Sample records for abstract salmonella enterica

  1. Draft Genome Sequences of 18 Salmonella enterica subsp. enterica Serovar Oranienburg Strains Isolated from Rivers in Northwestern Mexico

    PubMed Central

    Casteñeda-Ruelas, Gloria M.; Carreón-Gaxiola, César; Castelán-Sánchez, Hugo G.; Acatzi-Silva, Abraham; Romero-Martínez, Salvador; García-Molina, Alejandra

    2017-01-01

    ABSTRACT Salmonella enterica subsp. enterica serovar Oranienburg is recognized as a foodborne pathogen widely distributed in the environment. Here, we report 18 draft genomes of S. Oranienburg strains isolated from rivers in the northwestern region of Mexico. PMID:28280020

  2. Pangenome and taxonomic analysis of Salmonella enterica subspecies enterica

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subspecies enterica (S. enterica ssp. I) contains almost all the major pathogens in this genus. We sequenced 354 new S. enterica ssp. I genomes using paired end 100 base reads to ~80-fold coverage. These genomes were chosen to maximize genetic diversity, representing at least 100...

  3. Household Contamination with Salmonella enterica1

    PubMed Central

    Hancock, Dale D.; Roozen, Paivi M.; Szymanski, Maryanne H.; Scheenstra, Beth C.; Cady, Kirsten M.; Besser, Thomas E.; Chudek, Paul A.

    2003-01-01

    Household contamination with Salmonella enterica increases when occupational exposure exists (cattle farms with known salmonellosis in cattle, a salmonella research laboratory, or a veterinary clinic experiencing an outbreak of salmonellosis). Fifteen of 55 (27.2%) vacuum cleaner bags from households with occupational exposure to S. enterica were positive versus 1 of 24 (4.2% without known exposure. Use of a carpet cleaner and several cleaners/disinfectants reduced, but failed to eliminate, S. enterica from artificially contaminated carpet. PMID:12533294

  4. Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Infantis Strain SPE101, Isolated from a Chronic Human Infection

    PubMed Central

    Iriarte, Andrés; Giner-Lamia, Joaquín; Betancor, Laura; Astocondor, Lizeth; Cestero, Juan J.; Ochoa, Theresa; García, Coralith; Puente, José L.; Chabalgoity, José A.

    2017-01-01

    ABSTRACT We report a 4.99-Mb draft genome sequence of Salmonella enterica subsp. enterica serovar Infantis strain SPE101, isolated from feces of a 5-month-old breast-fed female showing diarrhea associated with severe dehydration and malnutrition. The infection prolonged for 6 months despite antibiotic treatment. PMID:28729277

  5. Use of biochemical kinetic data to determine strain relatedness among Salmonella enterica subsp. enterica isolates.

    PubMed

    de la Torre, E; Tello, M; Mateu, E M; Torre, E

    2005-11-01

    Classical biotyping characterizes strains by creating biotype profiles that consider only positive and negative results for a predefined set of biochemical tests. This method allows Salmonella subspecies to be distinguished but does not allow serotypes and phage types to be distinguished. The objective of this study was to determine the relatedness of isolates belonging to distinct Salmonella enterica subsp. enterica serotypes by using a refined biotyping process that considers the kinetics at which biochemical reactions take place. Using a Vitek GNI+ card for the identification of gram-negative organisms, we determined the biochemical kinetic reactions (28 biochemical tests) of 135 Salmonella enterica subsp. enterica strains of pig origin collected in Spain from 1997 to 2002 (59 Salmonella serotype Typhimurium strains, 25 Salmonella serotype Typhimurium monophasic variant strains, 25 Salmonella serotype Anatum strains, 12 Salmonella serotype Tilburg strains, 7 Salmonella serotype Virchow strains, 6 Salmonella serotype Choleraesuis strains, and 1 Salmonella enterica serotype 4,5,12:-:- strain). The results were expressed as the colorimetric and turbidimetric changes (in percent) and were used to enhance the classical biotype profile by adding kinetic categories. A hierarchical cluster analysis was performed by using the enhanced profiles and resulted in 14 clusters. Six major clusters grouped 94% of all isolates with a similarity of > or =95% within any given cluster, and eight clusters contained a single isolate. The six major clusters grouped not only serotypes of the same type but also phenotypic serotype variations into individual clusters. This suggests that metabolic kinetic reaction data from the biochemical tests commonly used for classic Salmonella enterica subsp. enterica biotyping can possibly be used to determine the relatedness between isolates in an easy and timely manner.

  6. Population structure of Salmonella enterica subspecies enterica (subspecies 1)

    USDA-ARS?s Scientific Manuscript database

    We sequenced and assembled 354 new Salmonella enterica ssp. enterica genomes. These genomes were chosen to maximize genetic diversity, representing at least 100 different serovars and distinct PFGE patterns within these serovars. 119 of the strains were of known antibiotic resistance,...

  7. Complete Whole-Genome Sequence of Salmonella enterica subsp. enterica Serovar Java NCTC5706.

    PubMed

    Fazal, Mohammed-Abbas; Alexander, Sarah; Burnett, Edward; Deheer-Graham, Ana; Oliver, Karen; Holroyd, Nancy; Parkhill, Julian; Russell, Julie E

    2016-11-03

    Salmonellae are a significant cause of morbidity and mortality globally. Here, we report the first complete genome sequence for Salmonella enterica subsp. enterica serovar Java strain NCTC5706. This strain is of historical significance, having been isolated in the pre-antibiotic era and was deposited into the National Collection of Type Cultures in 1939. © Crown copyright 2016.

  8. Whole-genome sequencing of Salmonella enterica subsp. enterica serovar Cubana strains isolated from agricultural sources

    USDA-ARS?s Scientific Manuscript database

    We report draft genomes of Salmonella enterica subsp. enterica Serovar Cubana strain CVM42234 isolated from chick feed in 2012 and Salmonella Cubana strain 76814 isolated from swine in 2004. The genome sizes are 4,975,046 and 4,936,251 base pairs, respectively....

  9. Specific Discrimination of Three Pathogenic Salmonella enterica subsp. enterica Serotypes by carB-Based Oligonucleotide Microarray

    PubMed Central

    Shin, Hwa Hui; Hwang, Byeong Hee; Seo, Jeong Hyun

    2014-01-01

    It is important to rapidly and selectively detect and analyze pathogenic Salmonella enterica subsp. enterica in contaminated food to reduce the morbidity and mortality of Salmonella infection and to guarantee food safety. In the present work, we developed an oligonucleotide microarray containing duplicate specific capture probes based on the carB gene, which encodes the carbamoyl phosphate synthetase large subunit, as a competent biomarker evaluated by genetic analysis to selectively and efficiently detect and discriminate three S. enterica subsp. enterica serotypes: Choleraesuis, Enteritidis, and Typhimurium. Using the developed microarray system, three serotype targets were successfully analyzed in a range as low as 1.6 to 3.1 nM and were specifically discriminated from each other without nonspecific signals. In addition, the constructed microarray did not have cross-reactivity with other common pathogenic bacteria and even enabled the clear discrimination of the target Salmonella serotype from a bacterial mixture. Therefore, these results demonstrated that our novel carB-based oligonucleotide microarray can be used as an effective and specific detection system for S. enterica subsp. enterica serotypes. PMID:24185846

  10. Specific discrimination of three pathogenic Salmonella enterica subsp. enterica serotypes by carB-based oligonucleotide microarray.

    PubMed

    Shin, Hwa Hui; Hwang, Byeong Hee; Seo, Jeong Hyun; Cha, Hyung Joon

    2014-01-01

    It is important to rapidly and selectively detect and analyze pathogenic Salmonella enterica subsp. enterica in contaminated food to reduce the morbidity and mortality of Salmonella infection and to guarantee food safety. In the present work, we developed an oligonucleotide microarray containing duplicate specific capture probes based on the carB gene, which encodes the carbamoyl phosphate synthetase large subunit, as a competent biomarker evaluated by genetic analysis to selectively and efficiently detect and discriminate three S. enterica subsp. enterica serotypes: Choleraesuis, Enteritidis, and Typhimurium. Using the developed microarray system, three serotype targets were successfully analyzed in a range as low as 1.6 to 3.1 nM and were specifically discriminated from each other without nonspecific signals. In addition, the constructed microarray did not have cross-reactivity with other common pathogenic bacteria and even enabled the clear discrimination of the target Salmonella serotype from a bacterial mixture. Therefore, these results demonstrated that our novel carB-based oligonucleotide microarray can be used as an effective and specific detection system for S. enterica subsp. enterica serotypes.

  11. A comprehensive review of non-enterica subspecies of Salmonella enterica.

    PubMed

    Lamas, Alexandre; Miranda, José Manuel; Regal, Patricia; Vázquez, Beatriz; Franco, Carlos Manuel; Cepeda, Alberto

    2018-01-01

    Salmonella is a major foodborne pathogen with a complex nomenclature. This genus is composed of two species, S. enterica and S. bongori. S. enterica is divided into six subspecies. S. enterica subspecies enterica is composed of more than 1500 serotypes with some of great importance, such as S. Typhimurium and S. Enteritidis. S. enterica subsp. enterica is responsible of more than 99% of human salmonellosis and therefore it is widely studied. However, the non-enterica subspecies of S. enterica have been little studied. These subspecies are considered to be related to cold-blooded animals and their pathogenicity is very limited. Phenotype and genotype information generated from different studies of non-enterica subspecies reveal poor ability to invade host cells and the absence or modification of important virulence factors. Also, the great majority of human infections due to non-enterica subspecies are related to a previous depressed immune system. Therefore, we propose to treat these subspecies only as opportunistic pathogens. For establish this premise, the present review evaluated, among other things, the genomic characteristics, prevalence, antimicrobial resistance and reported human cases of the non-enterica subspecies. Copyright © 2017 Elsevier GmbH. All rights reserved.

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

    PubMed Central

    Andino, A.; Hanning, I.

    2015-01-01

    Data indicate that prevalence of specific serovars of Salmonella enterica in human foodborne illness is not correlated with their prevalence in feed. Given that feed is a suboptimal environment for S. enterica, it appears that survival in poultry feed may be an independent factor unrelated to virulence of specific serovars of Salmonella. Additionally, S. enterica serovars appear to have different host specificity and the ability to cause disease in those hosts is also serovar dependent. These differences among the serovars may be related to gene presence or absence and expression levels of those genes. With a better understanding of serovar specificity, mitigation methods can be implemented to control Salmonella at preharvest and postharvest levels. PMID:25664339

  13. Survival and Filamentation of Salmonella enterica Serovar Enteritidis PT4 and Salmonella enterica Serovar Typhimurium DT104 at Low Water Activity

    PubMed Central

    Mattick, K. L.; Jørgensen, F.; Legan, J. D.; Cole, M. B.; Porter, J.; Lappin-Scott, H. M.; Humphrey, T. J.

    2000-01-01

    In this study we investigated the long-term survival of and morphological changes in Salmonella strains at low water activity (aw). Salmonella enterica serovar Enteritidis PT4 and Salmonella enterica serovar Typhimurium DT104 survived at low aw for long periods, but minimum humectant concentrations of 8% NaCl (aw, 0.95), 96% sucrose (aw, 0.94), and 32% glycerol (aw, 0.92) were bactericidal under most conditions. Salmonella rpoS mutants were usually more sensitive to bactericidal levels of NaCl, sucrose, and glycerol. At a lethal aw, incubation at 37°C resulted in more rapid loss of viability than incubation at 21°C. At aw values of 0.93 to 0.98, strains of S. enterica serovar Enteritidis and S. enterica serovar Typhimurium formed filaments, some of which were at least 200 μm long. Filamentation was independent of rpoS expression. When the preparations were returned to high-aw conditions, the filaments formed septa, and division was complete within approximately 2 to 3 h. The variable survival of Salmonella strains at low aw highlights the importance of strain choice when researchers produce modelling data to simulate worst-case scenarios or conduct risk assessments based on laboratory data. The continued increase in Salmonella biomass at low aw (without a concomitant increase in microbial count) would not have been detected by traditional microbiological enumeration tests if the tests had been performed immediately after low-aw storage. If Salmonella strains form filaments in food products that have low aw values (0.92 to 0.98), there are significant implications for public health and for designing methods for microbiological monitoring. PMID:10742199

  14. The taxonomic structure of Salmonella enterica subspecies enterica

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is the leading cause of food-borne bacterial infection in humans and has a high economic burden in agriculture. Strains differ by sequence additions and losses of up to ~10% of each genome. In the last few decades, some serovars have become more common. Many strains have acquired...

  15. Complete genome sequence of salmonella enterica subsp. enterica Serovar Thompson Strain RM6836

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica serovar Thompson (S. Thompson) strain RM6836 was isolated from lettuce in 2002. We report the complete sequence and annotation of the genome of S. Thompson strain RM6836. This is the first reported complete genome sequence for S. Thompson and will provide a point ...

  16. Plasmid-mediated quinolone resistance in non-Typhi serotypes of Salmonella enterica.

    PubMed

    Gay, Kathryn; Robicsek, Ari; Strahilevitz, Jacob; Park, Chi Hye; Jacoby, George; Barrett, Timothy J; Medalla, Felicita; Chiller, Tom M; Hooper, David C

    2006-08-01

    Serious infections with Salmonella species are often treated with fluoroquinolones or extended-spectrum beta-lactams. Increasingly recognized in Enterobacteriaceae, plasmid-mediated quinolone resistance is encoded by qnr genes. Here, we report the presence of qnr variants in human isolates of non-Typhi serotypes of Salmonella enterica (hereafter referred to as non-Typhi Salmonella) from the United States National Antimicrobial Resistance Monitoring System for Enteric Bacteria. All non-Typhi Salmonella specimens from the United States National Antimicrobial Resistance Monitoring System for Enteric Bacteria collected from 1996 to 2003 with ciprofloxacin minimum inhibitory concentrations > or = 0.06 microg/mL (233 specimens) and a subset with minimum inhibitory concentrations < or = 0.03 microg/mL (102 specimens) were screened for all known qnr genes (A, B, and S) by polymerase chain reaction. For isolates with positive results, qnr and quinolone resistance-determining region sequences were determined. Plasmids containing qnr genes were characterized by conjugation or transformation. Conjugative plasmids harboring qnrB variants were detected in 7 Salmonella enterica serotype Berta isolates and 1 Salmonella enterica serotype Mbandaka isolate. The S. Mbandaka plasmid also had an extended-spectrum beta -lactamase. Variants of qnrS on nonconjugative plasmids were detected in isolates of Salmonella enterica serotype Anatum and Salmonella enterica serotype Bovismorbificans. Plasmid-mediated quinolone resistance appears to be widely distributed, though it is still uncommon in non-Typhi Salmonella isolates from the United States, including strains that are quinolone susceptible by the criteria of the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards). The presence of this gene in non-Typhi Salmonella that causes infection in humans suggests potential for spread through the food supply, which is a public health

  17. Biofilm Formation and Morphotypes of Salmonella enterica subsp.arizonae Differs from Those of Other Salmonella enterica Subspecies in Isolates from Poultry Houses.

    PubMed

    Lamas, A; Fernandez-No, I C; Miranda, J M; Vázquez, B; Cepeda, A; Franco, C M

    2016-07-01

    Salmonella serovars are responsible for foodborne diseases around the world. The ability to form biofilms allows microorganisms to survive in the environment. In this study, 73 Salmonella strains, belonging to four different subspecies, were isolated from poultry houses and foodstuffs and tested. Biofilm formation was measured at four different temperatures and two nutrient concentrations. Morphotypes and cellulose production were evaluated at three different temperatures. The presence of several genes related to biofilm production was also examined. All strains and subspecies of Salmonella had the ability to form biofilms, and 46.57% of strains produced biofilms under all conditions tested. Biofilm formation was strain dependent and varied according to the conditions. This is the first study to analyze biofilm formation in a wide number of Salmonella enterica subsp. arizonae strains, and no direct relationship between the high prevalence of Salmonella enterica subsp. arizonae strains and their ability to form biofilm was established. Morphotypes and cellulose production varied as the temperature changed, with 20°C being the optimum temperature for expression of the red, dry, and rough morphotype and cellulose. Salmonella enterica subsp. arizonae, whose morphotype is poorly studied, only showed a smooth and white morphotype and lacked the csgD and gcpA genes that are implicated in biofilm production. Thus, Salmonella biofilm formation under different environmental conditions is a public health problem because it can survive and advance through the food chain to reach the consumer.

  18. Breast abscess in a man due to Salmonella enterica serotype Enteritidis.

    PubMed

    Brncic, Nada; Gorup, Lari; Strcic, Miroslav; Abram, Maja; Mustac, Elvira

    2012-01-01

    Nontyphoidal salmonellae can cause breast infection only exceptionally. A case of breast abscess in a 70-year-old man due to Salmonella enterica serotype Enteritidis (Salmonella Enteritidis) is reported. The infection was successfully treated with a combination of surgical and antibiotic treatment.

  19. Molecular Characterization of Multiresistant d-Tartrate-Positive Salmonella enterica Serovar Paratyphi B Isolates

    PubMed Central

    Miko, Angelika; Guerra, Beatriz; Schroeter, Andreas; Dorn, Christina; Helmuth, Reiner

    2002-01-01

    Since 1996, the National Salmonella Reference Laboratory of Germany has received an increasing number of Salmonella enterica subsp. enterica serovar Paratyphi B isolates. Nearly all of these belonged to the dextrorotatory tartrate-positive variant (S. enterica subsp. enterica serovar Paratyphi B dT+), formerly called S. enterica subsp. enterica serovar Java. A total of 55 selected contemporary and older S. enterica subsp. enterica serovar Paratyphi B dT+ isolates were analyzed by plasmid profiling, antimicrobial resistance testing, pulsed-field gel electrophoresis, IS200 profiling, and PCR-based detection of integrons. The results showed a high genetic heterogeneity among 10 old strains obtained from 1960 to 1993. In the following years, however, new distinct multiresistant S. enterica subsp. enterica serovar Paratyphi B dT+ clones emerged, and one clonal lineage successfully displaced the older ones. Since 1994, 88% of the isolates investigated were multiple drug resistant. Today, a particular clone predominates in some German poultry production lines, poultry products, and various other sources. It was also detected in contemporary isolates from two neighboring countries as well. PMID:12202551

  20. Methodologies for Salmonella enterica subsp. enterica Subtyping: Gold Standards and Alternatives▿

    PubMed Central

    Wattiau, Pierre; Boland, Cécile; Bertrand, Sophie

    2011-01-01

    For more than 80 years, subtyping of Salmonella enterica has been routinely performed by serotyping, a method in which surface antigens are identified based on agglutination reactions with specific antibodies. The serotyping scheme, which is continuously updated as new serovars are discovered, has generated over time a data set of the utmost significance, allowing long-term epidemiological surveillance of Salmonella in the food chain and in public health control. Conceptually, serotyping provides no information regarding the phyletic relationships inside the different Salmonella enterica subspecies. In epidemiological investigations, identification and tracking of salmonellosis outbreaks require the use of methods that can fingerprint the causative strains at a taxonomic level far more specific than the one achieved by serotyping. During the last 2 decades, alternative methods that could successfully identify the serovar of a given strain by probing its DNA have emerged, and molecular biology-based methods have been made available to address phylogeny and fingerprinting issues. At the same time, accredited diagnostics have become increasingly generalized, imposing stringent methodological requirements in terms of traceability and measurability. In these new contexts, the hand-crafted character of classical serotyping is being challenged, although it is widely accepted that classification into serovars should be maintained. This review summarizes and discusses modern typing methods, with a particular focus on those having potential as alternatives for classical serotyping or for subtyping Salmonella strains at a deeper level. PMID:21856826

  1. Breast Abscess in a Man Due to Salmonella enterica Serotype Enteritidis

    PubMed Central

    Brnčić, Nada; Strčić, Miroslav; Abram, Maja; Mustač, Elvira

    2012-01-01

    Nontyphoidal salmonellae can cause breast infection only exceptionally. A case of breast abscess in a 70-year-old man due to Salmonella enterica serotype Enteritidis (Salmonella Enteritidis) is reported. The infection was successfully treated with a combination of surgical and antibiotic treatment. PMID:22031702

  2. Immunogenicity of Salmonella enterica serovar Enteritidis virulence protein, InvH, and cross-reactivity of its antisera with Salmonella strains.

    PubMed

    Dehghani, Behzad; Rasooli, Iraj; Gargari, Seyed Latif Mousavi; Nadooshan, Mohammad Reza Jalali; Owlia, Parviz; Nazarian, Shahram

    2013-02-22

    Acellular vaccines containing bacterial immunodominant components such as surface proteins may be potent alternatives to live attenuated vaccines in order to reduce salmonellosis risk to human health. invH gene, an important part of needle complex in type three secretion system (TTSS) plays important role in efficient bacterial adherence and entry into epithelial cells. In this work we hypothesize that use of a 15 kDa recombinant InvH as Salmonella enterica serovar Enteritidis surface protein could provoke antibody production in mouse and would help us study feasibility of its potential for diagnosis and/or a recombinant vaccine. The purified InvH provoked significant rise of IgG in mice. Active protection induced by immunization with InvH against variable doses of S. enterica serovar Enteritidis, indicated that the immunized mice were completely protected against challenge with 10(4) LD(50). The immunoreaction of sera from immunized mice with other Salmonella strains or cross reaction with sera of Salmonella strains inoculated mice is indicative of possessing by Salmonella strains of the surface protein, InvH, that can be employed in both prophylactic and diagnostic measures against S. enterica. Bacteria free spleen and ileum of the immunized mice in this study indicate that the invH gene affects bacterial invasion. Efficacy of the virulence protein, InvH, in shuttling into host cells in injectisome of S. enterica serovar Enteritidis and inhibition of this phenomenon by active immunization was shown in this study. In conclusion immunization with InvH protein can develop protection against S. enterica serovar Enteritidis infections. InvH in Salmonella strains can be exploited in protective measures as well as a diagnostic tool in Salmonella infections. Copyright © 2012 Elsevier GmbH. All rights reserved.

  3. Draft Genome Sequences of 18 Salmonella enterica subsp. enterica Serovar Oranienburg Strains Isolated from Rivers in Northwestern Mexico.

    PubMed

    Casteñeda-Ruelas, Gloria M; Carreón-Gaxiola, César; Castelán-Sánchez, Hugo G; Acatzi-Silva, Abraham; Romero-Martínez, Salvador; García-Molina, Alejandra; Jiménez-Edeza, Maribel

    2017-03-09

    Salmonella enterica subsp. enterica serovar Oranienburg is recognized as a foodborne pathogen widely distributed in the environment. Here, we report 18 draft genomes of S  Oranienburg strains isolated from rivers in the northwestern region of Mexico. Copyright © 2017 Casteñeda-Ruelas et al.

  4. Novel small RNA (sRNA) landscape of the starvation-stress response transcriptome of Salmonella enterica serovar typhimurium

    PubMed Central

    Amin, Shivam V.; Roberts, Justin T.; Patterson, Dillon G.; Coley, Alexander B.; Allred, Jonathan A.; Denner, Jason M.; Johnson, Justin P.; Mullen, Genevieve E.; O'Neal, Trenton K.; Smith, Jason T.; Cardin, Sara E.; Carr, Hank T.; Carr, Stacie L.; Cowart, Holly E.; DaCosta, David H.; Herring, Brendon R.; King, Valeria M.; Polska, Caroline J.; Ward, Erin E.; Wise, Alice A.; McAllister, Kathleen N.; Chevalier, David; Spector, Michael P.; Borchert, Glen M.

    2016-01-01

    ABSTRACT Small RNAs (sRNAs) are short (∼50–200 nucleotides) noncoding RNAs that regulate cellular activities across bacteria. Salmonella enterica starved of a carbon-energy (C) source experience a host of genetic and physiological changes broadly referred to as the starvation-stress response (SSR). In an attempt to identify novel sRNAs contributing to SSR control, we grew log-phase, 5-h C-starved and 24-h C-starved cultures of the virulent Salmonella enterica subspecies enterica serovar Typhimurium strain SL1344 and comprehensively sequenced their small RNA transcriptomes. Strikingly, after employing a novel strategy for sRNA discovery based on identifying dynamic transcripts arising from “gene-empty” regions, we identify 58 wholly undescribed Salmonella sRNA genes potentially regulating SSR averaging an ∼1,000-fold change in expression between log-phase and C-starved cells. Importantly, the expressions of individual sRNA loci were confirmed by both comprehensive transcriptome analyses and northern blotting of select candidates. Of note, we find 43 candidate sRNAs share significant sequence identity to characterized sRNAs in other bacteria, and ∼70% of our sRNAs likely assume characteristic sRNA structural conformations. In addition, we find 53 of our 58 candidate sRNAs either overlap neighboring mRNA loci or share significant sequence complementarity to mRNAs transcribed elsewhere in the SL1344 genome strongly suggesting they regulate the expression of transcripts via antisense base-pairing. Finally, in addition to this work resulting in the identification of 58 entirely novel Salmonella enterica genes likely participating in the SSR, we also find evidence suggesting that sRNAs are significantly more prevalent than currently appreciated and that Salmonella sRNAs may actually number in the thousands. PMID:26853797

  5. Detection of Salmonella enterica in pigs at slaughter and comparison with human isolates in Italy.

    PubMed

    Bonardi, Silvia; Alpigiani, Irene; Bruini, Ilaria; Barilli, Elena; Brindani, Franco; Morganti, Marina; Cavallini, Pierugo; Bolzoni, Luca; Pongolini, Stefano

    2016-02-02

    In 2013-2014, 201 pigs belonging to 67 batches were tested for Salmonella in their mesenteric lymph nodes (MLN) in one abattoir of Northern Italy. For each batch, faecal material was collected at lairage by swabbing the pen floor for approximately 1600 cm(2). The aim of this study was to investigate the prevalence of Salmonella in MLN of pigs at slaughter, to assess Salmonella contamination at lairage and to evaluate the effect of lairage duration on its prevalence. Serotyping, XbaI PFGE typing and antimicrobial testing of the isolates were performed. Pig and human Salmonella isolates of the same region of Italy were compared to evaluate possible correlations. Salmonella enterica was isolated from 19.9% of the MLN and 49.3% of the environmental faecal samples. Nine different serovars were identified among 75 S. enterica isolates. In MLN Salmonella Derby was the most common (52.5%), followed by S. enterica 4,[5],12:i:- (17.5%) and Salmonella Rissen (10.0%). In faecal samples S. Derby was prevalent (51.4%), followed by S. enterica 4,[5], 12:i:- (20.0%) and Salmonella Brandenburg (14.3%). Lairage holding varied between 1 and ≥ 12 h (median value: 2.5h). In pigs held for 1-3h, 14.1% were positive for Salmonella in MLN but the prevalence reached 31.8% when they were held for ≥ 12 h. The contamination of MLN was statistically different (p=0.0045) between the two groups, thus confirming the role of long-lasting lairage in Salmonella contamination of pigs. XbaI PFGE typing detected 36 PFGE types. Twenty-three PFGE types were identified among the 40 MLN isolates and 22 PFGE types among the 35 faecal isolates. A total of 11 PFGE types were shared between the MLN of pigs and the lairage environment. Among S. Derby, 6 shared PFGE types between MLN and faeces were found and among S. enterica 4,[5],12:i:- one PFGE type was common between MLN and the faecal samples. Shared profiles between human and swine isolates of S. Derby, S. enterica 4,[5],12:i:-, S. Rissen, Salmonella

  6. Phylogenetic Diversity of the Enteric Pathogen Salmonella enterica subsp. enterica Inferred from Genome-Wide Reference-Free SNP Characters

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is a major cause of food-borne illness in the US, leading to more deaths than any other food-related pathogen. This is an extremely diverse bacterial species consisting of six subspecies and over 2500 named serovars. Examining the evolutionary history within Salmonella with techn...

  7. Cross-sectional Study Examining Salmonella enterica Carriage in Subiliac Lymph Nodes of Cull and Feedlot Cattle at Harvest

    PubMed Central

    Gragg, Sara E.; Loneragan, Guy H.; Brashears, Mindy M.; Arthur, Terrance M.; Bosilevac, Joseph M.; Kalchayanand, Norasak; Wang, Rong; Schmidt, John W.; Brooks, J. Chance; Shackelford, Steven D.; Wheeler, Tommy L.; Brown, Tyson R.; Edrington, Thomas S.

    2013-01-01

    Abstract Bovine peripheral lymph nodes (LNs), including subiliac LNs, have been identified as a potential source of human exposure to Salmonella enterica, when adipose trim containing these nodes is incorporated into ground beef. In order to gain a better understanding of the burden of S. enterica in peripheral LNs of feedlot and cull cattle, a cross-sectional study was undertaken in which 3327 subiliac LNs were collected from cattle at harvest in seven plants, located in three geographically distinct regions of the United States. Samples were collected in three seasons: Fall 2010, Winter/Spring 2011, and Summer/Fall 2011. A convenience sample of 76 LNs per day, 2 days per season (approximately 1 month apart), was collected per plant, from carcasses held in the cooler for no less than 24 h. Every 10th carcass half on a rail was sampled, in an attempt to avoid oversampling any single cohort of cattle. Median point estimates of S. enterica contamination were generally low (1.3%); however, median Salmonella prevalence was found to be greater in subiliac LNs of feedlot cattle (11.8%) compared to those of cull cattle (0.65%). Enumeration analysis of a subset of 618 feedlot cattle LNs showed that 67% of those harboring S. enterica (97 of 144) did so at concentrations ranging from <0.1 to 1.8 log10 CFU/g, while 33% carried a higher burden of S. enterica, with levels ranging from 1.9 to >3.8 log10 CFU/g. Serotyping of S. enterica isolated identified 24 serotypes, with the majority being Montevideo (44.0%) and Anatum (24.8%). Antimicrobial susceptibility phenotypes were determined for all isolates, and the majority (86.1%) were pansusceptible; however, multidrug-resistant isolates (8.3%) were also occasionally observed. As Salmonella contained within LNs are protected from carcass interventions, research is needed to define opportunities for mitigating the risk of Salmonella contamination in LNs of apparently healthy cattle. PMID:23566273

  8. Multidrug-resistant Salmonella enterica serovar Infantis, Israel.

    PubMed

    Gal-Mor, Ohad; Valinsky, Lea; Weinberger, Miriam; Guy, Sara; Jaffe, Joseph; Schorr, Yosef Ilan; Raisfeld, Abraham; Agmon, Vered; Nissan, Israel

    2010-11-01

    To determine whether rapid emergence of Salmonella enterica serovar Infantis in Israel resulted from an increase in different biotypes or spread of 1 clone, we characterized 87 serovar Infantis isolates on the genotypic and phenotypic levels. The emerging strain comprised 1 genetic clone with a distinct pulsed-field gel electrophoresis profile and a common antimicrobial drug resistance pattern.

  9. Ceftriaxone-Resistant Salmonella enterica Serotype Newport, France

    PubMed Central

    Egorova, Svetlana; Timinouni, Mohammed; Demartin, Marie; Granier, Sophie A.; Whichard, Jean M.; Sangal, Vartul; Fabre, Laëtitia; Delauné, Aurélia; Pardos, Maria; Millemann, Yves; Espié, Emmanuelle; Achtman, Mark; Grimont, Patrick A.D.

    2008-01-01

    The multidrug-resistant (MDR) Salmonella enterica serotype Newport strain that produces CMY-2 β-lactamase (Newport MDR-AmpC) was the source of sporadic cases and outbreaks in humans in France during 2000–2005. Because this strain was not detected in food animals, it was most likely introduced into France through imported food products. PMID:18507913

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

    PubMed Central

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

    2016-01-01

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

  11. Foodborne outbreak and nonmotile Salmonella enterica variant, France.

    PubMed

    Le Hello, Simon; Brisabois, Anne; Accou-Demartin, Marie; Josse, Adeline; Marault, Muriel; Francart, Sylvie; Da Silva, Nathalie Jourdan; Weill, François-Xavier

    2012-01-01

    We report a food-related outbreak of salmonellosis in humans caused by a nonmotile variant of Salmonella enterica serotype Typhimurium in France in 2009. This nonmotile variant had been circulating in laying hens but was not considered as Typhimurium and consequently escaped European poultry flock regulations.

  12. Salmonella enterica serovar-specific transcriptional reprogramming of infected cells.

    PubMed

    Hannemann, Sebastian; Galán, Jorge E

    2017-07-01

    Despite their high degree of genomic similarity, different Salmonella enterica serovars are often associated with very different clinical presentations. In humans, for example, the typhoidal S. enterica serovar Typhi causes typhoid fever, a life-threatening systemic disease. In contrast, the non-typhoidal S. enterica serovar Typhimurium causes self-limiting gastroenteritis. The molecular bases for these different clinical presentations are incompletely understood. The ability to re-program gene expression in host cells is an essential virulence factor for typhoidal and non-typhoidal S. enterica serovars. Here, we have compared the transcriptional profile of cultured epithelial cells infected with S. Typhimurium or S. Typhi. We found that both serovars stimulated distinct transcriptional responses in infected cells that are associated with the stimulation of specific signal transduction pathways. These specific responses were associated with the presence of a distinct repertoire of type III secretion effector proteins. These observations provide major insight into the molecular bases for potential differences in the pathogenic mechanisms of typhoidal and non-typhoidal S. enterica serovars.

  13. Effects of postharvest handling conditions on internalization and growth of Salmonella enterica in tomatoes.

    PubMed

    Zhou, Bin; Luo, Yaguang; Nou, Xiangwu; Yang, Yang; Wu, Yunpeng; Wang, Qin

    2014-03-01

    Salmonella internalization in tomatoes during postharvest handling is a major food safety concern. This study was conducted to determine the effect of immersion time, immersion depth, and temperature differential between bacterial suspension and tomato pulp on the internalization of Salmonella enterica in tomato fruits. The effect of storage temperature and duration on the survival and growth of internalized Salmonella cells was also evaluated. Overall, immersion time significantly affected the incidence and extent of S. enterica internalization (P < 0.0001), with a linear correlation between immersion time and Salmonella internalization. The depth of Salmonella internalization in tomato tissues also increased with increasing immersion time. Immersion time also significantly influenced the degree to which the temperature differential affected Salmonella internalization. With an immersion time of 2 min, the temperature differential had no significant effect on Salmonella internalization (P = 0.2536). However, with an immersion time of 15 min, a significantly larger Salmonella population became internalized in tomatoes immersed in solutions with a -30°F (-16.7°C) temperature differential. Internalized S. enterica cells persisted in the core tissues during 14 days of storage. Strain type and storage duration significantly affected (P < 0.05) both the frequency detected and the population of internalized Salmonella recovered, but storage temperatures of 55 to 70°F (12.8 to 21.1°C) did not (P > 0.05). These findings indicate the importance of preventing pathogen internalization during postharvest handling.

  14. Variable Number of Tandem Repeats in Salmonella enterica subsp. enterica for Typing Purposes

    PubMed Central

    Ramisse, Vincent; Houssu, Perrine; Hernandez, Eric; Denoeud, France; Hilaire, Valérie; Lisanti, Olivier; Ramisse, Françoise; Cavallo, Jean-Didier; Vergnaud, Gilles

    2004-01-01

    The genomic sequences of Salmonella enterica subsp. enterica strains CT18, Ty2 (serovar Typhi), and LT2 (serovar Typhimurium) were analyzed for potential variable number tandem repeats (VNTRs). A multiple-locus VNTR analysis (MLVA) of 99 strains of S. enterica supsp. enterica based on 10 VNTRs distinguished 52 genotypes and placed them into four groups. All strains tested were independent human isolates from France and did not reflect isolates from outbreak episodes. Of these 10 VNTRs, 7 showed variability within serovar Typhi, whereas 1 showed variability within serovar Typhimurium. Four VNTRs showed high Nei's diversity indices (DIs) of 0.81 to 0.87 within serovar Typhi (n = 27). Additionally, three of these more variable VNTRs showed DIs of 0.18 to 0.58 within serovar Paratyphi A (n = 10). The VNTR polymorphic site within multidrug-resistant (MDR) serovar Typhimurium isolates (n = 39; resistance to ampicillin, chloramphenicol, spectinomycin, sulfonamides, and tetracycline) showed a DI of 0.81. Cluster analysis not only identified three genetically distinct groups consistent with the present serovar classification of salmonellae (serovars Typhi, Paratyphi A, and Typhimurium) but also discriminated 25 subtypes (93%) within serovar Typhi isolates. The analysis discriminated only eight subtypes within serovar Typhimurium isolates resistant to ampicillin, chloramphenicol, spectinomycin, sulfonamides, and tetracycline, possibly reflecting the emergence in the mid-1990s of the DT104 phage type, which often displays such an MDR spectrum. Coupled with the ongoing improvements in automated procedures offered by capillary electrophoresis, use of these markers is proposed in further investigations of the potential of MLVA in outbreaks of salmonellosis, especially outbreaks of typhoid fever. PMID:15583305

  15. Arginine-Dependent Acid Resistance in Salmonella enterica Serovar Typhimurium

    PubMed Central

    Kieboom, Jasper; Abee, Tjakko

    2006-01-01

    Salmonella enterica serovar Typhimurium does not survive a pH 2.5 acid challenge under conditions similar to those used for Escherichia coli (J. W. Foster, Nat. Rev. Microbiol. 2:898-907, 2004). Here, we provide evidence that S. enterica serovar Typhimurium can display arginine-dependent acid resistance (AR) provided the cells are grown under anoxic conditions and not under the microaerobic conditions used for assessment of AR in E. coli. The role of the arginine decarboxylase pathway in Salmonella AR was shown by the loss of AR in mutants lacking adiA, which encodes arginine decarboxylase; adiC, which encodes the arginine-agmatine antiporter; or adiY, which encodes an AraC-like regulator. Transcription of adiA and adiC was found to be dependent on AdiY, anaerobiosis, and acidic pH. PMID:16855258

  16. Interaction of Antibiotics with Innate Host Defense Factors against Salmonella enterica Serotype Newport

    PubMed Central

    Kumaraswamy, Monika; Kousha, Armin; Nizet, Victor

    2017-01-01

    ABSTRACT This study examines the pharmacodynamics of antimicrobials that are used to treat Salmonella with each other and with key components of the innate immune system. Antimicrobial synergy was assessed using time-kill and checkerboard assays. Antimicrobial interactions with innate immunity were studied by employing cathelicidin LL-37, whole-blood, and neutrophil killing assays. Ceftriaxone and ciprofloxacin were found to be synergistic in vitro against Salmonella enterica serotype Newport. Ceftriaxone, ciprofloxacin, and azithromycin each demonstrated synergy with the human cathelicidin defense peptide LL-37 in killing Salmonella. Exposure of Salmonella to sub-MICs of ceftriaxone resulted in enhanced susceptibility to LL-37, whole blood, and neutrophil killing. The activity of antibiotics in vivo against Salmonella may be underestimated in bacteriologic media lacking components of innate immunity. The pharmacodynamic interactions of antibiotics used to treat Salmonella with each other and with components of innate immunity warrant further study in light of recent findings showing in vivo selection of antimicrobial resistance by single agents in this pathogen. IMPORTANCE It is becoming increasingly understood that the current paradigms of in vitro antimicrobial susceptibility testing may have significant shortcomings in predicting activity in vivo. This study evaluated the activity of several antibiotics alone and in combination against clinical isolates of Salmonella enterica serotype Newport (meningitis case) utilizing both conventional and physiological media. In addition, the interactions of these antibiotics with components of the innate immune system were evaluated. Azithromycin, which has performed quite well clinically despite high MICs in conventional media, was shown to be more active in physiological media and to enhance innate immune system killing. Alternatively, chloramphenicol did not show enhanced immune system killing, paralleling its inferior

  17. Foodborne Outbreak and Nonmotile Salmonella enterica Variant, France

    PubMed Central

    Brisabois, Anne; Accou-Demartin, Marie; Josse, Adeline; Marault, Muriel; Francart, Sylvie; Da Silva, Nathalie Jourdan; Weill, François-Xavier

    2012-01-01

    We report a food-related outbreak of salmonellosis in humans caused by a nonmotile variant of Salmonella enterica serotype Typhimurium in France in 2009. This nonmotile variant had been circulating in laying hens but was not considered as Typhimurium and consequently escaped European poultry flock regulations. PMID:22257550

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

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  20. Draft Genome Sequences of 20 Salmonella enterica subsp. enterica Serovar Typhimurium Strains Isolated from Swine in Santa Catarina, Brazil.

    PubMed

    Seribelli, Amanda Aparecida; Frazão, Miliane Rodrigues; Gonzales, Júlia Cunha; Cao, Guojie; Leon, Maria Sanchez; Kich, Jalusa Deon; Allard, Marc William; Falcão, Juliana Pfrimer

    2018-04-19

    Salmonellosis is a disease with a high incidence worldwide, and Salmonella enterica subsp. enterica serovar Typhimurium is one of the most clinically important serovars. We report here the draft genome sequences of 20 S. Typhimurium strains isolated from swine in Santa Catarina, Brazil. These draft genomes will improve our understanding of S. Typhimurium in Brazil.

  1. Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Infantis Strain SPE101, Isolated from a Chronic Human Infection.

    PubMed

    Iriarte, Andrés; Giner-Lamia, Joaquín; Silva, Claudia; Betancor, Laura; Astocondor, Lizeth; Cestero, Juan J; Ochoa, Theresa; García, Coralith; Puente, José L; Chabalgoity, José A; García-Del Portillo, Francisco

    2017-07-20

    We report a 4.99-Mb draft genome sequence of Salmonella enterica subsp. enterica serovar Infantis strain SPE101, isolated from feces of a 5-month-old breast-fed female showing diarrhea associated with severe dehydration and malnutrition. The infection prolonged for 6 months despite antibiotic treatment. Copyright © 2017 Iriarte et al.

  2. Multidrug-Resistant Salmonella enterica Serovar Infantis, Israel

    PubMed Central

    Valinsky, Lea; Weinberger, Miriam; Guy, Sara; Jaffe, Joseph; Schorr, Yosef Ilan; Raisfeld, Abraham; Agmon, Vered; Nissan, Israel

    2010-01-01

    To determine whether rapid emergence of Salmonella enterica serovar Infantis in Israel resulted from an increase in different biotypes or spread of 1 clone, we characterized 87 serovar Infantis isolates on the genotypic and phenotypic levels. The emerging strain comprised 1 genetic clone with a distinct pulsed-field gel electrophoresis profile and a common antimicrobial drug resistance pattern. PMID:21029536

  3. Quinolone Resistance Mechanisms Among Salmonella enterica in Malaysia.

    PubMed

    Thong, Kwai Lin; Ngoi, Soo Tein; Chai, Lay Ching; Teh, Cindy Shuan Ju

    2016-06-01

    The prevalence of quinolone-resistant Salmonella enterica is on the rise worldwide. Salmonella enterica is one of the major foodborne pathogens in Malaysia. Therefore, we aim to investigate the occurrence and mechanisms of quinolone resistance among Salmonella strains isolated in Malaysia. A total of 283 Salmonella strains isolated from food, humans, and animals were studied. The disk diffusion method was used to examine the quinolone susceptibility of the strains, and the minimum inhibitory concentration (MIC) values of nalidixic acid and ciprofloxacin were also determined. DNA sequencing of the quinolone resistance-determining regions (QRDRs) of gyrase and topoisomerase IV genes and the plasmid-borne qnr genes was performed. The transfer of the qnr gene was examined through transconjugation experiment. A total of 101 nalidixic acid-resistant Salmonella strains were identified. In general, all strains were highly resistant to nalidixic acid (average MICNAL, 170 μg/ml). Resistance to ciprofloxacin was observed in 30.7% of the strains (1 ≤ MICCIP ≤ 2 μg/ml). Majority of the strains contained missense mutations in the QRDR of gyrA (69.3%). Silent mutations were frequently detected in gyrB (75.2%), parC (27.7%), and parE (51.5%) within and beyond the QRDRs. Novel mutations were detected in parC and parE. The plasmid-borne qnrS1 variant was found in 36.6% of the strains, and two strains were found to be able to transfer the qnrS1 gene. Overall, mutations in gyrA and the presence of qnrS1 genes might have contributed to the high level of quinolone resistance among the strains. Our study provided a better understanding on the status of quinolone resistance among Salmonella strains circulating in Malaysia.

  4. Prophage Integrase Typing Is a Useful Indicator of Genomic Diversity in Salmonella enterica

    PubMed Central

    Colavecchio, Anna; D’Souza, Yasmin; Tompkins, Elizabeth; Jeukens, Julie; Freschi, Luca; Emond-Rheault, Jean-Guillaume; Kukavica-Ibrulj, Irena; Boyle, Brian; Bekal, Sadjia; Tamber, Sandeep; Levesque, Roger C.; Goodridge, Lawrence D.

    2017-01-01

    Salmonella enterica is a bacterial species that is a major cause of illness in humans and food-producing animals. S. enterica exhibits considerable inter-serovar diversity, as evidenced by the large number of host adapted serovars that have been identified. The development of methods to assess genome diversity in S. enterica will help to further define the limits of diversity in this foodborne pathogen. Thus, we evaluated a PCR assay, which targets prophage integrase genes, as a rapid method to investigate S. enterica genome diversity. To evaluate the PCR prophage integrase assay, 49 isolates of S. enterica were selected, including 19 clinical isolates from clonal serovars (Enteritidis and Heidelberg) that commonly cause human illness, and 30 isolates from food-associated Salmonella serovars that rarely cause human illness. The number of integrase genes identified by the PCR assay was compared to the number of integrase genes within intact prophages identified by whole genome sequencing and phage finding program PHASTER. The PCR assay identified a total of 147 prophage integrase genes within the 49 S. enterica genomes (79 integrase genes in the food-associated Salmonella isolates, 50 integrase genes in S. Enteritidis, and 18 integrase genes in S. Heidelberg). In comparison, whole genome sequencing and PHASTER identified a total of 75 prophage integrase genes within 102 intact prophages in the 49 S. enterica genomes (44 integrase genes in the food-associated Salmonella isolates, 21 integrase genes in S. Enteritidis, and 9 integrase genes in S. Heidelberg). Collectively, both the PCR assay and PHASTER identified the presence of a large diversity of prophage integrase genes in the food-associated isolates compared to the clinical isolates, thus indicating a high degree of diversity in the food-associated isolates, and confirming the clonal nature of S. Enteritidis and S. Heidelberg. Moreover, PHASTER revealed a diversity of 29 different types of prophages and 23

  5. Prophage Integrase Typing Is a Useful Indicator of Genomic Diversity in Salmonella enterica.

    PubMed

    Colavecchio, Anna; D'Souza, Yasmin; Tompkins, Elizabeth; Jeukens, Julie; Freschi, Luca; Emond-Rheault, Jean-Guillaume; Kukavica-Ibrulj, Irena; Boyle, Brian; Bekal, Sadjia; Tamber, Sandeep; Levesque, Roger C; Goodridge, Lawrence D

    2017-01-01

    Salmonella enterica is a bacterial species that is a major cause of illness in humans and food-producing animals. S. enterica exhibits considerable inter-serovar diversity, as evidenced by the large number of host adapted serovars that have been identified. The development of methods to assess genome diversity in S. enterica will help to further define the limits of diversity in this foodborne pathogen. Thus, we evaluated a PCR assay, which targets prophage integrase genes, as a rapid method to investigate S. enterica genome diversity. To evaluate the PCR prophage integrase assay, 49 isolates of S. enterica were selected, including 19 clinical isolates from clonal serovars (Enteritidis and Heidelberg) that commonly cause human illness, and 30 isolates from food-associated Salmonella serovars that rarely cause human illness. The number of integrase genes identified by the PCR assay was compared to the number of integrase genes within intact prophages identified by whole genome sequencing and phage finding program PHASTER. The PCR assay identified a total of 147 prophage integrase genes within the 49 S. enterica genomes (79 integrase genes in the food-associated Salmonella isolates, 50 integrase genes in S . Enteritidis, and 18 integrase genes in S . Heidelberg). In comparison, whole genome sequencing and PHASTER identified a total of 75 prophage integrase genes within 102 intact prophages in the 49 S. enterica genomes (44 integrase genes in the food-associated Salmonella isolates, 21 integrase genes in S . Enteritidis, and 9 integrase genes in S . Heidelberg). Collectively, both the PCR assay and PHASTER identified the presence of a large diversity of prophage integrase genes in the food-associated isolates compared to the clinical isolates, thus indicating a high degree of diversity in the food-associated isolates, and confirming the clonal nature of S . Enteritidis and S . Heidelberg. Moreover, PHASTER revealed a diversity of 29 different types of prophages and 23

  6. Genomic investigation of Salmonella enterica sequences associated with long-term colonization of the bovine gut

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica is a leading cause of food and waterborne infections globally in both humans and livestock with an estimated 93 million annual human infections caused by nontyphoidal S. enterica alone. However, some serotypes within this species are known to cause mild infection...

  7. Serotypes of Salmonella enterica subspecies I isolated from mice caught on US poultry farms 1995 through 1998

    USDA-ARS?s Scientific Manuscript database

    Whole genome analysis of foodborne pathogens is standard practice for regulatory agencies in the US, and a goal of 1 million genomes for Salmonella enterica is currently 76% complete. Inclusion of a range of Salmonella enterica subspecies I serotypes is important because only 30 of approximately 150...

  8. Diversity and antimicrobial resistance of Salmonella enterica isolates from surface water in Southeastern United States.

    PubMed

    Li, Baoguang; Vellidis, George; Liu, Huanli; Jay-Russell, Michele; Zhao, Shaohua; Hu, Zonglin; Wright, Anita; Elkins, Christopher A

    2014-10-01

    A study of prevalence, diversity, and antimicrobial resistance of Salmonella enterica in surface water in the southeastern United States was conducted. A new scheme was developed for recovery of Salmonella from irrigation pond water and compared with the FDA's Bacteriological Analytical Manual (8th ed., 2014) (BAM) method. Fifty-one isolates were recovered from 10 irrigation ponds in produce farms over a 2-year period; nine Salmonella serovars were identified by pulsed-field gel electrophoresis analysis, and the major serovar was Salmonella enterica serovar Newport (S. Newport, n = 29), followed by S. enterica serovar Enteritidis (n = 6), S. enterica serovar Muenchen (n = 4), S. enterica serovar Javiana (n = 3), S. enterica serovar Thompson (n = 2), and other serovars. It is noteworthy that the PulseNet patterns of some of the isolates were identical to those of the strains that were associated with the S. Thompson outbreaks in 2010, 2012, and 2013, S. Enteritidis outbreaks in 2011 and 2013, and an S. Javiana outbreak in 2012. Antimicrobial susceptibility testing confirmed 16 S. Newport isolates of the multidrug resistant-AmpC (MDR-AmpC) phenotype, which exhibited resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (ACSSuT), and to the 1st, 2nd, and 3rd generations of cephalosporins (cephalothin, amoxicillin-clavulanic acid, and ceftriaxone). Moreover, the S. Newport MDR-AmpC isolates had a PFGE pattern indistinguishable from the patterns of the isolates from clinical settings. These findings suggest that the irrigation water may be a potential source of contamination of Salmonella in fresh produce. The new Salmonella isolation scheme significantly increased recovery efficiency from 21.2 (36/170) to 29.4% (50/170) (P = 0.0002) and streamlined the turnaround time from 5 to 9 days with the BAM method to 4 days and thus may facilitate microbiological analysis of environmental water. Copyright © 2014, American Society for

  9. Complete Genome Sequences of 17 Canadian Isolates of Salmonella enterica subsp. enterica Serovar Heidelberg from Human, Animal, and Food Sources

    PubMed Central

    Labbé, Geneviève; Ziebell, Kim; Bekal, Sadjia; Parmley, E. Jane; Agunos, Agnes; Desruisseau, Andrea; Daignault, Danielle; Slavic, Durda; Hoang, Linda; Ramsay, Danielle; Pollari, Frank; Robertson, James; Nash, John H. E.

    2016-01-01

    Salmonella enterica subsp. enterica serovar Heidelberg is a highly clonal serovar frequently associated with foodborne illness. To facilitate subtyping efforts, we report fully assembled genome sequences of 17 Canadian S. Heidelberg isolates including six pairs of epidemiologically related strains. The plasmid sequences of eight isolates contain several drug resistance genes. PMID:27635008

  10. Prevalence of Salmonella enterica and Shiga toxin-producing Escherichia coli in zoo animals from Chile.

    PubMed

    Marchant, Paulina; Hidalgo-Hermoso, Ezequiel; Espinoza, Karen; Retamal, Patricio

    2016-12-30

    Salmonella (S.) enterica and Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens. Here, we report the prevalence of S. enterica and STEC in feces of 316 zoo animals belonging to 61 species from Chile. S. enterica and STEC strains were detected in 7.5% and 4.4% of animals, respectively. All Salmonella isolates corresponded to the serotype Enteritidis. To the best of our knowledge, this is the first report of S. Enteritidis in the culpeo fox ( Lycalopex culpaeus ), black-capped capuchin ( Sapajus apella ) and Peruvian pelican ( Pelecanus thagus ) and the first STEC report in Thomson's gazelle ( Eudorcas thomsonii ).

  11. Prevalence of Salmonella enterica and Shiga toxin-producing Escherichia coli in zoo animals from Chile

    PubMed Central

    Marchant, Paulina; Hidalgo-Hermoso, Ezequiel; Espinoza, Karen

    2016-01-01

    Salmonella (S.) enterica and Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens. Here, we report the prevalence of S. enterica and STEC in feces of 316 zoo animals belonging to 61 species from Chile. S. enterica and STEC strains were detected in 7.5% and 4.4% of animals, respectively. All Salmonella isolates corresponded to the serotype Enteritidis. To the best of our knowledge, this is the first report of S. Enteritidis in the culpeo fox (Lycalopex culpaeus), black-capped capuchin (Sapajus apella) and Peruvian pelican (Pelecanus thagus) and the first STEC report in Thomson's gazelle (Eudorcas thomsonii). PMID:27030195

  12. Complete Genome Sequences of 17 Canadian Isolates of Salmonella enterica subsp. enterica Serovar Heidelberg from Human, Animal, and Food Sources.

    PubMed

    Labbé, Geneviève; Ziebell, Kim; Bekal, Sadjia; Macdonald, Kimberley A; Parmley, E Jane; Agunos, Agnes; Desruisseau, Andrea; Daignault, Danielle; Slavic, Durda; Hoang, Linda; Ramsay, Danielle; Pollari, Frank; Robertson, James; Nash, John H E; Johnson, Roger P

    2016-09-15

    Salmonella enterica subsp. enterica serovar Heidelberg is a highly clonal serovar frequently associated with foodborne illness. To facilitate subtyping efforts, we report fully assembled genome sequences of 17 Canadian S Heidelberg isolates including six pairs of epidemiologically related strains. The plasmid sequences of eight isolates contain several drug resistance genes. © Crown copyright 2016.

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

    PubMed

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

    2014-01-01

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

  14. Inactivation of Salmonella enterica by UV-C Light Alone and in Combination with Mild Temperatures

    PubMed Central

    Gayán, E.; Serrano, M. J.; Raso, J.; Álvarez, I.

    2012-01-01

    The aim of this investigation was to study the efficacy of the combined processes of UV light and mild temperatures for the inactivation of Salmonella enterica subsp. enterica and to explore the mechanism of inactivation. The doses to inactivate the 99.99% (4D) of the initial population ranged from 18.03 (Salmonella enterica serovar Typhimurium STCC 878) to 12.75 J ml−1 (Salmonella enterica serovar Enteritidis ATCC 13076). The pH and water activity of the treatment medium did not change the UV tolerance, but it decreased exponentially by increasing the absorption coefficient. An inactivating synergistic effect was observed by applying simultaneous UV light and heat treatment (UV-H). A less synergistic effect was observed by applying UV light first and heat subsequently. UV did not damage cell envelopes, but the number of injured cells was higher after a UV-H treatment than after heating. The synergistic effect observed by combining simultaneous UV and heat treatment opens the possibility to design combined treatments for pasteurization of liquid food with high UV absorptivity, such as fruit juices. PMID:23001665

  15. A Nutrient-Tunable Bistable Switch Controls Motility in Salmonella enterica Serovar Typhimurium

    PubMed Central

    Koirala, Santosh; Mears, Patrick; Sim, Martin; Golding, Ido; Chemla, Yann R.; Aldridge, Phillip D.

    2014-01-01

    ABSTRACT Many bacteria are motile only when nutrients are scarce. In contrast, Salmonella enterica serovar Typhimurium is motile only when nutrients are plentiful, suggesting that this bacterium uses motility for purposes other than foraging, most likely for host colonization. In this study, we investigated how nutrients affect motility in S. enterica and found that they tune the fraction of motile cells. In particular, we observed coexisting populations of motile and nonmotile cells, with the distribution being determined by the concentration of nutrients in the growth medium. Interestingly, S. enterica responds not to a single nutrient but apparently to a complex mixture of them. Using a combination of experimentation and mathematical modeling, we investigated the mechanism governing this behavior and found that it results from two antagonizing regulatory proteins, FliZ and YdiV. We also found that a positive feedback loop involving the alternate sigma factor FliA is required, although its role appears solely to amplify FliZ expression. We further demonstrate that the response is bistable: that is, genetically identical cells can exhibit different phenotypes under identical growth conditions. Together, these results uncover a new facet of the regulation of the flagellar genes in S. enterica and further demonstrate how bacteria employ phenotypic diversity as a general mechanism for adapting to change in their environment. PMID:25161191

  16. Previously uncharacterized Salmonella enterica genes required for swarming play a role in seedling colonization

    USDA-ARS?s Scientific Manuscript database

    Incidences of bacterial foodborne illness caused by ingestion of fresh produce are rising. Instead of being a case of incidental contamination, the animal pathogen Salmonella enterica utilizes specific molecular mechanisms to attach to and colonize plants. This work characterizes two S. enterica gen...

  17. Salmonella enterica Prophage Sequence Profiles Reflect Genome Diversity and Can Be Used for High Discrimination Subtyping.

    PubMed

    Mottawea, Walid; Duceppe, Marc-Olivier; Dupras, Andrée A; Usongo, Valentine; Jeukens, Julie; Freschi, Luca; Emond-Rheault, Jean-Guillaume; Hamel, Jeremie; Kukavica-Ibrulj, Irena; Boyle, Brian; Gill, Alexander; Burnett, Elton; Franz, Eelco; Arya, Gitanjali; Weadge, Joel T; Gruenheid, Samantha; Wiedmann, Martin; Huang, Hongsheng; Daigle, France; Moineau, Sylvain; Bekal, Sadjia; Levesque, Roger C; Goodridge, Lawrence D; Ogunremi, Dele

    2018-01-01

    Non-typhoidal Salmonella is a leading cause of foodborne illness worldwide. Prompt and accurate identification of the sources of Salmonella responsible for disease outbreaks is crucial to minimize infections and eliminate ongoing sources of contamination. Current subtyping tools including single nucleotide polymorphism (SNP) typing may be inadequate, in some instances, to provide the required discrimination among epidemiologically unrelated Salmonella strains. Prophage genes represent the majority of the accessory genes in bacteria genomes and have potential to be used as high discrimination markers in Salmonella . In this study, the prophage sequence diversity in different Salmonella serovars and genetically related strains was investigated. Using whole genome sequences of 1,760 isolates of S. enterica representing 151 Salmonella serovars and 66 closely related bacteria, prophage sequences were identified from assembled contigs using PHASTER. We detected 154 different prophages in S. enterica genomes. Prophage sequences were highly variable among S. enterica serovars with a median ± interquartile range (IQR) of 5 ± 3 prophage regions per genome. While some prophage sequences were highly conserved among the strains of specific serovars, few regions were lineage specific. Therefore, strains belonging to each serovar could be clustered separately based on their prophage content. Analysis of S . Enteritidis isolates from seven outbreaks generated distinct prophage profiles for each outbreak. Taken altogether, the diversity of the prophage sequences correlates with genome diversity. Prophage repertoires provide an additional marker for differentiating S. enterica subtypes during foodborne outbreaks.

  18. Antimicrobial Susceptibility to Azithromycin among Salmonella enterica Isolates from the United States▿

    PubMed Central

    Sjölund-Karlsson, Maria; Joyce, Kevin; Blickenstaff, Karen; Ball, Takiyah; Haro, Jovita; Medalla, Felicita M.; Fedorka-Cray, Paula; Zhao, Shaohua; Crump, John A.; Whichard, Jean M.

    2011-01-01

    Due to emerging resistance to traditional antimicrobial agents, such as ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol, azithromycin is increasingly used for the treatment of invasive Salmonella infections. In the present study, 696 isolates of non-Typhi Salmonella collected from humans, food animals, and retail meats in the United States were investigated for antimicrobial susceptibility to azithromycin. Seventy-two Salmonella enterica serotype Typhi isolates from humans were also tested. For each isolate, MICs of azithromycin and 15 other antimicrobial agents were determined by broth microdilution. Among the non-Typhi Salmonella isolates, azithromycin MICs among human isolates ranged from 1 to 32 μg/ml, whereas the MICs among the animal and retail meat isolates ranged from 2 to 16 μg/ml and 4 to 16 μg/ml, respectively. Among Salmonella serotype Typhi isolates, the azithromycin MICs ranged from 4 to 16 μg/ml. The highest MIC observed in the present study was 32 μg/ml, and it was detected in three human isolates belonging to serotypes Kentucky, Montevideo, and Paratyphi A. Based on our findings, we propose an epidemiological cutoff value (ECOFF) for wild-type Salmonella of ≤16 μg/ml of azithromycin. The susceptibility data provided could be used in combination with clinical outcome data to determine tentative clinical breakpoints for azithromycin and Salmonella enterica. PMID:21690279

  19. Evaluation of the association between feeding raw meat and Salmonella enterica infections at a Greyhound breeding facility.

    PubMed

    Morley, Paul S; Strohmeyer, Rachel A; Tankson, Jeanetta D; Hyatt, Doreene R; Dargatz, David A; Fedorka-Cray, Paula J

    2006-05-15

    To investigate Salmonella enterica infections at a Greyhound breeding facility. Cross-sectional study. ANIMAL AND SAMPLE POPULATIONS: 138 adult and juvenile dogs and S. enterica isolates recovered from the dogs and their environment. The investigation was conducted at the request of a Greyhound breeder. Observations regarding the environment and population of dogs were recorded. Fecal, food, and environmental specimens were collected and submitted for Salmonella culture. Isolates were serotyped and tested for susceptibility to 16 antimicrobials. Isolates underwent genetic analyses by use of pulsed-field gel electrophoresis and ribotyping. S. enterica was recovered from 88 of 133 (66%) samples of all types and from 57 of 61 (93%) fecal samples. Eighty-three (94.3%) of the isolates were serotype Newport, 77 (87.5%) of which had identical resistance phenotypes. Genetic evaluations suggested that several strains of S. enterica existed at the facility, but there was a high degree of relatedness among many of the Newport isolates. Multiple strains of Salmonella enterica serotype Newport were recovered from raw meat fed on 1 day. S. enterica infections and environmental contamination were common at this facility. A portion of the Salmonella strains detected on the premises was likely introduced via raw meat that was the primary dietary constituent. Some strains appeared to be widely disseminated in the population. Feeding meat that had not been cooked properly, particularly meat classified as unfit for human consumption, likely contributed to the infections in these dogs.

  20. ssrA (tmRNA) Plays a Role in Salmonella enterica Serovar Typhimurium Pathogenesis

    PubMed Central

    Julio, Steven M.; Heithoff, Douglas M.; Mahan, Michael J.

    2000-01-01

    Escherichia coli ssrA encodes a small stable RNA molecule, tmRNA, that has many diverse functions, including tagging abnormal proteins for degradation, supporting phage growth, and modulating the activity of DNA binding proteins. Here we show that ssrA plays a role in Salmonella enterica serovar Typhimurium pathogenesis and in the expression of several genes known to be induced during infection. Moreover, the phage-like attachment site, attL, encoded within ssrA, serves as the site of integration of a region of Salmonella-specific sequence; adjacent to the 5′ end of ssrA is another region of Salmonella-specific sequence with extensive homology to predicted proteins encoded within the unlinked Salmonella pathogenicity island SPI4. S. enterica serovar Typhimurium ssrA mutants fail to support the growth of phage P22 and are delayed in their ability to form viable phage particles following induction of a phage P22 lysogen. These data indicate that ssrA plays a role in the pathogenesis of Salmonella, serves as an attachment site for Salmonella-specific sequences, and is required for the growth of phage P22. PMID:10692360

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

    PubMed Central

    Parvej, Md. Shafiullah; Nazir, K. H. M. Nazmul Hussain; Rahman, M. Bahanur; Jahan, Mueena; Khan, Mohammad Ferdousur Rahman; Rahman, Marzia

    2016-01-01

    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 highly clonal for

  2. Adaptive Resistance to Biocides in Salmonella enterica and Escherichia coli O157 and Cross-Resistance to Antimicrobial Agents

    PubMed Central

    Braoudaki, M.; Hilton, A. C.

    2004-01-01

    The mechanisms by which bacteria resist killing by antibiotics and biocides are still poorly defined, although repeated exposure to sublethal concentrations of antibacterial agents undoubtedly contributes to their development. This study aimed both to investigate the potential of Salmonella enterica and Escherichia coli O157 for adaptive resistance to commonly used biocides and to determine any cross-resistance to antibiotics. Strains were repeatedly passaged in media containing increasing concentrations of a biocide or antibiotic until adaptive resistance was obtained. A wide panel of antimicrobial agents was then screened by using the adapted strain to determine cross-resistance, if any. Adaptive resistance was readily achieved for both S. enterica and E. coli O157. Cross-resistance in adaptively resistant S. enterica varied with the serotype; Salmonella enterica serovar Enteritidis expressed cross-resistance to chloramphenicol, whereas Salmonella enterica serovar Typhimurium expressed cross-resistance to chlorhexidine. Benzalkonium chloride-resistant Salmonella enterica serovar Virchow showed elevated resistance to chlorhexidine; however, chlorhexidine-resistant Salmonella serovar Virchow did not demonstrate reciprocal cross-resistance to benzalkonium chloride, suggesting specific rather than generic resistance mechanisms. E. coli O157 strains acquired high levels of resistance to triclosan after only two sublethal exposures and, when adapted, repeatedly demonstrated decreased susceptibilities to various antimicrobial agents, including chloramphenicol, erythromycin, imipenem, tetracycline, and trimethoprim, as well as to a number of biocides. These observations raise concern over the indiscriminate and often inappropriate use of biocides, especially triclosan, in situations where they are unnecessary, whereby they may contribute to the development of microbial resistance mechanisms. PMID:14715734

  3. Dissemination of antimicrobial-resistant clones of Salmonella enterica among domestic animals, wild animals, and humans.

    PubMed

    Palomo, Gonzalo; Campos, Maria Jorge; Ugarte, María; Porrero, María Concepción; Alonso, Juan Manuel; Borge, Carmen; Vadillo, Santiago; Domínguez, Lucas; Quesada, Alberto; Píriz, Segundo

    2013-02-01

    Non-typhoidal salmonellosis is an important zoonotic disease caused by Salmonella enterica. This work focuses on the identification of Salmonella enterica clonal strains which, presenting a wide distribution potential, express resistance determinants that compromise effectiveness of the antimicrobial therapy. The screening was performed on 506 Salmonella enterica isolates from animals and humans, which were characterized by serovar and phage typing, genome macrorestriction and pulsed-field gel electrophoresis, and detection of phenotypic and genotypic traits for antimicrobial resistance. A Salmonella Enteritidis strain with strong quinolone resistance is spread on three host environments carrying one of the four variants found for the GyrA protein: (1) Asp87Tyr, the major polymorphism found in 39 Salmonella isolates from human origin and six from poultry; (2) Ser83Phe, with four isolates from human origin and one from white stork (Ciconia ciconia); and (3) Asp87Asn or (4) Asp87Gly, with two isolates each from human origins. Several Salmonella Typhimurium strains that presented int1 elements and the classically associated pentaresistance (ACSSuT) phenotype were found distributed between two host environments: domestic animals and humans, domestics and wild animals, or wild fauna plus humans. This study points out the importance of monitoring gut microbiota and its antimicrobial resistance from wildlife, in parallel to livestock animals and humans, especially for animal species that are in close contact with people.

  4. ESBL-Producing Salmonella enterica Serovar Typhi in Traveler Returning from Guatemala to Spain

    PubMed Central

    Piedra-Carrasco, Nuria; Salvador, Fernando; Rodríguez, Virginia; Sánchez-Montalvá, Adrián; Planes, Anna M.; Molina, Israel; Larrosa, M. Nieves

    2014-01-01

    We report a case of typhoid fever in a traveler returning to Spain from Guatemala that was caused by Salmonella enterica serovar Typhi which produced an extended-spectrum β-lactamase (ESBL). This finding demonstrates the presence of ESBL-producing S. enterica ser. Typhi strains in the Americas. Enhanced surveillance is necessary to prevent further spread. PMID:25340972

  5. Method for the detection of Salmonella enterica serovar Enteritidis

    DOEpatents

    Agron, Peter G.; Andersen, Gary L.; Walker, Richard L.

    2008-10-28

    Described herein is the identification of a novel Salmonella enterica serovar Enteritidis locus that serves as a marker for DNA-based identification of this bacterium. In addition, three primer pairs derived from this locus that may be used in a nucleotide detection method to detect the presence of the bacterium are also disclosed herein.

  6. Quantification of the Sensitivity of Mycobacterium avium subsp paratuberculosis and Salmonella enterica subsp enterica to Low pH and High Organic Acids using Propidium Monoazide and Quantitative PCR

    USDA-ARS?s Scientific Manuscript database

    Mycobacterium avium subsp paratuberculosis (Map) and Salmonella enterica subsp enterica (S. enterica) are two pathogens that are a concern to food and animal safety due to their ability to withstand harsh conditions encountered in the natural environment and within the host during pathogenesis. Acid...

  7. Requirement of siderophore biosynthesis for plant colonization by Salmonella enterica

    USDA-ARS?s Scientific Manuscript database

    Contaminated fresh produce has become the number one vector of non-typhoidal salmonellosis to humans. However, Salmonella enterica genes essential for the life cycle of this organism outside the mammalian host are for the most part unknown. Screening deletion mutants led to the discovery that an aro...

  8. Salmonella enterica isolated from wildlife at two Ohio rehabilitation centers.

    PubMed

    Jijón, Steffani; Wetzel, Amy; LeJeune, Jeffrey

    2007-09-01

    Between May and September 2004, fecal samples from various wildlife species admitted to two rehabilitation centers in Ohio were cultured for Salmonella enterica and Escherichia coli O157:H7. Eight of 71 (11%) samples, including specimens from three opossums (Didelphis virginiana), two gray squirrels (Sciurus carolinensis), a woodchuck (Marmota monax), a Harris hawk (Parabuteo unicinctus), and a screech owl (Otus asio) tested positive for Salmonella serovars Braenderup, Senftenberg, Oranienburg, and Kentucky. The Salmonella Oranienburg isolates were indistinguishable by pulsed-field gel electrophoresis. Most isolates were susceptible to commonly used antibiotics; however, the Salmonella Kentucky isolate was resistant to multiple beta-lactam antibiotics (amoxicillin/clavulanic acid and ampicillin), cefoxitin, and ceftiofur, a third-generation cephalosporin. Escherichia coli O157:H7 was not isolated from any sample. Transmission of Salmonella from wildlife may occur between animals at rehabilitation centers.

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

    PubMed

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

    2014-11-01

    We found a strong association between nalidixic acid-resistant Salmonella enterica serotype Enteritidis infections in the United States and recent international travel by linking Salmonella Enteritidis data from the National Antimicrobial Resistance Monitoring System and the Foodborne Diseases Active Surveillance Network. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  10. Identification and characterization of multidrug-resistant Salmonella enterica serotype Albert isolates in the United States

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is one of the most common causes of bacterial foodborne illness in the United States. Although most Salmonella infections are self-limiting, antimicrobial treatment is critical for invasive salmonellosis. Primary antimicrobial treatment options include fluoroquinolones or extende...

  11. Pork Meat as a Potential Source of Salmonella enterica subsp. arizonae Infection in Humans

    PubMed Central

    Kritas, Spyridon; Govaris, Alexander; Burriel, Angeliki R.

    2014-01-01

    Salmonella enterica subsp. arizonae was isolated from 13 of 123 slaughtered pigs in central Greece. The samples cultured were feces, ileum tissue, mesenteric lymph nodes, and gallbladder swabs. A total of 74 isolates from 492 samples were identified as Salmonella spp. by use of standard laboratory culture media and two commercial micromethods and by use of a polyvalent slide agglutination test for the detection of O and H antigens. Among them were 19 (25.68%) suspected to be S. enterica subsp. arizonae according to analysis with standard laboratory culture media. Of those, 14 were identified as S. enterica subsp. arizonae by the API 20E (bioMérieux, France) and the Microgen GnA+B-ID (Microgen Bioproducts, Ltd., United Kingdom) identification systems. All the isolates were tested for resistance to 23 antimicrobials. Strains identified as S. enterica subsp. arizonae were resistant to 17 (70.8%) antibiotics. The highest proportions of resistance were observed for sulfamethoxazole-trimethoprim (71.4%), tetracycline (71.4%), ampicillin (64.3%), and amoxicillin (57.1%). Two isolates were resistant to aztreonam (7.1%) and tigecycline (7.1%), used only for the treatment of humans. Thus, pork meat may play a role in the transmission of antibiotic-resistant S. enterica subsp. arizonae to human consumers. This is the first report of S. enterica subsp. arizonae isolation from pigs. PMID:24335956

  12. Pork meat as a potential source of Salmonella enterica subsp. arizonae infection in humans.

    PubMed

    Evangelopoulou, Grammato; Kritas, Spyridon; Govaris, Alexander; Burriel, Angeliki R

    2014-03-01

    Salmonella enterica subsp. arizonae was isolated from 13 of 123 slaughtered pigs in central Greece. The samples cultured were feces, ileum tissue, mesenteric lymph nodes, and gallbladder swabs. A total of 74 isolates from 492 samples were identified as Salmonella spp. by use of standard laboratory culture media and two commercial micromethods and by use of a polyvalent slide agglutination test for the detection of O and H antigens. Among them were 19 (25.68%) suspected to be S. enterica subsp. arizonae according to analysis with standard laboratory culture media. Of those, 14 were identified as S. enterica subsp. arizonae by the API 20E (bioMérieux, France) and the Microgen GnA+B-ID (Microgen Bioproducts, Ltd., United Kingdom) identification systems. All the isolates were tested for resistance to 23 antimicrobials. Strains identified as S. enterica subsp. arizonae were resistant to 17 (70.8%) antibiotics. The highest proportions of resistance were observed for sulfamethoxazole-trimethoprim (71.4%), tetracycline (71.4%), ampicillin (64.3%), and amoxicillin (57.1%). Two isolates were resistant to aztreonam (7.1%) and tigecycline (7.1%), used only for the treatment of humans. Thus, pork meat may play a role in the transmission of antibiotic-resistant S. enterica subsp. arizonae to human consumers. This is the first report of S. enterica subsp. arizonae isolation from pigs.

  13. Draft Genome Sequences of Two Novel Salmonella enterica subsp. enterica Strains Isolated from Low-Moisture Foods with Applications in Food Safety Research.

    PubMed

    Radford, Devon R; Leon-Velarde, Carlos G; Chen, Shu; Hamidi Oskouei, Amir M; Balamurugan, Sampathkumar

    2018-03-29

    The genomes of two strains of Salmonella enterica subsp. enterica serovar Cubana and serovar Muenchen, isolated from dry hazelnuts and chia seeds, respectively, were sequenced using the Illumina MiSeq platform, assembled de novo using the overlap-layout-consensus method, and aligned to their respective most identical sequence genome scaffolds using MUMMER and BLAST searches. Copyright © 2018 Radford et al.

  14. Characterization of the RpoS Status of Clinical Isolates of Salmonella enterica

    PubMed Central

    Robbe-Saule, Véronique; Algorta, Gabriela; Rouilhac, Isabelle; Norel, Françoise

    2003-01-01

    The stationary-phase-inducible sigma factor, σS (RpoS), is the master regulator of the general stress response in Salmonella and is required for virulence in mice. rpoS mutants can frequently be isolated from highly passaged laboratory strains of Salmonella. We examined the rpoS status of 116 human clinical isolates of Salmonella, including 41 Salmonella enterica serotype Typhi strains isolated from blood, 38 S. enterica serotype Typhimurium strains isolated from blood, and 37 Salmonella serotype Typhimurium strains isolated from feces. We examined the abilities of these strains to produce the σS protein, to express RpoS-dependent catalase activity, and to resist to oxidative stress in the stationary phase of growth. We also carried out complementation experiments with a cloned wild-type rpoS gene. Our results showed that 15 of the 41 Salmonella serotype Typhi isolates were defective in RpoS. We sequenced the rpoS allele of 12 strains. This led to identification of small insertions, deletions, and point mutations resulting in premature stop codons or affecting regions 1 and 2 of σS, showing that the rpoS mutations are not clonal. Thus, mutant rpoS alleles can be found in freshly isolated clinical strains of Salmonella serotype Typhi, and they may affect virulence properties. Interestingly however, no rpoS mutants were found among the 75 Salmonella serotype Typhimurium isolates. Strains that differed in catalase activity and resistance to hydrogen peroxide were found, but the differences were not linked to the rpoS status. This suggests that Salmonella serotype Typhimurium rpoS mutants are counterselected because rpoS plays a role in the pathogenesis of Salmonella serotype Typhimurium in humans or in the transmission cycle of the disease. PMID:12902215

  15. Improvements to a PCR-based serogrouping scheme for Salmonella enterica from dairy farm samples

    USDA-ARS?s Scientific Manuscript database

    The PCR method described by Herrera-León, et al. (Research in Microbiology 158:122-127, 2007) has proved to be a simple and useful technique for characterizing isolates of Salmonella enterica enterica belonging to serogroups B, C1, C2, D1, and E1, groups which encompass a majority of the isolates fr...

