. A comparison of the prediction results with transcriptomic data shows a clear overlap between the host proteins predicted to be targeted by PPIs and their gene ontology enrichment in both host species and regulation of gene expression. In particular, the cellular processes Salmonella interferes with in plants and humans are catabolic processes. The details of how these processes are targeted, however, are quite different between the two organisms, as expected based on their evolutionary and habitat differences. Possible implications of this observation on evolution of host-pathogen communication are discussed.

  7. Simultaneous detection of Listeria monocytogenes and Salmonella spp. in dairy products using real time PCR-melt curve analysis

    OpenAIRE

    Singh, Jitender; Batish, Virender K.; Grover, Sunita

    2011-01-01

    The present investigation reports development of post real time PCR (RTi-PCR) - melt curve analysis for simultaneous detection of Listeria monocytogenes and Salmonella spp. The optimal Sybr Green I (SG-I) concentration of 1.6 μM resulted in two specific peaks with melting temperature (Tm) of 79.90 ± 0.39 °C and 86.29 ± 0.13 °C for L. monocytogenes and Salmonella spp respectively. The detection sensitivity of the assay in reconstituted non-fat dried milk (NFDM; 11%) spiked with the target path...

  8. Salmonella surveillance and control at post-harvest in the Belgian pork meat chain.

    Science.gov (United States)

    Delhalle, L; Saegerman, C; Farnir, F; Korsak, N; Maes, D; Messens, W; De Sadeleer, L; De Zutter, L; Daube, G

    2009-05-01

    Salmonella remains the primary cause of reported bacterial food borne disease outbreaks in Belgium. Pork and pork products are recognized as one of the major sources of human salmonellosis. In contrast with the primary production and slaughterhouse phases of the pork meat production chain, only a few studies have focussed on the post-harvest stages. The goal of this study was to evaluate Salmonella and Escherichia coli contamination at the Belgian post-harvest stages. E. coli counts were estimated in order to evaluate the levels of faecal contamination. The results of bacteriological analysis from seven cutting plants, four meat-mincing plants and the four largest Belgian retailers were collected from official and self-monitoring controls. The prevalence of Salmonella in the cutting plants and meat-mincing plants ranged from 0% to 50%. The most frequently isolated serotype was Salmonella typhimurium. The prevalence in minced meat at retail level ranged from 0.3% to 4.3%. The levels of Salmonella contamination estimated from semi-quantitative analysis of data relating to carcasses, cuts of meat and minced meat were equal to -3.40+/-2.04 log CFU/cm(2), -2.64+/-1.76 log CFU/g and -2.35+/-1.09 log CFU/g, respectively. The E. coli results in meat cuts and minced meat ranged from 0.21+/-0.50 to 1.23+/-0.89 log CFU/g and from 1.33+/-0.58 to 2.78+/-0.43 log CFU/g, respectively. The results showed that faecal contamination still needs to be reduced, especially in specific individual plants. PMID:19269567

  9. Differential Killing of Salmonella enterica Serovar Typhi by Antibodies Targeting Vi and Lipopolysaccharide O:9 Antigen.

    Science.gov (United States)

    Hart, Peter J; O'Shaughnessy, Colette M; Siggins, Matthew K; Bobat, Saeeda; Kingsley, Robert A; Goulding, David A; Crump, John A; Reyburn, Hugh; Micoli, Francesca; Dougan, Gordon; Cunningham, Adam F; MacLennan, Calman A

    2016-01-01

    Salmonella enterica serovar Typhi expresses a capsule of Vi polysaccharide, while most Salmonella serovars, including S. Enteritidis and S. Typhimurium, do not. Both S. Typhi and S. Enteritidis express the lipopolysaccharide O:9 antigen, yet there is little evidence of cross-protection from anti-O:9 antibodies. Vaccines based on Vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against Vi confer protection. Here we investigate the role of Vi capsule and antibodies against Vi and O:9 in antibody-dependent complement- and phagocyte-mediated killing of Salmonella. Using isogenic Vi-expressing and non-Vi-expressing derivatives of S. Typhi and S. Typhimurium, we show that S. Typhi is inherently more sensitive to serum and blood than S. Typhimurium. Vi expression confers increased resistance to both complement- and phagocyte-mediated modalities of antibody-dependent killing in human blood. The Vi capsule is associated with reduced C3 and C5b-9 deposition, and decreased overall antibody binding to S. Typhi. However, purified human anti-Vi antibodies in the presence of complement are able to kill Vi-expressing Salmonella, while killing by anti-O:9 antibodies is inversely related to Vi expression. Human serum depleted of antibodies to antigens other than Vi retains the ability to kill Vi-expressing bacteria. Our findings support a protective role for Vi capsule in preventing complement and phagocyte killing of Salmonella that can be overcome by specific anti-Vi antibodies, but only to a limited extent by anti-O:9 antibodies.

  10. Differential Killing of Salmonella enterica Serovar Typhi by Antibodies Targeting Vi and Lipopolysaccharide O:9 Antigen.

    Directory of Open Access Journals (Sweden)

    Peter J Hart

    Full Text Available Salmonella enterica serovar Typhi expresses a capsule of Vi polysaccharide, while most Salmonella serovars, including S. Enteritidis and S. Typhimurium, do not. Both S. Typhi and S. Enteritidis express the lipopolysaccharide O:9 antigen, yet there is little evidence of cross-protection from anti-O:9 antibodies. Vaccines based on Vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against Vi confer protection. Here we investigate the role of Vi capsule and antibodies against Vi and O:9 in antibody-dependent complement- and phagocyte-mediated killing of Salmonella. Using isogenic Vi-expressing and non-Vi-expressing derivatives of S. Typhi and S. Typhimurium, we show that S. Typhi is inherently more sensitive to serum and blood than S. Typhimurium. Vi expression confers increased resistance to both complement- and phagocyte-mediated modalities of antibody-dependent killing in human blood. The Vi capsule is associated with reduced C3 and C5b-9 deposition, and decreased overall antibody binding to S. Typhi. However, purified human anti-Vi antibodies in the presence of complement are able to kill Vi-expressing Salmonella, while killing by anti-O:9 antibodies is inversely related to Vi expression. Human serum depleted of antibodies to antigens other than Vi retains the ability to kill Vi-expressing bacteria. Our findings support a protective role for Vi capsule in preventing complement and phagocyte killing of Salmonella that can be overcome by specific anti-Vi antibodies, but only to a limited extent by anti-O:9 antibodies.

