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Sample records for salmonella paratyphi b

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

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    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.

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

    Science.gov (United States)

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

    2008-01-01

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

  3. Development of a PCR test system for specific detection of Salmonella Paratyphi B in foods.

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    Zhai, Ligong; Yu, Qian; Bie, Xiaomei; Lu, Zhaoxin; Lv, Fengxia; Zhang, Chong; Kong, Xiaohan; Zhao, Haizhen

    2014-06-01

    Salmonella enterica serotype Paratyphi B is a globally distributed human-specific pathogen causing paratyphoid fever. The aim of this study was to develop a rapid and reliable polymerase chain reaction (PCR) assay for its detection in food. The SPAB_01124 gene was found to be unique to S. Paratyphi B using comparative genomics. Primers for fragments of the SPAB_01124 gene and the Salmonella-specific invA gene were used in combination to establish a multiplex PCR assay that showed 100% specificity across 45 Salmonella strains (representing 34 serotypes) and 18 non-Salmonella strains. The detection limit was 2.2 CFU mL(-1) of S. Paratyphi B after 12-h enrichment in pure culture. It was shown that co-culture with S. Typhimurium or Escherichia coli up to concentrations of 3.6 × 10(5)  CFU and 3.3 × 10(4)  CFU, respectively, did not interfere with PCR detection of S. Paratyphi B. In artificially contaminated milk, the assay could detect as few as 62 CFU mL(-1) after 8 h of enrichment. In conclusion, comparative genomics was found to be an efficient approach to the mining of pathogen-specific target genes, and the PCR assay that was developed from this provided a rapid, specific, and sensitive method for detection of S. Paratyphi B. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  4. Isolation and characterization of a rare waterborne lytic phage of Salmonella enterica serovar Paratyphi B.

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    Ahiwale, Sangeeta S; Bankar, Ashok V; Tagunde, Sujata N; Zinjarde, Smita; Ackermann, Hans W; Kapadnis, B P

    2013-05-01

    A lytic phage of Salmonella serovar Paratyphi B, named φSPB, was isolated from surface waters of the Pavana River in India. Phage φSPB is a member of the Podoviridae family and is morphologically similar to the 7-11 phages of the C3 morphotype of tailed phages, characterized by a very long, cigar-shaped head. The head measured approximately 153 × 57 nm, and the tail size was 12 × 7 nm. The phage was stable over a wide range of pH (4-9) and temperature (4-40 °C). The adsorption rate constant was 4.7 × 10(-10). Latent and eclipse periods were 10 and 15 min, respectively, and the burst size was 100 plaque-forming units/infected cell after 25 min at 37 °C. The phage DNA was 59 kb in size. Ten major proteins were observed on SDS-PAGE, although some of these proteins could be bacterial contaminants. This is the first report of Salmonella enterica subsp. enterica serovar Paratyphi B phage of C3 morphotype from India that has many unique features, such as high replication potential, short replication time, and stability over a wide range of pH and temperature, making it a promising biocontrol agent against the drug-resistant strains of Salmonella Paratyphi B.

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

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    Thomas R. Connor

    2016-08-01

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

  6. [About problems of carriers of Salmonella typhi and paratyphi B under hygienic, epidemiologic and sociologic view (authors transl)].

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    Brossmann, D

    1977-01-01

    The carriers of salmonella typhi and paratyphi B are the central figures of the epidemiology of typhoid illnesses. The files available at the medical authorities' office of the Hansestadt Lübeck, with regards to all 543 carriers registered up to 1972, have been analysed, and 102 of 108 carriers who were inhabitants of Lübeck on 31.10.72, have been interviewed in their lodgings.--Following results are mentionable: 1. 55 carriers have been traced during a hospital stay, 22 of them were under hospital treatment because of cholecystectomy. 2. The circle of persons to be obligated for medical examination as per $ 17 of the Federal Republic of Germany's law of epidemics has proved as too small. For instance two female carriers--known since years--did their job without any hindering as plates washer or waitress in restaurants. 3. 21 persons=4% of the patients excreted salmonellae in urine only. 4. 10% of the carriers of salmonella typhi and 16% of the carriers of salmonella paratypi B had in their faeces as least 5-years intervals of non-excretion. 5. The precentage of carriers with at least 5-years intervals of non-excretion in urine was significantly larger than the corresponding percentage in faeces. 6. Falling ill of 280 persons out of the environs of the carriers have been lead back to the latters. 73% of these infections were placed by the carriers before their detection through the medical authorities' office. 7. For 10 patients whose health was recreated excretion did not cease promptly after the cholecystecystectomy. Salmonellae had been found in the faeces for several months more, at two persons even two years after the operation. 8. For 8 carriers a final decision with regards to the success of cholecystectomy is impossible because they denied a duodenal soundation. 9. 123 persons of 23% of total 543 carriers had--before their ascertation--professions not allowed for those persons. Efforts for a successful job arrangement, possibly combined with a change in

  7. Proposal of Salmonella paratyphi sp. nov., nom. rev. and request for an opinion to conserve the specific epithet paratyphi in the binary combination Salmonella paratyphi as nomen epitheton conservandum.

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    Ezaki, T; Amano, M; Kawamura, Y; Yabuuchi, E

    2000-03-01

    We propose Salmonella paratyphi sp. nov., nom. rev., by raising Salmonella choleraesuis subsp. choleraesuis serovar Paratyphi A to species status and request an Opinion to include the specific epithet paratyphi in the binary combination of Salmonella paratyphi in the list of epitheta specifica conservanda.

  8. Human infections attributable to the D-tartrate-fermenting variant of Salmonella enterica serovar Paratyphi B in Germany originate in reptiles and, on rare occasions, poultry.

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    Toboldt, Anne; Tietze, Erhard; Helmuth, Reiner; Fruth, Angelika; Junker, Ernst; Malorny, Burkhard

    2012-10-01

    In this study, the population structure, incidence, and potential sources of human infection caused by the d-tartrate-fermenting variant of Salmonella enterica serovar Paratyphi B [S. Paratyphi B (dT+)] was investigated. In Germany, the serovar is frequently isolated from broilers. Therefore, a selection of 108 epidemiologically unrelated S. enterica serovar Paratyphi B (dT+) strains isolated in Germany between 2002 and 2010 especially from humans, poultry/poultry meat, and reptiles was investigated by phenotypic and genotypic methods. Strains isolated from poultry and products thereof were strongly associated with multilocus sequence type ST28 and showed antimicrobial multiresistance profiles. Pulsed-field gel electrophoresis XbaI profiles were highly homogeneous, with only a few minor XbaI profile variants. All strains isolated from reptiles, except one, were strongly associated with ST88, another distantly related type. Most of the strains were susceptible to antimicrobial agents, and XbaI profiles were heterogeneous. Strains isolated from humans yielded seven sequence types (STs) clustering in three distantly related lineages. The first lineage, comprising five STs, represented mainly strains belonging to ST43 and ST149. The other two lineages were represented only by one ST each, ST28 and ST88. The relatedness of strains based on the pathogenicity gene repertoire (102 markers tested) was mostly in agreement with the multilocus sequence type. Because ST28 was frequently isolated from poultry but rarely in humans over the 9-year period investigated, overall, this study indicates that in Germany S. enterica serovar Paratyphi B (dT+) poses a health risk preferentially by contact with reptiles and, to a less extent, by exposure to poultry or poultry meat.

  9. [Molecular epidemiology, antimicrobial resistance and characterization of extended-spectrum beta-lactamases of Salmonella enterica serotype Paratyphi B clinical isolates].

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    Bayramoglu, Gülçin; Ozgumus, Osman Birol; Kolayli, Fetiye; Kamburoglu, Ahu; Besli, Yeşim; Dinc, Uğur; Tosun, Ilknur; Aydin, Faruk

    2014-04-01

    Although Salmonella enterica serotype Paratyphi B is the less frequently isolated serotype worldwide and in Turkey, it is the most common serotype in our hospital, with a marked increase in 2007. The purpose of this study was to investigate the antibiotic susceptibility and the extended spectrum beta-lactamase (ESBL) profile, and molecular epidemiology of S. Paratyphi B isolates detected in our hospital microbiology laboratory. Seventy isolates identified as S. Paratyphi B from 109 Salmonella isolates obtained from clinical specimens from different patients between October 2005 and December 2012, were included in the study. In addition to conventional methods, isolates were identified using the Phoenix automated microbiology system (Becton Dickinson, USA). Serotyping of the isolates was performed on the basis of slide agglutination and the Kauffmann-White scheme. The antibiotic susceptibility of the isolates was determined using the BD Phoenix' automated system and disk diffusion test. ESBL enzymes were investigated using the combined disk test, isoelectric focusing, polymerase chain reaction (PCR) and sequence analysis. The molecular epidemiology of the 51 isolates obtained between October 2005 and August 2008 was examined with pulsed-field gel electrophoresis (PFGE) using the XbaI enzyme. S. Paratyphi B isolates were obtained from 70 specimens (46 blood, 16 fecal, 4 bone marrow, 2 urine and 2 wound) each from different patients. Resistance to nalidixic acid was determined in 18.6%, resistance to ampicillin, cefotaxime and cefepime in 2.9% and to ceftazidime and co-trimoxazole in 1.4% of the isolates. ESBL production was detected only in two isolates; in one TEM-1 was accompanied by CTX-M-15 and in the other isolate CTX-M-3 was found. Forty-six of the 51 isolates (90%) were found to be genetically related by PFGE and were placed in cluster A. The distribution of the isolates in cluster A revealed six subtypes as A1 (n= 7), A2 (n= 11), A3 (n= 7), A4 (n= 18), A5 (n

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

    DEFF Research Database (Denmark)

    Borowiak, Maria; Fischer, Jennie; Hammerl, Jens A

    2017-01-01

    phosphoethanolamine transferase genes involved in colistin resistance. Subsequently PCR screening, S1-PFGE and DNA-DNA hybridization were performed to analyse the prevalence and location of the identified mcr-5 gene. Cloning and transformation experiments in Escherichia coli DH5α and Salmonella Paratyphi B d Ta...... during 2011-13. The respective gene, further termed as mcr-5 (1644 bp), is part of a 7337 bp transposon of the Tn 3 family and usually located on related multi-copy ColE-type plasmids. Interestingly, in one isolate an additional subclone with a chromosomal location of the mcr-5 transposon was observed....... Our findings suggest that the transfer of colistin-resistance-mediating phosphoethanolamine transferase genes from bacterial chromosomes to mobile genetic elements has occurred in multiple independent events raising concern regarding their variety, prevalence and impact on public health....

  11. Salmonella paratyphi C: genetic divergence from Salmonella choleraesuis and pathogenic convergence with Salmonella typhi.

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    Wei-Qiao Liu

    Full Text Available BACKGROUND: Although over 1400 Salmonella serovars cause usually self-limited gastroenteritis in humans, a few, e.g., Salmonella typhi and S. paratyphi C, cause typhoid, a potentially fatal systemic infection. It is not known whether the typhoid agents have evolved from a common ancestor (by divergent processes or acquired similar pathogenic traits independently (by convergent processes. Comparison of different typhoid agents with non-typhoidal Salmonella lineages will provide excellent models for studies on how similar pathogens might have evolved. METHODOLOGIES/PRINCIPAL FINDINGS: We sequenced a strain of S. paratyphi C, RKS4594, and compared it with previously sequenced Salmonella strains. RKS4594 contains a chromosome of 4,833,080 bp and a plasmid of 55,414 bp. We predicted 4,640 intact coding sequences (4,578 in the chromosome and 62 in the plasmid and 152 pseudogenes (149 in the chromosome and 3 in the plasmid. RKS4594 shares as many as 4346 of the 4,640 genes with a strain of S. choleraesuis, which is primarily a swine pathogen, but only 4008 genes with another human-adapted typhoid agent, S. typhi. Comparison of 3691 genes shared by all six sequenced Salmonella strains placed S. paratyphi C and S. choleraesuis together at one end, and S. typhi at the opposite end, of the phylogenetic tree, demonstrating separate ancestries of the human-adapted typhoid agents. S. paratyphi C seemed to have suffered enormous selection pressures during its adaptation to man as suggested by the differential nucleotide substitutions and different sets of pseudogenes, between S. paratyphi C and S. choleraesuis. CONCLUSIONS: S. paratyphi C does not share a common ancestor with other human-adapted typhoid agents, supporting the convergent evolution model of the typhoid agents. S. paratyphi C has diverged from a common ancestor with S. choleraesuis by accumulating genomic novelty during adaptation to man.

  12. O:2-CRM(197) conjugates against Salmonella Paratyphi A.

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    Micoli, Francesca; Rondini, Simona; Gavini, Massimiliano; Lanzilao, Luisa; Medaglini, Donata; Saul, Allan; Martin, Laura B

    2012-01-01

    Enteric fevers remain a common and serious disease, affecting mainly children and adolescents in developing countries. Salmonella enterica serovar Typhi was believed to cause most enteric fever episodes, but several recent reports have shown an increasing incidence of S. Paratyphi A, encouraging the development of a bivalent vaccine to protect against both serovars, especially considering that at present there is no vaccine against S. Paratyphi A. The O-specific polysaccharide (O:2) of S. Paratyphi A is a protective antigen and clinical data have previously demonstrated the potential of using O:2 conjugate vaccines. Here we describe a new conjugation chemistry to link O:2 and the carrier protein CRM(197), using the terminus 3-deoxy-D-manno-octulosonic acid (KDO), thus leaving the O:2 chain unmodified. The new conjugates were tested in mice and compared with other O:2-antigen conjugates, synthesized adopting previously described methods that use CRM(197) as carrier protein. The newly developed conjugation chemistry yielded immunogenic conjugates with strong serum bactericidal activity against S. Paratyphi A.

  13. Lack of efflux mediated quinolone resistance in Salmonella enterica serovars Typhi and Paratyphi A

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    Sylvie eBaucheron

    2014-01-01

    Full Text Available Salmonella enterica serovars Typhi and Paratyphi A isolates from human patients in France displaying different levels of resistance to quinolones or fluoroquinolones were studied for resistance mechanisms to these antimicrobial agents. All resistant isolates carried either single or multiple target gene mutations (i.e. in gyrA, gyrB, or parC correlating with the resistance levels observed. Active efflux, through upregulation of multipartite efflux systems, has also been previously reported as contributing mechanism for other serovars. Therefore, we investigated also the occurrence of non-target gene mutations in regulatory regions affecting efflux pump expression. However, no mutation was detected in these regions in both Typhi and Paratyphi isolates of this study. Besides, no overexpression of the major efflux systems was observed for these isolates. Nevertheless, a large deletion of 2334 bp was identified in the acrS-acrE region of all S. Typhi strains but which did not affect the resistance phenotype. As being specific to S. Typhi, this deletion could be used for specific molecular detection purposes. In conclusion, the different levels of quinolone or FQ resistance in both S. Typhi and S. Paratyphi A seem to rely only on target modifications.

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

    LENUS (Irish Health Repository)

    Song, Yajun

    2010-08-01

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

  15. Molecular and Clinical Epidemiology of Salmonella Paratyphi A Isolated from Patients with Bacteremia in Nepal.

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    Sherchan, Jatan Bahadur; Morita, Masatomo; Matono, Takashi; Izumiya, Hidemasa; Ohnishi, Makoto; Sherchand, Jeevan B; Tandukar, Sarmila; Laghu, Ujjwal; Nagamatsu, Maki; Kato, Yasuyuki; Ohmagari, Norio; Hayakawa, Kayoko

    2017-12-01

    Little is known about the epidemiology of typhoid and paratyphoid fever in Nepal. We aimed to elucidate the molecular and clinical epidemiology of Salmonella Paratyphi A in Nepal. Isolates were collected from 23 cases of bacteremia due to S. Paratyphi A between December 2014 and October 2015. Thirteen patients (57%) were male, and the median age was 21 years. None of the patients had an underlying chronic disease. All S. Paratyphi A isolates were sensitive to ampicillin, trimethoprim/sulfamethoxazole, ceftriaxone, and chloramphenicol. All isolates were resistant to nalidixic acid and were categorized as intermediately susceptible to levofloxacin. Phylogenetic analysis revealed close relatedness among the isolates, including several clonal groups, suggesting local spread. Patients with bacteremia due to S. Paratyphi A in Kathmandu, Nepal, were relatively young and nondebilitated. Improving control of S. Paratyphi infections should focus on effective infection control measures and selection of empirical therapy based on current resistance patterns.

  16. [Establishment of protein fingerprint database of Salmonella paratyphi A using SELDI-TOF-MS].

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    Li, Xiao-qing; Huang, Wen-fang; Liu, Hua; Yang, Yong-chang; Xiao, Dai-wen; Yan, Hui; Luo, Chun-li

    2012-06-01

    To establish a protein fingerprint database of Salmonella paratyphi A by surface enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Thirty-six clinical bacterial isolates and 96 control bacteria isolates were collected and identified using 16S rDNA sequencing. Bacterial proteins were detected by SELDI-TOF-MS, and all protein fingerprints were analyzed by ProteinChip and Biomarker Wizard software. The analysis results were used to set up a classification tree model by means of BioMarker Patterns software. At the same time, the data were tested by a blinded validation. In the range of M(r); 3 000-20 000, we obtained 104 protein peaks, of which 90 were of statistical significance (P<0.01). A protein peak with mass-to-charge ratio(M/Z) 10 061.7 was chosen to establish the classification tree model of Salmonella paratyphi A, and the sensitivity and specificity of Salmonella paratyphi A diagnosis was 100% as shown by the blinded validation. The classification tree model of Salmonella paratyphi A can be not only established using SELDI-TOF-MS technology, but also used for the rapid identification of Salmonella paratyphi A.

  17. Microcontact Imprinted Plasmonic Nanosensors: Powerful Tools in the Detection of Salmonella paratyphi

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    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.

  18. Outbreaks of Salmonella paratyphi A in a commercial poultry farm in ...

    African Journals Online (AJOL)

    An outbreak of Salmonella paratyphi A in a commercial poultry farm in Ibadan is hereby reported. The clinical findings manifested by the birds were reduced appetite, increased water consumption and passed yellowish green stool. There was decreased egg production, prostration and death. Morbidity was 50% while ...

  19. The discrimination of d-tartrate positive and d-tartrate negative S. enterica subsp. enterica serovar Paratyphi B isolated in Malaysia by phenotypic and genotypic methods.

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    Ahmad, Norazah; Hoon, Shirley Tang Gee; Ghani, Mohamed Kamel Abd; Tee, Koh Yin

    2012-06-01

    Serotyping is not sufficient to differentiate between Salmonella species that cause paratyphoid fever from the strains that cause milder gastroenteritis as these organisms share the same serotype Salmonella Paratyphi B (S. Paratyphi B). Strains causing paratyphoid fever do not ferment d-tartrate and this key feature was used in this study to determine the prevalence of these strains among the collection of S. Paratyphi B strains isolated from patients in Malaysia. A total of 105 isolates of S. Paratyphi B were discriminated into d-tartrate positive (dT+) and d-tartrate negative (dT) variants by two lead acetate test protocols and multiplex PCR. The lead acetate test protocol 1 differed from protocol 2 by a lower inoculum size and different incubation conditions while the multiplex PCR utilized 2 sets of primers targeting the ATG start codon of the gene STM3356. Lead acetate protocol 1 discriminated 97.1% of the isolates as S. Paratyphi B dT+ and 2.9% as dT while test protocol 2 discriminated all the isolates as S. Paratyphi B dT+. The multiplex PCR test identified all 105 isolates as S. Paratyphi B dT+ strains. The concordance of the lead acetate test relative to that of multiplex PCR was 97.7% and 100% for protocol 1 and 2 respectively. This study showed that S. Paratyphi B dT+ is a common causative agent of gastroenteritis in Malaysia while paratyphoid fever appears to be relatively uncommon. Multiplex PCR was shown to be a simpler, more rapid and reliable method to discriminate S. Paratyphi B than the phenotypic lead acetate test.

  20. [Multilocus sequence typing and pulsed-field gel electrophoresis analysis of Salmonella Paratyphi A isolates from 2000 to 2008, China].

    Science.gov (United States)

    Han, Hui; Zhou, Hai-jian; Cui, Zhi-gang; DU, Peng-cheng; Kan, Biao

    2010-09-01

    To analyze molecular and evolution characteristics of Salmonella Paratyphi A isolates from 2000 to 2008, China. Using pulsed-field gel electrophoresis (PFGE) method with SpeI restriction enzyme, and multilocus sequence typing (MLST) method based on housekeeping genes (aroC, thrA, hisD, purE, sucA, dnaN, hemD, adk, and purA), the genomic variations of 118 Salmonella Paratyphi A isolates from 10 regions during 2000 to 2008 were analyzed. Using PFGE method, 118 Salmonella Paratyphi A isolates were clustered into 32 PFGE patterns, and 5 patterns were predominant (5 isolates or above). However, only 2 MLST types were identified for all isolates with MLST method. Among all Salmonella Paratyphi A isolates, the sequences of housekeeping genes were highly conservative and showed a high degree of cloning. For Chinese epidemic Salmonella Paratyphi A isolates during 2000 - 2008, MLST method showed low discrimination power and the MLST method should not be applied to outbreak and epidemiological surveillance of Salmonella Paratyphi A. Currently, nationwide paratyphoid fever epidemics is caused by highly clonal isolates in China. As the time changes, these isolates also accumulate sporadic mutations.

  1. A 23-year retrospective investigation of Salmonella Typhi and Salmonella Paratyphi isolated in a tertiary Kathmandu hospital.

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    Zellweger, Raphaël M; Basnyat, Buddha; Shrestha, Poojan; Prajapati, Krishna G; Dongol, Sabina; Sharma, Paban K; Koirala, Samir; Darton, Thomas C; Dolecek, Christiane; Thompson, Corinne N; Thwaites, Guy E; Baker, Stephen G; Karkey, Abhilasha

    2017-11-01

    Salmonella serovars Typhi (S. Typhi) and Paratyphi A (S. Paratyphi A), the causative agents of enteric fever, have been routinely isolated organisms from the blood of febrile patients in the Kathmandu Valley since the early 1990s. Susceptibility against commonly used antimicrobials for treating enteric fever has gradually changed throughout South Asia since this time, posing serious treatment challenges. Here, we aimed to longitudinally describe trends in the isolation of Salmonella enterica and assess changes in their antimicrobial susceptibility in Kathmandu over a 23-year period. We conducted a retrospective analysis of standardised microbiological data from April 1992 to December 2014 at a single healthcare facility in Kathmandu, examining time trends of Salmonella-associated bacteraemia and the corresponding antimicrobial susceptibility profiles of the isolated organisms. Over 23 years there were 30,353 positive blood cultures. Salmonella enterica accounted for 65.4% (19,857/30,353) of all the bacteria positive blood cultures. S. Typhi and S. Paratyphi A were the dominant serovars, constituting 68.5% (13,592/19,857) and 30.5% (6,057/19,857) of all isolated Salmonellae. We observed (i) a peak in the number of Salmonella-positive cultures in 2002, a year of heavy rainfall and flooding in the Kathmandu Valley, followed by a decline toward pre-flood baseline by 2014, (ii) an increase in the proportion of S. Paratyphi in all Salmonella-positive cultures between 1992 and 2014, (iii) a decrease in the prevalence of MDR for both S. Typhi and S. Paratyphi, and (iv) a recent increase in fluoroquinolone non-susceptibility in both S. Typhi and S. Paratyphi isolates. Our work describes significant changes in the epidemiology of Salmonella enterica in the Kathmandu Valley during the last quarter of a century. We highlight the need to examine current treatment protocols for enteric fever and suggest a change from fluoroquinolone monotherapy to combination therapies of

  2. A 23-year retrospective investigation of Salmonella Typhi and Salmonella Paratyphi isolated in a tertiary Kathmandu hospital.

    Directory of Open Access Journals (Sweden)

    Raphaël M Zellweger

    2017-11-01

    Full Text Available Salmonella serovars Typhi (S. Typhi and Paratyphi A (S. Paratyphi A, the causative agents of enteric fever, have been routinely isolated organisms from the blood of febrile patients in the Kathmandu Valley since the early 1990s. Susceptibility against commonly used antimicrobials for treating enteric fever has gradually changed throughout South Asia since this time, posing serious treatment challenges. Here, we aimed to longitudinally describe trends in the isolation of Salmonella enterica and assess changes in their antimicrobial susceptibility in Kathmandu over a 23-year period.We conducted a retrospective analysis of standardised microbiological data from April 1992 to December 2014 at a single healthcare facility in Kathmandu, examining time trends of Salmonella-associated bacteraemia and the corresponding antimicrobial susceptibility profiles of the isolated organisms.Over 23 years there were 30,353 positive blood cultures. Salmonella enterica accounted for 65.4% (19,857/30,353 of all the bacteria positive blood cultures. S. Typhi and S. Paratyphi A were the dominant serovars, constituting 68.5% (13,592/19,857 and 30.5% (6,057/19,857 of all isolated Salmonellae. We observed (i a peak in the number of Salmonella-positive cultures in 2002, a year of heavy rainfall and flooding in the Kathmandu Valley, followed by a decline toward pre-flood baseline by 2014, (ii an increase in the proportion of S. Paratyphi in all Salmonella-positive cultures between 1992 and 2014, (iii a decrease in the prevalence of MDR for both S. Typhi and S. Paratyphi, and (iv a recent increase in fluoroquinolone non-susceptibility in both S. Typhi and S. Paratyphi isolates.Our work describes significant changes in the epidemiology of Salmonella enterica in the Kathmandu Valley during the last quarter of a century. We highlight the need to examine current treatment protocols for enteric fever and suggest a change from fluoroquinolone monotherapy to combination therapies

  3. Infection Dynamics and Antimicrobial Resistance Profile of Salmonella Paratyphi B d-tartrate Positive (Java) in a Persistently Infected Broiler Barn.

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    Kloska, Franziska; Beyerbach, Martin; Klein, Günter

    2017-01-21

    The infection dynamics of S. Java were examined in three consecutive rearing periods on a broiler farm in Northwestern Germany which had been persistently infected with S. Java for more than five years. The barn was investigated for Salmonella occurrence after cleaning and disinfection to verify the persistent contamination of the broiler house with S. Java before the start of the first rearing cycle. Confirmation of Salmonella absence in day-old chicks (time-point 1) as well as early establishment of infection between days 5-7 (time-point 2) were confirmed by caecal swabs prepared for qPCR and classical microbiological methods. At three time-periods (between days 11-15 (time-point 3), days 25-28 (time-point 4), and days 38-40 (time-point 5)) caecal content was examined for colony forming units (CFU) Salmonella/g. In general, there was an increase in Salmonella Java load at time-point 4 compared to time-points 3 and 5. Therefore, we observed a bell-shaped course of infection resulting in higher rates of Salmonella CFU/g prior to prethinning than at final slaughter. The antimicrobial susceptibility testing revealed resistance to tetracycline, fluorquinolones, trimethoprim, and cefoxitin.

  4. Infection Dynamics and Antimicrobial Resistance Profile of Salmonella Paratyphi B d-tartrate Positive (Java in a Persistently Infected Broiler Barn

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    Franziska Kloska

    2017-01-01

    Full Text Available The infection dynamics of S. Java were examined in three consecutive rearing periods on a broiler farm in Northwestern Germany which had been persistently infected with S. Java for more than five years. The barn was investigated for Salmonella occurrence after cleaning and disinfection to verify the persistent contamination of the broiler house with S. Java before the start of the first rearing cycle. Confirmation of Salmonella absence in day-old chicks (time-point 1 as well as early establishment of infection between days 5–7 (time-point 2 were confirmed by caecal swabs prepared for qPCR and classical microbiological methods. At three time-periods (between days 11–15 (time-point 3, days 25–28 (time-point 4, and days 38–40 (time-point 5 caecal content was examined for colony forming units (CFU Salmonella/g. In general, there was an increase in Salmonella Java load at time-point 4 compared to time-points 3 and 5. Therefore, we observed a bell-shaped course of infection resulting in higher rates of Salmonella CFU/g prior to prethinning than at final slaughter. The antimicrobial susceptibility testing revealed resistance to tetracycline, fluorquinolones, trimethoprim, and cefoxitin.

