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Sample records for salmonella pathogenicity island-2

  1. Swiss Army Pathogen: The Salmonella Entry Toolkit

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    Peter J. Hume

    2017-08-01

    Full Text Available Salmonella causes disease in humans and animals ranging from mild self-limiting gastroenteritis to potentially life-threatening typhoid fever. Salmonellosis remains a considerable cause of morbidity and mortality globally, and hence imposes a huge socio-economic burden worldwide. A key property of all pathogenic Salmonella strains is the ability to invade non-phagocytic host cells. The major determinant of this invasiveness is a Type 3 Secretion System (T3SS, a molecular syringe that injects virulence effector proteins directly into target host cells. These effectors cooperatively manipulate multiple host cell signaling pathways to drive pathogen internalization. Salmonella does not only rely on these injected effectors, but also uses several other T3SS-independent mechanisms to gain entry into host cells. This review summarizes our current understanding of the methods used by Salmonella for cell invasion, with a focus on the host signaling networks that must be coordinately exploited for the pathogen to achieve its goal.

  2. Pathogenicity of Salmonella Paratyphi A in Pullets

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    A. O. Ogunleye

    2006-01-01

    Full Text Available The pathogenicity of Salmonella Paratyphi A isolated at Debiwise Poultry Farm during a fulminating outbreak was tested. Twenty 16-week-old pullets were inoculated orally with 0.5 ml of 1.3 x 108 CFU/bird Salmonella Paratyphi A, while 20 others of the same age served as uninfected control. By the fourth day postinoculation (p.i. dullness, ruffled and unkempt feathers, somnolence, yellowish- green diarrhea, decreased water and feed consumption were observed in the infected birds; mortality was 95% by day 16 p.i. Remarkable pathological lesions were recorded between days 7 and 14 p.i. The liver was moderately enlarged, with multiple necrotic foci, and dark brown to bronze coloration. The kidneys were swollen, with widespread focal pale necrotic areas, while the spleen was slightly enlarged. Histopathologically, the proventriculus showed focal glandular necrosis, mononuclear cell infiltration and moderate perivascular leucocytic infiltration. There was mucosal hemorrhage, matting of intestinal villi with reduction of villous height and presence of epithelial debris in the lumen with increased leucocytic infiltration in the lamina propriae. The liver showed moderate, diffuse congestion of the sinusoid and central veins, as well as multiple foci of necrosis of hepatocytes, mononuclear infiltration and perivascular cellular infiltration. There was diffuse lymphoid depletion in the nodule and around the splenic arterioles as well as throughout the parenchyma. The kidneys were congested with tubular epithelial necrosis characterized by karyorrhexis of the nuclei. The organism was recovered from the liver, spleen, heart, heart blood and bone marrow of infected birds. No clinical sign or gross lesion or pathogen was observed in the negative control.

  3. Pathogenicity, Epidemiology and Virulence Factors of Salmonella species: A Review

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    Tamègnon Victorien DOUGNON

    2017-12-01

    Full Text Available Salmonella infections are major public health problems worldwide. The hereby review aimed to establish an overview on the pathogenicity, epidemiology and virulence factors of Salmonella spp. in the world. A systematic search was conducted online using the keywords ‘Salmonella’, ‘Salmonella spp.’, ‘Salmonella spp. Epidemiology’, ‘virulence factors of Salmonella spp. in the world’, ‘bacteria responsible for the contamination of meat products’, ‘non-typhoid salmonella’. These keywords were entered into databases such as PubMed and Google Scholar using mainly French language. The obtained articles were included based on the reliability of their source, the study area (usually Benin and Africa and the subject. The review revealed that Salmonella spp. is motile Gram-negative rod-shaped bacteria, of the family Enterobacteriaceae, currently counting more than 2,600 serovars. Human contamination occurs through the ingestion of contaminated water and food and can cause gastroenteritis or typhoid fever, which are two serious public health problems. A gene set constituting the pathogenicity islands determines the pathogenesis of Salmonella spp. The diagnosis is based on bacteriological, serological and molecular techniques. Salmonella infections are usually treated using antibiotics; however, emergence of antibiotic resistance in these microorganisms suggests that the anti-salmonella control should explore new sources such as medicinal plants

  4. Immunity to intestinal pathogens: lessons learned from Salmonella

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    McSorley, Stephen J.

    2014-01-01

    Summary Salmonella are a common source of food or water-borne infection and cause a wide range of clinical disease in human and animal hosts. Salmonella are relatively easy to culture and manipulate in a laboratory setting, and the infection of laboratory animals induces robust innate and adaptive immune responses. Thus, immunologists have frequently turned to Salmonella infection models to expand understanding of immunity to intestinal pathogens. In this review, I summarize current knowledge of innate and adaptive immunity to Salmonella and highlight features of this response that have emerged from recent studies. These include the heterogeneity of the antigen-specific T-cell response to intestinal infection, the prominence of microbial mechanisms to impede T and B-cell responses, and the contribution of non-cognate pathways for elicitation of T-cell effector functions. Together, these different issues challenge an overly simplistic view of host-pathogen interaction during mucosal infection but also allow deeper insight into the real-world dynamic of protective immunity to intestinal pathogens. PMID:24942689

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

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    Sandeepa M Eswarappa

    Full Text Available The genus Salmonella includes many pathogens of great medical and veterinary importance. Bacteria belonging to this genus are very closely related to those belonging to the genus Escherichia. lacZYA operon and lacI are present in Escherichia coli, but not in Salmonella enterica. It has been proposed that Salmonella has lost lacZYA operon and lacI during evolution. In this study, we have investigated the physiological and evolutionary significance of the absence of lacI in Salmonella enterica. Using murine model of typhoid fever, we show that the expression of LacI causes a remarkable reduction in the virulence of Salmonella enterica. LacI also suppresses the ability of Salmonella enterica to proliferate inside murine macrophages. Microarray analysis revealed that LacI interferes with the expression of virulence genes of Salmonella pathogenicity island 2. This effect was confirmed by RT-PCR and Western blot analysis. Interestingly, we found that SBG0326 of Salmonella bongori is homologous to lacI of Escherichia coli. Salmonella bongori is the only other species of the genus Salmonella and it lacks the virulence genes of Salmonella pathogenicity island 2. Overall, our results demonstrate that LacI is an antivirulence factor of Salmonella enterica and suggest that absence of lacI has facilitated the acquisition of virulence genes of Salmonella pathogenicity island 2 in Salmonella enterica making it a successful systemic pathogen.

  6. Salmonella Pathogenicity and Host Adaptation in Chicken-Associated Serovars

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    Johnson, Timothy J.; Ricke, Steven C.; Nayak, Rajesh; Danzeisen, Jessica

    2013-01-01

    SUMMARY Enteric pathogens such as Salmonella enterica cause significant morbidity and mortality. S. enterica serovars are a diverse group of pathogens that have evolved to survive in a wide range of environments and across multiple hosts. S. enterica serovars such as S. Typhi, S. Dublin, and S. Gallinarum have a restricted host range, in which they are typically associated with one or a few host species, while S. Enteritidis and S. Typhimurium have broad host ranges. This review examines how S. enterica has evolved through adaptation to different host environments, especially as related to the chicken host, and continues to be an important human pathogen. Several factors impact host range, and these include the acquisition of genes via horizontal gene transfer with plasmids, transposons, and phages, which can potentially expand host range, and the loss of genes or their function, which would reduce the range of hosts that the organism can infect. S. Gallinarum, with a limited host range, has a large number of pseudogenes in its genome compared to broader-host-range serovars. S. enterica serovars such as S. Kentucky and S. Heidelberg also often have plasmids that may help them colonize poultry more efficiently. The ability to colonize different hosts also involves interactions with the host's immune system and commensal organisms that are present. Thus, the factors that impact the ability of Salmonella to colonize a particular host species, such as chickens, are complex and multifactorial, involving the host, the pathogen, and extrinsic pressures. It is the interplay of these factors which leads to the differences in host ranges that we observe today. PMID:24296573

  7. Pathogenicity of Salmonella Strains Isolated from Egg Shells and the Layer Farm Environment in Australia

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    McWhorter, Andrea R.; Davos, Dianne

    2014-01-01

    In Australia, the egg industry is periodically implicated during outbreaks of Salmonella food poisoning. Salmonella enterica serovar Typhimurium and other nontyphoidal Salmonella spp., in particular, are a major concern for Australian public health. Several definitive types of Salmonella Typhimurium strains, but primarily Salmonella Typhimurium definitive type 9 (DT9), have been frequently reported during egg-related food poisoning outbreaks in Australia. The aim of the present study was to generate a pathogenicity profile of nontyphoidal Salmonella isolates obtained from Australian egg farms. To achieve this, we assessed the capacity of Salmonella isolates to cause gastrointestinal disease using both in vitro and in vivo model systems. Data from in vitro experiments demonstrated that the invasion capacity of Salmonella serovars cultured to stationary phase (liquid phase) in LB medium was between 90- and 300-fold higher than bacterial suspensions in normal saline (cultured in solid phase). During the in vivo infection trial, clinical signs of infection and mortality were observed only for mice infected with either 103 or 105 CFU of S. Typhimurium DT9. No mortality was observed for mice infected with Salmonella serovars with medium or low invasive capacity in Caco-2 cells. Pathogenicity gene profiles were also generated for all serovars included in this study. The majority of serovars tested were positive for selected virulence genes. No relationship between the presence or absence of virulence genes by PCR and either in vitro invasive capacity or in vivo pathogenicity was detected. Our data expand the knowledge of strain-to-strain variation in the pathogenicity of Australian egg industry-related Salmonella spp. PMID:25362057

  8. Salmonella

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    ... Compartir Find out about Salmonella infections linked to Kellogg’s Honey Smacks Cereal Find out about Salmonella infections ... Outbreaks Multistate Outbreak of Salmonella Infections Linked to Kellogg’s Honey Smacks Cereal Multistate Outbreak of Salmonella Adelaide ...

  9. Biofilm formation by Salmonella Enteritidis and Salmonella Typhimurium isolated from avian sources is partially related with their in vivo pathogenicity.

    Science.gov (United States)

    Borges, Karen Apellanis; Furian, Thales Quedi; de Souza, Sara Neves; Menezes, Rafaela; de Lima, Diane Alves; Fortes, Flávia Bornancini Borges; Salle, Carlos Tadeu Pippi; Moraes, Hamilton Luiz Souza; Nascimento, Vladimir Pinheiro

    2018-03-22

    Salmonella Enteritidis and Salmonella Typhimurium are among the most prevalent serotypes isolated from salmonellosis outbreaks and poultry. Salmonella spp. have the capacity to form biofilms on several surfaces, which can favour survival in hostile environments, such as slaughterhouses. Salmonella strains present differences in pathogenicity. However, there is little information regarding the pathogenicity of S. Enteritidis and S. Typhimurium isolated from avian sources and their relationship to biofilm production. The aim of this study was to use a novel pathogenicity index and a biofilm production assay to evaluate their relationships within these serotypes. In addition, we detected the presence of the spiA and agfA genes in these strains. Biofilm formation was investigated at two temperatures (37 °C and 28 °C) using microtiter plate assay, and the results were compared with the individual pathogenicity index of each strain. PCR was used to detect spiA and agfA, virulence genes associated with biofilm production. S. Enteritidis and S. Typhimurium strains were capable of producing biofilm at 37 °C and 28 °C. Sixty-two percent and 59.5% of S. Enteritidis and 73.8% and 46.2% of S. Typhimurium produced biofilm at 37 °C and 28 °C, respectively. Biofilm production at 37 °C was significantly higher in both serotypes. Only S. Enteritidis was capable of adhering strongly at both temperatures. Biofilm production was related to pathogenicity index only at 28 °C for S. Enteritidis. spiA and agfA were found in almost all strains and were not statistically associated with biofilm production. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Harizi Khalil

    2009-01-01

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

  11. Laboratory monitoring of bacterial gastroenteric pathogens Salmonella and Shigella in Shanghai, China 2006-2012.

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    Zhang, J; Wang, F; Jin, H; Hu, J; Yuan, Z; Shi, W; Yang, X; Meng, J; Xu, X

    2015-02-01

    In 2006 we initiated an enhanced laboratory-based surveillance of Salmonella and Shigella infections in Shanghai, China. A total of 4483 Salmonella and 2226 Shigella isolates were recovered from stool specimens by 2012. In 80 identified Salmonella serovars, Enteritidis (34·5%) and Typhimurium (26·2%) were the most common. Shigella (S.) sonnei accounted for 63·9% of human Shigella infections over the same time period, and replaced S. flexneri to become the primary cause of shigellosis since 2010. Overall, a high level of antimicrobial resistance was observed in Salmonella and Shigella, particularly to nalidixic acid, ampicillin, and tetracycline. Ciprofloxacin resistance was common in Salmonella Typhimurium (21·0%) and S. flexneri (37·6%). The cephalosporin resistance in both pathogens also increased over the years, ranging from 3·4% to 7·0% in Salmonella, and from 10·4% to 28·6% in Shigella. Resistance to multiple antimicrobials was also identified in a large number of the isolates. This study provides insight into the distribution of Salmonella and Shigella in diarrhoeal diseases.

  12. Use of high-throughput mass spectrometry to elucidate host pathogen interactions in Salmonella

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    Rodland, Karin D.; Adkins, Joshua N.; Ansong, Charles; Chowdhury, Saiful M.; Manes, Nathan P.; Shi, Liang; Yoon, Hyunjin; Smith, Richard D.; Heffron, Fred

    2008-12-01

    Capabilities in mass spectrometry are evolving rapidly, with recent improvements in sensitivity, data analysis, and most important, from the standpoint of this review, much higher throughput allowing analysis of many samples in a single day. This short review describes how these improvements in mass spectrometry can be used to dissect host-pathogen interactions using Salmonella as a model system. This approach enabled direct identification of the majority of annotated Salmonella proteins, quantitation of expression changes under various in vitro growth conditions, and new insights into virulence and expression of Salmonella proteins within host cell cells. One of the most significant findings is that a very high percentage of the all annotated genes (>20%) in Salmonella are regulated post-transcriptionally. In addition, new and unexpected interactions have been identified for several Salmonella virulence regulators that involve protein-protein interactions, suggesting additional functions of these regulators in coordinating virulence expression. Overall high throughput mass spectrometry provides a new view of pathogen-host interactions emphasizing the protein products and defining how protein interactions determine the outcome of infection.

  13. Salmonella typhimurium DT104: a virulent and drug-resistant pathogen.

    OpenAIRE

    Poppe, C; Smart, N; Khakhria, R; Johnson, W; Spika, J; Prescott, J

    1998-01-01

    Salmonella typhimurium phage type (PT) or definitive type (DT) 104 is a virulent pathogen for humans and animals, particularly cattle. It has been isolated increasingly from humans and animals in the United Kingdom and several other European countries and, more recently, in the United States and Canada. Humans may acquire the infection from foods of animal origin contaminated with the infective organism. Farm families are particularly at risk of acquiring the infection by contact with infecte...

  14. Control of Salmonella and other pathogenic and spoilage microorganisms in poultry by gamma and electron irradiation

    International Nuclear Information System (INIS)

    Singh, H.

    1992-07-01

    Salmonella contamination of chicken is a major public health concern, causing sickness and loss of productivity. Modern, concentrated production methods increase the difficulty of Salmonella control. The current and suggested treatments with chlorinated water or heat pasteurization are unsatisfactory. In pasteurization, the end product is partially cooked, and in the chlorine water wash the poultry skin gets bleached if too much chlorine is used. There is also a risk of formation of toxic chloro-organic compounds. Further, the chlorine water wash does not completely eliminate salmonella. Low-dose radiation treatment is much more effective for the control of Salmonella and has the additional benefit of preserving the freshness of the product. Irradiation of fresh chicken carcasses, pieces or deboned chicken meat with a dose of 2.5 kGy appears to be sufficient to eliminate naturally occurring Salmonella contamination, which is generally present in extremely low numbers on this continent (1 to 30 cells/100 g). For elimination of Salmonella in frozen chicken, doses higher than 2.5 kGy are required. There is a large range of D 10 - values for the different Salmonella serotypes that have been tested, with the highest being 0.72 kGy for S. oranienberg at 22 degrees C. Thus the 2.5-kGy dose would reduce the most radio-resistant Salmonella serotype by four orders of magnitude, and the most common serotypes (with D 10 - values of 0.3 to 0.4 kGy) by greater than six orders of magnitude. The 2.5-kGy dose also appears to be sufficient to eliminate other bacterial pathogens, such as Campylobactor jejuni and Yersinia enterocolitica. The microbiological shelf life of fresh chicken carcass or deboned chicken meat (6 to 11 d) is extended by a factor of 2 to 3 with irradiation to a dose of 2.5 kGy followed by storage between 1 and 4 degrees C. In radappertization (at a dose of ≥ 45 kGy at -30 degrees C), the shelf life of enzyme-inactivated chicken meat is extended to years, on

  15. Use of high-throughput mass spectrometry to elucidate host-pathogen interactions in Salmonella

    Energy Technology Data Exchange (ETDEWEB)

    Rodland, Karin D.; Adkins, Joshua N.; Ansong, Charles; Chowdhury, Saiful M.; Manes, Nathan P.; Shi, Liang; Yoon, Hyunjin; Smith, Richard D.; Heffron, Fred

    2008-12-01

    New improvements to mass spectrometry include increased sensitivity, improvements in analyzing the collected data, and most important, from the standpoint of this review, a much higher throughput allowing analysis of many samples in a single day. This short review describes how host-pathogen interactions can be dissected by mass spectrometry using Salmonella as a model system. The approach allowed direct identification of the majority of annotate Salmonella proteins, how expression changed under various in vitro growth conditions, and how this relates to virulence and expression within host cell cells. One of the most significant findings is that a very high percentage of the all annotated genes (>20%) are regulated post-transcriptionally. In addition, new and unexpected interactions have been identified for several Salmonella virulence regulators that involve protein-protein interactions suggesting additional functions of the regulator in coordinating virulence expression. Overall high throughput mass spectrometer provides a new view of pathogen-host interaction emphasizing the protein products and defining how protein interactions determine the outcome of infection.

  16. Comparative genomics of transport proteins in probiotic and pathogenic Escherichia coli and Salmonella enterica strains.

    Science.gov (United States)

    Do, Jimmy; Zafar, Hassan; Saier, Milton H

    2017-06-01

    Escherichia coli is a genetically diverse species that can be pathogenic, probiotic, commensal, or a harmless laboratory strain. Pathogenic strains of E. coli cause urinary tract infections, diarrhea, hemorrhagic colitis, and pyelonephritis, while the two known probiotic E. coli strains combat inflammatory bowel disease and play a role in immunomodulation. Salmonella enterica, a close relative of E. coli, includes two important pathogenic serovars, Typhi and Typhimurium, causing typhoid fever and enterocolitis in humans, respectively, with the latter strain also causing a lethal typhoid fever-like disease in mice. In this study, we identify the transport systems and their substrates within seven E. coli strains: two probiotic strains, two extracellular pathogens, two intracellular pathogens, and K-12, as well as the two intracellular pathogenic S. enterica strains noted above. Transport systems characteristic of each probiotic or pathogenic species were thus identified, and the tabulated results obtained with all of these strains were compared. We found that the probiotic and pathogenic strains generally contain more iron-siderophore and sugar transporters than E. coli K-12. Pathogens have increased numbers of pore-forming toxins, protein secretion systems, decarboxylation-driven Na + exporters, electron flow-driven monovalent cation exporters, and putative transporters of unknown function compared to the probiotic strains. Both pathogens and probiotic strains encode metabolite transporters that reflect their intracellular versus extracellular environments. The results indicate that the probiotic strains live extracellularly. It seems that relatively few virulence factors can convert a beneficial or commensal microorganism into a pathogen. Taken together, the results reveal the distinguishing features of these strains and provide a starting point for future engineering of beneficial enteric bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Multiplex TaqMan® detection of pathogenic and multi-drug resistant Salmonella.

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    Singh, Prashant; Mustapha, Azlin

    2013-09-02

    Overuse of antibiotics in the medical and animal industries is one of the major causes for the development of multi-drug-resistant (MDR) food pathogens that are often difficult to treat. In the past few years, higher incidences of outbreaks caused by MDR Salmonella have been increasingly documented. The objective of this study was to develop a rapid multiplex real-time polymerase chain reaction (PCR) assay for simultaneous detection of pathogenic and MDR Salmonella spp. A multiplex TaqMan®real-time PCR was designed by targeting the invasin virulence gene (invA), and four commonly found antibiotic resistance genes, viz. ampicillin, chloramphenicol, streptomycin and tetracycline. To avoid false negative results and to increase the reliability of the assay, an internal amplification control (IAC) was added which was detected using a locked nucleic acid (LNA) probe. In serially diluted (5 ng-50 fg) DNA samples, the assay was able to detect 100 genomic equivalents of Salmonella, while in a multiplex format, the sensitivity was 1000 genomic equivalents. The assay performed equally well on artificially contaminated samples of beef trim, ground beef of different fat contents (73:27, 80:20, 85:15 and 93:7), chicken rinse, ground chicken, ground turkey, egg, spinach and tomato. While the detection limit for un-enriched inoculated food samples was 10(4) CFU/g, this was improved to 10 CFU/g after a 12-h enrichment in buffered peptone water, with 100% reproducibility. The multiplex real-time assay developed in this study can be used as a valuable tool to detect MDR virulent Salmonella, thus enhancing the safety of food. © 2013.

  18. The FUN of identifying gene function in bacterial pathogens; insights from Salmonella functional genomics.

    Science.gov (United States)

    Hammarlöf, Disa L; Canals, Rocío; Hinton, Jay C D

    2013-10-01

    The availability of thousands of genome sequences of bacterial pathogens poses a particular challenge because each genome contains hundreds of genes of unknown function (FUN). How can we easily discover which FUN genes encode important virulence factors? One solution is to combine two different functional genomic approaches. First, transcriptomics identifies bacterial FUN genes that show differential expression during the process of mammalian infection. Second, global mutagenesis identifies individual FUN genes that the pathogen requires to cause disease. The intersection of these datasets can reveal a small set of candidate genes most likely to encode novel virulence attributes. We demonstrate this approach with the Salmonella infection model, and propose that a similar strategy could be used for other bacterial pathogens. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

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    Sandhya A Marathe

    Full Text Available 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.

  20. Experimental annotation of post-translational features and translated coding regions in the pathogen Salmonella Typhimurium

    Energy Technology Data Exchange (ETDEWEB)

    Ansong, Charles; Tolic, Nikola; Purvine, Samuel O.; Porwollik, Steffen; Jones, Marcus B.; Yoon, Hyunjin; Payne, Samuel H.; Martin, Jessica L.; Burnet, Meagan C.; Monroe, Matthew E.; Venepally, Pratap; Smith, Richard D.; Peterson, Scott; Heffron, Fred; Mcclelland, Michael; Adkins, Joshua N.

    2011-08-25

    Complete and accurate genome annotation is crucial for comprehensive and systematic studies of biological systems. For example systems biology-oriented genome scale modeling efforts greatly benefit from accurate annotation of protein-coding genes to develop proper functioning models. However, determining protein-coding genes for most new genomes is almost completely performed by inference, using computational predictions with significant documented error rates (> 15%). Furthermore, gene prediction programs provide no information on biologically important post-translational processing events critical for protein function. With the ability to directly measure peptides arising from expressed proteins, mass spectrometry-based proteomics approaches can be used to augment and verify coding regions of a genomic sequence and importantly detect post-translational processing events. In this study we utilized “shotgun” proteomics to guide accurate primary genome annotation of the bacterial pathogen Salmonella Typhimurium 14028 to facilitate a systems-level understanding of Salmonella biology. The data provides protein-level experimental confirmation for 44% of predicted protein-coding genes, suggests revisions to 48 genes assigned incorrect translational start sites, and uncovers 13 non-annotated genes missed by gene prediction programs. We also present a comprehensive analysis of post-translational processing events in Salmonella, revealing a wide range of complex chemical modifications (70 distinct modifications) and confirming more than 130 signal peptide and N-terminal methionine cleavage events in Salmonella. This study highlights several ways in which proteomics data applied during the primary stages of annotation can improve the quality of genome annotations, especially with regards to the annotation of mature protein products.

  1. Obacunone Represses Salmonella Pathogenicity Islands 1 and 2 in an envZ-Dependent Fashion

    Science.gov (United States)

    Vikram, Amit; Jayaprakasha, Guddadarangavvanahally K.; Jesudhasan, Palmy R.

    2012-01-01

    Obacunone belongs to a class of unique triterpenoids called limonoids, present in Citrus species. Previous studies from our laboratory suggested that obacunone possesses antivirulence activity and demonstrates inhibition of cell-cell signaling in Vibrio harveyi and Escherichia coli O157:H7. The present work sought to determine the effect of obacunone on the food-borne pathogen Salmonella enterica serovar Typhimurium LT2 by using a cDNA microarray. Transcriptomic studies indicated that obacunone represses Salmonella pathogenicity island 1 (SPI1), the maltose transporter, and the hydrogenase operon. Furthermore, phenotypic data for the Caco-2 infection assay and maltose utilization were in agreement with microarray data suggesting repression of SPI1 and maltose transport. Further studies demonstrated that repression of SPI1 was plausibly mediated through hilA. Additionally, obacunone seems to repress SPI2 under SPI2-inducing conditions as well as in Caco-2 infection models. Furthermore, obacunone seems to repress hilA in an EnvZ-dependent fashion. Altogether, the results of the study seems to suggest that obacunone exerts an antivirulence effect on S. Typhimurium and may serve as a lead compound for development of antivirulence strategies for S. Typhimurium. PMID:22843534

  2. Salmonella: Salmonellosis

    DEFF Research Database (Denmark)

    Löfström, Charlotta; Hansen, Trine; Maurischat, Sven

    2015-01-01

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

  3. Isolation, antibiogram and pathogenicity of Salmonella spp. Recovered from slaughtered food animals in Nagpur region of Central India

    Directory of Open Access Journals (Sweden)

    D. G. Kalambhe

    2016-02-01

    Full Text Available Aim: To determine the prevalence, antibiogram and pathogenicity of Salmonella spp. in the common food animals slaughtered for consumption purpose at government approved slaughter houses located in and around Nagpur region during a period of 2010-2012. Materials and Methods: A total of 400 samples comprising 50 each of blood and meat from each slaughtered male cattle, buffaloes, pigs and goats were collected. Isolation was done by pre-enrichment in buffered peptone water and enrichment in Rappaport-Vassiliadis broth with subsequent selective plating onto xylose lysine deoxycholate agar. Presumptive Salmonella colonies were biochemically confirmed and analyzed for pathogenicity by hemolysin production and Congo red dye binding assay (CRDA. An antibiotic sensitivity test was performed to assess the antibiotic resistance pattern of the isolates. Results: A total of 10 isolates of Salmonella spp. from meat (3 from cattle, 1 from buffaloes and 6 from pigs with an overall prevalence of 5% among food animals was recorded. No isolation was reported from any blood samples. Pathogenicity assays revealed 100% and 80% positivity for CRDA and hemolytic activity, respectively. Antimicrobial sensitivity test showed multi-drug resistance. The overall resistance of 50% was noted for trimethoprim followed by ampicillin (20%. A maximum sensitivity (80% was reported to gentamycin followed by 40% each to ampicillin and trimethoprim, 30% to amikacin and 10% to kanamycin. Conclusion: The presence of multidrug resistant and potentially pathogenic Salmonella spp. in slaughtered food animals in Nagpur region can be a matter of concern for public health.

  4. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella Typhimurium on Chicken Breast Fillet during Cooking

    NARCIS (Netherlands)

    Jong, de A.E.I.; Asselt, van E.D.; Zwietering, M.H.; Nauta, M.J.; Jonge, de R.

    2012-01-01

    The aim of this research was to determine the decimal reduction times of bacteria present on chicken fillet in boiling water. The experiments were conducted with Campylobacter jejuni, Salmonella, and Escherichia coli. Whole chicken breast fillets were inoculated with the pathogens, stored overnight

  5. A rapid and specific detection of pathogenic serovar Salmonella typhimurium by loop-mediated isothermal amplification method (LAMP

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    Hadi Ravan

    2017-09-01

    Discussion and conclusion: As a result of a high sensitivity and specificity of the method as well as its low cost per assay, it could be concluded that the present LAMP assay is a powerful, accurate, and efficient method for detecting pathogenic serovar Salmonella typhimurium in food-processing industries and diagnostic laboratories.

  6. Search and molecular identification of two pathogenic bacteria (Salmonella and Listeria) in different food matrices

    International Nuclear Information System (INIS)

    Wislati, Mohamed Amine

    2010-01-01

    A food is a substance consumed in the natural state or after a cooking. The essential role of food is the apport of essential elements in the growth and in the energy needs as well as in the reserves of the body. Foodstuffs may be contaminated by microorganisms such as the viruses, the parasites, the bacteria at the different steps of production, transformation, transport and manipulation being able to engender food collective toxi-infections (T.I.A.C), infections. This study contains a research directed by two pathogenic germs; Listeria and Salmonella as food contaminants, ending at the man's respectively in two diseases: the Listeriosis and the Salmonellosis and the enumeration of the fecal coliform as indicators of lack of hygiene and a contamination of fecal origin. 90 samples of various types and origins are analyzed in the laboratory of biology and molecular microbiology of the (CNSTN) and are identified by Api (Listeria, 20E) and by PCR. Three origins of Listeria and four origins of Salmonella were isolated. Then, the healthiness of various lots was estimated (dairy products, produced meat-based and produced ready to be eaten) according to the plan of interpretation of the result (plan 2 classes) and (plan 3 classes).The obtained results confirm the contamination of our products taken from the market of public consumption. So the strengthen measures of prevention and health control are very important in the food industry.

  7. Lectin-Like Molecules of Lactobacillus rhamnosus GG Inhibit Pathogenic Escherichia coli and Salmonella Biofilm Formation

    Science.gov (United States)

    Petrova, Mariya I.; Imholz, Nicole C. E.; Verhoeven, Tine L. A.; Balzarini, Jan; Van Damme, Els J. M.; Schols, Dominique; Vanderleyden, Jos; Lebeer, Sarah

    2016-01-01

    Objectives Increased antibiotic resistance has catalyzed the research on new antibacterial molecules and alternative strategies, such as the application of beneficial bacteria. Since lectin molecules have unique sugar-recognizing capacities, and pathogens are often decorated with sugars that affect their survival and infectivity, we explored whether lectins from the probiotic strain Lactobacillus rhamnosus GG have antipathogenic properties. Methods The genome sequence of L. rhamnosus GG was screened for the presence of lectin-like proteins. Two genes, LGG_RS02780 and LGG_RS02750, encoding for polypeptides with an N-terminal conserved L-type lectin domain were detected and designated Llp1 (lectin-like protein 1) and Llp2. The capacity of Llp1 and Llp2 to inhibit biofilm formation of various pathogens was investigated. Sugar specificity was determined by Sepharose beads assays and glycan array screening. Results The isolated lectin domains of Llp1 and Llp2 possess pronounced inhibitory activity against biofilm formation by various pathogens, including clinical Salmonella species and uropathogenic E. coli, with Llp2 being more active than Llp1. In addition, sugar binding assays with Llp1 and Llp2 indicate specificity for complex glycans. Both proteins are also involved in the adhesion capacity of L. rhamnosus GG to gastrointestinal and vaginal epithelial cells. Conclusions Lectins isolated from or expressed by beneficial lactobacilli could be considered promising bio-active ingredients for improved prophylaxis of urogenital and gastrointestinal infections. PMID:27537843

  8. Lectin-Like Molecules of Lactobacillus rhamnosus GG Inhibit Pathogenic Escherichia coli and Salmonella Biofilm Formation.

    Science.gov (United States)

    Petrova, Mariya I; Imholz, Nicole C E; Verhoeven, Tine L A; Balzarini, Jan; Van Damme, Els J M; Schols, Dominique; Vanderleyden, Jos; Lebeer, Sarah

    2016-01-01

    Increased antibiotic resistance has catalyzed the research on new antibacterial molecules and alternative strategies, such as the application of beneficial bacteria. Since lectin molecules have unique sugar-recognizing capacities, and pathogens are often decorated with sugars that affect their survival and infectivity, we explored whether lectins from the probiotic strain Lactobacillus rhamnosus GG have antipathogenic properties. The genome sequence of L. rhamnosus GG was screened for the presence of lectin-like proteins. Two genes, LGG_RS02780 and LGG_RS02750, encoding for polypeptides with an N-terminal conserved L-type lectin domain were detected and designated Llp1 (lectin-like protein 1) and Llp2. The capacity of Llp1 and Llp2 to inhibit biofilm formation of various pathogens was investigated. Sugar specificity was determined by Sepharose beads assays and glycan array screening. The isolated lectin domains of Llp1 and Llp2 possess pronounced inhibitory activity against biofilm formation by various pathogens, including clinical Salmonella species and uropathogenic E. coli, with Llp2 being more active than Llp1. In addition, sugar binding assays with Llp1 and Llp2 indicate specificity for complex glycans. Both proteins are also involved in the adhesion capacity of L. rhamnosus GG to gastrointestinal and vaginal epithelial cells. Lectins isolated from or expressed by beneficial lactobacilli could be considered promising bio-active ingredients for improved prophylaxis of urogenital and gastrointestinal infections.

  9. Role of soil, crop debris, and a plant pathogen in Salmonella enterica contamination of tomato plants.

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    Jeri D Barak

    Full Text Available BACKGROUND: In the U.S., tomatoes have become the most implicated vehicle for produce-associated Salmonellosis with 12 outbreaks since 1998. Although unconfirmed, trace backs suggest pre-harvest contamination with Salmonella enterica. Routes of tomato crop contamination by S. enterica in the absence of direct artificial inoculation have not been investigated. METHODOLOGY/PRINCIPAL FINDINGS: This work examined the role of contaminated soil, the potential for crop debris to act as inoculum from one crop to the next, and any interaction between the seedbourne plant pathogen Xanthomonas campestris pv. vesicatoria and S. enterica on tomato plants. Our results show S. enterica can survive for up to six weeks in fallow soil with the ability to contaminate tomato plants. We found S. enterica can contaminate a subsequent crop via crop debris; however a fallow period between crop incorporation and subsequent seeding can affect contamination patterns. Throughout these studies, populations of S. enterica declined over time and there was no bacterial growth in either the phyllosphere or rhizoplane. The presence of X. campestris pv. vesicatoria on co-colonized tomato plants had no effect on the incidence of S. enterica tomato phyllosphere contamination. However, growth of S. enterica in the tomato phyllosphere occurred on co-colonized plants in the absence of plant disease. CONCLUSIONS/SIGNIFICANCE: S. enterica contaminated soil can lead to contamination of the tomato phyllosphere. A six week lag period between soil contamination and tomato seeding did not deter subsequent crop contamination. In the absence of plant disease, presence of the bacterial plant pathogen, X. campestris pv. vesicatoria was beneficial to S. enterica allowing multiplication of the human pathogen population. Any event leading to soil contamination with S. enterica could pose a public health risk with subsequent tomato production, especially in areas prone to bacterial spot disease.

  10. A Multi-Omic View of Host-Pathogen-Commensal Interplay in Salmonella-Mediated Intestinal Infection

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Brooke LD; Li, Jie; Sanford, James A.; Kim, Young-Mo; Kronewitter, Scott R.; Jones, Marcus B.; Peterson, Christine; Peterson, Scott N.; Frank, Bryan C.; Purvine, Samuel O.; Brown, Joseph N.; Metz, Thomas O.; Smith, Richard D.; Heffron, Fred; Adkins, Joshua N.

    2013-06-26

    The potential for commensal microorganisms indigenous to a host (the ‘microbiome’ or ‘microbiota’) to alter infection outcome by influencing host-pathogen interplay is largely unknown. We used a multi-omics “systems” approach, incorporating proteomics, metabolomics, glycomics, and metagenomics, to explore the molecular interplay between the murine host, the pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium), and commensal gut microorganisms during intestinal infection with S. Typhimurium. We find proteomic evidence that S. Typhimurium thrives within the infected 129/SvJ mouse gut without antibiotic pre-treatment, inducing inflammation and disrupting the intestinal microbiome (e.g., suppressing Bacteroidetes and Firmicutes while promoting growth of Salmonella and Enterococcus). Alteration of the host microbiome population structure was highly correlated with gut environmental changes, including the accumulation of metabolites normally consumed by commensal microbiota. Finally, the less characterized phase of S. Typhimurium’s lifecycle was investigated, and both proteomic and glycomic evidence suggests S. Typhimurium may take advantage of increased fucose moieties to metabolize fucose while growing in the gut. The application of multiple omics measurements to Salmonella-induced intestinal inflammation provides insights into complex molecular strategies employed during pathogenesis between host, pathogen, and the microbiome.

  11. Real-time PCR Detection of Food-borne Pathogenic Salmonella spp

    DEFF Research Database (Denmark)

    Malorny, B.; Mäde, D.; Löfström, Charlotta

    2013-01-01

    Infections by Salmonella enterica are a significant public health concern worldwide. Salmonellae form a complex group of bacteria consisting of two species, six subspecies and more than 2500 serovars (serotypes). Mainly through ingestion of contaminated food or feed, they cause self-limiting gast......Infections by Salmonella enterica are a significant public health concern worldwide. Salmonellae form a complex group of bacteria consisting of two species, six subspecies and more than 2500 serovars (serotypes). Mainly through ingestion of contaminated food or feed, they cause self...

  12. A multi-pathogen selective enrichment broth for simultaneous growth of Salmonella enteria, Escherichia coli O157:H7 and Shigella flexneri

    Science.gov (United States)

    Salmonella, Shigella, and Escherichia coli O157:H7 contaminate similar types of food and all three can cause foodborne disease. Traditional microbiological enrichment broths to detect these pathogens are different in terms of their composition, which limits the application of multi-pathogen detectio...

  13. Neutral genomic microevolution of a recently emerged pathogen, Salmonella enterica serovar Agona.

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    Zhemin Zhou

    2013-04-01

    Full Text Available Salmonella enterica serovar Agona has caused multiple food-borne outbreaks of gastroenteritis since it was first isolated in 1952. We analyzed the genomes of 73 isolates from global sources, comparing five distinct outbreaks with sporadic infections as well as food contamination and the environment. Agona consists of three lineages with minimal mutational diversity: only 846 single nucleotide polymorphisms (SNPs have accumulated in the non-repetitive, core genome since Agona evolved in 1932 and subsequently underwent a major population expansion in the 1960s. Homologous recombination with other serovars of S. enterica imported 42 recombinational tracts (360 kb in 5/143 nodes within the genealogy, which resulted in 3,164 additional SNPs. In contrast to this paucity of genetic diversity, Agona is highly diverse according to pulsed-field gel electrophoresis (PFGE, which is used to assign isolates to outbreaks. PFGE diversity reflects a highly dynamic accessory genome associated with the gain or loss (indels of 51 bacteriophages, 10 plasmids, and 6 integrative conjugational elements (ICE/IMEs, but did not correlate uniquely with outbreaks. Unlike the core genome, indels occurred repeatedly in independent nodes (homoplasies, resulting in inaccurate PFGE genealogies. The accessory genome contained only few cargo genes relevant to infection, other than antibiotic resistance. Thus, most of the genetic diversity within this recently emerged pathogen reflects changes in the accessory genome, or is due to recombination, but these changes seemed to reflect neutral processes rather than Darwinian selection. Each outbreak was caused by an independent clade, without universal, outbreak-associated genomic features, and none of the variable genes in the pan-genome seemed to be associated with an ability to cause outbreaks.

  14. Host and Pathogen Copper-Transporting P-Type ATPases Function Antagonistically during Salmonella Infection.

    Science.gov (United States)

    Ladomersky, Erik; Khan, Aslam; Shanbhag, Vinit; Cavet, Jennifer S; Chan, Jefferson; Weisman, Gary A; Petris, Michael J

    2017-09-01

    Copper is an essential yet potentially toxic trace element that is required by all aerobic organisms. A key regulator of copper homeostasis in mammalian cells is the copper-transporting P-type ATPase ATP7A, which mediates copper transport from the cytoplasm into the secretory pathway, as well as copper export across the plasma membrane. Previous studies have shown that ATP7A-dependent copper transport is required for killing phagocytosed Escherichia coli in a cultured macrophage cell line. In this investigation, we expanded on these studies by generating Atp7a LysMcre mice, in which the Atp7a gene was specifically deleted in cells of the myeloid lineage, including macrophages. Primary macrophages isolated from Atp7a LysMcre mice exhibit decreased copper transport into phagosomal compartments and a reduced ability to kill Salmonella enterica serovar Typhimurium compared to that of macrophages isolated from wild-type mice. The Atp7a LysMcre mice were also more susceptible to systemic infection by S Typhimurium than wild-type mice. Deletion of the S Typhimurium copper exporters, CopA and GolT, was found to decrease infection in wild-type mice but not in the Atp7a LysMcre mice. These studies suggest that ATP7A-dependent copper transport into the phagosome mediates host defense against S Typhimurium, which is counteracted by copper export from the bacteria via CopA and GolT. These findings reveal unique and opposing functions for copper transporters of the host and pathogen during infection. Copyright © 2017 American Society for Microbiology.

  15. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella typhimurium on Chicken Breast Fillet during Cooking

    OpenAIRE

    de Jong, Aarieke E. I.; van Asselt, Esther D.; Zwietering, Marcel H.; Nauta, Maarten J.; de Jonge, Rob

    2012-01-01

    The aim of this research was to determine the decimal reduction times of bacteria present on chicken fillet in boiling water. The experiments were conducted with Campylobacter jejuni, Salmonella, and Escherichia coli. Whole chicken breast fillets were inoculated with the pathogens, stored overnight (4∘C), and subsequently cooked. The surface temperature reached 70∘C within 30 sec and 85∘C within one minute. Extremely high decimal reduction times of 1.90, 1.97, and 2.20 min were obtained fo...

  16. Occurrence and antimicrobial resistance of pathogenic Escherichia coli and Salmonella spp. in retail raw table eggs sold for human consumption in Enugu state, Nigeria

    Science.gov (United States)

    Okorie-Kanu, O. Josephine; Ezenduka, E. Vivienne; Okorie-Kanu, C. Onwuchokwe; Ugwu, L. Chinweokwu; Nnamani, U. John

    2016-01-01

    Aim: This study was conducted to investigate the occurrence of pathogenic Escherichia coli and Salmonella species in retail raw table eggs sold for human consumption in Enugu State and to determine the resistance of these pathogens to antimicrobials commonly used in human and veterinary practices in Nigeria. Materials and Methods: A total of 340 raw table eggs comprising 68 composite samples (5 eggs per composite sample) were collected from five selected farms (13 composite samples from the farms) and 10 retail outlets (55 composite samples from the retail outlets) in the study area over a period of 4-month (March-June, 2014). The eggs were screened for pathogenic E. coli and Salmonella species following standard procedures within 24 h of sample collection. Isolates obtained were subjected to in-vitro antimicrobial susceptibility test with 15 commonly used antimicrobials using the disk diffusion method. Results: About 37 (54.4%) and 7 (10.3%) of the 68 composite samples were positive for pathogenic E. coli and Salmonella species, respectively. The shells showed significantly higher (p0.05). The organisms obtained showed a multiple drug resistance. They were completely resistant to nitrofurantoin, sulfamethoxazole/trimethoprim, penicillin G and oxacillin. In addition to these, Salmonella spp. also showed 100% resistance to tetracycline. The pathogenic E. coli isolates obtained were 100% susceptible to gentamicin, neomycin, ciprofloxacin, and amoxicillin-clavulanic acid while Salmonella spp. showed 100% susceptibility to erythromycin, neomycin, and rifampicin. Both organisms showed varying degrees of resistance to streptomycin, amoxicillin, vancomycin, and doxycycline. Conclusion: From the results of the study, it can be concluded that the raw table eggs marketed for human consumption in Enugu State, Nigeria is contaminated with pathogenic E. coli and Salmonella species that showed multiple drug resistance to antimicrobial agents commonly used in veterinary and human

  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

    Science.gov (United States)

    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. Salmonella infection in healthy pet reptiles: Bacteriological isolation and study of some pathogenic characters.

    Science.gov (United States)

    Bertelloni, Fabrizio; Chemaly, Marianne; Cerri, Domenico; Gall, Françoise Le; Ebani, Valentina Virginia

    2016-06-01

    The fecal samples from 213 captive reptiles were examined, and 29 (13.61%) Salmonella enterica isolates were detected: 14/62 (22.58%) from chelonians, 14/135 (10.37%) from saurians, and 1/16 (6.25%) from ophidians. The isolates were distributed among 14 different serotypes: Miami, Ebrie, Hermannsweder, Tiergarten, Tornov, Pomona, Poona, Goteborg, Abaetetube, Nyanza, Kumasi, Typhimurium, 50:b:z6, 9,12:z29:1,5, and a non-motile serotype with antigenic formula 1,4,[5],12:-:-. Salmonella typhimurium and 50:b:z6 isolates showed the spv plasmid virulence genes, responsible of the capability to induce extra-intestinal infections. In some cases, pulsed field gel electrophoresis revealed different profiles for the strains of the same serotypes, showing different origins, whereas a common source of infection was supposed when one pulsotype had been observed for isolates of a serovar. Twenty-seven (93.10%) isolates showed resistance to one or more antibiotics. Ceftazidime was active to all the tested isolates, whereas the highest percentages of strains were no susceptible to tigecycline (93.10%), streptomycin (89.66%), and sulfonamide (86.21%).

  19. The microbiota mediates pathogen clearance from the gut lumen after non-typhoidal Salmonella diarrhea.

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    Kathrin Endt

    Full Text Available Many enteropathogenic bacteria target the mammalian gut. The mechanisms protecting the host from infection are poorly understood. We have studied the protective functions of secretory antibodies (sIgA and the microbiota, using a mouse model for S. typhimurium diarrhea. This pathogen is a common cause of diarrhea in humans world-wide. S. typhimurium (S. tm(att, sseD causes a self-limiting gut infection in streptomycin-treated mice. After 40 days, all animals had overcome the disease, developed a sIgA response, and most had cleared the pathogen from the gut lumen. sIgA limited pathogen access to the mucosal surface and protected from gut inflammation in challenge infections. This protection was O-antigen specific, as demonstrated with pathogens lacking the S. typhimurium O-antigen (wbaP, S. enteritidis and sIgA-deficient mice (TCRβ(-/-δ(-/-, J(H (-/-, IgA(-/-, pIgR(-/-. Surprisingly, sIgA-deficiency did not affect the kinetics of pathogen clearance from the gut lumen. Instead, this was mediated by the microbiota. This was confirmed using 'L-mice' which harbor a low complexity gut flora, lack colonization resistance and develop a normal sIgA response, but fail to clear S. tm(att from the gut lumen. In these mice, pathogen clearance was achieved by transferring a normal complex microbiota. Thus, besides colonization resistance ( = pathogen blockage by an intact microbiota, the microbiota mediates a second, novel protective function, i.e. pathogen clearance. Here, the normal microbiota re-grows from a state of depletion and disturbed composition and gradually clears even very high pathogen loads from the gut lumen, a site inaccessible to most "classical" immune effector mechanisms. In conclusion, sIgA and microbiota serve complementary protective functions. The microbiota confers colonization resistance and mediates pathogen clearance in primary infections, while sIgA protects from disease if the host re-encounters the same pathogen. This has

  20. Comparative genome analysis of the high pathogenicity Salmonella Typhimurium strain UK-1.

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    Yingqin Luo

    Full Text Available Salmonella enterica serovar Typhimurium, a gram-negative facultative rod-shaped bacterium causing salmonellosis and foodborne disease, is one of the most common isolated Salmonella serovars in both developed and developing nations. Several S. Typhimurium genomes have been completed and many more genome-sequencing projects are underway. Comparative genome analysis of the multiple strains leads to a better understanding of the evolution of S. Typhimurium and its pathogenesis. S. Typhimurium strain UK-1 (belongs to phage type 1 is highly virulent when orally administered to mice and chickens and efficiently colonizes lymphoid tissues of these species. These characteristics make this strain a good choice for use in vaccine development. In fact, UK-1 has been used as the parent strain for a number of nonrecombinant and recombinant vaccine strains, including several commercial vaccines for poultry. In this study, we conducted a thorough comparative genome analysis of the UK-1 strain with other S. Typhimurium strains and examined the phenotypic impact of several genomic differences. Whole genomic comparison highlights an extremely close relationship between the UK-1 strain and other S. Typhimurium strains; however, many interesting genetic and genomic variations specific to UK-1 were explored. In particular, the deletion of a UK-1-specific gene that is highly similar to the gene encoding the T3SS effector protein NleC exhibited a significant decrease in oral virulence in BALB/c mice. The complete genetic complements in UK-1, especially those elements that contribute to virulence or aid in determining the diversity within bacterial species, provide key information in evaluating the functional characterization of important genetic determinants and for development of vaccines.

  1. Pathogen translocation and histopathological lesions in an experimental model of Salmonella Dublin infection in calves receiving lactic acid bacteria and lactose supplements

    Science.gov (United States)

    Zbrun, María V.; Soto, Lorena P.; Bertozzi, Ezequiel; Sequeira, Gabriel J.; Marti, Luis E.; Signorini, Marcelo L.; Armesto, Roberto Rodríguez; Rosmini, Marcelo R.

    2012-01-01

    The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 109 CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 × 1010 CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection. PMID:23000583

  2. Vaccines for viral and bacterial pathogens causing acute gastroenteritis: Part II: Vaccines for Shigella, Salmonella, enterotoxigenic E. coli (ETEC) enterohemorragic E. coli (EHEC) and Campylobacter jejuni

    Science.gov (United States)

    O’Ryan, Miguel; Vidal, Roberto; del Canto, Felipe; Carlos Salazar, Juan; Montero, David

    2015-01-01

    In Part II we discuss the following bacterial pathogens: Shigella, Salmonella (non-typhoidal), diarrheogenic E. coli (enterotoxigenic and enterohemorragic) and Campylobacter jejuni. In contrast to the enteric viruses and Vibrio cholerae discussed in Part I of this series, for the bacterial pathogens described here there is only one licensed vaccine, developed primarily for Vibrio cholerae and which provides moderate protection against enterotoxigenic E. coli (ETEC) (Dukoral®), as well as a few additional candidates in advanced stages of development for ETEC and one candidate for Shigella spp. Numerous vaccine candidates in earlier stages of development are discussed. PMID:25715096

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

    Directory of Open Access Journals (Sweden)

    Shin Sook-Il

    2011-01-01

    Full Text Available Abstract Background Metabolic reconstructions (MRs are common denominators in systems biology and represent biochemical, genetic, and genomic (BiGG knowledge-bases for target organisms by capturing currently available information in a consistent, structured manner. Salmonella enterica subspecies I serovar Typhimurium is a human pathogen, causes various diseases and its increasing antibiotic resistance poses a public health problem. Results Here, we describe a community-driven effort, in which more than 20 experts in S. Typhimurium biology and systems biology collaborated to reconcile and expand the S. Typhimurium BiGG knowledge-base. The consensus MR was obtained starting from two independently developed MRs for S. Typhimurium. Key results of this reconstruction jamboree include i development and implementation of a community-based workflow for MR annotation and reconciliation; ii incorporation of thermodynamic information; and iii use of the consensus MR to identify potential multi-target drug therapy approaches. Conclusion Taken together, with the growing number of parallel MRs a structured, community-driven approach will be necessary to maximize quality while increasing adoption of MRs in experimental design and interpretation.

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

    Science.gov (United States)

    Thiele, Ines; Hyduke, Daniel R; Steeb, Benjamin; Fankam, Guy; Allen, Douglas K; Bazzani, Susanna; Charusanti, Pep; Chen, Feng-Chi; Fleming, Ronan M T; Hsiung, Chao A; De Keersmaecker, Sigrid C J; Liao, Yu-Chieh; Marchal, Kathleen; Mo, Monica L; Özdemir, Emre; Raghunathan, Anu; Reed, Jennifer L; Shin, Sook-il; Sigurbjörnsdóttir, Sara; Steinmann, Jonas; Sudarsan, Suresh; Swainston, Neil; Thijs, Inge M; Zengler, Karsten; Palsson, Bernhard O; Adkins, Joshua N; Bumann, Dirk

    2011-01-18

    Metabolic reconstructions (MRs) are common denominators in systems biology and represent biochemical, genetic, and genomic (BiGG) knowledge-bases for target organisms by capturing currently available information in a consistent, structured manner. Salmonella enterica subspecies I serovar Typhimurium is a human pathogen, causes various diseases and its increasing antibiotic resistance poses a public health problem. Here, we describe a community-driven effort, in which more than 20 experts in S. Typhimurium biology and systems biology collaborated to reconcile and expand the S. Typhimurium BiGG knowledge-base. The consensus MR was obtained starting from two independently developed MRs for S. Typhimurium. Key results of this reconstruction jamboree include i) development and implementation of a community-based workflow for MR annotation and reconciliation; ii) incorporation of thermodynamic information; and iii) use of the consensus MR to identify potential multi-target drug therapy approaches. Taken together, with the growing number of parallel MRs a structured, community-driven approach will be necessary to maximize quality while increasing adoption of MRs in experimental design and interpretation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Thiele, Ines; Hyduke, Daniel R.; Steeb, Benjamin; Fankam, Guy; Allen, Douglas K.; Bazzani, Susanna; Charusanti, Pep; Chen, Feng-Chi; Fleming, Ronan MT; Hsiung, Chao A.; De Keersmaecker, Sigrid CJ; Liao, Yu-Chieh; Marchal, Kathleen; Mo, Monica L.; Özdemir, Emre; Raghunathan, Anu; Reed, Jennifer L.; Shin, Sook-Il; Sigurbjörnsdóttir, Sara; Steinmann, Jonas; Sudarsan, Suresh; Swainston, Neil; Thijs, Inge M.; Zengler, Karsten; Palsson, Bernhard O.; Adkins, Joshua N.; Bumann, Dirk

    2011-01-01

    Metabolic reconstructions (MRs) are common denominators in systems biology and represent biochemical, genetic, and genomic (BiGG) knowledge-bases for target organisms by capturing currently available information in a consistent, structured manner. Salmonella enterica subspecies I serovar Typhimurium is a human pathogen, causes various diseases and its increasing antibiotic resistance poses a public health problem. Here, we describe a community-driven effort, in which more than 20 experts in S. Typhimurium biology and systems biology collaborated to reconcile and expand the S. Typhimurium BiGG knowledge-base. The consensus MR was obtained starting from two independently developed MRs for S. Typhimurium. Key results of this reconstruction jamboree include i) development and implementation of a community-based workflow for MR annotation and reconciliation; ii) incorporation of thermodynamic information; and iii) use of the consensus MR to identify potential multi-target drug therapy approaches. Finally, taken together, with the growing number of parallel MRs a structured, community-driven approach will be necessary to maximize quality while increasing adoption of MRs in experimental design and interpretation.

  6. Quantification of Salmonella Survival and Infection in an In vitro Model of the Human Intestinal Tract as Proxy for Foodborne Pathogens

    Directory of Open Access Journals (Sweden)

    Lucas M. Wijnands

    2017-06-01

    Full Text Available Different techniques are available for assessing differences in virulence of bacterial foodborne pathogens. The use of animal models or human volunteers is not expedient for various reasons; the use of epidemiological data is often hampered by lack of crucial data. In this paper, we describe a static, sequential gastrointestinal tract (GIT model system in which foodborne pathogens are exposed to simulated gastric and intestinal contents of the human digestive tract, including the interaction of pathogens with the intestinal epithelium. The system can be employed with any foodborne bacterial pathogens. Five strains of Salmonella Heidelberg and one strain of Salmonella Typhimurium were used to assess the robustness of the system. Four S. Heidelberg strains originated from an outbreak, the fifth S. Heidelberg strain and the S. Typhimurium strain originated from routine meat inspections. Data from plate counts, collected for determining the numbers of surviving bacteria in each stage, were used to quantify both the experimental uncertainty and biological variability of pathogen survival throughout the system. For this, a hierarchical Bayesian framework using Markov chain Monte Carlo (MCMC was employed. The model system is able to distinguish serovars/strains for in vitro infectivity when accounting for within strain biological variability and experimental uncertainty.

  7. Surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen Erwinia tracheiphila.

    Directory of Open Access Journals (Sweden)

    Dhiraj Gautam

    Full Text Available Outbreaks of foodborne illness attributed to the consumption of Salmonella-tainted cantaloupe have occurred repeatedly, but understanding of the ecology of Salmonella on cantaloupe fruit surfaces is limited. We investigated the interactions between Salmonella enterica Poona, the plant pathogenic bacterium Erwinia tracheiphila, and cantaloupe fruit. Fruit surfaces were inoculated at the natural cracking stage by spreading S. enterica and E. tracheiphila, 20 µl at 107 cfu/ml, independently or together, over a 2×2 cm rind area containing a crack. Microbial and microscopic analyses were performed at 0, 9 and 24 days post inoculation (DPI. Even at 24 DPI (fruit maturity S. enterica was detected on 14% and 40% of the fruit inoculated with S. enterica alone and the two-pathogen mixture, respectively. However, the population of S. enterica declined gradually after initial inoculation. E. tracheiphila, inoculated alone or together with Salmonella, caused watersoaked lesions on cantaloupe fruit; but we could not conclude in this study that S. enterica survival on the fruit surface was enhanced by the presence of those lesions. Of fruit inoculated with E. tracheiphila alone and sampled at 24 DPI, 61% had watersoaked lesions on the surface. In nearly half of those symptomatic fruits the watersoaking extended into the sub-rind mesocarp, and E. tracheiphila was recovered from that tissue in 50% of the symptomatic fruit. In this work, E. tracheiphila internalized through natural cracks on developing fruits. S. enterica was never detected in the fruit interior (ca. 2-3 mm below rind surface under the limited conditions of our experiments, but the possibility that it, or other human pathogens that contaminate fresh produce, might also do so should be investigated under a wider range of conditions and produce types.

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

    Science.gov (United States)

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

  9. A Thermostable Salmonella Phage Endolysin, Lys68, with Broad Bactericidal Properties against Gram-Negative Pathogens in Presence of Weak Acids

    DEFF Research Database (Denmark)

    Oliveira, Hugo; Thiagarajan, Viruthachalam; Walmagh, Maarten

    2014-01-01

    Resistance rates are increasing among several problematic Gram-negative pathogens, a fact that has encouraged the development of new antimicrobial agents. This paper characterizes a Salmonella phage endolysin (Lys68) and demonstrates its potential antimicrobial effectiveness when combined...... with organic acids towards Gram-negative pathogens. Biochemical characterization reveals that Lys68 is more active at pH 7.0, maintaining 76.7% of its activity when stored at 4°C for two months. Thermostability tests showed that Lys68 is only completely inactivated upon exposure to 100°C for 30 min......, and circular dichroism analysis demonstrated the ability to refold into its original conformation upon thermal denaturation. It was shown that Lys68 is able to lyse a wide panel of Gram-negative bacteria (13 different species) in combination with the outer membrane permeabilizers EDTA, citric and malic acid...

  10. A thermostable Salmonella phage endolysin, Lys68, with broad bactericidal properties against gram-negative pathogens in presence of weak acids.

    Directory of Open Access Journals (Sweden)

    Hugo Oliveira

    Full Text Available Resistance rates are increasing among several problematic Gram-negative pathogens, a fact that has encouraged the development of new antimicrobial agents. This paper characterizes a Salmonella phage endolysin (Lys68 and demonstrates its potential antimicrobial effectiveness when combined with organic acids towards Gram-negative pathogens. Biochemical characterization reveals that Lys68 is more active at pH 7.0, maintaining 76.7% of its activity when stored at 4°C for two months. Thermostability tests showed that Lys68 is only completely inactivated upon exposure to 100°C for 30 min, and circular dichroism analysis demonstrated the ability to refold into its original conformation upon thermal denaturation. It was shown that Lys68 is able to lyse a wide panel of Gram-negative bacteria (13 different species in combination with the outer membrane permeabilizers EDTA, citric and malic acid. While the EDTA/Lys68 combination only inactivated Pseudomonas strains, the use of citric or malic acid broadened Lys68 antibacterial effect to other Gram-negative pathogens (lytic activity against 9 and 11 species, respectively. Particularly against Salmonella Typhimurium LT2, the combinatory effect of malic or citric acid with Lys68 led to approximately 3 to 5 log reductions in bacterial load/CFUs after 2 hours, respectively, and was also able to reduce stationary-phase cells and bacterial biofilms by approximately 1 log. The broad killing capacity of malic/citric acid-Lys68 is explained by the destabilization and major disruptions of the cell outer membrane integrity due to the acidity caused by the organic acids and a relatively high muralytic activity of Lys68 at low pH. Lys68 demonstrates good (thermostability properties that combined with different outer membrane permeabilizers, could become useful to combat Gram-negative pathogens in agricultural, food and medical industry.

  11. Pathogen update: Salmonella

    DEFF Research Database (Denmark)

    Hald, Tine

    2013-01-01

    - Introduction - Incidence and burden of human salmonellosis - Epidemiology and disease transmission in humans - Classification and subtypes - Tracing the sources of human salmonellosis – source attribution - Discussion on sources to human salmonellosis - References...

  12. Determination of Profiles of Salmonella and Pathogenic Vibrio SPP. in Black Tiger Shrimp for Export by Introduction of Quality Assured Microbiological Assays

    Energy Technology Data Exchange (ETDEWEB)

    Wongchinda, N.; Sirimanuyutt, S.; Piromrak, R.; Rachniyom, S. [Fishery Technological Development Institute, Department of Fisheries, Bangkok (Thailand)

    2005-01-15

    Studies were conducted on contamination by Salmonella and pathogenic Vibrio spp. in samples of aquaculture black tiger shrimp, the water supply (canal water which is supplied as raw pond water before treatment), pond water, feed materials, and fresh and frozen shrimp. Salmonella was detected in samples of the water supply, pond water, feed materials, fresh shrimp at farm, fresh shrimp from wholesale market and frozen shrimp destined for export at levels of 13.95%, 1.53%, 1.14%, 3.17%, 30.4% and 0.21% respectively. V. cholerae non 01 was found in one sample of water from a culture pond of 131 tested (0.8%). V. parahaemolyticus was found in samples of canal water, pond water, fresh black tiger shrimp collected at farms, fresh black tiger shrimp collected at wholesale shrimp markets and frozen black tiger shrimp destined for export at levels of 2.3%, 5.3%, 14.3%, 48 % and 0.2% respectively. The strains identified as V. parahaemolyticus were examined for the presence or absence of the TDH and TRH. The incidence of TDH (KP+) was 2.67% (seven of 262 strains) and of TRH (urease reaction) was 1.15% (three of 262 strains). Salmonella and V. parahaemolyticus were found in a high percentage in fresh black tiger shrimp collected from wholesale shrimp markets. These shrimp are used as raw material for domestic consumption and for processing for exported shrimp products. Therefore GMP and/or Hazard Analysis Critical Control Point (HACCP) system for shrimp distributors/producers should be applied. (author)

  13. Degradation of the HilC and HilD regulator proteins by ATP-dependent Lon protease leads to downregulation of Salmonella pathogenicity island 1 gene expression.

    Science.gov (United States)

    Takaya, Akiko; Kubota, Yohsuke; Isogai, Emiko; Yamamoto, Tomoko

    2005-02-01

    Salmonella pathogenicity island 1 (SPI1) enables infecting Salmonella to cross the small intestinal barrier and to escape phagocytosis by inducing apoptosis. Several environmental signals and transcriptional regulators modulate the expression of hilA, which encodes a protein playing a central role in the regulatory hierarchy of SPI1 gene expression. We have previously shown that Lon, a stress-induced ATP-dependent protease, is a negative regulator of hilA, suggesting that it targets factors required for activating hilA expression. To elucidate the mechanisms by which Lon protease negatively regulates SPI1 transcription, we looked for its substrate proteins. We found that HilC and HilD, which are positive regulators of hilA expression, accumulate in Lon-depleted cells, and that the enhancement of SPI1 expression that occurs in a lon-disrupted mutant is not observed in the lon hilC hilD triple null mutant. Furthermore, we demonstrated that the half-lives of HilC and HilD are, respectively, about 12 times and three times longer in the Lon-depleted mutant, than in the Lon+ cells, suggesting that Lon targets both of HilC and HilD. In view of these findings, we suggest that the regulation of SPI1 expression is negatively controlled through degradation of the HilC and HilD transcriptional regulators by Lon.