  11. Bayesian estimation of true between-herd and within-herd prevalence of Salmonella in Danish veal calves

    DEFF Research Database (Denmark)

    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...... to slaughter from infected herds are unknown in Denmark. Due to uncertainties about test sensitivity and specificity, these prevalences are not straightforward to assess. The objective of this study was to estimate the within-herd- and between-herd prevalence of Salmonella in veal calves delivered...... was sufficient to establish high posterior estimates of freedom from infection in individual herds. We used Bayesian analysis to avoid bias as a result of fixed test validity estimates. Serological test results from 753 animals and faecal culture from 1233 animals from 68 randomly selected Danish veal producing...

  12. Evaluation of milk yield losses associated with Salmonella antibodies in bulk tank milk in bovine dairy herds

    DEFF Research Database (Denmark)

    Nielsen, Torben Dahl; Green, L. E.; Kudahl, Anne Margrethe Braad;

    2012-01-01

    The effect of Salmonella on milk production is not well established in cattle. The objective of this study was to investigate whether introduction of Salmonella into dairy cattle herds was associated with reduced milk yield and determine the duration of any such effect. Longitudinal data from 2005...... through 2009 were used, with data from 12 mo before until 18 mo after the estimated date of infection. Twenty-eight case herds were selected based on an increase in the level of Salmonella-specific antibodies in bulk-tank milk from ... was randomly allocated to the control herds. Hierarchical mixed effect models with the outcome test-day yield of energy-corrected milk (ECM)/cow were used to investigate daily milk yield before and after the estimated herd infection date for cows in parities 1, 2, and 3+. Control herds were used to evaluate...

  13. Intestinal inflammation allows Salmonella to use ethanolamine to compete with the microbiota

    OpenAIRE

    Thiennimitr, Parameth; Winter, Sebastian E.; Winter, Maria G.; Xavier, Mariana N.; Tolstikov, Vladimir; Huseby, Douglas L.; Sterzenbach, Torsten; Tsolis, Renée M.; Roth, John R.; Bäumler, Andreas J.

    2011-01-01

    Conventional wisdom holds that microbes support their growth in vertebrate hosts by exploiting a large variety of nutrients. We show here that use of a specific nutrient (ethanolamine) confers a marked growth advantage on Salmonella enterica serovar Typhimurium (S. Typhimurium) in the lumen of the inflamed intestine. In the anaerobic environment of the gut, ethanolamine supports little or no growth by fermentation. However, S. Typhimurium is able to use this carbon source by inducing the gut ...

  14. Regulation of fucose and 1,2-propanediol utilization by Salmonella enterica serovar Typhimurium

    OpenAIRE

    Staib, Lena; Fuchs, Thilo M.

    2015-01-01

    After ingestion, Salmonella enterica serovar Typhimurium (S. Typhimurium) encounters a densely populated, competitive environment in the gastrointestinal tract. To escape nutrient limitation caused by the intestinal microbiota, this pathogen has acquired specific metabolic traits to use compounds that are not metabolized by the commensal bacteria. For example, the utilization of 1,2-propanediol (1,2-PD), a product of the fermentation of L-fucose, which is present in foods of herbal origin and...

  15. Epidemiology and control measures for Salmonella in pigs and pork

    DEFF Research Database (Denmark)

    Wong, Danilo Lo Fo; Hald, Tine; Wolf, P. J. van der;

    2002-01-01

    In order to effectively manage the problem of human salmonellosis attributable to pork and pork products, control measures should be taken simultaneously at all levels of production. These measures require an understanding of the epidemiology of Salmonella within and between links of the production...... chain. Two major factors of pre-harvest Salmonella epidemiology are the introduction and subsequent transmission of infection within and between herds. Stress imposed by transportation and the associated handling can significantly increase the number of pigs excreting Salmonella upon arrival...... at the abattoir and during lairage, exposing negative pigs to Salmonella. Positive pigs carry Salmonella on the skin, in the gastro-intestinal system or in the mouth. The (cross-)contamination of carcasses is basically a matter of redistributing the Salmonella bacteria from the positive pigs during the various...

  16. Chasing Salmonella Typhimurium in free range egg production system.

    Science.gov (United States)

    Chousalkar, Kapil; Gole, Vaibhav; Caraguel, Charles; Rault, Jean-Loup

    2016-08-30

    Free range production systems are becoming a major source of egg production in Australia and worldwide. This study investigated shedding and ecology of Salmonella Typhimurium and Salmonella species in a free range layer flock, wild birds and foxes in the vicinity of the free range farm in different seasons. Shedding of Salmonella was significantly higher in summer. Within the shed, overall, Salmonella prevalence was highest in dust. Corticosterone level in faeces was highest in spring and lowest in winter. There was no direct association between the Salmonella shedding (MPN/gm) and corticosterone levels in faeces. Salmonella Typhimurium MLVA types isolated from fox and wild birds were similar to MLVA types isolated from layer flock and reported during human food borne illness. Wild birds and foxes appear to play an important role in S. Typhimurium ecology and food safety. Environmental factors could play a role in evolution of S. Typhimurium in free range environment. PMID:27527766

  17. Spatio-temporal analysis of Salmonella surveillance data in Thailand

    DEFF Research Database (Denmark)

    Coutinho Calado Domingues, Ana Rita; Vieira, Antonio; Hendriksen, Rene S.;

    2014-01-01

    isolates from Thailand was analysed. Data was grouped into human and non-human categories and the analysis was performed for the top five occurring serovars for each year of the study period. A total 91 human and 39 non-human significant spatio-temporal clusters were observed, accounting for 11% and 16......This study evaluates the usefulness of spatio-temporal statistical tools to detect outbreaks using routine surveillance data where limited epidemiological information is available. A dataset from 2002 to 2007 containing information regarding date, origin, source and serotype of 29 586 Salmonella......% of the isolates, respectively. Serovar-specific associations between human and non-human clusters were also evaluated. Results show that these statistical tools can provide information for use in outbreak prevention and detection, in countries where only limited data is available. Moreover, it is suggested...

  18. 沙门氏致病菌标准阳性模板的构建及实时荧光定量聚合酶链式反应检测%Construction of Standard Positive Template and Development of a Real-Time Fluorescence Quantitative Polymerase Chain Reaction (FQ-PCR) Assay for PathogenicSalmonella spp.