  16. Distribution of extended-spectrum cephalosporin resistance determinants in Salmonella enterica and Escherichia coli isolated from broilers in southern Japan.

    PubMed

    Shahada, F; Chuma, T; Kosugi, G; Kusumoto, M; Iwata, T; Akiba, M

    2013-06-01

    This study was conducted to investigate the distribution and diversity of extended-spectrum cephalosporin (ESC) resistance determinants in Salmonella enterica and Escherichia coli obtained from the same cecal samples and to provide evidence of transmission of the resistance determinants among these bacteria in broiler farms in southern Japan. Salmonella enterica and E. coli were characterized by serotyping and multilocus sequence typing, respectively. An antimicrobial susceptibility test, plasmid analysis, and identification and localization of resistance genes were performed to determine the relatedness of ESC resistance determinants among the isolates. Of 48 flocks examined, 14 had S. enterica. In total, 57 S. enterica isolates were obtained, 45 of which showed ESC resistance. Extended-spectrum cephalosporin-resistant E. coli were also obtained from all of these ESC-resistant Salmonella-positive samples. β-Lactamase genes, blaTEM-52 (38 isolates), blaCTX-M-14 (1 isolate), and blaCMY-2 (6 isolates), were carried by conjugative untypable or IncP plasmids detected in the S. enterica serovars Infantis and Manhattan. The β-lactamase genes blaCTX-M-14 (3 isolates), blaCTX-M-15 (3 isolates), blaSHV-2 (1 isolate), blaSHV-12 (2 isolates), and blaCMY-2 (32 isolates) associated with IncI1-Iγ, IncFIB, IncFIC, IncK, IncB/O, and IncY plasmids were detected in E. coli co-isolates. Restriction mapping revealed similar plasmids in Salmonella Infantis and Salmonella Manhattan and in different sequence types of E. coli. Intraspecies transmission of plasmids was suggested within S. enterica and E. coli populations, whereas interspecies transmission was not observed. This study highlights the importance of plasmids as carriers of ESC resistance determinants.

  17. Porcine response to a multidrug-resistant Salmonella enterica serovar I 4,[5],12:i:- outbreak isolate

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serovar I 4,[5],12:i:- has emerged as a common nontyphoidal Salmonella serovar to cause human foodborne illness. An interesting trait of serovar I 4,[5],12:i:- is it only expresses the fliC gene for bacterial motility (i.e. monophasic), while most Salmonella strains alternately e...

  18. IroN, a Novel Outer Membrane Siderophore Receptor Characteristic of Salmonella enterica

    PubMed Central

    Bäumler, Andreas J.; Norris, Tracy L.; Lasco, Todd; Voigt, Wolfgang; Reissbrodt, Rolf; Rabsch, Wolfgang; Heffron, Fred

    1998-01-01

    Speciation in enterobacteria involved horizontal gene transfer. Therefore, analysis of genes acquired by horizontal transfer that are present in one species but not its close relatives is expected to give insights into how new bacterial species were formed. In this study we characterize iroN, a gene located downstream of the iroBC operon in the iroA locus of Salmonella enterica serotype Typhi. Like iroBC, the iroN gene is present in all phylogenetic lineages of S. enterica but is absent from closely related species such as Salmonella bongori or Escherichia coli. Comparison of the deduced amino acid sequence of iroN with other proteins suggested that this gene encodes an outer membrane siderophore receptor protein. Mutational analysis in S. enterica and expression in E. coli identified a 78-kDa outer membrane protein as the iroN gene product. When introduced into an E. coli fepA cir fiu aroB mutant on a cosmid, iroN mediated utilization of structurally related catecholate siderophores, including N-(2,3-dihydroxybenzoyl)-l-serine, myxochelin A, benzaldehyde-2,3-dihydroxybenzhydrazone, 2-N,6-N-bis(2,3-dihydroxybenzoyl)-l-lysine, 2-N,6-N-bis(2,3-dihydroxybenzoyl)-l-lysine amide, and enterochelin. These results suggest that the iroA locus functions in iron acquisition in S. enterica. PMID:9515912

  19. Genetic relatedness of a rarely isolated Salmonella: Salmonella enterica serotype Niakhar from NARMS animal isolates.

    PubMed

    Tankson, J D; Fedorka-Cray, P J; Jackson, C R; Headrick, M

    2006-02-01

    In the United States, Salmonella enterica serotype Niakhar is infrequently isolated. Between 1997 and 2000, the animal arm of the National Antimicrobial Resistance Monitoring System-Enteric Bacteria (NARMS) assayed a total of 22,383 Salmonella isolates from various animal sources (swine, cattle, chickens, turkeys, cats, horses, exotics and dogs) for antimicrobial susceptibility. Isolates originated from diagnostic and non-diagnostic submissions. To study the phenotypic and genotypic characteristics of Salmonella Niakhar. Only five (0.02%) of the 22,383 isolates were identified as Salmonella Niakhar. Antimicrobial resistance testing indicated that three isolates were pan-susceptible, one isolate was resistant to ampicillin and one isolate was resistant to ampicillin, chloramphenicol, ciprofloxacin, kanamycin, nalidixic acid, streptomycin, sulfamethoxazole, tetracycline and trimethoprim/sulfamethoxazole. RAPD-PCR analysis, PFGE and ribotyping indicated that two pan-susceptible isolates were genetically similar, whereas the three remaining isolates were genetically different. The one Salmonella Niakhar isolate that was multiresistant harboured a class I integron, intI1 and two large plasmids. This study represents the first report of a ciprofloxacin-resistant Salmonella isolate from the animal arm of NARMS.

  20. Mobilome differences between Salmonella enterica serovars Anatum and Typhimurium isolated from cattle and humans and potential impact on virulence

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica is an important group of pathogens capable of inhabiting a range of niches and hosts with varying degrees of impact, from commensal colonization to invasive infection. Recent outbreaks of multi-drug resistant S. enterica, attributed to consumption of contaminated ...

  1. Population Dynamics of Salmonella enterica Serotypes in Commercial Egg and Poultry Production ▿

    PubMed Central

    Foley, Steven L.; Nayak, Rajesh; Hanning, Irene B.; Johnson, Timothy J.; Han, Jing; Ricke, Steven C.

    2011-01-01

    Fresh and processed poultry have been frequently implicated in cases of human salmonellosis. Furthermore, increased consumption of meat and poultry has increased the potential for exposure to Salmonella enterica. While advances have been made in reducing the prevalence and frequency of Salmonella contamination in processed poultry, there is mounting pressure on commercial growers to prevent and/or eliminate these human pathogens in preharvest production facilities. Several factors contribute to Salmonella colonization in commercial poultry, including the serovar and the infectious dose. In the early 1900s, Salmonella enterica serovars Pullorum and Gallinarum caused widespread diseases in poultry, but vaccination and other voluntary programs helped eradicate pullorum disease and fowl typhoid from commercial flocks. However, the niche created by the eradication of these serovars was likely filled by S. Enteritidis, which proliferated in the bird populations. While this pathogen remains a significant problem in commercial egg and poultry production, its prevalence among poultry has been declining since the 1990s. Coinciding with the decrease of S. Enteritidis, S. Heidelberg and S. Kentucky have emerged as the predominant serovars in commercial broilers. In this review, we have highlighted bacterial genetic and host-related factors that may contribute to such shifts in Salmonella populations in commercial poultry and intervention strategies that could limit their colonization. PMID:21571882

  2. Plant Pathogen-Induced Water-Soaking Promotes Salmonella enterica Growth on Tomato Leaves

    PubMed Central

    Potnis, Neha; Colee, James; Jones, Jeffrey B.

    2015-01-01

    Plant pathogen infection is a critical factor for the persistence of Salmonella enterica on plants. We investigated the mechanisms responsible for the persistence of S. enterica on diseased tomato plants by using four diverse bacterial spot Xanthomonas species that differ in disease severities. Xanthomonas euvesicatoria and X. gardneri infection fostered S. enterica growth, while X. perforans infection did not induce growth but supported the persistence of S. enterica. X. vesicatoria-infected leaves harbored S. enterica populations similar to those on healthy leaves. Growth of S. enterica was associated with extensive water-soaking and necrosis in X. euvesicatoria- and X. gardneri-infected plants. The contribution of water-soaking to the growth of S. enterica was corroborated by an increased growth of populations on water-saturated leaves in the absence of a plant pathogen. S. enterica aggregates were observed with bacterial spot lesions caused by either X. euvesicatoria or X. vesicatoria; however, more S. enterica aggregates formed on X. euvesicatoria-infected leaves as a result of larger lesion sizes per leaf area and extensive water-soaking. Sparsely distributed lesions caused by X. vesicatoria infection do not support the overall growth of S. enterica or aggregates in areas without lesions or water-soaking; S. enterica was observed as single cells and not aggregates. Thus, pathogen-induced water-soaking and necrosis allow S. enterica to replicate and proliferate on tomato leaves. The finding that the pathogen-induced virulence phenotype affects the fate of S. enterica populations in diseased plants suggests that targeting of plant pathogen disease is important in controlling S. enterica populations on plants. PMID:26386057

  3. Ciprofloxacin-resistant Salmonella enterica Serotype Typhi, United States, 1999-2008.

    PubMed

    Medalla, Felicita; Sjölund-Karlsson, Maria; Shin, Sanghyuk; Harvey, Emily; Joyce, Kevin; Theobald, Lisa; Nygren, Benjamin N; Pecic, Gary; Gay, Kathryn; Austin, Jana; Stuart, Andrew; Blanton, Elizabeth; Mintz, Eric D; Whichard, Jean M; Barzilay, Esra J

    2011-06-01

    We report 9 ciprofloxacin-resistant Salmonella enterica serotype Typhi isolates submitted to the US National Antimicrobial Resistance Monitoring System during 1999-2008. The first 2 had indistinguishable pulsed-field gel electrophoresis patterns and identical gyrA and parC mutations. Eight of the 9 patients had traveled to India within 30 days before illness onset.

  4. Foreign travel and decreased ciprofloxacin susceptibility in Salmonella enterica infections.

    PubMed

    Al-Mashhadani, Manar; Hewson, Robert; Vivancos, Roberto; Keenan, Alex; Beeching, Nick J; Wain, John; Parry, Christopher M

    2011-01-01

    To determine antimicrobial drug resistance patterns, we characterized nontyphoidal Salmonella enterica strains isolated in Liverpool, UK, January 2003 through December 2009. Decreased susceptibility to ciprofloxacin was found in 103 (20.9%) of 492 isolates. The lower susceptibility was associated with ciprofloxacin treatment failures and with particular serovars and phage types often acquired during foreign travel.

  5. Antibody- and TRIM21-dependent intracellular restriction of Salmonella enterica.

    PubMed

    Rakebrandt, Nikolas; Lentes, Sabine; Neumann, Heinz; James, Leo C; Neumann-Staubitz, Petra

    2014-11-01

    TRIM21 ('tripartite motif-containing protein 21', Ro52) is a ubiquitously expressed cytosolic Fc receptor, which has a potent role in protective immunity against nonenveloped viruses. TRIM21 mediates intracellular neutralisation of antibody-coated viruses, a process called ADIN (antibody-dependent intracellular neutralisation). Our results reveal a similar mechanism to fight bacterial infections. TRIM21 is recruited to the intracellular pathogen Salmonella enterica in epithelial cells early in infection. TRIM21 does not bind directly to S. enterica, but to antibodies opsonising it. Most importantly, bacterial restriction is dependent on TRIM21 as well as on the opsonisation state of the bacteria. Finally, Salmonella and TRIM21 colocalise with the autophagosomal marker LC3, and intracellular defence is enhanced in starved cells suggesting an involvement of the autophagocytic pathway. Our data extend the protective role of TRIM21 from viruses to bacteria and thereby strengthening the general role of ADIN in cellular immunity. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  6. Characterization of tetracycline resistance in Salmonella enterica strains recovered from irrigation water in the Culiacan Valley, Mexico

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is one of the most important pathogens responsible for gastrointestinal infections in humans. The increase of S. enterica strains showing resistance against antibiotics has resulted in limiting the effective treatment of human infections. The present study characterized the resi...

  7. Occurrence of antimicrobial-resistant Escherichia coli and Salmonella enterica in the beef cattle production and processing continuum

    USDA-ARS?s Scientific Manuscript database

    Specific concerns have been raised that 3rd-generation cephalosporin-resistant (3GCr) Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COTr) E. coli, 3GCr Salmonella enterica, and nalidixic acid-resistant (NALr) S. enterica, may be present in cattle production environments, persist through...

  8. Whole genome sequencing of multidrug-resistant Salmonella enterica serovar Typhimurium isolated from humans and poultry in Burkina Faso

    USDA-ARS?s Scientific Manuscript database

    Background. Multidrug-resistant Salmonella is an important cause of morbidity and mortality in developing countries. The aim of this study was to characterize and compare multidrug-resistant Salmonella enterica serovar Typhimurium isolates from patients and poultry feces. Methods. Salmonella strains...

  9. Detection of Salmonella enterica Serovar Typhimurium by Using a Rapid, Array-Based Immunosensor

    PubMed Central

    Taitt, Chris Rowe; Shubin, Yura S.; Angel, Roselina; Ligler, Frances S.

    2004-01-01

    The multianalyte array biosensor (MAAB) is a rapid analysis instrument capable of detecting multiple analytes simultaneously. Rapid (15-min), single-analyte sandwich immunoassays were developed for the detection of Salmonella enterica serovar Typhimurium, with a detection limit of 8 × 104 CFU/ml; the limit of detection was improved 10-fold by lengthening the assay protocol to 1 h. S. enterica serovar Typhimurium was also detected in the following spiked foodstuffs, with minimal sample preparation: sausage, cantaloupe, whole liquid egg, alfalfa sprouts, and chicken carcass rinse. Cross-reactivity tests were performed with Escherichia coli and Campylobacter jejuni. To determine whether the MAAB has potential as a screening tool for the diagnosis of asymptomatic Salmonella infection of poultry, chicken excretal samples from a private, noncommercial farm and from university poultry facilities were tested. While the private farm excreta gave rise to signals significantly above the buffer blanks, none of the university samples tested positive for S. enterica serovar Typhimurium without spiking; dose-response curves of spiked excretal samples from university-raised poultry gave limits of detection of 8 × 103 CFU/g. PMID:14711637

  10. Salmonella enterica serovar Kentucky flagella are required for broiler skin adhesion and Caco-2 cell invasion

    USDA-ARS?s Scientific Manuscript database

    Nontyphoidal Salmonella strains are the main source of pathogenic bacterial contamination in the poultry industry. Recently, Salmonella enterica serovar Kentucky has been recognized as the most prominent serovar on carcasses in poultry-processing plants. Previous studies showed that flagella are one...

  11. Refined Live Attenuated Salmonella enterica Serovar Typhimurium and Enteritidis Vaccines Mediate Homologous and Heterologous Serogroup Protection in Mice

    PubMed Central

    Schmidlein, Patrick; Simon, Raphael; Pasetti, Marcela F.; Galen, James E.; Levine, Myron M.

    2015-01-01

    Invasive nontyphoidal Salmonella (NTS) infections constitute a major health problem among infants and toddlers in sub-Saharan Africa; these infections also occur in infants and the elderly in developed countries. We genetically engineered a Salmonella enterica serovar Typhimurium strain of multilocus sequence type 313, the predominant genotype circulating in sub-Saharan Africa. We evaluated the capacities of S. Typhimurium and Salmonella enterica serovar Enteritidis ΔguaBA ΔclpX live oral vaccines to protect mice against a highly lethal challenge dose of the homologous serovar and determined protection against other group B and D serovars circulating in sub-Saharan Africa. The vaccines S. Typhimurium CVD 1931 and S. Enteritidis CVD 1944 were immunogenic and protected BALB/c mice against 10,000 50% lethal doses (LD50) of S. Typhimurium or S. Enteritidis, respectively. S. Typhimurium CVD 1931 protected mice against the group B serovar Salmonella enterica serovar Stanleyville (91% vaccine efficacy), and S. Enteritidis CVD 1944 protected mice against the group D serovar Salmonella enterica serovar Dublin (85% vaccine efficacy). High rates of survival were observed when mice were infected 12 weeks postimmunization, indicating that the vaccines elicited long-lived protective immunity. Whereas CVD 1931 did not protect against S. Enteritidis R11, CVD 1944 did mediate protection against S. Typhimurium D65 (81% efficacy). These findings suggest that a bivalent (S. Typhimurium and S. Enteritidis) vaccine would provide broad protection against the majority of invasive NTS infections in sub-Saharan Africa. PMID:26351285

  12. Development and application of novel SNP-based serotyping assays in targeting Salmonella enterica within the poultry production and processing continuum.

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica serotype Enteriditis (S. Enteriditis) is the leading cause of salmonellosis worldwide. While some S. enterica serotypes are specific to birds, many represent human zoonotic pathogens, thus their presence and survival throughout the continuum of poultry production...

  13. Plant pathogen-induced water-soaking promotes Salmonella enterica growth on tomato leaves.

    PubMed

    Potnis, Neha; Colee, James; Jones, Jeffrey B; Barak, Jeri D

    2015-12-01

    Plant pathogen infection is a critical factor for the persistence of Salmonella enterica on plants. We investigated the mechanisms responsible for the persistence of S. enterica on diseased tomato plants by using four diverse bacterial spot Xanthomonas species that differ in disease severities. Xanthomonas euvesicatoria and X. gardneri infection fostered S. enterica growth, while X. perforans infection did not induce growth but supported the persistence of S. enterica. X. vesicatoria-infected leaves harbored S. enterica populations similar to those on healthy leaves. Growth of S. enterica was associated with extensive water-soaking and necrosis in X. euvesicatoria- and X. gardneri-infected plants. The contribution of water-soaking to the growth of S. enterica was corroborated by an increased growth of populations on water-saturated leaves in the absence of a plant pathogen. S. enterica aggregates were observed with bacterial spot lesions caused by either X. euvesicatoria or X. vesicatoria; however, more S. enterica aggregates formed on X. euvesicatoria-infected leaves as a result of larger lesion sizes per leaf area and extensive water-soaking. Sparsely distributed lesions caused by X. vesicatoria infection do not support the overall growth of S. enterica or aggregates in areas without lesions or water-soaking; S. enterica was observed as single cells and not aggregates. Thus, pathogen-induced water-soaking and necrosis allow S. enterica to replicate and proliferate on tomato leaves. The finding that the pathogen-induced virulence phenotype affects the fate of S. enterica populations in diseased plants suggests that targeting of plant pathogen disease is important in controlling S. enterica populations on plants. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Genome Sequences of Multidrug-Resistant Salmonella enterica subsp. enterica Serovar Infantis Strains from Broiler Chicks in Hungary

    PubMed Central

    Wilk, Tímea; Szabó, Móni; Szmolka, Ama; Kiss, János; Barta, Endre; Nagy, Tibor

    2016-01-01

    Three strains of Salmonella enterica serovar Infantis isolated from healthy broiler chickens from 2012 to 2013 have been sequenced. Comparison of these and previously published S. Infantis genome sequences of broiler origin in 1996 and 2004 will provide new insight into the genome evolution and recent spread of S. Infantis in poultry. PMID:27979950

  15. Transcriptome and proteome analysis of Salmonella enterica serovar Typhimurium systemic infection of wild type and immune-deficient mice

    PubMed Central

    Oshota, Olusegun; Fookes, Maria; Schreiber, Fernanda; Chaudhuri, Roy R.; Yu, Lu; Clare, Simon; Choudhary, Jyoti; Thomson, Nicholas R.; Lio, Pietro

    2017-01-01

    Salmonella enterica are a threat to public health. Current vaccines are not fully effective. The ability to grow in infected tissues within phagocytes is required for S. enterica virulence in systemic disease. As the infection progresses the bacteria are exposed to a complex host immune response. Consequently, in order to continue growing in the tissues, S. enterica requires the coordinated regulation of fitness genes. Bacterial gene regulation has so far been investigated largely using exposure to artificial environmental conditions or to in vitro cultured cells, and little information is available on how S. enterica adapts in vivo to sustain cell division and survival. We have studied the transcriptome, proteome and metabolic flux of Salmonella, and the transcriptome of the host during infection of wild type C57BL/6 and immune-deficient gp91-/-phox mice. Our analyses advance the understanding of how S. enterica and the host behaves during infection to a more sophisticated level than has previously been reported. PMID:28796780

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

    USDA-ARS?s Scientific Manuscript database

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

  17. Salmonella enterica Serovar Kentucky Flagella are Required for Broiler Skin Adhesion and Caco-2 Cell Invasion

    USDA-ARS?s Scientific Manuscript database

    Non-typhoidal Salmonella are the main source of pathogenic bacterial contamination in the poultry industry. Recently, Salmonella enterica serovar Kentucky has been recognized as the most prominent serovar on carcasses in poultry processing plants. Previous studies showed that flagella are one of the...

  18. What’s in a Name? Species-Wide Whole-Genome Sequencing Resolves Invasive and Noninvasive Lineages of Salmonella enterica Serotype Paratyphi B

    PubMed Central

    Owen, Sian V.; Langridge, Gemma; Connell, Steve; Nair, Satheesh; Reuter, Sandra; Dallman, Timothy J.; Corander, Jukka; Tabing, Kristine C.; Le Hello, Simon; Fookes, Maria; Doublet, Benoît; Zhou, Zhemin; Feltwell, Theresa; Ellington, Matthew J.; Herrera, Silvia; Gilmour, Matthew; Cloeckaert, Axel; Achtman, Mark; Wain, John; De Pinna, Elizabeth; Weill, François-Xavier; Peters, Tansy; Thomson, Nick

    2016-01-01

    ABSTRACT For 100 years, it has been obvious that Salmonella enterica strains sharing the serotype with the formula 1,4,[5],12:b:1,2—now known as Paratyphi B—can cause diseases ranging from serious systemic infections to self-limiting gastroenteritis. Despite considerable predicted diversity between strains carrying the common Paratyphi B serotype, there remain few methods that subdivide the group into groups that are congruent with their disease phenotypes. Paratyphi B therefore represents one of the canonical examples in Salmonella where serotyping combined with classical microbiological tests fails to provide clinically informative information. Here, we use genomics to provide the first high-resolution view of this serotype, placing it into a wider genomic context of the Salmonella enterica species. These analyses reveal why it has been impossible to subdivide this serotype based upon phenotypic and limited molecular approaches. By examining the genomic data in detail, we are able to identify common features that correlate with strains of clinical importance. The results presented here provide new diagnostic targets, as well as posing important new questions about the basis for the invasive disease phenotype observed in a subset of strains. PMID:27555304

  19. Complete Genome Sequence of a Multidrug-Resistant Salmonella enterica Serovar Typhimurium var. 5- Strain Isolated from Chicken Breast.

    PubMed

    Hoffmann, Maria; Muruvanda, Tim; Allard, Marc W; Korlach, Jonas; Roberts, Richard J; Timme, Ruth; Payne, Justin; McDermott, Patrick F; Evans, Peter; Meng, Jianghong; Brown, Eric W; Zhao, Shaohua

    2013-12-19

    Salmonella enterica subsp. enterica serovar Typhimurium is a leading cause of salmonellosis. Here, we report a closed genome sequence, including sequences of 3 plasmids, of Salmonella serovar Typhimurium var. 5- CFSAN001921 (National Antimicrobial Resistance Monitoring System [NARMS] strain ID N30688), which was isolated from chicken breast meat and shows resistance to 10 different antimicrobials. Whole-genome and plasmid sequence analyses of this isolate will help enhance our understanding of this pathogenic multidrug-resistant serovar.

  20. Genome sequences of Salmonella enterica subsp. Kentucky ST152 isolated from dairy cows in the United States

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica serovar Kentucky is frequently isolated from dairy cows in the United States, but is an infrequent cause of human salmonellosis. To investigate the genomic features of S. Kentucky strains isolated from these animals, genomes of eight isolates were sequenced and ad...

  1. Antimicrobial resistance patterns of bovine Salmonella enterica isolates submitted to the Wisconsin Veterinary Diagnostic Laboratory: 2006-2015.

    PubMed

    Valenzuela, J R; Sethi, A K; Aulik, N A; Poulsen, K P

    2017-02-01

    Salmonellosis on the dairy continues to have a significant effect on animal health and productivity and in the United States. Additionally, Salmonella enterica ssp. enterica causes an estimated 1.2 million cases of human illness annually. Contributing to the morbidity and mortality in both human and domestic animal species is emergence of antimicrobial resistance by Salmonella species and increased incidence of multidrug-resistant isolates. This study describes serotype distribution and the antimicrobial resistance patterns for various Salmonella serotypes isolated from bovine samples submitted to the Wisconsin Veterinary Diagnostic Laboratory (WVDL) over the past 10 yr. Salmonella serotyping and antimicrobial susceptibility testing data were obtained from the laboratory information management system at WVDL. Data from accessions were limited to bovine samples submitted to the WVDL between January 2006 and June 2015 and those that had both a definitive serotype and complete results for antimicrobial susceptibility testing. A total of 4,976 isolates were identified. Salmonella enterica ser. Dublin was the most prevalent serotype identified among bovine samples submitted to the WVDL, accounting for a total of 1,153 isolates (23% of total isolates) over the study period. Along with Dublin, Salmonella enterica ser. Cerro (795, 16%), Newport (720, 14%), Montevideo (421, 8%), Kentucky (419, 8%), and Typhimurium (202, 4%) comprised the top 6 most commonly isolated serotypes during that time. Overall, resistance of bovine Salmonella isolates in the study population remained stable, although decreases in resistance were noted for gentamicin, neomycin, and trimethoprim sulfamethoxazole during the study period. All isolates remained susceptible to enrofloxacin. These data show that antimicrobial susceptibility for bovine Salmonella has changed in the population served by WVDL in the past 10 yr. This information is important for understanding Salmonella disease ecology in

  2. Molecular typing of Salmonella enterica serovar typhi isolates from various countries in Asia by a multiplex PCR assay on variable-number tandem repeats.

    PubMed

    Liu, Yichun; Lee, May-Ann; Ooi, Eng-Eong; Mavis, Yeo; Tan, Ai-Ling; Quek, Hung-Hiang

    2003-09-01

    A multiplex PCR method incorporating primers flanking three variable-number tandem repeat (VNTR) loci (arbitrarily labeled TR1, TR2, and TR3) in the CT18 strain of Salmonella enterica serovar Typhi has been developed for molecular typing of S. enterica serovar Typhi clinical isolates from several Asian countries, including Singapore, Indonesia, India, Bangladesh, Malaysia, and Nepal. We have demonstrated that the multiplex PCR could be performed on crude cell lysates and that the VNTR banding profiles produced could be easily analyzed by visual inspection after conventional agarose gel electrophoresis. The assay was highly discriminative in identifying 49 distinct VNTR profiles among 59 individual isolates. A high level of VNTR profile heterogeneity was observed in isolates from within the same country and among countries. These VNTR profiles remained stable after the strains were passaged extensively under routine laboratory culture conditions. In contrast to the S. enterica serovar Typhi isolates, an absence of TR3 amplicons and a lack of length polymorphisms in TR1 and TR2 amplicons were observed for other S. enterica serovars, such as Salmonella enterica serovar Typhimurium, Salmonella enterica serovar Enteritidis, and Salmonella enterica serovar Paratyphi A, B, and C. DNA sequencing of the amplified VNTR regions substantiated these results, suggesting the high stability of the multiplex PCR assay. The multiplex-PCR-based VNTR profiling developed in this study provides a simple, rapid, reproducible, and high-resolution molecular tool for the epidemiological analysis of S. enterica serovar Typhi strains.

  3. Repression of Salmonella enterica phoP Expression by Small Molecules from Physiological Bile

    PubMed Central

    Antunes, L. Caetano M.; Wang, Melody; Andersen, Sarah K.; Ferreira, Rosana B. R.; Kappelhoff, Reinhild; Han, Jun; Borchers, Christoph H.

    2012-01-01

    Infection with Salmonella enterica serovar Typhi in humans causes the life-threatening disease typhoid fever. In the laboratory, typhoid fever can be modeled through the inoculation of susceptible mice with Salmonella enterica serovar Typhimurium. Using this murine model, we previously characterized the interactions between Salmonella Typhimurium and host cells in the gallbladder and showed that this pathogen can successfully invade gallbladder epithelial cells and proliferate. Additionally, we showed that Salmonella Typhimurium can use bile phospholipids to grow at high rates. These abilities are likely important for quick colonization of the gallbladder during typhoid fever and further pathogen dissemination through fecal shedding. To further characterize the interactions between Salmonella and the gallbladder environment, we compared the transcriptomes of Salmonella cultures grown in LB broth or physiological murine bile. Our data showed that many genes involved in bacterial central metabolism are affected by bile, with the citric acid cycle being repressed and alternative respiratory systems being activated. Additionally, our study revealed a new aspect of Salmonella interactions with bile through the identification of the global regulator phoP as a bile-responsive gene. Repression of phoP expression could also be achieved using physiological, but not commercial, bovine bile. The biological activity does not involve PhoPQ sensing of a bile component and is not caused by bile acids, the most abundant organic components of bile. Bioactivity-guided purification allowed the identification of a subset of small molecules from bile that can elicit full activity; however, a single compound with phoP inhibitory activity could not be isolated, suggesting that multiple molecules may act in synergy to achieve this effect. Due to the critical role of phoP in Salmonella virulence, further studies in this area will likely reveal aspects of the interaction between Salmonella

  4. Adaptation and Preadaptation of Salmonella enterica to Bile

    PubMed Central

    Hernández, Sara B.; Cota, Ignacio; Ducret, Adrien; Aussel, Laurent; Casadesús, Josep

    2012-01-01

    Bile possesses antibacterial activity because bile salts disrupt membranes, denature proteins, and damage DNA. This study describes mechanisms employed by the bacterium Salmonella enterica to survive bile. Sublethal concentrations of the bile salt sodium deoxycholate (DOC) adapt Salmonella to survive lethal concentrations of bile. Adaptation seems to be associated to multiple changes in gene expression, which include upregulation of the RpoS-dependent general stress response and other stress responses. The crucial role of the general stress response in adaptation to bile is supported by the observation that RpoS− mutants are bile-sensitive. While adaptation to bile involves a response by the bacterial population, individual cells can become bile-resistant without adaptation: plating of a non-adapted S. enterica culture on medium containing a lethal concentration of bile yields bile-resistant colonies at frequencies between 10−6 and 10−7 per cell and generation. Fluctuation analysis indicates that such colonies derive from bile-resistant cells present in the previous culture. A fraction of such isolates are stable, indicating that bile resistance can be acquired by mutation. Full genome sequencing of bile-resistant mutants shows that alteration of the lipopolysaccharide transport machinery is a frequent cause of mutational bile resistance. However, selection on lethal concentrations of bile also provides bile-resistant isolates that are not mutants. We propose that such isolates derive from rare cells whose physiological state permitted survival upon encountering bile. This view is supported by single cell analysis of gene expression using a microscope fluidic system: batch cultures of Salmonella contain cells that activate stress response genes in the absence of DOC. This phenomenon underscores the existence of phenotypic heterogeneity in clonal populations of bacteria and may illustrate the adaptive value of gene expression fluctuations. PMID:22275872

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

    USDA-ARS?s Scientific Manuscript database

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

  6. Refined live attenuated Salmonella enterica serovar Typhimurium and Enteritidis vaccines mediate homologous and heterologous serogroup protection in mice.

    PubMed

    Tennant, Sharon M; Schmidlein, Patrick; Simon, Raphael; Pasetti, Marcela F; Galen, James E; Levine, Myron M

    2015-12-01

    Invasive nontyphoidal Salmonella (NTS) infections constitute a major health problem among infants and toddlers in sub-Saharan Africa; these infections also occur in infants and the elderly in developed countries. We genetically engineered a Salmonella enterica serovar Typhimurium strain of multilocus sequence type 313, the predominant genotype circulating in sub-Saharan Africa. We evaluated the capacities of S. Typhimurium and Salmonella enterica serovar Enteritidis ΔguaBA ΔclpX live oral vaccines to protect mice against a highly lethal challenge dose of the homologous serovar and determined protection against other group B and D serovars circulating in sub-Saharan Africa. The vaccines S. Typhimurium CVD 1931 and S. Enteritidis CVD 1944 were immunogenic and protected BALB/c mice against 10,000 50% lethal doses (LD50) of S. Typhimurium or S. Enteritidis, respectively. S. Typhimurium CVD 1931 protected mice against the group B serovar Salmonella enterica serovar Stanleyville (91% vaccine efficacy), and S. Enteritidis CVD 1944 protected mice against the group D serovar Salmonella enterica serovar Dublin (85% vaccine efficacy). High rates of survival were observed when mice were infected 12 weeks postimmunization, indicating that the vaccines elicited long-lived protective immunity. Whereas CVD 1931 did not protect against S. Enteritidis R11, CVD 1944 did mediate protection against S. Typhimurium D65 (81% efficacy). These findings suggest that a bivalent (S. Typhimurium and S. Enteritidis) vaccine would provide broad protection against the majority of invasive NTS infections in sub-Saharan Africa. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Generation and selection of anti-flagellin monoclonal antibodies useful for serotyping Salmonella enterica.

    PubMed

    Hiriart, Yanina; Serradell, Maria; Martínez, Araci; Sampaolesi, Sofia; Maciel, Dolores Gonzalez; Chabalgoity, Jose Alejandro; Yim, Lucía; Algorta, Gabriela; Rumbo, Martin

    2013-01-01

    In developing countries, bacterial acute gastroenteritis continues to be an important cause of morbidity and mortality among young children. Salmonellosis constitutes a major cause of infectious enteritis worldwide, most of them associated to the consumption of contaminated food products. Traditionally, Salmonella has been classified in serovars based on varieties of O and H surface antigens. In the present work we generated and characterized a panel of anti-flagellin monoclonal antibodies (MAbs) in order to select antibodies useful for detecting the H surface antigen. Four different MAbs were obtained by somatic hybridization of splenocytes. We found two MAbs that recognised regions of flagellin conserved among different Salmonella serovars. Other two MAbs recognised structures restricted to Salmonella enterica sv. Typhimurium, being one of them suitable for agglutination tests. Using a diverse panel of S. enterica serovars with different H antigen varieties we confirmed that this MAb agglutinates specifically S. Typhimurium (antigenic formula: 4,12:i:1,2) or other serovars expressing flagellar factor i. In conclusion, we generated a valuable immunochemical tool to be used in simple assays for serotyping of epidemiologically relevant strains. The capacity to characterize specific strains and determine the primary sources of Salmonella contamination generate valuable information of the epidemiology of this microorganism, contributing to the improvement of public health.

  8. Persistence of two Salmonella enterica ser. Montevideo strains throughout horn fly (Diptera: Muscidae) larval and pupal development

    USDA-ARS?s Scientific Manuscript database

    Strains of Salmonella enterica can be subdivided into clades that differ in their composition of genes, including those that influence microbial ecology and bacterial transmission. Salmonella serovar Montevideo strains 1110 and 304, representatives of two different clades, were used throughout this ...

  9. Physiological and molecular responses of Lactuca sativa to colonization by Salmonella enterica serovar Dublin.

    PubMed

    Klerks, M M; van Gent-Pelzer, M; Franz, E; Zijlstra, C; van Bruggen, A H C

    2007-08-01

    This paper describes the physiological and molecular interactions between the human-pathogenic organism Salmonella enterica serovar Dublin and the commercially available mini Roman lettuce cv. Tamburo. The association of S. enterica serovar Dublin with lettuce plants was first determined, which indicated the presence of significant populations outside and inside the plants. The latter was evidenced from significant residual concentrations after highly efficient surface disinfection (99.81%) and fluorescence microscopy of S. enterica serovar Dublin in cross sections of lettuce at the root-shoot transition region. The plant biomass was reduced significantly compared to that of noncolonized plants upon colonization with S. enterica serovar Dublin. In addition to the physiological response, transcriptome analysis by cDNA amplified fragment length polymorphism analysis also provided clear differential gene expression profiles between noncolonized and colonized lettuce plants. From these, generally and differentially expressed genes were selected and identified by sequence analysis, followed by reverse transcription-PCR displaying the specific gene expression profiles in time. Functional grouping of the expressed genes indicated a correlation between colonization of the plants and an increase in expressed pathogenicity-related genes. This study indicates that lettuce plants respond to the presence of S. enterica serovar Dublin at physiological and molecular levels, as shown by the reduction in growth and the concurrent expression of pathogenicity-related genes. In addition, it was confirmed that Salmonella spp. can colonize the interior of lettuce plants, thus potentially imposing a human health risk when processed and consumed.

  10. Rapid detection and classification of Salmonella enterica shedding in feedlot cattle utilizing Roka Bioscience Atlas Salmonella detection assay for the analysis of rectoanal mucosal swabs

    USDA-ARS?s Scientific Manuscript database

    With an increasing focus on preharvest food safety, rapid methods are required for the detection and quantification of foodborne pathogens such as Salmonella enterica in beef cattle. We validated the Atlas Salmonella Detection Assay (SEN), a nucleic acid amplification technology that targets Salmone...

  11. Salmonella enterica serotype enteritidis in French Polynesia, South Pacific, 2008-2013.

    PubMed

    Le Hello, Simon; Maillard, Fiona; Mallet, Henri-Pierre; Daudens, Elise; Levy, Marc; Roy, Valérie; Branaa, Philippe; Bertrand, Sophie; Fabre, Laetitia; Weill, François-Xavier

    2015-06-01

    Outbreaks of Salmonella enterica serotype Enteritidis infections associated with eggs occurred in French Polynesia during 2008-2013. Molecular analysis of isolates by using clustered regularly interspaced short palindromic repeat polymorphisms and multilocus variable-number tandem-repeat analysis was performed. This subtyping made defining the epidemic strain, finding the source, and decontaminating affected poultry flocks possible.

  12. Complete Genome Sequences of Salmonella enterica Serovars Anatum and Anatum var. 15+, Isolated from Retail Ground Turkey

    PubMed Central

    Marasini, Daya; Abo-Shama, Usama H.

    2016-01-01

    The complete genome sequences of two isolates of Salmonella enterica serovars Anatum and Anatum var. 15+ revealed the presence of two plasmids of 112 kb and 3 kb in size in each. The chromosome of Salmonella Anatum (4.83 Mb) was slightly smaller than that of Salmonella Anatum var. 15+ (4.88 Mb). PMID:26798111

  13. Complete genomic sequences of two salmonella enterica subsp. enterica serogroup C2 (O:6,8) strains from central California

    USDA-ARS?s Scientific Manuscript database

    Salmonella enteric subsp. enterica strains RM11060, serotype 6,8:d:-, and RM11065, serotype 6,8:-:e,n,z15, were isolated from environmental sampling in Central California in 2009. We report the complete genome sequences and annotation of these two strains. These genomic sequences are distinct and wi...

  14. Characterization of non-typhoidal Salmonella enterica strains of human origin in central and southern Italy

    PubMed Central

    Proroga, Yolande T.R.; Capuano, Federico; Capparelli, Rosanna; Bilei, Stefano; Bernardo, Mariano; Cocco, Maria Pia; Campagnuolo, Rosalba; Pasquale, Vincenzo

    2018-01-01

    Non-typhoidal Salmonella enterica infection is a significant public health problem worldwide. The aim of this study was to characterize Salmonella enterica strains isolated from human specimens in central and southern Italy, for epidemiological studies. One hundred and fifty S. enterica strains were serotyped. Isolates were tested for their antimicrobial susceptibility, by disk diffusion method. The molecular characterizations, based on PCR, were carried out for the detection of invA gene and other virulence elements and phage marker genes. Eighteen different Salmonella serotypes were identified. The most common serotypes detected were S. Typhimurium, S. Enteritidis, the monophasic variant of S. Typhimurium (S. 4,[5],12:i:-), and S. Napoli. High resistance rates were recorded for tetracycline (64%), streptomycin (62%), sulphonamide (57%), and ampicillin (56%). The ASSuT R-type, also associated to resistance to other antibiotics, was highly prevalent in S. 4,[5],12:i:- (97%) and S. Typhimurium (55%), while the ACSSuT R-type, also associated to other antibiotics, was observed prevalently in S. Typhimurium (20.4%). The genes of more common detection were invA (100%), sspH2 (86.6%), gtgB (84.6%), g8 (80%), sodC1 (77.3%), gipA (52.6%), sspH1 (52.6%). PMID:29732321

  15. Molecular epidemiological characteristics of Salmonella enterica serovars Enteritidis, Typhimurium and Livingstone strains isolated in a Tunisian university hospital.

    PubMed

    Ktari, Sonia; Ksibi, Boutheina; Gharsallah, Houda; Mnif, Basma; Maalej, Sonda; Rhimi, Fouzia; Hammami, Adnene

    2016-03-01

    Enteritidis, Typhimurium and Livingstone are the main Salmonella enterica serovars recovered in Tunisia. Here, we aimed to assess the genetic diversity of fifty-seven Salmonella enterica strains from different sampling periods, origins and settings using pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST) and multi-locus variable-number tandem repeat analysis (MLVA). Salmonella Enteritidis, isolated from human and food sources from two regions in Sfax in 2007, were grouped into one cluster using PFGE. However, using MLVA these strains were divided into two clusters. Salmonella Typhimurium strains, recovered in 2012 and represent sporadic cases of human clinical isolates, were included in one PFGE cluster. Nevertheless, the MLVA technique, divided Salmonella Typhimurium isolates into six clusters with diversity index reaching (DI = 0.757). For Salmonella Livingstone which was responsible of two nosocomial outbreaks during 2000-2003, the PFGE and MLVA methods showed that these strains were genetically closely related. Salmonella Enteritidis and Salmonella Livingstone populations showed a single ST lineage ST11 and ST543 respectively. For Salmonella Typhimurium, two MLST sequence types ST19 and ST328 were defined. Salmonella Enteritidis and Salmonella Typhimurium strains were clearly differentiated by MLVA which was not the case using PFGE. © 2015 APMIS. Published by John Wiley & Sons Ltd.

  16. Chlortetracycline and florfenicol induce expression of genes associated with pathogenicity in multidrug-resistant Salmonella enterica serovar Typhimurium

    USDA-ARS?s Scientific Manuscript database

    Background Multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium (S. Typhimurium) is a serious public health threat as infections caused by these strains are more difficult and expensive to treat. Livestock serve as a reservoir for MDR Salmonella, and the antibiotics chlortetracycline an...

  17. Complete Genome Sequence of a Multidrug-Resistant Salmonella enterica Serovar Typhimurium var. 5− Strain Isolated from Chicken Breast

    PubMed Central

    Muruvanda, Tim; Allard, Marc W.; Korlach, Jonas; Roberts, Richard J.; Timme, Ruth; Payne, Justin; McDermott, Patrick F.; Evans, Peter; Meng, Jianghong; Brown, Eric W.; Zhao, Shaohua

    2013-01-01

    Salmonella enterica subsp. enterica serovar Typhimurium is a leading cause of salmonellosis. Here, we report a closed genome sequence, including sequences of 3 plasmids, of Salmonella serovar Typhimurium var. 5− CFSAN001921 (National Antimicrobial Resistance Monitoring System [NARMS] strain ID N30688), which was isolated from chicken breast meat and shows resistance to 10 different antimicrobials. Whole-genome and plasmid sequence analyses of this isolate will help enhance our understanding of this pathogenic multidrug-resistant serovar. PMID:24356834

  18. Ciprofloxacin-Resistant Salmonella enterica Serotype Typhi, United States, 1999–2008

    PubMed Central

    Sjölund-Karlsson, Maria; Shin, Sanghyuk; Harvey, Emily; Joyce, Kevin; Theobald, Lisa; Nygren, Benjamin L.; Pecic, Gary; Gay, Kathryn; Austin, Jana; Stuart, Andrew; Blanton, Elizabeth; Mintz, Eric D.; Whichard, Jean M.; Barzilay, Ezra J.

    2011-01-01

    We report 9 ciprofloxacin-resistant Salmonella enterica serotype Typhi isolates submitted to the US National Antimicrobial Resistance Monitoring System during 1999–2008. The first 2 had indistinguishable pulsed-field gel electrophoresis patterns and identical gyrA and parC mutations. Eight of the 9 patients had traveled to India within 30 days before illness onset. PMID:21749779

  19. Growth dynamics of Salmonella enterica strains on alfalfa sprouts and in waste seed irrigation water.

    PubMed

    Howard, Michael B; Hutcheson, Steven W

    2003-01-01

    Alfalfa sprouts and other seed sprouts have been implicated in numerous outbreaks of salmonellosis. The source of these epidemics appears to have been low-level contamination of seeds by Salmonella bacteria that developed into clinically significant populations during the seed germination process. To test the possibility that Salmonella enterica strains carry host range determinants that allow them to grow on alfalfa, strains isolated from alfalfa or other sources were surveyed for their ability to grow on germinating alfalfa seeds. An S. enterica serovar Cubana strain originally isolated from contaminated alfalfa sprouts multiplied most rapidly during the initial 24 h of the seed germination process. Germinating alfalfa seeds supported the multiplication of S. enterica cells prior to the emergence of the root radicle at 72 h. Thereafter, much lower rates of multiplication were apparent. The ability of S. enterica to grow on germinating alfalfa seeds was independent of the serovar, isolation source, or virulence of the strain. Isolates obtained from alfalfa attained population levels similar to those observed for strains isolated from contaminated meat products or stools. Each of the strains could be detected in the waste irrigation water, with populations being strongly correlated with those detected on the germinating alfalfa seeds. The S. enterica strains were capable of utilizing the waste irrigation water as a sole carbon and nitrogen source. S. enterica strains thus appear to grow saprophytically on soluble organics released from seeds during early phases of germination. The ability to detect S. enterica in the waste irrigation water early in the germination process indicates that this method may be used as a simple way to monitor the contamination of sprouts during commercial operations.

  20. Novel small RNA (sRNA) landscape of the starvation-stress response transcriptome of Salmonella enterica serovar typhimurium.

    PubMed

    Amin, Shivam V; Roberts, Justin T; Patterson, Dillon G; Coley, Alexander B; Allred, Jonathan A; Denner, Jason M; Johnson, Justin P; Mullen, Genevieve E; O'Neal, Trenton K; Smith, Jason T; Cardin, Sara E; Carr, Hank T; Carr, Stacie L; Cowart, Holly E; DaCosta, David H; Herring, Brendon R; King, Valeria M; Polska, Caroline J; Ward, Erin E; Wise, Alice A; McAllister, Kathleen N; Chevalier, David; Spector, Michael P; Borchert, Glen M

    2016-01-01

    Small RNAs (sRNAs) are short (∼50-200 nucleotides) noncoding RNAs that regulate cellular activities across bacteria. Salmonella enterica starved of a carbon-energy (C) source experience a host of genetic and physiological changes broadly referred to as the starvation-stress response (SSR). In an attempt to identify novel sRNAs contributing to SSR control, we grew log-phase, 5-h C-starved and 24-h C-starved cultures of the virulent Salmonella enterica subspecies enterica serovar Typhimurium strain SL1344 and comprehensively sequenced their small RNA transcriptomes. Strikingly, after employing a novel strategy for sRNA discovery based on identifying dynamic transcripts arising from "gene-empty" regions, we identify 58 wholly undescribed Salmonella sRNA genes potentially regulating SSR averaging an ∼1,000-fold change in expression between log-phase and C-starved cells. Importantly, the expressions of individual sRNA loci were confirmed by both comprehensive transcriptome analyses and northern blotting of select candidates. Of note, we find 43 candidate sRNAs share significant sequence identity to characterized sRNAs in other bacteria, and ∼70% of our sRNAs likely assume characteristic sRNA structural conformations. In addition, we find 53 of our 58 candidate sRNAs either overlap neighboring mRNA loci or share significant sequence complementarity to mRNAs transcribed elsewhere in the SL1344 genome strongly suggesting they regulate the expression of transcripts via antisense base-pairing. Finally, in addition to this work resulting in the identification of 58 entirely novel Salmonella enterica genes likely participating in the SSR, we also find evidence suggesting that sRNAs are significantly more prevalent than currently appreciated and that Salmonella sRNAs may actually number in the thousands.

  1. Survival of Salmonella enterica serovar infantis on and within stored table eggs.

    PubMed

    Lublin, Avishai; Maler, Ilana; Mechani, Sara; Pinto, Riky; Sela-Saldinger, Shlomo

    2015-02-01

    Contaminated table eggs are considered a primary source of foodborne salmonellosis globally. Recently, a single clone of Salmonella enterica serovar Infantis emerged in Israel and became the predominant serovar isolated in poultry. This clone is currently the most prevalent strain in poultry and is the leading cause of salmonellosis in humans. Because little is known regarding the potential transmission of this strain from contaminated eggs to humans, the objective of this study was to evaluate the ability of Salmonella Infantis to survive on the eggshell or within the egg during cold storage or at room temperature. Salmonella cells (5.7 log CFU per egg) were inoculated on the surface of 120 intact eggs or injected into the egg yolk (3.7 log CFU per egg) of another 120 eggs. Half of the eggs were stored at 5.5 ± 0.3°C and half at room temperature (25.5 ± 0.1°C) for up to 10 weeks. At both temperatures, the number of Salmonella cells on the shell declined by 2 log up to 4 weeks and remained constant thereafter. Yolk-inoculated Salmonella counts at cold storage declined by 1 log up to 4 weeks and remained constant, while room-temperature storage supported the growth of the pathogen to a level of 8 log CFU/ml of total egg content, as early as 4 weeks postinoculation. Examination of egg content following surface inoculation revealed the presence of Salmonella in a portion of the eggs at both temperatures up to 10 weeks, suggesting that this strain can also penetrate through the shell and survive within the egg. These findings imply that Salmonella enterica serovar Infantis is capable of survival both on the exterior and interior of table eggs and even multiply inside the egg at room temperature. Our findings support the need for prompt refrigeration to prevent Salmonella multiplication during storage of eggs at room temperature.

  2. Effect of direct-fed microbial supplementation on the presence of Salmonella enterica in bovine peripheral lymph nodes

    USDA-ARS?s Scientific Manuscript database

    Introduction: Bovine peripheral lymph nodes (LN) contained within adipose trim, have been identified as a potential source of human exposure to Salmonella enterica, when incorporated into ground beef. How Salmonella gain entry to peripheral LN is a question yet to be answered, however recent survey...

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

    USDA-ARS?s Scientific Manuscript database

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

  4. Salmonella enterica Suppresses Pectobacterium carotovorum subsp. carotovorum Population and Soft Rot Progression by Acidifying the Microaerophilic Environment

    PubMed Central

    Kwan, Grace; Charkowski, Amy O.; Barak, Jeri D.

    2013-01-01

    ABSTRACT Although enteric human pathogens are usually studied in the context of their animal hosts, a significant portion of their life cycle occurs on plants. Plant disease alters the phyllosphere, leading to enhanced growth of human pathogens; however, the impact of human pathogens on phytopathogen biology and plant health is largely unknown. To characterize the interaction between human pathogens and phytobacterial pathogens in the phyllosphere, we examined the interactions between Pectobacterium carotovorum subsp. carotovorum and Salmonella enterica or Escherichia coli O157:H7 with regard to bacterial populations, soft rot progression, and changes in local pH. The presence of P. carotovorum subsp. carotovorum enhanced the growth of both S. enterica and E. coli O157:H7 on leaves. However, in a microaerophilic environment, S. enterica reduced P. carotovorum subsp. carotovorum populations and soft rot progression by moderating local environmental pH. Reduced soft rot was not due to S. enterica proteolytic activity. Limitations on P. carotovorum subsp. carotovorum growth, disease progression, and pH elevation were not observed on leaves coinoculated with E. coli O157:H7 or when leaves were coinoculated with S. enterica in an aerobic environment. S. enterica also severely undermined the relationship between the phytobacterial population and disease progression of a P. carotovorum subsp. carotovorum budB mutant defective in the 2,3-butanediol pathway for acid neutralization. Our results show that S. enterica and E. coli O157:H7 interact differently with the enteric phytobacterial pathogen P. carotovorum subsp. carotovorum. S. enterica inhibition of soft rot progression may conceal a rapidly growing human pathogen population. Whereas soft rotted produce can alert consumers to the possibility of food-borne pathogens, healthy-looking produce may entice consumption of contaminated vegetables. PMID:23404399

  5. Salmonella enterica serovar Kentucky isolates from dairy cows and poultry demonstrate different evolutionary histories and host-specific polymorphisms

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica serovar Kentucky is commonly isolated from dairy cows and poultry in the United States. Although it is not among the most frequently isolated serovars from cases of human salmonellosis, its high prevalence in livestock and poultry indicate it is a potential public...

  6. Oral administration of a Salmonella enterica-based vaccine expressing Bacillus anthracis protective antigen confers protection against aerosolized B. anthracis.

    PubMed

    Stokes, Margaret G M; Titball, Richard W; Neeson, Brendan N; Galen, James E; Walker, Nicola J; Stagg, Anthony J; Jenner, Dominic C; Thwaite, Joanne E; Nataro, James P; Baillie, Leslie W J; Atkins, Helen S

    2007-04-01

    Bacillus anthracis is the causative agent of anthrax, a disease that affects wildlife, livestock, and humans. Protection against anthrax is primarily afforded by immunity to the B. anthracis protective antigen (PA), particularly PA domains 4 and 1. To further the development of an orally delivered human vaccine for mass vaccination against anthrax, we produced Salmonella enterica serovar Typhimurium expressing full-length PA, PA domains 1 and 4, or PA domain 4 using codon-optimized PA DNA fused to the S. enterica serovar Typhi ClyA and under the control of the ompC promoter. Oral immunization of A/J mice with Salmonella expressing full-length PA protected five of six mice against a challenge with 10(5) CFU of aerosolized B. anthracis STI spores, whereas Salmonella expressing PA domains 1 and 4 provided only 25% protection (two of eight mice), and Salmonella expressing PA domain 4 or a Salmonella-only control afforded no measurable protection. However, a purified recombinant fusion protein of domains 1 and 4 provided 100% protection, and purified recombinant 4 provided protection in three of eight immunized mice. Thus, we demonstrate for the first time the efficacy of an oral S. enterica-based vaccine against aerosolized B. anthracis spores.

  7. Complete genome sequence of a ciprofloxacin resistant Salmonella enterica subsp. enterica serovar Kentucky sequence of a ciprofloxacin strain, PU131, isolated from a human patient in Washington State.

    USDA-ARS?s Scientific Manuscript database

    A ciprofloxacin resistant (CipR) Salmonella enterica subsp. enterica serovar Kentucky ST198 has rapidly and extensively disseminated globally to become a major food-safety and public health concern. Here, we report a complete genome sequence of a CipR S. Kentucky ST198 strain PU131 isolated from a ...

  8. Prevalence, distribution, and diversity of Salmonella enterica in a major produce region of California.

    PubMed

    Gorski, Lisa; Parker, Craig T; Liang, Anita; Cooley, Michael B; Jay-Russell, Michele T; Gordus, Andrew G; Atwill, E Robert; Mandrell, Robert E

    2011-04-01

    A survey was initiated to determine the prevalence of Salmonella enterica in the environment in and around Monterey County, CA, a major agriculture region of the United States. Trypticase soy broth enrichment cultures of samples of soil/sediment (n = 617), water (n = 252), wildlife (n = 476), cattle feces (n = 795), and preharvest lettuce and spinach (n = 261) tested originally for the presence of pathogenic Escherichia coli were kept in frozen storage and later used to test for the presence of S. enterica. A multipathogen oligonucleotide microarray was employed to identify a subset of samples that might contain Salmonella in order to test various culture methods to survey a larger number of samples. Fifty-five of 2,401 (2.3%) samples yielded Salmonella, representing samples obtained from 20 different locations in Monterey and San Benito Counties. Water had the highest percentage of positives (7.1%) among sample types. Wildlife yielded 20 positive samples, the highest number among sample types, with positive samples from birds (n = 105), coyotes (n = 40), deer (n = 104), elk (n = 39), wild pig (n = 41), and skunk (n = 13). Only 16 (2.6%) of the soil/sediment samples tested positive, and none of the produce samples had detectable Salmonella. Sixteen different serotypes were identified among the isolates, including S. enterica serotypes Give, Typhimurium, Montevideo, and Infantis. Fifty-four strains were sensitive to 12 tested antibiotics; one S. Montevideo strain was resistant to streptomycin and gentamicin. Pulsed-field gel electrophoresis (PFGE) analysis of the isolates revealed over 40 different pulsotypes. Several strains were isolated from water, wildlife, or soil over a period of several months, suggesting that they were persistent in this environment.

  9. Serotype Diversity and Antimicrobial Resistance among Salmonella enterica Isolates from Patients at an Equine Referral Hospital.

    PubMed

    Leon, I M; Lawhon, S D; Norman, K N; Threadgill, D S; Ohta, N; Vinasco, J; Scott, H M

    2018-07-01

    Although Salmonella enterica can produce life-threatening colitis in horses, certain serotypes are more commonly associated with clinical disease. Our aim was to evaluate the proportional morbidity attributed to different serotypes, as well as the phenotypic and genotypic antimicrobial resistance (AMR) of Salmonella isolates from patients at an equine referral hospital in the southern United States. A total of 255 Salmonella isolates was obtained from clinical samples of patients admitted to the hospital between 2007 and 2015. Phenotypic resistance to 14 antibiotics surveilled by the U.S. National Antimicrobial Resistance Monitoring System was determined using a commercially available panel. Whole-genome sequencing was used to identify serotypes and genotypic AMR. The most common serotypes were Salmonella enterica serotype Newport (18%), Salmonella enterica serotype Anatum (15.2%), and Salmonella enterica serotype Braenderup (11.8%). Most ( n = 219) of the isolates were pansusceptible, while 25 were multidrug resistant (≥3 antimicrobial classes). Genes encoding beta-lactam resistance, such as bla CMY-2 , bla SHV-12 , bla CTX-M-27 , and bla TEM-1B , were detected. The qnr B2 and aac(6')-Ib-cr genes were present in isolates with reduced susceptibility to ciprofloxacin. Genes encoding resistance to gentamicin ( aph(3')-Ia , aac(6')-IIc ), streptomycin ( str A and str B), sulfonamides ( sul1 ), trimethoprim ( dfrA ), phenicols ( catA ), tetracyclines [ tet (A) and tet (E)], and macrolides [ ere (A)] were also identified. The main predicted incompatibility plasmid type was I1 (10%). Core genome-based analyses revealed phylogenetic associations between isolates of common serotypes. The presence of AMR Salmonella in equine patients increases the risk of unsuccessful treatment and causes concern for potential zoonotic transmission to attending veterinary personnel, animal caretakers, and horse owners. Understanding the epidemiology of Salmonella in horses admitted to

  10. Increased Resistance to Multiple Antimicrobials and Altered Resistance Gene Expression in CMY-2-Positive Salmonella enterica following a Simulated Patient Treatment with Ceftriaxone

    PubMed Central

    Hamilton, Russell D.; Hulsebus, Holly J.; Akbar, Samina

    2012-01-01

    Salmonellosis is one of the most common causes of food-borne disease in the United States. Increasing antimicrobial resistance and corresponding increases in virulence present serious challenges. Currently, empirical therapy for invasive Salmonella enterica infection includes either ceftriaxone or ciprofloxacin (E. L. Hohmann, Clin. Infect. Dis. 32:263–269, 2001). The blaCMY-2 gene confers resistance to ceftriaxone, the antimicrobial of choice for pediatric patients with invasive Salmonella enterica infections, making these infections especially dangerous (J. M. Whichard et al., Emerg. Infect. Dis. 11:1464–1466, 2005). We hypothesized that blaCMY-2-positive Salmonella enterica would exhibit increased MICs to multiple antimicrobial agents and increased resistance gene expression following exposure to ceftriaxone using a protocol that simulated a patient treatment in vitro. Seven Salmonella enterica strains survived a simulated patient treatment in vitro and, following treatment, exhibited a significantly increased ceftriaxone MIC. Not only would these isolates be less responsive to further ceftriaxone treatment, but because the blaCMY-2 genes are commonly located on large, multidrug-resistant plasmids, increased expression of the blaCMY-2 gene may be associated with increased expression of other drug resistance genes located on the plasmid (N. D. Hanson and C. C. Sanders, Curr. Pharm. Des. 5:881–894, 1999). The results of this study demonstrate that a simulated patient treatment with ceftriaxone can alter the expression of antimicrobial resistance genes, including blaCMY-2 and floR in S. enterica serovar Typhimurium and S. enterica serovar Newport. Additionally, we have shown increased MICs following a simulated patient treatment with ceftriaxone for tetracycline, amikacin, ceftriaxone, and cefepime, all of which have resistance genes commonly located on CMY-2 plasmids. The increases in resistance observed are significant and may have a negative impact on both

  11. Integration host factor is important for biofilm formation by Salmonella enterica Enteritidis.

    PubMed

    Leite, Bruna; Werle, Catierine Hirsch; Carmo, Camila Pinheiro do; Nóbrega, Diego Borin; Milanez, Guilherme Paier; Culler, Hebert Fabricio; Sircili, Marcelo Palma; Alvarez-Martinez, Cristina E; Brocchi, Marcelo

    2017-08-31

    Salmonella enterica Enteritidis forms biofilms and survives in agricultural environments, infecting poultry and eggs. Bacteria in biofilms are difficult to eradicate compared to planktonic cells, causing serious problems in industry and public health. In this study, we evaluated the role of ihfA and ihfB in biofilm formation by S. enterica Enteritidis by employing different microbiology techniques. Our data indicate that ihf mutant strains are impaired in biofilm formation, showing a reduction in matrix formation and a decrease in viability and metabolic activity. Phenotypic analysis also showed that deletion of ihf causes a deficiency in curli fimbriae expression, cellulose production and pellicle formation. These results show that integration host factor has an important regulatory role in biofilm formation by S. enterica Enteritidis. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Incidence and growth of Salmonella enterica on the peel and pulp of avocado (Persea americana) and custard apple (Annona squamosa).

    PubMed

    Rezende, Ana Carolina B; Crucello, Juliana; Moreira, Rafael C; Silva, Beatriz S; Sant'Ana, Anderson S

    2016-10-17

    The aim of this study was to assess the incidence and to estimate the growth kinetic parameters (maximum growth rate, μ; lag time, λ; and maximum population, κ) of Salmonella on the peel and pulp of avocado (Perseaamericana var. americana) and custard apple (Annona squamosa L.) as affected by temperature (10-30°C). The incidence of Salmonella was assessed on the peel and pulp of the fruits (n=200 of each fruit), separately, totalizing 800 analyses. Only three samples of custard apple pulp were positive for Salmonella enterica and the three isolates recovered belonged to serotype S. Typhimurium. Salmonella was not recovered from avocado and custard apple peels and from avocado pulp. Generally, the substrate (pulp or peel) of growth did not affect μ values of S. enterica (p>0.05). Very similar μ values were found for S. enterica inoculated in custard apple and avocado. S. enterica presented the highest λ in the peel of the fruits. The growth of S. enterica resulted in larger λ in custard apple in comparison to avocado. For example, the λ of S. enterica in the pulp of custard apple and avocado were 47.0±0.78h and 10.0±3.78h, respectively. The lowest values of κ were obtained at the lower storage temperature conditions (10°C). For instance, κ values of 3.7±0.06log CFU/g and 2.9±0.03log CFU/g were obtained from the growth of S. enterica in avocado and custard apple pulps at 10°C (p<0.05), respectively. On the other hand, at 30°C, κ values were 6.5±0.25log CFU/g and 6.5±0.05log CFU/g, respectively. Significantly higher κ were obtained from the growth of S. enterica in the pulp than in the peel of the fruits (p<0.05). For instance, the growth of S. enterica in the pulp of avocado led to a κ value of 6.5±0.25log CFU/g, while in the peel led to a κ value of 4.6±0.23log CFU/g (p<0.05). In general, growth kinetic parameters indicated that avocado comprises a better substrate than custard apple for the growth of S. enterica. The square root model

  13. Role of anionic charges of osmoregulated periplasmic glucans of Salmonella enterica Serovar Typhimurium SL1344 in mice virulence

    USDA-ARS?s Scientific Manuscript database

    Osmoregulated periplasmic glucans (OPGs) are important periplasmic constituents of Salmonella spp. and are required for optimal growth in hypoosmotic environments such as irrigation and vegetable wash waters as well as for mice virulence. opgB gene of Salmonella enterica serovar Typhimurium was ide...

  14. Rcs and PhoPQ regulatory overlap in the control of Salmonella enterica virulence.

    PubMed

    García-Calderón, Clara B; Casadesús, Josep; Ramos-Morales, Francisco

    2007-09-01

    Genetic screens based on the use of MudJ-generated lac fusions permitted the identification of novel genes regulated by the Rcs signal transduction system in Salmonella enterica serovar Typhimurium. Besides genes that are also found in the Escherichia coli genome, our screens identified Salmonella-specific genes regulated by RcsB, including bapA, siiE, srfA, and srfB. Here we show that the srfABC operon is negatively regulated by RcsB and by PhoP. In vivo studies using mutants with constitutive activation of the Rcs and/or PhoPQ system suggested that there is an overlap between these regulatory systems in the control of Salmonella virulence.

  15. Genomic Epidemiology of Salmonella enterica Serotype Enteritidis based on Population Structure of Prevalent Lineages

    PubMed Central

    Desai, Prerak T.; den Bakker, Henk C.; Mikoleit, Matthew; Tolar, Beth; Trees, Eija; Hendriksen, Rene S.; Frye, Jonathan G.; Porwollik, Steffen; Weimer, Bart C.; Wiedmann, Martin; Weinstock, George M.; Fields, Patricia I.; McClelland, Michael

    2014-01-01

    Salmonella enterica serotype Enteritidis is one of the most commonly reported causes of human salmonellosis. Its low genetic diversity, measured by fingerprinting methods, has made subtyping a challenge. We used whole-genome sequencing to characterize 125 S. enterica Enteritidis and 3 S. enterica serotype Nitra strains. Single-nucleotide polymorphisms were filtered to identify 4,887 reliable loci that distinguished all isolates from each other. Our whole-genome single-nucleotide polymorphism typing approach was robust for S. enterica Enteritidis subtyping with combined data for different strains from 2 different sequencing platforms. Five major genetic lineages were recognized, which revealed possible patterns of geographic and epidemiologic distribution. Analyses on the population dynamics and evolutionary history estimated that major lineages emerged during the 17th–18th centuries and diversified during the 1920s and 1950s. PMID:25147968

  16. A CRISPR-based MLST Scheme for Understanding the Population Biology and Epidemiology of Salmonella Enterica

    DTIC Science & Technology

    2015-05-26

    in other systems , or whether it has alternative functions. Here, we report that CRISPR can be used to subtype Salmonella enterica serovariants...protects the bacteria against foreign DNA as described in other systems , or whether it has alternative functions. Here, we report that CRISPR can be...N. Shariat, R. E. Timme, J. B. Pettengill, R. Barrangou, E. G. Dudley. Characterization and evolution of Salmonella CRISPR-Cas systems

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

    PubMed

    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.

  18. Vi Capsular Polysaccharide Produced by Recombinant Salmonella enterica Serovar Paratyphi A Confers Immunoprotection against Infection by Salmonella enterica Serovar Typhi

    PubMed Central

    Xiong, Kun; Zhu, Chunyue; Chen, Zhijin; Zheng, Chunping; Tan, Yong; Rao, Xiancai; Cong, Yanguang

    2017-01-01

    Enteric fever is predominantly caused by Salmonella enterica serovar Typhi and Salmonella enterica serovar Paratyphi A, and accounts for an annual global incidence of 26.9 millions. In recent years, the rate of S. Paratyphi A infection has progressively increased. Currently licensed vaccines for typhoid fever, live Ty21a vaccine, Vi subunit vaccine, and Vi-conjugate vaccine, confer inadequate cross immunoprotection against enteric fever caused by S. Paratyphi A. Therefore, development of bivalent vaccines against enteric fever is urgently required. The immunogenic Vi capsular polysaccharide is characteristically produced in S. Typhi, but it is absent in S. Paratyphi A. We propose that engineering synthesis of Vi in S. Paratyphi A live-attenuated vaccine may expand its protection range to cover S. Typhi. In this study, we cloned the viaB locus, which contains 10 genes responsible for Vi biosynthesis, and integrated into the chromosome of S. Paratyphi A CMCC 50093. Two virulence loci, htrA and phoPQ, were subsequently deleted to achieve a Vi-producing attenuated vaccine candidate. Our data showed that, despite more than 200 passages, the viaB locus was stably maintained in the chromosome of S. Paratyphi A and produced the Vi polysaccharide. Nasal immunization of the vaccine candidate stimulated high levels of Vi-specific and S. Paratyphi A-specific antibodies in mice sera as well as total sIgA in intestinal contents, and showed significant protection against wild-type challenge of S. Paratyphi A or S. Typhi. Our study show that the Vi-producing attenuated S. Paratyphi A is a promising bivalent vaccine candidate for the prevention of enteric fever. PMID:28484685

  19. An outbreak of multidrug-resistant Salmonella enterica subsp. enterica serotype Typhimurium, DT104L linked to dried anchovy in Singapore.

    PubMed Central

    Ling, M. L.; Goh, K. T.; Wang, G. C. Y.; Neo, K. S.; Chua, T.

    2002-01-01

    Multidrug-resistant Salmonella enterica subsp. enterica serotype Typhimurium DT104L was first reported in Singapore from mid-July to mid-October 2000. Salmonella strains isolated from clinical laboratories were submitted to a reference laboratory for serotyping, phage-typing and pulsed-field gel electrophoresis (PFGE) using XbaI restriction endonuclease. An epidemiological investigation was conducted to determine the source of infection and mode of transmission using a structured questionnaire. A total of 33 cases involving mainly infants and toddlers were detected in the 3-month long outbreak. The outbreak strain was of the R-type ACGSTSu, i.e. resistant to ampicillin, chloramphenicol, gentamicin, streptomycin, tetracycline and sulphonamide. PFGE showed all isolates had an indistinguishable pattern, indicating a common source of infection. Consumption of imported dried anchovy was found to be the vehicle of transmission after adjusting for all confounding variables in the case-control study using stepwise logistic regression (OR 25.6; 95% CI 3.9-167.9; P = 0.001). Imported dried seafood should be properly processed, packed, labelled, and thoroughly cooked to prevent transmission of multidrug-resistant S. Typhimurium. PMID:11895083

  20. Salmonella enterica Serotype Enteritidis in French Polynesia, South Pacific, 2008–2013

    PubMed Central

    Maillard, Fiona; Mallet, Henri-Pierre; Daudens, Elise; Levy, Marc; Roy, Valérie; Branaa, Philippe; Bertrand, Sophie; Fabre, Laetitia; Weill, François-Xavier

    2015-01-01

    Outbreaks of Salmonella enterica serotype Enteritidis infections associated with eggs occurred in French Polynesia during 2008–2013. Molecular analysis of isolates by using clustered regularly interspaced short palindromic repeat polymorphisms and multilocus variable-number tandem-repeat analysis was performed. This subtyping made defining the epidemic strain, finding the source, and decontaminating affected poultry flocks possible. PMID:25988406

  1. Receptor Diversity and Host Interaction of Bacteriophages Infecting Salmonella enterica Serovar Typhimurium

    PubMed Central

    Kim, Hyeryen; Choi, Younho; Heu, Sunggi; Ryu, Sangryeol

    2012-01-01

    Background Salmonella enterica subspecies enterica serovar Typhimurium is a Gram-negative pathogen causing salmonellosis. Salmonella Typhimurium-targeting bacteriophages have been proposed as an alternative biocontrol agent to antibiotics. To further understand infection and interaction mechanisms between the host strains and the bacteriophages, the receptor diversity of these phages needs to be elucidated. Methodology/Principal Findings Twenty-five Salmonella phages were isolated and their receptors were identified by screening a Tn5 random mutant library of S. Typhimurium SL1344. Among them, three types of receptors were identified flagella (11 phages), vitamin B12 uptake outer membrane protein, BtuB (7 phages) and lipopolysaccharide-related O-antigen (7 phages). TEM observation revealed that the phages using flagella (group F) or BtuB (group B) as a receptor belong to Siphoviridae family, and the phages using O-antigen of LPS as a receptor (group L) belong to Podoviridae family. Interestingly, while some of group F phages (F-I) target FliC host receptor, others (F-II) target both FliC and FljB receptors, suggesting that two subgroups are present in group F phages. Cross-resistance assay of group B and L revealed that group L phages could not infect group B phage-resistant strains and reversely group B phages could not infect group L SPN9TCW-resistant strain. Conclusions/Significance In this report, three receptor groups of 25 newly isolated S. Typhimurium-targeting phages were determined. Among them, two subgroups of group F phages interact with their host receptors in different manner. In addition, the host receptors of group B or group L SPN9TCW phages hinder other group phage infection, probably due to interaction between receptors of their groups. This study provides novel insights into phage-host receptor interaction for Salmonella phages and will inform development of optimal phage therapy for protection against Salmonella. PMID:22927964

  2. Validation of Thermal Lethality against Salmonella enterica in Poultry Offal during Rendering.

    PubMed

    Jones-Ibarra, Amie-Marie; Acuff, Gary R; Alvarado, Christine Z; Taylor, T Matthew

    2017-09-01

    Recent outbreaks of human disease following contact with companion animal foods cross-contaminated with enteric pathogens, such as Salmonella enterica, have resulted in increased concern regarding the microbiological safety of animal foods. Additionally, the U.S. Food and Drug Administration Food Safety Modernization Act and its implementing rules have stipulated the implementation of current good manufacturing practices and food safety preventive controls for livestock and companion animal foods. Animal foods and feeds are sometimes formulated to include thermally rendered animal by-product meals. The objective of this research was to determine the thermal inactivation of S. enterica in poultry offal during rendering at differing temperatures. Raw poultry offal was obtained from a commercial renderer and inoculated with a mixture of Salmonella serovars Senftenberg, Enteritidis, and Gallinarum (an avian pathogen) prior to being subjected to heating at 150, 155, or 160°F (65.5, 68.3, or 71.1°C) for up to 15 min. Following heat application, surviving Salmonella bacteria were enumerated. Mean D-values for the Salmonella cocktail at 150, 155, and 160°F were 0.254 ± 0.045, 0.172 ± 0.012, and 0.086 ± 0.004 min, respectively, indicative of increasing susceptibility to increased application of heat during processing. The mean thermal process constant (z-value) was 21.948 ± 3.87°F. Results indicate that a 7.0-log-cycle inactivation of Salmonella may be obtained from the cumulative lethality encountered during the heating come-up period and subsequent rendering of raw poultry offal at temperatures not less than 150°F. Current poultry rendering procedures are anticipated to be effective for achieving necessary pathogen control when completed under sanitary conditions.

  3. Interactions of Salmonella enterica Serovar Typhimurium and Pectobacterium carotovorum within a Tomato Soft Rot

    PubMed Central

    Cox, Clayton E.; Desai, Prerak; Porwollik, Steffen; Chu, Weiping; de Moraes, Marcos H.; McClelland, Michael; Brandl, Maria T.; Teplitski, Max

    2017-01-01

    ABSTRACT Salmonella spp. are remarkably adaptable pathogens, and this adaptability allows these bacteria to thrive in a variety of environments and hosts. The mechanisms with which these pathogens establish within a niche amid the native microbiota remain poorly understood. Here, we aimed to uncover the mechanisms that enable Salmonella enterica serovar Typhimurium strain ATCC 14028 to benefit from the degradation of plant tissue by a soft rot plant pathogen, Pectobacterium carotovorum. The hypothesis that in the soft rot, the liberation of starch (not utilized by P. carotovorum) makes this polymer available to Salmonella spp., thus allowing it to colonize soft rots, was tested first and proven null. To identify the functions involved in Salmonella soft rot colonization, we carried out transposon insertion sequencing coupled with the phenotypic characterization of the mutants. The data indicate that Salmonella spp. experience a metabolic shift in response to the changes in the environment brought on by Pectobacterium spp. and likely coordinated by the csrBC small regulatory RNA. While csrBC and flhD appear to be of importance in the soft rot, the global two-component system encoded by barA sirA (which controls csrBC and flhDC under laboratory conditions) does not appear to be necessary for the observed phenotype. Motility and the synthesis of nucleotides and amino acids play critical roles in the growth of Salmonella spp. in the soft rot. IMPORTANCE Outbreaks of produce-associated illness continue to be a food safety concern. Earlier studies demonstrated that the presence of phytopathogens on produce was a significant risk factor associated with increased Salmonella carriage on fruits and vegetables. Here, we genetically characterize some of the requirements for interactions between Salmonella and phytobacteria that allow Salmonella spp. to establish a niche within an alternate host (tomato). Pathways necessary for nucleotide synthesis, amino acid synthesis, and

  4. Prevalence, Distribution, and Diversity of Salmonella enterica in a Major Produce Region of California▿†

    PubMed Central

    Gorski, Lisa; Parker, Craig T.; Liang, Anita; Cooley, Michael B.; Jay-Russell, Michele T.; Gordus, Andrew G.; Atwill, E. Robert; Mandrell, Robert E.

