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Sample records for intracellular salmonella enterica

  1. Salmonella enterica.

    USDA-ARS?s Scientific Manuscript database

    Avian Salmonella infections are important as both a cause of clinical disease in poultry and as a source of food-borne transmission of disease to humans. Host-adapted salmonellae (Salmonella enterica serovar Pullorum and Gallinarum) are responsible for severe systemic diseases, whereas numerous sero...

  2. Proteomes of Host Cell Membranes Modified by Intracellular Activities of Salmonella enterica*

    PubMed Central

    Vorwerk, Stephanie; Krieger, Viktoria; Deiwick, Jörg; Hensel, Michael; Hansmeier, Nicole

    2015-01-01

    Intracellular pathogens need to establish a growth-stimulating host niche for survival and replication. A unique feature of the gastrointestinal pathogen Salmonella enterica serovar Typhimurium is the creation of extensive membrane networks within its host. An understanding of the origin and function of these membranes is crucial for the development of new treatment strategies. However, the characterization of this compartment is very challenging, and only fragmentary knowledge of its composition and biogenesis exists. Here, we describe a new proteome-based approach to enrich and characterize Salmonella-modified membranes. Using a Salmonella mutant strain that does not form this unique membrane network as a reference, we identified a high-confidence set of host proteins associated with Salmonella-modified membranes. This comprehensive analysis allowed us to reconstruct the interactions of Salmonella with host membranes. For example, we noted that Salmonella redirects endoplasmic reticulum (ER) membrane trafficking to its intracellular niche, a finding that has not been described for Salmonella previously. Our system-wide approach therefore has the potential to rapidly close gaps in our knowledge of the infection process of intracellular pathogens and demonstrates a hitherto unrecognized complexity in the formation of Salmonella host niches. PMID:25348832

  3. Role of Host Cell-Derived Amino Acids in Nutrition of Intracellular Salmonella enterica

    PubMed Central

    Popp, Jasmin; Noster, Janina; Busch, Kim; Kehl, Alexander; zur Hellen, Gero

    2015-01-01

    The facultative intracellular pathogen Salmonella enterica resides in a specific membrane-bound compartment termed the Salmonella-containing vacuole (SCV). Despite being segregated from access to metabolites in the host cell cytosol, Salmonella is able to efficiently proliferate within the SCV. We set out to unravel the nutritional supply of Salmonella in the SCV with focus on amino acids. We studied the availability of amino acids by the generation of auxotrophic strains for alanine, asparagine, aspartate, glutamine, and proline in a macrophage cell line (RAW264.7) and an epithelial cell line (HeLa) and examined access to extracellular nutrients for nutrition. Auxotrophies for alanine, asparagine, or proline attenuated intracellular replication in HeLa cells, while aspartate, asparagine, or proline auxotrophies attenuated intracellular replication in RAW264.7 macrophages. The different patterns of intracellular attenuation of alanine- or aspartate-auxotrophic strains support distinct nutritional conditions in HeLa cells and RAW264.7 macrophages. Supplementation of medium with individual amino acids restored the intracellular replication of mutant strains auxotrophic for asparagine, proline, or glutamine. Similarly, a mutant strain deficient in succinate dehydrogenase was complemented by the extracellular addition of succinate. Complementation of the intracellular replication of auxotrophic Salmonella by external amino acids was possible if bacteria were proficient in the induction of Salmonella-induced filaments (SIFs) but failed in a SIF-deficient background. We propose that the ability of intracellular Salmonella to redirect host cell vesicular transport provides access of amino acids to auxotrophic strains and, more generally, is essential to continuously supply bacteria within the SCV with nutrients. PMID:26351287

  4. Role of host cell-derived amino acids in nutrition of intracellular Salmonella enterica.

    PubMed

    Popp, Jasmin; Noster, Janina; Busch, Kim; Kehl, Alexander; Zur Hellen, Gero; Hensel, Michael

    2015-12-01

    The facultative intracellular pathogen Salmonella enterica resides in a specific membrane-bound compartment termed the Salmonella-containing vacuole (SCV). Despite being segregated from access to metabolites in the host cell cytosol, Salmonella is able to efficiently proliferate within the SCV. We set out to unravel the nutritional supply of Salmonella in the SCV with focus on amino acids. We studied the availability of amino acids by the generation of auxotrophic strains for alanine, asparagine, aspartate, glutamine, and proline in a macrophage cell line (RAW264.7) and an epithelial cell line (HeLa) and examined access to extracellular nutrients for nutrition. Auxotrophies for alanine, asparagine, or proline attenuated intracellular replication in HeLa cells, while aspartate, asparagine, or proline auxotrophies attenuated intracellular replication in RAW264.7 macrophages. The different patterns of intracellular attenuation of alanine- or aspartate-auxotrophic strains support distinct nutritional conditions in HeLa cells and RAW264.7 macrophages. Supplementation of medium with individual amino acids restored the intracellular replication of mutant strains auxotrophic for asparagine, proline, or glutamine. Similarly, a mutant strain deficient in succinate dehydrogenase was complemented by the extracellular addition of succinate. Complementation of the intracellular replication of auxotrophic Salmonella by external amino acids was possible if bacteria were proficient in the induction of Salmonella-induced filaments (SIFs) but failed in a SIF-deficient background. We propose that the ability of intracellular Salmonella to redirect host cell vesicular transport provides access of amino acids to auxotrophic strains and, more generally, is essential to continuously supply bacteria within the SCV with nutrients. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. Salmonella enterica serovar Typhimurium RamA, intracellular oxidative stress response, and bacterial virulence.

    PubMed

    van der Straaten, Tahar; Zulianello, Laurence; van Diepen, Angela; Granger, Donald L; Janssen, Riny; van Dissel, Jaap T

    2004-02-01

    Escherichia coli and Salmonella enterica serovar Typhimurium have evolved genetic systems, such as the soxR/S and marA regulons, to detoxify reactive oxygen species, like superoxide, which are formed as by-products of metabolism. Superoxide also serves as a microbicidal effector mechanism of the host's phagocytes. Here, we investigate whether regulatory genes other than soxR/S and marA are active in response to oxidative stress in Salmonella and may function as virulence determinants. We identified a bacterial gene, which was designated ramA (342 bp) and mapped at 13.1 min on the Salmonella chromosome, that, when overexpressed on a plasmid in E. coli or Salmonella, confers a pleiotropic phenotype characterized by increased resistance to the redox-cycling agent menadione and to multiple unrelated antibiotics. The ramA gene is present in Salmonella serovars but is absent in E. coli. The gene product displays 37 to 52% homology to the transcriptional activators soxR/S and marA and 80 to 100% identity to a multidrug resistance gene in Klebsiella pneumoniae and Salmonella enterica serovar Paratyphi A. Although a ramA soxR/S double null mutant is highly susceptible to intracellular superoxide generated by menadione and displays decreased Mn-superoxide dismutase activity, intracellular survival of this mutant within macrophage-like RAW 264.7 cells and in vivo replication in the spleens in Ityr mice are not affected. We concluded that despite its role in the protective response of the bacteria to oxidative stress in vitro, the newly identified ramA gene, together with soxR/S, does not play a role in initial replication of Salmonella in the organs of mice.

  6. Salmonella enterica Serovar Typhimurium Response Involved in Attenuation of Pathogen Intracellular Proliferation

    PubMed Central

    Cano, David A.; Martínez-Moya, Marina; Pucciarelli, M. Graciela; Groisman, Eduardo A.; Casadesús, Josep; García-Del Portillo, Francisco

    2001-01-01

    Salmonella enterica serovar Typhimurium proliferates within cultured epithelial and macrophage cells. Intracellular bacterial proliferation is, however, restricted within normal fibroblast cells. To characterize this phenomenon in detail, we investigated the possibility that the pathogen itself might contribute to attenuating the intracellular growth rate. S. enterica serovar Typhimurium mutants were selected in normal rat kidney fibroblasts displaying an increased intracellular proliferation rate. These mutants harbored loss-of-function mutations in the virulence-related regulatory genes phoQ, rpoS, slyA, and spvR. Lack of a functional PhoP-PhoQ system caused the most dramatic change in the intracellular growth rate. phoP- and phoQ-null mutants exhibited an intracellular growth rate 20- to 30-fold higher than that of the wild-type strain. This result showed that the PhoP-PhoQ system exerts a master regulatory function for preventing bacterial overgrowth within fibroblasts. In addition, an overgrowing clone was isolated harboring a mutation in a previously unknown serovar Typhimurium open reading frame, named igaA for intracellular growth attenuator. Mutations in other serovar Typhimurium virulence genes, such as ompR, dam, crp, cya, mviA, spiR (ssrA), spiA, and rpoE, did not result in pathogen intracellular overgrowth. Nonetheless, lack of either SpiA or the alternate sigma factor RpoE led to a substantial decrease in intracellular bacterial viability. These results prove for the first time that specific serovar Typhimurium virulence regulators are involved in a response designed to attenuate the intracellular growth rate within a nonphagocytic host cell. This growth-attenuating response is accompanied by functions that ensure the viability of intracellular bacteria. PMID:11553591

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

    PubMed

    Szeto, Jason; Brumell, John H

    2005-11-01

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

  8. Dormant Intracellular Salmonella enterica Serovar Typhimurium Discriminates among Salmonella Pathogenicity Island 2 Effectors To Persist inside Fibroblasts

    PubMed Central

    Núñez-Hernández, Cristina; Alonso, Ana; Pucciarelli, M. Graciela; Casadesús, Josep

    2014-01-01

    Salmonella enterica uses effector proteins delivered by type III secretion systems (TTSS) to colonize eukaryotic cells. Recent in vivo studies have shown that intracellular bacteria activate the TTSS encoded by Salmonella pathogenicity island-2 (SPI-2) to restrain growth inside phagocytes. Growth attenuation is also observed in vivo in bacteria colonizing nonphagocytic stromal cells of the intestinal lamina propria and in cultured fibroblasts. SPI-2 is required for survival of nongrowing bacteria persisting inside fibroblasts, but its induction mode and the effectors involved remain unknown. Here, we show that nongrowing dormant intracellular bacteria use the two-component system OmpR-EnvZ to induce SPI-2 expression and the PhoP-PhoQ system to regulate the time at which induction takes place, 2 h postentry. Dormant bacteria were shown to discriminate the usage of SPI-2 effectors. Among the effectors tested, SseF, SseG, and SseJ were required for survival, while others, such as SifA and SifB, were not. SifA and SifB dispensability correlated with the inability of intracellular bacteria to secrete these effectors even when overexpressed. Conversely, SseJ overproduction resulted in augmented secretion and exacerbated bacterial growth. Dormant bacteria produced other effectors, such as PipB and PipB2, that, unlike what was reported for epithelial cells, did not to traffic outside the phagosomal compartment. Therefore, permissiveness for secreting only a subset of SPI-2 effectors may be instrumental for dormancy. We propose that the S. enterica serovar Typhimurium nonproliferative intracellular lifestyle is sustained by selection of SPI-2 effectors that are produced in tightly defined amounts and delivered to phagosome-confined locations. PMID:24144726

  9. Functional dissection of SseF, a membrane-integral effector protein of intracellular Salmonella enterica.

    PubMed

    Müller, Petra; Chikkaballi, Deepak; Hensel, Michael

    2012-01-01

    During intracellular life, the bacterial pathogen Salmonella enterica translocates a complex cocktail of effector proteins by means of the SPI2-encoded type III secretions system. The effectors jointly modify the endosomal system and vesicular transport in host cells. SseF and SseG are two effectors encoded by genes within Salmonella Pathogenicity Island 2 and both effector associate with endosomal membranes and microtubules and are involved in the formation of Salmonella-induced filaments. Our previous deletional analyses identified protein domains of SseF required for the effector function. Here we present a detailed mutational analysis that identifies a short hydrophobic motif as functionally essential. We demonstrate that SseF and SseG are still functional if translocated as a single fusion protein, but also mediate effector function if translocated in cells co-infected with sseF and sseG strains. SseF has characteristics of an integral membrane protein after translocation into host cells.

  10. Thiol Peroxidase Protects Salmonella enterica from Hydrogen Peroxide Stress In Vitro and Facilitates Intracellular Growth▿

    PubMed Central

    Horst, Sarah A.; Jaeger, Timo; Denkel, Luisa A.; Rouf, Syed Fazle; Rhen, Mikael; Bange, Franz-Christoph

    2010-01-01

    At present, Salmonella is considered to express two peroxiredoxin-type peroxidases, TsaA and AhpC. Here we describe an additional peroxiredoxin, Tpx, in Salmonella enterica and show that a single tpx mutant is susceptible to exogenous hydrogen peroxide (H2O2), that it has a reduced capacity to degrade H2O2 compared to the ahpCF and tsaA mutants, and that its growth is affected in activated macrophages. These results suggest that Tpx contributes significantly to the sophisticated defense system that the pathogen has evolved to survive oxidative stress. PMID:20304995

  11. Use of mixed infections to study cell invasion and intracellular proliferation of Salmonella enterica in eukaryotic cell cultures.

    PubMed

    Segura, Ignacio; Casadesús, Josep; Ramos-Morales, Francisco

    2004-01-01

    Epithelial cell lines are widely used as an in vitro model to study cell invasion by Salmonella. In turn, phagocytic cell lines are used to study Salmonella intracellular survival and proliferation. We describe a novel method, derived from the classical mixed infection procedure, to quantify invasion and proliferation defects in Salmonella enterica serovar Typhimurium. A eukaryotic cell culture is infected with two strains (e.g., a mutant and the wild-type). After infection, bacterial cells that remain extracellular are eliminated with gentamicin. At the end of the trial, intracellular bacteria are recovered and plated. Colonies from each strain are then counted for the calculation of a competitive index. Strain discrimination can be achieved either with antibiotic resistance markers or using plasmids encoding color markers (e.g., fluorescent proteins). Because both strains are exposed to the same conditions throughout the process, the procedure decreases the variability between independent trials and allows a direct measurement of the impairment of the mutant in invasion or intracellular proliferation.

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

    PubMed

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

    2016-12-09

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

  13. Inhibition of Intracellular Growth of Salmonella enterica Serovar Typhimurium in Tissue Culture by Antisense Peptide-Phosphorodiamidate Morpholino Oligomer ▿

    PubMed Central

    Mitev, Georgi M.; Mellbye, Brett L.; Iversen, Patrick L.; Geller, Bruce L.

    2009-01-01

    Two types of phosphorodiamidate morpholino oligomers (PMOs) were tested for inhibition of growth of Salmonella enterica serovar Typhimurium. Both PMOs have the same 11-base sequence that is antisense to the region near the start codon of acpP, which is essential for lipid biosynthesis and viability. To the 3′ end of each is attached the membrane-penetrating peptide (RXR)4XB (R, X, and B indicate arginine, 6-aminohexanoic acid, and β-alanine, respectively). One peptide-PMO (AcpP PPMO) has no charge on the PMO moiety. The second PPMO has three cations (piperazine) attached to the phosphorodiamidate linkages (3+Pip-AcpP PPMO). A scrambled-sequence PPMO (Scr PPMO) was synthesized for each type of PMO. The MICs of AcpP PPMO, 3+Pip-AcpP PPMO, and either one of the Scr PPMOs were 1.25 μM (7 μg/ml), 0.156 μM (0.94 μg/ml), and >160 μM (>900 μg/ml), respectively. 3+Pip-AcpP PPMO at 1.25 or 2.5 μM significantly reduced the growth rates of pure cultures, whereas AcpP PPMO or either Scr PPMO had no effect. However, the viable cell count was significantly reduced at either concentration of 3+Pip-AcpP PPMO or AcpP PPMO, but not with either Scr PPMO. In other experiments, macrophages were infected intracellularly with S. enterica and treated with 3 μM 3+Pip-AcpP PPMO. Intracellular bacteria were reduced >99% with 3+Pip-AcpP PPMO, whereas intracellular bacteria increased 3 orders of magnitude in untreated or Scr PPMO-treated cultures. We conclude that either AcpP PPMO or 3+Pip-AcpP PPMO inhibited growth of S. enterica in pure culture and that 3+Pip-AcpP PPMO reduced intracellular viability of S. enterica in macrophages. PMID:19581453

  14. IL-10 Produced by Trophoblast Cells Inhibits Phagosome Maturation Leading to Profound Intracellular Proliferation of Salmonella enterica Typhimurium

    PubMed Central

    Nguyen, Tina; Robinson, Nirmal; Allison, Sarah E.; Coombes, Brian K; Sad, Subash; Krishnan, Lakshmi

    2013-01-01

    Introduction Salmonella enterica Typhimurium (ST) is a phagosomal pathogen that can infect placental trophoblast cells leading to abortion and severe maternal illness. It is unclear how the trophoblast cells promote profound bacterial proliferation. Methods The mechanism of internalization, intracellular growth and phagosomal biogenesis in ST-infected human epithelial (HeLa), macrophage (THP-1) and trophoblast-derived cell lines (JEG-3, BeWo and HTR-8) was studied. Specific inhibitors were used to block bacterial internalization. Phagosomal maturation was determined by confocal microscopy, western-blotting and release of lysosomal β-galactosidase by infected cells. Bacterial colony forming units were determined by plating infected cell lysates on agar plates. Results ST proliferated minimally in macrophages but replicated profoundly within trophoblast cells. The ST-∆invA (a mutant of Salmonella pathogenicity island-1 gene effector proteins) was unable to infect epithelial.cells, but was internalized by scavenger receptors on trophoblasts and macrophages. However, ST was contrastingly localized in early (Rab5+) or late (LAMP1+) phagosomes within trophoblast cells and macrophages respectively. Furthermore trophoblast cells (unlike macrophages) did not exhibit phagoso-lysosomal fusion. ST-infected macrophages produced IL-6 whereas trophoblast cells produced IL-10. Neutralizing IL-10 in JEG-3 cells accelerated phagolysomal fusion and reduced proliferation of ST. Placental bacterial burden was curtailed in vivo in anti-IL-10 antibody treated and IL-10-deficient mice. Discussion Macrophages phagocytose but curtail intracellular replication of ST in late phagosomes. In contrast, phagocytosis by trophoblast cells results in an inappropriate cytokine response and proliferation of ST in early phagosomes. Conclusion IL-10 production by trophoblast cells that delays phagosomal maturation may facilitate proliferation of pathogens in placental cells. PMID:23834952

  15. 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...

  16. Complete Genome and Methylome Sequences of Salmonella enterica subsp. enterica Serovar Panama (ATCC 7378) and Salmonella enterica subsp. enterica Serovar Sloterdijk (ATCC 15791)

    PubMed Central

    Yao, Kuan; Muruvanda, Tim; Roberts, Richard J.; Payne, Justin; Allard, Marc W.

    2016-01-01

    Salmonella enterica spp. are pathogenic bacteria commonly associated with food-borne outbreaks in human and animals. Salmonella enterica spp. are characterized into more than 2,500 different serotypes, which makes epidemiological surveillance and outbreak control more difficult. In this report, we announce the first complete genome and methylome sequences from two Salmonella type strains associated with food-borne outbreaks, Salmonella enterica subsp. enterica serovar Panama (ATCC 7378) and Salmonella enterica subsp. enterica serovar Sloterdijk (ATCC 15791). PMID:26988049

  17. Complete Genome and Methylome Sequences of Salmonella enterica subsp. enterica Serovar Panama (ATCC 7378) and Salmonella enterica subsp. enterica Serovar Sloterdijk (ATCC 15791).

    PubMed

    Yao, Kuan; Muruvanda, Tim; Roberts, Richard J; Payne, Justin; Allard, Marc W; Hoffmann, Maria

    2016-03-17

    Salmonella enterica spp. are pathogenic bacteria commonly associated with food-borne outbreaks in human and animals. Salmonella enterica spp. are characterized into more than 2,500 different serotypes, which makes epidemiological surveillance and outbreak control more difficult. In this report, we announce the first complete genome and methylome sequences from two Salmonella type strains associated with food-borne outbreaks, Salmonella enterica subsp. enterica serovar Panama (ATCC 7378) and Salmonella enterica subsp. enterica serovar Sloterdijk (ATCC 15791).

  18. Genome Expression Analysis of Nonproliferating Intracellular Salmonella enterica Serovar Typhimurium Unravels an Acid pH-Dependent PhoP-PhoQ Response Essential for Dormancy

    PubMed Central

    Núñez-Hernández, Cristina; Tierrez, Alberto; Ortega, Álvaro D.; Pucciarelli, M. Graciela; Godoy, Marta; Eisman, Blanca; Casadesús, Josep

    2013-01-01

    Genome-wide expression analyses have provided clues on how Salmonella proliferates inside cultured macrophages and epithelial cells. However, in vivo studies show that Salmonella does not replicate massively within host cells, leaving the underlying mechanisms of such growth control largely undefined. In vitro infection models based on fibroblasts or dendritic cells reveal limited proliferation of the pathogen, but it is presently unknown whether these phenomena reflect events occurring in vivo. Fibroblasts are distinctive, since they represent a nonphagocytic cell type in which S. enterica serovar Typhimurium actively attenuates intracellular growth. Here, we show in the mouse model that S. Typhimurium restrains intracellular growth within nonphagocytic cells positioned in the intestinal lamina propria. This response requires a functional PhoP-PhoQ system and is reproduced in primary fibroblasts isolated from the mouse intestine. The fibroblast infection model was exploited to generate transcriptome data, which revealed that ∼2% (98 genes) of the S. Typhimurium genome is differentially expressed in nongrowing intracellular bacteria. Changes include metabolic reprogramming to microaerophilic conditions, induction of virulence plasmid genes, upregulation of the pathogenicity islands SPI-1 and SPI-2, and shutdown of flagella production and chemotaxis. Comparison of relative protein levels of several PhoP-PhoQ-regulated functions (PagN, PagP, and VirK) in nongrowing intracellular bacteria and extracellular bacteria exposed to diverse PhoP-PhoQ-inducing signals denoted a regulation responding to acidic pH. These data demonstrate that S. Typhimurium restrains intracellular growth in vivo and support a model in which dormant intracellular bacteria could sense vacuolar acidification to stimulate the PhoP-PhoQ system for preventing intracellular overgrowth. PMID:23090959

  19. Uptake and Replication of Salmonella enterica in Acanthamoeba rhysodes

    PubMed Central

    Tezcan-Merdol, Dilek; Ljungström, Marianne; Winiecka-Krusnell, Jadwiga; Linder, Ewert; Engstrand, Lars; Rhen, Mikael

    2004-01-01

    The ability of salmonellae to become internalized and to survive and replicate in amoebae was evaluated by using three separate serovars of Salmonella enterica and five different isolates of axenic Acanthamoeba spp. In gentamicin protection assays, Salmonella enterica serovar Dublin was internalized more efficiently than Salmonella enterica serovar Enteritidis or Salmonella enterica serovar Typhimurium in all of the amoeba isolates tested. The bacteria appeared to be most efficiently internalized by Acanthamoeba rhysodes. Variations in bacterial growth conditions affected internalization efficiency, but this effect was not altered by inactivation of hilA, a key regulator in the expression of the invasion-associated Salmonella pathogenicity island 1. Microscopy of infected A. rhysodes revealed that S. enterica resided within vacuoles. Prolonged incubation resulted in a loss of intracellular bacteria associated with morphological changes and loss of amoebae. In part, these alterations were associated with hilA and the Salmonella virulence plasmid. The data show that Acanthamoeba spp. can differentiate between different serovars of salmonellae and that internalization is associated with cytotoxic effects mediated by defined Salmonella virulence loci. PMID:15184177

  20. 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

  1. Substructure within Salmonella enterica subsp. enterica Isolates from Australian Wildlife▿

    PubMed Central

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

    2011-01-01

    Multilocus sequence typing of 56 Salmonella enterica subsp. enterica strains isolated from Australian wildlife hosts was performed. The results of population assignment algorithms revealed that the 56 strains could be subdivided into two distinct clades. Strains belonging to the two clades were further distinguished phenotypically, genotypically, and with respect to host distribution. PMID:21378038

  2. 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,...

  3. Interaction of Salmonella enterica with Fresh Produce Leaves

    USDA-ARS?s Scientific Manuscript database

    Attachment and colonization of Salmonella enterica serovars to fresh produce leaves was investigated. Biofilm assay and attachment of Salmonella serovars to intact and cut leaves were determined. Salmonella Tennessee and Salmonella Thompson produced stronger biofilms compared to Salmonella Newpor...

  4. 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...

  5. Comparative proteomic analysis of Salmonella enterica serovar Typhimurium ppGpp-deficient mutant to identify a novel virulence protein required for intracellular survival in macrophages

    PubMed Central

    2010-01-01

    Background The global ppGpp-mediated stringent response in pathogenic bacteria plays an important role in the pathogenesis of bacterial infections. In Salmonella enterica serovar Typhimurium (S. Typhimurium), several genes, including virulence genes, are regulated by ppGpp when bacteria are under the stringent response. To understand the control of virulence genes by ppGpp in S. Typhimurium, agarose 2-dimensional electrophoresis (2-DE) combined with mass spectrometry was used and a comprehensive 2-DE reference map of amino acid-starved S. Typhimurium strain SH100, a derivative of ATCC 14028, was established. Results Of the 366 examined spots, 269 proteins were successfully identified. The comparative analysis of the wild-type and ppGpp0 mutant strains revealed 55 proteins, the expression patterns of which were affected by ppGpp. Using a mouse infection model, we further identified a novel virulence-associated factor, STM3169, from the ppGpp-regulated and Salmonella-specific proteins. In addition, Salmonella strains carrying mutations in the gene encoding STM3169 showed growth defects and impaired growth within macrophage-like RAW264.7 cells. Furthermore, we found that expression of stm3169 was controlled by ppGpp and SsrB, a response regulator of the two-component system located on Salmonella pathogenicity island 2. Conclusions A proteomic approach using a 2-DE reference map can prove a powerful tool for analyzing virulence factors and the regulatory network involved in Salmonella pathogenesis. Our results also provide evidence of a global response mediated by ppGpp in S. enterica. PMID:21176126

  6. Draft Genome Sequences of Salmonella enterica subsp. enterica Serovars Typhimurium and Nottingham Isolated from Food Products

    PubMed Central

    Zheng, Jie; Ayers, Sherry; Melka, David C.; Curry, Phillip E.; Payne, Justin S.; Laasri, Anna; Wang, Charles; Hammack, Thomas S.; Brown, Eric W.

    2016-01-01

    A quantitative real-time PCR (qPCR) designed to detect Salmonella enterica subsp. enterica serovar Enteritidis, targeting the sdf gene, generated positive results for S. enterica subsp. enterica serovar Typhimurium (CFSAN033950) and S. enterica subsp. enterica serovar Nottingham (CFSAN006803) isolated from food samples. Both strains show pulsed-field gel electrophoresis (PFGE) patterns distinct from those of S. Enteritidis. Here, we report the genome sequences of these two strains. PMID:27445384

  7. Biofilm formation by Salmonella enterica serovar Typhimurium colonizing solid tumours.

    PubMed

    Crull, Katja; Rohde, Manfred; Westphal, Kathrin; Loessner, Holger; Wolf, Kathrin; Felipe-López, Alfonso; Hensel, Michael; Weiss, Siegfried

    2011-08-01

    Systemic administration of Salmonella enterica serovar Typhimurium to tumour bearing mice results in preferential colonization of the tumours and retardation of tumour growth. Although the bacteria are able to invade the tumour cells in vitro, in tumours they were never detected intracellularly. Ultrastructural analysis of Salmonella-colonized tumours revealed that the bacteria had formed biofilms. Interestingly, depletion of neutrophilic granulocytes drastically reduced biofilm formation. Obviously, bacteria form biofilms in response to the immune reactions of the host. Importantly, we tested Salmonella mutants that were no longer able to form biofilms by deleting central regulators of biofilm formation. Such bacteria could be observed intracellularly in immune cells of the host or in tumour cells. Thus, tumour colonizing S. typhimurium might form biofilms as protection against phagocytosis. Since other bacteria are behaving similarly, solid murine tumours might represent a unique model to study biofilm formation in vivo. © 2011 Blackwell Publishing Ltd.

  8. An inducible and secreted eukaryote-like serine/threonine kinase of Salmonella enterica serovar Typhi promotes intracellular survival and pathogenesis.

    PubMed

    Theeya, Nagaraja; Ta, Atri; Das, Sayan; Mandal, Rahul S; Chakrabarti, Oishee; Chakrabarti, Saikat; Ghosh, Amar N; Das, Santasabuj

    2015-02-01

    Eukaryote-like serine/threonine kinases (eSTKs) constitute an important family of bacterial virulence factors. Genome analysis had predicted putative eSTKs in Salmonella enterica serovar Typhi, although their functional characterization and the elucidation of their role in pathogenesis are still awaited. We show here that the primary sequence and secondary structure of the t4519 locus of Salmonella Typhi Ty2 have all the signatures of eukaryotic superfamily kinases. t4519 encodes a ∼39-kDa protein (T4519), which shows serine/threonine kinase activities in vitro. Recombinant T4519 (rT4519) is autophosphorylated and phosphorylates the universal substrate myelin basic protein. Infection of macrophages results in decreased viability of the mutant (Ty2Δt4519) strain, which is reversed by gene complementation. Moreover, reactive oxygen species produced by the macrophages signal to the bacteria to induce T4519, which is translocated to the host cell cytoplasm. That T4519 may target a host substrate(s) is further supported by the activation of host cellular signaling pathways and the induction of cytokines/chemokines. Finally, the role of T4519 in the pathogenesis of Salmonella Typhi is underscored by the significantly decreased mortality of mice infected with the Ty2Δt4519 strain and the fact that the competitive index of this strain for causing systemic infection is 0.25% that of the wild-type strain. This study characterizes the first eSTK of Salmonella Typhi and demonstrates its role in promoting phagosomal survival of the bacteria within macrophages, which is a key determinant of pathogenesis. This, to the best of our knowledge, is the first study to describe the essential role of eSTKs in the in vivo pathogenesis of Salmonella spp.

  9. Salmonella pathogenicity islands in host specificity, host pathogen-interactions and antibiotics resistance of Salmonella enterica.

    PubMed

    Gerlach, Roman G; Hensel, Michael

    2007-01-01

    Salmonella enterica is a pathogen highly successful in causing a variety of gastrointestinal and systemic diseases in animals and humans. While some serovars of S. enterica are able to infect a broad range of host organisms, other serovars are highly restricted to specific host species. The colonization of hosts by S. enterica depends on the function of a large number of virulence determinants. The molecular analyses of virulence genes demonstrated that most of these loci are clustered within Salmonella Pathogenicity Islands (SPI). SPI1 and SPI2 each encode type III secretion systems (T355) that confer main virulence traits of S. enterica, i.e. invasion, enteropathogenesis and intracellular survival and proliferation. Further SPI encode factors that contribute to intracellular survival, different types of adhesins, or effector proteins of the SPI1-T3SS or SPI2-T3SS. The availability of genome sequences of several serovars of S. enterica also revealed serovar-specific SPI. In this review, the main characteristics of the currently known SPI are summarized with focus on their roles in various animal hosts and putative functions in human infections.

  10. Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Bardo Strain CRJJGF_00099 (Phylum Gammaproteobacteria)

    PubMed Central

    Gupta, Sushim K.; McMillan, Elizabeth A.; Jackson, Charlene R.; Desai, Prerak T.; Porwollik, Steffen; McClelland, Michael; Hiott, Lari M.; Humayoun, Shaheen B.

    2016-01-01

    Here, we report a 4.87-Mbp draft genome sequence of the multidrug-resistant (MDR) Salmonella enterica subsp. enterica serovar Bardo strain CRJJGF_00099, isolated from dairy cattle in 2005. PMID:27634995

  11. Evolutionary Genomics of Salmonella enterica Subspecies

    PubMed Central

    Desai, Prerak T.; Porwollik, Steffen; Long, Fred; Cheng, Pui; Wollam, Aye; Clifton, Sandra W.; Weinstock, George M.; McClelland, Michael

    2013-01-01

    ABSTRACT Six subspecies are currently recognized in Salmonella enterica. Subspecies I (subspecies enterica) is responsible for nearly all infections in humans and warm-blooded animals, while five other subspecies are isolated principally from cold-blooded animals. We sequenced 21 phylogenetically diverse strains, including two representatives from each of the previously unsequenced five subspecies and 11 diverse new strains from S. enterica subspecies enterica, to put this species into an evolutionary perspective. The phylogeny of the subspecies was partly obscured by abundant recombination events between lineages and a relatively short period of time within which subspeciation took place. Nevertheless, a variety of different tree-building methods gave congruent evolutionary tree topologies for subspeciation. A total of 285 gene families were identified that were recruited into subspecies enterica, and most of these are of unknown function. At least 2,807 gene families were identified in one or more of the other subspecies that are not found in subspecies I or Salmonella bongori. Among these gene families were 13 new candidate effectors and 7 new candidate fimbrial clusters. A third complete type III secretion system not present in subspecies enterica (I) isolates was found in both strains of subspecies salamae (II). Some gene families had complex taxonomies, such as the type VI secretion systems, which were recruited from four different lineages in five of six subspecies. Analysis of nonsynonymous-to-synonymous substitution rates indicated that the more-recently acquired regions in S. enterica are undergoing faster fixation rates than the rest of the genome. Recently acquired AT-rich regions, which often encode virulence functions, are under ongoing selection to maintain their high AT content. PMID:23462113

  12. Salmonella enterica Remodels the Host Cell Endosomal System for Efficient Intravacuolar Nutrition.

    PubMed

    Liss, Viktoria; Swart, A Leoni; Kehl, Alexander; Hermanns, Natascha; Zhang, Yuying; Chikkaballi, Deepak; Böhles, Nathalie; Deiwick, Jörg; Hensel, Michael

    2017-03-08

    Salmonella enterica is a facultative intracellular pathogen that survives and proliferates in the Salmonella-containing vacuole (SCV), yet how these vacuolar bacteria acquire nutrition remains to be determined. Intracellular Salmonella convert the host endosomal system into an extensive network of interconnected tubular vesicles, of which Salmonella-induced filaments (SIFs) are the most prominent. We found that membranes and lumen of SIFs and SCVs form a continuum, giving vacuolar Salmonella access to various types of endocytosed material. Membrane proteins and luminal content rapidly diffuse between SIFs and SCVs. Salmonella in SCVs without connection to SIFs have reduced access to endocytosed components. On a single-cell level, Salmonella within the SCV-SIF continuum were found to exhibit higher metabolic activity than vacuolar bacteria lacking SIFs. Our data demonstrate that formation of the SCV-SIF continuum allows Salmonella to bypass nutritional restriction in the intracellular environment by acquiring nutrients from the host cell endosomal system.

  13. Two draft genome sequences of a new serovar of Salmonella enterica, serovar Lubbock

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is principally a foodborne pathogen that shows considerable serovar diversity. In this report, we present two draft genome sequences of Salmonella enterica subsp. enterica serovar Lubbock, a novel serovar....

  14. Two Draft Genome Sequences of a New Serovar of Salmonella enterica, Serovar Lubbock

    PubMed Central

    den Bakker, Henk C.; Nightingale, Kendra K.; Brichta-Harhay, Dayna M.; Edrington, Thomas S.; Loneragan, Guy H.

    2015-01-01

    Salmonella enterica is principally a foodborne pathogen that shows considerable serovar diversity. In this report, we present two draft genome sequences of Salmonella enterica subsp. enterica serovar Lubbock, a novel serovar. PMID:25883279

  15. 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.

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

    PubMed Central

    Fazal, Mohammed-Abbas; Burnett, Edward; Deheer-Graham, Ana; Oliver, Karen; Holroyd, Nancy; Russell, Julie E.

    2016-01-01

    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. PMID:27811100

  17. 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....

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

    PubMed Central

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

    2013-01-01

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

  19. Is the Evolution of Salmonella enterica subsp. enterica Linked to Restriction-Modification Systems?

    PubMed

    Roer, Louise; Hendriksen, Rene S; Leekitcharoenphon, Pimlapas; Lukjancenko, Oksana; Kaas, Rolf Sommer; Hasman, Henrik; Aarestrup, Frank M

    2016-01-01

    Salmonella enterica subsp. enterica bacteria are highly diverse foodborne pathogens that are subdivided into more than 1,500 serovars. The diversity is believed to result from mutational evolution, as well as intra- and interspecies recombination that potentially could be influenced by restriction-modification (RM) systems. The aim of this study was to investigate whether RM systems were linked to the evolution of Salmonella enterica subsp. enterica. The study included 221 Salmonella enterica genomes, of which 68 were de novo sequenced and 153 were public available genomes from ENA. The data set covered 97 different serovars of Salmonella enterica subsp. enterica and an additional five genomes from four other Salmonella subspecies as an outgroup for constructing the phylogenetic trees. The phylogenetic trees were constructed based on multiple alignment of core genes, as well as the presence or absence of pangenes. The topology of the trees was compared to the presence of RM systems, antimicrobial resistance (AMR) genes, Salmonella pathogenicity islands (SPIs), and plasmid replicons. We did not observe any correlation between evolution and the RM systems in S. enterica subsp. enterica. However, sublineage correlations and serovar-specific patterns were observed. Additionally, we conclude that plasmid replicons, SPIs, and AMR were all better correlated to serovars than to RM systems. This study suggests a limited influence of RM systems on the evolution of Salmonella enterica subsp. enterica, which could be due to the conjugational mode of horizontal gene transfer in Salmonella. Thus, we conclude that other factors must be involved in shaping the evolution of bacteria. IMPORTANCE The evolution of bacterial pathogens, their plasticity and ability to rapidly change and adapt to new surroundings are crucial for understanding the epidemiology and public health. With the application of genomics, it became clear that horizontal gene transfer played a key role in evolution

  20. Results of Salmonella enterica subsp. enterica serotype identification by Salmonella Check&Trace microarray in international External Quality Assurance Systems.

    PubMed

    Madaczak, Grzegorz; Szych, Jolanta; Wasiak, Monika

    2015-01-01

    Traditionally Salmonella enterica subsp. enterica serotypes are identified by slide agglutination with specific antisera for somatic, flagellar and sometimes capsular antigens. An alternative way is genoserotyping using for example a microarray, eg. commercially available test Check&Trace Salmonella. The goal of this study was to evaluate the Check&Trace Salmonella microarray for Salmonella enterica subsp. enterica serotype identification, using Salmonella strains provided by reference laboratories during External Quality Assurance Systems organized for national reference laboratories by ECDC and WHO GFN. 80 Salmonella enterica subsp. enterica have been tested using Check & Trace Salmonella (Check-Points BC, Netherlands). Also classical slide agglutination was performed according to EN ISO 6579:2003/Al:2007 norm, used as reference method. In the group of 80 tested strains, 66% were identified correctly, 4% gave uncertain results and 29% showed "Salmonella, genovar" without a serotype, of which 69% were not included in the CTS list of serotypes. Finally one strain has been recognized incorrectly. Because of IVD certification lack, the CTS test could not be recommended to clinical laboratories. AOAC-RI and OIE certification for test cause, that CTS could be used in most food, environmental and veterinary laboratories with the condition, that all unrecognized strains should be sent to a reference laboratory, to type according to EN ISO 6579:2003/Al:2007 norm, by KWM serotyping or other equal alternative methods.

  1. Fingerprinting of Salmonella enterica subsp. enterica serovar Enteritidis by ribotyping.

    PubMed

    Lippelt, Meike; de Isele, Theresa Sanabria; Kist, Manfred

    1997-04-01

    OBJECTIVE: To carry out an epidemiologic evaluation of Salmonella enterica subsp. enterica serovar Enteritidis outbreaks in households and small communities by means of rRNA gene restriction pattern analysis (ribotyping). METHODS: One hundred Enteritidis isolates dating from 1989 to 1994 which could be allocated epidemiologically to different sources or to small community outbreaks were investigated with ribotyping, a fingerprinting method in which bacterial DNA is hybridized with the biotin-labeled plasmid pKK 3535 containing a ribosomal RNA operon of Escherichia coli to determine the ribosomal RNA gene restriction patterns. RESULTS: Four different ribotyping patterns were found with the restriction endonuclease Smal and nine with Sphl. Ribotypes of isolates which could be allocated epidemiologically to a common source usually corresponded. Almost 60% of the Enteritidis infections had the ribotyping pattern Sphl-A. In contrast, this pattern was not found in any of the five Enteritidis strains isolated in 1989. The suspicion that Enteritidis phage type 4 infections are caused by consumption of insufficiently heated eggs is supported by the fact that the ribotyping pattern Sph1-A was found in isolates from eggs and from human specimens. CONCLUSIONS: As patterns Sphl-A and Smal-J appeared in 58% and 75% of the isolates, respectively, ribotyping cannot be used for the differentiation between various outbreaks with these two patterns. In cases where the Enteritidis strains showed less frequent patterns, ribotyping seems to be a practical tool for the identification of infection chains. In addition newly appearing ribotyping patterns can give information about the epidemiologic development of Enteritidis infection.

  2. Complete Genome Sequences of 16 Canadian Strains of Salmonella enterica subsp. enterica Serovar Enteritidis

    PubMed Central

    Rehman, Muhammad A.; Ziebell, Kim; Nash, John H. E.; Kropinski, Andrew M.; Ross, Ashley; Al-Lami, Mariam; Boerlin, Patrick; Chui, Linda; Devenish, John; Bekal, Sadjia; Graham, Morag; Amoako, Kingsley K.

    2014-01-01

    Salmonella enterica subsp. enterica serovar Enteritidis is an important zoonotic food-borne pathogen causing serious human illnesses frequently linked to poultry products. Here, we report fully assembled genome sequences of 16 S. Enteritidis strains with common pulsed-field gel electrophoresis (PFGE) and phage types (8, 13, 13a, and 14b) that predominate in North America. PMID:24762938

  3. Complete Genome Sequence and Methylome of Salmonella enterica subsp. enterica Cerro, a Frequent Dairy Cow Serovar.

    PubMed

    Haley, Bradd J; Pirone, Cary; Muruvanda, Tim; Brown, Eric; Allard, Marc; Karns, Jeffrey S; Van Kessel, Jo Ann S

    2016-01-28

    Salmonella enterica subsp. enterica serovar Cerro is an infrequent pathogen of humans and other mammals but is frequently isolated from the hindgut of asymptomatic cattle in the United States. To further understand the genomic determinants of S. Cerro specificity for the bovine hindgut, the genome of isolate CFSAN001588 was fully sequenced and deposited in the GenBank database.

  4. Whole-Genome Sequencing of Salmonella enterica subsp. enterica Serovar Cubana Strains Isolated from Agricultural Sources.

    PubMed

    Benahmed, Faiza H; Gopinath, Gopal R; Wang, Hua; Jean-Gilles Beaubrun, Junia; Grim, Christopher; Cheng, Chorng-Ming; McClelland, Michael; Ayers, Sherry; Abbott, Jason; Desai, Prerak; Frye, Jonathan G; Weinstock, George; Hammack, Thomas S; Hanes, Darcy E; Rasmussen, Mark A; Davidson, Maureen K

    2014-01-23

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

  5. Whole-Genome Sequencing of Salmonella enterica subsp. enterica Serovar Cubana Strains Isolated from Agricultural Sources

    PubMed Central

    Benahmed, Faiza H.; Gopinath, Gopal R.; Wang, Hua; Jean-Gilles Beaubrun, Junia; Grim, Christopher; Cheng, Chorng-Ming; McClelland, Michael; Ayers, Sherry; Abbott, Jason; Desai, Prerak; Frye, Jonathan G.; Weinstock, George; Hammack, Thomas S.; Hanes, Darcy E.; Rasmussen, Mark A.

    2014-01-01

    We report the draft genomes of Salmonella enterica subsp. enterica serovar Cubana strain CVM42234, isolated from chick feed in 2012, and S. Cubana strain 76814, isolated from swine in 2004. The genome sizes are 4,975,046 and 4,936,251 bp, respectively. PMID:24459266

  6. Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Mishmarhaemek Isolated from Bovine Feces

    PubMed Central

    Cooper, Ashley; Lambert, Dominic; Koziol, Adam G.; Seyer, Karine

    2015-01-01

    Salmonella enterica subsp. enterica serovar Mishmarhaemek is a Gram-negative, non-spore-forming, rod-shaped bacterium implicated in human clinical disease. Here, we report a 4.8-Mbp draft genome sequence of a nalidixic acid-resistant isolate of S. serovar Mishmarhaemek. PMID:26472847

  7. Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Mishmarhaemek Isolated from Bovine Feces.

    PubMed

    Cooper, Ashley; Lambert, Dominic; Koziol, Adam G; Seyer, Karine; Carrillo, Catherine D

    2015-10-15

    Salmonella enterica subsp. enterica serovar Mishmarhaemek is a Gram-negative, non-spore-forming, rod-shaped bacterium implicated in human clinical disease. Here, we report a 4.8-Mbp draft genome sequence of a nalidixic acid-resistant isolate of S. serovar Mishmarhaemek. Copyright © 2015 Cooper et al.

  8. Complete Genome and Methylome Sequences of Salmonella enterica subsp. enterica Serovars Typhimurium, Saintpaul, and Stanleyville from the SARA/SARB Collection

    PubMed Central

    Yao, Kuan; Roberts, Richard J.; Allard, Marc W.

    2017-01-01

    ABSTRACT In this announcement, we report the complete genome and methylome sequences of three Salmonella enterica strains from the SARA and SARB collection: S. enterica subsp. enterica serovar Typhimurium (SARA13), S. enterica subsp. enterica serovar Saintpaul (SARA26), and S. enterica subsp. enterica serovar Stanleyville (SARB61). PMID:28302778

  9. Sensitive and rapid molecular detection assays for Salmonella enterica serovar Typhimurium and Heidelberg

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is a significant cause of gastroenteritis worldwide, with S. enterica serovars Typhimurium and Heidelberg being particularly prevalent. S. enterica serovars Typhimurium and Heidelberg have broad host ranges infecting poultry, dairy animals and humans. Traditional methods used fo...

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

    PubMed Central

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

    2012-01-01

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

  11. Xanthomonas perforans Colonization Influences Salmonella enterica in the Tomato Phyllosphere

    PubMed Central

    Potnis, Neha; Soto-Arias, José Pablo; Cowles, Kimberly N.; van Bruggen, Ariena H. C.; Jones, Jeffrey B.

    2014-01-01

    Salmonella enterica rarely grows on healthy, undamaged plants, but its persistence is influenced by bacterial plant pathogens. The interactions between S. enterica, Xanthomonas perforans (a tomato bacterial spot pathogen), and tomato were characterized. We observed that virulent X. perforans, which establishes disease by suppressing pathogen-associated molecular pattern (PAMP)-triggered immunity that leads to effector-triggered susceptibility, created a conducive environment for persistence of S. enterica in the tomato phyllosphere, while activation of effector-triggered immunity by avirulent X. perforans resulted in a dramatic reduction in S. enterica populations. S. enterica populations persisted at ∼10 times higher levels in leaves coinoculated with virulent X. perforans than in those where S. enterica was applied alone. In contrast, S. enterica populations were ∼5 times smaller in leaves coinoculated with avirulent X. perforans than in leaves inoculated with S. enterica alone. Coinoculation with virulent X. perforans increased S. enterica aggregate formation; however, S. enterica was not found in mixed aggregates with X. perforans. Increased aggregate formation by S. enterica may serve as the mechanism of persistence on leaves cocolonized by virulent X. perforans. S. enterica association with stomata was altered by X. perforans; however, it did not result in appreciable populations of S. enterica in the apoplast even in the presence of large virulent X. perforans populations. Gene-for-gene resistance against X. perforans successively restricted S. enterica populations. Given the effect of this interaction, breeding for disease-resistant cultivars may be an effective strategy to limit both plant disease and S. enterica populations and, consequently, human illness. PMID:24632252

  12. 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.

  13. Salmonella enterica Strains with Reduced Susceptibility to Quarternary Ammonium Compounds

    USDA-ARS?s Scientific Manuscript database

    Background: Salmonella spp. are responsible for 76 million illnesses per year in the U.S. Quaternary ammonium compounds (QAC) are commonly used antimicrobial agents. Reduced susceptibility to these compounds by a broad spectrum of organisms is a concern. Methods: Salmonella enterica strains with r...

  14. Draft Genome Sequence of Salmonella enterica subsp. enterica Serotype Oranienburg Strain S-76, Isolated from an Aquatic Environment

    PubMed Central

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

    2013-01-01

    Salmonella is a widespread microorganism and a common causative agent of food-borne illnesses. Salmonella enterica subsp. enterica serotype Oranienburg is highly prevalent in surface water from tropical ecosystems and is not commonly related to illnesses. Here, we report the first genome sequence of Salmonella Oranienburg strain S-76, isolated from an aquatic environment. PMID:24336368

  15. First Fully Closed Genome Sequence of Salmonella enterica subsp. enterica Serovar Cubana Associated with a Food-Borne Outbreak.

    PubMed

    Hoffmann, Maria; Muruvanda, Tim; Pirone, Cary; Korlach, Jonas; Timme, Ruth; Payne, Justin; Evans, Peter; Meng, Jianghong; Brown, Eric W; Allard, Marc W

    2014-10-30

    Salmonella enterica subsp. enterica serovar Cubana (Salmonella serovar Cubana) is associated with human and animal disease. Here, we used third-generation, single-molecule, real-time DNA sequencing to determine the first complete genome sequence of Salmonella serovar Cubana CFSAN002050, which was isolated from fresh alfalfa sprouts during a multistate outbreak in 2012. Copyright © 2014 Hoffmann et al.