    Institute of Scientific and Technical Information of China (English)

    陈晨; 邵彪; 陈刚; 黄伟东

    2014-01-01

    Objective: To construct recombinant plasmids for use as standard positive template and establish a real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) assay for determining pathogenicSalmonellaspp. in foods. Methods: Primers and Taqman probe were designed and synthesized with the specific fragment of InvA gene as the target sequence. Recombinant plasmids were constructed by inserting the target gene into PGM-T carriers. Real-time fluorescent quantitative PCR method was established and its sensitivity, specificity, repeatability and accuracy were investigated. Results: The recombinant plasmids constructed using the specific sequence of pathogenicSalmonella spp. could be used as a standard positive template for fluorescent quantitative PCR. The standard curve wasY=-3.151 lgX+42.86 (R2=0.999), and the sensitivity of the method was 80 copies per reaction. It was specific to detect Salmonellaspp. with good repeatability (the inter-batch and intra-batch coefficients of variation were both less than 5%). Conclusion: The FQ-PCR method allows qualitative and quantitative detection of pathogenicSalmonellaspp.%目的:构建重组质粒作为标准阳性模板,建立食品中沙门氏致病菌实时荧光定量聚合酶链式反应检测方法。方法:以致病性沙门氏菌invA基因上特异性片段为目标,设计并合成引物和TaqMan探针,将目标片段连接到PGM-T载体上构建重组质粒,建立实时荧光定量检测体系,并考察方法的灵敏性、特异性、重复性和准确性。结果:构建出致病性沙门氏菌特异性基因片段的重组质粒,能够作为实时荧光定量聚合酶链式反应检测方法的标准阳性模板,标准曲线方程为Y=-3.151 lgX+42.86(R2=0.999),灵敏度80拷贝反应体系,能特异区分沙门氏菌与类型的细菌,同时,批内和批间的变异系数均小于5%,具有良好的重复性。结论:本方法能够实现对食品

  19. Prolonged inhibition of bacterial protein synthesis abolishes Salmonella invasion.

    OpenAIRE

    MacBeth, K J; Lee, C. A.

    1993-01-01

    We have found that prolonged inhibition of bacterial protein synthesis abolishes the ability of Salmonella typhimurium to enter HEp-2 cells. Our results suggest that an essential invasion factor has a functional half-life that is seen as a gradual loss of invasiveness in the absence of protein synthesis. Therefore, Salmonella invasiveness appears to be a transient phenotype that is lost unless protein synthesis is maintained. This finding may explain why salmonellae grown to stationary phase ...

  20. Ludwig′s angina by Salmonella Typhi: A clinical dilemma

    Directory of Open Access Journals (Sweden)

    R K Mahajan

    2015-01-01

    Full Text Available Salmonella Typhi has rarely been associated with focal abscesses; and in literature, there is no evidence of its association with abscesses in the neck spaces. Ability of Salmonella Typhi to invade and localise in the neck spaces not only poses a diagnostic challenge but also underscores the necessity to understand the mechanisms that facilitate Salmonella Typhi to establish infections at sites completely non-traditional to the organism.

  1. Salmonella induces prominent gene expression in the rat colon

    Directory of Open Access Journals (Sweden)

    Roosing Susanne

    2007-09-01

    Full Text Available Abstract Background Salmonella enteritidis is suggested to translocate in the small intestine. In vivo it induces gene expression changes in the ileal mucosa and Peyer's patches. Stimulation of Salmonella translocation by dietary prebiotics fermented in colon suggests involvement of the colon as well. However, effects of Salmonella on colonic gene expression in vivo are largely unknown. We aimed to characterize time dependent Salmonella-induced changes of colonic mucosal gene expression in rats using whole genome microarrays. For this, rats were orally infected with Salmonella enteritidis to mimic a foodborne infection and colonic gene expression was determined at days 1, 3 and 6 post-infection (n = 8 rats per time-point. As fructo-oligosaccharides (FOS affect colonic physiology, we analyzed colonic mucosal gene expression of FOS-fed versus cellulose-fed rats infected with Salmonella in a separate experiment. Colonic mucosal samples were isolated at day 2 post-infection. Results Salmonella affected transport (e.g. Chloride channel calcium activated 6, H+/K+ transporting Atp-ase, antimicrobial defense (e.g. Lipopolysaccharide binding protein, Defensin 5 and phospholipase A2, inflammation (e.g. calprotectin, oxidative stress related genes (e.g. Dual oxidase 2 and Glutathione peroxidase 2 and Proteolysis (e.g. Ubiquitin D and Proteosome subunit beta type 9. Furthermore, Salmonella translocation increased serum IFNγ and many interferon-related genes in colonic mucosa. The gene most strongly induced by Salmonella infection was Pancreatitis Associated Protein (Pap, showing >100-fold induction at day 6 after oral infection. Results were confirmed by Q-PCR in individual rats. Stimulation of Salmonella translocation by dietary FOS was accompanied by enhancement of the Salmonella-induced mucosal processes, not by induction of other processes. Conclusion We conclude that the colon is a target tissue for Salmonella, considering the abundant changes in

  2. Faecal Salmonella shedding in fattening pigs in relation to the presence of Salmonella antibodies in three pig production systems

    DEFF Research Database (Denmark)

    Bonde, Marianne Kjær; Sørensen, Jan Tind

    2012-01-01

    Human salmonellosis originating from pork is an important zoonotic disease, and the production of outdoor pigs may increase the risk of contaminating the food chain with Salmonella from environmental sources. The prevalence of faecal Salmonella shedding has therefore been compared in organic...... was 5.4% with no significant differences between systems. Pigs with Salmonella shedding on farm were more likely to also be shedding Salmonella at slaughter (P<0.001). The serological test result was a significant predictor of Salmonella shedding at slaughter in indi-vidual pigs from conventional......, conventional outdoor and indoor finishing pig herds in a Danish survey with participation of 34 herds. Individual faecal samples were collected from 30 to 50 pigs per herd before and after transport to slaughter and analysed for the presence of Salmonella. Further meat juice samples were collected from the...

  3. Prevalence and antibiotic resistance of Salmonella Enteritidis and Salmonella Typhimurium in raw chicken meat at retail markets in Malaysia.