    2011-01-01

    A survey was initiated to determine the prevalence of Salmonella enterica in the environment in and around Monterey County, CA, a major agriculture region of the United States. Trypticase soy broth enrichment cultures of samples of soil/sediment (n = 617), water (n = 252), wildlife (n = 476), cattle feces (n = 795), and preharvest lettuce and spinach (n = 261) tested originally for the presence of pathogenic Escherichia coli were kept in frozen storage and later used to test for the presence of S. enterica. A multipathogen oligonucleotide microarray was employed to identify a subset of samples that might contain Salmonella in order to test various culture methods to survey a larger number of samples. Fifty-five of 2,401 (2.3%) samples yielded Salmonella, representing samples obtained from 20 different locations in Monterey and San Benito Counties. Water had the highest percentage of positives (7.1%) among sample types. Wildlife yielded 20 positive samples, the highest number among sample types, with positive samples from birds (n = 105), coyotes (n = 40), deer (n = 104), elk (n = 39), wild pig (n = 41), and skunk (n = 13). Only 16 (2.6%) of the soil/sediment samples tested positive, and none of the produce samples had detectable Salmonella. Sixteen different serotypes were identified among the isolates, including S. enterica serotypes Give, Typhimurium, Montevideo, and Infantis. Fifty-four strains were sensitive to 12 tested antibiotics; one S. Montevideo strain was resistant to streptomycin and gentamicin. Pulsed-field gel electrophoresis (PFGE) analysis of the isolates revealed over 40 different pulsotypes. Several strains were isolated from water, wildlife, or soil over a period of several months, suggesting that they were persistent in this environment. PMID:21378057

  5. Rapid Emergence and Clonal Dissemination of CTX-M-15-Producing Salmonella enterica Serotype Virchow, South Korea.

    PubMed

    Kim, Jin Seok; Yun, Young-Sun; Kim, Soo Jin; Jeon, Se-Eun; Lee, Deog-Yong; Chung, Gyung Tae; Yoo, Cheon-Kwon; Kim, Junyoung

    2016-01-01

    The prevalence of cefotaxime-resistant Salmonella enterica serotype Virchow has dramatically increased in South Korea since the first isolation in 2011. Of 68 isolates collected over 10 years, 28 cefotaxime-resistant isolates harbored the bla(CTX-M-15) extended-spectrum β-lactamase gene and were closely related genetically, demonstrating the clonal dissemination of CTX-M-15-producing Salmonella Virchow in South Korea.

  6. Identification and characterization of multidrug-resistant Salmonella enterica serotype Albert isolates in the United States.

    PubMed

    Folster, Jason P; Campbell, Davina; Grass, Julian; Brown, Allison C; Bicknese, Amelia; Tolar, Beth; Joseph, Lavin A; Plumblee, Jodie R; Walker, Carrie; Fedorka-Cray, Paula J; Whichard, Jean M

    2015-05-01

    Salmonella enterica is one of the most common causes of bacterial foodborne illness in the United States. Although most Salmonella infections are self-limiting, antimicrobial treatment of invasive salmonellosis is critical. The primary antimicrobial treatment options include fluoroquinolones or extended-spectrum cephalosporins, and resistance to these antimicrobial drugs may complicate treatment. At present, S. enterica is composed of more than 2,600 unique serotypes, which vary greatly in geographic prevalence, ecological niche, and the ability to cause human disease, and it is important to understand and mitigate the source of human infection, particularly when antimicrobial resistance is found. In this study, we identified and characterized 19 S. enterica serotype Albert isolates collected from food animals, retail meat, and humans in the United States during 2005 to 2013. All five isolates from nonhuman sources were obtained from turkeys or ground turkey, and epidemiologic data suggest poultry consumption or live-poultry exposure as the probable source of infection. S. enterica serotype Albert also appears to be geographically localized to the midwestern United States. All 19 isolates displayed multidrug resistance, including decreased susceptibility to fluoroquinolones and resistance to extended-spectrum cephalosporins. Turkeys are a likely source of multidrug-resistant S. enterica serotype Albert, and circulation of resistance plasmids, as opposed to the expansion of a single resistant strain, is playing a role. More work is needed to understand why these resistance plasmids spread and how their presence and the serotype they reside in contribute to human disease. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. 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▿

    PubMed Central

    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

  8. Mechanisms of antimicrobial resistant Salmonella enterica transmission associated with starling-livestock interactions.

    PubMed

    Carlson, James C; Hyatt, Doreene R; Ellis, Jeremy W; Pipkin, David R; Mangan, Anna M; Russell, Michael; Bolte, Denise S; Engeman, Richard M; DeLiberto, Thomas J; Linz, George M

    2015-08-31

    Bird-livestock interactions have been implicated as potential sources for bacteria within concentrated animal feeding operations (CAFO). European starlings (Sturnus vulgaris) in particular are known to contaminate cattle feed and water with Salmonella enterica through their fecal waste. We propose that fecal waste is not the only mechanisms through which starlings introduce S. enterica to CAFO. The goal of this study was to assess if starlings can mechanically move S. enterica. We define mechanical movement as the transportation of media containing S. enterica, on the exterior of starlings within CAFO. We collected 100 starlings and obtained external wash and gastrointestinal tract (GI) samples. We also collected 100 samples from animal pens. Within each pen we collected one cattle fecal, feed, and water trough sample. Isolates from all S. enterica positive samples were subjected to antimicrobial susceptibility testing. All sample types, including 17% of external starling wash samples, contained S. enterica. All sample types had at least one antimicrobial resistant (AMR) isolate and starling GI samples harbored multidrug resistant S. enterica. The serotypes isolated from the starling external wash samples were all found in the farm environment and 11.8% (2/17) of isolates from positive starling external wash samples were resistant to at least one class of antibiotics. This study provides evidence of a potential mechanism of wildlife introduced microbial contamination in CAFO. Mechanical movement of microbiological hazards, by starlings, should be considered a potential source of bacteria that is of concern to veterinary, environmental and public health. Published by Elsevier B.V.

  9. Early immune response following Salmonella enterica subspecies enterica serovar Typhimurium infection in porcine jejunal gut loops

    PubMed Central

    Meurens, François; Berri, Mustapha; Auray, Gael; Melo, Sandrine; Levast, Benoît; Virlogeux-Payant, Isabelle; Chevaleyre, Claire; Gerdts, Volker; Salmon, Henri

    2009-01-01

    Salmonella enterica subspecies enterica serovar Typhimurium, commonly called S. Typhimurium, can cause intestinal infections in humans and various animal species such as swine. To analyze the host response to Salmonella infection in the pig we used an in vivo gut loop model, which allows the analysis of multiple immune responses within the same animal. Four jejunal gut-loops were each inoculated with 3×108 cfu of S. Typhimurium in 3 one-month-old piglets and mRNA expressions of various cytokines, chemokines, transcription factors, antimicrobial peptides, toll like and chemokine receptors were assessed by quantitative real-time PCR in the Peyer’s patch and the gut wall after 24 h. Several genes such as the newly cloned CCRL1/CCX-CKR were assessed for the first time in the pig at the mRNA level. Pro-inflammatory and T-helper type-1 (Th1) cytokine mRNA were expressed at higher levels in infected compared to non-infected control loops. Similarly, some B cell activation genes, NOD2 and toll like receptor 2 and 4 transcripts were more expressed in both tissues while TLR5 mRNA was down-regulated. Interestingly, CCL25 mRNA expression as well as the mRNA expressions of its receptors CCR9 and CCRL1 were decreased both in the Peyer’s patch and gut wall suggesting a potential Salmonella strategy to reduce lymphocyte homing to the intestine. In conclusion, these results provide insight into the porcine innate mucosal immune response to infection with entero-invasive microorganisms such as S. Typhimurium. In the future, this knowledge should help in the development of improved prophylactic and therapeutic approaches against porcine intestinal S. Typhimurium infections. PMID:18922229

  10. Multidrug-Resistant Salmonella enterica Serotype Typhi, Gulf of Guinea Region, Africa

    PubMed Central

    Baltazar, Murielle; Ngandjio, Antoinette; Holt, Kathryn Elizabeth; Lepillet, Elodie; Pardos de la Gandara, Maria; Collard, Jean-Marc; Bercion, Raymond; Nzouankeu, Ariane; Le Hello, Simon; Dougan, Gordon; Fonkoua, Marie-Christine

    2015-01-01

    We identified 3 lineages among multidrug-resistant (MDR) Salmonella enterica serotype Typhi isolates in the Gulf of Guinea region in Africa during the 2000s. However, the MDR H58 haplotype, which predominates in southern Asia and Kenya, was not identified. MDR quinolone-susceptible isolates contained a 190-kb incHI1 pST2 plasmid or a 50-kb incN pST3 plasmid. PMID:25811307

  11. Genome sequence of the thermotolerant foodborne pathogen Salmonella enterica serovar Senftenberg ATCC 43845 and phylogenetic analysis of Loci encoding increased protein quality control mechanisms

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica bacteria are important foodborne pathogens with major economic impact. Some isolates exhibit increased heat tolerance, a concern for food safety. Analysis of a finished-quality genome sequence of an isolate commonly used in heat resistance studies, S. enterica sub...

  12. Thrombin-activatable fibrinolysis inhibitor is degraded by Salmonella enterica and Yersinia pestis.

    PubMed

    Valls Serón, M; Haiko, J; DE Groot, P G; Korhonen, T K; Meijers, J C M

    2010-10-01

     Pathogenic bacteria modulate the host coagulation system to evade immune responses or to facilitate dissemination through extravascular tissues. In particular, the important bacterial pathogens Salmonella enterica and Yersinia pestis intervene with the plasminogen/fibrinolytic system. Thrombin-activatable fibrinolysis inhibitor (TAFI) has anti-fibrinolytic properties as the active enzyme (TAFIa) removes C-terminal lysine residues from fibrin, thereby attenuating accelerated plasmin formation.  Here, we demonstrate inactivation and cleavage of TAFI by homologous surface proteases, the omptins Pla of Y. pestis and PgtE of S. enterica. We show that omptin-expressing bacteria decrease TAFI activatability by thrombin-thrombomodulin and that the anti-fibrinolytic potential of TAFIa was reduced by recombinant Escherichia coli expressing Pla or PgtE. The functional impairment resulted from C-terminal cleavage of TAFI by the omptins.  Our results indicate that TAFI is degraded directly by the omptins PgtE of S. enterica and Pla of Y. pestis. This may contribute to the ability of PgtE and Pla to damage tissue barriers, such as fibrin, and thereby to enhance spread of S. enterica and Y. pestis during infection. © 2010 International Society on Thrombosis and Haemostasis.

  13. Microgravity as a novel environmental signal affecting Salmonella enterica serovar Typhimurium virulence

    NASA Technical Reports Server (NTRS)

    Nickerson, C. A.; Ott, C. M.; Mister, S. J.; Morrow, B. J.; Burns-Keliher, L.; Pierson, D. L.

    2000-01-01

    The effects of spaceflight on the infectious disease process have only been studied at the level of the host immune response and indicate a blunting of the immune mechanism in humans and animals. Accordingly, it is necessary to assess potential changes in microbial virulence associated with spaceflight which may impact the probability of in-flight infectious disease. In this study, we investigated the effect of altered gravitational vectors on Salmonella virulence in mice. Salmonella enterica serovar Typhimurium grown under modeled microgravity (MMG) were more virulent and were recovered in higher numbers from the murine spleen and liver following oral infection compared to organisms grown under normal gravity. Furthermore, MMG-grown salmonellae were more resistant to acid stress and macrophage killing and exhibited significant differences in protein synthesis than did normal-gravity-grown cells. Our results indicate that the environment created by simulated microgravity represents a novel environmental regulatory factor of Salmonella virulence.

  14. Salmonella enterica Serovar Enteritidis, England and Wales, 1945–2011

    PubMed Central

    Lane, Christopher R.; LeBaigue, Susan; Esan, Oluwaseun B.; Awofisyo, Adedoyin A.; Adams, Natalie L.; Fisher, Ian S.T.; Grant, Kathie A.; Peters, Tansy M.; Larkin, Lesley; Davies, Robert H.

    2014-01-01

    In England and Wales, the emergence of Salmonella enterica serovar Enteritidis resulted in the largest and most persistent epidemic of foodborne infection attributable to a single subtype of any pathogen since systematic national microbiological surveillance was established. We reviewed 67 years of surveillance data to examine the features, underlying causes, and overall effects of S. enterica ser. Enteritidis. The epidemic was associated with the consumption of contaminated chicken meat and eggs, and a decline in the number of infections began after the adoption of vaccination and other measures in production and distribution of chicken meat and eggs. We estimate that >525,000 persons became ill during the course of the epidemic, which caused a total of 6,750,000 days of illness, 27,000 hospitalizations, and 2,000 deaths. Measures undertaken to control the epidemic have resulted in a major reduction in foodborne disease in England and Wales. PMID:24960614

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

    PubMed Central

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

    2013-01-01

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

  16. Adhesion and splash dispersal of Salmonella enterica Typhimurium on tomato leaflets: effects of rdar morphotype and trichome density.

    PubMed

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

    2012-11-01

    Salmonella enterica strains with rdar (red dry and rough) and saw (smooth and white) morphotypes have previously been associated with tomato outbreaks but the dispersal mechanisms of these morphotypes are still poorly understood. In this study, Salmonella adhesion was distinguished from attachment by comparing different contact periods. Initial adhesion of rdar and saw morphotypes of Salmonella was compared in relation to tomato plants with different leaf trichome densities. Trichome densities were increased or reduced by treatment with jasmonic or salicylic acid, respectively. The overall effect of Salmonella morphotype and trichome density on splash dispersal was assessed in a rain simulator and correlated to cell hydrophobicity and initial adhesion. The presence of the rdar morphotype increased initial adhesion at high trichome densities but not at low trichome densities. Attachment of the rdar strain occurred after 30s contact time regardless of trichome density. Splash dispersal was slightly further for the saw morphotype than the rdar morphotype of S. enterica at all trichome densities. Salmonella cells of both morphotypes survived significantly better on the surface of high trichome density leaflets. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    PubMed Central

    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. PMID:24548159

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

    PubMed Central

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

    2012-01-01

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

  19. Genomic epidemiology of Salmonella enterica serotype Enteritidis based on population structure of prevalent lineages

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serotype Enteritidis (SE) is one of the most commonly reported causes of human salmonellosis. The low genetic diversity of SE measured by fingerprinting methods has made subtyping a challenge. In this study, we used whole genome sequencing to characterize a total of 125 SE and Sa...

  20. Impact of Strain Variation on the Ability of Biosensor Technology to Detect Salmonella enterica

    USDA-ARS?s Scientific Manuscript database

    Introduction: It is important to develop methods that can quickly and accurately detect the presence of bacteria in the food supply that cause disease. Salmonella enterica is a bacteria that is often associated with contamination of food. Strains vary in their ability to cause illness and to spread...

  1. Draft Genome Sequences of 37 Salmonella enterica Strains Isolated from Poultry Sources in Nigeria

    PubMed Central

    Useh, Nicodemus M.; Ngbede, Emmanuel O.; Akange, Nguavese; Thomas, Milton; Foley, Andrew; Keena, Mitchel Chan; Nelson, Eric; Christopher-Hennings, Jane; Tomita, Masaru

    2016-01-01

    Here, we report the availability of draft genomes of several Salmonella serotypes, isolated from poultry sources from Nigeria. These genomes will help to further understand the biological diversity of S. enterica and will serve as references in microbial trace-back studies to improve food safety. PMID:27151793

  2. aroA-Deficient Salmonella enterica Serovar Typhimurium Is More Than a Metabolically Attenuated Mutant

    PubMed Central

    Frahm, Michael; Kocijancic, Dino; Rohde, Manfred; Eckweiler, Denitsa; Bielecka, Agata; Bueno, Emilio; Cava, Felipe; Abraham, Wolf-Rainer; Curtiss, Roy; Häussler, Susanne; Erhardt, Marc; Weiss, Siegfried

    2016-01-01

    ABSTRACT Recombinant attenuated Salmonella enterica serovar Typhimurium strains are believed to act as powerful live vaccine carriers that are able to elicit protection against various pathogens. Auxotrophic mutations, such as a deletion of aroA, are commonly introduced into such bacteria for attenuation without incapacitating immunostimulation. In this study, we describe the surprising finding that deletion of aroA dramatically increased the virulence of attenuated Salmonella in mouse models. Mutant bacteria lacking aroA elicited increased levels of the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) after systemic application. A detailed genetic and phenotypic characterization in combination with transcriptomic and metabolic profiling demonstrated that ΔaroA mutants display pleiotropic alterations in cellular physiology and lipid and amino acid metabolism, as well as increased sensitivity to penicillin, complement, and phagocytic uptake. In concert with other immunomodulating mutations, deletion of aroA affected flagellin phase variation and gene expression of the virulence-associated genes arnT and ansB. Finally, ΔaroA strains displayed significantly improved tumor therapeutic activity. These results highlight the importance of a functional shikimate pathway to control homeostatic bacterial physiology. They further highlight the great potential of ΔaroA-attenuated Salmonella for the development of vaccines and cancer therapies with important implications for host-pathogen interactions and translational medicine. PMID:27601574

  3. Streptomycin Induced Stress Response in Salmonella enterica Serovar Typhimurium Shows Distinct Colony Scatter Signature

    PubMed Central

    Singh, Atul K.; Drolia, Rishi; Bai, Xingjian; Bhunia, Arun K.

    2015-01-01

    We investigated the streptomycin-induced stress response in Salmonella enterica serovars with a laser optical sensor, BARDOT (bacterial rapid detection using optical scattering technology). Initially, the top 20 S. enterica serovars were screened for their response to streptomycin at 100 μg/mL. All, but four S. enterica serovars were resistant to streptomycin. The MIC of streptomycin-sensitive serovars (Enteritidis, Muenchen, Mississippi, and Schwarzengrund) varied from 12.5 to 50 μg/mL, while streptomycin-resistant serovar (Typhimurium) from 125–250 μg/mL. Two streptomycin-sensitive serovars (Enteritidis and Mississippi) were grown on brain heart infusion (BHI) agar plates containing sub-inhibitory concentration of streptomycin (1.25–5 μg/mL) and a streptomycin-resistant serovar (Typhimurium) was grown on BHI containing 25–50 μg/mL of streptomycin and the colonies (1.2 ± 0.1 mm diameter) were scanned using BARDOT. Data show substantial qualitative and quantitative differences in the colony scatter patterns of Salmonella grown in the presence of streptomycin than the colonies grown in absence of antibiotic. Mass-spectrometry identified overexpression of chaperonin GroEL, which possibly contributed to the observed differences in the colony scatter patterns. Quantitative RT-PCR and immunoassay confirmed streptomycin-induced GroEL expression while, aminoglycoside adenylyltransferase (aadA), aminoglycoside efflux pump (aep), multidrug resistance subunit acrA, and ribosomal protein S12 (rpsL), involved in streptomycin resistance, were unaltered. The study highlights suitability of the BARDOT as a non-invasive, label-free tool for investigating stress response in Salmonella in conjunction with the molecular and immunoassay methods. PMID:26252374

  4. Variable-Number Tandem Repeats That Are Useful in Genotyping Isolates of Salmonella enterica subsp. enterica Serovars Typhimurium and Newport▿

    PubMed Central

    Witonski, D. ; Stefanova, R.; Ranganathan, A.; Schutze, G. E.; Eisenach, K. D.; Cave, M. D.

    2006-01-01

    The genome of Salmonella enterica subsp. enterica serovar Typhimurium strain LT2 was analyzed for direct repeats, and 54 sequences containing variable-number tandem repeat loci were identified. Ten primer pairs that anneal upstream and downstream of each selected locus were designed and used to amplify PCR targets in isolates of S. enterica serovars Typhimurium and Newport. Four of the 10 loci did not show polymorphism in the length of products. Six loci were selected for analysis. Isolates of S. enterica serovars Typhimurium and Newport that were related to specific outbreaks and showed identical pulsed-field gel electrophoresis patterns were indistinguishable by the length of the six variable-number tandem repeats. Isolates that differed in their pulsed-field gel electrophoresis patterns showed polymorphism in variable-number tandem repeat profiles. Length of the products was confirmed by DNA sequence analysis. Only 2 of the 10 loci contained exact integers of the direct repeat. Eight loci contained partial copies. The partial copies were maintained at the ends of the variable-number tandem repeat loci in all isolates. In spite of having partial copies that were maintained in all isolates, the number of direct repeats at a locus was polymorphic. Six variable-number tandem repeat loci were useful in distinguishing isolates of S. enterica serovars Typhimurium and Newport that had different pulsed-field gel electrophoresis patterns and in identifying outbreak-associated cases that shared a common pulsed-field gel pattern. PMID:16943354

  5. Repeated isolation of Salmonella enterica Goverdhan, a very rare serovar, from Danish poultry surveillance samples.

    PubMed

    Pedersen, Karl; Sørensen, Gitte; Szabo, Istvan; Hächler, Herbert; Le Hello, Simon

    2014-12-05

    We report here the appearance of a very rare serovar of Salmonella, S. enterica subsp. enterica serovar Goverdhan, in routine Salmonella surveillance samples from Danish poultry production. S. Goverdhan was found on nine occasions: in one broiler breeder farm in October 2010, four broiler farms and one broiler breeder farm in June-September 2012, two broiler breeder flocks simultaneously in June 2013, and one layer flock in July 2013. The five isolates from 2012 and the three isolates from 2013 had identical pulsed-field gel electrophoresis profiles, whereas the profile of the isolate from 2010 deviated in a single band. It is the first time this serovar has been described in samples from poultry. The origin of the bacterium is still unknown, but it is suggested that it may have been a pseudo-outbreak caused by contaminated sampling material. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Variable abattoir conditions affect Salmonella enterica prevalence and meat quality in swine and pork.

    PubMed

    Hurd, H S; Gailey, J K; McKean, J D; Griffith, R W

    2005-01-01

    Research suggests that abattoir holding pens pose significant Salmonella enterica risk to swine immediately preharvest. The goal of this study was to evaluate those factors related to holding that increased the prevalence of S. enterica in swine at slaughter. To accomplish this goal, we focused on holding time and flooring. Our objectives were to (1) compare Salmonella enterica prevalence among pigs held for short (15-45 min) versus long (up to 4 h) periods before slaughter; and (2) determine the impact of flooring (slatted vs. concrete) as it relates to the prevalence of S. enterica. The study consisted of seven repetitions at a large volume (11,000 head/day) Midwest abattoir. Each repetition consisted of one truck load of pigs (n = 170) sorted into one of three groups: (1) animals held for a short time (15-45 min) on solid floors (short-hold); (2) animals held for 4 +/- 0.5 h on slatted floors; and (3) animals held for 4 +/- 0.5 h on solid concrete floors. At slaughter, samples were collected from 30 pigs in each group. Cecal contents (20 mL), feces (20 g), and the ileocecal lymph node were cultured for S. enterica. Additionally, the effect of holding time on meat quality parameters (loin pH at 35 min and 6 h, color, drip loss) was evaluated for the first four replicates. The proportion of S. enterica-positive samples was highest (p < 0.05) in the cecum of pigs held on solid concrete floors (72.4%), and slightly less for pigs held on slatted floors (63.3%). Animals held for less than 45 min before slaughter demonstrated the lowest proportion of S. enterica-positive samples (52.9%). The pig prevalence, as measured by any one of the three samples being positive, was significantly different (p < 0.05) between animals held on solid floors (81%) and those animals held for 45 min or less before slaughter (69%). Meat quality, as measured by multiple parameters, was adversely affected by lack of a rest period. The mean 24-h pH was significantly lower for the short

  7. Outer membrane protein a of Salmonella enterica serovar Typhimurium activates dendritic cells and enhances Th1 polarization

    PubMed Central

    2010-01-01

    Background Typhoid, which is caused by Salmonella enterica serovar Typhimurium, remains a major health concern worldwide. Multidrug-resistant strains of Salmonella have emerged which exhibit increased survivability and virulence, thus leading to increased morbidity. However, little is known about the protective immune response against this microorganism. The outer membrane protein (Omp)A of bacteria plays an important role in pathogenesis. Results We purified OmpA from S. enterica serovar Typhimurium (OmpA-sal) and characterized the role of OmpA-sal in promoting adaptive and innate immune responses. OmpA-sal functionally activated bone marrow-derived dendritic cells by augmenting expression of CD80, CD86, and major histocompatibility complex classes I and II. Interestingly, OmpA-sal induced production of interferon-γ from T cells in mixed lymphocyte reactions, thus indicating Th1-polarizing capacity. The expression of surface markers and cytokine production in dendritic cells was mediated by the TLR4 signaling pathway in a TLR4 Knock-out system. Conclusions Our findings suggest that OmpA-sal modulates the adaptive immune responses to S. enterica serovar Typhimurium by activating dendritic cells and driving Th1 polarization, which are important properties to consider in the development of effective S. enterica serovar Typhimurium vaccines and immunotherapy adjuvant. PMID:20950448

  8. An Evaluation of Alternatives to Nitrites and Sulfites to Inhibit the Growth of Salmonella enterica and Listeria monocytogenes in Meat Products

    PubMed Central

    Lamas, Alexandre; Miranda, José Manuel; Vázquez, Beatriz; Cepeda, Alberto; Franco, Carlos Manuel

    2016-01-01

    In recent years, the use of nitrites and sulfites as food preservatives has been a cause for concern due to the health problems that these additives can cause in humans. Natural products have been studied as an alternative, but most of them have hardly been applied in the food industry for technological and economic reasons. In this sense, organic salts such as sodium acetate are a good alternative due to their affordability. Thus, this study evaluated the capacity of sodium nitrite, sodium sulfite, a sodium acetate product (TQI C-6000), and chitosan to inhibit two important foodborne pathogens, Salmonella enterica and Listeria monocytogenes. The MIC of each chemical was in vitro evaluated and their antibacterial action was subsequently checked in situ using minced meat as a food model. MIC values of sodium nitrite (10,000 mg/L) and sodium sulfite (50,000 mg/L) for Salmonella enterica were higher than the values allowed by legislation (450 mg/L for sulfites and 150 mg/L for nitrites). Additionally, the sodium acetate product caused the inhibition of Salmonella enterica and Listeria at a relative low quantity. The two foodborne pathogens were inhibited in the food model with 1% of the sodium acetate product. Additionally, there were no significant differences between sodium nitrite, sodium sulfite, and sodium acetate products in the inhibition of Salmonella enterica and Listeria monocytogenes in the food model. Thus, products based on sodium acetate can be an alternative to traditional preservatives in food products. PMID:28231169

  9. An Evaluation of Alternatives to Nitrites and Sulfites to Inhibit the Growth of Salmonella enterica and Listeria monocytogenes in Meat Products.

    PubMed

    Lamas, Alexandre; Miranda, José Manuel; Vázquez, Beatriz; Cepeda, Alberto; Franco, Carlos Manuel

    2016-10-31

    In recent years, the use of nitrites and sulfites as food preservatives has been a cause for concern due to the health problems that these additives can cause in humans. Natural products have been studied as an alternative, but most of them have hardly been applied in the food industry for technological and economic reasons. In this sense, organic salts such as sodium acetate are a good alternative due to their affordability. Thus, this study evaluated the capacity of sodium nitrite, sodium sulfite, a sodium acetate product (TQI C-6000), and chitosan to inhibit two important foodborne pathogens, Salmonella enterica and Listeria monocytogenes . The MIC of each chemical was in vitro evaluated and their antibacterial action was subsequently checked in situ using minced meat as a food model. MIC values of sodium nitrite (10,000 mg/L) and sodium sulfite (50,000 mg/L) for Salmonella enterica were higher than the values allowed by legislation (450 mg/L for sulfites and 150 mg/L for nitrites). Additionally, the sodium acetate product caused the inhibition of Salmonella enterica and Listeria at a relative low quantity. The two foodborne pathogens were inhibited in the food model with 1% of the sodium acetate product. Additionally, there were no significant differences between sodium nitrite, sodium sulfite, and sodium acetate products in the inhibition of Salmonella enterica and Listeria monocytogenes in the food model. Thus, products based on sodium acetate can be an alternative to traditional preservatives in food products.

  10. Food poisoning due to Salmonella enterica serotype weltevreden in Mangalore.

    PubMed

    Antony, B; Dias, M; Shetty, A K; Rekha, B

    2009-01-01

    An outbreak of food poisoning due to Salmonella enterica serotype Weltevreden ( S.weltevreden ) involving 34 students has been reported from a tertiary care hospital in Mangalore. The symptoms developed 8-10 hours, after consuming a non- vegetarian dish, probably fish, from an outside caterer. The identity of the organism was confirmed at Central Research Institute, Kasauli. This report emphasizes the geographical distribution of this organism in the Coastal Karnataka region. S.Weltevreden may be overlooked due to the biochemical similarity to S. Paratyphi B & S. Typhimurium.

  11. Comparative genomics of 28 Salmonella enterica isolates: evidence for CRISPR-mediated adaptive sublineage evolution.

    PubMed

    Fricke, W Florian; Mammel, Mark K; McDermott, Patrick F; Tartera, Carmen; White, David G; Leclerc, J Eugene; Ravel, Jacques; Cebula, Thomas A

    2011-07-01

    Despite extensive surveillance, food-borne Salmonella enterica infections continue to be a significant burden on public health systems worldwide. As the S. enterica species comprises sublineages that differ greatly in antigenic representation, virulence, and antimicrobial resistance phenotypes, a better understanding of the species' evolution is critical for the prediction and prevention of future outbreaks. The roles that virulence and resistance phenotype acquisition, exchange, and loss play in the evolution of S. enterica sublineages, which to a certain extent are represented by serotypes, remains mostly uncharacterized. Here, we compare 17 newly sequenced and phenotypically characterized nontyphoidal S. enterica strains to 11 previously sequenced S. enterica genomes to carry out the most comprehensive comparative analysis of this species so far. These phenotypic and genotypic data comparisons in the phylogenetic species context suggest that the evolution of known S. enterica sublineages is mediated mostly by two mechanisms, (i) the loss of coding sequences with known metabolic functions, which leads to functional reduction, and (ii) the acquisition of horizontally transferred phage and plasmid DNA, which provides virulence and resistance functions and leads to increasing specialization. Matches between S. enterica clustered regularly interspaced short palindromic repeats (CRISPR), part of a defense mechanism against invading plasmid and phage DNA, and plasmid and prophage regions suggest that CRISPR-mediated immunity could control short-term phenotype changes and mediate long-term sublineage evolution. CRISPR analysis could therefore be critical in assessing the evolutionary potential of S. enterica sublineages and aid in the prediction and prevention of future S. enterica outbreaks.

  12. Development of stable reporter system cloning luxCDABE genes into chromosome of Salmonella enterica serotypes using Tn7 transposon.

    PubMed

    Howe, Kevin; Karsi, Attila; Germon, Pierre; Wills, Robert W; Lawrence, Mark L; Bailey, Richard H

    2010-07-23

    Salmonellosis may be a food safety problem when raw food products are mishandled and not fully cooked. In previous work, we developed bioluminescent Salmonella enterica serotypes using a plasmid-based reporting system that can be used for real-time monitoring of the pathogen's growth on food products in short term studies. In this study, we report the use of a Tn7-based transposon system for subcloning of luxCDABE genes into the chromosome of eleven Salmonella enterica serotypes isolated from the broiler production continuum. We found that the lux operon is constitutively expressed from the chromosome post-transposition and the lux cassette is stable without external pressure, i.e. antibiotic selection, for all Salmonella enterica serotypes used. Bioluminescence expression is based on an active electron transport chain and is directly related with metabolic activity. This relationship was quantified by measuring bioluminescence against a temperature gradient in aqueous solution using a luminometer. In addition, bioluminescent monitoring of two serotypes confirmed that our chicken skin model has the potential to be used to evaluate pathogen mitigation strategies. This study demonstrated that our new stable reporting system eliminates bioluminescence variation due to plasmid instability and provides a reliable real-time experimental system to study application of preventive measures for Salmonella on food products in real-time for both short and long term studies.

  13. Assessing the ability of Salmonella enterica to translocate Type III effectors into plant cells

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica, a human enteric pathogen, has the ability to multiply and survive endophytically in plants, and mutations in genes encoding the type III secretion system (T3SS) or its effectors (T3Es) may contribute to this colonization. Two reporter plasmids for T3E translocation into plant ce...

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

    USDA-ARS?s Scientific Manuscript database

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

  15. Metabolic parameters linked by Phenotype MicroArray to acid resistance profiles of poultry-associated Salmonella enterica.

    USDA-ARS?s Scientific Manuscript database

    Phenotype microarrays were analyzed for 51 datasets derived from Salmonella enterica. The top 4 serovars associated with poultry products and one associated with turkey, respectively Typhimurium, Enteritidis, Heidelberg, Infantis and Senftenberg, were represented. Datasets were clustered into two ...

  16. Isolation and characterization of two novel groups of Kanamycin-resistance ColE1-like plasmids in Salmonella enterica serotypes from food animals

    USDA-ARS?s Scientific Manuscript database

    While antimicrobial resistance in Salmonella enterica is largely attributed to large plasmids, small plasmids may also harbor antimicrobial resistance genes. Previously, three major groups of ColE1-like plasmids conferring kanamycin-resistance (KanR) in various S. enterica serotypes from diagnostic...

  17. PREVALENCE OF SALMONELLA IN CAPTIVE REPTILES FROM CROATIA.

    PubMed

    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.

  18. SadA, a trimeric autotransporter from Salmonella enterica serovar Typhimurium, can promote biofilm formation and provides limited protection against infection.

    PubMed

    Raghunathan, Dhaarini; Wells, Timothy J; Morris, Faye C; Shaw, Robert K; Bobat, Saeeda; Peters, Sarah E; Paterson, Gavin K; Jensen, Karina Tveen; Leyton, Denisse L; Blair, Jessica M A; Browning, Douglas F; Pravin, John; Flores-Langarica, Adriana; Hitchcock, Jessica R; Moraes, Claudia T P; Piazza, Roxane M F; Maskell, Duncan J; Webber, Mark A; May, Robin C; MacLennan, Calman A; Piddock, Laura J; Cunningham, Adam F; Henderson, Ian R

    2011-11-01

    Salmonella enterica is a major cause of morbidity worldwide and mortality in children and immunocompromised individuals in sub-Saharan Africa. Outer membrane proteins of Salmonella are of significance because they are at the interface between the pathogen and the host, they can contribute to adherence, colonization, and virulence, and they are frequently targets of antibody-mediated immunity. In this study, the properties of SadA, a purported trimeric autotransporter adhesin of Salmonella enterica serovar Typhimurium, were examined. We demonstrated that SadA is exposed on the Salmonella cell surface in vitro and in vivo during infection of mice. Expression of SadA resulted in cell aggregation, biofilm formation, and increased adhesion to human intestinal Caco-2 epithelial cells. Immunization of mice with folded, full-length, purified SadA elicited an IgG response which provided limited protection against bacterial challenge. When anti-SadA IgG titers were enhanced by administering alum-precipitated protein, a modest additional protection was afforded. Therefore, despite SadA having pleiotropic functions, it is not a dominant, protective antigen for antibody-mediated protection against Salmonella.

  19. Draft Genome Sequences of 37 Salmonella enterica Strains Isolated from Poultry Sources in Nigeria.

    PubMed

    Useh, Nicodemus M; Ngbede, Emmanuel O; Akange, Nguavese; Thomas, Milton; Foley, Andrew; Keena, Mitchel Chan; Nelson, Eric; Christopher-Hennings, Jane; Tomita, Masaru; Suzuki, Haruo; Scaria, Joy

    2016-05-05

    Here, we report the availability of draft genomes of several Salmonella serotypes, isolated from poultry sources from Nigeria. These genomes will help to further understand the biological diversity of S. enterica and will serve as references in microbial trace-back studies to improve food safety. Copyright © 2016 Useh et al.

  20. Comparative genomic analysis and characterization of incompatibility group FIB plasmid encoded virulence factors of Salmonella enterica isolated from food sources.

    PubMed

    Khajanchi, Bijay K; Hasan, Nur A; Choi, Seon Young; Han, Jing; Zhao, Shaohua; Colwell, Rita R; Cerniglia, Carl E; Foley, Steven L

    2017-08-02

    The degree to which the chromosomal mediated iron acquisition system contributes to virulence of many bacterial pathogens is well defined. However, the functional roles of plasmid encoded iron acquisition systems, specifically Sit and aerobactin, have yet to be determined for Salmonella spp. In a recent study, Salmonella enterica strains isolated from different food sources were sequenced on the Illumina MiSeq platform and found to harbor the incompatibility group (Inc) FIB plasmid. In this study, we examined sequence diversity and the contribution of factors encoded on the IncFIB plasmid to the virulence of S. enterica. Whole genome sequences of seven S. enterica isolates were compared to genomes of serovars of S. enterica isolated from food, animal, and human sources. SeqSero analysis predicted that six strains were serovar Typhimurium and one was Heidelberg. Among the S. Typhimurium strains, single nucleotide polymorphism (SNP)-based phylogenetic analyses revealed that five of the isolates clustered as a single monophyletic S. Typhimurium subclade, while one of the other strains branched with S. Typhimurium from a bovine source. DNA sequence based phylogenetic diversity analyses showed that the IncFIB plasmid-encoded Sit and aerobactin iron acquisition systems are conserved among bacterial species including S. enterica. The IncFIB plasmid was transferred to an IncFIB plasmid deficient strain of S. enterica by conjugation. The transconjugant SE819::IncFIB persisted in human intestinal epithelial (Caco-2) cells at a higher rate than the recipient SE819. Genes of the Sit and aerobactin operons in the IncFIB plasmid were differentially expressed in iron-rich and iron-depleted growth media. Minimal sequence diversity was detected in the Sit and aerobactin operons in the IncFIB plasmids present among different bacterial species, including foodborne Salmonella strains. IncFIB plasmid encoded factors play a role during infection under low-iron conditions in host cells.

  1. Purification and Characterization of the Bacterial Flagellar Basal Body from Salmonella enterica.

    PubMed

    Aizawa, Shin-Ichi

    2017-01-01

    The bacterial flagellum is a motility organelle. The flagellum is composed of three main structures: the basal body as a rotary engine embedded in the cellular membranes and cell wall, the long external filament that acts as a propeller, and the hook acting as a universal joint that connects them. I describe protocols for the purification of the filament and hook-basal body from Salmonella enterica serovar Typhimurium.

  2. Epidemiology of a Salmonella enterica subsp. Enterica serovar Typhimurium strain associated with a songbird outbreak.

    USGS Publications Warehouse

    Blehert, David S.; Hernandez, Sonia M.; Keel, Kevin; Sanchez, Susan; Trees, Eija; ,

    2012-01-01

    Salmonella enterica subsp. enterica serovar Typhimurium is responsible for the majority of salmonellosis cases worldwide. This Salmonella serovar is also responsible for die-offs in songbird populations. In 2009, there was an S. Typhimurium epizootic reported in pine siskins in the eastern United States. At the time, there was also a human outbreak with this serovar that was associated with contaminated peanuts. As peanuts are also used in wild-bird food, it was hypothesized that the pine siskin epizootic was related to this human outbreak. A comparison of songbird and human S. Typhimurium pulsed-field gel electrophoresis (PFGE) patterns revealed that the epizootic was attributed not to the peanut-associated strain but, rather, to a songbird strain first characterized from an American goldfinch in 1998. This same S. Typhimurium strain (PFGE type A3) was also identified in the PulseNet USA database, accounting for 137 of 77,941 total S. Typhimurium PFGE entries. A second molecular typing method, multiple-locus variable-number tandem-repeat analysis (MLVA), confirmed that the same strain was responsible for the pine siskin epizootic in the eastern United States but was distinct from a genetically related strain isolated from pine siskins in Minnesota. The pine siskin A3 strain was first encountered in May 2008 in an American goldfinch and later in a northern cardinal at the start of the pine siskin epizootic. MLVA also confirmed the clonal nature of S. Typhimurium in songbirds and established that the pine siskin epizootic strain was unique to the finch family. For 2009, the distribution of PFGE type A3 in passerines and humans mirrored the highest population density of pine siskins for the East Coast.

  3. Dose-dependent effects on survival of Salmonella enterica serovar Typhimurium in house flies (Musca domestica L.)

    USDA-ARS?s Scientific Manuscript database

    Adult house flies ingest variable numbers of bacteria when they encounter microbe-rich substrates. Bacterial abundance may affect survival within the fly gut, which subsequently impacts vector potential. This study investigated the dose-dependent survival of GFP-expressing Salmonella enterica serova...

  4. Effects of Pseudomonas chlororaphis and gaseous chlorine dioxide on the survival of Salmonella enterica on tomatoes

    USDA-ARS?s Scientific Manuscript database

    Produce contamination incited by Salmonella enterica serovars on tomatoes and various outbreaks of Salmonellisis have been reported periodically. Post-harvest intervention measures applied to limit produce contamination will improve food and consumer safety. The aim of this reserach was to evaluat...

  5. Report: Prevalence and antibiotic trials against Salmonella enterica isolated from diarrheic lambs and kids.

    PubMed

    Iqbal, Muhammad Kashif; Ijaz, Muhammad; Aslam, Hassaan Bin; Farooqi, Shahid Hussain; Ahmad, Syed Saleem; Akhtar, Raheela

    2017-11-01

    Salmonella enterica (S. enterica) is the major zoonotic threat for small ruminants and humans responsible for huge economic losses and high mortality in Pakistan. Lambs and kids of Lahore district were examined to determine the prevalence, hematology and chemotherapy of S. enterica. A total of 200 diarrheic samples (n=100 lambs; n=100 kids) were collected and examined; 59 (29.50%) were found positive for S. enterica. Lambs had lightly greater prevalence (31%) than kids (29%). The frequency analysis (OR=1.16 [reciprocal =0.87]) showed non-significant difference in both the lambs and kids. The significant decrease (Pℜ0.001) in hemoglobin, pack cell volume and total erythrocyte count was observed in infected lambs and kids. Results of in-vitro antibiotic susceptibility test revealed that S. enteric isolated from both lambs and kids were susceptible to levofloxacin, ciprofloxacin, ofloxacin, gentamicin, azithromycin, tobramycin, amoxicillin, ampicillin and nalidixic acid. Where as the results of in vivo antibiotic trials showed that isolates from both lambs and the kids with diarrhea were susceptible to levofloxacin and ciprofloxacin.

  6. Outbreak-associated Salmonella enterica Serotypes and Food Commodities, United States, 1998–2008

    PubMed Central

    Griffin, Patricia M.; Cole, Dana; Walsh, Kelly A.; Chai, Shua J.

    2013-01-01

    Salmonella enterica infections are transmitted not only by animal-derived foods but also by vegetables, fruits, and other plant products. To clarify links between Salmonella serotypes and specific foods, we examined the diversity and predominance of food commodities implicated in outbreaks of salmonellosis during 1998–2008. More than 80% of outbreaks caused by serotypes Enteritidis, Heidelberg, and Hadar were attributed to eggs or poultry, whereas >50% of outbreaks caused by serotypes Javiana, Litchfield, Mbandaka, Muenchen, Poona, and Senftenberg were attributed to plant commodities. Serotypes Typhimurium and Newport were associated with a wide variety of food commodities. Knowledge about these associations can help guide outbreak investigations and control measures. PMID:23876503

  7. Genomic comparison of the closely-related Salmonella enterica serovars enteritidis, dublin and gallinarum

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Matthews, T. David; Schmieder, Robert; Silva, Genivaldo G. Z.

    The Salmonella enterica serovars Enteritidis, Dublin, and Gallinarum are closely related but differ in virulence and host range. To identify the genetic elements responsible for these differences and to better understand how these serovars are evolving, we sequenced the genomes of Enteritidis strain LK5 and Dublin strain SARB12 and compared these genomes to the publicly available Enteritidis P125109, Dublin CT 02021853 and Dublin SD3246 genome sequences. We also compared the publicly available Gallinarum genome sequences from biotype Gallinarum 287/91 and Pullorum RKS5078. Using bioinformatic approaches, we identified single nucleotide polymorphisms, insertions, deletions, and differences in prophage and pseudogene content betweenmore » strains belonging to the same serovar. Through our analysis we also identified several prophage cargo genes and pseudogenes that affect virulence and may contribute to a host-specific, systemic lifestyle. These results strongly argue that the Enteritidis, Dublin and Gallinarum serovars of Salmonella enterica evolve by acquiring new genes through horizontal gene transfer, followed by the formation of pseudogenes. As a result, the loss of genes necessary for a gastrointestinal lifestyle ultimately leads to a systemic lifestyle and niche exclusion in the host-specific serovars.« less

  8. Genomic comparison of the closely-related Salmonella enterica serovars enteritidis, dublin and gallinarum

    DOE PAGES

    Matthews, T. David; Schmieder, Robert; Silva, Genivaldo G. Z.; ...

    2015-06-03

    The Salmonella enterica serovars Enteritidis, Dublin, and Gallinarum are closely related but differ in virulence and host range. To identify the genetic elements responsible for these differences and to better understand how these serovars are evolving, we sequenced the genomes of Enteritidis strain LK5 and Dublin strain SARB12 and compared these genomes to the publicly available Enteritidis P125109, Dublin CT 02021853 and Dublin SD3246 genome sequences. We also compared the publicly available Gallinarum genome sequences from biotype Gallinarum 287/91 and Pullorum RKS5078. Using bioinformatic approaches, we identified single nucleotide polymorphisms, insertions, deletions, and differences in prophage and pseudogene content betweenmore » strains belonging to the same serovar. Through our analysis we also identified several prophage cargo genes and pseudogenes that affect virulence and may contribute to a host-specific, systemic lifestyle. These results strongly argue that the Enteritidis, Dublin and Gallinarum serovars of Salmonella enterica evolve by acquiring new genes through horizontal gene transfer, followed by the formation of pseudogenes. As a result, the loss of genes necessary for a gastrointestinal lifestyle ultimately leads to a systemic lifestyle and niche exclusion in the host-specific serovars.« less

  9. Genomic Comparison of the Closely-Related Salmonella enterica Serovars Enteritidis, Dublin and Gallinarum

    PubMed Central

    Matthews, T. David; Schmieder, Robert; Silva, Genivaldo G. Z.; Busch, Julia; Cassman, Noriko; Dutilh, Bas E.; Green, Dawn; Matlock, Brian; Heffernan, Brian; Olsen, Gary J.; Farris Hanna, Leigh; Schifferli, Dieter M.; Maloy, Stanley; Dinsdale, Elizabeth A.; Edwards, Robert A.

    2015-01-01

    The Salmonella enterica serovars Enteritidis, Dublin, and Gallinarum are closely related but differ in virulence and host range. To identify the genetic elements responsible for these differences and to better understand how these serovars are evolving, we sequenced the genomes of Enteritidis strain LK5 and Dublin strain SARB12 and compared these genomes to the publicly available Enteritidis P125109, Dublin CT 02021853 and Dublin SD3246 genome sequences. We also compared the publicly available Gallinarum genome sequences from biotype Gallinarum 287/91 and Pullorum RKS5078. Using bioinformatic approaches, we identified single nucleotide polymorphisms, insertions, deletions, and differences in prophage and pseudogene content between strains belonging to the same serovar. Through our analysis we also identified several prophage cargo genes and pseudogenes that affect virulence and may contribute to a host-specific, systemic lifestyle. These results strongly argue that the Enteritidis, Dublin and Gallinarum serovars of Salmonella enterica evolve by acquiring new genes through horizontal gene transfer, followed by the formation of pseudogenes. The loss of genes necessary for a gastrointestinal lifestyle ultimately leads to a systemic lifestyle and niche exclusion in the host-specific serovars. PMID:26039056

  10. A rapid method to identify Salmonella enterica serovar Gallinarum biovar Pullorum using a specific target gene ipaJ.

    PubMed

    Xu, Lijuan; Liu, Zijian; Li, Yang; Yin, Chao; Hu, Yachen; Xie, Xiaolei; Li, Qiuchun; Jiao, Xinan

    2018-06-01

    Salmonella enterica serovar Gallinarum biovar Pullorum (S. Pullorum) is the pathogen of pullorum disease, which leads to severe economic losses in many developing countries. Traditional methods to identify S. enterica have relied on biochemical reactions and serotyping, which are time-consuming with accurate identification if properly carried out. In this study, we developed a rapid polymerase chain reaction (PCR) method targeting the specific gene ipaJ to detect S. Pullorum. Among the 650 S. Pullorum strains isolated from 1962 to 2016 all over China, 644 strains were identified to harbour ipaJ gene in the plasmid pSPI12, accounting for a detection rate of 99.08%. Six strains were ipaJ negative because pSPI12 was not found in these strains according to whole genome sequencing results. There was no cross-reaction with other Salmonella serotypes, including Salmonella enterica serovar Gallinarum biovar Gallinarum (S. Gallinarum), which show a close genetic relationship with S. Pullorum. This shows that the PCR method could distinguish S. Gallinarum from S. Pullorum in one-step PCR without complicated biochemical identification. The limit of detection of this PCR method was as low as 90 fg/μl or 10 2 CFU, which shows a high sensitivity. Moreover, this method was applied to identify Salmonella isolated from the chicken farm and the results were consistent with what we obtained from biochemical reactions and serotyping. Together, all the results demonstrated that this one-step PCR method is simple and feasible to efficiently identify S. Pullorum.

  11. Development and Evaluation of a Multiplex Real-Time Polymerase Chain Reaction Procedure to Clinically Type Prevalent Salmonella enterica Serovars

    PubMed Central

    Muñoz, Nélida; Diaz-Osorio, Miguel; Moreno, Jaime; Sánchez-Jiménez, Miryan; Cardona-Castro, Nora

    2010-01-01

    A multiplex real-time polymerase chain reaction procedure was developed to identify the most prevalent clinical isolates of Salmonella enterica subsp. enterica. Genes from the rfb, fliC, fljB, and viaB groups that encode the O, H, and Vi antigens were used to design 15 primer pairs and TaqMan probes specific for the genes rfbJ, wzx, fliC, fljB, wcdB, the sdf-l sequence, and invA, which was used as an internal amplification control. The primers and probes were variously combined into six sets. The first round of reactions used two of these sets to detect Salmonella O:4, O:9, O:7, O:8, and O:3,10 serogroups. Once the serogroups were identified, the results of a second round of reactions that used primers and probes for the flagellar antigen l genes, 1,2; e,h; g,m; d; e,n,x; and z10, and the Vi gene were used to identify individual serovars. The procedure was standardized using 18 Salmonella reference strains and other enterobacteria. The procedure's reliability and sensitivity was evaluated using 267 randomly chosen serotyped Salmonella clinical isolates. The procedure had a sensitivity of 95.5% and was 100% specific. Thus, our technique is a quick, sensitive, reliable, and specific means of identifying S. enterica serovars and can be used in conjunction with traditional serotyping. Other primer and probe combinations could be used to increase the number of identifiable serovars. PMID:20110454

  12. SALMONELLA ENTERICA SEROVAR ENTERITIDIS INFECTION MODULATES DIVERSE FUNCTIONAL PROCESSES OF CHICKEN MACROPHAGE AT THE TRANSCRIPTIONAL LEVEL

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serovar Enteritidis (SE) is a major etiologic agent of non-typhoid salmonellosis. The organisms colonize adult chicken hosts without causing overt clinical signs. The immunological mechanisms underlying the silent and persistent infection of chickens by SE are not clearly underst...

  13. Phenotyping and genetic characterization of Salmonella enterica isolates from Turkey revealing arise of different features specific to geography.

    PubMed

    Acar, Sinem; Bulut, Ece; Durul, Bora; Uner, Ilhan; Kur, Mehmet; Avsaroglu, M Dilek; Kirmaci, Hüseyin Avni; Tel, Yasar Osman; Zeyrek, Fadile Y; Soyer, Yesim

    2017-01-16

    192 Food samples (commonly consumed 8 food types), 355 animal samples (animal feces of bovine, ovine, goat and chicken) and 50 samples from clinical human cases in Sanliurfa city, Turkey in a year were collected to determine the Salmonella enterica subsp. enterica mosaic in Turkey. 161 Salmonella isolates represented 17 serotypes, 20 sequence types (STs) and 44 PFGE patterns (PTs). 3 serotypes, S. Enteritidis, S. Typhimurium and S. Kentucky, were recovered from three different hosts. The highest discriminatory power was obtained by PFGE (SID=0.945), followed by MLST (SID=0.902) and serotyping (SID=0.885) for all isolates. The prevalence of antimicrobial resistance genes (aadA1, aadA2, strA, strB, aphA 1-Iab , bla TEM-1 , bla PSE-1 , tetA) was highly correlated with phenotypic profiles of aminoglycoside, ß-lactam and tetracycline groups (kappa >0.85). From our knowledge, this is the first study reporting spatial and temporal distribution of Salmonella species through phenotypic and genetic approaches over farm to fork chain in Turkey. Thus, our data provided further information for evolution, ecology and transmission of Salmonella in Turkey. Copyright © 2016. Published by Elsevier B.V.

  14. Identification of Transcriptional Modules and Key Genes in Chickens Infected with Salmonella enterica Serovar Pullorum Using Integrated Coexpression Analyses.

    PubMed

    Liu, Bao-Hong; Cai, Jian-Ping

    2017-01-01

    Salmonella enterica Pullorum is one of the leading causes of mortality in poultry. Understanding the molecular response in chickens in response to the infection by S. enterica is important in revealing the mechanisms of pathogenesis and disease progress. There have been studies on identifying genes associated with Salmonella infection by differential expression analysis, but the relationships among regulated genes have not been investigated. In this study, we employed weighted gene coexpression network analysis (WGCNA) and differential coexpression analysis (DCEA) to identify coexpression modules by exploring microarray data derived from chicken splenic tissues in response to the S. enterica infection. A total of 19 modules from 13,538 genes were associated with the Jak-STAT signaling pathway, the extracellular matrix, cytoskeleton organization, the regulation of the actin cytoskeleton, G-protein coupled receptor activity, Toll-like receptor signaling pathways, and immune system processes; among them, 14 differentially coexpressed modules (DCMs) and 2,856 differentially coexpressed genes (DCGs) were identified. The global expression of module genes between infected and uninfected chickens showed slight differences but considerable changes for global coexpression. Furthermore, DCGs were consistently linked to the hubs of the modules. These results will help prioritize candidate genes for future studies of Salmonella infection.

  15. Identification of Transcriptional Modules and Key Genes in Chickens Infected with Salmonella enterica Serovar Pullorum Using Integrated Coexpression Analyses

    PubMed Central

    2017-01-01

    Salmonella enterica Pullorum is one of the leading causes of mortality in poultry. Understanding the molecular response in chickens in response to the infection by S. enterica is important in revealing the mechanisms of pathogenesis and disease progress. There have been studies on identifying genes associated with Salmonella infection by differential expression analysis, but the relationships among regulated genes have not been investigated. In this study, we employed weighted gene coexpression network analysis (WGCNA) and differential coexpression analysis (DCEA) to identify coexpression modules by exploring microarray data derived from chicken splenic tissues in response to the S. enterica infection. A total of 19 modules from 13,538 genes were associated with the Jak-STAT signaling pathway, the extracellular matrix, cytoskeleton organization, the regulation of the actin cytoskeleton, G-protein coupled receptor activity, Toll-like receptor signaling pathways, and immune system processes; among them, 14 differentially coexpressed modules (DCMs) and 2,856 differentially coexpressed genes (DCGs) were identified. The global expression of module genes between infected and uninfected chickens showed slight differences but considerable changes for global coexpression. Furthermore, DCGs were consistently linked to the hubs of the modules. These results will help prioritize candidate genes for future studies of Salmonella infection. PMID:28529955

  16. Susceptibility of Salmonella enterica Isolates from Tomato Farm Environments to Fatty Acids Naturally Found on Tomato Fruit.

    PubMed

    Dev Kumar, Govindaraj; Micallef, Shirley A

    2017-05-01

    Salmonella enterica subsp. enterica can colonize tomato fruit as it interacts with fruit surface compounds. The exometabolome of tomato fruit contains a mixture of compounds, including fatty acids, which could affect Salmonella fitness. Fatty acids detected in fruit exudates were investigated for Salmonella inhibition. Pelargonic, lauric, myristic, palmitic, margaric, stearic, and oleic acids were suspended in water dissolved in dimethyl sulfoxide (DMSO) or emulsified in water and quillaja saponin to assess how bioavailability impacted Salmonella growth. The minimum inhibitory concentrations of fatty acids were determined using a resazurin assay. Quillaja saponin emulsion and DMSO solution of pelargonic acid were inhibitory to Salmonella at 31.25 mM. Lauric and myristic acid emulsions inhibited growth at 1 M concentrations in quillaja emulsions and 62.5 mM in DMSO. Lauric and myristic acids significantly affected growth of Salmonella Newport, Javiana, and Typhimurium (p ≤ 0.05). Growth curve analysis using the Baranyi model revealed reduced maxima populations for all treatments (p ≤ 0.001) and shorter lag phase durations for Salmonella Newport with lauric acid (p < 0.01) and Salmonella Javiana with lauric (p < 0.001) and myristic (p < 0.001) acids. Salmonella Newport and Javiana exhibited an accelerated growth rate with lauric acid (p < 0.001) as a result of early stationary phase transition (shorter log phase). In myristic acid-amended media, Salmonella Javiana also displayed a faster growth rate (p < 0.001). Pelargonic acid (31.25 mM) treatment of Salmonella cells resulted in a drop in culturable cells to below detection in an hour. Microscopic analysis with Cyto-dye and propidium iodide of bacterial cells treated with pelargonic acid indicated a mixture of live and dead cells, with cell lysis of some cells. A subset of cells exhibited elongation-possibly indicating filament formation, a known antibiotic stress response

  17. Horizontal gene transfer of a ColV plasmid has resulted in a dominant avian clonal type of Salmonella enterica serovar Kentucky.

    PubMed

    Johnson, Timothy J; Thorsness, Jessica L; Anderson, Cole P; Lynne, Aaron M; Foley, Steven L; Han, Jing; Fricke, W Florian; McDermott, Patrick F; White, David G; Khatri, Mahesh; Stell, Adam L; Flores, Cristian; Singer, Randall S

    2010-12-22

    Salmonella enterica continues to be a significant cause of foodborne gastrointestinal illness in humans. A wide variety of Salmonella serovars have been isolated from production birds and from retail poultry meat. Recently, though, S. enterica subsp. enterica serovar Kentucky has emerged as one of the prominent Salmonella serovars isolated from broiler chickens. Recent work suggests that its emergence apparently coincides with its acquisition of a ColV virulence plasmid. In the present study, we examined 902 Salmonella isolates belonging to 59 different serovars for the presence of this plasmid. Of the serovars examined, the ColV plasmid was found only among isolates belonging to the serovars Kentucky (72.9%), Typhimurium (15.0%) and Heidelberg (1.7%). We demonstrated that a single PFGE clonal type of S. Kentucky harbors this plasmid, and acquisition of this plasmid by S. Kentucky significantly increased its ability to colonize the chicken cecum and cause extraintestinal disease. Comparison of the completed sequences of three ColV plasmids from S. Kentucky isolated from different geographical locales, timepoints and sources revealed a nearly identical genetic structure with few single nucleotide changes or insertions/deletions. Overall, it appears that the ColV plasmid was recently acquired by a single clonal type S. Kentucky and confers to its host enhanced colonization and fitness capabilities. Thus, the potential for horizontal gene transfer of virulence and fitness factors to Salmonella from other enteric bacteria exists in poultry, representing a potential human health hazard.

  18. Horizontal Gene Transfer of a ColV Plasmid Has Resulted in a Dominant Avian Clonal Type of Salmonella enterica Serovar Kentucky

    PubMed Central

    Johnson, Timothy J.; Thorsness, Jessica L.; Anderson, Cole P.; Lynne, Aaron M.; Foley, Steven L.; Han, Jing; Fricke, W. Florian; McDermott, Patrick F.; White, David G.; Khatri, Mahesh; Stell, Adam L.; Flores, Cristian; Singer, Randall S.

    2010-01-01

    Salmonella enterica continues to be a significant cause of foodborne gastrointestinal illness in humans. A wide variety of Salmonella serovars have been isolated from production birds and from retail poultry meat. Recently, though, S. enterica subsp. enterica serovar Kentucky has emerged as one of the prominent Salmonella serovars isolated from broiler chickens. Recent work suggests that its emergence apparently coincides with its acquisition of a ColV virulence plasmid. In the present study, we examined 902 Salmonella isolates belonging to 59 different serovars for the presence of this plasmid. Of the serovars examined, the ColV plasmid was found only among isolates belonging to the serovars Kentucky (72.9%), Typhimurium (15.0%) and Heidelberg (1.7%). We demonstrated that a single PFGE clonal type of S. Kentucky harbors this plasmid, and acquisition of this plasmid by S. Kentucky significantly increased its ability to colonize the chicken cecum and cause extraintestinal disease. Comparison of the completed sequences of three ColV plasmids from S. Kentucky isolated from different geographical locales, timepoints and sources revealed a nearly identical genetic structure with few single nucleotide changes or insertions/deletions. Overall, it appears that the ColV plasmid was recently acquired by a single clonal type S. Kentucky and confers to its host enhanced colonization and fitness capabilities. Thus, the potential for horizontal gene transfer of virulence and fitness factors to Salmonella from other enteric bacteria exists in poultry, representing a potential human health hazard. PMID:21203520

  19. Prevalence of ColE1-like plasmids and kanamycin resistance genes in Salmonella enterica serovars.

    PubMed

    Chen, Chin-Yi; Lindsey, Rebecca L; Strobaugh, Terence P; Frye, Jonathan G; Meinersmann, Richard J

    2010-10-01

    Multi-antimicrobial-resistant Salmonella enterica strains frequently carry resistance genes on plasmids. Recent studies focus heavily on large conjugative plasmids, and the role that small plasmids play in resistance gene transfer is largely unknown. To expand our previous studies in assessing the prevalence of the isolates harboring ColE1-like plasmids carrying the aph gene responsible for kanamycin resistance (Kan(r)) phenotypes, 102 Kan(r) Salmonella isolates collected through the National Antimicrobial Resistance Monitoring System (NARMS) in 2005 were screened by PCR using ColE1 primer sets. Thirty isolates were found to be positive for ColE1-like replicon. Plasmids from 23 isolates were able to propagate in Escherichia coli and were subjected to further characterization. Restriction mapping revealed three major plasmid groups found in three or more isolates, with each group consisting of two to three subtypes. The aph genes from the Kan(r) Salmonella isolates were amplified by PCR, sequenced, and showed four different aph(3')-I genes. The distribution of the ColE1 plasmid groups in association with the aph gene, Salmonella serovar, and isolate source demonstrated a strong linkage of the plasmid with S. enterica serovar Typhimurium DT104. Due to their high copy number and mobility, the ColE1-like plasmids may play a critical role in transmission of antibiotic resistance genes among enteric pathogens, and these findings warrant a close monitoring of this plasmid incompatibility group.

  20. Intermediate Susceptibility to Ciprofloxacin among Salmonella enterica Serovar Typhi Isolates in Lima, Peru

    PubMed Central

    Lejon, Veerle; Horna, Gertrudis; Astocondor, Lizeth; Vanhoof, Raymond; Bertrand, Sophie; Jacobs, Jan

    2014-01-01

    Thirty-three Salmonella enterica serovar Typhi blood isolates from Lima, Peru (2008 to 2012), were fully susceptible to trimethoprim-sulfamethoxazole, chloramphenicol, ceftriaxone, and tetracycline; 8/33 (24.2%) showed intermediate susceptibility to ciprofloxacin carrying mutations in the quinolone resistance-determining region of the gyrA gene (Ser83-Phe and Asp87-Asn) and in the gyrB gene (Ser464-Phe). PMID:24371234

  1. Effect of selective growth media on the differentiation of Salmonella enterica serovars by Fourier-Transform Mid-Infrared Spectroscopy.

    PubMed

    Baldauf, Nathan A; Rodriguez-Romo, Luis A; Männig, Annegret; Yousef, Ahmed E; Rodriguez-Saona, Luis E

    2007-01-01

    Salmonella enterica serovars are prevalent foodborne pathogens responsible for high numbers of salmonellosis each year. Complex Fourier-transform infrared (FTIR) spectra offer unique biochemical fingerprints of bacteria with bands due to major cellular components. Growth media effects on discrimination of Salmonella serovars by FTIR spectroscopy were investigated and a novel sample preparation technique was developed. S. enterica strains from six serovars were grown on xylose lysine desoxycholate (XLD), Miller-Mallinson (MM), and plate count (PCA) agar as a control (37 degrees C, 24 h). Isolated colonies were suspended in 50% acetonitrile and centrifuged; the remaining pellet was placed on an AMTIR (attenuated total reflectance) crystal and dried under vacuum. Classification models (Soft Independent Modeling of Class Analogy, SIMCA), generated from derivatized infrared spectra (1300-900 cm-1 or 1200-900 cm-1), successfully discriminated among Salmonella strains with major discrimination from 1000-970 cm-1 associated to stretching modes of O-specific polysaccharide chains of lipopolysaccharides. Sample treatment with acetonitrile enhanced safe handling of the bacteria, removed interfering signals and improved the discriminating ability of SIMCA. All media were able to discriminate the S. enterica strains studied, varying in discriminating peaks and class distances in SIMCA classification. This methodology, with the production of large libraries of pathogenic bacteria, could be applied for the rapid monitoring of bacterial contamination in food with minimal sample manipulation.

  2. Chromosomal Rearrangements in Salmonella enterica Serotype Typhi Affecting Molecular Typing in Outbreak Investigations

    PubMed Central

    Echeita, M. A.; Usera, M. A.

    1998-01-01

    Salmonella enterica serotype Typhi strains belonging to eight different outbreaks of typhoid fever that occurred in Spain between 1989 and 1994 were analyzed by ribotyping and pulsed-field gel electrophoresis. For three outbreaks, two different patterns were detected for each outbreak. The partial digestion analysis by the intron-encoded endonuclease I-CeuI of the two different strains from each outbreak provided an excellent tool for examining the organization of the genomes of epidemiologically related strains. S. enterica serotype Typhi seems to be more susceptible than other serotypes to genetic rearrangements produced by homologous recombinations between rrn operons; these rearrangements do not substantially alter the stability or survival of the bacterium. We conclude that genetic rearrangements can occur during the emergence of an outbreak. PMID:9650981

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

    PubMed

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

    2011-03-01

    This report presents SMM-system, a software package that implements various personalized pre- and post-BLASTN tasks for mining specific markers of microbial pathogens. The main functionalities of SMM-system are summarized as follows: (i) converting multi-FASTA file, (ii) cutting interesting genomic sequence, (iii) automatic high-throughput BLASTN searches, and (iv) screening target sequences. The utility of SMM-system was demonstrated by using it to identify 214 Salmonella enterica-specific protein-coding sequences (CDSs). Eighteen primer pairs were designed based on eighteen S. enterica-specific CDSs, respectively. Seven of these primer pairs were validated with PCR assay, which showed 100% inclusivity for the 101 S. enterica genomes and 100% exclusivity of 30 non-S. enterica genomes. Three specific primer pairs were chosen to develop a multiplex PCR assay, which generated specific amplicons with a size of 180bp (SC1286), 238bp (SC1598) and 405bp (SC4361), respectively. This study demonstrates that SMM-system is a high-throughput specific marker generation tool that can be used to identify genus-, species-, serogroup- and even serovar-specific DNA sequences of microbial pathogens, which has a potential to be applied in food industries, diagnostics and taxonomic studies. SMM-system is freely available and can be downloaded from http://foodsafety.sjtu.edu.cn/SMM-system.html. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. De novo amino acid biosynthesis contributes to salmonella enterica growth in Alfalfa seedling exudates.

    PubMed

    Kwan, Grace; Pisithkul, Tippapha; Amador-Noguez, Daniel; Barak, Jeri

    2015-02-01

    Salmonella enterica is a member of the plant microbiome. Growth of S. enterica in sprouting-seed exudates is rapid; however, the active metabolic networks essential in this environment are unknown. To examine the metabolic requirements of S. enterica during growth in sprouting-seed exudates, we inoculated alfalfa seeds and identified 305 S. enterica proteins extracted 24 h postinoculation from planktonic cells. Over half the proteins had known metabolic functions, and they are involved in over one-quarter of the known metabolic reactions. Ion and metabolite transport accounted for the majority of detected reactions. Proteins involved in amino acid transport and metabolism were highly represented, suggesting that amino acid metabolic networks may be important for S. enterica growth in association with roots. Amino acid auxotroph growth phenotypes agreed with the proteomic data; auxotrophs in amino acid-biosynthetic pathways that were detected in our screen developed growth defects by 48 h. When the perceived sufficiency of each amino acid was expressed as a ratio of the calculated biomass requirement to the available concentration and compared to growth of each amino acid auxotroph, a correlation between nutrient availability and bacterial growth was found. Furthermore, glutamate transport acted as a fitness factor during S. enterica growth in association with roots. Collectively, these data suggest that S. enterica metabolism is robust in the germinating-alfalfa environment; that single-amino-acid metabolic pathways are important but not essential; and that targeting central metabolic networks, rather than dedicated pathways, may be necessary to achieve dramatic impacts on bacterial growth. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. Isolation of Salmonella enterica serovar Enteritidis from houseflies (Musca domestica) found in rooms containing Salmonella serovar Enteritidis-challenged hens.

    PubMed

    Holt, Peter S; Geden, Christopher J; Moore, Randle W; Gast, Richard K

    2007-10-01

    Houseflies (Musca domestica) released into rooms containing hens challenged with Salmonella enterica serovar Enteritidis (Salmonella serovar Enteritidis) rapidly became contaminated with Salmonella serovar Enteritidis. Forty to 50% of the flies were contaminated at 48 h, and the percentage increased to 50 to 70% at 4 and 7 days postexposure and then decreased to 30% at day 15. Initial attempts at recovering surface organisms for culture using an aqueous rinse were largely unsuccessful, while cultures of internal contents readily recovered Salmonella serovar Enteritidis. However, when 0.5% detergent was incorporated into the rinse, high recovery levels of bacteria were observed from both external and internal culture regimens, indicating equal distribution of the organism on and in the fly and a tighter interaction of the organism with the host than previously thought. Salmonella serovar Enteritidis was isolated routinely from the fly gut, on rare occasions from the crop, and never from the salivary gland. Feeding contaminated flies to hens resulted in gut colonization of a third of the birds, but release of contaminated flies in a room containing previously unchallenged hens failed to result in colonization of any of the subject birds. These results indicate that flies exposed to an environment containing Salmonella serovar Enteritidis can become colonized with the organism and might serve as a source for transmission of Salmonella serovar Enteritidis within a flock situation.

  6. Isolation of Salmonella enterica Serovar Enteritidis from Houseflies (Musca domestica) Found in Rooms Containing Salmonella Serovar Enteritidis-Challenged Hens▿

    PubMed Central

    Holt, Peter S.; Geden, Christopher J.; Moore, Randle W.; Gast, Richard K.

    2007-01-01

    Houseflies (Musca domestica) released into rooms containing hens challenged with Salmonella enterica serovar Enteritidis (Salmonella serovar Enteritidis) rapidly became contaminated with Salmonella serovar Enteritidis. Forty to 50% of the flies were contaminated at 48 h, and the percentage increased to 50 to 70% at 4 and 7 days postexposure and then decreased to 30% at day 15. Initial attempts at recovering surface organisms for culture using an aqueous rinse were largely unsuccessful, while cultures of internal contents readily recovered Salmonella serovar Enteritidis. However, when 0.5% detergent was incorporated into the rinse, high recovery levels of bacteria were observed from both external and internal culture regimens, indicating equal distribution of the organism on and in the fly and a tighter interaction of the organism with the host than previously thought. Salmonella serovar Enteritidis was isolated routinely from the fly gut, on rare occasions from the crop, and never from the salivary gland. Feeding contaminated flies to hens resulted in gut colonization of a third of the birds, but release of contaminated flies in a room containing previously unchallenged hens failed to result in colonization of any of the subject birds. These results indicate that flies exposed to an environment containing Salmonella serovar Enteritidis can become colonized with the organism and might serve as a source for transmission of Salmonella serovar Enteritidis within a flock situation. PMID:17675422

  7. Higher Storage Temperature Causes Greater Salmonella enterica Serovar Typhimurium Internal Penetration of Artificially Contaminated, Commercially Available, Washed Free Range Eggs.

    PubMed

    Whiley, Alice; Fallowfield, Howard; Ross, Kirstin; McEvoy, Vanessa; Whiley, Harriet

    2016-07-01

    Foodborne salmonellosis is a major public health concern, with contaminated eggs identified as a significant source of infection. In Australia, the most prevalent cause of salmonellosis from eggs is Salmonella enterica subsp. enterica serovar Typhimurium. This study explored the effect of temperature after 1, 7, 14, 21, and 28 days of storage on commercially available washed free range eggs, artificially contaminated with Salmonella Typhimurium on the external surface. At each time point, the external surface of the egg, the crushed eggshell, and the internal egg yolk and albumen were analyzed for Salmonella. After 28 days of storage, 25% of eggs stored at 4°C, 50% of eggs stored at 14°C, and 100% of eggs stored at 23 and 35°C were internally contaminated with Salmonella. After 1 day of storage, more than 50% of all eggs had Salmonella present in the crushed shell after the external surface had been disinfected with ethanol. This is the first study to demonstrate that refrigeration reduced the potential for Salmonella Typhimurium to penetrate the eggshell membrane and internally contaminate table eggs commercially available in Australia. It also suggests that the processes of cracking eggs may be a source of cross-contamination within the kitchen.

  8. Transcriptional profile of Salmonella enterica subsp. enterica serovar Weltevreden during alfalfa sprout colonization.

    PubMed

    Brankatschk, Kerstin; Kamber, Tim; Pothier, Joël F; Duffy, Brion; Smits, Theo H M

    2014-11-01

    Sprouted seeds represent a great risk for infection by human enteric pathogens because of favourable growth conditions for pathogens during their germination. The aim of this study was to identify mechanisms of interactions of Salmonella enterica subsp. enterica Weltevreden with alfalfa sprouts. RNA-seq analysis of S. Weltevreden grown with sprouts in comparison with M9-glucose medium showed that among a total of 4158 annotated coding sequences, 177 genes (4.3%) and 345 genes (8.3%) were transcribed at higher levels with sprouts and in minimal medium respectively. Genes that were higher transcribed with sprouts are coding for proteins involved in mechanisms known to be important for attachment, motility and biofilm formation. Besides gene expression required for phenotypic adaption, genes involved in sulphate acquisition were higher transcribed, suggesting that the surface on alfalfa sprouts may be poor in sulphate. Genes encoding structural and effector proteins of Salmonella pathogenicity island 2, involved in survival within macrophages during infection of animal tissue, were higher transcribed with sprouts possibly as a response to environmental conditions. This study provides insight on additional mechanisms that may be important for pathogen interactions with sprouts. © 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  9. Interpretations of antibody responses to Salmonella enterica serotype enteritidis gm flagellin in poultry flocks are enhanced by a kinetics-based enzyme-linked immunosorbent assay.

    PubMed

    McDonough, P L; Jacobson, R H; Timoney, J F; Mutalib, A; Kradel, D C; Chang, Y F; Shin, S J; Lein, D H; Trock, S; Wheeler, K

    1998-07-01

    Many regulatory and diagnostic programs for the detection of Salmonella enterica serotype Enteritidis infection in commercial poultry flocks have relied on rapid Pullorum agglutination tests to screen birds because of the shared antigens of S. enterica Enteritidis and S. enterica Pullorum and Gallinarum; however, the use of the enzyme-linked immunosorbent assay (ELISA) format affords better analytical sensitivity than crude agglutination tests. In this study, we adapted our earlier conventional indirect ELISA, using gm flagellin as the antigen, to a kinetics-based, computer-controlled ELISA (KELA). The KELA was used to screen for flagellin antibody from three commercial flocks: (i) a large flock involved in a U.S. Department of Agriculture trace back from a human S. enterica Enteritidis foodborne outbreak (n = 3,209), (ii) a flock infected with the endemic S. enterica Enteritidis serotype but which also had multiple other Salmonella serotypes (n = 65), and (iii) an S. enterica Pullorum-infected flock (n = 12). The first flock (S. enterica Enteritidis prevalence of 2.45% based on culture) provided a field test of the KELA and allowed the calculation of diagnostic sensitivity (D-Sn) and diagnostic specificity (D-Sp). With a cutoff of 10 (used for screening flocks [i.e., high sensitivity]), the KELA has a D-Sn of 95.2% and a D-Sp of 18.5%; with a cutoff of 140 (used in confirmatory flock testing [i.e., high specificity]), the KELA has a D-Sn of 28.0% and a D-Sp of 99.1%. We found that with a cutoff of 60 (D-Sn = 63.1%; D-Sp = 91.6%), we could eliminate reactions in the KELA caused by other non-S. enterica Enteritidis salmonellae. The KELA was also compared to two commercial rapid Pullorum tests, the Solvay (D-Sn = 94.9%; D-Sp = 55.5%) and the Vineland (D-Sn = 62.0%; D-Sp = 75.3%).

  10. Salmonella enterica suppresses Pectobacterium carotovorum subsp. carotovorum population and soft rot progression by acidifying the microaerophilic environment.