  16. First Fully Closed Genome Sequence of Salmonella enterica subsp. enterica Serovar Cubana Associated with a Food-Borne Outbreak

    PubMed Central

    Muruvanda, Tim; Pirone, Cary; Korlach, Jonas; Timme, Ruth; Payne, Justin; Evans, Peter; Meng, Jianghong; Brown, Eric W.; Allard, Marc W.

    2014-01-01

    Salmonella enterica subsp. enterica serovar Cubana (Salmonella serovar Cubana) is associated with human and animal disease. Here, we used third-generation, single-molecule, real-time DNA sequencing to determine the first complete genome sequence of Salmonella serovar Cubana CFSAN002050, which was isolated from fresh alfalfa sprouts during a multistate outbreak in 2012. PMID:25359917

  17. Internal Colonization of Salmonella enterica Serovar Typhimurium in Tomato Plants

    PubMed Central

    Gu, Ganyu; Hu, Jiahuai; Cevallos-Cevallos, Juan M.; Richardson, Susanna M.; Bartz, Jerry A.; van Bruggen, Ariena H. C.

    2011-01-01

    Several Salmonella enterica outbreaks have been traced back to contaminated tomatoes. In this study, the internalization of S. enterica Typhimurium via tomato leaves was investigated as affected by surfactants and bacterial rdar morphotype, which was reported to be important for the environmental persistence and attachment of Salmonella to plants. Surfactants, especially Silwet L-77, promoted ingress and survival of S. enterica Typhimurium in tomato leaves. In each of two experiments, 84 tomato plants were inoculated two to four times before fruiting with GFP-labeled S. enterica Typhimurium strain MAE110 (with rdar morphotype) or MAE119 (without rdar). For each inoculation, single leaflets were dipped in 109 CFU/ml Salmonella suspension with Silwet L-77. Inoculated and adjacent leaflets were tested for Salmonella survival for 3 weeks after each inoculation. The surface and pulp of ripe fruits produced on these plants were also examined for Salmonella. Populations of both Salmonella strains in inoculated leaflets decreased during 2 weeks after inoculation but remained unchanged (at about 104 CFU/g) in week 3. Populations of MAE110 were significantly higher (P<0.05) than those of MAE119 from day 3 after inoculation. In the first year, nine fruits collected from one of the 42 MAE119 inoculated plants were positive for S. enterica Typhimurium. In the second year, Salmonella was detected in adjacent non-inoculated leaves of eight tomato plants (five inoculated with strain MAE110). The pulp of 12 fruits from two plants inoculated with MAE110 was Salmonella positive (about 106 CFU/g). Internalization was confirmed by fluorescence and confocal laser microscopy. For the first time, convincing evidence is presented that S. enterica can move inside tomato plants grown in natural field soil and colonize fruits at high levels without inducing any symptoms, except for a slight reduction in plant growth. PMID:22096553

  18. Pathogenicity of dodecyltrimethylammonium chloride-resistant Salmonella enterica.

    PubMed

    Kautz, Megan J M; Dvorzhinskiy, Aleksey; Frye, Jonathan G; Stevenson, Natalie; Herson, Diane S

    2013-04-01

    Salmonella infection causes a self-limiting gastroenteritis in humans but can also result in a life-threatening invasive disease, especially in old, young, and/or immunocompromised patients. The prevalence of antimicrobial and multidrug-resistant Salmonella has increased worldwide since the 1980s. However, the impact of antimicrobial resistance on the pathogenicity of Salmonella strains is not well described. In our study, a microarray was used to screen for differences in gene expression between a parental strain and a strain of Salmonella enterica serovar Enteritidis with reduced susceptibility (SRS) to the widely used antimicrobial sanitizer dodecyltrimethylammonium chloride (DTAC). Three of the genes, associated with adhesion, invasion, and intracellular growth (fimA, csgG, and spvR), that showed differences in gene expression of 2-fold or greater were chosen for further study. Real-time reverse transcriptase PCR (real-time RT-PCR) was used to confirm the microarray data and to compare the expression levels of these genes in the parental strain and four independently derived SRS strains. All SRS strains showed lower levels of gene expression of fimA and csgG than those of the parental strain. Three of the four SRS strains showed lower levels of spvR gene expression while one SRS strain showed higher levels of spvR gene expression than those of the parental strain. Transmission electron microscopy determined that fimbriae were absent in the four SRS strains but copiously present in the parental strain. All four SRS strains demonstrated a significantly reduced ability to invade tissue culture cells compared to the parental strains, suggesting reduced pathogenicity of the SRS strains.

  19. Colonization and internalization of Salmonella enterica in tomato plants.

    PubMed

    Zheng, Jie; Allard, Sarah; Reynolds, Sara; Millner, Patricia; Arce, Gabriela; Blodgett, Robert J; Brown, Eric W

    2013-04-01

    The consumption of fresh tomatoes has been linked to numerous food-borne outbreaks involving various serovars of Salmonella enterica. Recent advances in our understanding of plant-microbe interactions have shown that human enteric pathogenic bacteria, including S. enterica, are adapted to survive in the plant environment. In this study, tomato plants (Solanum lycopersicum cv. Micro-Tom) grown in sandy loam soil from Virginia's eastern shore (VES) were inoculated with S. enterica serovars to evaluate plausible internalization routes and to determine if there is any niche fitness for certain serovars. Both infested soil and contaminated blossoms can lead to low internal levels of fruit contamination with Salmonella. Salmonella serovars demonstrated a great ability to survive in environments under tomato cultivation, not only in soil but also on different parts of the tomato plant. Of the five serovars investigated, Salmonella enterica serovars Newport and Javiana were dominant in sandy loam soil, while Salmonella enterica serovars Montevideo and Newport were more prevalent on leaves and blossoms. It was also observed that Salmonella enterica serovar Typhimurium had a poor rate of survival in all the plant parts examined here, suggesting that postharvest contamination routes are more likely in S. Typhimurium contamination of tomato fruit. Conversely, S. Newport was the most prevalent serovar recovered in both the tomato rhizosphere and phyllosphere. Plants that were recently transplanted (within 3 days) had an increase in observable internalized bacteria, suggesting that plants were more susceptible to internalization right after transplant. These findings suggest that the particular Salmonella serovar and the growth stage of the plant were important factors for internalization through the root system.

  20. Colonization and Internalization of Salmonella enterica in Tomato Plants

    PubMed Central

    Allard, Sarah; Reynolds, Sara; Millner, Patricia; Arce, Gabriela; Blodgett, Robert J.; Brown, Eric W.

    2013-01-01

    The consumption of fresh tomatoes has been linked to numerous food-borne outbreaks involving various serovars of Salmonella enterica. Recent advances in our understanding of plant-microbe interactions have shown that human enteric pathogenic bacteria, including S. enterica, are adapted to survive in the plant environment. In this study, tomato plants (Solanum lycopersicum cv. Micro-Tom) grown in sandy loam soil from Virginia's eastern shore (VES) were inoculated with S. enterica serovars to evaluate plausible internalization routes and to determine if there is any niche fitness for certain serovars. Both infested soil and contaminated blossoms can lead to low internal levels of fruit contamination with Salmonella. Salmonella serovars demonstrated a great ability to survive in environments under tomato cultivation, not only in soil but also on different parts of the tomato plant. Of the five serovars investigated, Salmonella enterica serovars Newport and Javiana were dominant in sandy loam soil, while Salmonella enterica serovars Montevideo and Newport were more prevalent on leaves and blossoms. It was also observed that Salmonella enterica serovar Typhimurium had a poor rate of survival in all the plant parts examined here, suggesting that postharvest contamination routes are more likely in S. Typhimurium contamination of tomato fruit. Conversely, S. Newport was the most prevalent serovar recovered in both the tomato rhizosphere and phyllosphere. Plants that were recently transplanted (within 3 days) had an increase in observable internalized bacteria, suggesting that plants were more susceptible to internalization right after transplant. These findings suggest that the particular Salmonella serovar and the growth stage of the plant were important factors for internalization through the root system. PMID:23377940

  1. Salmonella enterica Serotype Arizonae Meningitis in a Neonate.

    PubMed

    Lakew, Wubishet; Girma, Abayneh; Triche, Elizabeth

    2013-01-01

    Typhoidal and nontyphoidal salmonella infections are common causes of gastroenteritis in the community. However, salmonella only rarely causes invasive infections like meningitis. We report a 13-day-old female neonate with signs and symptoms of meningitis whose cerebrospinal fluid (CSF) culture showed Salmonella enterica serotype Arizonae that was sensitive to ceftriaxone. She presented with fever and failure to feed for 2 days. Despite prompt treatment with ampicillin, gentamicin, and ceftriaxone, she developed communicating hydrocephalus, frequent seizures, and coma that progressed to death after 2 weeks of hospitalization. Salmonella enterica serotype Arizonae is a rare cause of human infection known to leading to meningitis symptoms similar to those caused by other salmonella species. This is the first report of it as a cause of meningitis in a child under one month of age. Therefore, it should be included in the differential diagnosis of Gram-negative bacillary meningitis in immunocompromised children, neonates, and those with contacts with reptiles.

  2. Characterization of the spv locus in Salmonella enterica serovar Arizona.

    PubMed

    Libby, Stephen J; Lesnick, Marc; Hasegawa, Patricia; Kurth, Michael; Belcher, Christopher; Fierer, Joshua; Guiney, Donald G

    2002-06-01

    Salmonella enterica serovar Arizona (S. enterica subspecies IIIa) is a common Salmonella isolate from reptiles and can cause serious systemic disease in humans. The spv virulence locus, found on large plasmids in Salmonella subspecies I serovars associated with severe infections, was confirmed to be located on the chromosome of serovar Arizona. Sequence analysis revealed that the serovar Arizona spv locus contains homologues of spvRABC but lacks the spvD gene and contains a frameshift in spvA, resulting in a different C terminus. The SpvR protein functions as a transcriptional activator for the spvA promoter, and SpvB and SpvC are highly conserved. The analysis supports the proposal that the chromosomal spv sequence more closely corresponds to the ancestral locus acquired during evolution of S. enterica, with plasmid acquisition of spv genes in the subspecies I strains involving addition of spvD and polymorphisms in spvA.

  3. Salmonella enterica: survival, colonization, and virulence differences among serovars.

    PubMed

    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.

  4. 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

  5. Salicylate reduces the antimicrobial activity of ciprofloxacin against extracellular Salmonella enterica serovar Typhimurium, but not against Salmonella in macrophages.

    PubMed

    Hartog, Efrat; Menashe, Ofir; Kler, Edna; Yaron, Sima

    2010-05-01

    Salicylate, a potent inducer of the MarA activator in Salmonella enterica, is the principal metabolite of aspirin, which is often consumed for medicinal and cosmetic uses. Our research was aimed at testing if salicylate activates the mar regulon in macrophage-associated Salmonella (intracellular bacteria), and investigating its effects on bacterial susceptibility to ciprofloxacin extracellularly and intracellularly. J774 macrophages were infected with S. enterica serovar Typhimurium (wild-type and marA null mutant), treated with ciprofloxacin with and without pre-exposure to salicylate, and the surviving bacteria were counted. Similar experiments were conducted with bacteria in broth (extracellular bacteria). Phe-Arg-beta-naphthylamide (PAbetaN) was added to investigate the role of efflux pumps in resistance. The transcriptional regulation of marRAB, acrAB and micF in extracellular and intracellular Salmonella Typhimurium with and without salicylate and ciprofloxacin was investigated using green fluorescent protein as a marker protein and quantitative real time PCR. Pre-exposure of Salmonella to salicylate increased the resistance of extracellular but not intracellular bacteria to ciprofloxacin, although salicylate stimulated the expression of mar genes in intracellular and extracellular bacteria. Using marA mutants and the inhibitor PAbetaN, we showed that the improved resistance in extracellular bacteria is derived from the induction of acrAB by salicylate, which is mediated by MarA. In intracellular bacteria, the expression of acrAB is already higher when compared with extracellular cells; therefore, salicylate does not result in significant acrAB induction intracellularly and subsequent resistance enhancement. Results show that conclusions raised from extracellular studies cannot be applied to intracellular bacteria, although the systems have similar functions.

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

    PubMed Central

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

    2016-01-01

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

  7. Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Give, Isolated from an Imported Chili Powder Product.

    PubMed

    Wang, Hua; Chen, Yi; Ayers, Sherry; Melka, David; Laasri, Anna; Payne, Justin S; Zheng, Jie; Son, Insook; Timme, Ruth; Kastanis, George; Hammack, Thomas S; Strain, Errol; Allard, Marc W; Evans, Peter S; Brown, Eric W

    2015-07-02

    We report the genome sequence of Salmonella enterica subsp. enterica serovar Give (CFSAN012622), isolated from imported chili powder in 2014. This genome contains genes previously reported to be specific only to S. enterica serovar Enteritidis. This strain shows a unique pulsed-field gel electrophoresis (PFGE) pattern clustering with serovar Enteritidis (JEG X01.0005).

  8. Complete Genome Sequences of Two Outbreak Strains of Salmonella enterica subsp. enterica Serovar Thompson Associated with Cilantro

    PubMed Central

    Huynh, Steven; Gorski, Lisa; Cooper, Kerry K.; Miller, William G.

    2015-01-01

    Salmonella enterica subsp. enterica serovar Thompson strains RM1984 (CADPH-99A2334) and RM1986 (CADPH-99A2345) are associated with a 1999 outbreak in contaminated cilantro. We report here the complete genome sequences and annotation of these two S. Thompson strains. These genomes are distinct and provide additional data for our understanding of S. enterica. PMID:26586897

  9. Transmission and Retention of Salmonella enterica by Phytophagous Hemipteran Insects

    PubMed Central

    Soto-Arias, José Pablo; Groves, Russell L.

    2014-01-01

    Several pest insects of human and livestock habitations are known as vectors of Salmonella enterica; however, the role of plant-feeding insects as vectors of S. enterica to agricultural crops remains unexamined. Using a hemipteran insect pest-lettuce system, we investigated the potential for transmission and retention of S. enterica. Specifically, Macrosteles quadrilineatus and Myzus persicae insects were fed S. enterica-inoculated lettuce leaf discs or artificial liquid diets confined in Parafilm sachets to allow physical contact or exclusively oral ingestion of the pathogen, respectively. After a 24-h acquisition access period, insects were moved onto two consecutive noninoculated leaf discs or liquid diets and allowed a 24-h inoculation access period on each of the two discs or sachets. Similar proportions of individuals from both species ingested S. enterica after a 24-h acquisition access period from inoculated leaf discs, but a significantly higher proportion of M. quadrilineatus retained the pathogen internally after a 48-h inoculation access period. S. enterica was also recovered from the honeydew of both species. After a 48-h inoculation access period, bacteria were recovered from a significantly higher proportion of honeydew samples from M. quadrilineatus than from M. persicae insects. The recovery of S. enterica from leaf discs and liquid diets postfeeding demonstrated that both species of insects were capable of transmitting the bacteria in ways that are not limited to mechanical transmission. Overall, these results suggest that phytophagous insects may serve as potential vectors of S. enterica in association with plants. PMID:24973069

  10. Genome Sequences of Salmonella enterica subsp. enterica Serovar Lubbock Strains Isolated from Liver Abscesses of Feedlot Cattle

    PubMed Central

    Amachawadi, Raghavendra G.; Thomas, Milton

    2016-01-01

    The genome sequencing of 13 Salmonella enterica subsp. enterica serovar Lubbock strains isolated from liver abscesses of feedlot cattle is reported here. The availability of these genomes will help to further understand the etiologic role of Salmonella strains in liver abscesses of cattle and will serve as references in microbial trace-back studies to improve food safety. PMID:27151794

  11. Cefotaxime-resistant Salmonella enterica in travelers returning from Thailand to Finland.

    PubMed

    Gunell, Marianne; Aulu, Laura; Jalava, Jari; Lukinmaa-Åberg, Susanna; Osterblad, Monica; Ollgren, Jukka; Huovinen, Pentti; Siitonen, Anja; Hakanen, Antti J

    2014-07-01

    During 1993-2011, cefotaxime resistance among Salmonella enterica isolates from patients in Finland increased substantially. Most of these infections originated in Thailand; many were qnr positive and belonged to S. enterica serovar Typhimurium and S. enterica monophasic serovar 4,[5],12:i:-. Although cefotaxime-resistant salmonellae mainly originate in discrete geographic areas, they represent a global threat.

  12. Cefotaxime-Resistant Salmonella enterica in Travelers Returning from Thailand to Finland

    PubMed Central

    Aulu, Laura; Jalava, Jari; Lukinmaa-Åberg, Susanna; Österblad, Monica; Ollgren, Jukka; Huovinen, Pentti; Siitonen, Anja; Hakanen, Antti J.

    2014-01-01

    During 1993–2011, cefotaxime resistance among Salmonella enterica isolates from patients in Finland increased substantially. Most of these infections originated in Thailand; many were qnr positive and belonged to S. enterica serovar Typhimurium and S. enterica monophasic serovar 4,[5],12:i:-. Although cefotaxime-resistant salmonellae mainly originate in discrete geographic areas, they represent a global threat. PMID:24960266

  13. 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.

  14. 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

  15. 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.

  16. Non-typhi Salmonella enterica urinary tract infections.

    PubMed

    Mellon, G; Delanoe, C; Roux, A L; Heym, B; Dubourg, O; Hardy, P; Chevallier, B; Perronne, C; Rouveix, E; Salomon, J

    2017-10-01

    Non-typhi Salmonella enterica urinary tract infections (UTIs) are not frequent and rarely reported in the literature. We aimed to characterize clinical presentations and risk factors for the infection. We performed a retrospective study of non-typhi Salmonella enterica strains isolated from urine cytobacteriological examinations (UCBE) collected between January 1, 1996 and October 30, 2014 and analyzed by the microbiology laboratories of the university hospitals of the western part of Île-de-France and of Paris, France. Twenty UCBEs positive for non-typhi Salmonella enterica were analyzed. The sex ratio was 0.53 and the average age of patients was 57 years. Clinical presentations were acute pyelonephritis, acute cystitis, and prostatitis. Eight cases of bacteremia were identified. Diarrhea was observed in half of patients, either before the UTI or simultaneously. No patient required to be transferred to the intensive care unit. Immunodeficiency and/or diabetes were observed in eight patients. Three patients presented with a uropathy. Prescribed antibiotics were third generation cephalosporins and fluoroquinolones. The average treatment duration was 20 days. A spondylitis and a purulent pleurisy were observed and deemed related to the UTI. Patient outcome was always favorable following treatment prescription. Non-typhi Salmonella enterica UTIs are rare. They are mainly observed in elderly patients presenting with immunodeficiency or an underlying urological disorder. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. 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

  18. 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...

  19. Effect of residual sanitizers on Salmonella enterica biofilm formation

    USDA-ARS?s Scientific Manuscript database

    Introduction: Salmonella enterica are a diverse group of bacteria that represent a serious risk to public health. Bacterial attachment on food and contact surfaces can lead to biofilm formation, and once in this state, bacteria are more resistant to sanitization and may serve as a continuous contam...

  20. Diversity of Genome Structure in Salmonella enterica Serovar Typhi Populations†

    PubMed Central

    Kothapalli, Sushma; Nair, Satheesh; Alokam, Suneetha; Pang, Tikki; Khakhria, Rasik; Woodward, David; Johnson, Wendy; Stocker, Bruce A. D.; Sanderson, Kenneth E.; Liu, Shu-Lin

    2005-01-01

    The genomes of most strains of Salmonella and Escherichia coli are highly conserved. In contrast, all 136 wild-type strains of Salmonella enterica serovar Typhi analyzed by partial digestion with I-CeuI (an endonuclease which cuts within the rrn operons) and pulsed-field gel electrophoresis and by PCR have rearrangements due to homologous recombination between the rrn operons leading to inversions and translocations. Recombination between rrn operons in culture is known to be equally frequent in S. enterica serovar Typhi and S. enterica serovar Typhimurium; thus, the recombinants in S. enterica serovar Typhi, but not those in S. enterica serovar Typhimurium, are able to survive in nature. However, even in S. enterica serovar Typhi the need for genome balance and the need for gene dosage impose limits on rearrangements. Of 100 strains of genome types 1 to 6, 72 were only 25.5 kb off genome balance (the relative lengths of the replichores during bidirectional replication from oriC to the termination of replication [Ter]), while 28 strains were less balanced (41 kb off balance), indicating that the survival of the best-balanced strains was greater. In addition, the need for appropriate gene dosage apparently selected against rearrangements which moved genes from their accustomed distance from oriC. Although rearrangements involving the seven rrn operons are very common in S. enterica serovar Typhi, other duplicated regions, such as the 25 IS200 elements, are very rarely involved in rearrangements. Large deletions and insertions in the genome are uncommon, except for deletions of Salmonella pathogenicity island 7 (usually 134 kb) from fragment I-CeuI-G and 40-kb insertions, possibly a prophage, in fragment I-CeuI-E. The phage types were determined, and the origins of the phage types appeared to be independent of the origins of the genome types. PMID:15805510

  1. Quantitative Oligonucleotide Microarray Fingerprinting of Salmonella enterica isolates

    SciTech Connect

    Willse, Alan R.; Straub, Tim M.; Wunschel, Sharon C.; Small, Jack A.; Call, Douglas R.; Daly, Don S.; Chandler, Darrell P.

    2004-03-22

    We report on a genome-independent microbial fingerprinting method using nucleic acid microarrays for microbial forensics and epidemiology applications. We demonstrate that the microarray method provides high-resolution differentiation between closely related microorganisms using Salmonella enterica strains. In replicate trials we used a simple 192-probe nonamer array to construct a fingerprint library of 25 closely related Salmonella isolates. Controlling false discovery rate for multiple testing at alpha =.05, at least 295 of 300 pairs of S. enterica isolate fingerprints were found to be statistically distinct using a modified Hotelling Tsquared test. Although we find most pairs of Salmonella fingerprints to be distinct, forensic applications will also require a protocol for library construction and reliable microbial classification against a fingerprint library. We outline additional steps required to produce a protocol for library construction and reliable classification of unknown organisms.

  2. 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.

  3. 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.

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

    PubMed

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

    2005-03-01

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

  5. Draft genome sequences of 21 Salmonella enterica serovar enteritidis strains.

    PubMed

    Timme, Ruth E; Allard, Marc W; Luo, Yan; Strain, Errol; Pettengill, James; Wang, Charles; Li, Cong; Keys, Christine E; Zheng, Jie; Stones, Robert; Wilson, Mark R; Musser, Steven M; Brown, Eric W

    2012-11-01

    Salmonella enterica subsp. enterica serovar Enteritidis is a common food-borne pathogen, often associated with shell eggs and poultry. Here, we report draft genomes of 21 S. Enteritidis strains associated with or related to the U.S.-wide 2010 shell egg recall. Eleven of these genomes were from environmental isolates associated with the egg outbreak, and 10 were reference isolates from previous years, unrelated to the outbreak. The whole-genome sequence data for these 21 human pathogen strains are being released in conjunction with the newly formed 100K Genome Project.

  6. Fitness of Salmonella enterica serovar Thompson in the cilantro phyllosphere.

    PubMed

    Brandl, Maria T; Mandrell, Robert E

    2002-07-01

    The epiphytic fitness of Salmonella enterica was assessed on cilantro plants by using a strain of S. enterica serovar Thompson that was linked to an outbreak resulting from cilantro. Salmonella serovar Thompson had the ability to colonize the surface of cilantro leaves, where it was detected by confocal laser scanning microscopy (CLSM) at high densities on the veins and in natural lesions. The population sizes of two common colonizers of plant surfaces, Pantoea agglomerans and Pseudomonas chlororaphis, were 10-fold higher than that of the human pathogen on cilantro incubated at 22 degrees C. However, Salmonella serovar Thompson achieved significantly higher population levels and accounted for a higher proportion of the total culturable bacterial flora on cilantro leaves when the plants were incubated at warm temperatures, such as 30 degrees C, after inoculation, indicating that the higher growth rates exhibited by Salmonella serovar Thompson at warm temperatures may increase the competitiveness of this organism in the phyllosphere. The tolerance of Salmonella serovar Thompson to dry conditions on plants at 60% relative humidity was at least equal to that of P. agglomerans and P. chlororaphis. Moreover, after exposure to low humidity on cilantro, Salmonella serovar Thompson recovered under high humidity to achieve its maximum population size in the cilantro phyllosphere. Visualization by CLSM of green fluorescent protein-tagged Salmonella serovar Thompson and dsRed-tagged P. agglomerans inoculated onto cilantro revealed that the human pathogen and the bacterial epiphyte formed large heterogeneous aggregates on the leaf surface. Our studies support the hypothesis that preharvest contamination of crops by S. enterica plays a role in outbreaks linked to fresh fruits and vegetables.

  7. Variable Carbon Catabolism among Salmonella enterica Serovar Typhi Isolates

    PubMed Central

    Chai, Lay Ching; Kong, Boon Hong; Elemfareji, Omar Ismail; Thong, Kwai Lin

    2012-01-01

    Background Salmonella enterica serovar Typhi (S. Typhi) is strictly a human intracellular pathogen. It causes acute systemic (typhoid fever) and chronic infections that result in long-term asymptomatic human carriage. S. Typhi displays diverse disease manifestations in human infection and exhibits high clonality. The principal factors underlying the unique lifestyle of S. Typhi in its human host during acute and chronic infections remain largely unknown and are therefore the main objective of this study. Methodology/Principal Findings To obtain insight into the intracellular lifestyle of S. Typhi, a high-throughput phenotypic microarray was employed to characterise the catabolic capacity of 190 carbon sources in S. Typhi strains. The success of this study lies in the carefully selected library of S. Typhi strains, including strains from two geographically distinct areas oftyphoid endemicity, an asymptomatic human carrier, clinical stools and blood samples and sewage-contaminated rivers. An extremely low carbon catabolic capacity (27% of 190 carbon substrates) was observed among the strains. The carbon catabolic profiles appeared to suggest that S. Typhi strains survived well on carbon subtrates that are found abundantly in the human body but not in others. The strains could not utilise plant-associated carbon substrates. In addition, α-glycerolphosphate, glycerol, L-serine, pyruvate and lactate served as better carbon sources to monosaccharides in the S. Typhi strains tested. Conclusion The carbon catabolic profiles suggest that S. Typhi could survive and persist well in the nutrient depleted metabolic niches in the human host but not in the environment outside of the host. These findings serve as caveats for future studies to understand how carbon catabolism relates to the pathogenesis and transmission of this pathogen. PMID:22662115

  8. Salmonella enterica induces and subverts the plant immune system.

    PubMed

    García, Ana V; Hirt, Heribert

    2014-01-01

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

  9. Analysis and construction of pathogenicity island regulatory pathways in Salmonella enterica serovar Typhi.

    PubMed

    Ong, Su Yean; Ng, Fui Ling; Badai, Siti Suriawati; Yuryev, Anton; Alam, Maqsudul

    2010-09-23

    Signal transduction through protein-protein interactions and protein modifications are the main mechanisms controlling many biological processes. Here we described the implementation of MedScan information extraction technology and Pathway Studio software (Ariadne Genomics Inc.) to create a Salmonella specific molecular interaction database. Using the database, we have constructed several signal transduction pathways in Salmonella enterica serovar Typhi which causes Typhoid Fever, a major health threat especially in developing countries. S. Typhi has several pathogenicity islands that control rapid switching between different phenotypes including adhesion and colonization, invasion, intracellular survival, proliferation, and biofilm formation in response to environmental changes. Understanding of the detailed mechanism for S. Typhi survival in host cells is necessary for development of efficient detection and treatment of this pathogen. The constructed pathways were validated using publically available gene expression microarray data for Salmonella.

  10. Virulence Gene Regulation by l-Arabinose in Salmonella enterica

    PubMed Central

    López-Garrido, Javier; Puerta-Fernández, Elena; Cota, Ignacio; Casadesús, Josep

    2015-01-01

    Invasion of the intestinal epithelium is a critical step in Salmonella enterica infection and requires functions encoded in the gene cluster known as Salmonella Pathogenicity Island 1 (SPI-1). Expression of SPI-1 genes is repressed by l-arabinose, and not by other pentoses. Transport of l-arabinose is necessary to repress SPI-1; however, repression is independent of l-arabinose metabolism and of the l-arabinose-responsive regulator AraC. SPI-1 repression by l-arabinose is exerted at a single target, HilD, and the mechanism appears to be post-translational. As a consequence of SPI-1 repression, l-arabinose reduces translocation of SPI-1 effectors to epithelial cells and decreases Salmonella invasion in vitro. These observations reveal a hitherto unknown role of l-arabinose in gene expression control and raise the possibility that Salmonella may use L-arabinose as an environmental signal. PMID:25991823

  11. [Arizonae subspecies Salmonella enterica urinary infection with confusional syndrome].

    PubMed

    Landron, Cédric; Le Moal, Gwénaël; Roblot, France; Grignon, Bernadette; Becq-Giraudon, Bertrand

    2003-04-26

    Infections due to subspecies arizonae Salmonella enterica are rare. These infections are transmitted by reptiles. We report the case of S. arizonae urinary tract infection that occurred in an immunocompetent woman. An 82 year-old woman was admitted for confusion. A urinary tract infection due to Salmonella arizonae was diagnosed. No neurological, iatrogenic or metabolic cause could explain the confusion. Treatment with ciprofloxacin was given. The confusion and the infectious syndrome disappeared. The prevalence of infections is probably underestimated because the digestive problems they generate are usually benign.

  12. Mannanoligosaccharide agglutination by Salmonella enterica strains isolated from carrier pigs

    PubMed Central

    Borowsky, Luciane; Corção, Gertrudes; Cardoso, Marisa

    2009-01-01

    Type-1 fimbriae are associated with most Salmonella enterica serovars and are an essential factor for host colonization. Mannanoligosaccharides (MOS), a prebiotic that is agglutinated by type-1 fimbriae, are proposed for the control of enterobacteria colonization and may be an alternative to Salmonella control in pigs. The aim of this study was to evaluate the capability of porcine Salmonella strains to adhere to MOS in vitro. A total of 108 strains of Salmonella sp. isolated from carrier pigs were evaluated for the amplification of fimA and fimH genes, agglutination of MOS and hemagglutination. In all tested strains, amplicons of expected size were detected for both fimA and fimH gene. In the hemagglutination assays, 31 (28.7%) strains presented mannose–sensitive agglutination of erythrocytes, indicating that the strains were expressing type-1 fimbriae. Considering only strains expressing the type-1 fimbriae, 23 (74.2%) presented a strong agglutination of MOS, 3 (9.6%) a weak reaction and 5 (16.2%) none. The results indicate that Salmonella enterica strains expressing type-1 fimbriae can agglutinate effectively in vitro to MOS. PMID:24031388

  13. 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...

  14. [Serovars of Salmonella enterica subspecies enterica and its antimicrobial resistance in slaughterhouse pigs].

    PubMed

    Ibar, M P; Vigo, G; Piñeyro, P; Caffer, M I; Quiroga, P; Perfumo, C; Centrón, D; Giacoboni, G

    2009-01-01

    A study was carried out in order to determine the prevalence of Salmonella and its serovars among porcine slaughterhouses, to evaluate the antimicrobial resistance profiles and to know the presence of class 1 integrons as possible reservoir of resistance. From a total of 386 samples from four porcine slaughterhouses of Buenos Aires and Santa Fe Provinces (Argentina), 93 (24.1%) Salmonella enterica subspecies enterica strains were identified, 52 (55.9%) from cecal contents and 41 (44.1%) from ileocecal lymph nodes. Thirteen serovars of S. enterica were found, the most prevalent were: S. Schwarzengrund, S. Heidelberg, S. subspecie I 6,8:e,h:-, S. Derby and S. Bredeney. Fifteen antimicrobials by the agar dilution method were tested: amikacin, gentamicin, ciprofloxacin, cephalotin, cefotaxime, enrofloxacin, fosfomycin, polimixin-B, tetracycline, chloramphenicol, streptomycin, trimethoprim-sulfamethoxazole, ampicillin, nitrofurantoin, and nalidixic acid. According to the CIM determination, 73% Salmonella enterica subspecies enterica strains were sensible to all the antimicrobials tested. Antimicrobial resistance was observed to tetracycline in 24 (25.8%) of 93 strains, to chloramphenicol in 22 (23.7%), to streptomycin in 22 (23.7%), to trimethoprim-sulfamethoxazole in 20 (21.5%), to ampicillin in 18 (19.4%), to nitrofurantoin in 3 (3.2%) and to nalidixic acid in 3 (3.2%). Some isolates of S. Typhimurium, S. Heidelberg, S. Derby, S. Orion showed multidrug resistance and carried the class 1 integrase gene. The highest percentage of resistance corresponded to the antimicrobials currently used in veterinary and porcine farms.

  15. Selection of Small-Colony Variants of Salmonella enterica Serovar Typhimurium in Nonphagocytic Eucaryotic Cells

    PubMed Central

    Cano, David A.; Pucciarelli, M. Graciela; Martínez-Moya, Marina; Casadesús, Josep; García-del Portillo, Francisco

    2003-01-01

    Salmonella enterica strains are enteropathogenic bacteria that survive and proliferate within vacuolar compartments of epithelial and phagocytic cells. Recently, it has been reported that fibroblast cells are capable of restricting S. enterica serovar Typhimurium intracellular growth. Here, we show that prolonged residence of bacteria in the intracellular environment of fibroblasts results in the appearance of genetically stable small-colony variants (SCV). A total of 103 SCV isolates, obtained from four independent infections, were subjected to phenotypic analysis. The following phenotypes were observed: (i) δ-aminolevulinic acid auxotrophy; (ii) requirement for acetate or succinate for growth in glucose minimal medium; (iii) auxotrophy for aromatic amino acids; and (iv) reduced growth rate under aerobic conditions not linked to nutrient auxotrophy. The exact mutations responsible for the SCV phenotype in three representative isolates were mapped in the lpd, hemL, and aroD genes, which code for dihydrolipoamide dehydrogenase, glutamate-1-semyaldehyde aminotransferase, and 3-dehydroquinate dehydratase, respectively. The lpd, hemL, and aroD mutants had intracellular persistence rates in fibroblasts that were 3 to 4 logs higher than that of the parental strain and decreased susceptibility to aminoglycoside antibiotics. All three of these SCV isolates were attenuated in the BALB/c murine typhoid model. Complementation with lpd+, hem+, and aroD+ genes restored the levels of intracellular persistence and antibiotic susceptibility to levels of the wild-type strain. However, virulence was not exhibited by any of the complemented strains. Altogether, our data demonstrate that similar to what it has been reported for SCV isolates of other pathogens, S. enterica SCV display enhanced intracellular persistence in eucaryotic cells and are impaired in the ability to cause overt disease. In addition, they also suggest that S. enterica SCV may be favored in vivo. PMID:12819049

  16. 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

  17. Complete, closed genome sequences of 10 Salmonella enterica subsp. enterica serovar Typhimurium strains isolated from human and bovine sources

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica are a leading cause of enterocolitis for humans and animals. S. enterica serovar Typhimurium infects a broad range of hosts. To facilitate genomic comparisons among isolates from different sources, we present the complete genome sequences of ten S. Typhimurium strains, five each...

  18. 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

  19. 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

  20. Complete genomic sequences of two outbreak strains of Salmonella enterica subsp. enterica serovar Thompson associated with cilantro

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica serovar Thompson strains RM1984 (CADPH-99A2334) and RM1986 (CADPH -99A2345) are clinical isolates from 1999, putatively related to an outbreak in California from contaminated cilantro. We report the complete genome sequences and annotation of these two S. Thompson...

  1. Genome Sequences of Salmonella enterica subsp. enterica Serovar Infantis Strains from Hungary Representing Two Peak Incidence Periods in Three Decades.

    PubMed

    Wilk, Tímea; Szabó, Móni; Szmolka, Ama; Kiss, János; Olasz, Ferenc; Nagy, Béla

    2017-03-02

    Four strains of Salmonella enterica subsp. enterica serovar Infantis isolated from humans (1980 to 1982) and broiler chickens (2016) have been sequenced. They represent the early and recent peak incidences of this serovar in Hungary. Genome sequences of these isolates provide comparative data on the evolution and rise of an endemic S Infantis clone in Hungary.

  2. Genome Sequences of Salmonella enterica subsp. enterica Serovar Infantis Strains from Hungary Representing Two Peak Incidence Periods in Three Decades

    PubMed Central

    Wilk, Tímea; Szabó, Móni; Szmolka, Ama; Kiss, János

    2017-01-01

    ABSTRACT Four strains of Salmonella enterica subsp. enterica serovar Infantis isolated from humans (1980 to 1982) and broiler chickens (2016) have been sequenced. They represent the early and recent peak incidences of this serovar in Hungary. Genome sequences of these isolates provide comparative data on the evolution and rise of an endemic S. Infantis clone in Hungary. PMID:28254986

  3. 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.

  4. Whole-Genome Sequence and Annotation of Salmonella enterica subsp. enterica Serovar Enteritidis Phage Type 8 Strain EN1660

    PubMed Central

    Perry, Benjamin J.; Fitzgerald, Stephen F.; Kröger, Carsten

    2017-01-01

    ABSTRACT The genome of Salmonella enterica subspecies enterica serovar Enteritidis phage type 8 strain EN1660, isolated from an outbreak in Thunder Bay, Canada, was sequenced to 46-fold coverage using an Illumina MiSeq with 300-bp paired-end sequencing chemistry to produce 28 contigs with an N50 value of 490,721 bp. PMID:28126943

  5. The complete genome sequence and methylome of Salmonella enterica subsp. enterica serovar Cerro, a frequent dairy cow strain

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica serovar Cerro is an infrequent pathogen of humans and other mammals, but is frequently isolated from the hindgut of asymptomatic cattle in the United States. To further understand the genomic determinants of S. Cerro specificity for the bovine hindgut, the genome ...

  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. Acid exposure induces multiplication of Salmonella enterica serovar Typhi.

    PubMed

    Ahirwar, Suneel Kumar; Pratap, Chandra Bhan; Patel, Saurabh Kumar; Shukla, Vijay K; Singh, Indarjeet Gambhir; Mishra, Om Prakash; Kumar, Kailash; Singh, Tej Bali; Nath, Gopal

    2014-12-01

    Salmonella enterica serovar Typhi faces several environmental stresses while going through the stomach (acidic pH) to the small intestine (basic pH) and intracellularly in macrophages (acidic pH) in humans. The acidic pH followed by alkaline pH in the small intestine might be responsible for expression of certain stress-induced genes, resulting in not only better survival but also induction of multiplication and invasion of the bacterium in the small intestine. Based on this hypothesis, we developed a process wherein we exposed the blood, urine, and stool specimens from 90 acute typhoid fever patients and 36 chronic typhoid carriers to acidic pH to see the effect on isolation rate of S. Typhi. About 5 g of freshly passed unpreserved stool, a centrifuged deposit of 15 ml of urine, and 5 ml of blood clot were subjected to 5 ml of Luria-Bertani (LB) broth (pH 3.5) for 20 min, followed by enrichment in bile broth-selenite F broth. When the combined isolation from all 3 specimens, i.e., blood, urine, and stool, after acid exposure was considered, a total of 77.7% of the acute typhoid patients were observed to be positive for the isolation of the S. Typhi serotype, compared to 8.8% by the conventional method. Similarly, 42% (15/36) of chronic carriers yielded positive for S. Typhi growth after acid exposure, compared to 5.5% (2/36) by the conventional method. It therefore can be concluded that acid shock triggers the multiplication of the bacteria, resulting in better isolation rates from blood clot, stool, and urine specimens.

  8. Novel haemolysins of Salmonella enterica spp. enterica serovar Gallinarum.

    PubMed

    Agrawal, Ravi Kant; Singh, B R; Babu, N; Chandra, Mudit

    2005-07-01

    Haemolysins of Salmonella are important due to their probable role in pathogenesis of systemic salmonellosis and use in sub-serovar level typing. The present study was undertaken to determine haemolytic potential of Salmonella Gallinarum strains through phenotypic and genotypic methods. Amplification of haemolysin gene (clyA) and cytolysin gene (slyA) was attempted in order to determine their role in haemolysin production. Study on 94 strains of S. Gallinarum revealed the production of two types of haemolysis viz., beneath the colony haemolysis (BCH) or contact haemolysis and clear zone haemolysis (CZH). Haemolysis was observed on blood agar prepared with blood of cattle, buffalo, sheep, goat, horse, rabbit, guinea pig, fowl, and human blood group A, B, AB and O. Although, haemolysis was also observed on blood agar prepared with whole blood, clarity of zone was more evident on blood agar made from washed erythrocytes. Clear zone haemolysis was best observed on blood agar prepared with washed erythrocytes of goat and a total of 12% (11 of 94) S. Gallinarum strains under study produced CZH on it. The clyA gene could not be detected in any of the 94 strains under study, while slyA gene could be amplified uniformly irrespective of haemolytic potential (CZH) and haemolytic pattern (BCH) of the strains. The study suggested that the two types of haemolysis (CZH and BCH) observed among S. Gallinarum strains may not be due to either slyA or clyA gene products and thus there may be some other gene responsible for haemolytic trait in Gallinarum serovar. Different haemolytic patterns of strains under study indicated multiplicity of haemolysins in S. Gallinarum.

  9. Persistence of Salmonella enterica during dehydration and subsequent cold storage.

    PubMed

    Gruzdev, Nadia; Pinto, Riky; Sela Saldinger, Shlomo

    2012-12-01

    Despite the fact that Salmonella enterica serotype Typhimurium SL 1344 has served as a model pathogen in many studies, information regarding its desiccation response is still scarce. In this study, we investigated environmental conditions that affect Salmonella survival following dehydration and subsequent cold storage, using a 96-well polystyrene plate model. The SL 1344 strain exhibited high survival compared with other Typhimurium isolates and S. enterica serotypes. Further characterization of desiccation tolerance in this strain revealed that temperature, stationary-phase of growth, solid medium, and the presence of increasing NaCl concentrations (0.5-5.0%) in the growth medium enhanced desiccation tolerance. Dehydration at basic pHs (8-10), or in trehalose, sucrose, but not in glycine-betaine, improved bacterial persistence. Dehydrated Salmonella survived over 100 weeks at 4 °C with a ∼5-log reduction in numbers. However, viability staining revealed only a ∼50% reduction in viable cells, suggesting bacterial transition into a viable-but-not-cultivable state (VBNC). Addition of chloramphenicol reduced bacterial survival implying that adaptation to desiccation stress requires de-novo protein synthesis. Consistent with this finding, shortening the dehydration time resulted in lower survival. This study emphasizes the impact of environmental conditions on the fate of dried Salmonella in the food chain and highlights the potential transition of the pathogen to the VBNC state. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Nifedipine Affects the Course of Salmonella enterica Serovar Typhimurium Infection by Modulating Macrophage Iron Homeostasis

    PubMed Central

    Mair, Sabine M.; Nairz, Manfred; Bellmann-Weiler, Rosa; Muehlbacher, Thomas; Schroll, Andrea; Theurl, Igor; Moser, Patrizia L.; Talasz, Heribert; Fang, Ferric C.

    2011-01-01

    Background. Iron overload can adversely influence the course of infection by increasing microbial replication and suppressing antimicrobial immune effector pathways. Recently, we have shown that the calcium channel blocker nifedipine can mobilize tissue iron in mouse models of iron overload. We therefore investigated whether nifedipine treatment affects the course of infection with intracellular bacteria via modulation of iron homeostasis. Methods. The effect of nifedipine on intramacrophage replication of bacteria and modulation of cellular iron homeostasis was investigated in the murine macrophage cell line RAW264.7, and the impact of nifedipine treatment on the course of systemic infection was investigated in C57BL/6 mice in vivo. Results. In RAW264.7 cells, nifedipine treatment significantly reduced intracellular bacterial survival of Salmonella enterica serovar Typhimurium and Chlamydophila pneumoniae. This could be attributed to the induction of the iron exporter ferroportin 1, which limited the availability of iron for intracellular Salmonella. When C57BL/6 mice were infected intraperitoneally with Salmonella and subsequently injected with nifedipine for 3 consecutive days, bacterial counts in livers and spleens were significantly reduced and survival of the mice significantly was prolonged compared with solvent-treated littermates. Nifedipine treatment increased expression of ferroportin 1 in the spleen, whereas splenic levels of the iron storage protein ferritin and serum iron concentrations were reduced. Conclusions. Our data provide evidence for a novel mechanism whereby nifedipine enhances host resistance to intracellular pathogens via limitation of iron availability. PMID:21844295

  11. 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

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

    PubMed Central

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

    2008-01-01

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

  13. Complete Genome Sequence of Salmonella enterica subsp. enterica Serovar Typhi Isolate B/SF/13/03/195 Associated with a Typhoid Carrier in Pasir Mas, Kelantan, Malaysia

    PubMed Central

    Sim, Kee-Shin; Mohd Nor, Fauziah; Mat Hussin, Hani; Hamzah, Wan Mansor; Najimudin, Nazalan

    2015-01-01

    We report here the complete genome sequence of Salmonella enterica subsp. enterica serovar Typhi B/SF/13/03/195 obtained from a typhoid carrier, who is a food handler in Pasir Mas, Kelantan. PMID:26564035

  14. 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.

  15. Ingress of Salmonella enterica Typhimurium into Tomato Leaves through Hydathodes

    PubMed Central

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

    2013-01-01

    Internal contamination of Salmonella in plants is attracting increasing attention for food safety reasons. In this study, three different tomato cultivars “Florida Lanai”, “Crown Jewel”, “Ailsa Craig” and the transgenic line Sp5 of “Ailsa Craig” were inoculated with 1 µl GFP-labeled Salmonella Typhimurium through guttation droplets at concentrations of 109 or 107 CFU/ml. Survival of Salmonella on/in tomato leaves was detected by both direct plating and enrichment methods. Salmonella cells survived best on/in the inoculated leaves of cultivar “Ailsa Craig” and decreased fastest on/in “Florida Lanai” leaves. Increased guttation in the abscisic acid over-expressing Sp5 plants may have facilitated the entrance of Salmonella into leaves and the colonization on the surface of tomato leaves. Internalization of Salmonella Typhimurium in tomato leaves through guttation drop inoculation was confirmed by confocal laser microscopy. For the first time, convincing evidence is presented that S. enterica can enter tomato leaves through hydathodes and move into the vascular system, which may result in the internal translocation of the bacteria inside plants. PMID:23320087

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

    PubMed

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

    2013-01-01

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

  17. Bile-induced peptidoglycan remodelling in Salmonella enterica.

    PubMed

    Hernández, Sara B; Cava, Felipe; Pucciarelli, M Graciela; García-Del Portillo, Francisco; de Pedro, Miguel A; Casadesús, Josep

    2015-04-01

    Changes in the peptidoglycan (PG) structure of Salmonella enterica are detected in the presence of a sublethal concentration of sodium deoxycholate (DOC): (i) lower proportions of Braun lipoprotein (Lpp)-bound muropeptides; (ii) reduced levels of muropeptides cross-linked by L(meso)-diaminopimelyl-D(meso)-diaminopimelic acid (L-D) peptide bridges (3-3 cross-links). Similar structural changes are found in S. enterica cultures adapted to grow in the presence of a lethal concentration of DOC, suggesting that reduced anchoring of Braun protein to PG and low occurrence of 3-3 cross-links may increase S. enterica resistance to bile. This view is further supported by additional observations: (i) A triple mutant lacking L,D-transpeptidases YbiS, ErfK, and YcfS, which does not contain Lpp anchored to PG, is hyper-resistant to bile; (ii) enhanced 3-3 cross-linking upon overexpression of YnhG transpeptidase causes a decrease in bile resistance. These observations suggest that remodelling of the cell wall may be added to the list of adaptive responses that permit survival of S. enterica in the presence of bile.

  18. Genome Sequence of Salmonella enterica subsp. enterica Serovar Typhi Isolate PM016/13 from Untreated Well Water Associated with a Typhoid Outbreak in Pasir Mas, Kelantan, Malaysia

    PubMed Central

    Sim, Kee-Shin; Najimudin, Nazalan

    2015-01-01

    Salmonella enterica subsp. enterica serovar Typhi is a human-restricted pathogen that causes typhoid fever. Even though it is a human-restricted pathogen, the bacterium is also isolated from environments such as groundwater and pond water. Here, we describe the genome sequence of the Salmonella enterica subsp. enterica serovar Typhi PM016/13 which was isolated from well water during a typhoid outbreak in Kelantan, Malaysia, in 2013. PMID:26564032

  19. Genome Sequence of Salmonella enterica subsp. enterica Serovar Typhi Isolate PM016/13 from Untreated Well Water Associated with a Typhoid Outbreak in Pasir Mas, Kelantan, Malaysia.

    PubMed

    Muhamad Harish, Salwani; Sim, Kee-Shin; Najimudin, Nazalan; Aziah, Ismail

    2015-11-12

    Salmonella enterica subsp. enterica serovar Typhi is a human-restricted pathogen that causes typhoid fever. Even though it is a human-restricted pathogen, the bacterium is also isolated from environments such as groundwater and pond water. Here, we describe the genome sequence of the Salmonella enterica subsp. enterica serovar Typhi PM016/13 which was isolated from well water during a typhoid outbreak in Kelantan, Malaysia, in 2013. Copyright © 2015 Muhamad Harish et al.