    Science.gov (United States)

    Thung, T Y; Mahyudin, N A; Basri, D F; Wan Mohamed Radzi, C W J; Nakaguchi, Y; Nishibuchi, M; Radu, S

    2016-08-01

    Salmonellosis is one of the major food-borne diseases in many countries. This study was carried out to determine the occurrence of Salmonella spp., Salmonella Enteritidis, and Salmonella Typhimurium in raw chicken meat from wet markets and hypermarkets in Selangor, as well as to determine the antibiotic susceptibility profile of S. Enteritidis and S. Typhimurium. The most probable number (MPN) in combination with multiplex polymerase chain reaction (mPCR) method was used to quantify the Salmonella spp., S. Enteritidis, and S. Typhimurium in the samples. The occurrence of Salmonella spp., S. Enteritidis, and S. Typhimurium in 120 chicken meat samples were 20.80%, 6.70%, and 2.50%, respectively with estimated quantity varying from retail chicken meat could be a source of multiple antimicrobial-resistance Salmonella and may constitute a public health concern in Malaysia. PMID:27118863

  4. Prevention of Salmonella contamination of finished soybean meal used for animal feed by a Norwegian production plant despite frequent Salmonella contamination of raw soy beans, 1994–2012

    OpenAIRE

    Wierup, Martin; Kristoffersen, Thor

    2014-01-01

    Background Salmonella contaminated animal feed is a major source for introducing Salmonella into the animal derived food chain. Because soybeans frequently are contaminated with Salmonella, soybean meal used as animal feed material, a by-product of a “crushing plant” which produces oil from soybeans, can be important source of Salmonella in the animal feed. We report the successful control of Salmonella from 1994 to 2012 in a Norwegian crushing plant producing soybean meal from imported soy b...

  5. DETEKSI Salmonella PADA NASI GORENG YANG DISEDIAKAN OLEH RESTORAN KERETA API KELAS EKONOMI [Detection of Salmonella on Fried Rice Served in Restaurant of Economic Class Train

    OpenAIRE

    Srianta; Elisa Rinihapsari

    2003-01-01

    Salmonella is a group of infective pathogenic bacteria for human being that cause many food borne disease outbreaks. Human, animal and some animal-based food products are whicle for Salmonella. Public transportation i.e. train/railway, often serve foods that potentially contaminated with Salmonella. Study on Salmonella detection on fried rice served in economic class train restaurant is necessary for controlling its safety and quality. Standard method was used to detect Salmonella on fried ri...

  6. Salmonella and Campylobacter: Antimicrobial resistance and bacteriophage control in poultry.

    Science.gov (United States)

    Grant, Ar'Quette; Hashem, Fawzy; Parveen, Salina

    2016-02-01

    Salmonella and Campylobacter are major causes of foodborne related illness and are traditionally associated with consuming undercooked poultry and/or consuming products that have been cross contaminated with raw poultry. Many of the isolated Salmonella and Campylobacter that can cause disease have displayed antimicrobial resistance phenotypes. Although poultry producers have reduced on-the-farm overuse of antimicrobials, antimicrobial resistant Salmonella and Campylobacter strains still persist. One method of bio-control, that is producing promising results, is the use of lytic bacteriophages. This review will highlight the current emergence and persistence of antimicrobial resistant Salmonella and Campylobacter recovered from poultry as well as bacteriophage research interventions and limitations.

  7. Modeling salmonella Dublin into the dairy herd simulation model Simherd

    DEFF Research Database (Denmark)

    Kudahl, Anne Braad

    2010-01-01

    of the simulations will therefore be used for decision support in the national surveillance and eradication program against Salmonella Dublin. Basic structures of the model are programmed and will be presented at the workshop. The model is in a phase of face-validation by a group of Salmonella......Infection with Salmonella Dublin in the dairy herd and effects of the infection and relevant control measures are currently being modeled into the dairy herd simulation model called Simherd. The aim is to compare the effects of different control strategies against Salmonella Dublin on both within...

  8. Detection of salmonellae from fish in a natural river system.

    Science.gov (United States)

    Gaertner, James; Wheeler, Phil E; Obafemi, Shola; Valdez, Jessica; Forstner, Michael R J; Bonner, Timothy H; Hahn, Dittmar

    2008-09-01

    Sediment, water, and fish gut samples taken at three sites near the headwaters of the San Marcos River, Texas, were analyzed for salmonellae Salmonella spp. by culture and molecular techniques. While enrichment cultures from sediment and water samples from the two uppermost sites were negative for salmonellae in polymerase chain reaction analyses, both sediment and water samples were positive at the downstream site. At all sites, salmonellae were present in the guts of different fishes (e.g., largemouth bass Micropterus salmoides, channel catfish Ictalurus punctatus, common carp Cyprinus carpio, and suckermouth catfish Hypostomus plecostomus). The highest percentage of detection (33% of analyzed fish) occurred at the downstream site, whereas detection percentages at the upper two sites were 18% and 17%. Detection of salmonellae was usually limited to one segment of the gut (i.e., upper or lower part). Serovars were highly variable among individuals and differed between the upper and lower gut in the only individual (a common carp) that had salmonellae in both gut segments. In situ hybridization demonstrated that salmonellae were normally associated with particulate material in the gut and occurred in highly variable numbers ranging from an occasional organism to a majority of the gut microbe population. These results demonstrate the presence of different serovars of potentially human pathogenic salmonellae among four ecologically distinct fishes within natural environments. They also suggest that salmonellae are not components of the indigenous microbial community in fish intestines but rather are ingested with particulate material.

  9. Immunity to intracellular Salmonella depends on surface-associated antigens.

    Directory of Open Access Journals (Sweden)

    Somedutta Barat

    Full Text Available Invasive Salmonella infection is an important health problem that is worsening because of rising antimicrobial resistance and changing Salmonella serovar spectrum. Novel vaccines with broad serovar coverage are needed, but suitable protective antigens remain largely unknown. Here, we tested 37 broadly conserved Salmonella antigens in a mouse typhoid fever model, and identified antigen candidates that conferred partial protection against lethal disease. Antigen properties such as high in vivo abundance or immunodominance in convalescent individuals were not required for protectivity, but all promising antigen candidates were associated with the Salmonella surface. Surprisingly, this was not due to superior immunogenicity of surface antigens compared to internal antigens as had been suggested by previous studies and novel findings for CD4 T cell responses to model antigens. Confocal microscopy of infected tissues revealed that many live Salmonella resided alone in infected host macrophages with no damaged Salmonella releasing internal antigens in their vicinity. In the absence of accessible internal antigens, detection of these infected cells might require CD4 T cell recognition of Salmonella surface-associated antigens that could be processed and presented even from intact Salmonella. In conclusion, our findings might pave the way for development of an efficacious Salmonella vaccine with broad serovar coverage, and suggest a similar crucial role of surface antigens for immunity to both extracellular and intracellular pathogens.