    PubMed

    Kwan, Grace; Charkowski, Amy O; Barak, Jeri D

    2013-02-12

    Although enteric human pathogens are usually studied in the context of their animal hosts, a significant portion of their life cycle occurs on plants. Plant disease alters the phyllosphere, leading to enhanced growth of human pathogens; however, the impact of human pathogens on phytopathogen biology and plant health is largely unknown. To characterize the interaction between human pathogens and phytobacterial pathogens in the phyllosphere, we examined the interactions between Pectobacterium carotovorum subsp. carotovorum and Salmonella enterica or Escherichia coli O157:H7 with regard to bacterial populations, soft rot progression, and changes in local pH. The presence of P. carotovorum subsp. carotovorum enhanced the growth of both S. enterica and E. coli O157:H7 on leaves. However, in a microaerophilic environment, S. enterica reduced P. carotovorum subsp. carotovorum populations and soft rot progression by moderating local environmental pH. Reduced soft rot was not due to S. enterica proteolytic activity. Limitations on P. carotovorum subsp. carotovorum growth, disease progression, and pH elevation were not observed on leaves coinoculated with E. coli O157:H7 or when leaves were coinoculated with S. enterica in an aerobic environment. S. enterica also severely undermined the relationship between the phytobacterial population and disease progression of a P. carotovorum subsp. carotovorum budB mutant defective in the 2,3-butanediol pathway for acid neutralization. Our results show that S. enterica and E. coli O157:H7 interact differently with the enteric phytobacterial pathogen P. carotovorum subsp. carotovorum. S. enterica inhibition of soft rot progression may conceal a rapidly growing human pathogen population. Whereas soft rotted produce can alert consumers to the possibility of food-borne pathogens, healthy-looking produce may entice consumption of contaminated vegetables. Salmonella enterica and Escherichia coli O157:H7 may use plants to move between animal

  11. Investigation of an outbreak of Salmonella enterica serovar Newport infection.

    PubMed

    Irvine, W N; Gillespie, I A; Smyth, F B; Rooney, P J; McClenaghan, A; Devine, M J; Tohani, V K

    2009-10-01

    A large outbreak of Salmonella enterica serotype Newport infection occurred in Northern Ireland during September and October 2004. Typing of isolates from patients confirmed that this strain was indistinguishable from that in concurrent outbreaks in regions of England, in Scotland and in the Isle of Man. A total of 130 cases were distributed unequally across local government district areas in Northern Ireland. The epidemic curve suggested a continued exposure over about 4 weeks. A matched case-control study of 23 cases and 39 controls found a statistically significant association with a history of having eaten lettuce in a meal outside the home and being a case (odds ratio 23.7, 95% confidence interval 1.4-404.3). This exposure was reported by 57% of cases. Although over 300 food samples were tested, none yielded any Salmonella spp. Complexity and limited traceability in salad vegetable distribution hindered further investigation of the ultimate source of the outbreak.

  12. Invasive Salmonella enterica Serotype Typhimurium Infections, Democratic Republic of the Congo, 2007–2011

    PubMed Central

    Ley, Benedikt; Le Hello, Simon; Lunguya, Octavie; Lejon, Veerle; Muyembe, Jean-Jacques; Jacobs, Jan

    2014-01-01

    Infection with Salmonella enterica serotype Typhimurium sequence type (ST) 313 is associated with high rates of drug resistance, bloodstream infections, and death. To determine whether ST313 is dominant in the Democratic Republic of the Congo, we studied 180 isolates collected during 2007–2011; 96% belonged to CRISPOL type CT28, which is associated with ST313. PMID:24655438

  13. Aggregation via the Red, Dry, and Rough Morphotype Is Not a Virulence Adaptation in Salmonella enterica Serovar Typhimurium▿

    PubMed Central

    White, A. P.; Gibson, D. L.; Grassl, G. A.; Kay, W. W.; Finlay, B. B.; Vallance, B. A.; Surette, M. G.

    2008-01-01

    The Salmonella rdar (red, dry, and rough) morphotype is an aggregative and resistant physiology that has been linked to survival in nutrient-limited environments. Growth of Salmonella enterica serovar Typhimurium was analyzed in a variety of nutrient-limiting conditions to determine whether aggregation would occur at low cell densities and whether the rdar morphotype was involved in this process. The resulting cultures consisted of two populations of cells, aggregated and nonaggregated, with the aggregated cells preferentially displaying rdar morphotype gene expression. The two groups of cells could be separated based on the principle that aggregated cells were producing greater amounts of thin aggregative fimbriae (Tafi or curli). In addition, the aggregated cells retained some physiological characteristics of the rdar morphotype, such as increased resistance to sodium hypochlorite. Competitive infection experiments in mice showed that nonaggregative ΔagfA cells outcompeted rdar-positive wild-type cells in all tissues analyzed, indicating that aggregation via the rdar morphotype was not a virulence adaptation in Salmonella enterica serovar Typhimurium. Furthermore, in vivo imaging experiments showed that Tafi genes were not expressed during infection but were expressed once Salmonella was passed out of the mice into the feces. We hypothesize that the primary role of the rdar morphotype is to enhance Salmonella survival outside the host, thereby aiding in transmission. PMID:18195033

  14. Hemorrhagic colitis associated with Salmonella enterica serotype Infantis infection in a captive western lowland gorilla (Gorilla gorilla gorilla) in Brazil.

    PubMed

    Paixão, Tatiane A; Malta, Marcelo C C; Soave, Semíramis A; Tinoco, Herlandes P; Costa, Maria E L T; Pessanha, Angela T; Silva, Rodrigo O S; Coura, Fernanda M; Costa, Luciana F; Turchetti, Andreia P; Lobato, Francisco C F; Melo, Marilia M; Heinemann, Marcos B; Santos, Renato L

    2014-04-01

    Enteric diseases are among the most common causes of morbidity and mortality in gorillas, and it is often caused by bacteria. A thirteen-year-old captive female western lowland gorilla (Gorilla gorilla gorilla) developed hemorrhagic diarrhea. Despite the treatment, the animal died 7 days after the onset of clinical signs. The animal was submitted to a thorough pathological and microbiological evaluation. Pathologic examination revealed a severe acute hemorrhagic colitis, neutrophilic splenitis, glomerulitis, and interstitial pneumonia. Salmonella enterica serotype Infantis was isolated from a mesenteric lymph node. A diagnosis of hemorrhagic colitis associated with Salmonella enterica serotype Infantis was established. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Postharvest transfer and survival of Salmonella enterica serotype enteritidis on living lettuce.

    PubMed

    Waitt, J A; Kuhn, D D; Welbaum, G E; Ponder, M A

    2014-02-01

    The potential for postharvest transfer of Salmonella to 'living lettuce' is not well understood. In this study, the transfer of Salmonella enterica Enteritidis (6 log CFU g(-1) ) from worker hands or contaminated roots to leaves of living lettuce was quantified. Transfer rates of Salmonella from contaminated gloves to sequentially handled lettuce heads ranged from 94% to head 1, 82% to head 2 and 69% to head 3. On average, 2.9 ± 0.1 log CFU g(-1) (64%) Salmonella was transferred from inoculated roots to leaves resulting from typical postharvest handling activities for living lettuce. Salmonella persisted on leaves stored at recommended storage temperatures (4°C) and increased 0.5 log CFU g(-1) when stored at temperature abuse conditions (12°C). Salmonella increased 1.6 log CFU g(-1) on roots after 18-day storage at 12°C, emphasizing the need to maintain temperature control to reduce the risk of human illness. Hydroponically grown lettuce packaged in plastic clamshells with intact roots, marketed as 'living lettuce', is increasing in popularity due to its extended shelf life. This study demonstrates the transfer of Salmonella from contaminated worker hands and contaminated roots to leaves where it persisted at 4°C for 18 day. Temperature abuse (12°C) increased Salmonella on roots and leaves. These findings suggest that failure to maintain temperatures below 12°C can pose a risk for consumers purchasing living lettuce at markets where recommended storage temperatures are not maintained. © 2013 The Society for Applied Microbiology.

  16. Resuscitation by Ferrioxamine E of Stressed Salmonella enterica Serovar Typhimurium from Soil and Water Microcosms

    PubMed Central

    Reissbrodt, R.; Heier, H.; Tschäpe, H.; Kingsley, R. A.; Williams, P. H.

    2000-01-01

    Storage of Salmonella enterica serovar Typhimurium strains in soil and water microcosms resulted in loss of culturability on standard plating media. Prior incubation in buffered peptone water supplemented with ferrioxamine E markedly extended the time that bacteria were recoverable by plating, except in the case of mutants deficient in ferrioxamine E uptake. PMID:10966440

  17. Comparison of two sampling and culture systems for detection of Salmonella enterica in the environment of a large animal hospital.

    PubMed

    Ruple-Czerniak, A; Bolte, D S; Burgess, B A; Morley, P S

    2014-07-01

    Nosocomial salmonellosis is an important problem in veterinary hospitals that treat horses and other large animals. Detection and mitigation of outbreaks and prevention of healthcare-associated infections often require detection of Salmonella enterica in the hospital environment. To compare 2 previously published methods for detecting environmental contamination with S. enterica in a large animal veterinary teaching hospital. Hospital-based comparison of environmental sampling techniques. A total of 100 pairs of environmental samples were collected from stalls used to house large animal cases (horses, cows or New World camelids) that were confirmed to be shedding S. enterica by faecal culture. Stalls were cleaned and disinfected prior to sampling, and the same areas within each stall were sampled for the paired samples. One method of detection used sterile, premoistened sponges that were cultured using thioglycolate enrichment before plating on XLT-4 agar. The other method used electrostatic wipes that were cultured using buffered peptone water, tetrathionate and Rappaport-Vassiliadis R10 broths before plating on XLT-4 agar. Salmonella enterica was recovered from 14% of samples processed using the electrostatic wipe sampling and culture procedure, whereas S. enterica was recovered from only 4% of samples processed using the sponge sampling and culture procedure. There was test agreement for 85 pairs of culture-negative samples and 3 pairs of culture-positive samples. However, the remaining 12 pairs of samples with discordant results created significant disagreement between the 2 detection methods (P<0.01). Persistence of Salmonella in the environment of veterinary hospitals can occur even with rigorous cleaning and disinfection. Use of sensitive methods for detection of environmental contamination is critical when detecting and mitigating this problem in veterinary hospitals. These results suggest that the electrostatic wipe sampling and culture method was

  18. Transcriptomic analysis of swarm motility phenotype of Salmonella enterica serovar Typhimurium mutant defective in periplasmic glucan synthesis

    USDA-ARS?s Scientific Manuscript database

    Movement of food-borne pathogens on moist surfaces enables them to migrate towards more favorable niches and facilitate their survival for extended periods of time. Salmonella enterica serovar Typhimurium mutants defective in OPG synthesis are unable to exhibit motility on moist surfaces (swarming) ...

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

    USDA-ARS?s Scientific Manuscript database

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

  20. An outbreak of Salmonella enterica serotype Choleraesuis in goitered gazelle (Gazella subgutrosa subgutrosa) and a Malayan tapir (Tapirus indicus).

    PubMed

    Wolf, Tiffany M; Wünschmann, Arno; Morningstar-Shaw, Brenda; Pantlin, Gayle C; Rasmussen, James M; Thompson, Rachel L

    2011-12-01

    An outbreak of Salmonella enterica serotype Choleraesuis enteritis occurred in two juvenile goitered gazelles and an adult Malayan tapir over a period of 5 wk at the Minnesota Zoo. Diagnosis was made postmortem on one gazelle and one tapir, and a second gazelle was diagnosed via fecal culture. The death of the tapir was attributed to S. enterica serovar Choleraesuis septicemia, while salmonellosis was considered to be a contributing factor besides ostertagiasis for the death of one goitered gazelle and for the diarrhea of another goitered gazelle. A third gazelle became ill in the same time period, but Salmonella infection was not confirmed by culture. All exhibited the clinical signs of profuse, watery diarrhea. The gazelles developed a protein-losing enteropathy, and the tapir showed signs of sepsis and endotoxemia. Serotyping and pulsed-field gel electrophoresis revealed the Salmonella isolates to be indistinguishable from each other. One year prior to this outbreak, Salmonella sp. was cultured from a Visayan warty pig (Sus cebifrons) housed in the same building as the tapir. After further investigation into the outbreak, spread of this pathogen was speculated to be associated with human movement across animal areas.

  1. SadA, a Trimeric Autotransporter from Salmonella enterica Serovar Typhimurium, Can Promote Biofilm Formation and Provides Limited Protection against Infection ▿ †

    PubMed Central

    Raghunathan, Dhaarini; Wells, Timothy J.; Morris, Faye C.; Shaw, Robert K.; Bobat, Saeeda; Peters, Sarah E.; Paterson, Gavin K.; Jensen, Karina Tveen; Leyton, Denisse L.; Blair, Jessica M. A.; Browning, Douglas F.; Pravin, John; Flores-Langarica, Adriana; Hitchcock, Jessica R.; Moraes, Claudia T. P.; Piazza, Roxane M. F.; Maskell, Duncan J.; Webber, Mark A.; May, Robin C.; MacLennan, Calman A.; Piddock, Laura J.; Cunningham, Adam F.; Henderson, Ian R.

    2011-01-01

    Salmonella enterica is a major cause of morbidity worldwide and mortality in children and immunocompromised individuals in sub-Saharan Africa. Outer membrane proteins of Salmonella are of significance because they are at the interface between the pathogen and the host, they can contribute to adherence, colonization, and virulence, and they are frequently targets of antibody-mediated immunity. In this study, the properties of SadA, a purported trimeric autotransporter adhesin of Salmonella enterica serovar Typhimurium, were examined. We demonstrated that SadA is exposed on the Salmonella cell surface in vitro and in vivo during infection of mice. Expression of SadA resulted in cell aggregation, biofilm formation, and increased adhesion to human intestinal Caco-2 epithelial cells. Immunization of mice with folded, full-length, purified SadA elicited an IgG response which provided limited protection against bacterial challenge. When anti-SadA IgG titers were enhanced by administering alum-precipitated protein, a modest additional protection was afforded. Therefore, despite SadA having pleiotropic functions, it is not a dominant, protective antigen for antibody-mediated protection against Salmonella. PMID:21859856

  2. Comparative Genomics of 28 Salmonella enterica Isolates: Evidence for CRISPR-Mediated Adaptive Sublineage Evolution ▿†

    PubMed Central

    Fricke, W. Florian; Mammel, Mark K.; McDermott, Patrick F.; Tartera, Carmen; White, David G.; LeClerc, J. Eugene; Ravel, Jacques; Cebula, Thomas A.

    2011-01-01

    Despite extensive surveillance, food-borne Salmonella enterica infections continue to be a significant burden on public health systems worldwide. As the S. enterica species comprises sublineages that differ greatly in antigenic representation, virulence, and antimicrobial resistance phenotypes, a better understanding of the species' evolution is critical for the prediction and prevention of future outbreaks. The roles that virulence and resistance phenotype acquisition, exchange, and loss play in the evolution of S. enterica sublineages, which to a certain extent are represented by serotypes, remains mostly uncharacterized. Here, we compare 17 newly sequenced and phenotypically characterized nontyphoidal S. enterica strains to 11 previously sequenced S. enterica genomes to carry out the most comprehensive comparative analysis of this species so far. These phenotypic and genotypic data comparisons in the phylogenetic species context suggest that the evolution of known S. enterica sublineages is mediated mostly by two mechanisms, (i) the loss of coding sequences with known metabolic functions, which leads to functional reduction, and (ii) the acquisition of horizontally transferred phage and plasmid DNA, which provides virulence and resistance functions and leads to increasing specialization. Matches between S. enterica clustered regularly interspaced short palindromic repeats (CRISPR), part of a defense mechanism against invading plasmid and phage DNA, and plasmid and prophage regions suggest that CRISPR-mediated immunity could control short-term phenotype changes and mediate long-term sublineage evolution. CRISPR analysis could therefore be critical in assessing the evolutionary potential of S. enterica sublineages and aid in the prediction and prevention of future S. enterica outbreaks. PMID:21602358

  3. Prevalence of ColE1-Like Plasmids and Kanamycin Resistance Genes in Salmonella enterica Serovars ▿

    PubMed Central

    Chen, Chin-Yi; Lindsey, Rebecca L.; Strobaugh, Terence P.; Frye, Jonathan G.; Meinersmann, Richard J.

    2010-01-01

    Multi-antimicrobial-resistant Salmonella enterica strains frequently carry resistance genes on plasmids. Recent studies focus heavily on large conjugative plasmids, and the role that small plasmids play in resistance gene transfer is largely unknown. To expand our previous studies in assessing the prevalence of the isolates harboring ColE1-like plasmids carrying the aph gene responsible for kanamycin resistance (Kanr) phenotypes, 102 Kanr Salmonella isolates collected through the National Antimicrobial Resistance Monitoring System (NARMS) in 2005 were screened by PCR using ColE1 primer sets. Thirty isolates were found to be positive for ColE1-like replicon. Plasmids from 23 isolates were able to propagate in Escherichia coli and were subjected to further characterization. Restriction mapping revealed three major plasmid groups found in three or more isolates, with each group consisting of two to three subtypes. The aph genes from the Kanr Salmonella isolates were amplified by PCR, sequenced, and showed four different aph(3′)-I genes. The distribution of the ColE1 plasmid groups in association with the aph gene, Salmonella serovar, and isolate source demonstrated a strong linkage of the plasmid with S. enterica serovar Typhimurium DT104. Due to their high copy number and mobility, the ColE1-like plasmids may play a critical role in transmission of antibiotic resistance genes among enteric pathogens, and these findings warrant a close monitoring of this plasmid incompatibility group. PMID:20693446

  4. Regulation of Flagellum Biosynthesis in Response to Cell Envelope Stress in Salmonella enterica Serovar Typhimurium

    PubMed Central

    2018-01-01

    ABSTRACT Flagellum-driven motility of Salmonella enterica serovar Typhimurium facilitates host colonization. However, the large extracellular flagellum is also a prime target for the immune system. As consequence, expression of flagella is bistable within a population of Salmonella, resulting in flagellated and nonflagellated subpopulations. This allows the bacteria to maximize fitness in hostile environments. The degenerate EAL domain protein RflP (formerly YdiV) is responsible for the bistable expression of flagella by directing the flagellar master regulatory complex FlhD4C2 with respect to proteolytic degradation. Information concerning the environmental cues controlling expression of rflP and thus about the bistable flagellar biosynthesis remains ambiguous. Here, we demonstrated that RflP responds to cell envelope stress and alterations of outer membrane integrity. Lipopolysaccharide (LPS) truncation mutants of Salmonella Typhimurium exhibited increasing motility defects due to downregulation of flagellar gene expression. Transposon mutagenesis and genetic profiling revealed that σ24 (RpoE) and Rcs phosphorelay-dependent cell envelope stress response systems sense modifications of the lipopolysaccaride, low pH, and activity of the complement system. This subsequently results in activation of RflP expression and degradation of FlhD4C2 via ClpXP. We speculate that the presence of diverse hostile environments inside the host might result in cell envelope damage and would thus trigger the repression of resource-costly and immunogenic flagellum biosynthesis via activation of the cell envelope stress response. PMID:29717015

  5. Ultrasound improves chemical reduction of natural contaminant microbiota and Salmonella enterica subsp. enterica on strawberries.

    PubMed

    do Rosário, Denes Kaic Alves; da Silva Mutz, Yhan; Peixoto, Jaqueline Moreira Curtis; Oliveira, Syllas Borburema Silva; de Carvalho, Raquel Vieira; Carneiro, Joel Camilo Souza; de São José, Jackline Freitas Brilhante; Bernardes, Patrícia Campos

    2017-01-16

    New sanitization methods have been evaluated to improve food safety and food quality and to replace chlorine compounds. However, these new methods can lead to physicochemical and sensory changes in fruits and vegetables. The present study evaluated the effects of acetic acid, peracetic acid, and sodium dodecylbenzenesulfonate isolated or combined with 5min of ultrasound treatment (40kHz, 500W) on strawberry quality over 9days of storage at 8°C. The strawberry natural contaminant microbiota (molds and yeasts, mesophilic aerobic and lactic acid bacteria), physicochemical quality (pH, total titratable acidity, total soluble solids, vitamin C, and color), sensory quality (triangle test) and inactivation of Salmonella enterica subsp. enterica intentionally inoculated onto strawberries were analyzed. Ultrasound increased the effect of all chemical compounds in the reduction of aerobic mesophilic, molds and yeasts. The best treatment for those groups of microorganisms was ultrasound combined with peracetic acid (US+PA) that reduced 1.8 and 2.0logcfu/g during 9days of storage. Bactericidal effect of peracetic acid was also improved by ultrasound inactivation of S. enterica, reaching a decimal reduction of 2.1logcfu/g. Moreover, synergistic effects were observed in contaminant natural microbiota inactivation for all tested compounds during storage, without any major physicochemical or sensory alteration to the strawberries. Therefore, ultrasound treatment can improve the effect of sanitizers that are substitutes of chlorine compounds without altering the quality of strawberries during storage. Acetic acid (PubChem CID: 176); Peracetic acid (PubChem CID: 6585); Sodium dodecylbenzenesulfonate (PubChem CID: 18372154). Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Complete Genome Sequencing of a Multidrug-Resistant and Human-Invasive Salmonella enterica Serovar Typhimurium Strain of the Emerging Sequence Type 213 Genotype

    PubMed Central

    Calva, Edmundo; Zaidi, Mussaret B.; Sanchez-Flores, Alejandro; Estrada, Karel; Silva, Genivaldo G. Z.; Soto-Jiménez, Luz M.; Wiesner, Magdalena; Fernández-Mora, Marcos; Edwards, Robert A.

    2015-01-01

    Salmonella enterica subsp. enterica serovar Typhimurium strain YU39 was isolated in 2005 in the state of Yucatán, Mexico, from a human systemic infection. The YU39 strain is representative of the multidrug-resistant emergent sequence type 213 (ST213) genotype. The YU39 complete genome is composed of a chromosome and seven plasmids. PMID:26089426

  7. Complete genome sequencing of a multidrug-resistant and human-invasive Salmonella enterica serovar Typhimurium strain of the emerging sequence type 213 genotype

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Calva, Edmundo; Silva, Claudia; Zaidi, Mussaret B.

    Salmonella enterica subsp. enterica serovar Typhimurium strain YU39 was isolated in 2005 in the state of Yucatán, Mexico, from a human systemic infection. The YU39 strain is representative of the multidrug-resistant emergent sequence type 213 (ST213) genotype. The YU39 complete genome is composed of a chromosome and seven plasmids.

  8. Complete genome sequencing of a multidrug-resistant and human-invasive Salmonella enterica serovar Typhimurium strain of the emerging sequence type 213 genotype

    DOE PAGES

    Calva, Edmundo; Silva, Claudia; Zaidi, Mussaret B.; ...

    2015-06-18

    Salmonella enterica subsp. enterica serovar Typhimurium strain YU39 was isolated in 2005 in the state of Yucatán, Mexico, from a human systemic infection. The YU39 strain is representative of the multidrug-resistant emergent sequence type 213 (ST213) genotype. The YU39 complete genome is composed of a chromosome and seven plasmids.

  9. Genomic Comparison of Non-Typhoidal Salmonella enterica Serovars Typhimurium, Enteritidis, Heidelberg, Hadar and Kentucky Isolates from Broiler Chickens

    PubMed Central

    Dhanani, Akhilesh S.; Block, Glenn; Dewar, Ken; Forgetta, Vincenzo; Topp, Edward; Beiko, Robert G.; Diarra, Moussa S.

    2015-01-01

    Background Non-typhoidal Salmonella enterica serovars, associated with different foods including poultry products, are important causes of bacterial gastroenteritis worldwide. The colonization of the chicken gut by S. enterica could result in the contamination of the environment and food chain. The aim of this study was to compare the genomes of 25 S. enterica serovars isolated from broiler chicken farms to assess their intra- and inter-genetic variability, with a focus on virulence and antibiotic resistance characteristics. Methodology/Principal Finding The genomes of 25 S. enterica isolates covering five serovars (ten Typhimurium including three monophasic 4,[5],12:i:, four Enteritidis, three Hadar, four Heidelberg and four Kentucky) were sequenced. Most serovars were clustered in strongly supported phylogenetic clades, except for isolates of serovar Enteritidis that were scattered throughout the tree. Plasmids of varying sizes were detected in several isolates independently of serovars. Genes associated with the IncF plasmid and the IncI1 plasmid were identified in twelve and four isolates, respectively, while genes associated with the IncQ plasmid were found in one isolate. The presence of numerous genes associated with Salmonella pathogenicity islands (SPIs) was also confirmed. Components of the type III and IV secretion systems (T3SS and T4SS) varied in different isolates, which could explain in part, differences of their pathogenicity in humans and/or persistence in broilers. Conserved clusters of genes in the T3SS were detected that could be used in designing effective strategies (diagnostic, vaccination or treatments) to combat Salmonella. Antibiotic resistance genes (CMY, aadA, ampC, florR, sul1, sulI, tetAB, and srtA) and class I integrons were detected in resistant isolates while all isolates carried multidrug efflux pump systems regardless of their antibiotic susceptibility profile. Conclusions/Significance This study showed that the predominant

  10. Genomic Comparison of Non-Typhoidal Salmonella enterica Serovars Typhimurium, Enteritidis, Heidelberg, Hadar and Kentucky Isolates from Broiler Chickens.

    PubMed

    Dhanani, Akhilesh S; Block, Glenn; Dewar, Ken; Forgetta, Vincenzo; Topp, Edward; Beiko, Robert G; Diarra, Moussa S

    2015-01-01

    Non-typhoidal Salmonella enterica serovars, associated with different foods including poultry products, are important causes of bacterial gastroenteritis worldwide. The colonization of the chicken gut by S. enterica could result in the contamination of the environment and food chain. The aim of this study was to compare the genomes of 25 S. enterica serovars isolated from broiler chicken farms to assess their intra- and inter-genetic variability, with a focus on virulence and antibiotic resistance characteristics. The genomes of 25 S. enterica isolates covering five serovars (ten Typhimurium including three monophasic 4,[5],12:i:, four Enteritidis, three Hadar, four Heidelberg and four Kentucky) were sequenced. Most serovars were clustered in strongly supported phylogenetic clades, except for isolates of serovar Enteritidis that were scattered throughout the tree. Plasmids of varying sizes were detected in several isolates independently of serovars. Genes associated with the IncF plasmid and the IncI1 plasmid were identified in twelve and four isolates, respectively, while genes associated with the IncQ plasmid were found in one isolate. The presence of numerous genes associated with Salmonella pathogenicity islands (SPIs) was also confirmed. Components of the type III and IV secretion systems (T3SS and T4SS) varied in different isolates, which could explain in part, differences of their pathogenicity in humans and/or persistence in broilers. Conserved clusters of genes in the T3SS were detected that could be used in designing effective strategies (diagnostic, vaccination or treatments) to combat Salmonella. Antibiotic resistance genes (CMY, aadA, ampC, florR, sul1, sulI, tetAB, and srtA) and class I integrons were detected in resistant isolates while all isolates carried multidrug efflux pump systems regardless of their antibiotic susceptibility profile. This study showed that the predominant Salmonella serovars in broiler chickens harbor genes encoding adhesins

  11. Assessment of contamination potential of lettuce by Salmonella enterica serovar Newport added to the plant growing medium.

    PubMed

    Bernstein, Nirit; Sela, Shlomo; Neder-Lavon, Sarit

    2007-07-01

    The capacity of Salmonella enterica serovar Newport to contaminate Romaine lettuce (Lactuca sativa L. cv. Nogal) via the root system was evaluated in 17-, 20-, and 33-day-old plants. Apparent internalization of Salmonella via the root to the above-ground parts was identified in 33- but not 17- or 20-day-old plants and was stimulated by root decapitation. Leaves of lettuce plants with intact and damaged roots harbored Salmonella at 500 +/- 120 and 5,130 +/- 440 CFU/g of leaf, respectively, at 2 days postinoculation but not 5 days later. These findings are first to suggest that Salmonella Newport can translocate from contaminated roots to the aerial parts of lettuce seedlings and propose that the process is dependent on the developmental stage of the plant.

  12. Lipopolysaccharide-Specific but Not Anti-Flagellar Immunoglobulin A Monoclonal Antibodies Prevent Salmonella enterica Serotype Enteritidis Invasion and Replication within HEp-2 Cell Monolayers

    PubMed Central

    Iankov, Ianko D.; Petrov, Dragomir P.; Mladenov, Ivan V.; Haralambieva, Iana H.; Mitov, Ivan G.

    2002-01-01

    The protective potential of immunoglobulin A (IgA) monoclonal antibodies (MAbs) directed against O and H antigens of Salmonella enterica serotype Enteritidis to prevent bacterial adhesion to and invasion of HEp-2 cells was evaluated. Although anti-flagellar IgA MAbs showed strong agglutinating capacities, they did not protect cell monolayers. In contrast, IgA MAbs specific for the O:9 epitope of Salmonella lipopolysaccharide antigen alone prevented S. enterica serotype Enteritidis entry and replication within HEp-2 cells, and the protection was not mediated by direct binding of antibodies to bacterial adhesins or by agglutination of microorganisms. PMID:11854252

  13. A case of Salmonella enterica serotype typhi in a patient without a history of international travel.

    PubMed

    Byers, David K; Petersen, Kyle

    2009-01-01

    Typhoid fever, endemic in the developing world, is associated with international travel in developed nations. We present a case of Salmonella enterica infection in a patient without a history of international travel acquired from his traveling ex-wife. History of overseas travel in family members should be investigated when evaluating suspected cases.

  14. Survival of Salmonella enterica on soybean sprouts following treatments with gaseous chlorine dioxide and biocontrol Pseudomonas bacteria

    USDA-ARS?s Scientific Manuscript database

    Control of Salmonella enterica on sprouts and minimally processed, ready-to-eat fruits and vegetables is important for food and consumer safety. The aim of this research was to assess the effects of gaseous chlorine dioxide(ClO2)and biocontrol microorganisms (Pseudomonas chlororaphis and P. fluoresc...

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

    PubMed Central

    Kisluk, Guy

    2012-01-01

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

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

    PubMed

    Kisluk, Guy; Yaron, Sima

    2012-06-01

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

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

    USDA-ARS?s Scientific Manuscript database

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

  18. Pediatric Epidemic of Salmonella enterica Serovar Typhimurium in the Area of L'Aquila, Italy, Four Years after a Catastrophic Earthquake.

    PubMed

    Nigro, Giovanni; Bottone, Gabriella; Maiorani, Daniela; Trombatore, Fabiana; Falasca, Silvana; Bruno, Gianfranco

    2016-05-06

    A Salmonella enterica epidemic occurred in children of the area of L'Aquila (Central Italy, Abruzzo region) between June 2013 and October 2014, four years after the catastrophic earthquake of 6 April 2009. Clinical and laboratory data were collected from hospitalized and ambulatory children. Routine investigations for Salmonella infection were carried out on numerous alimentary matrices of animal origin and sampling sources for drinking water of the L'Aquila district, including pickup points of the two main aqueducts. Salmonella infection occurred in 155 children (83 females: 53%), aged 1 to 15 years (mean 2.10). Of these, 44 children (28.4%) were hospitalized because of severe dehydration, electrolyte abnormalities, and fever resistant to oral antipyretic and antibiotic drugs. Three children (1.9%) were reinfected within four months after primary infection by the same Salmonella strain. Four children (2.6%), aged one to two years, were coinfected by rotavirus. A seven-year old child had a concomitant right hip joint arthritis. The isolated strains, as confirmed in about the half of cases or probable/possible in the remaining ones, were identified as S. enterica serovar Typhimurium [4,5:i:-], monophasic variant. Aterno river, bordering the L'Aquila district, was recognized as the main responsible source for the contamination of local crops and vegetables derived from polluted crops. The high rate of hospitalized children underlines the emergence of a highly pathogenic S. enterica strain probably subsequent to the contamination of the spring water sources after geological changes occurred during the catastrophic earthquake.

  19. THE DELTA UVRB MUTATIONS IN THE AMES STRAINS OF SALMONELLA SPAN 15-119 GENES

    EPA Science Inventory

    Abstract

    The 4uvrB mutationesent in strains of Salmonella enterica Typhirnurium used commonly in the Salmonella (Ames) mutagenicity assay were isolated independently on separate occasions: chl-1005 (bio uvrBgal) for the hisG46-containing strains TA1535 and TA100; chl- 10...

  20. Rapid multiplex PCR and Real-Time TaqMan PCR assays for detection of Salmonella enterica and the highly virulent serovars Choleraesuis and Paratyphi C

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is a human pathogen with over 2,500 serovars characterized. S. enterica serovars Choleraesuis (Cs) and Paratyphi C (Pc) are two globally distributed serovars. We have developed a rapid molecular typing method to detect Cs and Pc in food samples by using a comparative genomics ap...

  1. The Rcs-Regulated Colanic Acid Capsule Maintains Membrane Potential in Salmonella enterica serovar Typhimurium

    PubMed Central

    Pando, Jasmine M.; Karlinsey, Joyce E.; Lara, Jimmie C.; Libby, Stephen J.

    2017-01-01

    ABSTRACT The Rcs phosphorelay and Psp (phage shock protein) systems are envelope stress responses that are highly conserved in gammaproteobacteria. The Rcs regulon was found to be strongly induced during metal deprivation of Salmonella enterica serovar Typhimurium lacking the Psp response. Nineteen genes activated by the RcsA-RcsB response regulator make up an operon responsible for the production of colanic acid capsular polysaccharide, which promotes biofilm development. Despite more than half a century of research, the physiological function of colanic acid has remained elusive. Here we show that Rcs-dependent colanic acid production maintains the transmembrane electrical potential and proton motive force in cooperation with the Psp response. Production of negatively charged exopolysaccharide covalently bound to the outer membrane may enhance the surface potential by increasing the local proton concentration. This provides a unifying mechanism to account for diverse Rcs/colanic acid-related phenotypes, including susceptibility to membrane-damaging agents and biofilm formation. PMID:28588134

  2. In vitro evaluation of anti-infective activity of a Lactobacillus plantarum strain against Salmonella enterica serovar Enteritidis

    PubMed Central

    2013-01-01

    Background Salmonella enterica serovar Enteritidis infections are known to exhibit worldwide prevalence with increased morbidity and mortality. The conventional strategies like antibiotic therapy and vaccination have not only proved to be of sub-optimal efficacy but also led to the development of multidrug resistant strains of Salmonella. Antimicrobial activities of probiotics against various enteropathogens and other health promoting effects have assumed greater significance in recent years. The present study aims to evaluate the efficacy of a Lactobacillus plantarum strain (KSBT 56, isolated from a traditional food product of India), in preventing Salmonella enterica serovar Enteritidis growth and pathogenicity in vitro. Methods and results The cell free culture supernatant (CFCS) of KSBT 56 strain notably inhibited the growth of Salmonella Enteritidis without affecting the growth of other gram-positive lactic acid bacteria. The isolated KSBT 56 strain produces lactic acid similar to other standard probiotic strains like Lactobacillus plantarum MTCC 1407. The free radical production by KSBT 56 strain was studied by using sodC mutant of S. Enteritidis, which exhibited reduced growth in the presence of CFCS of the KSBT 56 strain, indicating the inhibitory activity of free radicals on the growth of S. Enteritidis. Our results also showed a significant reduction in the biofilm forming ability of Salmonella Enteritidis in the presence of the KSBT 56 strain (2 log cfu/ml, p = 0.01). Further, the anti-infective characteristics of KSBT 56 strain was validated by gentamicin protection assay which revealed 80% reduction in the invasion of Salmonella Enteritidis to HCT-116 cell line (Salmonella Enteritidis and KSBT 56 in a 1:1 ratio) and delayed addition of Salmonella Enteritidis by 1 h. Similarly, the reduced adhesion of Salmonella to the HCT-116 cells was observed along with the down regulation of hilA gene of Salmonella Pathogenicity Island 1 (SPI1) indicating that they

  3. Effects of leachate from crumb rubber and zinc in green roofs on the survival, growth, and resistance characteristics of Salmonella enterica subsp. enterica serovar Typhimurium.

    PubMed

    Crampton, Mollee; Ryan, Allayna; Eckert, Cori; Baker, Katherine H; Herson, Diane S

    2014-05-01

    The use of green roofs is a growing practice worldwide, particularly in densely populated areas. In an attempt to find new methods for recycling crumb rubber, incorporation of crumb rubber into artificial medium for plant growth in green roofs and similar engineered environments has become an attractive option for the recycling of waste tires. Though this approach decreases waste in landfills, there are concerns about the leaching of zinc and other heavy metals, as well as nutrient and organic compounds, into the environment. The present study analyzed the impact of leachate from crumb rubber and zinc on the growth and viability of Salmonella enterica subsp. enterica serovar Typhimurium. Zinc was chosen for further studies since it has been previously implicated with other biological functions, including biofilm formation, motility, and possible cross-resistance to antimicrobial agents. The study showed that Salmonella can colonize crumb rubber and that crumb rubber extract may provide nutrients that are usable by this bacterium. Salmonella strains with reduced susceptibility (SRS) to zinc were obtained after subculturing in increasing concentrations of zinc. The SRS exhibited differences in gene expression of flux pump genes zntA and znuA compared to that of the parent when exposed to 20 mM added zinc. In biofilm formation studies, the SRS formed less biofilm but was more motile than the parental strain.

  4. Effects of Leachate from Crumb Rubber and Zinc in Green Roofs on the Survival, Growth, and Resistance Characteristics of Salmonella enterica subsp. enterica Serovar Typhimurium

    PubMed Central

    Crampton, Mollee; Ryan, Allayna; Eckert, Cori; Baker, Katherine H.

    2014-01-01

    The use of green roofs is a growing practice worldwide, particularly in densely populated areas. In an attempt to find new methods for recycling crumb rubber, incorporation of crumb rubber into artificial medium for plant growth in green roofs and similar engineered environments has become an attractive option for the recycling of waste tires. Though this approach decreases waste in landfills, there are concerns about the leaching of zinc and other heavy metals, as well as nutrient and organic compounds, into the environment. The present study analyzed the impact of leachate from crumb rubber and zinc on the growth and viability of Salmonella enterica subsp. enterica serovar Typhimurium. Zinc was chosen for further studies since it has been previously implicated with other biological functions, including biofilm formation, motility, and possible cross-resistance to antimicrobial agents. The study showed that Salmonella can colonize crumb rubber and that crumb rubber extract may provide nutrients that are usable by this bacterium. Salmonella strains with reduced susceptibility (SRS) to zinc were obtained after subculturing in increasing concentrations of zinc. The SRS exhibited differences in gene expression of flux pump genes zntA and znuA compared to that of the parent when exposed to 20 mM added zinc. In biofilm formation studies, the SRS formed less biofilm but was more motile than the parental strain. PMID:24584242

  5. Expression of hilA in response to mild acid stress in Salmonella enterica is serovar and strain dependent.

    PubMed

    González-Gil, Francisco; Le Bolloch, Alexandre; Pendleton, Sean; Zhang, Nan; Wallis, Audra; Hanning, Irene

    2012-05-01

    Salmonella enterica is the leading cause of foodborne illness with poultry and poultry products being primary sources of infection. The 2 most common S. enterica serovars associated with human infection are Typhimurium and Enteritidis. However, Kentucky and Heidelburg and the 2 most prevalent serovars isolated from poultry environments. Given the prevalence of other serovars in poultry products and environments, research is needed to understand virulence modulation in response to stress in serovars other than Typhimurium and Enteritidis. Thus, the objective of this research was to compare hilA gene expression (a master regulator of the virulence pathogenicity island) in response to acid stress among different strains and serovars of Salmonella. A total of 11 serovars consisting of 15 strains of S. enterica were utilized for these experiments. Cultures were suspended in tryptic soy broth (TSB) adjusted to pH 7.2, 6.2, or 5.5 with HCl or acetic acid. Total RNA was extracted from cultures at specific time points (0, 2, 4, and 24 h). Gene expression of hilA was measured with quantitative reverse transcriptase real time PCR (qRT-PCR). Growth and pH were measured throughout the 24 h time frame. Regulation of hilA in response to acid stress varied by serovar and strain and type of acid. The results of these experiments indicate that hilA regulation may have some impact on virulence and colonization of S. enterica. However, these results warrant further research to more fully understand the significance of hilA regulation in response to mild acid stress in S. enterica. © 2012 Institute of Food Technologists®

  6. Interpretations of Antibody Responses to Salmonella enterica Serotype Enteritidis gm Flagellin in Poultry Flocks Are Enhanced by a Kinetics-Based Enzyme-Linked Immunosorbent Assay

    PubMed Central

    McDonough, Patrick L.; Jacobson, Richard H.; Timoney, John F.; Mutalib, Ahmed; Kradel, David C.; Chang, Yung-fu; Shin, Sang J.; Lein, Donald H.; Trock, Susan; Wheeler, Kaye

    1998-01-01

    Many regulatory and diagnostic programs for the detection of Salmonella enterica serotype Enteritidis infection in commercial poultry flocks have relied on rapid Pullorum agglutination tests to screen birds because of the shared antigens of S. enterica Enteritidis and S. enterica Pullorum and Gallinarum; however, the use of the enzyme-linked immunosorbent assay (ELISA) format affords better analytical sensitivity than crude agglutination tests. In this study, we adapted our earlier conventional indirect ELISA, using gm flagellin as the antigen, to a kinetics-based, computer-controlled ELISA (KELA). The KELA was used to screen for flagellin antibody from three commercial flocks: (i) a large flock involved in a U.S. Department of Agriculture trace back from a human S. enterica Enteritidis foodborne outbreak (n = 3,209), (ii) a flock infected with the endemic S. enterica Enteritidis serotype but which also had multiple other salmonella serotypes (n = 65), and (iii) an S. enterica Pullorum-infected flock (n = 12). The first flock (S. enterica Enteritidis prevalence of 2.45% based on culture) provided a field test of the KELA and allowed the calculation of diagnostic sensitivity (D-Sn) and diagnostic specificity (D-Sp). With a cutoff of 10 (used for screening flocks [i.e., high sensitivity]), the KELA has a D-Sn of 95.2% and a D-Sp of 18.5%; with a cutoff of 140 (used in confirmatory flock testing [i.e., high specificity]), the KELA has a D-Sn of 28.0% and a D-Sp of 99.1%. We found that with a cutoff of 60 (D-Sn = 63.1%; D-Sp = 91.6%), we could eliminate reactions in the KELA caused by other non-S. enterica Enteritidis salmonellae. The KELA was also compared to two commercial rapid Pullorum tests, the Solvay (D-Sn = 94.9%; D-Sp = 55.5%) and the Vineland (D-Sn = 62.0%; D-Sp = 75.3%). PMID:9665965

  7. Combining essential oils and olive extract for control of multi-drug resistant Salmonella enterica on organic leafy greens

    USDA-ARS?s Scientific Manuscript database

    We investigated the combined antimicrobial effects of plant essential oils and olive extract against antibiotic resistant Salmonella enterica serovar Newport on organic leafy greens. Organic baby spinach, mature spinach, romaine lettuce, and iceberg lettuce were inoculated with S. Newport and dip-t...

  8. Dietary rice bran promotes resistance to Salmonella enterica serovar Typhimurium colonization in mice.

    PubMed

    Kumar, Ajay; Henderson, Angela; Forster, Genevieve M; Goodyear, Andrew W; Weir, Tiffany L; Leach, Jan E; Dow, Steven W; Ryan, Elizabeth P

    2012-07-04

    Dietary rice bran consists of many bioactive components with disease fighting properties; including the capacity to modulate the gut microbiota. Studies point to the important roles of the gut microbiota and the mucosal epithelium in the establishment of protection against enteric pathogens, such as Salmonella. The ability of rice bran to reduce the susceptibility of mice to a Salmonella infection has not been previously investigated. Therefore, we hypothesized that the incorporation of rice bran into the diet would inhibit the colonization of Salmonella in mice through the induction of protective mucosal responses. Mice were fed diets containing 0%, 10% and 20% rice bran for one week prior to being orally infected with Salmonella enterica serovar Typhimurium. We found that mice consuming the 10 and 20% rice bran diets exhibited a reduction in Salmonella fecal shedding for up to nine days post-infection as compared to control diet fed animals (p < 0.05). In addition, we observed decreased concentrations of the pro-inflammatory cytokines, TNF-alpha, IFN-gamma, and IL-12 (p < 0.05) as well as increased colonization of native Lactobacillus spp. in rice bran fed mice (p < 0.05). Furthermore, in vitro experiments revealed the ability of rice bran extracts to reduce Salmonella entry into mouse small intestinal epithelial cells. Increasing rice bran consumption represents a novel dietary means for reducing susceptibility to enteric infection with Salmonella and potentially via induction of native Lactobacillus spp.

  9. Dietary rice bran promotes resistance to Salmonella enterica serovar Typhimurium colonization in mice

    PubMed Central

    2012-01-01

    Background Dietary rice bran consists of many bioactive components with disease fighting properties; including the capacity to modulate the gut microbiota. Studies point to the important roles of the gut microbiota and the mucosal epithelium in the establishment of protection against enteric pathogens, such as Salmonella. The ability of rice bran to reduce the susceptibility of mice to a Salmonella infection has not been previously investigated. Therefore, we hypothesized that the incorporation of rice bran into the diet would inhibit the colonization of Salmonella in mice through the induction of protective mucosal responses. Results Mice were fed diets containing 0%, 10% and 20% rice bran for one week prior to being orally infected with Salmonella enterica serovar Typhimurium. We found that mice consuming the 10 and 20% rice bran diets exhibited a reduction in Salmonella fecal shedding for up to nine days post-infection as compared to control diet fed animals (p < 0.05). In addition, we observed decreased concentrations of the pro-inflammatory cytokines, TNF-alpha, IFN-gamma, and IL-12 (p < 0.05) as well as increased colonization of native Lactobacillus spp. in rice bran fed mice (p < 0.05). Furthermore, in vitro experiments revealed the ability of rice bran extracts to reduce Salmonella entry into mouse small intestinal epithelial cells. Conclusions Increasing rice bran consumption represents a novel dietary means for reducing susceptibility to enteric infection with Salmonella and potentially via induction of native Lactobacillus spp. PMID:22583915

  10. Protective action of Lactobacillus kefir carrying S-layer protein against Salmonella enterica serovar Enteritidis.

    PubMed

    Golowczyc, M A; Mobili, P; Garrote, G L; Abraham, A G; De Antoni, G L

    2007-09-30

    Eight Lactobacillus kefir strains isolated from different kefir grains were tested for their ability to antagonize Salmonella enterica serovar Enteritidis (Salmonella enteritidis) interaction with epithelial cells. L. kefir surface properties such as autoaggregation and coaggregation with Salmonella and adhesion to Caco-2/TC-7 cells were evaluated. L. kefir strains showed significantly different adhesion capacities, six strains were able to autoaggregate and four strains coaggregated with Salmonella. Coincubation of Salmonella with coaggregating L. kefir strains significantly decreased its capacity to adhere to and to invade Caco-2/TC-7 cells. This was not observed with non coaggregating L. kefir strains. Spent culture supernatants of L. kefir contain significant amounts of S-layer proteins. Salmonella pretreated with spent culture supernatants (pH 4.5-4.7) from all tested L. kefir strains showed a significant decrease in association and invasion to Caco-2/TC-7 cells. Artificially acidified MRS containing lactic acid to a final concentration and pH equivalent to lactobacilli spent culture supernatants did not show any protective action. Pretreatment of this pathogen with spent culture supernatants reduced microvilli disorganization produced by Salmonella. In addition, Salmonella pretreated with S-layer proteins extracted from coaggregating and non coaggregating L. kefir strains were unable to invade Caco-2/TC-7 cells. After treatment, L. kefir S-layer protein was detected associated with Salmonella, suggesting a protective role of this protein on association and invasion.

  11. Antimicrobial susceptibility of Salmonella enterica isolates from healthy breeder and broiler flocks in Portugal.

    PubMed

    Clemente, Lurdes; Correia, Ivone; Themudo, Patrícia; Neto, Isabel; Caniça, Manuela; Bernardo, Fernando

    2014-05-01

    Three hundred and thirty-three isolates representing 40 different serotypes of Salmonella enterica, recovered from environmental and faecal samples of breeder and broiler flocks from 2009 to 2011, were studied. Antimicrobial susceptibility was determined by measuring the minimal inhibitory concentration of 11 antimicrobials using the agar dilution method. Salmonella Havana, S. Enteritidis and S. Mbandaka were the most common serotypes isolated from broiler flocks, while S. Enteritidis was the common isolate from breeder flocks. The frequency of non-wild-type Salmonella isolates (those with decreased susceptibility to the different antimicrobials) varied according to serotype. S. Mbandaka in broilers and S. Enteritidis in both breeders and broilers showed higher frequencies of reduced susceptibility to quinolones, but clinical resistance towards ciprofloxacin was not observed. Reduced susceptibility to sulfamethoxazole, tetracycline, ampicillin and streptomycin were common in Salmonella Typhimurium isolates. Two isolates of S. Havana from broilers were resistant to cefotaxime and phenotypically categorised as extended-spectrum β-lactamase producers. The results presented in this study provide useful data on the antimicrobial susceptibility of different Salmonella serotypes and highlight the high diversity of multi-drug resistance patterns present. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Salmonella enterica Pulsed-Field Gel Electrophoresis Clusters, Minnesota, USA, 2001–2007

    PubMed Central

    Hedberg, Craig W.; Meyer, Stephanie; Boxrud, David J.; Smith, Kirk E.

    2010-01-01

    We determined characteristics of Salmonella enterica pulsed-field gel electrophoresis clusters that predict their being solved (i.e., that result in identification of a confirmed outbreak). Clusters were investigated by the Minnesota Department of Health by using a dynamic iterative model. During 2001–2007, a total of 43 (12.5%) of 344 clusters were solved. Clusters of >4 isolates were more likely to be solved than clusters of 2 isolates. Clusters in which the first 3 case isolates were received at the Minnesota Department of Health within 7 days were more likely to be solved than were clusters in which the first 3 case isolates were received over a period >14 days. If resources do not permit investigation of all S. enterica pulsed-field gel electrophoresis clusters, investigation of clusters of >4 cases and clusters in which the first 3 case isolates were received at a public health laboratory within 7 days may improve outbreak investigations. PMID:21029524

  13. Multidrug-resistant strains of Salmonella enterica Typhimurium, United States, 1997-1998.

    PubMed

    Rabatsky-Ehr, Therese; Whichard, Jean; Rossiter, Shannon; Holland, Ben; Stamey, Karen; Headrick, Marcia L; Barrett, Timothy J; Angulo, Frederick J

    2004-05-01

    To evaluate multidrug-resistant strains of Salmonella enterica serotype Typhimurium, including definitive type 104 (DT104) in the United States, we reviewed data from the National Antimicrobial Resistance Monitoring System (NARMS). In 1997 to 1998, 703 (25%) of 2,767 serotyped Salmonella isolates received at NARMS were S. Typhimurium; antimicrobial susceptibility testing and phage typing were completed for 697. Fifty-eight percent (402) were resistant to > or = 1 antimicrobial agent. Three multidrug-resistant (> or = 5 drugs) strains accounted for (74%) 296 of all resistant isolates. Ceftriaxone resistance was present in 8 (3%), and nalidixic acid resistance in 4 (1%), of these multidrug-resistant strains. By phage typing, 259 (37%) of S. Typhimurium isolates were DT104, 209 (30%) were of undefined type and 103 (15%) were untypable. Fifty percent (202) of resistant (> or = 1 drug) isolates were DT104. Multidrug-resistant S. Typhimurium isolates, particularly DT104, account for a substantial proportion of S. Typhimurium isolates; ceftriaxone resistance is exhibited by some of these strains.

  14. Microarray-based detection of Salmonella enterica serovar Enteritidis genes involved in chicken reproductive tract colonization.

    PubMed

    Raspoet, R; Appia-Ayme, C; Shearer, N; Martel, A; Pasmans, F; Haesebrouck, F; Ducatelle, R; Thompson, A; Van Immerseel, F

    2014-12-01

    Salmonella enterica serovar Enteritidis has developed the potential to contaminate table eggs internally, by colonization of the chicken reproductive tract and internalization in the forming egg. The serotype Enteritidis has developed mechanisms to colonize the chicken oviduct more successfully than other serotypes. Until now, the strategies exploited by Salmonella Enteritidis to do so have remained largely unknown. For that reason, a microarray-based transposon library screen was used to identify genes that are essential for the persistence of Salmonella Enteritidis inside primary chicken oviduct gland cells in vitro and inside the reproductive tract in vivo. A total of 81 genes with a potential role in persistence in both the oviduct cells and the oviduct tissue were identified. Major groups of importance include the Salmonella pathogenicity islands 1 and 2, genes involved in stress responses, cell wall, and lipopolysaccharide structure, and the region-of-difference genomic islands 9, 21, and 40. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  15. Comparative Sequence Analysis of Multidrug-Resistant IncA/C Plasmids from Salmonella enterica.

    PubMed

    Hoffmann, Maria; Pettengill, James B; Gonzalez-Escalona, Narjol; Miller, John; Ayers, Sherry L; Zhao, Shaohua; Allard, Marc W; McDermott, Patrick F; Brown, Eric W; Monday, Steven R

    2017-01-01

    Determinants of multidrug resistance (MDR) are often encoded on mobile elements, such as plasmids, transposons, and integrons, which have the potential to transfer among foodborne pathogens, as well as to other virulent pathogens, increasing the threats these traits pose to human and veterinary health. Our understanding of MDR among Salmonella has been limited by the lack of closed plasmid genomes for comparisons across resistance phenotypes, due to difficulties in effectively separating the DNA of these high-molecular weight, low-copy-number plasmids from chromosomal DNA. To resolve this problem, we demonstrate an efficient protocol for isolating, sequencing and closing IncA/C plasmids from Salmonella sp. using single molecule real-time sequencing on a Pacific Biosciences (Pacbio) RS II Sequencer. We obtained six Salmonella enterica isolates from poultry, representing six different serovars, each exhibiting the MDR-Ampc resistance profile. Salmonella plasmids were obtained using a modified mini preparation and transformed with Escherichia coli DH10Br. A Qiagen Large-Construct kit™ was used to recover highly concentrated and purified plasmid DNA that was sequenced using PacBio technology. These six closed IncA/C plasmids ranged in size from 104 to 191 kb and shared a stable, conserved backbone containing 98 core genes, with only six differences among those core genes. The plasmids encoded a number of antimicrobial resistance genes, including those for quaternary ammonium compounds and mercury. We then compared our six IncA/C plasmid sequences: first with 14 IncA/C plasmids derived from S. enterica available at the National Center for Biotechnology Information (NCBI), and then with an additional 38 IncA/C plasmids derived from different taxa. These comparisons allowed us to build an evolutionary picture of how antimicrobial resistance may be mediated by this common plasmid backbone. Our project provides detailed genetic information about resistance genes in

  16. The relationship between the immune response and susceptibility to Salmonella enterica serovar Enteritidis infection in the laying hen

    USDA-ARS?s Scientific Manuscript database

    Chicken eggs are one of the main sources of human salmonellosis, with Salmonella enterica serovar Enteritidis the most frequent cause of human non-typhoid salmonellosis. Laying hens colonized with S. Enteritidis generally do not show clinical signs. The bacteria colonize and invade the intestinal ...

  17. Intergenic Sequence Ribotyping using a region neighboring dkgB links genovar to Kauffman-White serotype of Salmonella enterica

    USDA-ARS?s Scientific Manuscript database

    Previous research identified that the 5S ribosomal (rrn) gene and associated flanking sequences that are closely linked to the dkgB gene of Salmonella enterica were highly variable between serotypes, but not between subpopulations within the same serotype (PMID: 17005008). The degree of variability ...

  18. Baseline Antibody Titre against Salmonella enterica in Healthy Population of Mumbai, Maharashtra, India.

    PubMed

    Patki, Rucha; Lilani, Sunil; Lanjewar, Dhaneshwar

    2017-01-01

    The aim of this study was to establish a baseline titre for the population of Mumbai, Maharashtra, India. Four hundred healthy blood donors, attending blood donation camps, were screened using a survey questionnaire. Widal tube agglutination test was performed on the diluted sera (with 0.9% normal saline) of blood donors, with final dilution ranging from 1 : 40 to 1 : 320. Out of 400 individuals providing samples, 78 (19.5%) individuals showed antibody titres ≥ 1 : 40 for at least one antigen and 322 (80.5%) showed no agglutination. The baseline antibody titres against O antigen and H antigen of Salmonella enterica serotype Typhi were found to be 1 : 40 and 1 : 80, respectively. Similarly, the baseline antibody titres for the H antigen of Salmonella enterica serotypes Paratyphi A and Paratyphi B were found to be 1 : 40 and 1 : 80, respectively. Thus, it was noted that the diagnostically significant cutoff of antibody titre from acute phase sample was ≥ 1 : 80 for S. Typhi O antigen and titre of ≥ 1 : 160 for both S. Typhi H antigen and S. Paratyphi BH antigen. Antibody titre of ≥ 1 : 80 can be considered significant for S. Paratyphi AH antigen.

  19. Baseline Antibody Titre against Salmonella enterica in Healthy Population of Mumbai, Maharashtra, India

    PubMed Central

    Lilani, Sunil; Lanjewar, Dhaneshwar

    2017-01-01

    Objective The aim of this study was to establish a baseline titre for the population of Mumbai, Maharashtra, India. Method Four hundred healthy blood donors, attending blood donation camps, were screened using a survey questionnaire. Widal tube agglutination test was performed on the diluted sera (with 0.9% normal saline) of blood donors, with final dilution ranging from 1 : 40 to 1 : 320. Results Out of 400 individuals providing samples, 78 (19.5%) individuals showed antibody titres ≥ 1 : 40 for at least one antigen and 322 (80.5%) showed no agglutination. The baseline antibody titres against O antigen and H antigen of Salmonella enterica serotype Typhi were found to be 1 : 40 and 1 : 80, respectively. Similarly, the baseline antibody titres for the H antigen of Salmonella enterica serotypes Paratyphi A and Paratyphi B were found to be 1 : 40 and 1 : 80, respectively. Conclusion Thus, it was noted that the diagnostically significant cutoff of antibody titre from acute phase sample was ≥ 1 : 80 for S. Typhi O antigen and titre of ≥ 1 : 160 for both S. Typhi H antigen and S. Paratyphi BH antigen. Antibody titre of ≥ 1 : 80 can be considered significant for S. Paratyphi AH antigen. PMID:29081804

  20. Bacteriophage SP6 encodes a second tailspike protein that recognizes Salmonella enterica serogroups C{sub 2} and C{sub 3}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gebhart, Dana; Williams, Steven R.; Scholl, Dean,

    SP6 is a salmonella phage closely related to coliphage K1-5. K1-5 is notable in that it encodes two polysaccharide-degrading tailspike proteins, an endosialidase that allows it to infect E. coli K1, and a lyase that enables it to infect K5 strains. SP6 is similar to K1-5 except that it encodes a P22-like endorhamnosidase tailspike, gp46, allowing it to infect group B Salmonella. We show here that SP6 can also infect Salmonella serogroups C{sub 2} and C{sub 3} and that a mutation in a putative second tailspike, gp47, eliminates this specificity. Gene 47 was fused to the coding region of themore » N-terminal portion of the Pseudomonas aeruginosa R2 pyocin tail fiber and expressed in trans such that the fusion protein becomes incorporated into pyocin particles. These pyocins, termed AvR2-SP47, killed serogroups C{sub 2} and C{sub 3}Salmonella. We conclude that SP6 encodes two tail proteins providing it a broad host range among Salmonella enterica. - Highlights: • SP6 is a “dual specificity” bacteriophage that encodes two different receptor binding proteins giving it a broad host range. • These receptor binding proteins can be used to re-target the spectrum of R-type bacteriocins to Salmonella enterica. • Both SP6 and the engineered R-type bacteriocins can kill the Salmonella serovars most associated with human disease making them attractive for development as antimicrobial agents.« less

  1. Characterization of a T7-like lytic bacteriophage (phiSG-JL2) of Salmonella enterica serovar gallinarum biovar gallinarum.

    PubMed

    Kwon, Hyuk-Joon; Cho, Sun-Hee; Kim, Tae-Eun; Won, Yong-Jin; Jeong, Jihye; Park, Se Chang; Kim, Jae-Hong; Yoo, Han-Sang; Park, Yong-Ho; Kim, Sun-Joong

    2008-11-01

    PhiSG-JL2 is a newly discovered lytic bacteriophage infecting Salmonella enterica serovar Gallinarum biovar Gallinarum but is nonlytic to a rough vaccine strain of serovar Gallinarum biovar Gallinarum (SG-9R), S. enterica serovar Enteritidis, S. enterica serovar Typhimurium, and S. enterica serovar Gallinarum biovar Pullorum. The phiSG-JL2 genome is 38,815 bp in length (GC content, 50.9%; 230-bp-long direct terminal repeats), and 55 putative genes may be transcribed from the same strand. Functions were assigned to 30 genes based on high amino acid similarity to known proteins. Most of the expected proteins except tail fiber (31.9%) and the overall organization of the genomes were similar to those of yersiniophage phiYeO3-12. phiSG-JL2 could be classified as a new T7-like virus and represents the first serovar Gallinarum biovar Gallinarum phage genome to be sequenced. On the basis of intraspecific ratios of nonsynonymous to synonymous nucleotide changes (Pi[a]/Pi[s]), gene 2 encoding the host RNA polymerase inhibitor displayed Darwinian positive selection. Pretreatment of chickens with phiSG-JL2 before intratracheal challenge with wild-type serovar Gallinarum biovar Gallinarum protected most birds from fowl typhoid. Therefore, phiSG-JL2 may be useful for the differentiation of serovar Gallinarum biovar Gallinarum from other Salmonella serotypes, prophylactic application in fowl typhoid control, and understanding of the vertical evolution of T7-like viruses.

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

    PubMed

    Song, Won-Jae; Kang, Dong-Hyun

    2016-02-01

    This study evaluated the efficacy of a 915 MHz microwave with 3 different levels to inactivate 3 serovars of Salmonella in peanut butter. Peanut butter inoculated with Salmonella enterica serovar Senftenberg, S. enterica serovar Typhimurium and S. enterica serovar Tennessee were treated with a 915 MHz microwave with 2, 4 and 6 kW and acid and peroxide values and color changes were determined after 5 min of microwave heating. Salmonella populations were reduced with increasing treatment time and treatment power. Six kW 915 MHz microwave treatment for 5 min reduced these three Salmonella serovars by 3.24-4.26 log CFU/g. Four and two kW 915 MHz microwave processing for 5 min reduced these Salmonella serovars by 1.14-1.48 and 0.15-0.42 log CFU/g, respectively. Microwave treatment did not affect acid, peroxide, or color values of peanut butter. These results demonstrate that 915 MHz microwave processing can be used as a control method for reducing Salmonella in peanut butter without producing quality deterioration. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    PubMed

    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.

  4. Changes in the Salmonella enterica Enteritidis phenotypes in presence of acyl homoserine lactone quorum sensing signals.

    PubMed

    Campos-Galvão, Maria Emilene Martino; Ribon, Andrea Oliveira Barros; Araújo, Elza Fernandes; Vanetti, Maria Cristina Dantas

    2016-05-01

    Quorum sensing is used by bacteria to coordinate gene expression in response to population density and involves the production, detection and response to extracellular signaling molecules known as autoinducers (AIs). Salmonella does not synthesize the AI-1, acyl homoserine lactone (AHL) common to gram-negative bacteria; however, it has a receptor for AI-1, the SdiA protein. The effect of SdiA in modulating phenotypes of Salmonella has not been elucidated. In this report, we provide evidence that the AIs-1 affect Salmonella enterica serovar Enteritidis behavior by enhancing the biofilm formation and expression of virulence genes under anaerobic conditions. Biofilm formation by Salmonella was detected by the crystal violet method and by scanning electron microscopy. The presence of AHLs, particularly C12-HSL, increased biofilm formation and promoted expression of biofilm formation genes (lpfA, fimF, fliF, glgC) and virulence genes (hilA, invA, invF). Our results demonstrated that AHLs produced by other organisms played an important role in virulence phenotypes of Salmonella Enteritidis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The Inositol Phosphatase SHIP Controls Salmonella enterica Serovar Typhimurium Infection In Vivo▿

    PubMed Central

    Bishop, Jennifer L.; Sly, Laura M.; Krystal, Gerald; Finlay, B. Brett

    2008-01-01

    The SH2 domain-containing inositol 5′-phosphatase, SHIP, negatively regulates various hematopoietic cell functions and is critical for maintaining immune homeostasis. However, whether SHIP plays a role in controlling bacterial infections in vivo remains unknown. Salmonella enterica causes human salmonellosis, a disease that ranges in severity from mild gastroenteritis to severe systemic illness, resulting in significant morbidity and mortality worldwide. The susceptibility of ship+/+and ship−/− mice and bone marrow-derived macrophages to S. enterica serovar Typhimurium infection was compared. ship−/− mice displayed an increased susceptibility to both oral and intraperitoneal serovar Typhimurium infection and had significantly higher bacterial loads in intestinal and systemic sites than ship+/+mice, indicating a role for SHIP in the gut-associated and systemic pathogenesis of serovar Typhimurium in vivo. Cytokine analysis of serum from orally infected mice showed that ship−/− mice produce lower levels of Th1 cytokines than do ship+/+ animals at 2 days postinfection, and in vitro analysis of supernatants taken from infected bone marrow-derived macrophages derived to mimic the in vivo ship−/− alternatively activated (M2) macrophage phenotype correlated with these data. M2 macrophages were the predominant population in vivo in both oral and intraperitoneal infections, since tissue macrophages within the small intestine and peritoneal macrophages from ship−/− mice showed elevated levels of the M2 macrophage markers Ym1 and Arginase 1 compared to ship+/+ cells. Based on these data, we propose that M2 macrophage skewing in ship−/− mice contributes to ineffective clearance of Salmonella in vivo. PMID:18426884

  6. Salmonella enterica isolates from pasture-raised poultry exhibit antimicrobial resistance and class I integrons.

    PubMed

    Melendez, S N; Hanning, I; Han, J; Nayak, R; Clement, A R; Wooming, A; Hererra, P; Jones, F T; Foley, S L; Ricke, S C

    2010-12-01

    While considerable foodborne pathogen research has been conducted on conventionally produced broilers and turkeys, few studies have focused on free-range (organic) or pastured poultry. The current surveillance study was designed to isolate, identify and genetically characterize Salmonella from pastured poultry farm environment and from retail samples. In this study, 59 isolates were collected from two pastured poultry farms (n = 164; pens, feed, water and insect traps) and retail carcasses (n = 36) from a local natural foods store and a local processing plant. All isolates were serotyped and analysed phenotypically (antimicrobial resistance profiles) and genotypically (DNA fingerprints, plasmid profiles and integron analysis). Salmonella enterica was detected using standard microbiological methods. Salmonella Kentucky was the most prevalent serotype detected from the sampled sources (53%), followed by Salmonella Enteritidis (24%), Bareilly (10%), Mbandaka (7%), Montevideo (5%) or Newport (2%). All isolates were resistant to sulfisoxazole and novobiocin, and the majority (40/59) possessed class I integrons shown by PCR detection. Each Salmonella serotype elicited a distinct pulsed-field gel electrophoresis fingerprint profile, and unique differences were observed among the serotypes.  The findings of this study show that Salmonella serotypes isolated from pasture-raised poultry exhibit antimicrobial resistance and class I integrons.  This study demonstrates that despite the cessation of antibiotic usage in poultry production, antibiotic resistant Salmonella may still be recovered from the environment and poultry products. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  7. Anaerobic Cysteine Degradation and Potential Metabolic Coordination in Salmonella enterica and Escherichia coli

    PubMed Central

    Loddeke, Melissa; Schneider, Barbara; Oguri, Tamiko; Mehta, Iti; Xuan, Zhenyu

    2017-01-01

    ABSTRACT Salmonella enterica has two CyuR-activated enzymes that degrade cysteine, i.e., the aerobic CdsH and an unidentified anaerobic enzyme; Escherichia coli has only the latter. To identify the anaerobic enzyme, transcript profiling was performed for E. coli without cyuR and with overexpressed cyuR. Thirty-seven genes showed at least 5-fold changes in expression, and the cyuPA (formerly yhaOM) operon showed the greatest difference. Homology suggested that CyuP and CyuA represent a cysteine transporter and an iron-sulfur-containing cysteine desulfidase, respectively. E. coli and S. enterica ΔcyuA mutants grown with cysteine generated substantially less sulfide and had lower growth yields. Oxygen affected the CyuR-dependent genes reciprocally; cyuP-lacZ expression was greater anaerobically, whereas cdsH-lacZ expression was greater aerobically. In E. coli and S. enterica, anaerobic cyuP expression required cyuR and cysteine and was induced by l-cysteine, d-cysteine, and a few sulfur-containing compounds. Loss of either CyuA or RidA, both of which contribute to cysteine degradation to pyruvate, increased cyuP-lacZ expression, which suggests that CyuA modulates intracellular cysteine concentrations. Phylogenetic analysis showed that CyuA homologs are present in obligate and facultative anaerobes, confirming an anaerobic function, and in archaeal methanogens and bacterial acetogens, suggesting an ancient origin. Our results show that CyuA is the major anaerobic cysteine-catabolizing enzyme in both E. coli and S. enterica, and it is proposed that anaerobic cysteine catabolism can contribute to coordination of sulfur assimilation and amino acid synthesis. IMPORTANCE Sulfur-containing compounds such as cysteine and sulfide are essential and reactive metabolites. Exogenous sulfur-containing compounds can alter the thiol landscape and intracellular redox reactions and are known to affect several cellular processes, including swarming motility, antibiotic sensitivity, and

  8. Inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree by high hydrostatic pressure with/without added ascorbic acid

    USDA-ARS?s Scientific Manuscript database

    The objective of this research was to evaluate and develop a method for inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree (CP) by high hydrostatic pressure (HHP). Cantaloupe being the most netted varieties of melons presents a greater risk of pathogen transmission. ...

  9. Immersion in antimicrobial solutions reduces Salmonella enterica and Shiga toxin-producing Escherichia coli on beef cheek meat

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to determine the effect of immersing beef cheek meat in antimicrobial solutions on the reduction of O157:H7 Shiga toxin–producing Escherichia coli (STEC), non-O157:H7 STEC, and Salmonella enterica. Beef cheek meat was inoculated with O157:H7 STEC, non-O157:H7 STEC, an...

  10. Survival and heat resistance of Salmonella enterica and Escherichia coli O157:H7 in peanut butter.

    PubMed

    He, Yingshu; Guo, Dongjing; Yang, Jingyun; Tortorello, Mary Lou; Zhang, Wei

    2011-12-01

    Significant differences (P < 0.05) were found between the survival rates of Salmonella enterica and Escherichia coli O157:H7 in peanut butter with different formulations and water activity. High carbohydrate content in peanut butter and low incubation temperature resulted in higher levels of bacterial survival during storage but lower levels of bacterial resistance to heat treatment.

  11. Influence of ethanol adaptation on Salmonella enterica serovar Enteritidis survival in acidic environments and expression of acid tolerance-related genes

    USDA-ARS?s Scientific Manuscript database

    Aims: Salmonella enterica serovar Enteritidis (S. Enteritidis) can encounter mild ethanol stress during its life cycle. However, adaptation to a stressful condition may affect bacterial resistance to subsequent stresses. Hence, this work was undertaken to investigate the influences of ethanol adapta...

  12. Characterization of Salmonella enterica isolates from turkeys in commercial processing plants for resistance to antibiotics, disinfectants, and a growth promoter

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serovars isolated from turkeys in commercial processing plants were characterized for susceptibility to antibiotics, disinfectants, disinfectant components, and the organoarsenical growth promotant 4-hydroxy-3-nitrophenylarsonic acid (3-NHPAA) and its metabolites NaAsO2 (As[III])...

  13. Phenotypic and genotypic antimicrobial resistance and virulence genes of Salmonella enterica isolated from pet dogs and cats.

    PubMed

    Srisanga, Songsak; Angkititrakul, Sunpetch; Sringam, Patcharee; Le Ho, Phuong T; T Vo, An T; Chuanchuen, Rungtip

    2017-09-30

    Salmonella enterica isolates (n = 122), including 32 serotypes from 113 dogs and 9 cats, were obtained from household dogs (n = 250) and cats (n = 50) during 2012-2015. The isolates were characterized by serotyping, antimicrobial resistance phenotyping and genotyping, and virulence gene screening. Serovars Weltevreden (15.6%) and Typhimurium (13.9%) were the most common. The majority (43%) of the isolates were multidrug resistant. The dog isolates (12.3%) harbored class 1 integrons, of which the dfrA12 - aadA2 cassette was most frequent (66.7%). The only class integron in serovar Albany was located on a conjugative plasmid. Two ESBL-producing isolates ( i.e ., a serovar Krefeld and a serovar Enteritridis) carried bla TEM and bla CTX-M , and the bla TEM gene in both was horizontally transferred. Of the plasmid-mediated quinolone resistance genes tested, only qnrS (4.9%) was detected. Most Salmonella isolates harbored invA (100%), prgH (91.8%), and sipB (91%). Positive associations between resistance and virulence genes were observed for bla PSE-1 / orgA , cmlA / span , tolC , and sul1 / tolC ( p < 0.05). The results suggest that companion dogs and cats are potential sources of S. enterica strains that carry resistance and virulence genes and that antimicrobial use in companion animals may select for the examined Salmonella virulence factors.

  14. Phenotypic and genotypic antimicrobial resistance and virulence genes of Salmonella enterica isolated from pet dogs and cats

    PubMed Central

    Srisanga, Songsak; Angkititrakul, Sunpetch; Sringam, Patcharee; Le Ho, Phuong T.; Vo, An T. T.

    2017-01-01

    Salmonella enterica isolates (n = 122), including 32 serotypes from 113 dogs and 9 cats, were obtained from household dogs (n = 250) and cats (n = 50) during 2012–2015. The isolates were characterized by serotyping, antimicrobial resistance phenotyping and genotyping, and virulence gene screening. Serovars Weltevreden (15.6%) and Typhimurium (13.9%) were the most common. The majority (43%) of the isolates were multidrug resistant. The dog isolates (12.3%) harbored class 1 integrons, of which the dfrA12-aadA2 cassette was most frequent (66.7%). The only class integron in serovar Albany was located on a conjugative plasmid. Two ESBL-producing isolates (i.e., a serovar Krefeld and a serovar Enteritridis) carried blaTEM and blaCTX-M, and the blaTEM gene in both was horizontally transferred. Of the plasmid-mediated quinolone resistance genes tested, only qnrS (4.9%) was detected. Most Salmonella isolates harbored invA (100%), prgH (91.8%), and sipB (91%). Positive associations between resistance and virulence genes were observed for blaPSE-1/orgA, cmlA/spaN, tolC, and sul1/tolC (p < 0.05). The results suggest that companion dogs and cats are potential sources of S. enterica strains that carry resistance and virulence genes and that antimicrobial use in companion animals may select for the examined Salmonella virulence factors. PMID:27586467

  15. Ancient typhoid epidemic reveals possible ancestral strain of Salmonella enterica serovar Typhi.

    PubMed

    Papagrigorakis, Manolis J; Synodinos, Philippos N; Yapijakis, Christos

    2007-01-01

    In contrast to other serotypes of Salmonella enterica, S. Typhi is exclusively adapted to human hosts. Recently, S. Typhi was identified in ancient skeletal material, thereby incriminating typhoid fever for the Plague of Athens. Since, according to Thucydides' report, animals were also affected by the disease, a working hypothesis is constituted that the causative agent of the Plague might be the anticipated original strain of S. Typhi, purportedly capable of infecting animals as well as humans. Possible future sequencing of the discovered ancient strain of S. Typhi may help towards identifying its genomic differences responsible for its modern specification to humans.

  16. Genetic diversity and virulence genes of Salmonella enterica subspecies enterica serotype Enteritidis isolated from meats and eggs.

    PubMed

    Fardsanei, Fatemeh; Soltan Dallal, Mohammad Mehdi; Douraghi, Masoumeh; Zahraei Salehi, Taghi; Mahmoodi, Mahmood; Memariani, Hamed; Nikkhahi, Farhad

    2017-06-01

    Salmonella enterica subspecies enterica serotype Enteritidis (S. Enteritidis) is one of the leading causes of food-borne gastroenteritis associated with the consumption of contaminated food products of animal origin. Little is known about the genetic diversity and virulence content of S. Enteritidis isolated from poultry meats and eggs in Iran. A total of 34 S. Enteritidis strains were collected from different food sources of animal origin in Tehran from May 2015 to July 2016. All of the S. Enteritidis strains were serotyped, antimicrobial susceptibility tested, and characterized for virulence genes. Pulsed-field gel electrophoresis (PFGE) was also applied for comparison of genetic relatedness. All of the strains harbored invA, hilA, ssrA, sefA, spvC, and sipA genes. A high prevalence of resistance against certain antibiotics such as cefuroxime (79.4%), nalidixic acid (47%), and ciprofloxacin (44.2%) was also observed. Regarding PFGE, S. Enteritidis strains from different sources showed considerable overlap, suggesting the lack of diversity among these isolates. Moreover, no correlation between virulence profiles or antibiotypes and PFGE clusters was observed. In conclusion, our study provided valuable information on virulence gene content, antibiotic resistance, and genetic diversity of S. Enteritidis isolated from food sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Identification of a novel transposon-associated phosphoethanolamine transferase gene, mcr-5, conferring colistin resistance in d-tartrate fermenting Salmonella enterica subsp. enterica serovar Paratyphi B.