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

    USDA-ARS?s Scientific Manuscript database

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

  1. 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...

  2. 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

  3. Salmonella enterica serovar Enteritidis, England and Wales, 1945-2011.

    PubMed

    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; Adak, Goutam K

    2014-07-01

    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.

  4. Bile-Induced DNA Damage in Salmonella enterica

    PubMed Central

    Prieto, Ana I.; Ramos-Morales, Francisco; Casadesús, Josep

    2004-01-01

    In the absence of DNA adenine methylase, growth of Salmonella enterica serovar Typhimurium is inhibited by bile. Mutations in any of the mutH, mutL, and mutS genes suppress bile sensitivity in a Dam− background, indicating that an active MutHLS system renders Dam− mutants bile sensitive. However, inactivation of the MutHLS system does not cause bile sensitivity. An analogy with Escherichia coli, in which the MutHLS system sensitizes Dam− mutants to DNA-injuring agents, suggested that bile might cause DNA damage. In support of this hypothesis, we show that bile induces the SOS response in S. enterica and increases the frequency of point mutations and chromosomal rearrangements. Mutations in mutH, mutL, or mutS cause partial relief of virulence attenuation in a Dam− background (50- to 100-fold by the oral route and 10-fold intraperitoneally), suggesting that an active MutHLS system reduces the ability of Salmonella Dam− mutants to cope with DNA-damaging agents (bile and others) encountered during the infection process. The DNA-damaging ability of bile under laboratory conditions raises the possibility that the phenomenon may be relevant in vivo, since high bile concentrations are found in the gallbladder, the niche for chronic Salmonella infections. PMID:15611156

  5. Kidney allograft pyelonephritis caused by Salmonella enterica serovar Schwarzengrund.

    PubMed

    Ito, Kenta; Nishio, Haruomi; Iwatani, Yuji; Yamada, Ryo; Okawa, Takao; Yamamoto, Takumi; Murakami, Masaaki; Matsuo, Yoko; Matsuo, Ken; Tanaka, Satoshi; Mori, Kiyoshi; Mori, Noriko

    2017-03-13

    Kidney transplant recipients (KTRs) taking immunosuppressive drugs have a 20-fold greater risk of nontyphoidal Salmonella (NTS) infection than the healthy adult population. Among KTRs, the urinary tract is the most common site of infection. However, few cases of urinary tract infection caused by NTS have been documented in KTRs, and only one in Japan. Furthermore, it frequently induces acute allograft rejection with high mortality. Salmonella enterica subsp. enterica serovar Schwarzengrund (S. Schwarzengrund) is now among the more common Salmonella serovars isolated in Japan and is likely to be invasive. We present a case of a 45-year old female with vesicoureteral reflux to her transplanted kidney who developed kidney allograft pyelonephritis caused by S. Schwarzengrund. She was admitted to our hospital with fever, urodynia, lower abdominal pain, gross hematuria, and cloudy urine. Urine cultures were positive for S. Schwarzengrund. Exposure to cats, especially stray cats, were identified as the most likely source. We administered antibiotics for 4 weeks (ceftriaxone then amoxicillin, each for 2 weeks) and educated her about pet safety. She experienced no recurrence of infection or clinical kidney allograft rejection for 3 months post-treatment. NTS should be considered as a possible pathogen of urinary tract infection among KTRs, especially in cases with animal exposure or structural urologic abnormalities. When the pathogen is NTS, appropriate antibiotics and treatment periods are essential for preventing recurrence and allograft rejection after the completion of treatment.

  6. Ferrioxamine-Mediated Iron(III) Utilization by Salmonella enterica

    PubMed Central

    Kingsley, Robert A.; Reissbrodt, Rolf; Rabsch, Wolfgang; Ketley, Julian M.; Tsolis, Renée M.; Everest, Paul; Dougan, Gordon; Bäumler, Andreas J.; Roberts, Mark; Williams, Peter H.

    1999-01-01

    Utilization of ferrioxamines as sole sources of iron distinguishes Salmonella enterica serotypes Typhimurium and Enteritidis from a number of related species, including Escherichia coli. Ferrioxamine supplements have therefore been used in preenrichment and selection media to increase the bacterial growth rate while selectivity is maintained. We characterized the determinants involved in utilization of ferrioxamines B, E, and G by S. enterica serotype Typhimurium by performing siderophore cross-feeding bioassays. Transport of all three ferric siderophores across the outer membrane was dependent on the FoxA receptor encoded by the Fur-repressible foxA gene. However, only the transport of ferrioxamine G was dependent on the energy-transducing protein TonB, since growth stimulation of a tonB strain by ferrioxamines B and E was observed, albeit at lower efficiencies than in the parental strain. Transport across the inner membrane was dependent on the periplasmic binding protein-dependent ABC transporter complex comprising FhuBCD, as has been reported for other hydroxamate siderophores of enteric bacteria. The distribution of the foxA gene in the genus Salmonella, as indicated by DNA hybridization studies and correlated with the ability to utilize ferrioxamine E, was restricted to subspecies I, II, and IIIb, and this gene was absent from subspecies IIIa, IV, VI, and VII (formerly subspecies IV) and Salmonella bongori (formerly subspecies V). S. enterica serotype Typhimurium mutants with either a transposon insertion or a defined nonpolar frameshift (+2) mutation in the foxA gene were not able to utilize any of the three ferrioxamines tested. A strain carrying the nonpolar foxA mutation exhibited a significantly reduced ability to colonize rabbit ileal loops compared to the foxA+ parent. In addition, a foxA mutant was markedly attenuated in mice inoculated by either the intragastric or intravenous route. Mice inoculated with the foxA mutant were protected against

  7. 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.

  8. Genome-Wide Methylation Patterns in Salmonella enterica Subsp. enterica Serovars

    PubMed Central

    Pirone-Davies, Cary; Hoffmann, Maria; Roberts, Richard J.; Muruvanda, Tim; Timme, Ruth E.; Strain, Errol; Luo, Yan; Payne, Justin; Luong, Khai; Song, Yi; Tsai, Yu-Chih; Boitano, Matthew; Clark, Tyson A.; Korlach, Jonas; Evans, Peter S.; Allard, Marc W.

    2015-01-01

    The methylation of DNA bases plays an important role in numerous biological processes including development, gene expression, and DNA replication. Salmonella is an important foodborne pathogen, and methylation in Salmonella is implicated in virulence. Using single molecule real-time (SMRT) DNA-sequencing, we sequenced and assembled the complete genomes of eleven Salmonella enterica isolates from nine different serovars, and analysed the whole-genome methylation patterns of each genome. We describe 16 distinct N6-methyladenine (m6A) methylated motifs, one N4-methylcytosine (m4C) motif, and one combined m6A-m4C motif. Eight of these motifs are novel, i.e., they have not been previously described. We also identified the methyltransferases (MTases) associated with 13 of the motifs. Some motifs are conserved across all Salmonella serovars tested, while others were found only in a subset of serovars. Eight of the nine serovars contained a unique methylated motif that was not found in any other serovar (most of these motifs were part of Type I restriction modification systems), indicating the high diversity of methylation patterns present in Salmonella. PMID:25860355

  9. Cytotoxic T cell adjuvant effects of three Salmonella enterica flagellins

    PubMed Central

    Braga, Catarina J.M.; Massis, Liliana M.; Alencar, Bruna C.G.; Rodrigues, Maurício M.; Sbrogio-Almeida, M.E.; Ferreira, Luís C.S.

    2008-01-01

    Bacterial flagellins are important virulence-associated factors and strong inducers of inflammatory responses in mammalian hosts. Flagellins have also been investigated as potential vaccine adjuvants, either for induction of humoral or cellular immune responses, to different target antigens. In this study we investigated the adjuvant properties of three Salmonella enterica flagellins types (FliCd, FliCi and FljB) to an ovalbumin-derived CD8+ T cell-restricted epitope (OVA257–264). Although mice immunized with the three tested flagellins elicited antigen-specific activated CD8+ T cells, only animals immunized with FliCi and FliCd flagellins admixed with ovalbumin mounted specific in vivo cytotoxic responses to peptide-pulsed target cells. The present results indicate that Salmonella flagellins are endowed with type-specific adjuvant effects toward murine CD8+ T cells, a feature that may impact their use as adjuvants for prophylatic or therapeutic vaccines. PMID:24031176

  10. Proteomic analysis of triclosan resistance in Salmonella enterica serovar Typhimurium.

    PubMed

    Webber, Mark A; Coldham, Nick G; Woodward, Martin J; Piddock, Laura J V

    2008-07-01

    The aim of this study was to determine and compare the proteomes of three triclosan-resistant mutants of Salmonella enterica serovar Typhimurium in order to identify proteins involved in triclosan resistance. The proteomes of three distinct but isogenic triclosan-resistant mutants were determined using two-dimensional liquid chromatography mass separation. Bioinformatics was then used to identify and quantify tryptic peptides in order to determine protein expression. Proteomic analysis of the triclosan-resistant mutants identified a common set of proteins involved in production of pyruvate or fatty acid with differential expression in all mutants, but also demonstrated specific patterns of expression associated with each phenotype. These data show that triclosan resistance can occur via distinct pathways in Salmonella, and demonstrate a novel triclosan resistance network that is likely to have relevance to other pathogenic bacteria subject to triclosan exposure and may provide new targets for development of antimicrobial agents.

  11. Osteomyelitis caused by Salmonella enterica serovar derby in boa constrictor.

    PubMed

    de Souza, Suyene O; Casagrande, Renata A; Guerra, Priscila R; Cruz, Cláudio E F; Veit, Evandro; Cardoso, Marisa R I; Driemeier, David

    2014-09-01

    After demonstrating chronic weight loss, prostration, and muscle flaccidness, a captive-bred 9-mo-old boa constrictor (Boa constrictor constrictor) died and was submitted for necropsy. Along the spinal column there were multiple, yellowish white, macroscopic nodules of 1-5 mm in diameter in the ventral side of the vertebral body and in the intervertebral spaces. Severe multifocal necrotizing osteomyelitis associated with granulomatous inflammation was the main histologic finding in the vertebral column. In the liver, there was discrete but similar granulomatous changes. Positive anti-Salmonella immunostaining was observed in the spinal column and in the liver. Salmonella enterica serovar Derby was isolated from fragments of the spinal column. These bacteria are important cause of disease in captive reptiles.

  12. 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.

  13. Gene expression analysis of Salmonella enterica Enteritidis NalR and Salmonella enterica Kentucky 3795 exposed to HCl and acetic acid in rich medium

    USDA-ARS?s Scientific Manuscript database

    In the United States, serovar Kentucky has become one of the most frequently isolated Salmonella enterica serovars from chickens. The reasons for this prevalence are not well understood. Phenotypic comparisons of poultry Salmonella isolates belonging to various serovars demonstrated that serovar Ken...

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

    PubMed Central

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

    2015-01-01

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

  15. Inhibition of the PtdIns(5) kinase PIKfyve disrupts intracellular replication of Salmonella

    PubMed Central

    Kerr, Markus C; Wang, Jack T H; Castro, Natalie A; Hamilton, Nicholas A; Town, Liam; Brown, Darren L; Meunier, Frederic A; Brown, Nat F; Stow, Jennifer L; Teasdale, Rohan D

    2010-01-01

    3-phosphorylated phosphoinositides (3-PtdIns) orchestrate endocytic trafficking pathways exploited by intracellular pathogens such as Salmonella to gain entry into the cell. To infect the host, Salmonellae subvert its normal macropinocytic activity, manipulating the process to generate an intracellular replicative niche. Disruption of the PtdIns(5) kinase, PIKfyve, be it by interfering mutant, siRNA-mediated knockdown or pharmacological means, inhibits the intracellular replication of Salmonella enterica serovar typhimurium in epithelial cells. Monitoring the dynamics of macropinocytosis by time-lapse 3D (4D) videomicroscopy revealed a new and essential role for PI(3,5)P2 in macropinosome-late endosome/lysosome fusion, which is distinct from that of the small GTPase Rab7. This PI(3,5)P2-dependent step is required for the proper maturation of the Salmonella-containing vacuole (SCV) through the formation of Salmonella-induced filaments (SIFs) and for the engagement of the Salmonella pathogenicity island 2-encoded type 3 secretion system (SPI2-T3SS). Finally, although inhibition of PIKfyve in macrophages did inhibit Salmonella replication, it also appears to disrupt the macrophage's bactericidal response. PMID:20300065

  16. Survival of Salmonella enterica in aerated and nonaerated wastewaters from dairy lagoons

    USDA-ARS?s Scientific Manuscript database

    Salmonella is the most commonly identified foodborne pathogen in produce, meat and poultry. Cattle are known reservoirs of Salmonella and the pathogen excreted in feces end up in manure flush lagoons. Salmonella enterica survival was monitored in wastewater from on-site holding lagoons equipped with...

  17. Complete Sequences of Six IncA/C Plasmids of Multidrug-Resistant Salmonella enterica subsp. enterica Serotype Newport.

    PubMed

    Cao, Guojie; Allard, Marc W; Hoffmann, Maria; Monday, Steven R; Muruvanda, Tim; Luo, Yan; Payne, Justin; Rump, Lydia; Meng, Kevin; Zhao, Shaohua; McDermott, Patrick F; Brown, Eric W; Meng, Jianghong

    2015-02-26

    Multidrug-resistant (MDR) Salmonella enterica subsp. enterica serotype Newport has been a long-standing public health concern in the United States. We present the complete sequences of six IncA/C plasmids from animal-derived MDR S. Newport ranging from 80.1 to 158.5 kb. They shared a genetic backbone with S. Newport IncA/C plasmids pSN254 and pAM04528.

  18. 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

  19. Impact of pulsed light on cellular activity of Salmonella enterica.

    PubMed

    Kramer, B; Wunderlich, J; Muranyi, P

    2016-10-01

    The objective of this study was a comprehensive characterization of physiological changes of Salmonella enterica induced by intense broad spectrum pulsed light (PL). After exposing the bacteria to this nonthermal decontamination technology on a gel surface, multiple viability parameters beyond culturability were assessed. By applying flow cytometry, a luciferin-luciferase bioluminescence assay and a microplate assay to measure the current redox activity, the impact of pulsed light on the membrane potential, membrane integrity, esterase activity, efflux pump activity, expression of the green fluorescent protein (GFP), respiration activity and ATP-content of Salm. enterica ATCC BAA-1045 was determined. These culture-independent methods for assessing the bacterial activity were compared to the ability to grow on tryptic soy agar. It is shown that this strain is rather sensitive to PL considering colony count reductions, while on the other hand unculturable bacteria still exhibit significant cellular energetic functions. However, this residual activity after PL exposure significantly decreases during sample storage in buffer for 24 h. This study also shows that the GFP expression of PL-treated cells which have rendered unculturable is severely reduced. This study reveals that although not all cellular functions of Salm. enterica are immediately shut down after PL exposure, the synthesis of new GFP is strongly reduced and affected to a similar extent as the culturability. It is shown for the first time, that even there is significant bacterial activity measurable after PL exposure, it is likely that nongrowing pathogenic bacteria like Salm. enterica are unable to express proteins, which is of great importance regarding their pathogenicity. © 2016 The Society for Applied Microbiology.

  20. Single-cell RNA-seq ties macrophage polarization to growth rate of intracellular Salmonella.

    PubMed

    Saliba, Antoine-Emmanuel; Li, Lei; Westermann, Alexander J; Appenzeller, Silke; Stapels, Daphne A C; Schulte, Leon N; Helaine, Sophie; Vogel, Jörg

    2016-11-14

    Intracellular bacterial pathogens can exhibit large heterogeneity in growth rate inside host cells, with major consequences for the infection outcome. If and how the host responds to this heterogeneity remains poorly understood. Here, we combined a fluorescent reporter of bacterial cell division with single-cell RNA-sequencing analysis to study the macrophage response to different intracellular states of the model pathogen Salmonella enterica serovar Typhimurium. The transcriptomes of individual infected macrophages revealed a spectrum of functional host response states to growing and non-growing bacteria. Intriguingly, macrophages harbouring non-growing Salmonella display hallmarks of the proinflammatory M1 polarization state and differ little from bystander cells, suggesting that non-growing bacteria evade recognition by intracellular immune receptors. By contrast, macrophages containing growing bacteria have turned into an anti-inflammatory, M2-like state, as if fast-growing intracellular Salmonella overcome host defence by reprogramming macrophage polarization. Additionally, our clustering approach reveals intermediate host functional states between these extremes. Altogether, our data suggest that gene expression variability in infected host cells shapes different cellular environments, some of which may favour a growth arrest of Salmonella facilitating immune evasion and the establishment of a long-term niche, while others allow Salmonella to escape intracellular antimicrobial activity and proliferate.

  1. 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.

  2. 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

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

    PubMed Central

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

    2000-01-01

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

  4. The Type III Secretion System Effector SptP of Salmonella enterica Serovar Typhi.

    PubMed

    Johnson, Rebecca; Byrne, Alexander; Berger, Cedric N; Klemm, Elizabeth; Crepin, Valerie F; Dougan, Gordon; Frankel, Gad

    2017-02-15

    Strains of the various Salmonella enterica serovars cause gastroenteritis or typhoid fever in humans, with virulence depending on the action of two type III secretion systems (Salmonella pathogenicity island 1 [SPI-1] and SPI-2). SptP is a Salmonella SPI-1 effector, involved in mediating recovery of the host cytoskeleton postinfection. SptP requires a chaperone, SicP, for stability and secretion. SptP has 94% identity between S. enterica serovar Typhimurium and S Typhi; direct comparison of the protein sequences revealed that S Typhi SptP has numerous amino acid changes within its chaperone-binding domain. Subsequent comparison of ΔsptP S Typhi and S. Typhimurium strains demonstrated that, unlike SptP in S. Typhimurium, SptP in S Typhi was not involved in invasion or cytoskeletal recovery postinfection. Investigation of whether the observed amino acid changes within SptP of S Typhi affected its function revealed that S Typhi SptP was unable to complement S. Typhimurium ΔsptP due to an absence of secretion. We further demonstrated that while S. Typhimurium SptP is stable intracellularly within S Typhi, S Typhi SptP is unstable, although stability could be recovered following replacement of the chaperone-binding domain with that of S. Typhimurium. Direct assessment of the strength of the interaction between SptP and SicP of both serovars via bacterial two-hybrid analysis demonstrated that S Typhi SptP has a significantly weaker interaction with SicP than the equivalent proteins in S. Typhimurium. Taken together, our results suggest that changes within the chaperone-binding domain of SptP in S Typhi hinder binding to its chaperone, resulting in instability, preventing translocation, and therefore restricting the intracellular activity of this effector.

  5. Identification and characterization of outer membrane vesicle-associated proteins in Salmonella enterica serovar Typhimurium.

    PubMed

    Bai, Jaewoo; Kim, Seul I; Ryu, Sangryeol; Yoon, Hyunjin

    2014-10-01

    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. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  6. 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

  7. 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

  8. The Type III Secretion System Effector SptP of Salmonella enterica Serovar Typhi

    PubMed Central

    Johnson, Rebecca; Byrne, Alexander; Berger, Cedric N.; Klemm, Elizabeth; Crepin, Valerie F.; Dougan, Gordon

    2016-01-01

    ABSTRACT Strains of the various Salmonella enterica serovars cause gastroenteritis or typhoid fever in humans, with virulence depending on the action of two type III secretion systems (Salmonella pathogenicity island 1 [SPI-1] and SPI-2). SptP is a Salmonella SPI-1 effector, involved in mediating recovery of the host cytoskeleton postinfection. SptP requires a chaperone, SicP, for stability and secretion. SptP has 94% identity between S. enterica serovar Typhimurium and S. Typhi; direct comparison of the protein sequences revealed that S. Typhi SptP has numerous amino acid changes within its chaperone-binding domain. Subsequent comparison of ΔsptP S. Typhi and S. Typhimurium strains demonstrated that, unlike SptP in S. Typhimurium, SptP in S. Typhi was not involved in invasion or cytoskeletal recovery postinfection. Investigation of whether the observed amino acid changes within SptP of S. Typhi affected its function revealed that S. Typhi SptP was unable to complement S. Typhimurium ΔsptP due to an absence of secretion. We further demonstrated that while S. Typhimurium SptP is stable intracellularly within S. Typhi, S. Typhi SptP is unstable, although stability could be recovered following replacement of the chaperone-binding domain with that of S. Typhimurium. Direct assessment of the strength of the interaction between SptP and SicP of both serovars via bacterial two-hybrid analysis demonstrated that S. Typhi SptP has a significantly weaker interaction with SicP than the equivalent proteins in S. Typhimurium. Taken together, our results suggest that changes within the chaperone-binding domain of SptP in S. Typhi hinder binding to its chaperone, resulting in instability, preventing translocation, and therefore restricting the intracellular activity of this effector. IMPORTANCE Studies investigating Salmonella pathogenesis typically rely on Salmonella Typhimurium, even though Salmonella Typhi causes the more severe disease in humans. As such, an understanding of

  9. Antimicrobial susceptibility and plasmid replicon typing of Salmonella enterica serovar Kentucky isolates recovered from broilers

    USDA-ARS?s Scientific Manuscript database

    In the United States, Salmonella enterica serotype Kentucky has become the predominate serotype recovered from broiler slaughter samples and the prevalence of resistance to streptomycin and tetracycline has increased dramatically in this serotype. To characterize the relationships between antimicro...

  10. 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...

  11. Antibiotic resistant Escherichia coli and Salmonella enterica in the beef production and processing chain

    USDA-ARS?s Scientific Manuscript database

    Background: Concerns have been raised that extended-spectrum cephalosporin-resistant Escherichia coli (CefR EC), trimethoprim-sulfamethoxazole-resistant E. coli (TxsR EC), extended-spectrum cephalosporin-resistant Salmonella enterica (CefR SE), and nalidixic acid-resistant S. enterica (NalR SE) in c...

  12. Genome sequences of ten Salmonella enterica serovars isolated from a single dairy farm

    USDA-ARS?s Scientific Manuscript database

    Here we report draft genomes of twenty-seven isolates of Salmonella enterica subsp. enterica representing the seven serotypes isolated from cows in a Pennsylvania dairy herd, the farm on which they were reared, and the associated off-site heifer-raising facility over an eight year sampling period. ...

  13. Studies on Biofilm Formation and Interactions of Salmonella enterica with Romaine-Lettuce Leaves

    USDA-ARS?s Scientific Manuscript database

    The association between biofilm formation and the interactions of Salmonella enterica serovars with cut-Romaine-lettuce leaves was investigated. Biofilm formation by 8 S. enterica serovars was tested on polystyrene microtiter plates in the presence of different growth media. Maximal biofilm mass was...

  14. Genome-scale screening and validation of targets for identification of Salmonella enterica and serovar prediction

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is the most common foodborne pathogen worldwide, with a great diversity of 2500 recognized serovars. Detection of S. enterica and its classification into serovars are essential for food safety surveillance and clinical diagnosis. Recently, the polymerase chain reaction (PCR) meth...

  15. ESBL-producing Salmonella enterica serovar Typhi in traveler returning from Guatemala to Spain.

    PubMed

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

    2014-11-01

    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.

  16. 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

  17. [Antibiotic resistance and virulence factors in clinical Salmonella enterica isolates].

    PubMed

    de Toro, María; Seral, Cristina; Rojo-Bezares, Beatriz; Torres, Carmen; Castillo, F Javier; Sáenz, Yolanda

    2014-01-01

    The increase of Salmonella enterica isolates multi-resistant to different antibiotics, including β-lactams and fluoroquinolones, is a problem of clinical importance. The dissemination of Salmonella Typhimurium resistant to ampicillin (AMP)-chloramphenicol (CHL)-streptomycin (STR)-sulphonamides and (SUL)-tetracycline (TET), that harbour the Salmonella Genomic Island type 1 (SGI1), and the acquisition of transferable genetic material have favoured the multi-resistance in this genus. A total of 114 clinical S.enterica isolates were studied (period 2009-2010). The susceptibility to 20 antibiotics was determined by disc diffusion and microdilution. The antimicrobial resistance mechanisms and the integrons were analysed by PCR, and sequencing in the AMP(R) isolates. In all the blaPSE-1-positive isolates, the clonal relationship was determined by PFGE, as well as the presence of SGI1 and 29 virulence genes by PCR. Eighteen different serotypes were found among the 114 isolates studied, Typhimurium (61%) and Enteritidis (16%) being the most prevalent. High percentages of resistance to SUL (68%), TET (58%), AMP (55%) and STR (46%) were observed. The great majority (92%) of 63 AMP(R) isolates were multi-resistant, with the AMP-STR-TET-SUL phenotype (19 isolates) being the most frequent one and associated with the blaTEM-1b+strA-strB+tet(B)+sul2 genotype. Class 1 integrons (7 different structures) were observed in 48% AMP(R) isolates, highlighting the blaOXA-1+aadA1 structure (8 isolates), one empty integron and non-classical integrons (5 isolates). The blaPSE-1 gene was detected inside the classical SGI1 structure in 13 clonally-related isolates that showed the same virulence profile. The high percentage of multi-resistant S.enterica isolates, especially associated to S.Typhimurium, to the AMP, STR, TET and SUL phenotype, and to the blaTEM-1b+strA-strB+tet(B)+sul2 genotype, shows an important risk of possible failures in the treatment of serious infections caused by this

  18. Association of Salmonella enterica Serovar Enteritidis YafD with Resistance to Chicken Egg Albumen

    PubMed Central

    Lu, Sangwei; Killoran, Patrick B.; Riley, Lee W.

    2003-01-01

    Salmonella enterica serovar Enteritidis is a major cause of food-borne diseases in industrialized countries. The incidence of S. enterica serovar Enteritidis infections has increased substantially in recent decades, and S. enterica serovar Enteritidis is now one of the leading serovars of Salmonella in the United States. A unique epidemiological characteristic of S. enterica serovar Enteritidis is its association with chicken shell eggs, since approximately 80% of all human gastrointestinal diseases can be traced to contaminated egg products. Eggs are contaminated when bacteria from reproductive tissues of infected hens are packaged into the eggs and persist inside the hostile egg albumen environment. Therefore, resistance to egg albumen is an important aspect in the transmission of S. enterica serovar Enteritidis. We identified a gene, yafD from S. enterica serovar Enteritidis, whose overexpression conferred upon S. enterica serovar Typhimurium enhanced resistance to egg albumen, while disruption of this gene in S. enterica serovar Enteritidis rendered the organism more susceptible to egg albumen. YafD is homologous to members of an exonuclease-endonuclease-phosphatase family, including some enzymes involved in DNA repair. Furthermore, we discovered that egg albumen has nuclease activities and uses both circular and linear DNA as substrates. We propose that YafD provides a survival advantage to S. enterica serovar Enteritidis in eggs by repairing DNA damage caused by egg albumen and that it may be one of the biologic determinants that contribute to the epidemiological association of S. enterica serovar Enteritidis with egg products. PMID:14638758

  19. Association of Salmonella enterica serovar enteritidis yafD with resistance to chicken egg albumen.

    PubMed

    Lu, Sangwei; Killoran, Patrick B; Riley, Lee W

    2003-12-01

    Salmonella enterica serovar Enteritidis is a major cause of food-borne diseases in industrialized countries. The incidence of S. enterica serovar Enteritidis infections has increased substantially in recent decades, and S. enterica serovar Enteritidis is now one of the leading serovars of Salmonella in the United States. A unique epidemiological characteristic of S. enterica serovar Enteritidis is its association with chicken shell eggs, since approximately 80% of all human gastrointestinal diseases can be traced to contaminated egg products. Eggs are contaminated when bacteria from reproductive tissues of infected hens are packaged into the eggs and persist inside the hostile egg albumen environment. Therefore, resistance to egg albumen is an important aspect in the transmission of S. enterica serovar Enteritidis. We identified a gene, yafD from S. enterica serovar Enteritidis, whose overexpression conferred upon S. enterica serovar Typhimurium enhanced resistance to egg albumen, while disruption of this gene in S. enterica serovar Enteritidis rendered the organism more susceptible to egg albumen. YafD is homologous to members of an exonuclease-endonuclease-phosphatase family, including some enzymes involved in DNA repair. Furthermore, we discovered that egg albumen has nuclease activities and uses both circular and linear DNA as substrates. We propose that YafD provides a survival advantage to S. enterica serovar Enteritidis in eggs by repairing DNA damage caused by egg albumen and that it may be one of the biologic determinants that contribute to the epidemiological association of S. enterica serovar Enteritidis with egg products.

  20. Salmonella enterica serovar Typhi and the pathogenesis of typhoid fever.

    PubMed

    Dougan, Gordon; Baker, Stephen

    2014-01-01

    Salmonella enterica serovar Typhi, the cause of typhoid, is host restricted to humans. S. Typhi has a monophyletic population structure, indicating that typhoid in humans is a relatively new disease. Antimicrobial usage is reshaping the current S. Typhi global population and may be driving the emergence of a specific haplotype, H58, that is well adapted to transmission in modern settings and is able to resist antimicrobial killing more efficiently than other S. Typhi. Evidence gathered through genomics and functional studies using the mouse and in vitro cell systems, together with clinical investigations, has provided insight into the mechanisms that underpin the pathogenesis of human typhoid and host restriction. Here we review the latest scientific advances in typhoid research and discuss how these novel approaches are changing our understanding of the disease.

  1. Occurrence of Salmonella enterica serovar Dublin in Austria.

    PubMed

    Allerberger, F; Liesegang, A; Grif, K; Prager, R; Danzl, J; Höck, F; Ottl, J; Dierich, M P; Berghold, C; Neckstaller, I; Tschäpe, H; Fisher, I

    2002-04-01

    In Austria, Salmonella enterica subsp. enterica serovar Dublin, a bovine-adapted serovar, rarely causes infections in humans. In 2000, Austria was within the European mean with an incidence of 0.1 per million inhabitants. Our data show that the vast majority of all serovar Dublin infections (human and non-human) can be traced epidemiologically to two districts in the Tyrol. This concentration of cases can be explained by a particularly traditional aspect of cattle farming in this area, the alpine pasture. There is an increased risk of cross infection due to the communal keeping of animals from various farms. Infected cattle are a source of infection for humans, and transmission usually occurs from eating beef and drinking cows milk. Using pulsed field gel electrophoresis and automated ribotyping, three out of five isolates from human infections could be traced to characteristic Tyrolean Dublin clones. Bacteriological screening for faecal carriage before the transfer of cattle from risk-herds to the alpine pastures and before the return from risk-pastures to the farms would be a possible starting point to prevent cross-contamination of large mixed herds and contamination of pasture through latently infected cattle. Appropriate research is necessary.

  2. 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

  3. Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

    SciTech Connect

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

    2016-03-04

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

  4. 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

  5. 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

  6. 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...

  7. 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...

  8. 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

  9. 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).

  10. Potential Interactions between Salmonella enterica and Ralstonia solanacearum in tomato plants.

    PubMed

    Pollard, Stephanie; Barak, Jeri; Boyer, Renee; Reiter, Mark; Gu, Ganyu; Rideout, Steven

    2014-02-01

    Over the past decade, the Eastern Shore of Virginia (ESV) has been implicated in at least four outbreaks of salmonellosis associated with tomato, all originating from the same serovar, Salmonella enterica serovar Newport. In addition to Salmonella Newport contamination, the devastating plant disease bacterial wilt, caused by the phytopathogen Ralstonia solanacearum, threatens the sustainability of ESV tomato production. Bacterial wilt is present in most ESV tomato fields and causes devastating yield losses each year. Although the connection between bacterial wilt and tomato-related salmonellosis outbreaks in ESV is of interest, the relationship between the two pathogens has never been investigated. In this study, tomato plants were root dip inoculated with one of four treatments: (i) 8 log CFU of Salmonella Newport per ml, (ii) 5 log CFU of R. solanacearum per ml, (iii) a coinoculation of 8 log CFU of Salmonella Newport per ml plus 5 log CFU of R. solanacearum per ml, and (iv) sterile water as control. Leaf, stem, and fruit samples were collected at the early-green-fruit stage, and S. enterica contamination in the internal tissues was detected. S. enterica was recovered in 1.4 and 2.9% of leaf samples from plants inoculated with Salmonella Newport only and from plants coinoculated with Salmonella Newport plus R. solanacearum, respectively. S. enterica was recovered from 1.7 and 3.5% of fruit samples from plants inoculated with Salmonella Newport only and from plants coinoculated with Salmonella Newport plus R. solanacearum, respectively. There were significantly more stem samples from plants coinoculated with Salmonella Newport plus R. solanacearum that were positive for S. enterica (18.6%) than stem samples collected from plants inoculated with Salmonella Newport only (5.7%). Results suggested that R. solanacearum could influence S. enterica survival and transportation throughout the internal tissues of tomato plants.

  11. 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.

  12. Herd-level risk factors for Salmonella enterica subsp. enterica in U.S. market pigs.

    PubMed

    Bahnson, P B; Fedorka-Cray, P J; Ladely, S R; Mateus-Pinilla, N E

    2006-10-17

    Midwest U.S. herds (n=63) were studied to identify risk factors for harboring Salmonella enterica among slaughter-weight pigs. Samples collected on farms (feces) and at slaughter (distal colonic content, cecal content and ileocolic lymph nodes) were cultured using conventional means. Approximately 15 pigs were studied per herd, for a total of 3754 samples. The proportion of pigs positive in one or more samples was calculated for each herd. Herd characteristics were described by a combination of interview and written survey. Logistic regression was used to detect relationships between the detection of Salmonella and potential herd-level risk factors. The mean individual pig prevalence was 5% for feces, 4% for distal colonic content, 15% for ileocolic lymph nodes, and 17% for cecal contents. One or more Salmonella isolates were detected in at least one sample type in every herd. The five most common serovars were S. Agona, S. Derby, S. Schwarzengrund, S. Typhimurium and S. Senftenberg, with 25 additional serovars detected. Salmonella prevalence estimates were positively correlated among all samples except distal colonic content and ileocolic lymph nodes. Pigs with culture positive fecal samples were at increased odds of being detected positive for each of the slaughter-collected samples examined, namely distal colonic content (OR=30.5), ileocolic lymph nodes (OR=12.9) and cecal content (OR=23.2). Herds with positive fecal sample(s) had increased odds of having positive cecal content (OR>1.5), distal colonic content (OR=15.3) and ileocolic lymph nodes (OR=12.7). Pigs from herds with at least some bowl drinkers had eight-fold higher odds of testing Salmonella positive than did pigs from herds with only nipple drinkers. Pigs from herds with only dry feeders had five-fold higher odds of testing Salmonella positive when compared with pigs from herds with combinations of wet/dry style feeders. Interventions at these two points should be considered when designing growing

  13. 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.

  14. Epidemiology of a Salmonella enterica subsp. enterica Serovar Typhimurium Strain Associated with a Songbird Outbreak

    PubMed Central

    Hernandez, Sonia M.; Keel, Kevin; Sanchez, Susan; Trees, Eija; Gerner-Smidt, Peter; Adams, Jennifer K.; Cheng, Ying; Ray, Al; Martin, Gordon; Presotto, Andrea; Ruder, Mark G.; Brown, Justin; Blehert, David S.; Cottrell, Walter

    2012-01-01

    Salmonella enterica subsp. enterica serovar Typhimurium is responsible for the majority of salmonellosis cases worldwide. This Salmonella serovar is also responsible for die-offs in songbird populations. In 2009, there was an S. Typhimurium epizootic reported in pine siskins in the eastern United States. At the time, there was also a human outbreak with this serovar that was associated with contaminated peanuts. As peanuts are also used in wild-bird food, it was hypothesized that the pine siskin epizootic was related to this human outbreak. A comparison of songbird and human S. Typhimurium pulsed-field gel electrophoresis (PFGE) patterns revealed that the epizootic was attributed not to the peanut-associated strain but, rather, to a songbird strain first characterized from an American goldfinch in 1998. This same S. Typhimurium strain (PFGE type A3) was also identified in the PulseNet USA database, accounting for 137 of 77,941 total S. Typhimurium PFGE entries. A second molecular typing method, multiple-locus variable-number tandem-repeat analysis (MLVA), confirmed that the same strain was responsible for the pine siskin epizootic in the eastern United States but was distinct from a genetically related strain isolated from pine siskins in Minnesota. The pine siskin A3 strain was first encountered in May 2008 in an American goldfinch and later in a northern cardinal at the start of the pine siskin epizootic. MLVA also confirmed the clonal nature of S. Typhimurium in songbirds and established that the pine siskin epizootic strain was unique to the finch family. For 2009, the distribution of PFGE type A3 in passerines and humans mirrored the highest population density of pine siskins for the East Coast. PMID:22885752

  15. 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.

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

    PubMed

    Hernandez, Sonia M; Keel, Kevin; Sanchez, Susan; Trees, Eija; Gerner-Smidt, Peter; Adams, Jennifer K; Cheng, Ying; Ray, Al; Martin, Gordon; Presotto, Andrea; Ruder, Mark G; Brown, Justin; Blehert, David S; Cottrell, Walter; Maurer, John J

    2012-10-01

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

  17. Curcumin increases the pathogenicity of Salmonella enterica serovar Typhimurium in murine model.

    PubMed

    Marathe, Sandhya A; Ray, Seemun; Chakravortty, Dipshikha

    2010-07-09

    Curcumin has gained immense importance for its vast therapeutic and prophylactic applications. Contrary to this, our study reveals that it regulates the defense pathways of Salmonella enterica serovar Typhimurium (S. Typhimurium) to enhance its pathogenicity. In a murine model of typhoid fever, we observed higher bacterial load in Peyer's patches, mesenteric lymph node, spleen and liver, when infected with curcumin-treated Salmonella. Curcumin increased the resistance of S. Typhimurium against antimicrobial agents like antimicrobial peptides, reactive oxygen and nitrogen species. This increased tolerance might be attributed to the up-regulation of genes involved in resistance against antimicrobial peptides--pmrD and pmrHFIJKLM and genes with antioxidant function--mntH, sodA and sitA. We implicate that iron chelation property of curcumin have a role in regulating mntH and sitA. Interestingly, we see that the curcumin-mediated modulation of pmr genes is through the PhoPQ regulatory system. Curcumin downregulates SPI1 genes, required for entry into epithelial cells and upregulates SPI2 genes required to intracellular survival. Since it is known that the SPI1 and SPI2 system can be regulated by the PhoPQ system, this common regulator could explain curcumin's mode of action. This data urges us to rethink the indiscriminate use of curcumin especially during Salmonella outbreaks.

  18. Curcumin Increases the Pathogenicity of Salmonella enterica Serovar Typhimurium in Murine Model

    PubMed Central

    Marathe, Sandhya A.; Ray, Seemun; Chakravortty, Dipshikha

    2010-01-01

    Curcumin has gained immense importance for its vast therapeutic and prophylactic applications. Contrary to this, our study reveals that it regulates the defense pathways of Salmonella enterica serovar Typhimurium (S. Typhimurium) to enhance its pathogenicity. In a murine model of typhoid fever, we observed higher bacterial load in Peyer's patches, mesenteric lymph node, spleen and liver, when infected with curcumin-treated Salmonella. Curcumin increased the resistance of S. Typhimurium against antimicrobial agents like antimicrobial peptides, reactive oxygen and nitrogen species. This increased tolerance might be attributed to the up-regulation of genes involved in resistance against antimicrobial peptides - pmrD and pmrHFIJKLM and genes with antioxidant function - mntH, sodA and sitA. We implicate that iron chelation property of curcumin have a role in regulating mntH and sitA. Interestingly, we see that the curcumin-mediated modulation of pmr genes is through the PhoPQ regulatory system. Curcumin downregulates SPI1 genes, required for entry into epithelial cells and upregulates SPI2 genes required to intracellular survival. Since it is known that the SPI1 and SPI2 system can be regulated by the PhoPQ system, this common regulator could explain curcumin's mode of action. This data urges us to rethink the indiscriminate use of curcumin especially during Salmonella outbreaks. PMID:20634977

  19. Salmonella enterica serovars Typhimurium and Typhi as model organisms

    PubMed Central

    Garai, Preeti; Gnanadhas, Divya Prakash; Chakravortty, Dipshikha

    2012-01-01

    The lifestyle of intracellular pathogens has always questioned the skill of a microbiologist in the context of finding the permanent cure to the diseases caused by them. The best tool utilized by these pathogens is their ability to reside inside the host cell, which enables them to easily bypass the humoral immunity of the host, such as the complement system. They further escape from the intracellular immunity, such as lysosome and inflammasome, mostly by forming a protective vacuole-bound niche derived from the host itself. Some of the most dreadful diseases are caused by these vacuolar pathogens, for example, tuberculosis by Mycobacterium or typhoid fever by Salmonella. To deal with such successful pathogens therapeutically, the knowledge of a host-pathogen interaction system becomes primarily essential, which further depends on the use of a model system. A well characterized pathogen, namely Salmonella, suits the role of a model for this purpose, which can infect a wide array of hosts causing a variety of diseases. This review focuses on various such aspects of research on Salmonella which are useful for studying the pathogenesis of other intracellular pathogens. PMID:22722237

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

    PubMed

    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.

  1. 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

  2. Prevalence of Salmonella enterica in Poultry and Eggs in Uruguay during an Epidemic Due to Salmonella enterica Serovar Enteritidis▿

    PubMed Central

    Betancor, L.; Pereira, M.; Martinez, A.; Giossa, G.; Fookes, M.; Flores, K.; Barrios, P.; Repiso, V.; Vignoli, R.; Cordeiro, N.; Algorta, G.; Thomson, N.; Maskell, D.; Schelotto, F.; Chabalgoity, J. A.

    2010-01-01

    Salmonella enterica serovar Enteritidis (S. Enteritidis) is frequently associated with food-borne disease worldwide. Poultry-derived products are a major source. An epidemic of human infection with S. Enteritidis occurred in Uruguay, and to evaluate the extent of poultry contamination, we conducted a nationwide survey over 2 years that included the analysis of sera from 5,751 birds and 12,400 eggs. Serological evidence of infection with Salmonella group O:9 was found in 24.4% of the birds. All positive sera were retested with a gm flagellum-based enzyme-linked immunosorbent assay, and based on these results, the national prevalence of S. Enteritidis infection was estimated to be 6.3%. Salmonellae were recovered from 58 of 620 pools made up of 20 eggs each, demonstrating a prevalence of at least 1 in every 214 eggs. Surprisingly, the majority of the isolates were not S. Enteritidis. Thirty-nine isolates were typed as S. Derby, 9 as S. Gallinarum, 8 as S. Enteritidis, and 2 as S. Panama. Despite the highest prevalence in eggs, S. Derby was not isolated from humans in the period of analysis, suggesting a low capacity to infect humans. Microarray-based comparative genomic hybridization analysis of S. Derby and S. Enteritidis revealed more than 350 genetic differences. S. Derby lacked pathogenicity islands 13 and 14, the fimbrial lpf operon, and other regions encoding metabolic functions. Several of these regions are present not only in serovar Enteritidis but also in all sequenced strains of S. Typhimurium, suggesting that these regions might be related to the capacity of Salmonella to cause food-borne disease. PMID:20484605

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

    PubMed

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

    2011-01-01

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

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

    PubMed

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

    2017-03-07

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

  5. Differences in attachment of Salmonella enterica serovars to cabbage and lettuce leaves

    USDA-ARS?s Scientific Manuscript database

    This study investigated the ability of five Salmonella enterica serovars to attach to and colonize intact and cut lettuce (Iceberg, Romaine) and cabbage surfaces. Biofilm assay and attachment of Salmonella serovars to intact and cut leaves were determined. Bacterial populations of loosely and strong...

  6. 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.

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

    USDA-ARS?s Scientific Manuscript database

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

  8. Salmonella enterica Subspecies diarizonae Maxillary Sinusitis in a Snake Handler: First Report

    PubMed Central

    Horvath, Lukas; Kraft, Marcel; Fostiropoulos, Karolos; Falkowski, Anna; Tarr, Philip E.

    2016-01-01

    In this study, we report the first case of reptile-associated maxillary sinusitis due to Salmonella enterica subspecies diarizonae in a snake handler and the third case of salmonella-associated sinusitis worldwide. The case highlights the potential of respiratory transmission and atypical salmonellosis presentations. PMID:27186588

  9. Diagnostic accuracy of rectoanal mucosal swab of feedlot cattle for detection and enumeration of Salmonella enterica

    USDA-ARS?s Scientific Manuscript database

    Cattle are noted carriers of the foodborne pathogen Salmonella enterica. The perceived need to decrease the potential human health risk posed by excretion of this pathogen has resulted in numerous studies examining the factors that influence cattle shedding of Salmonella. Fecal grab (FG) samples hav...

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

    USDA-ARS?s Scientific Manuscript database

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

  11. New Zealand white rabbit as a nonsurgical experimental model for Salmonella enterica gastroenteritis.

    PubMed

    Hanes, D E; Robl, M G; Schneider, C M; Burr, D H

    2001-10-01

    Rabbits orally challenged with Salmonella enterica developed a dose-dependent diarrheal disease comparable to human salmonellosis. Viable Salmonella organisms recovered from the intestine and deep tissues indicate local and systemic infections. Therefore, results show that the rabbit can be used as a model for diarrheal disease and sequelae associated with salmonellosis.

  12. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

  14. Identification of Genes Affecting Salmonella enterica Serovar Enteritidis Infection of Chicken Macrophages

    PubMed Central

    Zhao, Yixian; Jansen, Ruud; Gaastra, Wim; Arkesteijn, Ger; van der Zeijst, Bernard A. M.; van Putten, Jos P. M.

    2002-01-01

    Screening of 7,680 Salmonella enterica serovar Enteritidis mutants for attenuation in a chicken macrophage infection model yielded a series of mutants including several with defects in previously unrecognized Salmonella virulence genes. One of the newly identified genes was the pbpA2 gene, belonging to the penicillin binding protein gene family. PMID:12183592

  15. 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...

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

    PubMed

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

    2017-08-15

    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 biofilm

  17. Characterization of osmotically induced filaments of Salmonella enterica.

    PubMed

    Pratt, Zachary L; Chen, Bingming; Czuprynski, Charles J; Wong, Amy C L; Kaspar, Charles W

    2012-09-01

    Salmonella enterica forms aseptate filaments with multiple nucleoids when cultured in hyperosmotic conditions. These osmotic-induced filaments are viable and form single colonies on agar plates even though they contain multiple genomes and have the potential to divide into multiple daughter cells. Introducing filaments that are formed during osmotic stress into culture conditions without additional humectants results in the formation of septa and their division into individual cells, which could present challenges to retrospective analyses of infectious dose and risk assessments. We sought to characterize the underlying mechanisms of osmotic-induced filament formation. The concentration of proteins and chromosomal DNA in filaments and control cells was similar when standardized by biomass. Furthermore, penicillin-binding proteins in the membrane of salmonellae were active in vitro. The activity of penicillin-binding protein 2 was greater in filaments than in control cells, suggesting that it may have a role in osmotic-induced filament formation. Filaments contained more ATP than did control cells in standardized cell suspensions, though the levels of two F(0)F(1)-ATP synthase subunits were reduced. Furthermore, filaments could septate and divide within 8 h in 0.2 × Luria-Bertani broth at 23°C, while nonfilamentous control cells did not replicate. Based upon the ability of filaments to septate and divide in this diluted broth, a method was developed to enumerate by plate count the number of individual, viable cells within a population of filaments. This method could aid in retrospective analyses of infectious dose of filamented salmonellae.

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

    PubMed Central

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

    2014-01-01

    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. PMID:24308841

  19. Salmonella enterica serovar Virchow meningitis in a young man in Italy: a case report

    PubMed Central

    2014-01-01

    Introduction Salmonella enterica is a leading cause of foodborne infections worldwide and includes more than 2500 different serovars, causing primarily gastroenteritis. However, the infection may occur elsewhere and produce characteristic clinical syndromes. Meningitis is a rare complication that occurs in less than 1% of clinical salmonellosis. Case presentation We describe a case of Salmonella Virchow meningitis in a 36-year-old Caucasian man presenting with headache in the occipital region, associated fever, nausea and vomiting, dyspnea and ambulatory difficulty. The cerebrospinal fluid culture showed growth of Salmonella, later confirmed to be Salmonella enterica serovar Virchow. Conclusions Salmonella Virchow infection is rare and this report highlights the risk of meningitis as a presentation of salmonellosis. To the best of our knowledge this is the first Italian case of meningitis due to Salmonella Virchow in a young adult. The probable route of transmission remains unclear and a long carriage state after a previous episode of gastroenteritis should be considered. PMID:24884674

  20. 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.

  1. 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

  2. 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 ...

  3. 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...

  4. The Type III Secretion System Effector SeoC of Salmonella enterica subsp. salamae and S. enterica subsp. arizonae ADP-Ribosylates Src and Inhibits Opsonophagocytosis.