  10. Salmonella enterica induces and subverts the plant immune system

    KAUST Repository

    García, Ana V.

    2014-04-04

    Infections with Salmonella enterica belong to the most prominent causes of food poisoning and infected fruits and vegetables represent important vectors for salmonellosis. Although it was shown that plants raise defense responses against Salmonella, these bacteria persist and proliferate in various plant tissues. Recent reports shed light into the molecular interaction between plants and Salmonella, highlighting the defense pathways induced and the means used by the bacteria to escape the plant immune system and accomplish colonization. It was recently shown that plants detect Salmonella pathogen-associated molecular patterns (PAMPs), such as the flagellin peptide flg22, and activate hallmarks of the defense program known as PAMP-triggered immunity (PTI). Interestingly, certain Salmonella strains carry mutations in the flg22 domain triggering PTI, suggesting that a strategy of Salmonella is to escape plant detection by mutating PAMP motifs. Another strategy may rely on the type III secretion system (T3SS) as T3SS mutants were found to induce stronger plant defense responses than wild type bacteria. Although Salmonella effector delivery into plant cells has not been shown, expression of Salmonella effectors in plant tissues shows that these bacteria also possess powerful means to manipulate the plant immune system. Altogether, these data suggest that Salmonella triggers PTI in plants and evolved strategies to avoid or subvert plant immunity. 2014 Garca and Hirt.

  11. Aspectos clínico-tomográficos da mucocele com invasão orbitária Clinical and computed tomography aspects of mucocele with orbital invasion

    Directory of Open Access Journals (Sweden)

    Mary Lúcia Bedran

    2003-08-01

    Full Text Available OBJETIVO: Avaliar e relacionar os achados clínico-radiológicos da mucocele orbitária. MÉTODOS: Análise clínica e de imagem referente a 166 pacientes com lesões expansivas da órbita examinadas com o tomógrafo Somaton DR da marca Siemens de terceira geração num período de 10 anos consecutivos em Hospital Universitário de referência. RESULTADOS: Os achados clínicos mais comuns foram tumoração e proptose do globo ocular. À tomografia computadorizada, o achado típico foi de massa com baixa densidade, originando-se em seios paranasais, com destruição óssea adjacente, invasão da órbita e deslocamento do globo ocular. CONCLUSÃO: O desenvolvimento da tomografia computadorizada foi decisivo no estudo da órbita pois propicia, por meio de exame radiológico altamente especializado, imagens de incrível fidelidade anatômica revelando informações sobre o processo patológico como sua localização, sua relação com as estruturas adjacentes e sua vascularização.PURPOSE: To analyze and establish clinical-radiological findings of orbital mucocele. METHODS: Clinical analysis and image of 166 patients with expansive orbital lesions submitted to third generation Siemens Somaton DR computed tomography from February 1986 to February 1995. RESULTS: The most common clinical findings were mass and proptosis. On computed tomography, the typical finding was mass with low density, coming from paranasal sinuses presenting adjacent bone destruction and orbital invasion, with displacement of ocular globe. CONCLUSION: The development of computed tomography was an important mark in orbital studies because it allows incredible anatomic imagings, yielding information about the pathologic process like its localization and anatomic relation.

  12. Anaerobiosis induced virulence of Salmonella typhi

    DEFF Research Database (Denmark)

    Kapoor, Sarika; Singh, R D; Sharma, P C;

    2002-01-01

    BACKGROUND & OBJECTIVES: Anaerobic conditions are frequently encountered by pathogens invading the gastrointestinal tract due to low/limiting oxygen conditions prevalent in the small intestine. This anaerobic stress has been suggested to enhance the virulence of gut pathogens. In the present study......, 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...... loop assay, hydrophobicity assay, expression of outer membrane proteins (OMPs) and antioxidant enzymes assay. RESULTS: Anaerobically grown S. Typhi showed significantly higher cell surface hydrophobicity as compared to aerobic bacteria. In vivo toxin production by rabbit ileal loop assay also showed...

  13. Salmonella Dublin kan give store tab

    DEFF Research Database (Denmark)

    Nielsen, Torben Dahl; Nielsen, Liza Rosenbaum; Kudahl, Anne Margrethe Braad;

    2012-01-01

    Store besætninger lider størst økonomisk tab ved infektion med Salmonella Dublin. Selv i en veldrevet besætning kan tabet løbe op i mellem 1,3 og 3,3 millioner kr. over en tiårs periode. Ved uhensigtsmæssige hygiejne- og managementrutiner kan tabet nemt blive meget højere.......Store besætninger lider størst økonomisk tab ved infektion med Salmonella Dublin. Selv i en veldrevet besætning kan tabet løbe op i mellem 1,3 og 3,3 millioner kr. over en tiårs periode. Ved uhensigtsmæssige hygiejne- og managementrutiner kan tabet nemt blive meget højere....

  14. Renal abscess caused by Salmonella Typhi

    Directory of Open Access Journals (Sweden)

    Amarjeet Kaur

    2015-01-01

    Full Text Available Salmonella typhi is a true pathogen, which is capable of causing both intestinal and extraintestinal infections. Unusual presentations of Salmonella should always be kept in mind as this organism can cause disease in almost any organ of the body. S. typhi has been reported to cause the life-threatening infections such as meningitis, endocarditis, myocarditis, empyema, and hepatic abscess. Renal involvement by S. typhi is a relatively rare presentation. We report a case of renal abscess caused by S. typhi in an afebrile, 10-year-old child who did not have any clinical history of enteric fever. To our knowledge, this is the first reported case of isolation of S. typhi from the renal abscess, and interestingly this isolate was found to be resistant to quinolones.

  15. Whole Genome Epidemiological Typing of Salmonella

    DEFF Research Database (Denmark)

    Leekitcharoenphon, Pimlapas

    . 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...... used for typing is crucial for successful discrimination. The core genes or the genes that are conserved in all members of a genus or species are potentially good candidates for investigating genomic variation in phylogeny and epidemiology. A total of 2,882 core genes have been observed among 73...... 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...

  16. Sublingual vaccination with sonicated Salmonella proteins and mucosal adjuvant induces mucosal and systemic immunity and protects mice from lethal enteritis.