  5. Enteric fever due to Salmonella Paratyphi A in Greece: a case report

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    Chalkias, Athanasios; Anastasopoulos, Dimitrios; Tsiaglis, Stavros

    2008-01-01

    Background Enteric fever is a major global public health problem and growing international travel leads to an increase in the risk of contracting infectious diseases that are endemic in the country of destination. Case presentation A 30-year-old Pakistani male was admitted feeling generally unwell with fever, vertigo, vomiting and headache. Admission blood cultures grew Salmonella ser. Paratyphi A. The patient was successfully treated with intravenous Amoxicillin/Clavulanic Acid and Ciprofloxacin. Conclusion This case report emphasizes the potent spread of Salmonellae bacilli in a developed country. PMID:19087343

  6. Clinically and Microbiologically Derived Azithromycin Susceptibility Breakpoints for Salmonella enterica Serovars Typhi and Paratyphi A

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    Thieu, Nga Tran Vu; Dolecek, Christiane; Karkey, Abhilasha; Gupta, Ruchi; Turner, Paul; Dance, David; Maude, Rapeephan R.; Ha, Vinh; Tran, Chinh Nguyen; Thi, Phuong Le; Be, Bay Pham Van; Phi, La Tran Thi; Ngoc, Rang Nguyen; Ghose, Aniruddha; Dongol, Sabina; Campbell, James I.; Thanh, Duy Pham; Thanh, Tuyen Ha; Moore, Catrin E.; Sona, Soeng; Gaind, Rajni; Deb, Monorama; Anh, Ho Van; Van, Sach Nguyen; Tinh, Hien Tran; Day, Nicholas P. J.; Dondorp, Arjen; Thwaites, Guy; Faiz, Mohamed Abul; Phetsouvanh, Rattanaphone; Newton, Paul; Basnyat, Buddha; Farrar, Jeremy J.; Baker, Stephen

    2015-01-01

    Azithromycin is an effective treatment for uncomplicated infections with Salmonella enterica serovar Typhi and serovar Paratyphi A (enteric fever), but there are no clinically validated MIC and disk zone size interpretative guidelines. We studied individual patient data from three randomized controlled trials (RCTs) of antimicrobial treatment in enteric fever in Vietnam, with azithromycin used in one treatment arm, to determine the relationship between azithromycin treatment response and the azithromycin MIC of the infecting isolate. We additionally compared the azithromycin MIC and the disk susceptibility zone sizes of 1,640 S. Typhi and S. Paratyphi A clinical isolates collected from seven Asian countries. In the RCTs, 214 patients who were treated with azithromycin at a dose of 10 to 20 mg/ml for 5 to 7 days were analyzed. Treatment was successful in 195 of 214 (91%) patients, with no significant difference in response (cure rate, fever clearance time) with MICs ranging from 4 to 16 μg/ml. The proportion of Asian enteric fever isolates with an MIC of ≤16 μg/ml was 1,452/1,460 (99.5%; 95% confidence interval [CI], 98.9 to 99.7) for S. Typhi and 207/240 (86.3%; 95% CI, 81.2 to 90.3) (P azithromycin disk identified S. Typhi isolates with an MIC of ≤16 μg/ml with a sensitivity of 99.7%. An azithromycin MIC of ≤16 μg/ml or disk inhibition zone size of ≥13 mm enabled the detection of susceptible S. Typhi isolates that respond to azithromycin treatment. Further work is needed to define the response to treatment in S. Typhi isolates with an azithromycin MIC of >16 μg/ml and to determine MIC and disk breakpoints for S. Paratyphi A. PMID:25733500

  7. The core proteome and pan proteome of Salmonella Paratyphi A epidemic strains.

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    Li Zhang

    Full Text Available Comparative proteomics of the multiple strains within the same species can reveal the genetic variation and relationships among strains without the need to assess the genomic data. Similar to comparative genomics, core proteome and pan proteome can also be obtained within multiple strains under the same culture conditions. In this study we present the core proteome and pan proteome of four epidemic Salmonella Paratyphi A strains cultured under laboratory culture conditions. The proteomic information was obtained using a Two-dimensional gel electrophoresis (2-DE technique. The expression profiles of these strains were conservative, similar to the monomorphic genome of S. Paratyphi A. Few strain-specific proteins were found in these strains. Interestingly, non-core proteins were found in similar categories as core proteins. However, significant fluctuations in the abundance of some core proteins were also observed, suggesting that there is elaborate regulation of core proteins in the different strains even when they are cultured in the same environment. Therefore, core proteome and pan proteome analysis of the multiple strains can demonstrate the core pathways of metabolism of the species under specific culture conditions, and further the specific responses and adaptations of the strains to the growth environment.

  8. The core proteome and pan proteome of Salmonella Paratyphi A epidemic strains.

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    Zhang, Li; Xiao, Di; Pang, Bo; Zhang, Qian; Zhou, Haijian; Zhang, Lijuan; Zhang, Jianzhong; Kan, Biao

    2014-01-01

    Comparative proteomics of the multiple strains within the same species can reveal the genetic variation and relationships among strains without the need to assess the genomic data. Similar to comparative genomics, core proteome and pan proteome can also be obtained within multiple strains under the same culture conditions. In this study we present the core proteome and pan proteome of four epidemic Salmonella Paratyphi A strains cultured under laboratory culture conditions. The proteomic information was obtained using a Two-dimensional gel electrophoresis (2-DE) technique. The expression profiles of these strains were conservative, similar to the monomorphic genome of S. Paratyphi A. Few strain-specific proteins were found in these strains. Interestingly, non-core proteins were found in similar categories as core proteins. However, significant fluctuations in the abundance of some core proteins were also observed, suggesting that there is elaborate regulation of core proteins in the different strains even when they are cultured in the same environment. Therefore, core proteome and pan proteome analysis of the multiple strains can demonstrate the core pathways of metabolism of the species under specific culture conditions, and further the specific responses and adaptations of the strains to the growth environment.

  9. Development and Evaluation of a Blood Culture PCR Assay for Rapid Detection of Salmonella Paratyphi A in Clinical Samples.

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    Zhou, Liqing; Jones, Claire; Gibani, Malick M; Dobinson, Hazel; Thomaides-Brears, Helena; Shrestha, Sonu; Blohmke, Christoph J; Darton, Thomas C; Pollard, Andrew J

    2016-01-01

    Enteric fever remains an important cause of morbidity in many low-income countries and Salmonella Paratyphi A has emerged as the aetiological agent in an increasing proportion of cases. Lack of adequate diagnostics hinders early diagnosis and prompt treatment of both typhoid and paratyphoid but development of assays to identify paratyphoid has been particularly neglected. Here we describe the development of a rapid and sensitive blood culture PCR method for detection of Salmonella Paratyphi A from blood, potentially allowing for appropriate diagnosis and antimicrobial treatment to be initiated on the same day. Venous blood samples from volunteers experimentally challenged orally with Salmonella Paratyphi A, who subsequently developed paratyphoid, were taken on the day of diagnosis; 10 ml for quantitative blood culture and automated blood culture, and 5 ml for blood culture PCR. In the latter assay, bacteria were grown in tryptone soy broth containing 2.4% ox bile and micrococcal nuclease for 5 hours (37°C) before bacterial DNA was isolated for PCR detection targeting the fliC-a gene of Salmonella Paratyphi A. An optimized broth containing 2.4% ox bile and micrococcal nuclease, as well as a PCR test was developed for a blood culture PCR assay of Salmonella Paratyphi A. The volunteers diagnosed with paratyphoid had a median bacterial burden of 1 (range 0.1-6.9) CFU/ml blood. All the blood culture PCR positive cases where a positive bacterial growth was shown by quantitative blood culture had a bacterial burden of ≥ 0.3 CFU/ ml blood. The blood culture PCR assay identified an equal number of positive cases as automated blood culture at higher bacterial loads (≥0.3 CFU/ml blood), but utilized only half the volume of specimens. The blood culture PCR method for detection of Salmonella Paratyphi A can be completed within 9 hours and offers the potential for same-day diagnosis of enteric fever. Using 5 ml blood, it exhibited a lower limit of detection equal to 0.3 CFU

  10. Development and Evaluation of a Blood Culture PCR Assay for Rapid Detection of Salmonella Paratyphi A in Clinical Samples.

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    Liqing Zhou

    Full Text Available Enteric fever remains an important cause of morbidity in many low-income countries and Salmonella Paratyphi A has emerged as the aetiological agent in an increasing proportion of cases. Lack of adequate diagnostics hinders early diagnosis and prompt treatment of both typhoid and paratyphoid but development of assays to identify paratyphoid has been particularly neglected. Here we describe the development of a rapid and sensitive blood culture PCR method for detection of Salmonella Paratyphi A from blood, potentially allowing for appropriate diagnosis and antimicrobial treatment to be initiated on the same day.Venous blood samples from volunteers experimentally challenged orally with Salmonella Paratyphi A, who subsequently developed paratyphoid, were taken on the day of diagnosis; 10 ml for quantitative blood culture and automated blood culture, and 5 ml for blood culture PCR. In the latter assay, bacteria were grown in tryptone soy broth containing 2.4% ox bile and micrococcal nuclease for 5 hours (37°C before bacterial DNA was isolated for PCR detection targeting the fliC-a gene of Salmonella Paratyphi A.An optimized broth containing 2.4% ox bile and micrococcal nuclease, as well as a PCR test was developed for a blood culture PCR assay of Salmonella Paratyphi A. The volunteers diagnosed with paratyphoid had a median bacterial burden of 1 (range 0.1-6.9 CFU/ml blood. All the blood culture PCR positive cases where a positive bacterial growth was shown by quantitative blood culture had a bacterial burden of ≥ 0.3 CFU/ ml blood. The blood culture PCR assay identified an equal number of positive cases as automated blood culture at higher bacterial loads (≥0.3 CFU/ml blood, but utilized only half the volume of specimens.The blood culture PCR method for detection of Salmonella Paratyphi A can be completed within 9 hours and offers the potential for same-day diagnosis of enteric fever. Using 5 ml blood, it exhibited a lower limit of detection

  11. Development and Evaluation of a Blood Culture PCR Assay for Rapid Detection of Salmonella Paratyphi A in Clinical Samples

    Science.gov (United States)

    Zhou, Liqing; Jones, Claire; Gibani, Malick M.; Dobinson, Hazel; Thomaides-Brears, Helena; Shrestha, Sonu; Blohmke, Christoph J.; Darton, Thomas C.; Pollard, Andrew J.

    2016-01-01

    Background Enteric fever remains an important cause of morbidity in many low-income countries and Salmonella Paratyphi A has emerged as the aetiological agent in an increasing proportion of cases. Lack of adequate diagnostics hinders early diagnosis and prompt treatment of both typhoid and paratyphoid but development of assays to identify paratyphoid has been particularly neglected. Here we describe the development of a rapid and sensitive blood culture PCR method for detection of Salmonella Paratyphi A from blood, potentially allowing for appropriate diagnosis and antimicrobial treatment to be initiated on the same day. Methods Venous blood samples from volunteers experimentally challenged orally with Salmonella Paratyphi A, who subsequently developed paratyphoid, were taken on the day of diagnosis; 10 ml for quantitative blood culture and automated blood culture, and 5 ml for blood culture PCR. In the latter assay, bacteria were grown in tryptone soy broth containing 2.4% ox bile and micrococcal nuclease for 5 hours (37°C) before bacterial DNA was isolated for PCR detection targeting the fliC-a gene of Salmonella Paratyphi A. Results An optimized broth containing 2.4% ox bile and micrococcal nuclease, as well as a PCR test was developed for a blood culture PCR assay of Salmonella Paratyphi A. The volunteers diagnosed with paratyphoid had a median bacterial burden of 1 (range 0.1–6.9) CFU/ml blood. All the blood culture PCR positive cases where a positive bacterial growth was shown by quantitative blood culture had a bacterial burden of ≥ 0.3 CFU/ ml blood. The blood culture PCR assay identified an equal number of positive cases as automated blood culture at higher bacterial loads (≥0.3 CFU/ml blood), but utilized only half the volume of specimens. Conclusions The blood culture PCR method for detection of Salmonella Paratyphi A can be completed within 9 hours and offers the potential for same-day diagnosis of enteric fever. Using 5 ml blood, it exhibited a

  12. Cell-associated flagella enhance the protection conferred by mucosally-administered attenuated Salmonella Paratyphi A vaccines.

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    Orit Gat

    2011-11-01

    Full Text Available Antibiotic-resistant Salmonella enterica serovar Paratyphi A, the agent of paratyphoid A fever, poses an emerging public health dilemma in endemic areas of Asia and among travelers, as there is no licensed vaccine. Integral to our efforts to develop a S. Paratyphi A vaccine, we addressed the role of flagella as a potential protective antigen by comparing cell-associated flagella with exported flagellin subunits expressed by attenuated strains.S. Paratyphi A strain ATCC 9150 was first deleted for the chromosomal guaBA locus, creating CVD 1901. Further chromosomal deletions in fliD (CVD 1901D or flgK (CVD 1901K were then engineered, resulting in the export of unpolymerized FliC, without impairing its overall expression. The virulence of the resulting isogenic strains was examined using a novel mouse LD(50 model to accommodate the human-host restricted S. Paratyphi A. The immunogenicity of the attenuated strains was then tested using a mouse intranasal model, followed by intraperitoneal challenge with wildtype ATCC 9150.Mucosal (intranasal immunization of mice with strain CVD 1901 expressing cell-associated flagella conferred superior protection (vaccine efficacy [VE], 90% against a lethal intraperitoneal challenge, compared with the flagellin monomer-exporting mutants CVD 1901K (30% VE or CVD 1901D (47% VE. The superior protection induced by CVD 1901 with its cell-attached flagella was associated with an increased IgG2a:IgG1 ratio of FliC-specific antibodies with enhanced opsonophagocytic capacity.Our results clearly suggest that enhanced anti-FliC antibody-mediated clearance of S. Paratyphi A by phagocytic cells, induced by vaccines expressing cell-associated rather than exported FliC, might be contributing to the vaccine-induced protection from S. Paratyphi A challenge in vivo. We speculate that an excess of IgG1 anti-FliC antibodies induced by the exported FliC may compete with the IgG2a subtype and block binding to specific phagocyte Fc

  13. Antimicrobial susceptibility pattern and sequence analysis of DNA gyrase and DNA topoisomerase IV in Salmonella enterica serovars Typhi and Paratyphi A isolates with decreased susceptibility to ciprofloxacin.

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    Misra, Richa; Thakare, Ritesh; Amrin, N; Prasad, Kashi Nath; Chopra, Sidharth; Dhole, Tapan Nirodhechand

    2016-08-01

    We describe the antimicrobial susceptibility pattern of 100 typhoidal Salmonella isolates recovered from blood cultures and also investigate the association of decreased ciprofloxacin susceptibility with mutations in the genes coding for DNA gyrase and topoisomerase IV in 55 isolates. The study was conducted between January 2013 and December 2015 at a tertiary care centre in north India. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion and E-test. Genotypic characterization included the screening of mutations in the quinolone resistance-determining region of gyrA, gyrB, parC, and parE by PCR. DNA sequence analysis was done for 55 isolates. Out of 100 isolates recovered 80 were S. Typhi, 18 were Paratyphi A and two were Paratyphi B. Eighty two percent (66/80) of S. Typhi and 15/18 S. Paratyphi A showed decreased ciprofloxacin susceptibility. The most common mutation in gyrA led to a change at codon 83 of serine to phenylalanine (n=37) or tyrosine (n=12). Five S. Typhi isolates that were resistant to ciprofloxacin (MICs of 12, 16, 24 and 32 μg/ml) had a second mutation at codon 87 in the gyrA gene changing aspartate to asparagine. There is a need to urgently review the use of fluoroquinolones for the management of enteric fever in endemic areas. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Analysis of Salmonella enterica serotype paratyphi A gene expression in the blood of bacteremic patients in Bangladesh.

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    Alaullah Sheikh

    2010-12-01

    Full Text Available Salmonella enterica serotype Paratyphi A is a human-restricted cause of paratyphoid fever, accounting for up to a fifth of all cases of enteric fever in Asia.In this work, we applied an RNA analysis method, Selective Capture of Transcribed Sequences (SCOTS, and cDNA hybridization-microarray technology to identify S. Paratyphi A transcripts expressed by bacteria in the blood of three patients in Bangladesh. In total, we detected 1,798 S. Paratyphi A mRNAs expressed in the blood of infected humans (43.9% of the ORFeome. Of these, we identified 868 in at least two patients, and 315 in all three patients. S. Paratyphi A transcripts identified in at least two patients encode proteins involved in energy metabolism, nutrient and iron acquisition, vitamin biosynthesis, stress responses, oxidative stress resistance, and pathogenesis. A number of detected transcripts are expressed from PhoP and SlyA-regulated genes associated with intra-macrophage survival, genes contained within Salmonella Pathogenicity Islands (SPIs 1-4, 6, 10, 13, and 16, as well as RpoS-regulated genes. The largest category of identified transcripts is that of encoding proteins with unknown function. When comparing levels of bacterial mRNA using in vivo samples collected from infected patients to samples from in vitro grown organisms, we found significant differences for 347, 391, and 456 S. Paratyphi A transcripts in each of three individual patients (approximately 9.7% of the ORFeome. Of these, expression of 194 transcripts (4.7% of ORFs was concordant in two or more patients, and 41 in all patients. Genes encoding these transcripts are contained within SPI-1, 3, 6 and 10, PhoP-regulated genes, involved in energy metabolism, nutrient acquisition, drug resistance, or uncharacterized genes. Using quantitative RT-PCR, we confirmed increased gene expression in vivo for a subset of these genes.To our knowledge, we describe the first microarray-based transcriptional analysis of a pathogen

  15. Evaluation of the Clinical and Microbiological Response to Salmonella Paratyphi A Infection in the First Paratyphoid Human Challenge Model.

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    Dobinson, Hazel C; Gibani, Malick M; Jones, Claire; Thomaides-Brears, Helena B; Voysey, Merryn; Darton, Thomas C; Waddington, Claire S; Campbell, Danielle; Milligan, Iain; Zhou, Liqing; Shrestha, Sonu; Kerridge, Simon A; Peters, Anna; Stevens, Zoe; Podda, Audino; Martin, Laura B; D'Alessio, Flavia; Thanh, Duy Pham; Basnyat, Buddha; Baker, Stephen; Angus, Brian; Levine, Myron M; Blohmke, Christoph J; Pollard, Andrew J

    2017-04-15

    To expedite the evaluation of vaccines against paratyphoid fever, we aimed to develop the first human challenge model of Salmonella enterica serovar Paratyphi A infection. Two groups of 20 participants underwent oral challenge with S. Paratyphi A following sodium bicarbonate pretreatment at 1 of 2 dose levels (group 1: 1-5 × 103 colony-forming units [CFU] and group 2: 0.5-1 × 103 CFU). Participants were monitored in an outpatient setting with daily clinical review and collection of blood and stool cultures. Antibiotic treatment was started when prespecified diagnostic criteria were met (temperature ≥38°C for ≥12 hours and/or bacteremia) or at day 14 postchallenge. The primary study objective was achieved following challenge with 1-5 × 103 CFU (group 1), which resulted in an attack rate of 12 of 20 (60%). Compared with typhoid challenge, paratyphoid was notable for high rates of subclinical bacteremia (at this dose, 11/20 [55%]). Despite limited symptoms, bacteremia persisted for up to 96 hours after antibiotic treatment (median duration of bacteremia, 53 hours [interquartile range, 24-85 hours]). Shedding of S. Paratyphi A in stool typically preceded onset of bacteremia. Challenge with S. Paratyphi A at a dose of 1-5 × 103 CFU was well tolerated and associated with an acceptable safety profile. The frequency and persistence of bacteremia in the absence of clinical symptoms was notable, and markedly different from that seen in previous typhoid challenge studies. We conclude that the paratyphoid challenge model is suitable for the assessment of vaccine efficacy using endpoints that include bacteremia and/or symptomatology. NCT02100397.

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

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    Laetitia Fabre

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

  17. Growth and survival of Salmonella Paratyphi A in roasted marinated chicken during refrigerated storage: Effect of temperature abuse and computer simulation for cold chain management

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    This research was conducted to evaluate the feasibility of using a one-step dynamic numerical analysis and optimization method to directly construct a tertiary model to describe the growth and survival of Salmonella Paratyphi A (SPA) in a marinated roasted chicken product. Multiple dynamic growth a...

  18. Differential epidemiology of Salmonella Typhi and Paratyphi A in Kathmandu, Nepal: a matched case control investigation in a highly endemic enteric fever setting.

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    Karkey, Abhilasha; Thompson, Corinne N; Tran Vu Thieu, Nga; Dongol, Sabina; Le Thi Phuong, Tu; Voong Vinh, Phat; Arjyal, Amit; Martin, Laura B; Rondini, Simona; Farrar, Jeremy J; Dolecek, Christiane; Basnyat, Buddha; Baker, Stephen

    2013-01-01

    Enteric fever, a systemic infection caused by the bacteria Salmonella Typhi and Salmonella Paratyphi A, is endemic in Kathmandu, Nepal. Previous work identified proximity to poor quality water sources as a community-level risk for infection. Here, we sought to examine individual-level risk factors related to hygiene and sanitation to improve our understanding of the epidemiology of enteric fever in this setting. A matched case-control analysis was performed through enrollment of 103 blood culture positive enteric fever patients and 294 afebrile community-based age and gender-matched controls. A detailed questionnaire was administered to both cases and controls and the association between enteric fever infection and potential exposures were examined through conditional logistic regression. Several behavioral practices were identified as protective against infection with enteric fever, including water storage and hygienic habits. Additionally, we found that exposures related to poor water and socioeconomic status are more influential in the risk of infection with S. Typhi, whereas food consumption habits and migration play more of a role in risk of S. Paratyphi A infection. Our work suggests that S. Typhi and S. Paratyphi A follow different routes of infection in this highly endemic setting and that sustained exposure to both serovars probably leads to the development of passive immunity. In the absence of a polyvalent vaccine against S. Typhi and S. Paratyphi A, we advocate better systems for water treatment and storage, improvements in the quality of street food, and vaccination with currently available S. Typhi vaccines.

  19. Construction of an attenuated Salmonella enterica serovar Paratyphi A vaccine strain harboring defined mutations in htrA and yncD.

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    Zhu, Chunyue; Xiong, Kun; Chen, Zhijin; Hu, Xiaomei; Li, Jianhua; Wang, Yiran; Rao, Xiancai; Cong, Yanguang

    2015-08-01

    The global epidemic features of enteric fever have changed greatly in recent years. The incidence of enteric fever caused by Salmonella enterica serovar Paratyphi A has progressively increased. In some areas of Asia, infections with S. Paratyphi A have exceeded those with S. Typhi, resulting in S. Paratyphi A becoming the main causative agent of enteric fever. However, two currently licensed typhoid vaccines do not confer adequate cross-protection against S. Paratyphi A infection. Therefore, development of specific vaccines against enteric fever caused by S. Paratyphi A is urgently needed. In the present study, an attenuated strain was constructed by double deletion of the htrA and yncD genes in a wild-type strain of S. Paratyphi A and its safety and immunogenicity assessed. In a mouse model, the 50% lethal dose of the double deletion mutant and the wild-type strain were 3.0 × 10(8) CFU and 1.9 × 10(3) CFU, respectively, suggesting that the double deletion resulted in remarkably decreased bacterial virulence. Bacterial colonization of the double deletion mutant in the livers and spleens of infected mice was strikingly less than that of the wild-type strain. A single nasal administration of the attenuated vaccine candidate elicited high concentrations of anti-LPS and anti-flagellin IgG in a mouse model and protected immunized mice against lethal challenge with the wild-type strain. Thus, our findings suggest that the attenuated vaccine strain is a promising candidate worthy of further evaluation both as a human enteric fever vaccine and as a vaccine delivery vector for heterologous antigens. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

  20. Differential epidemiology of Salmonella Typhi and Paratyphi A in Kathmandu, Nepal: a matched case control investigation in a highly endemic enteric fever setting.

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    Abhilasha Karkey

    Full Text Available Enteric fever, a systemic infection caused by the bacteria Salmonella Typhi and Salmonella Paratyphi A, is endemic in Kathmandu, Nepal. Previous work identified proximity to poor quality water sources as a community-level risk for infection. Here, we sought to examine individual-level risk factors related to hygiene and sanitation to improve our understanding of the epidemiology of enteric fever in this setting.A matched case-control analysis was performed through enrollment of 103 blood culture positive enteric fever patients and 294 afebrile community-based age and gender-matched controls. A detailed questionnaire was administered to both cases and controls and the association between enteric fever infection and potential exposures were examined through conditional logistic regression. Several behavioral practices were identified as protective against infection with enteric fever, including water storage and hygienic habits. Additionally, we found that exposures related to poor water and socioeconomic status are more influential in the risk of infection with S. Typhi, whereas food consumption habits and migration play more of a role in risk of S. Paratyphi A infection.Our work suggests that S. Typhi and S. Paratyphi A follow different routes of infection in this highly endemic setting and that sustained exposure to both serovars probably leads to the development of passive immunity. In the absence of a polyvalent vaccine against S. Typhi and S. Paratyphi A, we advocate better systems for water treatment and storage, improvements in the quality of street food, and vaccination with currently available S. Typhi vaccines.

  1. The Ecological Dynamics of Fecal Contamination and Salmonella Typhi and Salmonella Paratyphi A in Municipal Kathmandu Drinking Water

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    Walker, Alan W.; Thompson, Corinne N.; Torres, Andres; Dongol, Sabina; Tran Vu Thieu, Nga; Pham Thanh, Duy; Tran Thi Ngoc, Dung; Voong Vinh, Phat; Singer, Andrew C.; Parkhill, Julian; Thwaites, Guy; Basnyat, Buddha; Ferguson, Neil; Baker, Stephen

    2016-01-01

    One of the UN sustainable development goals is to achieve universal access to safe and affordable drinking water by 2030. It is locations like Kathmandu, Nepal, a densely populated city in South Asia with endemic typhoid fever, where this goal is most pertinent. Aiming to understand the public health implications of water quality in Kathmandu we subjected weekly water samples from 10 sources for one year to a range of chemical and bacteriological analyses. We additionally aimed to detect the etiological agents of typhoid fever and longitudinally assess microbial diversity by 16S rRNA gene surveying. We found that the majority of water sources exhibited chemical and bacterial contamination exceeding WHO guidelines. Further analysis of the chemical and bacterial data indicated site-specific pollution, symptomatic of highly localized fecal contamination. Rainfall was found to be a key driver of this fecal contamination, correlating with nitrates and evidence of S. Typhi and S. Paratyphi A, for which DNA was detectable in 333 (77%) and 303 (70%) of 432 water samples, respectively. 16S rRNA gene surveying outlined a spectrum of fecal bacteria in the contaminated water, forming complex communities again displaying location-specific temporal signatures. Our data signify that the municipal water in Kathmandu is a predominant vehicle for the transmission of S. Typhi and S. Paratyphi A. This study represents the first extensive spatiotemporal investigation of water pollution in an endemic typhoid fever setting and implicates highly localized human waste as the major contributor to poor water quality in the Kathmandu Valley. PMID:26735696

  2. Understanding paratyphoid infection: study protocol for the development of a human model of Salmonella enterica serovar Paratyphi A challenge in healthy adult volunteers.