  14. Prevalence of Salmonella enterica, Listeria monocytogenes, and pathogenic Escherichia coli in bulk tank milk and milk filters from US dairy operations in the National Animal Health Monitoring System Dairy 2014 study.

    Science.gov (United States)

    Sonnier, Jakeitha L; Karns, Jeffrey S; Lombard, Jason E; Kopral, Christine A; Haley, Bradd J; Kim, Seon-Woo; Van Kessel, Jo Ann S

    2018-03-01

    The dairy farm environment is a well-documented reservoir for zoonotic pathogens such as Salmonella enterica, Shiga-toxigenic Escherichia coli, and Listeria monocytogenes, and humans may be exposed to these pathogens via consumption of unpasteurized milk and dairy products. As part of the National Animal Health Monitoring System Dairy 2014 study, bulk tank milk (BTM, n = 234) and milk filters (n = 254) were collected from a total of 234 dairy operations in 17 major dairy states and analyzed for the presence of these pathogens. The invA gene was detected in samples from 18.5% of operations and Salmonella enterica was isolated from 18.0% of operations. Salmonella Dublin was detected in 0.7% of operations. Sixteen Salmonella serotypes were isolated, and the most common serotypes were Cerro, Montevideo, and Newport. Representative Salmonella isolates (n = 137) were tested against a panel of 14 antimicrobials. Most (85%) were pansusceptible; the remaining were resistant to 1 to 9 antimicrobials, and within the resistant strains the most common profile was resistance to ampicillin/clavulanic acid, ampicillin, cefoxitin, ceftiofur, ceftriaxone, chloramphenicol, streptomycin, sulfisoxazole, and tetracycline. Listeria spp. were isolated from 19.9% of operations, and L. monocytogenes was isolated from 3.0% of operations. Serogroups 1/2a and 1/2b were the most common, followed by 4b and 4a. One or more E. coli virulence genes were detected in the BTM from 30.5% of operations and in the filters from 75.3% of operations. A combination of stx 2 , eaeA, and γ-tir genes was detected in the BTM from 0.5% of operations and in the filters from 6.6% of operations. The results of this study indicate an appreciable prevalence of bacterial pathogens in BTM and filters, including serovars known to infect humans. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

  16. Inhibitory Activity of Lactid Acid Bacteria Isolated from Tape Waterlily Seed to Enteric Pathogenic Bacteria (Vibrio cholera, Salmonella typhi, Shigella disentri, and E.coli and Its’ Susceptibility to Antibiotic, Bile Salt and Acidic Condition

    Directory of Open Access Journals (Sweden)

    Iin Khusnul Khotimah

    2012-03-01

    Full Text Available The aim of this research was to observe inhibitory activity of LAB isolated from tape waterlily seed to enteric pathogenic bacteria (Vibrio cholera, Salmonella typhi, Shigella disentri, E.coli ATCC 25922 and it’s susceptibility to antibiotic, in bile salt and under acidic condition. Microbia in the tape ( a fermented product of waterlily seed to showed were Streptococcus thermophilus (IKH-1, Pediococcus pentosaceus (IKH-2 and Leuconostoc mesentroides (IKH-8. Streptococcus thermophillus showed inhibition against the growth of Shigella disentri with inhibition zones 16,28 mm, but did not against the growth of V. Cholera, S. typhi, E.coli. Pediococcus pentosaceus inhibit Vibrio cholera, dan Salmonella thypi with inhibition zones 18,59 mm dan 7,91 mm. So that, Leuconostoc mesenteroides inhibit Salmonella thypi with zones inhibits average 8,25 mm. Chloramfenicol at 0.05 mg concentrations did not show inhibition against the growth of isolated Streptococcus thermophillus, Pediococcus pentosaceus and Leuconostoc mesentroides. These isolates could survive too in bile salt (2% and acidified media (pH 3.   Keyword : The tape of  waterlily seed, LAB, probiotic and enteric pathogenic   KEMAMPUAN PENGHAMBATAN BAKTERI ASAM LAKTAT DARI TAPE BIJI TERATAI TERHADAP PATOGENIK ENTERIK (VIBRIO CHOLERA, SALMONELLA THYPI, SHIGELLA DISENTRI, E. COLI, ANTIBIOTIK, KETAHANANNYA TERHADAP BILE SALT DAN ASAM   ABSTRAK   Penelitian ini bertujuan untuk menguji kemampuan penghambatan bakteri asam laktat yang diisolasi dari tape biji teratai terhadap patogenik enterik (Vibrio cholera, Salmonella thypi, Shigella disentri, E. Coli ATCC 25922, antibiotik, bile salt dan asam. Jenis bakteri yang diketahui tumbuh selama fermentasi tape biji teratai adalah Streptococcus thermopilus (IKH-1, Pediococcus pentosaceus(IKH-2, dan Leuconostoc mesentroides (IKH-8. Pengamatan terhadap uji penghambatan patogenik enterik (Vibrio cholera, Salmonella thypi, Shigella disentri, dan E. Coli ATCC

  17. Phenotypic and molecular characterization of Salmonella serotypes ...

    African Journals Online (AJOL)

    The presence of Salmonella and human pathogens in unpasteurized milk remains a public health hazard. The study reported the phenotypic and molecular characterization of Salmonella serotypes in cow raw milk, cheese and traditional yoghurt marketed for man's consumption in Nigeria. Isolation of Salmonella was done ...

  18. Use of caprylic acid to control pathogens (Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium) in apple juice at mild heat temperature.

    Science.gov (United States)

    Kim, S A; Rhee, M S

    2015-11-01

    The aim of this study was to examine the effects of caprylic acid (CA) on pathogens in apple juice having intrinsic organic acids, and to determine any synergistic effects. Bactericidal effects of CA were examined against Escherichia coli O157:H7 and Salmonella Typhimurium present in apple juice at mild heating temperatures. Apple juice containing each of the pathogens was treated with CA (0·1, 0·2, 0·4, 0·6 or 0·8 mmol l(-1)) at 50 or 55°C. Treatment with 0·8 mmol l(-1) (0·013%) CA at 50°C for 5 min or with 0·6 mmol l(-1) (0·010%) CA at 55°C for 5 min resulted in the complete eradication of E. coli O157:H7 (initial population: 7·25-7·34 log CFU ml(-1)). Salmonella Typhimurium were more sensitive than E. coli O157:H7: all bacteria (7·81-7·55 log CFU ml(-1)) were eradicated by treatment with 0·2 mmol l(-1) (0·0032%) CA at 55°C for 5 min or with 0·6 mmol l(-1) CA at 50°C for 5 min. By contrast, when pH-adjusted apple juice (pH 7·0) was treated with 0·8 mmol l(-1) CA, there was no significant difference in bactericidal effects between CA-treated samples and controls (heat treatment alone or heat + 0·1% ethanol treatment). This result suggested that acidic pH in the apple juice boost the antibacterial effects of CA. CA treatment did not affect (P > 0·05) the pH, colour or °Brix of the apple juice. This study highlights the utility of CA as a natural antibacterial agent that can eliminate micro-organisms from apple juice at very low concentrations (≤0·013%) and temperatures (≤55°C) within a short time (≤10 min). The results of our study may contribute to the development of an efficient method for improving the microbiological safety of apple juice. © 2015 The Society for Applied Microbiology.

  19. Ralstonia insidiosa serves as bridges in biofilm formation by foodborne pathogens Listeria monocytogenes, Salmonella enterica, and enterohemorrhagic Escherichia coli

    Science.gov (United States)

    Biofilm formation on abiotic surfaces in fresh produce processing facilities might play a role in foodborne outbreaks by providing protective microniches for pathogenic bacteria. Our previous study showed that a strain of Ralstonia insidiosa isolated from a fresh produce processing plant could enhan...

  20. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella typhimurium on Chicken Breast Fillet during Cooking

    DEFF Research Database (Denmark)

    de Jong, Aarieke E I; van Asselt, Esther D; Zwietering, Marcel H

    2012-01-01

    cooking enlarged the heat resistance of the food borne pathogens. Additionally, a high challenge temperature or fast heating rate contributed to the level of heat resistance. The data were used to assess the probability of illness (campylobacteriosis) due to consumption of chicken fillet as a function...

  1. Interaction between Food-borne Pathogens (Campylobacter jejuni, Salmonella Typhimurium and Listeria monocytogenes) and a Common Soil Flagellate (Cercomonas sp.)

    DEFF Research Database (Denmark)

    Bui, Thanh Xuan; Wolff, Anders; Madsen, Mogens

    2012-01-01

    Free-living protozoa may harbor, protect, and disperse bacteria, including those ingested and passed in viable form in feces. The flagellates are very important predators on bacteria in soil, but their role in the survival of food-borne pathogens associated with fruits and vegetables is not well...

  2. Role of yqiC in the pathogenicity of Salmonella and innate immune responses of human intestinal epithelium

    Directory of Open Access Journals (Sweden)

    Ke-Chuan Wang

    2016-10-01

    Full Text Available The yqiC gene of Salmonella enterica serovar Typhimurium (S. Typhimurium regulates bacterial growth at different temperatures and mice survival after infection. However, the role of yqiC in bacterial colonization and host immunity remains unknown. We infected human LS174T, Caco-2, HeLa, and THP-1 cells with S. Typhimurium wild-type SL1344, its yqiC mutant, and its complemented strain. Bacterial colonization and internalization in the four cell lines significantly reduced on yqiC depletion. Postinfection production of interleukin-8 and human β-defensin-3 in LS174T cells significantly reduced because of yqiC deleted in S. Typhimurium. The phenotype of yqiC mutant exhibited few and short flagella, fimbriae on the cell surface, enhanced biofilm formation, upregulated type-1 fimbriae expression, and reduced bacterial motility. Type-1 fimbriae, flagella, SPI-1, and SPI-2 gene expression was quantified using real-time PCR. The data show that deletion of yqiC upregulated fimA and fimZ expression and downregulated flhD, fliZ, invA, and sseB expression. Furthermore, thin-layer chromatography and high-performance liquid chromatography revealed the absence of menaquinone in the yqiC mutant, thus validating the importance of yqiC in the bacterial electron transport chain. Therefore, YqiC can negatively regulate FimZ for type-1 fimbriae expression and manipulate the functions of its downstream virulence factors including flagella, SPI-1, and SPI-2 effectors.

  3. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella typhimurium on Chicken Breast Fillet during Cooking

    Directory of Open Access Journals (Sweden)

    Aarieke E.I. de Jong

    2012-01-01

    The surface temperature reached 70∘C within 30 sec and 85∘C within one minute. Extremely high decimal reduction times of 1.90, 1.97, and 2.20 min were obtained for C. jejuni, E. coli, and S. typhimurium, respectively. Chicken meat and refrigerated storage before cooking enlarged the heat resistance of the food borne pathogens. Additionally, a high challenge temperature or fast heating rate contributed to the level of heat resistance. The data were used to assess the probability of illness (campylobacteriosis due to consumption of chicken fillet as a function of cooking time. The data revealed that cooking time may be far more critical than previously assumed.

  4. Salmonella osteomyelitis

    OpenAIRE

    Somsri Wiwanitkit; Viroj Wiwanitkit

    2016-01-01

    Salmonella infection can cause four predominant clinical syndromes: enteric fever, acute gastroenteritis, bacteraemia with or without metastatic infection, and the asymptomatic carrier state. Salmonella as an aetiological agent in osteomyelitis is essentially rare and salmonella osteomyelitis in itself is predominantly seen in patients with haemoglobinopathies such as sickle cell disease or thalassemia. There are very few cases reported in the literature in which salmonella osteomyelitis is s...

  5. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2014. Scientific Opinion on the risk posed by pathogens in food of non-animal origin. Part 2 (Salmonella and Norovirus in tomatoes)

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    consumption between 2007 and 2012. Risk factors for tomato contamination by Salmonella and Norovirus were considered in the context of the whole food chain. Available estimates of the Salmonella and Norovirus occurrence in tomatoes were evaluated together with mitigation options relating to prevention...... of contamination and the relevance of microbiological criteria. It was concluded that each farm environment represents a unique combination of risk factors that can influence occurrence and persistence of pathogens in tomato production. Appropriate implementation of food safety management systems including Good...... Agricultural Practices (GAP), Good Hygiene Practices (GHP) and Good Manufacturing Practices (GMP), should be primary objectives of tomato producers. The current lack of data does not allow the proposal of a Hygiene Criterion for E. coli at primary production of tomatoes and it is also not possible to assess...

  6. Coordinated Regulation of Virulence during Systemic Infection of Salmonella enterica serovar Typhimurium

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hyunjin; McDermott, Jason E.; Porwollik, Steffen; Mcclelland, Michael; Heffron, Fred

    2009-02-20

    Salmonella must respond to a myriad of environmental cues during infection of a mouse and express specific subsets of genes in a temporal and spatial manner to subvert the host defense mechanisms but these regulatory pathways are poorly established. To unravel how micro-environmental signals are processed and integrated into coordinated action, we constructed in-frame non-polar deletions of 84 regulators inferred to play a role in Salmonella typhimurium virulence and tested them in three virulence assays (intraperitoneal (i.p.), and intragastric (i.g.) infection in BALB/c mice, and persistence in SvJ129 mice). Overall 36 regulators were identified that were less virulent in at least one assay, and of those, 15 regulators were required for systemic mouse infection in an acute infection model. As a first step towards understanding the interplay between a pathogen and its host from a systems biology standpoint we focused on these 15 genes. Transcriptional profiles were obtained for each of these 15 regulators from strains grown under four different environmental conditions. These results as well as publicly available transcriptional profiles were analyzed using both network inference and cluster analysis algorithms. The analysis predicts a regulatory network in which all 15 regulators control a specific set of genes necessary for Salmonella to cause systemic infection. We tested the regulatory model by expressing a subset of the regulators in trans and monitoring transcription of 7 known virulence factors located within Salmonella pathogenicity island 2 (SPI-2). These experiments validated the regulatory model and showed that, for these 7 genes, the response regulator SsrB and the marR type regulator SlyA co-regulate in a regulatory cascade by integrating multiple signals.

  7. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2014. Scientific Opinion on the risk posed by pathogens in food of non-animal origin. Part 2 (Salmonella and Norovirus in berries)

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    Berries are a perishable food which can be consumed as fresh or minimally-processed as well as a frozen ingredient added to many foods. Strawberries, raspberries, blackberries and blueberries are the most commonly consumed in the EU. Risk factors for berry contamination by Salmonella and Norovirus...... were considered in the context of the whole food chain. Available estimates of the prevalence of these pathogens in berries were evaluated together with mitigation options relating to prevention of contamination and the relevance of microbiological criteria. It was concluded that each farm environment...... represents a unique combination of risk factors that can influence occurrence and persistence of pathogens in berry production. Appropriate implementation of food safety management systems including Good Agricultural Practices (GAP), Good Hygiene Practices (GHP) and Good Manufacturing Practices (GMP), should...

  8. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2014. Scientific Opinion on the risk posed by pathogens in food of non-animal origin. Part 2 (Salmonella and Norovirus in leafy greens eaten raw as salads)

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    Leafy greens eaten raw as salads are minimally processed and widely consumed foods. Risk factors for leafy greens contamination by Salmonella spp. and Norovirus were considered in the context of the whole food chain including agricultural production and processing. Available estimates...... combination of numerous characteristics that can influence occurrence and persistence of pathogens in leafy greens production. Appropriate implementation of food safety management systems, including Good Agricultural Practices (GAP), Good Hygiene Practices (GHP) and Good Manufacturing Practices (GMP), should...... of the prevalence of these pathogens (together with the use of Escherichia coli as an indicator organism) in leafy greens were evaluated. Specific mitigation options relating to contamination of leafy greens were considered and qualitatively assessed. It was concluded that each farm environment represents a unique...

  9. Salmonella biofilms

    NARCIS (Netherlands)

    Castelijn, G.A.A.

    2013-01-01

    Biofilm formation by Salmonellaspp. is a problem in the food industry, since biofilms may act as a persistent source of product contamination. Therefore the aim of this study was to obtain more insight in the processes involved and the factors contributing to Salmonellabiofilm

  10. Salmonella, Shigella, and Yersinia

    Science.gov (United States)

    Dekker, John; Frank, Karen

    2015-01-01

    Synopsis Salmonella, Shigella, and Yersinia cause a well-characterized spectrum of disease in humans, ranging from asymptomatic carriage to hemorrhagic colitis and fatal typhoidal fever. These pathogens are responsible for millions of cases of food-borne illness in the U.S. each year, with substantial costs measured in hospitalizations and lost productivity. In the developing world, illness caused by these pathogens is not only more prevalent, but is also associated with a greater case-fatality rate. Classical methods for identification rely on selective media and serology, but newer methods based on mass spectrometry and PCR show great promise for routine clinical testing. PMID:26004640

  11. Persistent Salmonella enterica serovar Typhimurium Infection Increases the Susceptibility of Mice to Develop Intestinal Inflammation

    Directory of Open Access Journals (Sweden)

    Bárbara M. Schultz

    2018-05-01

    Full Text Available Chronic intestinal inflammations are triggered by genetic and environmental components. However, it remains unclear how specific changes in the microbiota, host immunity, or pathogen exposure could promote the onset and exacerbation of these diseases. Here, we evaluated whether Salmonella enterica serovar Typhimurium (S. Typhimurium infection increases the susceptibility to develop intestinal inflammation in mice. Two mouse models were used to evaluate the impact of S. Typhimurium infection: the chemical induction of colitis by dextran sulfate sodium (DSS and interleukin (IL-10−/− mice, which develop spontaneous intestinal inflammation. We observed that S. Typhimurium infection makes DSS-treated and IL-10−/− mice more susceptible to develop intestinal inflammation. Importantly, this increased susceptibility is associated to the ability of S. Typhimurium to persist in liver and spleen of infected mice, which depends on the virulence proteins secreted by Salmonella Pathogenicity Island 2-encoded type three secretion system (TTSS-2. Although immunization with a live attenuated vaccine resulted in a moderate reduction of the IL-10−/− mice susceptibility to develop intestinal inflammation due to previous S. Typhimurium infection, it did not prevent bacterial persistence. Our results suggest that persistent S. Typhimurium infection may increase the susceptibility of mice to develop inflammation in the intestine, which could be associated with virulence proteins secreted by TTSS-2.

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

    Science.gov (United States)

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

    2016-01-01

    Salmonella enterica is among the most burdensome of foodborne disease agents. There are over 2,600 serovars that cause a range of disease manifestations ranging from enterocolitis to typhoid fever. While there are two vaccines in use in humans to protect against typhoid fever, there are none that prevent enterocolitis. If vaccines preventing enterocolitis were to be developed, they would likely protect against only one or a few serovars. In this report, we tested the hypothesis that probiotic organisms could compete for the preferred nutrient sources of Salmonella and thus prevent or treat infection. To this end, we added the fra locus, which encodes a utilization pathway for the Salmonella-specific nutrient source fructose-asparagine (F-Asn), to the probiotic bacterium Escherichia coli Nissle 1917 (Nissle) to increase its ability to compete with Salmonella in mouse models. We also tested a metabolically competent, but avirulent, Salmonella enterica serovar Typhimurium mutant for its ability to compete with wild-type Salmonella. The modified Nissle strain became more virulent and less able to protect against Salmonella in some instances. On the other hand, the modified Salmonella strain was safe and effective in preventing infection with wild-type Salmonella. While we tested for efficacy only against Salmonella Typhimurium, the modified Salmonella strain may be able to compete metabolically with most, if not all, Salmonella serovars, representing a novel approach to control of this pathogen. PMID:27185789

  13. Pathogenic adaptation of intracellular bacteria by rewiring a cis-regulatory input function.

    Science.gov (United States)

    Osborne, Suzanne E; Walthers, Don; Tomljenovic, Ana M; Mulder, David T; Silphaduang, Uma; Duong, Nancy; Lowden, Michael J; Wickham, Mark E; Waller, Ross F; Kenney, Linda J; Coombes, Brian K

    2009-03-10

    The acquisition of DNA by horizontal gene transfer enables bacteria to adapt to previously unexploited ecological niches. Although horizontal gene transfer and mutation of protein-coding sequences are well-recognized forms of pathogen evolution, the evolutionary significance of cis-regulatory mutations in creating phenotypic diversity through altered transcriptional outputs is not known. We show the significance of regulatory mutation for pathogen evolution by mapping and then rewiring a cis-regulatory module controlling a gene required for murine typhoid. Acquisition of a binding site for the Salmonella pathogenicity island-2 regulator, SsrB, enabled the srfN gene, ancestral to the Salmonella genus, to play a role in pathoadaptation of S. typhimurium to a host animal. We identified the evolved cis-regulatory module and quantified the fitness gain that this regulatory output accrues for the bacterium using competitive infections of host animals. Our findings highlight a mechanism of pathogen evolution involving regulatory mutation that is selected because of the fitness advantage the new regulatory output provides the incipient clones.

  14. Prevalence of Salmonella on Sheep Carcasses Slaughtered at ...

    African Journals Online (AJOL)

    ... indicated that Salmonella is a common problem in slaughtered sheep carcasses in Adama municipal abattoir. Therefore, Sources of pathogens in food animals need to be investigated and a further study of pathogens in the food chain is recommended. Keywords: Adama Carcass Ethiopia Prevalence Salmonella Sheep.

  15. Involvement of SPI-2-encoded SpiC in flagellum synthesis in Salmonella enterica serovar Typhimurium

    Directory of Open Access Journals (Sweden)

    Sugita Asami

    2009-08-01

    Full Text Available Abstract Background SpiC encoded within Salmonella pathogenicity island 2 on the Salmonella enterica serovar Typhimurium chromosome is required for survival within macrophages and systemic infection in mice. Additionally, SpiC contributes to Salmonella-induced activation of the signal transduction pathways in macrophages by affecting the expression of FliC, a component of flagella filaments. Here, we show the contribution of SpiC in flagellum synthesis. Results Quantitative RT-PCR shows that the expression levels of the class 3 fliD and motA genes that encode for the flagella cap and motor torque proteins, respectively, were lower for a spiC mutant strain than for the wild-type Salmonella. Further, this mutant had lower expression levels of the class 2 genes including the fliA gene encoding the flagellar-specific alternative sigma factor. We also found differences in flagella assembly between the wild-type strain and the spiC mutant. Many flagella filaments were observed on the bacterial surface of the wild-type strain, whereas the spiC mutant had only few flagella. The absence of spiC led to reduced expression of the FlhD protein, which functions as the master regulator in flagella gene expression, although no significant difference at the transcription level of the flhDC operon was observed between the wild-type strain and the spiC mutant. Conclusion The data show that SpiC is involved in flagella assembly by affecting the post-transcription expression of flhDC.

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

    Directory of Open Access Journals (Sweden)

    Kumagai Yoshinori

    2010-12-01

    Full Text Available Abstract 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.

  17. SALMONELLA SPECIES

    African Journals Online (AJOL)

    DR. AMINU

    ... of Salmonella species serotypes in relation to age and sex among children, ..... However, most antimicrobials show sufficient selective toxicity to be of value in ... salmonellosis should be given good attention (Barrow et al., 2007). To reduce ...

  18. High relative humidity pre-harvest reduces post-harvest proliferation of Salmonella in tomatoes

    NARCIS (Netherlands)

    Devleesschauwer, Brecht; Marvasi, Massimiliano; Giurcanu, Mihai C.; Hochmuth, George J.; Speybroeck, Niko; Havelaar, Arie H.; Teplitski, Max

    2017-01-01

    Outbreaks of human illness caused by enteric pathogens such as Salmonella are increasingly linked to the consumption of fruits and vegetables. Knowledge on the factors affecting Salmonella proliferation on fresh produce therefore becomes increasingly important to safeguard public health. Previous

  19. Survival of foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Vibrio parahaemolyticus) in raw ready-to-eat crab marinated in soy sauce.

    Science.gov (United States)

    Cho, T J; Kim, N H; Kim, S A; Song, J H; Rhee, M S

    2016-12-05

    Knowing the survival characteristics of foodborne pathogens in raw ready-to-eat (RTE) seafood is the key to predicting whether they pose a microbiological hazard. The present study examined the survival of Escherichia coli O157:H7, Salmonella Typhimurium, Vibrio parahaemoliticus, Listeria monocytogenes, and Staphylococcus aureus in raw RTE crab marinated in soy sauce. Inoculated crabs (initial bacterial population=4.1-4.4logCFU/g) were immersed in soy sauce and then stored at refrigeration (5°C) or room temperature (22°C) for up to 28days. At 5°C, all bacteria (except V. parahaemolyticus) survived in crab samples until Day 28 (counts of 1.4, 1.6, 3.1, 3.2 log CFU/g for E. coli O157:H7, S. Typhimurium, L. monocytogenes, and S. aureus, respectively). However, at 22°C, all tested bacteria were more susceptible to the antimicrobial effects of marination. Regardless of temperature, foodborne pathogens attached to crab samples were more resistant to marination than those suspended in soy sauce samples; however, the survival pattern for each species was different. Gram-positive bacteria were most resistant to marination conditions (high salinity, low pH), whereas V. parahaemolyticus was extremely susceptible. Marination is the only antibacterial step in the manufacturing processes; however, the results presented herein reveal that this is not sufficient to inactivate foodborne pathogens. In particular, the survival of pathogens on crabs at refrigeration temperature may pose a major hazard for the consumption of raw RTE seafood. Thus, appropriate decontamination methods and implementation of safety management practices are needed. This study provides predictive microbiological information of foodborne pathogens in raw RTE seafood with marination. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Negligible import of enteric pathogens by newly-arrived asylum seekers and no impact on incidence of notified Salmonella and Shigella infections and outbreaks in Rhineland-Palatinate, Germany, January 2015 to May 2016.

    Science.gov (United States)

    Ehlkes, Lutz; George, Maja; Knautz, Donald; Burckhardt, Florian; Jahn, Klaus; Vogt, Manfred; Zanger, Philipp

    2018-05-01

    IntroductionThe 2015 refugee crisis raised concerns about an import of infectious diseases affecting the German population. Aims: To evaluate public and individual health benefits of stool screening, and explore whether importation of enteric pathogens by newly-arrived asylum seekers impacts on the host population. Methods : We used data from mandatory stool screening to determine the overall, age, sex, and country-specific prevalence of enteric bacteria and helminths. We used surveillance data to assess whether the number of incoming asylum seekers influenced notifications of salmonellosis and shigellosis in Rhineland-Palatinate. Results : Salmonella were found in 0.2% (95% confidence interval (CI) 0.2-0.3%) of 23,410 samples collected from January 2015 to May 2016. Prevalence was highest in children under 5 years (0.8%; 95% CI: 0.5-1.3%). No Shigella or invasive Salmonella spp. were detected. In a subset of 14,511 samples, the prevalence of helminth infestation was 2.4% (95% CI: 2.1-2.6%), with highest proportions detected in adolescents (4.6%; 95% CI 3.8-5.4%) and among Eritreans (9.3%; 95% CI: 7.0-12.0%); in the latter particularly Schistosoma mansoni and Taenia spp. The increase in asylum applications did not increase notifications of salmonellosis and shigellosis. No transmission from asylum seekers to German residents was notified. Conclusion : Public health risk associated with imported enteric pathogens is very low overall. Addressing individual and public health risks, we recommend replacing stool screening of all newly-arrived asylum seekers by a targeted approach, with target groups and approaches being adapted if necessary. Target groups supported by our data are children, adolescents, and Eritreans.

  1. Optimization of inactivated H5N9 highly pathogenic avian influenza vaccine and inactivated Salmonella enterica serovar Typhimurium vaccine with antigen dose and prime-boost regimen in domestic ducks.

    Science.gov (United States)

    Yuk, Seong-Su; To, Eredene-Ochir; Kwon, Jung-Hoon; Noh, Jin-Yong; Hong, Woo-Tack; Jeong, Jei-Hyun; Gwon, Gyeong-Bin; Song, Chang-Seon

    2017-09-01

    Owing to the increase in the number of diseases affecting ducks and the demand for food safety by consumers, vaccination has become one of the factors that influence duck meat productivity. The highly pathogenic avian influenza (HPAI) virus is one of the most prevalent and causes one of the most lethal diseases in domestic ducks, and Salmonella enterica serovar Typhimurium is a food-borne pathogen persistent in the domestic duck population. To better understand the optimal usage of HPAI and S. enterica serovar Typhimurium vaccines, we aimed to determine antigen dose, oil and gel adjuvant usage with prime-boost regimen, and vaccination age, inducing the best immune response in ducks, without an effect on body weight gain. In the case of the inactivated H5N9 vaccine, a single dose of vaccine was inadequate to induce proper antibody titer when administered to day-old ducks, which necessitates boost vaccination. Administration of the oil-adjuvanted H5N9 vaccine administration in day-old and 2-week-old ducks resulted in a lower body weight at the time of slaughtering, compared to that of gel-adjuvanted H5N9 vaccine. However, gel-adjuvanted H5N9 vaccine failed to induce proper immune response to an extent recommend by OIE-World Organization for Animal Health. In the case of the Salmonella enterica serovar Typhimurium vaccine, a moderate or low dose of vaccine was appropriate for day-old ducks receiving the gel prime-oil boost vaccination. Single vaccination with oil adjuvants affects the mean body weight of 7-week-old ducks, suggesting that the gel adjuvant is more suitable for meat production. We expect that the use of adjuvants in a prime-boost regimen and at antigen doses set in this study will be helpful to maximize body weight in the case of domestic duck production at the actual farm site. © 2017 Poultry Science Association Inc.

  2. Effective cancer vaccine platform based on attenuated salmonella and a type III secretion system.

    Science.gov (United States)

    Xu, Xin; Hegazy, Wael A H; Guo, Linjie; Gao, Xiuhua; Courtney, Amy N; Kurbanov, Suhrab; Liu, Daofeng; Tian, Gengwen; Manuel, Edwin R; Diamond, Don J; Hensel, Michael; Metelitsa, Leonid S

    2014-11-01

    Vaccines explored for cancer therapy have been based generally on injectable vector systems used to control foreign infectious pathogens, to which the immune system evolved to respond naturally. However, these vectors may not be effective at presenting tumor-associated antigens (TAA) to the immune system in a manner that is sufficient to engender antitumor responses. We addressed this issue with a novel orally administered Salmonella-based vector that exploits a type III secretion system to deliver selected TAA in the cytosol of professional antigen-presenting cells in situ. A systematic comparison of candidate genes from the Salmonella Pathogenicity Island 2 (SPI2) locus was conducted in the vaccine design, using model antigens and a codon-optimized form of the human TAA survivin (coSVN), an oncoprotein that is overexpressed in most human cancers. In a screen of 20 SPI2 promoter:effector combinations, a PsifB::sseJ combination exhibited maximal potency for antigen translocation into the APC cytosol, presentation to CD8 T cells, and murine immunogenicity. In the CT26 mouse model of colon carcinoma, therapeutic vaccination with a lead PsifB::sseJ-coSVN construct (p8032) produced CXCR3-dependent infiltration of tumors by CD8 T cells, reversed the CD8:Treg ratio at the tumor site, and triggered potent antitumor activity. Vaccine immunogenicity and antitumor potency were enhanced by coadministration of the natural killer T-cell ligand 7DW8-5, which heightened the production of IL12 and IFNγ. Furthermore, combined treatment with p8032 and 7DW8-5 resulted in complete tumor regression in A20 lymphoma-bearing mice, where protective memory was demonstrated. Taken together, our results demonstrate how antigen delivery using an oral Salmonella vector can provide an effective platform for the development of cancer vaccines. ©2014 American Association for Cancer Research.

  3. Food-borne pathogens

    International Nuclear Information System (INIS)

    Niemand, J.G.

    1985-01-01

    The Salmonella scare reinforced the importance of never taking chances when it comes to controlling pathogens. The issue has been resolved by radurisation. The article deals with the various pathogens that can effect food and argues the case for radurisation in dealing with them. It also looks at some of the other food products that can be treated using this process

  4. Autophagy Facilitates Salmonella Replication in HeLa Cells

    Science.gov (United States)

    Yu, Hong B.; Croxen, Matthew A.; Marchiando, Amanda M.; Ferreira, Rosana B. R.; Cadwell, Ken; Foster, Leonard J.; Finlay, B. Brett

    2014-01-01

    ABSTRACT Autophagy is a process whereby a double-membrane structure (autophagosome) engulfs unnecessary cytosolic proteins, organelles, and invading pathogens and delivers them to the lysosome for degradation. We examined the fate of cytosolic Salmonella targeted by autophagy and found that autophagy-targeted Salmonella present in the cytosol of HeLa cells correlates with intracellular bacterial replication. Real-time analyses revealed that a subset of cytosolic Salmonella extensively associates with autophagy components p62 and/or LC3 and replicates quickly, whereas intravacuolar Salmonella shows no or very limited association with p62 or LC3 and replicates much more slowly. Replication of cytosolic Salmonella in HeLa cells is significantly decreased when autophagy components are depleted. Eventually, hyperreplication of cytosolic Salmonella potentiates cell detachment, facilitating the dissemination of Salmonella to neighboring cells. We propose that Salmonella benefits from autophagy for its cytosolic replication in HeLa cells. PMID:24618251

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

    Directory of Open Access Journals (Sweden)

    S.F. Mazhar

    2014-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-04

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

  7. Interactions of Salmonella with animals and plants

    Directory of Open Access Journals (Sweden)

    Agnès eWiedemann

    2015-01-01

    Full Text Available Salmonella enterica species is a Gram negative bacterium, which is responsible for a wide range of food- and water-borne diseases in both humans and animals, thereby posing a major threat to public health. Recently, there has been an increasing number of reports, linking Salmonella contaminated raw vegetables and fruit with food poisoning. Many studies have shown that an essential feature of the pathogenicity of Salmonella is its capacity to cross a number of barriers requiring invasion of a large variety of cells and that the extent of internalization may be influenced by numerous factors. However, it is poorly understood how Salmonella successfully infects hosts as diversified as animals or plants. The aim of this review is to describe the different stages required for Salmonella interaction with its hosts: (i attachment to host surfaces; (ii entry processes; (iii, multiplication; (iv suppression of host defence mechanisms ; and to point out similarities and differences between animal and plant infections.

  8. Interactions of Salmonella with animals and plants.

    Science.gov (United States)

    Wiedemann, Agnès; Virlogeux-Payant, Isabelle; Chaussé, Anne-Marie; Schikora, Adam; Velge, Philippe

    2014-01-01

    Salmonella enterica species are Gram-negative bacteria, which are responsible for a wide range of food- and water-borne diseases in both humans and animals, thereby posing a major threat to public health. Recently, there has been an increasing number of reports, linking Salmonella contaminated raw vegetables and fruits with food poisoning. Many studies have shown that an essential feature of the pathogenicity of Salmonella is its capacity to cross a number of barriers requiring invasion of a large variety of cells and that the extent of internalization may be influenced by numerous factors. However, it is poorly understood how Salmonella successfully infects hosts as diversified as animals or plants. The aim of this review is to describe the different stages required for Salmonella interaction with its hosts: (i) attachment to host surfaces; (ii) entry processes; (iii) multiplication; (iv) suppression of host defense mechanisms; and to point out similarities and differences between animal and plant infections.

  9. Interactions of Salmonella with animals and plants

    Science.gov (United States)

    Wiedemann, Agnès; Virlogeux-Payant, Isabelle; Chaussé, Anne-Marie; Schikora, Adam; Velge, Philippe

    2015-01-01

    Salmonella enterica species are Gram-negative bacteria, which are responsible for a wide range of food- and water-borne diseases in both humans and animals, thereby posing a major threat to public health. Recently, there has been an increasing number of reports, linking Salmonella contaminated raw vegetables and fruits with food poisoning. Many studies have shown that an essential feature of the pathogenicity of Salmonella is its capacity to cross a number of barriers requiring invasion of a large variety of cells and that the extent of internalization may be influenced by numerous factors. However, it is poorly understood how Salmonella successfully infects hosts as diversified as animals or plants. The aim of this review is to describe the different stages required for Salmonella interaction with its hosts: (i) attachment to host surfaces; (ii) entry processes; (iii) multiplication; (iv) suppression of host defense mechanisms; and to point out similarities and differences between animal and plant infections. PMID:25653644

  10. The Salmonella enterica Pan-genome

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  11. Antibiotic Resistance in Foodborne Pathogens

    OpenAIRE

    Walsh, Ciara; Duffy, Geraldine

    2013-01-01

    Wide-spread antibiotic resistance among bacterial pathogens is now a serious public health issue and multi-antibiotic resistance has been reported in many foodborne pathogens including Salmonella and E. coli. A study to determine antibiotic resistance profiles of a range of Salmonella and Verocytotoxigenic E.coli (VTEC) isolated from Irish foods revealed significant levels of antibiotic resistance in the strains. S. typhimurium DT104 were multiantibiotic resistant with 97% resistant to 7 anti...

  12. Effects of Flower and Fruit Extracts of Melastoma malabathricum Linn. on Growth of Pathogenic Bacteria: Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium

    Directory of Open Access Journals (Sweden)

    Siti Nurhadis Che Omar

    2013-01-01

    Full Text Available Melastoma malabathricum Linn. is a shrub that comes with beautiful pink or purple flowers and has berries-like fruits rich in anthocyanins. This study was carried out with the aim to evaluate the inhibitory activities of different concentrations of the M. malabathricum Linn. flower and fruit crude extracts against Listeria monocytogenes IMR L55, Staphylococcus aureus IMR S244, Escherichia coli IMR E30, and Salmonella typhimurium IMR S100 using the disc diffusion method. The lowest concentrations of the extracts producing inhibition zones against the test microorganisms were used to determine their minimum inhibitory concentrations (MICs and minimum bactericidal concentrations (MBCs. In addition, the growth of Listeria monocytogenes IMR L55 and Staphylococcus aureus IMR S244 grown in medium supplemented with the respective extracts at different temperatures (4°C, 25°C, and 37°C and pHs (4, 6, 7, and 8 was determined.

  13. The transcriptional programme of Salmonella enterica serovar Typhimurium reveals a key role for tryptophan metabolism in biofilms.

    LENUS (Irish Health Repository)

    Hamilton, Shea

    2009-12-11

    Abstract Background Biofilm formation enhances the capacity of pathogenic Salmonella bacteria to survive stresses that are commonly encountered within food processing and during host infection. The persistence of Salmonella within the food chain has become a major health concern, as biofilms can serve as a reservoir for the contamination of food products. While the molecular mechanisms required for the survival of bacteria on surfaces are not fully understood, transcriptional studies of other bacteria have demonstrated that biofilm growth triggers the expression of specific sets of genes, compared with planktonic cells. Until now, most gene expression studies of Salmonella have focused on the effect of infection-relevant stressors on virulence or the comparison of mutant and wild-type bacteria. However little is known about the physiological responses taking place inside a Salmonella biofilm. Results We have determined the transcriptomic and proteomic profiles of biofilms of Salmonella enterica serovar Typhimurium. We discovered that 124 detectable proteins were differentially expressed in the biofilm compared with planktonic cells, and that 10% of the S. Typhimurium genome (433 genes) showed a 2-fold or more change in the biofilm compared with planktonic cells. The genes that were significantly up-regulated implicated certain cellular processes in biofilm development including amino acid metabolism, cell motility, global regulation and tolerance to stress. We found that the most highly down-regulated genes in the biofilm were located on Salmonella Pathogenicity Island 2 (SPI2), and that a functional SPI2 secretion system regulator (ssrA) was required for S. Typhimurium biofilm formation. We identified STM0341 as a gene of unknown function that was needed for biofilm growth. Genes involved in tryptophan (trp) biosynthesis and transport were up-regulated in the biofilm. Deletion of trpE led to decreased bacterial attachment and this biofilm defect was restored by

  14. In vitro selection of RNA aptamer specific to Salmonella typhimurium.

    Science.gov (United States)

    Han, Seung Ryul; Lee, Seong-Wook

    2013-06-28

    Salmonella is a major foodborne pathogen that causes a variety of human diseases. Development of ligands directly and specifically binding to the Salmonella will be crucial for the rapid detection of, and thus for efficient protection from, the virulent bacteria. In this study, we identified a RNA aptamer-based ligand that can specifically recognize Salmonella Typhimurium through SELEX technology. To this end, we isolated and characterized an RNase-resistant RNA aptamer that bound to the OmpC protein of Salmonella Typhimurium with high specificity and affinity (Kd ~ 20 nM). Of note, the selected aptamer was found to specifically bind to Salmonella Typhimurium, but neither to Gram-positive bacteria (Staphylococcus aureus) nor to other Gram-negative bacteria (Escherichia coli O157:H7). This was evinced by aptamer-immobilized ELISA and aptamer-linked precipitation experiments. This Salmonella species-specific aptamer could be useful as a diagnostic ligand against pathogen-caused foodborne sickness.

  15. Survival of Salmonella Newport in oysters.

    Science.gov (United States)

    Morrison, Christopher M; Armstrong, Alexandra E; Evans, Sanford; Mild, Rita M; Langdon, Christopher J; Joens, Lynn A

    2011-08-02

    Salmonella enterica is the leading cause of laboratory-confirmed foodborne illness in the United States and raw shellfish consumption is a commonly implicated source of gastrointestinal pathogens. A 2005 epidemiological study done in our laboratory by Brands et al., showed that oysters in the United States are contaminated with Salmonella, and in particular, a specific strain of the Newport serovar. This work sought to further investigate the host-microbe interactions between Salmonella Newport and oysters. A procedure was developed to reliably and repeatedly expose oysters to enteric bacteria and quantify the subsequent levels of bacterial survival. The results show that 10 days after an exposure to Salmonella Newport, an average concentration of 3.7 × 10(3)CFU/g remains within the oyster meat, and even after 60 days there still can be more than 10(2)CFU/g remaining. However, the strain of Newport that predominated in the market survey done by Brands et al. does not survive within oysters or the estuarine environment better than any other strains of Salmonella we tested. Using this same methodology, we compared Salmonella Newport's ability to survive within oysters to a non-pathogenic strain of E. coli and found that after 10 days the concentration of Salmonella was 200-times greater than that of E. coli. We also compared those same strains of Salmonella and E. coli in a depuration process to determine if a constant 120 L/h flux of clean seawater could significantly reduce the concentration of bacteria within oysters and found that after 3 days the oysters retained over 10(4)CFU/g of Salmonella while the oysters exposed to the non-pathogenic strain of E. coli contained 100-times less bacteria. Overall, the results of this study demonstrate that any of the clinically relevant serovars of Salmonella can survive within oysters for significant periods of time after just one exposure event. Based on the drastic differences in survivability between Salmonella and a non-pathogenic

  16. Vaccines against invasive Salmonella disease

    Science.gov (United States)

    MacLennan, Calman A; Martin, Laura B; Micoli, Francesca

    2014-01-01

    Though primarily enteric pathogens, Salmonellae are responsible for a considerable yet under-appreciated global burden of invasive disease. In South and South-East Asia, this manifests as enteric fever caused by serovars Typhi and Paratyphi A. In sub-Saharan Africa, a similar disease burden results from invasive nontyphoidal Salmonellae, principally serovars Typhimurium and Enteritidis. The existing Ty21a live-attenuated and Vi capsular polysaccharide vaccines target S. Typhi and are not effective in young children where the burden of invasive Salmonella disease is highest. After years of lack of investment in new Salmonella vaccines, recent times have seen increased interest in the area led by emerging-market manufacturers, global health vaccine institutes and academic partners. New glycoconjugate vaccines against S. Typhi are becoming available with similar vaccines against other invasive serovars in development. With other new vaccines under investigation, including live-attenuated, protein-based and GMMA vaccines, now is an exciting time for the Salmonella vaccine field. PMID:24804797

  17. Allspice, garlic and oregano plant essential oils in tomato films inactivate the foodborne pathogens, Escherichia coli O157:h7, Salmonella enterica and Listeria monocytogenes

    Science.gov (United States)

    Edible films containing plant essential oils arc gaining importance as potential antibacterial formulations to extend product shelf life and reduce risk of pathogen growth on food surfaces. An evaluation of both antimicrobial and physicochemical properties of edible films is important for applicatio...

  18. Allspice, garlic, and oregano plant essential oils in tomato films inactive the foodborne pathogens Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes

    Science.gov (United States)

    Edible films containing plant essential oils are gaining importance as potential antibacterial formulations to extend product shelf-life and reduce risk of pathogen growth on food surfaces. An evaluation of both antimicrobial and physicochemical properties of edible films is important for applicati...

  19. Modelling a national programme for the control of foodborne pathogens in livestock: the case of Salmonella Dublin in the Danish cattle industry

    DEFF Research Database (Denmark)

    Jordan, D.; Nielsen, L.R.; Warnick, L.D.

    2008-01-01

    A 'virtual hierarchy' model is described for studying the spread of pathogens between herds of livestock. This novel approach to simulating disease has animals. herds, and geographic regions in a national livestock industry arranged as a hierarchy of objects in computer memory. Superimposed on all...

  20. Quantification of Salmonella Survival and Infection in an In vitro Model of the Human Intestinal Tract as Proxy for Foodborne Pathogens.

    NARCIS (Netherlands)

    Wijnands, Lucas M; Teunis, Peter F M; Kuijpers, Angelina F A; Delfgou-Van Asch, Ellen H M; Pielaat, Annemarie

    2017-01-01

    Different techniques are available for assessing differences in virulence of bacterial foodborne pathogens. The use of animal models or human volunteers is not expedient for various reasons; the use of epidemiological data is often hampered by lack of crucial data. In this paper, we describe a

  1. Effect of Holarrhena antidysentrica (Ha) and Andrographis paniculata (Ap) on the biofilm formation and cell membrane integrity of opportunistic pathogen Salmonella typhimurium.

    Science.gov (United States)

    Tanwar, Ankit; Chawla, Raman; Chakotiya, Ankita Singh; Thakur, Pallavi; Goel, Rajeev; Basu, Mitra; Arora, Rajesh; Khan, Haider Ali

    2016-12-01

    Increasing occurrence of gastroenteritis outbreaks caused by food borne opportunistic microorganisms has become a major problem in food industry as well as in immunocompromised host. Antimicrobial agents are losing their efficacy due to increase in the microbial resistance. For such reasons, conventional treatment has become limited to manage the infections state. Need of the hour is to instigate the search for safer holistic alternatives. The present study was hence conducted to assess the antibiofilm effect and mode of action of aquo alcoholic extracts of Holarrhena antidysentrica (Ha) and Andrographis paniculata (Ap) against the Salmonella enterica serovar typhimurium. Both the extracts were screened for the presence of phytocompounds followed by the characterization using Attenuated Total Reflection (ATR) infrared spectroscopy and bioactivity finger print analysis. Anti-biofilm assays were determined to test the potential of both extracts to inhibit the biofilm formation, while Propidium Iodide (PI) uptake analysis revealed that cell membrane was damaged by the exposure of nutraceuticals for 1 h. This study has demonstrated that both nutraceuticals have anti-biofilm and antimicrobial activity perturbing the membrane integrity of food-borne S. typhimurium and could be used as curative remedy to control the food borne microbial infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Structural and Biochemical Characterization of SrcA, a Multi-cargo Type III Secretion Chaperone in Salmonella Required for Pathogenic Association with a Host

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, C.; Zhang, K; Andres, S; Fnag, Y; Kaniuk, N; Hannemann, M; Brumell, J; Foster, L; Junop, M; Coombes, B

    2010-01-01

    Many Gram-negative bacteria colonize and exploit host niches using a protein apparatus called a type III secretion system (T3SS) that translocates bacterial effector proteins into host cells where their functions are essential for pathogenesis. A suite of T3SS-associated chaperone proteins bind cargo in the bacterial cytosol, establishing protein interaction networks needed for effector translocation into host cells. In Salmonella enterica serovar Typhimurium, a T3SS encoded in a large genomic island (SPI-2) is required for intracellular infection, but the chaperone complement required for effector translocation by this system is not known. Using a reverse genetics approach, we identified a multi-cargo secretion chaperone that is functionally integrated with the SPI-2-encoded T3SS and required for systemic infection in mice. Crystallographic analysis of SrcA at a resolution of 2.5 {angstrom} revealed a dimer similar to the CesT chaperone from enteropathogenic E. coli but lacking a 17-amino acid extension at the carboxyl terminus. Further biochemical and quantitative proteomics data revealed three protein interactions with SrcA, including two effector cargos (SseL and PipB2) and the type III-associated ATPase, SsaN, that increases the efficiency of effector translocation. Using competitive infections in mice we show that SrcA increases bacterial fitness during host infection, highlighting the in vivo importance of effector chaperones for the SPI-2 T3SS.

  3. Structural and biochemical characterization of SrcA, a multi-cargo type III secretion chaperone in Salmonella required for pathogenic association with a host.

    Directory of Open Access Journals (Sweden)

    Colin A Cooper

    2010-02-01

    Full Text Available Many Gram-negative bacteria colonize and exploit host niches using a protein apparatus called a type III secretion system (T3SS that translocates bacterial effector proteins into host cells where their functions are essential for pathogenesis. A suite of T3SS-associated chaperone proteins bind cargo in the bacterial cytosol, establishing protein interaction networks needed for effector translocation into host cells. In Salmonella enterica serovar Typhimurium, a T3SS encoded in a large genomic island (SPI-2 is required for intracellular infection, but the chaperone complement required for effector translocation by this system is not known. Using a reverse genetics approach, we identified a multi-cargo secretion chaperone that is functionally integrated with the SPI-2-encoded T3SS and required for systemic infection in mice. Crystallographic analysis of SrcA at a resolution of 2.5 A revealed a dimer similar to the CesT chaperone from enteropathogenic E. coli but lacking a 17-amino acid extension at the carboxyl terminus. Further biochemical and quantitative proteomics data revealed three protein interactions with SrcA, including two effector cargos (SseL and PipB2 and the type III-associated ATPase, SsaN, that increases the efficiency of effector translocation. Using competitive infections in mice we show that SrcA increases bacterial fitness during host infection, highlighting the in vivo importance of effector chaperones for the SPI-2 T3SS.

  4. Salmonella typhi

    OpenAIRE

    Mochammad, Hatta

    2008-01-01

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

  5. [The gentic principles for the design of live Salmonella vaccines].

    Science.gov (United States)

    Petrovskaia, V G; Marakusha, B I; Bondarenko, V M

    1996-01-01

    The presently known methods of obtaining Salmonella vaccine strains are characterized, their advantages and drawbacks are noted. Great importance of the genetic safety of Salmonella attenuated strains to be controlled is emphasized, taking into account that they are also used as carrier strains for obtaining hybrid and gene-engineering (vector) vaccines carrying immunogenicity factors of other species of pathogenic microorganisms.

  6. Recent Trends in Salmonella Outbreaks and Emerging Technology for Biocontrol of Salmonella Using Phages in Foods: A Review.

    Science.gov (United States)

    Oh, Jun-Hyun; Park, Mi-Kyung

    2017-12-28

    Salmonella is one of the principal causes of foodborne outbreaks. As traditional control methods have shown less efficacy against emerging Salmonella serotypes or antimicrobialresistant Salmonella , new approaches have been attempted. The use of lytic phages for the biocontrol of Salmonella in the food industry has become an attractive method owing to the many advantages offered by the use of phages as biocontrol agents. Phages are natural alternatives to traditional antimicrobial agents; they have proven effective in the control of bacterial pathogens in the food industry, which has led to the development of different phage products. The treatment with specific phages in the food industry can prevent the decay of products and the spread of bacterial diseases, and ultimately promotes safe environments for animal and plant food production, processing, and handling. After an extensive investigation of the current literature, this review focuses predominantly on the efficacy of phages for the successful control of Salmonella spp. in foods. This review also addresses the current knowledge on the pathogenic characteristics of Salmonella , the prevalence of emerging Salmonella outbreaks, the isolation and characterization of Salmonella -specific phages, the effectiveness of Salmonella -specific phages as biocontrol agents, and the prospective use of Salmonella -specific phages in the food industry.

  7. Real-Time Pathogen Detection in the Era of Whole-Genome Sequencing and Big Data: Comparison of k-mer and Site-Based Methods for Inferring the Genetic Distances among Tens of Thousands of Salmonella Samples.

    Directory of Open Access Journals (Sweden)

    James B Pettengill

    Full Text Available The adoption of whole-genome sequencing within the public health realm for molecular characterization of bacterial pathogens has been followed by an increased emphasis on real-time detection of emerging outbreaks (e.g., food-borne Salmonellosis. In turn, large databases of whole-genome sequence data are being populated. These databases currently contain tens of thousands of samples and are expected to grow to hundreds of thousands within a few years. For these databases to be of optimal use one must be able to quickly interrogate them to accurately determine the genetic distances among a set of samples. Being able to do so is challenging due to both biological (evolutionary diverse samples and computational (petabytes of sequence data issues. We evaluated seven measures of genetic distance, which were estimated from either k-mer profiles (Jaccard, Euclidean, Manhattan, Mash Jaccard, and Mash distances or nucleotide sites (NUCmer and an extended multi-locus sequence typing (MLST scheme. When analyzing empirical data (whole-genome sequence data from 18,997 Salmonella isolates there are features (e.g., genomic, assembly, and contamination that cause distances inferred from k-mer profiles, which treat absent data as informative, to fail to accurately capture the distance between samples when compared to distances inferred from differences in nucleotide sites. Thus, site-based distances, like NUCmer and extended MLST, are superior in performance, but accessing the computing resources necessary to perform them may be challenging when analyzing large databases.

  8. Real-Time Pathogen Detection in the Era of Whole-Genome Sequencing and Big Data: Comparison of k-mer and Site-Based Methods for Inferring the Genetic Distances among Tens of Thousands of Salmonella Samples.

    Science.gov (United States)

    Pettengill, James B; Pightling, Arthur W; Baugher, Joseph D; Rand, Hugh; Strain, Errol

    2016-01-01

    The adoption of whole-genome sequencing within the public health realm for molecular characterization of bacterial pathogens has been followed by an increased emphasis on real-time detection of emerging outbreaks (e.g., food-borne Salmonellosis). In turn, large databases of whole-genome sequence data are being populated. These databases currently contain tens of thousands of samples and are expected to grow to hundreds of thousands within a few years. For these databases to be of optimal use one must be able to quickly interrogate them to accurately determine the genetic distances among a set of samples. Being able to do so is challenging due to both biological (evolutionary diverse samples) and computational (petabytes of sequence data) issues. We evaluated seven measures of genetic distance, which were estimated from either k-mer profiles (Jaccard, Euclidean, Manhattan, Mash Jaccard, and Mash distances) or nucleotide sites (NUCmer and an extended multi-locus sequence typing (MLST) scheme). When analyzing empirical data (whole-genome sequence data from 18,997 Salmonella isolates) there are features (e.g., genomic, assembly, and contamination) that cause distances inferred from k-mer profiles, which treat absent data as informative, to fail to accurately capture the distance between samples when compared to distances inferred from differences in nucleotide sites. Thus, site-based distances, like NUCmer and extended MLST, are superior in performance, but accessing the computing resources necessary to perform them may be challenging when analyzing large databases.

  9. Molecular detection of salmonella species from selected vegetables ...

    African Journals Online (AJOL)

    Molecular detection of salmonella species from selected vegetables sold in a north-central ... African Journal of Clinical and Experimental Microbiology ... of the pure isolates testing positive as being pathogenic after biochemical analysis.

  10. From Exit to Entry: Long-term Survival and Transmission of Salmonella

    Directory of Open Access Journals (Sweden)

    Landon L. Waldner

    2012-10-01

    Full Text Available Salmonella spp. are a leading cause of human infectious disease worldwide and pose a serious health concern. While we have an improving understanding of pathogenesis and the host-pathogen interactions underlying the infection process, comparatively little is known about the survival of pathogenic Salmonella outside their hosts. This review focuses on three areas: (1 in vitro evidence that Salmonella spp. can survive for long periods of time under harsh conditions; (2 observations and conclusions about Salmonella persistence obtained from human outbreaks; and (3 new information revealed by genomic- and population-based studies of Salmonella and related enteric pathogens. We highlight the mechanisms of Salmonella persistence and transmission as an essential part of their lifecycle and a prerequisite for their evolutionary success as human pathogens.

  11. Defuelling at Three Mile Island 2 continues on schedule

    International Nuclear Information System (INIS)

    Frew, J.E.

    1987-01-01

    In September GPU Nuclear announced that it had extracted half of the debris from the reactor vessel at Three Mile Island 2 and loaded it into casks for transport from the site. The work has been speeded by the development of special tools and working methods and has been accompanied by a continuous programme of decontamination. The health risks to workers are now considered to be no greater than those at operating plants. (author)

  12. Radiosensitivity study of salmonella enteritidis in chickens

    International Nuclear Information System (INIS)

    Fernandez Gianotti, Tomas

    1997-01-01

    One of the applications of ionizing radiations in food is the inactivation of vegetative phatogenic bacteria (radicidation) such as Salmonella, Shigella, Campylobacter, Vibro and Listeria. These bacteria are associated with the diseases transmitted by food (ETA). Fresh and frozen farmyard fowls can be contaminated with pathogenic microorganisms, between them Salmonella. In Argentine, between years 1987-1990, Salmonella enteritidis was the main cause of salmonellosis. In food irradiation, with the aim of improving and assuring its hygienic quality, it is important to know the radiosensitivity of microorganisms to be inactivated. Inactivation of a determined microorganism shall depend, between others factors, of the species, strain, number and of the irradiation conditions (temperature, media, etc.). D 10 value is a very useful data in order to compare radiosensitivities between the microorganisms and the influence of different factors in their sensitivities. In this paper, it was determined the sensitivity to the gamma radiation of Salmonella enteritidis in fresh and frozen chickens

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

    NARCIS (Netherlands)

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

    2010-01-01

    Background: 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.

  14. Prevalence of Salmonella spp. in oysters in the United States.

    Science.gov (United States)

    Brands, Danielle A; Inman, Allison E; Gerba, Charles P; Maré, C John; Billington, Stephen J; Saif, Linda A; Levine, Jay F; Joens, Lynn A

    2005-02-01

    Food-borne diseases such as salmonellosis can be attributed, in part, to the consumption of raw oysters. To determine the prevalence of Salmonella spp. in oysters, oysters harvested from 36 U.S. bays (12 each from the West, East, and Gulf coasts in the summer of 2002, and 12 bays, four per coast, in the winter of 2002-2003) were tested. Salmonella was isolated from oysters from each coast of the United States, and 7.4% of all oysters tested contained Salmonella. Isolation tended to be bay specific, with some bays having a high prevalence of Salmonella, while other bays had none. Differences in the percentage of oysters from which Salmonella was isolated were observed between the summer and winter months, with winter numbers much lower probably due to a variety of weather-related events. The vast majority (78/101) of Salmonella isolates from oysters were Salmonella enterica serovar Newport, a major human pathogen, confirming the human health hazard of raw oyster consumption. Contrary to previous findings, no relationship was found between the isolation of fecal coliforms and Salmonella from oysters, indicating a necessity for specific monitoring for Salmonella and other pathogens rather than the current reliance on fecal coliform testing.

  15. Persistence of salmonella Typhimurium in Nopal

    Science.gov (United States)

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

  16. Inhibition of Escherichia Coli, Salmonella and Staphylococcus ...

    African Journals Online (AJOL)

    Escherichia coli O157:H7, Salmonella typhimurium and Staphylococcus. aureus are of great concern to the food industry, especially in foods stored under refrigerated conditions where, unlike most food-borne pathogens are able to multiply. This investigation was conducted to study the inhibitory effect of some spice ...

  17. Fate of Salmonella Species and E

    African Journals Online (AJOL)

    user

    determining the growth potential of some food-borne pathogens in the juices at different holding temperatures. ... 3Institute of Pathology, Addis Ababa University P.O. Box 1176, Addis Ababa, Ethiopia ... Bacteriology laboratory, Ethiopian Health .... food poisoning caused by Salmonella .... Antiviral effect of commercial juices.

  18. Effect of Food Residues in Biofilm Formation on Stainless Steel and Polystyrene Surfaces by Salmonella enterica Strains Isolated from Poultry Houses

    OpenAIRE

    Paz-Méndez, Alba María; Lamas, Alexandre; Vázquez, Beatriz; Miranda, José Manuel; Cepeda, Alberto; Franco, Carlos Manuel

    2017-01-01

    Salmonella spp. is a major food-borne pathogen around the world. The ability of Salmonella to produce biofilm is one of the main obstacles in reducing the prevalence of these bacteria in the food chain. Most of Salmonella biofilm studies found in the literature used laboratory growth media. However, in the food chain, food residues are the principal source of nutrients of Salmonella. In this study, the biofilm formation, morphotype, and motility of 13 Salmonella strains belonging to three dif...

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

    DEFF Research Database (Denmark)

    Barua, Himel; Biswas, Paritosh K.; Olsen, Katharina E. P.

    2012-01-01

    Salmonella is a globally widespread food-borne pathogen having major impact on public health. All motile serovars of Salmonella enterica of poultry origin are zoonotic, and contaminated meat and raw eggs are an important source to human infections. Information on the prevalence of Salmonella...

  20. Prevalence, Virulence Genes and Antimicrobial Resistance Profiles of Salmonella Serovars from Retail Beef in Selangor, Malaysia.

    Science.gov (United States)

    Thung, Tze Y; Radu, Son; Mahyudin, Nor A; Rukayadi, Yaya; Zakaria, Zunita; Mazlan, Nurzafirah; Tan, Boon H; Lee, Epeng; Yeoh, Soo L; Chin, Yih Z; Tan, Chia W; Kuan, Chee H; Basri, Dayang F; Wan Mohamed Radzi, Che W J

    2017-01-01

    The aim of the present study was to investigate the prevalence of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in retail beef from different retail markets of Selangor area, as well as, to assess their pathogenic potential and antimicrobial resistance. A total of 240 retail beef meat samples (chuck = 60; rib = 60; round = 60; sirloin = 60) were randomly collected. The multiplex polymerase chain reaction (mPCR) in combination with the most probable number (MPN) method was employed to detect Salmonella spp., S . Enteritidis and S . Typhimurium in the meat samples. The prevalence of Salmonella spp., S . Enteritidis and S . Typhimurium in 240 beef meat samples were 7.50, 1.25, and 0.83%, respectively. The microbial loads of total Salmonella was found in the range of retail beef products tested were widely contaminated with multi-drug resistant (MDR) Salmonella and various virulence genes are present among the isolated Salmonella serovars.

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

    Directory of Open Access Journals (Sweden)

    Mohamed M Ali

    2014-06-01

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

  2. Salmonella Infections - Multiple Languages

    Science.gov (United States)

    ... Are Here: Home → Multiple Languages → All Health Topics → Salmonella Infections URL of this page: https://medlineplus.gov/ ... V W XYZ List of All Topics All Salmonella Infections - Multiple Languages To use the sharing features ...

  3. Applications of microscopy in Salmonella research.

    Science.gov (United States)

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

    2015-01-01

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

  4. 78 FR 42526 - Salmonella

    Science.gov (United States)

    2013-07-16

    ...] Salmonella Contamination of Dry Dog Food; Withdrawal of Compliance Policy Guide AGENCY: Food and Drug... the withdrawal of the compliance policy guide (CPG) entitled ``Sec. 690.700 Salmonella Contamination... entitled ``Sec. 690.700 Salmonella Contamination of Dry Dog Food (CPG 690.700)'' on October 1, 1980. CPG...

  5. Salmonella enterica Induces And Subverts The Plant Immune System

    Directory of Open Access Journals (Sweden)

    Ana Victoria Garcia

    2014-04-01

    Full Text Available Infections with Salmonella enterica belong to the most prominent causes of food poisoning and infected fruits and vegetables represent important vectors for salmonellosis. Whereas 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, the data gathered suggest that Salmonella triggers PTI in plants and evolved strategies to avoid or subvert plant immunity.

  6. Salmonella enterica induces and subverts the plant immune system

    KAUST Repository

    García, Ana V.