    Science.gov (United States)

    Huang, Ching-Feng; Wu, Tzee-Chung; Wu, Chia-Chao; Lee, Chin-Cheng; Lo, Wen-Tsung; Hwang, Kwei-Shuai; Hsu, Mu-Ling; Peng, Ho-Jen

    2011-07-01

    Salmonella enteritidis is one of the most common pathogens of enteritis. Most experimental vaccines against Salmonella infection have been applied through injections. This is a new trial to explore the effect of sublingual administration of Salmonella vaccines on systemic and mucosal immunity. Adult BALB/c mice were sublingually vaccinated with sonicated Salmonella proteins (SSP) alone, or plus adjuvant CpG DNA (CpG) or cholera toxin (CT). They were boosted 2 weeks later. Saliva specific secretory IgA (SIgA) antibody responses were significantly stimulated in the mice vaccinated with SSP only or together with CpG or CT. Whereas the mice sublingually vaccinated with SSP and CpG had higher spleen cell IFN-γ production and serum specific IgG2a antibody responses, those receiving SSP and CT showed enhanced spleen cell IL-4, IL-5 and IL-6 production, and serum specific IgG1 antibody responses. After oral challenge with live S. enteritidis, the same strain of the source of SSP, immune protection in those sublingually vaccinated with SSP and CpG or CT was found to prevent intestinal necrosis and to render a higher survival rate. In conclusion, sublingual vaccination together with mucosal adjuvant CpG or CT is a simple but effective way against enteric bacterial pathogens. PMID:21635554

  17. The roles of intrahepatic Valpha14(+) NK1.1(+) T cells for liver injury induced by Salmonella infection in mice.

    Science.gov (United States)

    Ishigami, M; Nishimura, H; Naiki, Y; Yoshioka, K; Kawano, T; Tanaka, Y; Taniguchi, M; Kakumu, S; Yoshikai, Y

    1999-06-01

    To investigate the roles of intrahepatic T cells in liver injury after Salmonella infection, we examined serum alanine transaminase (ALT), histopathology, and bacterial numbers in liver after infection with Salmonella choleraesuis strain 31N-1 in mice genetically lacking TCRalpha beta+, CD4(+), CD8(+), or NK1.1(+)T cells with C57BL/6 background. In control (+/+) mice, serum ALT reached a peak level by day 7 after an intraperitoneal inoculation of 2 x 10(6) CFU Salmonella choleraesuis 31N-1. In TCR-beta-/- mice, liver injury, as assessed by serum ALT level and histological examination, was significantly suppressed on day 7 after Salmonella infection but the numbers of bacteria in liver did not differ from those in normal mice, suggesting that alpha beta T cells are responsible for liver injury induced by Salmonella infection. To further determine which subsets in alpha beta T cells are important for the liver injury, we compared serum ALT level in mice genetically lacking CD4, CD8, beta2-microglobulin (beta2m, IAbeta, or Jalpha281 after Salmonella infection. In CD4(-/-) mice, serum ALT was significantly lower in comparison with control mice, but there was no difference in serum ALT levels in CD8(-/-) and IAbeta-/- mice from that in control mice. Notably, serum ALT levels and pathological lesions in liver were significantly decreased in beta2m-/- or Jalpha281(-/-) mice, which lacked in NK1.1(+) T cells bearing TCR Valpha14-Jalpha281 specific for beta2m-associated CD1d, following Salmonella infection. Taken together, it is suggested that alpha beta T cells bearing NK1.1 and CD4 may be main effector cells for liver injury after Salmonella infection.

  18. Assessment of serological response of chickens to Salmonella Gallinarum and Salmonella Pullorum by Elisa

    Directory of Open Access Journals (Sweden)

    GH de Oliveira

    2004-06-01

    Full Text Available This study was done to assess an enzyme-linked immunosorbent assay (ELISA to detect chicken serological response against Salmonella enterica serotypes Gallinarum and Pullorum. The assays have used soluble bacterial proteins of Salmonella Gallinarum strain 9 (AgSG as detecting antigen and peroxidase and alkaline phosphatase conjugates. According to the results, the antigen, sera and conjugate concentrations were optimized. In addition, the assay using alkaline phosphatase and peroxidase conjugates was helpful to distinguish positive serological reaction to serotypes Gallinarum and Pullorum from Enteritidis.

  19. Patogenia de Salmonella enteritidis FT 13a y Salmonella enteritidis biovar Issatschenko en pollos de engorda

    OpenAIRE

    Griselda Ruiz Flores; Fernando Constantino Casas; José Antonio Quintana López; Carlos Cedillo Peláez; Odette Urquiza Bravo

    2008-01-01

    El objetivo del presente estudio fue determinar la patogenia de Salmonella enteritidis fagotipo 13a (SE FT 13a) y de Salmonella enteritidis biovar Issatschenko fagotipo 6a (SI) en pollitos de engorda de cuatro días de edad. Veintiocho aves por tratamiento fueron inoculadas con dosis de 1 × 108 (SE FT 13a) y 1 × 109 (SI), respectivamente, y 14 pollitos fueron inoculados con solución salina fi siológica (SSF), como testigos negativos. Se tomaron muestras de hígado, bazo, corazón, pulmón, buche,...

  20. Study of Salmonella Typhimurium infection in laying hens

    Directory of Open Access Journals (Sweden)

    Kapil eChousalkar

    2016-02-01

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

  1. Study of Salmonella Typhimurium Infection in Laying Hens

    Science.gov (United States)

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

    2016-01-01

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

  2. Survival of Salmonella during baking of peanut butter cookies.

    Science.gov (United States)

    Lathrop, Amanda A; Taylor, Tiffany; Schnepf, James

    2014-04-01

    Peanuts and peanut-based products have been the source of recent Salmonella outbreaks worldwide. Because peanut butter is commonly used as an ingredient in baked goods, such as cookies, the potential risk of Salmonella remaining in these products after baking needs to be assessed. This research examines the potential hazard of Salmonella in peanut butter cookies when it is introduced via the peanut-derived ingredient. The survival of Salmonella during the baking of peanut butter cookies was determined. Commercial, creamy-style peanut butter was artificially inoculated with a five-strain Salmonella cocktail at a target concentration of 10(8) CFU/g. The inoculated peanut butter was then used to prepare peanut butter cookie dough following a standard recipe. Cookies were baked at 350 °F (177 °C) and were sampled after 10, 11, 12, 13, 14, and 15 min. Temperature profiles of the oven and cookies were monitored during baking. The water activity and pH of the inoculated and uninoculated peanut butter, raw dough, and baked cookies were measured. Immediately after baking, cookies were cooled, and the survival of Salmonella was determined by direct plating or enrichment. After baking cookies for 10 min, the minimum reduction of Salmonella observed was 4.8 log. In cookies baked for 13 and 14 min, Salmonella was only detectable by enrichment reflecting a Salmonella reduction in the range of 5.2 to 6.2 log. Cookies baked for 15 min had no detectable Salmonella. Results of this study showed that proper baking will reduce Salmonella in peanut butter cookies by 5 log or more.