    Science.gov (United States)

    McCullagh, David; Dobinson, Hazel C; Darton, Thomas; Campbell, Danielle; Jones, Claire; Snape, Matthew; Stevens, Zoe; Plested, Emma; Voysey, Merryn; Kerridge, Simon; Martin, Laura B; Angus, Brian; Pollard, Andrew J

    2015-06-16

    This study will develop the first human challenge model of paratyphoid infection which may then be taken forward to evaluate paratyphoid vaccine candidates. Salmonella Paratyphi A is believed to cause a quarter of the estimated 20 million cases of enteric fever annually. Epidemiological evidence also suggests that an increasing proportion of the enteric fever burden is attributable to S. Paratyphi infection meriting further attention and interest in vaccine development. Assessment of paratyphoid vaccine efficacy in preclinical studies is complicated by the lack of a small animal model and the human-restricted nature of the infection. The use of experimental human infection in healthy volunteers provides an opportunity to address these problems in a cost-effective manner. Volunteers will ingest virulent S. Paratyphi A bacteria (NVGH308 strain) with a bicarbonate buffer solution to establish the infectious dose resulting in an 'attack rate' of 60-75%. Using an a priori decision-making algorithm, the challenge dose will be escalated or de-escalated to achieve the target attack rate, with the aim of reaching the study end point while exposing as few individuals as possible to infection. The attack rate will be determined by the proportion of paratyphoid infection in groups of 20 healthy adult volunteers, with infection being defined by one or more positive blood cultures (microbiological end point) and/or fever, defined as an oral temperature exceeding 38 °C sustained for at least 12 h (clinical end point); 20-80 participants will be required. Challenge participants will start a 2-week course of an oral antibiotic on diagnosis of infection, or after 14 days follow-up. The strict eligibility criterion aims to minimise risk to participants and their close contacts. Ethical approval has been obtained. The results will be disseminated in a peer-reviewed journal and presented at international congresses. NCT02100397. Published by the BMJ Publishing Group Limited. For

  3. Clinicopathological profile of salmonella typhi and paratyphi infections presenting as Fever of unknown origin in a tropical country.

    Science.gov (United States)

    Iqbal, Nayyar; Basheer, Aneesh; Mookkappan, Sudhagar; Ramdas, Anita; Varghese, Renu G'Boy; Padhi, Somanath; Shrimanth, Bhairappa; Chidambaram, Saranya; Anandhalakshmi, S; Kanungo, Reba

    2015-01-01

    Enteric fever, a common infection in the tropics and endemic to India, often manifests as an acute febrile illness. However, presentation as fever of unknown origin (FUO) is not uncommon in tropical countries. We aim to describe the clinical, laboratory and pathological features of patients hospitalized with fever of unknown origin and diagnosed as enteric fever. All culture proven cases of enteric fever were analyzed retrospectively over a period of three years from January 2011 to December 2013. Seven of 88 (8%) cases with enteric fever presented as FUO. Abdominal pain was the most common symptom besides fever. Relative bradycardia and splenomegaly were uncommon. Thrombocytopenia was the most common haematological abnormality while leucopenia was rare. Transaminase elevation was almost universal. S. Typhi and S. Paratyphi A were isolated from six cases and one case respectively. Yield of organisms from blood culture was superior to that of bone marrow aspirate. Multiple granulomas were identified in 4 out of 6 (67%) of the bone marrows studied, including that due to S. Paratyphi A and histiocytic hemophagocytosis was noted in two cases. FUO is a relatively common manifestation of enteric fever in the tropics. Clinical and laboratory features may be atypical in such cases, including absence of relative bradycardia, leucopenia, and presence of thrombocytopenia, bicytopenia or pancytopenia. In addition, in endemic countries, enteric fever should be considered as a differential diagnosis, next to tuberculosis, in the evaluation of bone marrow granulomas in cases with FUO and culture correlation should be mandatory.

  4. Salmonellae carrier status of food vendors in Kumasi, Ghana | Feglo ...

    African Journals Online (AJOL)

    Methods: Screening of 258 (230 females of 28 males) healthy food vendors for Salmonella typhi, and S. paratyphi A, B, and C, using stool culture, the widal test, and standard microbiological identification methods. Main outcome measures: Prevalence of chronic typhoidal Salmonellae carriers among food vendors in ...

  5. Live attenuated vaccines for invasive Salmonella infections

    Science.gov (United States)

    Tennant, Sharon M.; Levine, Myron M.

    2015-01-01

    Salmonella enterica serovar Typhi produces significant morbidity and mortality worldwide despite the fact that there are licensed S. Typhi vaccines available. This is primarily due to the fact that these vaccines are not used in the countries that most need them. There is growing recognition that an effective invasive Salmonella vaccine formulation must also prevent infection due to other Salmonella serovars. We anticipate that a multivalent vaccine that targets the following serovars will be needed to control invasive Salmonella infections worldwide: S. Typhi, S. Paratyphi A, S. Paratyphi B (currently uncommon but may become dominant again), S. Typhimurium, S. Enteritidis and S. Choleraesuis (as well as other Group C Salmonella). Live attenuated vaccines are an attractive vaccine formulation for use in developing as well as developed countries. Here, we describe the methods of attenuation that have been used to date to create live attenuated Salmonella vaccines and provide an update on the progress that has been made on these vaccines. PMID:25902362

  6. O-Serotype Conversion in Salmonella Typhimurium Induces Protective Immune Responses against Invasive Non-Typhoidal Salmonella Infections

    OpenAIRE

    Li, Pei; Liu, Qing; Luo, Hongyan; Liang, Kang; Yi, Jie; Luo, Ying; Hu, Yunlong; Han, Yue; Kong, Qingke

    2017-01-01

    Salmonella infections remain a big problem worldwide, causing enteric fever by Salmonella Typhi (or Paratyphi) or self-limiting gastroenteritis by non-typhoidal Salmonella (NTS) in healthy individuals. NTS may become invasive and cause septicemia in elderly or immuno-compromised individuals, leading to high mortality and morbidity. No vaccines are currently available for preventing NTS infection in human. As these invasive NTS are restricted to several O-antigen serogroups including B1, D1, C...

  7. Treatment of enteric fever in children on the basis of current trends of antimicrobial susceptibility of Salmonella enterica serovar typhi and paratyphi A

    Directory of Open Access Journals (Sweden)

    Manchanda V

    2006-01-01

    Full Text Available Purpose: Recent reports indicate decreased susceptibility of S. typhi to fluoroquinolones, especially ciprofloxacin. Chloramphenicol has been suggested as first line therapy of enteric fever in many studies. This is a prospective study that describes the trends of antimicrobial susceptibility of S. typhi and S. paratyphi A causing bacteraemia in children and reports therapeutic failure to ciprofloxacin and evaluates the possible use of chloramphenicol, ampicillin, ciprofloxacin and third generation cephalosporins as first line therapy in the treatment of enteric fever in children. Methods: The present study was conducted from April 2004 to March 2005 in a superspeciality children hospital at New Delhi. A total of 56 S. typhi and five S. paratyphi A isolates were obtained among the 673 blood cultures performed. Antimicrobial testing was done using disk diffusion technique (NCCLS method for 13 antimicrobials and MICs were calculated for ampicillin, ciprofloxacin, chloramphenicol and cefotaxime. Analysis of data was done using WHONET software. Results: All 56 isolates of S. typhi were sensitive to amoxycillin+clavulanate, gentamicin, cefixime, cefotaxime and ceftazidime. Multidrug resistance (MDR, resistance to three drugs was seen in 22 cases (39% and resistance to five drugs was seen in 12 cases (21%. Only two isolates were resistant to chloramphenicol (3%. MIC 90 for ampicillin, chloramphenicol, ciprofloxacin and cefotaxime were 1.0 mg/ml, 4.0 mg/ml, 64 mg/ml and 0.125 mg/ml respectively. All S. paratyphi A isolates were sensitive to ampicillin and chloramphenicol and resistant to nalidixic acid.MIC distribution data for chloramphenicol revealed elevated MIC but still in susceptible range. Conclusions: There is an urgent need for further clinical studies to evaluate response to chloramphenicol in such cases. Antimicrobial susceptibility data and MIC distribution favour use of ampicillin as a drug of choice for the treatment of enteric fever

  8. SEROTYPING AND ANTIMICROBIAL DRUG RESISTANCE OF SALMONELLA ISOLATED FROM LETTUCE AND HUMAN DIARRHEA SAMPLES IN BURKINA FASO.

    Science.gov (United States)

    Siourimè, Somda Namwin; Isidore, Bonkoungou Ouindgueta Juste; Oumar, Traoré; Nestor, Bassolé Ismael Henri; Yves, Traoré; Nicolas, Barro; Aly, Savadogo

    2017-01-01

    In Burkina Faso dirty water in particular those of the stoppings and the gutter ones are used for vegetables irrigation in the gardens. The aim of this study was to determine the prevalence and antibiotic susceptibility of Salmonella serotypes from humans and lettuce samples inBurkina Faso. Materials and Methods:Salmonella strains isolated from patients in 2009 to 2015 and lettuce samples in 2014 in Burkina Faso were serotyped using specific antisera. All strains were subjected to a set of 14 antibiotics to study their antibiogram by using Baeur-Kirby disk diffusion method. Out of 154 Salmonella isolated, 60 were from human and 94 from lettuce samples. Serotyping revealed four different serotypes and 39% (60) untypeable strains from human and lettuce (14 and 46 strains). Salmonella serotypes from human and lettuce samples were: Paratyphi A (10% and 22%), Paratyphi B (34% and 8%), Paratyphi C (14% and 18%) and Typhi (21% and 1%). A high resistance of Salmonella Paratyphi B and Salmonella spp to tetracycline were 70% from human and 35 % from lettuce samples. Multiresistance was observed to tetracycline, chloramphenicol and amoxicillin/clavulanic-acid or ampicillin with Salmonella ParatyphiB 35% and Salmonella Typhi 33% from human samples and Salmonella spp 4% from lettuce samples. This study showed the diversity of Salmonella serotypes from both clinical and environmental samples and emergence of multiresistant Salmonella to antibiotics in Burkina Faso. A lettuce is a potential source of transmission of Salmonella causing diarrhea among human in Burkina Faso. List of non-standard Abbreviations : HDB: Hôpital du District de Bogodogo, LNSP: Laboratoire National de Santé Publique, DSG : District Sanitaire de Gourcy, DSB : District Sanitaire de Boromo.

  9. Salmonella species on meat contact surfaces and processing water in Sokoto main market and abattoir, Nigeria

    Directory of Open Access Journals (Sweden)

    Olufemi Oludayo Faleke

    2017-03-01

    Full Text Available This study was carried out to determine Salmonella contamination of food contact surfaces and processing water in meat, fish and poultry processing units in Sokoto State, Nigeria. A total of 200 swab (100 from abattoir and 100 from poultry and fish markets and 60 processing water samples (30 from abattoir and 30 from poultry and fish markets were collected between May to August 2015. Cultural isolation, bio-typing and sero-grouping using Salmonella Sero-Quick Group Kit was conducted to analyse the samples. Seventy-five (75/260, 28.8 % of the total samples were positive to Salmonella by cultural isolation and bio-typing. Thirty (30/130; 23.1 % of samples collected in abattoir and 45 (45/130; 34.6 % of those collected from poultry and fish markets were positive for Salmonella respectively. Sero-groups D+Vi (Salmonella Typhi, B (Salmonella Paratyphi B, Salmonella Typhimurium and C (Salmonella Paratyphi C, Salmonella Cholerae suis were identified as the prevailing sero-groups in this study. Sero-group D+Vi has the highest prevalence (73.3 %; 55/75 from the positive bio-typing isolates. This study revealed the presence of contaminating and pathogenic Salmonella on food contact surfaces and processing water in the meat retail markets, indicating there is an urgent need to improve on the hygienic status of retail meat, poultry and fish markets.

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

    Directory of Open Access Journals (Sweden)

    Sharon M Tennant

    Full Text Available Certain serovars of Salmonella enterica subsp. enterica cause invasive disease (e.g., enteric fever, bacteremia, septicemia, meningitis, etc. in humans and constitute a global public health problem. A rapid, sensitive diagnostic test is needed to allow prompt initiation of therapy in individual patients and for measuring disease burden at the population level. An innovative and promising new rapid diagnostic technique is microwave-accelerated metal-enhanced fluorescence (MAMEF. We have adapted this assay platform to detect the chromosomal oriC locus common to all Salmonella enterica subsp. enterica serovars. We have shown efficient lysis of biologically relevant concentrations of Salmonella spp. suspended in bacteriological media using microwave-induced lysis. Following lysis and DNA release, as little as 1 CFU of Salmonella in 1 ml of medium can be detected in <30 seconds. Furthermore the assay is sensitive and specific: it can detect oriC from Salmonella serovars Typhi, Paratyphi A, Paratyphi B, Paratyphi C, Typhimurium, Enteritidis and Choleraesuis but does not detect Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, Haemophilus influenzae or Acinetobacter baumanii. We have also performed preliminary experiments using a synthetic Salmonella oriC oligonucleotide suspended in whole human blood and observed rapid detection when the sample was diluted 1:1 with PBS. These pre-clinical data encourage progress to the next step to detect Salmonella in blood (and other ordinarily sterile, clinically relevant body fluids.

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

    Science.gov (United States)

    Tennant, Sharon M; Zhang, Yongxia; Galen, James E; Geddes, Chris D; Levine, Myron M

    2011-04-08

    Certain serovars of Salmonella enterica subsp. enterica cause invasive disease (e.g., enteric fever, bacteremia, septicemia, meningitis, etc.) in humans and constitute a global public health problem. A rapid, sensitive diagnostic test is needed to allow prompt initiation of therapy in individual patients and for measuring disease burden at the population level. An innovative and promising new rapid diagnostic technique is microwave-accelerated metal-enhanced fluorescence (MAMEF). We have adapted this assay platform to detect the chromosomal oriC locus common to all Salmonella enterica subsp. enterica serovars. We have shown efficient lysis of biologically relevant concentrations of Salmonella spp. suspended in bacteriological media using microwave-induced lysis. Following lysis and DNA release, as little as 1 CFU of Salmonella in 1 ml of medium can be detected in Salmonella serovars Typhi, Paratyphi A, Paratyphi B, Paratyphi C, Typhimurium, Enteritidis and Choleraesuis but does not detect Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, Haemophilus influenzae or Acinetobacter baumanii. We have also performed preliminary experiments using a synthetic Salmonella oriC oligonucleotide suspended in whole human blood and observed rapid detection when the sample was diluted 1:1 with PBS. These pre-clinical data encourage progress to the next step to detect Salmonella in blood (and other ordinarily sterile, clinically relevant body fluids).

  12. Ultra-Fast and Sensitive Detection of Non-Typhoidal Salmonella Using Microwave-Accelerated Metal-Enhanced Fluorescence (“MAMEF”)

    Science.gov (United States)

    Galen, James E.; Geddes, Chris D.; Levine, Myron M.

    2011-01-01

    Certain serovars of Salmonella enterica subsp. enterica cause invasive disease (e.g., enteric fever, bacteremia, septicemia, meningitis, etc.) in humans and constitute a global public health problem. A rapid, sensitive diagnostic test is needed to allow prompt initiation of therapy in individual patients and for measuring disease burden at the population level. An innovative and promising new rapid diagnostic technique is microwave-accelerated metal-enhanced fluorescence (MAMEF). We have adapted this assay platform to detect the chromosomal oriC locus common to all Salmonella enterica subsp. enterica serovars. We have shown efficient lysis of biologically relevant concentrations of Salmonella spp. suspended in bacteriological media using microwave-induced lysis. Following lysis and DNA release, as little as 1 CFU of Salmonella in 1 ml of medium can be detected in Salmonella serovars Typhi, Paratyphi A, Paratyphi B, Paratyphi C, Typhimurium, Enteritidis and Choleraesuis but does not detect Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, Haemophilus influenzae or Acinetobacter baumanii. We have also performed preliminary experiments using a synthetic Salmonella oriC oligonucleotide suspended in whole human blood and observed rapid detection when the sample was diluted 1∶1 with PBS. These pre-clinical data encourage progress to the next step to detect Salmonella in blood (and other ordinarily sterile, clinically relevant body fluids). PMID:21494634

  13. [Report on Salmonella isolates in livestock, food and feed, received at the German national reference laboratory for Salmonella during 2004-2008].

    Science.gov (United States)

    Friedrich, Alexandra; Dorn, Christina; Schroeter, Andreas; Szabo, Istvan; Jaber, Manuela; Berendonk, Gabriele; Brom, Martha; Ledwolorz, Johanna; Helmuth, Reiner

    2010-01-01

    The German National Reference Laboratory for Salmonella receives Salmonella isolates from diverse laboratories in Germany. Most of the Salmonella strains originated from livestock and food.This report summarizes the studies of the German National Reference Laboratory on the prevalence of Salmonella ssp. in livestock, food and feed for the years 2004-2008. In the past five years, the National Reference Laboratory received 23,949 Salmonella isolates with S. enterica serovar Typhimurium and S. enterica serovar Enteritidis as the most prevalent serovars. In addition, we summarize the incidence of emerging serovars, such as S. enterica serovar Paratyphi B (d-tartrate positive), the monophasic variant of S. enterica serovar Typhimurium (S. enterica subspecies (subsp.) enterica serovar 1,4,[5],12:i:-) and S. enterica subsp. enterica serovar 1,4,12:d:-.

  14. Characterisation of antimicrobial resistance in Salmonellae during 2014–2015 from four centres across India: An ICMR antimicrobial resistance surveillance network report

    Directory of Open Access Journals (Sweden)

    Sushila Dahiya

    2017-01-01

    Full Text Available Purpose: The main purpose of this study was to establish 'Antimicrobial Resistance Surveillance Network' in India and to monitor the antimicrobial susceptibility profile of clinical isolates to establish a national network across the country for monitoring antimicrobial resistance in Salmonella. Materials and Methods: This study was conducted at All India Institute of Medical Sciences, nodal centre with clinical isolates of Salmonellae collected from four centres across India, which included Christian Medical College, Vellore; Postgraduate Institute of Medical Education and Research, Chandigarh and Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry. Total 20% of the selected strains from each centre were characterised for molecular studies which included molecular mechanism of fluoroquinolones resistance and multiple locus sequence type. Results: A total of 622 Salmonellae were received from all centres during January 2014 to December 2015. Out of these 622 isolates, 380 were Salmonella Typhi, 162 were Salmonella Paratyphi A and 7 were S. Paratyphi B isolated from blood and 73 were other Salmonella serotypes. Multiple drug resistance (resistant to ampicillin, chloramphenicol and co-trimoxazole was less than 3% in S. Typhi. In S. Paratyphi A, chloramphenicol and co-trimoxazole susceptibility was 100% and 99%, respectively, whereas ampicillin susceptibility was 86% (139/161. Ciprofloxacin and nalidixic acid susceptibility was 15% (24/162 and 1% (2/162 from all centres. S. Paratyphi B was isolated from 7 patients. All isolates were third-generation cephalosporin sensitive. The most common mutations found were at codon 83 and at codon 87. We did not find any mutation in acrR gene. Efflux pump and qnr genes were not found in any isolate tested. All 86 S. Typhi isolates clustered into two sequence types - ST1 and ST2. Out of these 86 isolates, 70 S. Typhi were ST1 and 16 were ST2. All S. Paratyphi A was clustered in ST85

  15. The enhanced immune responses induced by Salmonella enteritidis ghosts loaded with Neisseria gonorrhoeae porB against Salmonella in mice.

    Science.gov (United States)

    Jiao, Hongmei; Yang, Hui; Zhao, Dan; He, Li; Chen, Jin; Li, Guocai

    2016-11-01

    Human health has been seriously endangered by highly prevalent salmonellosis and multidrug-resistant Salmonella strains. Current vaccines suffer from variable immune-protective effects, so more effective ones are needed to control Salmonella infection : Bacterial ghosts have been produced by the expression of lysis gene E from bacteriophage PhiX174 and can be filled with considerable exogenous substances such as DNA or drugs as a novel platform. In this study, Salmonella enteritidis (SE) ghosts were developed and loaded with Neisseria gonorrhoeae porin B (porB) to construct a novel inactive vaccine. Our new studies show that SE ghosts loaded with porB displayed increased production of pro-inflammatory cytokines (IL-1β, IL-6, IL-10 and IL-12p70) in bone marrow-derived dendritic cells (BMDCs), and elicited significantly higher specific systemic and mucosal immune responses to Salmonella than SE ghosts alone. In addition, the novel porB-loaded ghosts conferred higher protective effects on virulent Salmonella challenge. For the first time, we demonstrate that N. gonorrhoeae porB, as a novel adjuvant, can increase the immunogenicity of SE ghosts. Our studies suggested that Salmonella enteritidis ghosts loaded with Neisseria gonorrhoeae porin B might be a useful mucosal Salmonella vaccine candidate for practical use in the future. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Salmonella serotype distribution in the Dutch broiler supply chain.

    Science.gov (United States)

    van Asselt, E D; Thissen, J T N M; van der Fels-Klerx, H J

    2009-12-01

    Salmonella serotype distribution can give insight in contamination routes and persistence along a production chain. Therefore, it is important to determine not only Salmonella prevalence but also to specify the serotypes involved at the different stages of the supply chain. For this purpose, data from a national monitoring program in the Netherlands were used to estimate the serotype distribution and to determine whether this distribution differs for the available sampling points in the broiler supply chain. Data covered the period from 2002 to 2005, all slaughterhouses (n = 22), and the following 6 sampling points: departure from hatchery, arrival at the farm, departure from the farm, arrival at the slaughterhouse, departure from the slaughterhouse, and end of processing. Furthermore, retail data for 2005 were used for comparison with slaughterhouse data. The following serotypes were followed throughout the chain: Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Paratyphi B var. Java (Salmonella Java), Salmonella Infantis, Salmonella Virchow, and Salmonella Mbandaka. Results showed that serotype distribution varied significantly throughout the supply chain (P supply chain up to the retail phase.

  17. Salmonella on Raw Poultry in Retail Markets in Guatemala: Levels, Antibiotic Susceptibility, and Serovar Distribution.

    Science.gov (United States)

    Jarquin, Claudia; Alvarez, Danilo; Morales, Oneida; Morales, Ana Judith; López, Beatriz; Donado, Pilar; Valencia, Maria F; Arévalo, Alejandra; Muñoz, Fredy; Walls, Isabel; Doyle, Michael P; Alali, Walid Q

    2015-09-01

    The objective of this study was to determine Salmonella numbers on retail raw chicken carcasses in Guatemala and to phenotypically characterize the isolates (serotyping and antibiotic susceptibility). In total, 300 chicken carcasses were collected from seven departments in Guatemala. Salmonella numbers were determined using the most-probable-number method following the U. S. Department of Agriculture's Food Safety and Inspection Service protocol. In total, 103 isolates were obtained, all of which were tested for antibiotic susceptibility, whereas 46 isolates were serotyped. Overall, Salmonella prevalence and mean number (mean log most probable number per carcass) was 34.3% and 2.3 (95% confidence interval: 2.1 to 2.5), respectively. Significant differences (P < 0.05) in Salmonella prevalence were found by storage condition (refrigerated or ambient temperature), market type (wet markets, supermarkets, and independent poultry stores), chicken production system (integrated or nonintegrated production company), and chicken skin color (white or yellow). Chickens produced by integrated companies had lower Salmonella numbers (P < 0.05) than nonintegrated companies, and white-skin carcasses had lower numbers (P < 0.05) than yellow-skin carcasses. Among 13 different Salmonella serovars identified, Paratyphi B (34.8%) was most prevalent, followed by Heidelberg (16.3%) and Derby (11.6%). Of all the Salmonella isolates, 59.2% were resistant to one to three antibiotics and 13.6% to four or more antibiotics. Among all the serovars obtained, Salmonella Paratyphi B and Heidelberg were the most resistant to the antibiotics tested. Salmonella levels and antibiotic resistant profiles among isolates from raw poultry at the retail market level were high relative to other reports from North and South America. These data can be used by Guatemalan stakeholders to develop risk assessment models and support further research opportunities to control transmission of Salmonella spp. and

  18. Data for: Millennia of genomic stability within the invasive Para C Lineage of Salmonella enterica

    OpenAIRE

    Zhou, Zhemin; Lundstrøm, Inge; Dien, Alicia Tran; Duchêne, Sebastián; Alikhan, Nabil-Fareed; Sergeant, Martin J.; Langridge, Gemma; Fotakis, Anna K.; Nair, Satheesh; Stenøien, Hans K.; Hamre, Stian S.; Casjens, Sherwood; Green, Monica H.; Christophersen, Axel; Quince, Christopher

    2017-01-01

    Salmonella enterica serovar Paratyphi C causes enteric (paratyphoid) fever in humans. Its presentation can range from asymptomatic infections of the blood stream to gastrointestinal or urinary tract infection or even a fatal septicemia. Paratyphi C is very rare in Europe and North America, except for occasional travelers from South and East Asia or Africa where the disease is more common. However, early 20th century observations in Eastern Europe suggest that Paratyphi C enteric fever may onc...

  19. Multilocus sequence typing as a replacement for serotyping in Salmonella enterica.

    Directory of Open Access Journals (Sweden)

    Mark Achtman

    Full Text Available Salmonella enterica subspecies enterica is traditionally subdivided into serovars by serological and nutritional characteristics. We used Multilocus Sequence Typing (MLST to assign 4,257 isolates from 554 serovars to 1092 sequence types (STs. The majority of the isolates and many STs were grouped into 138 genetically closely related clusters called eBurstGroups (eBGs. Many eBGs correspond to a serovar, for example most Typhimurium are in eBG1 and most Enteritidis are in eBG4, but many eBGs contained more than one serovar. Furthermore, most serovars were polyphyletic and are distributed across multiple unrelated eBGs. Thus, serovar designations confounded genetically unrelated isolates and failed to recognize natural evolutionary groupings. An inability of serotyping to correctly group isolates was most apparent for Paratyphi B and its variant Java. Most Paratyphi B were included within a sub-cluster of STs belonging to eBG5, which also encompasses a separate sub-cluster of Java STs. However, diphasic Java variants were also found in two other eBGs and monophasic Java variants were in four other eBGs or STs, one of which is in subspecies salamae and a second of which includes isolates assigned to Enteritidis, Dublin and monophasic Paratyphi B. Similarly, Choleraesuis was found in eBG6 and is closely related to Paratyphi C, which is in eBG20. However, Choleraesuis var. Decatur consists of isolates from seven other, unrelated eBGs or STs. The serological assignment of these Decatur isolates to Choleraesuis likely reflects lateral gene transfer of flagellar genes between unrelated bacteria plus purifying selection. By confounding multiple evolutionary groups, serotyping can be misleading about the disease potential of S. enterica. Unlike serotyping, MLST recognizes evolutionary groupings and we recommend that Salmonella classification by serotyping should be replaced by MLST or its equivalents.