    PubMed

    Pollard, Dominic J; Young, Joanna C; Covarelli, Valentina; Herrera-León, Silvia; Connor, Thomas R; Fookes, Maria; Walker, Danielle; Echeita, Aurora; Thomson, Nicholas R; Berger, Cedric N; Frankel, Gad

    2016-12-01

    Salmonella species utilize type III secretion systems (T3SSs) to translocate effectors into the cytosol of mammalian host cells, subverting cell signaling and facilitating the onset of gastroenteritis. In this study, we compared a draft genome assembly of Salmonella enterica subsp. salamae strain 3588/07 against the genomes of S. enterica subsp. enterica serovar Typhimurium strain LT2 and Salmonella bongori strain 12419. S. enterica subsp. salamae encodes the Salmonella pathogenicity island 1 (SPI-1), SPI-2, and the locus of enterocyte effacement (LEE) T3SSs. Though several key S Typhimurium effector genes are missing (e.g., avrA, sopB, and sseL), S. enterica subsp. salamae invades HeLa cells and contains homologues of S. bongori sboK and sboC, which we named seoC SboC and SeoC are homologues of EspJ from enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively), which inhibit Src kinase-dependent phagocytosis by ADP-ribosylation. By screening 73 clinical and environmental Salmonella isolates, we identified EspJ homologues in S. bongori, S. enterica subsp. salamae, and Salmonella enterica subsp. arizonae The β-lactamase TEM-1 reporter system showed that SeoC is translocated by the SPI-1 T3SS. All the Salmonella SeoC/SboC homologues ADP-ribosylate Src E310 in vitro Ectopic expression of SeoC/SboC inhibited phagocytosis of IgG-opsonized beads into Cos-7 cells stably expressing green fluorescent protein (GFP)-FcγRIIa. Concurrently, S. enterica subsp. salamae infection of J774.A1 macrophages inhibited phagocytosis of beads, in a seoC-dependent manner. These results show that S. bongori, S. enterica subsp. salamae, and S. enterica subsp. arizonae share features of the infection strategy of extracellular pathogens EPEC and EHEC and shed light on the complexities of the T3SS effector repertoires of Enterobacteriaceae.

  5. 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.

  6. Salmonella enterica Typhimurium fljBA operon stability: implications regarding the origin of Salmonella enterica I 4,[5],12:i:.

    PubMed

    Tomiyama, M P O; Werle, C H; Milanez, G P; Nóbrega, D B; Pereira, J P; Calarga, A P; Flores, F; Brocchi, M

    2015-12-29

    Salmonella enterica subsp enterica serovar 4,5,12:i:- has been responsible for many recent Salmonella outbreaks worldwide. Several studies indicate that this serovar originated from S. enterica subsp enterica serovar Typhimurium, by the loss of the flagellar phase II gene (fljB) and adjacent sequences. However, at least two different clones of S. enterica 4,5,12:i:- exist that differs in the molecular events responsible for fljB deletion. The aim of this study was to test the stability of the fljBA operon responsible for the flagellar phase variation under different growth conditions in order to verify if its deletion is a frequent event that could explain the origin and dissemination of this serovar. In fact, coding sequences for transposons are present near this operon and in some strains, such as S. enterica Typhimurium LT2, the Fels-2 prophage gene is inserted near this operon. The presence of mobile DNA could confer instability to this region. In order to examine this, the cat (chloramphenicol acetyltransferase) gene was inserted adjacent to the fljBA operon so that deletions involving this genomic region could be identified. After growing S. enterica chloramphenicol-resistant strains under different conditions, more than 104 colonies were tested for the loss of chloramphenicol resistance. However, none of the colonies were sensitive to chloramphenicol. These data suggest that the origin of S. enterica serovar 4,5,12:i:- from Typhimurium by fljBA deletion is not a frequent event. The origin and dissemination of 4,5,12:i:- raise several questions about the role of flagellar phase variation in virulence.

  7. Analysis of antimicrobial resistance genes detected in multidrug-resistant salmonella enterica serovar typhimurium isolated from food animals

    USDA-ARS?s Scientific Manuscript database

    The development of multi drug resistance (MDR) in foodborne pathogens such as Salmonella enterica is a concern for both animal and human health. MDR Salmonella enterica serovar Typhimurium is the most prevalent penta-resistant serovar isolated from animals as part of the National Antimicrobial Resis...

  8. First Draft Genome Sequence of Salmonella enterica Serovar Gallinarum Strain VTCCBAA614, Isolated from Chicken in India

    PubMed Central

    Jindal, N.; Anand, T.; Bera, B. C.; Riyesh, T.; Virmani, N.; Barua, S.; Gupta, Renu; Mahajan, N. K.; Joshi, C. G.; Singh, R. K.

    2015-01-01

    Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum causes fowl typhoid (FT), which results in huge economic losses to poultry farmers in India. We report the draft genome sequence of Salmonella biovar Gallinarum strain VTCCBAA614, isolated from a chicken in an FT affected broiler flock. PMID:26494667

  9. Effects of integrated treatment of nonthermal UV-C light and different antimicrobial wash on Salmonella enterica on plum tomatoes

    USDA-ARS?s Scientific Manuscript database

    Produce contamination by foodborne pathogens remains a serious threat. This study investigated synergistic effects of ultraviolet-C and various active sanitizers’ washes against Salmonella enterica on plum tomatoes. A bacterial cocktail containing three serotypes of Salmonella enterica (S. Newport H...

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

    USDA-ARS?s Scientific Manuscript database

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

  11. 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.

  12. Novel Temperate Phages of Salmonella enterica subsp. salamae and subsp. diarizonae and Their Activity against Pathogenic S. enterica subsp. enterica Isolates.

    PubMed

    Mikalová, Lenka; Bosák, Juraj; Hříbková, Hana; Dědičová, Daniela; Benada, Oldřich; Šmarda, Jan; Šmajs, David

    2017-01-01

    Forty strains of Salmonella enterica (S. enterica) subspecies salamae (II), arizonae (IIIa), diarizonae (IIIb), and houtenae (IV) were isolated from human or environmental samples and tested for bacteriophage production. Production of bacteriophages was observed in 15 S. enterica strains (37.5%) belonging to either the subspecies salamae (8 strains) or diarizonae (7 strains). Activity of phages was tested against 52 pathogenic S. enterica subsp. enterica isolates and showed that phages produced by subsp. salamae had broader activity against pathogenic salmonellae compared to phages from the subsp. diarizonae. All 15 phages were analyzed using PCR amplification of phage-specific regions and 9 different amplification profiles were identified. Five phages (SEN1, SEN4, SEN5, SEN22, and SEN34) were completely sequenced and classified as temperate phages. Phages SEN4 and SEN5 were genetically identical, thus representing a single phage type (i.e. SEN4/5). SEN1 and SEN4/5 fit into the group of P2-like phages, while the SEN22 phage showed sequence relatedness to P22-like phages. Interestingly, while phage SEN34 was genetically distantly related to Lambda-like phages (Siphoviridae), it had the morphology of the Myoviridae family. Based on sequence analysis and electron microscopy, phages SEN1 and SEN4/5 were members of the Myoviridae family and phage SEN22 belonged to the Podoviridae family.

  13. Novel Temperate Phages of Salmonella enterica subsp. salamae and subsp. diarizonae and Their Activity against Pathogenic S. enterica subsp. enterica Isolates

    PubMed Central

    Hříbková, Hana; Dědičová, Daniela; Benada, Oldřich; Šmarda, Jan; Šmajs, David

    2017-01-01

    Forty strains of Salmonella enterica (S. enterica) subspecies salamae (II), arizonae (IIIa), diarizonae (IIIb), and houtenae (IV) were isolated from human or environmental samples and tested for bacteriophage production. Production of bacteriophages was observed in 15 S. enterica strains (37.5%) belonging to either the subspecies salamae (8 strains) or diarizonae (7 strains). Activity of phages was tested against 52 pathogenic S. enterica subsp. enterica isolates and showed that phages produced by subsp. salamae had broader activity against pathogenic salmonellae compared to phages from the subsp. diarizonae. All 15 phages were analyzed using PCR amplification of phage-specific regions and 9 different amplification profiles were identified. Five phages (SEN1, SEN4, SEN5, SEN22, and SEN34) were completely sequenced and classified as temperate phages. Phages SEN4 and SEN5 were genetically identical, thus representing a single phage type (i.e. SEN4/5). SEN1 and SEN4/5 fit into the group of P2-like phages, while the SEN22 phage showed sequence relatedness to P22-like phages. Interestingly, while phage SEN34 was genetically distantly related to Lambda-like phages (Siphoviridae), it had the morphology of the Myoviridae family. Based on sequence analysis and electron microscopy, phages SEN1 and SEN4/5 were members of the Myoviridae family and phage SEN22 belonged to the Podoviridae family. PMID:28118395

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

    PubMed

    Noto Llana, Mariángeles; Sarnacki, Sebastián Hernán; Aya Castañeda, María del Rosario; Pustovrh, María Carolina; Gartner, Alejandra Sonia; Buzzola, Fernanda Roxana; Cerquetti, María Cristina; Giacomodonato, Mónica Nancy

    2014-01-01

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

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

    PubMed

    Wick, Mary Jo

    2011-01-01

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

  16. Inhibition of Salmonella enterica Cells in Deli-Type Salad by Enterocin AS-48 in Combination with Other Antimicrobials.

    PubMed

    Cobo Molinos, Antonio; Lucas López, Rosario; Abriouel, Hikmate; Ben Omar, Nabil; Valdivia, Eva; Gálvez, Antonio

    2009-06-01

    The cyclic antibacterial peptide enterocin AS-48 acted synergistically with p-hydroxybenzoic acid methyl ester (PHBME) and with 2-nitropropanol against Salmonella enterica serovar Enteritidis CECT 4300 in Russian salad. In challenge tests on a cocktail of Salmonella strains (S. enterica ssp. enterica serotype Typhi CECT 409, S. enterica ssp. enterica serovar Choleraesuis CECT 915, S. enterica ssp. enterica serovar Enteritidis CECT 4300, S. enterica ssp. arizonae serovar Arizonae CECT 4395, and S. enterica ssp. salamae CECT 4000) in salad at 10°C, the combinations of PHBME and AS-48 (80 μg/g) or 2-nitropropanol and AS-48 (40 μg/g) reduced the concentrations of viable Salmonella from 4.27 to 4.75 log CFU/g down to the limit of detection for 7 days. Salmonella populations did not increase in control samples (without any antimicrobials or in the presence of AS-48 alone) probably due to the low pH of this type of salad and low temperature of incubation, but retained over 85% viability after 1 week. This work opens new possibilities to expand the spectrum of inhibition of enterocin AS-48 against Salmonella enterica.

  17. Identification and molecular characterization of Salmonella spp. from unpasteurized orange juices and identification of new serotype Salmonella strain S. enterica serovar Tempe.

    PubMed

    Khan, Ashraf A; Melvin, Cathy D; Dagdag, Elsie B

    2007-08-01

    Several Salmonella enterica serotypes were isolated from unpasteurized orange juice samples analysed as a follow-up to an outbreak in 1999 of S. enterica serotype Muenchen in the Pacific Northwest regions of United States. Eleven S. enterica strains were serotyped and identified as S. enterica serotype Muenchen (2), S. enterica serotype Hidalgo (2), S. enterica serotype Alamo (1), S. enterica serotype Gaminera (2), S. enterica serotype Javiana (2) and a new serotyped strain S. enterica serotype Tempe (2). The identity of the new serotype S. enterica serovar Tempe serotype 30:b:1,7:z33 was confirmed by the National Salmonella Reference Laboratory at NCID/CDC, Atlanta. These strains were sensitive to ampicillin, chloramphenicol, kanamycin, tetracycline, streptomycin and sulfisoxazole antibiotics. Isolates were screened for invasion (invA) and virulence (spvC) genes using specific primers for these two genes by polymerase chain reaction. All strains were positive for invA gene giving 321-bp fragment, however negative to virulence spvC gene. For pulsed-field gel electrophoresis (PFGE) analysis, Salmonella strain plugs were made and digested with XbaI and subjected to 18-h electrophoresis. The PFGE patterns were different for each S. enterica serotypes suggesting the several origins of contamination in outbreak. S. enterica serotype.

  18. Efflux Pump Overexpression Contributes to Tigecycline Heteroresistance in Salmonella enterica serovar Typhimurium.

    PubMed

    Chen, Yi; Hu, Daxing; Zhang, Qijing; Liao, Xiao-Ping; Liu, Ya-Hong; Sun, Jian

    2017-01-01

    Bacterial heteroresistance has been identified in several combinations of bacteria and antibiotics, and it complicated the therapeutic strategies. Tigecycline is being used as one of the optimal options for the treatment of infections caused by multidrug-resistant Salmonella. This study investigated whether heterorresistance to tigecycline exists in a Salmonella enterica serovar Typhimurium strain harboring the oqxAB-bearing IncHI2 plasmid pHXY0908. MIC and population analyses were performed to evaluate population-wide susceptibility to tigecycline. The effects of efflux pumps on MIC levels were assessed using the efflux pump inhibitor Phe-Arg-β-naphthylamide, measuring intracellular tigecycline accumulation as well as mRNA levels of regulatory and efflux pump genes. DNA sequencing of regulatory regions were performed and plasmid curing from a resistant strain provided an appropriate control. Results showed that MICs of a parental strain with and without pHXY0908 as well as a plasmid-cured strain 14028/Δp52 were 0.5, 1, and 1 μg/mL, respectively. Population analysis profiling (PAP) illustrated that only the pHXY0908-containg strain was heteroresistant to tigecycline. A fraction of colonies exhibited stable profiles with 4- to 8-fold increases in MIC. The frequencies of emergence of these isolates were higher in the plasmid-containing strain pHXY0908 than either the parental or the 14028/Δp52 strain. Phe-Arg-β-naphthylamide addition restored tigecycline susceptibility of these isolates and intracellular tigecycline accumulation was reduced. Heteroresistant isolates of the strain containing pHXY0908 also had elevated expression of acrB, ramA, and oqxB. DNA sequencing identified numerous mutations in RamR that have been shown to lead to ramA overexpression. In conclusions, heteroresistance to tigecycline in Salmonella enterica serovar Typhimurium was manifested in a plasmid-bearing strain. Our results suggest that this phenotype was associated with overexpression

  19. Efflux Pump Overexpression Contributes to Tigecycline Heteroresistance in Salmonella enterica serovar Typhimurium

    PubMed Central

    Chen, Yi; Hu, Daxing; Zhang, Qijing; Liao, Xiao-Ping; Liu, Ya-Hong; Sun, Jian

    2017-01-01

    Bacterial heteroresistance has been identified in several combinations of bacteria and antibiotics, and it complicated the therapeutic strategies. Tigecycline is being used as one of the optimal options for the treatment of infections caused by multidrug-resistant Salmonella. This study investigated whether heterorresistance to tigecycline exists in a Salmonella enterica serovar Typhimurium strain harboring the oqxAB-bearing IncHI2 plasmid pHXY0908. MIC and population analyses were performed to evaluate population-wide susceptibility to tigecycline. The effects of efflux pumps on MIC levels were assessed using the efflux pump inhibitor Phe-Arg-β-naphthylamide, measuring intracellular tigecycline accumulation as well as mRNA levels of regulatory and efflux pump genes. DNA sequencing of regulatory regions were performed and plasmid curing from a resistant strain provided an appropriate control. Results showed that MICs of a parental strain with and without pHXY0908 as well as a plasmid-cured strain 14028/Δp52 were 0.5, 1, and 1 μg/mL, respectively. Population analysis profiling (PAP) illustrated that only the pHXY0908-containg strain was heteroresistant to tigecycline. A fraction of colonies exhibited stable profiles with 4- to 8-fold increases in MIC. The frequencies of emergence of these isolates were higher in the plasmid-containing strain pHXY0908 than either the parental or the 14028/Δp52 strain. Phe-Arg-β-naphthylamide addition restored tigecycline susceptibility of these isolates and intracellular tigecycline accumulation was reduced. Heteroresistant isolates of the strain containing pHXY0908 also had elevated expression of acrB, ramA, and oqxB. DNA sequencing identified numerous mutations in RamR that have been shown to lead to ramA overexpression. In conclusions, heteroresistance to tigecycline in Salmonella enterica serovar Typhimurium was manifested in a plasmid-bearing strain. Our results suggest that this phenotype was associated with overexpression

  20. Increased water activity reduces the thermal resistance of Salmonella enterica in peanut butter.

    PubMed

    He, Yingshu; Li, Ye; Salazar, Joelle K; Yang, Jingyun; Tortorello, Mary Lou; Zhang, Wei

    2013-08-01

    Increased water activity in peanut butter significantly (P < 0.05) reduced the heat resistance of desiccation-stressed Salmonella enterica serotypes treated at 90 °C. The difference in thermal resistance was less notable when strains were treated at 126 °C. Using scanning electron microscopy, we observed minor morphological changes of S. enterica cells resulting from desiccation and rehydration processes in peanut oil.

  1. Increased Water Activity Reduces the Thermal Resistance of Salmonella enterica in Peanut Butter

    PubMed Central

    He, Yingshu; Li, Ye; Salazar, Joelle K.; Yang, Jingyun; Tortorello, Mary Lou

    2013-01-01

    Increased water activity in peanut butter significantly (P < 0.05) reduced the heat resistance of desiccation-stressed Salmonella enterica serotypes treated at 90°C. The difference in thermal resistance was less notable when strains were treated at 126°C. Using scanning electron microscopy, we observed minor morphological changes of S. enterica cells resulting from desiccation and rehydration processes in peanut oil. PMID:23728806

  2. Direct ROS Scavenging Activity of CueP from Salmonella enterica serovar Typhimurium

    PubMed Central

    Yoon, Bo-Young; Yeom, Ji-Hyun; Kim, Jin-Sik; Um, Si-Hyeon; Jo, Inseong; Lee, Kangseok; Kim, Yong-Hak; Ha, Nam-Chul

    2014-01-01

    Salmonella enterica serovar Typhimurium (S. Typhimurium) is an intracellular pathogen that has evolved to survive in the phagosome of macrophages. The periplasmic copper-binding protein CueP was initially known to confer copper resistance to S. Typhimurium. Crystal structure and biochemical studies on CueP revealed a putative copper binding site surrounded by the conserved cysteine and histidine residues. A recent study reported that CueP supplies copper ions to periplasmic Cu, Zn-superoxide dismutase (SodCII) at a low copper concentration and thus enables the sustained SodCII activity in the periplasm. In this study, we investigated the role of CueP in copper resistance at a high copper concentration. We observed that the survival of a cueP-deleted strain of Salmonella in macrophage phagosome was significantly reduced. Subsequent biochemical experiments revealed that CueP specifically mediates the reduction of copper ion using electrons released during the formation of the disulfide bond. We observed that the copper ion-mediated Fenton reaction in the presence of hydrogen peroxide was blocked by CueP. This study provides insight into how CueP confers copper resistance to S. Typhimurium in copper-rich environments such as the phagosome of macrophages. PMID:24598994

  3. Pyelonephritis in Japan caused by Salmonella enterica subspecies arizonae.

    PubMed

    Nishioka, Hiroaki; Doi, Asako; Takegawa, Hiroshi

    2017-08-21

    Salmonella enterica subsp. arizonae is a bacteria commonly found in the gut of reptiles. In humans, infections caused by this organism are rare. Most cases originate from southwestern United States, where rattlesnake products are often used in traditional medicine. In Asia, only a few cases have been described. This case report documents a case involving a 64-year-old woman with pyelonephritis caused by S. arizonae in Japan. She had no history of contact with reptiles or foreign travel. The likely route of transmission is unclear. She was treated with cephalosporins for 14 days and the pyelonephritis appeared to be resolved; however recurrence occurred twice -after two weeks and then after one month. Prolonged antibiotic therapy with amoxicillin resolved the infection. This case demonstrates that pyelonephritis associated with S. arizonae can be found outside of the typical geographic region and may not be associated with typical animal hosts. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  4. Occurrence of Salmonella enterica serovar Dublin in Austria.

    PubMed

    Allerberger, Franz; Liesegang, Almut; Grif, Katharina; Khaschabi, Daryusch; Prager, Rita; Danzl, Johann; Höck, Franz; Ottl, Josef; Dierich, Manfred P; Berghold, Christian; Neckstaller, Ingeborg; Tschäpe, Helmut; Fisher, Ian

    2003-01-01

    In Austria, Salmonella enterica serovar Dublin, a bovine-adapted serovar, rarely causes human infections. In the year 2000, Austria was within the European mean with an incidence of 0.1 per million inhabitants. Our data show that the vast majority of all Austrian serovar Dublin infections can be traced to two Tyrolian districts. This concentration of cases can be explained by a particularly traditional aspect of cattle farming in Tyrol, the alpine pasture. There is increased risk of cross-infection due to the communal keeping of animals from various farms. Infected cattle are a source of infection for people, and contagion usually occurs from eating beef and drinking cow's milk. Using pulsed-field gel electrophoresis and automated ribotyping, 3 out of 5 available isolates from human infections could be traced to characteristic Tyrolian S. Dublin clones. Bacteriological screening of herds with a known history of S. Dublin infection would be a start to prevent future contamination of alpine pastures through latently infected cattle excreting potentially infectious feces. Bacteriological screening for fecal carriage before the return of cattle from pastures known to be connected with infections could prevent cross-contamination of large mixed herds.

  5. Lag phase of Salmonella enterica under osmotic stress conditions.

    PubMed

    Zhou, K; George, S M; Métris, A; Li, P L; Baranyi, J

    2011-03-01

    Salmonella enterica serovar Typhimurium was grown at salt concentrations ranging from 0.5 to 7.5% in minimal medium with and without added osmoprotectant and in a rich medium. In minimal medium, the cells showed an initial decline period, and consequently the definition of the lag time of the resultant log count curve was revised. The model of Baranyi and Roberts (Int. J. Food Microbiol. 23:277-294, 1994) was modified to take into account the initial decline period, based on the assumption that the log count curve of the total population was the sum of a dying and a surviving-then-growing subpopulation. The lag time was defined as the lag of the surviving subpopulation. It was modeled by means of a parameter quantifying the biochemical work the surviving cells carry out during this phase, the "work to be done." The logarithms of the maximum specific growth rates as a function of the water activity in the three media differed only by additive constants, which gave a theoretical basis for bias factors characterizing the relationships between different media. Models for the lag and the "work to be done" as a function of the water activity showed similar properties, but in rich medium above 5% salt concentrations, the data showed a maximum for this work. An accurate description of the lag time is important to avoid food wastage, which is an issue of increasing significance in the food industry, while maintaining food safety standards.

  6. Mapping the Regulatory Network for Salmonella enterica Serovar Typhimurium Invasion

    PubMed Central

    Smith, Carol; Stringer, Anne M.; Mao, Chunhong; Palumbo, Michael J.

    2016-01-01

    ABSTRACT Salmonella enterica pathogenicity island 1 (SPI-1) encodes proteins required for invasion of gut epithelial cells. The timing of invasion is tightly controlled by a complex regulatory network. The transcription factor (TF) HilD is the master regulator of this process and senses environmental signals associated with invasion. HilD activates transcription of genes within and outside SPI-1, including six other TFs. Thus, the transcriptional program associated with host cell invasion is controlled by at least 7 TFs. However, very few of the regulatory targets are known for these TFs, and the extent of the regulatory network is unclear. In this study, we used complementary genomic approaches to map the direct regulatory targets of all 7 TFs. Our data reveal a highly complex and interconnected network that includes many previously undescribed regulatory targets. Moreover, the network extends well beyond the 7 TFs, due to the inclusion of many additional TFs and noncoding RNAs. By comparing gene expression profiles of regulatory targets for the 7 TFs, we identified many uncharacterized genes that are likely to play direct roles in invasion. We also uncovered cross talk between SPI-1 regulation and other regulatory pathways, which, in turn, identified gene clusters that likely share related functions. Our data are freely available through an intuitive online browser and represent a valuable resource for the bacterial research community. PMID:27601571

  7. Diversity and antimicrobial susceptibility of Salmonella enterica serovars isolated from pig farms in Ibadan, Nigeria.

    PubMed

    Fashae, Kayode; Hendriksen, Rene S

    2014-01-01

    Animals including food animals play a significant role in the epidemiology of Salmonella enterica. The control requires identification of sources and institution of targeted interventions. This study investigates the diversity of S. enterica serovars, antimicrobial susceptibility, and occurrence of plasmid-mediated quinolone resistance (PMQR) genes in pigs in Ibadan, Nigeria. Pooled fresh pen floor fecal samples of pigs collected from 31 pig farms were cultured; the Salmonella isolates were serotyped and their antimicrobial susceptibility was determined. PMQR genes were screened by polymerase chain reaction. The 229 Salmonella isolates were made of 50 serovars predominated by rare serovars Salmonella Give (n = 36; 15.7 %), Salmonella Brancaster (n = 17; 7.4 %), Salmonella Colindale (n = 15; 6.6 %), Salmonella Elisaberthville (n = 13; 5.7 %), Salmonella Hillingdon (n = 13; 5.7 %), and Salmonella Kingston (n = 13; 5.7 %). The most widely distributed serovars among the farms were Salmonella Give (six farms) and Salmonella Elisaberthville (six farms). Resistance to chloramphenicol, sulfonamides, nalidixic acid, streptomycin, and tetracycline ranged from 11.6 % (n = 26) to 22.8 % (n = 51). Resistance ciprofloxacin and gentamicin was low (n = 2; 0.9 %). Multiply resistant isolates included Salmonella Kentucky, the most resistant serovar. qnrB19 was found in two isolates of Salmonella Corvallis and one isolate of Salmonella Larochelle, respectively, while qnrS1 was found in two isolates of Salmonella Derby. Other PMQR genes were not detected. Pigs constitute an important source of diverse Salmonella serovars in Ibadan. The isolates were more resistant to old antimicrobials with some multiple resistant. Control measures and regulation of antimicrobials are warranted.

  8. 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

  9. Complete Genome and Plasmid Sequences of Three Canadian Strains of Salmonella enterica subsp. enterica Serovar Enteritidis Belonging to Phage Types 8, 13, and 13a

    PubMed Central

    Rehman, Muhammad Attiq; Labbé, Geneviève; Ziebell, Kim; Nash, John H. E.

    2015-01-01

    Salmonella enterica subsp. enterica serovar Enteritidis is a prominent cause of human salmonellosis frequently linked to poultry products. In Canada, S. Enteritidis phage types 8, 13, and 13a predominate among both clinical and poultry isolates. Here, we report the complete genome and plasmid sequences of poultry isolates of these three phage types. PMID:26404595

  10. Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Manhattan Strain 111113, from an Outbreak of Human Infections in Northern Italy.

    PubMed

    Sassera, Davide; Gaiarsa, Stefano; Scaltriti, Erika; Morganti, Marina; Bandi, Claudio; Casadei, Gabriele; Pongolini, Stefano

    2013-08-15

    We announce the draft genome sequence of Salmonella enterica subsp. enterica serovar Manhattan strain 111113, isolated from a patient during an outbreak in northern Italy. The genome, which was obtained with Illumina MiSeq technology, is composed of 21 contigs for a total of 4,684,342 bp, with a G+C content of 52.17%.

  11. Draft Genome Sequence and Annotation of Phyllosphere-Persisting Salmonella enterica subsp. enterica Serovar Livingstone Strain CKY-S4, Isolated from an Urban Lake in Regina, Canada.

    PubMed

    Tambalo, Dinah D; Perry, Benjamin J; Fitzgerald, Stephen F; Cameron, Andrew D S; Yost, Christopher K

    2015-08-13

    Here, we report the first draft genome sequence of Salmonella enterica subsp. enterica serovar Livingstone. This S. Livingstone strain CKY-S4 displayed biofilm formation and cellulose production and could persist on lettuce. This genome may help the study of mechanisms by which enteric pathogens colonize food crops.

  12. Complete Genome Sequence of Salmonella enterica subsp. enterica Serovar Typhi Isolate B/SF/13/03/195 Associated with a Typhoid Carrier in Pasir Mas, Kelantan, Malaysia.

    PubMed

    Muhamad Harish, Salwani; Sim, Kee-Shin; Mohd Nor, Fauziah; Mat Hussin, Hani; Hamzah, Wan Mansor; Najimudin, Nazalan; Aziah, Ismail

    2015-11-12

    We report here the complete genome sequence of Salmonella enterica subsp. enterica serovar Typhi B/SF/13/03/195 obtained from a typhoid carrier, who is a food handler in Pasir Mas, Kelantan. Copyright © 2015 Muhamad Harish et al.

  13. 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...

  14. Genome Sequences of Three Salmonella enterica subsp. enterica Serovar Infantis Strains from Healthy Broiler Chicks in Hungary and in the United Kingdom.

    PubMed

    Olasz, Ferenc; Nagy, Tibor; Szabó, Móni; Kiss, János; Szmolka, Ama; Barta, Endre; van Tonder, Andries; Thomson, Nicholas; Barrow, Paul; Nagy, Béla

    2015-02-12

    The genome sequences of three strains of Salmonella enterica subsp. enterica serovar Infantis isolated from broiler chickens in 1994 and 2004 in Hungary and in the 1980s in the United Kingdom are reported here. A sequence comparison should improve our understanding of the evolution of the genome and spread of S. Infantis in poultry.

  15. 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

  16. Diversity and Antimicrobial Resistance of Salmonella enterica Isolates from Surface Water in Southeastern United States

    PubMed Central

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

    2014-01-01

    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. PMID:25107969

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

    PubMed

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

    2012-05-01

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

  18. Salmonella enterica subsp. arizonae bone and joints sepsis. A case report and literature review.

    PubMed

    Schneider, L; Ehlinger, M; Stanchina, C; Giacomelli, M-C; Gicquel, P; Karger, C; Clavert, J-M

    2009-05-01

    Osteoarticular infections caused by Salmonella enterica subsp. arizonae are rarely seen in humans but young children and immunocompromised adults are at particular risk of acquiring this bacteria. Reptiles and their by-products (e.g. meat preparations or medications) are particularly likely to harbor Salmonella. We report on a case of septic arthritis of the hip transmitted by a reptile in a 10-month-old child. We carry out a recall of the complex nomenclature of Salmonella, a review of the literature and provide information on the recommended precautions for reducing the risk of transmission of Salmonella from reptiles to humans.

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

    PubMed

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

    2016-09-20

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

  20. Genomic Characterisation of Invasive Non-Typhoidal Salmonella enterica Subspecies enterica Serovar Bovismorbificans Isolates from Malawi

    PubMed Central

    Gilderthorp, Ruth; Ashelford, Kevin E.; Harris, Simon R.; Phiri, Amos; Hall, Neil; Gordon, Melita A.; Wain, John; Hart, Charles A.; Wigley, Paul; Thomson, Nicholas R.; Winstanley, Craig

    2013-01-01

    Background Invasive Non-typhoidal Salmonella (iNTS) are an important cause of bacteraemia in children and HIV-infected adults in sub-Saharan Africa. Previous research has shown that iNTS strains exhibit a pattern of gene loss that resembles that of host adapted serovars such as Salmonella Typhi and Paratyphi A. Salmonella enterica serovar Bovismorbificans was a common serovar in Malawi between 1997 and 2004. Methodology We sequenced the genomes of 14 Malawian bacteraemia and four veterinary isolates from the UK, to identify genomic variations and signs of host adaptation in the Malawian strains. Principal Findings Whole genome phylogeny of invasive and veterinary S. Bovismorbificans isolates showed that the isolates are highly related, belonging to the most common international S. Bovismorbificans Sequence Type, ST142, in contrast to the findings for S. Typhimurium, where a distinct Sequence Type, ST313, is associated with invasive disease in sub-Saharan Africa. Although genome degradation through pseudogene formation was observed in ST142 isolates, there were no clear overlaps with the patterns of gene loss seen in iNTS ST313 isolates previously described from Malawi, and no clear distinction between S. Bovismorbificans isolates from Malawi and the UK. The only defining differences between S. Bovismorbificans bacteraemia and veterinary isolates were prophage-related regions and the carriage of a S. Bovismorbificans virulence plasmid (pVIRBov). Conclusions iNTS S. Bovismorbificans isolates, unlike iNTS S. Typhiumrium isolates, are only distinguished from those circulating elsewhere by differences in the mobile genome. It is likely that these strains have entered a susceptible population and are able to take advantage of this niche. There are tentative signs of convergent evolution to a more human adapted iNTS variant. Considering its importance in causing disease in this region, S. Bovismorbificans may be at the beginning of this process, providing a reference

  1. Oxidoreductases that Act as Conditional Virulence Suppressors in Salmonella enterica Serovar Typhimurium

    PubMed Central

    Anwar, Naeem; Sem, Xiao Hui; Rhen, Mikael

    2013-01-01

    In Salmonella enterica serovar Typhimurium, oxidoreductases of the thioredoxin superfamily contribute to bacterial invasiveness, intracellular replication and to the virulence in BALB/c mice as well as in the soil nematode Caenorhabditis elegans. The scsABCD gene cluster, present in many but not all enteric bacteria, codes for four putative oxidoreductases of the thioredoxin superfamily. Here we have analyzed the potential role of the scs genes in oxidative stress tolerance and virulence in S. Typhimurium. An scsABCD deletion mutant showed moderate sensitization to the redox-active transition metal ion copper and increased protein carbonylation upon exposure to hydrogen peroxide. Still, the scsABCD mutant was not significantly affected for invasiveness or intracellular replication in respectively cultured epithelial or macrophage-like cells. However, we noted a significant copper chloride sensitivity of SPI1 T3SS mediated invasiveness that strongly depended on the presence of the scs genes. The scsABCD deletion mutant was not attenuated in animal infection models. In contrast, the mutant showed a moderate increase in its competitive index upon intraperitoneal challenge and enhanced invasiveness in small intestinal ileal loops of BALB/c mice. Moreover, deletion of the scsABCD genes restored the invasiveness of a trxA mutant in epithelial cells and its virulence in C. elegans. Our findings thus demonstrate that the scs gene cluster conditionally affects virulence and underscore the complex interactions between oxidoreductases of the thioredoxin superfamily in maintaining host adaptation of S. Typhimurium. PMID:23750221

  2. Characterization of multiple-antimicrobial-resistant Salmonella enterica Subsp. enterica isolated from indigenous vegetables and poultry in Malaysia.

    PubMed

    Yoke-Kqueen, C; Learn-Han, L; Noorzaleha, A S; Son, R; Sabrina, S; Jiun-Horng, S; Chai-Hoon, K

    2008-03-01

    The aims of this communication were to study characterization of serogroups among Salmonella isolates and the relationship of antimicrobial resistance to serogroups. Multiple antimicrobial resistance (MAR) was performed on 189 Salmonella enterica isolates associated with 38 different serovars that were recovered from poultry and four types of indigenous vegetables. Disc diffusion analysis was performed with a selection of 10 different antimicrobial agents. Isolates recovered from indigenous vegetables showed 100% (134/134) resistant to erythromycin and followed by 42%, 34%, 19% for tetracycline, streptomycin and trimethoprim-sulfamethoxazole respectively. In general, 90.1% (50/55) and 56.7% (76/134) of Salmonella isolated from poultry and indigenous vegetables, respectively, exhibited MAR index more than 0.2. Characterization of Salmonella isolates based on the MAR results indicated that poultry still remains as the main reservoir for multi-drug-resistant Salmonella. Four isolates from the indigenous vegetables showed the highest MAR index in this study. Further investigations need to be conducted to determine if Salmonella isolates recovered from indigenous vegetables were gaining more antimicrobial resistance. The study enabled us to determine antimicrobial patterns and trends in Salmonella from poultry and indigenous vegetables in Malaysia.

  3. Proteomic investigation of the time course responses of RAW 264.7 macrophages to infection with Salmonella enterica.

    PubMed

    Shi, Liang; Chowdhury, Saiful M; Smallwood, Heather S; Yoon, Hyunjin; Mottaz-Brewer, Heather M; Norbeck, Angela D; McDermott, Jason E; Clauss, Therese R W; Heffron, Fred; Smith, Richard D; Adkins, Joshua N

    2009-08-01

    To investigate the extent to which macrophages respond to Salmonella infection, we infected RAW 264.7 macrophages with Salmonella enterica serotype Typhimurium and analyzed macrophage proteins at various time points following infection by using a global proteomic approach. A total of 1,006 macrophage and 115 Salmonella proteins were identified with high confidence. Most of the Salmonella proteins were observed in the late stage of the infection time course, which is consistent with the fact that the bacterial cells proliferate inside RAW 264.7 macrophages. The peptide abundances of most of the identified macrophage proteins remained relatively constant over the time course of infection. Compared to those of the control, the peptide abundances of 244 macrophage proteins (i.e., 24% of the total identified macrophage proteins) changed significantly after infection. The functions of these Salmonella-affected macrophage proteins were diverse, including production of antibacterial nitric oxide (i.e., inducible nitric oxide synthase), production of prostaglandin H(2) (i.e., cyclooxygenase 2), and regulation of intracellular traffic (e.g., sorting nexin 5 [SNX5], SNX6, and SNX9). Diverse functions of the Salmonella-affected macrophage proteins demonstrate a global macrophage response to Salmonella infection. Western blot analysis not only confirmed the proteomic results for a selected set of proteins but also revealed that (i) the protein abundance of mitochondrial superoxide dismutase increased following macrophage infection, indicating an infection-induced oxidative stress in mitochondria, and (ii) in contrast to infection of macrophages by wild-type Salmonella, infection by the sopB deletion mutant had no negative impact on the abundance of SNX6, suggesting a role for SopB in regulating the abundance of SNX6.

  4. [Fluorescent and Magnetic Relaxation Switch Immunosensor for the Detecting Foodborne Pathogen Salmonella enterica in Water Samples].

    PubMed

    Wang, Song-bai; Zhang, Yan; An, Wen-ting; Wei, Yan-li; Wang, Yu; Shuang, Shao-min

    2015-11-01

    Fluoroimmunoassay based on quantum dots (QDs) and magnetic relaxation switch (MRS) immunoassay based on superparamagnetic nanoparticles (SMN) were constructed to detect Salmonella enterica (S. enterica) in water samples. In fluoroimmunoassay, magnetic beads was conjugated with S. enterica capture antibody (MB-Ab2) to enrich S. enterica from sample solution, then the QDs was conjugated with the S. enterica detection antibody (QDs-Ab1) to detect S. enterica based on sandwich immunoassay format. And the fluorescence intensity is positive related to the bacteria concentration of the sample. Results showed that the limit of detection (LOD) of this method was 102 cfu · mL⁻¹ and analysis time was 2 h. In MRS assay, magnetic nanoparticle-antibody conjugate (MN-Ab1) can switch their dispersed and aggregated state in the presence of the target. This state of change can modulate the spin-spin relaxation time (T₂) of the neighboring water molecule. The change in T₂(ΔT₂) positively correlates with the amount of the target in the sample. Thus, AT can be used as a detection signal in MRS immunosensors. Results showed that LOD of MRS sensor for S. enterica was 10³ cfu · mL⁻¹ and analysis time was 0.5 h. Two methods were compared in terms of advantages and disadvantages in detecting S. enterica.

  5. Molecular identification of Salmonella enterica subsp. enterica serovar Gallinarum biovars Gallinarum and Pullorum by a duplex PCR assay.

    PubMed

    Batista, Diego Felipe Alves; de Freitas Neto, Oliveiro Caetano; de Almeida, Adriana Maria; Barrow, Paul Andrew; de Oliveira Barbosa, Fernanda; Berchieri Junior, Angelo

    2016-07-01

    Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum (S Gallinarum) and biovar Pullorum (S Pullorum) are 2 poultry pathogens that cause major economic losses to the poultry industry worldwide. Control of both diseases mainly relies on the adoption of biosecurity programs, and success is dependent on accurate and fast detection. Based on this concept, we developed a duplex PCR assay, targeting 2 chromosomal sequences, which allowed us to precisely identify and differentiate S Gallinarum and S Pullorum field strains. This assay was validated by testing genomic DNA from 40 S Gallinarum and 29 S Pullorum field strains, 87 other Salmonella serovars, and 7 non-Salmonella strains. The serovar identifier region (SIR) primers produced a fragment only in S Gallinarum and S Pullorum strains, whereas the fragment from the ratA coding sequence, which was previously demonstrated to differentiate the 2 biovars, was also amplified from other Salmonella serovars. Our results showed that the combination of both SIR and ratA amplifications could be used to identify as well as to differentiate colonies of S Gallinarum and S Pullorum reliably. Thus, we believe this methodology can be a useful ancillary tool for routine veterinary diagnostic laboratories by providing rapid, accurate results.

  6. Characterization of Salmonella enterica serovar Typhimurium aconitase A.

    PubMed

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

    2013-06-01

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

  7. Aspartic Peptide Hydrolases in Salmonella enterica Serovar Typhimurium

    PubMed Central

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

    2001-01-01

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

  8. Aspartic peptide hydrolases in Salmonella enterica serovar typhimurium.

    PubMed

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

    2001-05-01

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

  9. Tigecycline therapy for bacteremia and aortitis caused by Salmonella enterica serotype Choleraesuis: A case report.

    PubMed

    Tang, Hung-Jen; Chen, Chi-Chung; Ko, Wen-Chien

    2016-02-01

    Non-typhoid Salmonella species represent a significant cause of aortitis. Few antimicrobial agents can be used when the patient is allergic or intolerable to cephalosporins or fluoroquinolones. Here, we report a case of bacteremia and aortitis caused by Salmonella enterica serotype Choleraesuis. This patient was cured by initial parenteral tigecycline and subsequent oral ciprofloxacin without surgical intervention. Copyright © 2012. Published by Elsevier B.V.

  10. CRISPRs: Molecular Markers for Tracking Antibiotic Resistant Strains of Salmonella Enterica

    DTIC Science & Technology

    2014-01-01

    0704-0188 3. DATES COVERED (From - To) - UU UU UU UU Approved for public release; distribution is unlimited. CRISPRs : molecular markers for tracking...Salmonella, CRISPR , antibiotic resistance REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR/MONITOR’S ACRONYM(S...ABSTRACT CRISPRs : molecular markers for tracking antibiotic resistant strains of Salmonella enterica Report Title Invited article with no abstract 2

  11. 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.

  12. Differences in Growth of Salmonella enterica and Escherichia coli O157:H7 on Alfalfa Sprouts

    PubMed Central

    Charkowski, A. O.; Barak, J. D.; Sarreal, C. Z.; Mandrell, R. E.

    2002-01-01

    Sprout producers have recently been faced with several Salmonella enterica and Escherichia coli O157:H7 outbreaks. Many of the outbreaks have been traced to sprout seeds contaminated with low levels of human pathogens. Alfalfa seeds were inoculated with S. enterica and E. coli O157:H7 strains isolated from alfalfa seeds or other environmental sources and sprouted to examine growth of these human pathogens in association with sprouting seeds. S. enterica strains grew an average of 3.7 log10 on sprouting seeds over 2 days, while E. coli O157:H7 strains grew significantly less, an average of 2.3 log10. The initial S. enterica or E. coli O157:H7 inoculum dose and seed-sprouting temperature significantly affected the levels of both S. enterica and E. coli O157:H7 on the sprouts and in the irrigation water, while the frequency of irrigation water replacement affected only the levels of E. coli O157:H7. Colonization of sprouting alfalfa seeds by S. enterica serovar Newport and E. coli O157:H7 strains transformed with a plasmid encoding the green fluorescent protein was examined with fluorescence microscopy. Salmonella serovar Newport colonized both seed coats and sprout roots as aggregates, while E. coli O157:H7 colonized only sprout roots. PMID:12039774

  13. 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.

  14. 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

  15. Development and evaluation of DNA and RNA real-time assays for food analysis using the hilA gene of Salmonella enterica subspecies enterica.

    PubMed

    McCabe, Evonne M; Burgess, Catherine M; O'Regan, Edel; McGuinness, Sheila; Barry, Thomas; Fanning, Séamus; Duffy, Geraldine

    2011-05-01

    The objective of this study was the development of DNA and RNA real-time PCR methods for detection of food-borne Salmonella sp. as rapid alternatives to the traditional cultural method (ISO 6579, 2004) in fresh meat carcasses and processed meat samples. These PCR methods were based on the hilA sequence, with primers and hybridisation probes designed against this gene target. The primers and probes were evaluated for their efficiency and dynamic range and subsequently the specificity of the assay was tested using 106 Salmonella enterica subspecies enterica strains and 30 non-salmonellae strains. An internal amplification control (IAC) was also developed for incorporation. The optimum copy number of IAC was determined to be 500 copies per reaction. A complementary enrichment protocol was adapted from the existing standard ISO 6579:2004 and consisted of enrichment in Buffered Peptone Water (BPW) 22 ± 2 h and a second selective enrichment for 6 h in Rappaport Vassiliadis with Soya (RVS). The DNA and RNA-based real-time PCR protocols, were applied to meat samples inoculated with Salmonella enterica subspecies enterica strains, including swabs from meat carcasses and minced beef samples which were heat treated or frozen. The developed methods have the potential as useful alternatives to the standard ISO 6579:2004 method for the detection of Salmonella enterica subspecies enterica on carcass swabs and raw meat using hilA as a target. The DNA assay is a useful tool for the screening of meat samples in the abattoir within 3 days of slaughter or in a food production process and the RNA-based assay has the potential to detect viable Salmonella enterica subspecies enterica in ready-to-eat products. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. TolA mediates the differential detergent resistance pattern between the Salmonella enterica subsp. enterica serovars Typhi and Typhimurium.

    PubMed

    Lahiri, Amit; Ananthalakshmi, T K; Nagarajan, Arvindhan G; Ray, Seemun; Chakravortty, Dipshikha

    2011-05-01

    The tol-pal genes are essential for maintaining the outer membrane integrity and detergent resistance in various Gram-negative bacteria, including Salmonella. The role of TolA has been well established for the bile resistance of Salmonella enterica subsp. enterica serovar Typhimurium. We compared the bile resistance pattern between the S. enterica serovars Typhi and Typhimurium and observed that Typhi is more resistant to bile-mediated damage. A closer look revealed a significant difference in the TolA sequence between the two serovars which contributes to the differential detergent resistance. The tolA knockout of both the serovars behaves completely differently in terms of membrane organization and morphology. The role of the Pal proteins and difference in LPS organization between the two serovars were verified and were found to have no direct connection with the altered bile resistance. In normal Luria broth (LB), S. Typhi ΔtolA is filamentous while S. Typhimurium ΔtolA grows as single cells, similar to the wild-type. In low osmolarity LB, however, S. Typhimurium ΔtolA started chaining and S. Typhi ΔtolA showed no growth. Further investigation revealed that the chaining phenomenon observed was the result of failure of the outer membrane to separate in the dividing cells. Taken together, the results substantiate the evolution of a shorter TolA in S. Typhi to counteract high bile concentrations, at the cost of lower osmotic tolerance.

  17. The Emergence of Reduced Ciprofloxacin Susceptibility in Salmonella enterica Causing Bloodstream Infections in Rural Ghana.

    PubMed

    Eibach, Daniel; Al-Emran, Hassan M; Dekker, Denise Myriam; Krumkamp, Ralf; Adu-Sarkodie, Yaw; Cruz Espinoza, Ligia Maria; Ehmen, Christa; Boahen, Kennedy; Heisig, Peter; Im, Justin; Jaeger, Anna; von Kalckreuth, Vera; Pak, Gi Deok; Panzner, Ursula; Park, Se Eun; Reinhardt, Alexander; Sarpong, Nimako; Schütt-Gerowitt, Heidi; Wierzba, Thomas F; Marks, Florian; May, Jürgen

    2016-03-15

    Salmonella ranks among the leading causes of bloodstream infections in sub-Saharan Africa. Multidrug resistant typhoidal and nontyphoidal Salmonella (NTS) isolates have been previously identified in this region. However, resistance to ciprofloxacin has rarely been reported in West Africa. This study aims to assess susceptibility against ciprofloxacin in Salmonella causing invasive bloodstream infections among children in rural Ghana. From May 2007 until May 2012, children attending a rural district hospital in central Ghana were eligible for recruitment. Salmonella enterica isolated from blood cultures were assessed for ciprofloxacin susceptibility by Etest (susceptible minimum inhibitory concentration [MIC] ≤ 0.06 µg/mL). The gyrA, gyrB, parC, and parE genes were sequenced to identify mutations associated with changes in susceptibility to fluoroquinolones. Two hundred eighty-five Salmonella enterica isolates from 5211 blood cultures were most commonly identified as Salmonella enterica serovar Typhimurium (n = 129 [45%]), Salmonella enterica serovar Typhi (n = 89 [31%]), Salmonella enterica serovar Dublin (n = 20 [7%]), and Salmonella enterica serovar Enteritidis (n = 19 [7%]). All S. Typhi and S. Dublin were susceptible to ciprofloxacin. Reduced susceptibility (MIC >0.06 µg/mL) was found in 53% (10/19) of S. Enteritidis and in 2% (3/129) of S. Typhimurium isolates. Sequencing detected a single gyrB mutation (Glu466Asp) and a single gyrA mutation (Ser83Tyr) in all 3 S. Typhimurium isolates, while 9 of 10 S. Enteritidis harbored single gyrA mutations (Asp87Gly, Asp87Asn, or Asp87Tyr). No mutations were found in the parC and parE genes. Ciprofloxacin susceptibility in invasive NTS in rural Ghana is highly dependent on serotype. Although reduced ciprofloxacin susceptibility is low in S. Typhimurium, more than half of all S. Enteritidis isolates are affected. Healthcare practitioners in Ghana should be aware of potential treatment failure in patients with invasive

  18. Draft Whole-Genome Sequences of 25 Salmonella enterica Strains Representing 24 Serovars

    PubMed Central

    Brumwell, Stephanie L.; Lingohr, Erika J.; Ahmad, Aaminah; Blimkie, Travis M.; Kogan, Benjamin A.; Pilsworth, Jessica; Rehman, Muhammad A.; Schleicher, Krista L.; Shanmugaraj, Jenitta; Kropinski, Andrew M.; Nash, John H. E.