    2014-04-04

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

  7. Salmonella rarely detected in Mississippi coastal waters and sediment.

    Science.gov (United States)

    Carr, M R; Wang, S Y; McLean, T I; Flood, C J; Ellender, R D

    2010-12-01

    Standards for the rapid detection of individual pathogens from environmental samples have not been developed, but in their absence, the use of molecular-based detection methods coupled with traditional microbiology techniques allows for rapid and accurate pathogen detection from environmental waters and sediment. The aim of this research was to combine the use of enrichment with PCR for detection of Salmonella in Mississippi coastal waters and sediment and observe if that presence correlated with levels of enterococci and climatological variables. Salmonella were primarily found in samples that underwent nutrient enrichment and were present more frequently in freshwater than marine waters. Salmonella were detected infrequently in marine and freshwater sediments. There was a significant positive correlation between the presence of detectable Salmonella and the average enterococcal count. An inverse relationship, however, was observed between the frequency of detection and the levels of salinity, turbidity and sunlight exposure. Results from this study indicated the presence of Salmonella in Mississippi coastal waters, and sediments are very low with significant differences between freshwater and marine environments. Using pathogenic and novel nonpathogenic molecular markers, Salmonella do not appear to be a significant pathogenic genus along the Mississippi Coast. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  8. Role of Rodents in transmission of Salmonella and Campylobacter

    NARCIS (Netherlands)

    Meerburg, B.G.; Kijlstra, A.

    2007-01-01

    Salmonella and Campylobacter are generally regarded as the most important food-borne pathogens in the world. Reduction or elimination of these pathogens in the first part of the food chain (on the farm) is important to prevent disease among consumers of animal products. In organic farming,

  9. Salmonella epidemiology: A whirlwind of change.

    Science.gov (United States)

    Besser, John M

    2018-05-01

    The field of infectious disease epidemiology for Salmonella and other enteric pathogens is undergoing some of the most profound changes since the time of Kauffman and White. Rapid advances in "big data" technologies such as genomics and metagenomics are making it possible to monitor and control salmonellosis in new and exciting ways. Epidemiological methods are becoming increasingly robust through the routine use of standardized hypothesis-generating questionnaires, iterative open-ended interviewing, informational trace-backs and new modeling techniques for describing the attribution of disease to food sources. In addition, Salmonella epidemiology is facing important challenges and new opportunities due to the rapid adoption of culture independent diagnostic test panels by clinical laboratories. Where is this unprecedented wave of change taking us? This chapter will examine emerging trends in Salmonella epidemiology, and take a peek into the not-so-distant future. Published by Elsevier Ltd.

  10. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2014. Scientific Opinion on the risk posed by pathogens in food of non-animal origin. Part 2 (Salmonella in melons)

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    and 2012. Risk factors for melon and watermelon contamination by Salmonella were considered in the context of the whole food chain, together with available estimates of Salmonella occurrence and mitigation options relating to prevention of contamination and the relevance of microbiological criteria......Melons and watermelons are ready-to-eat foods, with an internal pH of 5.1 to 6.7 and can be consumed whole, as fresh-cut products or as fresh juices. Epidemiological data from the EU identified one salmonellosis outbreak associated with consumption of both pre-cut and whole melon between 2007....... It was concluded that each farm environment represents a unique combination of risk factors that can influence occurrence and persistence of Salmonella in melon and watermelon production. Appropriate implementation of food safety management systems including Good Agricultural Practices (GAP), Good Hygiene...

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  12. Foodborne pathogens

    Directory of Open Access Journals (Sweden)

    Thomas Bintsis

    2017-06-01

    Full Text Available Foodborne pathogens are causing a great number of diseases with significant effects on human health and economy. The characteristics of the most common pathogenic bacteria (Bacillus cereus, Campylobacter jejuni, Clostridium botulinum, Clostridium perfringens, Cronobacter sakazakii, Esherichia coli, Listeria monocytogenes, Salmonella spp., Shigella spp., Staphylococccus aureus, Vibrio spp. and Yersinia enterocolitica, viruses (Hepatitis A and Noroviruses and parasites (Cyclospora cayetanensis, Toxoplasma gondii and Trichinella spiralis, together with some important outbreaks, are reviewed. Food safety management systems based on to classical hazard-based approach has been proved to be inefficient, and risk-based food safety approach is now suggested from leading researchers and organizations. In this context, a food safety management system should be designed in a way to estimate the risks to human health from food consumption and to identify, select and implement mitigation strategies in order to control and reduce these risks. In addition, the application of suitable food safety education programs for all involved people in the production and consumption of foods is suggested.

  13. E. coli Nissle 1917 Affects Salmonella adhesion to porcine intestinal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Peter Schierack

    Full Text Available BACKGROUND: The probiotic Escherichia coli strain Nissle 1917 (EcN has been shown to interfere in a human in vitro model with the invasion of several bacterial pathogens into epithelial cells, but the underlying molecular mechanisms are not known. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we investigated the inhibitory effects of EcN on Salmonella Typhimurium invasion of porcine intestinal epithelial cells, focusing on EcN effects on the various stages of Salmonella infection including intracellular and extracellular Salmonella growth rates, virulence gene regulation, and adhesion. We show that EcN affects the initial Salmonella invasion steps by modulating Salmonella virulence gene regulation and Salmonella SiiE-mediated adhesion, but not extra- and intracellular Salmonella growth. However, the inhibitory activity of EcN against Salmonella invasion always correlated with EcN adhesion capacities. EcN mutants defective in the expression of F1C fimbriae and flagellae were less adherent and less inhibitory toward Salmonella invasion. Another E. coli strain expressing F1C fimbriae was also adherent to IPEC-J2 cells, and was similarly inhibitory against Salmonella invasion like EcN. CONCLUSIONS: We propose that EcN affects Salmonella adhesion through secretory components. This mechanism appears to be common to many E. coli strains, with strong adherence being a prerequisite for an effective reduction of SiiE-mediated Salmonella adhesion.

  14. Survey of Salmonella contamination in chicken layer farms in three Caribbean countries.

    Science.gov (United States)

    Adesiyun, Abiodun; Webb, Lloyd; Musai, Lisa; Louison, Bowen; Joseph, George; Stewart-Johnson, Alva; Samlal, Sannandan; Rodrigo, Shelly

    2014-09-01

    This study was conducted to investigate the demography, management, and production practices on layer chicken farms in Trinidad and Tobago, Grenada, and St. Lucia and the frequency of risk factors for Salmonella infection. The frequency of isolation of Salmonella from the layer farm environment, eggs, feeds, hatchery, and imported day-old chicks was determined using standard methods. Of the eight risk factors (farm size, age group of layers, source of day-old chicks, vaccination, sanitation practices, biosecurity measures, presence of pests, and previous disease outbreaks) for Salmonella infection investigated, farm size was the only risk factor significantly associated (P = 0.031) with the prevalence of Salmonella; 77.8% of large farms were positive for this pathogen compared with 33.3 and 26.1% of medium and small farms, respectively. The overall isolation rate of Salmonella from 35 layer farms was 40.0%. Salmonella was isolated at a significantly higher rate (P hatcheries, and airports in this country were negative. Salmonella Anatum, Salmonella group C, and Salmonella Kentucky were the predominant serotypes in Trinidad and Tobago, Grenada, and St. Lucia, respectively. Although Salmonella infections were found in layer birds sampled, table eggs appear to pose minimal risk to consumers. However, the detection of Salmonella -contaminated farm environments and feeds cannot be ignored. Only 2.9% of the isolates belonged to Salmonella Enteritidis, a finding that may reflect the impact of changes in farm management and poultry production in the region.

  15. Plant innate immunity against human bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Maeli eMelotto

    2014-08-01

    Full Text Available Certain human bacterial pathogens such as the enterohemorrhagic Escherichia coli and Salmonella enterica are not proven to be plant pathogens yet. Nonetheless, under certain conditions they can survive on, penetrate into, and colonize internal plant tissues causing serious food borne disease outbreaks. In this review, we highlight current understanding on the molecular mechanisms of plant responses against human bacterial pathogens and discuss salient common and contrasting themes of plant interactions with phytopathogens or human pathogens.

  16. Resistance to antimicrobials drugs and control measures of Salmonella spp in the poultry industry

    Directory of Open Access Journals (Sweden)

    Velhner Maja

    2013-01-01

    Full Text Available The worldwide prevalence of multiple resistant Salmonella spp is described. Clonally distributed Salmonella Enteritidis PT4 and Salmonella Typhimurium DT104 are among the most pathogenic strains for humans. Recently there have been reports on the prevalence of ST “like” monophasic 4(5,12:i strains in some countries. Vaccination strategy and antimicorbial agent therapy is also briefly discussed. Products of animal origin must be safe and without the risk of antimicrobial resistance. Subsequently, the good management practice at farm level and HACCP in feed factories are required to cope with salmonella infections. Poultry producers in developed countries have been motivated to participate in salmonella control programs, because of public awareness on safe food and risks in the food chain. Export of poultry and poultry products is more successful in the regions where Salmonella Enteritidis and Salmonella Typhimurium have been eradicated. [Projekat Ministarstva nauke Republike Srbije, br. TR31071

  17. Role of rodents in transmission of Salmonella and Campylobacter

    OpenAIRE

    Meerburg, Dr BG; Kijlstra, Prof dr A

    2007-01-01

    Salmonella and Campylobacter are generally regarded as the most important food-borne pathogens in the world. Reduction or elimination of these pathogens in the first part of the food chain (on the farm) is important to prevent disease among consumers of animal products. In organic farming, elimination becomes more difficult, as food animals are allowed outdoors and have easy access to potential sources of hazardous pathogens. Whilst rodents are often associated by organic farmers with infr...

  18. Biofilm formation, antimicrobial resistance, and sanitizer tolerance of Salmonella entericia strains isolated from beef trim

    Science.gov (United States)

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

  19. 76 FR 22667 - Availability of Salmonella Compliance Guide for Small and Very Small Meat and Poultry...

    Science.gov (United States)

    2011-04-22

    ...] Availability of Salmonella Compliance Guide for Small and Very Small Meat and Poultry Establishments That... production of ready-to-eat (RTE) meat and poultry products with respect to Salmonella and other pathogens... This document provides small and very small meat and poultry establishments \\1\\ that manufacture RTE...

  20. A multiplex ligation detection assay for the characterization of Salmonella enterica strains

    DEFF Research Database (Denmark)

    Aarts, Henk J.M.; Vos, Pieter; Larsson, Jonas T.

    2011-01-01

    A proof of principle of a multi-target assay for genotyping Salmonella has been developed targeting 62 genomic marker sequences of Salmonella related to pathogenicity. The assay is based on multiplex ligation detection reaction (LDR) followed by customized ArrayTube® microarray detection. The fea...... assessors that support bio-traceability models....

  1. Virulence and metabolic characteristics of Salmonella Enteritidis sefD variants in hens.

    Science.gov (United States)

    Salmonella Enteritidis is one of a few pathogenic Salmonella enterica serotypes that have SEF14 fimbriae encoded by the sef operon, which consists of 4 co-transcribed genes sefABCD that are regulated by sefR. To explore the function of sefD within the infection pathway resulting in egg contamination...

  2. A multiplex ligation detection assay for the characterization of Salmonella enterica strains

    NARCIS (Netherlands)

    Aarts, H.J.M.; Vos, P.; Larsson, J.T.; Hoek, van A.H.A.M.; Huehn, S.; Weijers, T.; Gronlund, H.A.; Malorny, B.

    2011-01-01

    A proof of principle of a multi-target assay for genotyping Salmonella has been developed targeting 62 genomic marker sequences of Salmonella related to pathogenicity. The assay is based on multiplex ligation detection reaction (LDR) followed by customized ArrayTube (R) microarray detection. The

  3. Specificity tests of an oligonucleotide probe against food-outbreak salmonella for biosensor detection

    Science.gov (United States)

    Chen, I.-H.; Horikawa, S.; Xi, J.; Wikle, H. C.; Barbaree, J. M.; Chin, B. A.

    2017-05-01

    Phage based magneto-elastic (ME) biosensors have been shown to be able to rapidly detect Salmonella in various food systems to serve food pathogen monitoring purposes. In this ME biosensor platform, the free-standing strip-shaped magneto-elastic sensor is the transducer and the phage probe that recognizes Salmonella in food serves as the bio-recognition element. According to Sorokulova et al. at 2005, a developed oligonucleotide probe E2 was reported to have high specificity to Salmonella enterica Typhimurium. In the report, the specificity tests were focused in most of Enterobacterace groups outside of Salmonella family. Here, to understand the specificity of phage E2 to different Salmonella enterica serotypes within Salmonella Family, we further tested the specificity of the phage probe to thirty-two Salmonella serotypes that were present in the major foodborne outbreaks during the past ten years (according to Centers for Disease Control and Prevention). The tests were conducted through an Enzyme linked Immunosorbent Assay (ELISA) format. This assay can mimic probe immobilized conditions on the magnetoelastic biosensor platform and also enable to study the binding specificity of oligonucleotide probes toward different Salmonella while avoiding phage/ sensor lot variations. Test results confirmed that this oligonucleotide probe E2 was high specific to Salmonella Typhimurium cells but showed cross reactivity to Salmonella Tennessee and four other serotypes among the thirty-two tested Salmonella serotypes.

  4. Assessing the prevalence of Salmonella enterica in poultry hatcheries by using hatched eggshell membranes.

    Science.gov (United States)

    Chao, M-R; Hsien, C-H; Yeh, C-M; Chou, S-J; Chu, C; Su, Y-C; Yu, C-Y

    2007-08-01

    Salmonella enterica causes a number of significant poultry diseases and is also a major pathogen in humans. Most poultry infected by Salmonella become carriers; infection may also be fatal, depending on the particular serovar and the age of the bird at infection. Younger birds are more susceptible to infection by Salmonella, so it is critical that hatcheries monitor birds. We developed a method to use hatched eggshell membranes (HEM) to assess contamination by Salmonella in poultry hatching cabinets and to evaluate the prevalence of Salmonella in a goose hatchery and rearing farm. Comparison of the Salmonella isolation rate in hatching cabinets using 3 sampling methods showed that the highest Salmonella contamination was detected in HEM, and that these results differed significantly from those obtained from fluff samples and cabinet swab samples (P chicken, and duck hatcheries. The lowest Salmonella-positive rate was found for the chicken hatchery, followed by the goose and the duck hatcheries (P hatcheries: A, B, C1, C2, D, and E. The distribution of these serogroups differed among the hatcheries. Salmonella serogroup C1 was the major serogroup found in geese, compared with serogroup B in chickens and ducks. However, Salmonella Typhimurium was dominant in 1 goose hatchery and also in geese from this hatchery that had been transferred to a farm. Antibiotic susceptibility analysis showed that Salmonella Typhimurium strains isolated from the farm geese with diarrhea showed significantly higher resistance to doxycycline, colistin, sulfamethoxazole-trimethoprin, and cephalothin than those isolated from the hatchery (P hatcheries and rearing farms.

  5. Detection and characterization of foodborne pathogenic bacteria with hyperspectral microscope imaging

    Science.gov (United States)

    Rapid detection and identification of pathogenic microorganisms naturally occurring during food processing are important in developing intervention and verification strategies. In the poultry industry, contamination of poultry meat with foodborne pathogens (especially, Salmonella and Campylobacter) ...

  6. Real-Time Salmonella Detection Using Lead Zirconate Titanate-Titanium Microcantilevers

    National Research Council Canada - National Science Library

    McGovern, John-Paul; Shih, Wan Y; Shih, Wei-Heng; Sergi, Mauro; Chaiken, Irwin

    2005-01-01

    .... We have developed and investigated the use of a lead zirconate titanate - titanium (PZT-Ti) microcantilever for in situ detection of the common food- and water-born pathogen, Salmonella typhimurium...

  7. Immunological reactions to Salmonella FlgK and FliD flagellar proteins by broiler sera

    Science.gov (United States)

    Background: Salmonella is the leading foodborne pathogen that causes human acute bacterial gastroenteritis worldwide. Chickens are considered as one of major reservoirs of this bacterium. Because the bacterial flagellum is involved in motility, adhesion, quorum sensing and other virulence activit...

  8. Genomics of Salmonella Species

    Science.gov (United States)

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

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-01

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

  10. Transcriptional profiling avian beta-defensins in chicken oviduct epithelial cells before and after infection with Salmonella enterica serovar Enteritidis

    Directory of Open Access Journals (Sweden)

    Bailey R Hartford

    2009-07-01

    Full Text Available Abstract Background Salmonella enterica serovar Enteritidis (SE colonizes the ovary and oviduct of chickens without causing overt clinical signs which can lead to SE-contamination of the content and membrane of shell-eggs as well as hatchery eggs. The organism utilizes the Salmonella Pathogenicity Island-2 encoded type III secretion system (T3SS-2 to promote persistence in the oviduct of laying hens. In this study, reverse transcriptase-polymerase chain reaction (RT-PCR was carried out to determine the expression profiles of 14 known avian beta defensins (AvBDs in primary chicken oviduct epithelial cells (COEC before and after infections with a wild type SE strain and T3SS mutant SE strains carrying an inactivated sipA or pipB gene. Results Based on the expression levels in uninfected COEC, AvBDs can be loosely grouped into three categories with AvBD4-5 and AvBD9-12 being constitutively expressed at high levels; AvBD1, AvBD3, and AvBD13-14 at moderate levels; and AvBD2 and AvBD6-8 at minimal levels. Infection with the wild type SE strain temporarily repressed certain highly expressed AvBDs and induced the expression of minimally expressed AvBDs. The pipB mutant, compared to the wild type strain, had reduced suppressive effect on the expression of highly expressed AvBDs. Moreover, the pipB mutant elicited significantly higher levels of the minimally expressed AvBDs than the wild type SE or the sipA mutant did. Conclusion Chicken oviduct epithelial cells express most of the known AvBD genes in response to SE infection. PipB, a T3SS-2 effector protein, plays a role in dampening the β-defensin arm of innate immunity during SE invasion of chicken oviduct epithelium.

  11. Transcriptional profiling avian beta-defensins in chicken oviduct epithelial cells before and after infection with Salmonella enterica serovar Enteritidis.

    Science.gov (United States)

    Ebers, Katie L; Zhang, C Yan; Zhang, M Zhenyu; Bailey, R Hartford; Zhang, Shuping

    2009-07-30

    Salmonella enterica serovar Enteritidis (SE) colonizes the ovary and oviduct of chickens without causing overt clinical signs which can lead to SE-contamination of the content and membrane of shell-eggs as well as hatchery eggs. The organism utilizes the Salmonella Pathogenicity Island-2 encoded type III secretion system (T3SS-2) to promote persistence in the oviduct of laying hens. In this study, reverse transcriptase-polymerase chain reaction (RT-PCR) was carried out to determine the expression profiles of 14 known avian beta defensins (AvBDs) in primary chicken oviduct epithelial cells (COEC) before and after infections with a wild type SE strain and T3SS mutant SE strains carrying an inactivated sipA or pipB gene. Based on the expression levels in uninfected COEC, AvBDs can be loosely grouped into three categories with AvBD4-5 and AvBD9-12 being constitutively expressed at high levels; AvBD1, AvBD3, and AvBD13-14 at moderate levels; and AvBD2 and AvBD6-8 at minimal levels. Infection with the wild type SE strain temporarily repressed certain highly expressed AvBDs and induced the expression of minimally expressed AvBDs. The pipB mutant, compared to the wild type strain, had reduced suppressive effect on the expression of highly expressed AvBDs. Moreover, the pipB mutant elicited significantly higher levels of the minimally expressed AvBDs than the wild type SE or the sipA mutant did. Chicken oviduct epithelial cells express most of the known AvBD genes in response to SE infection. PipB, a T3SS-2 effector protein, plays a role in dampening the beta-defensin arm of innate immunity during SE invasion of chicken oviduct epithelium.

  12. Antimicrobial resistance among Salmonella enterica serovar Infantis from broiler carcasses in Serbia

    Science.gov (United States)

    Nikolić, A.; Baltić, T.; Velebit, B.; Babić, M.; Milojević, L.; Đorđević, V.

    2017-09-01

    This study aimed to investigate antimicrobial resistance of Salmonella Infantis isolates from poultry carcasses in Serbia. A total of 48 Salmonella isolates were examined for antimicrobial resistance. A panel of 10 antibiotics was selected for testing. Isolates showed resistance to sulfamethoxazole, ceftazidime and cefotaxime (100%). However, the highest number of Salmonella Infantis isolates were sensitive to chloramphenicol. The usage of antibiotics in food producing animals could result in antimicrobial resistance pathogenic bacteria especially Salmonella spp. in poultry, which may be transmitted to humans through the food chain and increase risk of treatment failures.

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

    Directory of Open Access Journals (Sweden)

    Sylvia eSchleker

    2015-01-01

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

  14. Prevalence of Salmonella among waterfowl along the Texas Gulf coast.

    Science.gov (United States)

    Grigar, M K; Cummings, K J; Rankin, S C

    2017-12-01

    Migratory waterfowl may play a role in the ecology and transmission of zoonotic pathogens, given their ability to travel long distances and their use of varied habitats. Our objectives were to estimate the prevalence of Salmonella among waterfowl along the Texas Gulf coast and to characterize the isolates. Faecal samples were collected from hunter-harvested waterfowl at four wildlife management areas from September through November, 2016. Standard bacteriologic culture methods were used to isolate Salmonella from samples, and isolates were characterized by serotyping and anti-microbial susceptibility testing. The apparent prevalence of faecal Salmonella shedding was 0.5% (2/375). Serotypes identified were Thompson and Braenderup, and both isolates were susceptible to all anti-microbial agents tested. Although faecal contamination of agricultural fields or surface waters could serve as a potential source of zoonotic Salmonella transmission, waterfowl along the Gulf coast during the fall hunting season appear to pose minimal risk. © 2017 Blackwell Verlag GmbH.

  15. Salmonella radicidation of poultry carcasses

    International Nuclear Information System (INIS)

    Mulder, R.W.A.W.

    1982-01-01

    This thesis reports investigations using gamma-radiation to decontaminate poultry carcasses. The application to foods of doses of ionizing radiation sufficient to reduce the number of viable specific non-sporeforming pathogenic microorganisms so that none is detectable in the treated food by any standard method is termed radicidation. The doses used in this study were at such a level that no undesirable or unfavourable side-effects occurred. The effects of these doses were studied on salmonellae and other microorganisms present in, or associated with poultry carcasses and in liquid and on solid culture media as well. Decimal reduction (D 10 ) values were estimated. These represent the dose (kGy) required to achieve a reduction in initial colony count from N 0 to 0.1 N 0 . Together with the estimation of the numbers of Salmonella present per carcass the data were used to predict the effect of an ionizing radiation treatment of poultry. Data on the effect of ionizing radiation on the total microflora of poultry carcasses were also collected. (Auth.)

  16. Priority setting of foodborne pathogens: disease burden and costs of selected enteric pathogens

    NARCIS (Netherlands)

    Kemmeren JM; Mangen MJJ; Duynhoven YTHP van; Havelaar AH; MGB

    2006-01-01

    Toxoplasmosis causes the highest disease burden among seven evaluated foodborne pathogens. This is the preliminary conclusion of a major study of the disease burden and related costs of foodborne pathogens. The other micro-organisms that were studied are Campylobacter spp., Salmonella spp.,

  17. Methods for detecting pathogens in the beef food chain: detecting particular pathogens

    Science.gov (United States)

    The main food-borne pathogens of concern in the beef food chain are Shiga toxin-producing Escherichia coli (STEC) and Salmonella spp.; however, the presence of other pathogens, including Listeria monocytogenes, Campylobacter spp., Clostridium spp., Bacillus cereus, and Mycobacterium avium subsp. par...

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

    Directory of Open Access Journals (Sweden)

    Grammato Evangelopoulou

    2013-07-01

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

  19. Radiation mapping helps in the Three Mile Island 2 clean up

    International Nuclear Information System (INIS)

    Nightingale, Brian

    1986-01-01

    Modelling to depict the location and nature of the radiation measurements needed before surveys are undertaken can save personnel exposure and improve the quality of the radiation data itself, as experience at Three Mile Island 2 has shown. (author)

  20. Salmonella biofilm formation on Aspergillus niger involves cellulose - chitin interactions

    Science.gov (United States)

    Salmonella cycles between host and nonhost environments, where it can become an active member of complex microbial communities. The role of fungi in the environmental adaptation of enteric pathogens remains relatively unexplored. We have discovered that S. enterica Typhimurium rapidly attaches to an...

  1. Salmonella Enteritidis experimental infection in chickens: Effects of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... challenge dose of Salmonella Enteritidis on detection of specific immunoglobulin G (IgG) ... Two groups of specific-pathogen-free chickens were infected ... Since chickens may be exposed to variable quantities ... A second group of 8 hens was orally .... where presence of serum antibodies by most birds that.

  2. Multidrug-resistant Salmonella enterica serovar Typhimurium isolates are resistant to antibiotics that influence their swimming and swarming motility

    Science.gov (United States)

    Motile bacteria utilize one or more strategies for movement, such as darting, gliding, sliding, swarming, swimming, and twitching. The ability to move is considered a virulence factor in many pathogenic bacteria, including Salmonella. Multidrug-resistant (MDR) Salmonella encodes acquired factors t...

  3. 77 FR 58089 - Availability of FSIS Salmonella Compliance Guidelines for Small and Very Small Meat and Poultry...

    Science.gov (United States)

    2012-09-19

    ...] Availability of FSIS Salmonella Compliance Guidelines for Small and Very Small Meat and Poultry Establishments... revised compliance guide for small and very small meat and poultry establishments on the safe production of ready-to-eat (RTE) meat and poultry products with respect to Salmonella and other pathogens. FSIS...

  4. Ecology of E. coli O157:H7 and Salmonella enterica in the primary vegetable production chain

    NARCIS (Netherlands)

    Franz, E.; Bruggen, van A.H.C.

    2008-01-01

    There is an increased concern that plants might be more important as a carrier for human enteric pathogens like E. coli O157:H7 and Salmonella enterica serovars than previously thought. This review summarizes the knowledge available on the ecology of E. coli O157:H7 and Salmonella enterica in the

  5. Bacteriophage cocktail for biocontrol of Salmonella in dried pet food.

    Science.gov (United States)

    Heyse, Serena; Hanna, Leigh Farris; Woolston, Joelle; Sulakvelidze, Alexander; Charbonneau, Duane

    2015-01-01

    Human salmonellosis has been associated with contaminated pet foods and treats. Therefore, there is interest in identifying novel approaches for reducing the risk of Salmonella contamination within pet food manufacturing environments. The use of lytic bacteriophages shows promise as a safe and effective way to mitigate Salmonella contamination in various food products. Bacteriophages are safe, natural, highly targeted antibacterial agents that specifically kill bacteria and can be targeted to kill food pathogens without affecting other microbiota. In this study, we show that a cocktail containing six bacteriophages had a broadspectrum activity in vitro against a library of 930 Salmonella enterica strains representing 44 known serovars. The cocktail was effective against 95% of the strains in this tested library. In liquid culture dose-ranging experiments, bacteriophage cocktail concentrations of ≥10(8) PFU/ml inactivated more than 90% of the Salmonella population (10(1) to 10(3) CFU/ml). Dried pet food inoculated with a mixture containing equal proportions of Salmonella serovars Enteritidis (ATCC 4931), Montevideo (ATCC 8387), Senftenberg (ATCC 8400), and Typhimurium (ATCC 13311) and then surface treated with the six-bacteriophage cocktail (≥2.5 ± 1.5 × 10(6) PFU/g) achieved a greater than 1-log (P contamination in samples taken from an undistributed lot of commercial dried dog food that tested positive for Salmonella. Our results indicate that bacteriophage biocontrol of S. enterica in dried pet food is technically feasible.

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

    Directory of Open Access Journals (Sweden)

    Arun K. Bhunia

    2009-07-01

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

  7. Persistence of a Salmonella enterica serovar typhimurium DT12 clone in a piggery and in agricultural soil amended with Salmonella-contaminated slurry

    DEFF Research Database (Denmark)

    Baloda, Suraj B.; Christensen, Lise; Trajcevska, Silvija

    2001-01-01

    Prevalence of Salmonella enterica on a Danish pig farm presenting recurrent infections was investigated. A comparison of the pulsed-held gel electrophoresis patterns of fecal isolates from piggeries, waste slurry, and agricultural soil amended with Salmonella-contaminated animal waste (slurry......) and subclinical isolates from the same farm (collected in 1996 and later) showed identical patterns, indicating long-term persistence of the Salmonella enterica serovar Typhimurium DT12 clone in the herd environment. Furthermore, when Salmonella-contaminated slurry was disposed of on the agricultural soil (a...... common waste disposal practice), the pathogen was isolated up to 14 days after the spread, indicating potentially high risks of transmission of the pathogen in the environment, animals, and humans....

  8. Factors Associated with Salmonella Prevalence in U.S. Swine Grower-Finisher Operations, 2012.

    Science.gov (United States)

    Bjork, Kathe E; Fields, Victoria; Garber, Lindsey P; Kopral, Christine A

    2018-05-15

    Nontyphoidal Salmonella is an important foodborne pathogen with diverse serotypes occurring in animal and human populations. The prevalence of the organism on swine farms has been associated with numerous risk factors, and although there are strong veterinary public health controls for preventing Salmonella from entering food, there remains interest in eradicating or controlling the organism in the preharvest environment. In this study, using data collected via the U.S. Department of Agriculture (USDA) National Animal Health Monitoring System Swine 2012 study, we describe nontyphoidal Salmonella and specific serotype prevalence on U.S. grower-finisher swine operations and investigate associations between Salmonella detection and numerous factors via multiple correspondence analysis (MCA) and regression analysis. MCA plots, complementary to univariate analyses, display relationships between covariates and Salmonella detection at the farm level. In the univariate analysis, Salmonella detection varied with feed characteristics and farm management practices, reports of diseases on farms and vaccinations administered, and administration of certain antimicrobials. Results from the univariate analysis reinforce the importance of biosecurity in managing diseases and pathogens such as Salmonella on farms. All multivariable regression models for the likelihood of Salmonella detection were strongly affected by multicollinearity among variables, and only one variable, pelleted feed preparation, remained in the final model. The study was limited by its cross-sectional nature, timelines of data collection, and reliance on operator-reported data via a convenience sample.

  9. Salmonella Persistence in Tomatoes Requires a Distinct Set of Metabolic Functions Identified by Transposon Insertion Sequencing

    Science.gov (United States)

    Desai, Prerak; Porwollik, Steffen; Canals, Rocio; Perez, Daniel R.; Chu, Weiping; McClelland, Michael; Teplitski, Max

    2016-01-01

    ABSTRACT Human enteric pathogens, such as Salmonella spp. and verotoxigenic Escherichia coli, are increasingly recognized as causes of gastroenteritis outbreaks associated with the consumption of fruits and vegetables. Persistence in plants represents an important part of the life cycle of these pathogens. The identification of the full complement of Salmonella genes involved in the colonization of the model plant (tomato) was carried out using transposon insertion sequencing analysis. With this approach, 230,000 transposon insertions were screened in tomato pericarps to identify loci with reduction in fitness, followed by validation of the screen results using competition assays of the isogenic mutants against the wild type. A comparison with studies in animals revealed a distinct plant-associated set of genes, which only partially overlaps with the genes required to elicit disease in animals. De novo biosynthesis of amino acids was critical to persistence within tomatoes, while amino acid scavenging was prevalent in animal infections. Fitness reduction of the Salmonella amino acid synthesis mutants was generally more severe in the tomato rin mutant, which hyperaccumulates certain amino acids, suggesting that these nutrients remain unavailable to Salmonella spp. within plants. Salmonella lipopolysaccharide (LPS) was required for persistence in both animals and plants, exemplifying some shared pathogenesis-related mechanisms in animal and plant hosts. Similarly to phytopathogens, Salmonella spp. required biosynthesis of amino acids, LPS, and nucleotides to colonize tomatoes. Overall, however, it appears that while Salmonella shares some strategies with phytopathogens and taps into its animal virulence-related functions, colonization of tomatoes represents a distinct strategy, highlighting this pathogen's flexible metabolism. IMPORTANCE Outbreaks of gastroenteritis caused by human pathogens have been increasingly associated with foods of plant origin, with tomatoes

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

    Science.gov (United States)

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

    2018-03-01

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

  11. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2014. Scientific Opinion on the risk posed by pathogens in food of non-animal origin. Part 2 (Salmonella Yersinia, Shigella and Norovirus in bulb and stem vegetables, and carrots)

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    , Shigella and Norovirus were considered in the context of the whole food chain. Available estimates of their occurrence in these vegetables were evaluated together with mitigation options relating to prevention of contamination and the relevance of microbiological criteria. Emphasis is given to vegetable...... of food safety management systems including Good Agricultural Practices (GAP), Good Hygiene Practices (GHP) and Good Manufacturing Practices (GMP) should be the primary objectives of producers of bulb and stem vegetables as well as carrots. Considering the limited evidence for both the occurrence......Bulb and stem vegetables as well as carrots may be minimally processed to obtain ready-to-eat products, and these steps include selection, washing, cleaning, cutting, packaging and storage. Risk factors for the contamination of bulb and stem vegetables as well as carrots with Salmonella, Yersinia...

  12. Investigations of Salmonella enterica serovar newport infections of oysters by using immunohistochemistry and knockout mutagenesis.

    Science.gov (United States)

    Morrison, Christopher M; Dial, Sharon M; Day, William A; Joens, Lynn A

    2012-04-01

    The consumption of raw oysters is an important risk factor in the acquisition of food-borne disease, with Salmonella being one of a number of pathogens that have been found in market oysters. Previous work by our lab found that Salmonella was capable of surviving in oysters for over 2 months under laboratory conditions, and this study sought to further investigate Salmonella's tissue affinity and mechanism of persistence within the oysters. Immunohistochemistry was used to show that Salmonella was capable of breaching the epithelial barriers, infecting the deeper connective tissues of the oysters, and evading destruction by the oysters' phagocytic hemocytes. To further investigate the mechanism of these infections, genes vital to the function of Salmonella's two main type III secretion systems were disrupted and the survivability of these knockout mutants within oysters was assayed. When the Salmonella pathogenicity island 1 and 2 mutant strains were exposed to oysters, there were no detectable deficiencies in their abilities to survive, suggesting that Salmonella's long-term infection of oysters does not rely upon these two important pathogenicity islands and must be due to some other, currently unknown, mechanism.

  13. Salmonella serovar-specific interaction with jejunal epithelial cells.

    Science.gov (United States)

    Razzuoli, Elisabetta; Amadori, Massimo; Lazzara, Fabrizio; Bilato, Dania; Ferraris, Monica; Vito, Guendalina; Ferrari, Angelo

    2017-08-01

    Gut is often a receptacle for many different pathogens in feed and/or the environment, such as Salmonella spp. The current knowledge about pathogenicity of Salmonella is restricted to few serotypes, whereas other important ones like S. Coeln, S. Thompson, S. Veneziana, have not been investigated yet in human and animal models. Therefore, the aim of our work was to verify the ability of widespread environmental Salmonella strains to penetrate and modulate innate immunity in pig intestinal IPEC-J2 cells. Our results outline the different ability of Salmonella strains to modulate innate immunity; the expression of the IFN-β gene was increased by S. Typhimurium, S. Ablogame and S. Diarizonae 2, that also caused an inflammatory response in terms of Interleukin (IL)-1β and/or IL-8 gene espression. In particular, IL-8 gene expression and protein release were significantly modulated by 5 Salmonella strains out of 7. Interestingly, S. Typhimurium, S. Coeln and S. Thompson strains, characterized by a peculiar ability to penetrate into IPEC-J2 cells, up-regulated both IL-8 and TNF-α gene expression. Accordingly, blocking IL-8 was shown to decrease the penetration of S. Typhimurium. On the contrary, S. Diarizonae strain 1, showing lesser invasion of IPEC-J2 cells, down-regulated the p38-MAPK pathway, and it did not induce an inflammatory response. Our results confirm that IPEC-J2 cells are a useful model to evaluate host-gut pathogen interaction and indicate IL-8 and TNF-α as possible predictive markers of invasiveness of Salmonella strains in enterocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Cattle drive Salmonella infection in the wildlife-livestock interface.

    Science.gov (United States)

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

    2013-11-01

    The genus Salmonella is found throughout the world and is a potential pathogen for most vertebrates. It is also the most common cause of food-borne illness in humans, and wildlife is an emerging source of food-borne disease in humans due to the consumption of game meat. Wild boar is one of the most abundant European game species and these wild swine are known to be carriers of zoonotic and food-borne pathogens such as Salmonella. Isolation of the pathogen, serotyping and molecular biology are necessary for elucidating epidemiological connections in multi-host populations. Although disease management at population level can be addressed using a number of different strategies, such management is difficult in free-living wildlife populations due to the lack of experience with the wildlife-livestock interface. Herein, we provide the results of a 4-year Salmonella survey in sympatric populations of wild boar and cattle in the Ports de Tortosa i Beseit National Game Reserve (NE Spain). We also evaluated the effects of two management strategies, cattle removal and increased wild boar harvesting (i.e. by hunting and trapping), on the prevalence of the Salmonella serovar community. The serovars Meleagridis and Anatum were found to be shared by cattle and wild boar, a finding that was confirmed by 100% DNA similarity patterns using pulse field gel electrophoresis. Cattle removal was more efficient than the culling of wild boar as a means of reducing the prevalence of shared serotypes, which underlines the role of cattle as a reservoir of Salmonella for wild boar. To our knowledge, this is the first attempt to manage Salmonella in the wild, and the results have implications for management. © 2012 Blackwell Verlag GmbH.

  15. Advanced Oxidation Process sanitization of hatching eggs reduces Salmonella in broiler chicks.

    Science.gov (United States)

    Rehkopf, A C; Byrd, J A; Coufal, C D; Duong, T

    2017-10-01

    The microbial quality of eggs entering the hatchery is an important critical control point for biosecurity, pathogen reduction, and food safety programs in poultry production. Developing interventions to reduce Salmonella contamination of eggs is important to improving the microbial food safety of poultry and poultry products. The hydrogen peroxide (H2O2) and ultraviolet light (UV) Advanced Oxidation Process (AOP) has been previously demonstrated to be effective in reducing Salmonella on the surface of experimentally contaminated eggs. The objective of this study was to evaluate the effect of treating eggs with an egg-sanitizing apparatus using the H2O2/UV AOP on Salmonella contamination during incubation, hatching, and in broiler chicks during grow-out. Experimentally contaminated eggs were treated using the automated H2O2/UV AOP egg sanitizer and incubated for 21 d. AOP sanitization reduced Salmonella up to 7 log10 cfu egg-1 (P Salmonella positive eggs by up to 75% (P Salmonella-positive eggs during incubation. Additionally, Salmonella was recovered from more chicks hatched from untreated eggs than from eggs treated using the H2O2/UV AOP egg sanitizer (P Salmonella contamination on the surface of eggs using the H2O2/UV AOP egg sanitizer prior to incubation may reduce the gastrointestinal colonization of chicks by Salmonella. © 2017 Poultry Science Association Inc.

  16. Prevalence and antimicrobial resistance of Salmonella spp. in raw retail frozen imported freshwater fish to Eastern Province of Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Nasreldin Elhadi

    2014-03-01

    Conclusions: The obtained results of this study shows that these raw retail imported frozen freshwater fish are contaminated with potentially pathogenic Salmonella spp. And the study recommend and suggest that there is a need for adequate consumer measures.

  17. Interactions of Salmonella enterica Serovar Typhimurium and Pectobacterium carotovorum within a tomato soft rot

    Science.gov (United States)

    The human pathogen Salmonella has shown a remarkable adaptability which allows these bacteria to thrive in a variety of environments and hosts. The manner in which these pathogens establish within a niche amidst the native microbiota remains poorly understood. Here, we aimed to uncover the mechanism...

  18. Coconut and Salmonella Infection

    Science.gov (United States)

    Schaffner, Carl P.; Mosbach, Klaus; Bibit, Venuso C.; Watson, Colin H.

    1967-01-01

    Raw, unprocessed coconut supports the growth of salmonellae as well as that of other enteric bacteria, salmonellae being particularly resistant to subsequent desiccation. Original contamination is not due to carriers or to polluted water supplies, but to contact with bacteria-containing soils followed by dispersion via infected coconut milk and shells. Pasteurization of raw coconut meat in a water bath at 80 C for 8 to 10 min effectively killed such bacteria, did not injure the product, and provided a prophylactic method now widely used by the coconut industry. PMID:5340650

  19. Factors associated with Salmonella shedding among equine colic patients at a veterinary teaching hospital.

    Science.gov (United States)

    Kim, L M; Morley, P S; Traub-Dargatz, J L; Salman, M D; Gentry-Weeks, C

    2001-03-01

    To evaluate factors potentially associated with fecal Salmonella shedding among equine patients hospitalized for colic at a veterinary teaching hospital and to determine the effects of probiotic treatment on fecal Salmonella shedding and clinical signs. Longitudinal study and controlled trial. 246 equine colic patients. History and medical information were obtained from patient records. Fecal and environmental samples were submitted for aerobic bacterial culture for Salmonella enterica. Fifty-one patients were treated with a commercially available probiotic; 46 were treated with a placebo. Logistic regression was used to evaluate data. Salmonella organisms were detected in feces from 23 (9%) patients at least once during hospitalization. Patients were more likely to shed Salmonella organisms if diarrhea was evident equine patients hospitalized at a veterinary teaching hospital because of colic and that pathogen monitoring in patients and the hospital environment and use of barrier nursing precautions for equine colic patients are beneficial.

  20. A sandwich-type optical immunosensor based on the alkaline phosphatase enzyme for Salmonella thypimurium detection

    Science.gov (United States)

    Widyastuti, E.; Puspitasari Schonherr, M. F.; Masruroh, A.; Anggraeni, R. A.; Nisak, Y. K.; Mursidah, S.

    2018-03-01

    Salmonella is pathogenic bacteria that caused foodborne diseases which being called Salmonellosis. Prevalence of Salmonellosis that being caused by Salmonella thypimurium in Indonesia is quite high. However, detection of Salmonella bacteria in food still limited, complicated, and required a lot time. Sensitive optical assay for Salmonella thypimurium paper based detection has been developed by integrating sandwich assay between antibody-antigen complex and alkaline phosphatase enzyme that produce visible bluish-purple colour with presence of NBT-BCIP substrate. The results showed that Limit of Quantitation of detection is 105 CFU mL-1 with detection time 15 minutes. Linearity test between Colour intensity that produced from Salmonella concentration presence on samples showed that detection has good linearity. Selectivity test exhibited excellent sensitivity with good discrimination against Escherichia coli.

  1. Simultaneous occurrence of Salmonella arizonae in a sulfur crested cockatoo (Cacatua galerita galerita) and iguanas.

    Science.gov (United States)

    Orós, J; Rodríguez, J L; Fernández, A; Herráez, P; Espinosa de los Monteros, A; Jacobson, E R

    1998-01-01

    A case of fatal hepatitis in a captive sulfur crested cockatoo (Cacatua galerita galerita) in which Salmonella arizonae was microbiologically and immunohistochemically detected is described. The death of the cockatoo was closely related to the arrival of a group of 10 green iguanas (Iguana iguana) at a pet shop, and no previous clinical signs were observed in the cockatoo. The most important lesion observed at necropsy of the cockatoo was a multifocal necrotic hepatitis. Salmonella arizonae was isolated from the liver of the cockatoo and was detected immunohistochemically mainly around the edges of necrotic foci. Four iguanas died 3 days later showing a severe enteritis, and Salmonella arizonae was isolated from these lesions. The importance of quarantine and, because of pathogens such as Salmonella, the need to house reptiles at a distance from avian species, mainly psittacids, are reinforced. This is the first report of Salmonella arizonae infection in a cockatoo.

  2. Host-pathogen interactions in typhoid fever

    NARCIS (Netherlands)

    de Jong, H.K.

    2015-01-01

    This thesis focuses on host-pathogen interactions in Salmonella Typhi and Burkholderia pseudomallei infections and explores the interplay between these bacteria and the innate immune system. Typhoid fever is one of the most common causes of bacterial infection in low-income countries. With adequate

  3. Antibiotic Resistant Salmonella and Vibrio Associated with Farmed Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Sanjoy Banerjee

    2012-01-01

    Full Text Available Salmonella and Vibrio species were isolated and identified from Litopenaeus vannamei cultured in shrimp farms. Shrimp samples showed occurrence of 3.3% of Salmonella and 48.3% of Vibrio. The isolates were also screened for antibiotic resistance to oxolinic acid, sulphonamides, tetracycline, sulfamethoxazole/trimethoprim, norfloxacin, ampicillin, doxycycline hydrochloride, erythromycin, chloramphenicol, and nitrofurantoin. Salmonella enterica serovar Corvallis isolated from shrimp showed individual and multiple antibiotic resistance patterns. Five Vibrio species having individual and multiple antibiotic resistance were also identified. They were Vibrio cholerae (18.3%, V. mimicus (16.7%, V. parahaemolyticus (10%, V. vulnificus (6.7%, and V. alginolyticus (1.7%. Farm owners should be concerned about the presence of these pathogenic bacteria which also contributes to human health risk and should adopt best management practices for responsible aquaculture to ensure the quality of shrimp.

  4. Seasonal stability of Cladophora-associated Salmonella in Lake Michigan watersheds

    Science.gov (United States)

    Byappanahalli, M.N.; Sawdey, R.; Ishii, S.; Shively, D.A.; Ferguson, J.A.; Whitman, R.L.; Sadowsky, M.J.

    2009-01-01

    The bacterial pathogens Shigella, Salmonella, Campylobacter, and shiga toxin-producing E. coli (STEC) were recently found to be associated with Cladophora growing in southern Lake Michigan. Preliminary results indicated that the Salmonella strains associated with Cladophora were genetically identical to each other. However, because of the small sample size (n = 37 isolates) and a lack of information on spatial-temporal relationships, the nature of the association between Cladophora and Salmonella remained speculative. In this study, we investigated the population structure and genetic relatedness of a large number of Cladophora-borne Salmonella isolates from Lake Michigan (n = 133), as well as those isolated from stream and lake water (n = 31), aquatic plants (n = 8), and beach sands and sediments (n = 8) from adjacent watersheds. Salmonella isolates were collected during 2005-2007 between May and August from Lake Michigan beachsheds in Wisconsin, Illinois, and Indiana. The genetic relatedness of Salmonella isolates was examined by using the horizontal, fluorophore-enhanced rep-PCR (HFERP) DNA fingerprinting technique. While the Salmonella isolates associated with Cladophora exhibited a high degree of genetic relatedness (???92% similarity), the isolates were not all genetically identical. Spatial and temporal relationships were evident in the populations examined, with tight clustering of the isolates both by year and location. These findings suggest that the relationship between Salmonella and Cladophora is likely casual and is related to input sources (e.g. wastewater, runoff, birds) and the predominant Salmonella genotype surviving in the environment during a given season. Our studies indicate that Cladophora is likely an important reservoir for Salmonella and other enteric bacterial pathogens in Lake Michigan beachsheds, which in turn may influence nearshore water quality. ?? 2008 Elsevier Ltd.

  5. Seasonal stability of Cladophora-associated Salmonella in Lake Michigan watersheds.

    Science.gov (United States)

    Byappanahalli, Muruleedhara N; Sawdey, Richard; Ishii, Satoshi; Shively, Dawn A; Ferguson, John A; Whitman, Richard L; Sadowsky, Michael J

    2009-02-01

    The bacterial pathogens Shigella, Salmonella, Campylobacter, and shiga toxin-producing E. coli (STEC) were recently found to be associated with Cladophora growing in southern Lake Michigan. Preliminary results indicated that the Salmonella strains associated with Cladophora were genetically identical to each other. However, because of the small sample size (n=37 isolates) and a lack of information on spatial-temporal relationships, the nature of the association between Cladophora and Salmonella remained speculative. In this study, we investigated the population structure and genetic relatedness of a large number of Cladophora-borne Salmonella isolates from Lake Michigan (n=133), as well as those isolated from stream and lake water (n=31), aquatic plants (n=8), and beach sands and sediments (n=8) from adjacent watersheds. Salmonella isolates were collected during 2005-2007 between May and August from Lake Michigan beachsheds in Wisconsin, Illinois, and Indiana. The genetic relatedness of Salmonella isolates was examined by using the horizontal, fluorophore-enhanced rep-PCR (HFERP) DNA fingerprinting technique. While the Salmonella isolates associated with Cladophora exhibited a high degree of genetic relatedness (>or=92% similarity), the isolates were not all genetically identical. Spatial and temporal relationships were evident in the populations examined, with tight clustering of the isolates both by year and location. These findings suggest that the relationship between Salmonella and Cladophora is likely casual and is related to input sources (e.g. wastewater, runoff, birds) and the predominant Salmonella genotype surviving in the environment during a given season. Our studies indicate that Cladophora is likely an important reservoir for Salmonella and other enteric bacterial pathogens in Lake Michigan beachsheds, which in turn may influence nearshore water quality.

  6. The effects of 137Cs irradiation and MAP on the survival and growth of salmonella Spp in pork

    International Nuclear Information System (INIS)

    Gao Meixu

    2000-01-01

    The effects of 137 Cs irradiation (0 to 2 kGy) and MAP combination treatment on the survival and growth of Salmonella Spp are studied in sterile pork in the absence of competing microflora. A central composite response-surface design is used to test the response of the pathogen to the treatments in a single experiment. Predictive equations are developed from the analyses of variances of the resulting data. The results show that the survival of Salmonella is significant decrease with the increasing of irradiation dose, but there are no evident effects on the survival of salmonella due to the MAP. Five kinds of MAP do not show the difference on the growth of Salmonella. 50% CO 2 treatment shows the irradiation protection of Salmonella compared with air. The results indicate that the treatment combined irradiation with MAP is not more effective for controlling the survival and growth of Salmonella Spp

  7. Salmonella from Baby Turtles

    Centers for Disease Control (CDC) Podcasts

    2017-01-09

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

  8. Salmonella burden in Lebanon.

    Science.gov (United States)

    Malaeb, M; Bizri, A R; Ghosn, N; Berry, A; Musharrafieh, U

    2016-06-01

    Salmonellosis is a disease that represents a major public health concern in both developing and developed countries. The aim of this article is to evaluate the public health burden of Salmonella illness in Lebanon. The current scope of the Salmonella infection problem was assessed in relation to disease incidence and distribution with respect to age, gender and district. Factors that provide a better understanding of the magnitude of the problem were explored and highlighted. Data reported to the Epidemiologic Surveillance Department at the Lebanese Ministry of Public Health between 2001 and 2013 was reviewed. Information obtained was compared to information reported regionally and globally. The estimated true incidence was derived using multipliers from the CDC and Jordan. A literature review of all published data from Lebanon about Salmonella susceptibility/resistance patterns and its serious clinical complications was conducted. The estimated incidence was 13·34 cases/100 000 individuals, most cases occurred in the 20-39 years age group with no significant gender variation. Poor and less developed districts of Lebanon had the highest number of cases and the peak incidence was in summer. Reflecting on the projected incidence derived from the use of multipliers indicates a major discrepancy between what is reported and what is estimated. We conclude that data about Salmonella infection in Lebanon and many Middle Eastern and developing countries lack crucial information and are not necessarily representative of the true incidence, prevalence and burden of illness.

  9. Food-borne pathogens. Is there a remedy

    Energy Technology Data Exchange (ETDEWEB)

    Niemand, J G

    1985-03-01

    The Salmonella scare reinforced the importance of never taking chances when it comes to controlling pathogens. The issue has been resolved by radurisation. The article deals with the various pathogens that can effect food and argues the case for radurisation in dealing with them. It also looks at some of the other food products that can be treated using this process.

  10. Enteric pathogen modification by anaecic earthworm, Lampito Mauritii

    African Journals Online (AJOL)

    The biosolids from municipal wastewater treatment plant contains several enteric microbial pathogens, predominantly Salmonella and Escherichia species in the range of 15-18 x 104 CFU/g and 11-12 x 104 CFU/g respectively. The present study investigates the influence of earthworm, Lampito mauritii on enteric pathogen ...

  11. Inactivation of Salmonella spp. on tomatoes by plant molecules.

    Science.gov (United States)

    Mattson, Tyler E; Johny, Anup Kollanoor; Amalaradjou, Mary Anne Roshni; More, Karen; Schreiber, David T; Patel, Jitu; Venkitanarayanan, Kumar

    2011-01-05

    The efficacy of carvacrol (CAR), trans-cinnamaldehyde (TC), eugenol (EUG) and β-resorcylic acid (BR) as a wash treatment for reducing Salmonella spp. on tomatoes was investigated. Plum tomatoes inoculated with a six-serotype mixture of Salmonella (10⁸CFU) were subjected to washing in sterile deionized water (control) or deionized water containing chlorine (100 ppm), CAR (0.25 and 0.75%), TC (0.5 and 0.75%), EUG (0.25 and 0.75%), or BR (0.75 and 1.0%) for 15 sec, 1 min, and 3 min. The plant molecules were more effective (Pwashing in water and chlorine. Both concentrations of CAR and TC, and 0.75% EUG decreased Salmonella counts on tomatoes by~6.0 log CFU/ml at 1 min. Both concentrations of BR decreased the pathogen on tomatoes to undetectable levels at 3 min of exposure. Washing of tomatoes in deionized water and chlorine for 3 min reduced Salmonella by ca. 2.0 and 4.0 log CFU/ml, respectively. No Salmonella was detected in the wash water containing the plant molecules or chlorine, whereas a substantial population of the pathogen survived in the control wash water. Moreover, none of the dipping treatments had any effect on the red color of tomatoes (P>0.05). Results indicate that CAR, TC, EUG and BR could effectively be used to kill Salmonella on tomatoes, but additional studies on sensory and quality characteristics of tomatoes treated with plant molecules are warranted. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Killing of salmonella in the biogas process; Abtoetung von Salmonellen im Biogasprozess

    Energy Technology Data Exchange (ETDEWEB)

    Froeschle, Bianca; Lebuhn, Michael

    2012-08-15

    Pathogenic Salmonella are used in ordinances as an indicator for assessing microbial reduction in biogas plants and for the epidemic-hygienic condition of digestate. This brochure presents results of a study that examined the hygienic effect of the biogas process on Salmonella. [German] Krankheitserregende Salmonellen werden in relevanten Rechtsverordnungen als Indikator zur Beurteilung der Keimreduzierung in Biogasanlagen und des seuchenhygienischen Zustands von Gaerresten herangezogen. Die vorliegende Broschuere stellt Ergebnisse einer Studie dar, die die hygienisierende Wirkung des Biogasprozesses auf Salmonellen untersuchte.

  13. Performing Comparative Peptidomics Analyses of Salmonella from Different Growth Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Adkins, Joshua N.; Mottaz, Heather; Metz, Thomas O.; Ansong, Charles K.; Manes, Nathan P.; Smith, Richard D.; Heffron, Fred

    2010-01-08

    Host–pathogen interactions are complex competitions during which both the host and the pathogen adapt rapidly to each other in order for one or the other to survive. Salmonella enterica serovar Typhimurium is a pathogen with a broad host range that causes a typhoid fever-like disease in mice and severe food poisoning in humans. The murine typhoid fever is a systemic infection in which S.typhimurium evades part of the immune system by replicating inside macrophages and other cells. The transition from a foodborne contaminant to an intracellular pathogen must occur rapidly in multiple,ordered steps in order for S. typhimurium to thrive within its host environment. Using S. typhimurium isolated from rich culture conditions and from conditions that mimic the hostile intracellular environment of the host cell, a native low molecular weight protein fraction, or peptidome, was enriched from cell lysates by precipitation with organic solvents. The enriched peptidome was analyzed by both LC–MS/MS and LC–MS-based methods, although several other methods are possible. Pre-fractionation of peptides allowed identification of small proteins and protein degradation products that would normally be overlooked. Comparison of peptides present in lysates prepared from Salmonella grown under different conditions provided a unique insight into cellular degradation processes as well as identification of novel peptides encoded in the genome but not annotated. The overall approach is detailed here as applied to Salmonella and is adaptable to a broad range of biological systems.

  14. Potential Regrowth and Recolonization of Salmonellae and Indicators in Biosolids and Biosolid-Amended Soil

    Science.gov (United States)

    Zaleski, Kathleen J.; Josephson, Karen L.; Gerba, Charles P.; Pepper, Ian L.

    2005-01-01

    This study evaluated the potential for conversion of Class B to Class A biosolids with respect to salmonellae and fecal coliforms during solar drying in concrete lined drying beds. Anaerobically (8% solids) and aerobically (2% solids) digested Class B biosolids were pumped into field-scale drying beds, and microbial populations and environmental conditions were monitored. Numbers of fecal coliforms and salmonellae decreased as temperature and rate of desiccation increased. After 3 to 4 weeks, Class A requirements were achieved in both biosolids for the pathogens and the indicators. However, following rainfall events, significant increase in numbers was observed for both fecal coliforms and salmonellae. In laboratory studies, regrowth of fecal coliforms was observed in both biosolids and biosolid-amended soil, but the regrowth of salmonellae observed in the concrete-lined drying beds did not occur. These laboratory studies demonstrated that pathogens decreased in numbers when soil was amended with biosolids. Based on serotyping, the increased numbers of salmonellae seen in the concrete lined drying beds following rainfall events was most likely due to recolonization due to contamination from fecal matter introduced by animals and not from regrowth of salmonellae indigenous to biosolids. Overall, we conclude that the use of concrete-lined beds created a situation in which moisture added as rainfall accumulated in the beds, promoting the growth of fecal coliforms and salmonellae added from external sources. PMID:16000779

  15. Breast abscess due to Salmonella paratyphi A : Case reports with review of literature.

    Science.gov (United States)

    Agrawal, Sonu; Yadav, Vishwanath Singh; Srivastava, Anurag; Kapil, Arti; Dhawan, Benu

    2018-05-01

    Salmonella paratyphi A causes paratyphoid fever which is characterized by acute onset of fever, abdominal pain, diarrhoea, nausea and vomiting. Localized disease can occur following both overt and silent bacteremia followed by seeding of bacteria at distant sites. Salmonella species though associated with abscess formation in various organs,are rarely associated with breast abscess. We report 2 cases of breast abscess due to Salmonella enterica serotype paratyphi A. Appropriate sampling, surgery supplemented by a comprehensive microbiological work up aided in pathogen identification and appropriate antibiotic administration for a successful outcome of these patients.

  16. An overview of the domestication and impact of the Salmonella mobilome.

    Science.gov (United States)

    Mebrhatu, Mehari Tesfazgi; Cenens, William; Aertsen, Abram

    2014-02-01

    Salmonella spp. are accountable for a large fraction of the global infectious disease burden, with most of their infections being food- or water-borne. The phenotypic features and adaptive potential of Salmonella spp. appear to be driven to a large extent by mobile or laterally acquired genetic elements. A better understanding of the conduct and diversification of these important pathogens consequently requires a more profound insight into the different mechanisms by which these pivotal elements establish themselves in the cell and affect its behavior. This review, therefore, provides an overview of the physiological impact and domestication of the Salmonella mobilome.

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

    Directory of Open Access Journals (Sweden)

    Van Parys Alexander

    2012-06-01

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

  18. A Perspective on Invasive Salmonella Disease in Africa.

    Science.gov (United States)

    Crump, John A; Heyderman, Robert S

    2015-11-01

    Salmonella enterica is a leading cause of community-acquired bloodstream infection in Africa. The contribution of typhoidal and nontyphoidal Salmonella serovars to invasive disease varies considerably in place and time, even within the same country. Nonetheless, many African countries are now thought to experience typhoid fever incidence >100 per 100,000 per year with approximately 1% of patients dying. Invasive nontyphoidal Salmonella (iNTS) disease was estimated to cause 3.4 million illnesses and 681 316 deaths in 2010, with the most disease in Africa. Antimicrobial drug resistance is a growing problem in S. enterica that threatens to further compromise patient outcomes. Reservoirs for nontyphoidal Salmonella and the predominant routes of transmission for typhoidal and nontyphoidal Salmonella are not well understood in Africa, hampering the design of evidence-based, non-vaccine- and vaccine-based prevention measures. It is difficult to distinguish clinically invasive Salmonella disease from febrile illnesses caused by other pathogens. Blood cultures are the mainstay of laboratory diagnosis, but lack sensitivity due to the low magnitude of bacteremia, do not produce results at point of care, and are not widely available in Africa. Serologic approaches to diagnosis remain inaccurate, and nucleic acid amplification tests are also compromised by low concentrations of bacteria. High-throughput whole-genome sequencing, together with a range of novel analytic pipelines, has provided new insights into the complex pattern of epidemiology, pathogenesis, and host adaptation. Concerted efforts are therefore needed to apply these new tools in the context of high-quality field surveillance to improve diagnosis, patient management, control, and prevention of invasive Salmonella infections in Africa. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Fate of Salmonella enterica and Enterohemorrhagic Escherichia coli Cells Artificially Internalized into Vegetable Seeds during Germination.

    Science.gov (United States)

    Liu, Da; Cui, Yue; Walcott, Ronald; Chen, Jinru

    2018-01-01

    Vegetable seeds contaminated with bacterial pathogens have been linked to fresh-produce-associated outbreaks of gastrointestinal infections. This study was undertaken to observe the physiological behavior of Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC) cells artificially internalized into vegetable seeds during the germination process. Surface-decontaminated seeds of alfalfa, fenugreek, lettuce, and tomato were vacuum-infiltrated with four individual strains of Salmonella or EHEC. Contaminated seeds were germinated at 25°C for 9 days, and different sprout/seedling tissues were microbiologically analyzed every other day. The internalization of Salmonella and EHEC cells into vegetable seeds was confirmed by the absence of pathogens in seed-rinsing water and the presence of pathogens in seed homogenates after postinternalization seed surface decontamination. Results show that 317 (62%) and 343 (67%) of the 512 collected sprout/seedling tissue samples were positive for Salmonella and EHEC, respectively. The average Salmonella populations were significantly larger ( P seed coat tissues, followed by the root tissues, but the mean EHEC populations from all sampled tissue sections were statistically similar, except in pregerminated seeds. Three Salmonella and two EHEC strains had significantly larger cell populations on sprout/seedling tissues than other strains used in the study. Salmonella and EHEC populations from fenugreek and alfalfa tissues were significantly larger than those from tomato and lettuce tissues. The study showed the fate of internalized human pathogens on germinating vegetable seeds and sprout/seedling tissues and emphasized the importance of using pathogen-free seeds for sprout production. IMPORTANCE The internalization of microorganisms into vegetable seeds could occur naturally and represents a possible pathway of vegetable seed contamination by human pathogens. The present study investigated the ability of two important

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

    OpenAIRE

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

    1981-01-01

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

  1. Salmonella enteridis Septic Arthritis: A Report of Two Cases

    Directory of Open Access Journals (Sweden)

    Esat Uygur

    2013-01-01

    Full Text Available Introduction. Nontyphoidal salmonellosis causes significant morbidity, is transmitted via fecal-oral route, and is a worldwide cause of gastroenteritis, bacteremia, and local infections. Salmonella is a less common etiologic factor for septic arthritis compared with other gram-negative bacteria. Cases. We present two septic arthritis cases with Salmonella enteridis as a confirmed pathogen and also discuss the predisposing factors and treatment. Discussion. Septic arthritis is an orthopedic emergency. The gold standard treatment of septic arthritis is joint debridement, antibiotic therapy according to the culture results, and physiotherapy, which should start in the early postoperative period to prevent limitation of motion. Salmonella is an atypical agent for septic arthritis. It must be particularly kept in mind as an etiologic factor for the acute arthritis of a patient with sickle cell anemia and systemic lupus erythematosus. Clinicians should be cautious that the white blood cell count in synovial fluid can be under 50.000/mm3 in immune compromised individuals with septic arthritis. The inflammatory response can be deficient, or the microorganism may be atypical. Conclusion. Atypical bacteria such as Salmonella species in immune compromised patients can cause joint infections. Therefore, Salmonella species must always be kept in mind for the differential diagnosis of septic arthritis in a clinically relevant setting.

  2. New paradigms for Salmonella source attribution based on microbial subtyping.

    Science.gov (United States)

    Mughini-Gras, Lapo; Franz, Eelco; van Pelt, Wilfrid

    2018-05-01

    Microbial subtyping is the most common approach for Salmonella source attribution. Typically, attributions are computed using frequency-matching models like the Dutch and Danish models based on phenotyping data (serotyping, phage-typing, and antimicrobial resistance profiling). Herewith, we critically review three major paradigms facing Salmonella source attribution today: (i) the use of genotyping data, particularly Multi-Locus Variable Number of Tandem Repeats Analysis (MLVA), which is replacing traditional Salmonella phenotyping beyond serotyping; (ii) the integration of case-control data into source attribution to improve risk factor identification/characterization; (iii) the investigation of non-food sources, as attributions tend to focus on foods of animal origin only. Population genetics models or simplified MLVA schemes may provide feasible options for source attribution, although there is a strong need to explore novel modelling options as we move towards whole-genome sequencing as the standard. Classical case-control studies are enhanced by incorporating source attribution results, as individuals acquiring salmonellosis from different sources have different associated risk factors. Thus, the more such analyses are performed the better Salmonella epidemiology will be understood. Reparametrizing current models allows for inclusion of sources like reptiles, the study of which improves our understanding of Salmonella epidemiology beyond food to tackle the pathogen in a more holistic way. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Atmospheric pressure plasma jet treatment of Salmonella Enteritidis inoculated eggshells.