  20. Determinación de la relación clonal de los aislamientos de Salmonella typhi recuperados en el programa de vigilancia por el laboratorio de EDA en Colombia durante el período 1997-2003 mediante la electroforesis en campo pulsado

    Directory of Open Access Journals (Sweden)

    Hidalgo Marylin

    2005-07-01

    Full Text Available La tipificación molecular de Salmonella typhi y paratyphi es necesaria para complementar los análisis epidemiológicos de las fiebres entéricas en Colombia. El objetivo del trabajo fue establecer la relación genética de los aislamientos de Salmonella typhi y paratyphi recuperados durante el período 1997-2003, en varias regiones del país. Se utilizaron 58 aislamientos de S. typhi, tres de S. paratyphi A, dos de S. paratyphi B y 1 de S. paratyphi C, recibidos por el programa de vigilancia de EDA del Instituto Nacional de Salud (INS. Para determinar la relación genética se empleó la electroforesis en gel de campo pulsado y se calculó un dendrograma; para evaluar la asociación entre los patrones electroforéticos obtenidos y las características de los aislamientos, como datos
    demográficos de los pacientes, tipo de muestra, año y procedencia, se utilizó un análisis de correspondencias. Los datos de S. typhi se analizaron en conjunto con 15  islamientos tipificados anteriormente en el INS. Se obtuvieron 36 patrones electroforéticos, 31/36 (86,1%, representados en 68/73 (93,1% aislamientos, estuvieron relacionados genéticamente. Los patrones S.Ty0001 y S.Ty0012 predominaron en el país. En el análisis de correspondencias, no se encontró asociación entre los patrones electroforéticos y las características de los aislamientos. Los aislamientos de S. paratyphi A estuvieron relacionados genéticamente mientras que los de S. paratyphi B no guardaron relación. A pesar de la considerable heterogeneidad de los aislamientos colombianos de Salmonella typhi, definida por el número de patrones electroforéticos, la mayoría de ellos guardan una relación genética, sugiriendo un origen común de los mismos.

  1. Phenotypic and Genotypic Antibiotic Resistance of Salmonella from Chicken Carcasses Marketed at Ibague, Colombia

    Directory of Open Access Journals (Sweden)

    D Cortes Vélez

    Full Text Available ABSTRACT Salmonella enterica is responsible for alimentary toxic infections associated with the consumption of contaminated poultry products and the antimicrobial resistant patterns of Salmonella circulating in the Tolima region are currently unknown. To address this issue, both the phenotype and genotype antibiotic resistance patterns of 47 Salmonella isolated from raw chicken carcasses sold at the Ibague city were analyzed by the disc diffusion, microdilution and PCR assays. All 47 Salmonella isolates showed resistance to five or more antimicrobial agents. Resistance to Ampicillin (AMP, Amikacin (AMK, Gentamicin (GEN, Tobramycin (TOB, Cefazoline (CFZ, Cefoxitin (FOX, Nitrofurantoin (NIT, Trimethoprim-Sulfamethoxazole (SXT, Tetracycline (TET, Ciprofloxacin (CIP and Enrofloxacin (ENR was observed in 42.35% of Salmonella isolates. All tested S. Paratyphi B var Java isolates showed resistance to at least 12 antibiotics. S. Hvittingfoss showed resistance to 5 antibiotics, whereas S. Muenster showed resistance to seven antibiotics. Amplification of a number of antibiotic resistance genes showed that blaTEM (100% correlated well with resistance to Ampicilin and Cephalosporin, whereas aadB (87% correlated well with resistance to Aminoglycosides. It is concluded that Salmonella isolated from raw chicken meat marketed at Ibague showed MDR by both phenotypic and genotypic methods and they may represent an important threat to human health. Additional studies are needed to establish the relationship between antibiotic resistance in Salmonella from poultry products and clinical isolates.

  2. Selective Infection of Antigen-Specific B Lymphocytes by Salmonella Mediates Bacterial Survival and Systemic Spreading of Infection

    Science.gov (United States)

    de Wit, Jelle; Martinoli, Chiara; Zagato, Elena; Janssen, Hans; Jorritsma, Tineke; Bar-Ephraïm, Yotam E.; Rescigno, Maria; Neefjes, Jacques; van Ham, S. Marieke

    2012-01-01

    Background The bacterial pathogen Salmonella causes worldwide disease. A major route of intestinal entry involves M cells, providing access to B cell-rich Peyer’s Patches. Primary human B cells phagocytose Salmonella typhimurium upon recognition by the specific surface Ig receptor (BCR). As it is unclear how Salmonella disseminates systemically, we studied whether Salmonella can use B cells as a transport device for spreading. Methodology/Principal Findings Human primary B cells or Ramos cell line were incubated with GFP-expressing Salmonella. Intracellular survival and escape was studied in vitro by live cell imaging, flow cytometry and flow imaging. HEL-specific B cells were transferred into C57BL/6 mice and HEL-expressing Salmonella spreading in vivo was analyzed investigating mesenteric lymph nodes, spleen and blood. After phagocytosis by B cells, Salmonella survives intracellularly in a non-replicative state which is actively maintained by the B cell. Salmonella is later excreted followed by reproductive infection of other cell types. Salmonella-specific B cells thus act both as a survival niche and a reservoir for reinfection. Adoptive transfer of antigen-specific B cells before oral infection of mice showed that these B cells mediate in vivo systemic spreading of Salmonella to spleen and blood. Conclusions/Significance This is a first example of a pathogenic bacterium that abuses the antigen-specific cells of the adaptive immune system for systemic spreading for dissemination of infection. PMID:23209805

  3. Fucoidan coated ciprofloxacin loaded chitosan nanoparticles for the treatment of intracellular and biofilm infections of Salmonella.

    Science.gov (United States)

    S, Elbi; T R, Nimal; V K, Rajan; Baranwal, Gaurav; Biswas, Raja; R, Jayakumar; S, Sathianarayanan

    2017-12-01

    Salmonella infections and their gallstone associated biofilm infections are difficult to treat due to poor penetration of antibiotics into the intracellular compartments of macrophages and within biofilms. Here we developed ciprofloxacin loaded chitosan nanoparticles (cCNPs) and fucoidan (Fu) coated cCNPs (Fu-cCNPs). Characterizations of these nanoparticles were carried out using Dynamic Light Scattering‎, Transmission electron microscopy and Fourier transform infrared spectroscopy. The prepared cCNPs and Fu-cCNPs have the size range of 124±7nm and 320±18nm, respectively. Both nanoparticles were found to be non-hemolytic and cytocompatible. In vitro sustained release of ciprofloxacin was observed from both cCNPs and Fu-cCNPs over a period of 2 weeks. The antimicrobial activity of cCNPs and Fu-cCNPs was tested under in vitro and in vivo conditions. The intracellular anti-Salmonella activity of Fu-cCNPs was 2 fold higher than cCNPs and 6 fold higher than ciprofloxacin alone. Fluorescence microscopic images confirmed enhanced delivery of Fu-cCNPs than the cCNPs within the intracellular compartment of macrophages. Both cCNPs and Fu-cCNPs are found to be equally effective in dispersing Salmonella Paratyphi A gallstone biofilms. The in vivo antibacterial activities of Fu-cCNPs were superior to cCNPs which we have validated using Salmonella Paratyphi A infected Drosophila melanogaster fly model. Our overall results showed that (1) Fu-cCNPs are more effective in eradicating Salmonella infections than cCNPs; (2) both cCNPs and Fu-cCNPs were equally effective in dispersing Salmonella gallstone biofilms. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Elevated temperature technique for the isolation of salmonellas from sewage and human faeces.

    Science.gov (United States)

    Nabbut, N H

    1973-03-01

    Modified Moore's swabs, placed in sewers for 5 days, were used to concentrate salmonellas from sewage. Duplicate cultures of swab strips in selenite broth were incubated at 41 and 37 degrees C. respectively. Salmonella organisms were recovered consistently from the swabs when the enrichment broths were incubated at 41 degrees C. However, when equal portions of the same swabs were incubated at 37 degrees C., only 22% of them yielded Salmonella organisms. These results indicate an advantage in incubating the selenite broths at 41 degrees C. rather than 37 degrees C. in attempting to isolate salmonellas from sewage.One hundred and fifty faecal samples were examined for salmonellas by culture in selenite broths incubated at 41 and 37 degrees C. Twelve (8%) samples were positive at 41 degrees C. compared to only 10 (6.7%) positive samples at 37 degrees C. This difference is not statistically significant to indicate an advantage of the elevated-temperature of incubation over the conventional temperature in attempting to isolate salmonellas from human faeces. Moreover, results of the recovery rates of S. paratyphi B, S. typhi, and S. typhimurium indicate that an incubation temperature of 37 degrees C. is more appropriate for recovering salmonellas from artificially infected faecal samples than an incubation temperature of 41 degrees C. This stresses the inability of laboratory studies to mimic conditions in nature.

  5. Cirtical role for Salmonella effector SopB in regulating inflammasome activation.

    Science.gov (United States)

    Hu, Gui-Qiu; Song, Pei-Xuan; Chen, Wei; Qi, Shuai; Yu, Shui-Xing; Du, Chong-Tao; Deng, Xu-Ming; Ouyang, Hong-Sheng; Yang, Yong-Jun

    2017-10-01

    Salmonella is known to evolve many mechanisms to avoid or delay inflammasome activation which remain largely unknown. In this study, we investigated whether the SopB protein critical to bacteria virulence capacity was an effector that involved in the regulation of inflammasome activation. BMDMs from NLRC4-, NLRP3-, caspase-1/-11-, IFI16- and AIM2-deficient mice were pretreated with LPS, and subsequently stimulated with a series of SopB-related strains of Salmonella, inflammasome induced cell death, IL-1β secretion, cleaved caspase-1 production and ASC speckle formation were detected. We found that SopB could inhibit host IL-1β secretion, caspase-1 activation and inflammasome induced cell death using a series of SopB-related strains of Salmonella; however the reduction of IL-1β secretion was not dependent on sensor that contain PYD domain, such as NLRP3, AIM2 or IFI16, but dependent on NLRC4. Notably, SopB specifically prevented ASC oligomerization and the enzymatic activity of SopB was responsible for the inflammasome inhibition. Furthermore, inhibition of Akt signaling induced enhanced inflammasome activation. These results revealed a novel role in inhibition of NLRC4 inflammasome for Salmonella effector SopB. Copyright © 2017. Published by Elsevier Ltd.

  6. Selective Infection of Antigen-Specific B Lymphocytes by Salmonella Mediates Bacterial Survival and Systemic Spreading of Infection

    NARCIS (Netherlands)

    Souwer, Yuri; Griekspoor, Alexander; de Wit, Jelle; Martinoli, Chiara; Zagato, Elena; Janssen, Hans; Jorritsma, Tineke; Bar-Ephraïm, Yotam E.; Rescigno, Maria; Neefjes, Jacques; van Ham, S. Marieke

    2012-01-01

    Background: The bacterial pathogen Salmonella causes worldwide disease. A major route of intestinal entry involves M cells, providing access to B cell-rich Peyer's Patches. Primary human B cells phagocytose Salmonella typhimurium upon recognition by the specific surface Ig receptor (BCR). As it is

  7. Pathogen specific carbohydrate antigen microarrays: a chip for detection of Salmonella O-antigen specific antibodies.

    Science.gov (United States)

    Blixt, Ola; Hoffmann, Julia; Svenson, Stefan; Norberg, Thomas

    2008-01-01

    A Salmonella O-antigen microarray was developed by covalent coupling of oligosaccharide antigens specific for serogroups Salmonella enterica sv. Paratyphi (group A), Typhimurium (group B) and Enteritidis (group D). Antibodies were correctly detected in sera from patients with culture verified salmonellosis. High serogroup-specificity was seen with the disaccharide antigens. With the larger antigens, containing the backbone sequence Manalpha1-2Rhaalpha1-2Gal (MRG), common backbone-specific antibodies (O-antigen 12) were also detected. This is "proof of principle" that pathogen-specific carbohydrate antigen microarrays constitute a novel technology for rapid and specific serological diagnosis in either individual patients or larger sero-epidemiological and vaccine studies.

  8. Salmonella Modulates B Cell Biology to Evade CD8+ T Cell-Mediated Immune Responses

    Science.gov (United States)

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

    2014-01-01

    Although B cells and antibodies are the central effectors of humoral immunity, B cells can also produce and secrete cytokines and present antigen to helper T cells. The uptake of antigen is mainly mediated by endocytosis; thus, antigens are often presented by MHC-II molecules. However, it is unclear if B cells can present these same antigens via MHC-I molecules. Recently, Salmonella bacteria were found to infect B cells, allowing possible antigen cross-processing that could generate bacterial peptides for antigen presentation via MHC-I molecules. Here, we will discuss available knowledge regarding Salmonella antigen presentation by infected B cell MHC-I molecules and subsequent inhibitory effects on CD8+ T cells for bacterial evasion of cell-mediated immunity. PMID:25484884

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

    Science.gov (United States)

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

    2015-02-01

    CD4(+) T cells and B cells are both essential for acquired immunity to Salmonella infection. It is well established that Salmonella inhibit host CD4(+) T-cell responses, but a corresponding inhibitory effect on B cells is less well defined. Here, we utilize an Ag tetramer and pull-down enrichment strategy to directly visualize OVA-specific B cells in mice, as they respond to infection with Salmonella-OVA. Surprisingly, OVA-specific B-cell expansion and germinal center formation was not detected until bacteria were cleared from the host. Furthermore, Salmonella infection also actively inhibited both B- and T-cell responses to the same coinjected Ag but this did not require the presence of iNOS. The Salmonella Pathogenicity Island 2 (SPI2) locus has been shown to be responsible for inhibition of Salmonella-specific CD4(+) T-cell responses, and an examination of SPI2-deficient bacteria demonstrated a recovery in B-cell expansion in infected mice. Together, these data suggest that Salmonella can simultaneously inhibit host B- and T-cell responses using SPI2-dependent mechanisms. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Immunogenicity and Pathology of Formalin-Killed-Sepa Salmonella ...

    African Journals Online (AJOL)

    Bulletin of Animal Health and Production in Africa ... Intensive poultry production in Nigeria is currently on the increase with associated health challenges. ... The unimmunized control group (UC) was infected with 1x108cfu /ml Salmonella enterica Paratyphi A. The formalin-killed vaccine of SEPA was immunogenic in poultry ...

  11. A novel contribution of spvB to pathogenesis of Salmonella Typhimurium by inhibiting autophagy in host cells.

    Science.gov (United States)

    Chu, Yuanyuan; Gao, Song; Wang, Ting; Yan, Jing; Xu, Guangmei; Li, Yuanyuan; Niu, Hua; Huang, Rui; Wu, Shuyan

    2016-02-16

    Salmonella plasmid virulence genes (spv) are highly conserved in strains of clinically important Salmonella serovars. It is essential for Salmonella plasmid-correlated virulence, although the exact mechanism remains to be elucidated. Autophagy has been reported to play an important role in host immune responses limiting Salmonella infection. Our previous studies demonstrated that Salmonella conjugative plasmid harboring spv genes could enhance bacterial cytotoxicity by inhibiting autophagy. In the present study, we investigated whether spvB, which is one of the most important constituents of spv ORF could intervene in autophagy pathway. Murine macrophage-like cells J774A.1, human epithelial HeLa cells, and BALB/c mice infected with Salmonella Typhimurium wild type, mutant and complementary strains (carrying or free spvB or complemented only with ADP-ribosyltransferase activity of SpvB) were used in vitro and in vivo assay, respectively. To further explore the molecular mechanisms, both SpvB ectopic eukaryotic expression system and cells deficient in essential autophagy components by siRNA were generated. Results indicated that spvB could suppress autophagosome formation through its function in depolymerizing actin, and aggravate inflammatory injury of the host in response to S. Typhimurium infection. Our studies demonstrated virulence of spvB involving in inhibition of autophagic flux for the first time, which could provide novel insights into Salmonella pathogenesis, and have potential application to develop new antibacterial strategies for Salmonellosis.

  12. Salmonella meningitis and septicaemia in an non-immunocompromised adult, associated with a cluster of Salmonella Enteritidis PT 14b, Ireland, November 2009.

    LENUS (Irish Health Repository)

    OhAiseadha, C O

    2010-01-01

    We report a fatal case of meningitis caused by Salmonella Enteritidis phage type 14b in a middle-aged man who had no history or findings to suggest he was immunocompromised. To our knowledge, this is the first reported case of Salmonella meningitis in an adult in Ireland, and the first case of meningitis in an adult caused by phage type 14b. This case was associated with a nationwide cluster of salmonellosis which is still under investigation at the time of writing.

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

    Directory of Open Access Journals (Sweden)

    JM Rodriguez

    2015-12-01

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

  14. Distribution of antibody titer against Salmonella enterica among healthy individuals in nepal

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    Koirala Janak

    2009-01-01

    Full Text Available Abstract Background Enteric fever is an endemic problem in Nepal and Widal agglutination test is widely used for its diagnosis but a normal baseline titer in healthy population and cutoff values have not been established. Methods We measured average baseline antibody titers against "O" and "H" antigens of Salmonella enterica serotype Typhi and "H" antigens of serotypes Paratyphi A and Paratyphi B among apparently healthy blood donors in Nepal. The antibody titers were measured using Standard Widal Confirmatory Quantitative Tube test. Results Among the 100 blood samples collected from healthy volunteers, 62 individuals had significant antibody titers (≥ 1:20 against one of the four antigens against S. enterica. Among 54 samples with an anti-O titer against serotype Typhi, 15 and 36 samples had titers of ≥ 1:60 and ≥ 1:40, respectively. A significant proportion (12% of all had anti-O titer of ≥ 1:80. Similarly, among the 59 samples demonstrating anti-H titers of ≥ 1:20 to S. enterica serotype Typhi, 29 had a titer of ≥ 1:80 and 12 had 1:160. For S. enterica serotypes Paratyphi A and B, anti-H titers of ≥ 1:20 were found only in 12% and 3%, respectively, of all samples tested. Conclusion When a single Widal agglutination titer is used for the diagnosis of enteric fever, it will be more appropriate to change the currently used cutoff levels against S. enterica serotype Typhi to > 1:80 for anti-O and > 1:160 for anti-H titers for Nepal.

  15. LA RESISTANCE AUX ANTIBIOTIQUES DES SALMONELLA DANS LES EAUX DE RIVIERES DE SETIF

    Directory of Open Access Journals (Sweden)

    H CHERIF

    2001-12-01

    Full Text Available La détection des Salmonella à partir des eaux des Oueds Bousselam et Bouaroua de Sétif et l'évaluation de leur antibiorésistance sont tentées. La méthode de numération suivie est celle du NPP utilisant l'eau peptonée tamponnée à 36°C/16 à 24 h pour le pré-enrichissement et le milieu Rappaport à 43°C/48 h pour l'enrichissement sélectif. L'isolement est effectué sur les milieux Brillant Green Agar (BGA et Hektoen additionné de novobiocine. Les eaux des deux oueds sont très chargées en Salmonella dans leur partie urbaine. Ce nombre chute significativement dans la partie en aval de l'Oued Bousselam pour s'annuler à l'entrée du Barrage de Aïn Zada. Parmi les 20 sérotypes détectés, S. Hadar, Paratyphi B, Infantis et Liverpool sont largement prédominants. Cinq semblent spécifiques à la région de Sétif: S. Adabraka, Aequatoria, Kedougou, Liverpool et Obogu. L'antibiogramme de 95 souches de Salmonella vis-à-vis de 16 antibiotiques réalisé par la méthode de diffusion sur disques a révélé que 90 % des souches sont résistants à un ou plusieurs antibiotiques. La résistance à un seul antibiotique (tétracycline, sulfamides est la plus élevée (56,84%. Elle concerne S. Hadar, Paratyphi B, Liverpool, Infantis et Ohio. La multirésistance à 2 ou plusieurs antibiotiques atteint 33,68%. Les souches, dans leur totalité, sont sensibles à la fosfomycine.

  16. Molecular Characterization of Motile Serovars of Salmonella enterica from Breeder and Commercial Broiler Poultry Farms in Bangladesh

    Science.gov (United States)

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

    2013-01-01

    Contaminated poultry and poultry products are a major source of motile Salmonellae for human salmonellosis worldwide. Local circulation of any motile Salmonella serovar in poultry has a wider public health impact beyond its source of origin for being dispersed elsewhere through poultry trades or human travels. To investigate the status of motile Salmonella serovars in breeder farms in Bangladesh, multiple flocks of two breeder farms were observed for a period of six months. In addition, a cross-sectional survey was carried out to determine the prevalence and serovar distribution of motile Salmonella by randomly selecting 100 commercial broiler poultry farms. Five pooled faecal samples representing an entire housed flock of breeders or broilers were screened for presence of motile Salmonella following conventional bacteriological procedures. The Salmonella isolates obtained were subsequently serotyped, and characterized by plasmid profiling and pulsed-field gel electrophoresis (PFGE). The results revealed that both the breeder farms were positive with three Salmonella serovars: S. Virchow, S. Paratyphi B var Java (S. Java) and S. Enteritidis. Eleven of the 100 broiler farms investigated were positive for motile Salmonella, giving a farm-level prevalence of 11% (95% confidence interval 5–17%). S. Virchow and S. Kentucky were the two predominant serovars isolated from the broiler farms. The PFGE genotyping demonstrated that the isolates belonging to the same serovars were closely related due to variation in only 1–4 bands. All the S. Virchow and S. Java isolates, irrespective of breeder or broiler farm origin, were plasmid-free, except for one S. Virchow isolate from a broiler farm that harboured a 9.7 kb-sized plasmid. The S. Kentucky isolates belonged to three plasmid profiles having plasmids of four different sizes, ranging from 2.7 to 109 kb. This is the first report of any motile Salmonella serovars from breeder and commercial broiler poultry farms in

  17. Characterization of Salmonella isolated from captive and free-living snakes in Germany.

    Science.gov (United States)

    Krautwald-Junghanns, Maria-Elisabeth; Stenkat, Julia; Szabo, Istvan; Ortlieb, Falk; Blindow, Irmgard; Neul, Ann-Kathrin; Pees, Michael; Schmidt, Volker

    2013-01-01

    Reptiles are well-known reservoirs of Salmonella spp. and cases of reptile-associated salmonellosis (RAS) are increasing since reptiles are becoming more popular as pets. In the present study, the presence, distribution and prevalence of serovars of Salmonella was investigated in captive snakes (n = 87) and in free-living snakes (n = 87) in Germany. A total of 43 S. enterica-isolates were recovered from organ samples and cloacal swabs, predominantly belonging to the subspecies diarizonae (IIIb) (n = 27), enterica (I) (n = 7) and houtenae (IV) (n = 6). S. enterica subsp. enterica (I) serovar Paratyphi B (n = 4) and S. enterica subsp. diarizonae (IIIb) serovar 47:l,v:z (n = 3) were the most frequently isolated serotypes. Nevertheless, the fact that most serotypes were only represented by a single isolate points out the high diversity of Salmonella present among snakes. Salmonella enterica subsp. diarizonae (IIIb) serotype 40:i:z53, which was isolated twice from two free-living Eurasian adders (Vipera berus) captured at different locations, has not been previously described. Our results confirm the role of both free-living and captive snakes as reservoirs of S. enterica in Germany.

  18. Salmonella infects B cells by macropinocytosis and formation of spacious phagosomes but does not induce pyroptosis in favor of its survival.

    Science.gov (United States)

    Rosales-Reyes, Roberto; Pérez-López, Araceli; Sánchez-Gómez, Concepción; Hernández-Mote, Rosaura Ruth; Castro-Eguiluz, Denisse; Ortiz-Navarrete, Vianney; Alpuche-Aranda, Celia Mercedes

    2012-06-01

    We have previously reported that Salmonella infects B cells and survives within endosomal-lysosomal compartments. However, the mechanisms used by Salmonella to enter B cells remain unknown. In this study, we have shown that Salmonella induces its own entry by the induction of localized ruffling, macropinocytosis, and spacious phagosome formation. These events were associated with the rearrangement of actin and microtubule networks. The Salmonella pathogenesis island 1 (SPI-1) was necessary to invade B cells. In contrast to macrophages, B cells were highly resistant to cell death induced by Salmonella. These data demonstrate the ability of Salmonella to infect these non-professional phagocytic cells, where the bacterium can find an ideal intracellular niche to support persistence and the possible dissemination of infection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Complete Proteome of a Quinolone-Resistant Salmonella Typhimurium Phage Type DT104B Clinical Strain

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    Susana Correia

    2014-08-01

    Full Text Available Salmonellosis is one of the most common and widely distributed foodborne diseases. The emergence of Salmonella strains that are resistant to a variety of antimicrobials is a serious global public health concern. Salmonella enterica serovar Typhimurium definitive phage type 104 (DT104 is one of these emerging epidemic multidrug resistant strains. Here we collate information from the diverse and comprehensive range of experiments on Salmonella proteomes that have been published. We then present a new study of the proteome of the quinolone-resistant Se20 strain (phage type DT104B, recovered after ciprofloxacin treatment and compared it to the proteome of reference strain SL1344. A total of 186 and 219 protein spots were recovered from Se20 and SL1344 protein extracts, respectively, after two-dimensional gel electrophoresis. The signatures of 94% of the protein spots were successfully identified through matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS. Three antimicrobial resistance related proteins, whose genes were previously detected by polymerase chain reaction (PCR, were identified in the clinical strain. The presence of these proteins, dihydropteroate synthase type-2 (sul2 gene, aminoglycoside resistance protein A (strA gene and aminoglycoside 6'-N-acetyltransferase type Ib-cr4 (aac(6'-Ib-cr4 gene, was confirmed in the DT104B clinical strain. The aac(6'-Ib-cr4 gene is responsible for plasmid-mediated aminoglycoside and quinolone resistance. This is a preliminary analysis of the proteome of these two S. Typhimurium strains and further work is being developed to better understand how antimicrobial resistance is developing in this pathogen.

  20. Complete Proteome of a Quinolone-Resistant Salmonella Typhimurium Phage Type DT104B Clinical Strain

    Science.gov (United States)

    Correia, Susana; Nunes-Miranda, Júlio D.; Pinto, Luís; Santos, Hugo M.; de Toro, María; Sáenz, Yolanda; Torres, Carmen; Capelo, José Luis; Poeta, Patrícia; Igrejas, Gilberto

    2014-01-01

    Salmonellosis is one of the most common and widely distributed foodborne diseases. The emergence of Salmonella strains that are resistant to a variety of antimicrobials is a serious global public health concern. Salmonella enterica serovar Typhimurium definitive phage type 104 (DT104) is one of these emerging epidemic multidrug resistant strains. Here we collate information from the diverse and comprehensive range of experiments on Salmonella proteomes that have been published. We then present a new study of the proteome of the quinolone-resistant Se20 strain (phage type DT104B), recovered after ciprofloxacin treatment and compared it to the proteome of reference strain SL1344. A total of 186 and 219 protein spots were recovered from Se20 and SL1344 protein extracts, respectively, after two-dimensional gel electrophoresis. The signatures of 94% of the protein spots were successfully identified through matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). Three antimicrobial resistance related proteins, whose genes were previously detected by polymerase chain reaction (PCR), were identified in the clinical strain. The presence of these proteins, dihydropteroate synthase type-2 (sul2 gene), aminoglycoside resistance protein A (strA gene) and aminoglycoside 6'-N-acetyltransferase type Ib-cr4 (aac(6')-Ib-cr4 gene), was confirmed in the DT104B clinical strain. The aac(6')-Ib-cr4 gene is responsible for plasmid-mediated aminoglycoside and quinolone resistance. This is a preliminary analysis of the proteome of these two S. Typhimurium strains and further work is being developed to better understand how antimicrobial resistance is developing in this pathogen. PMID:25196519

  1. O-Serotype Conversion in Salmonella Typhimurium Induces Protective Immune Responses against Invasive Non-Typhoidal Salmonella Infections.