    PubMed

    Borowiak, Maria; Fischer, Jennie; Hammerl, Jens A; Hendriksen, Rene S; Szabo, Istvan; Malorny, Burkhard

    2017-12-01

    Plasmid-mediated mobilized colistin resistance is currently known to be caused by phosphoethanolamine transferases termed MCR-1, MCR-2, MCR-3 and MCR-4. However, this study focuses on the dissection of a novel resistance mechanism in mcr-1-, mcr-2- and mcr-3-negative d-tartrate fermenting Salmonella enterica subsp. enterica serovar Paratyphi B (Salmonella Paratyphi B dTa+) isolates with colistin MIC values >2 mg/L. A selected isolate from the strain collection of the German National Reference Laboratory for Salmonella was investigated by WGS and bioinformatical analysis to identify novel phosphoethanolamine transferase genes involved in colistin resistance. Subsequently PCR screening, S1-PFGE and DNA-DNA hybridization were performed to analyse the prevalence and location of the identified mcr-5 gene. Cloning and transformation experiments in Escherichia coli DH5α and Salmonella Paratyphi B dTa+ control strains were carried out and the activity of MCR-5 was determined in vitro by MIC testing. In this study, we identified a novel phosphoethanolamine transferase in 14 mcr-1-, mcr-2- and mcr-3-negative Salmonella Paratyphi B dTa+ isolates with colistin MIC values >2 mg/L that were received during 2011-13. The respective gene, further termed as mcr-5 (1644 bp), is part of a 7337 bp transposon of the Tn3 family and usually located on related multi-copy ColE-type plasmids. Interestingly, in one isolate an additional subclone with a chromosomal location of the mcr-5 transposon was observed. Our findings suggest that the transfer of colistin-resistance-mediating phosphoethanolamine transferase genes from bacterial chromosomes to mobile genetic elements has occurred in multiple independent events raising concern regarding their variety, prevalence and impact on public health. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Multidrug-resistant Strains of Salmonella enterica Typhimurium, United States, 1997–19981

    PubMed Central

    Whichard, Jean; Rossiter, Shannon; Holland, Ben; Stamey, Karen; Headrick, Marcia L.; Barrett, Timothy J.; Angulo, Frederick J.

    2004-01-01

    To evaluate multidrug-resistant strains of Salmonella enterica Typhimurium, including definitive type 104 (DT104) in the United States, we reviewed data from the National Antimicrobial Resistance Monitoring System (NARMS). In 1997–1998, 25% (703) of 2,767 serotyped Salmonella isolates received at NARMS were S. Typhimurium; antimicrobial susceptibility testing and phage typing were completed for 697. Fifty-eight percent (402) were resistant to >1 antimicrobial agent. Three multidrug-resistant (>5 drugs) strains accounted for 74% (296) of all resistant isolates. Ceftriaxone resistance was present in 3% (8), and nalidixic acid resistance in 1% (4), of these multidrug-resistant strains. By phage typing, 37% (259) of S. Typhimurium isolates were DT104, 30% (209) were of undefined type and 15% (103) were untypable. Fifty percent (202) of resistant (>1 drug) isolates were DT104. Multidrug-resistant S. Typhimurium isolates, particularly DT104, account for a substantial proportion of S. Typhimurium isolates; ceftriaxone resistance is exhibited by some of these strains. PMID:15200811

  19. Epigenetic modification: possible approach to reduce Salmonella enterica serovar enteritidis susceptibility under stress conditions.

    PubMed

    Soleimani, A F; Zulkifli, I; Hair-Bejo, M; Ebrahimi, M; Jazayeri, S D; Hashemi, S R; Meimandipour, A; Goh, Y M

    2012-01-01

    Stressors may influence chicken susceptibility to pathogens such as Salmonella enterica. Feed withdrawal stress can cause changes in normal intestinal epithelial structure and may lead to increased attachment and colonization of Salmonella. This study aimed to investigate modulatory effects of epigenetic modification by feed restriction on S. enterica serovar Enteritidis colonization in broiler chickens subjected to feed withdrawal stress. Chicks were divided into four groups: ad libitum feeding; ad libitum feeding with 24-h feed withdrawal on day 42; 60% feed restriction on days 4, 5, and 6; and 60% feed restriction on days 4, 5, and 6 with 24-h feed withdrawal on day 42. Attachment of S. Enteritidis to ileal tissue was determined using an ex vivo ileal loop assay, and heat shock protein 70 (Hsp70) expression was evaluated using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and western blotting. Feed withdrawal stress increased S. Enteritidis attachment to ileal tissue. However, following feed withdrawal the epigenetically modified chickens had significantly lower attachment of S. Enteritidis than their control counterparts. A similar trend with a very positive correlation was observed for Hsp70 expression. It appears that epigenetic modification can enhance resistance to S. Enteritidis colonization later in life in chickens under stress conditions. The underlying mechanism could be associated with the lower Hsp70 expression in the epigenetically modified chickens.

  20. Differences in Pathogenesis for Salmonella enterica serovar Typhimurium in the Mouse Versus the Swine Model Identify Bacterial Gene Products Required for Systemic but not Gastrointestinal Disease

    USDA-ARS?s Scientific Manuscript database

    Over the last several decades, the mouse model of Typhoid fever has been an extremely productive model to investigate Salmonella enterica serovar Typhimurium pathogenesis. The mouse is the paradigm for investigating systemic disease due to infection by Salmonella; however, the swine model of gastro...

  1. Molecular and epidemiologic analysis of a county-wide outbreak caused by Salmonella enterica subsp. enterica serovar Enteritidis traced to a bakery

    PubMed Central

    Lu, Po-Liang; Hwang, In-Jane; Tung, Ya-Lina; Hwang, Shang-Jyh; Lin, Chun-Lu; Siu, LK

    2004-01-01

    Background An increase in the number of attendees due to acute gastroenteritis and fever was noted at one hospital emergency room in Taiwan over a seven-day period from July to August, 2001. Molecular and epidemiological surveys were performed to trace the possible source of infection. Methods An epidemiological investigation was undertaken to determine the cause of the outbreak. Stool and blood samples were collected according to standard protocols per Center for Disease Control, Taiwan. Typing of the Salmonella isolates from stool, blood, and food samples was performed with serotyping, antibiotypes, and pulsed field gel electrophoresis (PFGE) following XbaI restriction enzyme digestion. Results Comparison of the number of patients with and without acute gastroenteritis (506 and 4467, respectively) during the six weeks before the outbreak week revealed a significant increase in the number of patients during the outbreak week (162 and 942, respectively) (relative risk (RR): 1.44, 95% confidence interval (CI): 1.22–1.70, P value < 0.001). During the week of the outbreak, 34 of 162 patients with gastroenteritis were positive for Salmonella, and 28 of these 34 cases reported eating the same kind of bread. In total, 28 of 34 patients who ate this bread were positive for salmonella compared to only 6 of 128 people who did not eat this bread (RR: 17.6, 95%CI 7.9–39.0, P < 0.001). These breads were produced by the same bakery and were distributed to six different traditional Chinese markets., Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) was isolated from the stool samples of 28 of 32 individuals and from a recalled bread sample. All S. Enteritidis isolates were of the same antibiogram. PFGE typing revealed that all except two of the clinical isolates and the bread isolates were of the same DNA macrorestriction pattern. Conclusions The egg-covered bread contaminated with S. Enteritidis was confirmed as the vehicle of infection. Alertness in

  2. Spatial Variation and Survival of Salmonella enterica Subspecies in a Population of Australian Sleepy Lizards (Tiliqua rugosa)

    PubMed Central

    Parsons, Sandra K.; Bull, C. Michael

    2015-01-01

    The life cycles of many enteric bacterial species require a transition between two very distinct environments. Their primary habitat is the gastrointestinal tract of the host, while their secondary habitat, during transmission from one host to another, consists of environments external to the host, such as soil, water, and sediments. Consequently, both host and environmental factors shape the genetic structure of enteric bacterial populations. This study examined the distribution of four Salmonella enterica subspecies in a population of sleepy lizards, Tiliqua rugosa, in a semiarid region of South Australia. The lizards living within the 1,920-m by 720-m study site were radio tracked, and their enteric bacteria were sampled at regular intervals throughout their active seasons in the years 2001, 2002, and 2006. Four of the six subspecies of S. enterica were present in this population and were nonrandomly distributed among the lizards. In particular, S. enterica subsp. diarizonae was restricted to lizards living in the most shaded parts of the study site with an overstorey of Casuarina trees. Experiments undertaken to investigate the survival of S. enterica cells under seminatural conditions revealed that cell survival decreased with increased exposure to elevated temperatures and UV light. Among the three S. enterica subspecies tested, S. enterica subsp. diarizonae consistently had an average expected life span that was shorter than that observed for the other two subspecies. There was no indication in the data that there was any competitive dominance hierarchy among the S. enterica subspecies within individual hosts. Thus, the nonrandom distribution of S. enterica subspecies in this population of lizards appears to be driven by their different survival characteristics in the external environment. PMID:26092451

  3. Lack of evidence of spill-over of Salmonella enterica between cattle and sympatric Iberian ibex (Capra pyrenaica) from a protected area in Catalonia, NE Spain.

    PubMed

    Navarro-Gonzalez, N; Velarde, R; Porrero, M C; Mentaberre, G; Serrano, E; Mateos, A; Domínguez, L; Lavín, S

    2014-08-01

    Salmonella enterica is a zoonotic agent of worldwide importance found in a wide range of wild hosts. However, its prevalence in many popular game species has never been assessed. Iberian ibex (Capra pyrenaica) is the main game caprinae of the Iberian Peninsula and around two thousand individuals are hunted every year for trophy or for home consumption. In this work, 313 Iberian ibexes from the Ports de Tortosa i Beseit National Game Reserve (NE Spain) were tested for Salmonella enterica in faeces, and anti microbial susceptibility was determined. The exact location of shooting or capture was recorded with a GPS device to study the links of Salmonella infection with cattle presence and human proximity. Additionally, samples were taken from cattle grazing inside this reserve (n = 73). Only three Iberian ibexes (0.96%, 95% CI 0.2-2.8) were positive to Salmonella (serotype Enteritidis, Bardo and 35:r:z35), while prevalence was moderate in cattle: 21.92% (95% CI 13.10-33.14, serotype Meleagridis, Anatum, Kedougou and Othmarschen). All isolates were susceptible to the anti microbial agents tested. Moreover, a case of fatal septicaemic salmonellosis in an 11-year-old male Iberian ibex is described where Salmonella enterica serotype Enteritidis was isolated from the lung, liver and spleen samples. The low prevalence of Salmonella in Iberian ibex and the lack of shared serotypes suggest no association to cattle. Despite this, game meat aimed for human consumption should be examined, and it is strongly recommended that hunters and game keepers manipulate animals and carcasses under maximal hygienic conditions to avoid environmental contamination and human contagion. © 2012 Blackwell Verlag GmbH.

  4. Replication of Salmonella enterica Serovar Typhimurium in Human Monocyte-Derived Macrophages

    PubMed Central

    Lathrop, Stephanie K.; Binder, Kelsey A.; Starr, Tregei; Cooper, Kendal G.; Chong, Audrey; Carmody, Aaron B.

    2015-01-01

    Salmonella enterica serovar Typhimurium is a common cause of food-borne gastrointestinal illness, but additionally it causes potentially fatal bacteremia in some immunocompromised patients. In mice, systemic spread and replication of the bacteria depend upon infection of and replication within macrophages, but replication in human macrophages is not widely reported or well studied. In order to assess the ability of Salmonella Typhimurium to replicate in human macrophages, we infected primary monocyte-derived macrophages (MDM) that had been differentiated under conditions known to generate different phenotypes. We found that replication in MDM depends greatly upon the phenotype of the cells, as M1-skewed macrophages did not allow replication, while M2a macrophages and macrophages differentiated with macrophage colony-stimulating factor (M-CSF) alone (termed M0) did. We describe how additional conditions that alter the macrophage phenotype or the gene expression of the bacteria affect the outcome of infection. In M0 MDM, the temporal expression of representative genes from Salmonella pathogenicity islands 1 and 2 (SPI1 and SPI2) and the importance of the PhoP/Q two-component regulatory system are similar to what has been shown in mouse macrophages. However, in contrast to mouse macrophages, where replication is SPI2 dependent, we observed early SPI2-independent replication in addition to later SPI2-dependent replication in M0 macrophages. Only SPI2-dependent replication was associated with death of the host cell at later time points. Altogether, our results reveal a very nuanced interaction between Salmonella and human macrophages. PMID:25895967

  5. Characterization of a multidrug-resistant Salmonella enterica serovar Heidelberg outbreak strain in commercial turkeys: Colonization, transmission, and host transcriptional response

    USDA-ARS?s Scientific Manuscript database

    In recent years, multidrug-resistant (MDR) Salmonella enterica serovar Heidelberg has been associated with numerous human foodborne illness outbreaks due to consumption of poultry. For example, in 2011, an MDR S. Heidelberg outbreak associated with ground turkey sickened 136 individuals and resulted...

  6. Characterization of multidrug-resistant Salmonella enterica serovar Heidelberg from a ground turkey-associated outbreak in the United States in 2011

    USDA-ARS?s Scientific Manuscript database

    In March 2011, a multi-state outbreak of Salmonella enterica ser. Heidelberg infections was investigated. Pulsed-field gel electrophoresis (PFGE) analysis of isolates from suspected cases and an epidemiologic investigation identified 136 case patients from 34 states from February to September. Two...

  7. Sugar sulfates are not hydrolyzed by the acid-inducible sulfatase AslA from Salmonella enterica Enteritidis NalR and Kentucky 3795 at pH 5.5.

    PubMed

    Ganguly, Arpeeta; Joerger, Rolf D

    2017-08-01

    The open reading frames SEN0085 and SeKA_A4361, from Salmonella enterica serovar Enteritidis Nal R and serovar Kentucky 3795, respectively, corresponding to the acid-inducible sulfatase gene aslA from Salmonella enterica serovar Typhimurium, were previously suggested by microarray analysis to be differentially expressed under acid conditions. However, growth and enzyme activity tests in the present study demonstrated that both wild-type strains exhibited sulfatase activity with 4-nitrophenyl sulfate and 5-bromo-4-chloro-3 indolyl sulfate at pH 5.5. The acid sulfatase does not appear to be involved in sugar sulfate, tyrosine sulfate, 4-hydroxy-3-methoxyphenylglycol sulfate, heparin sulfate, or chondroitin sulfate hydrolysis at pH 5.5. Adhesion and invasion assays did not reveal differences between the serotypes and their corresponding aslA deletion mutants. Thus, the role and substrate(s) of AslA, a protein unique to salmonella and encoded in all sequenced Salmonella strains, remain elusive.

  8. Histopathology case definition of naturally acquired Salmonella enterica serovar Dublin infection in young Holstein cattle in the northeastern United States.

    PubMed

    Pecoraro, Heidi L; Thompson, Belinda; Duhamel, Gerald E

    2017-11-01

    Salmonella enterica subsp. enterica serovar Dublin ( Salmonella Dublin) is a host-adapted bacterium that causes high morbidity and mortality in dairy cattle worldwide. A retrospective search of archives at the New York Animal Health Diagnostic Center revealed 57 culture-confirmed Salmonella Dublin cases from New York and Pennsylvania in which detailed histology of multiple tissues was available. Tissues routinely submitted by referring veterinarians for histologic evaluation included sections of heart, lungs, liver, spleen, and lymph nodes. Of the 57 S almonella Dublin-positive cases, all were Holstein breed, 53 were female (93%), and 49 (86%) were <6 mo of age. Specifically, in calves <6 mo of age, >90% (45 of 49) of lungs, 90% (28 of 31) of livers, 50% (11 of 22) of spleens, and 62% (18 of 29) of lymph nodes examined had moderate-to-severe inflammation with or without necrosis. Inconstant lesions were seen in 48% (10 of 21) of hearts examined, and consisted of variable inflammatory infiltrates and rare areas of necrosis. We propose a histopathology case definition of Salmonella Dublin in <6-mo-old Holstein cattle that includes a combination of pulmonary alveolar capillary neutrophilia with or without hepatocellular necrosis and paratyphoid granulomas, splenitis, and lymphadenitis. These findings will assist in the development of improved protocols for the diagnosis of infectious diseases of dairy cattle.

  9. Salmonella enterica isolates from layer farm environments are able to form biofilm on eggshell surfaces.

    PubMed

    Pande, Vivek V; McWhorter, Andrea R; Chousalkar, Kapil K

    2016-08-01

    This study examined the eggshell biofilm forming ability of Salmonella enterica isolates recovered from egg farms. Multicellular behaviour and biofilm production were examined at 22 and 37°C by Congo red morphology and the crystal violet staining assay. The results indicated that the biofilm forming behaviour of Salmonella isolates was dependent on temperature and associated with serovars. Significantly greater biofilm production was observed at 22°C compared with 37°C. The number of viable biofilm cells attached to eggshells after incubation for 48 h at 22°C was significantly influenced by serovar. Scanning electron microscopic examination revealed firm attachment of bacterial cells to the eggshell surface. The relative expression of csgD and adrA gene was significantly higher in eggshell biofilm cells of S. Mbandaka and S. Oranienburg. These findings demonstrate that Salmonella isolates are capable of forming biofilm on the eggshell surface and that this behaviour is influenced by temperature and serovar.

  10. A periplasmic D-alanyl-D-alanine dipeptidase in the gram-negative bacterium Salmonella enterica.

    PubMed

    Hilbert, F; García-del Portillo, F; Groisman, E A

    1999-04-01

    The VanX protein is a D-alanyl-D-alanine (D-Ala-D-Ala) dipeptidase essential for resistance to the glycopeptide antibiotic vancomycin. While this enzymatic activity has been typically associated with vancomycin- and teicoplainin-resistant enterococci, we now report the identification of a D-Ala-D-Ala dipeptidase in the gram-negative species Salmonella enterica. The Salmonella enzyme is only 36% identical to VanX but exhibits a similar substrate specificity: it hydrolyzes D-Ala-D-Ala, DL-Ala-DL-Phe, and D-Ala-Gly but not the tripeptides D-Ala-D-Ala-D-Ala and DL-Ala-DL-Lys-Gly or the dipeptides L-Ala-L-Ala, N-acetyl-D-Ala-D-Ala, and L-Leu-Pro. The Salmonella dipeptidase gene, designated pcgL, appears to have been acquired by horizontal gene transfer because pcgL-hybridizing sequences were not detected in related bacterial species and the G+C content of the pcgL-containing region (41%) is much lower than the overall G+C content of the Salmonella chromosome (52%). In contrast to wild-type Salmonella, a pcgL mutant was unable to use D-Ala-D-Ala as a sole carbon source. The pcgL gene conferred D-Ala-D-Ala dipeptidase activity upon Escherichia coli K-12 but did not allow growth on D-Ala-D-Ala. The PcgL protein localizes to the periplasmic space of Salmonella, suggesting that this dipeptidase participates in peptidoglycan metabolism.

  11. Complete genome sequence of the thermotolerant foodborne pathogen Salmonella enterica serovar Senftenberg ATCC 43845 and phylogenetic analysis of loci encoding thermotolerance

    USDA-ARS?s Scientific Manuscript database

    Introduction: Previous studies in Cronobacter sakazakii, Klebsiella spp., and Escherichia coli have identified a genomic island that confers thermotolerance to its hosts. This island has recently been identified in Salmonella enterica serovar Senfentenberg ATCC 43845, a historically important, heat ...

  12. Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

  13. Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

    PubMed Central

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

    2016-01-01

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

  14. Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

    DOE PAGES

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

    2016-03-04

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

  15. Evolution of Salmonella enterica Virulence via Point Mutations in the Fimbrial Adhesin

    PubMed Central

    Kisiela, Dagmara I.; Chattopadhyay, Sujay; Libby, Stephen J.; Karlinsey, Joyce E.; Fang, Ferric C.; Tchesnokova, Veronika; Kramer, Jeremy J.; Beskhlebnaya, Viktoriya; Samadpour, Mansour; Grzymajlo, Krzysztof; Ugorski, Maciej; Lankau, Emily W.; Mackie, Roderick I.; Clegg, Steven; Sokurenko, Evgeni V.

    2012-01-01

    Whereas the majority of pathogenic Salmonella serovars are capable of infecting many different animal species, typically producing a self-limited gastroenteritis, serovars with narrow host-specificity exhibit increased virulence and their infections frequently result in fatal systemic diseases. In our study, a genetic and functional analysis of the mannose-specific type 1 fimbrial adhesin FimH from a variety of serovars of Salmonella enterica revealed that specific mutant variants of FimH are common in host-adapted (systemically invasive) serovars. We have found that while the low-binding shear-dependent phenotype of the adhesin is preserved in broad host-range (usually systemically non-invasive) Salmonella, the majority of host-adapted serovars express FimH variants with one of two alternative phenotypes: a significantly increased binding to mannose (as in S. Typhi, S. Paratyphi C, S. Dublin and some isolates of S. Choleraesuis), or complete loss of the mannose-binding activity (as in S. Paratyphi B, S. Choleraesuis and S. Gallinarum). The functional diversification of FimH in host-adapted Salmonella results from recently acquired structural mutations. Many of the mutations are of a convergent nature indicative of strong positive selection. The high-binding phenotype of FimH that leads to increased bacterial adhesiveness to and invasiveness of epithelial cells and macrophages usually precedes acquisition of the non-binding phenotype. Collectively these observations suggest that activation or inactivation of mannose-specific adhesive properties in different systemically invasive serovars of Salmonella reflects their dynamic trajectories of adaptation to a life style in specific hosts. In conclusion, our study demonstrates that point mutations are the target of positive selection and, in addition to horizontal gene transfer and genome degradation events, can contribute to the differential pathoadaptive evolution of Salmonella. PMID:22685400

  16. Characterization of Anti-Salmonella enterica Serotype Typhi Antibody Responses in Bacteremic Bangladeshi Patients Using Immuno-affinity Proteomic-based Technology (IPT)

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serotype Typhi (S. Typhi) is the cause of typhoid fever and a human-restricted pathogen. Currently available typhoid vaccines provide only 50-75% protection for 2-5 years, and available diagnostic assays to identify individuals with typhoid fever lack both sensitivity and specifi...

  17. Serovar distribution, antimicrobial resistance profiles, and PFGE typing of Salmonella enterica strains isolated from 2007–2012 in Guangdong, China

    PubMed Central

    2014-01-01

    Background Salmonella enterica includes the major serovars associated with human salmonellosis. In this study, 1764 clinical Salmonella enterica isolates from diarrhea outpatients were collected from fifteen cities in Guangdong province, China, between 2007 and 2012. These isolates represent all of the Salmonella isolates collected from the province during that period. Methods The isolates were characterized by serovar determination, antimicrobial susceptibility tests and PFGE fingerprint typing. Results The serovar distribution results demonstrated that Salmonella Typhimurium (n = 523, 29.65%) and Salmonella 4,5,12:i:- (n = 244, 13.83%) are the most common serovars causing infant salmonellosis, whereas Salmonella Enteritidis (n = 257, 14.57%) mainly causes human salmonellosis in adults. The serovar shift from Salmonella Enteritidis to Salmonella Typhimurium occurred in 2008. Antimicrobial susceptibility data showed a high burden of multidrug resistance (MDR) (n = 1128, 56.58%), and a 20%-30% increase in the number of isolates resistant to ciprofloxacin (n = 142, 8.05%) and third-generation cephalosporins (n = 88, 4.99%) from 2007–2012. Only 9.97% of isolates (n = 176) were fully susceptible to all agents tested. A high burden of MDR was observed in Salmonella Typhimurium and Salmonella 4,5,12:i:- for all age groups, and a reduced susceptibility to third-generation cephalosporins and quinolones occurred particularly in infants (≤6 years). The dominant PFGE patterns were JPXX01.GD0004, JEGX01.GD0006-7 and JNGX01.GD0006-7. ACSSuT was the predominant MDR profile in the Salmonella Typhimurium & 4,5,12:i:- complexes, while ASSuT-Nal and ASSu-Nal were the major MDR profiles in Salmonella Enteritidis. The predominant PFGE patterns of the Salmonella Typhimurium & 4,5,12:i:- complexes and Salmonella Stanley were most prevalent in infants (≤6 years). However, no obvious relationship was observed between these PFGE profiles and geographic

  18. Role of Environmental Factors in Shaping Spatial Distribution of Salmonella enterica Serovar Typhi, Fiji.

    PubMed

    de Alwis, Ruklanthi; Watson, Conall; Nikolay, Birgit; Lowry, John H; Thieu, Nga Tran Vu; Van, Tan Trinh; Ngoc, Dung Tran Thi; Rawalai, Kitione; Taufa, Mere; Coriakula, Jerimaia; Lau, Colleen L; Nilles, Eric J; Edmunds, W John; Kama, Mike; Baker, Stephen; Cano, Jorge

    2018-02-01

    Fiji recently experienced a sharp increase in reported typhoid fever cases. To investigate geographic distribution and environmental risk factors associated with Salmonella enterica serovar Typhi infection, we conducted a cross-sectional cluster survey with associated serologic testing for Vi capsular antigen-specific antibodies (a marker for exposure to Salmonella Typhi in Fiji in 2013. Hotspots with high seroprevalence of Vi-specific antibodies were identified in northeastern mainland Fiji. Risk for Vi seropositivity increased with increased annual rainfall (odds ratio [OR] 1.26/quintile increase, 95% CI 1.12-1.42), and decreased with increased distance from major rivers and creeks (OR 0.89/km increase, 95% CI 0.80-0.99) and distance to modeled flood-risk areas (OR 0.80/quintile increase, 95% CI 0.69-0.92) after being adjusted for age, typhoid fever vaccination, and home toilet type. Risk for exposure to Salmonella Typhi and its spatial distribution in Fiji are driven by environmental factors. Our findings can directly affect typhoid fever control efforts in Fiji.

  19. Role of Environmental Factors in Shaping Spatial Distribution of Salmonella enterica Serovar Typhi, Fiji

    PubMed Central

    Watson, Conall; Nikolay, Birgit; Lowry, John H.; Thieu, Nga Tran Vu; Van, Tan Trinh; Ngoc, Dung Tran Thi; Rawalai, Kitione; Taufa, Mere; Coriakula, Jerimaia; Lau, Colleen L.; Nilles, Eric J.; Edmunds, W. John; Kama, Mike; Baker, Stephen; Cano, Jorge

    2018-01-01

    Fiji recently experienced a sharp increase in reported typhoid fever cases. To investigate geographic distribution and environmental risk factors associated with Salmonella enterica serovar Typhi infection, we conducted a cross-sectional cluster survey with associated serologic testing for Vi capsular antigen–specific antibodies (a marker for exposure to Salmonella Typhi in Fiji in 2013. Hotspots with high seroprevalence of Vi-specific antibodies were identified in northeastern mainland Fiji. Risk for Vi seropositivity increased with increased annual rainfall (odds ratio [OR] 1.26/quintile increase, 95% CI 1.12–1.42), and decreased with increased distance from major rivers and creeks (OR 0.89/km increase, 95% CI 0.80–0.99) and distance to modeled flood-risk areas (OR 0.80/quintile increase, 95% CI 0.69–0.92) after being adjusted for age, typhoid fever vaccination, and home toilet type. Risk for exposure to Salmonella Typhi and its spatial distribution in Fiji are driven by environmental factors. Our findings can directly affect typhoid fever control efforts in Fiji. PMID:29350150

  20. A multiplex single nucleotide polymorphism typing assay for detecting mutations that result in decreased fluoroquinolone susceptibility in Salmonella enterica serovars Typhi and Paratyphi A

    PubMed Central

    Song, Yajun; Roumagnac, Philippe; Weill, François-Xavier; Wain, John; Dolecek, Christiane; Mazzoni, Camila J.; Holt, Kathryn E.; Achtman, Mark

    2010-01-01

    Objectives Decreased susceptibility to fluoroquinolones has become a major problem for the successful therapy of human infections caused by Salmonella enterica, especially the life-threatening typhoid and paratyphoid fevers. Methods By using Luminex xTAG beads, we developed a rapid, reliable and cost-effective multiplexed genotyping assay for simultaneously detecting 11 mutations in gyrA, gyrB and parE of S. enterica serovars Typhi and Paratyphi A that result in nalidixic acid resistance (NalR) and/or decreased susceptibility to fluoroquinolones. Results This assay yielded unambiguous single nucleotide polymorphism calls on extracted DNA from 292 isolates of Salmonella Typhi (NalR = 223 and NalS = 69) and 106 isolates of Salmonella Paratyphi A (NalR = 24 and NalS = 82). All of the 247 NalR Salmonella Typhi and Salmonella Paratyphi A isolates were found to harbour at least one of the target mutations, with GyrA Phe-83 as the most common one (143/223 for Salmonella Typhi and 18/24 for Salmonella Paratyphi A). We also identified three GyrB mutations in eight NalS Salmonella Typhi isolates (six for GyrB Phe-464, one for GyrB Leu-465 and one for GyrB Asp-466), and mutations GyrB Phe-464 and GyrB Asp-466 seem to be related to the decreased ciprofloxacin susceptibility phenotype in Salmonella Typhi. This assay can also be used directly on boiled single colonies. Conclusions The assay presented here would be useful for clinical and reference laboratories to rapidly screen quinolone-resistant isolates of Salmonella Typhi and Salmonella Paratyphi A, and decipher the underlying genetic changes for epidemiological purposes. PMID:20511368

  1. Contribution of the Salmonella enterica KdgR Regulon to Persistence of the Pathogen in Vegetable Soft Rots

    PubMed Central

    George, Andrée S.; Salas González, Isai; Lorca, Graciela L.

    2015-01-01

    During their colonization of plants, human enteric pathogens, such as Salmonella enterica, are known to benefit from interactions with phytopathogens. At least in part, benefits derived by Salmonella from the association with a soft rot caused by Pectobacterium carotovorum were shown to be dependent on Salmonella KdgR, a regulator of genes involved in the uptake and utilization of carbon sources derived from the degradation of plant polymers. A Salmonella kdgR mutant was more fit in soft rots but not in the lesions caused by Xanthomonas spp. and Pseudomonas spp. Bioinformatic, phenotypic, and gene expression analyses demonstrated that the KdgR regulon included genes involved in uptake and metabolism of molecules resulting from pectin degradation as well as those central to the utilization of a number of other carbon sources. Mutant analyses indicated that the Entner-Doudoroff pathway, in part controlled by KdgR, was critical for the persistence within soft rots and likely was responsible for the kdgR phenotype. PMID:26682862

  2. Characterization of biofilm formation by Salmonella enterica at the air-liquid interface in aquatic environments.

    PubMed

    Medrano-Félix, José Andrés; Chaidez, Cristóbal; Mena, Kristina D; Soto-Galindo, María Del Socorro; Castro-Del Campo, Nohelia

    2018-03-15

    Survival of bacterial pathogens in different environments is due, in part, to their ability to form biofilms. Four wild-type Salmonella enterica strains, two Oranienburg and two Saintpaul isolated from river water and animal feces, were tested for biofilm formation at the air-liquid interface under stressful conditions (pH and salinity treatments such as pH 3, NaCl 4.5 w/v; pH 7, NaCl 4.5 w/v; pH 10, NaCl 4.5 w/v; pH 3, Nacl 0.5 w/v; pH 7, NaCl 0.5 w/v; and pH 10, NaCl 0.5 w/v); Salmonella Typhimurium DT104 was used as a control strain. Salmonella Oranienburg and Saintpaul from feces were moderately hydrophobic and motile, while S. Saintpaul from water and the control strain S. Typhimurium showed high hydrophobicity, which helped them form more resistant biofilms than S. Oranienburg. Under stressful conditions, all strains experienced difficulties in forming biofilms. Salmonella Saintpaul and Typhimurium expressed the red dry and rough (RDAR) morphotype and were able to form biofilm at air-liquid interface, contrarily to Oranienburg that showed incomplete rough morphology. This study contributes to the knowledge of biofilm formation as a survival strategy for Salmonella in aquatic environments.

  3. Tolerance response of multidrug-resistant Salmonella enterica strains to habituation to Origanum vulgare L. essential oil

    PubMed Central

    Monte, Daniel F. M.; Tavares, Adassa G.; Albuquerque, Allan R.; Sampaio, Fábio C.; Oliveira, Tereza C. R. M.; Franco, Octavio L.; Souza, Evandro L.; Magnani, Marciane

    2014-01-01

    Multidrug-resistant Salmonella enterica isolates from human outbreaks or from poultry origin were investigated for their ability to develop direct-tolerance or cross-tolerance to sodium chloride, potassium chloride, lactic acid, acetic acid, and ciprofloxacin after habituation in subinhibitory amounts ( of the minimum inhibitory concentration – (MIC) and of the minimum inhibitory concentration – MIC) of Origanum vulgare L. essential oil (OVEO) at different time intervals. The habituation of S. enterica to OVEO did not induce direct-tolerance or cross-tolerance in the tested strains, as assessed by the modulation of MIC values. However, cells habituated to OVEO maintained or increased susceptibility to the tested antimicrobials agents, with up to fourfold double dilution decrease from previously determined MIC values. This study reports for the first time the non-inductive effect of OVEO on the acquisition of direct-tolerance or cross-tolerance in multidrug-resistant S. enterica strains to antimicrobial agents that are largely used in food preservation, as well as to CIP, the therapeutic drug of salmonellosis. PMID:25566231

  4. Spatial Variation and Survival of Salmonella enterica Subspecies in a Population of Australian Sleepy Lizards (Tiliqua rugosa).

    PubMed

    Parsons, Sandra K; Bull, C Michael; Gordon, David M

    2015-09-01

    The life cycles of many enteric bacterial species require a transition between two very distinct environments. Their primary habitat is the gastrointestinal tract of the host, while their secondary habitat, during transmission from one host to another, consists of environments external to the host, such as soil, water, and sediments. Consequently, both host and environmental factors shape the genetic structure of enteric bacterial populations. This study examined the distribution of four Salmonella enterica subspecies in a population of sleepy lizards, Tiliqua rugosa, in a semiarid region of South Australia. The lizards living within the 1,920-m by 720-m study site were radio tracked, and their enteric bacteria were sampled at regular intervals throughout their active seasons in the years 2001, 2002, and 2006. Four of the six subspecies of S. enterica were present in this population and were nonrandomly distributed among the lizards. In particular, S. enterica subsp. diarizonae was restricted to lizards living in the most shaded parts of the study site with an overstorey of Casuarina trees. Experiments undertaken to investigate the survival of S. enterica cells under seminatural conditions revealed that cell survival decreased with increased exposure to elevated temperatures and UV light. Among the three S. enterica subspecies tested, S. enterica subsp. diarizonae consistently had an average expected life span that was shorter than that observed for the other two subspecies. There was no indication in the data that there was any competitive dominance hierarchy among the S. enterica subspecies within individual hosts. Thus, the nonrandom distribution of S. enterica subspecies in this population of lizards appears to be driven by their different survival characteristics in the external environment. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. A Multicountry Molecular Analysis of Salmonella enterica Serovar Typhi With Reduced Susceptibility to Ciprofloxacin in Sub-Saharan Africa

    PubMed Central

    Al-Emran, Hassan M.; Eibach, Daniel; Krumkamp, Ralf; Ali, Mohammad; Baker, Stephen; Biggs, Holly M.; Bjerregaard-Andersen, Morten; Breiman, Robert F.; Clemens, John D.; Crump, John A.; Cruz Espinoza, Ligia Maria; Deerin, Jessica; Dekker, Denise Myriam; Gassama Sow, Amy; Hertz, Julian T.; Im, Justin; Ibrango, Samuel; von Kalckreuth, Vera; Kabore, Leon Parfait; Konings, Frank; Løfberg, Sandra Valborg; Meyer, Christian G.; Mintz, Eric D.; Montgomery, Joel M.; Olack, Beatrice; Pak, Gi Deok; Panzner, Ursula; Park, Se Eun; Razafindrabe, Jean Luco Tsiriniaina; Rabezanahary, Henintsoa; Rakotondrainiarivelo, Jean Philibert; Rakotozandrindrainy, Raphaël; Raminosoa, Tiana Mirana; Schütt-Gerowitt, Heidi; Sampo, Emmanuel; Soura, Abdramane Bassiahi; Tall, Adama; Warren, Michelle; Wierzba, Thomas F.; May, Jürgen; Marks, Florian

    2016-01-01

    Background. Salmonella enterica serovar Typhi is a predominant cause of bloodstream infections in sub-Saharan Africa (SSA). Increasing numbers of S. Typhi with resistance to ciprofloxacin have been reported from different parts of the world. However, data from SSA are limited. In this study, we aimed to measure the ciprofloxacin susceptibility of S. Typhi isolated from patients with febrile illness in SSA. Methods. Febrile patients from 9 sites within 6 countries in SSA with a body temperature of ≥38.0°C were enrolled in this study. Blood samples were obtained for bacterial culture, and Salmonella isolates were identified biochemically and confirmed by multiplex polymerase chain reaction (PCR). Antimicrobial susceptibility of all Salmonella isolates was performed by disk diffusion test, and minimum inhibitory concentrations (MICs) against ciprofloxacin were measured by Etest. All Salmonella isolates with reduced susceptibility to ciprofloxacin (MIC > 0.06 µg/mL) were screened for mutations in quinolone resistance-determining regions in target genes, and the presence of plasmid-mediated quinolone resistance (PMQR) genes was assessed by PCR. Results. A total of 8161 blood cultures were performed, and 100 (1.2%) S. Typhi, 2 (<0.1%) Salmonella enterica serovar Paratyphi A, and 27 (0.3%) nontyphoid Salmonella (NTS) were isolated. Multidrug-resistant S. Typhi were isolated in Kenya (79% [n = 38]) and Tanzania (89% [n = 8]) only. Reduced ciprofloxacin-susceptible (22% [n = 11]) S. Typhi were isolated only in Kenya. Among those 11 isolates, all had a Glu133Gly mutation in the gyrA gene combined with either a gyrA (Ser83Phe) or gyrB mutation (Ser464Phe). One Salmonella Paratyphi A isolate with reduced susceptibility to ciprofloxacin was found in Senegal, with 1 mutation in gyrA (Ser83Phe) and a second mutation in parC (Ser57Phe). Mutations in the parE gene and PMQR genes were not detected in any isolate. Conclusions. Salmonella Typhi with reduced susceptibility

  6. Few Differences in Metabolic Network Use Found Between Salmonella enterica Colonization of Plants and Typhoidal Mice.

    PubMed

    Kwan, Grace; Plagenz, Brett; Cowles, Kimberly; Pisithkul, Tippapha; Amador-Noguez, Daniel; Barak, Jeri D

    2018-01-01

    The human enteric pathogen Salmonella enterica leads a cross-kingdom lifestyle, actively colonizing and persisting on plants in between animal hosts. One of the questions that arises from this dual lifestyle is how S. enterica is able to adapt to such divergent hosts. Metabolic pathways required for S. enterica animal colonization and virulence have been previously identified, but the metabolism of this bacterium on plants is poorly understood. To determine the requirements for plant colonization by S. enterica , we first screened a library of metabolic mutants, previously examined in a systemic mouse typhoidal model, for competitive plant colonization fitness on alfalfa seedlings. By comparing our results to those reported in S. enterica -infected murine spleens, we found that the presence of individual nutrients differed between the two host niches. Yet, similar metabolic pathways contributed to S. enterica colonization of both plants and animals, such as the biosynthesis of amino acids, purines, and vitamins and the catabolism of glycerol and glucose. However, utilization of at least three metabolic networks differed during the bacterium's plant- and animal-associated lifestyles. Whereas both fatty acid biosynthesis and degradation contributed to S. enterica animal colonization, only fatty acid biosynthesis was required during plant colonization. Though serine biosynthesis was required in both hosts, S. enterica used different pathways within the serine metabolic network to achieve this outcome. Lastly, the metabolic network surrounding manA played different roles during colonization of each host. In animal models of infection, O-antigen production downstream of manA facilitates immune evasion. We discovered that manA contributed to S. enterica attachment, to seeds and germinated seedlings, and was essential for growth in early seedling exudates, when mannose is limited. However, only seedling attachment was linked to O-antigen production, indicating that man

  7. Dam methylation is required for efficient biofilm production in Salmonella enterica serovar Enteritidis.

    PubMed

    Aya Castañeda, María del Rosario; Sarnacki, Sebastián Hernán; Noto Llana, Mariángeles; López Guerra, Adriana Gabriela; Giacomodonato, Mónica Nancy; Cerquetti, María Cristina

    2015-01-16

    The ecological success of Salmonella enterica to survive in different environments is due, in part, to the ability to form biofilms, something which is especially important for food industry. The aim of the current study was to evaluate the involvement of Dam methylation in biofilm production in S. Enteritidis strains. The ability to generate biofilms was analyzed in wild type and dam mutant strains. In S. Enteritidis, the absence of Dam affected the capacity to develop pellicles at the air-liquid interface and reduced the ability to form biofilm on polystyrene surfaces. Curli and cellulose production, determined by Congo red and calcofluor assays, were affected in dam mutant strains. Relative quantitative real-time PCR experiments showed that the expression of csgD and csgA genes is reduced in mutants lacking dam gene with respect to the wild type strains, whereas transcript levels of bcsA are not affected in the absence of Dam. To our knowledge, this is the first report on the participation of Dam methylation on biofilm production in Enteritidis or any other serovar of S. enterica. Results presented here suggest that changes in gene expression required for biofilm production are finely regulated by Dam methylation. Thus, Dam methylation could modulate csgD expression and upregulate the expression of factors related with biofilm production, including curli and cellulose. This study contributes to the understanding of biofilm regulation in Salmonella spp. and to the design of new strategies to prevent food contamination and humans and animals infections. Copyright © 2014. Published by Elsevier B.V.

  8. Highly drug-resistant Salmonella enterica serotype Kentucky ST198-X1: a microbiological study.

    PubMed

    Le Hello, Simon; Harrois, Dorothée; Bouchrif, Brahim; Sontag, Lucile; Elhani, Dalèle; Guibert, Véronique; Zerouali, Khalid; Weill, François-Xavier

    2013-08-01

    Salmonella enterica is a major global food-borne pathogen, causing life-threatening infections. Ciprofloxacin and extended-spectrum cephalosporins (ESCs) are the drugs of choice for severe infections. We previously reported a ciprofloxacin-resistant S. enterica serotype Kentucky (S Kentucky) ST198-X1 strain that emerged in Egypt and spread throughout Africa and the Middle East from 2002 to 2008. We aimed to monitor recent trends in the location of transmission and antimicrobial resistance of this strain. We analysed isolates of S Kentucky collected by the French national surveillance system for salmonellosis in France from Jan 1, 2000, to Dec 31, 2011, and at two sites in Casablanca, Morocco, between Jan 1, 2003, and Dec 31, 2011. We analysed patterns of travel of patients infected with a ciprofloxacin-resistant strain of S Kentucky. We identified isolates showing resistance to ESCs or decreased susceptibility to carbapenems, characterised isolates by XbaI-pulsed field gel electrophoresis and multilocus sequence typing, and assessed mechanisms of bacterial resistance to antimicrobial drugs. 954 (1%) of 128,836 serotyped Salmonella spp isolates in France were identified as S Kentucky, as were 30 (13%) of 226 Salmonella spp isolates from Morocco. During 2000-08, 200 (40%) of 497 subculturable isolates of S Kentucky obtained in France were resistant to ciprofloxacin, compared with 376 (83%) of 455 isolates in 2009-11, suggesting a recent increase in ciprofloxacin resistance in France. Travel histories suggested S Kentucky infections originated predominantly in east Africa, north Africa, west Africa, and the Middle East, but also arose in India. We report several occurrences of acquisition of extended-spectrum β-lactamase (CTX-M-1, CTX-M-15), plasmid-encoded cephalosporinase (CMY-2), or carbapenemase (OXA-48, VIM-2) genes by ciprofloxacin-resistant isolates of S Kentucky ST198-X1 from the Mediterranean area since 2009. Many of these highly drug-resistant isolates were

  9. Cross-Contamination and Biofilm Formation by Salmonella enterica Serovar Enteritidis on Various Cutting Boards.

    PubMed

    Dantas, Stéfani T A; Rossi, Bruna F; Bonsaglia, Erika C R; Castilho, Ivana G; Hernandes, Rodrigo T; Fernandes, Ary; Rall, Vera L M

    2018-02-01

    Cross-contamination is one of the main factors related to foodborne outbreaks. This study aimed to analyze the cross-contamination process of Salmonella enterica serovar Enteritidis from poultry to cucumbers, on various cutting board surfaces (plastic, wood, and glass) before and after washing and in the presence and absence of biofilm. Thus, 10 strains of Salmonella Enteritidis were used to test cross-contamination from poultry to the cutting boards and from thereon to cucumbers. Moreover, these strains were evaluated as to their capacity to form biofilm on hydrophobic (wood and plastic) and hydrophilic materials (glass). We recovered the 10 isolates from all unwashed boards and from all cucumbers that had contacted them. After washing, the recovery ranged from 10% to 100%, depending on the board material. In the presence of biofilm, the recovery of salmonellae was 100%, even after washing. Biofilm formation occurred more on wood (60%) and plastic (40%) than glass (10%) boards, demonstrating that bacteria adhered more to a hydrophobic material. It was concluded that the cutting boards represent a critical point in cross-contamination, particularly in the presence of biofilm. Salmonella Enteritidis was able to form a biofilm on these three types of cutting boards but glass showed the least formation.

  10. Replication of Salmonella enterica Serovar Typhimurium in Human Monocyte-Derived Macrophages.

    PubMed

    Lathrop, Stephanie K; Binder, Kelsey A; Starr, Tregei; Cooper, Kendal G; Chong, Audrey; Carmody, Aaron B; Steele-Mortimer, Olivia

    2015-07-01

    Salmonella enterica serovar Typhimurium is a common cause of food-borne gastrointestinal illness, but additionally it causes potentially fatal bacteremia in some immunocompromised patients. In mice, systemic spread and replication of the bacteria depend upon infection of and replication within macrophages, but replication in human macrophages is not widely reported or well studied. In order to assess the ability of Salmonella Typhimurium to replicate in human macrophages, we infected primary monocyte-derived macrophages (MDM) that had been differentiated under conditions known to generate different phenotypes. We found that replication in MDM depends greatly upon the phenotype of the cells, as M1-skewed macrophages did not allow replication, while M2a macrophages and macrophages differentiated with macrophage colony-stimulating factor (M-CSF) alone (termed M0) did. We describe how additional conditions that alter the macrophage phenotype or the gene expression of the bacteria affect the outcome of infection. In M0 MDM, the temporal expression of representative genes from Salmonella pathogenicity islands 1 and 2 (SPI1 and SPI2) and the importance of the PhoP/Q two-component regulatory system are similar to what has been shown in mouse macrophages. However, in contrast to mouse macrophages, where replication is SPI2 dependent, we observed early SPI2-independent replication in addition to later SPI2-dependent replication in M0 macrophages. Only SPI2-dependent replication was associated with death of the host cell at later time points. Altogether, our results reveal a very nuanced interaction between Salmonella and human macrophages. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Inactivation of Bacillus cereus and Salmonella enterica serovar Typhimurium by aqueous ozone (O3): Modeling and Uv-Vis spectroscopic analysis

    USDA-ARS?s Scientific Manuscript database

    Ozone (O3) is a natural antimicrobial agent with potential applications in food industry. In this study, inactivation of Bacillus cereus and Salmonella enterica Typhimurium by aqueous ozone was evaluated. Ozone gas was generated using a domestic ozone generator with an output of 200 mg/hr (approx. 0...

  12. Salmonella Enterica Serovar Typhimurium BipA Exhibits Two Distinct Ribosome Binding Modes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    deLivron, M.; Robinson, V

    BipA is a highly conserved prokaryotic GTPase that functions to influence numerous cellular processes in bacteria. In Escherichia coli and Salmonella enterica serovar Typhimurium, BipA has been implicated in controlling bacterial motility, modulating attachment and effacement processes, and upregulating the expression of virulence genes and is also responsible for avoidance of host defense mechanisms. In addition, BipA is thought to be involved in bacterial stress responses, such as those associated with virulence, temperature, and symbiosis. Thus, BipA is necessary for securing bacterial survival and successful invasion of the host. Steady-state kinetic analysis and pelleting assays were used to assess themore » GTPase and ribosome-binding properties of S. enterica BipA. Under normal bacterial growth, BipA associates with the ribosome in the GTP-bound state. However, using sucrose density gradients, we demonstrate that the association of BipA and the ribosome is altered under stress conditions in bacteria similar to those experienced during virulence. The data show that this differential binding is brought about by the presence of ppGpp, an alarmone that signals the onset of stress-related events in bacteria.« less

  13. The evaluation and application of multilocus variable number tandem repeat analysis (MLVA) for the molecular epidemiological study of Salmonella enterica subsp. enterica serovar Enteritidis infection.

    PubMed

    Liu, Yao; Shi, Xiaolu; Li, Yinghui; Chen, Qiongcheng; Jiang, Min; Li, Wanli; Qiu, Yaqun; Lin, Yiman; Jiang, Yixiang; Kan, Biao; Sun, Qun; Hu, Qinghua

    2016-01-29

    Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) is one of the most prevalent Salmonella serotypes that cause gastroenteritis worldwide and the most prevalent serotype causing Salmonella infections in China. A rapid molecular typing method with high throughput and good epidemiological discrimination is urgently needed for detecting the outbreaks and finding the source for effective control of S. Enteritidis infections. In this study, 194 strains which included 47 from six outbreaks that were well-characterized epidemiologically were analyzed with pulse field gel electrophoresis (PFGE) and multilocus variable number tandem repeat analysis (MLVA). Seven VNTR loci published by the US Center for Disease Control and Prevention (CDC) were used to evaluate and develop MLVA scheme for S. Enteritidis molecular subtyping by comparing with PFGE, and then MLVA was applied to the suspected outbreaks detection. All S. Enteritidis isolates were analyzed with MLVA to establish a MLVA database in Shenzhen, Guangdong province, China to facilitate the detection of S. Enteritidis infection clusters. There were 33 MLVA types and 29 PFGE patterns among 147 sporadic isolates. These two measures had Simpson indices of 0.7701 and 0.8043, respectively, which did not differ significantly. Epidemiological concordance was evaluated by typing 47 isolates from six epidemiologically well-characterized outbreaks and it did not differ for PFGE and MLVA. We applied the well established MLVA method to detect two S. Enteritidis foodborne outbreaks and find their sources successfully in 2014. A MLVA database of 491 S. Enteritidis strains isolated from 2004 to 2014 was established for the surveillance of clusters in the future. MLVA typing of S. Enteritidis would be an effective tool for early warning and epidemiological surveillance of S. Enteritidis infections.

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  16. Comparison of dkgB-linked intergenic sequence ribotyping to DNA microarray hybridization for assigning serotype to Salmonella enterica

    PubMed Central

    Guard, Jean; Sanchez-Ingunza, Roxana; Morales, Cesar; Stewart, Tod; Liljebjelke, Karen; Kessel, JoAnn; Ingram, Kim; Jones, Deana; Jackson, Charlene; Fedorka-Cray, Paula; Frye, Jonathan; Gast, Richard; Hinton, Arthur

    2012-01-01

    Two DNA-based methods were compared for the ability to assign serotype to 139 isolates of Salmonella enterica ssp. I. Intergenic sequence ribotyping (ISR) evaluated single nucleotide polymorphisms occurring in a 5S ribosomal gene region and flanking sequences bordering the gene dkgB. A DNA microarray hybridization method that assessed the presence and the absence of sets of genes was the second method. Serotype was assigned for 128 (92.1%) of submissions by the two DNA methods. ISR detected mixtures of serotypes within single colonies and it cost substantially less than Kauffmann–White serotyping and DNA microarray hybridization. Decreasing the cost of serotyping S. enterica while maintaining reliability may encourage routine testing and research. PMID:22998607

  17. Characterization of Anti-Salmonella enterica Serotype Typhi Antibody Responses in Bacteremic Bangladeshi Patients by an Immuno-affinity Proteomic-based Technology (IPT)

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serotype Typhi (S. Typhi) is the cause of typhoid fever and a human-restricted pathogen. Currently available typhoid vaccines provide only 50-75% protection for 2-5 years, and available diagnostic assays to identify individuals with typhoid fever lack both sensitivity and specif...

  18. A multiplex real-time PCR assay, based on invA and pagC genes, for the detection and quantification of Salmonella enterica from cattle lymph nodes.

    PubMed

    Bai, Jianfa; Trinetta, Valentina; Shi, Xiaorong; Noll, Lance W; Magossi, Gabriela; Zheng, Wanglong; Porter, Elizabeth P; Cernicchiaro, Natalia; Renter, David G; Nagaraja, Tiruvoor G

    2018-05-01

    Cattle lymph nodes can harbor Salmonella and potentially contaminate beef products. We have developed and validated a new real-time PCR (qPCR) assay for the detection and quantification of Salmonella enterica in cattle lymph nodes. The assay targets both the invA and pagC genes, the most conserved molecular targets in Salmonella enterica. An 18S rRNA gene assay that amplifies from cattle and other animal species was also included as an internal control. Available DNA sequences for invA, pagC and 18S rRNA genes were used for primer and probe selections. Three Salmonella serotypes, S. Typhimurium, S. Anatum, and S. Montevideo, were used to assess the assay's analytical sensitivity. Correlation coefficients of standard curves generated for each target and for all three serotypes were >99% and qPCR amplification efficiencies were between 93% and 110%. Assay sensitivity was also determined using standard curve data generated from Salmonella-negative cattle lymph nodes spiked with 10-fold dilutions of the three Salmonella serotypes. Assay specificity was determined using Salmonella culture method, and qPCR testing on 36 Salmonella strains representing 33 serotypes, 38 Salmonella strains of unknown serotypes, 252 E. coli strains representing 40 serogroups, and 31 other bacterial strains representing 18 different species. A collection of 647 cattle lymph node samples from steers procured from the Midwest region of the US were tested by the qPCR, and compared to culture-method of detection. Salmonella prevalence by qPCR for pre-enriched and enriched lymph nodes was 19.8% (128/647) and 94.9% (614/647), respectively. A majority of qPCR positive pre-enriched samples (105/128) were at concentrations between 10 4 and 10 5  CFU/mL. Culture method detected Salmonella in 7.7% (50/647) and 80.7% (522/647) of pre- and post-enriched samples, respectively; 96.0% (48/50) of pre-enriched and 99.4% (519/522) of post-enriched culture-positive samples were also positive by qPCR. More

  19. Prevalence and characterization of multidrug-resistant (type ACSSuT) Salmonella enterica serovar Typhimurium strains in isolates from four gosling farms and a hatchery farm.

    PubMed

    Yu, Chang-You; Chou, Shih-Jen; Yeh, Chia-Ming; Chao, Maw-Rong; Huang, Kwo-Ching; Chang, Yung-Fu; Chiou, Chien-Shun; Weill, Francois-Xavier; Chiu, Cheng-Hsun; Chu, Chi-Hong; Chu, Chishih

    2008-02-01

    Salmonella enterica serovar Typhimurium strains of phage types DT104 and U302 are often resistant to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline (the ACSSuT resistance type) and are major zoonotic pathogens. Increased consumption of goose meat may enhance the risk of transferring S. enterica serovar Typhimurium and other enteric pathogens from geese to human due to the consumption of meats from infected geese or improper preparation of meats. Therefore, we characterized S. enterica serovar Typhimurium strains isolated from four goose farms (farms A, B, C, and D) and one hatchery farm (farm E) to determine the epidemic and genetic differences among them. Antibiotic susceptibility tests and multiplex PCR confirmed that 77.6% (52/67) of strains were ACSSuT strains isolated from farms A, C, and E. Antibiotic-susceptible strains were isolated mostly from farm B, and no strain was observed in farm D. All ACSSuT strains harbored a 94.7-kb virulence plasmid and contained one 1.1-kb conserved segment identical to that of Salmonella genomic island 1. Four genotypes were determined among these S. enterica serovar Typhimurium isolates by pulsed-field gel electrophoresis analysis of XbaI-digested DNA fragments. Most isolates (85.29%; 29/34) of major genotype Ib were ACSSuT strains isolated mainly from goslings of farm C and egg membranes of farm E, a hatchery farm, suggesting that S. enterica serovar Typhimurium strains in isolates from goslings might originate from its hatchery, from the egg membranes to the gosling fluff after hatching. Multiple phage types, types 8, 12, U283, DT104, and U302, were identified. In conclusion, geese were a reservoir of diverse multidrug-resistant (type ACSSuT) S. enterica serovar Typhimurium strains, and each farm was colonized with genetically closely related S. enterica serovar Typhimurium strains.

  20. International spread of an epidemic population of Salmonella enterica serotype Kentucky ST198 resistant to ciprofloxacin.

    PubMed

    Le Hello, Simon; Hendriksen, Rene S; Doublet, Benoît; Fisher, Ian; Nielsen, Eva Møller; Whichard, Jean M; Bouchrif, Brahim; Fashae, Kayode; Granier, Sophie A; Jourdan-Da Silva, Nathalie; Cloeckaert, Axel; Threlfall, E John; Angulo, Frederick J; Aarestrup, Frank M; Wain, John; Weill, François-Xavier

    2011-09-01

    National Salmonella surveillance systems from France, England and Wales, Denmark, and the United States identified the recent emergence of multidrug-resistant isolates of Salmonella enterica serotype Kentucky displaying high-level resistance to ciprofloxacin. A total of 489 human cases were identified during the period from 2002 (3 cases) to 2008 (174 cases). These isolates belonged to a single clone defined by the multilocus sequence type ST198, the XbaI-pulsed-field gel electrophoresis cluster X1, and the presence of the Salmonella genomic island 1 variant SGI1-K. This clone was probably selected in 3 steps in Egypt during the 1990s and the early 2000s and has now spread to several countries in Africa and, more recently, in the Middle East. Poultry has been identified as a potential major vehicle for infection by this clone. Continued surveillance and appropriate control measures should be implemented by national and international authorities to limit the spread of this strain.

  1. Relationship of Triamine-Biocide Tolerance of Salmonella enterica Serovar Senftenberg to Antimicrobial Susceptibility, Serum Resistance and Outer Membrane Proteins.

    PubMed

    Futoma-Kołoch, Bożena; Dudek, Bartłomiej; Kapczyńska, Katarzyna; Krzyżewska, Eva; Wańczyk, Martyna; Korzekwa, Kamila; Rybka, Jacek; Klausa, Elżbieta; Bugla-Płoskońska, Gabriela

    2017-07-11

    A new emerging phenomenon is the association between the incorrect use of biocides in the process of disinfection in farms and the emergence of cross-resistance in Salmonella populations. Adaptation of the microorganisms to the sub-inhibitory concentrations of the disinfectants is not clear, but may result in an increase of sensitivity or resistance to antibiotics, depending on the biocide used and the challenged Salmonella serovar. Exposure of five Salmonella enterica subsp. enterica serovar Senftenberg ( S. Senftenberg) strains to triamine-containing disinfectant did not result in variants with resistance to antibiotics, but has changed their susceptibility to normal human serum (NHS). Three biocide variants developed reduced sensitivity to NHS in comparison to the sensitive parental strains, while two isolates lost their resistance to serum. For S. Senftenberg, which exhibited the highest triamine tolerance (6 × MIC) and intrinsic sensitivity to 22.5% and 45% NHS, a downregulation of flagellin and enolase has been demonstrated, which might suggest a lower adhesion and virulence of the bacteria. This is the first report demonstrating the influence of biocide tolerance on NHS resistance. In conclusion, there was a potential in S. Senftenberg to adjust to the conditions, where the biocide containing triamine was present. However, the adaptation did not result in the increase of antibiotic resistance, but manifested in changes within outer membrane proteins' patterns. The strategy of bacterial membrane proteins' analysis provides an opportunity to adjust the ways of infection treatments, especially when it is connected to the life-threating bacteremia caused by Salmonella species.

  2. Relationship of Triamine-Biocide Tolerance of Salmonella enterica Serovar Senftenberg to Antimicrobial Susceptibility, Serum Resistance and Outer Membrane Proteins

    PubMed Central

    Futoma-Kołoch, Bożena; Dudek, Bartłomiej; Kapczyńska, Katarzyna; Wańczyk, Martyna; Korzekwa, Kamila; Rybka, Jacek; Klausa, Elżbieta; Bugla-Płoskońska, Gabriela

    2017-01-01

    A new emerging phenomenon is the association between the incorrect use of biocides in the process of disinfection in farms and the emergence of cross-resistance in Salmonella populations. Adaptation of the microorganisms to the sub-inhibitory concentrations of the disinfectants is not clear, but may result in an increase of sensitivity or resistance to antibiotics, depending on the biocide used and the challenged Salmonella serovar. Exposure of five Salmonella enterica subsp. enterica serovar Senftenberg (S. Senftenberg) strains to triamine-containing disinfectant did not result in variants with resistance to antibiotics, but has changed their susceptibility to normal human serum (NHS). Three biocide variants developed reduced sensitivity to NHS in comparison to the sensitive parental strains, while two isolates lost their resistance to serum. For S. Senftenberg, which exhibited the highest triamine tolerance (6 × MIC) and intrinsic sensitivity to 22.5% and 45% NHS, a downregulation of flagellin and enolase has been demonstrated, which might suggest a lower adhesion and virulence of the bacteria. This is the first report demonstrating the influence of biocide tolerance on NHS resistance. In conclusion, there was a potential in S. Senftenberg to adjust to the conditions, where the biocide containing triamine was present. However, the adaptation did not result in the increase of antibiotic resistance, but manifested in changes within outer membrane proteins’ patterns. The strategy of bacterial membrane proteins’ analysis provides an opportunity to adjust the ways of infection treatments, especially when it is connected to the life-threating bacteremia caused by Salmonella species. PMID:28696348

  3. Interactions of Salmonella enterica Serovar Typhimurium and Pectobacterium carotovorum within a Tomato Soft Rot.

    PubMed

    George, Andrée S; Cox, Clayton E; Desai, Prerak; Porwollik, Steffen; Chu, Weiping; de Moraes, Marcos H; McClelland, Michael; Brandl, Maria T; Teplitski, Max

    2018-03-01

    Salmonella spp. are remarkably adaptable pathogens, and this adaptability allows these bacteria to thrive in a variety of environments and hosts. The mechanisms with which these pathogens establish within a niche amid the native microbiota remain poorly understood. Here, we aimed to uncover the mechanisms that enable Salmonella enterica serovar Typhimurium strain ATCC 14028 to benefit from the degradation of plant tissue by a soft rot plant pathogen, Pectobacterium carotovorum The hypothesis that in the soft rot, the liberation of starch (not utilized by P. carotovorum ) makes this polymer available to Salmonella spp., thus allowing it to colonize soft rots, was tested first and proven null. To identify the functions involved in Salmonella soft rot colonization, we carried out transposon insertion sequencing coupled with the phenotypic characterization of the mutants. The data indicate that Salmonella spp. experience a metabolic shift in response to the changes in the environment brought on by Pectobacterium spp. and likely coordinated by the csrBC small regulatory RNA. While csrBC and flhD appear to be of importance in the soft rot, the global two-component system encoded by barA sirA (which controls csrBC and flhDC under laboratory conditions) does not appear to be necessary for the observed phenotype. Motility and the synthesis of nucleotides and amino acids play critical roles in the growth of Salmonella spp. in the soft rot. IMPORTANCE Outbreaks of produce-associated illness continue to be a food safety concern. Earlier studies demonstrated that the presence of phytopathogens on produce was a significant risk factor associated with increased Salmonella carriage on fruits and vegetables. Here, we genetically characterize some of the requirements for interactions between Salmonella and phytobacteria that allow Salmonella spp. to establish a niche within an alternate host (tomato). Pathways necessary for nucleotide synthesis, amino acid synthesis, and motility

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

    PubMed Central

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

    2002-01-01

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

  5. Genetic diversity of clinical and environmental strains of Salmonella enterica serotype Weltevreden isolated in Malaysia.

    PubMed

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

    2002-07-01

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

  6. Biofilm formation, phenotypic production of cellulose and gene expression in Salmonella enterica decrease under anaerobic conditions.

    PubMed

    Lamas, A; Miranda, J M; Vázquez, B; Cepeda, A; Franco, C M

    2016-12-05

    Salmonella enterica subsp. enterica is one of the main food-borne pathogens. This microorganism combines an aerobic life outside the host with an anaerobic life within the host. One of the main concerns related to S. enterica is biofilm formation and cellulose production. In this study, biofilm formation, morphotype, cellulose production and transcription of biofilm and quorum sensing-related genes of 11 S. enterica strains were tested under three different conditions: aerobiosis, microaerobiosis, and anaerobiosis. The results showed an influence of oxygen levels on biofilm production. Biofilm formation was significantly higher (P<0.05) in aerobiosis than in microaerobiosis and anaerobiosis. Cellulose production and RDAR (red, dry, and rough) were expressed only in aerobiosis. In microaerobiosis, the strains expressed the SAW (smooth and white) morphotype, while in anaerobiosis the colonies appeared small and red. The expression of genes involved in cellulose synthesis (csgD and adrA) and quorum sensing (sdiA and luxS) was reduced in microaerobiosis and anaerobiosis in all S. enterica strains tested. This gene expression levels were less reduced in S. Typhimurium and S. Enteritidis compared to the tested serotypes. There was a relationship between the expression of biofilm and quorum sensing-related genes. Thus, the results from this study indicate that biofilm formation and cellulose production are highly influenced by atmospheric conditions. This must be taken into account as contamination with these bacteria can occur during food processing under vacuum or modified atmospheres. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Epidemic Typhoid in Vietnam: Molecular Typing of Multiple-Antibiotic-Resistant Salmonella enterica Serotype Typhi from Four Outbreaks

    PubMed Central

    Connerton, Phillippa; Wain, John; Hien, Tran T.; Ali, Tahir; Parry, Christopher; Chinh, Nguyen T.; Vinh, Ha; Ho, Vo A.; Diep, To S.; Day, Nicholas P. J.; White, Nicholas J.; Dougan, Gordon; Farrar, Jeremy J.

    2000-01-01

    Multidrug-resistant Salmonella enterica serotype Typhi isolates from four outbreaks of typhoid fever in southern Vietnam between 1993 and 1997 were compared. Pulsed-field gel electrophoresis, bacteriophage and plasmid typing, and antibiotic susceptibilities showed that independent outbreaks of multidrug-resistant typhoid fever in southern Vietnam are caused by single bacterial strains. However, different outbreaks do not derive from the clonal expansion of a single multidrug-resistant serotype Typhi strain. PMID:10655411

  8. The Genome sequences of four non-human/non-clinical Salmonella enterica serovar Kentucky ST198 isolates recovered between 1972 and 1973

    USDA-ARS?s Scientific Manuscript database

    Salmonella Kentucky is a polyphyletic member of S. enterica subclade A1 with multiple sequence types that often colonize the same hosts but in different frequencies on different continents. To evaluate the genomic features involved in S. Kentucky host specificity we sequenced the genomes of four iso...

  9. Failure of oral antibiotic therapy, including azithromycin, in the treatment of a recurrent breast abscess caused by Salmonella enterica serotype Paratyphi A.

    PubMed

    Fernando, Shelanah; Molland, Janice Gail; Gottlieb, Thomas

    2012-10-01

    We report a case of recurrent, multifocal Salmonella enterica serotype Paratyphi A breast abscesses, resistant to ciprofloxacin, which relapsed despite surgery, aspiration and multiple courses of antibiotics, including co-trimoxazole and azithromycin. The patient was cured after a prolonged course of intravenous ceftriaxone.

  10. Sensitivity of mycobacterium avium subsp paratuberculosis, escherichia coli and salmonella enterica serotype typhimurium to low pH, high organic acids and ensiling

    USDA-ARS?s Scientific Manuscript database

    The ability of Mycobacterium avium subsp paratuberculosis (M. paratuberculosis), Salmonella enterica serotype Typhimurium (S. Typhimurium) and a commensal Escherichia coli (E. coli) isolate to persist under low pH and high organic acid conditions was determined. Die-off rates were calculated followi...

  11. Molecular characterization and antimicrobial resistance of Salmonella enterica from swine slaughtered in two different types of Philippine abattoir.

    PubMed

    Calayag, Alyzza Marie B; Paclibare, Phyllis Anne P; Santos, Pauline Dianne M; Bautista, Corinne Aimee C; Rivera, Windell L

    2017-08-01

    Salmonella enterica is a well-known pathogen commonly acquired from the consumption of contaminated food. It has been estimated to affect millions of humans and cause hundreds of thousands of deaths per year globally. Pork, one of the most commonly consumed meats worldwide, has been identified as one of the main sources of human salmonellosis. In this study, we aimed to detect and characterize S. enterica from slaughtered swine and generate antimicrobial resistance profiles of select isolates. Tonsils and jejunum with mesenteric lymph nodes (MLN) were collected from a total of 240 swine from eight abattoirs (five accredited and three locally registered abattoirs) across Metro Manila. S. enterica were isolated using conventional culture methods and confirmed by PCR amplification of the invA gene. Isolates were further characterized based on somatic antigen by multiplex PCR. We report that there is no significant difference (P = 0.42) between the incidences of S. enterica in swine slaughtered in accredited (44.0%) and in locally registered abattoirs (46.7%). Most samples were contaminated with S. enterica under serogroup O:3,10. Antimicrobial susceptibility testing of 183 isolates using the VITEK ® 2 system revealed high resistance to ampicillin (67.8%) and trimethoprim/sulfamethoxazole (80.3%). Multidrug-resistance was found in 124 (67.8%) isolates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Core Proteomic Analysis of Unique Metabolic Pathways of Salmonella enterica for the Identification of Potential Drug Targets.

    PubMed

    Uddin, Reaz; Sufian, Muhammad

    2016-01-01

    Infections caused by Salmonella enterica, a Gram-negative facultative anaerobic bacteria belonging to the family of Enterobacteriaceae, are major threats to the health of humans and animals. The recent availability of complete genome data of pathogenic strains of the S. enterica gives new avenues for the identification of drug targets and drug candidates. We have used the genomic and metabolic pathway data to identify pathways and proteins essential to the pathogen and absent from the host. We took the whole proteome sequence data of 42 strains of S. enterica and Homo sapiens along with KEGG-annotated metabolic pathway data, clustered proteins sequences using CD-HIT, identified essential genes using DEG database and discarded S. enterica homologs of human proteins in unique metabolic pathways (UMPs) and characterized hypothetical proteins with SVM-prot and InterProScan. Through this core proteomic analysis we have identified enzymes essential to the pathogen. The identification of 73 enzymes common in 42 strains of S. enterica is the real strength of the current study. We proposed all 73 unexplored enzymes as potential drug targets against the infections caused by the S. enterica. The study is comprehensive around S. enterica and simultaneously considered every possible pathogenic strain of S. enterica. This comprehensiveness turned the current study significant since, to the best of our knowledge it is the first subtractive core proteomic analysis of the unique metabolic pathways applied to any pathogen for the identification of drug targets. We applied extensive computational methods to shortlist few potential drug targets considering the druggability criteria e.g. Non-homologous to the human host, essential to the pathogen and playing significant role in essential metabolic pathways of the pathogen (i.e. S. enterica). In the current study, the subtractive proteomics through a novel approach was applied i.e. by considering only proteins of the unique metabolic

  13. A comparison of transmission characteristics of Salmonella enterica serovar Enteritidis between pair-housed and group-housed laying hens.

    PubMed

    Thomas, Ekelijn; Bouma, Annemarie; Klinkenberg, Don

    2011-02-23

    Human cases of bacterial gastro-enteritis are often caused by the consumption of eggs contaminated with Salmonella species, mainly Salmonella enterica serovar Enteriditis (Salmonella Enteritidis). To reduce human exposure, in several countries worldwide surveillance programmes are implemented to detect colonized layer flocks. The sampling schemes are based on the within-flock prevalence, and, as this changes over time, knowledge of the within-flock dynamics of Salmonella Enteritidis is required. Transmission of Salmonella Enteritidis has been quantified in pairs of layers, but the question is whether the dynamics in pairs is comparable to transmission in large groups, which are more representative for commercial layer flocks. The aim of this study was to compare results of transmission experiments between pairs and groups of laying hens. Experimental groups of either 2 or 200 hens were housed at similar densities, and 1 or 4 hens were inoculated with Salmonella Enteritidis, respectively. Excretion was monitored by regularly testing of fecal samples for the presence of Salmonella Enteritidis. Using mathematical modeling, the group experiments were simulated with transmission parameter estimates from the pairwise experiments. Transmission of the bacteria did not differ significantly between pairs or groups. This finding suggests that the transmission parameter estimates from small-scale experiments might be extrapolated to the field situation.

  14. Occurrence of Antimicrobial-Resistant Escherichia coli and Salmonella enterica in the Beef Cattle Production and Processing Continuum

    PubMed Central

    Agga, Getahun E.; Bosilevac, Joseph M.; Brichta-Harhay, Dayna M.; Shackelford, Steven D.; Wang, Rong; Wheeler, Tommy L.; Arthur, Terrance M.

    2014-01-01

    Specific concerns have been raised that third-generation cephalosporin-resistant (3GCr) Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COTr) E. coli, 3GCr Salmonella enterica, and nalidixic acid-resistant (NALr) S. enterica may be present in cattle production environments, persist through beef processing, and contaminate final products. The prevalences and concentrations of these organisms were determined in feces and hides (at feedlot and processing plant), pre-evisceration carcasses, and final carcasses from three lots of fed cattle (n = 184). The prevalences and concentrations were further determined for strip loins from 103 of the carcasses. 3GCr Salmonella was detected on 7.6% of hides during processing and was not detected on the final carcasses or strip loins. NALr S. enterica was detected on only one hide. 3GCr E. coli and COTr E. coli were detected on 100.0% of hides during processing. Concentrations of 3GCr E. coli and COTr E. coli on hides were correlated with pre-evisceration carcass contamination. 3GCr E. coli and COTr E. coli were each detected on only 0.5% of final carcasses and were not detected on strip loins. Five hundred and 42 isolates were screened for extraintestinal pathogenic E. coli (ExPEC) virulence-associated markers. Only two COTr E. coli isolates from hides were ExPEC, indicating that fed cattle products are not a significant source of ExPEC causing human urinary tract infections. The very low prevalences of these organisms on final carcasses and their absence on strip loins demonstrate that current sanitary dressing procedures and processing interventions are effective against antimicrobial-resistant bacteria. PMID:25398858

  15. Identification and Characterization of Outer Membrane Vesicle-Associated Proteins in Salmonella enterica Serovar Typhimurium

    PubMed Central

    Bai, Jaewoo; Kim, Seul I; Ryu, Sangryeol

    2014-01-01

    Salmonella enterica serovar Typhimurium is a primary cause of enteric diseases and has acquired a variety of virulence factors during its evolution into a pathogen. Secreted virulence factors interact with commensal flora and host cells and enable Salmonella to survive and thrive in hostile environments. Outer membrane vesicles (OMVs) released from many Gram-negative bacteria function as a mechanism for the secretion of complex mixtures, including virulence factors. We performed a proteomic analysis of OMVs that were isolated under standard laboratory and acidic minimal medium conditions and identified 14 OMV-associated proteins that were observed in the OMV fraction isolated only under the acidic minimal medium conditions, which reproduced the nutrient-deficient intracellular milieu. The inferred roles of these 14 proteins were diverse, including transporter, enzyme, and transcriptional regulator. The absence of these proteins influenced Salmonella survival inside murine macrophages. Eleven of these proteins were predicted to possess secretion signal sequences at their N termini, and three (HupA, GlnH, and PhoN) of the proteins were found to be translocated into the cytoplasm of host cells. The comparative proteomic profiling of OMVs performed in this study revealed different protein compositions in the OMVs isolated under the two different conditions, which indicates that the OMV cargo depends on the growth conditions and provides a deeper insight into how Salmonella utilizes OMVs to adapt to environmental changes. PMID:24935973

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

    PubMed Central

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

    2014-01-01

    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. PMID:24570467

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

    PubMed

    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.

  18. Emergence of Salmonella enterica serovar Indiana and California isolates with concurrent resistance to cefotaxime, amikacin and ciprofloxacin from chickens in China.