    2016-01-01

    We report the draft genome sequences of 25 Salmonella enterica strains representing 24 different serotypes, many of which were not available in public repositories during our selection process. These draft genomes will provide useful reference for the genetic variation between serotypes and aid in the development of molecular typing tools. PMID:26941156

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

    USDA-ARS?s Scientific Manuscript database

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

  20. Draft Genome Sequences of Two Salmonella enterica Strains Isolated from Sprouted Chia and Flax Seed Powders.

    PubMed

    Ronholm, Jennifer; Petronella, Nicholas; Tamber, Sandeep

    2016-09-22

    A 2014 foodborne salmonellosis outbreak in Canada and the United States implicated, for the first time, sprouted chia seed powder as the vehicle of transmission. Here, we report the draft whole genome sequences of two Salmonella enterica strains isolated from sprouted powders related to the aforementioned outbreak. © Crown copyright 2016.

  1. 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

  2. Multiple environmental stress tests show no common phenotypes shared among contemporary epidemic strains of Salmonella enterica.

    PubMed

    Kang, Min-Su; Besser, Thomas E; Hancock, Dale D; Call, Douglas R

    2007-05-01

    Phenotypic traits of coexisting epidemic and nonepidemic strains of Salmonella enterica serovars Typhimurium and Newport were compared. Different stress conditions were relatively more or less favorable for the epidemic strains. Transcriptional analysis identified specific upregulated genes during defined stress conditions, but there were no common traits shared by epidemic serovars.

  3. 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...

  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. Kinetics of Salmonella enterica serotype Typhimurium DT104 growth and inactivation in pasteurised liquid egg products

    USDA-ARS?s Scientific Manuscript database

    The potential impact of intentional post-pasteurisation contamination of liquid egg products with the multi-antibiotic resistant pathogen Salmonella enterica serotype Typhimurium definitive type 104 (DT104) was assessed by determining the viability of this bacterium in whole egg, albumen and 10% sug...

  6. Natural Isolates of Salmonella enterica Serovar Dublin Carry a Single nadA Missense Mutation

    PubMed Central

    Bergthorsson, Ulfar; Roth, John R.

    2005-01-01

    Nicotinic acid is required by most isolates of Salmonella enterica (serovar Dublin), a pathogen of cattle. A single nadA missense mutation causes the nutritional requirement of all serovar Dublin isolates tested. Models for persistence of this allele are tested and discussed. PMID:15601727

  7. Natural isolates of Salmonella enterica serovar Dublin carry a single nadA missense mutation.

    PubMed

    Bergthorsson, Ulfar; Roth, John R

    2005-01-01

    Nicotinic acid is required by most isolates of Salmonella enterica (serovar Dublin), a pathogen of cattle. A single nadA missense mutation causes the nutritional requirement of all serovar Dublin isolates tested. Models for persistence of this allele are tested and discussed.

  8. 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

  9. 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

  10. 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.

  11. Prevalence of ColE1-like plasmids and kanamycinr resistance genes in Salmonella enterica serotypes

    USDA-ARS?s Scientific Manuscript database

    Multi-antibiotic resistant Salmonella enterica serotypes are increasing in prevalence and concern in human and animal health. Many strains carry resistance determinants on plasmids; current practices focus heavily on large plasmids, and the role that small plasmids play in resistance gene transfer ...

  12. Whole-Genome Shotgun Sequencing of Cephalosporin-Resistant Salmonella enterica Serovar Typhi.

    PubMed

    Rodrigues, Camilla; Kapil, Arti; Sharma, Anita; Devanga Ragupathi, Naveen Kumar; Inbanathan, Francis Yesurajan; Veeraraghavan, Balaji; Kang, Gagandeep

    2017-03-09

    Typhoid is one of the leading causes of mortality in developing countries. Here, we report the draft genome sequences of four Salmonella enterica serovar Typhi strains isolated from bloodstream infections in a tertiary care hospital. The sequence data indicate genomes of ~4.5 Mb for all isolates, with one plasmid in each.

  13. Subtyping of Salmonella enterica subspecies I using single nucleotide polymorphisms in adenylate cyclase (cyaA)

    USDA-ARS?s Scientific Manuscript database

    Methods to rapidly identify serotypes of Salmonella enterica subspecies I are of vital importance for protecting the safety of food. To supplement the serotyping method dkgB-linked intergenic sequence ribotyping (ISR), single nucleotide polymorphisms (SNPs) were characterized within adenylate cyclas...

  14. Recovery of Salmonella enterica serovar Enteritidis from hens initially infected with serovar Kentucky

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serovars Enteritidis and Kentucky differ greatly in epidemiology. We wanted to know if the non-pathogenic serotype Kentucky impacted the recovery of the pathogen Enteritidis from chickens. To explore this issue, 4 groups of hens were treated as follows: i) hens were inoculated or...

  15. Survival and fate of Salmonella enterica serovar Montevideo in adult Horn Flies (Diptera: Muscidae)

    USDA-ARS?s Scientific Manuscript database

    Contamination of cattle peripheral lymph nodes with Salmonella enterica is proposed to occur via a transdermal route of entry. If so, bacteria may be introduced to cattle by biting arthropods. Biting flies, such as horn flies (Haematobia irritans irritans (L.); Diptera: Muscidae), are intriguing ca...

  16. Complete Genome Sequence of Salmonella enterica Serovar Enteritidis Bacteriophage f18SE, Isolated in Chile

    PubMed Central

    Segovia, Cristopher; Vasquez, Ignacio; Maracaja-Coutinho, Vinicius; Robeson, James

    2015-01-01

    Bacteriophage f18SE was isolated from poultry sewage in Olmue, Chile, and lytic activity was demonstrated against Salmonella enterica serovar Enteritidis and serovar Pullorum strains. This bacteriophage has a 41,868-bp double-stranded DNA (ds-DNA) genome encoding 53 coding sequences (CDSs) and belongs to the family Siphoviridae, subfamily Jerseyvirinae. PMID:26450716

  17. TRANSCRIPTIONAL RESPONSE OF CHICKEN MACROPHAGES TO SALMONELLA ENTERICA SEROVAR ENTERITIDIS INFECTION

    USDA-ARS?s Scientific Manuscript database

    The transcriptional profiles of chicken macrophages (HD11) infected with Salmonella enterica serovar Enteritidis (SE) were analyzed by using avian macrophage microarray and real time RT-PCR. Out of 4,906 array elements interrogated, 269 genes exhibited a 2-fold change (P < 0.001) over a 24-hour time...

  18. Transcriptional Response of Chicken Macrophages to Salmonella enterica serovar Enteritidis Infection

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica serovar Enteritidis (SE) continues to be the predominant etiologic agent of salmonellosis, with contaminated egg products being the primary source of infection. At the present time, the molecular and immunological mechanisms involved in SE colonization of chicken hosts are not we...

  19. 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...

  20. Carvacrol and cinnamaldehyde inactivate antibiotic-resistant Salmonella enterica in buffer and on celery and oysters

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is one of the leading causes of gastrointestinal foodborne illness. The emergence of antibiotic resistant strains of this pathogen is of concern to food processors, including the produce, poultry, and oyster industries. The objective of this research was to identify the potenti...

  1. 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...

  2. 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...

  3. 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...

  4. Draft Genome Sequences of Four Salmonella enterica Strains Isolated from Turkey-Associated Sources

    PubMed Central

    Han, Jing; Gokulan, Kuppan; Zhao, Shaohua; Gies, Allen

    2016-01-01

    We report the draft genomes of four Salmonella enterica isolates evaluated for the contribution of plasmids to virulence. Strains SE163A, SE696A, and SE710A carry plasmids demonstrated to facilitate plasmid-associated virulence, while SE819 is less virulent and has been used as a recipient for conjugation experiments to assess plasmid-encoded virulence mechanisms. PMID:27738037

  5. Rapid Molecular Determination of Serotype from Clinical Isolates of Salmonella Enterica

    USDA-ARS?s Scientific Manuscript database

    Background: The conventional serotyping of Salmonella Enterica is time consuming, costly, and requires highly skilled staff. In the present study, we report a multiplex PCR typing method using capillary electrophoresis for fragment analysis that allows for the identification of the 30 most common h...

  6. Whole-Genome Shotgun Sequencing of Cephalosporin-Resistant Salmonella enterica Serovar Typhi

    PubMed Central

    Rodrigues, Camilla; Kapil, Arti; Sharma, Anita; Devanga Ragupathi, Naveen Kumar; Inbanathan, Francis Yesurajan; Kang, Gagandeep

    2017-01-01

    ABSTRACT Typhoid is one of the leading causes of mortality in developing countries. Here, we report the draft genome sequences of four Salmonella enterica serovar Typhi strains isolated from bloodstream infections in a tertiary care hospital. The sequence data indicate genomes of ~4.5 Mb for all isolates, with one plasmid in each. PMID:28280021

  7. 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...

  8. 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

  9. 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.

  10. The contribution of genes required for anaerobic respiration to the virulence of Salmonella enterica serovar Gallinarum for chickens.

    PubMed

    Paiva, J B; Penha Filho, R A C; Pereira, E A; Lemos, M V F; Barrow, P A; Lovell, M A; Berchieri, A

    2009-10-01

    Salmonella enterica serovar Gallinarum (SG) is an intracellular pathogen of chickens. To survive, to invade and to multiply in the intestinal tract and intracellularly it depends on its ability to produce energy in anaerobic conditions. The fumarate reductase (frdABCD), dimethyl sulfoxide (DMSO)-trimethylamine N-oxide (TMAO) reductase (dmsABC), and nitrate reductase (narGHIJ) operons in Salmonella Typhimurium (STM) encode enzymes involved in anaerobic respiration to the electron acceptors fumarate, DMSO, TMAO, and nitrate, respectively. They are regulated in response to nitrate and oxygen availability and changes in cell growth rate. In this study mortality rates of chickens challenged with mutants of Salmonella Gallinarum, which were defective in utilising anaerobic electron acceptors, were assessed in comparison to group of bird challenged with wild strain. The greatest degree of attenuation was observed with mutations affecting nitrate reductase (napA, narG) with additional attenuations induced by a mutation affecting fumarate reductase (frdA) and a double mutant (dmsA torC) affecting DMSO and TMAO reductase.

  11. Discovery of Novel Secreted Virulence Factors from Salmonella enterica Serovar Typhimurium by Proteomic Analysis of Culture Supernatants

    SciTech Connect

    Niemann, George; Brown, Roslyn N.; Gustin, Jean K.; Stufkens, Afke; Shaikh-Kidwai, Afshan S.; Li, Jie; McDermott, Jason E.; Brewer, Heather M.; Schepmoes, Athena A.; Smith, Richard D.; Adkins, Joshua N.; Heffron, Fred

    2011-01-01

    The intracellular pathogen Salmonella enterica serovar Typhimurium is a leading cause of acute gastroenteritis in the world. This pathogen has two type-III secretion systems (TTSS) necessary for virulence that are encoded in Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2) and are expressed during extracellular or intracellular infectious states, respectively, to deliver virulence factors (effectors) to the host cell cytoplasm. While many have been identified and at least partially characterized, the full repertoire of effectors has not been catalogued. In this mass spectrometry-based proteomics study, we identified effector proteins secreted under minimal acidic medium growth conditions that induced the SPI-2 TTSS and its effectors, and compared the secretome from the parent strain to the secretome from strains missing either essential (SsaK) or regulatory components (SsaL) of the SPI-2 secretion apparatus. We identified 75% of the known TTSS effector repertoire. Excluding translocon components, 95% of the known effectors were biased for identification in the ssaL mutant background, which demonstrated that SsaL regulates SPI-2 type III secretion. To confirm secretion to animal cells, we made translational fusions of several of the best candidates to the calmodulin-dependent adenylate cyclase of Bordetella pertussis and assayed cAMP levels of infected J774 macrophage-like cells. From these infected cells we identified six new TTSS effectors and two others that are secreted independent of TTSS. Our results substantiate reports of additional secretion systems encoded by Salmonella other than TTSS.

  12. 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

  13. Unsaturated Long Chain Free Fatty Acids Are Input Signals of the Salmonella enterica PhoP/PhoQ Regulatory System*

    PubMed Central

    Viarengo, Gastón; Sciara, Mariela I.; Salazar, Mario O.; Kieffer, Pablo M.; Furlán, Ricardo L. E.; García Véscovi, Eleonora

    2013-01-01

    The Salmonella enterica serovar Typhimurium PhoP/PhoQ system has largely been studied as a paradigmatic two-component regulatory system not only to dissect structural and functional aspects of signal transduction in bacteria but also to gain knowledge about the versatile devices that have evolved allowing a pathogenic bacterium to adjust to or counteract environmental stressful conditions along its life cycle. Mg2+ limitation, acidic pH, and the presence of cationic antimicrobial peptides have been identified as cues that the sensor protein PhoQ can monitor to reprogram Salmonella gene expression to cope with extra- or intracellular challenging conditions. In this work, we show for the first time that long chain unsaturated free fatty acids (LCUFAs) present in Salmonella growth medium are signals specifically detected by PhoQ. We demonstrate that LCUFAs inhibit PhoQ autokinase activity, turning off the expression of the PhoP-dependent regulon. We also show that LCUFAs exert their action independently of their cellular uptake and metabolic utilization by means of the β-oxidative pathway. Our findings put forth the complexity of input signals that can converge to finely tune the activity of the PhoP/PhoQ system. In addition, they provide a new potential biochemical platform for the development of antibacterial strategies to fight against Salmonella infections. PMID:23782700

  14. 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.

  15. 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

  16. A comparative study of thermal and acid inactivation kinetics in fruit juices of Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Senftenberg grown at acidic conditions.

    PubMed

    Alvarez-Ordóñez, Avelino; Fernández, Ana; Bernardo, Ana; López, Mercedes

    2009-11-01

    Acid and heat inactivation in orange and apple juices of Salmonella enterica serovar Typhimurium Colección Española de Cultivos Tipo (i.e., Spanish Type Culture Collection) 443 (CECT 443) (Salmonella Typhimurium) and S. enterica serovar Senftenberg CECT 4384 (Salmonella Senftenberg) grown in buffered brain heart infusion (pH 7.0) and acidified brain heart infusion up to pH 4.5 with acetic, citric, lactic, and hydrochloric acids was evaluated. Acid adaptation induced an adaptive response that increased the subsequent resistance to extreme pH conditions (pH 2.5) and to heat, although the magnitude of these responses differed between the two isolates and fruit juices. The acid resistance in orange juice for acid-adapted cells (D-values of 28.3-34.5 min for Salmonella Senftenberg and 30.0-39.2 min for Salmonella Typhimurium) resulted to be about two to three times higher than that corresponding to non-acid-adapted cells. In apple juice, acid-adapted Salmonella Senftenberg cells survived better than those of Salmonella Typhimurium, obtaining mean D-values of 114.8 +/- 12.3 and 41.9 +/- 2.5 min, respectively. The thermotolerance of non-acid-adapted Salmonella Typhimurium in orange (D(58)-value: 0.028 min) and apple juices (D(58)-value: 0.10 min) was approximately double for acid-adapted cells. This cross-protection to heat was more strongly expressed in Salmonella Senftenberg. D(58)-values obtained for non-acid-adapted cells in orange (0.11 min) and apple juices (0.19 min) increased approximately 10 and 5 times, respectively, after their growth in acidified media. The conditions prevailing during bacterial growth and heat treatment did not significantly influence the z-values observed (6.0 +/- 0.3 degrees C for Salmonella Typhimurium and 7.0 +/- 0.3 degrees C for Salmonella Senftenberg). The enhanced acid resistance found for both isolates could enable them to survive for prolonged time periods in the gastrointestinal tract, increasing the risk of illness. Further, it

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

    PubMed Central

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

    2017-01-01

    We aimed to analyze the antimicrobial resistance phenotypes and to elucidate the molecular mechanisms underlying resistance to cephalosporins, ciprofloxacin, and azithromycin in Salmonella enterica serovar Typhimurium isolates identified from patients with diarrhea in Shanghai. The isolates showed high rates of resistance to traditional antimicrobials, and 20.6, 12.7, and 5.5% of them exhibited decreased susceptibility to cephalosporins, ciprofloxacin, and azithromycin, respectively. Notably, 473 (84.6%) isolates exhibited multidrug resistance (MDR), including 161 (28.8%) isolates that showed an ACSSuT profile. Twenty-two MDR isolates concurrently exhibited decreased susceptibility to cephalosporins and ciprofloxacin, and six of them were co-resistant to azithromycin. Of all the 71 isolates with decreased susceptibility to ciprofloxacin, 65 showed at least one mutation (D87Y, D87N, or D87G) in gyrA, among which seven isolates simultaneously had mutations of parC (S80R) (n = 6) or parC (T57S/S80R) (n = 1), while 49 isolates with either zero or one mutation in gyrA contained plasmid-mediated quinolone resistance (PMQR) genes including qnrB, qnrS, and aac(6′)-Ib-cr. Among the 115 cephalosporin-resistant isolates, the most common ESBL gene was blaCTX-M, followed by blaTEM-1, blaOXA-1, and blaSHV -12. Eight subtypes of blaCTX-M were identified and blaCTX-M-14 (n = 22) and blaCTX-M-55 (n = 31) were found to be dominant. To the best of our knowledge, this is the first report of the presence of blaCTX-M-123 and blaCTX-M-125 in S. Typhimurium. Besides, mphA gene was identified in 15 of the 31 azithromycin-resistant isolates. Among the 22 isolates with reduced susceptibility to cephalosporins and ciprofloxacin, 15 contained ESBL and PMQR genes. Coexistence of these genes lead to the emergence of MDR and the transmission of them will pose great difficulties in S. Typhimurium treatments. Therefore, surveillance for these MDR isolates should be enhanced. PMID:28400764

  18. Diverse distribution of Toxin-Antitoxin II systems in Salmonella enterica serovars

    PubMed Central

    Di Cesare, Andrea; Losasso, Carmen; Barco, Lisa; Eckert, Ester M.; Conficoni, Daniele; Sarasini, Giulia; Corno, Gianluca; Ricci, Antonia

    2016-01-01

    Type II Toxin-Antitoxin systems (TAs), known for their presence in virulent and antibiotic resistant bacterial strains, were recently identified in Salmonella enterica isolates. However, the relationships between the presence of TAs (ccdAB and vapBC) and the epidemiological and genetic features of different non-typhoidal Salmonella serovars are largely unknown, reducing our understanding of the ecological success of different serovars. Salmonella enterica isolates from different sources, belonging to different serovars and epidemiologically unrelated according to ERIC profiles, were investigated for the presence of type II TAs, plasmid content, and antibiotic resistance. The results showed the ubiquitous presence of the vapBC gene in all the investigated Salmonella isolates, but a diverse distribution of ccdAB, which was detected in the most widespread Salmonella serovars, only. Analysis of the plasmid toxin ccdB translated sequence of four selected Salmonella isolates showed the presence of the amino acid substitution R99W, known to impede in vitro the lethal effect of CcdB toxin in the absence of its cognate antitoxin CcdA. These findings suggest a direct role of the TAs in promoting adaptability and persistence of the most prevalent Salmonella serovars, thus implying a wider eco-physiological role for these type II TAs. PMID:27357537

  19. Increased persistence of Salmonella enterica serovar Typhi in the presence of Acanthamoeba castellanii.

    PubMed

    Douesnard-Malo, Frédéric; Daigle, France

    2011-11-01

    Salmonella enterica serovar Typhi (S. Typhi) is the etiological agent of the systemic disease typhoid fever. Transmission occurs via ingestion of contaminated food or water. S. Typhi is specific to humans, and no animal or environmental reservoirs are known. As the free-living amoeba Acanthamoeba castellanii is an environmental host for many pathogenic bacteria, this study investigates interactions between S. Typhi and A. castellanii by using cocultures. Growth of both organisms was estimated by cell count, viable count, flow cytometry, and fluorescence microscopy. Results indicate that S. Typhi can survive at least 3 weeks when grown with A. castellanii, as opposed to less than 10 days when grown as singly cultured bacteria under the same conditions. Interestingly, growth rates of amoebae after 14 days were similar in cocultures or when amoebae were singly cultured, suggesting that S. Typhi is not cytotoxic to A. castellanii. Bacteria surviving in coculture were not intracellular and did not require a physical contact with amoebae for their survival. These results suggest that S. Typhi may have a selective advantage when it is associated with A. castellanii and that amoebae may contribute to S. Typhi persistence in the environment.

  20. Antimicrobial resistance-conferring plasmids with similarity to virulence plasmids from avian pathogenic Escherichia coli strains in Salmonella enterica serovar Kentucky isolates from poultry

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica, a leading cause of food-borne gastroenteritis worldwide, may be found in any raw food of animal, vegetable, or fruit origin. Salmonella serovars differ in distribution, virulence, and host specificity. Salmonella enterica serovar Kentucky, though often found in the food supply, ...

  1. 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 ...

  2. Role of Salmonella enterica exposure in Chilean Crohn's disease patients

    PubMed Central

    Alvarez-Lobos, Manuel; Pizarro, Daniela P; Palavecino, Christian E; Espinoza, Abner; Sebastián, Valentina P; Alvarado, Juan C; Ibañez, Patricio; Quintana, Carlos; Díaz, Orlando; Kalergis, Alexis M; Bueno, Susan M

    2013-01-01

    AIM: To study the association between exposure to Salmonella enterica (SE) and Crohn’s disease (CD) and its clinical implications in Chilean patients. METHODS: Ninety-four unrelated Chilean CD patients from CAREI (Active Cohort Registry of Inflammatory Bowel Disease) presenting to a single inflammatory bowel disease (IBD) unit of a University Hospital were prospectively included in this study. A complete clinical evaluation, including smoking history, was performed at the initial visit, and all the important data of clinical evolution of CD were obtained. Blood samples from these CD patients and 88 healthy sex- and age-matched control subjects were analyzed for exposure to SE and for their NOD2/CARD15 gene status using the presence of anti-Salmonella lipopolysaccharide antibodies [immunoglobulin-G type (IgG)] and polymerase chain reaction (PCR), respectively. We also evaluated exposure to SE in 90 sex- and age-matched patients without CD, but with known smoking status (30 smokers, 30 non-smokers, and 30 former smokers). RESULTS: CD patients comprised 54 females and 40 males, aged 35.5 ± 15.2 years at diagnosis with a mean follow-up of 9.0 ± 6.8 years. CD was inflammatory in 59 patients (62.7%), stricturing in 24 (25.5%) and penetrating in 15 (15.5%). Thirty cases (31.9%) had lesions in the ileum, 29 (30.8%) had ileocolonic lesions, 32 (34.0%) had colonic lesions and 23 (24.4%) had perianal disease. Sixteen CD patients (17%) were exposed to SE compared to 15 (17%) of 88 healthy control subjects (P = 0.8). Thirty-one CD patients (32.9%) were smokers, and 7 (7.4%) were former smokers at diagnosis. In the group exposed to SE, 10 of 16 patients (62.5%) were active smokers compared to 21 of 78 patients (26.9%) in the unexposed group (P = 0.01). On the other hand, 10 of 31 smoking patients (32%) were exposed to SE compared to 5 of 56 nonsmoking patients (9%), and one of the seven former smokers (14%) (P = 0.01). In the group of 90 patients without CD, but whose

  3. Role of Salmonella enterica exposure in Chilean Crohn's disease patients.

    PubMed

    Alvarez-Lobos, Manuel; Pizarro, Daniela P; Palavecino, Christian E; Espinoza, Abner; Sebastián, Valentina P; Alvarado, Juan C; Ibañez, Patricio; Quintana, Carlos; Díaz, Orlando; Kalergis, Alexis M; Bueno, Susan M

    2013-09-21

    To study the association between exposure to Salmonella enterica (SE) and Crohn's disease (CD) and its clinical implications in Chilean patients. Ninety-four unrelated Chilean CD patients from CAREI (Active Cohort Registry of Inflammatory Bowel Disease) presenting to a single inflammatory bowel disease (IBD) unit of a University Hospital were prospectively included in this study. A complete clinical evaluation, including smoking history, was performed at the initial visit, and all the important data of clinical evolution of CD were obtained. Blood samples from these CD patients and 88 healthy sex- and age-matched control subjects were analyzed for exposure to SE and for their NOD2/CARD15 gene status using the presence of anti-Salmonella lipopolysaccharide antibodies [immunoglobulin-G type (IgG)] and polymerase chain reaction (PCR), respectively. We also evaluated exposure to SE in 90 sex- and age-matched patients without CD, but with known smoking status (30 smokers, 30 non-smokers, and 30 former smokers). CD patients comprised 54 females and 40 males, aged 35.5 ± 15.2 years at diagnosis with a mean follow-up of 9.0 ± 6.8 years. CD was inflammatory in 59 patients (62.7%), stricturing in 24 (25.5%) and penetrating in 15 (15.5%). Thirty cases (31.9%) had lesions in the ileum, 29 (30.8%) had ileocolonic lesions, 32 (34.0%) had colonic lesions and 23 (24.4%) had perianal disease. Sixteen CD patients (17%) were exposed to SE compared to 15 (17%) of 88 healthy control subjects (P = 0.8). Thirty-one CD patients (32.9%) were smokers, and 7 (7.4%) were former smokers at diagnosis. In the group exposed to SE, 10 of 16 patients (62.5%) were active smokers compared to 21 of 78 patients (26.9%) in the unexposed group (P = 0.01). On the other hand, 10 of 31 smoking patients (32%) were exposed to SE compared to 5 of 56 nonsmoking patients (9%), and one of the seven former smokers (14%) (P = 0.01). In the group of 90 patients without CD, but whose smoking status was known, there

  4. Changes in the Porcine Intestinal Microbiome in Response to Infection with Salmonella enterica and Lawsonia intracellularis

    PubMed Central

    Singer, Randall S.; Gebhart, Connie J.; Sreevatsan, Srinand; Johnson, Timothy; Isaacson, Richard E.

    2015-01-01

    Salmonella enterica is a leading cause of food borne illness. Recent studies have shown that S. enterica is a pathogen capable of causing alterations to the composition of the intestinal microbiome. A recent prospective study of French pork production farms found a statistically significant association between Lawsonia intracellularis and carriage of S. enterica. In the current study the composition of the gut microbiome was determined in pigs challenged with S. enterica serovar Typhimurium and or L. intracellularis and compared to non-challenged control pigs. Principal coordinate analysis demonstrated that there was a disruption in the composition of the gut microbiome in the colon and cecum of pigs challenged with either pathogen. The compositions of the microbiomes of challenged pigs were similar to each other but differed from the non-challenged controls. There also were statistically significant increases in Anaerobacter, Barnesiella, Pediococcus, Sporacetigenium, Turicibacter, Catenibacterium, Prevotella, Pseudobutyrivibrio, and Xylanibacter in the challenged pigs. To determine if these changes were specific to experimentally challenged pigs, we determined the compositions of the fecal microbiomes of naturally infected pigs that were carriers of S. enterica. Pigs that were frequent shedders of S. enterica were shown to have similar fecal microbiomes compared to non-shedders or pigs that shed S. enterica infrequently. In a comparison of the differentially abundant bacteria in the naturally infected pigs compared to experimentally challenged pigs, 9 genera were differentially abundant and each exhibited the same increase or decrease in abundance between the two groups. Thus, there were similar changes in the GI microbiome associated with carriage of S. enterica regardless of whether the pigs were experimentally challenged with S. enterica or acquired it naturally. PMID:26461107

  5. Longitudinal prevalence, faecal shedding and molecular characterisation of Campylobacter spp. and Salmonella enterica in sheep.

    PubMed

    Yang, Rongchang; Jacobson, Caroline; Gardner, Graham; Carmichael, Ian; Campbell, Angus J D; Ryan, Una

    2014-11-01

    Faecal excretion of Campylobacter spp. and Salmonella enterica in sheep in Australia was determined using a quantitative multiplex PCR (qPCR) targeting the Campylobacter spp. purine biosynthesis gene (PurA) and the S. enterica outer membrane protein (ompF). The mutiplex qPCR was specific and Campylobacter spp. and S. enterica were each detected with a sensitivity of 5 organisms/µL faecal DNA extract. This multiplex qPCR was used to determine the prevalence and concentration of Campylobacter spp. and S. enterica in 3412 faecal samples collected from 1189 lambs on eight farms across South Australia (n = 2 farms), New South Wales (n = 1), Victoria (n = 2) and Western Australia (n = 3) at three sampling periods (weaning, post-weaning and pre-slaughter). The overall prevalences of Campylobacter spp. and S. enterica were 13.3% and 5.0%, respectively, with the highest prevalence for Campylobacter spp. in South Australia and the highest prevalence for S. enterica in New South Wales. Campylobacter jejuni was the only Campylobacter sp. identified from a subset of 120 positive samples sequenced at the 16S locus. S. enterica serovar Typhimurium was the only serovar of S. enterica identified from a subset of 120 positive samples sequenced at the ompF locus. Across all states, Campylobacter spp. had the highest median bacterial concentration in faeces at weaning and post-weaning (medians of 3.4 × 10(6) and 1.1 × 10(5), respectively), whereas S. enterica had the highest median bacterial concentration at pre-slaughter (1.8 × 10(5)/g faeces).

  6. 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...

  7. 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...

  8. Genome Sequences of Four Nonhuman/Nonclinical Salmonella enterica Serovar Kentucky ST198 Isolates Recovered between 1972 and 1973

    PubMed Central

    Kim, Seon-Woo; Haley, Bradd J.; Roberson, Dwayne; Allard, Marc; Hammack, Thomas S.; Brown, Eric W.

    2017-01-01

    ABSTRACT Salmonella enterica serovar 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 isolates recovered in the 1970s. PMID:28302786

  9. Draft Genome Sequence of Salmonella enterica subsp. diarizonae Serovar 61:k:1,5,(7) Strain CRJJGF_00165 (Phylum Gammaproteobacteria)

    PubMed Central

    Gupta, Sushim K.; McMillan, Elizabeth A.; Jackson, Charlene R.; Desai, Prerak T.; Porwollik, Steffen; McClelland, Michael; Hiott, Lari M.; Humayoun, Shaheen B.; Barrett, John B.

    2016-01-01

    Here, we report a 4.78-Mb draft genome sequence of the Salmonella enterica subsp. diarizonae serovar 61:k:1,5,(7) strain CRJJGF_00165 [also called S. enterica subsp. IIIb serovar 61:k:1,5,(7) strain CRJJGF_00165], isolated from ground beef in 2007. PMID:27881547

  10. 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...

  11. Isolation of Salmonella enterica Serotype Newport from a Partly Ruptured Splenic Abscess in a Traveler Returning from Zanzibar▿

    PubMed Central

    Tappe, Dennis; Müller, Andreas; Langen, Heinz-Jakob; Frosch, Matthias; Stich, August

    2007-01-01

    Salmonella enterica subsp. enterica serotype Newport is a pathogen of growing importance because of its epidemic spread in dairy cattle and increasing rate of antimicrobial resistance. Human infections, however, are rare. We report a case of a splenic abscess in a young traveler returning from East Africa. PMID:17634302

  12. Cross-sectional study examining Salmonella enterica carriage in subiliac lymph nodes of cull and feedlot cattle at harvest

    USDA-ARS?s Scientific Manuscript database

    Bovine peripheral lymph nodes, including subiliac lymph nodes, have been identified as a potential source of human exposure to Salmonella enterica when trim containing these nodes is incorporated into ground beef. In order to gain a better understanding of the burden of S. enterica in subiliac lymp...

  13. Cross-sectional study examining Salmonella enterica carriage in subiliac lymph nodes of cull and feedlot cattle at harvest

    USDA-ARS?s Scientific Manuscript database

    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 periphe...

  14. 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...

  15. 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.

  16. Identification and Characterization of Multidrug-Resistant Salmonella enterica Serotype Albert Isolates in the United States

    PubMed Central

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

    2015-01-01

    Salmonella enterica is one of the most common causes of bacterial foodborne illness in the United States. Although most Salmonella infections are self-limiting, antimicrobial treatment of invasive salmonellosis is critical. The primary antimicrobial treatment options include fluoroquinolones or extended-spectrum cephalosporins, and resistance to these antimicrobial drugs may complicate treatment. At present, S. enterica is composed of more than 2,600 unique serotypes, which vary greatly in geographic prevalence, ecological niche, and the ability to cause human disease, and it is important to understand and mitigate the source of human infection, particularly when antimicrobial resistance is found. In this study, we identified and characterized 19 S. enterica serotype Albert isolates collected from food animals, retail meat, and humans in the United States during 2005 to 2013. All five isolates from nonhuman sources were obtained from turkeys or ground turkey, and epidemiologic data suggest poultry consumption or live-poultry exposure as the probable source of infection. S. enterica serotype Albert also appears to be geographically localized to the midwestern United States. All 19 isolates displayed multidrug resistance, including decreased susceptibility to fluoroquinolones and resistance to extended-spectrum cephalosporins. Turkeys are a likely source of multidrug-resistant S. enterica serotype Albert, and circulation of resistance plasmids, as opposed to the expansion of a single resistant strain, is playing a role. More work is needed to understand why these resistance plasmids spread and how their presence and the serotype they reside in contribute to human disease. PMID:25733501

  17. Physiological and Molecular Responses of Lactuca sativa to Colonization by Salmonella enterica Serovar Dublin▿

    PubMed Central

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

    2007-01-01

    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. PMID:17513585

  18. 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

  19. Inactivation of Salmonella enterica by UV-C light alone and in combination with mild temperatures.

    PubMed

    Gayán, E; Serrano, M J; Raso, J; Alvarez, I; Condón, S

    2012-12-01

    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.

  20. The Type III Secretion System Effector SeoC of Salmonella enterica subsp. salamae and S. enterica subsp. arizonae ADP-Ribosylates Src and Inhibits Opsonophagocytosis

    PubMed Central

    Pollard, Dominic J.; Young, Joanna C.; Covarelli, Valentina; Herrera-León, Silvia; Connor, Thomas R.; Fookes, Maria; Walker, Danielle; Echeita, Aurora; Thomson, Nicholas R.; Berger, Cedric N.

    2016-01-01

    Salmonella species utilize type III secretion systems (T3SSs) to translocate effectors into the cytosol of mammalian host cells, subverting cell signaling and facilitating the onset of gastroenteritis. In this study, we compared a draft genome assembly of Salmonella enterica subsp. salamae strain 3588/07 against the genomes of S. enterica subsp. enterica serovar Typhimurium strain LT2 and Salmonella bongori strain 12419. S. enterica subsp. salamae encodes the Salmonella pathogenicity island 1 (SPI-1), SPI-2, and the locus of enterocyte effacement (LEE) T3SSs. Though several key S. Typhimurium effector genes are missing (e.g., avrA, sopB, and sseL), S. enterica subsp. salamae invades HeLa cells and contains homologues of S. bongori sboK and sboC, which we named seoC. SboC and SeoC are homologues of EspJ from enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively), which inhibit Src kinase-dependent phagocytosis by ADP-ribosylation. By screening 73 clinical and environmental Salmonella isolates, we identified EspJ homologues in S. bongori, S. enterica subsp. salamae, and Salmonella enterica subsp. arizonae. The β-lactamase TEM-1 reporter system showed that SeoC is translocated by the SPI-1 T3SS. All the Salmonella SeoC/SboC homologues ADP-ribosylate Src E310 in vitro. Ectopic expression of SeoC/SboC inhibited phagocytosis of IgG-opsonized beads into Cos-7 cells stably expressing green fluorescent protein (GFP)-FcγRIIa. Concurrently, S. enterica subsp. salamae infection of J774.A1 macrophages inhibited phagocytosis of beads, in a seoC-dependent manner. These results show that S. bongori, S. enterica subsp. salamae, and S. enterica subsp. arizonae share features of the infection strategy of extracellular pathogens EPEC and EHEC and shed light on the complexities of the T3SS effector repertoires of Enterobacteriaceae. PMID:27736780

  1. Survival of Salmonella enterica in aerated and nonaerated wastewaters from dairy lagoons.

    PubMed

    Ravva, Subbarao V; Sarreal, Chester Z

    2014-10-29

    Salmonella is the most commonly identified foodborne pathogen in produce, meat and poultry. Cattle are known reservoirs of Salmonella and the pathogen excreted in feces ends up in manure flush lagoons. Salmonella enterica survival was monitored in wastewater from on-site holding lagoons equipped or not with circulating aerators at two dairies. All strains had poor survival rates and none proliferated in waters from aerated or settling lagoons. Populations of all three Salmonella serovars declined rapidly with decimal reduction times (D) of <2 days in aerated microcosms prepared from lagoon equipped with circulators. Populations of Salmonella decreased significantly in aerated microcosms (D = 4.2 d) compared to nonaerated waters (D = 7.4 d) and in summer (D = 3.4 d) compared to winter (D = 9.0 d). We propose holding the wastewater for sufficient decimal reduction cycles in lagoons to yield pathogen-free nutrient-rich water for crop irrigations and fertilization.

  2. Survival of Salmonella enterica in Aerated and Nonaerated Wastewaters from Dairy Lagoons

    PubMed Central

    Ravva, Subbarao V.; Sarreal, Chester Z.

    2014-01-01

    Salmonella is the most commonly identified foodborne pathogen in produce, meat and poultry. Cattle are known reservoirs of Salmonella and the pathogen excreted in feces ends up in manure flush lagoons. Salmonella enterica survival was monitored in wastewater from on-site holding lagoons equipped or not with circulating aerators at two dairies. All strains had poor survival rates and none proliferated in waters from aerated or settling lagoons. Populations of all three Salmonella serovars declined rapidly with decimal reduction times (D) of <2 days in aerated microcosms prepared from lagoon equipped with circulators. Populations of Salmonella decreased significantly in aerated microcosms (D = 4.2 d) compared to nonaerated waters (D = 7.4 d) and in summer (D = 3.4 d) compared to winter (D = 9.0 d). We propose holding the wastewater for sufficient decimal reduction cycles in lagoons to yield pathogen-free nutrient-rich water for crop irrigations and fertilization. PMID:25358096

  3. Growth Dynamics of Salmonella enterica Strains on Alfalfa Sprouts and in Waste Seed Irrigation Water

    PubMed Central

    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. PMID:12514040

  4. 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.

  5. Fatal case of Salmonella enterica subsp. arizonae gastroenteritis in an infant with microcephaly.

    PubMed

    Mahajan, Rakesh Kumar; Khan, Shoeb Akhtar; Chandel, Dinesh Singh; Kumar, Navin; Hans, Charoo; Chaudhry, Rama

    2003-12-01

    Salmonella enterica subsp. arizonae is a common gut inhabitant of reptiles, with snakes as the most common reservoir. Though human cases due to this organism are exceedingly rare, it may infect young infants and immunocompromised individuals with a history of intimate associations with reptiles. Gastroenteritis is the most common presentation; others include peritonitis, pleuritis, osteomyelitis, meningitis, and bacteremia. We report a fatal case of S. enterica subsp. arizonae gastroenteritis in a 3-month-old child with microcephaly, with a review of earlier cases and problems encountered in identification of this rare human pathogen.

  6. Otitis interna (labyrinthitis) associated with Salmonella enterica arizonae in turkey poults.

    PubMed

    Shivaprasad, H L; Cortes, P; Crespo, R

    2006-03-01

    Otitis interna was diagnosed in five 9-to-21-day-old turkey poults with clinical signs of paralysis, opisthotonus, torticollis, blindness, and increased mortality. Gross and microscopic lesions in the poults included omphalitis, typhlitis, hepatitis, meningoencephalitis, ophthalmitis, neuritis and ganglionitis of the vestibulocochlear nerve, and otitis interna. Salmonella enterica arizonae was isolated from the brains, eyes, intestines, yolk sacs, and livers of poults. Birds with otitis interna also had meningoencephalitis. It is most likely that the S. enterica arizonae infection spread from the brain to the internal ears through the vestibulocochlear nerve. This is the first documentation of otitis interna caused by bacteria in an avian species.

  7. Fatal Case of Salmonella enterica subsp. arizonae Gastroenteritis in an Infant with Microcephaly

    PubMed Central

    Mahajan, Rakesh Kumar; Khan, Shoeb Akhtar; Chandel, Dinesh Singh; Kumar, Navin; Hans, Charoo; Chaudhry, Rama

    2003-01-01

    Salmonella enterica subsp. arizonae is a common gut inhabitant of reptiles, with snakes as the most common reservoir. Though human cases due to this organism are exceedingly rare, it may infect young infants and immunocompromised individuals with a history of intimate associations with reptiles. Gastroenteritis is the most common presentation; others include peritonitis, pleuritis, osteomyelitis, meningitis, and bacteremia. We report a fatal case of S. enterica subsp. arizonae gastroenteritis in a 3-month-old child with microcephaly, with a review of earlier cases and problems encountered in identification of this rare human pathogen. PMID:14662995

  8. 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

  9. [Therapeutic intervention alternatives in cancer, using attenuated live bacterial vectors: Salmonella enterica as a carrier of heterologous molecules].

    PubMed

    Hernández-Luna, Marco Antonio; Luria-Pérez, Rosendo; Huerta-Yépez, Sara

    2013-01-01

    Salmonella enterica is a facultative anaerobic bacteria, whose ability to colonize antigen-presenting cells (APCs) such as dendritic cells and macrophages, has allowed its successful use as an alive, attenuated bacterial vector for vaccination. Salmonella enterica elicits efficient cellular, humoral and mucosal immune responses, against heterologous antigens including viruses, parasites, other bacterial species and tumor-associated antigens, since it is capable of delivering these antigens to cells of the immune system. The extracellular expression of heterologous antigens on the surface of Salmonella enterica via its type I, III and V secretion systems, and their delivery into infected cells is essential for its stimulation of immune responses against these antigens. Moreover, Salmonella enterica is a promising therapeutic agent against cancer, as demonstrated by reports of pre-clinical and clinical studies indicating that, after systemic administration, Salmonella enterica preferentially localizes in solid tumors and metastases as compared to normal tissues. In this review, we focus on novel prophylactic and therapeutic anti-cancer approaches using Salmonella enterica as a delivery system of heterologous molecules with the aim of inhibiting tumor growth.

  10. Resistance phenotypes and genotypes of Salmonella enterica subsp. enterica isolates from feed, pigs, and carcasses in Brazil.

    PubMed

    Lopes, Graciela Volz; Pissetti, Caroline; da Cruz Payão Pellegrini, Débora; da Silva, Luis Eduardo; Cardoso, Marisa

    2015-02-01

    Salmonella enterica subsp. enterica plays a role as a foodborne pathogen worldwide. The consumption of contaminated pork has been associated with human salmonellosis and the increase in antimicrobial resistance among Salmonella from pigs and pork products is a concern. A total of 225 Salmonella isolates from feed mills, the lairage environment, and the intestinal contents of pigs and carcasses were investigated for their antimicrobial susceptibility. A MIC for ciprofloxacin was screened by agar dilution, and antimicrobial resistance genes were investigated by PCR assays. Among the tested isolates, 171 (76%) showed resistance to at least one antimicrobial agent, and 91 (40.4%) were multiresistant. Resistance occurred most frequently to tetracycline (54.5%), sulfonamides (39.6%), and streptomycin (33.7%). Thirty-two (94.1%) nalidixic acid-resistant isolates exhibited decreased susceptibility to ciprofloxacin. The resistance genes found were blaTEM (ampicillin), tet(A) (tetracycline), tet(B) (tetracycline/minocycline), sul1, sul2, and sul3 (sulfonamides), catA1 (chloramphenicol), floR (florfenicol/chloramphenicol), strA and strB (streptomycin), aph(3')-Ia (kanamycin), aac(3)-IIa and aac(3)-IVa (apramycin/gentamicin), aadA variant (streptomycin/spectinomycin), and dfrA1 (trimethoprim). Salmonella isolates from pig feces and carcasses displayed a higher frequency of resistance to most antimicrobials tested than isolates from feed mills. Common resistance gene profiles were found in isolates from the lairage and the intestinal content of pigs and carcasses, demonstrating that resistance genes selected on farms may be found in pork.

  11. High-Quality Draft Whole-Genome Sequences of 162 Salmonella enterica subsp. enterica Serovar Enteritidis Strains Isolated from Diverse Sources in Canada

    PubMed Central

    Rehman, Muhammad A.; Ziebell, Kim; Nash, John H. E.; Kropinski, Andrew M.; Zong, Zusheng; Nafziger, Emily; Boerlin, Patrick; Chui, Linda; Devenish, John; Bekal, Sadjia; Graham, Morag

    2014-01-01

    We report the high-quality draft genome sequences of 162 strains of Salmonella enterica subsp. enterica serovar Enteritidis representing diverse phage types and pulsed-field gel electrophoresis (PFGE) profiles. The analysis of these genomes will enable the identification of markers that are useful for differentiating strains of this highly clonal serovar and will provide insights into the evolution, virulence, and epidemiology of the strains. PMID:24786953

  12. Molecular characterization of Salmonella enterica isolates associated with starling-livestock interactions.

    PubMed

    Carlson, James C; Hyatt, Doreene R; Bentler, Kevin; Mangan, Anna M; Russell, Michael; Piaggio, Antoinette J; Linz, George M

    2015-08-31

    Bird-livestock interactions have been implicated as potential sources for bacteria within concentrated animal feeding operations (CAFO). In this study we characterized XbaI-digested genomic DNA from Salmonella enterica using pulsed-field gel electrophoresis (PFGE). The PFGE analysis was conducted using 182 S. enterica isolates collected from a single CAFO between 2009 and 2012. Samples collected in 2012 were subjected to antimicrobial susceptibility testing. The analysis was limited to S. enterica serotypes, with at least 10 isolates, known to occur in both European starlings (Sturnus vulgaris) and cattle (Bos taurus) within this CAFO. A total of five different serotypes were screened; S. Anatum, S. Kentucky, S. Meleagridis, S. Montevideo, S. Muenchen. These samples were recovered from five different sample types; starling gastrointestinal tracts (GI), starling external wash, cattle feces, cattle feed and cattle water troughs. Indistinguishable S. enterica PFGE profiles were recovered from isolates originating in all sample types. Antimicrobial resistance (AMR) was also associated with indistinguishable S. enterica isolates recovered from all samples types. These data suggests that AMR S. enterica is transmitted between cattle and starlings and that shared feed sources are likely contributing to infections within both species. Moreover we isolated indistinguishable PFGE profiles across all years of data collection, suggesting long-term environmental persistence may be mediated by starling visits to CAFO. Published by Elsevier B.V.

  13. Detection of low numbers of healthy and sub-lethally injured Salmonella enterica in chocolate.

    PubMed

    Jasson, Vicky; Baert, Leen; Uyttendaele, Mieke

    2011-02-28

    The capacity to detect low levels of healthy and sub-lethally injured Salmonella enterica cells in chocolate by two alternative rapid detection methods iQ-Check(TM)Salmonella II real-time PCR (Bio-Rad) and VIDAS® Easy SLM (BioMérieux) was assessed and compared with ISO 6579:2005. Chocolate, a low moisture food known to support the survival of Salmonella, was challenged as food matrix. Buffered peptone water (BPW) did not support the recovery of low levels of sub-lethally injured S. enterica independent of the detection method, while BPW supplemented with milk powder enabled detection by the three examined methods. However, inhibition of real-time PCR was observed since for one out of three repetitions of chocolate inoculated with a low number of sub-lethally injured S. enterica cells, no PCR signal was obtained. Therefore, attention should be paid to the enrichment step to avoid false negative results due to the presence of especially sub-lethally injured Salmonella cells in chocolate. An appropriate sample preparation (such as enrichment media and conditions for incubation) remains the key factor for reliable detection including sub-lethally injured cells and should be evaluated, if necessary optimized, for each detection assay. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Identification of Key Genes in the Response to Salmonella enterica Enteritidis, Salmonella enterica Pullorum, and Poly(I:C) in Chicken Spleen and Caecum

    PubMed Central

    Sheng, Zhongwei; Dai, Aiqin; Zhai, Fei; Li, Jianchao; Xia, Mingxiu; Hua, Dengke; Xu, Lu; Wang, Hongzhi; Chen, Jing; Liu, Lu; Chen, Guohong

    2014-01-01

    Salmonella enterica Enteritidis (S. Enteritidis) and Salmonella enterica Pullorum (S. pullorum) are regarded as a threat to poultry production. This study's aim is to characterize the expression profiles in response to three different challenges and to identify infection-related genes in the chicken spleen and caecum. Groups of the Chinese chicken breed Langshan were challenged with either S. Enteritidis, S. pullorum, or poly(I:C). The concentrations of cytokines and antibodies and the Salmonella colonization level of the caecum and liver were detected in each group at 7 days postinfection. Expression microarray experiments were conducted using mRNA isolated from both spleen and caecum. Crucial differentially expressed genes (DEGs) associated with immunity were identified. Four DEGs were identified in spleen of all three challenge groups (RBM16, FAH, SOX5, and RBM9) and different four genes in caecum (SOUL, FCN2, ANLN, and ACSL1). Expression profiles were clearly different among the three challenged groups. Genes enriched in the spleen of birds infected with S. pullorum were enriched in lymphocyte proliferation related pathways, but the enriched genes in the caecum of the same group were primarily enriched in innate immunity or antibacterial responses. The DEGs that appear across all three challenge groups might represent global response factors for different pathogens. PMID:24707473

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

    PubMed

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

    2011-04-27

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

  16. Differences in attachment of Salmonella enterica serovars to cabbage and lettuce leaves.

    PubMed

    Patel, Jitendra; Sharma, Manan

    2010-04-30

    This study investigated the ability of five Salmonella enterica serovars to attach to and colonize intact and cut lettuce (Iceberg, Romaine) and cabbage surfaces. Biofilm formation and attachment of Salmonella serovars to intact and cut leaves were determined. Populations of loosely and strongly attached Salmonella were obtained to calculate the attachment strength (S(R)). Biofilm formation, as determined by microtiter plate assay, varied with strain and growth medium used. Salmonella Tennessee and S. Thompson produced stronger biofilms compared to S. Newport, S. Negev, and S. Braenderup. Biofilm formation was also stronger when Salmonella spp. were grown in diluted TSB (1:10). S. Tennessee, which produced strong biofilms, attached to produce surfaces at significantly higher numbers than the populations of S. Negev. Overall, S. Tennessee displayed more biofilm formation in vitro and attached more strongly to lettuce than other serovars. All Salmonella serovars attached rapidly on intact and cut produce surfaces. Salmonella spp. attached to Romaine lettuce at significantly higher numbers than those attached to Iceberg lettuce or cabbage. Salmonella attached preferentially to cut surface of all produce; however, the difference between Salmonella populations attached to intact and cut surfaces was similar (P>0.05). Salmonella attachment to both intact and cut produce surfaces increased with time. The overall attachment strength of Salmonella was significantly lower on cabbage (0.12) followed by Iceberg (0.23) and Romaine lettuce (0.34). Cabbage, intact or cut, did not support attachment of Salmonella as well as Romaine lettuce. Understanding the attachment mechanisms of Salmonella to produce may be useful in developing new intervention strategies to prevent produce outbreaks.