    Science.gov (United States)

    Li, Pei; Liu, Qing; Luo, Hongyan; Liang, Kang; Yi, Jie; Luo, Ying; Hu, Yunlong; Han, Yue; Kong, Qingke

    2017-01-01

    Salmonella infections remain a big problem worldwide, causing enteric fever by Salmonella Typhi (or Paratyphi) or self-limiting gastroenteritis by non-typhoidal Salmonella (NTS) in healthy individuals. NTS may become invasive and cause septicemia in elderly or immuno-compromised individuals, leading to high mortality and morbidity. No vaccines are currently available for preventing NTS infection in human. As these invasive NTS are restricted to several O-antigen serogroups including B1, D1, C1, and C2, O-antigen polysaccharide is believed to be a good target for vaccine development. In this study, a strategy of O-serotype conversion was investigated to develop live attenuated S. Typhimurium vaccines against the major serovars of NTS infections. The immunodominant O4 serotype of S. Typhimurium was converted into O9, O7, and O8 serotypes through unmarked chromosomal deletion-insertion mutations. O-serotype conversion was confirmed by LPS silver staining and western blotting. All O-serotype conversion mutations were successfully introduced into the live attenuated S. Typhimurium vaccine S738 (Δcrp Δcya) to evaluate their immunogenicity in mice model. The vaccine candidates induced high amounts of heterologous O-polysaccharide-specific functional IgG responses. Vaccinated mice survived a challenge of 100 times the 50% lethality dose (LD50) of wild-type S. Typhimurium. Protective efficacy against heterologous virulent Salmonella challenges was highly O-serotype related. Furthermore, broad-spectrum protection against S. Typhimurium, S. Enteritidis, and S. Choleraesuis was observed by co-vaccination of O9 and O7 O-serotype-converted vaccine candidates. This study highlights the strategy of expressing heterologous O-polysaccharides via genetic engineering in developing live attenuated S. Typhimurium vaccines against NTS infections.

  2. O-Serotype Conversion in Salmonella Typhimurium Induces Protective Immune Responses against Invasive Non-Typhoidal Salmonella Infections

    Directory of Open Access Journals (Sweden)

    Pei Li

    2017-12-01

    Full Text Available Salmonella infections remain a big problem worldwide, causing enteric fever by Salmonella Typhi (or Paratyphi or self-limiting gastroenteritis by non-typhoidal Salmonella (NTS in healthy individuals. NTS may become invasive and cause septicemia in elderly or immuno-compromised individuals, leading to high mortality and morbidity. No vaccines are currently available for preventing NTS infection in human. As these invasive NTS are restricted to several O-antigen serogroups including B1, D1, C1, and C2, O-antigen polysaccharide is believed to be a good target for vaccine development. In this study, a strategy of O-serotype conversion was investigated to develop live attenuated S. Typhimurium vaccines against the major serovars of NTS infections. The immunodominant O4 serotype of S. Typhimurium was converted into O9, O7, and O8 serotypes through unmarked chromosomal deletion–insertion mutations. O-serotype conversion was confirmed by LPS silver staining and western blotting. All O-serotype conversion mutations were successfully introduced into the live attenuated S. Typhimurium vaccine S738 (Δcrp Δcya to evaluate their immunogenicity in mice model. The vaccine candidates induced high amounts of heterologous O-polysaccharide-specific functional IgG responses. Vaccinated mice survived a challenge of 100 times the 50% lethality dose (LD50 of wild-type S. Typhimurium. Protective efficacy against heterologous virulent Salmonella challenges was highly O-serotype related. Furthermore, broad-spectrum protection against S. Typhimurium, S. Enteritidis, and S. Choleraesuis was observed by co-vaccination of O9 and O7 O-serotype-converted vaccine candidates. This study highlights the strategy of expressing heterologous O-polysaccharides via genetic engineering in developing live attenuated S. Typhimurium vaccines against NTS infections.

  3. Salmonella enterica serovar Typhimurium ΔmsbB Triggers Exacerbated Inflammation in Nod2 Deficient Mice

    Science.gov (United States)

    Claes, Anne-Kathrin; Steck, Natalie; Schultz, Dorothee; Zähringer, Ulrich; Lipinski, Simone; Rosenstiel, Philip; Geddes, Kaoru; Philpott, Dana J.; Heine, Holger; Grassl, Guntram A.

    2014-01-01

    The intracellular pathogen Salmonella enterica serovar Typhimurium causes intestinal inflammation characterized by edema, neutrophil influx and increased pro-inflammatory cytokine expression. A major bacterial factor inducing pro-inflammatory host responses is lipopolysaccharide (LPS). S. Typhimurium ΔmsbB possesses a modified lipid A, has reduced virulence in mice, and is being considered as a potential anti-cancer vaccine strain. The lack of a late myristoyl transferase, encoded by MsbB leads to attenuated TLR4 stimulation. However, whether other host receptor pathways are also altered remains unclear. Nod1 and Nod2 are cytosolic pattern recognition receptors recognizing bacterial peptidoglycan. They play important roles in the host's immune response to enteric pathogens and in immune homeostasis. Here, we investigated how deletion of msbB affects Salmonella's interaction with Nod1 and Nod2. S. Typhimurium Δ msbB-induced inflammation was significantly exacerbated in Nod2−/− mice compared to C57Bl/6 mice. In addition, S. Typhimurium ΔmsbB maintained robust intestinal colonization in Nod2−/− mice from day 2 to day 7 p.i., whereas colonization levels significantly decreased in C57Bl/6 mice during this time. Similarly, infection of Nod1−/− and Nod1/Nod2 double-knockout mice revealed that both Nod1 and Nod2 play a protective role in S. Typhimurium ΔmsbB-induced colitis. To elucidate why S. Typhimurium ΔmsbB, but not wild-type S. Typhimurium, induced an exacerbated inflammatory response in Nod2−/− mice, we used HEK293 cells which were transiently transfected with pathogen recognition receptors. Stimulation of TLR2-transfected cells with S. Typhimurium ΔmsbB resulted in increased IL-8 production compared to wild-type S. Typhimurium. Our results indicate that S. Typhimurium ΔmsbB triggers exacerbated colitis in the absence of Nod1 and/or Nod2, which is likely due to increased TLR2 stimulation. How bacteria with “genetically detoxified” LPS

  4. Pattern of Anti-Microbial Sensitivity and Resistance against Salmonella Species in a Tertiary Hospital in Dhaka

    Directory of Open Access Journals (Sweden)

    Afsana Begum

    2015-05-01

    Full Text Available Background: Drug resistant Salmonella spp. continues to remain a health problem as last two decades have witnessed the emergence and spread of multidrug resistance against conventional anti-typhoid drugs. Multidrug resistant (MDR typhoid is now a serious problem in many developing countries including Bangladesh. Objectives: To find out antimicrobial sensitivity and resistance patterns of different types of Salmonella spp. in patients with enteric fever and to find out the epidemiological strains (e.g. resistant strain, epidemic strain, MDR strain in patients with enteric fever. Materials and Methods: This cross-sectional study was done during October 2009–November 2010 and January–December 2012 at United Hospital Limited, Dhaka. Laboratory reports of blood culture were collected from those patients who were investigated as suspected cases of enteric fever. Both the indoor and outdoor patients were enrolled in the study. Salmonella species resistant to one or more of the first line drugs were divided into resistant strain, epidemic strain and multi-drug resistant strain. Results: During the period October 2009–November 2010, total 210 subjects were enrolled. Among the participants, 122 were male and 88 were female. S. typhi were found in 133 samples whereas 76 were S. paratyphi A and only 1 S. paratyphi B. Sensitivity was found 77% for ampicillin, 91.4% for cotrimoxazole, 78.6% for chloramphenicol, 87.6% for ciprofloxacin, 96.6% for cefixime, 98% for ceftriaxone and only 22.1% for azithromycin (77.9% resistant. Total 91 (43.3% cases were found having resistant strain, 6 (2.8% epidemic strain and 8 (3.8% MDR strain Salmonella spp. The sensitivity of azithromycin was analyzed among different categories of strains and revealed that 52.7% showed resistance in resistant strain, 100% in epidemic strain and 87.5% in MDR strain. During the period between January–December 2012, total 139 subjects were enrolled. Among the participants 68 were male

  5. Antibiogram pattern of Salmonella in blood samples of enteric fever patients at Lalitpur, Nepal

    Directory of Open Access Journals (Sweden)

    Biraj Gurung

    2017-01-01

    Full Text Available Objective: To determine the status of isolation blood stream serotypes of enteric fever pathogens and their antibiotic susceptibility patterns and to guide clinicians for appropriate therapy. Methods: Samples were examined by microbiological techniques to identify the causative agent and determine their antimicrobial susceptibility patterns by Kirby-Bauer disk diffusion methods and interpreted as per Clinical and Laboratory Standards Institute guidelines. Results: Among 403 blood samples, 76 (18.85% showed growth for Salmonella isolates. Distribution of Salmonella typhi and Salmonella paratyphi A isolates were found to be 54% and 46% respectively. Among 76 Salmonella isolates, 28 (36.84% were from male and remaining 48 (63.15% were from female belonging to all age-groups. Multidrug-resistance was found to be 17% among the Salmonella isolates. Nalidixic acid resistance was 73.68% in Salmonella with higher proportion in Salmonella paratyphi A (85.7% in comparison to Salmonella typhi (63.42%. Salmonella isolates demonstrated 100% susceptibility to azithromycin, ceftriazone, ciprofloxacin, ofloxacin and imipenem. Conclusions: The need of continual surveillance of resistance levels to guide clinicians for appropriate therapy based on the antibiotic susceptibility pattern for Salmonella isolates is sustained with discouragement in misuse of antibiotics prior to prescription as multidrugresistance-nalidixic acid resistant strains.

  6. 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

  7. Lack of AcrB Efflux Function Confers Loss of Virulence on Salmonella enterica Serovar Typhimurium

    Directory of Open Access Journals (Sweden)

    Xuan Wang-Kan

    2017-07-01

    Full Text Available AcrAB-TolC is the paradigm resistance-nodulation-division (RND multidrug resistance efflux system in Gram-negative bacteria, with AcrB being the pump protein in this complex. We constructed a nonfunctional AcrB mutant by replacing D408, a highly conserved residue essential for proton translocation. Western blotting confirmed that the AcrB D408A mutant had the same native level of expression of AcrB as the parental strain. The mutant had no growth deficiencies in rich or minimal medium. However, compared with wild-type SL1344, the mutant had increased accumulation of Hoechst 33342 dye and decreased efflux of ethidium bromide and was multidrug hypersusceptible. The D408A mutant was attenuated in vivo in mouse and Galleria mellonella models and showed significantly reduced invasion into intestinal epithelial cells and macrophages in vitro. A dose-dependent inhibition of invasion was also observed when two different efflux pump inhibitors were added to the wild-type strain during infection of epithelial cells. RNA sequencing (RNA-seq revealed downregulation of bacterial factors necessary for infection, including those in the Salmonella pathogenicity islands 1, 2, and 4; quorum sensing genes; and phoPQ. Several general stress response genes were upregulated, probably due to retention of noxious molecules inside the bacterium. Unlike loss of AcrB protein, loss of efflux function did not induce overexpression of other RND efflux pumps. Our data suggest that gene deletion mutants are unsuitable for studying membrane transporters and, importantly, that inhibitors of AcrB efflux function will not induce expression of other RND pumps.

  8. Inactivation of Salmonella, Listeria monocytogenes and Enterococcus faecium NRRL B-2354 in a selection of low moisture foods.

    Science.gov (United States)

    Rachon, Grzegorz; Peñaloza, Walter; Gibbs, Paul A

    2016-08-16

    The aims of this study were to obtain data on survival and heat resistance of cocktails of Salmonella, Listeria monocytogenes and the surrogate Enterococcus faecium (NRRL B-2354) in four low moisture foods (confectionery formulation, chicken meat powder, pet food and savoury seasoning) during storage before processing. Inoculated samples were stored at 16°C and cell viability examined at day 0, 3, 7 and 21. At each time point, the heat resistance at 80°C was determined. The purpose was to determine a suitable storage time of inoculated foods that can be applied in heat resistance studies or process validations with similar cell viability and heat resistance characteristics. The main inactivation study was carried out within 7days after inoculation, the heat resistance of each bacterial cocktail was evaluated in each low moisture food heated in thermal cells exposed to temperatures between 70 and 140°C. The Weibull model and the first order kinetics (D-value) were used to express inactivation data and calculate the heating time to achieve 5 log reduction at each temperature. Results showed that the pathogens Salmonella and L. monocytogenes and the surrogate E. faecium NRRL B-2354, can survive well (maximum reduction 0.05). The inactivation kinetics of the pathogens and surrogate at temperatures between 70 and 140°C, were different between each organism and product. E. faecium NRRL B-2354 was a suitable Salmonella surrogate for three of the low moisture foods studied, but not for the sugar-containing confectionery formulation. Heating low moisture food in moisture-tight environments (thermal cells) to 111.2, 105.3 or 111.8°C can inactivate 5 log of Salmonella, L. monocytogenes or E. faecium NRRL B-2354 respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. 623-IJBCS-Article-Dr C O Edeogu

    African Journals Online (AJOL)

    DR GATSING

    febrile illness usually caused by Salmonella enterica serotypes Typhi, Paratyphi A,. Paratyphi B and Paratyphi ... noting that hepatocellular damage with the subsequent disruption of the plasma membrane account for the .... pathogen: extra-intestinal complications of salmonella enterica serotype typhi infection. Lancet Infect.

  10. 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.

  11. Immunogenicity of Salmonella vector vaccines expressing SBR of Streptococcus mutans under the control of a T7-nirB (dual) promoter system.

    Science.gov (United States)

    Salam, Mohammad Abdus; Katz, Jannet; Zhang, Ping; Hajishengallis, George; Michalek, Suzanne M

    2006-06-05

    The purpose of the present study was to determine if a Salmonella vector expressing the cloned saliva-binding region (SBR) of Streptococcus mutans or SBR linked to the A2 and B subunits of cholera toxin (CTA2/B) under the control of both the T7 and nirB promoters (T7-nirB dual promoter) was more effective in inducing mucosal and systemic anti-SBR antibody responses than Salmonella clones expressing the same antigens but under the control of either the nirB or T7 promoter. Mice were immunized by the intranasal route on days 0, 18 and 320 with Salmonella enterica serovar Typhimurium strain BRD 509 containing one of six plasmids encoding SBR or SBR-CTA2/B under the control of the T7-nirB, T7, or nirB promoter. Serum, saliva and vaginal wash samples were collected throughout the experiment and assessed for antibody activity by ELISA. Evidence is provided that Salmonella clones expressing SBR or SBR-CAT2/B under the control of either the T7 or T7-nirB promoter induced a high and persistent mucosal and systemic anti-SBR antibody response. All Salmonella clones induced good anti-SBR responses following the boost on day 320.

  12. Recurrent paratyphoid fever A co-infected with hepatitis A reactivated chronic hepatitis B.

    Science.gov (United States)

    Liu, Yanling; Xiong, Yujiao; Huang, Wenxiang; Jia, Bei

    2014-05-12

    We report here a case of recurrent paratyphoid fever A with hepatitis A co-infection in a patient with chronic hepatitis B. A 26-year-old male patient, who was a hepatitis B virus carrier, was co-infected with Salmonella enterica serovar Paratyphi A and hepatitis A virus. The recurrence of the paratyphoid fever may be ascribed to the coexistence of hepatitis B, a course of ceftriaxone plus levofloxacin that was too short and the insensitivity of paratyphoid fever A to levofloxacin. We find that an adequate course and dose of ceftriaxone is a better strategy for treating paratyphoid fever. Furthermore, the co-infection of paratyphoid fever with hepatitis A may stimulate cellular immunity and break immunotolerance. Thus, the administration of the anti-viral agent entecavir may greatly improve the prognosis of this patient with chronic hepatitis B, and the episodes of paratyphoid fever and hepatitis A infection prompt the use of timely antiviral therapy.

  13. Comparative genomic analysis uncovers 3 novel loci encoding type six secretion systems differentially distributed in Salmonella serotypes

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    Santiviago Carlos A

    2009-08-01

    Full Text Available Abstract Background The recently described Type VI Secretion System (T6SS represents a new paradigm of protein secretion in bacteria. A number of bioinformatic studies have been conducted to identify T6SS gene clusters in the available bacterial genome sequences. According to these studies, Salmonella harbors a unique T6SS encoded in the Salmonella Pathogenicity Island 6 (SPI-6. Since these studies only considered few Salmonella genomes, the present work aimed to identify novel T6SS loci by in silico analysis of every genome sequence of Salmonella available. Results The analysis of sequencing data from 44 completed or in progress Salmonella genome projects allowed the identification of 3 novel T6SS loci. These clusters are located in differentially-distributed genomic islands we designated SPI-19, SPI-20 and SPI-21, respectively. SPI-19 was identified in a subset of S. enterica serotypes including Dublin, Weltevreden, Agona, Gallinarum and Enteritidis. In the later, an internal deletion eliminated most of the island. On the other hand, SPI-20 and SPI-21 were restricted to S. enterica subspecies arizonae (IIIa serotype 62:z4,z23:-. Remarkably, SPI-21 encodes a VgrG protein containing a C-terminal extension similar to S-type pyocins of Pseudomonas aeruginosa. This is not only the first evolved VgrG described in Salmonella, but also the first evolved VgrG including a pyocin domain described so far in the literature. In addition, the data indicate that SPI-6 T6SS is widely distributed in S. enterica and absent in serotypes Enteritidis, Gallinarum, Agona, Javiana, Paratyphi B, Virchow, IIIa 62:z4,z23:- and IIIb 61:1,v:1,5,(7. Interestingly, while some serotypes harbor multiple T6SS (Dublin, Weltvreden and IIIa 62:z4,z23:- others do not encode for any (Enteritidis, Paratyphi B, Javiana, Virchow and IIIb 61:1,v:1,5,(7. Comparative and phylogenetic analyses indicate that the 4 T6SS loci in Salmonella have a distinct evolutionary history. Finally, we

  14. Comparative genomic analysis uncovers 3 novel loci encoding type six secretion systems differentially distributed in Salmonella serotypes.

    Science.gov (United States)

    Blondel, Carlos J; Jiménez, Juan C; Contreras, Inés; Santiviago, Carlos A

    2009-08-04

    The recently described Type VI Secretion System (T6SS) represents a new paradigm of protein secretion in bacteria. A number of bioinformatic studies have been conducted to identify T6SS gene clusters in the available bacterial genome sequences. According to these studies, Salmonella harbors a unique T6SS encoded in the Salmonella Pathogenicity Island 6 (SPI-6). Since these studies only considered few Salmonella genomes, the present work aimed to identify novel T6SS loci by in silico analysis of every genome sequence of Salmonella available. The analysis of sequencing data from 44 completed or in progress Salmonella genome projects allowed the identification of 3 novel T6SS loci. These clusters are located in differentially-distributed genomic islands we designated SPI-19, SPI-20 and SPI-21, respectively. SPI-19 was identified in a subset of S. enterica serotypes including Dublin, Weltevreden, Agona, Gallinarum and Enteritidis. In the later, an internal deletion eliminated most of the island. On the other hand, SPI-20 and SPI-21 were restricted to S. enterica subspecies arizonae (IIIa) serotype 62:z4,z23:-. Remarkably, SPI-21 encodes a VgrG protein containing a C-terminal extension similar to S-type pyocins of Pseudomonas aeruginosa. This is not only the first evolved VgrG described in Salmonella, but also the first evolved VgrG including a pyocin domain described so far in the literature. In addition, the data indicate that SPI-6 T6SS is widely distributed in S. enterica and absent in serotypes Enteritidis, Gallinarum, Agona, Javiana, Paratyphi B, Virchow, IIIa 62:z4,z23:- and IIIb 61:1,v:1,5,(7). Interestingly, while some serotypes harbor multiple T6SS (Dublin, Weltvreden and IIIa 62:z4,z23:-) others do not encode for any (Enteritidis, Paratyphi B, Javiana, Virchow and IIIb 61:1,v:1,5,(7)). Comparative and phylogenetic analyses indicate that the 4 T6SS loci in Salmonella have a distinct evolutionary history. Finally, we identified an orphan Hcp-like protein

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

    KAUST Repository

    Gangwar, Maulshree

    2012-09-23

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

  16. Analysis of the contribution of bacteriophage ST64B to in vitro virulence traits of Salmonella enterica serovar Typhimurium

    DEFF Research Database (Denmark)

    Fresno, Ana Herrero; Leekitcharoenphon, Pimlapas; Hendriksen, Rene S.

    2014-01-01

    Comparison of the publicly available genomes of the virulent Salmonella enterica serovar Typhimurium (S. Typhimurium) strains SL1344, 14028s and D23580 to that of the virulence-attenuated isolate LT2 revealed the absence of a full sequence of bacteriophage ST64B in the latter. Four selected ST64B...... in in vitro assays used to predict virulence association. No difference in invasion of the Int407 human cell line was observed between the wild-type and mutated strains, but the isolate carrying the whole ST64B prophage was found to have a slightly better survival in blood. The study showed a high prevalence...... and a strong association between the prophage ST64B and isolates of S. Typhimurium collected from blood, and may indicate that such strains constitute a selected subpopulation within this serovar. Further studies are indicated to determine whether the slight increase in blood survival observed in the strain...

  17. National outbreak of Salmonella Enteritidis phage type 14b in England, September to December 2009: case-control study.

    Science.gov (United States)

    Janmohamed, K; Zenner, D; Little, C; Lane, C; Wain, J; Charlett, A; Adak, B; Morgan, D

    2011-04-14

    We conducted an unmatched retrospective case–control study to investigate an upsurge of non-travel-related sporadic cases of infection with Salmonella enterica subsp. enterica serotype Enteritidis phage type 14b with antimicrobial resistance to nalidixic acid and partial resistance to ciprofloxacin (S. Enteritidis PT 14b NxCp(L)) that was reported in England from 1 September to 31 December 2009. We analysed data from 63 cases and 108 controls to determine whether cases had the same sources of infection as those found through investigation of 16 concurrent local foodborne outbreaks in England and Wales. Multivariable logistic regression analysis adjusting for age and sex identified food consumption at restaurants serving Chinese or Thai cuisine (odds ratio (OR): 4.4; 95% CI: 1.3–14.8; p=0.02), egg consumed away from home (OR: 5.1; 95% CI: 1.3–21.2; p=0.02) and eating vegetarian foods away from home (OR: 14.6; 95% CI: 2.1–99; p=0.006) as significant risk factors for infection with S. Enteritidis PT 14b NxCp(L). These findings concurred with those from the investigation of the16 outbreaks, which identified the same Salmonella strain in eggs from a specified source outside the United Kingdom. The findings led to a prohibition of imports from this source, in order to control the outbreak.

  18. Emerging Salmonella Enteritidis anaerogenic phage type 14b: outbreak in Norwegian, Swedish and Finnish travellers returning from Greece.

    Science.gov (United States)

    Guerin, P J; Nygard, K; Siitonen, A; Vold, L; Kuusi, M; de Jong, B; Rottingen, J A; Alvseike, O; Olsson, A; Lassen, J; Andersson, Y; Aavitsland, P

    2006-01-01

    In July 2001, the Norwegian Institute of Public Health (Folkehelseinstituttet, FHI) reported a cluster of Salmonella Enteritidis of phage type 14b infections in Norwegian travellers returning from Greece. An increase in the same uncommon phage type was also registered in Sweden and Finland at the same time. Cases of S. Enteritidis PT 14b in patients returning from Greece were reported in these three Nordic countries in 2001 (303 cases), 2002 (164 cases) and 2003 (199 cases). Case-control studies performed in 2001 in Norway and Sweden indicated that consumption of chicken was associated with illness. In 2002 and 2003, continuing case reports indicated that this uncommon phage type had probably become established in the Greek food chain. Tour operators were informed and contacts were made with Greek public health authorities. Because place of infection is not systematically included in most Salmonella notification systems, the S. Enteritidis phage type 14b outbreak reported here may represent only part of a larger outbreak among travellers visiting Greece. Infections are often reported only in the tourists' home countries and public health authorities in the tourist destinations may not be aware of the problem. Further collaboration between national institutes of public health in Europe is needed to detect outbreaks occurring among tourists.

  19. Association of Transferable Quinolone Resistance Determinant qnrB19 with Extended-Spectrum β-Lactamases in Salmonella Give and Salmonella Heidelberg in Venezuela

    Directory of Open Access Journals (Sweden)

    Fanny González

    2013-01-01

    Full Text Available Four nontyphoidal Salmonella strains with resistance to extended-spectrum cephalosporins and nonclassical quinolone resistance phenotype were studied. Two S. Give were isolated from pediatric patients with acute gastroenteritis, and two S. Heidelberg were recovered from raw chicken meat. Phenotypic characterization included antimicrobial susceptibility testing and detection of extended-spectrum β-lactamases (ESBLs by the double-disc synergy method. The detection of quinolone resistance-determining regions (QRDR of gyrA, gyrB, and gyrC genes, blaESBLs genes, and plasmid-mediated quinolone resistance (PMQR determinants was carried out by molecular methods. Plasmid analysis included Southern blot and restriction patterns. Transferability of resistance genes was examined by transformation. blaTEM-1 + blaSHV-12 genes were detected in S. Give SG9611 and blaTEM-1 + blaCTX-M-2 in the other three strains: S. Give SG9811, S. Heidelberg SH7511, and SH7911. Regardless of origin and serovars, the qnrB19 gene was detected in the 4 strains studied. All determinants of resistance were localized in plasmids and successfully transferred by transformation. This study highlights the circulation of qnrB19 associated with blaTEM-1, blaSHV-12, and blaCTX-M-2 in S. Give and S. Heidelberg in Venezuela. The recognition of factors associated with increasing resistance and the study of the molecular mechanisms involved can lead to a more focused use of antimicrobial agents.

  20. Contribution of the hdeB-like gene (SEN1493) to survival of Salmonella enterica enteritidis Nal(R) at pH 2.

    Science.gov (United States)

    Joerger, Rolf D; Choi, Steven

    2015-04-01

    Periplasmic proteins are particularly vulnerable to denaturation upon entry into a highly acid environment. In Escherichia coli, a level of protection of these proteins is afforded by acid-inducible chaperonins encoded by hdeAB. In contrast, Salmonella enterica only harbors an hdeB-like gene and it is currently not known what function it plays in this genus. In the present study, the hdeB-like gene was deleted in Salmonella enterica Enteritidis Nal(R) and Salmonella enterica Kentucky 3795. When grown overnight in tryptic soy broth (TSB) medium buffered at pH 5.5 and then exposed to TSB pH 2 for 20 min, Enteritidis wild-type strain experienced a 0.5-log10 reduction in colony-forming units, whereas the deletion strain's surviving cells were reduced by 1.6 log10. No difference in survival was observed in the corresponding Salmonella enterica Kentucky 3795 strains treated the same way. Exposure of the strains to pH 2.5 or 3 resulted in the same log reduction regardless of the presence of the hdeB-like gene. When wild-type and deletion strains of both serovars were grown in medium buffered at pH 7 prior to exposure to the acidic pHs, no difference in survival with respect to serovar or presence/absence of the hdeB-like gene was found. Salmonella enterica Enteritidis Nal(R) carrying its own or the intragenic region upstream of the hdeB-like from Salmonella enterica Kentucky 3795 cloned in front of the gfp gene from pFPV25 showed maximum fluorescence when grown at pH 5.5, whereas the corresponding plasmid-carrying Salmonella enterica Kentucky strains did not exhibit fluorescence regardless of the pH of the growth medium. Therefore, the hdeB-like gene in Salmonella enterica Enteritidis, but not in Salmonella enterica Kentucky 3795, contributed to survival at pH 2 and its expression is responsive to the pH of the medium.

  1. Evaluation of effects of EarlyBird associated with FloraMax-B11 on Salmonella Enteritidis, intestinal morphology, and performance of broiler chickens.