    Science.gov (United States)

    Moritz, Maike; Wiacek, Claudia; Koethe, Martin; Braun, Peggy G

    2017-03-20

    Contamination of eggshells with Salmonella Enteritidis remains a food safety concern. In many cases human salmonellosis within the EU can be traced back to raw or undercooked eggs and egg products. Atmospheric pressure plasma is a novel decontamination method that can reduce a wide range of pathogens. The aim of this work was to evaluate the possibility of using an effective short time cold plasma treatment to inactivate Salmonella Enteritidis on the eggshell. Therefore, artificially contaminated eggshells were treated with an atmospheric pressure plasma jet under different experimental settings with various exposure times (15-300s), distances from the plasma jet nozzle to the eggshell surface (5, 8 or 12mm), feed gas compositions (Ar, Ar with 0.2, 0.5 or 1.0% O 2 ), gas flow rates (5 and 7slm) and different inoculations of Salmonella Enteritidis (10 1 -10 6 CFU/cm 2 ). Atmospheric pressure plasma could reduce Salmonella Enteritidis on eggshells significantly. Reduction factors ranged between 0.22 and 2.27 log CFU (colony-forming units). Exposure time and, particularly at 10 4 CFU/cm 2 inoculation, feed gas had a major impact on Salmonella reduction. Precisely, longer exposure times led to higher reductions and Ar as feed gas was more effective than ArO 2 mixtures. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Salmonella Typhimurium gastroenteritis leading to chronic prosthetic vascular graft infection.

    Science.gov (United States)

    Cullinan, Milo; Clarke, Michael; Dallman, Tim; Peart, Steven; Wilson, Deborah; Weiand, Daniel

    2017-08-01

    Introduction. It is estimated up to 6 % of prosthetic vascular grafts become infected. Staphylococcus aureus is predominant in early infection and coagulase-negative staphylococci are predominant in late infections. Enterobacteriaceae cause 14-40 % of prosthetic vascular graft infections. This is, to our knowledge the first reported case of Salmonella gastroenteritis causing chronic prosthetic vascular graft infection (PVGI). Case presentation. A 57 years old lady presented with signs and symptoms of prosthetic vascular graft infection. Three years earlier, she had undergone a prosthetic axillo-femoral bypass graft for critical limb ischaemia. The infected prosthetic vascular graft was removed and Salmonella Typhimurium was isolated on culture. In the intervening period, Salmonella Typhimurium was isolated from a faecal specimen, collected during an episode of acute gastroenteritis. Whole-genome sequencing (WGS) showed that the respective Salmonella Typhimurium isolates differed by only a single nucleotide polymorphism (SNP). Salmonella Typhimurium was not isolated on culture of a faecal specimen collected five days following cessation of antimicrobial therapy. Six months after removal of the prosthetic graft, the patient remains under follow-up for her peripheral vascular disease, which currently requires no further surgical intervention. Conclusion. This case has clear implications for the management of chronic PVGI. It is vital to collect high-quality surgical specimens for microbiological analysis and empirical choices of antibiotics are unlikely to cover all potential pathogens. It may also be prudent to enquire about a history of acute gastroenteritis when assessing patients presenting with chronic PVGI.

  5. A Salmonella nanoparticle mimic overcomes multidrug resistance in tumours.

    Science.gov (United States)

    Mercado-Lubo, Regino; Zhang, Yuanwei; Zhao, Liang; Rossi, Kyle; Wu, Xiang; Zou, Yekui; Castillo, Antonio; Leonard, Jack; Bortell, Rita; Greiner, Dale L; Shultz, Leonard D; Han, Gang; McCormick, Beth A

    2016-07-25

    Salmonella enterica serotype Typhimurium is a food-borne pathogen that also selectively grows in tumours and functionally decreases P-glycoprotein (P-gp), a multidrug resistance transporter. Here we report that the Salmonella type III secretion effector, SipA, is responsible for P-gp modulation through a pathway involving caspase-3. Mimicking the ability of Salmonella to reverse multidrug resistance, we constructed a gold nanoparticle system packaged with a SipA corona, and found this bacterial mimic not only accumulates in tumours but also reduces P-gp at a SipA dose significantly lower than free SipA. Moreover, the Salmonella nanoparticle mimic suppresses tumour growth with a concomitant reduction in P-gp when used with an existing chemotherapeutic drug (that is, doxorubicin). On the basis of our finding that the SipA Salmonella effector is fundamental for functionally decreasing P-gp, we engineered a nanoparticle mimic that both overcomes multidrug resistance in cancer cells and increases tumour sensitivity to conventional chemotherapeutics.

  6. Prevalence, Virulence Genes and Antimicrobial Resistance Profiles of Salmonella Serovars from Retail Beef in Selangor, Malaysia

    Directory of Open Access Journals (Sweden)

    Tze Y. Thung

    2018-01-01

    Full Text Available The aim of the present study was to investigate the prevalence of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in retail beef from different retail markets of Selangor area, as well as, to assess their pathogenic potential and antimicrobial resistance. A total of 240 retail beef meat samples (chuck = 60; rib = 60; round = 60; sirloin = 60 were randomly collected. The multiplex polymerase chain reaction (mPCR in combination with the most probable number (MPN method was employed to detect Salmonella spp., S. Enteritidis and S. Typhimurium in the meat samples. The prevalence of Salmonella spp., S. Enteritidis and S. Typhimurium in 240 beef meat samples were 7.50, 1.25, and 0.83%, respectively. The microbial loads of total Salmonella was found in the range of <3 to 15 MPN/g. Eight different serovars of Salmonella were identified among the 23 isolates, and S. Agona was the predominant serovar (26.09%. Interestingly, all the Salmonella isolates were resistant to penicillin, erythromycin and vancomycin, but the sensitivity was observed for tetracycline, gentamicin and amoxicillin/clavulanic acid. All 23 isolates were resistant to at least three antibiotics. Two S. Typhimurium isolates (8.70% exhibited the highest multiple antibiotic resistance (MAR index value of 0.56 which shown resistance to nine antibiotics. PCR analysis of virulence genes showed that all Salmonella isolates (100% were positive for the invA gene. Meanwhile, pefA was only identified in S. Enteritidis and S. Typhimurium. The findings in this study indicate that retail beef products tested were widely contaminated with multi-drug resistant (MDR Salmonella and various virulence genes are present among the isolated Salmonella serovars.

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

    Science.gov (United States)

    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 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 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.

  8. Genetic diversity and antimicrobial resistance of Campylobacter and Salmonella strains isolated from decoys and raptors.

    Science.gov (United States)

    Jurado-Tarifa, E; Torralbo, A; Borge, C; Cerdà-Cuéllar, M; Ayats, T; Carbonero, A; García-Bocanegra, I

    2016-10-01

    Infections caused by thermotolerant Campylobacter spp. and Salmonella spp. are the leading causes of human gastroenteritis worldwide. Wild birds can act as reservoirs of both pathogens. A survey was carried out to determine the prevalence, genetic diversity and antimicrobial resistance of thermotolerant Campylobacter and Salmonella in waterfowl used as decoys and wild raptors in Andalusia (Southern Spain). The overall prevalence detected for Campylobacter was 5.9% (18/306; CI95%: 3.25-8.52) in decoys and 2.3% (9/387; CI95%: 0.82-3.83) in wild raptors. Isolates were identified as C. jejuni, C. coli and C. lari in both bird groups. Salmonella was isolated in 3.3% (10/306; CI95%: 2.3-4.3) and 4.6% (18/394; CI95%: 3.5-5.6) of the decoys and raptors, respectively. Salmonella Enteritidis and Typhimurium were the most frequently identified serovars, although Salmonella serovars Anatum, Bredeney, London and Mikawasima were also isolated. Pulsed-field gel electrophoresis analysis of isolates showed higher genetic diversity within Campylobacter species compared to Salmonella serovars. Campylobacter isolates showed resistance to gentamicin, ciprofloxacin and tetracycline, while resistance to erythromycin and tetracycline was found in Salmonella isolates. The results indicate that both decoys and raptors can act as natural carriers of Campylobacter and Salmonella in Spain, which may have important implications for public and animal health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Reorganization of the Endosomal System in Salmonella-Infected Cells: The Ultrastructure of Salmonella-Induced Tubular Compartments

    Science.gov (United States)

    Krieger, Viktoria; Liebl, David; Zhang, Yuying; Rajashekar, Roopa; Chlanda, Petr; Giesker, Katrin; Chikkaballi, Deepak; Hensel, Michael

    2014-01-01

    During the intracellular life of Salmonella enterica, a unique membrane-bound compartment termed Salmonella-containing vacuole, or SCV, is formed. By means of translocated effector proteins, intracellular Salmonella also induce the formation of extensive, highly dynamic membrane tubules termed Salmonella-induced filaments or SIF. Here we report the first detailed ultrastructural analyses of the SCV and SIF by electron microscopy (EM), EM tomography and live cell correlative light and electron microscopy (CLEM). We found that a subset of SIF is composed of double membranes that enclose portions of host cell cytosol and cytoskeletal filaments within its inner lumen. Despite some morphological similarities, we found that the formation of SIF double membranes is independent from autophagy and requires the function of the effector proteins SseF and SseG. The lumen of SIF network is accessible to various types of endocytosed material and our CLEM analysis of double membrane SIF demonstrated that fluid phase markers accumulate only between the inner and outer membrane of these structures, a space continual with endosomal lumen. Our work reveals how manipulation of the endosomal membrane system by an intracellular pathogen results in a unique tubular membrane compartmentalization of the host cell, generating a shielded niche permissive for intracellular proliferation of Salmonella. PMID:25254663

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

    Science.gov (United States)

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

    2013-04-01

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

  11. Detection of Salmonella enteritidis Using a Miniature Optical Surface Plasmon Resonance Biosensor

    International Nuclear Information System (INIS)

    Son, J R; Kim, G; Kothapalli, A; Morgan, M T; Ess, D

    2007-01-01

    The frequent outbreaks of foodborne illness demand rapid detection of foodborne pathogens. Unfortunately, conventional methods for pathogen detection and identification are labor-intensive and take days to complete. Biosensors have shown great potential for the rapid detection of foodborne pathogens. Surface plasmon resonance (SPR) sensors have been widely adapted as an analysis tool for the study of various biological binding reactions. SPR biosensors could detect antibody-antigen bindings on the sensor surface by measuring either a resonance angle or refractive index value. In this study, the feasibility of a miniature SPR sensor (Spreeta, TI, USA) for detection of Salmonella enteritidis has been evaluated. Anti-Salmonella antibodies were immobilized on the gold sensor surface by using neutravidin. Salmonella could be detected by the Spreeta biosensor at concentrations down to 10 5 cfu/ml

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    Salmonella is among the most important food borne pathogens worldwide contaminating a wide range of animal products including meat products. Human illnesses due to this pathogen are attributed to poor biosecurity in production, improper processing and handling of meat and meat products....... This is more likely where surveillance and regulatory control is weak. There is however limited information on the occurrence of these pathogens in foods in Nigeria. The extent of contamination of retail-beef and related meat products with Salmonellae in Zaria was evaluated. A total of 435 retailed beef...... and related meat products consisting of muscle meat, offal and processed meat products were tested for the presence of Salmonella species. Sample types included raw meat, ‘suya’ (roasted meat), ‘balangu’ (barbequed meat), ‘Kilishi’ (spiced sun dried meat) and ‘dambu’ (shredded fried meat). Samples were...

  13. Epidemiological data on food poisonings in Japan focused on Salmonella, 1998-2004.

    Science.gov (United States)

    Toyofuku, H

    2008-09-01

    In Japan, the numbers and cases of food poisonings must be reported as required by the Food Sanitation Law. This paper focuses on Salmonella, one of the leading food-borne pathogens in Japan, and it analyses the reported food poisoning data to assess the nature of Salmonella-associated food-borne disease. Obviously, these data do not exactly reflect the burden of food-borne illness associated with Salmonella; however, trends in Salmonella food poisoning and implicated foods could be identified for the purpose of setting priorities to mitigate the risk of food-borne salmonellosis. Summary information of Salmonella food poisoning investigation reports submitted by health departments of all prefectures and major cities between January 1998 and December 2004 was analysed. Both the number of reports and the cases of Salmonella food poisoning decreased drastically from 1999 (831 Salmonella food poisoning reports with 11,877 cases) to 2001 (265 reports with 7011 cases), increased in 2002, and then decreased again in 2003 and 2004 (231 reports with 3793 cases in 2004). About 80% of the Salmonella food poisoning reports and cases were associated with Salmonella enteritidis throughout the study period. Food vehicles were identified in 17-25% of the Salmonella food poisoning reports. Between 1998 and 2002, 45-60% of the Salmonella food poisoning cases were associated with eggs; however, the percentage dropped to 24.2% in 2003. The number of Salmonella food poisoning reports associated with beef, pork and poultry meat, and raw vegetables, which have been frequently reported in other countries, were very limited. Among the identified locations of disease break outs, 30-49% occurred in restaurant settings and the percentage of cases in restaurants increased during the study period. Thirteen to 41% of the Salmonella food poisoning cases occurred within the home, and the percentage declined. Phage types 1 and 4 were the predominant S. enteritidis isolated in 1998 and 1999; however

  14. Epitope mapping of salmonella flagellar hook-associated protein, FlgK, with mass spectrometry-based immuno-capture proteomics using chicken (gallus gallus domesticus] sera

    Science.gov (United States)

    Salmonella, a Gram-negative rod, is the leading foodborne pathogen associated with human acute bacterial gastroenteritis worldwide. The Salmonella flagellum is responsible for bacterial movement, colonization and invasion in the host gastrointestinal tract. The flagellum has a complex structure, c...

  15. A novel strategy to obtain quantitative data for modelling: Combined enrichment and real-time PCR for enumeration of salmonellae from pig carcasses

    DEFF Research Database (Denmark)

    Krämer, Nadine; Löfström, Charlotta; Vigre, Håkan

    2011-01-01

    Salmonella is a major zoonotic pathogen which causes outbreaks and sporadic cases of gastroenteritis in humans worldwide. The primary sources for Salmonella are food-producing animals such as pigs and poultry. For risk assessment and hazard analysis and critical control point (HACCP) concepts...

  16. Lactobacillus salivarius CTC2197 Prevents Salmonella enteritidis Colonization in Chickens

    OpenAIRE

    Pascual, Mònica; Hugas, Marta; Badiola, Jose Ignacio; Monfort, Josep Maria; Garriga, Margarita

    1999-01-01

    A rifampin-resistant Lactobacillus salivarius strain, CTC2197, was assessed as a probiotic in poultry, by studying its ability to prevent Salmonella enteritidis C-114 colonization in chickens. When the probiotic strain was dosed by oral gavage together with S. enteritidis C-114 directly into the proventriculus in 1-day-old Leghorn chickens, the pathogen was completely removed from the birds after 21 days. The same results were obtained when the probiotic strain was also administered through t...

  17. Analysis of interactions of Salmonella type three secretion mutants with 3-D intestinal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Andrea L Radtke

    Full Text Available The prevailing paradigm of Salmonella enteropathogenesis based on monolayers asserts that Salmonella pathogenicity island-1 Type Three Secretion System (SPI-1 T3SS is required for bacterial invasion into intestinal epithelium. However, little is known about the role of SPI-1 in mediating gastrointestinal disease in humans. Recently, SPI-1 deficient nontyphoidal Salmonella strains were isolated from infected humans and animals, indicating that SPI-1 is not required to cause enteropathogenesis and demonstrating the need for more in vivo-like models. Here, we utilized a previously characterized 3-D organotypic model of human intestinal epithelium to elucidate the role of all characterized Salmonella enterica T3SSs. Similar to in vivo reports, the Salmonella SPI-1 T3SS was not required to invade 3-D intestinal cells. Additionally, Salmonella strains carrying single (SPI-1 or SPI-2, double (SPI-1/2 and complete T3SS knockout (SPI-1/SPI-2: flhDC also invaded 3-D intestinal cells to wildtype levels. Invasion of wildtype and TTSS mutants was a Salmonella active process, whereas non-invasive bacterial strains, bacterial size beads, and heat-killed Salmonella did not invade 3-D cells. Wildtype and T3SS mutants did not preferentially target different cell types identified within the 3-D intestinal aggregates, including M-cells/M-like cells, enterocytes, or Paneth cells. Moreover, each T3SS was necessary for substantial intracellular bacterial replication within 3-D cells. Collectively, these results indicate that T3SSs are dispensable for Salmonella invasion into highly differentiated 3-D models of human intestinal epithelial cells, but are required for intracellular bacterial growth, paralleling in vivo infection observations and demonstrating the utility of these models in predicting in vivo-like pathogenic mechanisms.

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2013-12-01

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

  1. Increased colon cancer risk after severe Salmonella infection.

    Directory of Open Access Journals (Sweden)

    Lapo Mughini-Gras

    Full Text Available Colon cancer constitutes one of the most frequent malignancies. Previous studies showed that Salmonella manipulates host cell signaling pathways and that Salmonella Typhimurium infection facilitates colon cancer development in genetically predisposed mice. This epidemiological study examined whether severe Salmonella infection, usually acquired from contaminated food, is associated with increased colon cancer risk in humans.We performed a nationwide registry-based study to assess colon cancer risk after diagnosed Salmonella infection. National infectious disease surveillance records (1999-2015 for Dutch residents aged ≥20 years when diagnosed with salmonellosis (n = 14,264 were linked to the Netherlands Cancer Registry. Salmonella-infected patients were laboratory-confirmed under medical consultation after 1-2 weeks of illness. These datasets also contained information on Salmonella serovar and type of infection. Colon cancer risk (overall and per colon subsite among patients with a diagnosed Salmonella infection was compared with expected colon cancer risk in the general population. Data from the nationwide registry of histo- and cytopathology (PALGA and Statistics Netherlands (CBS allowed assessing potential effects of age, gender, latency, socioeconomic status, genetic predisposition, inflammatory bowel disease (IBD, and tumor features. We found that compared to the general population, colon cancer risk was significantly increased (standardized incidence ratio [SIR] 1.54; 95%CI 1.09-2.10 among patients with Salmonella infection diagnosed <60 years of age. Such increased risk concerned specifically the ascending/transverse colon (SIR 2.12; 95%CI 1.38-3.09 after S. Enteritidis infection (SIR 2.97; 95%CI 1.73-4.76. Salmonellosis occurred more frequently among colon cancer patients with pre-infectious IBD, a known risk factor for colon cancer. Colon tumors of patients with a history of Salmonella infection were mostly of low grade

  2. Increased colon cancer risk after severe Salmonella infection

    Science.gov (United States)

    Mooij, Sofie; Neefjes-Borst, E. Andra; van Pelt, Wilfrid; Neefjes, Jacques

    2018-01-01

    Background Colon cancer constitutes one of the most frequent malignancies. Previous studies showed that Salmonella manipulates host cell signaling pathways and that Salmonella Typhimurium infection facilitates colon cancer development in genetically predisposed mice. This epidemiological study examined whether severe Salmonella infection, usually acquired from contaminated food, is associated with increased colon cancer risk in humans. Methods and findings We performed a nationwide registry-based study to assess colon cancer risk after diagnosed Salmonella infection. National infectious disease surveillance records (1999–2015) for Dutch residents aged ≥20 years when diagnosed with salmonellosis (n = 14,264) were linked to the Netherlands Cancer Registry. Salmonella-infected patients were laboratory-confirmed under medical consultation after 1–2 weeks of illness. These datasets also contained information on Salmonella serovar and type of infection. Colon cancer risk (overall and per colon subsite) among patients with a diagnosed Salmonella infection was compared with expected colon cancer risk in the general population. Data from the nationwide registry of histo- and cytopathology (PALGA) and Statistics Netherlands (CBS) allowed assessing potential effects of age, gender, latency, socioeconomic status, genetic predisposition, inflammatory bowel disease (IBD), and tumor features. We found that compared to the general population, colon cancer risk was significantly increased (standardized incidence ratio [SIR] 1.54; 95%CI 1.09–2.10) among patients with Salmonella infection diagnosed transverse colon (SIR 2.12; 95%CI 1.38–3.09) after S. Enteritidis infection (SIR 2.97; 95%CI 1.73–4.76). Salmonellosis occurred more frequently among colon cancer patients with pre-infectious IBD, a known risk factor for colon cancer. Colon tumors of patients with a history of Salmonella infection were mostly of low grade. Conclusions Patients diagnosed with severe

  3. Preexisting Salmonella-specific immunity interferes with the subsequent development of immune responses against the Salmonella strains delivering H9N2 hemagglutinin.

    Science.gov (United States)

    Hajam, Irshad Ahmed; Lee, John Hwa

    2017-06-01

    Recombinant Salmonella strains expressing foreign heterologous antigens have been extensively studied as promising live vaccine delivery vehicles. In this study, we constructed attenuated smooth (S-HA) and rough (R-HA) Salmonella strains expressing hemagglutinin (HA) of H9N2, a low pathogenic avian influenza A virus. We then investigated the HA-specific immune responses following oral immunization with either S-HA or R-HA strain in chicken model. We further examined the effects of the preexisting anti-Salmonella immunity on the subsequent elicitation of the HA and the Salmonella ompA specific immune responses. Our results showed that primary immunization with either the S-HA or the R-HA strain elicited comparable HA-specific immune responses and the responses were significantly (pSalmonella vector control. When chickens were pre-immunized with the smooth Salmonella carrier alone and then vaccinated with either S-HA or R-HA strain 3, 6 and 9 weeks later, respectively, significant reductions were seen for HA-specific immune responses at week 6, a point which corresponded to the peak of the primary Salmonella-specific antibody responses. No reductions were seen at week 3 and 9, albeit, the HA-specific immune responses were boosted at week 9, a point which corresponded to the lowest primary Salmonella-specific antibody responses. The ompA recall responses remain refractory at week 3 and 6 following deliberate immunization with the carrier strain, but were significantly (pSalmonella immunity inhibits antigen-specific immune responses and this effect could be avoided by carefully selecting the time point when carrier-specific immune responses are relatively low. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Salmonella survival during thermal dehydration of fresh garlic and storage of dehydrated garlic products.

    Science.gov (United States)

    Zhang, Hongmei; Qi, Yan; Wang, Lei; Zhang, Shaokang; Deng, Xiangyu

    2017-12-18

    Salmonella survival was characterized and modeled during thermal dehydration of fresh garlic and storage of dehydrated garlic products. In our experiments that simulated commercial dehydration processing at 80±5°C, moderate level of Salmonella contamination (4-5logCFU/g) on fresh garlic was reduced below the enumeration limit (1.7logCFU/g) after 4.5h of dehydration and not detectable by culture enrichment after 7h. With high level of contamination (7-8logCFU/g), the Salmonella population persisted at 3.6logCFU/g after 8h of processing. By increasing the dehydration temperature to 90±5°C, the moderate and high levels of initial Salmonella load on fresh garlic dropped below the enumeration limit after 1.5 and 3.75h of processing and became undetectable by culture enrichment after 2.5 and 6h, respectively. During the storage of dried garlic products, Salmonella was not able to grow under all tested combinations of temperature (25 and 35°C) and water activity (0.56-0.98) levels, suggesting active inhibition. Storage temperature played a primary role in determining Salmonella survival on dehydrated garlic flakes. Under a typical storage condition at 25°C and ambient relative humidity, Salmonella could persist over months with the population gradually declining (4.3 log reduction over 88days). Granular size of dehydrated garlic had an impact on Salmonella survival, with better survival of the pathogen observed in bigger granules. At the early stage of dehydrated garlic storage (until 7days), rising water activity appeared to initially promote but then inhibited Salmonella survival, resulting in a water activity threshold at 0.73 where Salmonella displayed strongest persistence. However, this phenomenon was less apparent during extended storage (after 14days). Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Use of enrichment real-time PCR to enumerate salmonella on chicken parts.

    Science.gov (United States)

    Oscar, T P

    2014-07-01

    Salmonella bacteria that survive cooking or that cross-contaminate other food during meal preparation and serving represent primary routes of consumer exposure to this pathogen from chicken. In the present study, enrichment real-time PCR (qPCR) was used to enumerate Salmonella bacteria that contaminate raw chicken parts at retail or that cross-contaminate cooked chicken during simulated meal preparation and serving. Whole raw chickens obtained at retail were partitioned into wings, breasts, thighs, and drumsticks using a sterilized knife and cutting board, which were then used to partition a cooked chicken breast to assess cross-contamination. After enrichment in buffered peptone water (400 ml, 8 h, 40°C, 80 rpm), subsamples were used for qPCR and cultural isolation of Salmonella. In some experiments, chicken parts were spiked with 0 to 3.6 log of Salmonella Typhimurium var. 5- to generate a standard curve for enumeration by qPCR. Of 10 raw chickens examined, 7 (70%) had one or more parts contaminated with Salmonella. Of 80 raw parts examined, 15 (19%) were contaminated with Salmonella. Of 20 cooked chicken parts examined, 2 (10%) were cross-contaminated with Salmonella. Predominant serotypes identified were Typhimurium (71%) and its variants (var. 5-, monophasic, and nonmotile) and Kentucky (18%). The number of Salmonella bacteria on contaminated parts ranged from one to two per part. Results of this study indicated that retail chicken parts examined were contaminated with low levels of Salmonella, which resulted in low levels of cross-contamination during simulated meal preparation and serving. Thus, if consumers properly handle and prepare the chicken, it should pose no or very low risk of consumer exposure to Salmonella.

  6. Rapid detection of food-borne Salmonella contamination using IMBs-qPCR method based on pagC gene

    Directory of Open Access Journals (Sweden)

    Jiashun Wang

    Full Text Available Abstract Detection of Salmonella is very important to minimize the food safety risk. In this study, the recombinant PagC protein and PagC antibody were prepared and coupled with immunomagnetic beads (IMBs to capture Salmonella cells from pork and milk samples. And then the SYBR Green qualitative PCR was developed to detect the pathogenic Salmonella. The results showed that the PagC polyclonal antiserum is of good specificity and the capture rate of 0.1 mg IMBs for Salmonella tended to be stable at the range of 70-74% corresponding to the concentrations between 101 and 104 CFU/mL. The method developed demonstrated high specificity for the positive Salmonella samples when compared to non-specific DNA samples, such as Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica, and Yersinia pseudotuberculosis. The limit of detection of this assay was 18 CFU/mL. Detection and quantitative enumeration of Salmonella in samples of pork or milk shows good recoveries of 54.34% and 52.07%. In conclusion, the polyclonal antibody of recombinant PagC protein is effective to capture Salmonella from detected samples. The developed pagC antibody IMBs-qPCR method showed efficiency, sensitivity and specificity for 30 Salmonella detection, enabling detection within 10 h, which is a promising rapid method to detect Salmonella in emergency.

  7. Are Salmonella-Induced Gastroenteritis Neglected in Developing Countries? Feedback from Microbiological Investigations in N'Djamena Hospitals, Chad.

    Directory of Open Access Journals (Sweden)

    Djim-Adjim Tabo

    Full Text Available Salmonella is considered to be one of the main pathogens causing human gastroenteritis worldwide. Looking for Salmonella in Africa in patients suffering from gastroenteritis is rather unusual, and the use of antibiotics is not subject to any regulation. This study intends for stressing the possible prominent importance of Salmonella in digestive diseases in Africa as well as identifying antimicrobial resistance of Salmonella isolates from faeces samples of human origin. All samples were collected from five N'Djamena hospitals, from patients suffering from diarrhoea. The collecting was undertaken over two periods of six months each: from August 2010 to January 2011 and from September 2011 to February 2012. Salmonella isolates were obtained by standard cultivation and serotyping methods. A total of 43 Salmonella isolates were identified, belonging to 21 different serovars. The most prevalent serovar was Salmonella Stanleyville (n = 7, followed by S. Anatum (n = 4 and S. Kottbus (n = 3. The other serovars were under-represented. The majority of these isolates were susceptible to all antibiotics tested (CLSI Standards, except two S. Enteritidis isolates that exhibited resistance to fluoroquinolones. The different serovars and antibiotic resistance profiles that were observed highlight the substantial diversity of Salmonella in N'Djamena, Chad. Roughly, one out of ten patients who consulted for gastroenteritis was shedding Salmonella spp. and none of them would have been diagnosed outside the context of this research program. This study may encourage local clinicians to explore more often salmonellosis suspicion in their daily practice.

  8. Removal of salmonella-typhi, shigella-dysenteriae, vibrio-cholerae and rotavirus from water using a water-treatment tablet

    CSIR Research Space (South Africa)

    Rodda, N

    1993-01-01

    Full Text Available previously demonstrated. This study evaluated the efficiency of removal of Salmonella typhi, Shigella dysenteriae, Vibrio cholerae and rotavirus from simulated hard water of high organic content and colour. All four pathogenic micro organisms were...

  9. Inactivation of Salmonella enteritidis on raw poultry using microwave heating

    Directory of Open Access Journals (Sweden)

    Amanda B. Pucciarelli

    2005-11-01

    Full Text Available The effect of microwave heating on Salmonella Enteritidis inoculated on fresh chicken was investigated using a microwave oven (800 w to determine the destruction of Salmonella Enteritidis isolated from chicken carcasses, in relation to the time of heating at two power settings: high (power level 10 and medium (power level 6; The relationship between heating time and temperature was also been studied. The destruction was 6.4 log cycles at time 95 sec for the high power level, and 5 log cycles at time 140 sec for medium power setting. After 110 sec for higher power level, no survival of Salmonella Enteritidis was detected in samples (100g, but at 140 sec for medium power level, these food pathogens were still present.Foi investigado o efeito do aquecimento por microondas sobre Salmonella Enteritidis inoculada em frangos frescos usando um forno de microondas doméstico (800 W para determinar a destruição da Salmonella Enteritidis isolada a partir de carcaças de frangos, em relação com o tempo de aquecimento a dois níveis de potência: alta (nível 10 e média ( nível 6; a relação entre tempo de aquecimento e temperatura também foi estudada. A destruição foi de 6 log em 95 s de tempo para o nível alto e 5 log em 140 s de tempo para o nível médio de potência. Depois de 110 s no nível de potência alta, não foi detectada sobrevivência de Salmonella Enteritidis em amostras de 100g de peso, porém, depois de 140 s a potência média, esse patôgeno nos alimentos ainda permanecia.

  10. Silencing by H-NS potentiated the evolution of Salmonella.

    Directory of Open Access Journals (Sweden)

    Sabrina S Ali

    2014-11-01

    Full Text Available The bacterial H-NS protein silences expression from sequences with higher AT-content than the host genome and is believed to buffer the fitness consequences associated with foreign gene acquisition. Loss of H-NS results in severe growth defects in Salmonella, but the underlying reasons were unclear. An experimental evolution approach was employed to determine which secondary mutations could compensate for the loss of H-NS in Salmonella. Six independently derived S. Typhimurium hns mutant strains were serially passaged for 300 generations prior to whole genome sequencing. Growth rates of all lineages dramatically improved during the course of the experiment. Each of the hns mutant lineages acquired missense mutations in the gene encoding the H-NS paralog StpA encoding a poorly understood H-NS paralog, while 5 of the mutant lineages acquired deletions in the genes encoding the Salmonella Pathogenicity Island-1 (SPI-1 Type 3 secretion system critical to invoke inflammation. We further demonstrate that SPI-1 misregulation is a primary contributor to the decreased fitness in Salmonella hns mutants. Three of the lineages acquired additional loss of function mutations in the PhoPQ virulence regulatory system. Similarly passaged wild type Salmonella lineages did not acquire these mutations. The stpA missense mutations arose in the oligomerization domain and generated proteins that could compensate for the loss of H-NS to varying degrees. StpA variants most able to functionally substitute for H-NS displayed altered DNA binding and oligomerization properties that resembled those of H-NS. These findings indicate that H-NS was central to the evolution of the Salmonellae by buffering the negative fitness consequences caused by the secretion system that is the defining characteristic of the species.

  11. Study on E. coli and Salmonella biofilms from fresh fruits and vegetables.

    Science.gov (United States)

    Amrutha, Balagopal; Sundar, Kothandapani; Shetty, Prathapkumar Halady

    2017-04-01

    Foodborne outbreaks associated with fresh fruits and vegetables are on the rise worldwide. Biofilm formation is one of the important traits of pathogens making them strongly attached to substrates as well as express virulence phenotypes. Present study investigates the biofilm forming ability of E. coli and Salmonella sp. isolated from fresh fruits and vegetables. A total of 53 strains, including 35 E. coli and 18 Salmonella sp. isolated from different fruit and vegetable samples were taken into account for the study. Initial screening for biofilm formation was done using Congo Red agar plate test. Results revealed that 22.8% E. coli and 22.2% Salmonella sp. were potential biofilm formers. However, the MTP (Micro-Titre Plate) assay suggested more isolates of both E. coli and Salmonella sp. were moderate to strong biofilm producers. Agar plate diffusion assay with Agrobacterium tumefaciens NTL-4 showed the production of quorum signaling molecules (AHLs) by three isolates of E. coli and one Salmonella sp. Two E. coli isolates showed a significant amount of EPS production indicating higher biofilm forming potential. The Presence of LUX R homologue gene ( sdi A) in two of the Salmonella isolates were confirmed by PCR which demonstrated their potential pathogenicity. Results of the work underline the biofilm forming and potentially virulent capacities of isolates from the surface of fruits and vegetables.

  12. A rapid Salmonella detection method involving thermophilic helicase-dependent amplification and a lateral flow assay.

    Science.gov (United States)

    Du, Xin-Jun; Zhou, Tian-Jiao; Li, Ping; Wang, Shuo

    2017-08-01

    Salmonella is a major foodborne pathogen that is widespread in the environment and can cause serious human and animal disease. Since conventional culture methods to detect Salmonella are time-consuming and laborious, rapid and accurate techniques to detect this pathogen are critically important for food safety and diagnosing foodborne illness. In this study, we developed a rapid, simple and portable Salmonella detection strategy that combines thermophilic helicase-dependent amplification (tHDA) with a lateral flow assay to provide a detection result based on visual signals within 90 min. Performance analyses indicated that the method had detection limits for DNA and pure cultured bacteria of 73.4-80.7 fg and 35-40 CFU, respectively. Specificity analyses showed no cross reactions with Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Enterobacter aerogenes, Shigella and Campylobacter jejuni. The results for detection in real food samples showed that 1.3-1.9 CFU/g or 1.3-1.9 CFU/mL of Salmonella in contaminated chicken products and infant nutritional cereal could be detected after 2 h of enrichment. The same amount of Salmonella in contaminated milk could be detected after 4 h of enrichment. This tHDA-strip can be used for the rapid detection of Salmonella in food samples and is particularly suitable for use in areas with limited equipment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Identification of potential drug targets in Salmonella enterica sv. Typhimurium using metabolic modelling and experimental validation

    DEFF Research Database (Denmark)

    Hartman, Hassan B.; Fell, David A.; Rossell, Sergio

    2014-01-01

    Salmonella enterica sv. Typhimurium is an established model organism for Gram-negative, intracellular pathogens. Owing to the rapid spread of resistance to antibiotics among this group of pathogens, new approaches to identify suitable target proteins are required. Based on the genome sequence of ...

  14. Prevalence of Salmonella in Australian reptiles.

    Science.gov (United States)

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

    2011-01-01

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

  15. Characterization of Salmonella Occurring at High Prevalence in a Population of the Land Iguana Conolophus subcristatus in Galápagos Islands, Ecuador

    OpenAIRE

    Franco, Alessia; Hendriksen, Rene S.; Lorenzetti, Serena; Onorati, Roberta; Gentile, Gabriele; Dell'Omo, Giacomo; Aarestrup, Frank M.; Battisti, Antonio

    2011-01-01

    The aim of the study was to elucidate the association between the zoonotic pathogen Salmonella and a population of land iguana, Colonophus subcristatus, endemic to Galapagos Islands in Ecuador. We assessed the presence of Salmonella subspecies and serovars and estimated the prevalence of the pathogen in that population. Additionally, we investigated the genetic relatedness among isolates and serovars utilising pulsed field gel electrophoresis (PFGE) on XbaI-digested DNA and determined the ant...

  16. Antimicrobial resistance and typing of Salmonella isolated from street vended foods and associated environment.

    Science.gov (United States)

    Anukampa; Shagufta, Bi; Sivakumar, M; Kumar, Surender; Agarwal, Rajesh Kumar; Bhilegaonkar, Kiran Narayan; Kumar, Ashok; Dubal, Zunjar Baburao

    2017-07-01

    The present study was carried out to find out the occurrence and types of Salmonella present in street vended foods and associated environment, and their resistance pattern against various antibiotics. About 1075 street vended food and associated environment samples were processed for isolation and confirmation of different Salmonella spp. by targeting gene specific inv A gene and serotype specific Sdf I, Via B and Spy genes by PCR. Selected Salmonella isolates were screened for antibiotic resistance by using Baeur-Kirby disk diffusion test. Out of 1075 samples, only 31 (2.88%) isolates could be amplified the inv A gene of which 19 could be recovered from meat vendors; 8 from egg vendors while remaining 4 from milk vendors. Though, majority of Salmonella recovered from raw foods the ready-to-eat food like chicken gravy and rasmalai also showed its presence which pose a serious public health threat. Overall, 19, 6 and 1 isolates of S. Typhimurium, S. Enteritidis and S. Typhi could be detected by PCR while remaining 5 isolates could not be amplified suggesting other type of Salmonella. Selected Salmonella isolates were completely resistance to Oxacillin (100%) followed by Cefoxitin (30.43%) and Ampicillin (26.10%). Thus, it is observed that the street vended foods of animal origin and associated environment play an important role in transmission of food borne pathogens including Salmonella .

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

    Science.gov (United States)

    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.

  18. Detection of Salmonella enterica Serovar Typhimurium from Avians Using Multiplex-PCR

    Directory of Open Access Journals (Sweden)

    Alireza Talebi

    2011-09-01

    Full Text Available Abstract Salmonella enterica serovar Typhimurium and S.enterica serovar Enteritidis are the most frequently isolated serovars from food-borne diseases throughout the world. According to their antigenic profiles, salmonella shows different disease syndromes and host specificities. It is necessary and important to discriminate salmonella serovars from each other in order to ensure that each pathogen and its epidemiology are correctly recognized. Many PCR-based methods have been developed to identify salmonella serovars. The objective of present study was to identify S. Typhimurium in avians from different regions including: North, Northwest and capital city (Tehran of Iran. Also in this research, the quality of CHROMagar™ Salmonella medium (CAS medium in veterinary medicine was evaluated. The results of present study showed that out of 1870 intestine samples, fifty two S. Typhimurium including broiler (n=13, layer (n=12, duck (n=5, goose (n=5, sparrow (n=8, canary (n=3, pigeon (n=5 and African grey parrot (n=1 were identified using serotyping as well as multiplex-PCR. In conclusion, important measures must be taken on prevention and propagation of S. Typhimurium among avians. CHROMagar™ Salmonella medium has high levels of sensitivity and specificity and reduced the time to final identification of salmonella spp. in comparison with biochemical tests.

  19. Independent bottlenecks characterize colonization of systemic compartments and gut lymphoid tissue by salmonella.

    Science.gov (United States)

    Lim, Chee Han; Voedisch, Sabrina; Wahl, Benjamin; Rouf, Syed Fazle; Geffers, Robert; Rhen, Mikael; Pabst, Oliver

    2014-07-01

    Vaccination represents an important instrument to control typhoid fever in humans and protects mice from lethal infection with mouse pathogenic serovars of Salmonella species. Mixed infections with tagged Salmonella can be used in combination with probabilistic models to describe the dynamics of the infection process. Here we used mixed oral infections with tagged Salmonella strains to identify bottlenecks in the infection process in naïve and vaccinated mice. We established a next generation sequencing based method to characterize the composition of tagged Salmonella strains which offers a fast and reliable method to characterise the composition of genome-tagged Salmonella strains. We show that initial colonization of Salmonella was distinguished by a non-Darwinian selection of few bacteria setting up the infection independently in gut associated lymphoid tissue and systemic compartments. Colonization of Peyer's patches fuels the sustained spread of bacteria into mesenteric lymph nodes via dendritic cells. In contrast, infection of liver and spleen originated from an independent pool of bacteria. Vaccination only moderately reduced invasion of Peyer's patches but potently uncoupled bacterial populations present in different systemic compartments. Our data indicate that vaccination differentially skews the capacity of Salmonella to colonize systemic and gut immune compartments and provide a framework for the further dissection of infection dynamics.

  20. Independent bottlenecks characterize colonization of systemic compartments and gut lymphoid tissue by salmonella.

    Directory of Open Access Journals (Sweden)

    Chee Han Lim

    2014-07-01

    Full Text Available Vaccination represents an important instrument to control typhoid fever in humans and protects mice from lethal infection with mouse pathogenic serovars of Salmonella species. Mixed infections with tagged Salmonella can be used in combination with probabilistic models to describe the dynamics of the infection process. Here we used mixed oral infections with tagged Salmonella strains to identify bottlenecks in the infection process in naïve and vaccinated mice. We established a next generation sequencing based method to characterize the composition of tagged Salmonella strains which offers a fast and reliable method to characterise the composition of genome-tagged Salmonella strains. We show that initial colonization of Salmonella was distinguished by a non-Darwinian selection of few bacteria setting up the infection independently in gut associated lymphoid tissue and systemic compartments. Colonization of Peyer's patches fuels the sustained spread of bacteria into mesenteric lymph nodes via dendritic cells. In contrast, infection of liver and spleen originated from an independent pool of bacteria. Vaccination only moderately reduced invasion of Peyer's patches but potently uncoupled bacterial populations present in different systemic compartments. Our data indicate that vaccination differentially skews the capacity of Salmonella to colonize systemic and gut immune compartments and provide a framework for the further dissection of infection dynamics.

  1. Molecular Typing of Salmonella Isolates in Poultry by Pulsed-Field Gel Electrophoresis in Iran

    Directory of Open Access Journals (Sweden)

    Narges Golab

    2014-11-01

    Full Text Available Background: Salmonella is one of the most widespread zoonotic enter pathogenic microorganisms found in the global food chain. Poultryand Poultry products have been identified as one of the important foodborne sources of Salmonella. Pulsed-Field Gel Electrophoresis (PFGE is a gold standard typing method for identification of Salmonella isolates during outbreaks and epidemiological investigations. Objectives: The aim of this study was to carry out molecular typing of Salmonella enterica spp. by PFGE technique. Materials and Methods: All 47 Salmonella isolates were serotyped and then subjected to PFGE. Total isolates were analyzed by means of the molecular technique XbaI PFGE. Results: In the current work, PFGE and serotyping were used to subtype 47 Salmonella isolates belonging to 22 different serotypes and derived from poultry. Thirty-nine PFGE patterns out of 47 isolates were obtained. The Discrimination Index (DI by serotyping (0.93 was lower than PFGE (DI = 0.99. Conclusions: In conclusion, molecular methods such as PFGE can be used for epidemiological characterization of Salmonella serotypes.

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

    NARCIS (Netherlands)

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

    2006-01-01

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

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

    NARCIS (Netherlands)

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

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ohad eGal-Mor

    2014-08-01

    Full Text Available 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.

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

    DEFF Research Database (Denmark)

    Roer, Louise; Hendriksen, Rene S.; Leekitcharoenphon, Pimlapas

    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...... 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.......-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...

  6. Epidemiology of Salmonella spp., Listeria monocytogenes and Campylobacter spp., in the poultry chain production system

    Directory of Open Access Journals (Sweden)

    Realpe-Delgado, María Elena

    2016-10-01

    Full Text Available Salmonella spp., Campylobacter spp., and L. monocytogenes are zoonotic foodborne pathogens, associated with the consumption of contaminated foods of animal origin. In this study we determined the prevalence and risk factors associated with the presence of these microorganisms at all stages of the production system, in two Colombian poultry companies (EI-EI-I and II. In EI-I, Campylobacter spp., and Salmonella spp., were isolated from 10 % and 4.4 % of the specimens, and S. Heidelberg was the predominant serotype. Salmonella spp., was found in 6 % of hands and stool samples of workers. S. Saphra was the most prevalent serotype. In EI-II, the prevalence of Campylobacter spp., and Salmonella spp., from animal specimens was 7 % and 17 %, respectively. L. monocytogenes was not detected. This study established the prevalence of these zoonotic pathogens through the production chain and showed the presence of pathogen carriers among workers/food handlers. “Lack of medical examination of employees in the previous year” was found to be a possible risk factor for carriage of Salmonella spp.

  7. Vaccination against Salmonella Infection: the Mucosal Way.

    Science.gov (United States)

    Gayet, Rémi; Bioley, Gilles; Rochereau, Nicolas; Paul, Stéphane; Corthésy, Blaise

    2017-09-01

    Salmonella enterica subspecies enterica includes several serovars infecting both humans and other animals and leading to typhoid fever or gastroenteritis. The high prevalence of associated morbidity and mortality, together with an increased emergence of multidrug-resistant strains, is a current global health issue that has prompted the development of vaccination strategies that confer protection against most serovars. Currently available systemic vaccine approaches have major limitations, including a reduced effectiveness in young children and a lack of cross-protection among different strains. Having studied host-pathogen interactions, microbiologists and immunologists argue in favor of topical gastrointestinal administration for improvement in vaccine efficacy. Here, recent advances in this field are summarized, including mechanisms of bacterial uptake at the intestinal epithelium, the assessment of protective host immunity, and improved animal models that closely mimic infection in humans. The pros and cons of existing vaccines are presented, along with recent progress made with novel formulations. Finally, new candidate antigens and their relevance in the refined design of anti- Salmonella vaccines are discussed, along with antigen vectorization strategies such as nanoparticles or secretory immunoglobulins, with a focus on potentiating mucosal vaccine efficacy. Copyright © 2017 American Society for Microbiology.

  8. Molecular identification of common Salmonella serovars using multiplex DNA sensor-based suspension array.

    Science.gov (United States)

    Aydin, Muhsin; Carter-Conger, Jacqueline; Gao, Ning; Gilmore, David F; Ricke, Steven C; Ahn, Soohyoun

    2018-04-01

    Salmonella is one of major foodborne pathogens and the leading cause of foodborne illness-related hospitalizations and deaths. It is critical to develop a sensitive and rapid detection assay that can identify Salmonella to ensure food safety. In this study, a DNA sensor-based suspension array system of high multiplexing ability was developed to identify eight Salmonella serovars commonly associated with foodborne outbreaks to the serotype level. Each DNA sensor was prepared by activating pre-encoded microspheres with oligonucleotide probes that are targeting virulence genes and serovar-specific regions. The mixture of 12 different types of DNA sensors were loaded into a 96-well microplate and used as a 12-plex DNA sensor array platform. DNA isolated from Salmonella was amplified by multiplex polymerase chain reaction (mPCR), and the presence of Salmonella was determined by reading fluorescent signals from hybridization between probes on DNA sensors and fluorescently labeled target DNA using the Bio-Plex® system. The developed multiplex array was able to detect synthetic DNA at the concentration as low as 100 fM and various Salmonella serovars as low as 100 CFU/mL within 1 h post-PCR. Sensitivity of this assay was further improved to 1 CFU/mL with 6-h enrichment. The array system also correctly and specifically identified serotype of tested Salmonella strains without any cross-reactivity with other common foodborne pathogens. Our results indicate the developed DNA sensor suspension array can be a rapid and reliable high-throughput method for simultaneous detection and molecular identification of common Salmonella serotypes.

  9. Occurrence and antimicrobial resistance of Salmonella spp. isolated from food other than meat in Poland

    Directory of Open Access Journals (Sweden)

    Łukasz Mąka

    2015-09-01

    Full Text Available Introduction and objectives. Antimicrobial resistance of pathogenic bacteria can result in therapy failure, increased hospitalization, and increased risk of death. In Poland, [i]Salmonella[/i] spp. is a major bacterial agent of food poisoning. The majority of studies on antimicrobial resistance in [i]Salmonella[/i] spp. isolates from food have focused on meat products as the source of this pathogen. In comparison, this study examines the antimicrobial susceptibility of [i]Salmonella[/i] spp. isolated from retail food products other than meat in Poland. Materials and Methods. A collection of 122 [i]Salmonella[/i] spp. isolates were isolated in Poland in 2008–2012 from foods other than meat: confectionery products, eggs, fruits, vegetables, spices and others. The resistance of these isolates to 19 antimicrobial agents was tested using the disc diffusion method. Results. [i]Salmonella[/i] Enteritidis was the most frequently identified serotype (84.4% of all tested isolates. In total, 42.6% of the [i]Salmonella[/i] spp. isolates were resistant to antibiotics. The highest frequencies of resistance were observed in isolates from 2009 (60.0% and 2012 (59.5%. Antibiotic resistance was most prevalent among [i]Salmonella[/i] spp. isolated from egg-containing food samples (68.0%. Resistance to nalidixic acid was most common and was observed in 35.2% of all tested isolates. The isolates were less frequently resistant to sulphonamides (6.6%, ampicillin (4.9%, amoxicillin/clavulanic acid (2.5% and to streptomycin, cefoxitin, gentamicin and tetracycline (1.6%. Only one isolate showed resistance to chloramphenicol. Four isolates displayed multiresistance. Conclusions. Although, the level of resistance and multiresistance of [i]Salmonella[/i] spp. isolates from non-meat foods was lower than in those from meat products, the presence of these resistant bacteria poses a real threat to the health of consumers.

  10. Serovars of Salmonella from captive reptiles

    DEFF Research Database (Denmark)

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

    2009-01-01

    The distribution on serovars of 60 Salmonella isolates from reptiles kept in captivity in Denmark during the period 1995–2006 was investigated. The isolates were all recovered from clinical specimens submitted to the National Veterinary Institute. A majority of the samples were from reptiles...... in zoological gardens or similar, while a minor number was from reptiles kept in private homes. A total of 43 serovars were detected, most of them being what is usually called exotic serotypes, and many not having a trivial name, while a few isolates belonged to well-known human pathogenic serovars, such as S....... Enteritidis, S. Typhimurium, S. Bovismorbificans. One isolate was rough and two were non-typeable. Isolates from turtles belonged to the subspecies enterica, while many isolates from both sauria and snakes belonged to other subspecies. The findings underline the potential zoonotic risk by handling reptiles...

  11. Intraspecies Competition for Niches in the Distal Gut Dictate Transmission during Persistent Salmonella Infection

    Science.gov (United States)

    Lam, Lilian H.; Monack, Denise M.

    2014-01-01

    In order to be transmitted, a pathogen must first successfully colonize and multiply within a host. Ecological principles can be applied to study host-pathogen interactions to predict transmission dynamics. Little is known about the population biology of Salmonella during persistent infection. To define Salmonella enterica serovar Typhimurium population structure in this context, 129SvJ mice were oral gavaged with a mixture of eight wild-type isogenic tagged Salmonella (WITS) strains. Distinct subpopulations arose within intestinal and systemic tissues after 35 days, and clonal expansion of the cecal and colonic subpopulation was responsible for increases in Salmonella fecal shedding. A co-infection system utilizing differentially marked isogenic strains was developed in which each mouse received one strain orally and the other systemically by intraperitoneal (IP) injection. Co-infections demonstrated that the intestinal subpopulation exerted intraspecies priority effects by excluding systemic S. Typhimurium from colonizing an extracellular niche within the cecum and colon. Importantly, the systemic strain was excluded from these distal gut sites and was not transmitted to naïve hosts. In addition, S. Typhimurium required hydrogenase, an enzyme that mediates acquisition of hydrogen from the gut microbiota, during the first week of infection to exert priority effects in the gut. Thus, early inhibitory priority effects are facilitated by the acquisition of nutrients, which allow S. Typhimurium to successfully compete for a nutritional niche in the distal gut. We also show that intraspecies colonization resistance is maintained by Salmonella Pathogenicity Islands SPI1 and SPI2 during persistent distal gut infection. Thus, important virulence effectors not only modulate interactions with host cells, but are crucial for Salmonella colonization of an extracellular intestinal niche and thereby also shape intraspecies dynamics. We conclude that priority effects and

  12. The Role of Sphingolipids on Innate Immunity to Intestinal Salmonella Infection.

    Science.gov (United States)

    Huang, Fu-Chen

    2017-08-07

    Salmonella spp. remains a major public health problem for the whole world. To reduce the use of antimicrobial agents and drug-resistant Salmonella , a better strategy is to explore alternative therapy rather than to discover another antibiotic. Sphingolipid- and cholesterol-enriched lipid microdomains attract signaling proteins and orchestrate them toward cell signaling and membrane trafficking pathways. Recent studies have highlighted the crucial role of sphingolipids in the innate immunity against infecting pathogens. It is therefore mandatory to exploit the role of the membrane sphingolipids in the innate immunity of intestinal epithelia infected by this pathogen. In the present review, we focus on the role of sphingolipids in the innate immunity of intestinal epithelia against Salmonella infection, including adhesion, autophagy, bactericidal effect, barrier function, membrane trafficking, cytokine and antimicrobial peptide expression. The intervention of sphingolipid-enhanced foods to make our life healthy or pharmacological agents regulating sphingolipids is provided at the end.

  13. Main Concerns of Pathogenic Microorganisms in Meat

    Science.gov (United States)

    Nørrung, Birgit; Andersen, Jens Kirk; Buncic, Sava

    Although various foods can serve as sources of foodborne illness, meat and meat products are important sources of human infections with a variety of foodborne pathogens, i.e. Salmonella spp., Campylobacter jejuni/coli, Yersinia enterocolitica, Verotoxigenic E. coli and, to some extent, Listeria monocytogenes. All these may be harboured in the gastrointestinal tract of food-producing animals. The most frequent chain of events leading to meat-borne illness involves food animals, which are healthy carriers of the pathogens that are subsequently transferred to humans through production, handling and consumption of meat and meat products. Occurrences of Salmonella spp., C. jejuni/coli, Y. enterocolitica and Verotoxigenic E. coli in fresh red meat vary relatively widely, although most often are between 1 and 10%, depending on a range of factors including the organism, geographical factors, farming and/or meat production practices.

  14. Susceptibility of Salmonella Biofilm and Planktonic Bacteria to Common Disinfectant Agents Used in Poultry Processing.

    Science.gov (United States)

    Chylkova, Tereza; Cadena, Myrna; Ferreiro, Aura; Pitesky, Maurice

    2017-07-01

    Poultry contaminated with Salmonella enterica subsp. enterica are a major cause of zoonotic foodborne gastroenteritis. Salmonella Heidelberg is a common serotype of Salmonella that has been implicated as a foodborne pathogen associated with the consumption of improperly prepared chicken. To better understand the effectiveness of common antimicrobial disinfectants (i.e., peroxyacetic acid [PAA], acidified hypochlorite [aCH], and cetylpyridinium chloride [CPC]), environmental isolates of nontyphoidal Salmonella were exposed to these agents under temperature, concentration, and contact time conditions consistent with poultry processing. Under simulated processing conditions (i.e., chiller tank and dipping stations), the bacteriostatic and bactericidal effects of each disinfectant were assessed against biofilm and planktonic cultures of each organism in a disinfectant challenge. Log reductions, planktonic MICs, and mean biofilm eradication concentrations were computed. The biofilms of each Salmonella isolate were more resistant to the disinfectants than were their planktonic counterparts. Although PAA was bacteriostatic and bactericidal against the biofilm and planktonic Salmonella isolates tested at concentrations up to 64 times the concentrations commonly used in a chiller tank during poultry processing, aCH was ineffective against the same isolates under identical conditions. At the simulated 8-s dipping station, CPC was bacteriostatic against all seven and bactericidal against six of the seven Salmonella isolates in their biofilm forms at concentrations within the regulatory range. These results indicate that at the current contact times and concentrations, aCH and PAA are not effective against these Salmonella isolates in their biofilm state. The use of CPC should be considered as a tool for controlling Salmonella biofilms in poultry processing environments.

  15. Antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. isolated from chicken samples.

    Science.gov (United States)

    Er, Buket; Demirhan, Burak; Onurdag, Fatma Kaynak; Ozgacar, Selda Özgen; Oktem, Aysel Bayhan

    2014-03-01

    Salmonella spp. are widespread foodborne pathogens that contaminate egg and poultry meats. Attachment, colonization, as well as biofilm formation capacity of Salmonella spp. on food and contact surfaces of food may cause continuous contamination. Biofilm may play a crucial role in the survival of salmonellae under unfavorable environmental conditions, such as in animal slaughterhouses and processing plants. This could serve as a reservoir compromising food safety and human health. Addition of antimicrobial preservatives extends shelf lives of food products, but even when products are supplemented with adequate amounts of preservatives, it is not always possible to inhibit the microorganisms in a biofilm community. In this study, our aims were i) to determine the minimum inhibitory concentrations (MIC) and minimum biofilm inhibitory concentrations (MBIC) of selected preservatives against planktonic and biofilm forms of Salmonella spp. isolated from chicken samples and Salmonella Typhimurium SL1344 standard strain, ii) to show the differences in the susceptibility patterns of same strains versus the planktonic and biofilm forms to the same preservative agent, and iii) to determine and compare antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. For this purpose, Salmonella Typhimurium SL1344 standard strain and 4 Salmonella spp. strains isolated from chicken samples were used. Investigation of antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. was done according to Clinical and Laboratory Standards Institute M100-S18 guidelines and BioTimer assay, respectively. As preservative agents, pure ciprofloxacin, sodium nitrite, potassium sorbate, sodium benzoate, methyl paraben, and propyl paraben were selected. As a result, it was determined that MBIC values are greater than the MIC values of the preservatives. This result verified the resistance seen in a biofilm community to food

  16. The Antibiofilm Effect of Ginkgo biloba Extract Against Salmonella and Listeria Isolates from Poultry.

    Science.gov (United States)

    Wu, Yan; Park, Keun Cheol; Choi, Beom Geun; Park, Jin Hwa; Yoon, Ki Sun

    2016-05-01

    Salmonella spp. and Listeria spp. are common foodborne pathogens in poultry and have caused a large number of outbreaks worldwide. Biofilm formation is common in the food industry and is also a mechanism of antimicrobial resistance. The aim of this work was to investigate the antimicrobial effect and mechanism of Ginkgo biloba extract against the biofilm formation of Salmonella and Listeria isolates from poultry at retail markets. Bacteria detection, isolation, and enumeration were carried out on 27 chicken and 29 ducks at retail markets. The effects of temperature and G. biloba extract against biofilm formation of Salmonella and Listeria isolates were measured using the crystal violet assay and swimming and swarming motilities. The monitoring results of Salmonella and Listeria in 56 poultry carcasses at retail markets in Korea showed that the prevalence of Salmonella spp. in poultry was low (5.4%), but the prevalence of Listeria spp (78.6%) was high. L. innocua was the predominant serotype (80%) in the isolated Listeria species. Temperature, strain, and surface affected the biofilm formation of Salmonella spp. and Listeria spp. L. innocua showed the best biofilm formation ability on a 96-well plate, while Salmonella Enteritidis formed the most biofilm on a glass slide. Biofilm formation abilities of Salmonella spp. and Listeria spp. were increased with the increase of temperature. G. biloba extract at 75 μg/mL significantly inhibited biofilm formation of Salmonella spp. and Listeria spp (p Listeria, but not L. monocytogenes. The findings of this study provided the basis for the application of G. biloba extract as a food additive to promote the quality and safety of poultry products.

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

    Directory of Open Access Journals (Sweden)

    Min Yue

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

  18. Diversification of the Salmonella Fimbriae: A Model of Macro- and Microevolution

    Science.gov (United States)

    Yue, Min; Rankin, Shelley C.; Blanchet, Ryan T.; Nulton, James D.; Edwards, Robert A.; Schifferli, Dieter M.

    2012-01-01

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

  19. Airborne soil particulates as vehicles for Salmonella contamination of tomatoes.

    Science.gov (United States)

    Kumar, Govindaraj Dev; Williams, Robert C; Al Qublan, Hamzeh M; Sriranganathan, Nammalwar; Boyer, Renee R; Eifert, Joseph D

    2017-02-21

    The presence of dust is ubiquitous in the produce growing environment and its deposition on edible crops could occur. The potential of wind-distributed soil particulate to serve as a vehicle for S. Newport transfer to tomato blossoms and consequently, to fruits, was explored. Blossoms were challenged with previously autoclaved soil containing S. Newport (9.39log CFU/g) by brushing and airborne transfer. One hundred percent of blossoms brushed with S. Newport-contaminated soil tested positive for presence of the pathogen one week after contact (PCompressed air was used to simulate wind currents and direct soil particulates towards blossoms. Airborne soil particulates resulted in contamination of 29% of the blossoms with S. Newport one week after contact. Biophotonic imaging of blossoms post-contact with bioluminescent S. Newport-contaminated airborne soil particulates revealed transfer of the pathogen on petal, stamen and pedicel structures. Both fruits and calyxes that developed from blossoms contaminated with airborne soil particulates were positive for presence of S. Newport in both fruit (66.6%) and calyx (77.7%). Presence of S. Newport in surface-sterilized fruit and calyx tissue tested indicated internalization of the pathogen. These results show that airborne soil particulates could serve as a vehicle for Salmonella. Hence, Salmonella contaminated dust and soil particulate dispersion could contribute to pathogen contamination of fruit, indicating an omnipresent yet relatively unexplored contamination route. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Salmonella Control Programs in Denmark

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  1. Prevalence of Trichomonas, Salmonella, and Listeria in Wild Birds from Southeast Texas.

    Science.gov (United States)

    Brobey, Britni; Kucknoor, Ashwini; Armacost, Jim

    2017-09-01

    Infectious diseases can be a major threat to wildlife populations, especially in human-modified habitats, but infection rates in populations of wild animals are often poorly studied. Trichomonas, Salmonella, and Listeria are all pathogens known to infect birds, but their infection rates in wild bird populations are not well documented. This study documents infection rates of the three pathogens in wild bird populations inhabiting a suburban to rural gradient in Southeast Texas. Various species of wild birds were sampled at five sites in Southeastern Texas representing rural (Birds were captured in mist nets and samples were taken from the oral cavity, crop, and vent to detect the presence of pathogens. Samples were screened for Trichomonas by examining wet mounts under a light microscope, whereas samples were screened for Salmonella and Listeria by examining colonies grown on agar plates. Pathogens detected during the initial screening were further confirmed by PCR and DNA sequencing. Infection rates for Trichomonas, Salmonella, and Listeria were 9%, 17%, and 5%, respectively. The distributions of infection rates across habitats (i.e., rural, exurban, rural) did not differ significantly from the expected null distributions for any of the three pathogens; however, the data suggested some interesting patterns that should be confirmed with a larger dataset. Infection rates for Trichomonas and Salmonella were highest at the suburban sites, whereas the infection rate for Listeria was highest at the rural site. Feeder birds were more likely to be infected by all three pathogens than non-feeder birds. Small sample sizes prevent definitive conclusions regarding variation in infection rates along the suburban to rural gradient, but the results suggest that pathogens followed the predicted patterns. For many of the bird species sampled, this study presents the first report of infection rates by these three pathogens in wild populations.

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

    OpenAIRE

    Klerks, M.M.

    2007-01-01

    Salmonella is among the most commonly known bacterial pathogens to cause human illness. Often Salmonellosis is associated with the consumption of contaminated foods like meat, eggs or egg products. However, during the last decades an increase of outbreaks is recognized to be caused by human pathogenic bacteria in association with fresh produce. The use of manure for production of vegetables, e.g. lettuce, contributes significantly to the risk of contamination of fresh produce. Enteric pathoge...

  3. Antimicrobial resistance of Salmonella and E. coli from Pennsylvania dairy herds

    Science.gov (United States)

    Antimicrobial resistance in bacterial pathogens is an increasing public health concern. The objective of this study was to examine antimicrobial resistance in Salmonella and E. coli isolates from Pennsylvania dairy herds. Manure composite samples were collected from 76 farms: on each farm one sample...

  4. Accelerating sample preparation through enzyme-assisted microfiltration of Salmonella in chicken extract

    Science.gov (United States)

    Microfiltration of chicken extracts has the potential to significantly decrease the time required to detect Salmonella, as long as the extract can be efficiently filtered and the pathogenic microorganisms kept in a viable state during this process. We present conditions that enable microfiltration ...