  17. Oral sodium chlorate, topical disinfection, and younger weaning age reduce Salmonella enterica shedding in pigs.

    PubMed

    Patchanee, Prapas; Crenshaw, Thomas D; Bahnson, Peter B

    2007-08-01

    Salmonella enterica subsp. enterica can cause swine illness or human foodborne disease. Although nontoxic to mammalian cells, chlorate can be converted to cytotoxic chlorite by salmonellae. To test whether chlorate is effective at reducing Salmonella shedding in weaned pigs exposed to shedding dams, a chlorate-nitrate-lactate (chlorate) oral dose was administered daily for 5 days following weaning, and this treatment was evaluated in combination with two weaning ages and a topical disinfectant. A total of 80 pigs were weaned at 10 or 21 days of age. Half within each age group were topically disinfected at weaning. Piglets were selected from dams for which Salmonella was detected in feces shortly after giving birth. Chlorate treatment reduced Salmonella prevalence and estimated Salmonella concentration in feces, cecal contents, and ileocolic lymph nodes. Younger weaning age (10 days of age) was associated with reduced shedding (lower concentration and prevalence) in samples collected at 10 days postweaning (DPW) and later. Chlorate treatment reduced the concentration of Salmonella in fecal samples at 5 DPW and in cecal samples at 14 DPW. The protective effects persisted through the end of the study at 14 DPW, 9 days after the final administration of chlorate. Disinfectant treatment reduced shedding in fecal samples at 14 DPW. Interactions were detected between the effects of chlorate and disinfection and between chlorate and weaning age. Chlorate treatment, topical disinfection, and younger weaning age may be useful tools for reducing Salmonella shedding on farms that practice segregated weaning and where sow-to-piglet transfer of Salmonella is an important source of infection in nursery pigs.

  18. Acquisition of extended-spectrum cephalosporin- and colistin-resistant Salmonella enterica subsp. enterica serotype Newport by pilgrims during Hajj.

    PubMed

    Olaitan, Abiola Olumuyiwa; Dia, Ndèye Méry; Gautret, Philippe; Benkouiten, Samir; Belhouchat, Khadidja; Drali, Tassadit; Parola, Philippe; Brouqui, Philippe; Memish, Ziad; Raoult, Didier; Rolain, Jean-Marc

    2015-06-01

    Gatherings like the Hajj involving many people who travel from different parts of the world represent a risk for the acquisition and dissemination of infectious diseases. In this study, acquisition of multidrug-resistant (MDR) Salmonella spp. in 2013 Hajj pilgrims from Marseille, France, was investigated. In total, 267 rectal swabs were collected from 129 participants before their departure and after their return from the pilgrimage as well as during the pilgrimage from patients with diarrhoea. Samples were screened for the presence of Salmonella using quantitative real-time PCR and culture. Whole-genome sequencing was performed to characterise one of the isolates, and the mechanism leading to colistin resistance was investigated. Six post-Hajj samples and one sample collected during a diarrhoea episode in Hajj were positive for Salmonella by real-time PCR, with five Salmonella enterica belonging to several serotypes recovered by culture, whereas no pre-Hajj sample was positive. Two of the isolates belonged to the epidemic Newport serotype, were resistant to cephalosporins, gentamicin and colistin, and harboured the bla(CTX-M-2) gene and a 12-nucleotide deletion in the pmrB gene leading to colistin resistance. This study shows that pilgrims acquired Salmonella bacteria, including a novel MDR clone, during the Hajj pilgrimage. This calls for more improved public health surveillance during Hajj because Salmonella is one of the most common diarrhoea-causing bacteria worldwide. Therefore, returning pilgrims could disseminate MDR bacteria worldwide upon returning to their home countries. Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  19. 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.

  20. Ciprofloxacin-resistant Salmonella enterica Typhimurium and Choleraesuis from Pigs to Humans, Taiwan

    PubMed Central

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

    2004-01-01

    We evaluated the disk susceptibility data of 671 nontyphoid Salmonella isolates collected from different parts of Taiwan from March 2001 to August 2001 and 1,261 nontyphoid Salmonella isolates from the National Taiwan University Hospital from 1996 to 2001. Overall, ciprofloxacn resistance was found in 2.7% (18/671) of all nontyphoid Salmonella isolates, in 1.4% (5/347) of Salmonella enterica serotype Typhimurium and in 7.5% (8/107) in S. enterica serotype Choleraesuis nationwide. MICs of six newer fluoroquinolones were determined for the following isolates: 37 isolates of ciprofloxacin-resistant (human) S. enterica Typhimurium (N = 26) and Choleraesuis (N = 11), 10 isolates of ciprofloxacin-susceptible (MIC <1 μg/mL) (human) isolates of these two serotypes, and 15 swine isolates from S. enterica Choleraesuis (N = 13) and Typhmurium (N = 2) with reduced susceptibility to ciprofloxacin (MIC >0.12 μg/mL). Sequence analysis of the gryA, gyrB, parC, parE, and acrR genes, ciprofloxacin accumulation; and genotypes generated by pulsed-field gel electrophoresis with three restriction enzymes (SpeI, XbaI, and BlnI) were performed. All 26 S. enterica Typhimurium isolates from humans and pigs belonged to genotype I. For S. enterica Choleraesuis isolates, 91% (10/11) of human isolates and 54% (7/13) of swine isolates belonged to genotype B. These two genotypes isolates from humans all exhibited a high-level of resistance to ciprofloxacin (MIC 16–64 μg/mL). They had two-base substitutions in the gyrA gene at codons 83 (Ser83Phe) and 87 (Asp87Gly or Asp87Asn) and in the parC gene at codon 80 (Ser80Arg, Ser80Ile, or Ser84Lys). Our investigation documented that not only did these two S. enterica isolates have a high prevalence of ciprofloxacin resistance nationwide but also that some closely related ciprofloxacin-resistant strains are disseminated from pigs to humans. PMID:15078598

  1. First Complete Genome Sequence of Salmonella enterica subsp. enterica Serovar Typhimurium Strain ATCC 13311 (NCTC 74), a Reference Strain of Multidrug Resistance, as Achieved by Use of PacBio Single-Molecule Real-Time Technology

    PubMed Central

    Juan, Ayaka; Tamotsu, Hinako; Ashimine, Noriko; Nakano, Kazuma; Shimoji, Makiko; Shiroma, Akino; Teruya, Kuniko; Satou, Kazuhito; Hirano, Takashi

    2014-01-01

    We report the first complete genomic sequence of Salmonella enterica subsp. enterica serovar Typhimurium strain ATCC 13311, the leading food-borne pathogen and a reference strain used in drug resistance studies. De novo assembly with PacBio sequencing completed its chromosome and one plasmid. They will accelerate the investigation into multidrug resistance in Salmonella Typhimurium. PMID:25278532

  2. 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

  3. Salmonella enterica isolated from infections in Australian livestock remain susceptible to critical antimicrobials.

    PubMed

    Abraham, Sam; Groves, Mitchell D; Trott, Darren J; Chapman, Toni A; Turner, Bernadette; Hornitzky, Michael; Jordan, David

    2014-02-01

    Salmonella enterica is a zoonotic pathogen causing a variety of diseases in humans and animals. Many countries are reporting an increase in the prevalence of multidrug-resistant (MDR) S. enterica in food animals. The aim of this study was to determine whether S. enterica isolated from livestock in New South Wales, Australia, have similar resistance traits to those reported internationally. Salmonella enterica (n=165) from clinical infections in food animals between 2007 and 2011 were serotyped and tested for susceptibility to 18 antimicrobials. Also, 22 antimicrobial resistance genes (ARGs), 3 integrons and 18 plasmid replicon types were screened for using PCR. Most isolates (66.1%) remained susceptible to all antimicrobials; 8.5% of the isolates were resistant to four or more antimicrobials. Antimicrobials with the highest prevalence of resistance were sulfafurazole (28.5%), ampicillin (17.0%), tetracycline (15.8%) and trimethoprim (8.5%). There was no resistance to fluoroquinolones or third-generation cephalosporins. The most common ARGs were blaTEM (15.2%), sul2 (10.3%), tetB (9.1%), tetA (5.5%), aphA1 (4.8%) and dhfrV (4.8%). Class 1 integrons (7.9%) and IncFIIA (69.7%) were the most commonly detected integron and plasmid replicon types, respectively. Class 1 integrons were positively associated with MDR phenotypes and ARG carriage (P≤0.001). Internationally prominent MDR serovars associated with severe disease in humans (e.g. AmpC-positive Salmonella Newport) were not detected. Overall, the comparatively favourable resistance status of S. enterica in Australian livestock represents minimal public health risk associated with MDR strains and supports a conservative approach to the registration of antimicrobial drug classes in food-producing animals. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

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

    USDA-ARS?s Scientific Manuscript database

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

  5. A live attenuated Salmonella enterica serovar Typhimurium vaccine provides cross-protection against Salmonella serovars to reduce disease severity and pathogen transmission

    USDA-ARS?s Scientific Manuscript database

    A live attenuated Salmonella enterica serovar Typhimurium vaccine was developed to confer broad protection against multiple Salmonella serovars to prevent disease and reduce pathogen colonization and shedding. Two vaccine trials were performed in swine to determine the protection afforded by the vac...

  6. 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...

  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. Inhibition of Salmonella enterica biofilm formation using small-molecule adenosine mimetics.

    PubMed

    Koopman, Jacob A; Marshall, Joanna M; Bhatiya, Aditi; Eguale, Tadesse; Kwiek, Jesse J; Gunn, John S

    2015-01-01

    Biofilms have been widely implicated in chronic infections and environmental persistence of Salmonella enterica, facilitating enhanced colonization of surfaces and increasing the ability of the bacteria to be transmitted to new hosts. Salmonella enterica serovar Typhi biofilm formation on gallstones from humans and mice enhances gallbladder colonization and bacterial shedding, while Salmonella enterica serovar Typhimurium biofilms facilitate long-term persistence in a number of environments important to food, medical, and farming industries. Salmonella regulates expression of many virulence- and biofilm-related processes using kinase-driven pathways. Kinases play pivotal roles in phosphorylation and energy transfer in cellular processes and possess an ATP-binding pocket required for their functions. Many other cellular proteins also require ATP for their activity. Here we test the hypothesis that pharmacological interference with ATP-requiring enzymes utilizing adenosine mimetic compounds would decrease or inhibit bacterial biofilm formation. Through the screening of a 3,000-member ATP mimetic library, we identified a single compound (compound 7955004) capable of significantly reducing biofilm formation by S. Typhimurium and S. Typhi. The compound was not bactericidal or bacteriostatic toward S. Typhimurium or cytotoxic to mammalian cells. An ATP-Sepharose affinity matrix technique was used to discover potential protein-binding targets of the compound and identified GroEL and DeoD. Compound 7955004 was screened against other known biofilm-forming bacterial species and was found to potently inhibit biofilms of Acinetobacter baumannii as well. The identification of a lead compound with biofilm-inhibiting capabilities toward Salmonella provides a potential new avenue of therapeutic intervention against Salmonella biofilm formation, with applicability to biofilms of other bacterial pathogens.

  9. Resident bacteria on leaves enhance survival of immigrant cells of Salmonella enterica.

    PubMed

    Poza-Carrion, Cesar; Suslow, Trevor; Lindow, Steven

    2013-04-01

    Although Salmonella enterica apparently has comparatively low epiphytic fitness on plants, external factors that would influence its ability to survive on plants after contamination would be of significance in the epidemiology of human diseases caused by this human pathogen. Viable population sizes of S. enterica applied to plants preinoculated with Pseudomonas syringae or either of two Erwinia herbicola strains was ≥10-fold higher than that on control plants that were not precolonized by such indigenous bacteria when assessed 24 to 72 h after the imposition of desiccation stress. The protective effect of P. fluorescens, which exhibited antibiosis toward S. enterica in vitro, was only ≈50% that conferred by other bacterial strains. Although S. enterica could produce small cellular aggregates after incubation on wet leaves for several days, and the cells in such aggregates were less susceptible to death upon acute dehydration than solitary cells (as determined by propidium iodide staining), most Salmonella cells were found as isolated cells when it was applied to leaves previously colonized by other bacterial species. The proportion of solitary cells of S. enterica coincident with aggregates of cells of preexisting epiphytic species that subsequently were judged as nonviable by viability staining on dry leaves was as much as 10-fold less than those that had landed on uncolonized portions of the leaf. Thus, survival of immigrant cells of S. enterica on plants appears to be strongly context dependent, and the presence of common epiphytic bacteria on plants can protect such immigrants from at least one key stress (i.e., desiccation) encountered on leaf surfaces.

  10. 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.

  11. National surveillance of Salmonella enterica in food-producing animals in Japan

    PubMed Central

    Ishihara, Kanako; Takahashi, Toshio; Morioka, Ayako; Kojima, Akemi; Kijima, Mayumi; Asai, Tetsuo; Tamura, Yutaka

    2009-01-01

    A total of 518 fecal samples collected from 183 apparently healthy cattle, 180 pigs and 155 broilers throughout Japan in 1999 were examined to determine the prevalence and antimicrobial susceptibility of Salmonella. The isolation rates were 36.1% in broilers, 2.8% in pigs and 0.5% in cattle. S. enterica Infantis was the most frequent isolate, found in 22.6% of broiler fecal samples. Higher resistance rates were observed against oxytetracycline (82.0%), dihydrostreptomycin (77.9%), kanamycin (41.0%) and trimethoprim (35.2%). Resistance rates to ampicillin, ceftiofur, bicozamycin, chloramphenicol and nalidixic acid were <10%. CTX-M-2 β-lactamase producing S. enterica Senftenberg was found in the isolates obtained from one broiler fecal sample. This is the first report of cephalosporin-resistant Salmonella directly isolated from food animal in Japan. PMID:19703311

  12. Same species, different diseases: how and why typhoidal and non-typhoidal Salmonella enterica serovars differ

    PubMed Central

    Gal-Mor, Ohad; Boyle, Erin C.; Grassl, Guntram A.

    2014-01-01

    Human infections by the bacterial pathogen Salmonella enterica represent major disease burdens worldwide. This highly ubiquitous species consists of more than 2600 different serovars that can be divided into typhoidal and non-typhoidal Salmonella (NTS) serovars. Despite their genetic similarity, these two groups elicit very different diseases and distinct immune responses in humans. Comparative analyses of the genomes of multiple Salmonella serovars have begun to explain the basis of the variation in disease manifestations. Recent advances in modeling both enteric fever and intestinal gastroenteritis in mice will facilitate investigation into both the bacterial- and host-mediated mechanisms involved in salmonelloses. Understanding the genetic and molecular mechanisms responsible for differences in disease outcome will augment our understanding of Salmonella pathogenesis, host immunity, and the molecular basis of host specificity. This review outlines the differences in epidemiology, clinical manifestations, and the human immune response to typhoidal and NTS infections and summarizes the current thinking on why these differences might exist. PMID:25136336

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

    PubMed

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

    2000-06-01

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

  15. Microgravity as a Novel Environmental Signal Affecting Salmonella enterica Serovar Typhimurium Virulence

    PubMed Central

    Nickerson, Cheryl A.; Ott, C. Mark; Mister, Sarah J.; Morrow, Brian J.; Burns-Keliher, Lisa; Pierson, Duane 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. PMID:10816456

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

    PubMed

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

    2015-07-01

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

  17. Salmonella enterica prevalence and serotype distribution in swine at slaughter

    USDA-ARS?s Scientific Manuscript database

    The objective of this cross-sectional study was to analyze data available from multiple studies conducted by our research team estimating the prevalence of S. enterica, and the serotype distribution in swine at slaughter, based on different sample types. A total of 1,110 pigs from three large capaci...

  18. [Antimicrobial susceptibility of a selection of Salmonella enterica strains of various origins isolated in Spain].

    PubMed

    Cruchaga, S; Echeita, A; Usera, M A

    1999-09-01

    The widespread use of antimicrobials in human and veterinary practice is increasingly causing the emergence of different multidrug-resistant human pathogens. This situation makes treating infections caused by these microorganisms difficult. Salmonella enterica is an ubiquitous organism and may be a good indicator of the influence of the use and abuse of antimicrobials on the appearance of multiresistant strains. One hundred and ninety S. enterica strains of different origins isolated in Spain in 1996 were randomly selected. The minimal inhibitory concentration (MIC) was studied using the agar dilution method according to NCCLS criteria in the following antimicrobials: ampicillin, ticarcillin, amoxicillin-clavulanic acid, cefazolin, cefuroxime, cefotaxime, imipenem, gentamicin, apramycin, ciprofloxacin, streptomycin, chloramphenicol, tetracycline, sulfamethoxazole and co-trimoxazole. Sixty-three percent of the S. enterica tested were resistant and 24% were multiresistant. The percentage of resistant and multiresistant strains of S. enterica of human origin was slightly higher than those of nonhuman origin. Statistically, ampicillin, ticarcillin and amoxicillin-clavulanic acid were significantly more resistant in strains of human origin. Ninety-one percent of the strains of Typhimurium serotype and phagotype 104 were multiresistant. The Salmonella Typhimurium serotype and phagotype 104 ACSTSu-resistant clone, which is widespread in various Western countries, was also isolated in this study. The use of different antimicrobials in human and veterinary practice needs to be rationalized.

  19. Transcriptional response of turkeys to MDR Salmonella enterica serovar heidelberg

    USDA-ARS?s Scientific Manuscript database

    Food-producing animals such as swine, cattle and poultry are a major reservoir of the human foodborne pathogen Salmonella. While some Salmonella serovars can cause disease in food-producing animals, most serovars colonize these animals asymptomatically, resulting in the hosts becoming carriers and ...

  20. Experimental Salmonella Enterica Infection in Market-weight Pigs

    USDA-ARS?s Scientific Manuscript database

    Market pigs infected with Salmonella pose a significant food safety risk by carrying the pathogen into abattoirs. A study was conducted to determine the dynamic of Salmonella infection in market-weight pigs (220-240 lbs.). Pigs (n=24) were individually inoculated (intranasally; 108 cfu/mL) with Salm...

  1. Pathogenicity of Dodecyltrimethylammonium Chloride-Resistant Salmonella enterica

    USDA-ARS?s Scientific Manuscript database

    Salmonella infection causes a self-limiting gastroenteritis in humans but can also result in a life threatening invasive disease especially in old, young and/or immunocompromised patients. The prevalence of antimicrobial and multidrug-resistant Salmonella has increased worldwide since the 1980’s. Ho...

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

    PubMed

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

    2013-08-01

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

  3. Plasmid profiles as an epidemiological marker for Salmonella enterica serotype Enteritidis foodborne outbreaks.

    PubMed

    Luján, R; Echeita, A; Usera, M A; Martínez-Suárez, J V; Alonso, R; Sáez-Nieto, J A

    1990-06-01

    The incidence of enteritidis serotype of Salmonella enterica in salmonellae infections has steadily increased in Spain from 27.1% in 1982 up to 63.4% in 1987. Given this high incidence, we have studied the plasmid profiles of Enteritidis isolates to subclassify them. Different profiles were observed in 50 isolates. In 13 Enteritidis serotype outbreaks, up to 5 different plasmid profiles were found. Each outbreak correlated with a single plasmid profile except in one case where plasmids of two different profiles were observed in strains from the same outbreak.

  4. Pleural empyema due to Salmonella enterica serovar Enteritidis in an immunocompetent elderly patient: a case report

    PubMed Central

    Karachalios, Kostis; Siagris, Dimitrios; Lekkou, Alexandra; Anastassiou, Evangelos D.; Spiliopoulou, Iris; Gogos, Charalambos

    2016-01-01

    Introduction: Pleural empyema as a focal infection due to Salmonella enterica serovar Enteritidis is rare and most commonly described among immunosuppressed patients or patients who suffer from sickle cell anaemia and lung malignancies. Case presentation: Here, we present an 81-year-old immunocompetent Greek woman with bacteraemia and pleural empyema due to Salmonella Enteritidis without any gastrointestinal symptoms. Conclusion: In our case, we suggest that patient’s pleural effusion secondary to heart failure was complicated by empyema and that focal intravascular infection was the cause of bacteraemia. PMID:28348773

  5. 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 ...

  6. Correlating Blood Immune Parameters and a CCT7 Genetic Variant with the Shedding of Salmonella enterica Serovar Typhimurium in Swine

    USDA-ARS?s Scientific Manuscript database

    In the current study, 40 crossbred pigs were intranasally inoculated with Salmonella enterica serovar Typhimurium and monitored for Salmonella fecal shedding and blood immune parameters at 2, 7, 14 and 20 days post-inoculation (dpi). Using a multivariate permutation test, a positive correlation was...

  7. Characterization of Salmonella enterica strains isolated from beef trim contamination-biofilm formation, antimcrobial resistance, and sanitizer tolerance

    USDA-ARS?s Scientific Manuscript database

    In the beef industry, product contamination by Salmonella enterica is a serious public health concern, which may result in human infection and illness, as well as cause significant financial loss due to product recalls. Currently, the precise mechanism and pathogen source responsible for Salmonella...

  8. Tetracycline accelerates the temporally-regulated invasion response in specific isolates of multidrug-resistant Salmonella enterica serovar Typhimurium

    USDA-ARS?s Scientific Manuscript database

    Background Multidrug-resistant (MDR) Salmonella is associated with increased morbidity compared to antibiotic-sensitive strains and is an important health and safety concern in both humans and animals. Salmonella enterica serovar Typhimurium is a prevalent cause of foodborne disease, and a consider...

  9. Clinical isolates of Salmonella enterica serovar Agona producing NDM-1 metallo-β-lactamase: first report from Pakistan.

    PubMed

    Irfan, Seema; Khan, Erum; Jabeen, Kauser; Bhawan, Pushpa; Hopkins, Katie L; Day, Martin; Nasir, Amna; Meunier, Daniele; Woodford, Neil

    2015-01-01

    We report two cases of infantile diarrhea due to multidrug-resistant, NDM-1 metallo-β-lactamase-producing Salmonella enterica serovar Agona from Pakistan. This study alerts toward possible risk of NDM-1 transmission to enteric fever pathogens and encourages microbiologists to consider active screening of carbapenem resistance in nontyphoidal Salmonella isolates.

  10. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

  12. Evolutionary trends associated with niche specialization as modeled by whole genome analysis of egg-contaminating Salmonella enterica serovar Enteritidis

    USDA-ARS?s Scientific Manuscript database

    The mosaic nature of the Salmonella enterica genome facilitates its access to multiple environments. Many large scale genomic events have been described that contribute to the combinatorial complexity of the pathogenic Salmonellae. However, the impact of small scale genetic change occurring at the ...

  13. High-throughput Molecular Determination of Salmonella enterica Serovars Use of Multiplex PCR and Capillary Electrophoresis Analysis

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is a zoonotic pathogen and is a leading cause of food-borne illness worldwide. There are over 2,500 serotypes of Salmonella reported. Identification of the serotype is key in defining the etiological agent during an outbreak investigation. In the current study, a high-throughput ...

  14. 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...

  15. Serotypes of Salmonella enterica Present in the Internal Organs of Mice Caught On-farm From 1995 – 1998.

    USDA-ARS?s Scientific Manuscript database

    : Salmonella enterica is a persistent and pervasive pathogen that impacts the safety of the food supply, especially in regards to poultry and poultry products. The house mouse Mus musculus is a recognized risk factor for introduction on-farm. More information is needed about Salmonella serotypes tha...

  16. Population dynamics of Salmonella enterica serotypes in commercial egg and poultry production.

    PubMed

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

    2011-07-01

    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.

  17. Development of Microarray and Multiplex Polymerase Chain Reaction Assays for Identification of Serovars and Virulence Genes in Salmonella enterica of Human or Animal Origin

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica is an important enteric pathogen consisting of many serotypes that can cause severe clinical diseases in animals and humans. Rapid identification of Salmonella isolates is especially important for epidemiological monitoring and controlling outbreaks of disease. Although immunolo...

  18. 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

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

    PubMed Central

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

    2000-01-01

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

  20. Salmonella enterica Serotype Typhi Bacteremia Complicating Pregnancy in the Third Trimester

    PubMed Central

    Patel, Krunal; Gittens-Williams, Lisa; Apuzzio, Joseph J.; Martimucci, Kristina; Williams, Shauna F.

    2017-01-01

    Background. Salmonella enterica serotype Typhi (S. Typhi) is an anaerobic gram-negative enteric rod that causes infection when contaminated food or water is ingested and may cause illness in pregnancy. Case. This is a patient who presented at 31 weeks' gestation with abdominal pain and fever and was diagnosed with S. Typhi bacteremia. Conclusion. S. Typhi should be considered in febrile patients with recent travel presenting with abdominal discomfort with or without elevated liver enzymes. PMID:28203469

  1. Salmonella enterica Serovar Virchow with CTX-M-Like β-Lactamase in Spain

    PubMed Central

    Simarro, Encarna; Navarro, Ferrán; Ruiz, Joaquín; Miró, Elisenda; Gómez, Joaquín; Mirelis, Beatriz

    2000-01-01

    Four Salmonella enterica serovar Virchow strains resistant to broad-spectrum cephalosporins were isolated from patients with gastroenteritis in 1997 and 1998 in Murcia and Barcelona, Spain. The isolates expressed a β-lactamase with a pI of about 8 and a positive PCR when specific primers for CTX-M-9 were used. These results suggest the presence of a CTX-M-9 β-lactamase in these strains. PMID:11101623

  2. 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

  3. Draft Genome Sequence of the Tumor-Targeting Salmonella enterica Serovar Typhimurium Strain SL7207

    PubMed Central

    Johnson, Síle A.; Ormsby, Michael J.

    2017-01-01

    ABSTRACT Salmonella enterica serovar Typhimurium strain SL7207 is a genetically modified derivative of strain SL1344, which preferentially accumulates in tumors and can be used as a vehicle for tissue-specific gene delivery in vivo. Here, we report the draft genome sequence of SL7207, confirming a purported aroA deletion and four single-nucleotide polymorphisms compared to SL1344. PMID:28153911

  4. 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.

  5. Environmental Metabolomics of the Tomato Plant Surface Provides Insights on Salmonella enterica Colonization

    PubMed Central

    Han, Sanghyun

    2016-01-01

    ABSTRACT Foodborne illness-causing enteric bacteria are able to colonize plant surfaces without causing infection. We lack an understanding of how epiphytic persistence of enteric bacteria occurs on plants, possibly as an adaptive transit strategy to maximize chances of reentering herbivorous hosts. We used tomato (Solanum lycopersicum) cultivars that have exhibited differential susceptibilities to Salmonella enterica colonization to investigate the influence of plant surface compounds and exudates on enteric bacterial populations. Tomato fruit, shoot, and root exudates collected at different developmental stages supported growth of S. enterica to various degrees in a cultivar- and plant organ-dependent manner. S. enterica growth in fruit exudates of various cultivars correlated with epiphytic growth data (R2 = 0.504; P = 0.006), providing evidence that plant surface compounds drive bacterial colonization success. Chemical profiling of tomato surface compounds with gas chromatography-time of flight mass spectrometry (GC-TOF-MS) provided valuable information about the metabolic environment on fruit, shoot, and root surfaces. Hierarchical cluster analysis of the data revealed quantitative differences in phytocompounds among cultivars and changes over a developmental course and by plant organ (P < 0.002). Sugars, sugar alcohols, and organic acids were associated with increased S. enterica growth, while fatty acids, including palmitic and oleic acids, were negatively correlated. We demonstrate that the plant surface metabolite landscape has a significant impact on S. enterica growth and colonization efficiency. This environmental metabolomics approach provides an avenue to understand interactions between human pathogens and plants that could lead to strategies to identify or breed crop cultivars for microbiologically safer produce. IMPORTANCE In recent years, fresh produce has emerged as a leading food vehicle for enteric pathogens. Salmonella-contaminated tomatoes

  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.

  7. 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.

  8. 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.

  9. De Novo Amino Acid Biosynthesis Contributes to Salmonella enterica Growth in Alfalfa Seedling Exudates

    PubMed Central

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

    2014-01-01

    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. PMID:25416761

  10. Salmonella Enterica Prevalence in Finishing Pigs at Slaughter Plants in Northern Italy

    PubMed Central

    Bacci, Cristina; Lanzoni, Elisa; Brindani, Franco; Bonardi, Silvia

    2014-01-01

    Finishing pigs carrying Salmonella enterica are believed to be the main source of carcass contamination at the beginning of slaughtering. The aim of this study was to assess the S. enterica carrier status of finishing pigs at herd level by sampling pooled faeces on farm and mesenteric lymph nodes at slaughter in the North East of Italy. Environmental faecal samples belonging to 30 batches of pigs were collected on farm. At slaughter, mesenteric lymph nodes were collected from five randomly selected pigs per batch. S. enterica was isolated from 16 lymph nodes out of 150 (10.6%) and from seven out of 30 (23.3%) faecal samples. Four batches (13.3%) were positive to S. enterica both in lymph nodes and in faeces. The number of batches positive to S. enterica either in lymph nodes or in faeces was 13 out of 30 (43.3%). The most prevalent serovars from lymph nodes were S. Derby (25.0%) and S. Typhimurium monophasic variant 1, 4,[5],12:i:- (18.6%), which were also isolated from faecal material (14.3 and 42.8% respectively). Contaminated faecal material or lymph nodes could be a primary source of carcass contamination at slaughter during evisceration. S. enterica contamination is widespread on pig farms and carrier pigs pass undetected the inspection visits at slaughter, entering the food chain. Therefore, in order to control S. enterica in pigs, the need to quantify possible risk factors at slaughter and develop effective management strategies on farm is of paramount importance to ensure food safety. PMID:27800330

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

    USDA-ARS?s Scientific Manuscript database

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

  12. Salmonella enterica serovar Minnesota urosepsis in a patient with Crohn's disease in the absence of recent or current gastrointestinal symptoms.

    PubMed

    Steinebrunner, Niels; Sandig, Catharina; Zimmermann, Stefan; Stremmel, Wolfgang; Eisenbach, Christoph; Mischnik, Alexander

    2013-09-01

    Salmonella enterica serovar Minnesota is a rarely isolated organism in clinical samples mainly grown from stool cultures. Sepsis due to Salmonella is known in severely immunocompromised patients, but so far urosepsis due to S. enterica serovar Minnesota has not been described. We report a case of a 31-year-old patient suffering from Crohn's disease treated with infliximab and azathioprine, in whom was implanted a double-J ureteric catheter for urolithiasis. The patient presented with urinary tract infection and severe sepsis. S. enterica serovar Minnesota was grown from urine and blood cultures. After empiric antimicrobial treatment with meropenem and vancomycin, treatment was changed to ceftriaxone. Antimicrobial treatment was continued for a total of 3 weeks without evidence of Salmonella recurrence on follow-up visits. Salmonella spp. rarely cause urinary tract infection and sepsis. However, in immunocompromised patients, non-typhoidal salmonellosis merits a thorough clinical and microbiological evaluation.

  13. Salmonella Engages Host MicroRNAs To Modulate SUMOylation: a New Arsenal for Intracellular Survival.

    PubMed

    Verma, Smriti; Mohapatra, Gayatree; Ahmad, Salman Mustfa; Rana, Sarika; Jain, Swati; Khalsa, Jasneet Kaur; Srikanth, C V

    2015-09-01

    Posttranslational modifications (PTMs) can alter many fundamental properties of a protein. One or combinations of them have been known to regulate the dynamics of many cellular pathways and consequently regulate all vital processes. Understandably, pathogens have evolved sophisticated strategies to subvert these mechanisms to achieve instantaneous control over host functions. Here, we present the first report of modulation by intestinal pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) of host SUMOylation, a PTM pathway central to all fundamental cellular processes. Both in cell culture and in a mouse model, we observed that S. Typhimurium infection led to a dynamic SUMO-conjugated proteome alteration. The intracellular survival of S. Typhimurium was dependent on SUMO status as revealed by reduced infection and Salmonella-induced filaments (SIFs) in SUMO-upregulated cells. S. Typhimurium-dependent SUMO modulation was seen as a result of depletion of crucial SUMO pathway enzymes Ubc-9 and PIAS1, at both the protein and the transcript levels. Mechanistically, depletion of Ubc-9 relied on upregulation of small noncoding RNAs miR30c and miR30e during S. Typhimurium infection. This was necessary and sufficient for both down-modulation of Ubc-9 and a successful infection. Thus, we demonstrate a novel strategy of pathogen-mediated perturbation of host SUMOylation, an integral mechanism underlying S. Typhimurium infection and intracellular survival.

  14. Shoot Injury Increases the Level of Persistence of Salmonella enterica Serovar Sofia and Listeria innocua on Cos Lettuce and of Salmonella enterica Serovar Sofia on Chive.

    PubMed

    Harapas, Dean; Premier, Robert; Tomkins, Bruce; Hepworth, Graham; Ajlouni, Said

    2015-12-01

    Minor shoot injury significantly (P < 0.05) increased the level at which Salmonella enterica serovar Sofia persisted on cos lettuce in the greenhouse. Initial mean counts of the Salmonella on the injured and uninjured cos lettuce were on the order of 6 log CFU/g. After 3 days, the mean count decreased to 4.8 log CFU/g on the injured plants compared with the significantly (P < 0.05) smaller count of 3.4 log CFU/g on the uninjured plants. By the end of the 3-week experiment, the count from the injured plants was 2.9 log CFU/g compared with a count of below the level of detection from the uninjured plants. A similar pattern of bacterial persistence was observed on injured versus uninjured plants by using Listeria innocua on cos lettuce and S. enterica serovar Sofia on chive. The findings reaffirm earlier results with Escherichia coli and increase the impetus to avoid shoot injury during the production of cos lettuce and chive, if bacteria of food safety concern are present.

  15. Molecular Characterization of Salmonella enterica Serovar Aberdeen Negative for H2S Production in China

    PubMed Central

    Yi, Shengjie; Wang, Jian; Yang, Xiaoxia; Yang, Chaojie; Liang, Beibei; Ma, Qiuxia; Li, Hao; Song, Hongbin; Qiu, Shaofu

    2016-01-01

    Salmonella enterica infections continue to be a significant burden on public health worldwide. The ability of S. enterica to produce hydrogen sulfide (H2S) is an important phenotypic characteristic used to screen and identify Salmonella with selective medium; however, H2S-negative Salmonella have recently emerged. In this study, the H2S phenotype of Salmonella isolates was confirmed, and the selected isolates were subjected to antimicrobial susceptibility testing and molecular identification by multilocus sequence typing, pulsed-field gel electrophoresis, and clustered regularly interspaced short palindromic repeat (CRISPR) analysis. The phs genetic operon was also analyzed. A total of 160 S. enterica serovar Aberdeen isolates were detected between 2005 and 2013 in China. Of them, seven non-H2S-producing isolates were detected. Notably, four samples yielded four pairs of isolates with different H2S phenotypes, simultaneously. The data demonstrated that H2S-negative isolates were genetically closely related to H2S-positive isolates. Three new spacers (Abe1, Abe2, and Abe3) were identified in CRISPR locus 1 in four pairs of isolates with different H2S phenotypes from the same samples. Sequence analysis revealed a new nonsense mutation at position 208 in the phsA gene of all non-H2S-producing isolates. Additionally, we describe a new screening procedure to avoid H2S-negative Salmonella, which would normally be overlooked during laboratory and hospital screening. The prevalence of this pathogen may be underestimated; therefore, it is important to focus on improving surveillance of this organism to control its spread. PMID:27552230

  16. Molecular Characterization of Salmonella enterica Serovar Aberdeen Negative for H2S Production in China.

    PubMed

    Wu, Fuli; Xu, Xuebin; Xie, Jing; Yi, Shengjie; Wang, Jian; Yang, Xiaoxia; Yang, Chaojie; Liang, Beibei; Ma, Qiuxia; Li, Hao; Song, Hongbin; Qiu, Shaofu

    2016-01-01

    Salmonella enterica infections continue to be a significant burden on public health worldwide. The ability of S. enterica to produce hydrogen sulfide (H2S) is an important phenotypic characteristic used to screen and identify Salmonella with selective medium; however, H2S-negative Salmonella have recently emerged. In this study, the H2S phenotype of Salmonella isolates was confirmed, and the selected isolates were subjected to antimicrobial susceptibility testing and molecular identification by multilocus sequence typing, pulsed-field gel electrophoresis, and clustered regularly interspaced short palindromic repeat (CRISPR) analysis. The phs genetic operon was also analyzed. A total of 160 S. enterica serovar Aberdeen isolates were detected between 2005 and 2013 in China. Of them, seven non-H2S-producing isolates were detected. Notably, four samples yielded four pairs of isolates with different H2S phenotypes, simultaneously. The data demonstrated that H2S-negative isolates were genetically closely related to H2S-positive isolates. Three new spacers (Abe1, Abe2, and Abe3) were identified in CRISPR locus 1 in four pairs of isolates with different H2S phenotypes from the same samples. Sequence analysis revealed a new nonsense mutation at position 208 in the phsA gene of all non-H2S-producing isolates. Additionally, we describe a new screening procedure to avoid H2S-negative Salmonella, which would normally be overlooked during laboratory and hospital screening. The prevalence of this pathogen may be underestimated; therefore, it is important to focus on improving surveillance of this organism to control its spread.

  17. 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...

  18. Prevalence, serotyping and antimicrobials resistance mechanism of Salmonella enterica isolated from clinical and environmental samples in Saudi Arabia.

    PubMed

    El-Tayeb, Mohamed A; Ibrahim, Abdelnasser S S; Al-Salamah, Ali A; Almaary, Khalid S; Elbadawi, Yahya B

    2017-02-14

    Salmonella is recognized as a common foodborne pathogen, causing major health problems in Saudi Arabia. Herein, we report epidemiology, antimicrobial susceptibility and the genetic basis of resistance among S. enterica strains isolated in Saudi Arabia. Isolation of Salmonella spp. from clinical and environmental samples resulted in isolation of 33 strains identified as S. enterica based on their biochemical characteristics and 16S-rDNA sequences. S. enterica serovar Enteritidis showed highest prevalence (39.4%), followed by S. Paratyphi (21.2%), S. Typhimurium (15.2%), S. Typhi and S. Arizona (12.1%), respectively. Most isolates were resistant to 1st and 2nd generation cephalosporin; and aminoglycosides. Moreover, several S. enterica isolates exhibited resistance to the first-line antibiotics used for Salmonellosis treatment including ampicillin, trimethoprim-sulfamethoxazole and chloramphenicol. In addition, the results revealed the emergence of two S. enterica isolates showing resistance to third-generation cephalosporin. Analysis of resistance determinants in S. enterica strains (n=33) revealed that the resistance to β-lactam antibiotics, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline, was attributed to the presence of carb-like, dfrA1, floR, tetA gene, respectively. On the other hand, fluoroquinolone resistance was related to the presence of mutations in gyrA and parC genes. These findings improve the information about foodborne Salmonella in Saudi Arabia, alarming the emergence of multi-drug resistant S. enterica strains, and provide useful data about the resistance mechanisms.

  19. A Salmonella Enterica Subsp. Enterica Serovar Enteritidis Foodborne Outbreak after Consumption of Homemade Lasagne

    PubMed Central

    Gariano, Grazia Rosaria; Bianchi, Daniela Manila; Zuccon, Fabio; Sommariva, Marco; Nguon, Bovannrith; Malabaila, Aurelio; Gallina, Silvia; Decastelli, Lucia

    2015-01-01

    In the latest year, and also in 2013, Salmonella was the most frequently detected causative agent in foodborne outbreaks (FBOs) reported in Europe. As indicated in EFSA report (2015) the serotypes mostly associated to FBOs are S. Typhimurium and Enteritidis; while Salmonella Typhimurium is generally associated with the consumption of contaminated pork and beef, FBOs due to Salmonella Enteritidis are linked to eggs and poultry meat. In this study it is described the investigation of a domestic FBO involving four adults and linked to homemade lasagne. Investigations were performed to determine the relatedness of Salmonella strains, identify the sources of infection, and trace the routes of Salmonella contamination in this FBO. Salmonella strains were isolated in 3 out of 4 patient stool samples and from lasagne and all of them were serotyped as S. Enteritidis. Pulsed-field gel electrophoresis (PFGE) analysis revealed the genotypical similarity of all the strains. Although serotyping and PFGE analysis identified the common food source of infection in this FBO, it was not possible to determine how or at what point during food preparation the lasagne became contaminated with Salmonella. PMID:27800418

  20. 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.

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

    PubMed

    Grafanakis, E; Leontides, L; Genigeorgis, C

    2001-03-31

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

  2. 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.

  3. 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.

  4. Characterization of Small ColE1-Like Plasmids Conferring Kanamycin Resistance in Salmonella enterica subsp. enterica serovars Typhimurium and Newport

    USDA-ARS?s Scientific Manuscript database

    Multi-antibiotic resistant (MR) Salmonella enterica serovars Typhimurium and Newport are an increasing concern in human and animal health. Many strains are known to carry antibiotic resistance determinants on multiple plasmids, yet detailed information is scarce. Three plasmids conferring kanamycin...

  5. Live cell imaging reveals novel functions of Salmonella enterica SPI2-T3SS effector proteins in remodeling of the host cell endosomal system.

    PubMed

    Rajashekar, Roopa; Liebl, David; Chikkaballi, Deepak; Liss, Viktoria; Hensel, Michael

    2014-01-01

    Intracellular Salmonella enterica induce a massive remodeling of the endosomal system in infected host cells. One dramatic consequence of this interference is the induction of various extensive tubular aggregations of membrane vesicles, and tubules positive for late endosomal/lysosomal markers are referred to as Salmonella-induced filaments or SIF. SIF are highly dynamic in nature with extension and collapse velocities of 0.4-0.5 µm x sec-1. The induction of SIF depends on the function of the Salmonella Pathogenicity Island 2 (SPI2) encoded type III secretion system (T3SS) and a subset of effector proteins. In this study, we applied live cell imaging and electron microscopy to analyze the role of individual effector proteins in SIF morphology and dynamic properties of SIF. SIF in cells infected with sifB, sseJ, sseK1, sseK2, sseI, sseL, sspH1, sspH2, slrP, steC, gogB or pipB mutant strains showed a morphology and dynamics comparable to SIF induced by WT Salmonella. SIF were absent in cells infected with the sifA-deficient strain and live cell analyses allowed tracking of the loss of the SCV membrane of intracellular sifA Salmonella. In contrast to analyses in fixed cells, in living host cells SIF induced by sseF- or sseG-deficient strains were not discontinuous, but rather continuous and thinner in diameter. A very dramatic phenotype was observed for the pipB2-deficient strain that induced very bulky, non-dynamic aggregations of membrane vesicles. Our study underlines the requirement of the study of Salmonella-host interaction in living systems and reveals new phenotypes due to the intracellular activities of Salmonella.

  6. Prevalence and molecular characterization of Salmonella enterica isolates throughout an integrated broiler supply chain in China.

    PubMed

    Ren, X; Li, M; Xu, C; Cui, K; Feng, Z; Fu, Y; Zhang, J; Liao, M

    2016-10-01

    A total of 1145 samples were collected from chicken breeder farms, hatcheries, broiler farms, a slaughterhouse and retail refrigerated chicken stores in an integrated broiler supply chain in Guangdong Province, China, in 2013. One-hundred and two Salmonella enterica strains were isolated and subjected to serotyping, antimicrobial susceptibility testing, virulence profile determination and molecular subtyping by pulsed field gel electrophoresis (PFGE). The contamination rates in samples from breeder farms, hatcheries, broiler farms, the slaughterhouse and retail stores were 1·46%, 4·31%, 7·00%, 62·86% and 54·67%, respectively. The isolated strains of S. enterica belonged to 10 serotypes; most of them were S. Weltevreden (46·08%, 47/102) and S. Agona (18·63%, 19/102). Isolates were frequently resistant to streptomycin (38·2%), tetracycline (36·3%), sulfisoxazole (35·3%) and gentamicin (34·3%); 31·4% of isolates were multidrug resistant. The isolates were screened for 10 virulence factors. The Salmonella pathogenicity island genes avrA, ssaQ, mgtC, siiD, and sopB and the fimbrial gene bcfC were present in 100% of the strains. PFGE genotyping of the 102 S. enterica isolates yielded 24 PFGE types at an 85% similarity threshold. The PFGE patterns show that the genotypes of S. enterica in the production chain are very diverse, but some strains have 100% similarity in different parts of the production chain, which indicates that some S. enterica persist throughout the broiler supply chain.

  7. Emergence of Ciprofloxacin-Resistant Salmonella enterica Serovar Typhi in Italy.

    PubMed

    García-Fernández, Aurora; Gallina, Silvia; Owczarek, Slawomir; Dionisi, Anna Maria; Benedetti, Ildo; Decastelli, Lucia; Luzzi, Ida

    2015-01-01

    In developed countries, typhoid fever is often associated with persons who travel to endemic areas or immigrate from them. Typhoid fever is a systemic infection caused by Salmonella enterica serovar Typhi. Because of the emergence of antimicrobial resistance to standard first-line drugs, fluoroquinolones are the drugs of choice. Resistance to ciprofloxacin by this Salmonella serovar represents an emerging public health issue. Two S. enterica ser. Typhi strains resistant to ciprofloxacin (CIP) were reported to the Italian surveillance system for foodborne and waterborne diseases (EnterNet-Italia) in 2013. The strains were isolated from two Italian tourists upon their arrival from India. A retrospective analysis of 17 other S. enterica ser. Typhi strains isolated in Italy during 2011-2013 was performed to determine their resistance to CIP. For this purpose, we assayed for susceptibility to antimicrobial agents and conducted PCR and nucleotide sequence analyses. Moreover, all strains were typed using pulsed-field gel electrophoresis to evaluate possible clonal relationships. Sixty-eight percent of the S. enterica ser. Typhi strains were resistant to CIP (MICs, 0.125-16 mg/L), and all isolates were negative for determinants of plasmid-mediated quinolone resistance. Analysis of sequences encoding DNA gyrase and topoisomerase IV subunits revealed mutations in gyrA, gyrB, and parC. Thirteen different clonal groups were detected, and the two CIP-resistant strains isolated from the individuals who visited India exhibited the same PFGE pattern. Because of these findings, the emergence of CIP-resistant S. enterica ser. Typhi isolates in Italy deserves attention, and monitoring antibiotic susceptibility is important for efficiently managing cases of typhoid fever.

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

    PubMed Central

    Timme, Ruth E.; Pettengill, James B.; Allard, Marc W.; Strain, Errol; Barrangou, Rodolphe; Wehnes, Chris; Van Kessel, JoAnn S.; Karns, Jeffrey S.; Musser, Steven M.; Brown, Eric W.