    Science.gov (United States)

    Biloni, A; Quintana, C F; Menconi, A; Kallapura, G; Latorre, J; Pixley, C; Layton, S; Dalmagro, M; Hernandez-Velasco, X; Wolfenden, A; Hargis, B M; Tellez, G

    2013-09-01

    A posthatch fasting period of 24 to 72 h is a common and inevitable practice in commercial poultry production. This delay in start of feed intake has been reported to negatively affect yolk utilization, gastrointestinal development, slaughter weight, breast meat yield, performance, and to also depress immunological development, making the birds more susceptible to infection from pathogens such as Salmonella. Furthermore, public concerns regarding the considerable human rates of illness reported and the emergence of antibiotic-resistant strains of Salmonella have doubled the challenge on the poultry industry to find alternative means of Salmonella control. In the present study, we evaluated the effects of a combination of early feeding with probiotic supplementation on morphological development of mucosa, control of Salmonella, and overall performance in broiler chickens. We used a blend of a commercially available perinatal supplement, EarlyBird (EB; Pacific Vet Group USA Inc., Fayetteville, AR), and a successful probiotic supplement, FloraMax-B11 (FM; Pacific Vet Group USA Inc.), to evaluate the effects on gut morphology, Salmonella intestinal colonization, and horizontal transmission, along with its effects on BW and related performance in broiler chickens under simulated commercial hatching management and shipping conditions. Morphometric analysis showed increased villus height, villus width, villus to crypt ratio, and villus surface area index in chickens treated with EB + FM groups. Significant reductions in Salmonella recovery, incidence, and horizontal transmission were also observed among the same groups, suggesting beneficial effects of early feeding and competitive exclusion by probiotic bacteria. Improved gut morphology and Salmonella exclusion was very well supported by BW data with significantly lower early BW loss and overall BW gains in birds treated with EB + FM mixture. The results of this study demonstrated that the combination of EB and FM

  2. SseK3 Is a Salmonella Effector That Binds TRIM32 and Modulates the Host's NF-κB Signalling Activity.

    Directory of Open Access Journals (Sweden)

    Zhe Yang

    Full Text Available Salmonella Typhimurium employs an array of type III secretion system effectors that facilitate intracellular survival and replication during infection. The Salmonella effector SseK3 was originally identified due to amino acid sequence similarity with NleB; an effector secreted by EPEC/EHEC that possesses N-acetylglucoasmine (GlcNAc transferase activity and modifies death domain containing proteins to block extrinsic apoptosis. In this study, immunoprecipitation of SseK3 defined a novel molecular interaction between SseK3 and the host protein, TRIM32, an E3 ubiquitin ligase. The conserved DxD motif within SseK3, which is essential for the GlcNAc transferase activity of NleB, was required for TRIM32 binding and for the capacity of SseK3 to suppress TNF-stimulated activation of NF-κB pathway. However, we did not detect GlcNAc modification of TRIM32 by SseK3, nor did the SseK3-TRIM32 interaction impact on TRIM32 ubiquitination that is associated with its activation. In addition, lack of sseK3 in Salmonella had no effect on production of the NF-κB dependent cytokine, IL-8, in HeLa cells even though TRIM32 knockdown suppressed TNF-induced NF-κB activity. Ectopically expressed SseK3 partially co-localises with TRIM32 at the trans-Golgi network, but SseK3 is not recruited to Salmonella induced vacuoles or Salmonella induced filaments during Salmonella infection. Our study has identified a novel effector-host protein interaction and suggests that SseK3 may influence NF-κB activity. However, the lack of GlcNAc modification of TRIM32 suggests that SseK3 has further, as yet unidentified, host targets.

  3. Evaluating Pediococcus acidilactici and Enterococcus faecium NRRL B-2354 as Thermal Surrogate Microorganisms for Salmonella for In-Plant Validation Studies of Low-Moisture Pet Food Products.

    Science.gov (United States)

    Ceylan, Erdogan; Bautista, Derrick A

    2015-05-01

    Pediococcus acidilactici ATCC 8042 and Enterococcus faecium NRRL B-2354 were investigated as potential surrogates for Salmonella serovars using thermal death time kinetics in products such as dry pet foods. The D-values of P. acidilactici ATCC 8042, E. faecium NRRL B-2354, and a cocktail of seven Salmonella serovars associated with low-moisture products were determined in a preservative-free dry pet food product at moisture levels of 9.1, 17.9, and 27.0% and heated between 76.7 and 87.8°C. The D-values were calculated by least squares linear regression. The D-values of P. acidilactici ATCC 8042 were higher than those for the Salmonella serovar cocktail but lower than those for E. faecium NRRL 2354. At 9.1% moisture, D-values of 6.54, 11.51, and 11.66 min at 76.7°C, 2.66, 3.22, and 4.08 min at 82.2°C, and 1.07, 1.29, and 1.69 min at 87.8°C were calculated for Salmonella serovars, P. acidilactici ATCC 8042, and E. faecium NRRL B-2354, respectively. The data suggest that the thermal inactivation characteristics of P. acidilactici ATCC 8042 can be utilized as a surrogate to predict the response of Salmonella in dry pet food products that are thermally processed at <90°C.

  4. Genome-wide analysis of the PreA/PreB (QseB/QseC regulon of Salmonella enterica serovar Typhimurium

    Directory of Open Access Journals (Sweden)

    Bhatiya Aditi

    2009-02-01

    Full Text Available Abstract Background The Salmonella PreA/PreB two-component system (TCS is an ortholog of the QseBC TCS of Escherichia coli. In both Salmonella and E. coli, this system has been shown to affect motility and virulence in response to quorum-sensing and hormonal signals, and to affect the transcription of the Salmonella enterica serovar Typhimurium (S. Typhimurium pmrAB operon, which encodes an important virulence-associated TCS. Results To determine the PreA/PreB regulon in S. Typhimurium, we performed DNA microarrays comparing the wild type strain and various preA and/or preB mutants in the presence of ectopically expressed preA (qseB. These data confirmed our previous findings of the negative effect of PreB on PreA gene regulation and identified candidate PreA-regulated genes. A proportion of the activated loci were previously identified as PmrA-activated genes (yibD, pmrAB, cptA, etc. or were genes located in the local region around preA, including the preAB operon. The transcriptional units were defined in this local region by RT-PCR, suggesting three PreA activated operons composed of preA-preB, mdaB-ygiN, and ygiW-STM3175. Several putative virulence-related phenotypes were examined for preAB mutants, resulting in the observation of a host cell invasion and slight virulence defect of a preAB mutant. Contrary to previous reports on this TCS, we were unable to show a PreA/PreB-dependent effect of the quorum-sensing signal AI-2 or of epinephrine on S. Typhimurium with regard to bacterial motility. Conclusion This work further characterizes this unorthadox OmpR/EnvZ class TCS and provides novel candidate regulated genes for further study. This first in-depth study of the PreA/PreB regulatory system phenotypes and regulation suggests significant comparative differences to the reported function of the orthologous QseB/QseC in E. coli.

  5. blaCTX-M-I group extended spectrum beta lactamase-producing Salmonella typhi from hospitalized patients in Lagos, Nigeria

    Directory of Open Access Journals (Sweden)

    Akinyemi KO

    2015-05-01

    Full Text Available Kabiru O Akinyemi,1 Bamidele A Iwalokun,2 Olajide O Alafe,1 Sulaiman A Mudashiru,1 Christopher Fakorede,11Department of Microbiology, Lagos State University, Ojo, Lagos, Nigeria; 2Biochemistry and Nutrition Division, Nigerian Institute of Medical Research, Yaba, Lagos, NigeriaPurpose: The global spread of blaCTX-M-I extended-spectrum beta-lactamase (ESBL-producing Salmonella spp. remains a major threat to treatment and control. Evidence of emergence and spread of this marker are lacking in Nigeria. This study investigated blaCTX-M-I ESBL production among Salmonella isolates from hospitalized patients.Methods: Patients (158 total made up of two groups were evaluated. Group A was composed of 135 patients with persistent pyrexia and group B was composed of 23 gastroenteritis patients and their stool samples. Samples were cultured, and isolates were identified and were subjected to antibiotic susceptibility testing by standard methods. Isolates were further screened for ESBL production, blaCTX-M-I genes and transferability by double disk synergy test, plasmid extraction, polymerase chain reaction, and conjugation experiment.Results: Thirty-five (25.9% Salmonella isolates were identified from group A, of which 74.3% were S. typhi, 22.9% were S. paratyphi and two (5.7% were invasive non-typhoidal S. enteritidis. Nine Plasmodium falciparum infections were recorded, four of which were identified as co-infections with typhoidal Salmonella. Only two (8.7% S. enteritidis samples were obtained from group B (P>0.05. A total of 24 isolates were ESBL-positive, eliciting resistance to five to seven antibiotics, and were multiple-drug resistant. ESBL production due to the blaCTX-M-I gene cluster was detected in eleven (45.8% Salmonella isolates. Nine (81.8% of the eleven blaCTX-M-I ESBL producers were S. typhi and two (18.2% isolates were S. enteritidis. Four of nine S. typhi blaCTX-M-I ESBL-producing strains harbored 23 kb self-transmissible plasmid that was co

  6. Identification of the regulatory logic controlling Salmonella pathoadaptation by the SsrA-SsrB two-component system.

    Directory of Open Access Journals (Sweden)

    Ana M Tomljenovic-Berube

    2010-03-01

    Full Text Available Sequence data from the past decade has laid bare the significance of horizontal gene transfer in creating genetic diversity in the bacterial world. Regulatory evolution, in which non-coding DNA is mutated to create new regulatory nodes, also contributes to this diversity to allow niche adaptation and the evolution of pathogenesis. To survive in the host environment, Salmonella enterica uses a type III secretion system and effector proteins, which are activated by the SsrA-SsrB two-component system in response to the host environment. To better understand the phenomenon of regulatory evolution in S. enterica, we defined the SsrB regulon and asked how this transcription factor interacts with the cis-regulatory region of target genes. Using ChIP-on-chip, cDNA hybridization, and comparative genomics analyses, we describe the SsrB-dependent regulon of ancestral and horizontally acquired genes. Further, we used a genetic screen and computational analyses integrating experimental data from S. enterica and sequence data from an orthologous regulatory system in the insect endosymbiont, Sodalis glossinidius, to identify the conserved yet flexible palindrome sequence that defines DNA recognition by SsrB. Mutational analysis of a representative promoter validated this palindrome as the minimal architecture needed for regulatory input by SsrB. These data provide a high-resolution map of a regulatory network and the underlying logic enabling pathogen adaptation to a host.

  7. In vitro Antibacterial Activity of Alchornea cordifolia Bark Extract ...

    African Journals Online (AJOL)

    Four extracts of Alchornea cordifolia (Schumach.) Müll. Arg. (Euphorbiaceae) bark, including aqueous, methanol, acetone and hexane extracts, were tested for their antibacterial activities against Salmonella typhi, Salmonella paratyphi A and Salmonella paratyphi B, using both agar diffusion and broth dilution methods.

  8. The microbiological and clinical characteristics of invasive salmonella in gallbladders from cholecystectomy patients in kathmandu, Nepal.

    Directory of Open Access Journals (Sweden)

    Sabina Dongol

    Full Text Available Gallbladder carriage of invasive Salmonella is considered fundamental in sustaining typhoid fever transmission. Bile and tissue was obtained from 1,377 individuals undergoing cholecystectomy in Kathmandu to investigate the prevalence, characteristics and relevance of invasive Salmonella in the gallbladder in an endemic area. Twenty percent of bile samples contained a Gram-negative organism, with Salmonella Typhi and Salmonella Paratyphi A isolated from 24 and 22 individuals, respectively. Gallbladders that contained Salmonella were more likely to show evidence of acute inflammation with extensive neutrophil infiltrate than those without Salmonella, corresponding with higher neutrophil and lower lymphocyte counts in the blood of Salmonella positive individuals. Antimicrobial resistance in the invasive Salmonella isolates was limited, indicating that gallbladder colonization is unlikely to be driven by antimicrobial resistance. The overall role of invasive Salmonella carriage in the gallbladder is not understood; here we show that 3.5% of individuals undergoing cholecystectomy in this setting have a high concentration of antimicrobial sensitive, invasive Salmonella in their bile. We predict that such individuals will become increasingly important if current transmission mechanisms are disturbed; prospectively identifying these individuals is, therefore, paramount for rapid local and regional elimination.

  9. Crystallization and preliminary X-ray crystallographic analysis of biodegradative threonine deaminase (TdcB) from Salmonella typhimurium

    Energy Technology Data Exchange (ETDEWEB)

    Simanshu, Dhirendra K.; Chittori, Sagar [Molecular Biophysics Unit, Indian Institute of Science, Bangalore (India); Savithri, H. S. [Department of Biochemistry, Indian Institute of Science, Bangalore (India); Murthy, M. R. N., E-mail: mrn@mbu.iisc.ernet.in [Molecular Biophysics Unit, Indian Institute of Science, Bangalore (India)

    2006-03-01

    S. typhimurium biodegradative threonine deaminase (TdcB), a member of the β-family of PLP-dependent enzymes, has been overexpressed, purified and crystallized in three different crystal forms using the hanging-drop vapour-diffusion method. Biodegradative threonine deaminase (TdcB) catalyzes the deamination of l-threonine to α-ketobutyrate, the first reaction in the anaerobic breakdown of l-threonine to propionate. Unlike the biosynthetic threonine deaminase, TdcB is insensitive to l-isoleucine and is activated by AMP. Here, the cloning of TdcB (molecular weight 36 kDa) from Salmonella typhimurium with an N-terminal hexahistidine affinity tag and its overexpression in Escherichia coli is reported. TdcB was purified to homogeneity using Ni–NTA affinity column chromatography and crystallized using the hanging-drop vapour-diffusion technique in three different crystal forms. Crystal forms I (unit-cell parameters a = 46.32, b = 55.30, c = 67.24 Å, α = 103.09, β = 94.70, γ = 112.94°) and II (a = 56.68, b = 76.83, c = 78.50 Å, α = 66.12, β = 89.16, γ = 77.08°) belong to space group P1 and contain two and four molecules of TdcB, respectively, in the asymmetric unit. Poorly diffracting form III crystals were obtained in space group C2 and based on the unit-cell volume are most likely to contain one molecule per asymmetric unit. Two complete data sets of resolutions 2.2 Å (crystal form I) and 1.7 Å (crystal form II) were collected at 100 K using an in-house X-ray source.

  10. Analysis of the Salmonella regulatory network suggests involvement of SsrB and H-NS in σE-regulated SPI-2 gene expression

    Directory of Open Access Journals (Sweden)

    Jie eLi

    2015-02-01

    Full Text Available The extracytoplasmic functioning sigma factor σE is known to play an essential role for Salmonella enterica serovar Typhimurium to survive and proliferate in macrophages and mice. However, its regulatory network is not well characterized, especially during infection. Here we used microarray to identify genes regulated by σE in Salmonella grown in three conditions: a nutrient-rich condition and two others that mimic early and late intracellular infection. We found that in each condition σE regulated different sets of genes, and notably, several global regulators. When comparing nutrient-rich and infection-like conditions, large changes were observed in the expression of genes involved in Salmonella pathogenesis island (SPI-1 type-three secretion system (TTSS, SPI-2 TTSS, protein synthesis, and stress responses. In total, the expression of 58% of Salmonella genes was affected by σE in at least one of the three conditions. An important finding is that σE up-regulates SPI-2 genes, which are essential for Salmonella intracellular survival, by up-regulating SPI-2 activator ssrB expression at the early stage of infection and down-regulating SPI-2 repressor hns expression at a later stage. Moreover, σE is capable of countering the silencing of H-NS, releasing the expression of SPI-2 genes. This connection between E and SPI-2 genes, combined with the global regulatory effect of σE, may account for the lethality of rpoE-deficient Salmonella in murine infection.

  11. Salmonella Osteomyelitis

    National Research Council Canada - National Science Library

    McAnearney, S; McCall, D

    2015-01-01

    .... 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...

  12. Variabilidad genética de aislamientos de Salmonella typhimurium (grupo B obtenidos de hígados de pollo destinados para consumo humano

    Directory of Open Access Journals (Sweden)

    Martín Talavera Rojas

    2011-01-01

    Full Text Available Se determinó la frecuencia de aislamientos de Salmonella spp en hígados de pollo para venta, en cuatro mercados del área metropolitana de la ciudad de Toluca, México. El aislamiento bacteriológico se realizó de acuerdo a la norma NOM-114-SSA1- 1994 para la determinación de Salmonella en alimentos. Se realizó la prueba de ERIC-PCR para determinar la variedad genética de las cepas de Salmonella aisladas. De un total de 520 muestras incluidas en el estudio, 7 (1.34 % resultaron positivas a Salmonella serogrupo B (typhimurim. En el ERIC-PCR se observaron cuatro perfiles, encontrando similitud entre cepas de diferentes mercados, lo cual podría indicar que el manejo que se les da a las canales y vísceras es de suma importancia, además que la presencia en hígados de pollo para consumo humano debe ser considerado como una fuente importante de infección, ya que cualquier serovariedad de esta bacteria representa un potencial de infección para el humano.

  13. Supplemental effect of probiotic Bacillus subtilis B2A on productivity, organ weight, intestinal Salmonella microflora, and breast meat quality of growing broiler chicks.

    Science.gov (United States)

    Park, J H; Kim, I H

    2014-08-01

    One-day-old Ross 308 male broiler chicks were used to investigate the additive effect during growth of Bacillus subtilis B2A derived from soil samples on productivity, organ weight, intestinal Salmonella microflora, and breast meat quality. Five hundred seventy-six birds (46 ± 0.5 g) were fed 3 different levels of B. subtilis B2A (1.1 × 10(4), 1.0 × 10(5), and 1.0 × 10(6) cfu), in a basal diet based on corn-soybean meal, for 28 d. In the current study, feed intake and feed conversion during 1 to 28 d showed significant improvement as dietary B. subtilis B2A increased from 1.1 × 10(4) to 1.0 × 10(6) cfu (linear, P weights of the bursa of Fabricius were significantly increased linearly in B. subtilis B2A-fed groups (P loss was decreased (linear, P < 0.05). Our observations suggest that B. subtilis B2A benefits productivity and reduces Salmonella in broilers. © Poultry Science Association Inc.

  14. msbB deletion confers acute sensitivity to CO2 in Salmonella enterica serovar Typhimurium that can be suppressed by a loss-of-function mutation in zwf

    Directory of Open Access Journals (Sweden)

    Troy Kimberly

    2009-08-01

    Full Text Available Abstract Background Pathogens tolerate stress conditions that include low pH, oxidative stress, high salt and high temperature in order to survive inside and outside their hosts. Lipopolysaccharide (LPS, which forms the outer-leaflet of the outer membrane in Gram-negative bacteria, acts as a permeability barrier. The lipid A moiety of LPS anchors it to the outer membrane bilayer. The MsbB enzyme myristoylates the lipid A precursor and loss of this enzyme, in Salmonella, is correlated with reduced virulence and severe growth defects that can both be compensated with extragenic suppressor mutations. Results We report here that msbB (or msbB somA Salmonella are highly sensitive to physiological CO2 (5%, resulting in a 3-log reduction in plating efficiency. Under these conditions, msbB Salmonella form long filaments, bulge and lyse. These bacteria are also sensitive to acidic pH and high osmolarity. Although CO2 acidifies LB broth media, buffering LB to pH 7.5 did not restore growth of msbB mutants in CO2, indicating that the CO2-induced growth defects are not due to the effect of CO2 on the pH of the media. A transposon insertion in the glucose metabolism gene zwf compensates for the CO2 sensitivity of msbB Salmonella. The msbB zwf mutants grow on agar, or in broth, in the presence of 5% CO2. In addition, msbB zwf strains show improved growth in low pH or high osmolarity media compared to the single msbB mutant. Conclusion These results demonstrate that msbB confers acute sensitivity to CO2, acidic pH, and high osmolarity. Disruption of zwf in msbB mutants restores growth in 5% CO2 and results in improved growth in acidic media or in media with high osmolarity. These results add to a growing list of phenotypes caused by msbB and mutations that suppress specific growth defects.

  15. Genome wide evolutionary analyses reveal serotype specific patterns of positive selection in selected Salmonella serotypes

    Directory of Open Access Journals (Sweden)

    Sun Qi

    2009-11-01

    Full Text Available Abstract Background The bacterium Salmonella enterica includes a diversity of serotypes that cause disease in humans and different animal species. Some Salmonella serotypes show a broad host range, some are host restricted and exclusively associated with one particular host, and some are associated with one particular host species, but able to cause disease in other host species and are thus considered "host adapted". Five Salmonella genome sequences, representing a broad host range serotype (Typhimurium, two host restricted serotypes (Typhi [two genomes] and Paratyphi and one host adapted serotype (Choleraesuis were used to identify core genome genes that show evidence for recombination and positive selection. Results Overall, 3323 orthologous genes were identified in all 5 Salmonella genomes analyzed. Use of four different methods to assess homologous recombination identified 270 genes that showed evidence for recombination with at least one of these methods (false discovery rate [FDR] ompC, a gene encoding an outer membrane protein, which has also been found to be under positive selection in other bacteria. A total of 8, 16, 7, and 5 genes showed evidence for positive selection in Choleraesuis, Typhi, Typhimurium, and Paratyphi branch analyses, respectively. Sequencing and evolutionary analyses of four genes in an additional 42 isolates representing 23 serotypes confirmed branch specific positive selection and recombination patterns. Conclusion Our data show that, among the four serotypes analyzed, (i less than 10% of Salmonella genes in the core genome show evidence for homologous recombination, (ii a number of Salmonella genes are under positive selection, including genes that appear to contribute to virulence, and (iii branch specific positive selection contributes to the evolution of host restricted Salmonella serotypes.

  16. Salmonella Infections (For Parents)

    Science.gov (United States)

    ... Needs a Kidney Transplant Vision Facts and Myths Salmonella Infections KidsHealth > For Parents > Salmonella Infections Print A ... Last? Can Salmonella Infections Be Prevented? What Is Salmonella ? Salmonella is a kind of bacteria , with many ...

  17. The effects of the supplementation of Bacillus subtilis RX7 and B2A strains on the performance, blood profiles, intestinal Salmonella concentration, noxious gas emission, organ weight and breast meat quality of broiler challenged with Salmonella typhimurium.

    Science.gov (United States)

    Park, J H; Kim, I H

    2015-04-01

    An experiment was conducted to evaluate the effects of B. subtilis RX7 and B. subtilis B2A on growth performance, blood profiles, intestinal Salmonella population, noxious gas emission, organ weight and breast meat quality of broilers under S. typhimurium challenge. A total of 120, one-day-old Ross 308 male broiler chicks were assigned to four dietary treatments, composed of six replications, with five birds per replication, for 10 day. The dietary treatment groups were negative control (NC; no antibiotic, no B. subtilis), positive control (PC; NC + 0.1% virginiamycin), B. subtilis RX7 (NC + 0.1% B. subtilis RX7 1.0 × 10(9) cfu/g) and B. subtilis B2A (NC + 0.1% B. subtilis 1.0 × 10(9) cfu/g). All birds were orally challenged with 2 ml suspension, containing 10(4) cfu/ml of S. typhimurium KCCM 40253. Results indicated that the body weight gain, feed intake and feed conversion did not differ, among all comparative treatments. Serum haptoglobin concentration was lower in Bacillus treatments (RX7 + B2A) than the NC treatment (p meat after being stored for 1 day, under stress caused by the S. typhimurium challenge. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  18. Antimicrobial resistance surveillance of Salmonella isolates from the First People's Hospital of Yunnan Province, China.

    Science.gov (United States)

    Yaxian, Jiang; Hui, Zuo; Hua, Niu; Xiaoqin, Mao; Fengliang, Li; Ning, Xu; Jiajia, Li; Jie, Jiang; Rui, Zheng

    2015-04-15

    Typhoid fever is a common disease in Yunnan province; however, the resistant phenotype and epidemic characteristics of Salmonella in this area are still unclear. In this study, a 15-year surveillance of antimicrobial susceptibility of Salmonella is reported. From January 1999 to December 2013, Salmonella isolates were recovered from patients in the First People's Hospital of Yunnan Province. Antimicrobial susceptibility was detected and data were analyzed using WHONET5.6. A total of 845 Salmonella isolates were recovered between 1999 and 2013. The most frequently isolated Salmonella serovar was S. Paratyphi A (93%), and 75.1% (635/845) of the isolates were from the young and middle-aged population. The resistance rates of Salmonella spp. to ciprofloxacin, ampicillin, and ceftriaxone increased dramatically during the 15 years. Carbapenems retained the highest and most stable activity against isolates. The resistance rates of all Salmonella isolates to chloramphenicol and sulfamethoxazole were 0.4% (3/845) and 1.8% (15/845), respectively. As Salmonella isolates have been observed to be resistant to first-line antibiotics, antimicrobial agents should be used rationally and prescriptions should be based on case-by-case susceptibility testing.

  19. Plasmid-mediated quinolone resistance by genes qnrA1 and qnrB19 in Salmonella strains isolated in Brazil.

    Science.gov (United States)

    Ferrari, Rafaela; Galiana, Antonio; Cremades, Rosa; Rodriguez, Juan Carlos; Magnani, Marciane; Tognim, Maria Cristina B; Oliveira, Tereza C R M; Royo, Gloria

    2011-07-04

    Considering the importance of the mechanisms involved in quinolone resistance, this study evaluate the presence of PMQR in 126 epidemic and not epidemic strains of Salmonella spp. It was noted that presence of PMQR, by itself, did not generate resistance to ciprofloxacin; but detection of qnr genes in Salmonella spp. and the identification of the qnrB19 variant in a strain of poultry origin alert for the indiscriminate use of quinolones in poultry production, that can result in a pressure for mutant selection of resistant strains with a clinical limitation use of FQs in the near future. And last but not least, is the need to continued study of resistance mechanisms and to monitor the microbial resistance profile of epidemiological strains.

  20. Inhibition of NF-kB 1 (NF-kBp50 by RNA interference in chicken macrophage HD11 cell line challenged with Salmonella enteritidis

    Directory of Open Access Journals (Sweden)

    Hsin-I Chiang

    2009-01-01

    Full Text Available The NF-kB pathway plays an important role in regulating the immunity response in animals. In this study, small interfering RNAs (siRNA were used to specifically inhibit NF-kB 1 expression and to elucidate the role of NF-kB in the signal transduction pathway of the Salmonella challenge in the chicken HD11 cell line. The cells were transfected with either NF-kB 1 siRNA, glyceraldehyde 3-phosphate dehydrogenase siRNA (positive control or the negative control siRNA for 24 h, followed by Salmonella enteritidis (SE challenge or non-challenge for 1 h and 4 h. Eight candidate genes related to the signal pathway of SE challenge were selected to examine the effect of NF-kB 1 inhibition on their expressions by mRNA quantification. The results showed that, with a 36% inhibition of NF-kB 1 expression, gene expression of both Toll-like receptor (TLR 4 and interleukin (IL-6 was consistently and significantly increased at both 1 h and 4 h following SE challenge, whereas the gene expression of MyD88 and IL-1β was increased at 1 h and 4 h, respectively. These findings suggest a likely inhibitory regulation by NF-kB 1, and could lay the foundation for studying the gene network of the innate immune response of SE infection in chickens.

  1. 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...... properties, physiology, classification, and nomenclature. Thereafter, the epidemiology of the organism is introduced, including the routes of transmission. Finally, the disease salmonellosis, the virulence mechanisms, and the occurrence in different types of food are described....

  2. Removal of the phage-shock protein PspB causes reduction of virulence in Salmonella enterica serovar Typhimurium independently of NRAMP1

    DEFF Research Database (Denmark)

    Wallrodt, Inke; Jelsbak, Lotte; Thomsen, Line E.