    PubMed

    Wang, Yongxiang; Zhang, Anyun; Yang, Yongqiang; Lei, Changwei; Jiang, Wei; Liu, Bihui; Shi, Hongping; Kong, Linghan; Cheng, Guangyang; Zhang, Xiuzhong; Yang, Xin; Wang, Hongning

    2017-12-04

    The aim of this study was to investigate the prevalence and characterization of Salmonella concerning the poultry industry in China. A total of 170 non-duplicate Salmonella isolates were recovered from the 1540 chicken samples. Among the Salmonella isolates from chickens, the predominant serovars were S. enterica serovar Enteritidis (S. Enteritidis) (49/170, 28.8%), S. enterica serovar Indiana (S. Indiana) (37/170, 21.8%) and S. enterica serovar California (S. California) (34/170, 20.0%). High antimicrobial resistance was observed for ciprofloxacin (68.2%), amikacin (48.2%) and cefotaxime (44.7%). Of particular concerns were the 18 S. Indiana and 17 S. California isolates, which were concurrently resistant to cefotaxime, amikacin and ciprofloxacin. The bla CTX-M genes, 16S rRNA methylase genes (armA, rmtD or rmtC) and five plasmid-mediated quinolone resistance (PMQR) determinants (aac(6')-Ib-cr, oqxAB, qnrB, qepA and qnrD) were identified in 18 S. Indiana and 17 S. California isolates. To clarify their genetic correlation, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were further conducted. PFGE profiles showed that the majority of S. Indiana and S. California isolates were clonally unrelated with a standard cut-off of 85%. The results of MLST demonstrated that ST17 and ST40 were the most common ST types in S. Indiana and S. California isolates, respectively. Our findings indicated that the multiple antibiotic resistant S. Indiana and S. California isolates were widespread in chicken in China and might pose a potential threat to public health. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Failure of oral antibiotic therapy, including azithromycin, in the treatment of a recurrent breast abscess caused by Salmonella enterica serotype Paratyphi A

    PubMed Central

    Fernando, Shelanah; Molland, Janice Gail; Gottlieb, Thomas

    2012-01-01

    We report a case of recurrent, multifocal Salmonella enterica serotype Paratyphi A breast abscesses, resistant to ciprofloxacin, which relapsed despite surgery, aspiration and multiple courses of antibiotics, including co-trimoxazole and azithromycin. The patient was cured after a prolonged course of intravenous ceftriaxone. PMID:23182142

  20. The Vi Capsular Polysaccharide Enables Salmonella enterica Serovar Typhi to Evade Microbe-Guided Neutrophil Chemotaxis

    PubMed Central

    Wangdi, Tamding; Lee, Cheng-Yuk; Spees, Alanna M.; Yu, Chenzhou; Kingsbury, Dawn D.; Winter, Sebastian E.; Hastey, Christine J.; Wilson, R. Paul

    2014-01-01

    Salmonella enterica serovar Typhi (S. Typhi) causes typhoid fever, a disseminated infection, while the closely related pathogen S. enterica serovar Typhimurium (S. Typhimurium) is associated with a localized gastroenteritis in humans. Here we investigated whether both pathogens differ in the chemotactic response they induce in neutrophils using a single-cell experimental approach. Surprisingly, neutrophils extended chemotactic pseudopodia toward Escherichia coli and S. Typhimurium, but not toward S. Typhi. Bacterial-guided chemotaxis was dependent on the presence of complement component 5a (C5a) and C5a receptor (C5aR). Deletion of S. Typhi capsule biosynthesis genes markedly enhanced the chemotactic response of neutrophils in vitro. Furthermore, deletion of capsule biosynthesis genes heightened the association of S. Typhi with neutrophils in vivo through a C5aR-dependent mechanism. Collectively, these data suggest that expression of the virulence-associated (Vi) capsular polysaccharide of S. Typhi obstructs bacterial-guided neutrophil chemotaxis. PMID:25101794

  1. Antimicrobial Resistance of Salmonella enterica Isolates from Tonsil and Jejunum with Lymph Node Tissues of Slaughtered Swine in Metro Manila, Philippines

    PubMed Central

    Ng, Kamela Charmaine S.; Rivera, Windell L.

    2014-01-01

    Due to frequent antibiotic exposure, swine is now recognized as potential risk in disseminating drug-resistant Salmonella enterica strains. This study thus subjected 20 randomly selected S. enterica isolates from tonsil and jejunum with lymph node (JLN) tissues of swine slaughtered in Metro Manila, Philippines, to VITEK 2 antimicrobial susceptibility testing (AST). The test revealed all 20 isolates had resistance to at least one antimicrobial agent, in which highest occurrence of resistance was to amikacin (100%), cefazolin (100%), cefuroxime (100%), cefuroxime axetil (100%), cefoxitin (100%), and gentamicin (100%), followed by ampicillin (50%), and then by sulfamethoxazole trimethoprim (30%). Three multidrug-resistant (MDR) isolates were detected. The sole S. enterica serotype Enteritidis isolate showed resistance to 12 different antibiotics including ceftazidime, ceftriaxone, amikacin, gentamicin, and tigecycline. This study is the first to report worldwide on the novel resistance to tigecycline of MDR S. enterica serotype Enteritidis isolated from swine tonsil tissues. This finding poses huge therapeutic challenge since MDR S. enterica infections are associated with increased rate of hospitalization or death. Thus, continual regulation of antimicrobial use in food animals and prediction of resistant serotypes are crucial to limit the spread of MDR S. enterica isolates among hogs and humans. PMID:24724034

  2. Reduction of Salmonella enterica on the surface of eggshells by sequential treatment with aqueous chlorine dioxide and drying.

    PubMed

    Choi, Seonyeong; Park, Sunhyung; Kim, Yoonsook; Kim, Byeong-sam; Beuchat, Larry R; Hoikyung, Kim; Ryu, Jee-Hoon

    2015-10-01

    The synergistic effects of sequential treatments with chlorine dioxide (ClO2) and drying in killing Salmonella enterica on the surface of chicken eggshells were investigated. Initial experiments were focused on comparing lethalities of sodium hypochlorite (NaOCl) and ClO2. Eggs surface-inoculated with S. enterica in chicken feces as a carrier were immersed in water, NaOCl (50 or 200 μg/mL), or ClO2 (50 or 200 μg/mL) for 1 or 5 min. For 1-min treatments, lethal activities of sanitizers were not significantly different (P>0.05). However, after treatment with ClO2 for 5 min, reductions of S. enterica were significantly greater (P≤0.05) than reductions after treatment with water or NaOCl. The effect of treatment of eggs with ClO2 or NaOCl, followed by drying at 43% relative humidity and 25 °C for 24 and 48 h, were determined. Populations of S. enterica decreased during drying, regardless of the type of sanitizer treatment. ClO2 treatment, compared to water or NaOCl treatments, resulted in additional reductions of ca. >1.3 log CFU/egg during drying. This indicates that sequential treatments with ClO2 and drying induced synergistic lethal effects against S. enterica on the surface of eggshells. These observations will be useful when selecting a sanitizer to control S. enterica on the surface of eggshells and designing an effective egg sanitization system exploiting the synergistic lethal effects of sanitizer and drying. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Effect of X-ray treatments on salmonella enterica and spoilage bacteria on skin-on chicken breast fillets and shell eggs

    USDA-ARS?s Scientific Manuscript database

    The objectives of this study were to determine the efficacy of X-ray irradiation on the inactivation of a 3- strain mixture of Salmonella enterica (S. Enteritidis E190-88, S. Typhimurium ATCC 14028, and S. Montevideo ATCC 8387) using an RS 2400 X-ray system on chicken breast fillets and shell eggs a...

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

    PubMed

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

    2016-04-01

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

  5. Survival and Heat Resistance of Salmonella enterica and Escherichia coli O157:H7 in Peanut Butter ▿ †

    PubMed Central

    He, Yingshu; Guo, Dongjing; Yang, Jingyun; Tortorello, Mary Lou; Zhang, Wei

    2011-01-01

    Significant differences (P < 0.05) were found between the survival rates of Salmonella enterica and Escherichia coli O157:H7 in peanut butter with different formulations and water activity. High carbohydrate content in peanut butter and low incubation temperature resulted in higher levels of bacterial survival during storage but lower levels of bacterial resistance to heat treatment. PMID:21965404

  6. Salmonella enterica growth and biofilm formation in flesh and peel cantaloupe extracts on four food-contact surfaces.

    PubMed

    De Abrew Abeysundara, Piumi; Dhowlaghar, Nitin; Nannapaneni, Ramakrishna; Schilling, Mark W; Mahmoud, Barakat; Sharma, Chander S; Ma, Din-Pow

    2018-05-04

    Salmonella enterica is responsible for the highest number of foodborne disease outbreaks pertaining to cantaloupe industry. The objective of this study was to examine the growth and biofilm formation by outbreak strains of S. enterica ser. Poona (S. Poona), S. enterica ser. Stanley (S. Stanley) and S. enterica ser. Montevideo (S. Montevideo) on different food-contact processing surfaces in cantaloupe flesh and peel extracts at 22 °C and 10 °C. The generation time of all S. enterica strains tested was shorter in the high concentration (50 mg/ml) of cantaloupe extract and high temperature. In 50 mg/ml of cantaloupe flesh or peel extract, the populations of S. enterica were increased by 5 log CFU/ml in 24 h at 22 °C and 1 log CFU/ml in 72 h at 10 °C. In 2 mg/ml of cantaloupe flesh or peel extracts, the populations of S. enterica were increased by 3.5 log CFU/ml in 56 h at 22 °C, but there were no changes in 72 h at 10 °C. The biofilm production of S. enterica was greater at 50 mg/ml of cantaloupe extract and 22 °C, but no major differences (P ≥ 0.05) were found among the strains tested. In 50 mg/ml cantaloupe extract, S. enterica produced 5-6 log CFU/cm 2 biofilm in 4-7 d at 22 °C and approximately 3.5-4 log CFU/cm 2 in 7 d at 10 °C. In 2 mg/ml of cantaloupe extract, S. enterica produced 4-4.5 log CFU/cm 2 biofilms in 4-7 d at 22 °C and 3 log CFU/cm 2 in 7 d at 10 °C. Biofilm formation by S. Poona (01A4754) was lowest on buna-n rubber compared to stainless steel, polyethylene and polyurethane surfaces under the majority of conditions tested. Overall, these findings show that S. enterica strains can grow rapidly and form biofilms on different cantaloupe processing surfaces in the presence of low concentrations of cantaloupe flesh or peel extracts. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. A defective mutant of Salmonella enterica Serovar Gallinarum in cobalamin biosynthesis is avirulent in chickens

    PubMed Central

    de Paiva, Jacqueline Boldrin; Penha Filho, Rafael Antonio Casarin; Arguello, Yuli Melisa Sierra; Berchieri Junior, Ângelo; Lemos, Manuel Victor Franco; Barrow, Paul A.

    2009-01-01

    Salmonella enterica serovar Gallinarum (SG) is a fowl typhoid agent in chickens and is a severe disease with worldwide economic impact as its mortality may reach up to 80%. It is one of a small group of serovars that typically produces typhoid-like infections in a narrow range of host species and which therefore represents a good model for human typhoid. The survival mechanisms are not considered to be virulent mechanisms but are essential for the life of the bacterium. Mutants of Salmonella Gallinarum containing defective genes, related to cobalamin biosynthesis and which Salmonella spp. has to be produced to survive when it is in an anaerobic environment, were produced in this study. Salmonella Gallinarum is an intracellular parasite. Therefore, this study could provide information about whether vitamin B12 biosynthesis might be essential to its survival in the host. The results showed that the singular deletion in cbiA or cobS genes did not interfere in the life of Salmonella Gallinarum in the host, perhaps because single deletion is not enough to impede vitamin B12 biosynthesis. It was noticed that diluted SG mutants with single deletion produced higher mortality than the wild strain of SG. When double mutation was carried out, the Salmonella Gallinarum mutant was unable to provoke mortality in susceptible chickens. This work showed that B12 biosynthesis is a very important step in the metabolism of Salmonella Gallinarum during the infection of the chickens. Further research on bacterium physiology should be carried out to elucidate the events described in this research and to assess the mutant as a vaccine strain. PMID:24031393

  8. Virulence Characterisation of Salmonella enterica Isolates of Differing Antimicrobial Resistance Recovered from UK Livestock and Imported Meat Samples

    PubMed Central

    Card, Roderick; Vaughan, Kelly; Bagnall, Mary; Spiropoulos, John; Cooley, William; Strickland, Tony; Davies, Rob; Anjum, Muna F.

    2016-01-01

    Salmonella enterica is a foodborne zoonotic pathogen of significant public health concern. We have characterized the virulence and antimicrobial resistance gene content of 95 Salmonella isolates from 11 serovars by DNA microarray recovered from UK livestock or imported meat. Genes encoding resistance to sulphonamides (sul1, sul2), tetracycline [tet(A), tet(B)], streptomycin (strA, strB), aminoglycoside (aadA1, aadA2), beta-lactam (blaTEM), and trimethoprim (dfrA17) were common. Virulence gene content differed between serovars; S. Typhimurium formed two subclades based on virulence plasmid presence. Thirteen isolates were selected by their virulence profile for pathotyping using the Galleria mellonella pathogenesis model. Infection with a chicken invasive S. Enteritidis or S. Gallinarum isolate, a multidrug resistant S. Kentucky, or a S. Typhimurium DT104 isolate resulted in high mortality of the larvae; notably presence of the virulence plasmid in S. Typhimurium was not associated with increased larvae mortality. Histopathological examination showed that infection caused severe damage to the Galleria gut structure. Enumeration of intracellular bacteria in the larvae 24 h post-infection showed increases of up to 7 log above the initial inoculum and transmission electron microscopy (TEM) showed bacterial replication in the haemolymph. TEM also revealed the presence of vacuoles containing bacteria in the haemocytes, similar to Salmonella containing vacuoles observed in mammalian macrophages; although there was no evidence from our work of bacterial replication within vacuoles. This work shows that microarrays can be used for rapid virulence genotyping of S. enterica and that the Galleria animal model replicates some aspects of Salmonella infection in mammals. These procedures can be used to help inform on the pathogenicity of isolates that may be antibiotic resistant and have scope to aid the assessment of their potential public and animal health risk. PMID:27199965

  9. Endogenous Synthesis of 2-Aminoacrylate Contributes to Cysteine Sensitivity in Salmonella enterica

    PubMed Central

    Ernst, Dustin C.; Lambrecht, Jennifer A.; Schomer, Rebecca A.

    2014-01-01

    RidA, the archetype member of the widely conserved RidA/YER057c/UK114 family of proteins, prevents reactive enamine/imine intermediates from accumulating in Salmonella enterica by catalyzing their hydrolysis to stable keto acid products. In the absence of RidA, endogenous 2-aminoacrylate persists in the cellular environment long enough to damage a growing list of essential metabolic enzymes. Prior studies have focused on the dehydration of serine by the pyridoxal 5′-phosphate (PLP)-dependent serine/threonine dehydratases, IlvA and TdcB, as sources of endogenous 2-aminoacrylate. The current study describes an additional source of endogenous 2-aminoacrylate derived from cysteine. The results of in vivo analysis show that the cysteine sensitivity of a ridA strain is contingent upon CdsH, the predominant cysteine desulfhydrase in S. enterica. The impact of cysteine on 2-aminoacrylate accumulation is shown to be unaffected by the presence of serine/threonine dehydratases, revealing another mechanism of endogenous 2-aminoacrylate production. Experiments in vitro suggest that 2-aminoacrylate is released from CdsH following cysteine desulfhydration, resulting in an unbound aminoacrylate substrate for RidA. This work expands our understanding of the role played by RidA in preventing enamine stress resulting from multiple normal metabolic processes. PMID:25002544

  10. Characterization of Salmonella enterica Derivatives Harboring Defined aroC and Salmonella Pathogenicity Island 2 Type III Secretion System (ssaV) Mutations by Immunization of Healthy Volunteers

    PubMed Central

    Hindle, Zoë; Chatfield, Steven N.; Phillimore, Jo; Bentley, Matthew; Johnson, Julie; Cosgrove, Catherine A.; Ghaem-Maghami, Marjan; Sexton, Amy; Khan, Mohammad; Brennan, Frank R.; Everest, Paul; Wu, Tao; Pickard, Derek; Holden, David W.; Dougan, Gordon; Griffin, George E.; House, Deborah; Santangelo, Joseph D.; Khan, Shahid A.; Shea, Jaqueline E.; Feldman, Robert G.; Lewis, David J. M.

    2002-01-01

    The attenuation and immunogenicity of two novel Salmonella vaccine strains, Salmonella enterica serovar Typhi (Ty2 ΔaroC ΔssaV, designated ZH9) and S. enterica serovar Typhimurium (TML ΔaroC ΔssaV, designated WT05), were evaluated after their oral administration to volunteers as single escalating doses of 107, 108, or 109 CFU. ZH9 was well tolerated, not detected in blood, nor persistently excreted in stool. Six of nine volunteers elicited anti-serovar Typhi lipopolysaccharide (LPS) immunoglobulin A (IgA) antibody-secreting cell (ASC) responses, with three of three vaccinees receiving 108 and two of three receiving 109 CFU which elicited high-titer LPS-specific serum IgG. WT05 was also well tolerated with no diarrhea, although the administration of 108 and 109 CFU resulted in shedding in stools for up to 23 days. Only volunteers immunized with 109 CFU of WT05 mounted detectable serovar Typhimurium LPS-specific ASC responses and serum antibody responses were variable. These data indicate that mutations in type III secretion systems may provide a route to the development of live vaccines in humans and highlight significant differences in the potential use of serovars Typhimurium and Typhi. PMID:12065485

  11. Characterization of extended-spectrum cephalosporin-resistant Salmonella enterica serovar Heidelberg isolated from food animals, retail meat, and humans in the United States 2009

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is one of the most common causes of foodborne illness in the United States. Although salmonellosis is usually self-limiting, severe infections typically require antimicrobial treatment and ceftriaxone, an extended-spectrum cephalosporin, is commonly used in both adults and child...

  12. Roles of the outer membrane protein AsmA of Salmonella enterica in the control of marRAB expression and invasion of epithelial cells.

    PubMed

    Prieto, Ana I; Hernández, Sara B; Cota, Ignacio; Pucciarelli, M Graciela; Orlov, Yuri; Ramos-Morales, Francisco; García-del Portillo, Francisco; Casadesús, Josep

    2009-06-01

    A genetic screen for suppressors of bile sensitivity in DNA adenine methylase (dam) mutants of Salmonella enterica serovar Typhimurium yielded insertions in an uncharacterized locus homologous to the Escherichia coli asmA gene. Disruption of asmA suppressed bile sensitivity also in phoP and wec mutants of S. enterica and increased the MIC of sodium deoxycholate for the parental strain ATCC 14028. Increased levels of marA mRNA were found in asmA, asmA dam, asmA phoP, and asmA wec strains of S. enterica, suggesting that lack of AsmA activates expression of the marRAB operon. Hence, asmA mutations may enhance bile resistance by inducing gene expression changes in the marRAB-controlled Mar regulon. In silico analysis of AsmA structure predicted the existence of one transmembrane domain. Biochemical analysis of subcellular fractions revealed that the asmA gene of S. enterica encodes a protein of approximately 70 kDa located in the outer membrane. Because AsmA is unrelated to known transport and/or efflux systems, we propose that activation of marRAB in asmA mutants may be a consequence of envelope reorganization. Competitive infection of BALB/c mice with asmA(+) and asmA isogenic strains indicated that lack of AsmA attenuates Salmonella virulence by the oral route but not by the intraperitoneal route. Furthermore, asmA mutants showed a reduced ability to invade epithelial cells in vitro.

  13. Direct ROS scavenging activity of CueP from Salmonella enterica serovar Typhimurium.

    PubMed

    Yoon, Bo-Young; Yeom, Ji-Hyun; Kim, Jin-Sik; Um, Si-Hyeon; Jo, Inseong; Lee, Kangseok; Kim, Yong-Hak; Ha, Nam-Chul

    2014-02-01

    Salmonella enterica serovar Typhimurium (S. Typhimurium) is an intracellular pathogen that has evolved to survive in the phagosome of macrophages. The periplasmic copper-binding protein CueP was initially known to confer copper resistance to S. Typhimurium. Crystal structure and biochemical studies on CueP revealed a putative copper binding site surrounded by the conserved cysteine and histidine residues. A recent study reported that CueP supplies copper ions to periplasmic Cu, Zn-superoxide dismutase (SodCII) at a low copper concentration and thus enables the sustained SodCII activity in the periplasm. In this study, we investigated the role of CueP in copper resistance at a high copper concentration. We observed that the survival of a cueP-deleted strain of Salmonella in macrophage phagosome was significantly reduced. Subsequent biochemical experiments revealed that CueP specifically mediates the reduction of copper ion using electrons released during the formation of the disulfide bond. We observed that the copper ion-mediated Fenton reaction in the presence of hydrogen peroxide was blocked by CueP. This study provides insight into how CueP confers copper resistance to S. Typhimurium in copper-rich environments such as the phagosome of macrophages.

  14. Modelling the impact of water activity and fat content of dry-cured ham on the reduction of Salmonella enterica by high pressure processing.

    PubMed

    Bover-Cid, S; Belletti, N; Aymerich, T; Garriga, M

    2017-01-01

    This work aimed to quantify the impact of a w and fat content of dry-cured ham on the Log reduction of Salmonella enterica by high pressure (HP). Dry-cured ham with adjusted a w (0.86-0.96) and fat content (10-50%) was inoculated with S. enterica and pressurised (347-852MPa, 5min/15°C), following a Central Composite Design. Polynomial regression indicated a significant impact of pressure and a w on S. enterica HP-lethality. By lowering a w a clear piezoprotection was observed. At low a w (0.88) the S. enterica reduction was little affected by increasing pressure (e.g. 2.3 to 3.2 Logs at 450 to 750MPa, respectively). At the highest a w the estimated inactivation ranged from 3.3 to 8.9 Logs at 450 to 750MPa, respectively. No significant piezoprotective effect on S. enterica was recorded by the fat content. The relevance of food characteristics on the HP-lethality of S. enterica indicate the need to validate the HP effectiveness on the specific product. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to post-harvest proliferation of Salmonella enterica.

    PubMed

    Marvasi, Massimiliano; George, Andrée S; Giurcanu, Mihai; Hochmuth, George J; Noel, Jason T; Gause, Elizabeth; Teplitski, Max

    2014-10-01

    Fresh fruits and vegetables are increasingly recognized as vehicles of salmonellosis. Pre- and post-harvest environmental conditions, and physiological, and genetic factors are thought to contribute to the ability of human pathogens to persist in the production environment, attach to, colonize and proliferate in and on raw produce. How field production conditions affect the post-harvest food safety outcomes is not entirely understood. This study tested how varying nitrogen and potassium fertilization levels affected the "susceptibility" of tomatoes to Salmonella infections following the harvest of fruits. Two tomato varieties grown over three seasons under high, medium, and low levels of nitrogen and potassium fertilization in two locations were inoculated with seven strains of Salmonella. Even though the main effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to infections with Salmonella enterica were not statistically significant overall, differences in nitrogen concentrations in plant tissues correlated with the susceptibility of partially ripe tomatoes (cv. Solar Fire) to Salmonella. Tomato maturity and the season in which tomatoes were produced had the strongest effect on the ability of Salmonella to multiply in tomatoes. Tomato phenolics, accumulation of which is known to correlate with rates of the N fertilization, did not inhibit growth of Salmonella in vitro. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Multistate outbreak of Salmonella enterica serotype enteritidis infection associated with pet guinea pigs.

    PubMed

    Bartholomew, Michael L; Heffernan, Richard T; Wright, Jennifer G; Klos, Rachel F; Monson, Timothy; Khan, Sofiya; Trees, Eija; Sabol, Ashley; Willems, Robert A; Flynn, Raymond; Deasy, Marshall P; Jones, Benjamen; Davis, Jeffrey P

    2014-06-01

    Salmonella causes about one million illnesses annually in the United States. Although most infections result from foodborne exposures, animal contact is an important mode of transmission. We investigated a case of Salmonella enterica serotype Enteritidis (SE) sternal osteomyelitis in a previously healthy child who cared for two recently deceased guinea pigs (GPs). A case was defined as SE pulsed-field gel electrophoresis (PFGE) XbaI pattern JEGX01.0021, BlnI pattern JEGA26.0002 (outbreak strain) infection occurring during 2010 in a patient who reported GP exposure. To locate outbreak strain isolates, PulseNet and the US Department of Agriculture National Veterinary Service Laboratories (NVSL) databases were queried. Outbreak strain isolates underwent multilocus variable-number tandem repeat analysis (MLVA). Traceback and environmental investigations were conducted at homes, stores, and breeder or broker facilities. We detected 10 cases among residents of eight states and four NVSL GP outbreak strain isolates. One patient was hospitalized; none died. The median patient age was 9.5 (range, 1-61) years. Among 10 patients, two purchased GPs at independent stores, and three purchased GPs at different national retail chain (chain A) store locations; three were chain A employees and two reported GP exposures of unknown characterization. MLVA revealed four related patterns. Tracebacks identified four distributors and 92 sources supplying GPs to chain A, including one breeder potentially supplying GPs to all case-associated chain A stores. All environmental samples were Salmonella culture-negative. A definitive SE-contaminated environmental source was not identified. Because GPs can harbor Salmonella, consumers and pet industry personnel should be educated regarding risks.

  17. Three New Lactobacillus plantarum Strains in the Probiotic Toolbox against Gut Pathogen Salmonella enterica Serotype Typhimurium

    PubMed Central

    Potočnjak, Mia; Pušić, Petra; Frece, Jadranka; Abram, Maja; Janković, Tamara

    2017-01-01

    Summary The benefits of probiotic bacteria have been widely explored. However, fermented foods and digestive system of humans and animals are an inexhaustible source of new potentially probiotic microorganisms. In this study we present three new Lactobacillus plantarum strains isolated from different dairy products: cow′s cheese, sheep′s cheese and whey. In order to determine the antibacterial activity of yet unexplored L. plantarum strains against Salmonella enterica serotype Typhimurium, in vitro competition and co-culture tests were done. Furthermore, adhesion of these strains to Caco-2 cells and their influence on the adhesion of Salmonella were tested. Results showed the potential probiotic activity of isolated strains. L. plantarum strains survived in the presence of 1% bile salts, they possessed acidification ability, antibacterial activity and significantly attenuated the growth of S. Typhimurium in brain heart infusion broth. All tested L. plantarum strains were able to adhere to Caco-2 cells and significantly impair the adhesion of S. Typhimurium. All three L. plantarum strains exhibited significant probiotic potential and anti-Salmonella activity; therefore, further testing on in vivo models should follow. PMID:28559733

  18. The Homolog of the Gene bstA of the BTP1 Phage from Salmonella enterica Serovar Typhimurium ST313 Is an Antivirulence Gene in Salmonella enterica Serovar Dublin.

    PubMed

    Herrero-Fresno, Ana; Espinel, Irene Cartas; Spiegelhauer, Malene Roed; Guerra, Priscila Regina; Andersen, Karsten Wiber; Olsen, John Elmerdahl

    2018-01-01

    In a previous study, a novel virulence gene, bstA , identified in a Salmonella enterica serovar Typhimurium sequence type 313 (ST313) strain was found to be conserved in all published Salmonella enterica serovar Dublin genomes. In order to analyze the role of this gene in the host-pathogen interaction in S Dublin, a mutant where this gene was deleted ( S Dublin Δ bstA ) and a mutant which was further genetically complemented with bstA ( S Dublin 3246-C) were constructed and tested in models of in vitro and in vivo infection as well as during growth competition assays in M9 medium, Luria-Bertani broth, and cattle blood. In contrast to the results obtained for a strain of S Typhimurium ST313, the lack of bstA was found to be associated with increased virulence in S Dublin. Thus, S Dublin Δ bstA showed higher levels of uptake than the wild-type strain during infection of mouse and cattle macrophages and higher net replication within human THP-1 cells. Furthermore, during mouse infections, S Dublin Δ bstA was more virulent than the wild type following a single intraperitoneal infection and showed an increased competitive index during competitive infection assays. Deletion of bstA did not affect either the amount of cytokines released by THP-1 macrophages or the cytotoxicity toward these cells. The histology of the livers and spleens of mice infected with the wild-type strain and the S Dublin Δ bstA mutant revealed similar levels of inflammation between the two groups. The gene was not important for adherence to or invasion of human epithelial cells and did not influence bacterial growth in rich medium, minimal medium, or cattle blood. In conclusion, a lack of bstA affects the pathogenicity of S Dublin by decreasing its virulence. Therefore, it might be regarded as an antivirulence gene in this serovar. Copyright © 2017 American Society for Microbiology.

  19. Survival of Salmonella enterica in Freshwater and Sediments and Transmission by the Aquatic Midge Chironomus tentans (Chironomidae: Diptera)

    PubMed Central

    Moore, Barry C.; Martinez, Edward; Gay, John M.; Rice, Daniel H.

    2003-01-01

    Survival of a nalidixic acid-resistant strain of Salmonella enterica serovar Typhimurium mr-DT-104 in water and sediments was tested using artificially contaminated aquaria. Water samples remained culture positive for salmonella for up to 54 days. Sediment samples were culture positive up to 119 days. In addition, potential mechanisms for spreading salmonella in the environments by chironomid larvae and adults were tested. We evaluated the acquisition of mr-DT-104 by chironomids from contaminated aquatic sediments and subsequent spread to uncontaminated sediments. Larval chironomids raised in contaminated sediments became culture positive, and the bacteria were carried over to adults after emergence. Contamination of clean sediments by chironomid larvae was not demonstrated. These findings clearly suggest that mr-DT-104 serovar organisms can survive in aquatic sediments for at least several months. Uptake of salmonellae by chironomid larvae and adults suggests that they are possible vectors of mr-DT-104 in both aquatic and terrestrial environments, although the role of larval defecation in movement of bacteria to new sediments was not demonstrated. PMID:12902242

  20. Respiratory Hydrogen Use by Salmonella enterica Serovar Typhimurium Is Essential for Virulence

    PubMed Central

    Maier, R. J.; Olczak, A.; Maier, S.; Soni, S.; Gunn, J.

    2004-01-01

    Based on available annotated gene sequence information, the enteric pathogen salmonella, like other enteric bacteria, contains three putative membrane-associated H2-using hydrogenase enzymes. These enzymes split molecular H2, releasing low-potential electrons that are used to reduce quinone or heme-containing components of the respiratory chain. Here we show that each of the three distinct membrane-associated hydrogenases of Salmonella enterica serovar Typhimurium is coupled to a respiratory pathway that uses oxygen as the terminal electron acceptor. Cells grown in a blood-based medium expressed four times the amount of hydrogenase (H2 oxidation) activity that cells grown on Luria Bertani medium did. Cells suspended in phosphate-buffered saline consumed 2 mol of H2 per mol of O2 used in the H2-O2 respiratory pathway, and the activity was inhibited by the respiration inhibitor cyanide. Molecular hydrogen levels averaging over 40 μM were measured in organs (i.e., livers and spleens) of live mice, and levels within the intestinal tract (the presumed origin of the gas) were four times greater than this. The half-saturation affinity of S. enterica serovar Typhimurium for H2 is only 2.1 μM, so it is expected that H2-utilizing hydrogenase enzymes are saturated with the reducing substrate in vivo. All three hydrogenase enzymes contribute to the virulence of the bacterium in a typhoid fever-mouse model, based on results from strains with mutations in each of the three hydrogenase genes. The introduced mutations are nonpolar, and growth of the mutant strains was like that of the parent strain. The combined removal of all three hydrogenases resulted in a strain that is avirulent and (in contrast to the parent strain) one that is unable to invade liver or spleen tissue. The introduction of one of the hydrogenase genes into the triple mutant strain on a low-copy-number plasmid resulted in a strain that was able to both oxidize H2 and cause morbidity in mice within 11 days of

  1. Respiratory hydrogen use by Salmonella enterica serovar Typhimurium is essential for virulence.

    PubMed

    Maier, R J; Olczak, A; Maier, S; Soni, S; Gunn, J

    2004-11-01

    Based on available annotated gene sequence information, the enteric pathogen salmonella, like other enteric bacteria, contains three putative membrane-associated H2-using hydrogenase enzymes. These enzymes split molecular H2, releasing low-potential electrons that are used to reduce quinone or heme-containing components of the respiratory chain. Here we show that each of the three distinct membrane-associated hydrogenases of Salmonella enterica serovar Typhimurium is coupled to a respiratory pathway that uses oxygen as the terminal electron acceptor. Cells grown in a blood-based medium expressed four times the amount of hydrogenase (H2 oxidation) activity that cells grown on Luria Bertani medium did. Cells suspended in phosphate-buffered saline consumed 2 mol of H2 per mol of O2 used in the H2-O2 respiratory pathway, and the activity was inhibited by the respiration inhibitor cyanide. Molecular hydrogen levels averaging over 40 microM were measured in organs (i.e., livers and spleens) of live mice, and levels within the intestinal tract (the presumed origin of the gas) were four times greater than this. The half-saturation affinity of S. enterica serovar Typhimurium for H2 is only 2.1 microM, so it is expected that H2-utilizing hydrogenase enzymes are saturated with the reducing substrate in vivo. All three hydrogenase enzymes contribute to the virulence of the bacterium in a typhoid fever-mouse model, based on results from strains with mutations in each of the three hydrogenase genes. The introduced mutations are nonpolar, and growth of the mutant strains was like that of the parent strain. The combined removal of all three hydrogenases resulted in a strain that is avirulent and (in contrast to the parent strain) one that is unable to invade liver or spleen tissue. The introduction of one of the hydrogenase genes into the triple mutant strain on a low-copy-number plasmid resulted in a strain that was able to both oxidize H2 and cause morbidity in mice within 11

  2. Occurrence of Antimicrobial-Resistant Escherichia coli and Salmonella enterica in the Beef Cattle Production and Processing Continuum.

    PubMed

    Schmidt, John W; Agga, Getahun E; Bosilevac, Joseph M; Brichta-Harhay, Dayna M; Shackelford, Steven D; Wang, Rong; Wheeler, Tommy L; Arthur, Terrance M

    2015-01-01

    Specific concerns have been raised that third-generation cephalosporin-resistant (3GC(r)) Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COT(r)) E. coli, 3GC(r) Salmonella enterica, and nalidixic acid-resistant (NAL(r)) S. enterica may be present in cattle production environments, persist through beef processing, and contaminate final products. The prevalences and concentrations of these organisms were determined in feces and hides (at feedlot and processing plant), pre-evisceration carcasses, and final carcasses from three lots of fed cattle (n = 184). The prevalences and concentrations were further determined for strip loins from 103 of the carcasses. 3GC(r) Salmonella was detected on 7.6% of hides during processing and was not detected on the final carcasses or strip loins. NAL(r) S. enterica was detected on only one hide. 3GC(r) E. coli and COT(r) E. coli were detected on 100.0% of hides during processing. Concentrations of 3GC(r) E. coli and COT(r) E. coli on hides were correlated with pre-evisceration carcass contamination. 3GC(r) E. coli and COT(r) E. coli were each detected on only 0.5% of final carcasses and were not detected on strip loins. Five hundred and 42 isolates were screened for extraintestinal pathogenic E. coli (ExPEC) virulence-associated markers. Only two COT(r) E. coli isolates from hides were ExPEC, indicating that fed cattle products are not a significant source of ExPEC causing human urinary tract infections. The very low prevalences of these organisms on final carcasses and their absence on strip loins demonstrate that current sanitary dressing procedures and processing interventions are effective against antimicrobial-resistant bacteria. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  3. Phenotypic and genotypic profile of clinical and animal multidrug-resistant Salmonella enterica isolates from Mexico.

    PubMed

    Aguilar-Montes de Oca, S; Talavera-Rojas, M; Soriano-Vargas, E; Barba-León, J; Vázquez-Navarrete, J; Acosta-Dibarrat, J; Salgado-Miranda, C

    2018-01-01

    The objective of this study was to obtain a phenotypic and genotypic profile of Salmonella enterica including multidrug-resistant (MDR) isolates from food-producing animals and clinical isolates, as well as their genetic relatedness in two different States of Mexico (Jalisco and State of Mexico). A total of 243 isolates were evaluated in terms of antimicrobial resistance (AMR) and related genes through a disk diffusion method and PCR respectively; we found 16 MDR isolates, all of them harbouring the bla CMY gene but not qnr genes, these isolates represent less than 10% of the collection. The pulsed-field gel electrophoresis revealed a higher genotypic similitude within isolates of State of Mexico than Jalisco. A low percentage of Salmonella isolates were resistant to relevant antibiotics in human health, nevertheless, the AMR and involved genes were similar despite the different serovars and origin of the isolates. This investigation provided an insight of the current status of AMR of Salmonella isolates in two States of Mexico and pinpoint the genes involved in AMR and their epidemiological relationship, the information could help to determine an adequate therapy in human and veterinary medicine. © 2017 The Society for Applied Microbiology.

  4. Thermal inactivation and sublethal injury kinetics of Salmonella enterica and Listeria monocytogenes in broth versus agar surface.

    PubMed

    Wang, Xiang; Devlieghere, Frank; Geeraerd, Annemie; Uyttendaele, Mieke

    2017-02-21

    The objective of the present study was to compare the thermal inactivation and sublethal injury kinetics of Salmonella enterica and Listeria monocytogenes in broth (suspended cells) and on solid surface (agar-seeded cells). A 3-strain cocktail of S. enterica or L. monocytogenes inoculated in broth or on agar was subjected to heating in a water bath at various set temperatures (55.0, 57.5 and 60.0°C for S. enterica and 60.0, 62.5 and 65°C for L. monocytogenes). The occurrence of sublethally injured cells was determined by comparing enumerations on nonselective (TSAYE) and selective (XLD or ALOA) media. Results showed that the inactivation curves obtained from selective media were log-linear, and significant shoulders (p<0.05) were observed on some of the inactivation curves from TSAYE media. The D-values derived from the total population were higher than those from the uninjured cells. Generally, cells on agar surface exhibited higher heat resistance than those in broth. For S. enterica, cell injury increased with the exposure time, no difference was observed when treated at temperatures from 55.0 to 60.0°C, while for L. monocytogenes, cell injury increased significantly with heating time and treatment temperature (from 60.0 to 65°C). Moreover, the degree of sublethal injury affected by thermal treatment in broth or on agar surface depended upon the target microorganism. Higher proportions of injured S. enterica cells were observed for treatment in broth than on agar surface, while the opposite was found for L. monocytogenes. The provided information may be used to assess the efficacy of thermal treatment processes on surfaces for inactivation of S. enterica and L. monocytogenes, and it provides insight into the sublethally injured survival state of S. enterica and L. monocytogenes treated in liquid or on solid food. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Modeling the fate of Escherichia coli O157:H7 and Salmonella enterica in the agricultural environment: current perspective.

    PubMed

    Ongeng, Duncan; Haberbeck, Leticia U; Mauriello, Gianluigi; Ryckeboer, Jaak; Springael, Dirk; Geeraerd, Annemie H

    2014-04-01

    The significance of fresh vegetable consumption on human nutrition and health is well recognized. Human infections with Escherichia coli O157:H7 and Salmonella enterica linked to fresh vegetable consumption have become a serious public health problem inflicting a heavy economic burden. The use of contaminated livestock wastes such as manure and manure slurry in crop production is believed to be one of the principal routes of fresh vegetable contamination with E. coli O157:H7 and S. enterica at preharvest stage because both ruminant and nonruminant livestock are known carriers of E. coli O157:H7 and S. enterica in the environment. A number of challenge-testing studies have examined the fate of E. coli O157:H7 and S. enterica in the agricultural environment with the view of designing strategies for controlling vegetable contamination preharvest. In this review, we examined the mathematical modeling approaches that have been used to study the behavior of E. coli O157:H7 and S. enterica in the manure, manure-amended soil, and in manure-amended soil-plant ecosystem during cultivation of fresh vegetable crops. We focused on how the models have been applied to fit survivor curves, predict survival, and assess the risk of vegetable contamination preharvest. The inadequacies of the current modeling approaches are discussed and suggestions for improvements to enhance the applicability of the models as decision tools to control E. coli O157:H7 and S. enterica contamination of fresh vegetables during primary production are presented. © 2014 Institute of Food Technologists®

  6. Fibrinolytic and procoagulant activities of Yersinia pestis and Salmonella enterica.

    PubMed

    Korhonen, T K

    2015-06-01

    Pla of the plague bacterium Yersinia pestis and PgtE of the enteropathogen Salmonella enterica are surface-exposed, transmembrane β-barrel proteases of the omptin family that exhibit a complex array of interactions with the hemostatic systems in vitro, and both proteases are established virulence factors. Pla favors fibrinolysis by direct activation of plasminogen, inactivation of the serpins plasminogen activator inhibitor-1 and α2-antiplasmin, inactivation of the thrombin-activable fibrinolysis inhibitor, and activation of single-chain urokinase. PgtE is structurally very similar but exhibits partially different functions and differ in expression control. PgtE proteolysis targets control aspects of fibrinolysis, and mimicry of matrix metalloproteinases enhances cell migration that should favor the intracellular spread of the bacterium. Enzymatic activity of both proteases is strongly influenced by the environment-induced variations in lipopolysaccharide that binds to the β-barrel. Both proteases cleave the tissue factor pathway inhibitor and thus also express procoagulant activity. © 2015 International Society on Thrombosis and Haemostasis.

  7. Fluorescence-based thermal shift data on multidrug regulator AcrR from Salmonella enterica subsp. entrica serovar Typhimurium str. LT2.

    PubMed

    Manjasetty, Babu A; Halavaty, Andrei S; Luan, Chi-Hao; Osipiuk, Jerzy; Mulligan, Rory; Kwon, Keehwan; Anderson, Wayne F; Joachimiak, Andrzej

    2016-06-01

    The fluorescence-based thermal shift (FTS) data presented here include Table S1 and Fig. S1, and are supplemental to our original research article describing detailed structural, FTS, and fluorescence polarization analyses of the Salmonella enterica subsp. entrica serovar Typhimurium str. LT2 multidrug transcriptional regulator AcrR (StAcrR) (doi:10.1016/j.jsb.2016.01.008) (Manjasetty et al., 2015 [1]). Table S1 contains chemical formulas, a Chemical Abstracts Service (CAS) Registry Number (CAS no.), FTS rank (a ligand with the highest rank) has the largest difference in the melting temperature (ΔT m), and uses as drug molecules against various pathological conditions of sixteen small-molecule ligands that increase thermal stability of StAcrR. Thermal stability of human enolase 1, a negative control protein, was not affected in the presence of various concentrations of the top six StAcrR binders (Fig. S1).

  8. Detection of Escherichia coli O157:H7 and Salmonella enterica in air and droplets at three U.S. commercial beef processing plants

    USDA-ARS?s Scientific Manuscript database

    Bacteria are known to be present in air at beef processing plants but published data regarding the prevalences of airborne Escherichia coli O157:H7 and Salmonella enterica are very limited. To determine if airborne pathogens were present in beef processing facilities, we placed sedimentation sponges...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  10. Effect of X-ray treatments on Escherichia coli 0157:H7, Listeria monocytogenes, Shigella flexneri, Salmonella enterica and inherent microbiota on whole mangoes

    USDA-ARS?s Scientific Manuscript database

    The aims of this investigation were to; (i) study the effect of X-ray treatments in reducing Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica and Shigella flexneri on whole mangoes, and (ii) study the effect of Xray treatments on microflora counts (mesophilic counts, psychrotrop...

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

    PubMed

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

    2013-07-01

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

  12. A pulsed field gel electrophoresis (PFGE) study that suggests a major world-wide clone of Salmonella enterica serovar Enteritidis.

    PubMed

    Pang, Jen-Chieh; Chiu, Tsai-Hsin; Helmuth, Reiner; Schroeter, Andreas; Guerra, Beatriz; Tsen, Hau-Yang

    2007-05-30

    Since human infections by Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) have been increasing world-wide over the past years and epidemiological studies have implicated the consumption of meat, poultry, eggs and egg products, elucidation of the predominant subtypes for this Salmonella spp. is important. In this study, 107 poultry and food isolates of Salmonella Enteritidis obtained from Germany were analyzed by pulsed field gel electrophoresis (PFGE), and the subtypes were compared with those of the 124 human isolates obtained in Taiwan. Results showed that for these 107 poultry and food isolates, when XbaI, SpeI and NotI were used for chromosomal DNA digestion followed by PFGE analysis, a total of 19, 20 and 19 PFGE patterns, respectively, were identified. Of them, 51 (47.7%), 52 (48.6%) and 42 (39.3%) strains belong to a single pattern of X3, S3 and N3, respectively, and 34 strains belong to a pattern combination of X3S3N3, which was the major subtype. When PFGE patterns of these 107 German isolates were compared with those of the 124 human isolates obtained in Taiwan, pattern combination of X3S3N3 was found as the most common pattern shared by isolates from both areas. PT4 is a major phage type for German and Taiwan isolates. Although most of the X3S3N3 strains are of this phage type, some strains of other PFGE patterns are also of this phage type. Since strains used in this study were unrelated, i.e., they were isolated from different origins in areas geographically far apart from each other, the PFGE study suggests a major world-wide clone of S. enterica serovar Enteritidis.

  13. The Salmonella enterica serovar Typhimurium QseB Response Regulator Negatively Regulates Bacterial Motility and Swine Colonization in the Absence of the QseC Sensor Kinase

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serovar Typhimurium (S. Typhimurium) responds to the catecholamine, norepinephrine by increasing bacterial growth and enhancing motility. In this study, iron with or without the siderophore, ferrioxamine E also enhanced bacterial motility. Iron-enhanced motility was growth-rate ...

  14. ramR mutations affecting fluoroquinolone susceptibility in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198

    PubMed Central

    Baucheron, Sylvie; Le Hello, Simon; Doublet, Benoît; Giraud, Etienne; Weill, François-Xavier; Cloeckaert, Axel

    2013-01-01

    A screening for non-target mutations affecting fluoroquinolone susceptibility was conducted in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198. Among a panel of representative isolates (n = 27), covering the epidemic, only three showed distinct mutations in ramR resulting in enhanced expression of genes encoding the AcrAB-TolC efflux system and low increase in ciprofloxacin MIC. No mutations were detected in other regulatory regions of this efflux system. Ciprofloxacin resistance in serovar Kentucky ST198 is thus currently mainly due to multiple target gene mutations. PMID:23914184

  15. Assimilation of nicotinamide mononucleotide requires periplasmic AphA phosphatase in Salmonella enterica.

    PubMed

    Grose, Julianne H; Bergthorsson, Ulfar; Xu, Yaping; Sterneckert, Jared; Khodaverdian, Behzad; Roth, John R

    2005-07-01

    Salmonella enterica can obtain pyridine from exogenous nicotinamide mononucleotide (NMN) by three routes. In route 1, nicotinamide is removed from NMN in the periplasm and enters the cell as the free base. In route 2, described here, phosphate is removed from NMN in the periplasm by acid phosphatase (AphA), and the produced nicotinamide ribonucleoside (NmR) enters the cell via the PnuC transporter. Internal NmR is then converted back to NMN by the NmR kinase activity of NadR. Route 3 is seen only in pnuC* transporter mutants, which import NMN intact and can therefore grow on lower levels of NMN. Internal NMN produced by either route 2 or route 3 is deamidated to nicotinic acid mononucleotide and converted to NAD by the biosynthetic enzymes NadD and NadE.

  16. Salmonella enterica and extended-spectrum cephalosporin-resistant Escherichia coli recovered from Holstein dairy calves from 8 farms in New Brunswick, Canada.

    PubMed

    Awosile, Babafela; McClure, J; Sanchez, Javier; Rodriguez-Lecompte, Juan Carlos; Keefe, Greg; Heider, Luke C

    2018-04-01

    This study was carried out to determine the frequency of fecal carriage, antimicrobial susceptibility, and resistance genes in Salmonella enterica and Escherichia coli with reduced susceptibility to extended-spectrum cephalosporins (ESC) isolated from 488 dairy calves from 8 farms in New Brunswick, Canada. Both S. enterica and E. coli with reduced susceptibility to ESC were isolated using selective culture. Minimum inhibitory concentrations to a panel of antimicrobial drugs were determined for randomly selected E. coli isolates and all of the Salmonella isolates. Multiplex PCR were conducted on the selected ESC-resistant E. coli to assess the β-lactamase resistance genes (bla CTX-M , bla CMY-2 , bla SHV , and bla TEM ) and plasmid-mediated qnrB and qnrS resistant genes. Information on ceftiofur use and other farm management practices were collected by the use of a questionnaire to determine the risk factors for the fecal recovery of E. coli with reduced susceptibility to ESC. Salmonella enterica frequency in calves' fecal samples was 3.3%, and all were pansusceptible. Salmonella isolates belonged to 3 serovars namely Salmonella Senftenberg, Salmonella Typhimurium, and Salmonella Derby. The frequency of fecal carriage of E. coli with reduced susceptibility to ESC in calves was 81.2%. Of the selected isolates (n = 100), all were multi-drug resistant, whereas 88% were ESC resistant based on minimum inhibitory concentration testing. From the selected ESC-resistant E. coli isolates, bla TEM was detected in 84.1%, bla CMY-2 was detected in 52.2%, bla CTXM groups were detected in 30.7%, and bla SHV was detected in 1.1% of isolates. Plasmid-mediated quinolone resistance genes were identified in 7 of 9 isolates resistant to quinolones. Five isolates were positive for qnrB, whereas 2 isolates were positive for both qnrB and qnrS. Whereas neonatal calves [odds ratio (OR) = 2.42, 95% confidence interval (CI): 1.87-3.12], regular ceftiofur use on the farm (OR = 3.83, 95% CI: 2

  17. Inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree by high hydrostatic pressure with/without added ascorbic acid.

    PubMed

    Mukhopadhyay, Sudarsan; Sokorai, Kimberly; Ukuku, Dike; Fan, Xuetong; Juneja, Vijay; Sites, Joseph; Cassidy, Jennifer

    2016-10-17

    The objective of this research was to evaluate and develop a method for inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree (CP) by high hydrostatic pressure (HHP). Cantaloupe being the most netted varieties of melons presents a greater risk of pathogen transmission. Freshly prepared CP with or without 0.1% ascorbic acid (AA) was inoculated with a bacterial cocktail composed of a three serotype mixture of S. enterica (S. Poona, S. Newport H1275 and S. Stanley H0558) and a mixture of three strains of L. monocytogenes (Scott A, 43256 and 51742) to a population of ca. 10(8)CFU/g. Double sealed and double bagged inoculated CP (ca. 5g) were pressure treated at 300, 400 and 500MPa at 8°C and 15°C for 5min. Data indicated increased inactivation of both Salmonella and Listeria spp. with higher pressure. Log reduction for CP at 300MPa, 8°C for 5min was 2.4±0.2 and 1.6±0.5logCFU/g for Salmonella and Listeria, respectively. Survivability of the pathogens was significantly compromised at 400MPa and 8°C, inactivating 4.5±0.3logCFU/g of Salmonella and 3.0±0.4logCFU/g of Listeria spp. Complete inactivation of the pathogens in the puree (log reduction >6.7logCFU/g), with or without AA, was achieved when the pressure was further increased to 500MPa, except that for Listeria containing no AA at 8°C. Listeria presented higher resistance to pressure treatment compared to Salmonella spp. Initial temperatures (8 and 15°C) had no significant influence on Salmonella log reductions. Log reduction of pathogens increased but not significantly with increase of temperature. AA did not show any significant antimicrobial activity. Viable counts were about 0.2-0.4logCFU/g less in presence of 0.1% AA. These data validate that HHP can be used as an effective method for decontamination of cantaloupe puree. Published by Elsevier B.V.

  18. Identification of Salmonella enterica Serovar Typhimurium Genes Regulated during Biofilm Formation on Cholesterol Gallstone Surfaces

    PubMed Central

    Gonzalez-Escobedo, Geoffrey

    2013-01-01

    Salmonella spp. are able to form biofilms on abiotic and biotic surfaces. In vivo studies in our laboratory have shown that Salmonella can form biofilms on the surfaces of cholesterol gallstones in the gallbladders of mice and human carriers. Biofilm formation on gallstones has been demonstrated to be a mechanism of persistence. The purpose of this work was to identify and evaluate Salmonella sp. cholesterol-dependent biofilm factors. Differential gene expression analysis between biofilms on glass or cholesterol-coated surfaces and subsequent quantitative real-time PCR (qRT-PCR) revealed that type 1 fimbria structural genes and a gene encoding a putative outer membrane protein (ycfR) were specifically upregulated in Salmonella enterica serovar Typhimurium biofilms grown on cholesterol-coated surfaces. Spatiotemporal expression of ycfR and FimA verified their regulation during biofilm development on cholesterol-coated surfaces. Surprisingly, confocal and scanning electron microscopy demonstrated that a mutant of type 1 fimbria structural genes (ΔfimAICDHF) and a ycfR mutant showed increased biofilm formation on cholesterol-coated surfaces. In vivo experiments using Nramp1+/+ mice harboring gallstones showed that only the ΔycfR mutant formed extensive biofilms on mouse gallstones at 7 and 21 days postinfection; ΔfimAICDHF was not observed on gallstone surfaces after the 7-day-postinfection time point. These data suggest that in Salmonella spp., wild-type type 1 fimbriae are important for attachment to and/or persistence on gallstones at later points of chronic infection, whereas YcfR may represent a specific potential natural inhibitor of initial biofilm formation on gallstones. PMID:23897604

  19. TolC is important for bacterial survival and oxidative stress response in Salmonella enterica serovar Choleraesuis in an acidic environment.

    PubMed

    Lee, Jen-Jie; Wu, Ying-Chen; Kuo, Chih-Jung; Hsuan, Shih-Ling; Chen, Ter-Hsin

    2016-09-25

    The outer membrane protein TolC, which is one of the key components of several multidrug efflux pumps, is thought to be involved in various independent systems in Enterobacteriaceae. Since the acidic environment of the stomach is an important protection barrier against foodborne pathogen infections in hosts, we evaluated whether TolC played a role in the acid tolerance of Salmonella enterica serovar Choleraesuis. Comparison of the acid tolerance of the tolC mutant and the parental wild-type strain showed that the absence of TolC limits the ability of Salmonella to sustain life under extreme acidic conditions. Additionally, the mutant exhibited morphological changes during growth in an acidic medium, leading to the conflicting results of cell viability measured by spectrophotometry and colony-forming unit counting. Reverse-transcriptional-PCR analysis indicated that acid-related molecules, apparatus, or enzymes and oxidation-induced factors were significantly affected by the acidic environment in the null-tolC mutant. The elongated cellular morphology was restored by adding antioxidants to the culture medium. Furthermore, we found that increased cellular antioxidative activity provides an overlapping protection against acid killing, demonstrating the complexity of the bacterial acid stress response. Our findings reinforce the multifunctional characteristics of TolC in acid tolerance or oxidative stress resistance and support the correlative protection mechanism between oxygen- and acid-mediated stress responses in Salmonella enterica serovar Choleraesuis. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Control of Salmonella enterica and Listeria monocytogenes in hummus using allyl isothiocyanate.

    PubMed

    Olaimat, Amin N; Al-Holy, Murad A; Abu Ghoush, Mahmoud; Al-Nabulsi, Anas A; Holley, Richard A

    2018-08-02

    Hummus (chickpea dip) is a ready-to-eat product which has been implicated in several foodborne outbreaks and food recalls. This study aimed to screen the antimicrobial activity of allyl isothiocyanate (AITC) against 5 strains of each of Salmonella enterica and Listeria monocytogenes using a disc diffusion method. Additionally, the antimicrobial activity of 0.1-1.5% (v/w) AITC against both pathogens and aerobic bacteria in hummus was also investigated. The inhibition zones of AITC were 8.5-15 and 7.0-8.5 mm against the S. enterica and L. monocytogenes strains, respectively, at 37 °C. S. enterica numbers were reduced by >6 log 10 CFU/g in hummus containing ≥0.5% AITC by 3 days at both 4 and 10 °C. While 0.1-0.25% AITC reduced S. enterica by 2.5-5.1 log 10 CFU/g at 4 °C or by 4.7-6.0 log 10 CFU/g at 10 °C by 10 days. Similarly, L. monocytogenes numbers decreased by >6 log 10 CFU/g in hummus with ≥0.5% or ≥1.0% AITC at 4 or 10 °C, respectively, by 3 days. Further, 0.25% AITC significantly reduced L. monocytogenes in hummus by 2.7 and 4.3 log 10 CFU/g at 4 and 10 °C, respectively. Moreover, 0.1% AITC reduced L. monocytogenes by 1.8 log 10 CFU/g in hummus at 10 °C and inhibited the growth at 4 °C for up to 10 days. The aerobic bacterial count also significantly decreased in un-inoculated hummus treated with 1.0-1.5% AITC at both 4 and 10 °C, while a concentration of 0.25-0.5% AITC inhibited their growth at 4 °C. AITC can be used to reduce the risk of salmonellosis or listeriosis in hummus and extend its shelf-life. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Use of marination for controlling Salmonella enterica and Listeria monocytogenes in raw beef.

    PubMed

    Rhoades, J; Kargiotou, C; Katsanidis, E; Koutsoumanis, K P

    2013-12-01

    The effect of marination on the survival and growth of the pathogens Salmonella enterica and Listeria monocytogenes on beef pieces was investigated. Five marinades were used: soy sauce base marinade without (SB) or with lactic acid (SBLA), red wine base marinade without (WB) or with 0.5% v/v oregano essential oil (WBO), and sterile saline used as control (C). Inoculated fresh beef pieces were marinated for 18 h at 5 °C, removed from the marinade and subjected to storage trials at 5 °C and 15 °C. Heat inactivation studies were also performed on the isolates after exposure to the marinades to determine if marination affects heat resistance of the pathogens. The marinades with antimicrobials caused a significant decrease in viable count of the pathogens during marinations at 5 °C for 18 h of up to 2.1 and 3.4 log cfu cm(-2) for Salmonella and L. monocytogenes, respectively. Marinades without antimicrobials were less bactericidal resulting to reductions ranging from 0.3 to 0.4 and 1.3 to 2.0 log cfu cm(-2) for Salmonella and L. monocytogenes, respectively. Growth of L. monocytogenes was observed in the controls at both tested temperatures, while growth of Salmonella was observed in the controls stored at 15 °C. No growth of the pathogens was observed in any of the marinated samples at both temperature tested. No significant changes of heat resistance of the tested pathogens after exposure to the marinades were observed demonstrating the enhanced safety of the marinated beef product. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Viable-but-Nonculturable Listeria monocytogenes and Salmonella enterica Serovar Thompson Induced by Chlorine Stress Remain Infectious.

    PubMed

    Highmore, Callum J; Warner, Jennifer C; Rothwell, Steve D; Wilks, Sandra A; Keevil, C William

    2018-04-17

    The microbiological safety of fresh produce is monitored almost exclusively by culture-based detection methods. However, bacterial food-borne pathogens are known to enter a viable-but-nonculturable (VBNC) state in response to environmental stresses such as chlorine, which is commonly used for fresh produce decontamination. Here, complete VBNC induction of green fluorescent protein-tagged Listeria monocytogenes and Salmonella enterica serovar Thompson was achieved by exposure to 12 and 3 ppm chlorine, respectively. The pathogens were subjected to chlorine washing following incubation on spinach leaves. Culture data revealed that total viable L. monocytogenes and Salmonella Thompson populations became VBNC by 50 and 100 ppm chlorine, respectively, while enumeration by direct viable counting found that chlorine caused a <1-log reduction in viability. The pathogenicity of chlorine-induced VBNC L. monocytogenes and Salmonella Thompson was assessed by using Caenorhabditis elegans Ingestion of VBNC pathogens by C. elegans resulted in a significant life span reduction ( P = 0.0064 and P < 0.0001), and no significant difference between the life span reductions caused by the VBNC and culturable L. monocytogenes treatments was observed. L. monocytogenes was visualized beyond the nematode intestinal lumen, indicating resuscitation and cell invasion. These data emphasize the risk that VBNC food-borne pathogens could pose to public health should they continue to go undetected. IMPORTANCE Many bacteria are known to enter a viable-but-nonculturable (VBNC) state in response to environmental stresses. VBNC cells cannot be detected by standard laboratory culture techniques, presenting a problem for the food industry, which uses these techniques to detect pathogen contaminants. This study found that chlorine, a sanitizer commonly used for fresh produce, induces a VBNC state in the food-borne pathogens Listeria monocytogenes and Salmonella enterica It was also found that

  3. Comparison of Salmonella enterica Serovars Typhi and Typhimurium Reveals Typhoidal Serovar-Specific Responses to Bile

    PubMed Central

    Johnson, Rebecca; Ravenhall, Matt; Pickard, Derek; Dougan, Gordon; Byrne, Alexander

    2017-01-01

    ABSTRACT Salmonella enterica serovars Typhi and Typhimurium cause typhoid fever and gastroenteritis, respectively. A unique feature of typhoid infection is asymptomatic carriage within the gallbladder, which is linked with S. Typhi transmission. Despite this, S. Typhi responses to bile have been poorly studied. Transcriptome sequencing (RNA-Seq) of S. Typhi Ty2 and a clinical S. Typhi isolate belonging to the globally dominant H58 lineage (strain 129-0238), as well as S. Typhimurium 14028, revealed that 249, 389, and 453 genes, respectively, were differentially expressed in the presence of 3% bile compared to control cultures lacking bile. fad genes, the actP-acs operon, and putative sialic acid uptake and metabolism genes (t1787 to t1790) were upregulated in all strains following bile exposure, which may represent adaptation to the small intestine environment. Genes within the Salmonella pathogenicity island 1 (SPI-1), those encoding a type IIII secretion system (T3SS), and motility genes were significantly upregulated in both S. Typhi strains in bile but downregulated in S. Typhimurium. Western blots of the SPI-1 proteins SipC, SipD, SopB, and SopE validated the gene expression data. Consistent with this, bile significantly increased S. Typhi HeLa cell invasion, while S. Typhimurium invasion was significantly repressed. Protein stability assays demonstrated that in S. Typhi the half-life of HilD, the dominant regulator of SPI-1, is three times longer in the presence of bile; this increase in stability was independent of the acetyltransferase Pat. Overall, we found that S. Typhi exhibits a specific response to bile, especially with regard to virulence gene expression, which could impact pathogenesis and transmission. PMID:29229736

  4. Interaction of Phytophagous Insects with Salmonella enterica on Plants and Enhanced Persistence of the Pathogen with Macrosteles quadrilineatus Infestation or Frankliniella occidentalis Feeding

    PubMed Central

    Soto-Arias, José Pablo; Groves, Russell; Barak, Jeri D.

    2013-01-01

    Recently, most foodborne illness outbreaks of salmonellosis have been caused by consumption of contaminated fresh produce. Yet, the mechanisms that allow the human pathogen Salmonella enterica to contaminate and grow in plant environments remain poorly described. We examined the effect of feeding by phytophagous insects on survival of S. enterica on lettuce. Larger S. enterica populations were found on leaves infested with Macrosteles quadrilineatus. In contrast, pathogen populations among plants exposed to Frankliniella occidentalis or Myzus persicae were similar to those without insects. However, on plants infested with F. occidentalis, areas of the infested leaf with feeding damage sustained higher S. enterica populations than areas without damage. The spatial distribution of S. enterica cells on leaves infested with F. occidentalis may be altered resulting in higher populations in feeding lesions or survival may be different across a leaf dependent on local damage. Results suggest the possibility of some specificity with select insects and the persistence of S. enterica. Additionally, we demonstrated the potential for phytophagous insects to become contaminated with S. enterica from contaminated plant material. S. enterica was detected in approximately 50% of all M. quadrilineatus, F. occidentalis, and M. persicae after 24 h exposure to contaminated leaves. Particularly, 17% of F. occidentalis, the smallest of the insects tested, harbored more than 102 CFU/F. occidentalis. Our results show that phytophagous insects may influence the population dynamics of S. enterica in agricultural crops. This study provides evidence of a human bacterial pathogen interacting with phytophagous insect during plant infestation. PMID:24205384

  5. Interaction of phytophagous insects with Salmonella enterica on plants and enhanced persistence of the pathogen with Macrosteles quadrilineatus infestation or Frankliniella occidentalis feeding.

    PubMed

    Soto-Arias, José Pablo; Groves, Russell; Barak, Jeri D

    2013-01-01

    Recently, most foodborne illness outbreaks of salmonellosis have been caused by consumption of contaminated fresh produce. Yet, the mechanisms that allow the human pathogen Salmonella enterica to contaminate and grow in plant environments remain poorly described. We examined the effect of feeding by phytophagous insects on survival of S. enterica on lettuce. Larger S. enterica populations were found on leaves infested with Macrosteles quadrilineatus. In contrast, pathogen populations among plants exposed to Frankliniella occidentalis or Myzus persicae were similar to those without insects. However, on plants infested with F. occidentalis, areas of the infested leaf with feeding damage sustained higher S. enterica populations than areas without damage. The spatial distribution of S. enterica cells on leaves infested with F. occidentalis may be altered resulting in higher populations in feeding lesions or survival may be different across a leaf dependent on local damage. Results suggest the possibility of some specificity with select insects and the persistence of S. enterica. Additionally, we demonstrated the potential for phytophagous insects to become contaminated with S. enterica from contaminated plant material. S. enterica was detected in approximately 50% of all M. quadrilineatus, F. occidentalis, and M. persicae after 24 h exposure to contaminated leaves. Particularly, 17% of F. occidentalis, the smallest of the insects tested, harbored more than 10(2) CFU/F. occidentalis. Our results show that phytophagous insects may influence the population dynamics of S. enterica in agricultural crops. This study provides evidence of a human bacterial pathogen interacting with phytophagous insect during plant infestation.

  6. Transposon Mutagenesis of Salmonella enterica Serovar Enteritidis Identifies Genes That Contribute to Invasiveness in Human and Chicken Cells and Survival in Egg Albumen

    PubMed Central

    Zhou, Xiaohui; Kim, Hye-Young; Call, Douglas R.; Guard, Jean

    2012-01-01

    Salmonella enterica serovar Enteritidis is an important food-borne pathogen, and chickens are a primary reservoir of human infection. While most knowledge about Salmonella pathogenesis is based on research conducted on Salmonella enterica serovar Typhimurium, S. Enteritidis is known to have pathobiology specific to chickens that impacts epidemiology in humans. Therefore, more information is needed about S. Enteritidis pathobiology in comparison to that of S. Typhimurium. We used transposon mutagenesis to identify S. Enteritidis virulence genes by assay of invasiveness in human intestinal epithelial (Caco-2) cells and chicken liver (LMH) cells and survival within chicken (HD-11) macrophages as a surrogate marker for virulence. A total of 4,330 transposon insertion mutants of an invasive G1 Nalr strain were screened using Caco-2 cells. This led to the identification of attenuating mutations in a total of 33 different loci, many of which include genes previously known to contribute to enteric infection (e.g., Salmonella pathogenicity island 1 [SPI-1], SPI-4, SPI-5, CS54, fliH, fljB, csgB, spvR, and rfbMN) in S. Enteritidis and other Salmonella serovars. Several genes or genomic islands that have not been reported previously (e.g., SPI-14, ksgA, SEN0034, SEN2278, and SEN3503) or that are absent in S. Typhimurium or in most other Salmonella serovars (e.g., pegD, SEN1152, SEN1393, and SEN1966) were also identified. Most mutants with reduced Caco-2 cell invasiveness also showed significantly reduced invasiveness in chicken liver cells and impaired survival in chicken macrophages and in egg albumen. Consequently, these genes may play an important role during infection of the chicken host and also contribute to successful egg contamination by S. Enteritidis. PMID:22988017

  7. Nalidixic Acid-Resistant Salmonella enterica Serotype Typhi Presenting as a Primary Psoas Abscess: Case Report and Review of the Literature

    PubMed Central

    Shakespeare, William A.; Davie, Daniel; Tonnerre, Claude; Rubin, Michael A.; Strong, Michael; Petti, Cathy A.

    2005-01-01

    We report an unusual case of Salmonella enterica serotype Typhi presenting as a primary psoas abscess. The isolate tested susceptible to ciprofloxacin but resistant to nalidixic acid in vitro, a pattern associated with fluoroquinolone therapeutic failures. We review the literature for serovar Typhi psoas abscess in the absence of bacteremia and discuss the importance of identifying isolates with reduced susceptibility to fluoroquinolones. PMID:15695728

  8. Characterization of Salmonella enterica serovar Agona slaughter isolates from the animal arm of the National Antimicrobial Resistance Monitoring System-Enteric Bacteria (NARMS): 1997 through 2003.

    PubMed

    Douris, Aphrodite; Fedorka-Cray, Paula J; Jackson, Charlene R

    2008-03-01

    A total of 499 Salmonella enterica serovar Agona isolates from cattle, swine, chicken, and turkey samples were assayed for antimicrobial susceptibility and subtyped using pulsed-field gel electrophoresis (PFGE). Salmonella Agona isolates exhibited increased resistance to amoxicillin/clavulanic acid, ampicillin, cefoxitin, ceftiofur, cephalothin, and chloramphenicol, and a single isolate was resistant to ceftriaxone. Multiple drug resistance (MDR; resistance >or= 2 antimicrobials) was exhibited in 57% (n=282/499) of the Salmonella Agona isolates and 22% (n=111/499) of these Salmonella Agona isolates were resistant to five or more antimicrobials. PFGE patterns of 482 Salmonella Agona slaughter samples resulted in 165 unique patterns. Cluster analysis indicated that isolates indistinguishable by PFGE appeared to group according to antimicrobial resistance profiles. These data suggest that Salmonella Agona is increasing in prevalence in U.S. cattle presented for slaughter and should be further monitored.

  9. Recipes for antimicrobial wine marinades against Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica.

    PubMed

    Friedman, Mendel; Henika, P R; Levin, C E; Mandrell, R E

    2007-08-01

    We have evaluated bactericidal activities against Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica of several antimicrobial wine recipes, each consisting of red or white wine extracts of oregano leaves with added garlic juice and oregano oil. Dose-response plots were used to determine the percentage of the recipes that resulted in a 50% decrease in colony-forming units (CFU) at 60 min (BA(50)). Studies designed to optimize antibacterial activities of the recipes demonstrated that several combinations of the naturally occurring plant-derived ingredients rapidly inactivated the above mentioned 4 foodborne pathogens. We also showed that (a) incubation temperature affected activities in the following order: 37 degrees C > 21 degrees C > 4 degrees C; (b) varying the initial bacterial concentrations from 10(3) to 10(4) to 10(5) CFU/well did not significantly affect BA(50) values; (c) storage of 3 marinades up to 2 mo did not change their effectiveness against Salmonella enterica; and (d) polyphenolic compounds isolated by chromatography from red wine exhibited exceptional activity at nanogram levels against 2 strains of Bacillus cereus. These observations suggest that antimicrobial wine formulations have the potential to improve the microbiological safety of foods.

  10. FUNCTIONS EXERTED BY THE VIRULENCE ASSOCIATED TYPE THREE SECRETION SYSTEMS DURING SALMONELLA ENTERICA SEROVAR ENTERITIDIS INFECTION OF CHICKEN OVIDUCT EPITHELIAL CELLS AND MACROPHAGES

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serovar, Enteritidis (SE) infection of chicken is a major contributing factor to non-typhoidal salmonellosis. The roles of the type three secretion systems (T3SS-1 and T3SS-2) in the pathogenesis of SE infection of chickens are poorly understood. In this study, the functions exer...

  11. Salmonella infection and carriage in reptiles in a zoological collection.

    PubMed

    Clancy, Meredith M; Davis, Meghan; Valitutto, Marc T; Nelson, Kenrad; Sykes, John M

    2016-05-01

    OBJECTIVE To identify important subspecies and serovars of Salmonella enterica in a captive reptile population and clinically relevant risk factors for and signs of illness in Salmonella-positive reptiles. DESIGN Retrospective cross-sectional study. ANIMALS 11 crocodilians (4 samples), 78 snakes (91 samples), 59 lizards (57 samples), and 34 chelonians (23 samples) at the Bronx Zoo from 2000 through 2012. PROCEDURES Data pertaining to various types of biological samples obtained from reptiles with positive Salmonella culture results and the reptiles themselves were analyzed to determine period prevalence of and risk factors for various Salmonella-related outcomes. RESULTS Serovar distribution differences were identified for sample type, reptile phylogenetic family, and reptile origin and health. Salmonella enterica subsp enterica was the most common subspecies in Salmonella cultures (78/175 [45%]), identified across all reptilian taxa. Salmonella enterica subsp diarizonae was also common (42/175 [24%]) and was recovered almost exclusively from snakes (n = 33), many of which had been clinically ill (17). Clinically ill reptiles provided 37% (64) of Salmonella cultures. Factors associated with an increased risk of illness in reptiles with a positive culture result were carnivorous diet and prior confiscation. Snakes had a higher risk of illness than other reptile groups, whereas lizards had a lower risk. Bony changes, dermatitis, and anorexia were the most common clinical signs. CONCLUSIONS AND CLINICAL RELEVANCE This study provided new information on Salmonella infection or carriage and associated clinical disease in reptiles. Associations identified between serovars or subspecies and reptile groups or clinical disease can guide management of Salmonella-positive captive reptiles.

  12. blaCMY-2-positive IncA/C plasmids from escherichia coli and salmonella enterica are a distinct component of a larger lineage of plasmids

    USDA-ARS?s Scientific Manuscript database

    Large multidrug resistance plasmids of the A/C incompatibility complex (IncA/C) have been found in a diverse group of Gram-negative commensal and pathogenic bacteria. We present three completed sequences from IncA/C plasmids that originated from Escherichia coli (cattle) and Salmonella enterica sero...

  13. Effect of x-ray treatments on Escherichia coli O157:H7, Listeria monocytogenes, Shigella flexneri, Salmonella enterica and inherent microbiota on whole mangoes

    USDA-ARS?s Scientific Manuscript database

    The aims of this investigation were to; (i) study the effect of X-ray treatments in reducing Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica and Shigella flexneri on whole mangoes, and (ii) study the effect of Xray treatments on microflora counts (mesophilic counts, psychrotrop...

  14. Antibiotic resistance determinants and genetic analysis of Salmonella enterica isolated from food in Morocco.

    PubMed

    Murgia, Manuela; Bouchrif, Brahim; Timinouni, Mohammed; Al-Qahtani, Ahmed; Al-Ahdal, Mohammed N; Cappuccinelli, Pietro; Rubino, Salvatore; Paglietti, Bianca

    2015-12-23

    Antimicrobial-resistant non-typhoidal Salmonella (NTS) are an important cause of infection in Africa, but there is a lack of information on their molecular mechanisms of resistance and epidemiology. This study contributes to fill this gap through the characterization by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), plasmid profiling and analysis of antibiotic-resistance determinants of 94 Salmonella enterica strains isolated from food in Morocco. PFGE revealed considerable heterogeneity among the strains, showing 32 pulsotypes. MLST of strains representative of the different serovars evidenced 13 sequence types (STs), three of which were newly identified (ST1694, ST1768 and ST1818) and nine not previously reported in Morocco. Thirty-four strains harbored from one to four plasmids, of IncI1 group in S. Mbandaka, IncFIIA in S. Typhimurium, IncL/M in S. Hadar and S. Blockley. For the first time in Morocco an intact Salmonella Genomic Island 1 (SGI1) carrying the resistance genes aadA2, floR, tetG, blaPSE-1 and sul1 was detected in S. Typhimurium DT104. In serovar Hadar resistance to ampicillin, tetracycline and streptomycin was associated to blaTEM-1, tetA and strA genes respectively, whereas one mutation in gyrA (Asp87Asn) and one in parC (Thr54Ser) genes conferred resistance to nalidixic acid. These findings improve the information on foodborne Salmonella in Morocco, evidencing the presence of MDR strains potentially dangerous to humans, and provide useful data for future studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Candida krusei isolated from fruit juices ultrafiltration membranes promotes colonization of Escherichia coli O157:H7 and Salmonella enterica on stainless steel surfaces.

    PubMed

    Tarifa, María Clara; Lozano, Jorge Enrique; Brugnoni, Lorena Inés

    2017-02-01

    To clarify the interactions between a common food spoilage yeast and two pathogenic bacteria involved in outbreaks associated with fruit juices, the present paper studies the effect of the interplay of Candida krusei, collected from UF membranes, with Escherichia coli O157:H7 and Salmonella enterica in the overall process of adhesion and colonization of abiotic surfaces. Two different cases were tested: a) co-adhesion by pathogenic bacteria and yeasts, and b) incorporation of bacteria to pre-adhered C. krusei cells. Cultures were made on stainless steel at 25°C using apple juice as culture medium. After 24 h of co-adhesion with C. krusei, both E. coli O157:H7 and S. enterica increased their counts 1.05 and 1.11 log CFU cm 2 , respectively. Similar increases were obtained when incorporating bacteria to pre-adhered cells of Candida. Nevertheless C. krusei counts decreased in both experimental conditions, in a) 0.40 log CFU cm 2 and 0.55 log CFU cm 2 when exposed to E. coli O157:H7 and S. enterica and in b) 0.18 and 0.68 log CFU cm 2 , respectively. This suggests that C. krusei, E. coli O157:H7, and S. enterica have a complex relationship involving physical and chemical interactions on food contact surfaces. This study supports the possibility that pathogen interactions with members of spoilage microbiota, such as C. krusei, might play an important role for the survival and dissemination of E. coli O157:H7 and Salmonella enterica in food-processing environments. Based on the data obtained from the present study, much more attention should be given to prevent the contamination of these pathogens in acidic drinks.

  16. Phenotypic, Genotypic and Pathogenicity assessment of Salmonella Infantis strains isolated from poultry

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subspecies enterica serovar Infantis has been associated with human illnesslinked to contamination of poultry products. In the US, Salmonella Infantis has been recently associated to human cases of salmonellosis linked to live poultry. The presence of multidrug resistant strains ...