  3. Survival of Salmonella during baking of peanut butter cookies.

    Science.gov (United States)

    Lathrop, Amanda A; Taylor, Tiffany; Schnepf, James

    2014-04-01

    Peanuts and peanut-based products have been the source of recent Salmonella outbreaks worldwide. Because peanut butter is commonly used as an ingredient in baked goods, such as cookies, the potential risk of Salmonella remaining in these products after baking needs to be assessed. This research examines the potential hazard of Salmonella in peanut butter cookies when it is introduced via the peanut-derived ingredient. The survival of Salmonella during the baking of peanut butter cookies was determined. Commercial, creamy-style peanut butter was artificially inoculated with a five-strain Salmonella cocktail at a target concentration of 10(8) CFU/g. The inoculated peanut butter was then used to prepare peanut butter cookie dough following a standard recipe. Cookies were baked at 350 °F (177 °C) and were sampled after 10, 11, 12, 13, 14, and 15 min. Temperature profiles of the oven and cookies were monitored during baking. The water activity and pH of the inoculated and uninoculated peanut butter, raw dough, and baked cookies were measured. Immediately after baking, cookies were cooled, and the survival of Salmonella was determined by direct plating or enrichment. After baking cookies for 10 min, the minimum reduction of Salmonella observed was 4.8 log. In cookies baked for 13 and 14 min, Salmonella was only detectable by enrichment reflecting a Salmonella reduction in the range of 5.2 to 6.2 log. Cookies baked for 15 min had no detectable Salmonella. Results of this study showed that proper baking will reduce Salmonella in peanut butter cookies by 5 log or more. PMID:24680076

  4. Rapid identification of novel antigens of Salmonella Enteritidis by microarray-based immuno screening

    International Nuclear Information System (INIS)

    We report on an approach to rapidly screen thousands of Salmonella Enteritidis proteins with the goal of identifying novel immunodominant proteins. We used a microarray-based system that warrants high throughput and easy handling. Seven immunogenic candidates were selected after screening. Comparative analyses by ELISA and microarrays manifested their immunodominant character. The large repetitive protein (SEN4030) that plays a role as a putative adhesin in initial cell surface interaction and is highly specific to Salmonella is considered to be the most suitable protein for a diagnostic approach. The results further demonstrate that the strategy applied herein is convenient for specifically identifying immunogenic proteins of pathogenic microorganisms. Consequently, it enables a sound assessment of promising candidates for diagnostic applications and vaccine development. Moreover, the elucidation of immunogenic proteins may assist in unveiling unknown virulence-associated factors, thus furthering the understanding of the underlying pathogenicity of Salmonella in general, and of S. Enteritidis, one of the most frequently detected serovars of this pathogen, in particular. (author)

  5. A Real-Time PCR Detection of Genus Salmonella in Meat and Milk Samples

    Directory of Open Access Journals (Sweden)

    Jaroslav Pochop

    2013-05-01

    Full Text Available The aim of this study was follow the contamination of ready to eat milk and meat products with Salmonella spp. by using the Step One real-time PCR. Classical microbiological methods for detection of food-borne bacteria involve the use of pre-enrichment and/or specific enrichment, followed by the isolation of the bacteria in solid media and a final confirmation by biochemical and/or serological tests. We used the PrepSEQ Rapid Spin Sample Preparation Kit for isolation of DNA and SensiFAST SYBR Hi-ROX Kit for the real-time PCR performance. In the investigated samples without incubation we could detect strain of Salmonella sp. in five out of twenty three samples (swabs. This Step One real-time PCR assay is extremely useful for any laboratory in possession of a real-time PCR. It is a fast, reproducible, simple, specific and sensitive way to detect nucleic acids, which could be used in clinical diagnostic tests in the future. Our results indicated that the Step One real-time PCR assay developed in this study could sensitively detect Salmonella spp. in ready to eat food.

  6. Global Analysis of Host and Bacterial Ubiquitinome in Response to Salmonella Typhimurium Infection.

    Science.gov (United States)

    Fiskin, Evgenij; Bionda, Tihana; Dikic, Ivan; Behrends, Christian

    2016-06-16

    Ubiquitination serves as a critical signal in the host immune response to infection. Many pathogens have evolved strategies to exploit the ubiquitin (Ub) system to promote their own survival through a complex interplay between host defense machinery and bacterial virulence factors. Here we report dynamic changes in the global ubiquitinome of host epithelial cells and invading pathogen in response to Salmonella Typhimurium infection. The most significant alterations in the host ubiquitinome concern components of the actin cytoskeleton, NF-κB and autophagy pathways, and the Ub and RHO GTPase systems. Specifically, infection-induced ubiquitination promotes CDC42 activity and linear ubiquitin chain formation, both being required for NF-κB activation. Conversely, the bacterial ubiquitinome exhibited extensive ubiquitination of various effectors and several outer membrane proteins. Moreover, we reveal that bacterial Ub-modifying enzymes modulate a unique subset of host targets, affecting different stages of Salmonella infection. PMID:27211868

  7. Multicenter validation of PCR-based method for detection of Salmonella in chicken and pig samples

    DEFF Research Database (Denmark)

    Malorny, B.; Cook, N.; D'Agostino, M.;

    2004-01-01

    As part of a standardization project, an interlaboratory trial including 15 laboratories from 13 European countries was conducted to evaluate the performance of a noproprietary polymerase chain reaction (PCR)-based method for the detection of Salmonella on artificially contaminated chicken rinse......) and PCR assay (gel electrophoresis detection) were performed by the receiving laboratories. Aliquots of BPW enrichment cultures were sent to the participants, who analyzed them using a thermal lysis procedure followed by a validated Salmonella-specific PCR assay. The results were reported as negative...... and pig swab samples. The 3 levels were 1-10, 10-100, and 100-1000 colony-forming units (CFU)/100 mL. Sample preparations, including inoculation and pre-enrichment in buffered peptone water (BPW), were performed centrally in a German laboratory; the pre-PCR sample preparation (by a resin-based method...