    2014-01-01

    . In Salmonella enterica serovar Typhimurium (S. Typhimurium), it has recently been reported that PspA is essential for systemic infection of mice, but only in NRAMP1(+) mice, signifying that attenuation is related to coping with divalent cation starvation in the intracellular environment. In the present study......IV-induced secretin stress. In conclusion, our results demonstrate that removal of PspB reduces virulence in S. Typhimurium independently of host NRAMP1 expression, demonstrating that PspB has roles in intra-host survival distinct from the reported contributions of PspA....

  3. An epidemiological study of Salmonella enterica serovar 4, 12 : b :- in broiler chickens in Denmark

    DEFF Research Database (Denmark)

    Chadfield, M.; Skov, Marianne; Christensen, J.

    2001-01-01

    -free. The remaining isolates exhibited a common trend in plasmid content of 105 and 2 kb. Although no specific correlation to any particular source within the poultry industry was discernible using plasmid analysis, there were indications of clonality with local divergence. Ribotyping with EcoRI demonstrated limited...... profiles were also apparent. Eighteen variables were selected for multivariate logistic regression analysis in order to identify risk areas associated with broiler flocks within the industry. An increased risk for S. 4. 12:b:-infection was only associated with the feedmills used. Random effects...

  4. The serodominant secreted effector protein of Salmonella, SseB, is a strong CD4 antigen containing an immunodominant epitope presented by diverse HLA class II alleles.

    Science.gov (United States)

    Reynolds, Catherine J; Jones, Claire; Blohmke, Christoph J; Darton, Thomas C; Goudet, Amelie; Sergeant, Ruhena; Maillere, Bernard; Pollard, Andrew J; Altmann, Daniel M; Boyton, Rosemary J

    2014-11-01

    Detailed characterization of the protective T-cell response in salmonellosis is a pressing unmet need in light of the global burden of human Salmonella infections and the likely contribution of CD4 T cells to immunity against this intracellular infection. In previous studies screening patient sera against antigen arrays, SseB was noteworthy as a serodominant target of adaptive immunity, inducing significantly raised antibody responses in HIV-seronegative compared with seropositive patients. SseB is a secreted protein, part of the Espa superfamily, localized to the bacterial surface and forming part of the translocon of the type III secretion system (T3SS) encoded by Salmonella pathogenicity island 2. We demonstrate here that SseB is also a target of CD4 T-cell immunity, generating a substantial response after experimental infection in human volunteers, with around 0.1% of the peripheral repertoire responding to it. HLA-DR/peptide binding studies indicate that this protein encompasses a number of peptides with ability to bind to several different HLA-DR alleles. Of these, peptide 11 (p11) was shown in priming of both HLA-DR1 and HLA-DR4 transgenic mice to contain an immunodominant CD4 epitope. Analysis of responses in human donors showed immunity focused on p11 and another epitope in peptide 2. The high frequency of SseB-reactive CD4 T cells and the broad applicability to diverse HLA genotypes coupled with previous observations of serodominance and protective vaccination in mouse challenge experiments, make SseB a plausible candidate for next-generation Salmonella vaccines. © 2014 The Authors. Immunology published by John Wiley & Sons Ltd.

  5. Global systems-level analysis of Hfq and SmpB deletion mutants in Salmonella: implications for virulence and global protein translation.

    Directory of Open Access Journals (Sweden)

    Charles Ansong

    Full Text Available Using sample-matched transcriptomics and proteomics measurements it is now possible to begin to understand the impact of post-transcriptional regulatory programs in Enterobacteria. In bacteria post-transcriptional regulation is mediated by relatively few identified RNA-binding protein factors including CsrA, Hfq and SmpB. A mutation in any one of these three genes, csrA, hfq, and smpB, in Salmonella is attenuated for mouse virulence and unable to survive in macrophages. CsrA has a clearly defined specificity based on binding to a specific mRNA sequence to inhibit translation. However, the proteins regulated by Hfq and SmpB are not as clearly defined. Previous work identified proteins regulated by hfq using purification of the RNA-protein complex with direct sequencing of the bound RNAs and found binding to a surprisingly large number of transcripts. In this report we have used global proteomics to directly identify proteins regulated by Hfq or SmpB by comparing protein abundance in the parent and isogenic hfq or smpB mutant. From these same samples we also prepared RNA for microarray analysis to determine if alteration of protein expression was mediated post-transcriptionally. Samples were analyzed from bacteria grown under four different conditions; two laboratory conditions and two that are thought to mimic the intracellular environment. We show that mutants of hfq and smpB directly or indirectly modulate at least 20% and 4% of all possible Salmonella proteins, respectively, with limited correlation between transcription and protein expression. These proteins represent a broad spectrum of Salmonella proteins required for many biological processes including host cell invasion, motility, central metabolism, LPS biosynthesis, two-component regulatory systems, and fatty acid metabolism. Our results represent one of the first global analyses of post-transcriptional regulons in any organism and suggest that regulation at the translational level is

  6. SALMONELLA SPECIES

    African Journals Online (AJOL)

    DR. AMINU

    e. Biochemical screening and serological tests for Salmonellae. Identification of Salmonella species was done biochemically. Triple sugar Iron (TSI) agar motility, urease and citrate utilization tests were also used to screen the isolates before serologic testing was performed. (Cheesbrough, 2002; Perilla, 2003). Triple sugar ...

  7. NleB/SseK effectors from Citrobacter rodentium, Escherichia coli, and Salmonella enterica display distinct differences in host substrate specificity

    DEFF Research Database (Denmark)

    El Qaidi, Samir; Chen, Kangming; Halim, Adnan

    2017-01-01

    proteins with N-acetyl-D-glucosamine to inhibit antibacterial and inflammatory host responses. NleB is conserved among the attaching/effacing pathogens enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), and Citrobacter rodentium. Moreover, Salmonella enterica strains encode up to three Nle...... of these effectors. SseK1, SseK3, EHEC NleB1, EPEC NleB1, and C. rodentium NleB blocked TNF-mediated NF-κB pathway activation, whereas SseK2 and NleB2 did not. C. rodentium NleB, EHEC NleB1, and SseK1 glycosylated host glyceraldehyde 3-phosphate dehydrogenase (GAPDH). C. rodentium NleB, EHEC NleB1, EPEC NleB1......, and SseK2 glycosylated the Fas-associated death domain protein (FADD). SseK3 and NleB2 were not active against either substrate. We also found that EHEC NleB1 glycosylated two GAPDH arginine residues, R197 and R200 and that these two residues were essential for GAPDH-mediated activation of tumor necrosis...

  8. Characterization of a broad host-spectrum virulent Salmonella bacteriophage fmb-p1 and its application on duck meat.

    Science.gov (United States)

    Wang, Changbao; Chen, Qiming; Zhang, Chong; Yang, Jie; Lu, Zhaoxin; Lu, Fengxia; Bie, Xiaomei

    2017-05-15

    The aim of this study was to find a virulent bacteriophage for the biocontrol of Salmonella in duck meat. A broad host-spectrum virulent phage, fmb-p1, was isolated and purified from an duck farm, and its host range was determined to include S. Typhimurium, S. Enteritidis, S. Saintpaul, S. Agona, S. Miami, S. Anatum, S. Heidelberg and S. Paratyphi-C. Electron microscopy and genome sequencing showed that fmb-p1 belongs to the family Siphoviridae. The genome of fmb-p1 is composed of a 43,327-bp double-stranded DNA molecule with 60 open reading frames and a total G+C content of 46.09%. There are no deleterious sequences or genes encoding known harmful products in the phage fmb-p1 genome. Phage fmb-p1 was stable under different temperature (40-75°C), pH (4-10) and NaCl solutions (1-11%). The phage treatment (9.9×10 9 PFU/cm 2 ) caused a peak reduction in S. Typhimurium of 4.52 log CFU/cm 2 in ready-to-eat (RTE) duck meat, whereas potassium sorbate treatment (PS, 2mg/cm 2 ) resulted in a 0.05-0.12 log reduction. Compared to PS treatment, there was significant difference in the S. Typhimurium reduction (P˂0.05) by phage treatment at both 4°C and 25°C. The results suggested that phage could be applied to reduce Salmonella, on commercial poultry products. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Impact of plasmids, including those encodingVirB4/D4 type IV secretion systems, on Salmonella enterica serovar Heidelberg virulence in macrophages and epithelial cells.

    Science.gov (United States)

    Gokulan, Kuppan; Khare, Sangeeta; Rooney, Anthony W; Han, Jing; Lynne, Aaron M; Foley, Steven L

    2013-01-01

    Salmonella enterica serovar Heidelberg (S. Heidelberg) can cause foodborne illness in humans following the consumption of contaminated meat and poultry products. Recent studies from our laboratory have demonstrated that certain S. Heidelberg isolated from food-animal sources harbor multiple transmissible plasmids with genes that encode antimicrobial resistance, virulence and a VirB4/D4 type-IV secretion system. This study examines the potential role of these transmissible plasmids in bacterial uptake and survival in intestinal epithelial cells and macrophages, and the molecular basis of host immune system modulation that may be associated with disease progression. A series of transconjugant and transformant strains were developed with different combinations of the plasmids to determine the roles of the individual and combinations of plasmids on virulence. Overall the Salmonella strains containing the VirB/D4 T4SS plasmids entered and survived in epithelial cells and macrophages to a greater degree than those without the plasmid, even though they carried other plasmid types. During entry in macrophages, the VirB/D4 T4SS encoding genes are up-regulated in a time-dependent fashion. When the potential mechanisms for increased virulence were examined using an antibacterial Response PCR Array, the strain containing the T4SS down regulated several host innate immune response genes which likely contributed to the increased uptake and survival within macrophages and epithelial cells.

  10. Evolution of Salmonella Typhi outer membrane protein-specific T and B cell responses in humans following oral Ty21a vaccination: A randomized clinical trial.

    Directory of Open Access Journals (Sweden)

    Juan Manuel Carreño

    Full Text Available Vaccination against complex pathogens such as typhoidal and non-typhoidal Salmonella requires the concerted action of different immune effector mechanisms. Outer membrane proteins (Omps of Salmonella Typhi are potent immunogens, which elicit long-lasting and protective immunity. Here, we followed the evolution of S. Typhi OmpC and F-specific T and B cell responses in healthy volunteers after vaccination with the vaccine strain Ty21a. To follow humoral and cellular immune responses, pre- and post-vaccination samples (PBMC, serum and stool collected from 15 vaccinated and 5 non-vaccinated individuals. Immunoglobulin levels were assessed in peripheral blood by enzyme-linked immunosorbent assay. B cell and T cell activation were analyzed by flow cytometry. We observed a significant increase of circulating antibody-secreting cells and maximal Omp-specific serum IgG titers at day 25 post vaccination, while IgA titers in stool peaked at day 60. Likewise, Omp-specific CD4+ T cells in peripheral blood showed the highest expansion at day 60 post vaccination, concomitant with a significant increase in IFN-γ and TNFα production. These results indicate that S. Typhi Omp-specific B cell responses and polyfunctional CD4+ T cell responses evolve over a period of at least two months after application of the live attenuated vaccine. Moreover, these findings underscore the potential of S. Typhi Omps as subunit vaccine components.ISRCTN18360696.

  11. Salmonella enterica genomes from victims of a major sixteenth-century epidemic in Mexico.

    Science.gov (United States)

    Vågene, Åshild J; Herbig, Alexander; Campana, Michael G; Robles García, Nelly M; Warinner, Christina; Sabin, Susanna; Spyrou, Maria A; Andrades Valtueña, Aida; Huson, Daniel; Tuross, Noreen; Bos, Kirsten I; Krause, Johannes

    2018-01-15

    Indigenous populations of the Americas experienced high mortality rates during the early contact period as a result of infectious diseases, many of which were introduced by Europeans. Most of the pathogenic agents that caused these outbreaks remain unknown. Through the introduction of a new metagenomic analysis tool called MALT, applied here to search for traces of ancient pathogen DNA, we were able to identify Salmonella enterica in individuals buried in an early contact era epidemic cemetery at Teposcolula-Yucundaa, Oaxaca in southern Mexico. This cemetery is linked, based on historical and archaeological evidence, to the 1545-1550 CE epidemic that affected large parts of Mexico. Locally, this epidemic was known as 'cocoliztli', the pathogenic cause of which has been debated for more than a century. Here, we present genome-wide data from ten individuals for Salmonella enterica subsp. enterica serovar Paratyphi C, a bacterial cause of enteric fever. We propose that S. Paratyphi C be considered a strong candidate for the epidemic population decline during the 1545 cocoliztli outbreak at Teposcolula-Yucundaa.

  12. Oral Challenge with Wild-Type Salmonella Typhi Induces Distinct Changes in B Cell Subsets in Individuals Who Develop Typhoid Disease.

    Directory of Open Access Journals (Sweden)

    Franklin R Toapanta

    2016-06-01

    Full Text Available A novel human oral challenge model with wild-type Salmonella Typhi (S. Typhi was recently established by the Oxford Vaccine Group. In this model, 104 CFU of Salmonella resulted in 65% of participants developing typhoid fever (referred here as typhoid diagnosis -TD- 6-9 days post-challenge. TD was diagnosed in participants meeting clinical (oral temperature ≥38°C for ≥12h and/or microbiological (S. Typhi bacteremia endpoints. Changes in B cell subpopulations following S. Typhi challenge remain undefined. To address this issue, a subset of volunteers (6 TD and 4 who did not develop TD -NoTD- was evaluated. Notable changes included reduction in the frequency of B cells (cells/ml of TD volunteers during disease days and increase in plasmablasts (PB during the recovery phase (>day 14. Additionally, a portion of PB of TD volunteers showed a significant increase in activation (CD40, CD21 and gut homing (integrin α4β7 molecules. Furthermore, all BM subsets of TD volunteers showed changes induced by S. Typhi infections such as a decrease in CD21 in switched memory (Sm CD27+ and Sm CD27- cells as well as upregulation of CD40 in unswitched memory (Um and Naïve cells. Furthermore, changes in the signaling profile of some BM subsets were identified after S. Typhi-LPS stimulation around time of disease. Notably, naïve cells of TD (compared to NoTD volunteers showed a higher percentage of cells phosphorylating Akt suggesting enhanced survival of these cells. Interestingly, most these changes were temporally associated with disease onset. This is the first study to describe differences in B cell subsets directly related to clinical outcome following oral challenge with wild-type S. Typhi in humans.

  13. Oral Challenge with Wild-Type Salmonella Typhi Induces Distinct Changes in B Cell Subsets in Individuals Who Develop Typhoid Disease.

    Science.gov (United States)

    Toapanta, Franklin R; Bernal, Paula J; Fresnay, Stephanie; Magder, Laurence S; Darton, Thomas C; Jones, Claire; Waddington, Claire S; Blohmke, Christoph J; Angus, Brian; Levine, Myron M; Pollard, Andrew J; Sztein, Marcelo B

    2016-06-01

    A novel human oral challenge model with wild-type Salmonella Typhi (S. Typhi) was recently established by the Oxford Vaccine Group. In this model, 104 CFU of Salmonella resulted in 65% of participants developing typhoid fever (referred here as typhoid diagnosis -TD-) 6-9 days post-challenge. TD was diagnosed in participants meeting clinical (oral temperature ≥38°C for ≥12h) and/or microbiological (S. Typhi bacteremia) endpoints. Changes in B cell subpopulations following S. Typhi challenge remain undefined. To address this issue, a subset of volunteers (6 TD and 4 who did not develop TD -NoTD-) was evaluated. Notable changes included reduction in the frequency of B cells (cells/ml) of TD volunteers during disease days and increase in plasmablasts (PB) during the recovery phase (>day 14). Additionally, a portion of PB of TD volunteers showed a significant increase in activation (CD40, CD21) and gut homing (integrin α4β7) molecules. Furthermore, all BM subsets of TD volunteers showed changes induced by S. Typhi infections such as a decrease in CD21 in switched memory (Sm) CD27+ and Sm CD27- cells as well as upregulation of CD40 in unswitched memory (Um) and Naïve cells. Furthermore, changes in the signaling profile of some BM subsets were identified after S. Typhi-LPS stimulation around time of disease. Notably, naïve cells of TD (compared to NoTD) volunteers showed a higher percentage of cells phosphorylating Akt suggesting enhanced survival of these cells. Interestingly, most these changes were temporally associated with disease onset. This is the first study to describe differences in B cell subsets directly related to clinical outcome following oral challenge with wild-type S. Typhi in humans.

  14. CHARACTERIZATION OF SALMONELLA SPECIES FROM WATER BODIES IN DAR-ES-SALAAM CITY, TANZANIA

    Directory of Open Access Journals (Sweden)

    Eliningaya Kweka

    2013-03-01

    Full Text Available Background: Water-borne diseases are the most common cause of illness and death among the poor population from developing countries. The majority of the people are inadequately aware that aquatic environment is a major source of salmonellosis. Dar es Salaam city is among the cities with most of its population live in squatter. Typhoid fever ranks second with 14.3% of all notifiable disease cases in the city. The city experience water scarcity which forces water wells and rivers to become the main sources of water for domestic use and livestock. This study therefore, characterized Salmonella strains from different water bodies of city as possible sources for enteric diseases endemicity. Methods: The Salmonella Chromogenic Agar (SC Agar and Kligler Iron Agar (KIA media were used for isolation and enumeration of the strains. The inoculated cultures were incubated at 370C for 24 hours. Salmonella colonies were confirmed by magenta colorations and hydrogen sulfide production on SC Agar and KIA Agar, respectively. The Analytical Profile Index 20 Enterobacteriaceae kit (API 20E kit was used to identify Salmonella species. Results: Based on the API 20E kit, the identified Salmonella species from different water bodies were Salmonella ser. paratyphi A (96.9%, Salmonella cholelaesuis spp choleraesuis (99.5% and Salmonella typhi (99.9%. Conclusion: This study shows that shallow wells and rivers which are mainly used by the city dwellers were highly contaminated with Salmonella and were more contaminated than deep wells and marine water bodies. This warrants further investigation on the disease mapping in the urban and peri-urban areas.

  15. In ovo evaluation of FloraMax®-B11 on Marek´s disease HVT vaccine protective efficacy, hatchability, microbiota composition, morphometric analysis, and Salmonella Enteritidis infection in broiler chickens

    Science.gov (United States)

    Four experiments were conducted to evaluate the effect of in ovo administration of FloraMax®-B11 (FM) on Marek´s disease (MD) herpesvirus of turkeys (HVT) vaccine protective efficacy, hatchability, microbiota composition, morphometric analysis and Salmonella enteritidis (SE) infection in chickens. I...

  16. 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...

  17. One pathway can incorporate either adenine or dimethylbenzimidazole as an alpha-axial ligand of B12 cofactors in Salmonella enterica.

    Science.gov (United States)

    Anderson, Peter J; Lango, Jozsef; Carkeet, Colleen; Britten, Audrey; Kräutler, Bernhard; Hammock, Bruce D; Roth, John R

    2008-02-01

    Corrinoid (vitamin B12-like) cofactors contain various alpha-axial ligands, including 5,6-dimethylbenzimidazole (DMB) or adenine. The bacterium Salmonella enterica produces the corrin ring only under anaerobic conditions, but it can form "complete" corrinoids aerobically by importing an "incomplete" corrinoid, such as cobinamide (Cbi), and adding appropriate alpha- and beta-axial ligands. Under aerobic conditions, S. enterica performs the corrinoid-dependent degradation of ethanolamine if given vitamin B12, but it can make B12 from exogenous Cbi only if DMB is also provided. Mutants isolated for their ability to degrade ethanolamine without added DMB converted Cbi to pseudo-B12 cofactors (having adenine as an alpha-axial ligand). The mutations cause an increase in the level of free adenine and install adenine (instead of DMB) as an alpha-ligand. When DMB is provided to these mutants, synthesis of pseudo-B12 cofactors ceases and B12 cofactors are produced, suggesting that DMB regulates production or incorporation of free adenine as an alpha-ligand. Wild-type cells make pseudo-B12 cofactors during aerobic growth on propanediol plus Cbi and can use pseudo-vitamin B12 for all of their corrinoid-dependent enzymes. Synthesis of coenzyme pseudo-B12 cofactors requires the same enzymes (CobT, CobU, CobS, and CobC) that install DMB in the formation of coenzyme B12. Models are described for the mechanism and control of alpha-axial ligand installation.

  18. Characterization of antimicrobial resistance in Salmonella enterica food and animal isolates from Colombia: identification of a qnrB19-mediated quinolone resistance marker in two novel serovars

    DEFF Research Database (Denmark)

    Karczmarczyk, M.; Martins, M.; McCusker, M.

    2010-01-01

    Ninety-three Salmonella isolates recovered from commercial foods and exotic animals in Colombia were studied. The serotypes, resistance profiles and where applicable the quinolone resistance genes were determined. Salmonella Anatum (n=14), Uganda (19), Braenderup (10) and Newport (10) were the most...... hitherto unrecognized in various Salmonella serovars in Colombia. We also report unusual high-level quinolone resistance in the absence of any DNA gyrase mutations in serovars S. Carrau, Muenchen and Uganda....

  19. Interleukin-10 Production by T and B Cells Is a Key Factor to Promote Systemic Salmonella enterica Serovar Typhimurium Infection in Mice

    Directory of Open Access Journals (Sweden)

    Geraldyne A. Salazar

    2017-08-01

    Full Text Available Salmonella enterica serovar Typhimurium (S. Typhimurium is a Gram-negative bacterium that produces disease in numerous hosts. In mice, oral inoculation is followed by intestinal colonization and subsequent systemic dissemination, which leads to severe pathogenesis without the activation of an efficient anti-Salmonella immune response. This feature suggests that the infection caused by S. Typhimurium may promote the production of anti-inflammatory molecules by the host that prevent efficient T cell activation and bacterial clearance. In this study, we describe the contribution of immune cells producing the anti-inflammatory cytokine interleukin-10 (IL-10 to the systemic infection caused by S. Typhimurium in mice. We observed that the production of IL-10 was required by S. Typhimurium to cause a systemic disease, since mice lacking IL-10 (IL-10−/− were significantly more resistant to die after an infection as compared to wild-type (WT mice. IL-10−/− mice had reduced bacterial loads in internal organs and increased levels of pro-inflammatory cytokines in serum at 5 days of infection. Importantly, WT mice showed high bacterial loads in tissues and no increase of cytokines in serum after 5 days of S. Typhimurium infection, except for IL-10. In WT mice, we observed a peak of il-10 messenger RNA production in ileum, spleen, and liver after 5 days of infection. Importantly, the adoptive transfer of T or B cells from WT mice restored the susceptibility of IL-10−/− mice to systemic S. Typhimurium infection, suggesting that the generation of regulatory cells in vivo is required to sustain a systemic infection by S. Typhimurium. These findings support the notion that IL-10 production from lymphoid cells is a key process in the infective cycle of S. Typhimurium in mice due to generation of a tolerogenic immune response that prevents bacterial clearance and supports systemic dissemination.

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

    OpenAIRE

    Wierup, Martin; Kristoffersen, Thor

    2014-01-01

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

  1. European Food Safety Authority; Analysis of the baseline survey of Salmonella in holdings with breeding pigs, in the EU, 2008; Part B: Analysis of factors potentially associated with Salmonella pen positivity

    DEFF Research Database (Denmark)

    Hald, Tine

    , feed of commercial compound origin or pelleted feed. A tendency towards some Member State group-specific Salmonella serovars was identified, but spatial distribution of other serovars was heterogeneous. S. Typhimurium and S. Derby were widespread and dominant in the EU, in both breeding and production......A European Union-wide Salmonella baseline survey was conducted in 2008 in holdings with breeding pigs. A total of 1,609 randomly selected holdings housing and selling mainly breeding pigs (breeding holdings) and 3,508 holdings housing commercial breeding pigs and mainly selling pigs for fattening...... or slaughter (production holdings) were sampled. In each selected holding, pooled fresh faecal samples were collected from 10 randomly chosen pens of breeding pigs over six months of age, representing the different stages of the breeding herd, and examined for the presence of Salmonella. Analyses at country...

  2. Antimicrobial activity of the bioactive components of essential oils from Pakistani spices against Salmonella and other multi-drug resistant bacteria

    Science.gov (United States)

    2013-01-01

    Background The main objective of this study was the phytochemical characterization of four indigenous essential oils obtained from spices and their antibacterial activities against the multidrug resistant clinical and soil isolates prevalent in Pakistan, and ATCC reference strains. Methods Chemical composition of essential oils from four Pakistani spices cumin (Cuminum cyminum), cinnamon (Cinnamomum verum), cardamom (Amomum subulatum) and clove (Syzygium aromaticum) were analyzed on GC/MS. Their antibacterial activities were investigated by minimum inhibitory concentration (MIC) and Thin-Layer Chromatography-Bioautographic (TLC-Bioautographic) assays against pathogenic strains Salmonella typhi (D1 Vi-positive), Salmonella typhi (G7 Vi-negative), Salmonella paratyphi A, Escherichia coli (SS1), Staphylococcus aureus, Pseudomonas fluorescens and Bacillus licheniformis (ATCC 14580). The data were statistically analyzed by using Analysis of Variance (ANOVA) and Least Significant Difference (LSD) method to find out significant relationship of essential oils biological activities at p spices can be pursued against multidrug resistant bacteria. PMID:24119438

  3. 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

    B/SigD. The only host protein found to bind immunoprecipitated SopB was the small G-protein Cdc42. The interaction was confirmed by reciprocal immunoprecipitation, and Cdc42 also bound glutathione S-transferase-fused SopB and SopB delivered through infection by the bacteria, confirming the interaction...

  4. Dam methylation participates in the regulation of PmrA/PmrB and RcsC/RcsD/RcsB two component regulatory systems in Salmonella enterica serovar Enteritidis.

    Directory of Open Access Journals (Sweden)

    Sebastián Hernán Sarnacki

    Full Text Available The absence of Dam in Salmonella enterica serovar Enteritidis causes a defect in lipopolysaccharide (LPS pattern associated to a reduced expression of wzz gene. Wzz is the chain length regulator of the LPS O-antigen. Here we investigated whether Dam regulates wzz gene expression through its two known regulators, PmrA and RcsB. Thus, the expression of rcsB and pmrA was monitored by quantitative real-time RT-PCR and Western blotting using fusions with 3×FLAG tag in wild type (wt and dam strains of S. Enteritidis. Dam regulated the expression of both rcsB and pmrA genes; nevertheless, the defect in LPS pattern was only related to a diminished expression of RcsB. Interestingly, regulation of wzz in serovar Enteritidis differed from that reported earlier for serovar Typhimurium; RcsB induces wzz expression in both serovars, whereas PmrA induces wzz in S. Typhimurium but represses it in serovar Enteritidis. Moreover, we found that in S. Enteritidis there is an interaction between both wzz regulators: RcsB stimulates the expression of pmrA and PmrA represses the expression of rcsB. Our results would be an example of differential regulation of orthologous genes expression, providing differences in phenotypic traits between closely related bacterial serovars.

  5. Prevalence of extended-spectrum b-lactamase-producing Salmonella on retail chicken in six provinces and two national cities in the People's Republic of China.