  5. Antimicrobial growth promoters and Salmonella spp., Campylobacter spp. in poultry and swine, Denmark

    DEFF Research Database (Denmark)

    Evans, M. C.; Wegener, Henrik Caspar

    2003-01-01

    The use of antimicrobial growth promoters in Danish food animal production was discontinued in 1998. Contrary to concerns that pathogen load would increase; we found a significant decrease in Salmonella in broilers, swine, pork, and chicken meat and no change in the prevalence of Campylobacter in...

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

    NARCIS (Netherlands)

    Klerks, M.M.

    2007-01-01

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

  7. The Role of the st313-td Gene in Virulence of Salmonella Typhimurium ST313

    DEFF Research Database (Denmark)

    Herrero-Fresno, Ana; Wallrodt, Inke; Leekitcharoenphon, Pimlapas

    2014-01-01

    Multidrug-resistant Salmonella enterica serovar Typhimurium ST313 has emerged in sub-Saharan Africa causing severe infections in humans. Therefore, it has been speculated that this specific sequence type, ST313, carries factors associated with increased pathogenicity. We assessed the role in viru...

  8. Effectiveness of Sanitizer D7(TM) against Escherichia coli O157:H7 and Salmonella biofilms

    Science.gov (United States)

    Introduction: Biofilm formation by E. coli O157:H7 and Salmonella enterica at meat processing plants poses a serious risk of meat product contamination. Available studies have shown that many common sanitizers were unable to completely eradicate biofilms by these foodborne pathogens due to the 3-dim...

  9. Comparing Temperature Effects on E. Coli, Salmonella, and Enterococcus Survival in Surface Waters

    Science.gov (United States)

    The objective of this study was to compare dependency of survival rates on temperature for indicator organisms E. coli and Enterococcus and the pathogen Salmonella in surface waters. A database of 86 survival datasets from peer-reviewed papers on inactivation of E. coli, Salmonel...

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

    Science.gov (United States)

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

  11. Whole Genome Sequence Analysis of Salmonella Enteritidis Isolated from Wild Mice

    Science.gov (United States)

    Salmonella Enteritidis is a foodborne pathogen of global concern because of the high frequency isolated from foods and patients. Draft genomes of 64 S. Enteritidis strains from intestines and spleens of mice were reported. The availability of these genomes provides useful information on genomic dive...

  12. The Potential Link between Thermal Resistance and Virulence in Salmonella: A Review

    Directory of Open Access Journals (Sweden)

    Turki M. Dawoud

    2017-06-01

    Full Text Available In some animals, the typical body temperature can be higher than humans, for example, 42°C in poultry and 40°C in rabbits which can be a potential thermal stress challenge for pathogens. Even in animals with lower body temperatures, when infection occurs, the immune system may increase body temperature to reduce the chance of survival for pathogens. However, some pathogens can still easily overcome higher body temperatures and/or rise in body temperatures through expression of stress response mechanisms. Salmonella is the causative agent of one of the most prevalent foodborne illnesses, salmonellosis, and can readily survive over a wide range of temperatures due to the efficient expression of the heat (thermal stress response. Therefore, thermal resistance mechanisms can provide cross protection against other stresses including the non-specific host defenses found within the human body thus increasing pathogenic potential. Understanding the molecular mechanisms associated with thermal responses in Salmonella is crucial in designing and developing more effective or new treatments for reducing and eliminating infection caused by Salmonella that have survived heat stress. In this review, Salmonella thermal resistance is assessed followed by an overview of the thermal stress responses with a focus on gene regulation by sigma factors, heat shock proteins, along with the corresponding thermosensors and their association with virulence expression including a focus on a potential link between heat resistance and potential for infection.

  13. Hot water surface pasteurization for inactivating Salmonella on surfaces of mature green tomatoes

    Science.gov (United States)

    Outbreaks of salmonellosis have been associated with the consumption of tomatoes contaminated with Salmonella. Commercial washing processes for tomatoes are limited in their ability to inactivate and/or remove this human pathogen. Our objective was to develop a hot water surface pasteurization pro...

  14. Detection of Salmonella typhi by nested polymerase chain reaction in blood, urine, and stool samples

    NARCIS (Netherlands)

    Hatta, Mochammad; Smits, Henk L.

    2007-01-01

    A nested polymerase chain reaction (PCR) specific for Salmonella enterica serovar Typhi was used for the detection of the pathogen in blood, urine, and stool samples from 131 patients with clinical suspicion of typhoid fever. The sensitivity of blood culture, the PCRs with blood, urine, and feces,

  15. Pre-harvest surveillance of Campylobacter and Salmonella in Danish broiler flocks: a 2-year study

    DEFF Research Database (Denmark)

    Wedderkopp, A.; Gradel, K.O.; Jorgensen, J.C.

    2001-01-01

    was observed. For each flock, the presence of Campylobacter and Salmonella was recorded in order to estimate the possible correlation between colonisation with the two pathogens. In conclusion, no significant effects on intensive cleaning and disinfection procedures on Campylobacter occurrence could...

  16. In vitro characterization and in vivo properties of Salmonellae lytic bacteriophages isolated from free-range layers

    Directory of Open Access Journals (Sweden)

    L Fiorentin

    2004-06-01

    Full Text Available Occurrence of food poisoning related to Salmonella-contaminated eggs and chicken meat has been frequent in humans. Salmonella Enteritidis (SE and Salmonella Typhimurium (ST are included among the most important paratyphoid salmonellae associated with chicken meat and eggs. Elimination of Salmonella at the pre-harvest stage can play a significant role in preventing the introduction of this pathogen into the food chain and consequently in the reduction of food poisoning in humans. Bactericidal bacteriophages may provide a natural, nontoxic, feasible and non-expensive component of the multi-factorial approach for a pre-harvest control of Salmonella in poultry. Five bacteriophages lytic for SE PT4 and ST were obtained from 107 samples of feces of free-range layers in Brazil. All bacteriophages were characterized in vitro and in vivo, showing head and tail morphology and dsDNA as nucleic acids. Results of "in vivo" studies suggested that bacteriophages do not remain in Salmonella-free birds longer than one day, whereas they multiply in Salmonella-infected birds for longer periods. Besides, selection for phage-resistant SE PT4 did not seem to occur in the short term. Isolated bacteriophages will be investigated for their potential for pre-harvest biocontrol of SE PT4 in poultry.

  17. Salmonella Species' Persistence and Their High Level of Antimicrobial Resistance in Flooded Man-Made Rivers in China.

    Science.gov (United States)

    Song, Qifa; Zhang, Danyang; Gao, Hong; Wu, Junhua

    2018-05-11

    Man-made rivers, owing to proximity to human habitats, facilitate transmission of salmonellosis to humans. To determine the contamination situation by Salmonella in flooded man-made rivers and thereafter the exposure risk to public health, we investigated the prevalence of Salmonella species and their antimicrobial resistance in such rivers, as well as the relationship between the incidence of local infectious diarrhea cases and the number of Salmonella isolates from patients. After a heavy flood, 95 isolates of 13 Salmonella serotypes were isolated from 80 river water samples. The two most prevalent serotypes were Typhimurium and Derby. Eight Salmonella serotypes were newly detected after the flood. Overall, 50 isolates were resistant to ampicillin and/or cefotaxime and carried at least bla TEM . Twelve isolates of serotypes Typhimurium, Derby, Rissen, and Indiana were extended-spectrum β-lactamase (ESBL) producing and carried at least one of bla OXA and bla CTX-M-like genes. Twelve isolates of serotypes Typhimurium, Derby, Agona, Rissen, and Indiana were resistant to ciprofloxacin and had gyrA mutations. Isolates of Typhimurium, Derby, and Indiana were concurrently ciprofloxacin resistant and ESBL producing. Pulsed-field gel electrophoresis illustrates the circulation of two dominant clones of Salmonella Typhimurium isolates among patients, river, and food. High prevalence of various highly pathogenic and antimicrobial-resistant Salmonella serotypes shows that man-made rivers are prone to heavy contamination with Salmonella, and as a result put public health at greater risk.

  18. Efeitos da Salmonella Enteritidis experimentalmente inoculada na saúde gastrintestinal de perus Effects of experimentally inoculated Salmonella Enteritidis on the gastrointestinal health of turkeys

    Directory of Open Access Journals (Sweden)

    Carla Yoko Tanikawa de Andrade

    2012-03-01

    assessment, biometrics and histomorphometry. On days one, 15 and 28, samples of meconium/excreta were collected from all birds. The intestinal colonization increased during the initial phase when Salmonella was inoculated via eggshell. The intestine showed greater weight on the first, tenth and 28th days when Salmonella was present, with no differences regarding the intestine length. Salmonella Enteritidis was able to colonize the intestinal tract, establish infection, reduce bird performance and modify the cellular structures of the intestine. Contamination of the eggshell before hatching generated birds susceptible to infection at birth and the frequency of isolation of Salmonella Enteritidis persisted until 28 days of age. Salmonella inoculation by drinking water generated infected birds, but with less recovery of the pathogen with age increase. Inoculated birds showed inferior performance, confirming the potential damage to poultry production.

  19. The search of Listeria and Salmonella in different food matrices

    International Nuclear Information System (INIS)

    Ben Saad, Emna

    2010-01-01

    The foods safety and security does not cease to be a priority. Although foods contaminants generate changes in the sensory characteristics, they may cause diseases and pose a risk to human health. This study includes a targeted search of two food borne pathogens Listeria and Salmonella responsible respectively of two serious infections listeriosis and salmonellosis. 100 Food samples taken from the market for public consumption are analyzed in the CNSTN laboratory of microbiology and molecular biology. Once isolated (eight strains of Listeria and one of Salmonella), the strains were identified by Api (Listeria and 20E) and PCR. The results obtained show the ability of our products to be contaminated which arise the importance of strengthening measures of prevention and health control.

  20. Litter aeration and spread of Salmonella in broilers.

    Science.gov (United States)

    Bodí, Sara González; Garcia, Arantxa Villagra; García, Santiago Vega; Orenga, Clara Marín

    2013-08-01

    Litter quality in the poultry sector is one of the main parameters of health, productivity, and animal welfare. Therefore, innovative management methods have been developed to improve the quality of litter. One of them is litter aeration (LA) by tumbling. However, there is little information related to the effect of this technique on the spreading of pathogens of public health importance such as Salmonella. In this context, the objective of this study was to determine the epidemiology of Salmonella in poultry farms, when serial LA were implemented during the rearing cycle of broilers. For this purpose, an experimental broiler farm with 3 identical rooms was used in the study. Two rooms were assigned to the LA treatment, and the other one served as the control room. Environmental samples were taken in poultry houses after LA in 4 consecutive weeks at the end of the cycle. All samples collected were analyzed according to the standards of the International Organization for Standardization (ISO 6579:2002, Annex D). The results of this study showed that in the control and treated rooms, the percentage of positive samples for Salmonella decreased in the first 3 LA sessions (LA 1, LA 2, and LA 3). However, in the last LA session of rearing (LA 4), the percentage of positive samples increased from 8.2 to 33.2% in the control room instead the treated rooms where the positive samples decreased (P = 0.017). Thus, the aeration of the litter as litter management technique in poultry broiler production does not increase the shedding or the spread of Salmonella throughout broiler houses. In addition, it could be an effective technique to reduce the infective pressure of this bacterium in several areas of the farm or in certain moments of the rearing period with more risk of multiplication and spreading of Salmonella.

  1. Biofilm formation capacity of Salmonella serotypes at different temperature conditions

    Directory of Open Access Journals (Sweden)

    Karen A. Borges

    Full Text Available ABSTRACT: Salmonella spp. are one of the most important agents of foodborne disease in several countries, including Brazil. Poultry-derived products are the most common food products, including meat and eggs, involved in outbreaks of human salmonellosis. Salmonella has the capacity to form biofilms on both biotic and abiotic surfaces. The biofilm formation process depends on an interaction among bacterial cells, the attachment surface and environmental conditions. These structures favor bacterial survival in hostile environments, such as slaughterhouses and food processing plants. Biofilms are also a major problem for public health because breakage of these structures can cause the release of pathogenic microorganisms and, consequently, product contamination. The aim of this study was to determine the biofilm production capacity of Salmonella serotypes at four different temperatures of incubation. Salmonella strains belonging to 11 different serotypes, isolated from poultry or from food involved in salmonellosis outbreaks, were selected for this study. Biofilm formation was investigated under different temperature conditions (37°, 28°, 12° and 3°C using a microtiter plate assay. The tested temperatures are important for the Salmonella life cycle and to the poultry-products process. A total of 92.2% of the analyzed strains were able to produce biofilm on at least one of the tested temperatures. In the testing, 71.6% of the strains produced biofilm at 37°C, 63% at 28°C, 52.3% at 12°C and 39.5% at 3°C, regardless of the serotype. The results indicate that there is a strong influence of temperature on biofilm production, especially for some serotypes, such as S. Enteritidis, S. Hadar and S. Heidelberg. The production of these structures is partially associated with serotype. There were also significant differences within strains of the same serotype, indicating that biofilm production capacity may be strain-dependent.

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

    Directory of Open Access Journals (Sweden)

    Jorge Hernández

    2012-08-01

    Full Text Available A novel Salmonella serovar was isolated from Peregrine falcon (Falco peregrinus nestlings in northern Sweden in 2006. Three isolates of the same clone was retrieved from three falcon siblings and characterized as Salmonella enterica sub-species enterica: O-phase 13, 23:-: e, n, z 15 and the H-phase was not present. We propose the geographical name Salmonella enterica, sub-species enterica serovar Pajala to this novel Salmonella.

  3. Samsung Salmonella Detection Kit. AOAC Performance Tested Method(SM) 021203.

    Science.gov (United States)

    Li, Jun; Cheung, Win Den; Opdyke, Jason; Harvey, John; Chong, Songchun; Moon, Cheol Gon

    2012-01-01

    Salmonella, one of the most common causes of foodborne illness, is a significant public health concern worldwide. There is a need in the food industry for methods that are simple, rapid, and sensitive for the detection of foodborne pathogens. In this study, the Samsung Salmonella Detection Kit, a real-time PCR assay for the detection of Salmonella, was evaluated according to the current AOAC guidelines. The validation consisted of lot-to-lot consistency, stability, robustness, and inclusivity/exclusivity studies, as well as a method comparison of 10 different food matrixes. In the validation, the Samsung Salmonella Detection Kit was used in conjunction with the Applied Biosystems StepOnePlus PCR system and the Samsung Food Testing Software for the detection of Salmonella species. The performance of the assays was compared to the U.S. Department of Agriculture/Food Safety and Inspection Service-Microbiology Laboratory Guidebook (USDA/FSIS-MLG) 4.05: Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg, and Catfish and the and U.S. Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Chapter 5 Salmonella reference methods. The validation was conducted using an unpaired study design for detection of Salmonella spp. in raw ground beef, raw pork, raw ground pork, raw chicken wings, raw salmon, alfalfa sprouts, pasteurized orange juice, peanut butter, pasteurized whole milk, and shell eggs. The Samsung Salmonella Detection Kit demonstrated lot-to-lot consistency among three independent lots as well as ruggedness with minor modifications to changes in enrichment incubation time, enrichment incubation temperature, and DNA sample volume for PCR reaction. Stability was observed for 13 months at -20 degrees C and 3 months at 5 degrees C. For the inclusivity/exclusivity study, the Samsung Salmonella Detection Kit correctly identified 147 Salmonella species isolates out of 147 isolates tested from each of three different enrichment

  4. Comparing validation of four ELISA-systems for detection of Salmonella derby- and Salmonella infantis-infected pigs.

    Science.gov (United States)

    Roesler, Uwe; Szabo, Istvan; Matthies, Claudia; Albrecht, Kerstin; Leffler, Martin; Scherer, Kathrin; Nöckler, Karsten; Lehmann, Jörg; Methner, Ulrich; Hensel, Andreas; Truyen, Uwe

    2011-01-01

    The objective of this study was the comparative evaluation of four indirect Salmonella ELISA tests at study time approved in Germany to detect Salmonella infection in pigs.Three tests are based on a LPS-antigen mix and directed against specific IgG antibodies. The fourth test is based on a purified S. Typhimurium whole-cell lysate antigen and discriminates between Salmonella-specific IgM-, IgA-, and IgG- antibodies. In a longitudinal study, two groups of six weeks old hybrid piglets were orally infected with a porcine S. Infantis or S. Derby strain. Clinical and bacteriological parameters were monitored weekly during an observation period of 130 days after infection and serum samples were investigated in parallel with the respective ELISAs. Apparently, the LPS-based ELISA systems used in this study failed to recognize S. Infantis-infected pigs although those animals shed the pathogen in high amounts throughout the study until day 81 post infection (p. i.). In contrast, the isotype-specific Salmonella Typhimurium whole-cell-lysate based ELISA was capable of detecting Salmonella-infected pigs from day ten p. i. at all tested serotypes and revealed the highest sensitivity in detection of S. Infantis-infected pigs. Furthermore, it became apparent that the often used surveillance cut-off value of 40 OD% is not appropriate for intra-vitam detection of S. Infantis- and S. Derby-infected pigs. In contrast, the cut-off values of the ELISAs given by the suppliers result in considerable higher detection rates.

  5. [Detection of Salmonella and Mycobacterium species in seagulls captured in Talcahuano, Chile].

    Science.gov (United States)

    López-Martín, Juana; Junod, Tania; Riquelme, Fredy; Contreras, Cecilia; González-Acuña, Daniel

    2011-11-01

    Salmonella can be isolated from the feces of seagulls. Therefore these birds can be a vector for dissemination of this pathogen. To evaluate the possible role of gulls as vectors of two important human and animal pathogens (My-cobacteria and Salmonella). One hundred twenty three Kelp gull (Larus dominicanus) and 60 Franklin gulls (Leucophaeus pipixcan) captured off the coast of the seaport of Talcahuano, were analyzed. Using traditional microbiological methods, the presence of Mycobacteria in cloacal swabs and feet lavages, was analyzed in both types of gulls. To detect the presence of Salmonella, feces, fecal and tracheal swabs, and feet lavage were analyzed from Franklin gulls. Feces, feet lavage, intestine, spleen, liver, kidney and lung, were examined in Kelp gulls. All Mycobacteria cultures were negative. Salmonella enterica cultures were positive in 25 % of Kelp gulls and 6.7 % of Franklin gulls. Four serovars were identified by serotyping. Enteritidis and Senfteberg serovars were found in both types of gulls. Anatum and Infantis serovars were found only in Kelp gulls. Feces of gulls captured during the winter had the highest yield of positive cultures (36.1%). Seagulls are an important Salmonella vector in Chile.

  6. Prevalence of salmonella species in fishes and its control using irradiation

    International Nuclear Information System (INIS)

    Mohamed, W. S.

    2010-01-01

    The prevalence of Salmonella species infecting frozen Tilapia fish fillets and whole fishes was determined, during the summer seasons of years 2006 and 2007.Elimination of Salmonella species in Tilapia fishes with different doses of γ-rays was investigated. Doses of 1, 2, 3, 3.5, 5, 4 and 5 kGy were used to find out the least dose that will be sufficient to eliminate the pathogen from the examined samples. Two hundred fish fillet samples and 200 whole fishes were subjected for bacteriological examination for the incidence of Salmonella infection. Out of them 19 fillets and 8 whole fishes were infected with the pathogen in a percentage of 9.5 % and 4 % respectively. The serological determination detected the infection with Salmonella typhimurium in all the affected samples. A dose of 3.5 kGy γ-rays was determined to be the least appropriate dose for elimination of Salmonella typhimurium from Tilapia fishes. The best appearance characteristics were obtained at 3.5 kGy of γ-irradiation. There was a gradual decrease in the count of the micro-organism as the dose of irradiation increased (linear regression). So a dose of 3.5 kGy of γ-irradiation is recommended for healthy, good looking and economic fishes for public health benefits.

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

    Science.gov (United States)

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

    2011-01-01

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

  8. The Arf GTPase-activating protein family is exploited by Salmonella enterica serovar Typhimurium to invade nonphagocytic host cells.

    Science.gov (United States)

    Davidson, Anthony C; Humphreys, Daniel; Brooks, Andrew B E; Hume, Peter J; Koronakis, Vassilis

    2015-02-10

    To establish intracellular infections, Salmonella bacteria trigger host cell membrane ruffling and invasion by subverting cellular Arf guanine nucleotide exchange factors (GEFs) that activate Arf1 and Arf6 GTPases by promoting GTP binding. A family of cellular Arf GTPase-activating proteins (GAPs) can downregulate Arf signaling by stimulating GTP hydrolysis, but whether they do this during infection is unknown. Here, we uncovered a remarkable role for distinct Arf GAP family members in Salmonella invasion. The Arf6 GAPs ACAP1 and ADAP1 and the Arf1 GAP ASAP1 localized at Salmonella-induced ruffles, which was not the case for the plasma membrane-localized Arf6 GAPs ARAP3 and GIT1 or the Golgi-associated Arf1 GAP1. Surprisingly, we found that loss of ACAP1, ADAP1, or ASAP1 impaired Salmonella invasion, revealing that GAPs cannot be considered mere terminators of cytoskeleton remodeling. Salmonella invasion was restored in Arf GAP-depleted cells by expressing fast-cycling Arf derivatives, demonstrating that Arf GTP/GDP cycles facilitate Salmonella invasion. Consistent with this view, both constitutively active and dominant-negative Arf derivatives that cannot undergo GTP/GDP cycles inhibited invasion. Furthermore, we demonstrated that Arf GEFs and GAPs colocalize at invading Salmonella and collaborate to drive Arf1-dependent pathogen invasion. This study revealed that Salmonella bacteria exploit a remarkable interplay between Arf GEFs and GAPs to direct cycles of Arf GTPase activation and inactivation. These cycles drive Salmonella cytoskeleton remodeling and enable intracellular infections. To initiate infections, the Salmonella bacterial pathogen remodels the mammalian actin cytoskeleton and invades host cells by subverting host Arf GEFs that activate Arf1 and Arf6 GTPases. Cellular Arf GAPs deactivate Arf GTPases and negatively regulate cell processes, but whether they target Arfs during infection is unknown. Here, we uncovered an important role for the Arf GAP

  9. Pathogen Prevalence From Traditional Cage and Free Range Production

    Science.gov (United States)

    Overview: A study was conducted to determine if differences in pathogen prevalence occurred between a sister flock of conventional cage and free range laying hens. Both environmental and egg microbiology was monitored throughout 20 – 79 weeks of age. Salmonella, Campylobacter, and Listeria preval...

  10. Isolation of Salmonella spp. in cattle egrets (Bubulcus ibis) from Fernando de Noronha Archipelago, Brazil.

    Science.gov (United States)

    Silva, Marcio A; Fernandes, Érika F S T; Santana, Sandra C; Marvulo, Maria Fernanda V; Barros, Mércia R; Vilela, Sineide M O; Reis, Eliane M F; Mota, Rinaldo A; Silva, Jean C R

    2018-03-03

    The growth of the population of cattle egrets (Bubulcus ibis) in the archipelago of Fernando de Noronha constitutes a threat to public health and biological diversity because of their competition with and predation on native species and the possibility of transmission of pathogens to human beings, livestock and native wildlife. The aim here was to search for, isolate and identify serovars of Salmonella in clinically healthy local cattle egrets. Cloacal swabs were obtained from 456 clinically healthy cattle egrets of both sexes and a variety of ages. The swabs were divided into 51 pools. Six of these (11.7%) presented four serovars of Salmonella enterica subspecies enterica: Salmonella serovar Typhimurium; Salmonella serovar Newport; Salmonella serovar Duisburg; and Salmonella serovar Zega. One sample was identified as S. enterica subspecies enterica O16:y:-. Results in this study suggest that cattle egrets may be reservoirs of this agent on Fernando de Noronha and represent a risk to public health and biological diversity. Copyright © 2018. Published by Elsevier Editora Ltda.

  11. Occurrence of multidrug-resistant Salmonella enterica serovar Enteritidis isolates from poultry in Iran

    Directory of Open Access Journals (Sweden)

    Ghaderi, R.

    2016-03-01

    Full Text Available Salmonella enterica is recognized as one of the major food-borne pathogens with more than 2,500 serotypes worldwide. The present study addresses antimicrobial resistance of Salmonella enterica serovar Enteritidis isolates in Iran. A collection of 151 Salmonella spp. isolates collected from poultry were serotyped to identify Salmonella Enteritidis. Sixty-one Salmonella Enteritidis were subsequently tested against 30 antimicrobials. A high frequency of antimicrobial resistance was observed against nitrofurantoin (n=55, 90.2% followed by nalidixic acid (n=41, 67.2%, and cephalexin (n=23, 37.7%. Multi-drug resistance were observed in 35 (57.4% out of 61 isolates. Twenty-six antimicrobial resistance patterns were observed among the 61 Salmonella Enteritidis. All isolates were susceptible to ofloxacin, imipenem, enrofloxacin, chloramphenicol, gentamicin, and 3rd and 4th generation cephalosporins. In conclusion, our results revealed that implementing new policies toward overuse of antimicrobial drugs in Iranian poultry industry are of great importance.

  12. Effect of Antimicrobial Dosage Regimen on Salmonella and Escherichia coli Isolates from Feeder Swine▿

    Science.gov (United States)

    Wagner, Bruce A.; Straw, Barbara E.; Fedorka-Cray, Paula J.; Dargatz, David A.

    2008-01-01

    A body of evidence exists that suggests that antimicrobial use in food animals leads to resistance in both pathogenic and commensal bacteria. This study focused on the impact of three different antimicrobial regimes (low-level continuous, pulse, and no antimicrobial) for two antimicrobials (chlortetracycline and tylosin) on the presence of Salmonella spp. and on the prevalence of antimicrobial resistance of both Salmonella spp. and nonspecific Escherichia coli in fecal samples from feeder swine. The prevalence of fecal samples positive for Salmonella spp. significantly decreased between the samples taken at feeder placement compared to samples taken when the animals were close to market weight. Differences in resistance of Salmonella spp. did not appear to be influenced by dosing treatment including the control. Analysis of antimicrobial resistance examining both susceptibility and resistance, as well as MIC outcomes, demonstrated that only resistance to cephalothin increased in E. coli under the pulse chlortetracycline treatment. These results suggest that the dosing regimes examined in this study did not lead to an increase in either the prevalence of Salmonella spp. or the prevalence of antimicrobial resistance in isolates of Salmonella spp. or E. coli. PMID:18223115

  13. The Salmonella effector protein SpvC, a phosphothreonine lyase is functional in plant cells

    Directory of Open Access Journals (Sweden)

    Christina eNeumann

    2014-10-01

    Full Text Available Salmonella is one of the most prominent causes of food poisoning and growing evidence indicates that contaminated fruits and vegetables are an increasing concern for human health. Successful infection demands the suppression of the host immune system, which is often achieved via injection of bacterial effector proteins into host cells. In this report we present the function of Salmonella effector protein in plant cell, supporting the new concept of trans-kingdom competence of this bacterium. We screened a range of Salmonella Typhimurium effector proteins for interference with plant immunity. Among these, the phosphothreonine lyase SpvC attenuated the induction of immunity-related genes when present in plant cells. Using in vitro and in vivo systems we show that this effector protein interacts with and dephosphorylates activated Arabidopsis Mitogen-activated Protein Kinase 6 (MPK6, thereby inhibiting defense signaling. Moreover, the requirement of Salmonella SpvC was shown by the decreased proliferation of the ΔspvC mutant in Arabidopsis plants. These results suggest that some Salmonella effector proteins could have a conserved function during proliferation in different hosts. The fact that Salmonella and other Enterobacteriaceae use plants as hosts strongly suggests that plants represent a much larger reservoir for animal pathogens than so far estimated.

  14. [Incidence of Campylobacter spp. and Salmonella spp. in raw and roasted chicken in Guadalajara, Mexico].

    Science.gov (United States)

    Castillo-Ayala, A; Salas-Ubiarco, M G; Márquez-Padilla, M L; Osorio-Hernández, M D

    1993-01-01

    The presence of Campylobacter spp. and Salmonella was studied in 70 samples of fresh retail chicken pieces and in 40 samples of roast chicken. Total plate count was performed in every sample as well. Most of the samples of fresh chicken yielded total plate counts > 10(8)/piece (thigh), while in roast chicken these counts ranged from 10(3) to 10(5)/piece (leg and thigh). Campylobacter was isolated from 33% of fresh chicken and from no sample of roast chicken. Salmonella was isolated from 69% of fresh chicken and 2.5% of roast chicken. There was no relationship between total plate counts in fresh chicken and isolation of either Campylobacter or Salmonella. Sixty percent of the Salmonella isolates belonged to serotype S. anatum, and about 50% of the isolates of Campylobacter were identified as being C. coli. The only Salmonella-positive sample of roast chicken yielded three serotypes: S. give, S. muenster, and S. manhattan. Presence of Campylobacter and Salmonella in chicken is of concern, due to the risk of spreading from the raw food to other cooked foods. The isolation of pathogens from roast chicken indicates mishandling during processing and/or storage of the product.

  15. Concomitant uptake of antimicrobials and Salmonella in soil and into lettuce following wastewater irrigation

    International Nuclear Information System (INIS)

    Sallach, J. Brett; Zhang, Yuping; Hodges, Laurie; Snow, Daniel; Li, Xu; Bartelt-Hunt, Shannon

    2015-01-01

    The use of wastewater for irrigation may introduce antimicrobials and human pathogens into the food supply through vegetative uptake. The objective of this study was to investigate the uptake of three antimicrobials and Salmonella in two lettuce cultivars. After repeated subirrigation with synthetic wastewater, lettuce leaves and soil were collected at three sequential harvests. The internalization frequency of Salmonella in lettuce was low. A soil horizon-influenced Salmonella concentration gradient was determined with concentrations in bottom soil 2 log CFU/g higher than in top soil. Lincomycin and sulfamethoxazole were recovered from lettuce leaves at concentrations as high as 822 ng/g and 125 ng/g fresh weight, respectively. Antimicrobial concentrations in lettuce decreased from the first to the third harvest suggesting that the plant growth rate may exceed antimicrobial uptake rates. Accumulation of antimicrobials was significantly different between cultivars demonstrating a subspecies level variation in uptake of antibiotics in lettuce. - Highlights: • Antimicrobial uptake in lettuce is cultivar dependent. • Antimicrobial concentrations in lettuce decrease despite repeated exposure. • Lincomycin is better conserved in the soil-plant system than oxytetracycline or sulfamethoxazole. • Subirrigation resulted in more Salmonella in bottom soil than in top soil. • Internalization frequency of Salmonella in lettuce is low despite repeated exposure. - Cultivar-specific differences in lincomycin and sulfamethazine uptake were observed in lettuce, while uptake of Salmonella was low despite repeated exposure from wastewater

  16. Salmonella in Liquid Eggs and Other Foods in Fukuoka Prefecture, Japan

    Directory of Open Access Journals (Sweden)

    Koichi Murakami

    2013-01-01

    Full Text Available The study aimed to evaluate the prevalence of Salmonella in retail and wholesale foods in Fukuoka Prefecture, Japan. A total of 2,021 samples collected between 1999 and 2010 were tested using a culture method. Samples consisted of liquid eggs (n=30, meat (beef and pork (n=781, offal (n=69, processed meats (n=2, seafood (n=232, processed seafood (dried fish (n=76, vegetables (n=481, processed vegetables (n=87, fruits (n=167, and herbs (n=96 from 574 outlets and wholesale agents in 15 areas (five samples were undocumented regarding outlets. Overall, liquid egg showed significantly (P<0.001 higher frequencies of Salmonella contamination (13.3% than beef (1/423, 0.2% and pork (3/235, 1.3%. Salmonella enterica subsp. enterica serovar Enteritidis, the most common serovar as a human pathogen, were isolated from two liquid egg samples. No Salmonella were isolated from seafood and vegetable-related samples including seed sprouts (n=261. In conclusion, liquid egg is a significant Salmonella vehicle, showing a need to continue the vaccination of chickens to prevent S. Enteritidis contamination in Japanese eggs. Moreover, further study is needed to evaluate Salmonella contamination in seed sprouts with more sampling from retailers there.

  17. Salmonella in liquid eggs and other foods in fukuoka prefecture, Japan.

    Science.gov (United States)

    Murakami, Koichi; Noda, Tamie; Onozuka, Daisuke; Sera, Nobuyuki

    2013-01-01

    The study aimed to evaluate the prevalence of Salmonella in retail and wholesale foods in Fukuoka Prefecture, Japan. A total of 2,021 samples collected between 1999 and 2010 were tested using a culture method. Samples consisted of liquid eggs (n = 30), meat (beef and pork) (n = 781), offal (n = 69), processed meats (n = 2), seafood (n = 232), processed seafood (dried fish) (n = 76), vegetables (n = 481), processed vegetables (n = 87), fruits (n = 167), and herbs (n = 96) from 574 outlets and wholesale agents in 15 areas (five samples were undocumented regarding outlets). Overall, liquid egg showed significantly (P < 0.001) higher frequencies of Salmonella contamination (13.3%) than beef (1/423, 0.2%) and pork (3/235, 1.3%). Salmonella enterica subsp. enterica serovar Enteritidis, the most common serovar as a human pathogen, were isolated from two liquid egg samples. No Salmonella were isolated from seafood and vegetable-related samples including seed sprouts (n = 261). In conclusion, liquid egg is a significant Salmonella vehicle, showing a need to continue the vaccination of chickens to prevent S. Enteritidis contamination in Japanese eggs. Moreover, further study is needed to evaluate Salmonella contamination in seed sprouts with more sampling from retailers there.

  18. The Salmonella effector protein SpvC, a phosphothreonine lyase is functional in plant cells

    KAUST Repository

    Neumann, Christina

    2014-10-17

    Salmonella is one of the most prominent causes of food poisoning and growing evidence indicates that contaminated fruits and vegetables are an increasing concern for human health. Successful infection demands the suppression of the host immune system, which is often achieved via injection of bacterial effector proteins into host cells. In this report we present the function of Salmonella effector protein in plant cell, supporting the new concept of trans-kingdom competence of this bacterium. We screened a range of Salmonella Typhimurium effector proteins for interference with plant immunity. Among these, the phosphothreonine lyase SpvC attenuated the induction of immunity-related genes when present in plant cells. Using in vitro and in vivo systems we show that this effector protein interacts with and dephosphorylates activated Arabidopsis Mitogen-activated Protein Kinase 6 (MPK6), thereby inhibiting defense signaling. Moreover, the requirement of Salmonella SpvC was shown by the decreased proliferation of the ΔspvC mutant in Arabidopsis plants. These results suggest that some Salmonella effector proteins could have a conserved function during proliferation in different hosts. The fact that Salmonella and other Enterobacteriaceae use plants as hosts strongly suggests that plants represent a much larger reservoir for animal pathogens than so far estimated.

  19. Technologies and Approaches to Elucidate and Model the Virulence Program of Salmonella.

    Energy Technology Data Exchange (ETDEWEB)

    McDermott, Jason E.; Yoon, Hyunjin; Nakayasu, Ernesto S.; Metz, Thomas O.; Hyduke, Daniel R.; Kidwai, Afshan S.; Palsson, Bernhard O.; Adkins, Joshua N.; Heffron, Fred

    2011-04-01

    Salmonella is a primary cause of enteric diseases in a variety of animals. During its evolution into a pathogenic bacterium, Salmonella acquired an elaborate regulatory network that responds to multiple environmental stimuli within host animals and integrates them resulting in fine regulation of the virulence program. The coordinated action by this regulatory network involves numerous virulence regulators, necessitating genome-wide profiling analysis to assess and combine efforts from multiple regulons. In this review we discuss recent high-throughput analytic approaches to understand the regulatory network of Salmonella that controls virulence processes. Application of high-throughput analyses have generated a large amount of data and driven development of computational approaches required for data integration. Therefore, we also cover computer-aided network analyses to infer regulatory networks, and demonstrate how genome-scale data can be used to construct regulatory and metabolic systems models of Salmonella pathogenesis. Genes that are coordinately controlled by multiple virulence regulators under infectious conditions are more likely to be important for pathogenesis. Thus, reconstructing the global regulatory network during infection or, at the very least, under conditions that mimic the host cellular environment not only provides a bird’s eye view of Salmonella survival strategy in response to hostile host environments but also serves as an efficient means to identify novel virulence factors that are essential for Salmonella to accomplish systemic infection in the host.

  20. High relative humidity pre-harvest reduces post-harvest proliferation of Salmonella in tomatoes.

    Science.gov (United States)

    Devleesschauwer, Brecht; Marvasi, Massimiliano; Giurcanu, Mihai C; Hochmuth, George J; Speybroeck, Niko; Havelaar, Arie H; Teplitski, Max

    2017-09-01

    Outbreaks of human illness caused by enteric pathogens such as Salmonella are increasingly linked to the consumption of fruits and vegetables. Knowledge on the factors affecting Salmonella proliferation on fresh produce therefore becomes increasingly important to safeguard public health. Previous experiments showed a limited impact of pre-harvest production practices on Salmonella proliferation on tomatoes, but suggested a significant effect of harvest time. We explored the data from two previously published and one unpublished experiment using regression trees, which allowed overcoming the interpretational difficulties of classical statistical models with higher order interactions. We assessed the effect of harvest time by explicitly modeling the climatic conditions at harvest time and by performing confirmatory laboratory experiments. Across all datasets, regression trees confirmed the dominant effect of harvest time on Salmonella proliferation, with humidity-related factors emerging as the most important underlying climatic factors. High relative humidity the week prior to harvest was consistently associated with lower Salmonella proliferation. A controlled lab experiment confirmed that tomatoes containing their native epimicrobiota supported significantly lower Salmonella proliferation when incubated at higher humidity prior to inoculation. The complex interactions between environmental conditions and the native microbiota of the tomato crop remain to be fully understood. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Wehnes, C A; Rehberger, T G; Barrangou, R; Smith, A H

    2014-10-01

    Salmonella enterica ssp. enterica is a foodborne pathogen able to cause disease in both humans and animals. Diverse serovars of this pathogen exist, some of which are host specific, causing a range of clinical symptoms from asymptomatic infection through morbidity and mortality. According to a 2007 survey by the USDA National Animal Health Monitoring System, fecal shedding of Salmonella from healthy cows occurs on 39.7% of dairy farms in the United States. Certain serovars are frequently isolated from dairy farms and the majority of isolates from the National Animal Health Monitoring System study were represented by 5 serovars; however, genotypic diversity was not examined. The objective of this study was to determine the diversity of clustered regularly interspaced short palindromic repeats (CRISPR) loci in Salmonella collected from 8 dairy farms with a previous history of salmonellosis. None of the cows or calves sampled on 2 of the 8 dairy farms were shedding Salmonella, although Salmonella was detected in a cow bedding sample on 1 of these farms. Salmonella populations were discrete on each farm, according to CRISPR typing, with the exception of an Anatum var. 15+ type on farms 5 and 6 and the Montevideo type on farms 1 and 2. One to 4 distinct CRISPR genotypes were identified per farm. The CRISPR typing differed within serovars, as Montevideo, Anatum var. 15+, and Muenster serovars had no overlap of spacer content, even on the same farm, reflecting between- and within-serovar genetic diversity. The dynamic nature of Salmonella populations was shown in a farm that was sampled longitudinally over 13.5 mo. Changes in serovar from 3,19:-:z27 to Montevideo was observed between the first sampling time and 8 mo later, with concomitant change in CRISPR alleles. The results indicate that Salmonella strains present in smaller dairy herds (<500 head) are specific to that farm and new Salmonella strains may emerge over time. Copyright © 2014 American Dairy Science

  2. Salmonella Typhimurium transcription profiles in space flight

    Data.gov (United States)

    National Aeronautics and Space Administration — Salmonella transcription profiles were obtained from samples flown on space shuttle mission STS-115 and compared to profiles from Salmonella grown under identical...

  3. Assessment of Consumer Exposure to Salmonella spp., Campylobacter spp., and Shiga Toxin-Producing Escherichia coli in Meat Products at Retail in the City of Sao Paulo, Brazil.

    Science.gov (United States)

    Ristori, Christiane Asturiano; Rowlands, Ruth Estela Gravato; Martins, Cecília Geraldes; Barbosa, Maria Luisa; Dos Santos, Luis Fernando; Jakabi, Miyoko; de Melo Franco, Bernadette Dora Gombossy

    2017-08-01

    Meat products may be vehicles of bacterial pathogens to humans, and Salmonella spp., Campylobacter spp., and Shiga toxin-producing Escherichia coli (STEC) are the most relevant. The aim of this study was to generate data on prevalence of these three pathogens in 552 samples of meat products (hot dogs, pork sausages, raw ground beef, and raw chicken legs) sold at retail in the city of Sao Paulo, Brazil. Salmonella spp. was detected in 5.8% (32/552) of samples, comprising pork sausages 62.5% (20/32) and chicken legs 37.5% (12/32). The counts of Salmonella spp. were low, ranging from Salmonella Typhimurium (28.1%), Salmonella I 4,[5],12:i:- (15.6%), Salmonella Enteritidis (12.5%), Salmonella Derby, and Salmonella Brandenburg (9.4%). Campylobacter spp. was detected in 33 samples (6.0%), comprising chicken legs (82%) and ground beef (18%). All samples were negative for STEC. These results suggest that meat products when subjected to inadequate cooking and/or cross-contamination with other products ready for consumption can lead to occurrence of outbreaks, highlighting the risks associated with them.

  4. Quantification of contamination levels and particular risk of Salmonella spp. in pigs in slaughterhouses in Chiang Mai and Lamphun provinces, Thailand.

    Science.gov (United States)

    Tadee, Pakpoom; Boonkhot, Phacharaporn; Patchanee, Prapas

    2014-11-01

    Salmonella spp. is one of the important foodborne pathogens, and the slaughtering process is recognized as a potential point of contamination and the spread of the pathogens. The three objectives of this study are first, to quantify the contamination levels of Salmonella spp. in pig skins and carcasses, second, to evaluate the outcomes from different pig supply sources and different practices at three critical steps (scalding, splitting, and washing) for Salmonella spp. contamination, and third, to assess risk of Salmonella spp. contamination in pork products after slaughtering level. The study was performed in three representative slaughterhouses in Chiang Mai and Lamphun provinces, Thailand. Investigation conducted from May 2013 through October 2013 found the overall prevalence and contamination levels mean to be 11.85% and 0.34 MPN/cm2, respectively. There was no statistically significant in Salmonella spp. prevalence and contamination levels detected with different patterns at the slaughterhouses which were supplied pigs from either co-operative or integrated farms. Factors found to reduce Salmonella spp. loads on carcasses included good practices, e.g., regular changing of water in the scalding tank after each batch and the use of chlorine in the washing step. Risk of Salmonella spp. contamination of pork products at the final stage of slaughtering was nearly 10%. Good practices and proper hygiene measures should be applied to minimize the risk of Salmonella spp. exposure in the slaughtering line, which can reduce the contamination pressure downstream at retail shops as well as for end consumers.

  5. Yerba mate enhances probiotic bacteria growth in vitro but as a feed additive does not reduce Salmonella Enteritidis colonization in vivo.

    Science.gov (United States)

    Gonzalez-Gil, Francisco; Diaz-Sanchez, Sandra; Pendleton, Sean; Andino, Ana; Zhang, Nan; Yard, Carrie; Crilly, Nate; Harte, Federico; Hanning, Irene

    2014-02-01

    Yerba mate (Ilex paraguariensis) is a tea known to have beneficial effects on human health and antimicrobial activity against some foodborne pathogens. Thus, the application of yerba mate as a feed additive for broiler chickens to reduce Salmonella colonization was evaluated. The first in vitro evaluation was conducted by suspending Salmonella Enteritidis and lactic acid bacteria (LAB) in yerba mate extract. The in vivo evaluations were conducted using preventative and horizontal transmission experiments. In all experiments, day-of-hatch chicks were treated with one of the following 1) no treatment (control); 2) ground yerba mate in feed; 3) probiotic treatment (Lactobacillus acidophilus and Pediococcus; 9:1 administered once on day of hatch by gavage); or 4) both yerba mate and probiotic treatments. At d 3, all chicks were challenged with Salmonella Enteritidis (preventative experiment) or 5 of 20 chicks (horizontal transmission experiment). At d 10, all birds were euthanized, weighed, and cecal contents enumerated for Salmonella. For the in vitro evaluation, antimicrobial activity was observed against Salmonella and the same treatment enhanced growth of LAB. For in vivo evaluations, none of the yerba mate treatments significantly reduced Salmonella Enteritidis colonization, whereas the probiotic treatment significantly reduced Salmonella colonization in the horizontal transmission experiment. Yerba mate decreased chicken BW and decreased the performance of the probiotic treatment when used in combination. In conclusion, yerba mate had antimicrobial activity against foodborne pathogens and enhanced the growth of LAB in vitro, but in vivo yerba mate did not decrease Salmonella Enteritidis colonization.

  6. Comparative study of the protective capacity against Salmonella infection between probiotic and nonprobiotic Lactobacilli.

    Science.gov (United States)

    Castillo, N A; de Moreno de LeBlanc, A; M Galdeano, C; Perdigón, G

    2013-03-01

    To investigate the immunoprotective ability of three Lactobacilli strains against Salmonella enterica serovar Typhimurium in a mouse model. To identify the probiotic properties involved in the protection against infection caused by this pathogen. The immunomodulatory effect of three different lactobacilli strains: Lactobacillus (Lact.) casei CRL 431 (probiotic bacterium), Lact. delbrueckii subsp. bulgaricus CRL 423 (Lact. bulgaricus) and Lact.acidophilus CRL 730 was compared using a mouse model of Salmonella infection. Lactobacillus casei continuous administration improved animal survival, diminished pathogen spreading outside the intestine, attenuated the intestinal inflammation, modulated cytokine profile previous and postinfection and increased the expression and secretion of IgA in the gut. Additionally, the administration of this lactobacilli increased peritoneal, Peyer's patches and spleen macrophages' phagocytic activity in healthy mice and monocyte chemotactic protein (MCP-1) released by intestinal epithelial cells in an in vitro assay. Although Lact. acidophilus increased the number of IgA-secreting cells previous and postinfection, and Lact. bulgaricus increased MCP-1 released by intestinal epithelial cells and the phagocytic activity of macrophages, these effects alone were not enough to confer protection against Salmonella Typhimurium infection in mouse. Probiotic strain Lact. casei CRL 431 was the one that induced protection against Salmonella, by increasing the intestinal barrier function and by decreasing the local inflammatory response. Salmonella spp. constitutes an important agent of foodborne diseases in the world. Not all lactobacilli, even with some immunostimulating properties at gut level, can protect against Salmonella infection. Lactobacillus casei CRL 431, a probiotic bacterium, could be useful as an oral mucosal adjuvant of the immune system to improve gut health, especially in the prevention or amelioration of Salmonella infections. We

  7. Cold plasma inactivation of human pathogens on foods and regulatory status update

    Science.gov (United States)

    Contamination of foods with human pathogens such as Salmonella, Listeria monocytogenes, Escherichia coli O157:H7, norovirus, and other pathogens is an ongoing challenge for growers and processors. In recent years, cold plasma has emerged as a promising antimicrobial treatment for fresh and fresh-cut...

  8. Prebiotics in food animals, a potential to reduce foodborne pathogens and disease

    Science.gov (United States)

    Animals can be seriously impacted by bacterial pathogens that affect their growth efficiency and overall health, as well as food safety of animal-derived products. Some pathogenic bacteria, such as Salmonella, can be a shared problem for both human and animal health and can be found in many animal ...

  9. Prebiotics in food animals: A potential to reduce foodborne pathogens and disease

    Science.gov (United States)

    Animals can be seriously impacted by bacterial pathogens that affect their growth efficiency and overall health, as well as food safety of animal-derived products. Some pathogenic bacteria, such as Salmonella, can be a shared problem for both human and animal health and can be found in many animal ...

  10. Methods for detecting pathogens in the beef food chain: an overview

    Science.gov (United States)

    The main food-borne pathogens of concern in the beef chain are Shiga toxin-producing Escherichia coli (STEC) and Salmonella. Other pathogens, including Listeria monocytogenes and Campylobacter spp. may also be present and pose contamination concerns in both the cattle production environment and bee...

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

    Directory of Open Access Journals (Sweden)

    Dione, M.

    2010-01-01

    Full Text Available Non-Typhoidal Salmonella (NTS species are important food-borne pathogens. Although acute gastroenteritis is the most common clinical symptom, complications can occur resulting in bacteraemia with or without focal infections. Food products, especially food of animal origin such as poultry are associated with the transmission to humans. In Africa, NTS are among the most common cause of bloodstream infections in children younger than 5 years. Epidemiological data on NTS are lacking in Africa both for human and animal infections. Therefore, a study providing a better understanding of the factors that lead to the emergence of NTS is a prerequisite for the design of improved intervention strategies to control these pathogens. The aim of this thesis was to study the epidemiology of NTS pathogens in humans and animals in The Gambia and Senegal. Chapter 1 reviews the current status of knowledge on NTS infections in Africa with focus on The Gambia and Senegal. It also provides the background against which these studies were conducted. Chapter 2 describes the prevalence of NTS along the poultry production chain in Casamance, Senegal. Fifty seven randomly selected broiler farms, 42 street restaurants and 285 chicken carcasses were studied. The following farm prevalences were reported: 35.1, 38.6 and 29.8% in chicken faeces, on carcass skin, and in muscles, respectively. NTS were found in chicken meat servings of 14.3% of the 42 street restaurants and in 40.4% of the 285 chicken carcasses examined. The most prevalent serotypes among the eighteen identified were Salmonella Brancaster (57.9%, Salmonella Goelzau (10.7%, Salmonella Kentucky (8.4%, and Salmonella Hadar (7.3%. The following serotypes were for the first time identified in Senegal: Salmonella Bandia, Salmonella Bessi, Salmonella Brunei, Salmonella Hull, Salmonella Istanbul, Salmonella Javiana, Salmonella Magherafelt, Salmonella Molade, Salmonella oxford, Salmonella Poona, Salmonella Rubislaw

  12. Potassium transport of Salmonella is important for type III secretion and pathogenesis

    Science.gov (United States)

    Liu, Yehao; Ho, Katharina Kim; Su, Jing; Gong, Hao; Chang, Alexander C.

    2013-01-01

    Intracellular cations are essential for the physiology of all living organisms including bacteria. Cations such as potassium ion (K+), sodium ion (Na+) and proton (H+) are involved in nearly all aspects of bacterial growth and survival. K+ is the most abundant cation and its homeostasis in Escherichia coli and Salmonella is regulated by three major K+ transporters: high affinity transporter Kdp and low affinity transporters Kup and Trk. Previous studies have demonstrated the roles of cations and cation transport in the physiology of Escherichia coli; their roles in the virulence and physiology of pathogenic bacteria are not well characterized. We have previously reported that the Salmonella K+ transporter Trk is important for the secretion of effector proteins of the type III secretion system (TTSS) of Salmonella pathogenicity island 1 (SPI-1). Here we further explore the role of Salmonella cation transport in virulence in vitro and pathogenesis in animal models. Impairment of K+ transport through deletion of K+ transporters or exposure to the chemical modulators of cation transport, gramicidin and valinomycin, results in a severe defect in the TTSS of SPI-1, and this defect in the TTSS was not due to a failure to regulate intrabacterial pH or ATP. Our results also show that K+ transporters are critical to the pathogenesis of Salmonella in mice and chicks and are involved in multiple growth and virulence characteristics in vitro, including protein secretion, motility and invasion of epithelial cells. These results suggest that cation transport of the pathogenic bacterium Salmonella, especially K+ transport, contributes to its virulence in addition to previously characterized roles in maintaining homeostasis of bacteria. PMID:23728623

  13. Modeling the survival of Salmonella Enteritidis and Salmonella Typhimurium during the fermentation of yogurt.

    Science.gov (United States)

    Savran, Derya; Pérez-Rodríguez, Fernando; Halkman, A Kadir

    2018-03-01

    The objective of this study was to evaluate the behavior of Salmonella Enteritidis and Salmonella Typhimurium, the two most important serovars of salmonellosis , during the fermentation of yogurt. The microorganisms were enumerated in milk throughout the fermentation process at three initial inoculum levels (3, 5 and 7 log CFU/mL). DMFit software was used in the fitting procedure of the data (IFR, Norwich, UK, Version 3.5). The data provided sigmoidal curves that were successfully displayed with the Baranyi model. The results showed that the initial inoculum level did not affect the growth for both pathogens; thus, the µ max values (maximum specific growth rate) did not significantly differ across all the contamination levels, ranging from 0.26 to 0.38 for S. Enteritidis and from 0.50 to 0.56 log CFU/g/h for S. Typhimurium ( P > 0.05). However, the µ max values significantly differed between the two serovars ( P fermentation process of milk even at a low contamination level. In addition, the models presented in this study can be used in quantitative risk assessment studies to estimate the threat to consumers.

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

    Science.gov (United States)

    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.

  15. Prevalence and Characterization of Motile Salmonella in Commercial Layer Poultry Farms in Bangladesh

    Science.gov (United States)

    Barua, Himel; Biswas, Paritosh K.; Olsen, Katharina E. P.; Christensen, Jens P.

    2012-01-01

    Salmonella is a globally widespread food-borne pathogen having major impact on public health. All motile serovars of Salmonella enterica of poultry origin are zoonotic, and contaminated meat and raw eggs are an important source to human infections. Information on the prevalence of Salmonella at farm/holding level, and the zoonotic serovars circulating in layer poultry in the South and South-East Asian countries including Bangladesh, where small-scale commercial farms are predominant, is limited. To investigate the prevalence of Salmonella at layer farm level, and to identify the prevalent serovars we conducted a cross-sectional survey by randomly selecting 500 commercial layer poultry farms in Bangladesh. Faecal samples from the selected farms were collected following standard procedure, and examined for the presence of Salmonella using conventional bacteriological procedures. Thirty isolates were randomly selected, from the ninety obtained from the survey, for serotyping and characterized further by plasmid profiling and pulsed-field gel electrophoresis (PFGE). Results of the survey showed that the prevalence of motile Salmonella at layer farm level was 18% (95% confidence interval 15–21%), and Salmonella Kentucky was identified to be the only serovar circulating in the study population. Plasmid analysis of the S. Kentucky and non-serotyped isolates revealed two distinct profiles with a variation of two different sizes (2.7 and 4.8 kb). PFGE of the 30 S. Kentucky and 30 non-serotyped isolates showed that all of them were clonally related because only one genotype and three subtypes were determined based on the variation in two or three bands. This is also the first report on the presence of any specific serovar of Salmonella enterica in poultry in Bangladesh. PMID:22558269

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

    Directory of Open Access Journals (Sweden)

    Ana Andino

    2014-08-01

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

  17. Survival of Salmonella spp. and fecal indicator bacteria in Vietnamese biogas digesters receiving pig slurry.

    Science.gov (United States)

    Huong, Luu Quynh; Forslund, Anita; Madsen, Henry; Dalsgaard, Anders

    2014-09-01

    Small-scale biogas digesters are widely promoted worldwide as a sustainable technology to manage livestock manure. In Vietnam, pig slurry is commonly applied to biogas digesters for production of gas for electricity and cooking with the effluent being used to fertilize field crops, vegetables and fish ponds. Slurry may contain a variety of zoonotic pathogens, e.g. Salmonella spp., which are able to cause disease in humans either through direct contact with slurry or by fecal contamination of water and foods. The objective of this study was to evaluate the survival of Salmonella spp. and the fecal indicator bacteria, enterococci, E. coli, and spores of Clostridium perfringens in biogas digesters operated by small-scale Vietnamese pig farmers. The serovar and antimicrobial susceptibility of the Salmonella spp. isolated were also established. The study was conducted in 12 farms (6 farms with and 6 farms without toilet connected) located in Hanam province, Vietnam. Sampling of pig slurry and biogas effluent was done during two seasons. Results showed that the concentration of enterococci, E. coli, and Clostridium perfringens spores was overall reduced by only 1-2 log10-units in the biogas digesters when comparing raw slurry and biogas effluent. Salmonella spp. was found in both raw slurry and biogas effluent. A total of 19 Salmonella serovars were identified, with the main serovars being Salmonella Typhimurium (55/138), Salmonella enterica serovar 4,[5],12:i:- (19/138), Salmonella Weltevreden (9/138) and Salmonella Rissen (9/138). The Salmonella serovars showed similar antimicrobial resistance patterns to those previously reported from Vietnam. When promoting biogas, farmers should be made aware that effluent should only be used as fertilizer for crops not consumed raw and that indiscriminate discharge of effluent are likely to contaminate water recipients, e.g. drinking water sources, with pathogens. Relevant authorities should promote safe animal manure management

  18. Evaluation of respiratory route as a viable portal of entry for Salmonella in poultry

    Directory of Open Access Journals (Sweden)

    Kallapura G

    2014-08-01

    Full Text Available Gopala Kallapura,1 Xochitl Hernandez-Velasco,2 Neil R Pumford,1 Lisa R Bielke,1 Billy M Hargis,1 Guillermo Tellez1 1Department of Poultry Science, University of Arkansas, Fayetteville, AR, USA; 2College of Veterinary Medicine and Animal Husbandry, The National Autonomous University of Mexico, Mexico Abstract: With increasing reports of Salmonella infection, we are forced to question whether the fecal–oral route is the major route of infection and consider the possibility that airborne Salmonella infections might have a major unappreciated role. Today's large-scale poultry production, with densely stocked and enclosed production buildings, is often accompanied by very high concentrations of airborne microorganisms. Considering that the upper and lower respiratory lymphoid tissue requires up to 6 weeks to be fully developed, these immune structures seem to have a very minor role in preventing pathogen infection. In addition, the avian respiratory system in commercial poultry has anatomic and physiologic properties that present no challenge to the highly adapted Salmonella. The present review evaluates the hypothesis that transmission by the fecal–respiratory route may theoretically be a viable portal of entry for Salmonella in poultry. First, we update the current knowledge on generation of Salmonella bioaerosols, and the transport and fate of Salmonella at various stages of commercial poultry production. Further, emphasis is placed on survivability of Salmonella in these bioaerosols, as a means to assess the transport and subsequent risk of exposure and infection of poultry. Additionally, the main anatomic structures, physiologic functions, and immunologic defense in the avian respiratory system are discussed to understand the potential entry points inherent in each component that could potentially lead to infection and subsequent systemic infection of poultry by Salmonella. In this context, we also evaluate the role of the mucosal immune

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

    Directory of Open Access Journals (Sweden)

    Md. Shafiullah Parvej

    2016-01-01

    Full Text Available Aim: Salmonella is an important zoonotic pathogen responsible for animal and human diseases. The aim of the present study was to determine the prevalence and stereotyping of Salmonella isolates isolated from apparently healthy poultry. Furthermore, the clonal relatedness among the isolated Salmonella serovars was assessed. Materials and Methods: A total of 150 cloacal swab samples from apparently healthy chickens were collected, and were subjected for the isolation and identification of associated Salmonella organisms. The isolated colonies were identified and characterized on the basis of morphology, cultural characters, biochemical tests, slide agglutination test, polymerase chain reaction, and pulsed-field gel electrophoresis (PFGE. Antibiotic sensitivity patterns were also investigated using commonly used antibiotics. Results: Of the 150 samples, 11 (7.33% produced characteristics pink colony with black center on XLD agar medium, and all were culturally and biochemically confirmed to be Salmonella. All possessed serovar-specific gene SpeF and reacted uniformly with group D antisera, suggesting that all of the isolates were Salmonella Enterica serovar Gallinarum, biovar Pullorum and/or Gallinarum. Antimicrobial susceptibility testing revealed that 54.54% of the isolated Salmonella Enterica serovars were highly sensitive to ciprofloxacin, whereas the 81.81% isolates were resistant to amoxycillin, doxycycline, kanamycin, gentamycin, and tetracycline. Pulsed-field gel electrophoresis of the XbaI-digested genomic DNA exhibited identical banding patterns, suggesting that the multidrug resistant Salmonella Enterica serovars occurring in commercial layers are highly clonal in Bangladesh. Conclusion: The present study was conducted to find out the prevalence of poultry Salmonella in layer chicken and to find out the clonal relationship among them. The data in this study suggest the prevalence of Salmonella Enterica, which is multidrug resistant and

  20. Impact of Clinical Salmonellosis in Veal Calves on the Recovery of Salmonella in Lymph Nodes at Harvest.

    Science.gov (United States)

    Muñoz-Vargas, Lohendy; Finney, Sarah K; Hutchinson, Holden; Masterson, Margaret A; Habing, Greg

    2017-11-01

    The objective of this study was to determine the prevalence, serotypes, antimicrobial resistance phenotypes, and pulsed-field gel electrophoresis (PFGE) patterns of Salmonella recovered in feces and mesenteric and prefemoral lymph nodes (LNs) from cohorts of calves with and without a confirmed outbreak of salmonellosis. In a prospective cohort study, 160 calves from four farms without a reported outbreak (nonoutbreak farms) were sampled at farm and harvest. In addition, harvest samples from 80 calves of two farms with a confirmed outbreak (outbreak farms) were collected. A culture protocol for Salmonella isolation was applied for all samples and recovered isolates were further characterized by serotyping, antimicrobial susceptibility testing, and PFGE. Among nonoutbreak farms, Salmonella was recovered from 0% (0/160) farm fecal samples, 3.7% (6/160) harvest fecal swabs, 21.9% (35/160) mesenteric LNs, and 0.6% (1/160) prefemoral LNs. Serotypes identified in nonoutbreak herds included Salmonella Typhimurium, Cerro, Hartford, and Newport. Most isolates (64.3%, 27/42) exhibited a unique multidrug-resistant (MDR) phenotype, including resistance to extended-spectrum cephalosporins. Salmonella prevalence in harvest fecal samples and prefemoral LNs among calves from outbreak farms was numerically higher, but not significantly different than those without an outbreak. Serotypes recovered from outbreak farms included Salmonella Heidelberg and Typhimurium, and the monophasic Salmonella Typhimurium strains 4,5,12:i:- and 4,12:i:-, which have been also reported as highly pathogenic in humans. All isolates (33/33) exhibited an MDR phenotype. Salmonella strains recovered from ill calves in two outbreaks had indistinguishable PFGE patterns, suggesting between-farm transmission. In addition, the genotype of Salmonella Heidelberg causing an outbreak among calves was recovered from three prefemoral LNs of surviving members of the cohort at harvest. Implementation of preharvest

  1. [Analysis of Pathogenic Bacteria in Reclaimed Water and Impact of UV Disinfection on the Removal of Pathogenic Bacteria].

    Science.gov (United States)

    Jing, Ming; Wang, Lei

    2016-02-15

    In the study, 454-pyrosequencing technology was employed to investigate the species of pathogenic bacteria and the proportion of each pathogen in secondary effluent. Culture-based, qPCR and Q-RT-PCR methods were employed to analyze the removal of indicator (E. coli) and pathogen (Salmonella and Mycobacterium) by ultraviolet (UV) disinfection at a dose of 60 mJ x Cm(-2). The results showed that 11 kinds of pathogenic bacteria were found and the most abundant potentially pathogenic bacteria in the secondary effluent were affiliated with the genera of Clostridium (2.96%), Arcobacter (0.82%) and Mycobacterium (0.36%). 99.9% of culturable E. coli and Salmonella were removed by UV disinfection (60 mJ x cm(-2), however, less than 90% of culturable Mycobacterium were removed. The removal efficiencies of viable E. coli, Salmonella and Mycobacterium were low. Q-RT-PCR seemed to be a promising method for evaluating viable microorganisms in samples. Besides, pathogenic bacteria entered into VBNC state at a UV dose of 60 mJ x cm(-2). Other advanced treatment processes were needed to ensure safe utilization of reclaimed water.

  2. Salmonella and Campylobacter biofilm formation: a comparative assessment from farm to fork.

    Science.gov (United States)

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

    2018-02-09

    It takes several steps to bring food from the farm to the fork (dining table), and contamination with food-borne pathogens can occur at any point in the process. Campylobacter spp. and Salmonella spp. are the main microorganisms responsible for foodborne disease in the EU. These two pathogens are able to persist throughout the food supply chain thanks to their ability to form biofilms. Owing to the high prevalence of Salmonella and especially of Campylobacter in the food supply chain and the huge efforts of food authorities to reduce these levels, it is of great importance to fully understand their mechanisms of persistence. Diverse studies have evaluated the biofilm-forming capacity of foodborne pathogens isolated at different steps of food production. Nonetheless, the principal obstacle of these studies is to reproduce the real conditions that microorganisms encounter in the food supply chain. While there are a wide number of Salmonella biofilm studies, information on Campylobacter biofilms is still limited. A comparison between the two microorganisms could help to develop new research in the field of Campylobacter biofilms. Therefore, this review evaluates relevant work in the field of Salmonella and Campylobacter biofilms and the applicability of the data obtained from these studies to real working conditions. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

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

    DEFF Research Database (Denmark)

    Jelsbak, Lotte; Thomsen, Line Elnif; Wallrodt, Inke

    2012-01-01

    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...