  8. Signatures of adaptation in human invasive Salmonella Typhimurium ST313 populations from sub-Saharan Africa.

    Directory of Open Access Journals (Sweden)

    Chinyere K Okoro

    2015-03-01

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

  9. Antigenicity and Immunogenicity of Salmonella enteritidis: Its Implication for Diagnosis and Development of Local Isolate Vaccine for Poultry

    Directory of Open Access Journals (Sweden)

    Tati Ariyanti

    2008-12-01

    Full Text Available Genus Salmonella consists of more than 2,400 serovars, which can be identified by means of serological method based on the variation of their somatic (O, flagellar (H and capsular antigens (Vi. Salmonella serovars which are able to cause disease in animal or domestic animal are limited, such as: S. pullorum and S. gallinarum which are well adapted to poultry, cause fowl typhoid, S. cholerasuis causes disease in swine. S. typhimurium and S. enteritidis can infect all animals and humans. S. typhimurium and S. enteritidis could be isolated from salmonellosis of poultry, meat, milk and eggs. The prevalence of those isolates within the last two decades tends to increase. Pathogenic Salmonella serovars can infect both animals and humans, colonize the intestinal epithelial cells lead to diarrhoea. Salmonella spp. may enter the lower layer of epithelial cells and the lymphoid vascular system. Humoral antibody and cell mediated immunity responses may develop. Extraintestinal shedding or dissemination of Salmonella spp. may occur and multiply, this may cause latent infections and spread to the environment. Serologic diagnosis of infected animals can be done by means of serum or whole blood agglutination tests with whole cell antigen or ELISA with LPS coated tray, might demonstrate cross reactions among serovars within the one group. ELISA antibody by using fimbrial SEF14 antigen demonstrated specific diagnosis of S. enteritidis infection. The use of S. enteritidis inactive vaccines stimulates high humoral antibody response and protection against challenged homologous serovar within one group (D. The secretory antibody in mucosal surface of intestine and cell mediated immunity were not stimulated after vaccination with inactive Salmonella vaccine. Inactive vaccines (local isolate of S. enteritidis which was developed and evaluated on experimental layer chicken produced protection against challenged homologous and may be used to control vertical

  10. Molecular detection of Salmonella spp. isolated from apparently healthy pigeon in Mymensingh, Bangladesh and their antibiotic resistance pattern

    Directory of Open Access Journals (Sweden)

    Md. Khaled Saifullah

    2016-03-01

    Full Text Available Objectives: Here we determined the prevalence of Salmonella in cloacal swabs and pharyngeal swabs of apparently healthy pigeons sold in the live bird markets and villages in and around Bangladesh Agricultural University Campus, Mymensingh, Bangladesh. Materials and methods: A total of 50 samples, comprised of cloacal swabs (n=24 and pharyngeal swabs (n=26 were collected. The samples were processed, and Salmonella was isolated through a series of conventional bacteriological techniques and biochemical tests followed by polymerase chain reaction (PCR. Results: The prevalence rate of Salmonella was found to be 37.5% (n=9/24 in cloacal swabs and 30.77% (n=8/26 in pharyngeal swabs with an overall prevalence rate of 34% (n=17/50. The prevalence rate of Salmonella pigeon varied slightly among locations; 34.62% (n=9/26 in live bird markets, and 33.33% (n=8/24 in villages. Molecular detection of 17 Salmonella isolates obtained from biochemical test was performed by genus specific PCR, where all of them amplified a region of 496-bp segment of the histidine transport operon gene. Antibiogram study revealed multi-drug resistant traits in most of the isolates tested. The highest resistance was found against Ampicillin (88.23% followed by Cephalexin (82.35%. The rate of sensitivity of the isolates to Ciprofloxacin was 100% followed by Azithromycin (82.35%, Gentamicin (76.47% and Nalidixic acid (76.47%. Conclusion: Our findings suggest that pigeons carry multi-drug resistant Salmonella that may transfer to the humans and animals. [J Adv Vet Anim Res 2016; 3(1.000: 51-55

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

    Directory of Open Access Journals (Sweden)

    Verbrugghe Elin

    2012-03-01

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

  12. Microarray on digital versatile disc for identification and genotyping of Salmonella and Campylobacter in meat products.

    Science.gov (United States)

    Tortajada-Genaro, Luis Antonio; Rodrigo, Alejandro; Hevia, Elizabeth; Mena, Salvador; Niñoles, Regina; Maquieira, Ángel

    2015-09-01

    Highly portable, cost-effective, and rapid-response devices are required for the subtyping of the most frequent food-borne bacteria; thereby the sample rejection strategies and hygienization techniques along the food chain can be tailor-designed. Here, a novel biosensor is presented for the generic detection of Salmonella and Campylobacter and the discrimination between their most prevalent serovars (Salmonella Enteritidis, Salmonella Typhimurium) and species (Campylobacter jejuni, Campylobacter coli), respectively. The method is based on DNA microarray developed on a standard digital versatile disc (DVD) as support for a hybridization assay and a DVD driver as scanner. This approach was found to be highly sensitive (detection limit down to 0.2 pg of genomic DNA), reproducible (relative standard deviation 4-19 %), and high working capacity (20 samples per disc). The inclusivity and exclusivity assays indicated that designed oligonucleotides (primers and probes) were able to discriminate targeted pathogens from other Salmonella serovars, Campylobacter species, or common food-borne pathogens potentially present in the indigenous microflora. One hundred isolates from meat samples, collected in a poultry factory, were analyzed by the DVD microarraying and fluorescent real-time PCR. An excellent correlation was observed for both generic and specific detection (relative sensitivity 93-99 % and relative specificity 93-100 %). Therefore, the developed assay has been shown to be a reliable tool to be used in routine food safety analysis, especially in settings with limited infrastructure due to the excellent efficiency-cost ratio of compact disc technology. Graphical Abstract DNA microarray performed by DVD technology for pathogen genotyping.

  13. Hypermutator Salmonella Heidelberg induces an early cell death in epithelial cells.

    Science.gov (United States)

    Le Gall-David, Sandrine; Zenbaa, Neila; Bouchard, Damien; Lavault, Marie-Thérèse; B