    2013-01-01

    The enteric pathogen Salmonella enterica is one of the leading causes of foodborne illness in the world. The species is extremely diverse, containing more than 2,500 named serovars that are designated for their unique antigen characters and pathogenicity profiles—some are known to be virulent pathogens, while others are not. Questions regarding the evolution of pathogenicity, significance of antigen characters, diversity of clustered regularly interspaced short palindromic repeat (CRISPR) loci, among others, will remain elusive until a strong evolutionary framework is established. We present the first large-scale S. enterica subsp. enterica phylogeny inferred from a new reference-free k-mer approach of gathering single nucleotide polymorphisms (SNPs) from whole genomes. The phylogeny of 156 isolates representing 78 serovars (102 were newly sequenced) reveals two major lineages, each with many strongly supported sublineages. One of these lineages is the S. Typhi group; well nested within the phylogeny. Lineage-through-time analyses suggest there have been two instances of accelerated rates of diversification within the subspecies. We also found that antigen characters and CRISPR loci reveal different evolutionary patterns than that of the phylogeny, suggesting that a horizontal gene transfer or possibly a shared environmental acquisition might have influenced the present character distribution. Our study also shows the ability to extract reference-free SNPs from a large set of genomes and then to use these SNPs for phylogenetic reconstruction. This automated, annotation-free approach is an important step forward for bacterial disease tracking and in efficiently elucidating the evolutionary history of highly clonal organisms. PMID:24158624

  9. Salmonella enterica prevalence in leatherback sea turtles (Dermochelys coriacea) in St. Kitts, West Indies.

    PubMed

    Dutton, Clayton S; Revan, Floyd; Wang, Chengming; Xu, Chuanling; Norton, Terry M; Stewart, Kimberly M; Kaltenboeck, Bernhard; Soto, Esteban

    2013-09-01

    Salmonella spp. are gram-negative bacteria capable of causing diseases in a wide range of aquatic and terrestrial animals, including humans. Sea and terrestrial turtles have been recognized as carriers of this zoonotic pathogen. In this project, conventional and molecular diagnostic methods were combined to investigate the prevalence of Salmonella enterica in leatherback sea turtles (Dermochelys coriacea) that used the island of St. Kitts, West Indies as a nesting ground during 2011 (n = 21). Isolates obtained from selective media were screened and colonies suspected of being Salmonella spp. were confirmed by fluorescence resonance energy transfer polymerase chain reaction. The prevalence of S. enterica within this sample population during this period was found to be 14.2%. Moreover, due to the increasing risk of antibiotic resistance in enteric bacteria, antimicrobial susceptibility was investigated in all recovered Salmonella spp. isolates utilizing the broth microdilution method. All isolates were susceptible to the lowest concentration of kanamycin, gentamicin, ciprofloxacin, enrofloxacin, nalidixic acid, and trimethoprim/sulfamethoxazole tested. Further research should be pursued to understand the interaction of this bacterial pathogen with the environment, host, and other microbial communities, and to further develop faster, more sensitive, and more specific diagnostic methods.

  10. 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.

  11. 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.

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

    PubMed

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

    2016-04-01

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

  13. Multi-locus sequence typing of Salmonella enterica subsp. enterica serovar Enteritidis strains in Japan between 1973 and 2004.

    PubMed

    Noda, Tamie; Murakami, Koichi; Asai, Tetsuo; Etoh, Yoshiki; Ishihara, Tomoe; Kuroki, Toshiro; Horikawa, Kazumi; Fujimoto, Shuji

    2011-06-15

    Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) was responsible for a worldwide pandemic during the 1980s and 1990s; however, changes in the dominant lineage before and after this event remain unknown. This study determined S. Enteritidis lineages before and after this pandemic event in Japan using multilocus sequence typing (MLST). Thirty S. Enteritidis strains were collected in Japan between 1973 and 2004, consisting of 27 human strains from individual episodes, a bovine strain, a liquid egg strain and an eggshell strain. Strains showed nine phage types and 17 pulsed-field profiles with pulsed-field gel electrophoresis. All strains had homologous type 11 sequences without any nucleotide differences in seven housekeeping genes. These MLST results suggest that S. Enteritidis with the diversities revealed by phage typing and pulsed-field profiling has a highly clonal population. Although type 11 S. Enteritidis may exhibit both pleiotropic surface structure and pulsed-field type variation, it is likely to be a stable lineage derived from an ancestor before the 1980s and/or 1990s pandemic in Japan.

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

    PubMed

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

    2002-02-01

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

  15. The Bimodal Lifestyle of Intracellular Salmonella in Epithelial Cells: Replication in the Cytosol Obscures Defects in Vacuolar Replication

    PubMed Central

    Steele-Mortimer, Olivia

    2012-01-01

    Salmonella enterica serovar Typhimurium invades and proliferates within epithelial cells. Intracellular bacteria replicate within a membrane bound vacuole known as the Salmonella containing vacuole. However, this bacterium can also replicate efficiently in the cytosol of epithelial cells and net intracellular growth is a product of both vacuolar and cytosolic replication. Here we have used semi-quantitative single-cell analyses to investigate the contribution of each of these replicative niches to intracellular proliferation in cultured epithelial cells. We show that cytosolic replication can account for the majority of net replication even though it occurs in less than 20% of infected cells. Consequently, assays for net growth in a population of infected cells, for example by recovery of colony forming units, are not good indicators of vacuolar proliferation. We also show that the Salmonella Type III Secretion System 2, which is required for SCV biogenesis, is not required for cytosolic replication. Altogether this study illustrates the value of single cell analyses when studying intracellular pathogens. PMID:22719929

  16. The evolutionary history and diagnostic utility of the CRISPR-Cas system within Salmonella enterica ssp. enterica

    PubMed Central

    Timme, Ruth E.; Barrangou, Rodolphe; Toro, Magaly; Allard, Marc W.; Strain, Errol; Musser, Steven M.; Brown, Eric W.

    2014-01-01

    Evolutionary studies of clustered regularly interspaced short palindromic repeats (CRISPRs) and their associated (cas) genes can provide insights into host-pathogen co-evolutionary dynamics and the frequency at which different genomic events (e.g., horizontal vs. vertical transmission) occur. Within this study, we used whole genome sequence (WGS) data to determine the evolutionary history and genetic diversity of CRISPR loci and cas genes among a diverse set of 427 Salmonella enterica ssp. enterica isolates representing 64 different serovars. We also evaluated the performance of CRISPR loci for typing when compared to whole genome and multilocus sequence typing (MLST) approaches. We found that there was high diversity in array length within both CRISPR1 (median = 22; min = 3; max = 79) and CRISPR2 (median = 27; min = 2; max = 221). There was also much diversity within serovars (e.g., arrays differed by as many as 50 repeat-spacer units among Salmonella ser. Senftenberg isolates). Interestingly, we found that there are two general cas gene profiles that do not track phylogenetic relationships, which suggests that non-vertical transmission events have occurred frequently throughout the evolutionary history of the sampled isolates. There is also considerable variation among the ranges of pairwise distances estimated within each cas gene, which may be indicative of the strength of natural selection acting on those genes. We developed a novel clustering approach based on CRISPR spacer content, but found that typing based on CRISPRs was less accurate than the MLST-based alternative; typing based on WGS data was the most accurate. Notwithstanding cost and accessibility, we anticipate that draft genome sequencing, due to its greater discriminatory power, will eventually become routine for traceback investigations. PMID:24765574

  17. Antimicrobial Probiotics Reduce Salmonella enterica in Turkey Gastrointestinal Tracts

    PubMed Central

    Forkus, Brittany; Ritter, Seth; Vlysidis, Michail; Geldart, Kathryn; Kaznessis, Yiannis N.

    2017-01-01

    Despite the arsenal of technologies employed to control foodborne nontyphoidal Salmonella (NTS), infections have not declined in decades. Poultry is the primary source of NTS outbreaks, as well as the fastest growing meat sector worldwide. With recent FDA rules for phasing-out antibiotics in animal production, pressure is mounting to develop new pathogen reduction strategies. We report on a technology to reduce Salmonella enteritidis in poultry. We engineered probiotic E. coli Nissle 1917, to express and secrete the antimicrobial peptide, Microcin J25. Using in vitro experiments and an animal model of 300 turkeys, we establish the efficacy of this technology. Salmonella more rapidly clear the ceca of birds administered the modified probiotic than other treatment groups. Approximately 97% lower Salmonella carriage is measured in a treated group, 14 days post-Salmonella challenge. Probiotic bacteria are generally regarded as safe to consume, are bile-resistant and can plausibly be modified to produce a panoply of antimicrobial peptides now known. The reported systems may provide a foundation for platforms to launch antimicrobials against gastrointestinal tract pathogens, including ones that are multi-drug resistant. PMID:28094807

  18. Salmonella enterica serovar Typhimurium ΔmsbB Triggers Exacerbated Inflammation in Nod2 Deficient Mice

    PubMed Central

    Claes, Anne-Kathrin; Steck, Natalie; Schultz, Dorothee; Zähringer, Ulrich; Lipinski, Simone; Rosenstiel, Philip; Geddes, Kaoru; Philpott, Dana J.; Heine, Holger; Grassl, Guntram A.

    2014-01-01

    The intracellular pathogen Salmonella enterica serovar Typhimurium causes intestinal inflammation characterized by edema, neutrophil influx and increased pro-inflammatory cytokine expression. A major bacterial factor inducing pro-inflammatory host responses is lipopolysaccharide (LPS). S. Typhimurium ΔmsbB possesses a modified lipid A, has reduced virulence in mice, and is being considered as a potential anti-cancer vaccine strain. The lack of a late myristoyl transferase, encoded by MsbB leads to attenuated TLR4 stimulation. However, whether other host receptor pathways are also altered remains unclear. Nod1 and Nod2 are cytosolic pattern recognition receptors recognizing bacterial peptidoglycan. They play important roles in the host's immune response to enteric pathogens and in immune homeostasis. Here, we investigated how deletion of msbB affects Salmonella's interaction with Nod1 and Nod2. S. Typhimurium Δ msbB-induced inflammation was significantly exacerbated in Nod2−/− mice compared to C57Bl/6 mice. In addition, S. Typhimurium ΔmsbB maintained robust intestinal colonization in Nod2−/− mice from day 2 to day 7 p.i., whereas colonization levels significantly decreased in C57Bl/6 mice during this time. Similarly, infection of Nod1−/− and Nod1/Nod2 double-knockout mice revealed that both Nod1 and Nod2 play a protective role in S. Typhimurium ΔmsbB-induced colitis. To elucidate why S. Typhimurium ΔmsbB, but not wild-type S. Typhimurium, induced an exacerbated inflammatory response in Nod2−/− mice, we used HEK293 cells which were transiently transfected with pathogen recognition receptors. Stimulation of TLR2-transfected cells with S. Typhimurium ΔmsbB resulted in increased IL-8 production compared to wild-type S. Typhimurium. Our results indicate that S. Typhimurium ΔmsbB triggers exacerbated colitis in the absence of Nod1 and/or Nod2, which is likely due to increased TLR2 stimulation. How bacteria with “genetically detoxified” LPS

  19. 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.

  20. Solitary Intestinal Lymphoid Tissue Provides a Productive Port of Entry for Salmonella enterica Serovar Typhimurium▿

    PubMed Central

    Halle, Stephan; Bumann, Dirk; Herbrand, Heike; Willer, Yvonne; Dähne, Sabrina; Förster, Reinhold; Pabst, Oliver

    2007-01-01

    Oral infection of mice with Salmonella enterica serovar Typhimurium results in the colonization of Peyer's patches, triggering a vigorous inflammatory response and immunopathology at these sites. Here we demonstrate that in parallel to Peyer's patches a strong inflammatory response occurs in the intestine, resulting in the appearance of numerous inflammatory foci in the intestinal mucosa. These foci surround small lymphoid cell clusters termed solitary intestinal lymphoid tissue (SILT). Salmonella can be observed inside SILT at early stages of infection, and the number of infected structures matches the number of inflammatory foci arising at later time points. Infection leads to enlargement and morphological destruction of SILT but does not trigger de novo formation of lymphoid tissue. In conclusion, SILT, a lymphoid compartment mostly neglected in earlier studies, represents a major site for Salmonella invasion and ensuing mucosal pathology. PMID:17283101

  1. Poultry as a possible source of non-typhoidal Salmonella enterica serovars in humans in Bangladesh.

    PubMed

    Barua, Himel; Biswas, Paritosh Kumar; Talukder, Kaisar Ali; Olsen, Katharina E P; Christensen, Jens Peter

    2014-01-31

    We investigated Salmonella enterica isolates from human clinical cases of gastroenteritis to determine the distribution of non-typhoidal Salmonella serovars in the human population, and compared them to isolates originating from poultry by serotyping, phage typing, plasmid profiling, pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) to evaluate the potential role of poultry in human non-typhoidal salmonellosis in Bangladesh. Nine different serovars were identified among the human isolates of which Salmonella Paratyphi B var Java (S. Java), S. Kentucky, S. Enteritidis, S. Virchow and S. Weltevreden also were commonly isolated from poultry. The poultry isolates belonging to S. Java, S. Kentucky and S. Enteritidis were indistinguishable from human isolates or genetically closely related, based on PFGE profiles and MLST. S. Kentucky clone ST198 and S. Java clone ST43 both well-known cause of human infections were also isolated from poultry. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Transcriptomic Responses of Salmonella enterica Serovars Enteritidis and Typhimurium to Chlorine-Based Oxidative Stress▿ †

    PubMed Central

    Wang, Siyun; Phillippy, Adam M.; Deng, Kaiping; Rui, Xiaoqian; Li, Zengxin; Tortorello, Mary Lou; Zhang, Wei

    2010-01-01

    Salmonella enterica serovars Enteritidis and Typhimurium are the leading causative agents of salmonellosis in the United States. S. Enteritidis is predominantly associated with contamination of shell eggs and egg products, whereas S. Typhimurium is frequently linked to tainted poultry meats, fresh produce, and recently, peanut-based products. Chlorine is an oxidative disinfectant commonly used in the food industry to sanitize the surfaces of foods and food processing facilities (e.g., shell eggs and poultry meats). However, chlorine disinfection is not always effective, as some S. enterica strains may resist and survive the disinfection process. To date, little is known about the underlying mechanisms of how S. enterica responds to chlorine-based oxidative stress. In this study, we designed a custom bigenome microarray that consists of 385,000 60-mer oligonucleotide probes and targets 4,793 unique gene features in the genomes of S. Enteritidis strain PT4 and S. Typhimurium strain LT2. We explored the transcriptomic responses of both strains to two different chlorine treatments (130 ppm of chlorine for 30 min and 390 ppm of chlorine for 10 min) in brain heart infusion broth. We identified 209 S. enterica core genes associated with Fe-S cluster assembly, cysteine biosynthesis, stress response, ribosome formation, biofilm formation, and energy metabolism that were differentially expressed (>1.5-fold; P < 0.05). In addition, we found that serovars Enteriditis and Typhimurium differed in the responses of 33 stress-related genes and 19 virulence-associated genes to the chlorine stress. Findings from this study suggest that the oxidative-stress response may render S. enterica resistant or susceptible to certain types of environmental stresses, which in turn promotes the development of more effective hurdle interventions to reduce the risk of S. enterica contamination in the food supply. PMID:20562293

  3. Salmonella enterica virulence genes are required for bacterial attachment to plant tissue.

    PubMed

    Barak, Jeri D; Gorski, Lisa; Naraghi-Arani, Pejman; Charkowski, Amy O

    2005-10-01

    Numerous Salmonella enterica food-borne illness outbreaks have been associated with contaminated vegetables, in particular sprouted seeds, and the incidence of reported contamination has steadily risen. In order to understand the physiology of S. enterica serovar Newport on plants, a screen was developed to identify transposon mutants that were defective in attachment to alfalfa sprouts. Twenty independent mutants from a pool of 6,000 were selected for reduced adherence to alfalfa sprouts. Sixty-five percentage of these mutants had insertions in uncharacterized genes. Among the characterized genes were strains with insertions in the intergenic region between agfB, the surface-exposed aggregative fimbria (curli) nucleator, and agfD, a transcriptional regulator of the LuxR superfamily, and rpoS, the stationary-phase sigma factor. Both AgfD and RpoS have been reported to regulate curli and cellulose production and RpoS regulates other adhesins such as pili. The intergenic and rpoS mutants were reduced in initial attachment to alfalfa sprouts by 1 log unit compared to the wild type. Mutations of agfA, curli subunit, and agfB in S. enterica serovar Enteritidis differentially affected attachment to plant tissue. The agfA mutation was not reduced in ability to attach to or colonize alfalfa sprouts, whereas the agfB mutation was reduced. Thus, agfB alone can play a role in attachment of S. enterica to plant tissue. These results reveal that S. enterica genes important for virulence in animal systems are also required for colonization of plants, a secondary host that can serve as a vector of S. enterica from animal to animal.

  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. [Bovine lactoferrin decreases the invasion of Salmonella enterica to HEp-2 cells].

    PubMed

    Barreto Arce, Liz J; Contreras García, Carmen A; Durand Vara, David; Ochoa Woodell, Theresa

    2016-01-01

    To assess the effect of bovine lactoferrin (bLf) on the invasion of Salmonella enterica ser. Typhimurium to HEp-2 cells. HEp-2 monolayers were infected with 106 colony forming unit (CFU) of bacteria in the absence and presence of 1 and 10 mg/mL of bLf (iron-saturated) and incubated 1.5 hours at 37°C. Two treatments were evaluated: pre- infection (HEp-2 cells were incubated with bLf one hour prior to infection with Salmonella) and post-infection (bLf was added 15 minutes after the infection). Invasiveness of Salmonella was determined throgh quantification of CFU recovered from inside the HEp-2 cells (after treatment with 100 μg/mL and 10 μg/mL of gentamicin and Triton X -100). In the pre-infection treatment, we observed a decrease of 23% of Salmonella invasion when HEp-2 cells were pre incubated with 1 mg/mL of bLf (2.8x105 vs 2.1x105, p=0.04) and 50% when them were pre-incubated with 10 mg/mL of bLf (2.8x105 vs 1.4x105, p=0.04). In post-infection treatment, no changes were observed in the invasiveness of Salmonella. The results indicated that bLf reduces the invasiveness of Salmonella enterica ser. Typhimurium to HEp-2 cells in the pre-infection treatment.

  6. Characterization of quinolone resistance in Salmonella enterica serovar Indiana from chickens in China.

    PubMed

    Lu, Yan; Zhao, Hongyu; Liu, Yuqi; Zhou, Xuping; Wang, Jinyuan; Liu, Tiantian; Beier, Ross C; Hou, Xiaolin

    2015-03-01

    The aim of this study was to characterize the quinolone resistance of Salmonella enterica serovar Indiana isolated from chickens in China. A total of 293 Salmonella strains were isolated from chicken farms and slaughterhouses in Shandong province of China, and 130 (44.4%) were characterized as Salmonella enterica Indiana (chicken farms, n=52 strains; slaughter houses, n=78 strains). All isolate serotypes were tested with the Kauffmann-White classification system and examined for susceptibility to the quinolones: nalidixic acid, enrofloxacin, norfloxacin, and ciprofloxacin. The resistance of the Salmonella Indiana strains to nalidixic acid, enrofloxacin, norfloxacin, and ciprofloxacin were 100, 73.1, 71.2, and 82.7%, and 100, 59.0, 79.5, and 80.2%, respectively. Selected quinolone resistant strains were evaluated for mutations in genes (gyrA, gyrB, parC, and marA) by DNA sequencing. The gyrA mutation was found in all isolates, the parC mutation was only found in some isolates, and the gyrB and marA mutations were not observed. Quinolone resistance was evaluated in the representative isolates by screening for the quinolone resistance determinants, qnrA, qnrB, qnrS, qepA, and aac (6 ')-Ib-cr using PCR technology. The quinolone resistance determinants in Salmonella, qnrA, qnrB, qnrS, and qepA were negative by PCR, but aac(6 ')-Ib-cr had high detection rates of 90.4 and 96.2% in chicken farms and slaughterhouses, respectively. Salmonella Indiana containing the gyrA mutation was prevalent in farms and slaughterhouses and possessed a high frequency of the quinolone resistance determinant aac(6 ')-Ib-cr. These bacteria may have originated from the same source.

  7. Requirement of MgtC for Brucella suis Intramacrophage Growth: a Potential Mechanism Shared by Salmonella enterica and Mycobacterium tuberculosis for Adaptation to a Low-Mg2+ Environment

    PubMed Central

    Lavigne, Jean-Philippe; O'Callaghan, David; Blanc-Potard, Anne-Béatrice

    2005-01-01

    A Brucella suis mgtC mutant is defective for growth within macrophages and in low-Mg2+ medium. These phenotypes are strikingly similar to those observed with mgtC mutants from Salmonella enterica and Mycobacterium tuberculosis, two other pathogens that proliferate within phagosomes. MgtC appears as a remarkable virulence factor that would have been acquired by distantly related intracellular pathogens to contribute to the adaptation to a low-Mg2+ environment in the phagosome. PMID:15845525

  8. MarA and ramA regulate virulence in Salmonella enterica serovar Choleraesuis.

    PubMed

    Lee, Jen-Jie; Hsuan, Shih-Ling; Kuo, Chih-Jung; Wu, Ying-Chen; Chen, Ter-Hsin

    2015-12-31

    Salmonella enterica serovar Choleraesuis is considered as an important porcine pathogen that causes serious systemic infections and exhibits poor response to treatment because of an increase in multidrug resistance (MDR). Among the various regulators of resistance, multiple antibiotic resistance factor A (marA) and regulator of acetate metabolism A (ramA) are the most effective in conferring antibiotic tolerance by activation of multidrug efflux pumps. Here we investigated the regulation of virulence in Salmonella Choleraesuis through these two transcriptional regulators. We showed that marA andramA are important for the survival of Salmonella Choleraesuis in an environment of acid and bile salts, since marA- or ramA-deficient Salmonella Choleraesuis strains failed to increase protective responses, as observed by quantitative RT-PCR (qPCR). Further, reduced invasion and survival in host cells was observed in the marA and ramA mutant strains. The results from in vitrostudies with marA- and ramA-deficient strains showed attenuated characteristics in comparison to those in the wild-type strain of Salmonella Choleraesuis when it was used to challenge BALB/c mice. The mutant strains had higher LD50 and presented poor clearance efficiency compared to the parental strain. These findings indicate that MarA and RamA not only regulate drug resistance but also play a role in the virulence of SalmonellaCholeraesuis.

  9. Control of Salmonella enterica Typhimurium in chicken breast meat by irradiation combined with modified atmosphere packaging.

    PubMed

    Kudra, L L; Sebranek, J G; Dickson, J S; Mendonca, A F; Zhang, Q; Jackson-Davis, A; Prusa, K J

    2011-11-01

    Salmonella is one of the leading causes of human foodborne illnesses originating from meat and poultry products. Cross-contamination of Salmonella from raw to cooked products continues to be problematic in the food industry. Therefore, new intervention strategies are needed for meat and poultry products. Vacuum or modified atmosphere packaging (MAP) are common packaging techniques used to extend the shelf life of meat products. Irradiation has been well established as an antibacterial treatment to reduce pathogens on meat and poultry. Combining irradiation with high-CO(2)+CO MAP was investigated in this study for improving the control of Salmonella enterica Typhimurium on chicken breast meat. The radiation sensitivities (D10-values) of this pathogen in chicken breast meat were found to be similar in vacuum and in high-CO(2)+CO MAP (0.55 ± 0.03 kGy and 0.54 ± 0.03 kGy, respectively). Irradiation at 1.5 kGy reduced the Salmonella population by an average of 3 log. Some Salmonella cells survived in both vacuum and high-CO(2) + CO MAP through 6 weeks of refrigerated storage following irradiation. This pathogen also grew in both vacuum and MAP when the product was held at 25°C. This study demonstrated that irradiation is an effective means of reducing Salmonella on meat or poultry, but packaging in either vacuum or MAP had little impact during subsequent refrigerated storage.

  10. Introduction of new multidrug-resistant Salmonella enterica strains into commercial dairy herds.

    PubMed

    Adhikari, B; Besser, T E; Gay, J M; Fox, L K; Davis, M A; Cobbold, R N; Berge, A C; McClanahan, R; Hancock, D D

    2009-09-01

    A longitudinal observational study of 59 dairy herds was conducted in Washington State to estimate the rate of introduction of new multidrug-resistant (MDR) Salmonella enterica strains onto commercial dairy herds. Samples were collected on these herds over 7 visits separated by intervals of 2 to 4 mo over a period of 15 to 21 mo. Samples were cultured for Salmonella spp. and serogroup, serovar, and antimicrobial susceptibility patterns were identified for MDR Salmonella isolates. Fingerprinting generated by pulsed-field gel electrophoresis (PFGE) using XbaI restriction enzyme digestion generated genotyping profiles for all MDR isolates identified in the study. The rate of new MDR Salmonella strain introduction was 0.9 per herd-year (95% confidence interval: 0.6-1.4). The rates for the most commonly introduced MDR Salmonella serovars were 0.4/herd-year for Typhimurium, 1.2/herd-year for Newport, and 0.1/herd-year for Dublin. Thirty-three of 59 herds (56%) had at least one new MDR Salmonella introduction during the study period. The number of new MDR Salmonella strains acquired by dairy herds ranged from zero to 8. Thirteen of the 59 herds had a history of clinical salmonellosis. Among these 13 herds, 6 herds acquired new MDR Salmonella strains, although these strains were different than historical clinical strains. These data indicate that acquisition of new MDR Salmonella strains by dairy herds was a common event in participating herds, although the number of strains introduced varied greatly among herds.

  11. Effect of in vivo neutralization of tumor necrosis alpha on the efficacy of antibiotic treatment in systemic Salmonella enterica infections

    PubMed Central

    Grant, Andrew J.; Mastroeni, Pietro

    2017-01-01

    Abstract Immunity can co-operate with antibiotics, but can also antagonize drug efficacy by segregating the bacteria to areas of the body that are less accessible to antimicrobials, and by selecting for subpopulations with low division rates that are often difficult to eradicate. We studied the effect of an anti-inflammatory/immunosuppressive anti-TNFα treatment, which accelerates bacterial growth in the tissues and inhibits or reverses the formation of granulomas, on the efficacy of ampicillin and ciprofloxacin during a systemic Salmonella enterica infection of the mouse. The anti-TNFα treatment neither precluded nor enhanced the efficacy of antibiotic treatment. However, the anti-TNFα treatment rendered the animals susceptible to the rapid relapse of the infection seen after cessation of the antibiotic treatment. Reactivation of an established infection, due to late administration of anti-TNFα antibodies, could be successfully controlled by antibiotics, but full clearance of the bacterial load from the tissues was not achieved. We conclude that the lack of TNFα does not preclude the efficacy of antibiotic treatment and must be monitored with care due to post-treatment relapses. Combinations of anti-cytokine compounds and antibiotic molecules may not be the best way to treat persistent infections with intracellular bacteria like Salmonella. PMID:28087648

  12. 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.

  13. 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.

  14. Standardized laboratory-scale preparation of mayonnaise containing low levels of Salmonella enterica serovar Enteritidis.

    PubMed

    Leuschner, R G; Boughtflower, M P

    2001-05-01

    Salmonella enterica serovar Enteritidis PT4 and PT6 are associated with food poisoning outbreaks and are often found in food only in low concentrations. In this study a reproducible laboratory-scale procedure for preparation of mayonnaise is presented. The mayonnaise that simulates a naturally low-level contaminated product can be used for validation of new methods and is also suitable to study the behavior of low numbers of food pathogenic spoilage microorganisms in a food environment. During processing, liquid egg was artificially contaminated with low levels of S. enterica serovar Enteritidis that resulted in levels of 1 to 3 log10 CFU/g in the final mayonnaise. Cells of S. enterica serovar Enteritidis had increased stability in the mayonnaise when they were subjected to low pH in two stages, first to pH 5.8 and afterward to pH 4.5 before addition to the mayonnaise. The pH of the mayonnaise was between 4.2 to 4.5 and remained stable over the storage period. Low-level S. enterica serovar Enteritidis remained stable in artificially contaminated mayonnaise for 4 weeks at 4 degrees C.

  15. [Salmonella enterica with nonclassical quinolone resistance phenotype in pediatric patients].

    PubMed

    González-Abad, Ma José; Alonso-Sanz, Mercedes

    2015-02-01

    Decreased susceptibility to fluoroquinolones in Salmonella spp. may lead to treatment failures. The use of ciprofloxacin for extraintestinal and serious intestinal Salmonella infections in children is controversial and therefore the clinical relevance of these strains is not significant. Consequently little is know about the quinolone resistance of strains Salmonella of our paediatric population. The objective of this study was to assess the incidence of nonclassical quinolone resistance phenotype in paediatric patients. Two hundred and sixty eight Salmonella spp. from Hospital Infantil Universitario Niño Jesús of Madrid (2009-2013) were tested against nalidixic acid and ciprofloxacin by microdilution. Moreover, 146 strains (2011-2013) were tested against ciprofloxacin by E-test. Reduced ciprofloxacin susceptibility was defined as a MIC of 0.125-1 mg/L. Of 42 isolates with reduced ciprofloxacin susceptibility, four isolates showing nonclassical quinolone resistance phenotype. Three were confirmed as carrying of plasmid-mediated quinolone resistance-conferring genes qnr. The percentage of strains with a genotype that confers a nonclassical quinolone resistance phenotype is low in our series. The identification of these isolates is difficult using conventional methods, but its ability of horizontal spread recommends an appropriate identification. Taking into account the low isolation rate of these strains in this study, evaluation of ciprofloxacin MIC on every nalidixic acid susceptible strain would not be cost effective. Alternatively, we propose to evaluate periodically any changing trend.

  16. 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

  17. The β-Oxidation Systems of Escherichia coli and Salmonella enterica Are Not Functionally Equivalent

    PubMed Central

    Iram, Surtaj Hussain; Cronan, John E.

    2006-01-01

    Based on its genome sequence, the pathway of β-oxidative fatty acid degradation in Salmonella enterica serovar Typhimurium LT2 has been thought to be identical to the well-characterized Escherichia coli K-12 system. We report that wild-type strains of S. enterica grow on decanoic acid, whereas wild-type E. coli strains cannot. Mutant strains (carrying fadR) of both organisms in which the genes of fatty acid degradation (fad) are expressed constitutively are readily isolated. The S. enterica fadR strains grow more rapidly than the wild-type strains on decanoic acid and also grow well on octanoic and hexanoic acids (which do not support growth of wild-type strains). By contrast, E. coli fadR strains grow well on decanoic acid but grow only exceedingly slowly on octanoic acid and fail to grow at all on hexanoic acid. The two wild-type organisms also differed in the ability to grow on oleic acid when FadR was overexpressed. Under these superrepression conditions, E. coli failed to grow, whereas S. enterica grew well. Exchange of the wild-type fadR genes between the two organisms showed this to be a property of S. enterica rather than of the FadR proteins per se. This difference in growth was attributed to S. enterica having higher cytosolic levels of the inducing ligands, long-chain acyl coenzyme As (acyl-CoAs). The most striking results were the differences in the compositions of CoA metabolites of strains grown with octanoic acid or oleic acid. S. enterica cleanly converted all of the acid to acetyl-CoA, whereas E. coli accumulated high levels of intermediate-chain-length products. Exchange of homologous genes between the two organisms showed that the S. enterica FadE and FadBA enzymes were responsible for the greater efficiency of β-oxidation relative to that of E. coli. PMID:16385050

  18. Effect of EDTA on Salmonella enterica serovar Typhimurium involves a component not assignable to lipopolysaccharide release.

    PubMed

    Alakomi, H-L; Saarela, M; Helander, I M

    2003-08-01

    The effect of EDTA on Salmonella enterica serovar Typhimurium was studied in different growth phases with cells grown with or without Ca(2+) and Mg(2+) supplementation. EDTA affected the outer membrane much more strongly in the early exponential phase than in the mid- or late exponential phase, as indicated by uptake of 1-N-phenylnaphthylamine (a nonpolar hydrophobic probe, M(r) 219), and detergent (SDS) susceptibility. This effect was, however, not paralleled by LPS release (determined by measuring LPS-specific fatty acids or 14C-labelled LPS in cell-free supernatants, per a standardized cell density), which remained unchanged as a function of the growth curve. The conclusion from these results is that in the early exponential phase the effect of EDTA in S. enterica involves a component that is independent of LPS release.

  19. [Salmonella enterica: a review or the trilogy agent, host and environment and its importance in Chile].

    PubMed

    Barreto, Marlen; Castillo-Ruiz, Mario; Retamal, Patricio

    2016-10-01

    Salmonella enterica is a major foodborne pathogen worldwide, being the main cause of outbreaks by food consumption in Chile. Despite all efforts deployed for control and prevention, the high incidence in people still persists, with several factors that could be influencing the epidemiological behavior of this infection. The objective of this review is to identify these factors belonging to the biological agent, the human host and the environment, which probably have a greater importance in Chile. Thus, priority areas for research of S. enterica are inferred, which hopefully will help to understand its spread in nature and its success as a wide host range pathogen. In the future, increased understanding of these determinants will facilitate the implementation of biosecurity and surveillance strategies for the prevention of disease in people and animals.

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

    PubMed

    Maraki, Sofia; Papadakis, Ioannis S

    2014-01-01

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

  1. The Vi capsular polysaccharide enables Salmonella enterica serovar typhi to evade microbe-guided neutrophil chemotaxis.

    PubMed

    Wangdi, Tamding; Lee, Cheng-Yuk; Spees, Alanna M; Yu, Chenzhou; Kingsbury, Dawn D; Winter, Sebastian E; Hastey, Christine J; Wilson, R Paul; Heinrich, Volkmar; Bäumler, Andreas J

    2014-08-01

    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.

  2. 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

  3. 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

  4. DNA Adenine Methylation Regulates Virulence Gene Expression in Salmonella enterica Serovar Typhimurium▿

    PubMed Central

    Balbontín, Roberto; Rowley, Gary; Pucciarelli, M. Graciela; López-Garrido, Javier; Wormstone, Yvette; Lucchini, Sacha; García-del Portillo, Francisco; Hinton, Jay C. D.; Casadesús, Josep

    2006-01-01

    Transcriptomic analyses during growth in Luria-Bertani medium were performed in strain SL1344 of Salmonella enterica serovar Typhimurium and in two isogenic derivatives lacking Dam methylase. More genes were repressed than were activated by Dam methylation (139 versus 37). Key genes that were differentially regulated by Dam methylation were verified independently. The largest classes of Dam-repressed genes included genes belonging to the SOS regulon, as previously described in Escherichia coli, and genes of the SOS-inducible Salmonella prophages ST64B, Gifsy-1, and Fels-2. Dam-dependent virulence-related genes were also identified. Invasion genes in pathogenicity island SPI-1 were activated by Dam methylation, while the fimbrial operon std was repressed by Dam methylation. Certain flagellar genes were repressed by Dam methylation, and Dam− mutants of S. enterica showed reduced motility. Altered expression patterns in the absence of Dam methylation were also found for the chemotaxis genes cheR (repressed by Dam) and STM3216 (activated by Dam) and for the Braun lipoprotein gene, lppB (activated by Dam). The requirement for DNA adenine methylation in the regulation of specific virulence genes suggests that certain defects of Salmonella Dam− mutants in the mouse model may be caused by altered patterns of gene expression. PMID:16997949

  5. The flagellar regulator TviA reduces pyroptosis by Salmonella enterica serovar Typhi.

    PubMed

    Winter, Sebastian E; Winter, Maria G; Atluri, Vidya; Poon, Victor; Romão, Everton L; Tsolis, Renée M; Bäumler, Andreas J

    2015-04-01

    To discern virulent from innocuous microbes, the innate immune system senses events associated with bacterial access to immunoprivileged sites such as the host cell cytosol. One such pathway is triggered by the cytosolic delivery of flagellin, the major subunit of the flagellum, by bacterial secretion systems. This leads to inflammasome activation and subsequent proinflammatory cell death (pyroptosis) of the infected phagocyte. In this study, we demonstrate that the causative agent of typhoid fever, Salmonella enterica serovar Typhi, can partially subvert this critical innate immune recognition event. The transcriptional regulator TviA, which is absent from Salmonella serovars associated with human gastroenteritis, repressed the expression of flagellin during infection of human macrophage-like (THP-1) cells. This mechanism allowed S. Typhi to dampen inflammasome activation, leading to reduced interleukin-1β (IL-1β) secretion and diminished cell death. Likewise, the introduction of the tviA gene in nontyphoidal Salmonella enterica serovar Typhimurium reduced flagellin-induced pyroptosis. These data suggest that gene regulation of virulence factors enables S. Typhi to evade innate immune recognition by concealing a pathogen-induced process from being sensed by the inflammasome.

  6. High-Resolution Microbiome Profiling for Detection and Tracking of Salmonella enterica

    PubMed Central

    Grim, Christopher J.; Daquigan, Ninalynn; Lusk Pfefer, Tina S.; Ottesen, Andrea R.; White, James R.; Jarvis, Karen G.

    2017-01-01

    16S rRNA community profiling continues to be a useful tool to study microbiome composition and dynamics, in part due to advances in next generation sequencing technology that translate into reductions in cost. Reliable taxonomic identification to the species-level, however, remains difficult, especially for short-read sequencing platforms, due to incomplete coverage of the 16S rRNA gene. This is especially true for Salmonella enterica, which is often found as a low abundant member of the microbial community, and is often found in combination with several other closely related enteric species. Here, we report on the evaluation and application of Resphera Insight, an ultra-high resolution taxonomic assignment algorithm for 16S rRNA sequences to the species level. The analytical pipeline achieved 99.7% sensitivity to correctly identify S. enterica from WGS datasets extracted from the FDA GenomeTrakr Bioproject, while demonstrating 99.9% specificity over other Enterobacteriaceae members. From low-diversity and low-complexity samples, namely ice cream, the algorithm achieved 100% specificity and sensitivity for Salmonella detection. As demonstrated using cilantro and chili powder, for highly complex and diverse samples, especially those that contain closely related species, the detection threshold will likely have to be adjusted higher to account for misidentifications. We also demonstrate the utility of this approach to detect Salmonella in the clinical setting, in this case, bloodborne infections. PMID:28868052

  7. Subtyping of Salmonella enterica Subspecies I Using Single-Nucleotide Polymorphisms in Adenylate Cyclase

    PubMed Central

    Abdo, Zaid; Byers, Sara Overstreet; Kriebel, Patrick; Rothrock, Michael J.

    2016-01-01

    Abstract Methods to rapidly identify serotypes of Salmonella enterica subspecies I are of vital importance for protecting the safety of food. To supplement the serotyping method dkgB-linked intergenic sequence ribotyping (ISR), single-nucleotide polymorphisms were characterized within adenylate cyclase (cyaA). The National Center for Biotechnology Information (NCBI) database had 378 cyaA sequences from S. enterica subspecies I, which included 42 unique DNA sequences and 19 different amino acid sequences. Five representative isolates, namely serotypes Typhimurium, Kentucky, Enteritidis phage type PT4, and two variants of Enteritidis phage type PT13a, were differentiated within a microsphere-based fluidics system in cyaA by allele-specific primer extension. Validation against 25 poultry-related environmental Salmonella isolates representing 11 serotypes yielded a ∼89% success rate at identifying the serotype of the isolate, and a different region could be targeted to achieve 100%. When coupled with ISR, all serotypes were differentiated. Phage lineages of serotype Enteritidis 13a and 4 were identified, and a biofilm-forming strain of PT13a was differentiated from a smooth phenotype within phage type. Comparative ranking of mutation indices to genes such as the tRNA transferases, the diguanylate cyclases, and genes used for multilocus sequence typing indicated that cyaA is an appropriate gene for assessing epidemiological trends of Salmonella because of its relative stability in nucleotide composition. PMID:27035032

  8. High-Resolution Microbiome Profiling for Detection and Tracking of Salmonella enterica.

    PubMed

    Grim, Christopher J; Daquigan, Ninalynn; Lusk Pfefer, Tina S; Ottesen, Andrea R; White, James R; Jarvis, Karen G

    2017-01-01

    16S rRNA community profiling continues to be a useful tool to study microbiome composition and dynamics, in part due to advances in next generation sequencing technology that translate into reductions in cost. Reliable taxonomic identification to the species-level, however, remains difficult, especially for short-read sequencing platforms, due to incomplete coverage of the 16S rRNA gene. This is especially true for Salmonella enterica, which is often found as a low abundant member of the microbial community, and is often found in combination with several other closely related enteric species. Here, we report on the evaluation and application of Resphera Insight, an ultra-high resolution taxonomic assignment algorithm for 16S rRNA sequences to the species level. The analytical pipeline achieved 99.7% sensitivity to correctly identify S. enterica from WGS datasets extracted from the FDA GenomeTrakr Bioproject, while demonstrating 99.9% specificity over other Enterobacteriaceae members. From low-diversity and low-complexity samples, namely ice cream, the algorithm achieved 100% specificity and sensitivity for Salmonella detection. As demonstrated using cilantro and chili powder, for highly complex and diverse samples, especially those that contain closely related species, the detection threshold will likely have to be adjusted higher to account for misidentifications. We also demonstrate the utility of this approach to detect Salmonella in the clinical setting, in this case, bloodborne infections.

  9. Identification by PCR of Non-typhoidal Salmonella enterica Serovars Associated with Invasive Infections among Febrile Patients in Mali

    PubMed Central

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

    2010-01-01

    Background In sub-Saharan Africa, non-typhoidal Salmonella (NTS) are emerging as a prominent cause of invasive disease (bacteremia and focal infections such as meningitis) in infants and young children. Importantly, including data from Mali, three serovars, Salmonella enterica serovar Typhimurium, Salmonella Enteritidis and Salmonella Dublin, account for the majority of non-typhoidal Salmonella isolated from these patients. Methods We have extended a previously developed series of polymerase chain reactions (PCRs) based on O serogrouping and H typing to identify Salmonella Typhimurium and variants (mostly I 4,[5],12:i:-), Salmonella Enteritidis and Salmonella Dublin. We also designed primers to detect Salmonella Stanleyville, a serovar found in West Africa. Another PCR was used to differentiate diphasic Salmonella Typhimurium and monophasic Salmonella Typhimurium from other O serogroup B, H:i serovars. We used these PCRs to blind-test 327 Salmonella serogroup B and D isolates that were obtained from the blood cultures of febrile patients in Bamako, Mali. Principal Findings We have shown that when used in conjunction with our previously described O-serogrouping PCR, our PCRs are 100% sensitive and specific in identifying Salmonella Typhimurium and variants, Salmonella Enteritidis, Salmonella Dublin and Salmonella Stanleyville. When we attempted to differentiate 171 Salmonella Typhimurium (I 4,[ 5],12:i:1,2) strains from 52 monophasic Salmonella Typhimurium (I 4,[5],12:i:-) strains, we were able to correctly identify 170 of the Salmonella Typhimurium and 51 of the Salmonella I 4,[5],12:i:- strains. Conclusion We have described a simple yet effective PCR method to support surveillance of the incidence of invasive disease caused by NTS in developing countries. PMID:20231882

  10. ubiJ, a New Gene Required for Aerobic Growth and Proliferation in Macrophage, Is Involved in Coenzyme Q Biosynthesis in Escherichia coli and Salmonella enterica Serovar Typhimurium

    PubMed Central

    Aussel, Laurent; Loiseau, Laurent; Hajj Chehade, Mahmoud; Pocachard, Bérengère; Fontecave, Marc; Pierrel, Fabien

    2014-01-01

    Ubiquinone (coenzyme Q or Q8) is a redox active lipid which functions in the respiratory electron transport chain and plays a crucial role in energy-generating processes. In both Escherichia coli and Salmonella enterica serovar Typhimurium, the yigP gene is located between ubiE and ubiB, all three being likely to constitute an operon. In this work, we showed that the uncharacterized yigP gene was involved in Q8 biosynthesis in both strains, and we have renamed it ubiJ. Under aerobic conditions, an ubiJ mutant was found to be impaired for Q8 biosynthesis and for growth in rich medium but did not present any defect anaerobically. Surprisingly, the C-terminal 50 amino acids, predicted to interact with lipids, were sufficient to restore Q8 biosynthesis and growth of the ubiJ mutant. Salmonella ubiE and ubiB mutants were impaired in Q8 biosynthesis and in respiration using different electron acceptors. Moreover, ubiE, ubiJ, and ubiB mutants were all impaired for Salmonella intracellular proliferation in macrophages. Taken together, our data establish an important role for UbiJ in Q8 biosynthesis and reveal an unexpected link between Q8 and virulence. They also emphasize that Salmonella organisms in an intracellular lifestyle rely on aerobic respiration to survive and proliferate within macrophages. PMID:24142253

  11. 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

  12. Distribution and Characterization of Salmonella enterica Isolates from Irrigation Ponds in the Southeastern United States

    PubMed Central

    Luo, Zhiyao; Gu, Ganyu; Ginn, Amber; Giurcanu, Mihai C.; Adams, Paige; Vellidis, George; van Bruggen, Ariena H. C.; Danyluk, Michelle D.

    2015-01-01

    Irrigation water has been implicated as a likely source of produce contamination by Salmonella enterica. Therefore, the distribution of S. enterica was surveyed monthly in irrigation ponds (n = 10) located within a prime agricultural region in southern Georgia and northern Florida. All ponds and 28.2% of all samples (n = 635) were positive for Salmonella, with an overall geometric mean concentration (0.26 most probable number [MPN]/liter) that was relatively low compared to prior reports for rivers in this region. Salmonella peaks were seasonal; the levels correlated with increased temperature and rainfall (P < 0.05). The numbers and occurrence were significantly higher in water (0.32 MPN/liter and 37% of samples) than in sediment (0.22 MPN/liter and 17% of samples) but did not vary with depth. Representative isolates (n = 185) from different ponds, sample types, and seasons were examined for resistance to 15 different antibiotics; most strains were resistant to streptomycin (98.9%), while 20% were multidrug resistant (MDR) for 2 to 6 antibiotics. DiversiLab repetitive extragenic palindromic-element sequence-based PCR (rep-PCR) revealed genetic diversity and showed 43 genotypes among 191 isolates, as defined by >95% similarity. The genotypes did not partition by pond, season, or sample type. Genetic similarity to known serotypes indicated Hadar, Montevideo, and Newport as the most prevalent. All ponds achieved the current safety standards for generic Escherichia coli in agricultural water, and regression modeling showed that the E. coli level was a significant predictor for the probability of Salmonella occurrence. However, persistent populations of Salmonella were widely distributed in irrigation ponds, and the associated risks for produce contamination and subsequent human exposure are unknown, supporting continued surveillance of this pathogen in agricultural settings. PMID:25911476

  13. 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.

  14. DNA Sequence-Based Subtyping and Evolutionary Analysis of Selected Salmonella enterica Serotypes

    PubMed Central

    Sukhnanand, Sharinne; Alcaine, Sam; Warnick, Lorin D.; Su, Wan-Lin; Hof, Jessica; Craver, Mary Pat J.; McDonough, Patrick; Boor, Kathryn J.; Wiedmann, Martin

    2005-01-01

    While serotyping and phage typing have been used widely to characterize Salmonella isolates, sensitive subtyping methods that allow for evolutionary analyses are essential for examining Salmonella transmission, ecology, and evolution. A set of 25 Salmonella enterica isolates, representing five clinically relevant serotypes (serotypes Agona, Heidelberg, Schwarzengrund, Typhimurium, and Typhimurium var. Copenhagen) was initially used to develop a multilocus sequence typing (MLST) scheme for Salmonella targeting seven housekeeping and virulence genes (panB, fimA, aceK, mdh, icdA, manB, and spaN). A total of eight MLST types were found among the 25 isolates sequenced. A good correlation between MLST types and Salmonella serotypes was observed; only one serotype Typhimurium var. Copenhagen isolate displayed an MLST type otherwise typical for serotype Typhimurium isolates. Since manB, fimA, and mdh allowed for the highest subtype discrimination among the initial 25 isolates, we chose these three genes to perform DNA sequencing of an additional 41 Salmonella isolates representing a larger diversity of serotypes. This “three-gene sequence typing scheme” allowed discrimination of 25 sequence types (STs) among a total of 66 isolates; STs correlated well with serotypes and allowed within-serotype differentiation for 9 of the 12 serotypes characterized. Phylogenetic analyses showed that serotypes Kentucky and Newport could each be separated into two distinct, statistically well supported evolutionary lineages. Our results show that a three-gene sequence typing scheme allows for accurate serotype prediction and for limited subtype discrimination among clinically relevant serotypes of Salmonella. Three-gene sequence typing also supports the notion that Salmonella serotypes represent both monophyletic and polyphyletic lineages. PMID:16081897

  15. Effect of essential oil compound on shedding and colonization of Salmonella enterica serovar Heidelberg in broilers.

    PubMed

    Alali, W Q; Hofacre, C L; Mathis, G F; Faltys, G

    2013-03-01

    The objectives of this study were to determine the effect of an essential oil blend (EO; carvacrol, thymol, eucalyptol, lemon) administered in drinking water on the performance, mortality, water consumption, pH of crop and ceca, and Salmonella enterica serovar Heidelberg fecal shedding and colonization in broiler birds following Salmonella Heidelberg challenge and feed withdrawal. Chicks were randomly assigned to water treatments containing 0.05, 0.025, or 0.0125% EO or untreated controls. Treatments were administered in drinking water on 0 to 7 and 35 to 42 d. One-half of the chicks were challenged with Salmonella Heidelberg and placed in pens with unchallenged chicks on d 1. Performance, mortality, water consumption, and pH were determined during the 42-d study. Prevalence of Salmonella Heidelberg was determined on drag swabs (0, 14, and 42 d) and in the ceca and crops (42 d). The 0.05% EO administered in drinking water significantly (P < 0.05) reduced Salmonella Heidelberg colonization in crops of challenged birds, significantly lowered the feed conversion ratio, and increased weight gain compared with controls. The 0.025% and 0.015% EO in drinking water significantly lowered the feed conversion ratio and increased weight gain compared with controls, but did not significantly reduce Salmonella Heidelberg colonization in the crops. The EO in drinking water did not significantly reduce Salmonella Heidelberg colonization in ceca or fecal shedding in broilers. The EO used in the study may control Salmonella Heidelberg contamination in crops of broilers when administered in drinking water and therefore may reduce the potential for cross-contamination of the carcass when the birds are processed.