  4. Impact of relative humidity, inoculum carrier and size, and native microbiota on Salmonella ser. Typhimurium survival in baby lettuce.

    Science.gov (United States)

    López-Gálvez, Francisco; Gil, Maria Isabel; Allende, Ana

    2018-04-01

    The effects of relative humidity (RH), fluctuating climate conditions, inoculum size and carrier on the survival of Salmonella enterica serovar Typhimurium on baby lettuce in environmental test chambers were studied. Buffered peptone water (BPW), distilled water (DW), and irrigation water (IW) were compared as inoculum carriers. Additionally, survival of Salmonella in suspensions prepared using filtered and unfiltered IW was assessed. Salmonella Typhimurium survived better on baby lettuce plants at high RH independently of the inoculum size. When lettuce plants were grown under fluctuating environmental conditions, Salmonella survival was similar under both RH conditions. Regarding the inoculum carrier, the inoculated microorganism survived better on lettuce plants when BPW was used as carrier both at high and low RH. Survival rate of Salmonella in IW was affected by the presence of native microbiota. Native microbiota present in IW did not affect survival of Salmonella or the levels of mesophilic bacteria on the baby lettuce leaves. The information obtained in the present study contributes to the knowledge on the effect of environmental conditions on pathogenic bacteria survival on growing edible plants. These results are useful when selecting the methodology to carry out experimental studies on the survival of microbial pathogens under different pre-harvest conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Biofilm Formation Protects Salmonella from the Antibiotic Ciprofloxacin In Vitro and In Vivo in the Mouse Model of chronic Carriage.

    Science.gov (United States)

    González, Juan F; Alberts, Halley; Lee, Joel; Doolittle, Lauren; Gunn, John S

    2018-01-09

    Typhoid fever is caused by the human-restricted pathogen Salmonella enterica sv. Typhi. Approximately 5% of people that resolve the disease become chronic carriers, with the gallbladder as the main reservoir of the bacteria. Of these, about 90% present with gallstones, on which Salmonella form biofilms. Because S. Typhi is a human-restricted pathogen, these carriers are the main source of dissemination of the disease; unfortunately, antibiotic treatment has shown to be an ineffective therapy. This is believed to be caused by the inherent antibiotic resistance conferred by Salmonella biofilms growing on gallstones. The gallstone mouse model with S. Typhimurium has proven to be an excellent surrogate for S. Typhi chronic infection. In this study, we test the hypothesis that the biofilm state confers Salmonella with the increased resistance to antibiotics observed in cases of chronic carriage. We found that, in the biofilm state, Salmonella is significantly more resistant to ciprofloxacin, a common antibiotic used for the treatment of Salmonella, both in vitro (p < 0.001 for both S. Typhi and S. Typhimurium with respect to planktonic cells) and in vivo (p = 0.0035 with respect to control mice).

  6. Quantification of viable but nonculturable Salmonella spp. and Shigella spp. during sludge anaerobic digestion and their reactivation during cake storage.

    Science.gov (United States)

    Fu, B; Jiang, Q; Liu, H-B; Liu, H

    2015-10-01

    The presence of viable but nonculturable (VBNC) bacterial pathogens which often fail to be detected by cultivation and can regain the cultivability if the living conditions improve were reported. The objective of this study was to determine the occurrence of VBNC Salmonella spp. and Shigella spp. in the biosolids during anaerobic digestion and its reactivation during the cake storage. The occurrence of VBNC Salmonella spp. and Shigella spp. during mesophilic, temperature-phased, thermophilic anaerobic digestion of sewage sludge and the subsequent storage were studied by RT-qPCR and most probable number (MPN) method. The VBNC incidence of Salmonella spp. and Shigella spp. during thermophilic digestion was four orders of magnitude higher than those of mesophilic digestion. Accordingly, higher resuscitation ratio of VBNC pathogens was also achieved in thermophilic digested sludge. As a result, the culturable Salmonella typhimurium contents in thermophilic digested sludge after cake storage were two orders of magnitude higher than mesophilic digestion. Both quantitative PCR and reverse transcription quantitative PCR assay results showed the two bacterial counting numbers remained stable throughout the cake storage. The results indicate that the increase in the culturable Salmonella spp. and Shigella spp. after centrifugal dewatering was attributed to the resuscitation from the VBNC state to the culturable state. Thermophilic anaerobic digestion mainly induced Salmonella spp. and Shigella spp. into VBNC state rather than killed them, suggesting that the biological safety of sewage sludge by temperature-phased anaerobic digestion should be carefully assessed. © 2015 The Society for Applied Microbiology.

  7. Detection of Salmonella in Meat

    DEFF Research Database (Denmark)

    Löfström, Charlotta; Hansen, Flemming; Mansdal, Susanne

    2012-01-01

    Cost-effective and rapid monitoring of Salmonella in the meat production chain can contribute to food safety. The objective of this study was to validate an easy-to-use pre-PCR sample preparation method based on a simple boiling protocol for screening of Salmonella in meat and carcass swab samples...... obtained (SP, SE, and AC were 100, 95, and 97%, respectively). This test is under implementation by the Danish meat industry, and can be useful for screening of large number of samples in the meat production, especially for fast release of minced meat with a short shelf life....

  8. Effects of transparent exopolymer particles and suspended particles on the survival of Salmonella enterica serovar Typhimurium in seawater.

    Science.gov (United States)

    Davidson, Marion C F; Berardi, Terra; Aguilar, Beatriz; Byrne, Barbara A; Shapiro, Karen

    2015-03-01

    The bacterium Salmonella enterica can infect marine mammals and has been increasingly implicated in seafood-borne disease outbreaks in humans. Despite the risk this zoonotic agent poses to animals and people, little is known regarding the environmental factors that affect its persistence in the sea. The goal of this study was to evaluate the impact of two constituents on the survival of Salmonella in the marine environment: transparent exopolymer particles (TEP) and suspended particles. A decay experiment was conducted by spiking Salmonella into bottles containing seawater, seawater with alginic acid as a source of TEP, filtered seawater or filtered seawater with alginic acid. Survival of Salmonella was monitored using culture followed by enrichment assays to evaluate if the bacteria entered a viable but non-cultivable (VBNC) state. Salmonella cell counts dropped significantly faster (P ≤ 0.05) in the unfiltered seawater samples with and without TEP. The slowest decay occurred in filtered seawater containing alginic acid, with VBNC Salmonella persisting for 17 months. These findings suggest that TEP may favor Salmonella survival while suspended particles facilitate its decay. Insight on the survival of allochthonous, zoonotic pathogens in seawater can guide monitoring, management and policy decisions relevant to wildlife and human public health. © FEMS 2015. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Prevalence and susceptibility of salmonella Typhi and salmonella ...

    African Journals Online (AJOL)

    Methods: Blood samples collected from presumptive typhoid fever patients from Ahmadu Bello University (ABU), Federal College of Education (FCE) and presumptive typhoid fever patients that attended two private clinics (Salama Clinics and Savanna Polyclinics) in Zaria were cultured for Salmonella species and identified ...

  10. Pathogen intelligence

    Directory of Open Access Journals (Sweden)

    Michael eSteinert

    2014-01-01

    Full Text Available Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behaviour, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behaviour, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies.

  11. Isolation, Characterization, and Application of Bacteriophage LPSE1 Against Salmonella enterica in Ready to Eat (RTE Foods

    Directory of Open Access Journals (Sweden)

    Chenxi Huang

    2018-05-01

    Full Text Available Salmonella infection is an important foodborne consumer health concern that can be mitigated during food processing. Bacteriophage therapy imparts many advantages over conventional chemical preservatives including pathogen specificity, natural derivation, potency, and providing a high degree of safety. The objective of this study aimed to isolate and characterize a phage that effectively control Salmonella food contamination. Out of 35 isolated phages, LPSE1 demonstrated a broad Salmonella host range, robust lytic ability, extensive pH tolerance, and prolonged thermal stability. The capacity for phage LPSE1 to control Salmonella Enteritidis-ATCC13076 in milk, sausage, and lettuce was established. Incubation of LPSE1 at 28°C in milk reduced recoverable Salmonella by approximately 1.44 log10 CFU/mL and 2.37 log10 CFU/mL at MOI of 1 and 100, respectively, as relative to the phage-excluded control. Upon administration of LPSE1 at an MOI of 1 in sausage, Salmonella count decreased 0.52 log10 at 28°C. At MOI of 100, the count decreased 0.49 log10 at 4°C. Incubation of LPSE1 on lettuce reduced recoverable Salmonella by 2.02 log10, 1.71 log10, and 1.45 log10 CFU/mL at an MOI of 1, 10, and 100, respectively, as relative to the negative control. Taken together, these findings establish LPSE1 as an effective weapon against human pathogenic Salmonella in various ready to eat foods.

  12. Typhoid toxin provides a window into typhoid fever and the biology of Salmonella Typhi.

    Science.gov (United States)

    Galán, Jorge E

    2016-06-07

    Salmonella Typhi is the cause of typhoid fever, a disease that has challenged humans throughout history and continues to be a major public health concern. Unlike infections with most other Salmonellae, which result in self-limiting gastroenteritis, typhoid fever is a life-threatening systemic disease. Furthermore, in contrast to most Salmonellae, which can infect a broad range of hosts, S. Typhi is a strict human pathogen. The unique features of S. Typhi pathogenesis and its stringent host specificity have been a long-standing puzzle. The discovery of typhoid toxin not only has provided major insight into these questions but also has offered unique opportunities to develop novel therapeutic and prevention strategies to combat typhoid fever.

  13. Human genetic variation in VAC14 regulates Salmonella invasion and typhoid fever through modulation of cholesterol.

    Science.gov (United States)

    Alvarez, Monica I; Glover, Luke C; Luo, Peter; Wang, Liuyang; Theusch, Elizabeth; Oehlers, Stefan H; Walton, Eric M; Tram, Trinh Thi Bich; Kuang, Yu-Lin; Rotter, Jerome I; McClean, Colleen M; Chinh, Nguyen Tran; Medina, Marisa W; Tobin, David M; Dunstan, Sarah J; Ko, Dennis C

    2017-09-12

    Risk, severity, and outcome of infection depend on the interplay of pathogen virulence and host susceptibility. Systematic identification of genetic susceptibility to infection is being undertaken through genome-wide association studies, but how to expeditiously move from genetic differences to functional mechanisms is unclear. Here, we use genetic association of molecular, cellular, and human disease traits and experimental validation to demonstrate that genetic variation affects expression of VAC14, a phosphoinositide-regulating protein, to influence susceptibility to Salmonella enterica serovar Typhi ( S Typhi) infection. Decreased VAC14 expression increased plasma membrane cholesterol, facilitating Salmonella docking and invasion. This increased susceptibility at the cellular level manifests as increased susceptibility to typhoid fever in a Vietnamese population. Furthermore, treating zebrafish with a cholesterol-lowering agent, ezetimibe, reduced susceptibility to S Typhi. Thus, coupling multiple genetic association studies with mechanistic dissection revealed how VAC14 regulates Salmonella invasion and typhoid fever susceptibility and may open doors to new prophylactic/therapeutic approaches.

  14. Concomitant uptake of antimicrobials and Salmonella in soil and into lettuce following wastewater irrigation.

    Science.gov (United States)

    Sallach, J Brett; Zhang, Yuping; Hodges, Laurie; Snow, Daniel; Li, Xu; Bartelt-Hunt, Shannon

    2015-02-01

    The use of wastewater for irrigation may introduce antimicrobials and human pathogens into the food supply through vegetative uptake. The objective of this study was to investigate the uptake of three antimicrobials and Salmonella in two lettuce cultivars. After repeated subirrigation with synthetic wastewater, lettuce leaves and soil were collected at three sequential harvests. The internalization frequency of Salmonella in lettuce was low. A soil horizon-influenced Salmonella concentration gradient was determined with concentrations in bottom soil 2 log CFU/g higher than in top soil. Lincomycin and sulfamethoxazole were recovered from lettuce leaves at concentrations as high as 822 ng/g and 125 ng/g fresh weight, respectively. Antimicrobial concentrations in lettuce decreased from the first to the third harvest suggesting that the plant growth rate may exceed antimicrobial uptake rates. Accumulation of antimicrobials was significantly different between cultivars demonstrating a subspecies level variation in uptake of antibiotics in lettuce. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Predicting Salmonella populations from biological, chemical, and physical indicators in Florida surface waters.

    Science.gov (United States)

    McEgan, Rachel; Mootian, Gabriel; Goodridge, Lawrence D; Schaffner, Donald W; Danyluk, Michelle D

    2013-07-01

    Coliforms, Escherichia coli, and various physicochemical water characteristics have been suggested as indicators of microbial water quality or index organisms for pathogen populations. The relationship between the presence and/or concentration of Salmonella and biological, physical, or chemical indicators in Central Florida surface water samples over 12 consecutive months was explored. Samples were taken monthly for 12 months from 18 locations throughout Central Florida (n = 202). Air and water temperature, pH, oxidation-reduction potential (ORP), turbidity, and conductivity were measured. Weather data were obtained from nearby weather stations. Aerobic plate counts and most probable numbers (MPN) for Salmonella, E. coli, and coliforms were performed. Weak linear relationships existed between biological indicators (E. coli/coliforms) and Salmonella levels (R(2) Florida surface water through logistic regression.

  16. Shellfish as reservoirs of bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Harry Hariharan

    2016-04-01

    Full Text Available The objective of this article is to present an overview on bacterial pathogens associated with shellfish in Grenada and other countries including the authors’ experience. Although there have been considerable published work on vibrios, there is a lack of information on Salmonella serovars associated with various shellfish. In Grenada, for instance the blue land crabs collected from their habitats were found to harbor several Salmonella serovars. Also, it is notable that only minimal research has been done on shellfish such as conchs and whelks, which are common in the Caribbean and West Indies. Information on anaerobic bacteria, particularly, non-spore forming bacteria associated with shellfish, in general, is also scanty. This review re-examines this globally important topic based on the recent findings as well as past observations. Strategies for reduction of bacteria in oysters are briefly mentioned because of the fact that oysters are consumed commonly without complete cooking.

  17. Effects of subtherapeutic concentrations of antimicrobials on gene acquisition events in Yersinia, Proteus, Shigella, and Salmonella recipient organisms in isolated ligated intestinal loops of swine.

    Science.gov (United States)

    Brewer, Matt T; Xiong, Nalee; Anderson, Kristi L; Carlson, Steve A

    2013-08-01

    To assess antimicrobial resistance and transfer of virulence genes facilitated by subtherapeutic concentrations of antimicrobials in swine intestines. 20 anesthetized pigs experimentally inoculated with donor and recipient bacteria. 4 recipient pathogenic bacteria (Salmonella enterica serotype Typhimurium, Yersinia enterocolitica, Shigella flexneri, or Proteus mirabilis) were incubated with donor bacteria in the presence of subinhibitory concentrations of 1 of 16 antimicrobials in isolated ligated intestinal loops in swine. Donor Escherichia coli contained transferrable antimicrobial resistance or virulence genes. After coincubations, intestinal contents were removed and assessed for pathogens that acquired new antimicrobial resistance or virulence genes following exposure to the subtherapeutic concentrations of antimicrobials. 3 antimicrobials (apramycin, lincomycin, and neomycin) enhanced transfer of an antimicrobial resistance plasmid from commensal E coli organisms to Yersinia and Proteus organisms, whereas 7 antimicrobials (florfenicol, hygromycin, penicillin G, roxarsone, sulfamethazine, tetracycline, and tylosin) exacerbated transfer of an integron (Salmonella genomic island 1) from Salmonella organisms to Yersinia organisms. Sulfamethazine induced the transfer of Salmonella pathogenicity island 1 from pathogenic to nonpathogenic Salmonella organisms. Six antimicrobials (bacitracin, carbadox, erythromycin, sulfathiazole, tiamulin, and virginiamycin) did not mediate any transfer events. Sulfamethazine was the only antimicrobial implicated in 2 types of transfer events. 10 of 16 antimicrobials at subinhibitory or subtherapeutic concentrations augmented specific antimicrobial resistance or transfer of virulence genes into pathogenic bacteria in isolated intestinal loops in swine. Use of subtherapeutic antimicrobials in animal feed may be associated with unwanted collateral effects.

  18. Cellulitis Due to Salmonella infantis.

    Directory of Open Access Journals (Sweden)

    Satish R Patil

    2013-01-01

    Full Text Available Bacteria of the genus Salmonella are highly adapted for the growth in both humans and animals and cause a wide spectrum of disease. The growth of Serotypes S. typhi and S. paratyphi is restricted to human hosts, in whom these organisms cause enteric (typhoid fever. The remaining Serotypes (non typhoidal Salmonella or NTS can colonize the gastrointestinal tracts of the broad range of animals, including mammals, reptiles, birds and insects. The usual clinical presentation of non-typhoidal salmonellae (NTS infection is self limited gastroenteritis; however bacteremia and focal extra intestinal infection may occur. However salmonella localization to the skin presenting as cutaneous ulceration is regarded as a rare event. Rates of morbidity and mortality associated with NTS are highest among the elderly, infants, and immunocompromised individuals, including those with hemoglobinopathies, HIV infection, or infections that cause blockade of the reticuloendothelial system. We isolated S.infantis in 50 years old man with left leg cellulitis. The serotype was confirmed at Central Research Institute, Kasauli.

  19. Salmonella radicidation of poultry carcasses

    NARCIS (Netherlands)

    Mulder, R.W.A.W.

    1982-01-01

    Validity of methods

    Experiments were carried out In which it was assessed which Salmonella isolation method is the most productive one In the examination of broiler carcasses. Refrigerated, refrigerated and radiated (2.50 kGy), frozen and frozen and

  20. Salmonella-secreted Virulence Factors

    Energy Technology Data Exchange (ETDEWEB)

    Heffron, Fred; Niemann, George; Yoon, Hyunjin; Kidwai, Afshan S.; Brown, Roslyn N.; McDermott, Jason E.; Smith, Richard D.; Adkins, Joshua N.

    2011-05-01

    In this short review we discuss secreted virulence factors of Salmonella, which directly affect Salmonella interaction with its host. Salmonella secretes protein to subvert host defenses but also, as discussed, to reduce virulence thereby permitting the bacteria to persist longer and more successfully disperse. The type III secretion system (TTSS) is the best known and well studied of the mechanisms that enable secretion from the bacterial cytoplasm to the host cell cytoplasm. Other secretion systems include outer membrane vesicles, which are present in all Gram-negative bacteria examined to date, two-partner secretion, and type VI secretion will also be addressed. Excellent reviews of Salmonella secreted effectors have focused on themes such as actin rearrangements, vesicular trafficking, ubiquitination, and the activities of the virulence factors themselves. This short review is based on S. Typhimurium infection of mice because it is a model of typhoid like disease in humans. We have organized effectors in terms of events that happen during the infection cycle and how secreted effectors may be involved.

  1. Salmonella Infection and Water Frogs

    Centers for Disease Control (CDC) Podcasts

    2010-01-12

    This podcast, featuring lead investigator Shauna Mettee, discusses the first known outbreak of Salmonella in people due to contact with water frogs.  Created: 1/12/2010 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 1/12/2010.

  2. Inactivation of Salmonella on pecan nutmeats by hot air treatment and oil roasting.

    Science.gov (United States)

    Beuchat, Larry R; Mann, David A

    2011-09-01

    Studies were done to determine the effectiveness of hot air drying, dry roasting, and oil roasting in killing Salmonella on pecan nutmeats. Pecan halves and pieces were inoculated by immersion in a five-serotype suspension of Salmonella or by surface application of powdered chalk containing the pathogen. Hot air treatment of low-moisture (2.8 to 4.1%) and high-moisture (10.5 to 11.2%) immersion-inoculated nutmeats (initial population, 6.18 to 7.16 log CFU/g) at 120°C for 20 min reduced the number of Salmonella by 1.18 to 1.26 and 1.89 to 2.04 log CFU/g, respectively. However, regardless of the moisture content, hot air treatment of pecan halves containing 0.77 log CFU/g at 120°C for 20 min failed to eliminate Salmonella. Reductions were >7 log CFU/g when dry pieces were dry roasted at 160°C for 15 min. Treatment of halves at 140°C for 20 min, 150°C for 15 min, or 170°C for 10 min reduced Salmonella by 5 log CFU/g. The pathogen was slightly more heat resistant in immersion-inoculated nutmeats than on surface-inoculated nutmeats. Exposure of immersion-inoculated pieces to peanut oil at 127°C for 1.5 min or 132°C for 1.0 min reduced the number of Salmonella by 5 log CFU/g. Treatment of halves at 138°C for 2.0 min reduced Salmonella by 5 log CFU/g; treatment at 132°C for 2.5 to 4.0 min did not always achieve this reduction. Hot air treatment cannot be relied upon to reduce Salmonella by 5 log CFU/g of raw pecan nutmeats without changing sensory qualities. Treatment temperatures and times typically used to oil roast nutmeats appear to be sufficient to reduce Salmonella by 5 log CFU/g.

  3. Influence of Natural Organic Matter on Attachment Kinetics of Salmonella Typhimurium

    Science.gov (United States)

    Chowdhury, I.; Zorlu, O.; Hill, J. E.; Walker, S. L.

    2011-12-01

    Salmonella enterica serovar Typhimurium is one of the most common and virulent bacterial pathogens, usually found in food and water. This waterborne pathogen has been attributed to causing gastroenteritis and typhoid fever, leading to 16 million cases and over half a million deaths worldwide each year. Natural organic matter (NOM) is ubiquitous in environment and previous work has shown NOM to enhance the stability and transport of bacteria cells; hence NOM will certainly interact with Salmonella and affect its transport in environment. The objective of this study was to investigate the influence of NOM (Suwannee River humic acid standard II, SRHA) on the attachment kinetics of a model Salmonella (Salmonella enterica serovar Typhimurium SA5983) to glass. The transport study was conducted in a parallel plate flow chamber using fluorescent microscope to visualize the bacterial cells, which were tagged with green fluorescent protein (GFP). The solution pH was unadjusted, and the flow rate through parallel plate channel was 0.1 mL/min to simulate groundwater conditions. Parameters varied in this study were NOM presence, ion valence (K+, Ca2+) as well as cell growth phase (mid-exponential and late-exponential growth phases). These parameters were chosen because ion valence may alter the NOM conformation and capacity for bridging, as well growth phase impacts the cellular surface chemistry. Extensive characterization of the bacterial cells was conducted including measurements of electrophoretic mobility, hydrophobicity, acidity, surface charge density and extracellular polymeric substance content. Additionally, electrokintic characterization was conducted for the glass. Preliminary results demonstrated the sensitivity of cell attachment to ionic valence and cell growth phase. Also the addition of NOM reduced the attachment of the Salmonella cells significantly under all of these conditions. Without NOM, attachment efficiencies (α) in KCl were similar at both growth

  4. Long-term variations in abundance and distribution of sewage pollution indicator and human pathogenic bacteria along the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rodrigues, V.; Ramaiah, N.; Kakti, S.; Samant, D.

    - FC and Escherichia coli - EC) and potential pathogens (Vibrio cholerae - VC, Shigella - SH, and Salmonella spp. - SA). In both Mandovi and Zuari estuaries, where fishing and tourist-related activities are sizable and long-term data collection...

  5. Selected lactic acid-producing bacterial isolates with the capacity to reduce Salmonella translocation and virulence gene expression in chickens.

    Directory of Open Access Journals (Sweden)

    Xiaojian Yang

    Full Text Available BACKGROUND: Probiotics have been used to control Salmonella colonization/infection in chickens. Yet the mechanisms of probiotic effects are not fully understood. This study has characterized our previously-selected lactic acid-producing bacterial (LAB isolates for controlling Salmonella infection in chickens, particularly the mechanism underlying the control. METHODOLOGY/PRINCIPAL FINDINGS: In vitro studies were conducted to characterize 14 LAB isolates for their tolerance to low pH (2.0 and high bile salt (0.3-1.5% and susceptibility to antibiotics. Three chicken infection trials were subsequently carried out to evaluate four of the isolates for reducing the burden of Salmonella enterica serovar Typhimurium in the broiler cecum. Chicks were gavaged with LAB cultures (10(6-7 CFU/chick or phosphate-buffered saline (PBS at 1 day of age followed by Salmonella challenge (10(4 CFU/chick next day. Samples of cecal digesta, spleen, and liver were examined for Salmonella counts on days 1, 3, or 4 post-challenge. Salmonella in the cecum from Trial 3 was also assessed for the expression of ten virulence genes located in its pathogenicity island-1 (SPI-1. These genes play a role in Salmonella intestinal invasion. Tested LAB isolates (individuals or mixed cultures were unable to lower Salmonella burden in the chicken cecum, but able to attenuate Salmonella infection in the spleen and liver. The LAB treatments also reduced almost all SPI-1 virulence gene expression (9 out of 10 in the chicken cecum, particularly at the low dose. In vitro treatment with the extracellular culture fluid from a LAB culture also down-regulated most SPI-1 virulence gene expression. CONCLUSIONS/SIGNIFICANCE: The possible correlation between attenuation of Salmonella infection in the chicken spleen and liver and reduction of Salmonella SPI-1 virulence gene expression in the chicken cecum by LAB isolates is a new observation. Suppression of Salmonella virulence gene expression in

  6. Interdigitated microelectrode based impedance biosensor for detection of salmonella enteritidis in food samples

    International Nuclear Information System (INIS)

    Kim, G; Morgan, M; Hahm, B K; Bhunia, A; Mun, J H; Om, A S

    2008-01-01

    Salmonella enteritidis outbreaks continue to occur, and S. enteritidis-related outbreaks from various food sources have increased public awareness of this pathogen. Conventional methods for pathogens detection and identification are labor-intensive and take days to complete. Some immunological rapid assays are developed, but these assays still require prolonged enrichment steps. Recently developed biosensors have shown great potential for the rapid detection of foodborne pathogens. To develop the biosensor, an interdigitated microelectrode (IME) was fabricated by using semiconductor fabrication process. Anti-Salmonella antibodies were immobilized based on avidin-biotin binding on the surface of the IME to form an active sensing layer. To increase the sensitivity of the sensor, three types of sensors that have different electrode gap sizes (2 μm, 5 μm, 10 μm) were fabricated and tested. The impedimetric biosensor could detect 10 3 CFU/mL of Salmonella in pork meat extract with an incubation time of 5 minutes. This method may provide a simple, rapid and sensitive method to detect foodborne pathogens

  7. Interdigitated microelectrode based impedance biosensor for detection of salmonella enteritidis in food samples

    Energy Technology Data Exchange (ETDEWEB)

    Kim, G [National Institute of Agricultural Engineering, 249 Seodun-dong, Suwon, Republic of Korea, 441-100 (Korea, Republic of); Morgan, M; Hahm, B K; Bhunia, A [Department of Food Science, Purdue University, West Lafayette, IN 47907 (United States); Mun, J H; Om, A S [Department of Food and Nutrient, Hanyang University, 17 Haengdang-dong, Seoul, Republic of Korea, 133-791 (Korea, Republic of)], E-mail: giyoungkim@rda.go.kr

    2008-03-15

    Salmonella enteritidis outbreaks continue to occur, and S. enteritidis-related outbreaks from various food sources have increased public awareness of this pathogen. Conventional methods for pathogens detection and identification are labor-intensive and take days to complete. Some immunological rapid assays are developed, but these assays still require prolonged enrichment steps. Recently developed biosensors have shown great potential for the rapid detection of foodborne pathogens. To develop the biosensor, an interdigitated microelectrode (IME) was fabricated by using semiconductor fabrication process. Anti-Salmonella antibodies were immobilized based on avidin-biotin binding on the surface of the IME to form an active sensing layer. To increase the sensitivity of the sensor, three types of sensors that have different electrode gap sizes (2 {mu}m, 5 {mu}m, 10 {mu}m) were fabricated and tested. The impedimetric biosensor could detect 10{sup 3} CFU/mL of Salmonella in pork meat extract with an incubation time of 5 minutes. This method may provide a simple, rapid and sensitive method to detect foodborne pathogens.

  8. A novel strategy to obtain quantitative data for modelling: Combined enrichment and real-time PCR for enumeration of salmonellae from pig carcasses

    DEFF Research Database (Denmark)

    Burkhard, Malorny; Krämer, Nadine; Vigre, Håkan

    2011-01-01

    The primary sources for the major zoonotic pathogen Salmonella are food-producing animals such as pigs and poultry. For risk assessment and hazard analysis and critical control point (HACCP) concepts, it is essential to produce large amounts of quantitative data, which is currently not achievable....../sample. The precision was similar to the standard reference most probable number (MPN) method. A screening of 200 potentially naturally contaminated cork borer samples obtained over seven weeks in a slaughterhouse resulted in 25 Salmonella-positive samples. The analysis of salmonellae within these samples showed...

  9. A simple, rapid, cost-effective and sensitive method for detection of Salmonella in environmental and pecan samples.

    Science.gov (United States)

    Dobhal, S; Zhang, G; Rohla, C; Smith, M W; Ma, L M

    2014-10-01

    PCR is widely used in the routine detection of foodborne human pathogens; however, challenges remain in overcoming PCR inhibitors present in some sample matrices. The objective of this study was to develop a simple, sensitive, cost-effective and rapid method for processing large numbers of environmental and pecan samples for Salmonella detection. This study was also aimed at validation of a new protocol for the detection of Salmonella from in-shell pecans. Different DNA template preparation methods, including direct boiling, prespin, multiple washing and commercial DNA extraction kits, were evaluated with pure cultures of Salmonella Typhimurium and with enriched soil, cattle feces and in-shell pecan each spiked individually with Salmonella Typhimurium. PCR detection of Salmonella was conducted using invA and 16S rRNA gene (internal amplification control) specific primers. The effect of amplification facilitators, including bovine serum albumin (BSA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG) and gelatin on PCR sensitivity, was also evaluated. Conducting a prespin of sample matrices in combination with the addition of 0·4% (w/v) BSA and 1% (w/v) PVP in PCR mix was the simplest, most rapid, cost-effective and sensitive method for PCR detection of Salmonella, with up to 40 CFU Salmonella per reaction detectable in the presence of over 10(9 ) CFU ml(-1) of background micro-organisms from enriched feces soil or pecan samples. The developed method is rapid, cost-effective and sensitive for detection of Salmonella from different matrices. This study provides a method with broad applicability for PCR detection of Salmonella in complex sample matrices. This method has a potential for its application in different research arenas and diagnostic laboratories. © 2014 The Society for Applied Microbiology.

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

    Directory of Open Access Journals (Sweden)

    Uday Shankar Allam

    Full Text Available Salmonella enterica is an important enteric pathogen and its various serovars are involved in causing both systemic and intestinal diseases in humans and domestic animals. The emergence of multidrug-resistant strains of Salmonella leading to increased morbidity and mortality has further complicated its management. Live attenuated vaccines have been proven superior over killed or subunit vaccines due to their ability to induce protective immunity. Of the various strategies used for the generation of live attenuated vaccine strains, focus has gradually shifted towards manipulation of virulence regulator genes. Hfq is a RNA chaperon which mediates the binding of small RNAs to the mRNA and assists in post-transcriptional gene regulation in bacteria. In this study, we evaluated the efficacy of the Salmonella Typhimurium Δhfq strain as a candidate for live oral vaccine in murine model of typhoid fever. Salmonella hfq deletion mutant is highly attenuated in cell culture and animal model implying a significant role of Hfq in bacterial virulence. Oral immunization with the Salmonella hfq deletion mutant efficiently protects mice against subsequent oral challenge with virulent strain of Salmonella Typhimurium. Moreover, protection was induced upon both multiple as well as single dose of immunizations. The vaccine strain appears to be safe for use in pregnant mice and the protection is mediated by the increase in the number of CD4(+ T lymphocytes upon vaccination. The levels of serum IgG and secretory-IgA in intestinal washes specific to lipopolysaccharide and outer membrane protein were significantly increased upon vaccination. Furthermore, hfq deletion mutant showed enhanced antigen presentation by dendritic cells compared to the wild type strain. Taken together, the studies in murine immunization model suggest that the Salmonella hfq deletion mutant can be a novel live oral vaccine candidate.

  11. Brucella lipopolysaccharide reinforced Salmonella delivering Brucella immunogens protects mice against virulent challenge.

    Science.gov (United States)

    Lalsiamthara, Jonathan; Lee, John Hwa

    2017-06-01

    Intracellular pathogen Salmonella exhibits natural infection broadly analogous to Brucella, this phenomenon makes Salmonella a pragmatic choice for an anti-Brucella vaccine delivery platform. In this study we developed and formulated a combination of four attenuated Salmonella Typhimurium live vector strains delivering heterologous Brucella antigens (rBs), namely lumazine synthase, proline racemase subunit A, lipoprotein outer membrane protein-19, and Cu-Zn superoxide dismutase. With an aim to develop a cross-protecting vaccine, Brucella pan-species conserved rBs were selected. The present study compared the efficacy of smooth and rough variants of Salmonella delivery vector and also evaluated the inclusion of purified Brucella lipopolysaccharide (LPS) in the formulation. Immunization of SPF-BALB/c mice with the vaccine combinations significantly (P≤0.05) reduced splenic wild-type Brucella abortus 544 colonization as compared to non-immunized mice as well as Salmonella only immunized mice. Increased induction of Brucella specific-IgG, sIgA production, and antigen-specific splenocyte proliferative responses were observed in the mice immunized with the formulations as compared to naïve or vector only immunized mice. Modulatory effects of rB and LPS on production of interleukin (IL)-4, IL-12, and interferon-γ were detected in splenocytes of mice immunized with the formulation. Rough Salmonella variant in combination with LPS could further enhance the efficacy of the delivery when applied intraperitoneally. Taken together, it is compelling that Brucella LPS-augmented Salmonella vector delivering immunogenic Brucella proteins may be more suitable than the current non-ideal live Brucella abortus vaccine. The vaccine system also provides a basis for the development of cross-protecting vaccine capable of preventing multispecies brucellosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Detection of Salmonella Carriers in Sheep and Goat Flocks of Bushehr and Lorestan Provinces, Iran

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    Hossein Esmaeili

    2017-01-01

    Full Text Available Background:    Salmonellosis is an infectious and a food-borne disease of humans and animals. The initial source of the infection is the intestinal tracts of birds and other animals. Apparently healthy animals can become subclinical carriers and persistently shed Salmonella in their feces which can act as a reservoir for the pathogen. The aim of this study is to detect the carriers of Salmonella among apparently healthy sheep and goat flocks of Bushehr and Lorestan provinces, Iran.Methods:    A total of 389 fecal samples were aseptically collected from the rectum of apparently healthy sheep and goat flocks of Bushehr and Lorestan provinces. Bacteriological culture was conducted using selenite cystine, Rappaport–Vassiliadis, brilliant green and xylose lysine deoxycholate agar. Suspected colonies were inoculated in to TSI, peptone water, Simmon’s Citrate, Urea medium and MRVP. Sero-groups were detected by antisera.              Results:    Two samples from 189 samples (1.05% were positive for Salmonella in Bushehr province. Salmonella abortusovis and Salmonella typhimurium were detected following serotyping. No Salmonella carriers were detected in Lorestan province.Conclusion:    As the rate of carriers of Salmonella was low, the risk of food-borne salmonellosis due to consumption of small ruminant's meat is low, especially in the condition of well cooked meat. Since S. abortusovis was detected, strategies of prevention and control of abortion due to this agent must be taken to reduce the economic losses. Moreover, the presence of S. typhimurium is a hazard to public health and people who have close contact to sheep and goats.

  13. Thermal Inactivation of Listeria monocytogenes and Salmonella during Water and Steam Blanching of Vegetables.

    Science.gov (United States)

    Ceylan, Erdogan; McMahon, Wendy; Garren, Donna M

    2017-09-01

    Thermal inactivation of Listeria monocytogenes and Salmonella was evaluated on peas, spinach, broccoli, potatoes, and carrots that were treated with hot water and steam. One gram-positive bacterium, L. monocytogenes, and one gram-negative bacterium, Salmonella, were selected as pertinent human pathogens for evaluation. Samples were inoculated with a composite of five strains each of L. monocytogenes and Salmonella to achieve approximately 10 8 to 10 9 CFU/g. Inoculated samples were treated with hot water at 85 and 87.8°C and with steam at 85 and 96.7°C for up to 3.5 min. A greater than 5-log reduction of L. monocytogenes and Salmonella was achieved on all products within 0.5 min by hot water blanching at 85 and 87.8°C. Steam blanching at 85°C reduced Salmonella populations by greater than 5 log on spinach and peas within 2 min and on carrots and broccoli within 3.5 min. Populations of Salmonella were reduced by more than 5 log within 1 min on carrot, spinach, and broccoli and within 2 min on peas by steam blanching at 96.7°C. Steam blanching at 85°C reduced L. monocytogenes populations by more than 5 log on carrots and spinach within 2 min and on broccoli and peas within 3.5 min. L. monocytogenes populations were reduced more than 5 log within 1 min on carrot, spinach, peas and broccoli by steam blanching at 96.7°C. Longer treatment times and higher temperatures were required for steam-blanched samples than for samples blanched with hot water. Results suggest that hot water and steam blanching practices commonly used by the frozen vegetable industry will achieve the desired 5-log lethality of L. monocytogenes and Salmonella and will enhance microbiological safety prior to freezing.

  14. Persistence of Salmonella Typhimurium LT2 in Soil Enhanced after Growth in Lettuce Medium

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    Kornelia Smalla

    2017-04-01

    Full Text Available The persistence of Salmonella in the environment is influenced by a multitude of biotic and abiotic factors. In addition, its persistence can be influenced by preadaptation before the introduction into the environment. In order to study how preadaptation changes the survival of Salmonella in soil and therefore its potential to colonize the phytosphere, we developed a new medium based on lettuce material [lettuce medium (LM]. Salmonella enterica serovar Typhimurium strain LT2 was used as a model for Salmonella in this study. LT2 was inoculated into soil microcosms after pregrowth in Luria Bertani (LB broth or in LM. Survival of LT2 in soil was monitored over 56 days by plate counts and quantification of the Typhimurium-specific gene STM4497 using qPCR in total community DNA for which primers and TaqMan probe were designed in this study. Significantly enhanced persistence was observed for LT2 pregrown in LM compared to LT2 pregrown in LB, indicating a preadaptation effect. Surprisingly, no improved survival could be observed for S. Typhimurium strain 14028s and S. enterica serovar Senftenberg after pregrowth on LM. This indicates a high strain specificity of preadaptation. Results from previous studies suggested that biofilm formation could enhance the survival of human pathogens in various environments and might contribute to enhanced survival on plants. In vitro biofilm assays with several Salmonella strains revealed a strain-specific effect of LM on the biofilm formation. While LM significantly improved the biofilm formation of S. Senftenberg, the biofilm formation of LT2 was better in LB. This indicates that the better survival of LM-pregrown LT2 in soil was not linked to an improved ability to form biofilms but was likely due to other factors. Most importantly, this study showed that the medium used to pregrow Salmonella can influence its survival in soil and its biofilm formation which might influence the fate of Salmonella in soil.

  15. Heat inactivation of Salmonella spp. in fresh poultry compost by simulating early phase of composting process.

    Science.gov (United States)

    Singh, R; Kim, J; Jiang, X

    2012-05-01

    The purpose of this study was to determine the effect of moisture on thermal inactivation of Salmonella spp. in poultry litter under optimal composting conditions. Thermal inactivation of Salmonella was studied in fresh poultry compost by simulating early phase of composting process. A mixture of three Salmonella serotypes grown in Tryptic soy broth with rifampin (TSB-R) was inoculated in fresh compost with 40 or 50% moisture at a final concentration of c. 7 log CFU g(-1). The inoculated compost was kept in an environmental chamber which was programmed to rise from room temperature to target composting temperatures in 2 days. In poultry compost with optimal moisture content (50%), Salmonella spp. survived for 96, 72 and 24 h at 50, 55 and 60°C, respectively, as compared with 264, 144 and 72 h at 50, 55 and 60°C, respectively, in compost with suboptimal moisture (40%). Pathogen decline was faster during the come-up time owing to higher ammonia volatilization. Our results demonstrated that Salmonella spp. survived longer in fresh poultry compost with suboptimal moisture of 40% than in compost with optimal moisture of 50% during thermophilic composting. High nitrogen content of the poultry compost is an additional factor contributing to Salmonella inactivation through ammonia volatilization during thermal exposure. This research validated the effectiveness of the current composting guidelines on Salmonella inactivation in fresh poultry compost. Both initial moisture level and ammonia volatilization are important factors affecting microbiological safety and quality of compost product. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  16. Prevalence and risk factors for Salmonella spp. colonization in broiler flocks in Shiraz, southern Iran

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    Maryam Ansari-Lari

    2014-04-01

    Full Text Available Salmonella spp. are important food borne pathogens worldwide that frequently infect poultry flocks. This cross-sectional study was conducted to determine the prevalence of Salmonella spp. colonization in broiler flocks in Shiraz (southern Iran and to find the possible association of infection status with some potential risk factors including vaccination program and use of antibiotics. During October 2009 to April 2010, a total of 40 broiler flocks were selected in slaughterhouse and 20 cloacae contents were collected from each flock. Every five cloacae contents were pooled and investigated for Salmonella spp. using appropriate culture methods. The flock was considered positive if any of the pooled samples turned positive in culture. Statistical analysis was performed using multiple logistic regression. Nine out of 40 flocks (22.50%, 95% CI: 9-36 were positive for Salmonella spp. colonization. Nearly 75.00% of flock owners reported that they used antibiotics during production period, more frequently fluoroquinolones, combination of trimethoprim-sulfonamides (TMP/SU and tetracycline. Nearly 60.00% of the flocks which had used TMP/SU were positive for Salmonella spp. compared with 10.00% of the flocks which did not use this antibiotic (p = 0.006. Increasing flock age was associated with a decreased chance of Salmonella spp. detection (p = 0.003. In flocks which received infectious bronchitis vaccine, 36.00% were positive for Salmonella spp. whereas this was 15.00% for flocks which did not receive this vaccine (p = 0.08. Careful monitoring of antibiotics use and further studies to determine the most appropriate vaccination program in the field is recommended.

  17. 76 FR 81513 - Guidance for Industry: Prevention of Salmonella

    Science.gov (United States)

    2011-12-28

    ...] Guidance for Industry: Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and... ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation.'' The... final rule ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and...

  18. 75 FR 48973 - Draft Guidance for Industry: Prevention of Salmonella

    Science.gov (United States)

    2010-08-12

    ...] Draft Guidance for Industry: Prevention of Salmonella Enteritidis in Shell Eggs During Production... entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and... on how to comply with certain provisions contained in FDA's final rule ``Prevention of Salmonella...

  19. Salmonella risk to consumers via pork is related to the Salmonella prevalence in pig feed.

    Science.gov (United States)

    Rönnqvist, M; Välttilä, V; Ranta, J; Tuominen, P

    2018-05-01

    Pigs are an important source of human infections with Salmonella, one of the most common causes of sporadic gastrointestinal infections and foodborne outbreaks in the European region. Feed has been estimated to be a significant source of Salmonella in piggeries in countries of a low Salmonella prevalence. To estimate Salmonella risk to consumers via the pork production chain, including feed production, a quantitative risk assessment model was constructed. The Salmonella prevalence in feeds and in animals was estimated to be generally low in Finland, but the relative importance of feed as a source of Salmonella in pigs was estimated as potentially high. Discontinuation of the present strict Salmonella control could increase the risk of Salmonella in slaughter pigs and consequent infections in consumers. The increased use of low risk and controlled feed ingredients could result in a consistently lower residual contamination in pigs and help the tracing and control of the sources of infections. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Determination of the sources and antimicrobial resistance patterns of Salmonella isolated from the poultry industry in Southern Ethiopia.

    Science.gov (United States)

    Abdi, Reta Duguma; Mengstie, Fisseha; Beyi, Ashenafi Feyisa; Beyene, Takele; Waktole, Hika; Mammo, Bedasso; Ayana, Dinka; Abunna, Fufa

    2017-05-18

    Ethiopia set an ambitious masterplan to increase chicken meat and egg production from 2015 to 2020. Poultry breeding, multiplication and distribution centers in the country have received executive order to import, amplify and distribute commercial chickens to end users. The biosecurity and the pathogen fauna of the centers have not been evaluated as to whether the centers could implement the mission effectively without any risk. Thus, the aim of this study was to evaluate the biosecurity practices and the pathogen prevalence, risk factors and their antimicrobial resistance (AMR) using Salmonella as case study. Routine farm workers of the centers were interviewed about the different management (biosecurity) practices using a checklist. Samples (n = 270) from different sources consisting of chicken's cloacal swab (n = 244), personnel hand swab (n = 9) and bedding (n = 17) were collected from three chicken multiplication centers. Standard bacteriological methods were used for the isolation of Salmonella. Disk diffusion method was used for drug sensitivity testing. Antimicrobials were often over prescribed without confirming the cause of ill health and without susceptibility testing. The general biosecurity and flock management practices were substandard. Salmonella was isolated from 45 (16.7%) of the 270 samples. Its prevalence was significantly (pSalmonella isolation from (i) bedding, (ii) personnel hand swabs (iii) chickens, (iv) presence of more MDR isolates, (v) coupled with poor biosecurity practices in the centers could pose a risk for spreading of pathogens and drug resistant genes to the smallholder chicken producers and the public. We conclude that the poultry breeding, multiplication and distribution centers in Ethiopia, as they stand currently, seem to be a source of pathogens and AMR isolates at least for Salmonella. Therefore, strict biosecurity, personnel safety, prudent drug use, regular monitoring and traceability of Salmonella serotypes or genotypes

  1. Presence of Campylobacter and Salmonella in sand from bathing beaches.

    Science.gov (United States)

    Bolton, F J; Surman, S B; Martin, K; Wareing, D R; Humphrey, T J

    1999-02-01

    The purpose of this study was to determine the presence of thermophilic Campylobacter spp. and Salmonella spp. in sand from non-EEC standard and EEC standard designated beaches in different locations in the UK and to assess if potentially pathogenic strains were present. Campylobacter spp. were detected in 82/182 (45%) of sand samples and Salmonella spp. in 10/182 (6%). Campylobacter spp. were isolated from 46/92 (50%) of samples from non-EEC standard beaches and 36/90 (40%) from EEC standard beaches. The prevalence of Campylobacter spp. was greater in wet sand from both types of beaches but, surprisingly, more than 30% of samples from dry sand also contained these organisms. The major pathogenic species C. jejuni and C. coli were more prevalent in sand from non-EEC standard beaches. In contrast, C. lari and urease positive thermophilic campylobacters, which are associated with seagulls and other migratory birds, were more prevalent in sand from EEC standard beaches. Campylobacter isolates were further characterized by biotyping and serotyping, which confirmed that strains known to be of types associated with human infections were frequently found in sand on bathing beaches.

  2. Salmonella Typhi genomics: envisaging the future of typhoid eradication.

    Science.gov (United States)

    Yap, Kien-Pong; Thong, Kwai Lin

    2017-08-01

    Next-generation whole-genome sequencing has revolutionised the study of infectious diseases in recent years. The availability of genome sequences and its understanding have transformed the field of molecular microbiology, epidemiology, infection treatments and vaccine developments. We review the key findings of the publicly accessible genomes of Salmonella enterica serovar Typhi since the first complete genome to the most recent release of thousands of Salmonella Typhi genomes, which remarkably shape the genomic research of S. Typhi and other pathogens. Important new insights acquired from the genome sequencing of S. Typhi, pertaining to genomic variations, evolution, population structure, antibiotic resistance, virulence, pathogenesis, disease surveillance/investigation and disease control are discussed. As the numbers of sequenced genomes are increasing at an unprecedented rate, fine variations in the gene pool of S. Typhi are captured in high resolution, allowing deeper understanding of the pathogen's evolutionary trends and its pathogenesis, paving the way to bringing us closer to eradication of typhoid through effective vaccine/treatment development. © 2017 John Wiley & Sons Ltd.

  3. Production of recombinant flagellin to develop ELISA-based detection of Salmonella Enteritidis

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    Seyed Ali Mirhosseini

    Full Text Available ABSTRACT Food-borne diseases, caused by the pathogenic bacteria, are highly prevalent in the world. Salmonella is one of the most important bacterial genera responsible for this. Salmonella Enteritidis (SE is one of the non-typhoid Salmonellae that can be transmitted to human from poultry products, water, and contaminated food. In recent years, new and rapid detection methods such as enzyme-linked immunosorbent assay (ELISA and polymerase chain reaction (PCR have been developed. In this study, recombinant FliC (rFliC was produced to be used as an antigen. The immunization was conducted in mice with the purified recombinant FliC (rFliC. The mice were subcutaneously immunized with rFliC and elicited significant rFliC specific serum IgG antibodies. An indirect ELISA system was established for the detection of Salmonella Enteritidis. Our results confirmed that the recombinant flagellin can be one of the excellent indicators for the detection of Salmonella Enteritidis.

  4. Salmonella in the pork production chain and its impact on human health in the European Union.

    Science.gov (United States)

    Bonardi, S

    2017-06-01

    Salmonella spp. comprise the second most common food-borne pathogens in the European Union (EU). The role of pigs as carriers of Salmonella has been intensively studied both on farm and at slaughter. Salmonella infection in pigs may cause fever, diarrhoea, prostration and mortality. However, most infected pigs remain healthy carriers, and those infected at the end of the fattening period could pose a threat to human health. Contamination of pig carcasses can occur on the slaughter line, and it is linked to cross-contamination from other carcasses and the presence of Salmonella in the environment. Therefore, Salmonella serovars present on pig carcasses can be different from those detected in the same bathes on the farm. In recent years, S. Typhimurium, S. Derby and S. serotype 4,[5],12:i:- (a monophasic variant of S. Typhimurium) have been the most common serovars to be detected in pigs in EU countries, but S. Rissen, S. Infantis, S. Enteritidis and S. Brandenburg have also been reported. In humans, several cases of salmonellosis have been linked to the consumption of raw or undercooked pork and pork products. Among the main serovars of porcine origin detected in confirmed human cases, S. Typhimurium, the monophasic variant S. 4,[5],12:i:- and S. Derby are certainly the most important.

  5. Salmonella Intracellular Lifestyles and Their Impact on Host-to-Host Transmission.

    Science.gov (United States)

    Pucciarelli, M Graciela; García-Del Portillo, Francisco

    2017-07-01

    More than a century ago, infections by Salmonella were already associated with foodborne enteric diseases with high morbidity in humans and cattle. Intestinal inflammation and diarrhea are hallmarks of infections caused by nontyphoidal Salmonella serovars, and these pathologies facilitate pathogen transmission to the environment. In those early times, physicians and microbiologists also realized that typhoid and paratyphoid fever caused by some Salmonella serovars could be transmitted by "carriers," individuals outwardly healthy or at most suffering from some minor chronic complaint. In his pioneering study of the nontyphoidal serovar Typhimurium in 1967, Takeuchi published the first images of intracellular bacteria enclosed by membrane-bound vacuoles in the initial stages of the intestinal epithelium penetration. These compartments, called Salmonella -containing vacuoles, are highly dynamic phagosomes with differing biogenesis depending on the host cell type. Single-cell studies involving real-time imaging and gene expression profiling, together with new approaches based on genetic reporters sensitive to growth rate, have uncovered unprecedented heterogeneous responses in intracellular bacteria. Subpopulations of intracellular bacteria displaying fast, reduced, or no growth, as well as cytosolic and intravacuolar bacteria, have been reported in both in vitro and in vivo infection models. Recent investigations, most of them focused on the serovar Typhimurium, point to the selection of persisting bacteria inside macrophages or following an autophagy attack in fibroblasts. Here, we discuss these heterogeneous intracellular lifestyles and speculate on how these disparate behaviors may impact host-to-host transmissibility of Salmonella serovars.

  6. Incidence of Salmonella Infantis in poultry meat and products and the resistance of isolates to antimicrobials

    Science.gov (United States)

    Kalaba, V.; Golić, B.; Sladojević, Ž.; Kalaba, D.

    2017-09-01

    Globalisation, climate change, changes in eating habits and the food industry, modern animal husbandry and market demands often have a negative impact on quality assurance, food safety and animal health. After the eradication of some zoonotic diseases that previously often jeopardized the human population, today in developed countries, the focus is mainly on the control of zoonoses transmitted by food. Salmonella is one of the most common pathogens that can be transmitted from animals to humans, and its reservoirs are poultry, cattle and pigs, so one transmission route to humans is from contaminated food of animal origin. Multidrug-resistant isolates of Salmonella, which can transfer their resistance genes to other microorganisms, are considered a serious threat to public health. Control of Salmonella primarily depends on a good monitoring system and knowledge of the presence of serovars and strains in an epizootiological area. During the first nine months of 2016, 1321 samples of poultry meat and products were examined, among which 108 harboured Salmonella. Altogether, 29 of the 108 isolates (26.85%) were Salmonella Infantis. For all 29 S. Infantis isolates, antimicrobial resistance was tested by the disc diffusion method. The isolates showed 100% resistance to amoxicillin, and nalidixic acid.

  7. Prevalence and antimicrobial resistance of Listeria, Salmonella, and Yersinia species isolates in ducks and geese.

    Science.gov (United States)

    Jamali, Hossein; Radmehr, Behrad; Ismail, Salmah

    2014-04-01

    The aims of this study were to determine the prevalence and antimicrobial resistance of Listeria, Salmonella, and Yersinia spp. isolated from duck and goose intestinal contents. A total of 471 samples, including 291 duck and 180 goose intestinal contents, were purchased from wet markets between November 2008 and July 2010. Listeria, Salmonella, and Yersinia spp. were isolated from 58 (12.3%), 107 (22.7%), and 80 (17%) of the samples, respectively. It was concluded that Listeria ivanovii, Salmonella Thompson, and Yersinia enterocolitica were the predominant serovars among Listeria, Salmonella, and Yersinia spp., respectively. Moreover, resistance to tetracycline was common in Listeria (48.3%) and Salmonella spp. (63.6%), whereas 51.3% of the Yersinia spp. isolates were resistant to cephalothin. Therefore, continued surveillance of the prevalence of the pathogens and also of emerging antibiotic resistance is needed to render possible the recognition of foods that may represent risks and also ensure the effective treatment of listeriosis, salmonellosis, and yersiniosis.

  8. Genome-wide methylation patterns in Salmonella enterica Subsp. enterica Serovars.

    Directory of Open Access Journals (Sweden)

    Cary Pirone-Davies

    Full Text Available 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.

  9. Survey of co-infection by Salmonella and oxyurids in tortoises

    Directory of Open Access Journals (Sweden)

    Dipineto Ludovico

    2012-05-01

    Full Text Available Abstract Background Salmonella spp. and oxyurids are among the most prevalent bacterial and parasitic agents in reptiles. These organisms are routinely isolated in healthy tortoises, although heavy infections may cause significant pathology. Tortoises are considered a common source of reptile-associated salmonellosis, an important zoonosis reported worldwide. A survey of the prevalence of Salmonella spp. and oxyurids in 53 tortoises was conducted in southern Italy and a possible correlation between the two pathogens was therefore investigated. Results Salmonella spp. and oxyurids were detected with a prevalence of 49.1 and 81.1%, respectively. A significant positive correlation between Salmonella spp. and oxyurids was demonstrated. However, confounding factors related to husbandry could have been involved in determining this correlation. Conclusions Our results suggest that caution should be exercised in translocation, husbandry, and human contact with tortoises and other exotic pets. Further studies on the epidemiology, molecular characterization and pathogenesis of Salmonella and oxyurids are needed to assess the actual impact of these organisms, as single or associated infections, on tortoises and on other exotic pets.

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

    Science.gov (United States)

    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.

  11. ISOLATION STUDIES ON THE PREVALENCE OF SALMONELLAE IN CHICKEN ORGANS, EGGS AND FEED COMPONENTS.

    Science.gov (United States)

    Sajid, Saraj-Uddin; Sajid, Mahum; Hashmi, Ramiz Iqbal

    2015-01-01

    Salmonella is an important zoonotic pathogen and its prevalence in the chicken meat and eggs acts as a continuous threat to human population. The current studies covering a time period of three years, was carried out to report the isolation of salmonellae from the chicken tissues, eggs and feed ingredient. A total of 1747 random samples from twelve different sources and 56 locations in Islamabad and Northern Punjab area of Pakistan, were screened for isolation studies according to the already published established protocols. The analysis of 1747 random samples comprising of 1069 (61.19%) chicken organs and 678 (38.81%) allied sources including eggs and feed ingredients, showed that a total of 162 (9.27%) were positive for salmonellae. Isolation prevalence in various chicken organs and allied sources was 86 (8.04%) and 76 (11.20%) respectively. The maximum isolation prevalence was recorded in meat meal (19.35%), followed by fish meal (17.54%), hatchery fluff (14.63%), livers (13.17%), poultry litter (10.89%), and eggs (9.64%). The range of Salmonella isolated varied from 19.35% to 4.72% in various organs and allied sources. Our findings highlighted a potential public health hazard and emphasized the significance of continuous surveillance system in the country to understand the ever changing epidemiological pattern of Salmonella serovers. The endemic prevalence of various serovars can cause outbreaks of human salmonellosis due to the consumption of contaminated meat and eggs as has already been reported worldwide.

  12. Salmonella adhesion, invasion and cellular immune responses are differentially affected by iron concentrations in a combined in vitro gut fermentation-cell model.

    Science.gov (United States)

    Dostal, Alexandra; Gagnon, Mélanie; Chassard, Christophe; Zimmermann, Michael Bruce; O'Mahony, Liam; Lacroix, Christophe

    2014-01-01

    In regions with a high infectious disease burden, concerns have been raised about the safety of iron supplementation because higher iron concentrations in the gut lumen may increase risk of enteropathogen infection. The aim of this study was to investigate interactions of the enteropathogen Salmonella enterica ssp. enterica Typhimurium with intestinal cells under different iron concentrations encountered in the gut lumen during iron deficiency and supplementation using an in vitro colonic fermentation system inoculated with immobilized child gut microbiota combined with Caco-2/HT29-MTX co-culture monolayers. Colonic fermentation effluents obtained during normal, low (chelation by 2,2'-dipyridyl) and high iron (26.5 mg iron/L) fermentation conditions containing Salmonella or pure Salmonella cultures with similar iron conditions were applied to cellular monolayers. Salmonella adhesion and invasion capacity, cellular integrity and immune response were assessed. Under high iron conditions in pure culture, Salmonella adhesion was 8-fold increased compared to normal iron conditions while invasion was not affected leading to decreased invasion efficiency (-86%). Moreover, cellular cytokines IL-1β, IL-6, IL-8 and TNF-α secretion as well as NF-κB activation in THP-1 cells were attenuated under high iron conditions. Low iron conditions in pure culture increased Salmonella invasion correlating with an increase in IL-8 release. In fermentation effluents, Salmonella adhesion was 12-fold and invasion was 428-fold reduced compared to pure culture. Salmonella in high iron fermentation effluents had decreased invasion efficiency (-77.1%) and cellular TNF-α release compared to normal iron effluent. The presence of commensal microbiota and bacterial metabolites in fermentation effluents reduced adhesion and invasion of Salmonella compared to pure culture highlighting the importance of the gut microbiota as a barrier during pathogen invasion. High iron concentrations as

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

    Science.gov (United States)

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

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

    Science.gov (United States)

    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.

  15. Comparative analysis of codon usage patterns and identification of predicted highly expressed genes in five Salmonella genomes

    Directory of Open Access Journals (Sweden)

    Mondal U

    2008-01-01

    Full Text Available Purpose: To anlyse codon usage patterns of five complete genomes of Salmonella , predict highly expressed genes, examine horizontally transferred pathogenicity-related genes to detect their presence in the strains, and scrutinize the nature of highly expressed genes to infer upon their lifestyle. Methods: Protein coding genes, ribosomal protein genes, and pathogenicity-related genes were analysed with Codon W and CAI (codon adaptation index Calculator. Results: Translational efficiency plays a role in codon usage variation in Salmonella genes. Low bias was noticed in most of the genes. GC3 (guanine cytosine at third position composition does not influence codon usage variation in the genes of these Salmonella strains. Among the cluster of orthologous groups (COGs, translation, ribosomal structure biogenesis [J], and energy production and conversion [C] contained the highest number of potentially highly expressed (PHX genes. Correspondence analysis reveals the conserved nature of the genes. Highly expressed genes were detected. Conclusions: Selection for translational efficiency is the major source of variation of codon usage in the genes of Salmonella . Evolution of pathogenicity-related genes as a unit suggests their ability to infect and exist as a pathogen. Presence of a lot of PHX genes in the information and storage-processing category of COGs indicated their lifestyle and revealed that they were not subjected to genome reduction.

  16. Recovery of Cephalosporin Resistant Escherichia coli and Salmonella from Pork, Beef and Chicken Marketed in Nova Scotia

    Directory of Open Access Journals (Sweden)

    Kevin R Forward

    2004-01-01

    Full Text Available BACKGROUND: Antimicrobial use in farm animals is a potentially important contributor to the emergence of antimicrobial resistance. Resistant Salmonella may lead to serious human infections and resistant Escherichia coli may transfer plasmid-encoded resistance genes to other pathogens.

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

    Science.gov (United States)

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

  18. Single and Combined Effects of Curcumin and Trans-cinnamaldehyde to Inhibit the Growth of Salmonella Typhimurium

    Science.gov (United States)

    In the last 15 years Salmonella has stayed at a steady pace with no decrease than other foodborne pathogens. Currently, the antimicrobial resistance is one of the most serious health threats and there is a strong needs to search for alternative therapeutics including herbal plants extracts. Curcuma...

  19. Draft Genome Sequences of Four Salmonella enterica subsp. enterica Serovar Enteritidis Strains Implicated in Infections of Avian and Human Hosts

    KAUST Repository

    An, Ran; Lin, Pengpeng; Bougouffa, Salim; Essack, Magbubah; Boxrud, David; Bajic, Vladimir B.; Vidovic, Sinisa

    2018-01-01

    Salmonella enterica subsp. enterica serovar Enteritidis is a wide-host-range pathogen. Occasionally, it is involved in invasive infections, leading to a high mortality rate. Here, we present the draft genome sequences of four S Enteritidis strains obtained from human and avian hosts that had been involved in bacteremia, gastroenteritis, and primary infections.

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

    Science.gov (United States)

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

  1. Draft Genome Sequences of Four Salmonella enterica subsp. enterica Serovar Enteritidis Strains Implicated in Infections of Avian and Human Hosts

    KAUST Repository

    An, Ran

    2018-01-24

    Salmonella enterica subsp. enterica serovar Enteritidis is a wide-host-range pathogen. Occasionally, it is involved in invasive infections, leading to a high mortality rate. Here, we present the draft genome sequences of four S Enteritidis strains obtained from human and avian hosts that had been involved in bacteremia, gastroenteritis, and primary infections.

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

    Science.gov (United States)

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

  3. Evaluation of the Impact of Varied Carvacrol Concentrations on Salmonella Recovery in Oregano and How Corn Oil Can Minimize the Effect of Carvacrol during Preenrichment.

    Science.gov (United States)

    Beaubrun, Junia Jean-Gilles; Addy, Nicole; Keltner, Zachary; Farris, Samantha; Ewing, Laura; Gopinath, Gopal; Hanes, Darcy E

    2018-06-01

    Phenolic compounds, like carvacrol, in oregano interfere with the detection of foodborne pathogens such as Salmonella enterica. Carvacrol concentration varies based on plant cultivars and growth region. Six oregano cultivars were used to compare the impact of carvacrol concentration on Salmonella and to evaluate the effectiveness of corn oil to help increase Salmonella survival for detection. The results of Agilent 1200 series high-performance liquid chromatography analysis showed that carvacrol concentration in the six oregano cultivars ranged from 64 to 11,200 ppm. Oregano samples were artificially contaminated with S. enterica and were preenriched in Trypticase soy broth with or without 2% (v/v) corn oil. After 18 to 24 h at 37°C, aliquots were transferred to selective enrichment broths. Salmonella was recovered onto xylose lysine Tergitol 4 agar. Six Salmonella serovars were compared, and recovery varied based on carvacrol concentration and serovar. Samples with higher concentrations of carvacrol showed Salmonella recovery only when they were preenriched with corn oil. Based on metagenomic analysis, the microflora associated with the oregano also varied per cultivar. The results show that, as carvacrol levels increased, Salmonella survival decreased. However, the addition of corn oil to the preenrichment broth can minimize the antimicrobial effects of the phenolic compounds, thus allowing for increased detection of Salmonella from oregano cultivars.