  17. Three-dimensional tissue assemblies: novel models for the study of Salmonella enterica serovar Typhimurium pathogenesis

    NASA Technical Reports Server (NTRS)

    Nickerson, C. A.; Goodwin, T. J.; Terlonge, J.; Ott, C. M.; Buchanan, K. L.; Uicker, W. C.; Emami, K.; LeBlanc, C. L.; Ramamurthy, R.; Clarke, M. S.; hide

    2001-01-01

    The lack of readily available experimental systems has limited knowledge pertaining to the development of Salmonella-induced gastroenteritis and diarrheal disease in humans. We used a novel low-shear stress cell culture system developed at the National Aeronautics and Space Administration in conjunction with cultivation of three-dimensional (3-D) aggregates of human intestinal tissue to study the infectivity of Salmonella enterica serovar Typhimurium for human intestinal epithelium. Immunohistochemical characterization and microscopic analysis of 3-D aggregates of the human intestinal epithelial cell line Int-407 revealed that the 3-D cells more accurately modeled human in vivo differentiated tissues than did conventional monolayer cultures of the same cells. Results from infectivity studies showed that Salmonella established infection of the 3-D cells in a much different manner than that observed for monolayers. Following the same time course of infection with Salmonella, 3-D Int-407 cells displayed minimal loss of structural integrity compared to that of Int-407 monolayers. Furthermore, Salmonella exhibited significantly lower abilities to adhere to, invade, and induce apoptosis of 3-D Int-407 cells than it did for infected Int-407 monolayers. Analysis of cytokine expression profiles of 3-D Int-407 cells and monolayers following infection with Salmonella revealed significant differences in expression of interleukin 1alpha (IL-1alpha), IL-1beta, IL-6, IL-1Ra, and tumor necrosis factor alpha mRNAs between the two cultures. In addition, uninfected 3-D Int-407 cells constitutively expressed higher levels of transforming growth factor beta1 mRNA and prostaglandin E2 than did uninfected Int-407 monolayers. By more accurately modeling many aspects of human in vivo tissues, the 3-D intestinal cell model generated in this study offers a novel approach for studying microbial infectivity from the perspective of the host-pathogen interaction.

  18. Three-Dimensional Tissue Assemblies: Novel Models for the Study of Salmonella enterica Serovar Typhimurium Pathogenesis

    PubMed Central

    Nickerson, Cheryl A.; Goodwin, Thomas J.; Terlonge, Jacqueline; Ott, C. Mark; Buchanan, Kent L.; Uicker, William C.; Emami, Kamal; LeBlanc, Carly L.; Ramamurthy, Rajee; Clarke, Mark S.; Vanderburg, Charles R.; Hammond, Timothy; Pierson, Duane L.

    2001-01-01

    The lack of readily available experimental systems has limited knowledge pertaining to the development of Salmonella-induced gastroenteritis and diarrheal disease in humans. We used a novel low-shear stress cell culture system developed at the National Aeronautics and Space Administration in conjunction with cultivation of three-dimensional (3-D) aggregates of human intestinal tissue to study the infectivity of Salmonella enterica serovar Typhimurium for human intestinal epithelium. Immunohistochemical characterization and microscopic analysis of 3-D aggregates of the human intestinal epithelial cell line Int-407 revealed that the 3-D cells more accurately modeled human in vivo differentiated tissues than did conventional monolayer cultures of the same cells. Results from infectivity studies showed that Salmonella established infection of the 3-D cells in a much different manner than that observed for monolayers. Following the same time course of infection with Salmonella, 3-D Int-407 cells displayed minimal loss of structural integrity compared to that of Int-407 monolayers. Furthermore, Salmonella exhibited significantly lower abilities to adhere to, invade, and induce apoptosis of 3-D Int-407 cells than it did for infected Int-407 monolayers. Analysis of cytokine expression profiles of 3-D Int-407 cells and monolayers following infection with Salmonella revealed significant differences in expression of interleukin 1α (IL-1α), IL-1β, IL-6, IL-1Ra, and tumor necrosis factor alpha mRNAs between the two cultures. In addition, uninfected 3-D Int-407 cells constitutively expressed higher levels of transforming growth factor β1 mRNA and prostaglandin E2 than did uninfected Int-407 monolayers. By more accurately modeling many aspects of human in vivo tissues, the 3-D intestinal cell model generated in this study offers a novel approach for studying microbial infectivity from the perspective of the host-pathogen interaction. PMID:11598087

  19. Resistance to essential oils affects survival of Salmonella enterica serovars in growing and harvested basil.

    PubMed

    Kisluk, Guy; Kalily, Emmanuel; Yaron, Sima

    2013-10-01

    The number of outbreaks of food-borne illness associated with consumption of fresh products has increased. A recent and noteworthy outbreak occurred in 2007. Basil contaminated with Salmonella enterica serovar Senftenberg was the source of this outbreak. Since basil produces high levels of antibacterial compounds the aim of this study was to investigate if the emerging outbreak reflects ecological changes that occurred as a result of development of resistance to ingredients of the basil oil. We irrigated basil plants with contaminated water containing two Salmonella serovars, Typhimurium and Senftenberg, and showed that Salmonella can survive on the basil plants for at least 100 days. S. Senftenberg counts in the phyllosphere were significantly higher than S. Typhimurium, moreover, S. Senftenberg was able to grow on stored harvested basil leaves. Susceptibility experiments demonstrated that S. Senftenberg is more resistant to basil oil and to its antimicrobial constituents: linalool, estragole and eugenol. This may indicate that S. Senftenberg had adapted to the basil environment by developing resistance to the basil oil. The emergence of resistant pathogens has a significant potential to change the ecology, and opens the way for pathogens to survive in new niches in the environment such as basil and other plants. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

  20. Growth of Salmonella enterica and Staphylococcus aureus in no-knead bread dough during prolonged yeast fermentation.

    PubMed

    Pao, Steven; Kim, Chyer; Jordan, Larry; Long, Wilbert; Inserra, Paula; Sayre, Brian

    2011-02-01

    A convenient bread making method involving prolonged fermentation of no-knead (nonkneaded) dough has become popular in recent years. In the present study, the microbial safety of no-knead dough made with a 375:325:5:1 weight ratio of flour, water, salt, and bread yeast was investigated. Three brands of dehydrated yeast were used for this study. The growth of inoculated Salmonella enterica and Staphylococcus aureus in no-knead dough during fermentation was significant (P<0.05), regardless of yeast brand. The multiplication rates of S. enterica in the initial 12 h and S. aureus over the entire 24 h of fermentation were positively correlated with fermentation temperatures of 21 to 38°C (P<0.005; r≥0.996). Mean counts of S. enterica increased by 0.5, 1.5, 1.9, and 2.4 log CFU/g, respectively, after 6, 12, 18, and 24 h of fermentation at 21 °C. The level of S. aureus increased by 0.4, 1.1, 1.7, and 2.2 CFU/g, respectively, after 18 h of fermentation at 21, 27, 32, and 38 °C. Because prolonged fermentation permits substantial growth of infectious and/or toxin-producing foodborne pathogens, the making of slow-rise, no-knead bread may compromise consumer kitchen sanitation and food safety. Copyright ©, International Association for Food Protection

  1. The molecular adjuvant mC3d enhances the immunogenicity of FimA from type I fimbriae of Salmonella enterica serovar Enteritidis.

    PubMed

    Musa, Hassan-Hussein; Zhang, Wei-Juan; Lv, Jing; Duan, Xiao-Li; Yang, Yang; Zhu, Chun-Hong; Li, Hui-Fang; Chen, Kuan-Wei; Meng, Xia; Zhu, Guo-Qiang

    2014-02-01

    The fimbriae of Salmonella enterica serovar Enteritidis are used for colonization and invasion into host cells, and have drawn considerable interest because fimbriae can serve as potential immunogens against many pathogenic bacteria that colonize on epithelial surfaces. The purpose of the study is to use a molecular adjuvant, C3d, to enhance the immunogenicity of FimA proteins against Salmonella enterica serovar Enteritidis. FimA of type I fimbriae from Salmonella enteritidis and FimA with one copy of mC3d, two copies of mC3d2 and three copies of mC3d3 were cloned into the expression vector pCold-TF. Soluble fusion proteins of FimA with different copy of mC3d were induced by IPTG and expressed into Escherichia coli BL21 (DE3). Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed that the recombinant proteins from pCold-TF-fimA, TF-fimA-mC3d, TF-fimA-mC3d2, TF-fimA-mC3d3 were 70 kDa, 100 kDa, 130 kDa and 160 kDa, respectively. The fusion protein was recognized by rabbit anti-fimbriae polyclonal antibodies, and then visualized by goat anti-rabbit polyclonal antibodies with a chrome appearance by enzyme-subtract interaction. The recombinant proteins were purified by Ni-TED (tris-carboxymethyl ethylene diamine), immobilized metal ion affinity chromatography (IMAC). Balb/c mice were subcutaneously immunized with the purified proteins and the immune response was monitored by an enzyme-linked immunosorbent assay (ELISA) for FimA-specific antibody. The immunized mice were challenged with a 10-fold LD50 dose (i.e., 100 CFU) of Salmonella enterica serovar Enteritidis standard strain (SD-2) 1 week after the second immunization. The immunized mice with the fusion proteins FimA-mC3d2 and FimA-mC3d3 had increased levels of ELISA titer of antibody that were 2 and 4 logs, respectively, more immunogenic than the TF-FimA protein alone. The challenge results showed that immune protection rate in the mice immunized with 10 μg of FimA, FimA-mC3d2, and FimA-mC3d3

  2. Commercially laid eggs vs. discarded hatching eggs: contamination by Salmonella spp.

    PubMed

    Kottwitz, Luciana B M; Leão, Joice Aparecida; Back, Alberto; Rodrigues, Dalia dos P; Magnani, Marciane; de Oliveira, Tereza C R M

    2013-01-01

    Salmonella enterica is frequently associated with outbreaks of human salmonellosis, and products of avian origin, such as eggs and chicken meat, are the main vehicles of its transmission. The present study describes the occurrence of different serovars of Salmonella enterica and phagotypes of S. enterica serovar Enteritidis in eggs destined for human consumption. Four thousand eggs obtained from commercial egg laying farms and one thousand discarded hatching eggs from broiler farms, which were acquired at farmers' markets and informal shops, were analyzed. Salmonella spp. was isolated from 52.0% of the discarded hatching eggs, in which the predominant serovar was Enteritidis (84.6%), and the predominant Salmonella Enteritidis phagotype (PT) was PT7 (26.9%). Salmonella spp. was not isolated from eggs obtained from commercial egg laying farms. The antimicrobial resistance profile showed that 23.1% (n = 6) of the SE strains were resistant to nalidixic acid. The results suggest that the consumption of discarded hatching eggs represents an important source of Salmonella transmission to humans.

  3. Purulent Pericarditis with Salmonella enterica Subspecies arizona in a Patient with Type 2 Diabetes Mellitus

    PubMed Central

    Suzuki, Ai; Tanaka, Takamitsu; Ohba, Kenji; Ito, Naomi; Sakai, Yuki; Kaneko, Akane; Machii, Masashi; Nonaka, Daishi; Goto, Yoshie; Takase, Hiroyuki

    2017-01-01

    Purulent pericarditis is a life-threatening disorder, even in the modern antibiotic era. Although diabetes mellitus is known to be associated with an increased risk of multiple types of infections, purulent pericarditis is extremely rare. We herein report an unusual case of pericarditis caused by Salmonella enterica subspecies arizona that was not associated with any evident underlying immunosuppressive disorder apart from uncontrolled type 2 diabetes mellitus. Because a pet snake was suspected as being the source of infection in the present case, patient education and a detailed review of exposure history could play an important role in treating patients with diabetes mellitus. PMID:28781305

  4. Role of outer membrane lipopolysaccharides in the protection of Salmonella enterica serovar Typhimurium from desiccation damage.

    PubMed

    Garmiri, Penelope; Coles, Karen E; Humphrey, Tom J; Cogan, Tristan A

    2008-04-01

    The ability to survive desiccation between hosts is often essential to the success of pathogenic bacteria. The bacterial outer membrane is both the cellular interface with hostile environments and the focus of much of the drying-induced damage. This study examined the contribution of outer membrane-associated polysaccharides to the survival of Salmonella enterica serovar Typhimurium in air-dried blood droplets following growth in high and low osmolarity medium and under conditions known to induce expression of these polysaccharides. Strains lacking the O polysaccharide (OPS) element of the outer membrane lipopolysaccharide were more sensitive to desiccation. Lipopolysaccharide core mutation further to OPS loss did not result in increased susceptibility to drying. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed lipopolysaccharide profiles that supported the hypothesis that OPS expression is required for optimal drying resistance in S. Typhimurium. The role of O antigen in Salmonella spp. in maintaining a hydrated layer around the dried cell or in slowing the rate of dehydration and rehydration is discussed.

  5. Effect of lime juice on Vibrio parahaemolyticus and Salmonella enterica inactivation during the preparation of the raw fish dish ceviche.

    PubMed

    Mathurand, Prateek; Schaffner, Donald W

    2013-06-01

    Ceviche is a raw fish dish common in Peru and other Latin American counties. The most characteristic feature of ceviche is the use of lime juice for marinating or "cooking" the raw fish. Confirmed cases of cholera in Peru, New Jersey, and Florida have been associated with ceviche. Although the effect of organic acids on pathogenic bacteria has been well characterized, few data exist on the effect of these acids in seafood systems. The objective of the study was to evaluate the effects of lime juice marination on pathogens likely to be present in ceviche. Tilapia (Oreochromis niloticus) fillet pieces were inoculated with Vibrio parahaemolyticus and Salmonella enterica (>7 log CFU/g) and incubated at 25 and 4°C for 30 or 120 min in the presence of fresh lime juice at concentrations typical for the preparation of ceviche. Similar levels of cells were also inoculated into fresh lime juice without tilapia. Surviving cells were enumerated on selective (xylose lysine Tergitol 4 and thiosulfate-bile-citrate-sucrose) and nonselective (tryptic soy agar) media. V. parahaemolyticus levels were reduced to below detection limits (∼5-log reduction) under all conditions studied. Salmonella strains on tilapia were much more resistant to inactivation and were only slightly reduced (∼1- to 2-log reduction). Salmonella and V. parahaemolyticus inoculated directly into lime juice without tilapia were all reduced to below detection limits (∼5-log reduction). A typical ceviche recipe reduces V. parahaemolyticus risk significantly but is less effective for control of S. enterica.

  6. Evaluation of corn oil as an additive in the pre-enrichment step to increase recovery of Salmonella enterica from oregano.

    PubMed

    Jean-Gilles Beaubrun, Junia; Flamer, Marie-Laure; Addy, Nicole; Ewing, Laura; Gopinath, Gopal; Jarvis, Karen; Grim, Chris; Hanes, Darcy E

    2016-08-01

    Phenolic compounds associated with essential oils of spices and herbs possess a variety of antioxidant and antimicrobial properties that interfere with Salmonella detection from fresh and dried products. Finding a compound to neutralize the effect of these antimicrobial compounds, while allowing Salmonella growth during pre-enrichment, is a crucial step in both traditional pathogen isolation and molecular detection from these foods. This study evaluated the effectiveness of corn oil as a component of the pre-enrichment broth to counteract antimicrobial compounds properties and increase the recovery of Salmonella from spices. Oregano samples artificially contaminated with Salmonella enterica were pre-enriched in modified Buffered Peptone Water (mBPW) supplemented with and without 2% (vol/vol) corn oil respectively. Samples were incubated overnight at 37 °C. The results showed that recovery of Salmonella from oregano samples was increased by ≥50% when pre-enriched with corn oil. Serovars were confirmed using a PCR serotyping method. In addition, shot-gun metagenomics analyses demonstrated bacterial diversity and the effect of corn oil on the relative prevalence of Salmonella in the oregano samples. Modifying pre-enrichment broths with corn oil improved the detection and isolation of Salmonella from oregano, and may provide an alternative method for pathogen detection in dried food matrices such as spices. Published by Elsevier Ltd.

  7. Genetic Fine Structure of a Salmonella enterica Serovar Typhi Strain Associated with the 2005 Outbreak of Typhoid Fever in Kelantan, Malaysia

    PubMed Central

    Baddam, Ramani; Kumar, Narender; Thong, Kwai-Lin; Ngoi, Soo-Tein; Teh, Cindy Shuan Ju; Yap, Kien-Pong; Chai, Lay-Ching; Avasthi, Tiruvayipati Suma

    2012-01-01

    Among enteric pathogens, Salmonella enterica serovar Typhi is responsible for the largest number of food-borne outbreaks and fatalities. The ability of the pathogen to cause systemic infection for extended durations leads to a high cost of disease control. Chronic carriers play important roles in the evolution of Salmonella Typhi; therefore, identification and in-depth characterization of isolates from clinical cases and carriers, especially those from zones of endemicity where the pathogen has not been extensively studied, are necessary. Here, we describe the genome sequence of the highly virulent Salmonella Typhi strain BL196/05 isolated during the outbreak of typhoid in Kelantan, Malaysia, in 2005. The whole-genome sequence and comparative genomics of this strain should enable us to understand the virulence mechanisms and evolutionary dynamics of this pathogen in Malaysia and elsewhere. PMID:22689247

  8. Genome and transcriptome adaptation accompanying emergence of the definitive type 2 host-restricted Salmonella enterica serovar Typhimurium pathovar.

    PubMed

    Kingsley, Robert A; Kay, Sally; Connor, Thomas; Barquist, Lars; Sait, Leanne; Holt, Kathryn E; Sivaraman, Karthi; Wileman, Thomas; Goulding, David; Clare, Simon; Hale, Christine; Seshasayee, Aswin; Harris, Simon; Thomson, Nicholas R; Gardner, Paul; Rabsch, Wolfgang; Wigley, Paul; Humphrey, Tom; Parkhill, Julian; Dougan, Gordon

    2013-08-27

    Salmonella enterica serovar Typhimurium definitive type 2 (DT2) is host restricted to Columba livia (rock or feral pigeon) but is also closely related to S. Typhimurium isolates that circulate in livestock and cause a zoonosis characterized by gastroenteritis in humans. DT2 isolates formed a distinct phylogenetic cluster within S. Typhimurium based on whole-genome-sequence polymorphisms. Comparative genome analysis of DT2 94-213 and S. Typhimurium SL1344, DT104, and D23580 identified few differences in gene content with the exception of variations within prophages. However, DT2 94-213 harbored 22 pseudogenes that were intact in other closely related S. Typhimurium strains. We report a novel in silico approach to identify single amino acid substitutions in proteins that have a high probability of a functional impact. One polymorphism identified using this method, a single-residue deletion in the Tar protein, abrogated chemotaxis to aspartate in vitro. DT2 94-213 also exhibited an altered transcriptional profile in response to culture at 42°C compared to that of SL1344. Such differentially regulated genes included a number involved in flagellum biosynthesis and motility. IMPORTANCE Whereas Salmonella enterica serovar Typhimurium can infect a wide range of animal species, some variants within this serovar exhibit a more limited host range and altered disease potential. Phylogenetic analysis based on whole-genome sequences can identify lineages associated with specific virulence traits, including host adaptation. This study represents one of the first to link pathogen-specific genetic signatures, including coding capacity, genome degradation, and transcriptional responses to host adaptation within a Salmonella serovar. We performed comparative genome analysis of reference and pigeon-adapted definitive type 2 (DT2) S. Typhimurium isolates alongside phenotypic and transcriptome analyses, to identify genetic signatures linked to host adaptation within the DT2 lineage.

  9. An evaluation of the effect of sodium bisulfate as a feed additive on Salmonella enterica serotype Enteritidis in experimentally infected broilers.

    PubMed

    Kassem, I I; Sanad, Y M; Stonerock, R; Rajashekara, G

    2012-04-01

    The colonization of broiler chickens with Salmonella can pose serious health and economic risks for both consumers and the poultry industry. Because colonization with Salmonella can lead to subsequent contamination of chicken carcasses during processing, preemptive control measures should include the reduction of this pathogen in chickens before slaughter. In this study, we evaluated the effect of sodium bisulfate, a potential antimicrobial feed additive, on Salmonella colonization of experimentally infected broiler chickens. Two hundred and forty 1-d-old chickens were infected orally with Salmonella enterica serotype Enteritidis and divided into 4 groups (each comprised of 60 chickens). Three groups received different concentrations of sodium bisulfate integrated into their feed, while the feed of the fourth group (positive control) was not treated. At time points before the broilers' slaughter age, different organs/tissues (liver, spleen, cecum, and bone marrow) and feces were aseptically collected and tested for the occurrence and density of Salmonella Enteritidis. Our results show that at 3 d postinfection, high colonization with Salmonella Enteritidis was detected and affected all tested tissues and fecal samples. Although colonization decreased across time, Salmonella Enteritidis persisted in the cecum, feces, spleen, and bone marrow, but not in the liver, until slaughter age. Furthermore, the addition of sodium bisulfate to the feed did not significantly reduce Salmonella Enteritidis numbers in infected chickens or affect the shedding of the pathogen.

  10. The Type VI Secretion System Encoded in Salmonella Pathogenicity Island 19 Is Required for Salmonella enterica Serotype Gallinarum Survival within Infected Macrophages

    PubMed Central

    Blondel, Carlos J.; Jiménez, Juan C.; Leiva, Lorenzo E.; Álvarez, Sergio A.; Pinto, Bernardo I.; Contreras, Francisca; Pezoa, David; Santiviago, Carlos A.

    2013-01-01

    Salmonella enterica serotype Gallinarum is the causative agent of fowl typhoid, a disease characterized by high morbidity and mortality that causes major economic losses in poultry production. We have reported that S. Gallinarum harbors a type VI secretion system (T6SS) encoded in Salmonella pathogenicity island 19 (SPI-19) that is required for efficient colonization of chicks. In the present study, we aimed to characterize the SPI-19 T6SS functionality and to investigate the mechanisms behind the phenotypes previously observed in vivo. Expression analyses revealed that SPI-19 T6SS core components are expressed and produced under in vitro bacterial growth conditions. However, secretion of the structural/secreted components Hcp1, Hcp2, and VgrG to the culture medium could not be determined, suggesting that additional signals are required for T6SS-dependent secretion of these proteins. In vitro bacterial competition assays failed to demonstrate a role for SPI-19 T6SS in interbacterial killing. In contrast, cell culture experiments with murine and avian macrophages (RAW264.7 and HD11, respectively) revealed production of a green fluorescent protein-tagged version of VgrG soon after Salmonella uptake. Furthermore, infection of RAW264.7 and HD11 macrophages with deletion mutants of SPI-19 or strains with genes encoding specific T6SS core components (clpV and vgrG) revealed that SPI-19 T6SS contributes to S. Gallinarum survival within macrophages at 20 h postuptake. SPI-19 T6SS function was not linked to Salmonella-induced cytotoxicity or cell death of infected macrophages, as has been described for other T6SS. Our data indicate that SPI-19 T6SS corresponds to a novel tool used by Salmonella to survive within host cells. PMID:23357385

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

    PubMed Central

    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

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

    PubMed

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

    2016-07-27

    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.

  13. Babies and bearded dragons: sudden increase in reptile-associated Salmonella enterica serovar Tennessee infections, Germany 2008.

    PubMed

    Weiss, Bettina; Rabsch, Wolfgang; Prager, Rita; Tietze, Erhard; Koch, Judith; Mutschmann, Frank; Roggentin, Peter; Frank, Christina

    2011-09-01

    In 2008 a marked increase in Salmonella enterica serovar Tennessee infections in infants occurred in Germany. In March and April 2008, eight cases were notified compared to a median of 0-1 cases in 2001-2006. We carried out an investigation including a case-control study to identify the source of infection. A patient was a child < 3 years of age with Salmonella Tennessee isolated from stool from September 1, 2007, through December 31, 2008, identified through the national surveillance system. A control was a child with a notified rotavirus infection in the matching district, frequency matched by age group. We conducted telephone interviews on feeding, herbal infusions, and animal contact. Matched odds ratios (mOR) were calculated using exact conditional logistic regression. For Salmonella Tennessee isolates, pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis were performed. Further cloacal swab samples of reptiles kept in case households were investigated. We identified 18 cases < 3 years. Ten children were male; median age was 3 months (1-32 months). In 8 of 16 case households reptiles were kept. Direct contact between child and reptile was denied. Other forms of reptile contact were reported in four of the remaining eight households. Ten case- and 21 control-patients were included in the study. Only keeping of a reptile and "any reptile contact" were associated with Salmonella Tennessee infection (mOR 29.0; 95% CI 3.1 ± ∞ and mOR 119.5; 95% CI 11.7 - ∞). Identical Salmonella Tennessee strains of child and reptile kept in the same household could be shown in 2 cases. Reptiles were the apparent source of Salmonella Tennessee infection in these infants. Indirect contact between infants and reptiles seems to be sufficient to cause infection and should therefore be avoided.

  14. Metabolic parameters linked by phenotype microarray to acid resistance profiles of poultry-associated Salmonella enterica.

    PubMed

    Guard, Jean; Rothrock, Michael J; Shah, Devendra H; Jones, Deana R; Gast, Richard K; Sanchez-Ingunza, Roxana; Madsen, Melissa; El-Attrache, John; Lungu, Bwalya

    Phenotype microarrays were analyzed for 51 datasets derived from Salmonella enterica. The top 4 serotypes associated with poultry products and one associated with turkey, respectively Typhimurium, Enteritidis, Heidelberg, Infantis and Senftenberg, were represented. Datasets were partitioned initially into two clusters based on ranking by values at pH 4.5 (PM10 A03). Negative control wells were used to establish 90 respiratory units as the point differentiating acid resistance from sensitive strains. Thus, 24 isolates that appeared most acid-resistant were compared initially to 27 that appeared most acid-sensitive (24 × 27 format). Paired cluster analysis was also done and it included the 7 most acid-resistant and -sensitive datasets (7 × 7 format). Statistical analyses of ranked data were then calculated in order of standard deviation, probability value by the Student's t-test and a measure of the magnitude of difference called effect size. Data were reported as significant if, by order of filtering, the following parameters were calculated: i) a standard deviation of 24 respiratory units or greater from all datasets for each chemical, ii) a probability value of less than or equal to 0.03 between clusters and iii) an effect size of at least 0.50 or greater between clusters. Results suggest that between 7.89% and 23.16% of 950 chemicals differentiated acid-resistant isolates from sensitive ones, depending on the format applied. Differences were more evident at the extremes of phenotype using the subset of data in the paired 7 × 7 format. Results thus provide a strategy for selecting compounds for additional research, which may impede the emergence of acid-resistant Salmonella enterica in food. Published by Elsevier Masson SAS.

  15. Multi-locus variable-number tandem repeat analysis for outbreak studies of Salmonella enterica serotype Enteritidis

    PubMed Central

    Malorny, Burkhard; Junker, Ernst; Helmuth, Reiner

    2008-01-01

    Background Salmonella enterica subsp. enterica serotype Enteritidis is known as an important and pathogenic clonal group which continues to cause worldwide sporadic cases and outbreaks in humans. Here a new multiple-locus variable-number tandem repeat analysis (MLVA) method is reported for highly-discriminative subtyping of Salmonella Enteritidis. Emphasis was given on the most predominant phage types PT4 and PT8. The method comprises multiplex PCR specifically amplifying repeated sequences from nine different loci followed by an automatic fragment size analysis using a multicolor capillary electrophoresis instrument. A total of 240 human, animal, food and environmental isolates of S. Enteritidis including 23 definite phage types were used for development and validation. Furthermore, the MLVA types were compared to the phage types of several isolates from two recent outbreaks to determine the concordance between both methods and to estimate their in vivo stability. The in vitro stability of the two MLVA types specifically for PT4 and PT8 strains were determined by multiple freeze-thaw cycles. Results Seventy-nine different MLVA types were identified in 240 S. Enteritidis strains. The Simpson's diversity index for the MLVA method was 0.919 and Nei diversity values for the nine VNTR loci ranged from 0.07 to 0.65. Twenty-four MLVA types could be assigned to 62 PT4 strains and 21 types to 81 PT8 strains. All outbreak isolates had an indistinguishable outbreak specific MLVA type. The in vitro stability experiments showed no changes of the MLVA type compared to the original isolate. Conclusion This MLVA method is useful to discriminate S. Enteritidis strains even within a single phage type. It is easy in use, fast, and cheap compared to other high-resolution molecular methods and therefore an important tool for surveillance and outbreak studies for S. Enteritidis. PMID:18513386

  16. Regulation of the Salmonella enterica std fimbrial operon by DNA adenine methylation, SeqA, and HdfR.

    PubMed

    Jakomin, Marcello; Chessa, Daniela; Bäumler, Andreas J; Casadesús, Josep

    2008-11-01

    DNA adenine methylase (dam) mutants of Salmonella enterica serovar Typhimurium grown under laboratory conditions express the std fimbrial operon, which is tightly repressed in the wild type. Here, we show that uncontrolled production of Std fimbriae in S. enterica serovar Typhimurium dam mutants contributes to attenuation in mice, as indicated by the observation that an stdA dam strain is more competitive than a dam strain upon oral infection. Dam methylation appears to regulate std transcription, rather than std mRNA stability or turnover. A genetic screen for std regulators showed that the GATC-binding protein SeqA directly or indirectly represses std expression, while the poorly characterized yifA gene product serves as an std activator. YifA encodes a putative LysR-like protein and has been renamed HdfR, like its Escherichia coli homolog. Activation of std expression by HdfR is observed only in dam and seqA backgrounds. These data suggest that HdfR directly or indirectly activates std transcription. Since SeqA is unable to bind nonmethylated DNA, it is possible that std operon derepression in dam and seqA mutants may result from unconstrained HdfR-mediated activation of std transcription. Derepression of std in dam and seqA mutants of S. enterica occurs in only a fraction of the bacterial population, suggesting the occurrence of either bistable expression or phase variation.

  17. OXA-48 carbapenemase-producing Salmonella enterica serovar Kentucky isolate of sequence type 198 in a patient transferred from Libya to Switzerland.

    PubMed

    Seiffert, Salome N; Perreten, Vincent; Johannes, Sönke; Droz, Sara; Bodmer, Thomas; Endimiani, Andrea

    2014-01-01

    Here, we report a case of OXA-48-producing Salmonella enterica serovar Kentucky of sequence type 198 (ST198) from perianal screening cultures of a patient transferred from Libya to Switzerland. The blaOXA-48 gene was carried by Tn1999.2 and located on an ∼60-kb IncL/M plasmid. This Salmonella strain also possessed the blaVEB-8, aac(6)-Ib, tet(A), sul1, and mphA resistance genes and substitutions in GyrA (Ser83Phe and Asp87Asn) and ParC (Ser80Ile). This finding emphasizes that prompt screening strategies are essential to prevent the dissemination of carbapenemase producers imported from countries where they are endemic.

  18. Multidrug resistant Salmonella enterica isolated from conventional pig farms using antimicrobial agents in preventative medicine programmes.

    PubMed

    Cameron-Veas, Karla; Fraile, Lorenzo; Napp, Sebastian; Garrido, Victoria; Grilló, María Jesús; Migura-Garcia, Lourdes

    2018-04-01

    A longitudinal study was conducted to investigate the presence of multidrug antimicrobial resistance (multi-AR) in Salmonella enterica in pigs reared under conventional preventative medicine programmes in Spain and the possible association of multi-AR with ceftiofur or tulathromycin treatment during the pre-weaning period. Groups of 7-day-old piglets were treated by intramuscular injection with ceftiofur on four farms (n=40 piglets per farm) and with tulathromycin on another four farms (n=40 piglets per farm). A control group of untreated piglets (n=30 per farm) was present on each farm. Faecal swabs were collected for S. enterica culture prior to treatment, at 2, 7 and 180days post-treatment, and at slaughter. Minimal inhibitory concentrations of 14 antimicrobial agents, pulsed-field gel electrophoresis and detection of resistance genes representing five families of antimicrobial agents were performed. Plasmids carrying cephalosporin resistant (CR) genes were characterised. Sixty-six S. enterica isolates were recovered from five of eight farms. Forty-seven isolates were multi-AR and four contained bla CTX-M genes harboured in conjugative plasmids of the IncI1 family; three of these isolates were recovered before treatment with ceftiofur. The most frequent AR genes detected were tet(A) (51/66, 77%), sul1 (17/66, 26%); tet(B) (15/66, 23%) and qnrB (10/66, 15%). A direct relation between the use of ceftiofur in these conditions and the occurrence of CR S. enterica was not established. However, multi-AR was common, especially for ampicillin, streptomycin, sulphonamides and tetracycline. These antibiotics are used frequently in veterinary medicine in Spain and, therefore, should be used sparingly to minimise the spread of multi-AR. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Research note: Molecular subtyping of Salmonella enterica serovar Tshiongwe recently isolated in Malaysia during 2001-2002.

    PubMed

    Thong, Kwai Lin; Bakeri, Shamsilawani Ahmad; Lai, Kin Seng; Koh, Yin Tee; Taib, Mohd Zainuldin; Lim, V K E; Yasin, Rohani Md

    2004-03-01

    Pulsed field gel electrophoresis (PFGE) and antimicrobial susceptibility analysis were undertaken on twenty-three strains of Salmonella enterica serovar Tshiongwe, an unusual serovar, which recently emerged in Malaysia. Antimicrobial susceptibility analysis showed that all the strains were sensitive to ampicilin, chloramphenicol, cotrimoxazole, and kanamycin. Twenty (87%) and 8 (3.5%) strains had resistance to tetracycline and streptomycin respectively. PFGE analysis subtyped 23 strains into 10 profiles (Dice coefficient of similarity, F = 0.7-1.0). The predominant profile, X1 was found in both clinical and environmental isolates and was widely distributed in different parts of Malaysia during the study period. In addition, isolates recovered from food, a hand-towel, apron and the surface of a table-top in one particular location had unique, indistinguishable profiles (X4/4a) and identical antibiograms. Similarly, isolates from cooked meat and a chopping board had PFGE profiles similar to some human isolates. These probably indicated cross-contamination and poor hygiene in food practices, hence contributing to Salmonellosis. Factors causing the emergence of this rare Salmonella serovar being responsible for food poisoning episodes during the study period remained unclear. The study reiterated the usefulness and versatility of PFGE in the molecular subtyping of this rare Salmonella serovar in Malaysia.

  20. Specific Responses of Salmonella enterica to Tomato Varieties and Fruit Ripeness Identified by In Vivo Expression Technology

    PubMed Central

    Noel, Jason T.; Arrach, Nabil; Alagely, Ali; McClelland, Michael; Teplitski, Max

    2010-01-01

    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 pathogens, and relies

  1. Laboratory-acquired infections of Salmonella enterica serotype Typhi in South Africa: phenotypic and genotypic analysis of isolates.

    PubMed

    Smith, Anthony Marius; Smouse, Shannon Lucrecia; Tau, Nomsa Pauline; Bamford, Colleen; Moodley, Vineshree Mischka; Jacobs, Charlene; McCarthy, Kerrigan Mary; Lourens, Adré; Keddy, Karen Helena

    2017-09-29

    Workers in clinical microbiology laboratories are exposed to a variety of pathogenic microorganisms. Salmonella species is among the most commonly reported bacterial causes of laboratory-acquired infections. We report on three cases of laboratory-acquired Salmonella enterica serotype Typhi (Salmonella Typhi) infection which occurred over the period 2012 to 2016 in South Africa. Laboratory investigation included phenotypic and genotypic characterization of isolates. Phenotypic analysis included standard microbiological identification techniques, serotyping and antimicrobial susceptibility testing. Genotypic analysis included the molecular subtyping methodologies of pulsed-field gel electrophoresis analysis, multilocus sequence typing and whole-genome sequencing (WGS); with WGS data analysis including phylogenetic analysis based upon comparison of single nucleotide polymorphism profiles of isolates. All cases of laboratory-acquired infection were most likely the result of lapses in good laboratory practice and laboratory safety. The following critical issues were highlighted. There was misdiagnosis and misreporting of Salmonella Typhi as nontyphoidal Salmonella by a diagnostic laboratory, with associated public health implications. We highlight issues concerning the importance of accurate fluoroquinolone susceptibility testing and interpretation of results according to updated guidelines. We describe potential shortcomings of a single disk susceptibility screening test for fluoroquinolone susceptibility and suggest that confirmatory minimum inhibitory concentration testing should always be performed in cases of invasive Salmonella infections. These antimicrobial susceptibility testing issues resulted in inappropriate ciprofloxacin therapy which may have been responsible for failure in clearance of pathogen from patients. Salmonella Typhi capsular polysaccharide vaccine was not protective in one case, possibly secondarily to a faulty vaccine. Molecular subtyping of

  2. Isolation of Salmonella spp. in cattle egrets (Bubulcus ibis) from Fernando de Noronha Archipelago, Brazil.

    PubMed

    Silva, Marcio A; Fernandes, Érika F S T; Santana, Sandra C; Marvulo, Maria Fernanda V; Barros, Mércia R; Vilela, Sineide M O; Reis, Eliane M F; Mota, Rinaldo A; Silva, Jean C R

    2018-03-03

    The growth of the population of cattle egrets (Bubulcus ibis) in the archipelago of Fernando de Noronha constitutes a threat to public health and biological diversity because of their competition with and predation on native species and the possibility of transmission of pathogens to human beings, livestock and native wildlife. The aim here was to search for, isolate and identify serovars of Salmonella in clinically healthy local cattle egrets. Cloacal swabs were obtained from 456 clinically healthy cattle egrets of both sexes and a variety of ages. The swabs were divided into 51 pools. Six of these (11.7%) presented four serovars of Salmonella enterica subspecies enterica: Salmonella serovar Typhimurium; Salmonella serovar Newport; Salmonella serovar Duisburg; and Salmonella serovar Zega. One sample was identified as S. enterica subspecies enterica O16:y:-. Results in this study suggest that cattle egrets may be reservoirs of this agent on Fernando de Noronha and represent a risk to public health and biological diversity. Copyright © 2018. Published by Elsevier Editora Ltda.

  3. Free-Living Turtles Are a Reservoir for Salmonella but Not for Campylobacter

    PubMed Central

    Marin, Clara; Ingresa-Capaccioni, Sofia; González-Bodi, Sara; Marco-Jiménez, Francisco; Vega, Santiago

    2013-01-01

    Different studies have reported the prevalence of Salmonella in turtles and its role in reptile-associated salmonellosis in humans, but there is a lack of scientific literature related with the epidemiology of Campylobacter in turtles. The aim of this study was to evaluate the prevalence of Campylobacter and Salmonella in free-living native (Emys orbicularis, n=83) and exotic ( Trachemys scripta elegans, n=117) turtles from 11 natural ponds in Eastern Spain. In addition, different types of samples (cloacal swabs, intestinal content and water from Turtle containers) were compared. Regardless of the turtle species, natural ponds where individuals were captured and the type of sample taken, Campylobacter was not detected. Salmonella was isolated in similar proportions in native (8.0±3.1%) and exotic (15.0±3.3%) turtles (p=0.189). The prevalence of Salmonella positive turtles was associated with the natural ponds where animals were captured. Captured turtles from 8 of the 11 natural ponds were positive, ranged between 3.0±3.1% and 60.0±11.0%. Serotyping revealed 8 different serovars among four Salmonella enterica subspecies: S. enterica subsp. enterica (n = 21), S. enterica subsp. salamae (n = 2), S. enterica subsp. diarizonae (n = 3), and S. enterica subsp. houtenae (n = 1). Two serovars were predominant: S. Thompson (n=16) and S . typhimurium (n=3). In addition, there was an effect of sample type on Salmonella detection. The highest isolation of Salmonella was obtained from intestinal content samples (12.0±3.0%), while lower percentages were found for water from the containers and cloacal swabs (8.0±2.5% and 3.0±1.5%, respectively). Our results imply that free-living turtles are a risk factor for Salmonella transmission, but do not seem to be a reservoir for Campylobacter . We therefore rule out turtles as a risk factor for human campylobacteriosis. Nevertheless, further studies should be undertaken in other countries to confirm these results. PMID:23951312

  4. Prevalence and Characteristics of Salmonella and Campylobacter in Retail Poultry Meat in Japan.

    PubMed

    Furukawa, Ichiro; Ishihara, Tomoe; Teranishi, Hiroshi; Saito, Shioko; Yatsuyanagi, Jun; Wada, Eriko; Kumagai, Yuko; Takahashi, Shiho; Konno, Takayuki; Kashio, Hiroko; Kobayashi, Akihiko; Kato, Naoki; Hayashi, Ken-Ichi; Fukushima, Keisuke; Ishikawa, Kazuhiko; Horikawa, Kazumi; Oishi, Akira; Izumiya, Hidemasa; Ohnishi, Takahiro; Konishi, Yoshiko; Kuroki, Toshiro

    2017-05-24

    This study was performed to determine the prevalence, antimicrobial susceptibility, and genetic relatedness of Salmonella enterica subsp. enterica and Campylobacter spp. in poultry meat, and to analyze the association of genetic types of these bacteria with their geographical distribution and antimicrobial resistance profiles. Salmonella and Campylobacter isolates have been detected, respectively, in 54 and 71 samples out of 100 samples tested. Nine Salmonella serotypes were found, including S. enterica subsp. enterica serovar Infantis (33%), Schwarzengrund (12%), Manhattan (9%), and others. Campylobacter jejuni and C. coli were detected in 64 (64%) and 14 (14%) samples, respectively. S. enterica subsp. enterica isolates were very frequently resistant to tetracycline (78.3%) and streptomycin (68.3%). Many C. jejuni and C. coli isolates were resistant to sulfamethoxazole/trimethoprim (90.5%), nalidixic acid (47.3%), ampicillin (45.9%), and ciprofloxacin (40.5%). Cluster analysis was performed for the Salmonella isolates using pulsed-field gel electrophoresis (PFGE) data. For Campylobacter isolates, the cluster analysis was based on both PFGE and comparative genomic fingerprinting. The molecular typing results were compared with the information about antimicrobial resistance and geographical locations in which the poultry meat was produced. This analysis revealed that C. jejuni strains with a particular genotype and antimicrobial resistance profile are spreading in specific areas of Japan.

  5. Fate of Salmonella enterica in a mixed ingredient salad containing lettuce, cheddar cheese, and cooked chicken meat.

    PubMed

    Bovo, Federica; De Cesare, Alessandra; Manfreda, Gerardo; Bach, Susan; Delaquis, Pascal

    2015-03-01

    Food service and retail sectors offer consumers a variety of mixed ingredient salads that contain fresh-cut vegetables and other ingredients such as fruits, nuts, cereals, dairy products, cooked seafood, cooked meat, cured meats, or dairy products obtained from external suppliers. Little is known about the behavior of enteric bacterial pathogens in mixed ingredient salads. A model system was developed to examine the fate of Salmonella enterica (inoculum consisting of S. enterica serovars Agona, Typhimurium, Enteritidis, Brandenberg, and Kentucky) on the surface of romaine lettuce tissues incubated alone and in direct contact with Cheddar cheese or cooked chicken. S. enterica survived but did not grow on lettuce tissues incubated alone or in contact with Cheddar cheese for 6 days at either 6 or 14°C. In contrast, populations increased from 2.01 ± 0.22 to 9.26 ± 0.22 CFU/cm(2) when lettuce washed in water was incubated in contact with cooked chicken at 14°C. Populations on lettuce leaves were reduced to 1.28 ± 0.14 CFU/cm(2) by washing with a chlorine solution (70 ppm of free chlorine) but increased to 8.45 ± 0.22 CFU/cm(2) after 6 days at 14°C. Experimentation with a commercial product in which one third of the fresh-cut romaine lettuce was replaced with inoculated lettuce revealed that S. enterica populations increased by 4 log CFU/g during storage for 3 days at 14°C. These findings indicate that rapid growth of bacterial enteric pathogens may occur in mixed ingredient salads; therefore, strict temperature control during the manufacture, distribution, handling, and storage of these products is critical.

  6. Prevalence of antimicrobial resistance in fecal Escherichia coli and Salmonella enterica in Canadian commercial meat, companion, laboratory, and shelter rabbits (Oryctolagus cuniculus) and its association with routine antimicrobial use in commercial meat rabbits.

    PubMed

    Kylie, Jennifer; McEwen, Scott A; Boerlin, Patrick; Reid-Smith, Richard J; Weese, J Scott; Turner, Patricia V

    2017-11-01

    Antimicrobial resistance (AMR) in zoonotic (e.g. Salmonella spp.), pathogenic, and opportunistic (e.g. E. coli) bacteria in animals represents a potential reservoir of antimicrobial resistant bacteria and resistance genes to bacteria infecting humans and other animals. This study evaluated the prevalence of E. coli and Salmonella enterica, and the presence of associated AMR in commercial meat, companion, research, and shelter rabbits in Canada. Associations between antimicrobial usage and prevalence of AMR in bacterial isolates were also examined in commercial meat rabbits. Culture and susceptibility testing was conducted on pooled fecal samples from weanling and adult commercial meat rabbits taken during both summer and winter months (n=100, 27 farms), and from pooled laboratory (n=14, 8 laboratory facilities), companion (n=53), and shelter (n=15, 4 shelters) rabbit fecal samples. At the facility level, E. coli was identified in samples from each commercial rabbit farm, laboratory facility, and 3 of 4 shelters, and in 6 of 53 companion rabbit fecal samples. Seventy-nine of 314 (25.2%; CI: 20.7-30.2%) E. coli isolates demonstrated resistance to >1 antimicrobial agent. At least one E. coli isolate resistant to at least one antimicrobial agent was present in samples from 55.6% of commercial farms, and from 25% of each laboratory and shelter facilities, with resistance to tetracycline being most common; no resistance was identified in companion animal samples. Salmonella enterica subsp. was identified exclusively in pooled fecal samples from commercial rabbit farms; Salmonella enterica serovar London from one farm and Salmonella enterica serovar Kentucky from another. The S. Kentucky isolate was resistant to amoxicillin/clavulanic acid, ampicillin, cefoxitin, ceftiofur, ceftriaxone, streptomycin, and tetracycline, whereas the S. London isolate was pansusceptible. Routine use of antimicrobials on commercial meat rabbit farms was not significantly associated with the

  7. Oral immunisation with live aroA attenuated Salmonella enterica serovar Typhimurium expressing the Yersinia pestis V antigen protects mice against plague.

    PubMed

    Garmory, Helen S; Griffin, Kate F; Brown, Katherine A; Titball, Richard W

    2003-06-20

    Bubonic and pneumonic plague are caused by the bacterium Yersinia pestis. The V antigen of Y. pestis is a protective antigen against plague. In this study, an aroA attenuated strain of Salmonella enterica serovar Typhimurium (SL3261) has been used to deliver the Y. pestis V antigen as a candidate oral plague vaccine. SL3261 was transformed with the expression plasmid pTrc-LcrV, containing the lcrV gene encoding V antigen. Immunoblot analysis showed V antigen expression in SL3261 in vitro and intragastric immunisation of mice with the recombinant Salmonella resulted in the induction of V antigen-specific serum antibody responses and afforded protection against Y. pestis challenge. However, the antibody responses induced by the recombinant Salmonella did not correlate with the protection afforded, indicating that immune responses other than antibody may play a role in the protection afforded against plague by this candidate vaccine.

  8. The Legacy of Genetic Analysis Advances Contemporary Research with Escherichia coli K-12 and Salmonella enterica serovar Typhimurium LT2.

    PubMed

    Stewart, Valley

    2017-04-01

    Escherichia coli K-12 and Salmonella enterica serovar Typhimurium LT2 became standard organisms for genetic analysis during the Truman administration. Half a century later, genetic analysis with these strains had become an art form, interpreted through 23 articles in the ambitious two-volume masterpiece edited by the late Fred Neidhardt and colleagues. These legacy articles now are available through EcoSal Plus , so as to inform and inspire contemporary genetic analyses in these standard organisms and their relatives.

  9. Effect of the surfactant Tween 80 on the detachment and dispersal of Salmonella enterica Thompson single cells and aggregates from cilantro leaves as revealed by image analysis

    USDA-ARS?s Scientific Manuscript database

    Biofilms formed by human enteric pathogens on plants are a great concern to the produce industry. Salmonella enterica has the ability to form biofilms and large aggregates on leaf surfaces, including on cilantro leaves. Aggregates that remained attached after rigorous washing of cilantro leaves and ...

  10. Molecular and cellular characterization of a Salmonella enterica serovar Paratyphi a outbreak strain and the human immune response to infection.

    PubMed

    Gal-Mor, Ohad; Suez, Jotham; Elhadad, Dana; Porwollik, Steffen; Leshem, Eyal; Valinsky, Lea; McClelland, Michael; Schwartz, Eliezer; Rahav, Galia

    2012-02-01

    Enteric fever is an invasive life-threatening systemic disease caused by the Salmonella enterica human-adapted serovars Typhi and Paratyphi. Increasing incidence of infections with Salmonella enterica serovar Paratyphi A and the spreading of its antibiotic-resistant derivates pose a significant health concern in some areas of the world. Herein, we describe a molecular and phenotypic characterization of an S. Paratyphi A strain accounted for a recent paratyphoid outbreak in Nepal that affected at least 37 travelers. Pulsed-field gel electrophoresis analysis of the outbreak isolates revealed one genetic clone (pulsotype), confirming a single infecting source. Genetic profiling of the outbreak strain demonstrated the contribution of specific bacteriophages as a prime source of genetic diversity among clinical isolates of S. Paratyphi A. Phenotypic characterization in comparison with the S. Paratyphi A ATCC 9150 reference sequenced strain showed differences in flagellar morphology and increased abilities of the outbreak strain with respect to its motility, invasion into nonphagocytic cells, intracellular multiplication, survival within macrophages, and higher induction of interleukin-8 (IL-8) secreted by host cells. Collectively, these differences suggest an enhanced virulence potential of this strain and demonstrate an interesting phenotypic variation among S. Paratyphi A isolates. In vivo profiling of 16 inflammatory cytokines in patients infected with the outbreak strain revealed a common profile of a remarkable gamma interferon (IFN-γ) induction together with elevated concentrations of tumor necrosis factor alpha (TNF-α), IL-6, IL-8, IL-10, and IL-15, but not IL-12, which was previously demonstrated as elevated in nontyphoidal Salmonella infections. This apparent profile implies a distinct immune response to paratyphoid infections.

  11. Investigation of Outbreaks of Salmonella enterica Serovar Typhimurium and Its Monophasic Variants Using Whole-Genome Sequencing, Denmark

    PubMed Central

    Gymoese, Pernille; Sørensen, Gitte; Litrup, Eva; Olsen, John Elmerdal; Nielsen, Eva Møller

    2017-01-01

    Whole-genome sequencing is rapidly replacing current molecular typing methods for surveillance purposes. Our study evaluates core-genome single-nucleotide polymorphism analysis for outbreak detection and linking of sources of Salmonella enterica serovar Typhimurium and its monophasic variants during a 7-month surveillance period in Denmark. We reanalyzed and defined 8 previously characterized outbreaks from the phylogenetic relatedness of the isolates, epidemiologic data, and food traceback investigations. All outbreaks were identified, and we were able to exclude unrelated and include additional related human cases. We were furthermore able to link possible food and veterinary sources to the outbreaks. Isolates clustered according to sequence types (STs) 19, 34, and 36. Our study shows that core-genome single-nucleotide polymorphism analysis is suitable for surveillance and outbreak investigation for Salmonella Typhimurium (ST19 and ST36), but whole genome–wide analysis may be required for the tight genetic clone of monophasic variants (ST34). PMID:28930002

  12. A Mutation in the PoxA Gene of Salmonella enterica Serovar Typhimurium Results in Altered Protein Production, Elevated Susceptibility to Environmental Challenges, and Decreased Swine Colonization

    USDA-ARS?s Scientific Manuscript database

    Using signature-tagged mutagenesis of Salmonella enterica serovar Typhimurium (S. Typhimurium), a mutation in the poxA gene (STM4344; yjeA; poxR), encoding a putative lysyl-tRNA synthetase, was previously identified by our research group which caused decreased survival in an ex vivo swine stomach co...

  13. Factors associated with the serological prevalence of Salmonella enterica in Greek finishing swineherds.

    PubMed Central

    Leontides, L. S.; Grafanakis, E.; Genigeorgis, C.

    2003-01-01

    Blood samples were taken from 50 finishing pigs at 90-105 kg in each of 59 randomly selected farrow-to-finish herds. The sera were tested for antibodies to Salmonella enterica by the Danish mix-ELISA. Samples with an optical density of > 10% were considered to be positive. Associations between the odds of seropositivity of pigs and possible risk factors were evaluated in multivariable logistic regression models. The results of the analysis indicated that pigs fed non-pelleted dry or wet ration had 11 (P = 0.0004) or 9 (P = 0.02) times, respectively, lower odds of seropositivity than those fed pelleted ration. The risk of seropositivity was 4 (P = 0.0006) times higher in pigs fed a combination of chlortetracycline, procaine penicillin and sulphamethazine during fattening than in those fed an approved growth promotor or a probiotic. PMID:12948357

  14. Evaluation of vaccine candidate potential of deltaaroA, deltahtrA and deltaaroAdeltahtrA mutants of Salmonella enterica subspecies enterica serovar Abortusequi in guinea pigs.

    PubMed

    Singh, Bhoj Raj; Chandra, Mudit; Hansda, Dhananjoy; Alam, Javed; Babu, Narayanan; Siddiqui, Mehtab Z; Agrawal, Ravi K; Sharma, Gautam

    2013-04-01

    Salmonella enterica subspecies enterica serovar Abortusequi (S. Abortusequi), a host adapted Salmonella causes abortions, still births and foal mortality in equids. Though known since more than 100 years, it is still a problem in many of the developing countries including India. There is dearth of really good vaccine affording immunity lasting at least for one full gestation. In search of a potential vaccine candidate, three defined deletion mutants (deltaaroA, deltahtrA and deltaaroAdeltahtrA) of S. Abortusequi were tested in guinea pig model for attenuation, safety, immunogenicity, humoral immune response, protective efficacy and persistence in host. The deltahtrA and deltaaroAdeltahtrA mutants were found to be safe on oral inoculation in doses as high as 4.2 x 10(9) cfu/animal. Also through subcutaneous inoculation deltaaroAdeltahtrA mutant did not induce any abortion in pregnant guinea pigs. All the three mutants did not induce any illness or death in 1-2 week-old baby guinea pigs except deltahtrA mutant which caused mortality on intraperitoneal inoculation. Inoculation with mutants protected against challenge and increased breeding efficiency of guinea pigs. After >4.5 months of mutant inoculation, guinea pigs were protected against abortifacient dose of wild type S. Abortusequi and mother guinea pigs also conferred resistance to their babies to the similar challenge. Early humoral immune response of S. Abortusequi mutants was characteristic. Faecal excretion of deltaaroA and htrA mutants was detected up to 45 days of inoculation in guinea pigs while deltaaroAdeltahtrA mutant could not be detected after 21 days of inoculation. The results indicated that the double deletion mutant (deltaaroAdeltahtrA) was the most effective and safe candidate for vaccination against S. Abortusequi through mucosal route of inoculation.

  15. Increased lymphocyte subpopulations and macrophages in the ovaries and oviducts of laying hens infected with Salmonella enterica serovar Enteritidis.

    PubMed

    Withanage, G S K; Sasai, K; Fukata, T; Miyamoto, T; Lillehoj, H S; Baba, E

    2003-12-01

    Salmonella enterica serovar Enteritidis (SE) is a causative agent for human food poisoning cases throughout the world. The ovaries and the oviducts of the laying hens are the major sites of SE colonization from which vertical transmission to eggs occurs. In this study, Salmonella-induced changes in T lymphocytes, B lymphocytes and macrophages in the ovaries and oviducts were assessed after primary and secondary experimental inoculations of laying hen with SE. Statistically significant increases in the numbers of T cells (both CD4+ and CD8+) and macrophages were observed 7 to 14 days after primary inoculation, followed by a peak in B-cell numbers from the 14th day post-primary inoculation onwards in the secretory areas of the oviducts. The peak in lymphocyte numbers immediately preceded a decline in the rate of SE recovery from the reproductive tract beginning at day 14. The correlation of decreased Salmonella recovery with elevated lymphocyte and macrophage numbers strongly suggests that local cell-mediated immunity is involved in controlling SE injection in the ovaries and oviducts.

  16. Molecular typing and resistance analysis of travel-associated Salmonella enterica serotype Typhi.

    PubMed

    Tatavarthy, A; Sanderson, R; Peak, K; Scilabro, G; Davenhill, P; Cannons, A; Amuso, P

    2012-08-01

    Salmonella enterica serotype Typhi is a human pathogen causing 12 to 30% mortality and requiring antibiotic therapy to control the severity of the infection. Typhoid fever in United States is often associated with foreign travel to areas of endemicity. Increasing resistance to multiple drugs, including quinolones, is associated with decreased susceptibility to ciprofloxacin (DCS). We investigated 31 clinical strains isolated in Florida from 2007 to 2010, associated with travel to six countries, to examine the clonal distribution of the organism and apparent nalidixic acid (NAL) resistance. The strains were isolated from blood or stool of patients aged 2 to 68 years. The isolates were subtyped by ribotyping and pulsed-field gel electrophoresis. Susceptibilities to 15 antimicrobials were determined, and the isolates were screened for integrons and gyrase A gene mutations. Both typing techniques effectively segregated the strains. Identical clones were associated with different countries, while diverse types coexisted in the same geographic location. Fifty-one percent of the strains were resistant to at least one antimicrobial, and five were resistant to three or more drugs (multidrug resistant [MDR]). All 12 isolates from the Indian subcontinent were resistant to at least one drug, and 83% of those were resistant to NAL. Three of the MDR strains harbored a 750-bp integron containing the dfr7 gene. Ninety-three percent of the resistant strains showed a DCS profile. All the NAL-resistant strains contained point mutations in the quinolone resistance-determining region of gyrA. This study affirms the global clonal distribution, concomitant genetic heterogeneity, and increased NAL resistance of S. enterica serovar Typhi.

  17. Aneurysm of the cranial mesenteric artery as a site of carriage of Salmonella enterica subsp. enterica serovar Abortusequi in the horse.

    PubMed

    Niwa, Hidekazu; Hobo, Seiji; Kinoshita, Yuta; Muranaka, Masanori; Ochi, Akihiro; Ueno, Takanori; Oku, Kazuomi; Hariu, Kazuhisa; Katayama, Yoshinari

    2016-07-01

    Salmonella enterica subsp. enterica serovar Abortusequi is a pathogen restricted to horses. Our investigation targeted 4 draft horses (9-10 months old) kept on a Japanese farm that had suffered an outbreak of S. Abortusequi abortion. The 4 horses were suspected to be carriers of the bacterium owing to their high agglutination titers (≥1:2,560) in tube agglutination testing. The owners' on-farm observations confirmed that the horses had no apparent abnormalities, and S. Abortusequi was not isolated from their blood, rectal swabs, or sternal bone marrow fluid at antemortem investigation. However, at autopsy, all horses displayed the following: suppurative aneurysm of the cranial mesenteric artery with heavy infection with Strongylus vulgaris larvae; heavy intestinal parasitic infection with Gasterophilus intestinalis, Parascaris equorum, Anoplocephala perfoliata, and S. vulgaris; and enlargement of the systemic lymph nodes. In each case, large numbers of S. Abortusequi were isolated from the anterior mesenteric artery thrombus. The thrombus isolates harbored a single virulence plasmid, and the pulsed-field gel electrophoresis profiles of the isolates were identical not only to each other but also to those of Japanese enzootic strains of S. Abortusequi. These results reveal that parasitic aneurysms of the cranial mesenteric artery should be considered an important possible site of carriage of S. Abortusequi in horses. The results also suggest high clonality of the isolated serovar in the horse population in Japan. © 2016 The Author(s).

  18. Biofilms promote survival and virulence of Salmonella enterica sv. Tennessee during prolonged dry storage and after passage through an in vitro digestion system.

    PubMed

    Aviles, Bryan; Klotz, Courtney; Eifert, Joseph; Williams, Robert; Ponder, Monica

    2013-04-01

    Salmonella enterica serotypes have been linked to outbreaks associated with low water activity foods. While the biofilm-forming abilities of Salmonella improve its survival during thermal processing and sanitation it is unclear whether biofilms enhance survival to desiccation and gastric stresses. The purpose of this study was to quantify the effect of physiological state (planktonic versus biofilm) and prior exposure to desiccation and storage in dry milk powder on Salmonella survival and gene expression after passage through an in vitro digestion model. Planktonic cells of Salmonella enterica serotype Tennessee were deposited onto membranes while biofilms were formed on glass beads. The cells were subsequently dried at room temperature and stored in dried milk powder (a(w)=0.3) for up to 30 days. Salmonella survival was quantified by serial dilution onto Brilliant Green Agar before desiccation, after desiccation, after 1-day storage and after 30-day storage. At each sampling period both physiological states were tested for survival through a simulated gastrointestinal system. RNA was extracted at the identical time points and Quantitative Real-Time PCR was used to determine relative expression for genes associated with stress response (rpoS, otsB), virulence (hilA, invA, sipC) and a housekeeping gene 16S rRNA. The physiological state and length of storage affected the survival and gene expression of Salmonella within the desiccated milk powder environment and after passage through an in vitro digestion system (p<0.05). Larger numbers of S. Tennessee were recovered by plate counts for biofilms compared to planktonic, however, the numbers of Salmonella genomes detected by qPCR were not significantly different suggesting entry of the planktonic cells of S. Tennessee into a viable but non-culturable state. The increased expression of stress response genes rpoS and otsB correlated with survival, indicating cross-protection to low water activity and acid stress

  19. Homologous stress adaptation, antibiotic resistance, and biofilm forming ability of Salmonella enterica serovar Heidelberg (ATCC8326) on different food-contact surfaces following exposure to sub-lethal chlorine concentrations

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serovar Heidelberg (American Type Culture Collection; ATCC 8326) was examined for the ability to adapt to the homologous stress of chlorine through exposure to increasing chlorine concentrations (25 ppm daily increments) in tryptic soy broth (TSB). The tested strain exhibited an ...

  20. Salmonella DNA Adenine Methylase Mutants Confer Cross-Protective Immunity

    PubMed Central

    Heithoff, Douglas M.; Enioutina, Elena Y.; Daynes, Raymond A.; Sinsheimer, Robert L.; Low, David A.; Mahan, Michael J.

    2001-01-01

    Salmonella isolates that lack or overproduce DNA adenine methylase (Dam) elicited a cross-protective immune response to different Salmonella serovars. The protection afforded by the Salmonella enterica serovar Typhimurium Dam vaccine was greater than that elicited in mice that survived a virulent infection. S. enterica serovar Typhimurium Dam mutant strains exhibited enhanced sensitivity to mediators of innate immunity such as antimicrobial peptides, bile salts, and hydrogen peroxide. Also, S. enterica serovar Typhimurium Dam− vaccines were not immunosuppressive; unlike wild-type vaccines, they failed to induce increased nitric oxide levels and permitted a subsequent robust humoral response to diptheria toxoid antigen in infected mice. Dam mutant strains exhibited a low-grade persistence which, coupled with the nonimmunosuppression and the ectopic protein expression caused by altered levels of Dam, may provide an expanded source of potential antigens in vaccinated hosts. PMID:11598044

  1. Antimicrobial resistance among invasive nontyphoidal Salmonella enterica isolates in the United States: National Antimicrobial Resistance Monitoring System, 1996 to 2007.

    PubMed

    Crump, John A; Medalla, Felicita M; Joyce, Kevin W; Krueger, Amy L; Hoekstra, R Michael; Whichard, Jean M; Barzilay, Ezra J

    2011-03-01

    Nontyphoidal salmonellae (NTS) are important causes of community-acquired bloodstream infection. We describe patterns of antimicrobial resistance among invasive NTS in the United States. We compared bloodstream NTS isolates with those from stool submitted to the National Antimicrobial Resistance Monitoring System (NARMS) from 1996 to 2007. We describe antimicrobial resistance among invasive strains by serogroup and serotype. Of the 19,302 NTS isolates, 17,804 (92.2%) were from stool or blood. Of these, 1,050 (5.9%) were bloodstream isolates. The median ages (ranges) of patients with and without bacteremia were 36 (<1 to 97) years and 20 (<1 to 105) years, respectively (P < 0.001). Males (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.06 to 1.38) and those ≥65 years of age were at greater risk for invasive disease. Salmonella enterica serotypes Enteritidis, Typhimurium, and Heidelberg were the most common serotypes isolated from blood; S. enterica serotypes Dublin, Sandiego, and Schwarzengrund were associated with the greatest risk for bloodstream isolation. Of invasive isolates, 208 (19.8%) were resistant to ampicillin, 117 (11.1%) to chloramphenicol, and 26 (2.5%) to trimethoprim-sulfamethoxazole; 28 (2.7%) isolates were resistant to nalidixic acid and 26 (2.5%) to ceftriaxone. Antimicrobial resistance to traditional agents is common. However, the occurrence of nalidixic acid and ceftriaxone resistance among invasive NTS is cause for clinical and public health vigilance.

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

    PubMed Central

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

    2016-01-01

    Salmonella enterica is among the most burdensome of foodborne disease agents. There are over 2,600 serovars that cause a range of disease manifestations ranging from enterocolitis to typhoid fever. While there are two vaccines in use in humans to protect against typhoid fever, there are none that prevent enterocolitis. If vaccines preventing enterocolitis were to be developed, they would likely protect against only one or a few serovars. In this report, we tested the hypothesis that probiotic organisms could compete for the preferred nutrient sources of Salmonella and thus prevent or treat infection. To this end, we added the fra locus, which encodes a utilization pathway for the Salmonella-specific nutrient source fructose-asparagine (F-Asn), to the probiotic bacterium Escherichia coli Nissle 1917 (Nissle) to increase its ability to compete with Salmonella in mouse models. We also tested a metabolically competent, but avirulent, Salmonella enterica serovar Typhimurium mutant for its ability to compete with wild-type Salmonella. The modified Nissle strain became more virulent and less able to protect against Salmonella in some instances. On the other hand, the modified Salmonella strain was safe and effective in preventing infection with wild-type Salmonella. While we tested for efficacy only against Salmonella Typhimurium, the modified Salmonella strain may be able to compete metabolically with most, if not all, Salmonella serovars, representing a novel approach to control of this pathogen. PMID:27185789

  3. Salmonella enterica serovar Typhimurium adhesion and cytotoxicity during epithelial cell stress is reduced by Lactobacillus rhamnosus GG

    PubMed Central

    Burkholder, Kristin M; Bhunia, Arun K

    2009-01-01

    Background Physiological stressors may alter susceptibility of the host intestinal epithelium to infection by enteric pathogens. In the current study, cytotoxic effect, adhesion and invasion of Salmonella enterica serovar Typhimurium (S. Typhimurium) to Caco-2 cells exposed to thermal stress (41°C, 1 h) was investigated. Probiotic bacteria have been shown to reduce interaction of pathogens with the epithelium under non-stress conditions and may have a significant effect on epithelial viability during infection; however, probiotic effect on pathogen interaction with epithelial cells under physiological stress is not known. Therefore, we investigated the influence of Lactobacillus rhamnosus GG and Lactobacillus gasseri on Salmonella adhesion and Salmonella-induced cytotoxicity of Caco-2 cells subjected to thermal stress. Results Thermal stress increased the cytotoxic effect of both S. Typhimurium (P = 0.0001) and nonpathogenic E. coli K12 (P = 0.004) to Caco-2 cells, and resulted in greater susceptibility of cell monolayers to S. Typhimurium adhesion (P = 0.001). Thermal stress had no significant impact on inflammatory cytokines released by Caco-2 cells, although exposure to S. Typhimurium resulted in greater than 80% increase in production of IL-6 and IL-8. Blocking S. Typhimurium with anti-ShdA antibody prior to exposure of Salmonella decreased adhesion (P = 0.01) to non-stressed and thermal-stressed Caco-2 cells. Pre-exposure of Caco-2 cells to L. rhamnosus GG significantly reduced Salmonella-induced cytotoxicity (P = 0.001) and Salmonella adhesion (P = 0.001) to Caco-2 cells during thermal stress, while L. gasseri had no effect. Conclusion Results suggest that thermal stress increases susceptibility of intestinal epithelial Caco-2 cells to Salmonella adhesion, and increases the cytotoxic effect of Salmonella during infection. Use of L. rhamnosus GG as a probiotic may reduce the severity of infection during epithelial cell stress. Mechanisms by which thermal

  4. Characterization of antimicrobial resistance in Salmonella enterica strains isolated from Brazilian poultry production.

    PubMed

    Mattiello, Samara P; Drescher, Guilherme; Barth, Valdir C; Ferreira, Carlos A S; Oliveira, Sílvia D

    2015-11-01

    Antimicrobial resistance profiles and presence of resistance determinants and integrons were evaluated in Salmonella enterica strains from Brazilian poultry. The analysis of 203 isolates showed that those from the poultry environment (88 isolates) were significantly more resistant to antimicrobials than isolates from other sources, particularly those isolated from poultry by-product meal (106 isolates). Thirty-seven isolates were resistant to at least three antimicrobial classes. Class 1 integrons were detected in 26 isolates, and the analysis of the variable region between the 5' conserved segment (CS) and 3' CS of each class 1 integron-positive isolate showed that 13 contained a typical 3' CS and 14 contained an atypical 3' CS. One Salmonella Senftenberg isolate harbored two class 1 integrons, showing both typical and atypical 3' CSs. The highest percentage of resistance was found to sulfonamides, and sul genes were detected in the majority of the resistant isolates. Aminoglycoside resistance was detected in 50 isolates, and aadA and aadB were present in 28 and 32 isolates, respectively. In addition, strA and strB were detected in 78.1 and 65.6% isolates resistant to streptomycin, respectively. Twenty-one isolates presented reduced susceptibility to β-lactams and harbored bla(TEM), bla(CMY), and/or bla(CTX-M). Forty isolates showed reduced susceptibility to tetracycline, and most presented tet genes. These results highlight the importance of the environment as a reservoir of resistant Salmonella, which may enable the persistence of resistance determinants in the poultry production chain, contributing, therefore, to the debate regarding the impacts that antimicrobial use in animal production may exert in human health.

  5. Blood invasiveness of Salmonella enterica as a function of age and serotype.

    PubMed Central

    Weinberger, M.; Andorn, N.; Agmon, V.; Cohen, D.; Shohat, T.; Pitlik, S. D.

    2004-01-01

    We explored the dual influence of the patient's age and the infecting serotype on the blood invasiveness patterns of non-Typhi Salmonella enterica (NTS). Blood invasiveness ratio (BIR) was calculated as the ratio between the number of blood and blood + stool isolates. Analysis of 14,951 NTS isolates showed that the BIR increased drastically above the age of 60 years, reaching levels 3.5-7 times higher compared to age group < 2 years. Different patterns of age-related invasiveness were observed for the five most common NTS serotypes (Enteritidis, Typhimurium, Virchow, Hadar, Infantis). Among children < 2 years, the BIR was highest for serotype Virchow and lowest for serotype Hadar, while in persons > or = 60 years it was highest for serotypes Enteritidis and lowest for serotype Infantis. The tendency of NTS serotypes to invade the bloodstream was significantly influenced by the patient's age, however the impact of age differed for various NTS serotypes. PMID:15635958

  6. Interaction of graphene family materials with Listeria monocytogenes and Salmonella enterica

    NASA Astrophysics Data System (ADS)

    Kurantowicz, Natalia; Sawosz, Ewa; Jaworski, Sławomir; Kutwin, Marta; Strojny, Barbara; Wierzbicki, Mateusz; Szeliga, Jacek; Hotowy, Anna; Lipińska, Ludwika; Koziński, Rafał; Jagiełło, Joanna; Chwalibog, André

    2015-01-01

    Graphene family materials have unique properties, which make them valuable for a range of applications. The antibacterial properties of graphene have been reported; however, findings have been contradictory. This study reports on the antimicrobial proprieties of three different graphene materials (pristine graphene (pG), graphene oxide (GO), and reduced graphene oxide (rGO)) against the food-borne bacterial pathogens Listeria monocytogenes and Salmonella enterica. A high concentration (250 μg/mL) of all the analyzed graphenes completely inhibited the growth of both pathogens, despite their difference in bacterial cell wall structure. At a lower concentration (25 μg/mL), similar effects were only observed with GO, as growth inhibition decreased with pG and rGO at the lower concentration. Interaction of the nanoparticles with the pathogenic bacteria was found to differ depending on the form of graphene. Microscopic imaging demonstrated that bacteria were arranged at the edges of pG and rGO, while with GO, they adhered to the nanoparticle surface. GO was found to have the highest antibacterial activity.

  7. Synthesis of Metallo-β-Lactamase VIM-2 Is Associated with a Fitness Reduction in Salmonella enterica Serovar Typhimurium

    PubMed Central

    Cordeiro, Nicolás F.; Chabalgoity, José A.; Yim, Lucía

    2014-01-01

    Antibiotic resistance, especially due to β-lactamases, has become one of the main obstacles in the correct treatment of Salmonella infections; furthermore, antibiotic resistance determines a gain of function that may encompass a biological cost, or fitness reduction, to the resistant bacteria. The aim of this work was to determine in vitro if the production of the class B β-lactamase VIM-2 determined a fitness cost for Salmonella enterica serovar Typhimurium. To that end the gene blaVIM-2 was cloned into the virulent strain S. Typhimurium SL1344, using both the tightly regulated pBAD22 vector and the natural plasmid pST12, for inducible and constitutive expression, respectively. Fitness studies were performed by means of motility, growth rate, invasiveness in epithelial cells, and plasmid stability. The expression of blaVIM-2 was accompanied by alterations in micro- and macroscopic morphology and reduced growth rate and motility, as well as diminished invasiveness in epithelial cells. These results suggest that VIM-2 production entails a substantial fitness cost for S. Typhimurium, which in turn may account for the extremely low number of reports of metallo-β-lactamase-producing Salmonella spp. PMID:25136026

  8. Efficacy of Pulsed-Field Gel Electrophoresis and Repetitive Element Sequence-Based PCR in Typing of Salmonella Isolates from Assam, India.

    PubMed

    Gogoi, Purnima; Borah, Probodh; Hussain, Iftikar; Das, Leena; Hazarika, Girin; Tamuly, Shantanu; Barkalita, Luit Moni

    2018-05-01

    A total of 12 Salmonella isolates belonging to different serovars, viz , Salmonella enterica serovar Enteritidis ( n = 4), Salmonella enterica serovar Weltevreden ( n = 4), Salmonella enterica serovar Newport ( n = 1), Salmonella enterica serovar Litchifield ( n = 1), and untypeable strains ( n = 2) were isolated from 332 diarrheic fecal samples collected from animals, birds, and humans. Of the two molecular typing methods applied, viz , repetitive element sequence-based PCR (REP-PCR) and pulsed-field gel electrophoresis (PFGE), PFGE could clearly differentiate the strains belonging to different serovars as well as differentiate between strains of the same serovar with respect to their source of isolation, whereas REP-PCR could not differentiate between strains of the same serovar. Thus, it can be suggested that PFGE is more useful and appropriate for molecular typing of Salmonella isolates during epidemiological investigations than REP-PCR. Copyright © 2018 American Society for Microbiology.

  9. Plant-Microbe and Abiotic Factors Influencing Salmonella Survival and Growth on Alfalfa Sprouts and Swiss Chard Microgreens

    PubMed Central

    Reed, Elizabeth; Ferreira, Christina M.; Bell, Rebecca; Brown, Eric W.

    2018-01-01

    ABSTRACT Microgreens, like sprouts, are relatively fast-growing products and are generally consumed raw. Moreover, as observed for sprouts, microbial contamination from preharvest sources may also be present in the production of microgreens. In this study, two Salmonella enterica serovars (Hartford and Cubana), applied at multiple inoculation levels, were evaluated for survival and growth on alfalfa sprouts and Swiss chard microgreens by using the most-probable-number (MPN) method. Various abiotic factors were also examined for their effects on Salmonella survival and growth on sprouts and microgreens. Community-level physiological profiles (CLPPs) of sprout/microgreen rhizospheres with different levels of S. enterica inoculation at different growth stages were characterized by use of Biolog EcoPlates. In the seed contamination group, the ability of S. enterica to grow on sprouting alfalfa seeds was affected by both seed storage time and inoculation level but not by serovar. However, the growth of S. enterica on Swiss chard microgreens was affected by serovar and inoculation level. Seed storage time had little effect on the average level of Salmonella populations in microgreens. In the irrigation water contamination group, the growth of Salmonella on both alfalfa sprouts and microgreens was largely affected by inoculation level. Surprisingly, the growth medium was found to play an important role in Salmonella survival and growth on microgreens. CLPP analysis showed significant changes in the microbial community metabolic diversity during sprouting for alfalfa sprouts, but few temporal changes were seen with microgreens. The data suggest that the change in rhizosphere bacterial functional diversity was dependent on the host but independent of Salmonella contamination. IMPORTANCE Sprouts and microgreens are considered “functional foods,” i.e., foods containing health-promoting or disease-preventing properties in addition to normal nutritional values. However, the

  10. Influence of Sterilized Human Fecal Extract on the Sensitivity of Salmonella enterica ATCC 13076 and Listeria monocytogenes ATCC 15313 to Enrofloxacin.

    PubMed

    Ahn, Youngbeom; Stuckey, Ryan; Sung, Kidon; Rafii, Fatemeh; Cerniglia, Carl E

    2013-12-02

    There is much debate on whether continuous exposure of commensal bacteria and potential pathogens residing in the human intestinal tract to low levels of antimicrobial agents from treated food animals pose a public health concern. To investigate antimicrobial effects on bacteria under colonic conditions, we studied resistance development in Salmonella enterica and Listeria monocytogenes exposed to enrofloxacin in the presence of fecal extract. The bacteria were incubated at 37 °C in Mueller-Hinton broth, with and without 0.01~0.5 μg/mL enrofloxacin, in the presence and absence of sucrose, and with 1% or 2.5% filter-sterilized fecal extract, for three passages. In the second and third passages, only the bacteria incubated in the media containing sterilized fecal extract grew in 0.5 μg/mL of enrofloxacin. Fecal extract (1% and 2.5%) decreased the sensitivity of S. enterica to enrofloxacin in the medium containing the efflux pump inhibitors reserpine and carbonyl cyanide-m-chlorophenylhydrazone (CCCP) and affected the accumulation of ethidium bromide (EtBr) in this bacterium. Enrofloxacin (0.06 µg/mL) and fecal extract altered the composition of fatty acids in S. enterica and L. monocytogenes. We conclude that fecal extract decreased the susceptibilities of S. enterica and L. monocytogenes to concentrations of enrofloxacin higher than the MIC and resulted in rapid resistance selection.