  16. 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.

  17. 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

  18. Preslaughter holding environment in pork plants is highly contaminated with Salmonella enterica.

    PubMed

    Rostagno, M H; Hurd, H S; McKean, J D; Ziemer, C J; Gailey, J K; Leite, R C

    2003-08-01

    The objective of this study was to determine whether abattoir pens can provide a Salmonella enterica infection source during the 2 to 4 h of preharvest holding. Previous work has suggested that pigs may be getting infected, but little has been reported on the environmental contamination of abattoir holding pens. For 24 groups of pigs studied ( approximately 150 animals/group) at two high-capacity abattoirs, six pooled fecal samples (n, 10 per pool) were collected from each transport trailer immediately after pigs were unloaded. Holding pens were sampled (one drinking water sample and six pooled floor samples consisting of swabs, residual liquid, and feces) prior to entry of study pigs for the routine holding period ( approximately 2.5 h). After slaughter, cecal contents and ileocecal lymph nodes were collected, on the processing line, from 30 pigs in each studied group. All samples were cultured for the isolation and identification of S. enterica by primary enrichment in GN-Hajna and tetrathionate broths, secondary enrichment in Rappaport-Vassiliadis broth, and plating on brilliant green sulfa and xylose-lysine-tergitol-4 agars, followed by biochemical and serological identification. The study pens were highly contaminated with S. enterica; all holding pens sampled had at least one positive sample. Additionally, 33% (8 of 24) of drinking water samples were positive for S. enterica. All 24 groups of pigs had S. enterica-positive cecal contents and ileocecal lymph nodes, including those groups from transport trailers with no positive samples. From pigs, trailers, and pens, 586 isolates representing 36 different Salmonella serovars were isolated. Of the 353 isolates from pigs (109 from ileocecal lymph nodes plus 244 from cecal contents), 19% were identified as belonging to the same serovars as those isolated from the respective pens; 27% were identified as belonging to the same serovars as those isolated from the trailers. Sixteen percent of the unique serovars were

  19. Accuracy and Sensitivity of Commercial PCR-Based Methods for Detection of Salmonella enterica in Feed ▿

    PubMed Central

    Koyuncu, Sevinc; Andersson, M. Gunnar; Häggblom, Per

    2010-01-01

    The present study compared the performance of commercial PCR-based Salmonella enterica detection methods (BAX System Q7, the iQ-Check Salmonella II kit, and the TaqMan Salmonella enterica detection kit) with culture-based methods (modified semisolid Rappaport-Vassiliadis [MSRV] and NMKL71) in spiked and naturally contaminated samples of feed mill scrapings (FMS), palm kernel meal (PKM), pelleted feed (PF), rape seed meal (RSM), soybean meal (SM), and wheat grain (WG). When results from the various feeds were compared, the number of Salmonella enterica CFU/25 g required to produce a positive were as follows: PKM > FMS = WG > RSM = SM = PF. These data are similar to those developed in earlier studies with culture-based Salmonella detection methods. PCR-based methods were performed similarly to culture-based methods, with respect to sensitivity and specificity. However, many PCR positives could not be confirmed by Salmonella isolation and for that reason the evaluated methods were found to be suitable only when rapid results were paramount. Nevertheless, PCR-based methods cannot presently replace culture-based methods when typing information is required for tracing studies or epidemiological investigations. The observed difference in detection levels is a potential problem when prevalence data are compared as well as when feed ingredients are tested for conformance with microbiological criteria. This paper also presents a statistical model that describes the detection probability when different levels (CFU) of Salmonella contamination are present in feed materials. PMID:20228106

  20. Cathelicidin antimicrobial peptide expression is not induced or required for bacterial clearance during salmonella enterica infection of human monocyte-derived macrophages.

    PubMed

    Strandberg, Kristi L; Richards, Susan M; Gunn, John S

    2012-11-01

    Salmonella enterica serovar Typhimurium is able to resist antimicrobial peptide killing by induction of the PhoP-PhoQ and PmrA-PmrB two-component systems and the lipopolysaccharide (LPS) modifications they mediate. Murine cathelin-related antimicrobial peptide (CRAMP) has been reported to inhibit S. Typhimurium growth in vitro and in vivo. We hypothesize that infection of human monocyte-derived macrophages (MDMs) with Salmonella enterica serovar Typhi and S. Typhimurium will induce human cathelicidin antimicrobial peptide (CAMP) production, and exposure to LL-37 (processed, active form of CAMP/hCAP18) will lead to upregulation of PmrAB-mediated LPS modifications and increased survival in vivo. Unlike in mouse macrophages, in which CRAMP is upregulated during infection, camp gene expression was not induced in human MDMs infected with S. Typhi or S. Typhimurium. Upon infection, intracellular levels of ΔphoPQ, ΔpmrAB, and PhoP(c) S. Typhi decreased over time but were not further inhibited by the vitamin D(3)-induced increase in camp expression. MDMs infected with wild-type (WT) S. Typhi or S. Typhimurium released similar levels of proinflammatory cytokines; however, the LPS modification mutant strains dramatically differed in MDM-elicited cytokine levels. Overall, these findings indicate that camp is not induced during Salmonella infection of MDMs nor is key to Salmonella intracellular clearance. However, the cytokine responses from MDMs infected with WT or LPS modification mutant strains differ significantly, indicating a role for LPS modifications in altering the host inflammatory response. Our findings also suggest that S. Typhi and S. Typhimurium elicit different proinflammatory responses from MDMs, despite being capable of adding similar modifications to their LPS structures.

  1. DNA Sequence Analysis of Plasmids from Multidrug Resistant Salmonella enterica Serotype Heidelberg Isolates

    PubMed Central

    David, Donna E.; Tang, Hailin; Xu, Joshua; Nayak, Rajesh; Kaldhone, Pravin; Logue, Catherine M.; Foley, Steven L.

    2012-01-01

    Salmonella enterica serovar Heidelberg is among the most detected serovars in swine and poultry, ranks among the top five serotypes associated with human salmonellosis and is disproportionately associated with invasive infections and mortality in humans. Salmonella are known to carry plasmids associated with antimicrobial resistance and virulence. To identify plasmid-associated genes in multidrug resistant S. enterica serovar Heidelberg, antimicrobial resistance plasmids from five isolates were sequenced using the 454 LifeSciences pyrosequencing technology. Four of the isolates contained incompatibility group (Inc) A/C multidrug resistance plasmids harboring at least eight antimicrobial resistance genes. Each of these strains also carried a second resistance plasmid including two IncFIB, an IncHI2 and a plasmid lacking an identified Inc group. The fifth isolate contained an IncI1 plasmid, encoding resistance to gentamicin, streptomycin and sulfonamides. Some of the IncA/C plasmids lacked the full concert of transfer genes and yet were able to be conjugally transferred, likely due to the transfer genes carried on the companion plasmids in the strains. Several non-IncA/C resistance plasmids also carried putative virulence genes. When the sequences were compared to previously sequenced plasmids, it was found that while all plasmids demonstrated some similarity to other plasmids, they were unique, often due to differences in mobile genetic elements in the plasmids. Our study suggests that Salmonella Heidelberg isolates harbor plasmids that co-select for antimicrobial resistance and virulence, along with genes that can mediate the transfer of plasmids within and among other bacterial isolates. Prevalence of such plasmids can complicate efforts to control the spread of S. enterica serovar Heidelberg in food animal and human populations. PMID:23251446

  2. Effect of desiccation on tolerance of salmonella enterica to multiple stresses.

    PubMed

    Gruzdev, Nadia; Pinto, Riky; Sela, Shlomo

    2011-03-01

    Reducing the available water in food is a long-established method for controlling bacterial growth in the food industry. Nevertheless, food-borne outbreaks of salmonellosis due to consumption of dry foods have been continuously reported. Previous studies showed that dried Salmonella cells acquire high tolerance to heat and ethanol. In order to examine if dehydration also induces tolerance to other stressors, dried Salmonella enterica serotype Typhimurium cells were exposed to multiple stresses, and their viability was assessed. Indeed, desiccated S. Typhimurium acquired higher tolerance to multiple stressors than nondesiccated cells. The dried cells were significantly more resistant to most stressors, including ethanol (10 to 30%, 5 min), sodium hypochlorite (10 to 100 ppm, 10 min), didecyl dimethyl ammonium chloride (0.05 to 0.25%, 5 min), hydrogen peroxide (0.5 to 2.0%, 30 min), NaCl (0.1 to 1 M, 2 h), bile salts (1 to 10%, 2 h), dry heat (100°C, 1 h), and UV irradiation (125 μW/cm(2), 25 min). In contrast, exposure of Salmonella to acetic and citric acids reduced the survival of the dried cells (1.5 log) compared to that of nondesiccated cells (0.5 log). Three other S. enterica serotypes, S. Enteritidis, S. Newport, and S. Infantis, had similar stress responses as S. Typhimurium, while S. Hadar was much more susceptible and gained tolerance to only a few stressors. Our findings indicate that dehydration induces cross-tolerance to multiple stresses in S. enterica, demonstrating the limitations of current chemical and physical treatments utilized by the food industry to inactivate food-borne pathogens.

  3. Effect of Desiccation on Tolerance of Salmonella enterica to Multiple Stresses▿

    PubMed Central

    Gruzdev, Nadia; Pinto, Riky; Sela, Shlomo

    2011-01-01

    Reducing the available water in food is a long-established method for controlling bacterial growth in the food industry. Nevertheless, food-borne outbreaks of salmonellosis due to consumption of dry foods have been continuously reported. Previous studies showed that dried Salmonella cells acquire high tolerance to heat and ethanol. In order to examine if dehydration also induces tolerance to other stressors, dried Salmonella enterica serotype Typhimurium cells were exposed to multiple stresses, and their viability was assessed. Indeed, desiccated S. Typhimurium acquired higher tolerance to multiple stressors than nondesiccated cells. The dried cells were significantly more resistant to most stressors, including ethanol (10 to 30%, 5 min), sodium hypochlorite (10 to 100 ppm, 10 min), didecyl dimethyl ammonium chloride (0.05 to 0.25%, 5 min), hydrogen peroxide (0.5 to 2.0%, 30 min), NaCl (0.1 to 1 M, 2 h), bile salts (1 to 10%, 2 h), dry heat (100°C, 1 h), and UV irradiation (125 μW/cm2, 25 min). In contrast, exposure of Salmonella to acetic and citric acids reduced the survival of the dried cells (1.5 log) compared to that of nondesiccated cells (0.5 log). Three other S. enterica serotypes, S. Enteritidis, S. Newport, and S. Infantis, had similar stress responses as S. Typhimurium, while S. Hadar was much more susceptible and gained tolerance to only a few stressors. Our findings indicate that dehydration induces cross-tolerance to multiple stresses in S. enterica, demonstrating the limitations of current chemical and physical treatments utilized by the food industry to inactivate food-borne pathogens. PMID:21216905

  4. 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

  5. The Response to 2-Aminoacrylate Differs in Escherichia coli and Salmonella enterica, despite Shared Metabolic Components.

    PubMed

    Borchert, Andrew J; Downs, Diana M

    2017-07-15

    The metabolic network of an organism includes the sum total of the biochemical reactions present. In microbes, this network has an impeccable ability to sense and respond to perturbations caused by internal or external stimuli. The metabolic potential (i.e., network structure) of an organism is often drawn from the genome sequence, based on the presence of enzymes deemed to indicate specific pathways. Escherichia coli and Salmonella enterica are members of the Enterobacteriaceae family of Gram-negative bacteria that share the majority of their metabolic components and regulatory machinery as the "core genome." In S. enterica, the ability of the enamine intermediate 2-aminoacrylate (2AA) to inactivate a number of pyridoxal 5'-phosphate (PLP)-dependent enzymes has been established in vivo In this study, 2AA metabolism and the consequences of its accumulation were investigated in E. coli The data showed that despite the conservation of all relevant enzymes, S. enterica and E. coli differed in both the generation and detrimental consequences of 2AA. In total, these findings suggest that the structure of the metabolic network surrounding the generation and response to endogenous 2AA stress differs between S. enterica and E. coliIMPORTANCE This work compared the metabolic networks surrounding the endogenous stressor 2-aminoacrylate in two closely related members of the Enterobacteriaceae The data showed that despite the conservation of all relevant enzymes in this metabolic node, the two closely related organisms diverged in their metabolic network structures. This work highlights how a set of conserved components can generate distinct network architectures and how this can impact the physiology of an organism. This work defines a model to expand our understanding of the 2-aminoacrylate stress response and the differences in metabolic structures and cellular milieus between S. enterica and E. coli. Copyright © 2017 American Society for Microbiology.

  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.

  7. 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

  8. Regulatory and Structural Differences in the Cu,Zn-Superoxide Dismutases of Salmonella enterica and Their Significance for Virulence*S⃞

    PubMed Central

    Ammendola, Serena; Pasquali, Paolo; Pacello, Francesca; Rotilio, Giuseppe; Castor, Margaret; Libby, Stephen J.; Figueroa-Bossi, Nara; Bossi, Lionello; Fang, Ferric C.; Battistoni, Andrea

    2008-01-01

    Many of the most virulent strains of Salmonella enterica produce two distinct Cu,Zn-superoxide dismutases (SodCI and SodCII). The bacteriophage-encoded SodCI enzyme makes the greater contribution to Salmonella virulence. We have performed a detailed comparison of the functional, structural, and regulatory properties of the Salmonella SodC enzymes. Here we demonstrate that SodCI and SodCII differ with regard to specific activity, protease resistance, metal affinity, and peroxidative activity, with dimeric SodCI exhibiting superior stability and activity. In particular, monomeric SodCII is unable to retain its catalytic copper ion in the absence of zinc. We have also found that SodCI and SodCII are differentially affected by oxygen, zinc availability, and the transcriptional regulator FNR. SodCII is strongly down-regulated under anaerobic conditions and dependent on the high affinity ZnuABC zinc transport system, whereas SodCI accumulation in vitro and within macrophages is FNR-dependent. We have confirmed earlier findings that SodCII accumulation in intracellular Salmonella is negligible, whereas SodCI is strongly up-regulated in macrophages. Our observations demonstrate that differences in expression, activity, and stability help to account for the unique contribution of the bacteriophage-encoded SodCI enzyme to Salmonella virulence. PMID:18362154

  9. Outbreak of Salmonella enterica serotype Manhattan infection associated with meat products, France, 2005.

    PubMed

    Noël, H; Dominguez, M; Weill, F X; Brisabois, A; Duchazeaubeneix, C; Kerouanton, A; Delmas, G; Pihier, N; Couturier, E

    2006-01-01

    Between August 2005 and March 2006 in France, 69 cases of Salmonella enterica serotype Manhattan (Salmonella Manhattan) were reported, 51 (74%) of them from southeastern France. At the time of the alert (November 2005), 13 cases and 33 controls were interviewed. Cases were more likely than controls to have eaten pork sausages (OR=5.9, confidence interval CI [1.3; 26.9]) and beef (OR=9.3, CI [1.3; 68.6]). At the same time, 19 strains of Salmonella Manhattan isolated from meat products in southeastern France, reported to the French food safety agency (Afssa, Agence francaise de securite sanitaire des aliments) in September and November 2005, had an indistinguishable PFGE profile to the 7 human isolates of Salmonella Manhattan from the outbreak in southeastern France. Trace-back investigations revealed that pork samples came from one wholesaler whose pork products had tested positive for S. Manhattan during routine food testing in August 2005. This wholesaler supplied retail outlets in southeastern France. Additionally, a slaughterhouse supplying the wholesaler was inspected and widespread contamination with Salmonella spp. and S. Manhattan was found. Cooperation between the national agencies in charge of human health (Institut de veille sanitaire, InVS) and food safety (Afssa) allowed us to determine the most probable source of contamination and to take appropriate control measures.

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

    PubMed

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

    2013-11-01

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

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

    PubMed Central

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

    2011-01-01

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

  12. Survival of Campylobacter jejuni and Salmonella enterica Typhimurium in vacuum-packed, moisture-enhanced pork.

    PubMed

    Wen, Xuesong; Dickson, James S

    2012-03-01

    The abilities of Campylobacter jejuni and Salmonella enterica Typhimurium to survive in vacuum-packaged, moisture-enhanced pork stored at 4 or 10°C were examined. Pork loins were surface inoculated with either C. jejuni or Salmonella Typhimurium and then moisture enhanced to a target of 10 or 20%. The enhanced pork loins were sliced 1 cm thick and vacuum packaged. A pork loin without moisture enhancement was sliced and vacuum packaged as a control. Samples were collected, plated, and the numbers of surviving organisms were determined periodically during storage at 4 and 10°C. The numbers of C. jejuni or Salmonella Typhimurium in samples with different moisture enhancement levels were similar (P > 0.05). No significant differences (P > 0.05) in C. jejuni counts were observed between samples at 10°C and those at 4°C. In contrast, the numbers of Salmonella Typhimurium in samples at 10°C had significantly (P < 0.05) increased (0.41 log CFU/g) from those at the refrigerated temperature of 4°C. Vacuum storage at 4 and 10°C for 28 days did not result in dramatic reductions in the mean numbers of C. jejuni and Salmonella Typhimurium. Our findings indicate that vacuum packaging under chilled conditions will not add substantially to safety for moisture-enhanced pork. Strict hygienic practices or the implementation of decontamination technologies is recommended.

  13. 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.

  14. Characterization of DalS, an ATP-binding Cassette Transporter for d-Alanine, and Its Role in Pathogenesis in Salmonella enterica*

    PubMed Central

    Osborne, Suzanne E.; Tuinema, Brian R.; Mok, Mac C. Y.; Lau, Pui Sai; Bui, Nhat Khai; Tomljenovic-Berube, Ana M.; Vollmer, Waldemar; Zhang, Kun; Junop, Murray; Coombes, Brian K.

    2012-01-01

    Expansion into new host niches requires bacterial pathogens to adapt to changes in nutrient availability and to evade an arsenal of host defenses. Horizontal acquisition of Salmonella Pathogenicity Island (SPI)-2 permitted the expansion of Salmonella enterica serovar Typhimurium into the intracellular environment of host cells by allowing it to deliver bacterial effector proteins across the phagosome membrane. This is facilitated by the SsrA-SsrB two-component regulatory system and a type III secretion system encoded within SPI-2. SPI-2 acquisition was followed by evolution of existing regulatory DNA, creating an expanded SsrB regulon involved in intracellular fitness and host infection. Here, we identified an SsrB-regulated operon comprising an ABC transporter in Salmonella. Biochemical and structural studies determined that the periplasmic solute-binding component, STM1633/DalS, transports d-alanine and that DalS is required for intracellular survival of the bacteria and for fitness in an animal host. This work exemplifies the role of nutrient exchange at the host-pathogen interface as a critical determinant of disease outcome. PMID:22418438

  15. Extended-Spectrum Cephalosporin-Resistant Salmonella enterica serovar Heidelberg Strains, the Netherlands1

    PubMed Central

    Geurts, Yvon; Dierikx, Cindy M.; Brouwer, Michael S.M.; Kant, Arie; Wit, Ben; Heymans, Raymond; van Pelt, Wilfrid; Mevius, Dik J.

    2016-01-01

    Extended-spectrum cephalosporin-resistant Salmonella enterica serovar Heidelberg strains (JF6X01.0022/XbaI.0251, JF6X01.0326/XbaI.1966, JF6X01.0258/XbaI.1968, and JF6X01.0045/XbaI.1970) have been identified in the United States with pulsed-field gel electrophoresis. Our examination of isolates showed introduction of these strains in the Netherlands and highlight the need for active surveillance and intervention strategies by public health organizations. PMID:27314180

  16. 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.

  17. Development of triclosan and antibiotic resistance in Salmonella enterica serovar Typhimurium.

    PubMed

    Birosová, Lucia; Mikulásová, Mária

    2009-04-01

    The possible association between the use of triclosan and the development of antibiotic resistance was examined in triclosan-resistant mutants of Salmonella enterica serovar Typhimurium. These mutants were obtained from a sensitive parental strain and from ciprofloxacin-resistant isogenic strains using spontaneous mutagenesis or selection after one short exposure or continuous exposure to low concentrations of triclosan. The results showed that triclosan in the environment does not increase the mutation frequency but selects bacterial strains with reduced antibiotic susceptibility. This property depended on the multiple antibiotic resistance (Mar) phenotype of bacterial strains and on the triclosan concentration.

  18. Purulent Pericarditis with Salmonella enterica Subspecies arizona in a Patient with Type 2 Diabetes Mellitus.

    PubMed

    Suzuki, Ai; Tanaka, Takamitsu; Ohba, Kenji; Ito, Naomi; Sakai, Yuki; Kaneko, Akane; Machii, Masashi; Nonaka, Daishi; Goto, Yoshie; Takase, Hiroyuki

    2017-08-15

    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.

  19. 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

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

    PubMed

    Salehi, Sanaz; Howe, Kevin; Lawrence, Mark L; Brooks, John P; Bailey, R Hartford; Karsi, Attila

    2017-01-15

    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 of the main factors that contribute to bacterial attachment to broiler skin. However, the precise role of flagella and the mechanism of attachment are unknown. There are two different flagellar subunits (fliC and fljB) expressed alternatively in Salmonella enterica serovars using phase variation. Here, by making deletions in genes encoding flagellar structural subunits (flgK, fliC, and fljB), and flagellar motor (motA), we were able to differentiate the role of flagella and their rotary motion in the colonization of broiler skin and cellular attachment. Utilizing a broiler skin assay, we demonstrated that the presence of FliC is necessary for attachment to broiler skin. Expression of the alternative flagellar subunit FljB enables Salmonella motility, but this subunit is unable to mediate tight attachment. Deletion of the flgK gene prevents proper flagellar assembly, making Salmonella significantly less adherent to broiler skin than the wild type. S Kentucky with deletions in all three structural genes, fliC, fljB, and flgK, as well as a flagellar motor mutant (motA), exhibited less adhesion and invasion of Caco-2 cells, while an fljB mutant was as adherent and invasive as the wild-type strain. In this work, we answered clearly the role of flagella in S Kentucky attachment to the chicken skin and Caco-2 cells. We demonstrated that the presence of FliC is necessary for attachment to broiler skin. Expression of the alternative flagellar subunit FljB enables Salmonella motility, but this subunit is unable to mediate strong attachment. Deletion of the flgK gene prevents proper flagellar assembly, making Salmonella significantly less adherent to broiler skin than the wild

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

    PubMed Central

    Salehi, Sanaz; Howe, Kevin; Lawrence, Mark L.; Brooks, John P.

    2016-01-01

    ABSTRACT 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 of the main factors that contribute to bacterial attachment to broiler skin. However, the precise role of flagella and the mechanism of attachment are unknown. There are two different flagellar subunits (fliC and fljB) expressed alternatively in Salmonella enterica serovars using phase variation. Here, by making deletions in genes encoding flagellar structural subunits (flgK, fliC, and fljB), and flagellar motor (motA), we were able to differentiate the role of flagella and their rotary motion in the colonization of broiler skin and cellular attachment. Utilizing a broiler skin assay, we demonstrated that the presence of FliC is necessary for attachment to broiler skin. Expression of the alternative flagellar subunit FljB enables Salmonella motility, but this subunit is unable to mediate tight attachment. Deletion of the flgK gene prevents proper flagellar assembly, making Salmonella significantly less adherent to broiler skin than the wild type. S. Kentucky with deletions in all three structural genes, fliC, fljB, and flgK, as well as a flagellar motor mutant (motA), exhibited less adhesion and invasion of Caco-2 cells, while an fljB mutant was as adherent and invasive as the wild-type strain. IMPORTANCE In this work, we answered clearly the role of flagella in S. Kentucky attachment to the chicken skin and Caco-2 cells. We demonstrated that the presence of FliC is necessary for attachment to broiler skin. Expression of the alternative flagellar subunit FljB enables Salmonella motility, but this subunit is unable to mediate strong attachment. Deletion of the flgK gene prevents proper flagellar assembly, making Salmonella significantly less adherent to broiler

  2. In vitro synergism of ciprofloxacin and cefotaxime against nalidixic acid-resistant Salmonella enterica serotypes Paratyphi A and Paratyphi B.

    PubMed

    Neupane, Ganesh Prasad; Kim, Dong-Min; Kim, Sung Hun; Lee, Bok Kwon

    2010-09-01

    Paratyphoid fever is considered an emerging systemic intracellular infection caused by Salmonella enterica serotypes Paratyphi A, B, and C. We performed in vitro time-kill studies on three clinical isolates of nalidixic acid-resistant Salmonella serotype Paratyphi (NARSP) with different concentrations of ciprofloxacin and cefotaxime to identify combinations of antibiotics with synergistic activity against paratyphoid fever. Furthermore, we identify the frequency of mutations to ciprofloxacin, cefotaxime, and rifampin resistance and also sequenced the gyrA, gyrB, parC, and parE genes to identify the cause of resistance in NARSP. When the activity of ciprofloxacin at 0.75x MIC (0.012 to 0.38 microg/ml) with cefotaxime at the MIC (0.125 to 0.25 microg/ml) against all three NARSP isolates was investigated, synergy was observed at 24 h, and the bacterial counts were reduced by >3 log(10) CFU/ml. This synergy was elongated for up to 72 h in two out of three isolates. When ciprofloxacin at 0.75x MIC (0.012 to 0.38 microg/ml) was combined with cefotaxime at 2x MIC (0.25 to 0.50 microg/ml), synergy was prolonged for up to 72 h in all three isolates. Both Salmonella serotype Paratyphi A isolates carried single mutations in codon 83 of the gyrA gene and codon 84 of the parC gene that were responsible for their reduced susceptibility to ciprofloxacin, while no mutations were found in the gyrB or parE gene. The ciprofloxacin-plus-cefotaxime regimen was very effective in reducing the bacterial counts at 24 h for all three isolates, and this combination therapy may be helpful in reducing the chance of the emergence of fluoroquinolone-resistant mutants in patients with severe paratyphoid fever.

  3. Proteomic Investigation of the Time Course Responses of RAW 264.7 Macrophages to Infection with Salmonella enterica

    SciTech Connect

    Shi, Liang; Chowdhury, Saiful M.; Smallwood, Heather S.; Yoon, Hyunjin; Mottaz-Brewer, Heather M.; Norbeck, Angela D.; McDermott, Jason E.; Clauss, Therese RW; Heffron, Fred; Smith, Richard D.; Adkins, Joshua N.

    2009-08-01

    Macrophages plan important roles in controlling Salmonella-mediated systemic infection. To investigate the responses of macrophages to Salmonella infection, we infected RAW 264.7 macrophages with Salmonella enterica serovar Typhimurium (STM) and then performed a comparative liquid chromatography-tandem mass spectrometry [LC-MS(/MS)]-based proteomics analysis of the infected macrophages. A total of 1006 macrophage and 115 STM proteins were indentified from this study. Most of STM proteins were found at late stage of the time course of infection, consistent with the fact that STM proliferates inside RAW 264.7 macrophages. Majority of the identified macrophage proteins were house keeping-related, including cytoplasmic superoxide dismutase 1 (SOD1), whose peptide abundances were relatively constant during the time course of infection. Compared to those in no infection control, the peptide abundances of 244 macrophage proteins (or 24% of total indentified macrophage proteins) changed considerably after STM infection. The functions of these STM infection-affected macrophage proteins were diverse and ranged from production of antibacterial nitric oxide (i.e., inducible nitric oxide synthase or iNOS) or production of prostaglandin H2 (i.e., prostaglandin-endoperoxide synthase 2, also know as cyclooxygenase-2 or COX-2) to regulation of intracellular traffic (e.g., sorting nexin or SNX 5, 6 and 9), demonstrating a global impact of STM infection on macrophage proteome. Western-blot analysis not only confirmed the LC-MS(/MS) results of SOD1, COX-2 and iNOS, but also revealed that the protein abundances of mitochondrial SOD2 increased after STM infection, indicating an infection-induced oxidative stress in mitochondria.

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

    PubMed

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

    2016-04-01

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

  5. Diagnostic and Public Health Dilemma of Lactose-Fermenting Salmonella enterica Serotype Typhimurium in Cattle in the Northeastern United States

    PubMed Central

    McDonough, Patrick L.; Shin, Sang J.; Lein, Donald H.

    2000-01-01

    The presence of lactose-fermenting Salmonella strains in clinical case materials presented to microbiology laboratories presents problems in detection and identification. Failure to detect these strains also presents a public health problem. The laboratory methods used in detecting lactose-fermenting Salmonella enterica serotype Typhimurium from six outbreaks of salmonellosis in veal calves are described. Each outbreak was caused by a multiply-resistant and lactose-fermenting strain of S. enterica serotype Typhimurium. The use of Levine eosin-methylene blue agar in combination with screening of suspect colonies for C8 esterase enzyme and inoculation of colonies into sulfide-indole-motility medium for hydrogen sulfide production was particularly effective for their detection. A hypothesis for the creation of lactose-fermenting salmonellae in the environment is presented. It is proposed that the environment and husbandry practices of veal-raising barns provide a unique niche in which lactose-fermenting salmonellae may arise. PMID:10699026

  6. Application of molecular methods for identification of strains classified as Salmonella enterica serovar 6, 7:-:- by conventional serotyping.

    PubMed

    Chadfield, M S; Christensen, J P; Madsen, M; Sonne-Hansen, J; Bisgaard, M

    2002-06-01

    An increased prevalence of Salmonella enterica serovar Tennessee (6, 7: z(29):-) was observed in broiler flocks in Denmark in 1994 and a parallel increase in the prevalence of Salmonella enterica serovar 6, 7:-:- was demonstrated, albeit at a lower level. Plasmid profiling and ribotyping revealed similar genotypes and it was speculated that serovar 6, 7:-:- could represent a non-motile variant of Salmonella Tennessee. Re-testing of the Salmonella 6, 7:-:- isolates demonstrated the presence of flagella through positive motility. All isolates but one demonstrated motility using both tube tests and light microscopy of overnight broth cultures. Molecular characterization indicated that all but two isolates previously classified as Salmonella 6, 7:-:, were isolates of Salmonella Tennessee and Salmonella Infantis, exhibiting reduced motility. Re-serotyping and multiplex polymerase chain reaction analysis for the phase 2 gene fljB demonstrated variants of Salmonella Infantis (6, 7: r: z(49)) expressing the R-phase antigen (Rz(49)) and possessing the gene for normal phase 2 antigen H: 1, 5. One of the two undefined strains demonstrated genotypic identity with a Salmonella Livingstone reference strain. The remaining putative 6, 7:-:- strain could not be identified and was genuinely non-motile. Diagnostic procedures performed initially were thus insufficient to differentiate between the different levels of motility and also resulted in mis-serotyping. As similar observations were made with two of 14 isolates received from a foreign laboratory, this may represent a general diagnostic problem.

  7. Adaptive resistance to biocides in Salmonella enterica and Escherichia coli O157 and cross-resistance to antimicrobial agents.

    PubMed

    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.

  8. Effect of short-term lairage on the prevalence of Salmonella enterica in cull sows.

    PubMed

    Larsen, S T; Hurd, H S; McKean, J D; Griffith, R W; Wesley, I V

    2004-07-01

    This study was designed to compare Salmonella enterica prevalence in sows held in a holding pen at the abattoir for approximately 2 h (hold sows) with sows slaughtered immediately after transport to the abattoir (no-hold sows). Cull sows (n = 160) were sampled from four sampling periods over 8 weeks (February to March 2002) at the abattoir. Sows originated from an integrated swine farm and were sent to a live-hog market and then to the slaughter facility. Before testing, sows entered the abattoir pen and four 100-cm2 four-ply gauze squares were placed randomly on the pen floor for S. enterica culture. Sows were alternatively assigned to the hold or no-hold group. Samples collected from sows during slaughter were ileocecal lymph node, cecal contents, transverse colon contents, subiliac lymph node, sponge swabs of the left and right carcass section (300 cm2), and chopped meat. Overall, S. enterica was isolated from 44% (35 of 80) of the no-hold sows, which was significantly less (P < 0.05) than 59% (47 of 80) of the held sows. Also, no-hold sows had a lower cecal content prevalence (39%, 31 of 80) compared with that (55%, 44 of 80) of held sows (P < 0.05). S. enterica serovars isolated from no-hold sows were Brandenburg (n = 16), Derby (n = 12), Hadar (n = 8), Infantis (n = 6), Johannesburg (n = 3), 6,7:z10-monophasic (n = 3), and Typhimurium (n = 1). S. enterica serovars isolated from held sows (n = 61 isolates) were Derby (n = 19), 6,7: z10-monophasic (n = 15), Brandenburg (n = 10), Infantis (n = 6), Hadar (n = 5), Johannesburg (n = 4), and Tennessee (n = 2). Serovars recovered from the pen were Reading (n = 6), Derby (n = 4), Uganda (n = 2), and Manhattan (n = 2). Results of this study suggest that holding pens contribute to increased S. enterica carriage in cull sows. Abattoir holding pens might be an important control point for S. enterica in the ground pork production chain.

  9. 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

  10. Virulent Salmonella enterica Serovar Typhimurium Evades Adaptive Immunity by Preventing Dendritic Cells from Activating T Cells

    PubMed Central

    Tobar, Jaime A.; Carreño, Leandro J.; Bueno, Susan M.; González, Pablo A.; Mora, Jorge E.; Quezada, Sergio A.; Kalergis, Alexis M.

    2006-01-01

    Dendritic cells (DCs) constitute the link between innate and adaptive immunity by directly recognizing pathogen-associated molecular patterns (PAMPs) in bacteria and by presenting bacterial antigens to T cells. Recognition of PAMPs renders DCs as professional antigen-presenting cells able to prime naïve T cells and initiate adaptive immunity against bacteria. Therefore, interfering with DC function would promote bacterial survival and dissemination. Understanding the molecular mechanisms that have evolved in virulent bacteria to evade activation of adaptive immunity requires the characterization of virulence factors that interfere with DC function. Salmonella enterica serovar Typhimurium, the causative agent of typhoid-like disease in the mouse, can prevent antigen presentation to T cells by avoiding lysosomal degradation in DCs. Here, we show that this feature of virulent Salmonella applies in vivo to prevent activation of adaptive immunity. In addition, this attribute of virulent Salmonella requires functional expression of a type three secretion system (TTSS) and effector proteins encoded within the Salmonella pathogenicity island 2 (SPI-2). In contrast to wild-type virulent Salmonella, mutant strains carrying specific deletions of SPI-2 genes encoding TTSS components or effectors proteins are targeted to lysosomes and are no longer able to prevent DCs from activating T cells in vitro or in vivo. SPI-2 mutant strains are attenuated in vivo, showing reduced tissue colonization and enhanced T-cell activation, which confers protection against a challenge with wild-type virulent Salmonella. Our data suggest that impairment of DC function by the activity of SPI-2 gene products is crucial for Salmonella pathogenesis. PMID:17057096

  11. Occurrence of purulent arthritis broilers vertically infected with Salmonella enterica serovar Enteritidis in Korea.

    PubMed

    Oh, J-Y; Kang, M-S; An, B-K; Song, E-A; Kwon, J-H; Kwon, Y-K

    2010-10-01

    Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) has been associated with morbidity and mortality in broiler chickens worldwide. The present study described purulent arthritis of broilers infected with Salmonella Enteritidis and investigated antibiograms and genetic characteristics of Salmonella Enteritidis isolates from epidemiologically related properties such as a hatchery and breeder farm in an attempt to elucidate the source of contamination. Clinical disease and mortality were observed in the affected broiler flock. Mortality was 5.8% until 12 d of age. The birds typically showed lameness with moderately swollen hock joints and footpads. The most prevalent lesions were severely purulent arthritis with polyserositis. Histopathology revealed moderate to severe inflammation in the synovial membrane of leg joints and visceral organs. When the antimicrobial susceptibility test was performed against 7 isolates of Salmonella Enteritidis from broilers, and relevant hatchery and breeder farms by the disk diffusion method using 18 antimicrobial agents, isolates from broiler and breeder farms had the same antibiogram characterized by multiple drug resistance to ampicillin, ceftiofur, cephalothin, gentamycin, nalidixic acid, streptomycin, sulfisoxazole, and tetracycline, whereas isolates from the hatchery were differently resistant to only nalidixic acid. Through the genetic analysis with pulsed-field gel electrophoresis using the restriction enzyme XbaI, Salmonella Enteritidis isolates from both broiler and breeder farms also showed the same PFGE pattern compared with the hatchery isolates resistant to nalidixic acid. As a result, the same PFGE profiles and antibiogram patterns among isolates from broilers and breeder farms provided direct evidence of vertical Salmonella Enteritidis transmission from the contaminated breeder farm to commercial broiler.

  12. Isolation of Salmonella enterica serovar Enteritidis in blue-fronted Amazon parrot (Amazona aestiva).

    PubMed

    Marietto-Gonçalves, Guilherme Augusto; de Almeida, Sílvia Maria; de Lima, Edna Tereza; Okamoto, Adriano Sakai; Pinczowski, Pedro; Andreatti Filho, Raphael Lucio

    2010-03-01

    Avian salmonellosis is a disease caused by bacteria of the genus Salmonella that can cause three distinct diseases in birds: pullorum diseases, fowl typhoid, and paratyphoid infection. Various wildlife species are susceptible to infections by Salmonella, regardless of whether they live in captivity or freely in the wild. The present study verified the presence of Salmonella enterica serovar Enteritidis in three captive specimens of Amazona aestiva. The study involved a total of 103 birds undergoing rehabilitation to prepare for living in the wild, after having been captured from animal traffickers and delivered to the Centrofauna Project of the Floravida Institute in Sao Paulo, Brazil. This is the first report of Salmonella Enteritidis isolation in A. aestiva that originated from capture associated with animal trafficking; Salmonella was detected during the study by the serologic method of rapid serum agglutination on a plate with bacterial isolate. The antimicrobial profile exam of the isolated samples demonstrated sensitivity to ampicillin, cefaclor, ciprofloxacin, and cloranfenicol. The three samples also presented resistance to more than four antibiotics. The presence of the genes invA and spvC was verified by PCR technique and was associated with virulence and absence of class 1 integron, a gene related to antimicrobial resistance. The commercial antigen for pullorum disease was shown to be a useful tool for rapid detection in the screening of Salmonella of serogroup D1 in Psittaciformes. New studies on Salmonella carriage in birds involved in trafficking must be performed to better understand their participation in the epidemiologic cycle of salmonellosis in humans and other animals.

  13. Salmonella Enterica Serovar Pomona Infection in Farmed Juvenile American Alligators ( Alligator Mississippiensis).

    PubMed

    Sakaguchi, K; Nevarez, J G; Del Piero, F

    2017-03-01

    A fatal epizootic of salmonellosis occurred in farmed juvenile American alligators in Louisiana. Six animals were examined. Gross lesions included severe fibrinonecrotizing enterocolitis, necrotizing splenitis, coelomic effusion, and perivisceral and pulmonary edema. Microscopic examination revealed severe necrotizing enterocolitis and splenitis with intralesional bacteria and pneumocyte necrosis with fibrin thrombi. Salmonella enterica serovar Pomona was isolated from intestine and lung. Clinical salmonellosis is a rare finding in reptiles and salmonellosis caused by S. Pomona is not previously reported in American alligators. Since S. Pomona is a commonly isolated Salmonella serotype from patients with reptile-associated salmonellosis in the United States, and since alligator meat is consumed and the skin is exported to numerous countries, risk of human and animal infection should be considered.

  14. Identification of in vivo-induced genes during infection of chickens with Salmonella enterica serovar Enteritidis.

    PubMed

    Geng, Shizhong; Liu, Zhicheng; Lin, Zhijie; Barrow, Paul; Pan, Zhiming; Li, Qiuchun; Jiao, Xinan

    2015-06-01

    Chickens are an important source of food worldwide and are often infected with food-poisoning serovars of Salmonella enterica, frequently Salmonella Enteritidis (SE), without exhibiting clinical signs of disease. Ivi (in vivo induced) genes identified using in vivo-induced antigen technology (IVIAT) are expressed only during bacterial infection and have the potential value of identifying epidemic strains and antigens which can form the basis for sub-unit vaccine development. We applied IVIAT to SE strain 50041 and identified 42 ivi genes. Eight representative ivi genes were further confirmed by qRT-PCR as being expressed only in vivo within 48 h of infection compared with that of in vitro-cultured. Although our results indicated that the identified ivi genes are expressed only in vivo, further research is needed to elucidate the exact roles of these genes during infection and pathogenesis.

  15. 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.

  16. Heat tolerance of Salmonella enterica serovars Agona, Enteritidis, and Typhimurium in peanut butter.

    PubMed

    Shachar, Dina; Yaron, Sima

    2006-11-01

    Recent large foodborne outbreaks caused by Salmonella enterica serovars have been associated with consumption of foods with high fat content and reduced water activity, even though their ingredients usually undergo pasteurization. The present study was focused on the heat tolerance of Salmonella enterica serovars Agona, Enteritidis, and Typhimurium in peanut butter. The Salmonella serovars in the peanut butter were resistant to heat, and even at a temperature as high as 90 degrees C only 3.2-log reduction in CFU was observed. The obtained thermal inactivation curves were upwardly concave, indicating rapid death at the beginning (10 min) followed by lower death rates and an asymptotic tail. The curves fitted the nonlinear Weibull model with beta parameters < 1, indicating that the remaining cells have a lower probability of dying. beta at 70 degrees C (0.40 +/- 0.04) was significantly lower than beta at 80 degrees C (0.73 +/- 0.19) and 90 degrees C (0.69 +/- 0.17). Very little decrease in the viable population (less than 2-log decrease) was noted in cultures that were exposed to a second thermal treatment. Peanut butter is a highly concentrated colloidal suspension of lipid and water in a peanut meal phase. We hypothesized that differences in the local environments of the bacteria, with respect to fat content or water activity, explained the observed distribution and high portion of surviving cells (0.1%, independent of the initial cell number). These results demonstrate that thermal treatments are inadequate to consistently destroy Salmonella in highly contaminated peanut butter and that the pasteurization process cannot be improved significantly by longer treatment or higher temperatures.

  17. An outbreak of gastroenteritis caused by Salmonella enterica serotype Enteritidis traced to cream cakes

    PubMed Central

    Chan, Pei Pei; Kurupatham, Lalitha; Foong, Bok Huay; Ooi, Peng Lim; James, Lyn; Phua, Leslie; Tan, Ai Ling; Koh, Diana; Goh, Kee Tai

    2011-01-01

    Introduction This paper describes the epidemiological, microbiological and environmental investigations conducted during an outbreak of Salmonella gastroenteritis in Singapore. Methods A case-control study was undertaken to identify the vehicle of transmission. Microbiological testing was performed on faecal, food and environmental samples. Isolates of Salmonella were further characterized by phage typing and ribotyping. Results There were 216 gastroenteritis cases reported from 20 November to 4 December 2007. The causative agent was identified as Salmonella enterica subspecies enterica serotype Enteritidis for 14 out of 20 cases tested. The vehicle of transmission was traced to cream cakes produced by a bakery and sold at its retail outlets (P < 0.001, OR = 143.00, 95% Cl = 27.23–759.10). More than two-thirds of the 40 Salmonella strains isolated from hospitalized cases, food samples and asymptomatic food handlers were of phage type 1; the others reacted but did not conform to any phage type. The phage types correlated well with their unique antibiograms. The ribotype patterns of 22 selected isolates tested were highly similar, indicating genetic relatedness. The dendrogram of the strains from the outbreak showed distinct clustering and correlation compared to the non-outbreak strains, confirming a common source of infection. Discussion The cream cakes were likely contaminated by one of the ingredients used in the icing. Cross-contamination down the production line and subsequent storage of cakes at ambient temperatures for a prolonged period before consumption could have contributed to the outbreak. PMID:23908880

  18. Diversity of Multidrug-Resistant Salmonella enterica Strains Associated with Cattle at Harvest in the United States ▿

    PubMed Central

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

    2011-01-01

    The prevalence and diversity of multidrug-resistant (MDR) Salmonella enterica strains associated with cattle at harvest in the United States were examined. Hides and carcasses of cattle were sampled at processing plants (n = 6) located in four geographically distant regions from July 2005 to April 2006. The mean prevalences of Salmonella on hides, preevisceration carcasses (immediately after hide removal), and postintervention carcasses (in the chiller and after the full complement of interventions) were 89.6%, 50.2%, and 0.8%, respectively. The values for MDR Salmonella enterica strains (defined as those resistant to two or more antimicrobials) as percentages of Salmonella prevalence were 16.7% (95% confidence interval [CI], 8.3 to 25.1%; median percent prevalence, 6.9%), 11.7% (95% CI, 4.4 to 19.0%; median, 4.8%), and 0.33% (95% CI, −0.3 to 0.70%; median, 0%), respectively. In this study, 16,218 Salmonella hide and carcass isolates were screened for antimicrobial resistance. Of these, 978 (6.0%) unique MDR S. enterica isolates were identified and serotyped and their XbaI pulsed-field gel electrophoresis (PFGE) profiles determined. The predominant MDR S. enterica serotypes observed were Newport (53.1%), Typhimurium (16.6%), and Uganda (10.9%). Differences in MDR S. enterica prevalence were detected, and PFGE analysis revealed both epidemic clusters (profiles found in plants in multiple regions/seasons) and endemic clusters (profiles observed in plants in limited regions/seasons) within several of the MDR serotypes examined. Despite these differences, multiple-hurdle processing interventions employed at all plants were found to be quite effective and decreased Salmonella carcass contamination by 98.4% (95% CI, 97.6 to 99.7%). PMID:21239549

  19. The iron-sulfur cluster sensor IscR is a negative regulator of Spi1 type III secretion system in Salmonella enterica.

    PubMed

    Vergnes, Alexandra; Viala, Julie P M; Ouadah-Tsabet, Rabah; Pocachard, Bérengère; Loiseau, Laurent; Méresse, Stéphane; Barras, Frédéric; Aussel, Laurent

    2017-04-01

    Iron-sulfur (Fe-S)-containing proteins contribute to various biological processes, including redox reactions or regulation of gene expression. Living organisms have evolved by developing distinct biosynthetic pathways to assemble these clusters, including iron sulfur cluster (ISC) and sulfur mobilization (SUF). Salmonella enterica serovar Typhimurium is an intracellular pathogen responsible for a wide range of infections, from gastroenteritis to severe systemic diseases. Salmonella possesses all known prokaryotic systems to assemble Fe-S clusters, including ISC and SUF. Because iron starvation and oxidative stress are detrimental for Fe-S enzyme biogenesis and because such environments are often met by Salmonella during its intracellular life, we investigated the role of the ISC and SUF machineries during the course of the infection. The iscU mutant, which is predicted to have no ISC system functioning, was found to be defective for epithelial cell invasion and for mice infection, whereas the sufBC mutant, which is predicted to have no SUF system functioning, did not present any defect. Moreover, the iscU mutant was highly impaired in the expression of Salmonella pathogenicity island 1 (Spi1) type III secretion system that is essential for the first stage of Salmonella infection. The Fe-S cluster sensor IscR, a transcriptional regulator matured by the ISC machinery, was shown to bind the promoter of hilD, which encodes the master regulator of Spi1. IscR was also demonstrated to repress hilD and subsequently Spi1 gene expression, consistent with the observation that an IscR mutant is hyper-invasive in epithelial cells. Collectively, our findings indicate that the ISC machinery plays a central role in Salmonella virulence through the ability of IscR to down-regulate Spi1 gene expression. At a broader level, this model illustrates an adaptive mechanism used by bacterial pathogens to modulate their infectivity according to iron and oxygen availability.

  20. Effects of indole on drug resistance and virulence of Salmonella enterica serovar Typhimurium revealed by genome-wide analyses

    PubMed Central

    2012-01-01

    Background Many Gram-positive and Gram-negative bacteria produce large quantities of indole as an intercellular signal in microbial communities. Indole demonstrated to affect gene expression in Escherichia coli as an intra-species signaling molecule. In contrast to E. coli, Salmonella does not produce indole because it does not harbor tnaA, which encodes the enzyme responsible for tryptophan metabolism. Our previous study demonstrated that E. coli-conditioned medium and indole induce expression of the AcrAB multidrug efflux pump in Salmonella enterica serovar Typhimurium for inter-species communication; however, the global effect of indole on genes in Salmonella remains unknown. Results To understand the complete picture of genes regulated by indole, we performed DNA microarray analysis of genes in the S. enterica serovar Typhimurium strain ATCC 14028s affected by indole. Predicted Salmonella phenotypes affected by indole based on the microarray data were also examined in this study. Indole induced expression of genes related to efflux-mediated multidrug resistance, including ramA and acrAB, and repressed those related to host cell invasion encoded in the Salmonella pathogenicity island 1, and flagella production. Reduction of invasive activity and motility of Salmonella by indole was also observed phenotypically. Conclusion Our results suggest that indole is an important signaling molecule for inter-species communication to control drug resistance and virulence of S. enterica. PMID:22632036