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

    Directory of Open Access Journals (Sweden)

    Swarmistha Devi Aribam

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

  5. Detection of Salmonella Typhimurium on Spinach Using Phage-Based Magnetoelastic Biosensors

    Directory of Open Access Journals (Sweden)

    Fengen Wang

    2017-02-01

    Full Text Available Phage-based magnetoelastic (ME biosensors have been studied as an in-situ, real-time, wireless, direct detection method of foodborne pathogens in recent years. This paper investigates an ME biosensor method for the detection of Salmonella Typhimurium on fresh spinach leaves. A procedure to obtain a concentrated suspension of Salmonella from contaminated spinach leaves is described that is based on methods outlined in the U.S. FDA Bacteriological Analytical Manual for the detection of Salmonella on leafy green vegetables. The effects of an alternative pre-enrichment broth (LB broth vs. lactose broth, incubation time on the detection performance and negative control were investigated. In addition, different blocking agents (BSA, Casein, and Superblock were evaluated to minimize the effect of nonspecific binding. None of the blocking agents was found to be superior to the others, or even better than none. Unblocked ME biosensors were placed directly in a concentrated suspension and allowed to bind with Salmonella cells for 30 min before measuring the resonant frequency using a surface-scanning coil detector. It was found that 7 h incubation at 37 °C in LB broth was necessary to detect an initial spike of 100 cfu/25 g S. Typhimurium on spinach leaves with a confidence level of difference greater than 95% (p < 0.05. Thus, the ME biosensor method, on both partly and fully detection, was demonstrated to be a robust and competitive method for foodborne pathogens on fresh products.

  6. Molecular-Based Identification and Detection of Salmonella in Food Production Systems: Current Perspectives.

    Science.gov (United States)

    Ricke, Steven C; Kim, Sun Ae; Shi, Zhaohao; Park, Si Hong

    2018-04-19

    Salmonella remains a prominent cause of foodborne illnesses and can originate from a wide range of food products. Given the continued presence of pathogenic Salmonella in food production systems, there is a consistent need to improve identification and detection methods that can identify this pathogen at all stages in food systems. Methods for subtyping have evolved over the years, and the introduction of whole genome sequencing and advancements in PCR technologies has greatly improved the resolution for differentiating strains within a particular serovar. This, in turn, has led to the continued improvement in Salmonella detection technologies for utilization in food production systems. In this review, the focus will be on recent advancements in these technologies, as well as potential issues associated with the application of these tools in food production. In addition, the recent and emerging research developments on Salmonella detection and identification methodologies and their potential application in food production systems will be discussed. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Comparison between digital PCR and real-time PCR in detection of Salmonella typhimurium in milk.

    Science.gov (United States)

    Wang, Meng; Yang, Junjie; Gai, Zhongtao; Huo, Shengnan; Zhu, Jianhua; Li, Jun; Wang, Ranran; Xing, Sheng; Shi, Guosheng; Shi, Feng; Zhang, Lei

    2018-02-02

    As a kind of zero-tolerance foodborne pathogens, Salmonella typhimurium poses a great threat to quality of food products and public health. Hence, rapid and efficient approaches to identify Salmonella typhimurium are urgently needed. Combined with PCR and fluorescence technique, real-time PCR (qPCR) and digital PCR (ddPCR) are regarded as suitable tools for detecting foodborne pathogens. To compare the effect between qPCR and ddPCR in detecting Salmonella typhimurium, a series of nucleic acid, pure strain culture and spiking milk samples were applied and the resistance to inhibitors referred in this article as well. Compared with qPCR, ddPCR exhibited more sensitive (10 -4 ng/μl or 10 2 cfu/ml) and less pre-culturing time (saving 2h). Moreover, ddPCR had stronger resistance to inhibitors than qPCR, yet absolute quantification hardly performed when target's concentration over 1ng/μl or 10 6 cfu/ml. This study provides an alternative strategy in detecting foodborne Salmonella typhimurium. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Gamma radiation in the reduction of Salmonella spp. inoculated on minimally processed watercress (Nasturtium officinalis)

    International Nuclear Information System (INIS)

    Martins, C.G.; Behrens, J.H.; Destro, M.T.; Franco, B.D.G.M.; Vizeu, D.M.; Hutzler, B.; Landgraf, M.

    2004-01-01

    Consumer attitudes towards foods have changed in the last two decades increasing requirements for freshlike products. Consequently, less extreme treatments or additives are being required. Minimally processed foods have freshlike characteristics and satisfy this new consumer demand. Besides freshness, the minimally processing also provide convenience required by the market. Salad vegetables can be source of pathogen such as Salmonella, Escherichia coli O157:H7, Shigella spp. The minimal processing does not reduce the levels of pathogenic microorganisms to safe levels. Therefore, this study was carried out in order to improve the microbiological safety and the shelf-life of minimally processed vegetables using gamma radiation. Minimally processed watercress inoculated with a cocktail of Salmonella spp was exposed to 0.0, 0.2, 0.5, 0.7, 1.0, 1.2 and 1.5 kGy. Irradiated samples were diluted 1:10 in saline peptone water and plated onto tryptic soy agar that were incubated at 37 deg. C/24 h. D 10 values for Salmonella spp. inoculated in watercress varied from 0.29 to 0.43 kGy. Therefore, a dose of 1.7 kGy will reduce Salmonella population in watercress by 4 log 10 . The shelf-life was increased by 1 1/2 day when the product was exposed to 1 kGy

  9. Salmonella contamination: a significant challenge to the global marketing of animal food products.

    Science.gov (United States)

    L Plym, Forshell; Wierup, M

    2006-08-01

    Salmonellosis is the most common food-borne bacterial disease in the world. Salmonella is a significant pathogen for food-producing animals and these animals are the primary source of salmonellosis. It is estimated that herd prevalence varies between 0% and 90%, depending on the animal species and region. The pathogen is spread by trade in animals and non-heated animal food products. The emergence of strains that are resistant to antimicrobials, often as a result of antimicrobial usage in animals, is a public health hazard of great concern. It is increasingly accepted that the prevalence of Salmonella in animal production must be decreased and, in the European Union, plans to achieve this are currently being implemented. In this paper, the authors propose various risk mitigation strategies. Successful control must focus on a range of preventive actions because there is no simple 'silver bullet' solution to reduce Salmonella contamination. The authors conclude that the key to controlling Salmonella is to follow the general rules that have been successfully applied to other infectious diseases.

  10. A Switchable Linker-Based Immunoassay for Ultrasensitive Visible Detection of Salmonella in Tomatoes.

    Science.gov (United States)

    Hahn, Jungwoo; Kim, Eunghee; You, Young Sang; Gunasekaran, Sundaram; Lim, Seokwon; Choi, Young Jin

    2017-10-01

    On-site detection for sensitive identification of foodborne pathogens on fresh produce with minimal use of specialized instrumentation is crucial to the food industry. A switchable linker (SL)-based immunoassay was designed for ultrasensitive on-site detection of Salmonella in tomato samples. The assay is based on large-scale aggregation of gold nanoparticles (GNPs), induced by a quantitative relationship among the biotinylated Salmonella polyclonal antibody (b-Ab) used as the SL, the functionalized GNPs, and Salmonella. Important factors such as the concentration of SLs, time required for large-scale aggregation, and selectivity of b-Ab were optimized to minimize the detection time (within 45 min with gentle agitation) and achieve the lowest limit of detection (LOD; 10 CFU/g in tomato samples) possible. This SL-based immunoassay with its relatively low LOD and short detection time may meet the need for rapid, simple, on-site analysis of pathogens in fresh produce. The novel switchable linker-based immunoassay is a rapid, specific, and sensitive method that has potential applications for routine diagnostics of Salmonella in tomato products. These advantages make it a practical approach for general use in the processing industry to detect Salmonella rapidly and to implement appropriate regulatory procedures. Furthermore, it could be applied to other fresh products including cantaloupe, strawberry, and cucumbers. © 2017 Institute of Food Technologists®.

  11. Effect of ionizing radiation on the quantitative detection of Salmonella using real-time PCR

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sangyong; Jung, Jinwoo [Radiation Research Center for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Kim, Minjeong; Ryu, Sangryeol [Department of Food and Animal Biotechnology, School of Agricultural Biotechnology, Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921 (Korea, Republic of); Kim, Dongho [Radiation Research Center for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: fungikim@kaeri.re.kr

    2008-09-15

    Food irradiation is an economically viable technology for inactivating foodborne pathogens, but irradiation can mask pathogens in unhygienically prepared food. The aim of this study was to investigate the effect of irradiation treatment on the detection of Salmonella using real-time PCR. Three commercially available kits were tested, of which the InstaGene Matrix procedure was most effective in preparing template DNA from Salmonella exposed to radiation in broth culture. The minimum level of detection by real-time PCR combined with InstaGene Matrix was 3 log units of Salmonella per milliliter. However, when pure cultures of Salmonella were irradiated at 3 and 5 kGy, the cycle threshold (C{sub T}) increased 1-1.5-fold compared to irradiation at 0 and 1 kGy. This indicated that irradiation treatment may result in an underestimation of bacterial counts due to radiation-induced DNA lesions. We also compared C{sub T} values in inoculated chicken homogenates before and after irradiation, which in this model caused a 1.3-3.3-fold underestimation of bacterial counts with respect to irradiation dose.

  12. Molecular study on some antibiotic resistant genes in Salmonella spp. isolates

    Science.gov (United States)

    Nabi, Ari Q.

    2017-09-01

    Studying the genes related with antimicrobial resistance in Salmonella spp. is a crucial step toward a correct and faster treatment of infections caused by the pathogen. In this work Integron mediated antibiotic resistant gene IntI1 (Class I Integrase IntI1) and some plasmid mediated antibiotic resistance genes (Qnr) were scanned among the isolated non-Typhoid Salmonellae strains with known resistance to some important antimicrobial drugs using Sybr Green real time PCR. The aim of the study was to correlate the multiple antibiotics and antimicrobial resistance of Salmonella spp. with the presence of integrase (IntI1) gene and plasmid mediated quinolone resistant genes. Results revealed the presence of Class I Integrase gene in 76% of the isolates with confirmed multiple antibiotic resistances. Moreover, about 32% of the multiple antibiotic resistant serotypes showed a positive R-PCR for plasmid mediated qnrA gene encoding for nalidixic acid and ciprofloxacin resistance. No positive results could be revealed form R-PCRs targeting qnrB or qnrS. In light of these results we can conclude that the presence of at least one of the qnr genes and/or the presence of Integrase Class I gene were responsible for the multiple antibiotic resistance to for nalidixic acid and ciprofloxacin from the studied Salmonella spp. and further studies required to identify the genes related with multiple antibiotic resistance of the pathogen.

  13. Gamma radiation in the reduction of Salmonella spp. inoculated on minimally processed watercress (Nasturtium officinalis)

    Energy Technology Data Exchange (ETDEWEB)

    Martins, C.G.; Behrens, J.H.; Destro, M.T.; Franco, B.D.G.M.; Vizeu, D.M.; Hutzler, B.; Landgraf, M. E-mail: landgraf@usp.br

    2004-10-01

    Consumer attitudes towards foods have changed in the last two decades increasing requirements for freshlike products. Consequently, less extreme treatments or additives are being required. Minimally processed foods have freshlike characteristics and satisfy this new consumer demand. Besides freshness, the minimally processing also provide convenience required by the market. Salad vegetables can be source of pathogen such as Salmonella, Escherichia coli O157:H7, Shigella spp. The minimal processing does not reduce the levels of pathogenic microorganisms to safe levels. Therefore, this study was carried out in order to improve the microbiological safety and the shelf-life of minimally processed vegetables using gamma radiation. Minimally processed watercress inoculated with a cocktail of Salmonella spp was exposed to 0.0, 0.2, 0.5, 0.7, 1.0, 1.2 and 1.5 kGy. Irradiated samples were diluted 1:10 in saline peptone water and plated onto tryptic soy agar that were incubated at 37 deg. C/24 h. D{sub 10} values for Salmonella spp. inoculated in watercress varied from 0.29 to 0.43 kGy. Therefore, a dose of 1.7 kGy will reduce Salmonella population in watercress by 4 log{sub 10}. The shelf-life was increased by 1 1/2 day when the product was exposed to 1 kGy.

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

    Directory of Open Access Journals (Sweden)

    Shima Shaigan nia

    2014-06-01

    Conclusions: To our best knowledge the present study is the first prevalence report of Salmonella spp., Salmonella enteritidis and Salmonella typhimurium in raw sheep and goat samples in Iran. Consumption of pasteurized milk and dairy products can reduce the risk of salmonellosis.

  15. Evaluation of the protective efficacy of Salmonella Gallinarum 9R ...

    African Journals Online (AJOL)

    Evaluation of the protective efficacy of Salmonella Gallinarum 9R strain vaccine against Salmonella strains isolated from cases suspected of salmonellosis outbreaks in poultry farms in central Ethiopia.

  16. Salmonella Typhimurium infection in the porcine intestine

    DEFF Research Database (Denmark)

    Schauser, Kirsten; Olsen, John Elmerdahl; Larsson, Lars-Inge

    2005-01-01

    The normal intestinal epithelium is renewed with a turnover rate of 3-5 days. During Salmonella infection increased cell loss is observed, possibly as a result of programmed cell death (PCD). We have, therefore, studied the effects of Salmonella Typhimurium infection on three elements involved...... in scattered epithelial cells and the number of positive cells increased with increasing times of exposure to Salmonella (P

  17. Número mais provável de Salmonella isoladas de carcaças de frango resfriadas Most probable number of Salmonella isolated from refrigerated broiler carcasses

    Directory of Open Access Journals (Sweden)

    Anderlise Borsoi

    2010-11-01

    Full Text Available A Salmonella permanece um importante problema na avicultura e, considerando os patógenos transmitidos por alimentos, aparece como um dos agentes principais em surtos de toxinfecções alimentares. Para auxiliar na avaliação de riscos em adquirir infecção alimentar via carne de frangos que sofreram cocção inadequada, ou através de contaminação cruzada a partir desses animais, torna-se importante determinar a extensão de contaminação por patógenos em carne crua. No presente trabalho, foram analisadas 180 carcaças de frangos resfriadas, adquiridas em varejos, para pesquisa de Salmonella com determinação do número de células da bactéria. Foi utilizado o método do número mais provável (NMP nos ágares para isolamento verde brilhante com novobiocina (BGN e xilose-lisina tergitol 4 (XLT4. Os resultados mostraram 12,2% de ocorrência de Salmonella nas carcaças de frangos resfriadas e a média de NMP de Salmonella por mL, na leitura pelo ágar XLT4 foi de 2,7 células e no ágar BGN foi de 1,3 células. Os sorovares de Salmonella isolados das carcaças de frangos no estudo foram S. Enteritidis, S. Agona, S.Rissen, S. Heidelberg e S. Livingstone. A análise dos resultados demonstrou existir um número variável de células de Salmonella contaminando as carcaças de frango resfriadas que estão à venda ao consumidor.Salmonella in poultry remains an important worldwide problem, and among foodborne pathogens, the Salmonella appears as one of the most important outbreaks agents. To assess the risks of acquiring infection via undercooked poultry or cross contamination from chickens, it is important to determine the extent of the contamination on raw poultry with this pathogen. In this study, 180 refrigerated broiler carcasses, obtained from local stores, were assessed to recover Salmonella by the most probable number (MPN method to quantify bacterias cells onto brilliant green agar with novobiocin (BGN and xylose lysin tergitol 4 agar

  18. Rapid detection of Salmonella in pet food: design and evaluation of integrated methods based on real-time PCR detection.

    Science.gov (United States)

    Balachandran, Priya; Friberg, Maria; Vanlandingham, V; Kozak, K; Manolis, Amanda; Brevnov, Maxim; Crowley, Erin; Bird, Patrick; Goins, David; Furtado, Manohar R; Petrauskene, Olga V; Tebbs, Robert S; Charbonneau, Duane

    2012-02-01

    Reducing the risk of Salmonella contamination in pet food is critical for both companion animals and humans, and its importance is reflected by the substantial increase in the demand for pathogen testing. Accurate and rapid detection of foodborne pathogens improves food safety, protects the public health, and benefits food producers by assuring product quality while facilitating product release in a timely manner. Traditional culture-based methods for Salmonella screening are laborious and can take 5 to 7 days to obtain definitive results. In this study, we developed two methods for the detection of low levels of Salmonella in pet food using real-time PCR: (i) detection of Salmonella in 25 g of dried pet food in less than 14 h with an automated magnetic bead-based nucleic acid extraction method and (ii) detection of Salmonella in 375 g of composite dry pet food matrix in less than 24 h with a manual centrifugation-based nucleic acid preparation method. Both methods included a preclarification step using a novel protocol that removes food matrix-associated debris and PCR inhibitors and improves the sensitivity of detection. Validation studies revealed no significant differences between the two real-time PCR methods and the standard U.S. Food and Drug Administration Bacteriological Analytical Manual (chapter 5) culture confirmation method.

  19. Selected Lactobacillus strains isolated from sugary and milk kefir reduce Salmonella infection of epithelial cells in vitro.

    Science.gov (United States)

    Zavala, L; Golowczyc, M A; van Hoorde, K; Medrano, M; Huys, G; Vandamme, P; Abraham, A G

    2016-09-01

    The isolation of potentially probiotic strains and the subsequent study of their properties are very important steps to gain insight in the health benefits ascribed to sugary and milk kefir. The aim of the present study was to characterise fifteen Lactobacillus strains isolated from these beverages by determining some surface properties and their ability to antagonise enterocyte cell damage after Salmonella infection in vitro. Lactobacillus surface properties were determined by hydrophobicity, autoaggregation, and coaggregation assays with Salmonella. In addition, lactobacilli adhesion to Caco-2/TC-7 cells and the effect on Salmonella invasion were evaluated. Finally, the disassembly of F-actin cytoskeleton on intestinal epithelial cells was assayed in vitro when Salmonella infection was performed in the presence of selected Lactobacillus strains. Ten out of the 15 strains showed a high adhesion capacity to Caco-2/TC-7 cells. Most of the strains were hydrophilic and non-autoaggregating. Strains isolated from sugary kefir were non-coaggregating with Salmonella, while strains Lactobacillus paracasei CIDCA 83120, 83121, 83123, 83124, 8339, 83102 isolated from milk kefir were able to coaggregate after 1 h. L. paracasei CIDCA 8339 and Lactobacillus kefiri CIDCA 83102 were able to diminish Salmonella invasion to the enterocytes. An antagonistic effect on cytoskeleton disruption elicited by the pathogen was also demonstrated. Our results suggest that both strains isolated from milk kefir could be considered as appropriate probiotic candidates.

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

    Directory of Open Access Journals (Sweden)

    Mariángeles Noto Llana

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

  1. Radiosensitivity of Salmonella spp and Vibrio parahaemolyticus artificially incorporated by oysters (Crassostrea brasiliana).; Radiossensibilidade de Salmonella spp e Vibrio parahaemolyticus incorporadas artificialmente por ostras (Crassostrea brasiliana)

    Energy Technology Data Exchange (ETDEWEB)

    Jakabi, Miyoko

    2001-07-01

    Irradiation is considered one of the most efficient technological process to reduce the number of microorganisms in food. It can be used to improve the safety of food products as well as their shelf life. Oysters are considered one of the most important vehicle of pathogenic bacteria due to their feeding characteristic and because they are usually ingested raw. The aim of this study was to evaluate the influence of gamma radiation process on high levels of Salmonella Enteritidis, Salmonella Infantis and Vibrio parahaemolyticus incorporated by oysters (Crassostrea brasiliana) as well as on the survival of the animals and sensory attributes. The oysters were submitted to gamma radiation treatment ({sup 60}Co) with doses ranging from 0.5 kGy to 3.0 kGy. At least four trials were conducted for each serotype. The dose of 3.0 kGy was, generally, sufficient to reduce the level of Salmonella serotypes in 6 log while for V.parahaemolyticus the dose as 1.o kGy. Animals were not killed and sensory attributes were not changed by the highest irradiation dose. Therefore, 3.0 kGy is a dose that is effective on the inactivation of Salmonella spp and V.parahaemolyticus in oysters without changing their odour, flavour and appearance. (author)

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

    International Nuclear Information System (INIS)

    Fei, Jianfeng; Dou, Wenchao; Zhao, Guangying

    2015-01-01

    This article describes an electrochemical immunosensor for rapid determination of Salmonella pullorum and Salmonella gallinarum. The first step in the preparation of the immunosensor involves the electrodeposition of gold nanoparticles used for capturing antibody and enhancing signals. In order to generate a benign microenvironment for the antibody, the ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate was used to modify the surface of a screen-printed carbon electrode (SPCE). The single steps of modification were monitored via cyclic voltammetry and electrochemical impedance spectroscopy. Based on these findings, a sandwich immunoassay was worked out for the two Salmonella species by immobilizing the respective unlabeled antibodies on the SPCE. Following exposure to the analytes, secondary antibody (labeled with HRP) is added to form the sandwich. After adding hydrogen peroxide and thionine, the latter is oxidized and its signal measured via CV. A linear response to the Salmonella species is obtained in the 10 4 to 10 9 cfu · mL −1 concentration range, and the detection limits are 3.0 × 10 3 cfu · mL −1 for both species (at an SNR of 3). This assay is sensitive, highly specific, acceptably accurate and reproducible. Given its low detection limit, it represents a promising tool for the detection of S. pullorum, S. gallinarum, and - conceivably - of other food-borne pathogens by exchanging the antibody. (author)

  3. Antibiotic of resistence profile of Salmonella spp. serotypes isolated from retail beef in Mexico City.

    OpenAIRE

    Nova Nayarit-Ballesteros; María Salud Rubio-Lozano; Enrique Delgado-Suárez; Danilo Méndez-Medina; Diego Braña-Varela; Oscar Rodas-Suárez

    2016-01-01

    Objective. To determine the serotype and antibiotic resistance profile of Salmonella spp. isolated from retail ground beef in Mexico City. Materials and methods. A total of 100 samples of ground beef were analyzed. The pathogen was isolated by conventional methods and confirmed by PCR (invA gene, 284 bp). The antibiotic resistance profile was determined by the Kirby-Bauer method while serotyping was performed according to the Kauffman-White scheme. Results. We isolated a total of 19 strains o...

  4. Investigation of Listeria, Salmonella, and toxigenic Escherichia coli in various pet foods.

    Science.gov (United States)

    Nemser, Sarah M; Doran, Tara; Grabenstein, Michael; McConnell, Terri; McGrath, Timothy; Pamboukian, Ruiqing; Smith, Angele C; Achen, Maya; Danzeisen, Gregory; Kim, Sun; Liu, Yong; Robeson, Sharon; Rosario, Grisel; McWilliams Wilson, Karen; Reimschuessel, Renate

    2014-09-01

    The Veterinary Laboratory Investigation and Response Network (Vet-LIRN), in collaboration with the Food Emergency Response Network (FERN) and its Microbiology Cooperative Agreement Program (MCAP) laboratories, conducted a study to evaluate the prevalence of selected microbial organisms in various types of pet foods. The goal of this blinded study was to help the Center for Veterinary Medicine prioritize potential future pet food-testing efforts. The study also increased the FERN laboratories' screening capabilities for foodborne pathogens in animal feed matrices, since such pathogens may also be a significant health risk to consumers who come into contact with pet foods. Six U.S. Food and Drug Administration FERN MCAP laboratories analyzed approximately 1056 samples over 2 years. Laboratories tested for Salmonella, Listeria, Escherichia coli O157:H7 enterohemorrhagic E. coli, and Shiga toxin-producing strains of E. coli (STEC). Dry and semimoist dog and cat foods purchased from local stores were tested during Phase 1. Raw dog and cat foods, exotic animal feed, and jerky-type treats purchased through the Internet were tested in Phase 2. Of the 480 dry and semimoist samples, only 2 tested positive: 1 for Salmonella and 1 for Listeria greyii. However, of the 576 samples analyzed during Phase 2, 66 samples were positive for Listeria (32 of those were Listeria monocytogenes) and 15 samples positive for Salmonella. These pathogens were isolated from raw foods and jerky-type treats, not the exotic animal dry feeds. This study showed that raw pet foods may harbor food safety pathogens, such as Listeria monocytogenes and Salmonella. Consumers should handle these products carefully, being mindful of the potential risks to human and animal health.

  5. Predicting Salmonella Populations from Biological, Chemical, and Physical Indicators in Florida Surface Waters

    OpenAIRE

    McEgan, Rachel; Mootian, Gabriel; Goodridge, Lawrence D.; Schaffner, Donald W.; Danyluk, Michelle D.

    2013-01-01

    Coliforms, Escherichia coli, and various physicochemical water characteristics have been suggested as indicators of microbial water quality or index organisms for pathogen populations. The relationship between the presence and/or concentration of Salmonella and biological, physical, or chemical indicators in Central Florida surface water samples over 12 consecutive months was explored. Samples were taken monthly for 12 months from 18 locations throughout Central Florida (n = 202). Air and wat...

  6. Production of the Plant Hormone Auxin by Salmonella and Its Role in the Interactions with Plants and Animals.

    Science.gov (United States)

    Cox, Clayton E; Brandl, Maria T; de Moraes, Marcos H; Gunasekera, Sarath; Teplitski, Max

    2017-01-01

    The ability of human enteric pathogens to colonize plants and use them as alternate hosts is now well established. Salmonella , similarly to phytobacteria, appears to be capable of producing the plant hormone auxin via an indole-3-pyruvate decarboxylase (IpdC), a key enzyme of the IPyA pathway. A deletion of the Salmonella ipdC significantly reduced auxin synthesis in laboratory culture. The Salmonella ipdC gene was expressed on root surfaces of Medicago truncatula . M. truncatula auxin-responsive GH3::GUS reporter was activated by the wild type Salmonella , and not but the ipdC mutant, implying that the bacterially produced IAA (Indole Acetic Acid) was detected by the seedlings. Seedling infections with the wild type Salmonella caused an increase in secondary root formation, which was not observed in the ipdC mutant. The wild type Salmonella cells were detected as aggregates at the sites of lateral root emergence, whereas the ipdC mutant cells were evenly distributed in the rhizosphere. However, both strains appeared to colonize seedlings well in growth pouch experiments. The ipdC mutant was also less virulent in a murine model of infection. When mice were infected by oral gavage, the ipdC mutant was as proficient as the wild type strain in colonization of the intestine, but it was defective in the ability to cross the intestinal barrier. Fewer cells of the ipdC mutant, compared with the wild type strain, were detected in Peyer's patches, spleen and in the liver. Orthologs of ipdC are found in all Salmonella genomes and are distributed among many animal pathogens and plant-associated bacteria of the Enterobacteriaceae , suggesting a broad ecological role of the IpdC-catalyzed pathway.

  7. Enteric pathogen sampling of tourist restaurants in Bangkok, Thailand.

    Science.gov (United States)

    Teague, Nathan S; Srijan, Apichai; Wongstitwilairoong, Boonchai; Poramathikul, Kamonporn; Champathai, Thanaporn; Ruksasiri, Supaporn; Pavlin, Julie; Mason, Carl J

    2010-01-01

    Travelers' diarrhea (TD) is the most prevalent disorder affecting travelers to developing countries. Thailand is considered "moderately risky" for TD acquisition, but the risk by city visited or behavior of the visitor has yet to be definitely defined. Restaurant eating is consistently associated with the acquisition of diarrhea while traveling, and pathogen-free meals serve as a marker of public health success. This study seeks to ascertain a traveler's risk of exposure to certain bacterial gastric pathogens while eating at Bangkok restaurants recommended in popular tourist guide books. A cross-sectional tourist restaurant survey was conducted. Thirty-five restaurants recommended in the two top selling Bangkok guidebooks on Amazon.com were sampled for bacterial pathogens known to cause diarrhea in Thailand, namely Salmonella, Campylobacter, and Arcobacter (a Campylobacter-like organism). A total of 70 samples from two meals at each restaurant were obtained. Suspected bacterial pathogens were isolated by differential culture and tested for antibiotic resistance. Salmonella group E was isolated from one meal (2%), and Arcobacter butzleri from nine meals (13%). Campylobacter spp. were not found. The large majority of A butzleri isolates were resistant to azithromycin but susceptible to ciprofloxacin and an aminoglycoside. A traveler's risk of exposure to established bacterial pathogens, Salmonella and Campylobacter, by eating in recommended restaurants is small. Arcobacter butzleri exposure risk is 13% per meal eaten, and rises to 75% when 10 meals are eaten. All restaurants, regardless of price, appear to be equally "risky." Current evidence points to Arcobacter being pathogenic in humans; however, further research is needed to conclusively define pathogenicity. Routine prophylaxis for diarrhea is not recommended; however, travelers should be aware of the risk and come prepared with adequate and appropriate self-treatment medications.

  8. Acidic pH sensing in the bacterial cytoplasm is required for Salmonella virulence.

    Science.gov (United States)

    Choi, Jeongjoon; Groisman, Eduardo A

    2016-09-01

    pH regulates gene expression, biochemical activities and cellular behaviors. A mildly acidic pH activates the master virulence regulatory system PhoP/PhoQ in the facultative intracellular pathogen Salmonella enterica serovar Typhimurium. The sensor PhoQ harbors an extracytoplasmic domain implicated in signal sensing, and a cytoplasmic domain controlling activation of the regulator PhoP. We now report that, surprisingly, a decrease in Salmonella's own cytoplasmic pH induces transcription of PhoP-activated genes even when the extracytoplasmic pH remains neutral. Amino acid substitutions in PhoQ's cytoplasmic domain hindered activation by acidic pH and attenuated virulence in mice, but did not abolish activation by low Mg(2+) or the antimicrobial peptide C18G. Conversely, removal of PhoQ's extracytoplasmic domains prevented the response to the latter PhoQ-activating signals but not to acidic pH. PhoP-dependent genes were minimally induced by acidic pH in the non-pathogenic species Salmonella bongori but were activated by low Mg(2+) and C18G as in pathogenic S. enterica. Our findings indicate that the sensor PhoQ enables S. enterica to respond to both host- and bacterial-derived signals that alter its cytoplasmic pH. © 2016 John Wiley & Sons Ltd.

  9. Dissemination of Zoonotic Antibiotic Resistant Serotypes of Salmonella by Caspian Pond Turtles, Golestan and Mazandaran Provinces, Iran

    Directory of Open Access Journals (Sweden)

    Somayeh Namroodi

    2017-03-01

    Full Text Available Background: Salmonella spp. are widespread zoonotic pathogens with economic importance for both humans and animals. They are categorized as the natural flora of the gastrointestinal tract of many reptiles. Human salmonellosis acquired from contact with reptiles is a well-recognized medical problem. Objective: The frequency of Salmonella contamination in Caspian pond turtles was surveyed to evaluate the danger of exposure or disease risk for humans as these species are abundant around the villages in Golestan and Mazandaran provinces. Materials and Methods: One hundred fifty fecal samples from Caspian pond turtles were tested by standard bacteriological methods and positive samples were serotyped. Antimicrobial susceptibility tests on isolated Salmonella strains were also performed. Results: Out of 150 samples, 54 turtles were detected to be contaminated with Salmonella. Of the 54 Salmonella isolates, 38.8% (21/54 were serotyped as S. typhimurium; 35.1% (19/54 as S. enterica subsp. enterica; 9.2% (5/54 as S. enterica subsp. salamae; 9.2% (5/54 as S. enterica subsp. arizona; and 7.4% (4/54 as S. enterica subsp. houtenae. Female (28/80, 35% and male (26/74, 35.1% turtles showed equal incidence of Salmonella spp. contamination. Resistance was mostly observed against ampicillin (37% followed by tetracycline (33.3%, nalidixic acid (7.4%, ciprofloxacin (5.5%, and cotrimoxazole (3.7%. The highest susceptibility was observed against gentamicin (100% and trimethoprim (98.1%. Conclusion: Our findings confirmed that people who are in close exposure to Caspian pond turtles and their feces are at the risk of Salmonella contamination. Accordingly, fundamental principles of hygiene should be applied in human contact with Caspian pond turtles. Furthermore, people should be educated about the Salmonella contamination which may occur through Caspian pond turtles.

  10. Effect of Food Residues in Biofilm Formation on Stainless Steel and Polystyrene Surfaces by Salmonella enterica Strains Isolated from Poultry Houses

    Directory of Open Access Journals (Sweden)

    Alba María Paz-Méndez

    2017-11-01

    Full Text Available Salmonella spp. is a major food-borne pathogen around the world. The ability of Salmonella to produce biofilm is one of the main obstacles in reducing the prevalence of these bacteria in the food chain. Most of Salmonella biofilm studies found in the literature used laboratory growth media. However, in the food chain, food residues are the principal source of nutrients of Salmonella. In this study, the biofilm formation, morphotype, and motility of 13 Salmonella strains belonging to three different subspecies and isolated from poultry houses was evaluated. To simulate food chain conditions, four different growth media (Tryptic Soy Broth at 1/20 dilution, milk at 1/20 dilution, tomato juice, and chicken meat juice, two different surfaces (stainless steel and polystyrene and two temperatures (6 °C and 22 °C were used to evaluate the biofilm formation. The morphotype, motility, and biofilm formation of Salmonella was temperature-dependent. Biofilm formation was significantly higher with 1/20 Tryptic Soy Broth in all the surfaces and temperatures tested, in comparison with the other growth media. The laboratory growth medium 1/20 Tryptic Soy Broth enhanced biofilm formation in Salmonella. This could explain the great differences in biofilm formation found between this growth medium and food residues. However, Salmonella strains were able to produce biofilm on the presence of food residues in all the conditions tested. Therefore, the Salmonella strain can use food residues to produce biofilm on common surfaces of the food chain. More studies combining more strains and food residues are necessary to fully understand the mechanism used by Salmonella to produce biofilm on the presence of these sources of nutrients.

  11. Effect of Food Residues in Biofilm Formation on Stainless Steel and Polystyrene Surfaces by Salmonella enterica Strains Isolated from Poultry Houses.

    Science.gov (United States)

    Paz-Méndez, Alba María; Lamas, Alexandre; Vázquez, Beatriz; Miranda, José Manuel; Cepeda, Alberto; Franco, Carlos Manuel

    2017-11-29

    Salmonella spp. is a major food-borne pathogen around the world. The ability of Salmonella to produce biofilm is one of the main obstacles in reducing the prevalence of these bacteria in the food chain. Most of Salmonella biofilm studies found in the literature used laboratory growth media. However, in the food chain, food residues are the principal source of nutrients of Salmonella . In this study, the biofilm formation, morphotype, and motility of 13 Salmonella strains belonging to three different subspecies and isolated from poultry houses was evaluated. To simulate food chain conditions, four different growth media (Tryptic Soy Broth at 1/20 dilution, milk at 1/20 dilution, tomato juice, and chicken meat juice), two different surfaces (stainless steel and polystyrene) and two temperatures (6 °C and 22 °C) were used to evaluate the biofilm formation. The morphotype, motility, and biofilm formation of Salmonella was temperature-dependent. Biofilm formation was significantly higher with 1/20 Tryptic Soy Broth in all the surfaces and temperatures tested, in comparison with the other growth media. The laboratory growth medium 1/20 Tryptic Soy Broth enhanced biofilm formation in Salmonella . This could explain the great differences in biofilm formation found between this growth medium and food residues. However, Salmonella strains were able to produce biofilm on the presence of food residues in all the conditions tested. Therefore, the Salmonella strain can use food residues to produce biofilm on common surfaces of the food chain. More studies combining more strains and food residues are necessary to fully understand the mechanism used by Salmonella to produce biofilm on the presence of these sources of nutrients.

  12. Contamination of Carcasses and Utensils in Small Swine Slaughterhouses by Salmonella in the Northwestern Region of the State of Rio de Janeiro, Brazil.

    Science.gov (United States)

    Cabral, Claudius Couto; Panzenhagen, Pedro Henrique Nunes; Delgado, Karina Frensel; Silva, Gabriela Rodrigues Alves; Rodrigues, Dália Dos Prazeres; Franco, Robson Maia; Conte-Junior, Carlos Adam

    2017-07-01

    Salmonella is a major foodborne pathogen that constantly threatens food safety in developed countries and underdeveloped countries such as Brazil, where it is responsible for 38% of notified cases of foodborne illness. Swine are one of the main meat-producing species that may asymptomatically carry Salmonella, periodically shedding the bacteria through feces. The state of Rio de Janeiro is not a major producer of swine meat, but small slaughterhouses are operational and produce meat for consumption within the state, although few studies have been conducted in the region. In this context, this study was designed to evaluate Salmonella contamination in carcasses, lymph nodes, feces, utensils, and the environment of three small slaughterhouses in the state of Rio de Janeiro. A total of 344 samples from carcasses, utensils, equipment, water, and the environment were collected from these slaughterhouses in the northwestern region of Rio de Janeiro. Salmonella was isolated from 36 (10.5%) samples: 10 of 48 carcasses, 19 of 96 lymph nodes, 4 of 48 fecal samples, 2 of 6 water samples, and 1 of 6 bleeding knives; 55 isolates were recovered. Serotyping revealed the predominance of Salmonella Typhimurium (20 isolates) followed by Salmonella Abony (10 isolates), Salmonella Give (7 isolates), Salmonella Heidelberg (4 isolates), and Salmonella Infantis (1 isolate). Ten isolates were only partially typeable, with only their O antigen identified, and three isolates had rough, nontypeable colonies. Despite the overall low prevalence of Salmonella in this study, all three slaughterhouses had poor hygienic and sanitary conditions, providing easy routes for carcass and, consequently, meat contamination. Thus, it is imperative to enforce sanitary inspections in these establishments and to apply good manufacture practices to assure the safety of the produced pork.

  13. Anaerobiosis induced virulence of Salmonella typhi

    DEFF Research Database (Denmark)

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

    2002-01-01

    , we examined the effect of anaerobiosis on the virulence of Salmonella Typhi, a Gram negative bacteria which invades through the gut mucosa and is responsible for typhoid fever. METHODS: Salmonella Typhi (ty2) was cultured in aerobic and anaerobic conditions to compare its virulence by rabbit ileal...

  14. Antibiotic susceptibilities of Salmonella species prevalent among ...

    African Journals Online (AJOL)

    This study was conducted to assess the prevalence of Salmonella species among children having diarrhea in Katsina State, Nigeria. A total of 220 diarrhea stool samples of children aged five years and below (0-5 years) were collected and screened for Salmonella species using culture technique. Presumptively positive ...

  15. antimicrobial susceptibility pattern of Salmonella species

    African Journals Online (AJOL)

    user

    ABSTRACT. Treatment of enteric fever is increasingly becoming very challenging due to the increasing wave of antibiotic resistance. This study is a review of the contemporary antimicrobial susceptibility pattern of. Salmonella species. The antimicrobial susceptibility pattern of Salmonella species to a wide range of.

  16. Case Report: Salmonella lung infection | Ohanu | International ...

    African Journals Online (AJOL)

    A case of an 84 year old man admitted because of fever, abdominal discomfort, weakness, past history of cough wheezing and abuse of prednisolone and Erythromycin. He had Bronchopneumonia and diabetes. Salmonella typhimurium was isolated from both his sputum and blood while stool was negative for salmonella.

  17. Rapid detection and characterization of Salmonella enterica ...

    African Journals Online (AJOL)

    Multiplex polymerase chain reaction (PCR) was used for molecular typing of Salmonella enterica serovars in Egypt. During the summer of 2010, a total of 1075 samples were collected from cattle, sheep and poultry farms to be subjected for isolation of Salmonella (290 rectal swabs from cattle, 335 rectal swabs from sheep ...

  18. Salmonella infection acquired from reptilian pets.

    Science.gov (United States)

    Sanyal, D; Douglas, T; Roberts, R

    1997-10-01

    Two children presented with signs and symptoms of gastroenteritis. Salmonella chameleon was isolated from the stool of one child and also from an iguana kept in the home as a pet. Salmonella arizonae was isolated from the stool of the other child and also from four snakes sharing the same household. Exotic reptiles are unsuitable pets to share the home environment with infants.

  19. Salmonella in the lairage of pig slaughterhouses

    NARCIS (Netherlands)

    Swanenburg, M.; Urlings, H.A.P.; Keuzenkamp, D.A.; Snijders, J.M.A.

    2001-01-01

    The purpose of this study was to determine if lairages of pig slaughterhouses can act as a source of contamination of slaughtered pigs with Salmonella. The prevalence and variety of serotypes of Salmonella in the lairages of two pig slaughterhouses were determined, and the efficacy of the usual

  20. Subversion of the cytoskeleton by intracellular bacteria: lessons from Listeria, Salmonella, and Vibrio

    Science.gov (United States)

    de Souza Santos, Marcela; Orth, Kim

    2018-01-01

    Summary Entry into host cells and intracellular persistence by invasive bacteria are tightly coupled to the ability of the bacterium to disrupt the eukaryotic cytoskeletal machinery. Herein we review the main strategies used by three intracellular pathogens to harness key modulators of the cytoskeleton. Two of these bacteria, namely Listeria monocytogenes and Salmonella enterica serovar Typhimurium, exhibit quite distinct intracellular lifestyles, and therefore, provide a comprehensive panel for the understanding of the intricate bacteria-cytoskeleton interplay during infections. The emerging intracellular pathogen Vibrio parahaemolyticus is depicted as a developing model for the uncovering of novel mechanisms used to hijack the cytoskeleton. PMID:25440316

  1. Inactivation of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhimurium with compounds available in households.

    Science.gov (United States)

    Yang, Hua; Kendall, Patricia A; Medeiros, Lydia; Sofos, John N

    2009-06-01

    Solutions of selected household products were tested for their effectiveness against Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium. Hydrogen peroxide (1.5 and 3%), vinegar (2.5 and 5% acetic acid), baking soda (11, 33, and 50% sodium bicarbonate), household bleach (0.0314, 0.0933, and 0.670% sodium hypochlorite), 5% acetic acid (prepared from glacial acetic acid), and 5% citric acid solutions were tested against the three pathogens individually (five-strain composites of each, 10(8) CFU/ml) by using a modified AOAC International suspension test at initial temperatures of 25 and 55degrees C for 1 and 10 min. All bleach solutions (pH 8.36 to 10.14) produced a >5-log reduction of all pathogens tested after 1 min at 25 degrees C, whereas all baking soda solutions (pH 7.32 to 7.55) were ineffective (5-log reduction of both Salmonella Typhimurium and E. coli O157:H7, whereas undiluted vinegar (pH 2.58) had a similar effect only against Salmonella Typhimurium. Compared with 1 min at 25 degrees C, greater reductions of L. monocytogenes (P 3% hydrogen peroxide > undiluted vinegar and 5% acetic acid > 5% citric acid > baking soda (50% sodium bicarbonate). The sensitivity of the tested pathogens to all tested household compounds followed the sequence of Salmonella Typhimurium > E. coli O157: H7 > L. monocytogenes.

  2. Identification of CsrC and Characterization of Its Role in Epithelial Cell Invasion in Salmonella enterica Serovar Typhimurium

    OpenAIRE

    Fortune, Doreen R.; Suyemoto, Mitsu; Altier, Craig

    2006-01-01

    The csr regulatory system of Salmonella regulates the expression of the genes of Salmonella pathogenicity island 1 (SPI1) required for the invasion of epithelial cells. This system consists of the posttranscriptional regulator CsrA and an untranslated regulatory RNA, CsrB, that opposes the action of CsrA. Here we identify and characterize the role of a second regulatory RNA, CsrC, whose ortholog was discovered previously in Escherichia coli. We show that a mutant of csrC has only mild defects...

  3. Viable-but-Nonculturable Listeria monocytogenes and Salmonella enterica Serovar Thompson Induced by Chlorine Stress Remain Infectious

    Directory of Open Access Journals (Sweden)

    Callum J. Highmore

    2018-04-01

    Full Text Available The microbiological safety of fresh produce is monitored almost exclusively by culture-based detection methods. However, bacterial food-borne pathogens are known to enter a viable-but-nonculturable (VBNC state in response to environmental stresses such as chlorine, which is commonly used for fresh produce decontamination. Here, complete VBNC induction of green fluorescent protein-tagged Listeria monocytogenes and Salmonella enterica serovar Thompson was achieved by exposure to 12 and 3 ppm chlorine, respectively. The pathogens were subjected to chlorine washing following incubation on spinach leaves. Culture data revealed that total viable L. monocytogenes and Salmonella Thompson populations became VBNC by 50 and 100 ppm chlorine, respectively, while enumeration by direct viable counting found that chlorine caused a <1-log reduction in viability. The pathogenicity of chlorine-induced VBNC L. monocytogenes and Salmonella Thompson was assessed by using Caenorhabditis elegans. Ingestion of VBNC pathogens by C. elegans resulted in a significant life span reduction (P = 0.0064 and P < 0.0001, and no significant difference between the life span reductions caused by the VBNC and culturable L. monocytogenes treatments was observed. L. monocytogenes was visualized beyond the nematode intestinal lumen, indicating resuscitation and cell invasion. These data emphasize the risk that VBNC food-borne pathogens could pose to public health should they continue to go undetected.

  4. Distinct fermentation and antibiotic sensitivity profiles exist in salmonellae of canine and human origin.

    Science.gov (United States)

    Wallis, Corrin V; Lowden, Preena; Marshall-Jones, Zoe V; Hilton, Anthony C

    2018-02-26

    Salmonella enterica is a recognised cause of diarrhoea in dogs and humans, yet the potential for transfer of salmonellosis between dogs and their owners is unclear, with reported evidence both for and against Salmonella as a zoonotic pathogen. A collection of 174 S. enterica isolates from clinical infections in humans and dogs were analysed for serotype distribution, carbon source utilisation, chemical and antimicrobial sensitivity profiles. The aim of the study was to understand the degree of conservation in phenotypic characteristics of isolates across host species. Serovar distribution across human and canine isolates demonstrated nine serovars common to both host species, 24 serovars present in only the canine collection and 39 solely represented within the human collection. Significant differences in carbon source utilisation profiles and ampicillin, amoxicillin and chloramphenicol sensitivity profiles were detected in isolates of human and canine origin. Differences between the human and canine Salmonella collections were suggestive of evolutionary separation, with canine isolates better able to utilise several simple sugars than their human counterparts. Generally higher minimum inhibitory concentrations of three broad-spectrum antimicrobials, commonly used in veterinary medicine, were also observed in canine S. enterica isolates. Differential carbon source utilisation and antimicrobial sensitivity profiles in pathogenic Salmonella isolated from humans and dogs are suggestive of distinct reservoirs of infection for these hosts. Although these findings do not preclude zoonotic or anthroponotic potential in salmonellae, the separation of carbon utilisation and antibiotic profiles with isolate source is indicative that infectious isolates are not part of a common reservoir shared frequently between these host species.

  5. The dietary polysaccharide maltodextrin promotes Salmonella survival and mucosal colonization in mice.

    Directory of Open Access Journals (Sweden)

    Kourtney P Nickerson

    Full Text Available In the latter half of the 20th century, societal and technological changes led to a shift in the composition of the American diet to include a greater proportion of processed, pre-packaged foods high in fat and carbohydrates, and low in dietary fiber (a "Western diet". Over the same time period, there have been parallel increases in Salmonella gastroenteritis cases and a broad range of chronic inflammatory diseases associated with intestinal dysbiosis. Several polysaccharide food additives are linked to bacterially-driven intestinal inflammation and may contribute to the pathogenic effects of a Western diet. Therefore, we examined the effect of a ubiquitous polysaccharide food additive, maltodextrin (MDX, on clearance of the enteric pathogen Salmonella using both in vitro and in vivo infection models. When examined in vitro, murine bone marrow-derived macrophages exposed to MDX had altered vesicular trafficking, suppressed NAPDH oxidase expression, and reduced recruitment of NADPH oxidase to Salmonella-containing vesicles, which resulted in persistence of Salmonella in enlarged Rab7+ late endosomal vesicles. In vivo, mice consuming MDX-supplemented water had a breakdown of the anti-microbial mucous layer separating gut bacteria from the intestinal epithelium surface. Additionally, oral infection of these mice with Salmonella resulted in increased cecal bacterial loads and enrichment of lamina propria cells harboring large Rab7+ vesicles. These findings indicate that consumption of processed foods containing the polysaccharide MDX contributes to suppression of intestinal anti-microbial defense mechanisms and may be an environmental priming factor for the development of chronic inflammatory disease.

  6. Heat Tolerances of Salmonella, Cronobacter sakazakii, and Pediococcus acidilactici Inoculated into Galactooligosaccharide.

    Science.gov (United States)

    Bang, Jihyun; Choi, Moonkak; Jeong, Haeseok; Lee, Sangseob; Kim, Yoonbin; Ryu, Jee-Hoon; Kim, Hoikyung

    2017-07-01

    Food-grade galactooligosaccharide (GOS) with low water activity (a w of ca. 0.7) is used as an ingredient in various foods. We evaluated heat tolerances of Salmonella, Cronobacter sakazakii, and Pediococcus acidilactici at temperatures (70 to 85°C) used during the saturation process of GOS by comparing decimal reduction time (D-values) and thermal resistance constants (z-values). To determine the D- and z-values, GOS containing Salmonella (5.1 to 5.8 log CFU/g) or C. sakazakii (5.3 to 5.9 log CFU/g) was heat treated at 70, 77.5, or 85°C for up to 40, 25, or 15 s, respectively, and GOS containing P. acidilactici (6.1 to 6.5 log CFU/g) was heat treated at 70, 77.5, or 85°C for up to 150, 75, or 40 s, respectively. The D-values were calculated using a linear model for heating time versus microbial population for each bacterium. When the D-values for Salmonella, C. sakazakii, and P. acidilactici in GOS were compared, the thermal resistance of all bacteria decreased as the temperature increased. Among the three bacteria, P. acidilactici had higher D-values than did Salmonella and C. sakazakii. The z-values of Salmonella, C. sakazakii, and P. acidilactici were 30.10, 33.18, and 13.04°C, respectively. Overall order of thermal resistance was P. acidilactici > Salmonella ≈ C. sakazakii. These results will be useful for selecting appropriate heat treatment conditions for the decontamination of pathogenic microorganisms during GOS manufacturing.

  7. Differential Levels of Cecal Colonization by Salmonella Enteritidis in Chickens Triggers Distinct Immune Kinome Profiles

    Directory of Open Access Journals (Sweden)

    Christina L. Swaggerty

    2017-12-01

    Full Text Available Salmonella enterica serovar Enteritidis are facultative intracellular bacteria that cause disease in numerous species. Salmonella-related infections originating from poultry and/or poultry products are a major cause of human foodborne illness with S. Enteritidis the leading cause worldwide. Despite the importance of Salmonella to human health and chickens being a reservoir, little is known of the response to infection within the chicken gastrointestinal tract. Using chicken-specific kinome immune peptide arrays we compared a detailed kinomic analysis of the chicken jejunal immune response in a single line of birds with high and low Salmonella loads. Four-day-old chicks were challenged with S. Enteritidis (105 cfu and cecal content and a section of jejunum collected at three times: early [4–7 days post-infection (dpi], middle (10–17 dpi, and late (24–37 dpi. Salmonella colonization was enumerated and birds with the highest (n = 4 and lowest (n = 4 loads at each time were selected for kinomic analyses. Key biological processes associated with lower loads of Salmonella clustered around immune responses, including cell surface receptor signaling pathway, positive regulation of cellular processes, defense response, innate immune response, regulation of immune response, immune system process, and regulation of signaling. Further evaluation showed specific pathways including chemokine, Jak–Stat, mitogen activated protein kinase, and T cell receptor signaling pathways were also associated with increased resistance. Collectively, these findings demonstrate that it is possible to identify key mechanisms and pathways that are associated with increased resistance against S. Enteritidis cecal colonization in chickens. Therefore, providing a foundation for future studies to identify specific proteins within these pathways that are associated with resistance, which could provide breeders additional biomarkers to identify birds naturally

  8. Efficacy of disinfectants and detergents intended for a pig farm environment where Salmonella is present.

    Science.gov (United States)

    Gosling, Rebecca J; Mawhinney, Ian; Vaughan, Kelly; Davies, Robert H; Smith, Richard P

    2017-05-01

    Disinfection is a useful component of disease control, although products and chemical groups vary in their activity against different pathogens. This study investigated the ability of fifteen disinfectants to eliminate pig-associated Salmonella. Active compounds of products included chlorocresol, glutaraldehyde/formaldehyde, glutaraldehyde/quaternary ammonium compounds (QAC), iodine, peracetic acid and potassium peroxomonosulphate. Six detergents were also tested for their ability to dislodge faecal material, and interactions with specific disinfectants. Eight serovars were screened against all products using dilution tests and a monophasic Salmonella Typhimurium strain was selected for further testing. The disinfectants were tested using models to replicate boot dip (faecal suspension) and animal housing (surface contamination) disinfection respectively at the Department for Environment, Food and Rural Affairs Approved Disinfectant General Orders (GO) concentration, half GO and twice GO. Stability over time and ability to eliminate Salmonella in biofilm was also assessed. The most effective products were then field tested. Most products at GO concentration eliminated Salmonella in the faecal suspension model. One glutaraldehyde/QAC and one glutaraldehyde/formaldehyde-based product at GO concentration eliminated Salmonella in the surface contamination model. Chlorocresol-based products were more stable in the faecal suspension model. One chlorocresol and the glutaraldehyde/formaldehyde-based product were most successful in eliminating Salmonella from biofilms. All products tested on farm reduced bacterial log counts; the glutaraldehyde/QAC based product produced the greatest reduction. The type of product and the application concentration can impact on efficacy of farm disinfection; therefore, clearer guidance is needed to ensure the appropriate programmes are used for specific environments. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  9. A novel secretion pathway of Salmonella enterica acts as an antivirulence modulator during salmonellosis.

    Directory of Open Access Journals (Sweden)

    Ohad Gal-Mor

    2008-04-01

    Full Text Available Salmonella spp. are Gram-negative enteropathogenic bacteria that infect a variety of vertebrate hosts. Like any other living organism, protein secretion is a fundamental process essential for various aspects of Salmonella biology. Herein we report the identification and characterization of a horizontally acquired, autonomous and previously unreported secretion pathway. In Salmonella enterica serovar Typhimurium, this novel secretion pathway is encoded by STM1669 and STM1668, designated zirT and zirS, respectively. We show that ZirT is localized to the bacterial outer membrane, expected to adopt a compact beta-barrel conformation, and functions as a translocator for ZirS. ZirS is an exoprotein, which is secreted into the extracellular environment in a ZirT-dependent manner. The ZirTS secretion pathway was found to share several important features with two-partner secretion (TPS systems and members of the intimin/invasin family of adhesions. We show that zirTS expression is affected by zinc; and that in vivo, induction of zirT occurs distinctively in Salmonella colonizing the small intestine, but not in systemic sites. Additionally, strong expression of zirT takes place in Salmonella shed in fecal pellets during acute and persistent infections of mice. Inactivation of ZirTS results in a hypervirulence phenotype of Salmonella during oral infection of mice. Cumulatively, these results indicate that the ZirTS pathway plays a unique role as an antivirulence modulator during systemic disease and is involved in fine-tuning a host-pathogen balance during salmonellosis.

  10. Evolution of Salmonella enterica virulence via point mutations in the fimbrial adhesin.

    Directory of Open Access Journals (Sweden)

    Dagmara I Kisiela

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

  11. Non-Typhoidal Salmonella Aortitis in a transplant patient

    International Nuclear Information System (INIS)

    Tarif, N.; Azam, M.N.; Mitwalli, Ahmad H.; Al-Wakeel, Jamal S.; El-Kheder, A. Al-Aboud

    2002-01-01

    Non-typhoidal salmonella bacteremia may result in extra gastrointestinallocalization of infection. Aortitis due to non-typhoidal salmonella wasreported to be the cause of 38-42% of all infected abdominal aortitis.Underlying atherosclerosis is a frequent site for salmonella aortitis. Wedescribe here a case of possible salmonella aortitis in a renal transplantpatient. (author)

  12. 9 CFR 113.123 - Salmonella Dublin Bacterin.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Salmonella Dublin Bacterin. 113.123... Inactivated Bacterial Products § 113.123 Salmonella Dublin Bacterin. Salmonella Dublin Bacterin shall be prepared from a culture of Salmonella dublin which has been inactivated and is nontoxic. Each serial of...

  13. 9 CFR 113.122 - Salmonella Choleraesuis Bacterin.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Salmonella Choleraesuis Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.122 Salmonella Choleraesuis Bacterin. Salmonella Choleraesuis Bacterin shall be prepared from a culture of Salmonella choleraesuis which has been inactivated and is...

  14. 9 CFR 113.120 - Salmonella Typhimurium Bacterin.

    Science.gov (United States)

    2010-01-01

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

  15. Occurrence of Foodborne Pathogens and Molds in Turkish Foods

    OpenAIRE

    Sebnem Ozturkogu-Budak

    2016-01-01

    A survey of the occurrence of food pathogens like Salmonella, Listeria, Escherichia, Clostridium, Bacillus and Staphylococcus analyses were performed on 301 food samples from 8 different food categories such as dry legumes, milk products, meat products, fish, frozen foods, deserts, nuts and vegetables and fruits. Yeast and mold analyses were also performed on 364 food products from 9 main food categories such as dry legumes, milk products, meat products, seasonings, deserts, nuts, bee product...

  16. Antimicrobial Resistance Percentages of Salmonella and Shigella in Seafood Imported to Jordan: Higher Percentages and More Diverse Profiles in Shigella.

    Science.gov (United States)

    Obaidat, Mohammad M; Bani Salman, Alaa E

    2017-03-01

    This study determined the prevalence and antimicrobial resistance of human-specific ( Shigella spp.) and zoonotic ( Salmonella enterica ) foodborne pathogens in internationally traded seafood. Sixty-four Salmonella and 61 Shigella isolates were obtained from 330 imported fresh fish samples from Egypt, Yemen, and India. The pathogens were isolated on selective media, confirmed by PCR, and tested for antimicrobial resistance. Approximately 79 and 98% of the Salmonella and Shigella isolates, respectively, exhibited resistance to at least one antimicrobial, and 8 and 49% exhibited multidrug resistance (resistance to three or more antimicrobial classes). Generally, Salmonella exhibited high resistance to amoxicillin-clavulanic acid, cephalothin, streptomycin, and ampicillin; very low resistance to kanamycin, tetracycline, gentamicin, chloramphenicol, nalidixic acid, sulfamethoxazole-trimethoprim, and ciprofloxacin; and no resistance to ceftriaxone. Meanwhile, Shigella spp. exhibited high resistance to tetracycline, amoxicillin-clavulanic acid, cephalothin, streptomycin, and ampicillin; low resistance to kanamycin, nalidixic acid, sulfamethoxazole-trimethoprim, and ceftriaxone; and very low resistance to gentamicin and ciprofloxacin. Salmonella isolates exhibited 14 resistance profiles, Shigella isolates 42. This study is novel in showing that a human-specific pathogen has higher antimicrobial resistance percentages and more diverse profiles than a zoonotic pathogen. Thus, the impact of antimicrobial use in humans is as significant as, if not more significant than, it is in animals in spreading antibiotic resistance through food. This study also demonstrates that locally derived antimicrobial resistance can spread and pose a public health risk worldwide through seafood trade and that high resistance would make a possible outbreak difficult to control. So, capacity building and monitoring harvest water areas are encouraged in fish producing countries.

  17. Colonisation of poultry by Salmonella Enteritidis S1400 is reduced by combined administration of Lactobacillus salivarius 59 and Enterococcus faecium PXN-33.

    Science.gov (United States)

    Carter, Alun; Adams, Martin; La Ragione, Roberto M; Woodward, Martin J

    2017-02-01

    Salmonella Enteritidis remains a significant issue within the poultry industry and one potential solution is to use probiotic bacteria to prevent Salmonella colonisation through competitive exclusion (CE). We demonstrate that combined administration of Lactobacillus salivarius 59 and Enterococcus faecium PXN33 were effective competitive excluders of Salmonella Enteritidis S1400 in poultry. Two models were developed to evaluate the efficacy of probiotic where birds received Salmonella Enteritidis S1400 by a) oral gavage and b) sentinel bird to bird transmission. A statistically significant (p<0.001) 2 log reduction of Salmonella Enteritidis S1400 colonisation was observed in the ileum, caecum and colon at day 43 using combined administration of the two probiotic bacteria. However, no Salmonella Enteritidis S1400 colonisation reduction was observed when either probiotic was administered individually. In the sentinel bird model the combined probiotic administered at days 12 and 20 was more effective than one-off or double administrations at age 1 and 12days. In vitro cell free culture supernatant studies suggest the mechanism of Salmonella Enteritidis S1400 inhibition was due to a reduction in pH by the probiotic bacteria. Our current study provides further evidence that probiotics can significantly reduce pathogenic bacterial colonisation in poultry and that mixed preparation of probiotics provide superior performance when compared to individual bacterial preparations. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Prevalence, serotype diversity, and antimicrobial resistance of Salmonella in imported shipments of spice offered for entry to the United States, FY2007-FY2009.

    Science.gov (United States)

    Van Doren, Jane M; Kleinmeier, Daria; Hammack, Thomas S; Westerman, Ann

    2013-06-01

    In response to increased concerns about spice safety, the U.S. FDA initiated research to characterize the prevalence of Salmonella in imported spices. Shipments of imported spices offered for entry to the United Sates were sampled during the fiscal years 2007-2009. The mean shipment prevalence for Salmonella was 0.066 (95% CI 0.057-0.076). A wide diversity of Salmonella serotypes was isolated from spices; no single serotype constituted more than 7% of the isolates. A small percentage of spice shipments were contaminated with antimicrobial-resistant Salmonella strains (8.3%). Trends in shipment prevalence for Salmonella associated with spice properties, extent of processing, and export country, were examined. A larger proportion of shipments of spices derived from fruit/seeds or leaves of plants were contaminated than those derived from the bark/flower of spice plants. Salmonella prevalence was larger for shipments of ground/cracked capsicum and coriander than for shipments of their whole spice counterparts. No difference in prevalence was observed between shipments of spice blends and non-blended spices. Some shipments reported to have been subjected to a pathogen reduction treatment prior to being offered for U.S. entry were found contaminated. Statistical differences in Salmonella shipment prevalence were also identified on the basis of export country. Published by Elsevier Ltd.

  19. Salmonella spp. and antibiotic-resistant strains in wild mammals and birds in north-western Italy from 2002 to 2010

    Directory of Open Access Journals (Sweden)

    Velca Botti

    2013-06-01

    Full Text Available Salmonella is an important zoonotic pathogen of economic importance. In Europe, salmonellosis is the second food-borne infection, in Italy, Salmonella is still the major cause of food-borne outbreaks. In Europe, there are many Salmonella surveillance plans on farmed animals, while Salmonella survey of wild animals is occasionally performed. The aim of this study was to investigate the presence of Salmonella including the antibiotic-resistant strains in wild animals. Between 2002 and 2010, 2,713 wild animals (canids, mustelids, birds, rodents, ungulates, were collected in north-western Italy and tested for Salmonella by classical microbiological culture method followed by serological and biochemical typing. One hundred and seventeen wild animals (63 canids, 25 mustelids, 24 birds, 5 ungulates were found positive for Salmonella (4.3%. One hundred and thirty strains, belonging to several serotypes were isolated, and S. Typhimurium was the most common serotype found. Antibiotic susceptibility was tested by disk-diffusion test on 88 strains. Almost all the analyzed strains (97.7% showed resistance/intermediate resistance to at least one class of antibiotics and the highest resistance values were observed for the tetracycline class. In conclusion, zoonotic and antibiotic-resistant serotypes were found in many species of wildlife.

  20. Class 1 integrons characterization and multilocus sequence typing of Salmonella spp. from swine production chains in Chiang Mai and Lamphun provinces, Thailand.