  11. Molecular Properties of Salmonella enterica Serotype Paratyphi B Distinguish between Its Systemic and Its Enteric Pathovars

    PubMed Central

    Prager, Rita; Rabsch, Wolfgang; Streckel, Wiebke; Voigt, Wolfgang; Tietze, Erhardt; Tschäpe, Helmut

    2003-01-01

    Salmonella enterica serotype O1,4,5,12:Hb:1,2, designated according to the current Kauffmann-White scheme as S. enterica serotype Paratyphi B, is a very diverse serotype with respect to its clinical and microbiological properties. PCR and blot techniques, which identify the presence, polymorphism, and expression of various effector protein genes, help to distinguish between strains with systemic and enteric outcomes of disease. All serotype Paratyphi B strains from systemic infections have been found to be somewhat genetically related with respect to the pattern of their virulence genes sopB, sopD, sopE1, avrA, and sptP as well as other molecular properties (multilocus enzyme electrophoresis type, pulsed-field gel electrophoresis [PFGE] type, ribotype, and IS200 type). They have been classified as members of the systemic pathovar (SPV). All these SPV strains possess a new sopE1-carrying bacteriophage (designated ΦSopE309) with high SopE1 protein expression but lack the commonly occurring avrA determinant. They exhibit normal SopB protein expression but lack SopD protein production. In contrast, strains from enteric infections classified as belonging to the enteric pathovar possess various combinations of the respective virulence genes, PFGE pattern, and ribotypes. We propose that the PCR technique for testing for the presence of the virulence genes sopE1 and avrA be used as a diagnostic tool for identifying both pathovars of S. enterica serotype Paratyphi B. This will be of great public health importance, since strains of serotype Paratyphi B have recently reemerged worldwide. PMID:12958256

  12. Negative supercoiling of DNA by gyrase is inhibited in Salmonella enterica serovar Typhimurium during adaptation to acid stress.

    PubMed

    Colgan, Aoife M; Quinn, Heather J; Kary, Stefani C; Mitchenall, Lesley A; Maxwell, Anthony; Cameron, Andrew D S; Dorman, Charles J

    2018-03-01

    DNA in intracellular Salmonella enterica serovar Typhimurium relaxes during growth in the acidified (pH 4-5) macrophage vacuole and DNA relaxation correlates with the upregulation of Salmonella genes involved in adaptation to the macrophage environment. Bacterial ATP levels did not increase during adaptation to acid pH unless the bacterium was deficient in MgtC, a cytoplasmic-membrane-located inhibitor of proton-driven F 1 F 0 ATP synthase activity. Inhibiting ATP binding by DNA gyrase and topo IV with novobiocin enhanced the effect of low pH on DNA relaxation. Bacteria expressing novobiocin-resistant (Nov R ) derivatives of gyrase or topo IV also exhibited DNA relaxation at acid pH, although further relaxation with novobiocin was not seen in the strain with Nov R gyrase. Thus, inhibition of the negative supercoiling activity of gyrase was the primary cause of enhanced DNA relaxation in drug-treated bacteria. The Salmonella cytosol reaches pH 5-6 in response to an external pH of 4-5: the ATP-dependent DNA supercoiling activity of purified gyrase was progressively inhibited by lowering the pH in this range, as was the ATP-dependent DNA relaxation activity of topo IV. We propose that DNA relaxation in Salmonella within macrophage is due to acid-mediated impairment of the negative supercoiling activity of gyrase. © 2018 John Wiley & Sons Ltd.

  13. Conjugal Transfer of the Pathogenicity Island ROD21 in Salmonella enterica serovar Enteritidis Depends on Environmental Conditions

    PubMed Central

    Salazar-Echegarai, Francisco J.; Tobar, Hugo E.; Nieto, Pamela A.; Riedel, Claudia A.; Bueno, Susan M.

    2014-01-01

    Unstable pathogenicity islands are chromosomal elements that can be transferred from one bacterium to another. Salmonella enterica serovar Enteritidis (S. Enteritidis) is a pathogenic bacterium containing such unstable pathogenicity islands. One of them, denominated ROD21, is 26.5 kb in size and capable of excising from the chromosome in certain culture conditions, as well as during bacterial infection of phagocytic cells. In this study we have evaluated whether ROD21 can be effectively transferred from one bacterium to another. We generated a donor and several recipient strains of S. Enteritidis to carry out transfer assays in liquid LB medium. These assays showed that ROD21 is effectively transferred from donor to recipient strains of S. Enteritidis and S. Typhimurium. When Escherichia coli was used as the recipient strain, ROD21 transfer failed to be observed. Subsequently, we showed that a conjugative process was required for the transfer of the island and that changes in temperature and pH increased the transfer frequency between Salmonella strains. Our data indicate that ROD21 is an unstable pathogenicity island that can be transferred by conjugation in a species-specific manner between Salmonellae. Further, ROD21 transfer frequency increases in response to environmental changes, such as pH and temperature. PMID:24705125

  14. DksA-dependent resistance of Salmonella enterica serovar Typhimurium against the antimicrobial activity of inducible nitric oxide synthase.

    PubMed

    Henard, Calvin A; Vázquez-Torres, Andrés

    2012-04-01

    In coordination with the ppGpp alarmone, the RNA polymerase regulatory protein DksA controls the stringent response of eubacteria, negatively regulating transcription of translational machinery and directly activating amino acid promoters and de novo amino acid biosynthesis. Given the effects of nitric oxide (NO) on amino acid biosynthetic pathways and the intimate relationship of DksA with amino acid synthesis and transport, we tested whether DksA contributes to the resistance of Salmonella to reactive nitrogen species (RNS). Our studies show that the zinc finger predicted to position DksA in the secondary channel of the RNA polymerase is essential for the resistance of Salmonella enterica serovar Typhimurium to RNS in a murine model of systemic salmonellosis. Despite exhibiting auxotrophies for various amino acids, ΔdksA mutant Salmonella strains regain virulence in mice lacking inducible NO synthase (iNOS). DksA is also important for growth of this intracellular pathogen in the presence of NO congeners generated by iNOS during the innate response of murine macrophages. Accordingly, dksA mutant Salmonella strains are hypersusceptible to chemically generated NO, a phenotype that can be prevented by adding amino acids. The DksA-dependent antinitrosative defenses do not rely on the Hmp flavohemoprotein that detoxifies NO to NO(3)(-) and appear to operate independently of the ppGpp alarmone. Our investigations are consistent with a model by which NO produced in the innate response to Salmonella exerts considerable pressure on amino acid biosynthesis. The cytotoxicity of NO against Salmonella amino acid biosynthetic pathways is antagonized in great part by the DksA-dependent regulation of amino acid biosynthesis and transport.

  15. Infection of the reproductive tract and eggs with Salmonella enterica serovar pullorum in the chicken is associated with suppression of cellular immunity at sexual maturity.

    PubMed

    Wigley, Paul; Hulme, Scott D; Powers, Claire; Beal, Richard K; Berchieri, Angelo; Smith, Adrian; Barrow, Paul

    2005-05-01

    Salmonella enterica serovar Pullorum causes persistent infections in laying hens. Splenic macrophages are the main site of persistence. At sexual maturity, numbers of bacteria increase and spread to the reproductive tract, which may result in vertical transmission to eggs or chicks. In this study we demonstrate that both male and female chickens may develop a carrier state following infection but that the increases in bacterial numbers and spread to the reproductive tract are phenomena restricted to hens, indicating that such changes are likely to be related to the onset of egg laying. The immunological responses during the carrier state and through the onset of laying in hens were determined. These indicate that chickens produce both humoral and T-cell responses to infection, but at the onset of laying both the T-cell response to Salmonella and nonspecific responses to mitogenic stimulation fall sharply in both infected and noninfected birds. The fall in T-cell responsiveness coincided with the increase in numbers of Salmonella serovar Pullorum and its spread to the reproductive tract. Three weeks after the onset of egg laying, T-cell responsiveness began to increase and bacterial numbers declined. Specific antibody levels changed little at the onset of laying but increased following the rise in bacterial numbers in a manner reminiscent of a secondary antibody response to rechallenge. These findings indicate that a nonspecific suppression of cellular responses occurs at the onset of laying and plays a major role the ability of Salmonella serovar Pullorum to infect the reproductive tract, leading to transmission to eggs. The loss of T-cell activity at the point of laying also has implications for Salmonella enterica serovar Enteritidis infection and transmission to eggs, along with its control by vaccination offering a "window of opportunity" in which infection may occur.

  16. Salmonella enterica serovar Oranienburg outbreak in a veterinary medical teaching hospital with evidence of nosocomial and on-farm transmission.

    PubMed

    Cummings, Kevin J; Rodriguez-Rivera, Lorraine D; Mitchell, Katharyn J; Hoelzer, Karin; Wiedmann, Martin; McDonough, Patrick L; Altier, Craig; Warnick, Lorin D; Perkins, Gillian A

    2014-07-01

    Nosocomial salmonellosis continues to pose an important threat to veterinary medical teaching hospitals. The objectives of this study were to describe an outbreak of salmonellosis caused by Salmonella enterica serovar Oranienburg within our hospital and to highlight its unique features, which can be used to help mitigate or prevent nosocomial outbreaks in the future. We retrospectively analyzed data from patients that were fecal culture-positive for Salmonella Oranienburg between January 1, 2006, and June 1, 2011, including historical, clinical, and pulsed-field gel electrophoresis (PFGE) data. Salmonella Oranienburg was identified in 20 horses, five alpacas, and three cows during this time frame, with dates of admission spanning the period from August, 2006, through January, 2008. We consider most of these patients to have become infected through either nosocomial or on-farm transmission, as evidenced by molecular subtyping results and supportive epidemiologic data. Interpretation of PFGE results in this outbreak was challenging because of the identification of several closely related Salmonella Oranienburg subtypes. Furthermore, a high percentage of cases were fecal culture-positive for Salmonella Oranienburg within 24 h of admission. These patients initially appeared to represent new introductions of Salmonella into the hospital, but closer inspection of their medical records revealed epidemiologic links to the hospital following the index case. Cessation of this outbreak was observed following efforts to further heighten biosecurity efforts, with no known cases or positive environmental samples after January, 2008. This study demonstrates that a Salmonella-positive culture result within 24 h of admission does not exclude the hospital as the source of infection, and it underscores the important role played by veterinary medical teaching hospitals as nodes of Salmonella infection that can promote transmission outside of the hospital setting.

  17. Effect of Water Activity on the Thermal Tolerance and Survival of Salmonella enterica Serovars Tennessee and Senftenberg in Goat's Milk Caramel.

    PubMed

    Acosta, Oscar; Usaga, Jessie; Churey, John J; Worobo, Randy W; Padilla-Zakour, Olga I

    2017-06-01

    The low thermal tolerance of Salmonella enterica in foods with intermediate moisture levels, such as caramel sauces, ensures that mild heat treatment is sufficient to achieve 5-log reductions of this pathogen. This treatment mitigates the risk posed by salmonellae in raw materials; however, recontamination might occur because of survival of the pathogen in products that are not heated before consumption. This study was conducted to evaluate the effect of water activity (a w ) on the thermal tolerance and survival of S. enterica serovars Tennessee and Senftenberg. The D-values at 76, 78, and 80°C, z-values, and survival at 20.0 ± 0.5°C for 32 weeks of these two serovars were determined in goat's milk caramel at three a w values (0.85, 0.90, and 0.93). The highest thermal tolerance was observed at a w = 0.85 for Salmonella Senftenberg (D 76°C = 2.9 ± 0.3 min), and the lowest was at a w = 0.93 for Salmonella Tennessee (D 80°C = 0.131 ± 0.007 min). After a logarithmic transformation of the z-values, a significant interaction between serovar and a w was found (P < 0.0001), but no consistent trends were observed at the three evaluated a w levels for either serovar. Survival response was modeled using two sigmoidal three-parameter models. A significant interaction was found between nominal variables a w and serovar when comparing inflection points of the resulting curves: P < 0.0016 for the logistic model (R 2 = 0.91) and P < 0.0014 for the Gompertz model (R 2 = 0.92). Although a >8-log reduction was observed at week 20 of storage, regardless of the product's a w and the serovar, low levels of salmonellae were found in the product up to week 32 of storage. Our findings may assist the food industry with the establishment of critical limits for the safe thermal treatment of milk- and sugar-based foods with intermediate moisture levels. The survival data presented here highlight the relevance of implementing and effectively maintaining good sanitation and hygiene

  18. Biocontrol of the internalization of Salmonella enterica and Enterohaemorrhagic Escherichia coli in mung bean sprouts with an endophytic Bacillus subtilis.

    PubMed

    Shen, Zhenyu; Mustapha, Azlin; Lin, Mengshi; Zheng, Guolu

    2017-06-05

    Internalization of Salmonella enterica and enterohaemorrhagic Escherichia coli (EHEC) in seed sprouts poses a health risk to consumers, and the conventional sanitization methods are not always effective to reduce this risk. This study initiated a biocontrol approach to limit the internalization using endophytic Bacillus subtilis strains, which were isolated from the inner tissue of mung bean seeds or lettuce stems. By using the deferred agar method, 12 strains of B. subtilis out of 94 putative Bacillus isolates displayed inhibitory activity against at least one of the pathogenic indicators, S. enterica Typhimurium ATCC 14028 and E. coli O157:H7 505B. Two B. subtilis isolates (LCA1 and M24) showed a broad inhibitory spectrum against multiple strains of S. enterica and EHEC, Staphylococcus aureus sp., Klebsiella pneumoniae ATCC 700603, and Listeria monocytogenes Scott A, while the laboratory B. subtilis strain 168 was only moderately inhibitory against L. monocytogenes. To facilitate the tracking of the three B. subtilis strains (LCA1, M24, and 168) in the mung bean sprouts, the three strains were genetically engineered to carry the chloramphenicol acetyltransferase (cat), generating the strains LCA1-cat, M24-cat, and 168-cat, respectively. Data of the study using the cat-tagged strains demonstrated that both the two vegetable-associated and the laboratory B. subtilis strains could internalize in mung bean sprouts during the sprouting, but the latter displayed about 1.2 lg CFU/g of seeds lower in internalization. Overall, the presence of the three B. subtilis strains could significantly reduce the internalization of S. enterica or EHEC cocktail in mung bean sprouts during the sprouting. Among them, LCA1 showed the greatest inhibition against the EHEC cocktails with a reduction of about 2.0lg CFU/g of seeds by the end of sprouting (day 5), while 168 had the smallest reduction at about 0.6lg CFU/g of seeds. In addition, the three strains demonstrated a similar

  19. Fate of Salmonella enterica and Enterohemorrhagic Escherichia coli Cells Artificially Internalized into Vegetable Seeds during Germination.

    PubMed

    Liu, Da; Cui, Yue; Walcott, Ronald; Chen, Jinru

    2018-01-01

    Vegetable seeds contaminated with bacterial pathogens have been linked to fresh-produce-associated outbreaks of gastrointestinal infections. This study was undertaken to observe the physiological behavior of Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC) cells artificially internalized into vegetable seeds during the germination process. Surface-decontaminated seeds of alfalfa, fenugreek, lettuce, and tomato were vacuum-infiltrated with four individual strains of Salmonella or EHEC. Contaminated seeds were germinated at 25°C for 9 days, and different sprout/seedling tissues were microbiologically analyzed every other day. The internalization of Salmonella and EHEC cells into vegetable seeds was confirmed by the absence of pathogens in seed-rinsing water and the presence of pathogens in seed homogenates after postinternalization seed surface decontamination. Results show that 317 (62%) and 343 (67%) of the 512 collected sprout/seedling tissue samples were positive for Salmonella and EHEC, respectively. The average Salmonella populations were significantly larger ( P < 0.05) than the EHEC populations. Significantly larger Salmonella populations were recovered from the cotyledon and seed coat tissues, followed by the root tissues, but the mean EHEC populations from all sampled tissue sections were statistically similar, except in pregerminated seeds. Three Salmonella and two EHEC strains had significantly larger cell populations on sprout/seedling tissues than other strains used in the study. Salmonella and EHEC populations from fenugreek and alfalfa tissues were significantly larger than those from tomato and lettuce tissues. The study showed the fate of internalized human pathogens on germinating vegetable seeds and sprout/seedling tissues and emphasized the importance of using pathogen-free seeds for sprout production. IMPORTANCE The internalization of microorganisms into vegetable seeds could occur naturally and represents a possible pathway of

  20. Salmonella enterica serovar Typhimurium and Escherichia coli contamination of root and leaf vegetables grown in soils with incorporated bovine manure.

    PubMed

    Natvig, Erin E; Ingham, Steven C; Ingham, Barbara H; Cooperband, Leslie R; Roper, Teryl R

    2002-06-01

    Bovine manure, with or without added Salmonella enterica serovar Typhimurium (three strains), was incorporated into silty clay loam (SCL) and loamy sand (LS) soil beds (53- by 114-cm surface area, 17.5 cm deep) and maintained in two controlled-environment chambers. The S. enterica serovar Typhimurium inoculum was 4 to 5 log CFU/g in manure-fertilized soil. The conditions in the two environmental chambers, each containing inoculated and uninoculated beds of manure-fertilized soil, simulated daily average Madison, Wis., weather conditions (hourly temperatures, rainfall, daylight, and humidity) for a 1 March or a 1 June manure application and subsequent vegetable growing seasons ending 9 August or 28 September, respectively. Core soil samples were taken biweekly from both inoculated and uninoculated soil beds in each chamber. Radishes, arugula, and carrots were planted in soil beds, thinned, and harvested. Soils, thinned vegetables, and harvested vegetables were analyzed for S. enterica serovar Typhimurium and Escherichia coli (indigenous in manure). After the 1 March manure application, S. enterica serovar Typhimurium was detected at low levels in both soils on 31 May, but not on vegetables planted 1 May and harvested 12 July from either soil. After the 1 June manure application, S. enterica serovar Typhimurium was detected in SCL soil on 7 September and on radishes and arugula planted in SCL soil on 15 August and harvested on 27 September. In LS soil, S. enterica serovar Typhimurium died at a similar rate (P >or= 0.05) after the 1 June manure application and was less often detected on arugula and radishes harvested from this soil compared to the SCL soil. Pathogen levels on vegetables were decreased by washing. Manure application in cool (daily average maximum temperature of <10 degrees C) spring conditions is recommended to ensure that harvested vegetables are not contaminated with S. enterica serovar Typhimurium. Manure application under warmer (daily average

  1. Salmonella enterica Serovar Typhimurium and Escherichia coli Contamination of Root and Leaf Vegetables Grown in Soils with Incorporated Bovine Manure

    PubMed Central

    Natvig, Erin E.; Ingham, Steven C.; Ingham, Barbara H.; Cooperband, Leslie R.; Roper, Teryl R.

    2002-01-01

    Bovine manure, with or without added Salmonella enterica serovar Typhimurium (three strains), was incorporated into silty clay loam (SCL) and loamy sand (LS) soil beds (53- by 114-cm surface area, 17.5 cm deep) and maintained in two controlled-environment chambers. The S. enterica serovar Typhimurium inoculum was 4 to 5 log CFU/g in manure-fertilized soil. The conditions in the two environmental chambers, each containing inoculated and uninoculated beds of manure-fertilized soil, simulated daily average Madison, Wis., weather conditions (hourly temperatures, rainfall, daylight, and humidity) for a 1 March or a 1 June manure application and subsequent vegetable growing seasons ending 9 August or 28 September, respectively. Core soil samples were taken biweekly from both inoculated and uninoculated soil beds in each chamber. Radishes, arugula, and carrots were planted in soil beds, thinned, and harvested. Soils, thinned vegetables, and harvested vegetables were analyzed for S. enterica serovar Typhimurium and Escherichia coli (indigenous in manure). After the 1 March manure application, S. enterica serovar Typhimurium was detected at low levels in both soils on 31 May, but not on vegetables planted 1 May and harvested 12 July from either soil. After the 1 June manure application, S. enterica serovar Typhimurium was detected in SCL soil on 7 September and on radishes and arugula planted in SCL soil on 15 August and harvested on 27 September. In LS soil, S. enterica serovar Typhimurium died at a similar rate (P ≥ 0.05) after the 1 June manure application and was less often detected on arugula and radishes harvested from this soil compared to the SCL soil. Pathogen levels on vegetables were decreased by washing. Manure application in cool (daily average maximum temperature of <10°C) spring conditions is recommended to ensure that harvested vegetables are not contaminated with S. enterica serovar Typhimurium. Manure application under warmer (daily average maximum

  2. Neutral Genomic Microevolution of a Recently Emerged Pathogen, Salmonella enterica Serovar Agona

    PubMed Central

    Litrup, Eva; Murphy, Ronan; Cormican, Martin; Fanning, Seamus; Brown, Derek; Guttman, David S.; Brisse, Sylvain; Achtman, Mark

    2013-01-01

    Salmonella enterica serovar Agona has caused multiple food-borne outbreaks of gastroenteritis since it was first isolated in 1952. We analyzed the genomes of 73 isolates from global sources, comparing five distinct outbreaks with sporadic infections as well as food contamination and the environment. Agona consists of three lineages with minimal mutational diversity: only 846 single nucleotide polymorphisms (SNPs) have accumulated in the non-repetitive, core genome since Agona evolved in 1932 and subsequently underwent a major population expansion in the 1960s. Homologous recombination with other serovars of S. enterica imported 42 recombinational tracts (360 kb) in 5/143 nodes within the genealogy, which resulted in 3,164 additional SNPs. In contrast to this paucity of genetic diversity, Agona is highly diverse according to pulsed-field gel electrophoresis (PFGE), which is used to assign isolates to outbreaks. PFGE diversity reflects a highly dynamic accessory genome associated with the gain or loss (indels) of 51 bacteriophages, 10 plasmids, and 6 integrative conjugational elements (ICE/IMEs), but did not correlate uniquely with outbreaks. Unlike the core genome, indels occurred repeatedly in independent nodes (homoplasies), resulting in inaccurate PFGE genealogies. The accessory genome contained only few cargo genes relevant to infection, other than antibiotic resistance. Thus, most of the genetic diversity within this recently emerged pathogen reflects changes in the accessory genome, or is due to recombination, but these changes seemed to reflect neutral processes rather than Darwinian selection. Each outbreak was caused by an independent clade, without universal, outbreak-associated genomic features, and none of the variable genes in the pan-genome seemed to be associated with an ability to cause outbreaks. PMID:23637636

  3. Antimicrobial effect of the Tunisian Nana variety Punica granatum L. extracts against Salmonella enterica (serovars Kentucky and Enteritidis) isolated from chicken meat and phenolic composition of its peel extract.

    PubMed

    Wafa, Ben Ajmia; Makni, Mohamed; Ammar, Sonda; Khannous, Lamia; Hassana, Amal Ben; Bouaziz, Mohamed; Es-Safi, Nour Eddine; Gdoura, Radhouane

    2017-01-16

    Punica granatum L. is widely recognized for its potency against a broad spectrum of bacterial pathogens. The purpose of this study was to explore the inhibitory and the bactericidal activities of Punica granatum against Salmonella strains. The effect of extracts obtained from different parts (peels, seeds, juice and flowers) of pomegranate and using different solvents against Salmonella enterica serovars Kentucky and Enteritidis isolated from chicken meat was thus investigated. Salmonella strains were identified with the standard API-20E system and confirmed by real time PCR. The obtained results showed that the highest antibacterial activity against Salmonella strains was observed with the peels ethanolic extract giving MIC values ranging from 10.75 to 12.5mg/mL. The ethanolic extract of P. granatum Nana peels at 0.8 and 1.6mg/g significantly inhibited the growth of Salmonella Kentucky in chicken meat stored at 4°C. The phenolic composition of the ethanolic peel extract was explored by HPLC coupled to both DAD and ESI/TOF-MS detections. The obtained results allowed the detection of 21 phytochemical compounds among which various phenolic compounds have been identified on the basis of their UV and MS spectra as well as with literature data. Among the detected compounds, anthocyanins, ellagitannins, ellagic acid derivatives and flavanols were further characterized through MS-MS analysis. Our results showed thus that the Tunisian variety Nana pomegranate constitutes a good source of bioactive compounds with potent antimicrobial activity on the growth of Salmonella strains suggesting that the studied pomegranate cultivar could be a natural remedy to minimize the emergence of Salmonella enterica strains which is often involved in food borne illness. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Iron acquisition pathways and colonization of the inflamed intestine by Salmonella enterica serovar Typhimurium

    PubMed Central

    Costa, Luciana F.; Mol, Juliana P. S.; Silva, Ana Patricia C.; Macêdo, Auricélio A.; Silva, Teane M. A.; Alves, Geraldo E. S.; Winter, Sebastian; Winter, Maria G.; Velazquez, Eric M.; Byndloss, Mariana X.; Bäumler, Andreas J.; Tsolis, Renée M.; Paixão, Tatiane A.; Santos, Renato L.

    2016-01-01

    Salmonella enterica serotype Typhimurium is able to expand in the lumen of the inflamed intestine through mechanisms that have not been fully resolved. Here we utilized streptomycin-pretreated mice and dextran sodium sulfate (DSS)-treated mice to investigate how pathways for S. Typhimurium iron acquisition contribute to pathogen expansion in the inflamed intestine. Competitive infection with an iron uptake-proficient S. Typhimurium strain and mutant strains lacking tonB feoB, feoB, tonB or iroN in streptomycin pretreated mice demonstrated that ferric iron uptake requiring IroN and TonB conferred a fitness advantage during growth in the inflamed intestine. However, the fitness advantage conferred by ferrous iron uptake mechanisms was independent of inflammation and was only apparent in models where the normal microbiota composition had been disrupted by antibiotic treatment. PMID:27760693

  5. Reduced Burden of Salmonella enterica in Bovine Subiliac Lymph Nodes Associated with Administration of a Direct-fed Microbial.

    PubMed

    Vipham, J L; Loneragan, G H; Guillen, L M; Brooks, J C; Johnson, B J; Pond, A; Pond, N; Brashears, M M

    2015-12-01

    Despite effective food safety interventions within abattoirs, Salmonella enterica remains a common contaminant of raw ground beef. Research has recently implicated peripheral lymph nodes (PLNs) as a potential route by which Salmonella contaminates ground beef. This study examined the efficacy of using Lactobacillus animalis (formerly designated Lactobacillus acidophilus; NP51) and Propionibacterium freudenreichii (NP24), at 10(9) cfu/head/day, as a direct-fed microbial (DFM) in feedlot cattle diets to control Salmonella within PLNs. Two studies were conducted in which cattle were randomly allocated into either control or DFM treatment groups. Diets of treated cattle were supplemented with 10(9) cfu/head/day of the DFM, while control groups received no DFM supplementation. During slaughter at abattoirs, one subiliac lymph node (SLN) per carcass was collected from 627 carcasses from one study and 99 carcasses from the second study. Lymph nodes were cultured to estimate the presence and concentration of Salmonella. In the first study, effects of DFM supplementation varied across slaughter days. On the first and second slaughter days, prevalence was reduced by 50% (P = 0.0072) and 31% (P = 0.0093), respectively. No significant difference was observed on slaughter day three (P = 0.1766). In the second study, Salmonella was 82% less likely (P = 0.008) to be recovered from SLNs of treatment cattle. While a greater relative risk reduction was observed in the latter study, absolute risk reductions were similar across studies. A significant reduction in the concentration of Salmonella in SLNs (P < 0.0001) on a cfu/g and cfu/node basis was also observed in cattle administered NP51 and NP24 in the first study; in the second study, too few quantifiable SLNs were observed to facilitate meaningful comparisons. The results indicate that NP51 and NP24 supplementation may aid in reducing the prevalence and concentration of Salmonella in SLNs and, therefore, serve as an effective

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

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is the leading cause of health burdens in the United States. Although the pathogen is not able to grow at aw levels below 0.94, it can survive in low-moisture foods for long periods of time. Temperature, aw, substrate and serotype affect its persistence. The aim of this study was...

  7. Prevalence and characterization of Salmonella enterica from the feces of cattle, poultry, swine and hedgehogs in Burkina Faso and their comparison to human Salmonella isolates

    PubMed Central

    2013-01-01

    Background Production and wild animals are major sources of human salmonellosis and animals raised for food also play an important role in transmission of antimicrobial resistant Salmonella strains to humans. Furthermore, in sub-Saharan Africa non-typhoidal Salmonella serotypes are common bloodstream isolates in febrile patients. Yet, little is known about the environmental reservoirs and predominant modes of transmission of these pathogens. The purpose of this study was to discover potential sources and distribution vehicles of Salmonella by isolating strains from apparently healthy slaughtered food animals and wild hedgehogs and by determining the genetic relatedness between the strains and human isolates. For this purpose, 729 feces samples from apparently healthy slaughtered cattle (n = 304), poultry (n = 350), swine (n = 50) and hedgehogs (n = 25) were examined for the presence of Salmonella enterica in Burkina Faso. The isolates were characterized by serotyping, antimicrobial-susceptibility testing, phage typing, and pulsed-field gel electrophoresis (PFGE) with XbaI and BlnI restriction enzymes. Results Of the 729 feces samples, 383 (53%) contained Salmonella, representing a total of 81 different serotypes. Salmonella was present in 52% of the cattle, 55% of the poultry, 16% of the swine and 96% of the hedgehog feces samples. Antimicrobial resistance was detected in 14% of the isolates. S. Typhimurium isolates from poultry and humans (obtained from a previous study) were multiresistant to the same antimicrobials (ampicillin, chloramphenicol, streptomycin, sulfonamides and trimethoprim), had the same phage type DT 56 and were closely related in PFGE. S. Muenster isolates from hedgehogs had similar PFGE patterns as the domestic animals. Conclusions Based on our results it seems that production and wild animals can share the same Salmonella serotypes and potentially transmit some of them to humans. As the humans and animals often live in close

  8. Application of Scutellariae radix, Gardeniae fructus, and Probiotics to Prevent Salmonella enterica Serovar Choleraesuis Infection in Swine

    PubMed Central

    Chang, Chiung-Hung; Chen, Yueh-Sheng; Chiou, Ming-Tang; Su, Chiu-Hsian; Chen, Daniel S.; Tsai, Chin-En; Yu, Bi; Hsu, Yuan-Man

    2013-01-01

    Salmonella enterica serovar Choleraesuis, a host-adapted pathogen of swine, usually causes septicemia. Lactic acid bacteria (LAB) strains have been widely studied in recent years for their probiotic properties. In this study, a mouse infection model first screened for potential agents against infection, then a pig infection model evaluated effects of LAB strains and herbal plants against infection. Scutellariae radix (SR) and Gardeniae fructus (GF) showed abilities to reduce bacteria shedding and suppressing serum level of TNF-α induced by infection in swine. Bioactivities of SR and GF were enhanced by combining with LAB strains, which alone could speed up the bacteria elimination time in feces and boost immunity of infected pigs. Baicalein and genipin exhibited stronger cytotoxicity than baicalin and geniposide did, as well as prevent Salmonella from invading macrophages. Our study suggests LAB strains as exhibiting multiple functions: preventing infection, enhancing immunity to prepare host defenses against further infection, and adjusting intestinal microbes' enzymatic activity in order to convert herbal compounds to active compounds. The SR/GF-LAB strain mixture holds potential infection-prevention agents supplied as feed additives. PMID:23533497

  9. Heterogeneity of Multidrug-Resistant Salmonella enterica Isolates with Increasing Frequency of Resistance to Ciprofloxacin During a 4-Year Period in Iran.

    PubMed

    Bakhshi, Bita; Dehghan-Mouriaabadi, Arezoo; Kiani, Parisa

    2018-05-01

    The study was conducted to assess the trend of antimicrobial resistance among Salmonella enterica strains during a period of 4 years and to compare the effectiveness of three genotyping methods, including flagellin polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP), enterobacterial repetitive intergenic consensus (ERIC)-PCR, and pulsed-field gel electrophoresis (PFGE), and to determine the most efficient method for S. enterica genotyping. About 50 S. enterica isolates were isolated from 5,064 stool samples. All of the isolates harbored fliC gene, 29 of which (58%) showed diphasic characteristic with a fliC + /fljB + genotype. Simpson diversity index (Di) for RFLP analysis of fliC and fljB genes was calculated as 0.71 and 0.82, respectively. Strains were differentiated into 40 ERIC genotypes and 27 pulsotypes. All isolates with identical pulsotypes belonged to common serogroups which depict their correlation in a good manner. The Di calculated for ERIC-PCR and PFGE analysis was 0.99 and 0.94, respectively. The frequency of multidrug resistance (MDR) was dramatically increased from 25% in 2009-2010 to 63% in 2011-2012 with the emergence of 10% ciprofloxacin resistance in the latter period. About 44% increase in MDR phenotype among S. enterica isolates during a 4-year period and concomitant appearance of ciprofloxacin resistance is a traumatic situation for health professionals in Iran. PFGE profiles offered a satisfactory discriminatory power, which was positively correlated with S. enterica serogrouping. The current study marks the superiority of PFGE method over other conventional molecular techniques in epidemiological investigations; however, their limitations need to be addressed for further refinement.

  10. Presence of Salmonella Enteritidis and Salmonella Gallinarum in commercial laying hens diagnosed with Fowl Typhoid Disease in Colombia

    USDA-ARS?s Scientific Manuscript database

    : A severe outbreak of salmonellosis in commercial brown table egg layers first occurred in Colombia in 2006. From 2008 to 2012, 35 samples collected from commercial layers farms in the states of Cundinamarca, Santander, Bolivar and San Andres, were positive to Salmonella enterica. Salmonella (S) wa...

  11. In Vivo Visualization of Bacterial Colonization, Antigen Expression, and Specific T-Cell Induction following Oral Administration of Live Recombinant Salmonella enterica Serovar Typhimurium

    PubMed Central

    Bumann, Dirk

    2001-01-01

    Live attenuated Salmonella strains that express a foreign antigen are promising oral vaccine candidates. Numerous genetic modifications have been empirically tested, but their effects on immunogenicity are difficult to interpret since important in vivo properties of recombinant Salmonella strains such as antigen expression and localization are incompletely characterized and the crucial early inductive events of an immune response to the foreign antigen are not fully understood. Here, methods were developed to directly localize and quantitate the in situ expression of an ovalbumin model antigen in recombinant Salmonella enterica serovar Typhimurium using two-color flow cytometry and confocal microscopy. In parallel, the in vivo activation, blast formation, and division of ovalbumin-specific CD4+ T cells were followed using a well-characterized transgenic T-cell receptor mouse model. This combined approach revealed a biphasic induction of ovalbumin-specific T cells in the Peyer's patches that followed the local ovalbumin expression of orally administered recombinant Salmonella cells in a dose- and time-dependent manner. Interestingly, intact Salmonella cells and cognate T cells seemed to remain in separate tissue compartments throughout induction, suggesting a transport of killed Salmonella cells from the colonized subepithelial dome area to the interfollicular inductive sites. The findings of this study will help to rationally optimize recombinant Salmonella strains as efficacious live antigen carriers for oral vaccination. PMID:11402006

  12. Dynamics of Salmonella Shedding and Welfare of Hens in Free-Range Egg Production Systems

    PubMed Central

    Gole, Vaibhav C.; Woodhouse, Rebecca; Caraguel, Charles; Moyle, Talia; Rault, Jean-Loup; Sexton, Margaret

    2016-01-01

    ABSTRACT The current study investigated the effect of environmental stressors (i.e., weather changes) on Salmonella shedding in free-range production systems and the correlations with behavioral and physiological measures (i.e., fecal glucocorticoid metabolites). This involved longitudinal and point-in-time surveys of Salmonella shedding and environmental contamination on four commercial free-range layer farms. The shedding of Salmonella was variable across free-range farms and in different seasons. There was no significant effect of season on the Salmonella prevalence during this investigation. In this study, the combined Salmonella most probable number (MPN) counts in environmental (including feces, egg belt, dust, nest box, and ramp) samples were highest in samples collected during the summer season (4th sampling, performed in February). The predominant serovars isolated during this study were Salmonella enterica serovar Mbandaka and Salmonella enterica serovar Typhimurium phage types 135 and 135a. These two phage types were involved in several egg product-related Salmonella outbreaks in humans. Multilocus variable-number tandem-repeat analysis (MLVA) results indicated that MLVA types detected from human food poisoning cases exhibited MLVA patterns similar to the strains isolated during this study. All Salmonella isolates (n = 209) were tested for 15 different genes involved in adhesion, invasion, and survival of Salmonella spp. We also observed variations for sopA, ironA, and misL. There were no positive correlations between fecal corticosterone metabolite (FCM) and Salmonella prevalence and/or shedding in feces. Also, there were no positive correlations between Salmonella prevalence and Salmonella count (log MPN) and any of the other welfare parameters. IMPORTANCE In this study, the welfare of laying hens and Salmonella shedding were compared over a prolonged period of time in field conditions. This study investigated the long-term shedding of Salmonella

  13. Proteins from latex of Calotropis procera prevent septic shock due to lethal infection by Salmonella enterica serovar Typhimurium.

    PubMed

    Lima-Filho, José V; Patriota, Joyce M; Silva, Ayrles F B; Filho, Nicodemos T; Oliveira, Raquel S B; Alencar, Nylane M N; Ramos, Márcio V

    2010-06-16

    The latex of Calotropis procera has been used in traditional medicine to treat different inflammatory diseases. The anti-inflammatory activity of latex proteins (LP) has been well documented using different inflammatory models. In this work the anti-inflammatory protein fraction was evaluated in a true inflammatory process by inducing a lethal experimental infection in the murine model caused by Salmonella enterica Subsp. enterica serovar Typhimurium. Experimental Swiss mice were given 0.2 ml of LP (30 or 60 mg/kg) by the intraperitoneal route 24 h before or after lethal challenge (0.2 ml) containing 10(6) CFU/ml of Salmonella Typhimurium using the same route of administration. All the control animals succumbed to infection within 6 days. When given before bacterial inoculums LP prevented the death of mice, which remained in observation until day 28. Even, LP-treated animals exhibited only discrete signs of infection which disappeared latter. LP fraction was also protective when given orally or by subcutaneous route. Histopathological examination revealed that necrosis and inflammatory infiltrates were similar in both the experimental and control groups on days 1 and 5 after infection. LP activity did not clear Salmonella Typhimurium, which was still present in the spleen at approximately 10(4) cells/g of organ 28 days after challenge. However, no bacteria were detected in the liver at this stage. LP did not inhibit bacterial growth in culture medium at all. In the early stages of infection bacteria population was similar in organs and in the peritoneal fluid but drastically reduced in blood. Titration of TNF-alpha in serum revealed no differences between experimental and control groups on days 1 and 5 days after infection while IL-12 was only discretely diminished in serum of experimental animals on day 5. Moreover, cultured macrophages treated with LP and stimulated by LPS released significantly less IL-1beta. LP-treated mice did not succumb to septic shock when

  14. Isolation and molecular characterization of Salmonella enterica, Escherichia coli O157:H7 and Shigella spp. from meat and dairy products in Egypt.

    PubMed

    Ahmed, Ashraf M; Shimamoto, Tadashi

    2014-01-03

    Foodborne pathogens are a major threat to food safety, especially in developing countries where hygiene and sanitation facilities are often poor. Salmonella enterica, Escherichia coli O157:H7 and Shigella spp. are among the major causes of outbreaks of foodborne diseases. This large-scale study investigated the prevalence of these foodborne pathogens in meat (beef and chicken) and dairy products collected from street vendors, butchers, retail markets and slaughterhouses in Egypt. A total of 1600 food samples (800 meat products and 800 dairy products) were analyzed using culture and PCR based methods. S. enterica, E. coli O157:H7 and Shigella spp. were detected in 69 (4.3%), 54 (3.4%) and 27 (1.7%) samples respectively. S. enterica serovar Typhimurium, S. enterica serovar Enteritidis, S. enterica serovar Infantis and non-typable serovars were detected in 28 (1.8%), 22 (1.4%), 16 (1.0%) and 3 (0.1%) samples respectively. All E. coli O157:H7 isolates were positive for stx1 and/or stx2 virulence toxin genes. Shigella flexneri, Shigella sonnei and Shigella dysenteriae were detected in 18 (1.2%), 7 (0.4%) and 2 (0.1%) samples respectively. The incidences of S. enterica and Shigella spp. were higher in meat products (53; 6.6% and 16; 2.0%, respectively) than in dairy products (16; 2.0% and 11; 1.4%, respectively), while, E. coli O157:H7 was higher in dairy products (29; 3.6%) than in meat products (25; 3.1%). The incidence of foodborne pathogens in meat and dairy products was determined in a large-scale survey in Africa. © 2013.

  15. Genetic diversity of human isolates of Salmonella enterica serovar Enteritidis in Malaysia.

    PubMed

    Bakeri, S A; Yasin, R M; Koh, Y T; Puthucheary, S D; Thong, K L

    2003-01-01

    The study was undertaken to determine clonal relationship and genetic diversity of the human strains of Salmonella enterica serovar Enteritidis isolated from 1995 to 2002 from different parts of Malaysia. Antimicrobial susceptibility test, plasmid profiling and pulsed-field gel electrophoresis were applied to analyse 65 human isolates of S. Enteritidis obtained over an eight year period from different parts of Malaysia. Four nonhuman isolates were included for comparison. A total of 14 distinct XbaI-pulsed-field profiles (PFPs) were observed, although a single PFP X1 was predominant and this particular clone was found to be endemic in Malaysia. The incidence of drug resistant S. Enteritidis remained relatively low with only 37% of the strains analysed being resistant to one or more antimicrobial agents. All except one resistant strain carried at least one plasmid ranging in size from 3.7 to 62 MDa giving nine plasmid profiles. The three isolates from raw milk and one from well-water had similar PFPs to that of the human isolates. Salmonella Enteritidis strains were more diverse than was previously thought. Fourteen subtypes were noted although one predominant clone persisted in Malaysia. The combination of pulsed-field gel electrophoresis, plasmid profiling and antibiograms provided additional discrimination to the highly clonal strains of S. Enteritidis. This is the first report to assess the genotypes of the predominant clinical S. Enteritidis in different parts of the country. As S. Enteritidis is highly endemic in Malaysia, the data generated would be useful for tracing the source during outbreaks of gastroenteritis in the study area.

  16. Spatial distribution of antibodies to Salmonella enterica serovar Typhimurium O antigens in bulk milk from Texas dairy herds.

    PubMed

    Graham, S L; Barling, K S; Waghela, S; Scott, H M; Thompson, J A

    2005-06-10

    Environmental factors that enhance either the survivability or dispersion of Salmonella enterica serovar Typhimurium (S. Typhimurium) could result in a spatial pattern of disease risk. The objectives of this study were to: (1) describe herd status based on antibody response to Salmonella Typhimurium as estimated from bulk tank milk samples and (2) to describe the resulting geographical patterns found among Texas dairy herds. Eight hundred and fifty-two bulk milk samples were collected from georeferenced dairy farms and assayed by an indirect enzyme-linked immunosorbent assay (ELISA) using S. Typhimurium lipopolysaccharide (LPS). ELISA signal-to-noise ratios for each bulk tank milk sample were calculated and used for geostatistical analyses. Best-fit parameters for the exponential theoretical variogram included a range of 438.8 km, partial sill of 0.060 and nugget of 0.106. The partial sill is the classical geostatistical term for the variance that can be explained by the herd's location and the nugget is the spatially random component of the variance. We have identified a spatial process in bulk milk tank titers for S. Typhimurium in Texas dairy herds and present a map of the expected smoothed surface. Areas with higher expected titers should be targeted in further studies on controlling Salmonella infection with environmental modifications.

  17. Studies on the effects of phosphine on Salmonella enterica serotype Enteritidis in culture medium and in black pepper (Piper nigrum).

    PubMed

    Castro, M F P M; Rezende, A C B; Benato, E A; Valentini, S R T; Furlani, R P Z; Tfouni, S A V

    2011-04-01

    The effect of phosphine on Salmonella enterica serotype Enteritidis inoculated in culture medium and in black pepper grains (Piper nigrum), as well as on the reduction of the microbial load of the dried and moisturized product, was verified. The postfumigation effect was verified in inoculated samples with 0.92 and 0.97 water activity (a(w)) exposed to 6 g/m(3) phosphine for 72 h, dried to 0.67 a(w), and stored for 24, 48, and 72 h. No decreases were observed in Salmonella Enteritidis populations in culture medium when fumigant concentrations up to 6 g/m(3) were applied for 48 h at 35°C. However, the colonies showed reductions in size and atypical coloration as the phosphine concentration increased. No reduction in Salmonella counts occurred on the inoculated dried samples after fumigation. On the other hand, when phosphine at concentrations of 6 g/m(3) was applied on moisturized black pepper for 72 h, decreases in Salmonella counts of around 80% were observed. The counts of total aerobic mesophilic bacterium populations of the dried and moisturized black pepper were not affected by the fumigant treatment. The results of the postfumigation studies indicated that Salmonella Enteritidis was absent in the fumigated grains after drying and storage for 72 h, indicating a promising application for this technique. It was concluded that for Salmonella Enteritidis control, phosphine fumigation could be applied to black pepper grains before drying and the producers should rigidly follow good agricultural practices, mainly during the drying process, in order to avoid product recontamination. Additional work is needed to confirm the findings with more Salmonella serotypes and strains.

  18. Evidence for Lack of Acquisition of Tolerance in Salmonella enterica Serovar Typhimurium ATCC 14028 after Exposure to Subinhibitory Amounts of Origanum vulgare L. Essential Oil and Carvacrol

    PubMed Central

    Luz, Isabelle da Silva; Gomes Neto, Nelson Justino; Tavares, Adassa Gama; Nunes, Pollyana Campos; Magnani, Marciane

    2012-01-01

    Overnight exposure of Salmonella enterica serovar Typhimurium to sublethal amounts of Origanum vulgare essential oil (OV) and carvacrol (CAR) did not result in direct and cross-bacterial protection. Cells subcultured with increasing amounts of OV or CAR survived up to the MIC of either compound, revealing few significant changes in bacterial susceptibility. PMID:22544235

  19. Internalisation potential of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium and Staphylococcus aureus in lettuce seedlings and mature plants.

    PubMed

    Standing, Taryn-Ann; du Plessis, Erika; Duvenage, Stacey; Korsten, Lise

    2013-06-01

    The internalisation potential of Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7 and Salmonella enterica subsp. enterica serovar Typhimurium in lettuce was evaluated using seedlings grown in vermiculite in seedling trays as well as hydroponically grown lettuce. Sterile distilled water was spiked with one of the four human pathogenic bacteria (10(5) CFU/mL) and used to irrigate the plants. The potential for pathogen internalisation was investigated over time using light microscopy, transmission electron microscopy and viable plate counts. Additionally, the identities of the pathogens isolated from internal lettuce plant tissues were confirmed using polymerase chain reaction with pathogen-specific oligonucleotides. Internalisation of each of the human pathogens was evident in both lettuce seedlings and hydroponically grown mature lettuce plants. To our knowledge, this is the first report of S. aureus internalisation in lettuce plants. In addition, the levels of background microflora in the lettuce plants were determined by plate counting and the isolates identified using matrix-assisted laser ionisation-time of flight (MALDI-TOF). Background microflora assessments confirmed the absence of the four pathogens evaluated in this study. A low titre of previously described endophytes and soil inhabitants, i.e., Enterobacter cloacae, Enterococcus faecalis, Lysinibacillus fusiformis, Rhodococcus rhodochrous, Staphylococcus epidermidis and Staphylococcus hominis were identified.

  20. rpoS-Regulated Core Genes Involved in the Competitive Fitness of Salmonella enterica Serovar Kentucky in the Intestines of Chickens

    PubMed Central

    Cheng, Ying; Pedroso, Adriana Ayres; Porwollik, Steffen; McClelland, Michael; Lee, Margie D.; Kwan, Tiffany; Zamperini, Katherine; Soni, Vivek; Sellers, Holly S.; Russell, Scott M.

    2014-01-01

    Salmonella enterica serovar Kentucky has become the most frequently isolated serovar from poultry in the United States over the past decade. Despite its prevalence in poultry, it causes few human illnesses in the United States. The dominance of S. Kentucky in poultry does not appear to be due to single introduction of a clonal strain, and its reduced virulence appears to correlate with the absence of virulence genes grvA, sseI, sopE, and sodC1. S. Kentucky's prevalence in poultry is possibly attributable to its metabolic adaptation to the chicken cecum. While there were no difference in the growth rate of S. Kentucky and S. Typhimurium grown microaerophilically in cecal contents, S. Kentucky persisted longer when chickens were coinfected with S. Typhimurium. The in vivo advantage that S. Kentucky has over S. Typhimurium appears to be due to differential regulation of core Salmonella genes via the stationary-phase sigma factor rpoS. Microarray analysis of Salmonella grown in cecal contents in vitro identified several metabolic genes and motility and adherence genes that are differentially activated in S. Kentucky. The contributions of four of these operons (mgl, prp, nar, and csg) to Salmonella colonization in chickens were assessed. Deletion of mgl and csg reduced S. Kentucky persistence in competition studies in chickens infected with wild-type or mutant strains. Subtle mutations affecting differential regulation of core Salmonella genes appear to be important in Salmonella's adaptation to its animal host and especially for S. Kentucky's emergence as the dominant serovar in poultry. PMID:25362062

  1. Assessment of the effect of a Salmonella enterica ser. Typhimurium culture supernatant on the single-cell lag time of foodborne pathogens.

    PubMed

    Blana, Vasiliki A; Lianou, Alexandra; Nychas, George-John E

    2015-12-23

    The objective of this study was the in vitro evaluation of the effect of a cell-free microbial supernatant, produced by a luxS-positive Salmonella enterica ser. Typhimurium strain, on the single-cell growth kinetic behavior of two strains of S. enterica (serotypes Enteritidis and Typhimurium) and a methicillin-resistant Staphylococcus aureus strain. The single-cell lag time (λ) of the pathogens was estimated in the absence and presence (20% v/v) of microbial supernatant based on optical density measurements. As demonstrated by the obtained results, the tested microbial supernatant had a strain-specific effect on the single-cell λ and its variability. Although the mean λ values were similar in the absence and presence of microbial supernatant in the case of Salmonella Enteritidis, a significant (P ≤ 0.05) reduction and increase in the mean value of this parameter in the presence of microbial supernatant were observed for Salmonella Typhimurium and St. aureus, respectively. With regard to the effect of the tested microbial supernatant on the single-cell variability of λ, similar λ distributions were obtained in its absence and presence for S. Enteritidis, while considerable differences were noted for the other two tested organisms; the coefficient of variation of λ in the absence and presence of microbial supernatant was 41.6 and 69.8% for S. Typhimurium, respectively, with the corresponding values for St. aureus being 74.0 and 56.9%. As demonstrated by the results of bioassays, the tested microbial supernatant exhibited autoinducer-2 activity, indicating a potential association of such quorum sensing compounds with the observed effects. Although preliminary in nature, the collected data provide a good basis for future research on the role of quorum sensing in the single-cell growth behavior of foodborne pathogens.

  2. Analysis of antimicrobial resistance genes detected in multidrug-resistant Salmonella enterica serovar Typhimurium isolated from food animals.

    PubMed

    Glenn, LaShanda M; Lindsey, Rebecca L; Frank, Joseph F; Meinersmann, Richard J; Englen, Mark D; Fedorka-Cray, Paula J; Frye, Jonathan G

    2011-09-01

    Multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium is the most prevalent penta-resistant serovar isolated from animals by the U.S. National Antimicrobial Resistance Monitoring System. Penta-resistant isolates are often resistant to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline. To investigate MDR in Salmonella Typhimurium (including variant 5-), one isolate each from cattle, poultry, and swine with at least the ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline phenotype were selected for each year from 1997 to 2007 (n = 33) for microarray analysis of antimicrobial resistance, incompatibility IncA/C, and HI1 plasmid genes. Cluster analysis based on these data separated 31 of the isolates into two groups A and B (15 and 16 isolates, respectively). Isolates in group A were phage type DT104 or U302 and were mostly swine isolates (7/15). Genes detected included intI1, bla(PSE-1), floR, aadA, sulI, tet(G), and tetR, which are often found in Salmonella Genomic Island I. Isolates in group B had numerous IncA/C plasmid genes detected and were mostly cattle isolates (9/16). Genes detected included bla(CMY-2), floR, aac(3), aadA, aphA1, strA, strB, sulI, sulII, dfrA, dhf, tet(A)(B)(C)(D), and tetR, which are often found on MDR-AmpC IncA/C plasmids. The IncA/C replicon was also detected in all group B isolates. The two remaining isolates did not cluster with any others and both had many HI1 plasmid genes detected. Linkage disequilibrium analysis detected significant associations between plasmid replicon type, phage type, and animal source. These data suggest that MDR in Salmonella Typhimurium is associated with DT104/Salmonella Genomic Island I or IncA/C MDR-AmpC encoding plasmids and these genetic elements have persisted throughout the study period.

  3. Aminoimidazole Carboxamide Ribotide Exerts Opposing Effects on Thiamine Synthesis in Salmonella enterica

    PubMed Central

    Bazurto, Jannell V.; Heitman, Nicholas J.

    2015-01-01

    ABSTRACT In Salmonella enterica, the thiamine biosynthetic intermediate 5-aminoimidazole ribotide (AIR) can be synthesized de novo independently of the early purine biosynthetic reactions. This secondary route to AIR synthesis is dependent on (i) 5-amino-4-imidazolecarboxamide ribotide (AICAR) accumulation, (ii) a functional phosphoribosylaminoimidazole-succinocarboxamide (SAICAR) synthetase (PurC; EC 6.3.2.6), and (iii) methionine and lysine in the growth medium. Studies presented here show that AICAR is a direct precursor to AIR in vivo. PurC-dependent conversion of AICAR to AIR was recreated in vitro. Physiological studies showed that exogenous nutrients (e.g., methionine and lysine) antagonize the inhibitory effects of AICAR on the ThiC reaction and decreased the cellular thiamine requirement. Finally, genetic results identified multiple loci that impacted the effect of AICAR on thiamine synthesis and implicated cellular aspartate levels in AICAR-dependent AIR synthesis. Together, the data here clarify the mechanism that allows conditional growth of a strain lacking the first five biosynthetic enzymes, and they provide additional insights into the complexity of the metabolic network and its plasticity. IMPORTANCE In bacteria, the pyrimidine moiety of thiamine is derived from aminoimidazole ribotide (AIR), an intermediate in purine biosynthesis. A previous study described conditions under which AIR synthesis is independent of purine biosynthesis. This work is an extension of that previous study and describes a new synthetic pathway to thiamine that depends on a novel thiamine precursor and a secondary activity of the biosynthetic enzyme PurC. These findings provide mechanistic details of redundancy in the synthesis of a metabolite that is essential for nucleotide and coenzyme biosynthesis. Metabolic modifications that allow the new pathway to function or enhance it are also described. PMID:26100042

  4. Human Milk Mucin 1 and Mucin 4 Inhibit Salmonella enterica Serovar Typhimurium Invasion of Human Intestinal Epithelial Cells In Vitro123

    PubMed Central

    Liu, Bo; Yu, Zhuoteng; Chen, Ceng; Kling, David E.; Newburg, David S.

    2012-01-01

    Many human milk glycans inhibit pathogen binding to host receptors and their consumption by infants is associated with reduced risk of disease. Salmonella infection is more frequent among infants than among the general population, but the incidence is lower in breast-fed babies, suggesting that human milk could contain components that inhibit Salmonella. This study aimed to test whether human milk per se inhibits Salmonella invasion of human intestinal epithelial cells in vitro and, if so, to identify the milk components responsible for inhibition. Salmonella enterica serovar Typhimurium SL1344 (SL1344) invasion of FHs 74 Int and Caco-2 cells were the models of human intestinal epithelium infection. Internalization of fluorescein-5-isothiocyanate–labeled SL1344 into intestinal cells was measured by flow cytometry to quantify infection. Human milk and its fractions inhibited infection; the inhibitory activity localized to the high molecular weight glycans. Mucin 1 and mucin 4 were isolated to homogeneity. At 150 μg/L, a typical concentration in milk, human milk mucin 1 and mucin 4 inhibited SL1344 invasion of both target cell types. These mucins inhibited SL1344 invasion of epithelial cells in a dose-dependent manner. Thus, mucins may prove useful as a basis for developing novel oral prophylactic and therapeutic agents that inhibit infant diseases caused by Salmonella and related pathogens. PMID:22718031

  5. Inhibition of the early stage of Salmonella enterica serovar Enteritidis biofilm development on stainless steel by cell-free supernatant of a Hafnia alvei culture.

    PubMed

    Chorianopoulos, Nikos G; Giaouris, Efstathios D; Kourkoutas, Yiannis; Nychas, George-John E

    2010-03-01

    Compounds present in Hafnia alvei cell-free culture supernatant cumulatively negatively influence the early stage of biofilm development by Salmonella enterica serovar Enteritidis on stainless steel while they also reduce the overall metabolic activity of S. Enteritidis planktonic cells. Although acylhomoserine lactones (AHLs) were detected among these compounds, the use of several synthetic AHLs was not able to affect the initial stage of biofilm formation by this pathogen.

  6. Low-Shear modeled microgravity alters the Salmonella enterica serovar typhimurium stress response in an RpoS-independent manner

    NASA Technical Reports Server (NTRS)

    Wilson, James W.; Ott, C. Mark; Ramamurthy, Rajee; Porwollik, Steffen; McClelland, Michael; Pierson, Duane L.; Nickerson, Cheryl A.

    2002-01-01

    We have previously demonstrated that low-shear modeled microgravity (low-shear MMG) serves to enhance the virulence of a bacterial pathogen, Salmonella enterica serovar Typhimurium. The Salmonella response to low-shear MMG involves a signaling pathway that we have termed the low-shear MMG stimulon, though the identities of the low-shear MMG stimulon genes and regulatory factors are not known. RpoS is the primary sigma factor required for the expression of genes that are induced upon exposure to different environmental-stress signals and is essential for virulence in mice. Since low-shear MMG induces a Salmonella acid stress response and enhances Salmonella virulence, we reasoned that RpoS would be a likely regulator of the Salmonella low-shear MMG response. Our results demonstrate that low-shear MMG provides cross-resistance to several environmental stresses in both wild-type and isogenic rpoS mutant strains. Growth under low-shear MMG decreased the generation time of both strains in minimal medium and increased the ability of both strains to survive in J774 macrophages. Using DNA microarray analysis, we found no evidence of induction of the RpoS regulon by low-shear MMG but did find that other genes were altered in expression under these conditions in both the wild-type and rpoS mutant strains. Our results indicate that, under the conditions of these studies, RpoS is not required for transmission of the signal that induces the low-shear MMG stimulon. Moreover, our studies also indicate that low-shear MMG can be added to a short list of growth conditions that can serve to preadapt an rpoS mutant for resistance to multiple environmental stresses.

  7. Characterization of Salmonella enterica isolates causing bacteremia in Lima, Peru, using multiple typing methods

    PubMed Central

    Betancor, Laura; García, Coralith; Astocondor, Lizeth; Hinostroza, Noemí; Bisio, Julieta; Rivera, Javier; Perezgasga, Lucía; Pérez Escanda, Victoria; Yim, Lucía; Jacobs, Jan; García-del Portillo, Francisco; Chabalgoity, José A.; Puente, José L.

    2017-01-01

    In this study, different molecular typing tools were applied to characterize 95 Salmonella enterica blood isolates collected between 2008 and 2013 from patients at nine public hospitals in Lima, Peru. Combined results of multiplex PCR serotyping, two- and seven-loci multilocus sequence typing (MLST) schemes, serotyping, IS200 amplification and RAPD fingerprints, showed that these infections were caused by eight different serovars: Enteritidis, Typhimurium, Typhi, Choleraesuis, Dublin, Paratyphi A, Paratyphi B and Infantis. Among these, Enteritidis, Typhimurium and Typhi were the most prevalent, representing 45, 36 and 11% of the isolates, respectively. Most isolates (74%) were not resistant to ten primarily used antimicrobial drugs; however, 37% of the strains showed intermediate susceptibility to ciprofloxacin (ISC). Antimicrobial resistance integrons were carried by one Dublin (dfra1 and aadA1) and two Infantis (aadA1) isolates. The two Infantis isolates were multidrug resistant and harbored a large megaplasmid. Amplification of spvC and spvRA regions showed that all Enteritidis (n = 42), Typhimurium (n = 34), Choleraesuis (n = 3) and Dublin (n = 1) isolates carried the Salmonella virulence plasmid (pSV). We conclude that the classic serotyping method can be substituted by the multiplex PCR and, when necessary, sequencing of only one or two loci of the MLST scheme is a valuable tool to confirm the results. The effectiveness and feasibility of different typing tools is discussed. PMID:29267322

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

    PubMed

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

    2016-01-01

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

  9. [Salmonella spp. strains resistant to drugs].

    PubMed

    Białucha, Agata; Kozuszko, Sylwia; Gospodarek, Eugenia

    2010-01-01

    The aim of the study was retrospective analysis of Salmonella spp. strains isolated from patients of State Infectious Diseases Observatory Hospital of T. Browicz in Bydgoszcz (SZAK) and University of dr. A. Jurasz in Bydgoszcz (SU CM UMK) in 2006-2009. The percentages of Salmonella spp. strains resistant to at least one drug were: 19,0% in 2006, 12,5% in 2007, 50,6% in 2008 and 43,8% in the first half of 2009 year. The highest number of Salmonella spp. strains resistant to drugs were isolated from stool (96,7%) and from patients of SZAK (83,3%). Among all isolated Salmonella spp. strains resistant to drugs the highest percentage were S. enterica serovar Enteritidis (56,7%). Among S. enterica bacilli predominated resitant phenotypes to ampicillin, amoxicillin, chloramphenicol and nalidixic acid. The increasing number of strains resistant to ciprofloxacin (0,0 - 26,7%) and high percentage of strains resistant to nalidixic acid (97,3%) were noted. Decreasing resistance to chloramphenicol was observed in our study (54,5 - 14,3%).

  10. Inactivation of Salmonella enterica in chicken feces on the surface of eggshells by simultaneous treatments with gaseous chlorine dioxide and mild wet heat.

    PubMed

    Park, Sunhyung; Beuchat, Larry R; Kim, Hoikyung; Ryu, Jee-Hoon

    2017-04-01

    The aim of this study was to investigate the lethal effects of simultaneous treatments with gaseous chlorine dioxide (ClO 2 ) and mild wet heat (55 °C at 100% relative humidity [RH]) on Salmonella enterica in chicken feces on the surface of eggshells. Gaseous ClO 2 production decreased significantly (P ≤ 0.05) as the RH (23, 43, 68, 85, and 100%) at 25 °C was increased. The lethality of gaseous ClO 2 against S. enterica in feces on eggshells increased significantly (P ≤ 0.05) as RH increased. For example, when treated with gaseous ClO 2 at 85 and 100% RH at 25 °C, S. enterica (5.9 log CFU/egg) was inactivated within 4 h. In contrast, at 23, 43, and 68% RH, the pathogen remained at 5.1, 5.0, and 2.8 log CFU/egg, respectively, after 6 h. Finally, when eggshells surface-contaminated with S. enterica (5.8 log CFU/egg) were treated with gaseous ClO 2 (peak concentration of ClO 2 : 185.6 ppm) at 100% RH and 55 °C, inactivation occurred within 1 h. These results indicate that treatment of surface-contaminated shell eggs with gaseous ClO 2 at elevated RH and temperature is effective in inactivating S. enterica. These observations will be useful when developing an effective sanitation program to enhance the microbiological safety of shell eggs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Antimicrobial Resistance among Invasive Nontyphoidal Salmonella enterica Isolates in the United States: National Antimicrobial Resistance Monitoring System, 1996 to 2007 ▿

    PubMed Central

    Crump, John A.; Medalla, Felicita M.; Joyce, Kevin W.; Krueger, Amy L.; Hoekstra, R. Michael; Whichard, Jean M.; Barzilay, Ezra J.

    2011-01-01

    Nontyphoidal salmonellae (NTS) are important causes of community-acquired bloodstream infection. We describe patterns of antimicrobial resistance among invasive NTS in the United States. We compared bloodstream NTS isolates with those from stool submitted to the National Antimicrobial Resistance Monitoring System (NARMS) from 1996 to 2007. We describe antimicrobial resistance among invasive strains by serogroup and serotype. Of the 19,302 NTS isolates, 17,804 (92.2%) were from stool or blood. Of these, 1,050 (5.9%) were bloodstream isolates. The median ages (ranges) of patients with and without bacteremia were 36 (<1 to 97) years and 20 (<1 to 105) years, respectively (P < 0.001). Males (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.06 to 1.38) and those ≥65 years of age were at greater risk for invasive disease. Salmonella enterica serotypes Enteritidis, Typhimurium, and Heidelberg were the most common serotypes isolated from blood; S. enterica serotypes Dublin, Sandiego, and Schwarzengrund were associated with the greatest risk for bloodstream isolation. Of invasive isolates, 208 (19.8%) were resistant to ampicillin, 117 (11.1%) to chloramphenicol, and 26 (2.5%) to trimethoprim-sulfamethoxazole; 28 (2.7%) isolates were resistant to nalidixic acid and 26 (2.5%) to ceftriaxone. Antimicrobial resistance to traditional agents is common. However, the occurrence of nalidixic acid and ceftriaxone resistance among invasive NTS is cause for clinical and public health vigilance. PMID:21199924

  12. Electron-beam-inactivated vaccine against Salmonella enteritidis colonization in molting hens

    USDA-ARS?s Scientific Manuscript database

    Electron Beam (eBeam) ionization technology has a variety of applications in modern society. The underlying hypothesis was that electron beam (eBeam) inactivated Salmonella enterica serovar Enteritidis (SE) cells can serve as a vaccine to control Salmonella colonization and Salmonella shedding in c...

  13. Modulation of systemic and mucosal immunity against an inactivated vaccine of Newcastle disease virus by oral co-administration of live attenuated Salmonella enterica serovar Typhimurium expressing chicken interleukin-18 and interferon-α

    PubMed Central

    RAHMAN, Md. Masudur; UYANGAA, Erdenebelig; HAN, Young Woo; HUR, Jin; PARK, Sang-Youel; LEE, John Hwa; KIM, Koanhoi; EO, Seong Kug

    2014-01-01

    Newcastle disease (ND) is a highly contagious disease of chickens causing significant economic losses worldwide. Due to limitations in the efficacy against currently circulating ND viruses, existing vaccination strategies require improvements, and incorporating immunomodulatory cytokines with existing vaccines might be a novel approach. Here, we investigated the systemic and mucosal immunomodulatory properties of oral co-administration of chicken interleukin-18 (chIL-18) and chicken interferon-α (chIFN-α) using attenuated Salmonella enterica serovar Typhimurium on an inactivated ND vaccine. Our results demonstrate that oral administration of S. enterica serovar Typhimurium expressing chIL-18 or chIFN-α provided enhanced systemic and mucosal immune responses, as determined by serum hemagglutination inhibition antibody and NDV Ag-specific IgG as well as NDV Ag-specific IgA in lung and duodenal lavages of chickens immunized with inactivated ND vaccine via the intramuscular or intranasal route. Notably, combined oral administration of S. enterica serovar Typhimurium expressing chIL-18 and chIFN-α significantly enhanced systemic and mucosal immunity in ND-vaccinated chickens, compared to single administration of S. enterica serovar Typhimurium expressing chIL-18 or chIFN-α. In addition, oral co-administration of S. enterica serovar Typhimurium expressing chIL-18 and chIFN-α provided enhanced NDV Ag-specific proliferation of peripheral blood mononuclear cells and Th1-biased cell-mediated immunity, compared to single administration of either construct. Therefore, our results provide valuable insight into the modulation of systemic and mucosal immunity by incorporation of immunomodulatory chIL-18 and chIFN-α using Salmonella vaccines into existing ND vaccines. PMID:25502364

  14. Ultra-Fast and Sensitive Detection of Non-Typhoidal Salmonella Using Microwave-Accelerated Metal-Enhanced Fluorescence (“MAMEF”)

    PubMed Central

    Galen, James E.; Geddes, Chris D.; Levine, Myron M.

    2011-01-01

    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). PMID:21494634

  15. Fast and efficient three-step target-specific curing of a virulence plasmid in Salmonella enterica.

    PubMed

    de Moraes, Marcos H; Teplitski, Max

    2015-12-01

    Virulence plasmids borne by serovars of Salmonella enterica carry genes involved in its pathogenicity, as well as other functions. Characterization of phenotypes associated with virulence plasmids requires a system for efficiently curing strains of their virulence plasmids. Here, we developed a 3-step protocol for targeted curing of virulence plasmids. The protocol involves insertion of an I-SecI restriction site linked to an antibiotic resistance gene into the target plasmid using λ-Red mutagenesis, followed by the transformation with a temperature-sensitive auxiliary plasmid which carries I-SecI nuclease expressed from a tetracycline-inducible promoter. Finally, the auxiliary plasmid is removed by incubation at 42 °C and the plasmid-less strains are verified on antibiotic-containing media. This method is fast and very efficient: over 90 % of recovered colonies lacked their virulence plasmid.

  16. Reduction of Salmonella enterica on alfalfa seeds with acidic electrolyzed oxidizing water and enhanced uptake of acidic electrolyzed oxidizing water into seeds by gas exchange.

    PubMed

    Stan, Silvia D; Daeschel, Mark A

    2003-11-01

    Alfalfa sprouts have been implicated in several salmonellosis outbreaks in recent years. The disinfectant effects of acidic electrolyzed oxidizing (EO) water against Salmonella enterica both in an aqueous system and on artificially contaminated alfalfa seeds were determined. The optimum ratio of seeds to EO water was determined in order to maximize the antimicrobial effect of EO water. Seeds were combined with EO water at ratios (wt/vol) of 1:4, 1:10, 1:20, 1:40, and 1:100, and the characteristics of EO water (pH, oxidation reduction potential [ORP], and free chlorine concentration) were determined. When the ratio of seeds to EO water was increased from 1:4 to 1:100, the pH decreased from 3.82 to 2.63, while the ORP increased from +455 to +1,073 mV. EO water (with a pH of 2.54 to 2.38 and an ORP of +1,083 to +1,092 mV) exhibited strong potential for the inactivation of S. enterica in an aqueous system (producing a reduction of at least 6.6 log CFU/ml). Treatment of artificially contaminated alfalfa seeds with EO water at a seed-to-EO water ratio of 1:100 for 15 and 60 min significantly reduced Salmonella populations by 2.04 and 1.96 log CFU/g, respectively (P < 0.05), while a Butterfield's buffer wash decreased Salmonella populations by 0.18 and 0.23 log CFU/g, respectively. After treatment, EO water was Salmonella negative by enrichment with or without neutralization. Germination of seeds was not significantly affected (P > 0.05) by treatment for up to 60 min in electrolyzed water. The uptake of liquid into the seeds was influenced by the internal gas composition (air, N2, or O2) of seeds before the liquid was added.

  17. A multiplex real-time PCR assay for the identification and differentiation of Salmonella enterica serovar Typhimurium and monophasic serovar 4,[5],12:i:-.

    PubMed

    Prendergast, Deirdre M; Hand, Darren; Nί Ghallchóir, Eadaoin; McCabe, Evonne; Fanning, Seamus; Griffin, Margaret; Egan, John; Gutierrez, Montserrat

    2013-08-16

    Salmonella enterica subsp. enterica serovar 4,[5],12:i:- is considered to be a monophasic variant of Salmonella Typhimurium and is increasingly associated with human infections. The use of PCR for the unequivocal identification of strains identified by conventional serotyping as 4,[5],12:i:- has been recommended by the European Food Safety Authority (EFSA), in particular the conventional multiplex PCR developed by Tennant et al. (2010). An alternative protocol for the identification and differentiation of S. Typhimurium and S. Typhimurium-like strains, including its monophasic variants, based on a multiplex real-time PCR assay was developed in our laboratory. A panel of 206 Salmonella strains was used to validate our multiplex real-time PCR against the conventional multiplex PCR recommended by EFSA, i.e. 43 Salmonella strains of serovars other than Typhimurium and 163 routine isolates determined by slide agglutination serotyping to have an incomplete antigenic formula compatible with the S. Typhimurium formula 4,[5],12:i:1,2. Both methods correctly identified the 43 Salmonella strains as non S. Typhimurium. Among the 163 isolates of undetermined serovar by conventional serotyping, both PCR protocols identified 54 isolates as S. Typhimurium, 101 as monophasic S. Typhimurium and 8 as non-S. Typhimurium. Twenty isolates phenotypically lacking the phase-2 H antigen were positive for the fljB.1,2 gene. These strains have been recently described in the literature by other workers and have been referred to as "inconsistent" variants of S. Typhimurium. Antimicrobial resistance and phage typing were also performed on the S. Typhimurium isolates, including monophasic variants, and approximately half of the isolates identified as monophasic S. Typhimurium by our multiplex real-time PCR protocol were DT193 with the resistance pattern ASSuT. There was 100% concordance between the conventional PCR and the multiplex real-time PCR method developed in this study which proved that

  18. Whole-Genome Sequencing Analysis of Salmonella enterica Serovar Enteritidis Isolates in Chile Provides Insights into Possible Transmission between Gulls, Poultry, and Humans

    PubMed Central

    Ayers, Sherry; Barreto, Marlen; Allard, Marc; Brown, Eric W.

    2016-01-01

    ABSTRACT Salmonella enterica subsp. enterica serotype Enteritidis is a major cause of human salmonellosis worldwide; however, little is known about the genetic relationships between S. Enteritidis clinical strains and S. Enteritidis strains from other sources in Chile. We compared the whole genomes of 30 S. Enteritidis strains isolated from gulls, domestic chicken eggs, and humans in Chile, to investigate their phylogenetic relationships and to establish their relatedness to international strains. Core genome multilocus sequence typing (cgMLST) analysis showed that only 246/4,065 shared loci differed among these Chilean strains, separating them into two clusters (I and II), with cluster II being further divided into five subclusters. One subcluster (subcluster 2) contained strains from all surveyed sources that differed at 1 to 18 loci (of 4,065 loci) with 1 to 18 single-nucleotide polymorphisms (SNPs), suggesting interspecies transmission of S. Enteritidis in Chile. Moreover, clusters were formed by strains that were distant geographically, which could imply that gulls might be spreading the pathogen throughout the country. Our cgMLST analysis, using other S. Enteritidis genomes available in the National Center for Biotechnology Information (NCBI) database, showed that S. Enteritidis strains from Chile and the United States belonged to different lineages, which suggests that S. Enteritidis regional markers might exist and could be used for trace-back investigations. IMPORTANCE This study highlights the importance of gulls in the spread of Salmonella Enteritidis in Chile. We revealed a close genetic relationship between some human and gull S. Enteritidis strains (with as few as 2 of 4,065 genes being different), and we also found that gull strains were present in clusters formed by strains isolated from other sources or distant locations. Together with previously published evidence, this suggests that gulls might be spreading this pathogen between different regions

  19. Lactic acid bacteria and bifidobacteria attenuate the proinflammatory response in intestinal epithelial cells induced by Salmonella enterica serovar Typhimurium.

    PubMed

    Carey, Christine M; Kostrzynska, Magdalena

    2013-01-01

    Inflammation is a physiological response to infections and tissue injury; however, abnormal immune responses can give rise to chronic inflammation and contribute to disease progression. Various dietary components, including probiotic lactic acid bacteria and prebiotics, have the potential to modulate intestinal inflammatory responses. One factor in particular, the chemokine interleukin-8 (IL-8, CXCL-8), is one of the major mediators of the inflammatory response. The purpose of this study was to investigate modulation of the inflammatory host response induced by Salmonella enterica serovar Typhimurium DT104 in the presence of selected probiotics and lactic acid bacteria (LAB) isolated from human sources, dairy products, and farm animals. IL-8 gene expression and protein production in HT-29 cells were evaluated by real-time PCR and ELISA, respectively. Pre-incubation of HT-29 cells with Lactobacillus kefir IM002, Bifidobacterium adolescentis FRP 61, Bifidobacterium longum FRP 68 and FRP 69, Bifidobacterium breve FRP 334, and Leuconostoc mesenteroides IM080 significantly inhibited IL-8 secretion induced by Salmonella Typhimurium DT104. Co-culture of selected probiotics and Salmonella Typhimurium DT104 reduced IL-8 production, while potential probiotics and LAB had no effect on IL-8 secretion in HT-29 cells preincubated with Salmonella Typhimurium DT104 prior to adding probiotics. Lactobacillus kefir IM002 supernatant also significantly reduced IL-8 production. In conclusion, our study suggests that probiotic bifidobacteria and LAB modulate cytokine induction and possess anti-inflammatory properties; however, the effectiveness is strain dependent.

  20. A Mutation in the Putative Lysl-tRNA Synthetase Gene, PoxR of Salmonella enterica Serovar Typhimurium Results in Altered Protein Production, Elevated Susceptibility to Environmental Challenges and Decreased Swine Colonization

    USDA-ARS?s Scientific Manuscript database

    Using signature-tagged mutagenesis, a mutation in the poxR gene of Salmonella enterica serovar Typhimurium was identified with decreased survival in an ex vivo swine stomach content assay(Bearson et al. Appl Environ Microbiol. 72:2829-36). Gastrointestinal colonization and fecal shedding of the pox...