    Science.gov (United States)

    Boonkhot, Phacharaporn; Tadee, Pakpoom; Yamsakul, Panuwat; Pocharoen, Chairoj; Chokesajjawatee, Nipa; Patchanee, Prapas

    2015-05-01

    Pigs and pork products are well known as an important source of Salmonella, one of the major zoonotic foodborne pathogens. The emergence and spread of antimicrobial resistance is becoming a major public health concern worldwide. Integrons are genetic elements known to have a role in the acquisition and expression of genes conferring antibiotic resistance. This study focuses on the prevalence of class 1 integrons-carrying Salmonella, the genetic diversity of strains of those organisms obtained from swine production chains in Chiang Mai and Lamphun provinces, Thailand, using multilocus sequence typing (MLST) and comparison of genetic diversity of sequence types of Salmonella from this study with pulsotypes identified in previous study. In 175 Salmonella strains, the overall prevalence of class 1 integrons-carrying-Salmonella was 14%. The gene cassettes array pattern "dfrA12-orfF-aadA2" was the most frequently observed. Most of the antimicrobial resistance identified was not associated with related gene cassettes harbored by Salmonella. Six sequence types were generated from 30 randomly selected strains detected by MLST. Salmonella at the human-animal-environment interface was confirmed. Linkages both in the farm to slaughterhouse contamination route and the horizontal transmission of resistance genes were demonstrated. To reduce this problem, the use of antimicrobials in livestock should be controlled by veterinarians. Education and training of food handlers as well as promotion of safe methods of food consumption are important avenues for helping prevent foodborne illness.

  1. Persistence and potential Viable but Non-culturable state of pathogenic bacteria during storage of digestates from agricultural biogas plants

    Directory of Open Access Journals (Sweden)

    Geraldine Maynaud

    2016-09-01

    Full Text Available Despite the development of on-farm anaerobic digestion as a process for making profitable use of animal by-products, factors leading to the inactivation of pathogenic bacteria during storage of digestates remain poorly described. Here, a microcosm approach was used to evaluate the persistence of three pathogenic bacteria (Salmonella enterica Derby, Campylobacter coli and Listeria monocytogenes in digestates from farms, stored for later land spreading. Nine samples, including raw digestates, liquid fractions of digestate and composted digestates, were inoculated with each pathogen and maintained for 40 days at 24°C. Concentrations of pathogens were monitored using culture and qPCR methods. The persistence of L. monocytogenes, detected up to 20 days after inoculation, was higher than that of Salmonella Derby, detected for 7-20 days, and of C. coli (not detected after 7 days. In some digestates, the concentration of the pathogens by qPCR assay was several orders of magnitude higher than the concentration of culturable cells, suggesting a potential loss of culturability and induction of Viable but Non-Culturable (VBNC state. The potential VBNC state which was generally not observed in the same digestate for the three pathogens, occurred more frequently for C. coli and L. monocytogenes than for Salmonella Derby. Composting a digestate reduced the persistence of seeded L. monocytogenes but promoted the maintenance of Salmonella Derby. The effect of NH4+/NH3 on the culturability of C. coli and Salmonella Derby was also shown.The loss of culturability may be the underlying mechanism for the regrowth of pathogens. We have also demonstrated the importance of using molecular tools to monitor pathogens in environmental samples since culture methods may underestimate cell concentration. Our results underline the importance of considering VBNC cells when evaluating the sanitary effect of an anaerobic digestion process and the persistence of pathogens during

  2. Splenic abscesses from Salmonella infection

    International Nuclear Information System (INIS)

    Gomez, Carmen Cecilia; Zuniga Eduardo

    2005-01-01

    Spleen abscesses are uncommon. We describe the case of a 56 year-old man who presented with diarrhea, fever, vomiting and weight loss. On physical examination, the main findings included jaundice, hepatomegaly and ascites. Diagnostic imaging showed the presence of spleen abscesses, due to Salmonella species. Considering the type of abscess, medical treatment was given without the need for interventional treatment, resulting in a satisfactory outcome. No other risk factor was found, other than the gastrointestinal focus as the precursor of the splenic abscess.

  3. Flow cytometry for rapid detection of Salmonella spp. in seed sprouts

    Directory of Open Access Journals (Sweden)

    Bledar Bisha

    2014-12-01

    Full Text Available Seed sprouts (alfalfa, mung bean, radish, etc. have been implicated in several recent national and international outbreaks of salmonellosis. Conditions used for sprouting are also conducive to the growth of Salmonella. As a result, this pathogen can quickly grow to very high cell densities during sprouting without any detectable organoleptic impact. Seed sprouts typically also support heavy growth (~108 CFU g−1 of a heterogeneous microbiota consisting of various bacterial, yeast, and mold species, often dominated by non-pathogenic members of the family Enterobacteriaceae. This heavy background may present challenges to the detection of Salmonella, especially if this pathogen is present in relatively low numbers. We combined DNA-based fluorescence in situ hybridization (FISH with flow cytometry (FCM for the rapid molecular detection of Salmonella enterica ser. Typhimurium in artificially contaminated alfalfa and other seed sprouts. Components of the assay included a set of cooperatively binding probes, a chemical blocking treatment intended to reduce non-specific background, and sample concentration via tangential flow filtration (TFF. We were able to detect S. Typhimurium in sprout wash at levels as low as 103 CFU ml−1 sprout wash (104 CFU g−1 sprouts against high microbial backgrounds (~108 CFU g−1 sprouts. Hybridization times were typically 30 min, with additional washing, but we ultimately found that S. Typhimurium could be readily detected using hybridization times as short as 2 min, without a wash step. These results clearly demonstrate the potential of combined DNA-FISH and FCM for rapid detection of Salmonella in this challenging food matrix and provide industry with a useful tool for compliance with sprout production standards proposed in the Food Safety Modernization Act (FSMA.

  4. Characteristics of Clusters of Salmonella and Escherichia coli O157 Detected by Pulsed-Field Gel Electrophoresis that Predict Identification of Outbreaks.

    Science.gov (United States)

    Jones, Timothy F; Sashti, Nupur; Ingram, Amanda; Phan, Quyen; Booth, Hillary; Rounds, Joshua; Nicholson, Cyndy S; Cosgrove, Shaun; Crocker, Kia; Gould, L Hannah

    2016-12-01

    Molecular subtyping of pathogens is critical for foodborne disease outbreak detection and investigation. Many clusters initially identified by pulsed-field gel electrophoresis (PFGE) are not confirmed as point-source outbreaks. We evaluated characteristics of clusters that can help prioritize investigations to maximize effective use of limited resources. A multiagency collaboration (FoodNet) collected data on Salmonella and Escherichia coli O157 clusters for 3 years. Cluster size, timing, extent, and nature of epidemiologic investigations were analyzed to determine associations with whether the cluster was identified as a confirmed outbreak. During the 3-year study period, 948 PFGE clusters were identified; 849 (90%) were Salmonella and 99 (10%) were E. coli O157. Of those, 192 (20%) were ultimately identified as outbreaks (154 [18%] of Salmonella and 38 [38%] of E. coli O157 clusters). Successful investigation was significantly associated with larger cluster size, more rapid submission of isolates (e.g., for Salmonella, 6 days for outbreaks vs. 8 days for nonoutbreaks) and PFGE result reporting to investigators (16 days vs. 29 days, respectively), and performance of analytic studies (completed in 33% of Salmonella outbreaks vs. 1% of nonoutbreaks) and environmental investigations (40% and 1%, respectively). Intervals between first and second cases in a cluster did not differ significantly between outbreaks and nonoutbreaks. Molecular subtyping of pathogens is a rapidly advancing technology, and successfully identifying outbreaks will vary by pathogen and methods used. Understanding criteria for successfully investigating outbreaks is critical for efficiently using limited resources.

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

    Science.gov (United States)

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

    2014-11-01

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

  6. Prevalence of intestinal pathogens in Danish finishing pig herds

    DEFF Research Database (Denmark)

    Stege, H.; Jensen, Tim Kåre; Møller, Kristian

    2000-01-01

    Our aim was to determine the prevalence of the intestinal bacteria: Lawsonia intracellularis, Brachyspira hyodysenteriae, Serpulina intermedia, Brachyspira innocens, Brachyspira pilosicoli, pathogenic Escherichia coli (serogroups 0138, 0139, 0141 and 0149) and Salmonella enterica in Danish...... were collected and examined by polymerase chain reaction (PCR) or culture. L. intracellularis was found in 74 herds (93.7%), B. hyodysenteriae in two herds (2.5%), S. intermedia in 10 herds (12.7%), B. innocens in 27 herds (34.2%), B. pilosicoli in 15 herds (19.0%), pathogenic E. call in 19 herds (24...

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

    International Nuclear Information System (INIS)

    Ben salem, Issam

    2007-01-01

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

  8. Detection of Salmonella spp. in veterinary samples by combining selective enrichment and real-time PCR.

    Science.gov (United States)

    Goodman, Laura B; McDonough, Patrick L; Anderson, Renee R; Franklin-Guild, Rebecca J; Ryan, James R; Perkins, Gillian A; Thachil, Anil J; Glaser, Amy L; Thompson, Belinda S

    2017-11-01

    Rapid screening for enteric bacterial pathogens in clinical environments is essential for biosecurity. Salmonella found in veterinary hospitals, particularly Salmonella enterica serovar Dublin, can pose unique challenges for culture and testing because of its poor growth. Multiple Salmonella serovars including Dublin are emerging threats to public health given increasing prevalence and antimicrobial resistance. We adapted an automated food testing method to veterinary samples and evaluated the performance of the method in a variety of matrices including environmental samples ( n = 81), tissues ( n = 52), feces ( n = 148), and feed ( n = 29). A commercial kit was chosen as the basis for this approach in view of extensive performance characterizations published by multiple independent organizations. A workflow was established for efficiently and accurately testing veterinary matrices and environmental samples by use of real-time PCR after selective enrichment in Rappaport-Vassiliadis soya (RVS) medium. Using this method, the detection limit for S. Dublin improved by 100-fold over subculture on selective agars (eosin-methylene blue, brilliant green, and xylose-lysine-deoxycholate). Overall, the procedure was effective in detecting Salmonella spp. and provided next-day results.

  9. Polisakarida Mengandung Mannan dari Bungkil Inti Sawit Sebagai Antimikroba Salmonella typhimurium pada Ayam

    Directory of Open Access Journals (Sweden)

    M. Tafsin

    2007-08-01

    Full Text Available Mannan containing polysaccharides could be used as an alternative to replace antibiotics due to their capacity to block the colonization of pathogenic bacteria in the intestine of poultry. The aim of this study was to investigate mannan containing polysaccharides from palm kernel meal (PKM and its inhibitory effect against Salmonella typhimurium. Hot water extractions were used to isolate mannan containing polysaccharides from cell wall of PKM. In vivo studies were conducted using broiler and layer chicks that were challenged orally with 104 cfu Salmonella typhimurium on third day. Split plot design was used as experimental design with strain as main plot and level of mannan polysaccharides as sub plot. The levels of mannan containing polysaccharides that were used consisted of 0 (R0; 1000 (R1; 2000 (R2; 3000 (R3; 4000 (R4 ppm, in term of total sugar. The results indicated that compared to the control group, feeding PKM containing mannan 4000 ppm decreased (P<0.01 Salmonella typhimurium incidence. The addition of mannan did not affect feed consumption. On the contrary, the addition of 4000 ppm mannan gave significantly higher feed/weight gain ratio of the chicks (P<0.05. The administration of feed supplemented with mannan from PKM did not influence weight gain of poultry. It is concluded that mannan from PKM can prevent the colonization of Salmonella typhimurium in poultry.

  10. Antibiotic Resistance of Salmonella spp. Isolated from Shrimp Farming Freshwater Environment in Northeast Region of Brazil

    Directory of Open Access Journals (Sweden)

    Fátima C. T. Carvalho

    2013-01-01

    Full Text Available This study investigated the presence and antibiotic resistance of Salmonella spp. in a shrimp farming environment in Northeast Region of Brazil. Samples of water and sediments from two farms rearing freshwater-acclimated Litopenaeus vannamei were examined for the presence of Salmonella. Afterwards, Salmonella isolates were serotyped, the antimicrobial resistance was determined by a disk diffusion method, and the plasmid curing was performed for resistant isolates. A total of 30 (16.12% of the 186 isolates were confirmed to be Salmonella spp., belonging to five serovars: S. serovar Saintpaul, S. serovar Infantis, S. serovar Panama, S. serovar Madelia, and S. serovar Braenderup, along with 2 subspecies: S. enterica serovar houtenae and S. enterica serovar enterica. About twenty-three percent of the isolates were resistant to at least one antibiotic, and twenty percent were resistant to at least two antibiotics. Three strains isolated from water samples (pond and inlet canal exhibited multiresistance to ampicillin, tetracycline, oxytetracycline, and nitrofurantoin. One of them had a plasmid with genes conferring resistance to nitrofurantoin and ampicillin. The incidence of bacteria pathogenic to humans in a shrimp farming environment, as well as their drug-resistance pattern revealed in this study, emphasizes the need for a more rigorous attention to this area.

  11. Microcontact Imprinted Plasmonic Nanosensors: Powerful Tools in the Detection of Salmonella paratyphi

    Directory of Open Access Journals (Sweden)

    Işık Perçin

    2017-06-01

    Full Text Available Identification of pathogenic microorganisms by traditional methods is slow and cumbersome. Therefore, the focus today is on developing new and quicker analytical methods. In this study, a Surface Plasmon Resonance (SPR sensor with a microcontact imprinted sensor chip was developed for detecting Salmonella paratyphi. For this purpose, the stamps of the target microorganism were prepared and then, microcontact S. paratyphi-imprinted SPR chips were prepared with the functional monomer N-methacryloyl-L-histidine methyl ester (MAH. Characterization studies of the SPR chips were carried out with ellipsometry and scanning electron microscopy (SEM. The real-time Salmonella paratyphi detection was performed within the range of 2.5 × 106–15 × 106 CFU/mL. Selectivity of the prepared sensors was examined by using competing bacterial strains such as Escherichia coli, Staphylococcus aureus and Bacillus subtilis. The imprinting efficiency of the prepared sensor system was determined by evaluating the responses of the SPR chips prepared with both molecularly imprinted polymers (MIPs and non-imprinted polymers (NIPs. Real sample experiments were performed with apple juice. The recognition of Salmonella paratyphi was achieved using these SPR sensor with a detection limit of 1.4 × 106 CFU/mL. In conclusion, SPR sensor has the potential to serve as an excellent candidate for monitoring Salmonella paratyphi in food supplies or contaminated water and clearly makes it possible to develop rapid and appropriate control strategies.

  12. Identification and Characterization of Outer Membrane Vesicle-Associated Proteins in Salmonella enterica Serovar Typhimurium

    Science.gov (United States)

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

    2014-01-01

    Salmonella enterica serovar Typhimurium is a primary cause of enteric diseases and has acquired a variety of virulence factors during its evolution into a pathogen. Secreted virulence factors interact with commensal flora and host cells and enable Salmonella to survive and thrive in hostile environments. Outer membrane vesicles (OMVs) released from many Gram-negative bacteria function as a mechanism for the secretion of complex mixtures, including virulence factors. We performed a proteomic analysis of OMVs that were isolated under standard laboratory and acidic minimal medium conditions and identified 14 OMV-associated proteins that were observed in the OMV fraction isolated only under the acidic minimal medium conditions, which reproduced the nutrient-deficient intracellular milieu. The inferred roles of these 14 proteins were diverse, including transporter, enzyme, and transcriptional regulator. The absence of these proteins influenced Salmonella survival inside murine macrophages. Eleven of these proteins were predicted to possess secretion signal sequences at their N termini, and three (HupA, GlnH, and PhoN) of the proteins were found to be translocated into the cytoplasm of host cells. The comparative proteomic profiling of OMVs performed in this study revealed different protein compositions in the OMVs isolated under the two different conditions, which indicates that the OMV cargo depends on the growth conditions and provides a deeper insight into how Salmonella utilizes OMVs to adapt to environmental changes. PMID:24935973

  13. Radiosensitivity of Salmonella spp and Vibrio parahaemolyticus artificially incorporated by oysters (Crassostrea brasiliana)

    International Nuclear Information System (INIS)

    Jakabi, Miyoko

    2001-01-01

    Irradiation is considered one of the most efficient technological process to reduce the number of microorganisms in food. It can be used to improve the safety of food products as well as their shelf life. Oysters are considered one of the most important vehicle of pathogenic bacteria due to their feeding characteristic and because they are usually ingested raw. The aim of this study was to evaluate the influence of gamma radiation process on high levels of Salmonella Enteritidis, Salmonella Infantis and Vibrio parahaemolyticus incorporated by oysters (Crassostrea brasiliana) as well as on the survival of the animals and sensory attributes. The oysters were submitted to gamma radiation treatment ( 60 Co) with doses ranging from 0.5 kGy to 3.0 kGy. At least four trials were conducted for each serotype. The dose of 3.0 kGy was, generally, sufficient to reduce the level of Salmonella serotypes in 6 log while for V.parahaemolyticus the dose as 1.o kGy. Animals were not killed and sensory attributes were not changed by the highest irradiation dose. Therefore, 3.0 kGy is a dose that is effective on the inactivation of Salmonella spp and V.parahaemolyticus in oysters without changing their odour, flavour and appearance. (author)

  14. Evaluation of an enhanced cleaning and disinfection protocol in Salmonella contaminated pig holdings in the United Kingdom.

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    Francesca Martelli

    Full Text Available Salmonella is the second most commonly reported zoonotic gastrointestinal pathogen in the European Union, and a significant proportion of the cases are linked to the consumption of contaminated pork. Reduction of Salmonella at the farm level helps to mininimise the contamination pressure at the slaughterhouse, and therefore the number of Salmonella bacteria entering the food chain. Cleaning and disinfection (C&D between batches of pigs is an intervention measure that has potential to reduce the transmission of Salmonella contamination within farms. In this study, two pig finisher buildings in each of 10 Salmonella positive farms were sampled pre-C&D, post-C&D, post-restocking with the following batch of pigs, and shortly before these pigs were sent to slaughter. The incoming batch of pigs was also sampled before it reached the study building (pre-restocking. At each visit, pooled and individual faecal samples were collected and Salmonella isolation was carried out according to an ISO 6579:2002 Annex D-based method. One building on each farm (intervention was cleaned and disinfected according to a rigorous protocol consisting of several steps and a Defra-approved disinfectant used at the General Orders concentration, whilst the other building (control was cleaned and disinfected as per normal farm routine. At the post-C&D visit, Enterobacteriaceae and total bacterial counts were determined to evaluate residual faecal contamination and general hygiene levels. Rodent specialists visited the farms before and after C&D and rodent carcasses were collected for Salmonella testing. The intervention buildings were significantly less likely (p = 0.004 to be positive for Salmonella after C&D. The pre-restocking pigs had the highest likelihood (p<0.001 of being Salmonella positive (often with multiple serovars and there was no significant difference between intervention and control buildings in Salmonella prevalence at the post-restocking visit (p = 0

  15. Surveillance Data Highlights Feed Form, Biosecurity, and Disease Control as Significant Factors Associated with Salmonella Infection on Farrow-to-Finish Pig Farms

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    Hector Argüello

    2018-02-01

    Full Text Available Among the zoonotic pathogens affecting pigs, Salmonella stands out due to the high number of human cases linked to pork consumption. In the last two decades many countries have put considerable effort into the control of the infection by surveillance and control strategies on farm. Despite this effort, many herds still have a high Salmonella prevalence and they require guidance to address this problem. The present study, using the serological surveillance data of finishing pigs from the Irish National pig Salmonella Control Programme, aimed to highlight factors associated with increased risk or that might mitigate Salmonella occurrence on farm. A questionnaire with 33 questions regarding herd characteristics, management, feeding, biosecurity, and health was completed for 61 individual herds. After the multivariate analysis by linear regression, nine variables were retained in the final model and linked to herd seroprevalence. Home produced-feed linked to the use of meal showed an eight points reduction in Salmonella prevalence compared to purchased feed (p = 0.042. Different biosecurity measures were associated to lower seroprevalence. Changing of footwear from outside to inside the farm decreased seroprevalence nearly 20 units (p = 0.014 and policies not permitting access to the farmyard to feed trucks (p = 0.048 or avoiding the presence of cats on the farm (p = 0.05 were estimated in 10 units less of seroprevalence. In contrast, the lack of perimeter fence increased the chance to have higher seroprevalence in five units (p = 0.05. Finally, intestinal diseases such as swine dysentery (p = 0.044 and E. coli diarrhea (p = 0.1 were estimated to increase Salmonella prevalence in ~20 and 10 units, respectively, demonstrating the importance of controlling other enteric pathogens in an on-farm Salmonella control programme. These results show the usefulness of surveillance data to improve on-farm control and confirm that Salmonella infection in pigs is

  16. Buffer capacity of food components influences the acid tolerance response in Salmonella Typhimurium during simulated gastric passage

    DEFF Research Database (Denmark)

    Aabo, Søren; Buschhardt, Tasja; Hansen, Tina Beck

    2014-01-01

    Food composition, buffer capacity, and fat and protein content have been shown to effect the gastric acid survival of pathogens (Waterman & Small 1998). In this study, simple food-model substances with different buffer capacities were investigated for their ability to support survival of stationary...... Heart Infusion Broth having a higher buffer capacity. We suggest this to be associated with a varying ability of Salmonella Typhimurium to mount a stationary phase acid tolerance response (ATR) depending on the buffer capacity of the food vehicle....... phase Salmonella Typhimurium during simulated gastric acid passage. We used a computer-controlled fermentor to employ pH changes in synthetic gastric fluid, mimicking the dynamic pH during gastric passage. In order to minimise variation, Salmonella enterica serovar Typhimurium was contained in dialysis...

  17. Lack of direct effects of agrochemicals on zoonotic pathogens and fecal indicator bacteria.

    Science.gov (United States)

    Staley, Zachery R; Senkbeil, Jacob K; Rohr, Jason R; Harwood, Valerie J

    2012-11-01

    Agrochemicals, fecal indicator bacteria (FIB), and pathogens frequently contaminate water simultaneously. No significant direct effects of fertilizer, atrazine, malathion, and chlorothalonil on the survival of Escherichia coli, Enterococcus faecalis, Salmonella enterica, human polyomaviruses, and adenovirus were detected, supporting the assertion that previously observed effects of agrochemicals on FIB were indirect.

  18. Potential of predatory bacteria as biocontrol agents for foodborne and plant pathogens

    Science.gov (United States)

    Foodborne pathogens such as Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, Shigella are responsible for frequent occurrences of illnesses and mortality in humans and produce losses. Pre-harvest yield losses and post-harvest decay on minimally processed produce (fruits, vegetables...

  19. Inhibition of enteric pathogens using integrated high intensity 405 nm LED on the surface of almonds

    Science.gov (United States)

    The disinfecting properties of 405 nm light were investigated against Escherichia coli O157:H7, Salmonella, and their non-pathogenic surrogates inoculated onto the surface of almonds. High intensity monochromatic light was generated from an array of narrow-band 405 nm light emitting diodes (LED). Al...

  20. Pleural Empyema due to Group D Salmonella

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    Jennifer C. Kam

    2012-01-01

    Full Text Available Non-typhi Salmonella normally presents as a bacteremia, enterocolitis, and endovascular infection but rarely manifests as pleuropulmonary disease. We present a case of a 66-year-old female with underlying pulmonary pathology, secondary to an extensive smoking history, who presented with a left-sided pleural effusion. The causative agent was identified as being group D Salmonella. Decortication of the lung was performed and the patient was discharged on antibiotics with resolution of her symptoms. This case helps to support the inclusion of Salmonella group D as a possible etiological agent of infection in the differential causes of exudative pleural effusions.

  1. The tenth CRL-Salmonella workshop; 28 and 29 April 2005, Bilthoven, the Netherlands

    NARCIS (Netherlands)

    Mooijman KA; MGB

    2006-01-01

    De tiende workshop georganiseerd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella) werd gehouden op 28 en 29 April 2005 in Bilthoven, Nederland. Deelnemers betroffen vertegenwoordigers van de Nationale Referentie Laboratoria voor Salmonella (NRLs-Salmonella) van de

  2. Incidence of Nontyphoidal Salmonella in Food-Producing Animals, Animal Feed, and the Associated Environment in South Africa, 2012-2014.

    Science.gov (United States)

    Magwedere, Kudakwashe; Rauff, Dionne; De Klerk, Grietjie; Keddy, Karen H; Dziva, Francis

    2015-11-01

    Nontyphoidal salmonellosis continues to pose a global threat to human health, primarily by causing food-borne illnesses, and food-producing animals are the principal reservoirs of many pathogenic serovars. To identify key control points and generate information that may enable future estimation of the transmission routes between the environment, animals, and humans, we examined data on Salmonella isolates in South Africa. Samples were obtained from livestock and poultry on farms, meat at abattoirs, raw materials at feed mills, animal feed, and environmental sources (eg, poultry houses, abattoirs, feed mills, water) from 2012 to 2014 in compliance with each establishment's protocols conforming to International Organization for Standardization (ISO) (ISO/TS 17728, ISO 18593:2004 and ISO 17604:2003) standards. Isolation and serotyping of Salmonella were performed according to the scope of accreditation of the respective laboratories conforming to ISO/IEC 17025:2005 standard techniques. Salmonella was isolated from 9031 of 180 298 (5.0%) samples, and these isolates were distributed among 188 different serovars. Salmonella Enteritidis was the most frequent isolate, with 1944 of 180 298 (21.5%) originating from poultry on farms, poultry meat, and poultry houses, followed by Salmonella Havana, with 677 of 180 298 (7.5%), mostly from environmental samples. Serovars that are uncommonly associated with human disease (Salmonella Idikan, Salmonella Salford, and Salmonella Brancaster) were isolated at higher frequencies than Salmonella Typhimurium, a common cause of human illness. Environmental samples accounted for 3869 of 9031 (42.8%) samples positive for Salmonella. We describe the frequent isolation of Salmonella of a wide variety of serovars, from an array of animal feeds, food animals, and food animal environment. As prevention of human salmonellosis requires the effective control of Salmonella in food animals, these data can be used to facilitate Salmonella control in

  3. Prevalence of Salmonella spp. and Listeria monocytogenes at small-scale spanish factories producing traditional fermented sausages.

    Science.gov (United States)

    Martin, Belen; Garriga, Margarita; Aymerich, Teresa

    2011-05-01

    The manufacturing of fermented sausages is subject to natural contamination processes that can potentially carry foodborne pathogens along the process chain and result in contamination of the final product. The aim of this study was to evaluate the occurrence of Salmonella spp. and Listeria monocytogenes at different sampling points during the manufacturing process of fuet, a type of traditional fermented sausage, at 10 small-scale Spanish factories. The presence of both pathogens was studied in the raw materials (19 casings and 19 meat batters), the final products (19 fermented sausages), and the factory equipment (12 mincing, 12 mixing, and 19 stuffing machines, 19 cutting tables, 11 knives, and 12 cold rooms) by using classical microbiological techniques and real-time PCR. Salmonella was not detected in the equipment analyzed or in the final products, but it was detected in the raw materials (23.7% of samples). L. monocytogenes showed higher incidence than Salmonella and was detected in the equipment (11.8% of samples), the raw materials (28.9%), and the final products (15.8%), confirming its ubiquity throughout the manufacturing process of fermented sausages. Five factories were further investigated to study the changes in the distribution of pathogens in the fuet production process over a period of either 2 or 3 years. There was considerable variation in the incidence of both pathogens at different sampling periods, and there was no relation between seasonal variations or geographic location of the factories.

  4. Salmonella in pork retail outlets and dissemination of its pulsotypes through pig production chain in Chiang Mai and surrounding areas, Thailand.

    Science.gov (United States)

    Patchanee, Prapas; Tansiricharoenkul, Kankanok; Buawiratlert, Tunyamai; Wiratsudakul, Anuwat; Angchokchatchawal, Kittipat; Yamsakul, Panuwat; Yano, Terdsak; Boonkhot, Phacharaporn; Rojanasatien, Suvichai; Tadee, Pakpoom

    2016-08-01

    Salmonella spp. is acknowledged as a significant zoonotic foodborne pathogen throughout the world. Contaminated pork consumption is considered as a main cause of human salmonellosis. In the later stage of the pig production chain, poor hygiene and unsuitable storage conditions in retail outlets are considered to be key factors linked to the risk of Salmonella infection. The purpose of current study, which was conducted throughout April 2014 to September 2014, was to determine the prevalence and characteristics of Salmonella spp. in pork sold at the retail stage in wet markets and supermarkets in the Chiang Mai urban area of Thailand. Additionally, clonal relations between Salmonella strains described in this study and those identified in earlier study from the same geographical area were considered. It is provided as a means of contributing to current knowledge regarding Salmonella epidemiology with an ultimate aim of improved food security and consumer protection in this region. From a total of 82 pork samples analyzed in this study, 41% were positive for Salmonella, with prevalence of 73.2% from wet markets (n=30/41) and 9.8% from supermarkets (n=4/41). Twelve Salmonella serovars were identified, S. Rissen being the most commonly encountered. Antibiotic resistance of the isolates was highest for ampicillin and tetracycline (53%), followed by streptomycin (44%). Pulsed-field gel electrophoresis (PFGE) and subsequent geographical distribution analysis indicated that the clonal Salmonella strains originated from multiple sources had been spread over a wide area. The existence of a common pig supply chain "farm-slaughterhouse-retail" transmission route is inferred. Continuous monitoring of Salmonella along the entire production chain is needed to reduce contamination loads and to ensure the safety of pork products for end consumers. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Histopathological analysis of Salmonella chronic carriage in the mouse hepatopancreatobiliary system.

    Directory of Open Access Journals (Sweden)

    Geoffrey Gonzalez-Escobedo

    Full Text Available Salmonella Typhi asymptomatic chronic carriage represents a challenge for the diagnosis and prevention of typhoid fever in endemic areas. Such carriers are thought to be reservoirs for further spread of the disease. Gallbladder carriage has been demonstrated to be mediated by biofilm formation on gallstones and by intracellular persistence in the gallbladder epithelium of mice. In addition, both gallstones and chronic carriage have been associated with chronic inflammation and the development of gallbladder carcinoma. However, the pathogenic relationship between typhoid carriage and the development of pre-malignant and/or malignant lesions in the hepatopancreatobiliary system as well as the host-pathogen interactions occurring during chronic carriage remains unclear. In this study, we monitored the histopathological features of chronic carriage up to 1 year post-infection. Chronic cholecystitis and hepatitis ranging from mild to severe were present in infected mice regardless of the presence of gallstones. Biliary epithelial hyperplasia was observed more commonly in the gallbladder of mice with gallstones (uninfected or infected. However, pre-malignant lesions, atypical hyperplasia and metaplasia of the gallbladder and exocrine pancreas, respectively, were only associated with chronic Salmonella carriage. This study has implications regarding the role of Salmonella chronic infection and inflammation in the development of pre-malignant lesions in the epithelium of the gallbladder and pancreas that could lead to oncogenesis.

  6. Salmonella biofilm formation on Aspergillus niger involves cellulose--chitin interactions.

    Directory of Open Access Journals (Sweden)

    Maria T Brandl

    Full Text Available Salmonella cycles between host and nonhost environments, where it can become an active member of complex microbial communities. The role of fungi in the environmental adaptation of enteric pathogens remains relatively unexplored. We have discovered that S. enterica Typhimurium rapidly attaches to and forms biofilms on the hyphae of the common fungus, Aspergillus niger. Several Salmonella enterica serovars displayed a similar interaction, whereas other bacterial species were unable to bind to the fungus. Bacterial attachment to chitin, a major constituent of fungal cell walls, mirrored this specificity. Pre-incubation of S. Typhimurium with N-acetylglucosamine, the monomeric component of chitin, reduced binding to chitin beads by as much as 727-fold and inhibited attachment to A. niger hyphae considerably. A cellulose-deficient mutant of S. Typhimurium failed to attach to chitin beads and to the fungus. Complementation of this mutant with the cellulose operon restored binding to chitin beads to 79% of that of the parental strain and allowed for attachment and biofilm formation on A. niger, indicating that cellulose is involved in bacterial attachment to the fungus via the chitin component of its cell wall. In contrast to cellulose, S. Typhimurium curli fimbriae were not required for attachment and biofilm development on the hyphae but were critical for its stability. Our results suggest that cellulose-chitin interactions are required for the production of mixed Salmonella-A. niger biofilms, and support the hypothesis that encounters with chitinaceous alternate hosts may contribute to the ecological success of human pathogens.

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

    Science.gov (United States)

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

    2016-01-01

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

  8. Rapid detection of salmonella using SERS with silver nano-substrate

    Science.gov (United States)

    Sundaram, J.; Park, B.; Hinton, A., Jr.; Windham, W. R.; Yoon, S. C.; Lawrence, K. C.

    2011-06-01

    Surface Enhanced Raman Scattering (SERS) can detect the pathogen in rapid and accurate. In SERS weak Raman scattering signals are enhanced by many orders of magnitude. In this study silver metal with biopolymer was used. Silver encapsulated biopolymer polyvinyl alcohol nano-colloid was prepared and deposited on stainless steel plate. This was used as metal substrate for SERS. Salmonella typhimurium a common food pathogen was selected for this study. Salmonella typhimurium bacteria cells were prepared in different concentrations in cfu/mL. Small amount of these cells were loaded on the metal substrate individually, scanned and spectra were recorded using confocal Raman microscope. The cells were exposed to laser diode at 785 nm excitation and object 50x was used to focus the laser light on the sample. Raman shifts were obtained from 400 to 2400 cm-1. Multivariate data analysis was carried to predict the concentration of unknown sample using its spectra. Concentration prediction gave an R2 of 0.93 and standard error of prediction of 0.21. The results showed that it could be possible to find out the Salmonella cells present in a low concentration in food samples using SERS.

  9. Systems analysis of multiple regulator perturbations allows discovery of virulence factors in Salmonella

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hyunjin; Ansong, Charles; McDermott, Jason E.; Gritsenko, Marina A.; Smith, Richard D.; Heffron, Fred; Adkins, Joshua N.

    2011-06-28

    Background: Systemic bacterial infections are highly regulated and complex processes that are orchestrated by numerous virulence factors. Genes that are coordinately controlled by the set of regulators required for systemic infection are potentially required for pathogenicity. Results: In this study we present a systems biology approach in which sample-matched multi-omic measurements of fourteen virulence-essential regulator mutants were coupled with computational network analysis to efficiently identify Salmonella virulence factors. Immunoblot experiments verified network-predicted virulence factors and a subset was determined to be secreted into the host cytoplasm, suggesting that they are virulence factors directly interacting with host cellular components. Two of these, SrfN and PagK2, were required for full mouse virulence and were shown to be translocated independent of either of the type III secretion systems in Salmonella or the type III injectisome-related flagellar mechanism. Conclusions: Integrating multi-omic datasets from Salmonella mutants lacking virulence regulators not only identified novel virulence factors but also defined a new class of translocated effectors involved in pathogenesis. The success of this strategy at discovery of known and novel virulence factors suggests that the approach may have applicability for other bacterial pathogens.

  10. Antimicrobial-resistant patterns of Escherichia coli and Salmonella strains in the aquatic Lebanese environments

    International Nuclear Information System (INIS)

    Harakeh, Steve; Yassine, Hadi; El-Fadel, Mutasem

    2006-01-01

    This study is the first to be conducted in Lebanon on the isolation and molecular characterization and the antimicrobial resistance profile of environmental pathogenic bacterial strains. Fifty-seven samples of seawater, sediment, crab, and fresh water were collected during the spring and summer seasons of 2003. The isolation of Escherichia coli and Salmonella using appropriate selective media revealed that 94.7% of the tested samples were contaminated with one or both of the tested bacteria. The polymerase chain reaction (PCR) was then used to identify the species of both bacteria using various sets of primers. Many pathogenic E. coli isolates were detected by PCR out of which two were identified as O157:H7 E. coli. Similarly, the species of many of the Salmonella isolates was molecularly identified. The confirmed isolates of Salmonella and E. coli were then tested using the disk diffusion method for their susceptibility to four different antimicrobials revealing high rates of antimicrobial resistance. - First report of antibiotic resistance in bacteria in the environment in Lebanon

  11. Effectiveness of superheated steam for inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Enteritidis phage type 30, and Listeria monocytogenes on almonds and pistachios.

    Science.gov (United States)

    Ban, Ga-Hee; Kang, Dong-Hyun

    2016-03-02

    This study was undertaken to evaluate the effectiveness of superheated steam (SHS) on the inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Enteritidis phage type (PT) 30 and Listeria monocytogenes on almonds and in-shell pistachios and to determine the effect of superheated steam heating on quality by measuring color and texture changes. Almonds and in-shell pistachios inoculated with four foodborne pathogens were treated with saturated steam (SS) at 100 °C and SHS at 125, 150, 175, and 200 °C for various times. Exposure of almonds and pistachios to SHS for 15 or 30s at 200 °C achieved >5l og reductions among all tested pathogens without causing significant changes in color values or texture parameters (P>0.05). For both almonds and pistachios, acid and peroxide values (PV) following SS and SHS treatment for up to 15s and 30s, respectively, were within the acceptable range (PV<1.0 meq/kg). These results show that thermal application of 200 °C SHS treatment for 15s and 30s did not affect the quality of almonds and pistachios, respectively. Therefore, SHS treatment is a very promising alternative technology for the tree nuts industry by improving inactivation of foodborne pathogens on almonds and pistachios while simultaneously reducing processing time. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Biofilm formation and disinfectant resistance of Salmonella sp. in mono- and dual-species with Pseudomonas aeruginosa.

    Science.gov (United States)

    Pang, X Y; Yang, Y S; Yuk, H G

    2017-09-01

    This study aimed to evaluate the biofilm formation and disinfectant resistance of Salmonella cells in mono- and dual-species biofilms with Pseudomonas aeruginosa, and to investigate the role of extracellular polymeric substances (EPS) in the protection of biofilms against disinfection treatment. The populations of Salmonella in mono- or dual-species biofilms with P. aeruginosa on stainless steel (SS) coupons were determined before and after exposure to commercial disinfectant, 50 μg ml -1 chlorine or 200 μg ml -1 Ecolab ® Whisper™ V (a blend of four effective quaternary ammonium compounds (QAC)). In addition, EPS amount from biofilms was quantified and biofilm structures were observed using scanning electron microscopy (SEM). Antagonistic interactions between Salmonella and P. aeruginosa resulted in lower planktonic population level of Salmonella, and lower density in dual-species biofilms compared to mono-species biofilms. The presence of P. aeruginosa significantly enhanced disinfectant resistance of S. Typhimurium and S. Enteritidis biofilm cells for 2 days, and led to an average of 50% increase in polysaccharides amount in dual-species biofilms than mono-species biofilms of Salmonella. Microscopy observation showed the presence of large microcolonies covered by EPS in dual-species biofilms but not in mono-species ones. The presence of P. aeruginosa in dual-species culture inhibited the growth of Salmonella cells in planktonic phase and in biofilms, but protected Salmonella cells in biofilms from disinfection treatment, by providing more production of EPS in dual-species biofilms than mono-species ones. This study provides insights into inter-species interaction, with regard to biofilm population dynamics and disinfectant resistance. Thus, a sanitation protocol should be designed considering the protective role of secondary species to pathogens in biofilms on SS surface which has been widely used at food surfaces and manufacturers. © 2017 The Society

  13. PREVALENCE OF SALMONELLA IN CAPTIVE REPTILES FROM CROATIA.

    Science.gov (United States)

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

    2015-06-01

    Salmonellosis transmitted by pet reptiles is an increasing public health issue worldwide. The aim of this study was to investigate the prevalence of Salmonella strains from captive reptiles in Croatia. From November 2009 to November 2011 a total of 292 skin, pharyngeal, cloacal, and fecal samples from 200 apparently healthy reptiles were tested for Salmonella excretions by bacteriologic culture and serotyping. These 200 individual reptiles included 31 lizards, 79 chelonians, and 90 snakes belonging to private owners or housed at the Zagreb Zoo, Croatia. Salmonella was detected in a total of 13% of the animals, among them 48.4% lizards, 8.9% snakes, and 3.8% turtles. Representatives of five of the six Salmonella enterica subspecies were identified with the following proportions in the total number of isolates: Salmonella enterica enterica 34.6%, Salmonella enterica houtenae 23.1%, Salmonella enterica arizonae 23.1%, Salmonella enterica diarizonae 15.4%, and Salmonella enterica salamae 3.8%. The 14 different serovars isolated included several rarely occurring serovars such as Salmonella Apapa, Salmonella Halle, Salmonella Kisarawe, and Salmonella Potengi. These findings confirm that the prevalence of Salmonella is considerable in captive reptiles in Croatia, indicating that these animals may harbor serovars not commonly seen in veterinary or human microbiologic practice. This should be addressed in the prevention and diagnostics of human reptile-transmitted infections.

  14. Epidemiology of bacterial pathogens associated with infectious diarrhea in Djibouti.

    Science.gov (United States)

    Mikhail, I A; Fox, E; Haberberger, R L; Ahmed, M H; Abbatte, E A

    1990-01-01

    During a survey examining the causes of diarrhea in the East African country of Djibouti, 140 bacterial pathogens were recovered from 209 diarrheal and 100 control stools. The following pathogens were isolated at comparable frequencies from both diarrheal and control stools: enteroadherent Escherichia coli (EAEC) (10.6 versus 13%), enterotoxigenic E. coli (ETEC) (11 versus 10%), enteropathogenic E. coli (EPEC) (7.7 versus 12%), Salmonella spp. (2.9 versus 3%), and Campylobacter jejuni-C. coli (3.3 versus 5%). Surprisingly, the EAEC strains isolated did not correspond to well-recognized EPEC serogroups. No Yersinia spp., enteroinvasive E. coli, or enterohemorrhagic E. coli were isolated during the course of this study. Only the following two genera were recovered from diarrheal stools exclusively: Shigella spp. (7.7%) and Aeromonas hydrophila group organisms (3.3%). Shigella flexneri was the most common Shigella species isolated. Patients with Shigella species were of a higher average age than were controls (27 versus 13 years), while subjects with Campylobacter or Salmonella species belonged to younger age groups (2.6 and 1.6 years, respectively). Salmonella cases were more often in females. Shigella diarrhea was associated with fecal blood or mucus and leukocytes. ETEC was not associated with nausea or vomiting. Anorexia, weight loss, and fever were associated with the isolation of Salmonella and Aeromonas species. EAEC, ETEC, EPEC, and Shigella species were resistant to most drugs used for treating diarrhea in Africa, while the antibiotic most active against all bacteria tested was norfloxacin. We conclude that in Djibouti in 1989, Shigella and Aeromonas species must be considered as potential pathogens whenever they are isolated from diarrheal stools and that norfloxacin should be considered the drug of choice in adults for treating severe shigellosis and for diarrhea prophylaxis in travelers. PMID:2351738

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

    Science.gov (United States)

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

    2016-12-01

    As the incidence of multidrug resistance (MDR) Salmonella enterica serotype Typhimurium is increasing, data regarding the antimicrobial interventions and pathogen internalization in marinated meat products are important. This study evaluated the antimicrobial intervention and internalization of Salm. Typhimurium in marinated beef sirloin steaks. Beef bottom sirloin flaps (IMPS #185A; USDA Select) inoculated (10 8  log 10  CFU ml -1 ) with Salm. Typhimurium were sprayed (lactic acid (4%) and buffered vinegar (2%)) prior to vacuum-tumbled marination (0·35% sodium chloride and 0·45% sodium tripolyphosphate) for 30 min. Pathogen presence after antimicrobial spray, vacuum-tumbled marination, and translocation was determined by direct plating on Xylose Lysine Deoxycholate (XLD) agar with tryptic soy agar (TSA) overlay. The data imply varied internalization and antimicrobial susceptibility pattern of Salm. Typhimurium in marinated meat. Lactic acid (4%) spray (P internalization and potential survival of Salmonella spp. in marinated beef products is a major concern. These results highlight the internalization of pathogens in vacuum-tumbled meat products and emphasize the importance of considering these products as nonintact. Similarly, these data confirm the efficacy and utility of interventions prior to vacuum-tumbled marination. Further research is needed to identify additional strategies to mitigate internalization and translocation of pathogens into vacuum-marinated meat products. © 2016 The Society for Applied Microbiology.

  16. Applications of immunomagnetic capture and time-resolved fluorescence to detect outbreak Escherichia coli O157 and Salmonella in alfalfa sprouts

    Science.gov (United States)

    Tu, Shu-I.; Gordon, Marsha; Fett, William F.; Gehring, Andrew G.; Irwin, Peter L.

    2004-03-01

    Commercially available alfalfa seeds were inoculated with low levels (~ 4 CFU/g) of pathogenic bacteria. The inoculated seeds were then allowed to sprout in sterile tap water at 22°C. After 48 hours, the irrigation water and sprouts were separately transferred to bovine heart infusion (BHI) media. The microbes in the BHI samples were allowed to grow for 4 hours at 37°C and 160 rpm. Specific immunomagnetic beads (IMB) were then applied to capture the E.coli O157 and/or Salmonella in the growth media. Separation and concentration of IMB-captured pathogens were achieved using magnetic separators. The captured E. coli O157:H7 and Salmonella spp were further tagged with europium (Eu) labeled anti-E. coli O157 antibodies and samarium (Sm) labeled anti-Salmonella antibodies, respectively. After washing, the lanthanide labels were extracted out from the complexes by specific chelators to form strongly fluorescent chelates. The specific time-resolved fluorescence (TRF) associated with Eu or Sm was measured to estimate the extent of capture of the E. coli O157 and Salmonella, respectively. The results indicated that the approach could detect E. coli O157 and Salmonella enterica from the seeds inoculated with ~ 4 CFU/g of the pathogens. Non-targeted bacteria, e.g., Aeromonas and Citrobacter exhibited essentially no cross reactivity. Since the pathogen detection from the sprouts was achieved within 6 hours, the developed methodology could be use as a rapid, sensitive and specific screening process for E. coli O157 and Salmonella enterica in this popular salad food.

  17. O-polysaccharide is important for Salmonella Pullorum survival in egg albumen, and virulence and colonization in chicken embryos.

    Science.gov (United States)

    Guo, Rongxian; Li, Zhuoyang; Jiao, Yang; Geng, Shizhong; Pan, Zhiming; Chen, Xiang; Li, Qiuchun; Jiao, Xinan

    2017-10-01

    The pathogen Salmonella Pullorum is the causative agent of persistent systemic infection of poultry, leading to economic losses in developing countries due to morbidity, mortality and reduction in egg production. These infections may result in vertical transmission to eggs or progeny. Limited information is available regarding the mechanisms involved in the survival of Salmonella Pullorum in egg albumen and developing chicken embryos. Hence, we investigated the role of O-polysaccharide in the contamination of eggs and the colonization of chicken embryos. Compared with the wild-type strain, the isogenic waaL mutant exhibited an O-antigen-deficient rough phenotype, and increased sensitivity to egg albumen and chicken serum, as well as reduced adherence to DF-1 cells. Infection with Salmonella Pullorum lacking O-polysaccharide resulted in significantly reduced embryo lethality and bacterial colonization. These results suggest that O-polysaccharide is essential for Salmonella Pullorum colonization in eggs, both post-lay and developing embryos. The chicken embryo infection model could be used to characterize the interaction between Salmonella Pullorum and developing embryos, and it will also contribute to the development of more rational vaccines to protect laying hens and embryos.

  18. Genomic and Phenotypic Analyses Reveal the Emergence of an Atypical Salmonella enterica Serovar Senftenberg Variant in China

    KAUST Repository

    Abd El Ghany, Moataz

    2016-05-25

    Human infections with Salmonella enterica subspecies enterica serovar Senftenberg are often associated with exposure to poultry flocks, farm environments, or contaminated food. The recent emergence of multidrug-resistant isolates has raised public health concerns. In this study, comparative genomics and phenotypic analysis were used to characterize 14 Salmonella Senftenberg clinical isolates recovered from multiple outbreaks in Shenzhen and Shanghai, China, between 2002 and 2011. Single-nucleotide polymorphism analyses identified two phylogenetically distinct clades of S. Senftenberg, designated SC1 and SC2, harboring variations in Salmonella pathogenicity island 1 (SPI-1) and SPI-2 and exhibiting distinct biochemical and phenotypic signatures. Although the two variants shared the same serotype, the SC2 isolates of sequence type 14 (ST14) harbored intact SPI-1 and -2 and hence were characterized by possessing efficient invasion capabilities. In contrast, the SC1 isolates had structural deletion patterns in both SPI-1 and -2 that correlated with an impaired capacity to invade cultured human cells and also the year of their isolation. These atypical SC1 isolates also lacked the capacity to produce hydrogen sulfide. These findings highlight the emergence of atypical Salmonella Senftenberg variants in China and provide genetic validation that variants lacking SPI-1 and regions of SPI-2, which leads to impaired invasion capacity, can still cause clinical disease. These data have identified an emerging public health concern and highlight the need to strengthen surveillance to detect the prevalence and transmission of nontyphoidal Salmonella species.

  19. Vectorial competence of larvae and adults of Alphitobius diaperinus in the transmission of Salmonella enteritidis in poultry.

    Science.gov (United States)

    Leffer, Andreia M; Kuttel, Javier; Martins, Lidiane M; Pedroso, Antonio Carlos; Astolfi-Ferreira, Claudete S; Ferreira, Fernando; Ferreira, Antonio J Piantino

    2010-06-01

    The ingestion of food products originating from poultry infected with Salmonella spp. is one of the major causes of food poisoning in humans. The control of poultry salmonellosis is particularly difficult since birds are asymptomatic and numerous factors may expedite the maintenance of bacteria in poultry production facilities. The aim of the study was to determine the vectorial capacity of adults and larvae of Alphitobius diaperinus (Coleoptera: Tenebrionidae) in the experimental transmission of Salmonella Enteritidis phage type 4 to 1-day-old specific pathogen-free White Leghorn chicks. Adult insects and larvae were starved for 1 day, fed for 24 h or 7 days on sterile ration that had been treated with Salmonella Enteritidis phage type 4, and the levels of bacterial infection were determined. Infected adult insects and larvae were fed to groups of day-old chicks, after which bacteria were recovered from cecum, liver, and spleen samples over a 7-day period. Infected larvae were more efficient than adult insects in transmitting Salmonella Enteritidis to chicks. Higher concentrations of bacteria could be reisolated from the cecum, liver, and spleen of chicks that had ingested infected larvae compared with those that had ingested infected adults. The control of A. diaperinus, and particularly of the larvae, represents a critical factor in the reduction of Salmonella spp. in poultry farms.

  20. antimicrobial susceptibility pattern of Salmonella species

    African Journals Online (AJOL)

    user

    GLOBAL JOURNAL OF COMMUNITY MEDICINE VOL. 2 NO. 1 & 2 2009: 5 - ... This study is a review of the contemporary antimicrobial susceptibility pattern of. Salmonella species. ... south-east Asia, parts of Latin America, the. Caribbean, and ...

  1. Elimination of salmonella from animal glandular products.

    Science.gov (United States)

    De Fiebre, C W; Burck, K T; Feldman, D

    1969-03-01

    Methods for the elimination of salmonellae from selected powdered pharmaceuticals of animal glandular origin were studied. Terminal heat treatment under carefully controlled conditions was effective for pancreatin-a powder containing proteolytic, amylolytic, and lipolytic enzymes prepared from hog pancreas glands. Use of this method resulted in a significant reduction in the number of salmonella-positive batches and also reduced the testing procedures required to confirm the absence of viable salmonellae among the majority of samples tested. Powders such as stomach substance and thyroid, in which the biological activity is not enzyme in nature, were treated successfully with acidified organic solvents. Other methods were investigated but were not suitable because of a deleterious effect on the biological activity or physical properties of the product or an inability to effect salmonella elimination.

  2. Elimination of Salmonellae from Animal Glandular Products

    Science.gov (United States)

    De Fiebre, Conrad W.; Burck, Kenneth T.; Feldman, David

    1969-01-01

    Methods for the elimination of salmonellae from selected powdered pharmaceuticals of animal glandular origin were studied. Terminal heat treatment under carefully controlled conditions was effective for pancreatin—a powder containing proteolytic, amylolytic, and lipolytic enzymes prepared from hog pancreas glands. Use of this method resulted in a significant reduction in the number of salmonella-positive batches and also reduced the testing procedures required to confirm the absence of viable salmonellae among the majority of samples tested. Powders such as stomach substance and thyroid, in which the biological activity is not enzyme in nature, were treated successfully with acidified organic solvents. Other methods were investigated but were not suitable because of a deleterious effect on the biological activity or physical properties of the product or an inability to effect salmonella elimination. PMID:5780395

  3. Antibiotic susceptibilities of Salmonella species prevalent among ...

    African Journals Online (AJOL)

    Arun Kumar Agnihotri

    2016-03-21

    Mar 21, 2016 ... The highest incidence was observed in children of 13-24 ... incidence of Salmonella and continued health education of ..... until it formed a homogenous suspension. ..... Salvador, Bahia, Brazil. .... Lagos University Teaching.

  4. A carbon nanotube immunosensor for Salmonella

    Science.gov (United States)

    Lerner, Mitchell B.; Goldsmith, Brett R.; McMillon, Ronald; Dailey, Jennifer; Pillai, Shreekumar; Singh, Shree R.; Johnson, A. T. Charlie

    2011-12-01

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

  5. The occurrence of Salmonella in airline meals.

    Science.gov (United States)

    Hatakka, M; Asplund, K

    1993-01-01

    The occurrence of Salmonella in airline meals was studied in 1989-1992. Samples were collected from flight kitchens in 29 countries. The material consisted of 400 cold dishes and 1,288 hot dishes as well as salads, cheese plates and deserts. Total number of samples was 2211. Salmonella spp. were isolated from 6 samples; 1 contaminated sample was a cold dish prepared in Bangkok, 1 was a hot dish prepared in Mombasa and the remaining 4 contaminated samples were hot dishes prepared within one week in Beijing. The isolated serotypes were S. ohio, S. manchester and S. braenderup. The contaminated cold dish prepared by a flight kitchen in Bangkok was found to be connected with a Salmonella outbreak which occurred in Finland in 1990. Cold airline dishes containing food of animal origin seems to be more risky as a source of Salmonella infections among airline passengers.

  6. spv locus aggravates Salmonella infection of zebrafish adult by inducing Th1/Th2 shift to Th2 polarization.

    Science.gov (United States)

    Wu, Shu-Yan; Wang, Li-Dan; Xu, Guang-Mei; Yang, Si-di; Deng, Qi-Feng; Li, Yuan-Yuan; Huang, Rui

    2017-08-01

    Salmonella enterica serovar typhimurium (S. typhimurium) are facultative intracellular enteric pathogens causing disease with a broad range of hosts. It was known that Th1-type cytokines such as IFN-γ, IL-12, and TNF-α etc. could induce protective immunity against intracellular pathogens, while Th2-type cytokines such as IL-4, IL-10, and IL-13 etc. are proved to help pathogens survive inside hosts and cause severe infection. One of the critical virulence factor attributes to the pathogenesis of S. typhimurium is Salmonella plasmid virulence genes (spv). Until now, the interaction between spv locus and the predictable generation of Th1 or Th2 immune responses to Salmonella has not been identified. In this study, zebrafish adults were employed to explore the effect of spv locus on Salmonella pathogenesis as well as host adaptive immune responses especially shift of Th1/Th2 balance. The pathological changes of intestines and livers in zebrafish were observed by hematoxylin-eosin (HE) staining and electron microscopy. Levels of the transcription factors of Th1 (Tbx21) and Th2 (GATA3) were measured by real-time quantitative PCR (RT-qPCR). Expression of cytokines were determined by using RT-qPCR and ELISA, respectively. Results showed that spv operon aggravates damage of zebrafish. Furthermore, it demonstrated that spv locus could inhibit the transcription of tbx21 gene and suppress the expression of cytokines IFN-γ, IL-12 and TNF-α. On the contrary, the transcription of gata3 gene could be promoted and the expression of cytokines IL-4, IL-10 and IL-13 were enhanced by spv locus. Taken together, our data revealed that spv locus could aggravate Salmonella infection of zebrafish adult by inducing an imbalance of Th1/Th2 immune response and resulting in a detrimental Th2 bias of host. Copyright © 2017. Published by Elsevier Ltd.

  7. LPS structure and PhoQ activity are important for Salmonella Typhimurium virulence in the Galleria mellonella infection model [corrected].

    Directory of Open Access Journals (Sweden)

    Jennifer K Bender

    Full Text Available The larvae of the wax moth, Galleria mellonella, have been used experimentally to host a range of bacterial and fungal pathogens. In this study we evaluated the suitability of G. mellonella as an alternative animal model of Salmonella infection. Using a range of inoculum doses we established that the LD₅₀ of SalmonellaTyphimurium strain NCTC 12023 was 3.6 × 10³ bacteria per larva. Further, a set of isogenic mutant strains depleted of known virulence factors was tested to identify determinants essential for S. Typhimurium pathogenesis. Mutants depleted of one or both of the type III secretion systems encoded by Salmonella Pathogenicity Islands 1 and 2 showed no virulence defect. In contrast, we observed reduced pathogenic potential of a phoQ mutant indicating an important role for the PhoPQ two-component signal transduction system. Lipopolysaccharide (LPS structure was also shown to influence Salmonella virulence in G. mellonella. A waaL(rfaL mutant, which lacks the entire O-antigen (OAg, was virtually avirulent, while a wzz(ST/wzz(fepE double mutant expressing only a very short OAg was highly attenuated for virulence. Furthermore, shortly after infection both LPS mutant strains showed decreased replication when compared to the wild type in a flow cytometry-based competitive index assay. In this study we successfully established a G. mellonella model of S. Typhimurium infection. By identifying PhoQ and LPS OAg length as key determinants of virulence in the wax moth larvae we proved that there is an overlap between this and other animal model systems, thus confirming that the G. mellonella infection model is suitable for assessing aspects of Salmonella virulence function.

  8. A novel strategy to obtain quantitative data for modelling: Combined enrichment and real-time PCR for enumeration of salmonellae from pig carcasses

    DEFF Research Database (Denmark)

    Malorny, Burkhard; Krämer, Nadine; Vigre, Håkan

    2011-01-01

    The primary sources for the major zoonotic pathogen Salmonella are food-producing animals such as pigs and poultry. For risk assessment and hazard analysis and critical control point (HACCP) concepts, it is essential to produce large amounts of quantitative data, which is currently not achievable...

  9. Performance and mechanism of standard nano-TiO2(P-25) in photocatalytic disinfection of foodborne microorganisms - salmonella typhimurium and listeria monocytogenes

    Science.gov (United States)

    In this paper, effects of disinfection by nano-TiO2 were studied on the two typical foodborne microorganisms, Gram-negative bacterium Salmonella typhimurium and Gram-positive bacterium-Listeria monocytogenes, in meat products. The performance of nano-TiO2 against the foodborne pathogens was evaluate...

  10. Antimicrobial activities of red wine-based formulations containing plant extracts against Escherichia coli O157:H7 and Salmonella enterica serovar Hadar

    Science.gov (United States)

    We evaluated the bactericidal activities of red wine and red wine solutions containing a commercial olive extract called Hydrox-12, oregano oil, or a mixture of both in red wine against the following foodborne pathogens: Escherichia coli O157:H7, Salmonella enterica, Listeria monocytogenes, and Stap...

  11. Proteomic pleiotropy of OpgGH, an operon necessary for efficient growth of Salmonella enterica serovar Typhimurium under low-osmotic conditions

    Science.gov (United States)

    Salmonella enterica, a bacterial, food-borne pathogen of humans, can contaminate raw fruits and vegetables. Causing much public concern, the bacteria can survive in water used to wash produce. The ability to survive the low-osmolarity of the wash waters is attributed to the OpgGH operon that leads...

  12. Effects of bacterial dose and fly sex on persistence and excretion of Salmonella enterica serovar Typhimurium from adult house flies (Diptera: Muscidae)

    Science.gov (United States)

    Salmonella Typhimurium is a pathogen that causes gastroenteritis in humans and can be harbored by house flies. Factors influencing excretion of S. Typhimurium from infected flies have not been elucidated, but are essential for assessing transmission potential. We determined the persistence and excre...

  13. Neural network model for survival and growth of Salmonella 8,20:-:z6 in ground chicken thigh meat during cold storage: extrapolation to other serotypes

    Science.gov (United States)

    Mathematical models that predict behavior of human bacterial pathogens in food are valuable tools for assessing and managing this risk to public health. A study was undertaken to develop a model for predicting behavior of Salmonella 8,20:-:z6 in chicken meat during cold storage and to determine how...

  14. Interrelationships of food safety and plant pathology: the life cycle of human pathogens on plants.

    Science.gov (United States)

    Barak, Jeri D; Schroeder, Brenda K

    2012-01-01

    Bacterial food-borne pathogens use plants as vectors between animal hosts, all the while following the life cycle script of plant-associated bacteria. Similar to phytobacteria, Salmonella, pathogenic Escherichia coli, and cross-domain pathogens have a foothold in agricultural production areas. The commonality of environmental contamination translates to contact with plants. Because of the chronic absence of kill steps against human pathogens for fresh produce, arrival on plants leads to persistence and the risk of human illness. Significant research progress is revealing mechanisms used by human pathogens to colonize plants and important biological interactions between and among bacteria in planta. These findings articulate the difficulty of eliminating or reducing the pathogen from plants. The plant itself may be an untapped key to clean produce. This review highlights the life of human pathogens outside an animal host, focusing on the role of plants, and illustrates areas that are ripe for future investigation.

  15. Experimental reproduction of rotavirus and Salmonella pullorum ...

    African Journals Online (AJOL)

    Group A chicks were inoculated with 1 X 106 pfu/ml of rotavirus, group B chicks were inoculated with 1 X 106 cfu/ml of Salmonella pullorum, group C chicks were inoculated with 1 X 106 pfu/ml of rotavirus and 1 X 106 cfu/ml of Salmonella pullorum, while group D birds were given 1ml of PBS alone. Birds in all groups were ...

  16. Salmonella in beef and produce from honduras.

    Science.gov (United States)

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

    2015-03-01

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

  17. Emerging Pathogens Initiative (EPI)

    Data.gov (United States)

    Department of Veterans Affairs — The Emerging Pathogens Initiative (EPI) database contains emerging pathogens information from the local Veterans Affairs Medical Centers (VAMCs). The EPI software...

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

    Directory of Open Access Journals (Sweden)

    Lawrence Mark L

    2010-07-01

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

  19. Tentative Colistin Epidemiological Cut-Off Value for Salmonella spp

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Torpdahl, Mia; Zachariasen, Camilla

    2012-01-01

    . Interestingly, Salmonella Dublin and Salmonella Enteritidis belong to the same O-group (O:1, 9,12), suggesting that surface lipopolysaccharides (LPS) of the cell (O-antigen) play a role in colistin susceptibility. The epidemiological cut-off value of >2 mg/L for colistin suggested by European Committee...... on Antimicrobial Susceptibility Testing (EUCAST) is placed inside the distribution for both Salmonella Dublin and Salmonella Enteritidis. All tested Salmonella Dublin isolates, regardless of MIC colistin value, had identical pmrA and pmrB sequences. Missense mutations were found only in pmrA in one Salmonella...

  20. Transcriptomic analysis of Salmonella desiccation resistance.

    Science.gov (United States)

    Li, Haiping; Bhaskara, Anuhya; Megalis, Christina; Tortorello, Mary Lou

    2012-12-01

    The survival of Salmonella in low moisture foods and processing environments remains a great challenge for the food industry and public health. To explore the mechanisms of Salmonella desiccation resistance, we studied the transcriptomic responses in Salmonella Tennessee (Tennessee), using Salmonella Typhimurium LT2 (LT2), a strain weakly resistant to desiccation, as a reference strain. In response to 2 h of air-drying at 11% equilibrated relative humidity, approximately one-fourth of the open reading frames (ORFs) in the Tennessee genome and one-fifth in LT2 were differentially expressed (>2-fold). Among all differentially expressed functional groups (>5-fold) in both strains, the expression fold change associated with fatty acid metabolism was the highest, and constituted 51% and 35% of the total expression fold change in Tennessee and LT2, respectively. Tennessee showed greater changes in expression of genes associated with stress response and envelope modification than LT2, while showing lesser changes in protein biosynthesis expression. Expression of flagella genes was significantly more inhibited in stationary phase cells of Tennessee than LT2 both before and after desiccation. The accumulation of the osmolyte trehalose was significantly induced by desiccation in Tennessee, but no increase was detectable in LT2, which is consistent with the expression patterns of the entire trehalose biosynthesis and degradation pathways in both strains. Results from this study present a global view of the dynamic desiccation responses in Salmonella, which will guide future research efforts to control Salmonella in low moisture environments.