    Science.gov (United States)

    Wu, Haiyun; Xia, Xiaodong; Cui, Yue; Hu, Yuanyuan; Xi, Meili; Wang, Xin; Shi, Xianming; Wang, Dapeng; Meng, Jianghong; Yang, Baowei

    2013-12-01

    Prevalence of extended-spectrum β-lactamase (ESBL)-producing Salmonella in food is not well documented. This study investigated the prevalence of ESBL-producing Salmonella in 699 Salmonella isolates recovered from 1,152 retail chickens collected from six provinces and two national cities in the People's Republic of China in 2011. ESBL-producing isolates were screened by double-disk synergy test and confirmed using PCR and DNA sequencing. Of the 699 isolates tested, 60 (8.58%) were identified to be ESBL-producing Salmonella. Prevalence of ESBL-producing Salmonella was the highest in Shanghai city (17 [24.64%] of 69), followed by Shaanxi (10 [15.38%] of 65), Fujian (9 [11.69%] of 77), Guangdong (9 [7.69%] of 117), Sichuan (5 [7.25%] of 69), Beijing (6 [5.17%] of 116), Henan (4 [4.65%] of 86), and Guangxi (0 [0%] of 100) province. Significant difference (P Salmonella was found among six provinces and two cities. No significant difference (P > 0.05) in the prevalence was found between wet markets and supermarkets or between whole chickens and chopped chickens. The prevalence of ESBL-producing Salmonella differed significantly (P Salmonella varied significantly (P Salmonella serotypes: Abony (1 [33.33%] of 3), Indiana (28 [28.57%] of 98), Edinburg (6 [24.00%] of 25), Shubra (2 [20.00%] of 10), Uppsala (1 [16.67%] of 6), Thompson (8 [14.81%] of 54), Haardt (1 [12.50%] of 8), Agona (3 [9.68%] of 31), Gueuletapee (1 [6.25%] of 16), Typhimurium (4 [5.56%] of 72), Heidelberg (1 [4.55%] of 22), and Enteritidis (4 [3.17%] of 126). This study revealed that ESBL-producing Salmonella do exist in retail chicken in the People's Republic of China and that the potential risk of their presence in foods needs further exploration.

  6. Salmonella typhimurium PtsJ is a novel MocR-like transcriptional repressor involved in regulating the vitamin B6 salvage pathway.

    Science.gov (United States)

    Tramonti, Angela; Milano, Teresa; Nardella, Caterina; di Salvo, Martino L; Pascarella, Stefano; Contestabile, Roberto

    2017-02-01

    The vitamin B6 salvage pathway, involving pyridoxine 5'-phosphate oxidase (PNPOx) and pyridoxal kinase (PLK), recycles B6 vitamers from nutrients and protein turnover to produce pyridoxal 5'-phosphate (PLP), the catalytically active form of the vitamin. Regulation of this pathway, widespread in living organisms including humans and many bacteria, is very important to vitamin B6 homeostasis but poorly understood. Although some information is available on the enzymatic regulation of PNPOx and PLK, little is known on their regulation at the transcriptional level. In the present work, we identified a new MocR-like regulator, PtsJ from Salmonella typhimurium, which controls the expression of the pdxK gene encoding one of the two PLKs expressed in this organism (PLK1). Analysis of pdxK expression in a ptsJ knockout strain demonstrated that PtsJ acts as a transcriptional repressor. This is the first case of a MocR-like regulator acting as repressor of its target gene. Expression and purification of PtsJ allowed a detailed characterisation of its effector and DNA-binding properties. PLP is the only B6 vitamer acting as effector molecule for PtsJ. A DNA-binding region composed of four repeated nucleotide sequences is responsible for binding of PtsJ to its target promoter. Analysis of binding stoichiometry revealed that protein subunits/DNA molar ratio varies from 4 : 1 to 2 : 1, depending on the presence or absence of PLP. Structural characteristics of DNA transcriptional factor-binding sites suggest that PtsJ binds DNA according to a different model with respect to other characterised members of the MocR subgroup. © 2016 Federation of European Biochemical Societies.

  7. In vitro effects of thymol-B-D-glucopyranoside on Salmonella enterica serovar Typhimurium and Escherichia coli K88

    Science.gov (United States)

    Although thymol is bactericidal against many pathogens in vitro, its in vivo effectiveness against pathogens in the lower gastrointestinal tract is limited because of its rapid absorption in the proximal gut. Thymol-b-D-glucopyranoside (b-thymol), a conjugated form of thymol, can deliver thymol to ...

  8. FAKTOR VIRULENSI Salmonella enterica SEROVAR TYPHI

    Directory of Open Access Journals (Sweden)

    Marvy Khrisna Pranamartha

    2015-09-01

    Full Text Available ABSTRAK Demam tifoid disebabkan oleh bakteri Salmonella typhi, dengan gejala umum berupa demam tinggi dan nyeri perut. Tifoid adalah penyakit infeksi yang disebabkan oleh bakteri Salmonella typhi, yang masuk ke dalam tubuh melalui mulut dan saluran cerna.1 Untuk bisa memahami patogenesis dari demam tifoid sampai ke tingkat selular dan molekular, ada 5 hal penting yang harus digaris bawahi, yaitu: 1.\tTipe 3 Sistem Sekresi (T3SS 2.\tVirulence Genes dari Salmonella yang mengkode 5 SIP (Salmonella Invasion Protein SIP A, B, C, D, dan E. 3.\tToll R2 dan toll R3 yang merupakan lapisan luar dari makrofag. 4.\tSistem imun lumen usus sampai ke organ dalam 5.\tFungsi endotelial sel dalam inflamasi. Infeksi Salmonella dapat berakibat fatal kepada bayi, balita, ibu hamil dan kandungannya serta orang lanjut usia. Hal ini disebabkan karena kekebalan tubuh mereka yang menurun. Virulensi salmonella tidak lepas dari peranan SPI, yang terletak di dalam kromosom dan plasmid bakteri. Dimana SPI 1 dan SPI 2 telah dikaji cukup mendalam karena keterkaitannya dengan T3SS, dan berperan sangat penting pada invasi awal serta siklus hidup intrasel dari bakteri Salmonella. Kontaminasi Salmonella dapat dicegah dengan mencuci tangan dan menjaga kebersihan makanan yang dikonsumsi. Selalu menjaga kebersihan lingkungan hidup kita agar terhindar dari kontaminasi dengan bakteri Salmonella typhi. Agar mewaspadai sejak dini pencegahan dan pengobatan penyakit typhus. Studi mendalam perlu dilakukan agar kita mampu lebih memahami proses kompleks antara patogen dan sel inang. Mengingat dari 15 SPI yang sudah diketahui, hanya SPI 1 dan SPI 2 yang sudah dikaji secara mendalam. Kata Kunci: Salmonella, Salmonella Invasion Protein, Typhi.

  9. Liquid based formulations of bacteriophages for the management of waterborne bacterial pathogens in water microcosms

    National Research Council Canada - National Science Library

    Ahiwale, Sangeeta; Tagunde, Sujata; Khopkar, Sushama; Karni, Mrudula; Gajbhiye, Milind; Kapadnis, Balasaheb

    2013-01-01

    .... In the present study, highly potent lytic phages against multidrug-resistant Salmonella enterica serovar Paratyphi B, Pseudomonas aeruginosa and Klebsiella pneumoniae were isolated from the Pavana river water...

  10. Occurrence of Salmonella sp in laying hens

    Directory of Open Access Journals (Sweden)

    Gama NMSQ

    2003-01-01

    Full Text Available This study was carried out to investigate the presence of Salmonella sp in flocks of white laying hens. In different farms, the transport boxes of twelve flocks were inspected at arrival for the presence of Salmonella. Four positive (A, B, L and M and one negative (I flocks were monitored at each four weeks using bacteriological examination of cecal fresh feces up to 52 weeks. Birds were also evaluated at 52 weeks, when 500 eggs were taken randomly, and at 76 weeks, after forced molt. Salmonella enterica serovar Enteritidis and S. enterica rough strain were isolated from the transport boxes of the four positive flocks (flocks A, B, L and M. Salmonella sp was not isolated from the transport boxes or from the feces after 76 weeks-old in flock I. Salmonella sp was isolated in the 1st, 11th, 34th, 42nd and 76th weeks from flock A; in the 1st, 4th, 11th and 76th weeks from flock B; in the first week and in the 17th to 52nd weeks from flock L; and in the 1st and 76th weeks from flock M. S. Enteritidis, S. enterica rough strain and Salmonella enterica serovar Infantis were isolated from the four positive flocks. Besides, Salmonella enterica serovar Javiana was isolated from flocks B and L, and Salmonella enterica serovar Mbandaka was isolated from flock L. Eggs produced by flock A and by flock L were contaminated with S. Enteritidis and S. enterica rough strain. According to these results, Salmonella-infected flocks may produce contaminated eggs.

  11. Differential roles for pathogenicity islands SPI-13 and SPI-8 in the interaction of Salmonella Enteritidis and Salmonella Typhi with murine and human macrophages.

    Science.gov (United States)

    Espinoza, Rodrigo A; Silva-Valenzuela, Cecilia A; Amaya, Fernando A; Urrutia, Ítalo M; Contreras, Inés; Santiviago, Carlos A

    2017-02-15

    Salmonella pathogenicity island (SPI)-13 is conserved in many serovars of S. enterica, including S. Enteritidis, S. Typhimurium and S. Gallinarum. However, it is absent in typhoid serovars such as S. Typhi and Paratyphi A, which carry SPI-8 at the same genomic location. Because the interaction with macrophages is a critical step in Salmonella pathogenicity, in this study we investigated the role played by SPI-13 and SPI-8 in the interaction of S. Enteritidis and S. Typhi with cultured murine (RAW264.7) and human (THP-1) macrophages. Our results showed that SPI-13 was required for internalization of S. Enteritidis in murine but not human macrophages. On the other hand, SPI-8 was not required for the interaction of S. Typhi with human or murine macrophages. Of note, the presence of an intact copy of SPI-13 in a S. Typhi mutant carrying a deletion of SPI-8 did not improve its ability to be internalized by, or survive in human or murine macrophages. Altogether, our results point out to different roles for SPI-13 and SPI-8 during Salmonella infection. While SPI-13 contributes to the interaction of S. Enteritidis with murine macrophages, SPI-8 is not required in the interaction of S. Typhi with murine or human macrophages. We hypothesized that typhoid serovars have lost SPI-13 and maintained SPI-8 to improve their fitness during another phase of human infection.

  12. Salmonella Diagnosis and Treatment

    Science.gov (United States)

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

  13. Salmonella in Swedish cattle

    OpenAIRE

    Ågren, Estelle

    2017-01-01

    In Sweden, all herds detected with salmonella are put under restrictions and measures aiming at eradication are required. The purpose of these studies was to provide a basis for decisions on how surveillance and control of salmonella in Swedish cattle can be made more cost-efficient. Results from a bulk milk screening were used to investigate seroprevalence of salmonella and to study associations between salmonella status and geographical location, local animal density, number of test pos...

  14. Assessment of Salmonella survival in dry-cured Italian salami.

    Science.gov (United States)

    Bonardi, S; Bruini, I; Bolzoni, L; Cozzolino, P; Pierantoni, M; Brindani, F; Bellotti, P; Renzi, M; Pongolini, S

    2017-12-04

    this study. In particular the lower aw values due to longer curing were associated with lower Salmonella presence in traditional dry-cured salami. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. 78 FR 42526 - Salmonella

    Science.gov (United States)

    2013-07-16

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

  16. Influence of On-farm pig Salmonella status on Salmonella Shedding at Slaughter.

    Science.gov (United States)

    Casanova-Higes, A; Andrés-Barranco, S; Mainar-Jaime, R C

    2017-08-01

    The risk of Salmonella shedding among pigs at slaughter with regard to their previous on-farm Salmonella status was assessed in a group of pigs from a farm from NE of Spain. A total of 202 pigs that had been serologically monitored monthly during the fattening period and from which mesenteric lymph nodes (MLN) and faecal (SFEC) samples were collected at slaughter for Salmonella isolation were included. A repeated-measures anova was used to assess the relationship between mean OD% values during the fattening period and sampling time and bacteriology on MLN and SFEC. Pigs were also grouped into four groups, that is pigs seronegative during the fattening period and Salmonella negative in MLN (group A; n = 69); pigs seronegative during the fattening period but Salmonella positive in MLN (B; n = 36); pigs seropositive at least once and Salmonella positive in MLN (C; n = 50); and pigs seropositive at least once but Salmonella negative in (D; n = 47). Pigs shedding at slaughter seroconverted much earlier and showed much higher mean OD% values than non-shedders pigs. The proportion of Salmonella shedders in groups A and D was high and similar (26.1% and 29.8%, respectively), but significantly lower than that for groups B and C. The odds of shedding Salmonella for groups B and C were 4.8 (95% CI = 1.5-15.5) and 20.9 (3.7-118) times higher, respectively, when compared to A. It was concluded that a large proportion of Salmonella seronegative pigs may shed Salmonella at slaughter, which would be likely associated to previous exposure with contaminated environments (i.e. transport and lairage). For pigs already infected at farm, the likelihood of shedding Salmonella was much higher and may depend on whether the bacterium has colonized the MLN or not. The odds of shedding Salmonella spp. were always much higher for pigs in which Salmonella was isolated from MLN. © 2016 Blackwell Verlag GmbH.

  17. 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 ...

  18. A feed-forward loop between SroC and MgrR small RNAs modulates the expression of eptB and the susceptibility to polymyxin B in Salmonella Typhimurium.

    Science.gov (United States)

    Acuña, Lillian G; Barros, M José; Peñaloza, Diego; Rodas, Paula I; Paredes-Sabja, Daniel; Fuentes, Juan A; Gil, Fernando; Calderón, Iván L

    2016-11-01

    Base-pairing small RNAs (sRNAs) regulate gene expression commonly by direct interaction with cognate mRNAs. Nevertheless, recent studies have expanded this knowledge with the discovery of the RNA 'sponges' which are able to interact and repress the functions of classical base-pairing sRNAs. In this work, we present evidence indicating that the sponge RNA SroC from Salmonella enterica serovar Typhimurium base pairs with the MgrR sRNA, thereby antagonizing its regulatory effects on both gene expression and resistance to the antimicrobial peptide polymyxin B (PMB). By a predictive algorithm, we determined putative SroC-MgrR base-pairing regions flanking the interaction area between MgrR and its target mRNA, eptB, encoding a LPS-modifying enzyme. With a two-plasmid system and compensatory mutations, we confirmed that SroC directly interacts and down-regulates the levels of MgrR, thus relieving the MgrR-mediated repression of eptB mRNA. Since it was previously shown that an Escherichia coli strain carrying an mgrR deletion is more resistant to PMB, we assessed the significance of SroC in the susceptibility of S. Typhimurium to PMB. Whereas the sroC deletion increased the sensitivity to PMB, as compared to the wild-type, the resistance phenotypes between the ΔmgrR and ΔsroCΔmgrR strains were comparable, evidencing that mgrR mutation is epistatic to the sroC mutation. Together, these results indicate that both SroC and MgrR sRNAs compose a coherent feed-forward loop controlling the eptB expression and hence the LPS modification in S. Typhimurium.

  19. Protection by Lactobacillus acidophilus UFV-H2B20 against experimental oral infection with Salmonella enterica subsp. enterica Ser. Typhimurium in gnotobiotic and conventional mice Proteção por Lactobacillus acidophilus UFV-H2B20 contra o desafio oral experimental com Salmonella enterica subsp. enterica Ser. Typhimurium em camundongos gnotobióticos e convencionais

    Directory of Open Access Journals (Sweden)

    Lilian Nobre Moura

    2001-03-01

    Full Text Available The ability of Lactobacillus acidophilus UFV-H2B20 to antagonize Salmonella enterica subsp. enterica ser. Typhimurium and to reduce the pathological consequences for the host was determining using conventional and gnotobiotic animals. Conventional NIH mice received daily by gavage a 0.1 ml suspension containing about 10(8 cfu L. acidophilus UFV-H2B20 and germfree animals received a single 0.1 ml dose. The gnotobiotic and conventional groups were infected orally with 10² and 10(5 cfu of S. Typhimurium, respectively, 7 days after the beginning of treatment. Control groups were treated with sterile saline instead of Lactobacillus. Survival data showed a protective effect against the pathogenic bacteria in both conventional and gnotobiotic Lactobacillus-treated mice. L. acidophilus UFV-H2B20 colonized the digestive tract of gnotobiotic mice and the number of viable cells ranged from 10(9 to 10(10 cfu/g of faeces. In both experimental and control gnotobiotic animals, S. Typhimurium became rapidly established at a level ranging from 10(8 to 10(10 cfu/g of faeces and remained at high levels until the animals died or were sacrificed. In conclusion, the previous treatment of mice with L. acidophilus UFV-H2B20 protects the animals against the experimental infection with S. Typhimurium but this protection was not due to the reduction of the pathogenic populations in the intestines.A capacidade de Lactobacillus acidophilus UFV-H2B20 de antagonizar Salmonella enterica subsp. enterica ser. Typhimurium, e de reduzir as conseqüências patológicas para o hospedeiro foram determinadas em animais convencionais e gnotobióticos. Camundongos NIH convencionais receberam diariamente, por via oral, 0,1 ml de uma suspensão contendo em torno de 10(8 ufc de L. acidophilus UFV-H2B20 e os animais sem germes receberam uma única dose de 0,1 ml. Os grupos gnotobióticos e convencionais foram desafiados oralmente com, respectivamente, 10² e 10(5 ufc de S. Typhimurium 7

  20. beta-Lactamases among extended-spectrum beta-lactamase (ESBL)-resistant Salmonella from poultry, poultry products and human patients in The Netherlands

    DEFF Research Database (Denmark)

    Hasman, Henrik; Mevius, D.; Veldman, K.

    2005-01-01

    enterica serovars Blockley, Thomson, London, Enteritidis phage type 14b, Paratyphi B, Virchow and Typhimurium phage types 11 and 507. We also found the bla(TEM-20) gene in S. Paratyphi B var. Java and the bla(TEM-63) gene in S. Isangi. Furthermore, we detected the bla(CTX-M-28) gene in S. Isangi...... and the bla(CTX-M-3) gene in S. Typhimurium phage type 507. The bla(CTX-M-2) gene was identified in S. Virchow, which also contained a copy of the bla(SHV-2) gene and a copy of the bla(TEM-1) gene. The bla(SHV-12) gene was found alone in S. Concord and together with the bla(TEM-52) gene in S. Typhimurium...

  1. Beta-lactamases among Extended spectrum Beta-lactamase resistant (ESBL) Salmonella from poultry, poultry products and human patients in The Netherlands

    DEFF Research Database (Denmark)

    Hasman, Henrik; Mevius, D.; Veldman, K.

    2006-01-01

    enterica serovars Blockley, Thomson, London, Enteritidis phage type 14b, Paratyphi B, Virchow and Typhimurium phage types 11 and 507. We also found the bla(TEM-20) gene in S. Paratyphi B var. Java and the bla(TEM-63) gene in S. Isangi. Furthermore, we detected the bla(CTX-M-28) gene in S. Isangi...... and the bla(CTX-M-3) gene in S. Typhimurium phage type 507. The bla(CTX-M-2) gene was identified in S. Virchow, which also contained a copy of the bla(SHV-2) gene and a copy of the bla(TEM-1) gene. The bla(SHV-12) gene was found alone in S. Concord and together with the bla(TEM-52) gene in S. Typhimurium...

  2. A multi-country Salmonella Enteritidis phage type 14b outbreak associated with eggs from a German producer: 'near real-time' application of whole genome sequencing and food chain investigations, United Kingdom, May to September 2014.

    Science.gov (United States)

    Inns, T; Lane, C; Peters, T; Dallman, T; Chatt, C; McFarland, N; Crook, P; Bishop, T; Edge, J; Hawker, J; Elson, R; Neal, K; Adak, G K; Cleary, P

    2015-04-23

    We report an outbreak of Salmonella Enteritidis phage type 14b (PT14b) in the United Kingdom (UK) between May and September 2014 where Public Health England launched an investigation to identify the source of infection and implement control measures. During the same period, outbreaks caused by a Salmonella Enteritidis strain with a specific multilocus variable-number tandem repeat analysis (MLVA) profile occurred in other European Union Member States. Isolates from a number of persons affected by the UK outbreak, who had initially been tested by MLVA also shared this particular profile. Cases were defined as any person infected with S. Enteritidis PT14b, resident in England or Wales and without history of travel outside of this geographical area during the incubation period, reported from 1 June 2014 onwards, with a MLVA profile of 2–11–9-7–4-3–2-8–9 or a single locus variant thereof. In total, 287 cases met the definition. Food traceback investigations in the UK and other affected European countries linked the outbreaks to chicken eggs from a German company. We undertook whole genome sequencing of isolates from UK and European cases, implicated UK premises, and German eggs: isolates were highly similar. Combined with food traceback information, this confirmed that the UK outbreak was also linked to a German producer.

  3. 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

    -pathogenic relative, the results of this study also suggest that unidentified virulence factors may play a role in Salmonella's interactions with oysters. Published by Elsevier B.V.

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

    Science.gov (United States)

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

    2016-02-16

    Predictive models, to estimate the reduction in Escherichia coli O157:H7 concentration in beef burgers, have been developed to inform risk management decisions; no analogous model exists for Salmonella spp. in pork burgers. In this study, "Extra Lean" and "Regular" fat pork minces were inoculated with Salmonella spp. (Salmonella 4,[5],12,i:-, Salmonella Senftenberg and Salmonella Typhimurium) and formed into pork burger patties. Patties were cooked on an electric skillet (to imitate home cooking) to one of seven internal temperatures (46, 49, 52, 55, 58, 61, 64 °C) and Salmonella enumerated. A generalised linear logistic regression model was used to develop a predictive model for the Salmonella concentration based on the internal endpoint temperature. It was estimated that in pork mince with a fat content of 6.1%, Salmonella survival will be decreased by -0.2407log10 CFU/g for a 1 °C increase in internal endpoint temperature, with a 5-log10 reduction in Salmonella concentration estimated to occur when the geometric centre temperature reaches 63 °C. The fat content influenced the rate of Salmonella inactivation (P=0.043), with Salmonella survival increasing as fat content increased, though this effect became negligible as the temperature approached 62 °C. Fat content increased the time required for patties to achieve a specified internal temperature (P=0.0106 and 0.0309 for linear and quadratic terms respectively), indicating that reduced fat pork mince may reduce the risk of salmonellosis from consumption of pork burgers. Salmonella serovar did not significantly affect the model intercepts (P=0.86) or slopes (P=0.10) of the fitted logistic curve. This predictive model can be applied to estimate the reduction in Salmonella in pork burgers after cooking to a specific endpoint temperature and hence to assess food safety risk. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  5. Salmonellae in avian wildlife in Norway from 1969 to 2000

    DEFF Research Database (Denmark)

    Refsum, T.; Handeland, K.; Baggesen, Dorte Lau

    2002-01-01

    -B var. Java. Variant 0:4,12 comprised 96% (451 cases) of all serovar Typhimurium isolates, including all the passerines, while variant 0:4,5,12 accounted for the remaining 4% (18 cases). The occurrence of salmonellae in small passerines showed a distinct seasonality, with a peak in February and March......Postmortem records of wild-living birds in Norway with laboratory-confirmed findings of salmonella infection were summarized for the period from 1969 to 2000. Salmonella spp. were isolated from 470 birds belonging to 26 species. The salmonella-positive birds included 441 small passerines, 15 gulls...

  6. Salmonella species isolated from animal feed in Iraq.

    Science.gov (United States)

    Al-Hindawi, N; Taha, R R

    1979-01-01

    Of 700 animal feed samples, 32 (4.5%) harbored Salmonella. The highest percentage of contamination was found in sheep feed and local protein. A total of 17 Salmonella serotypes were identified. The most frequent serotypes were Salmonella meleagridis. S. bornum, S. montevideo, and S. drypool. S. bornum was isolated for the first time in Iraq and from both local feed and its ingredients. The common somatic group found was that of Salmonella group C; then came groups E, G, B, and D. Three serotypes (S. enteritidis, S. california, and S. muenchen) seemed to form a link of infection among feed, food, patients, and carriers. PMID:453836

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

    African Journals Online (AJOL)

    Out of 100 animals examined sheep, 14 (14.0%) were Salmonella carriers. ... Out of the 17 Salmonella isolates, three different Serogroups were identified of which Serogroup B was predominant (63.6%) ... http://dx.doi.org/10.4314/star.v3i3.18.

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

    Directory of Open Access Journals (Sweden)

    Sharon M Tennant

    2010-03-01

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

  9. Identification by PCR of Non-typhoidal Salmonella enterica Serovars Associated with Invasive Infections among Febrile Patients in Mali

    Science.gov (United States)

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

    2010-01-01

    Background In sub-Saharan Africa, non-typhoidal Salmonella (NTS) are emerging as a prominent cause of invasive disease (bacteremia and focal infections such as meningitis) in infants and young children. Importantly, including data from Mali, three serovars, Salmonella enterica serovar Typhimurium, Salmonella Enteritidis and Salmonella Dublin, account for the majority of non-typhoidal Salmonella isolated from these patients. Methods We have extended a previously developed series of polymerase chain reactions (PCRs) based on O serogrouping and H typing to identify Salmonella Typhimurium and variants (mostly I 4,[5],12:i:-), Salmonella Enteritidis and Salmonella Dublin. We also designed primers to detect Salmonella Stanleyville, a serovar found in West Africa. Another PCR was used to differentiate diphasic Salmonella Typhimurium and monophasic Salmonella Typhimurium from other O serogroup B, H:i serovars. We used these PCRs to blind-test 327 Salmonella serogroup B and D isolates that were obtained from the blood cultures of febrile patients in Bamako, Mali. Principal Findings We have shown that when used in conjunction with our previously described O-serogrouping PCR, our PCRs are 100% sensitive and specific in identifying Salmonella Typhimurium and variants, Salmonella Enteritidis, Salmonella Dublin and Salmonella Stanleyville. When we attempted to differentiate 171 Salmonella Typhimurium (I 4,[ 5],12:i:1,2) strains from 52 monophasic Salmonella Typhimurium (I 4,[5],12:i:-) strains, we were able to correctly identify 170 of the Salmonella Typhimurium and 51 of the Salmonella I 4,[5],12:i:- strains. Conclusion We have described a simple yet effective PCR method to support surveillance of the incidence of invasive disease caused by NTS in developing countries. PMID:20231882

  10. Lactobacillus bulgaricus, Lactobacillus rhamnosus and Lactobacillus paracasei Attenuate Salmonella Enteritidis, Salmonella Heidelberg and Salmonella Typhimurium Colonization and Virulence Gene Expression In Vitro

    Directory of Open Access Journals (Sweden)

    Muhammed Shafeekh Muyyarikkandy

    2017-11-01

    Full Text Available Salmonella Enteritidis (SE, Salmonella Typhimurium (ST, and Salmonella Heidelberg (SH have been responsible for numerous outbreaks associated with the consumption of poultry meat and eggs. Salmonella colonization in chicken is characterized by initial attachment to the cecal epithelial cells (CEC followed by dissemination to the liver, spleen, and oviduct. Since cecal colonization is critical to Salmonella transmission along the food chain continuum, reducing this intestinal association could potentially decrease poultry meat and egg contamination. Hence, this study investigated the efficacy of Lactobacillus delbreuckii sub species bulgaricus (NRRL B548; LD, Lactobacillus paracasei (DUP-13076; LP, and Lactobacillus rhamnosus (NRRL B442; LR in reducing SE, ST, and SH colonization in CEC and survival in chicken macrophages. Additionally, their effect on expression of Salmonella virulence genes essential for cecal colonization and survival in macrophages was evaluated. All three probiotics significantly reduced Salmonella adhesion and invasion in CEC and survival in chicken macrophages (p < 0.05. Further, the probiotic treatment led to a significant reduction in Salmonella virulence gene expression (p < 0.05. Results of the study indicate that LD, LP, and LR could potentially be used to control SE, ST, and SH colonization in chicken. However, these observations warrant further in vivo validation.

  11. A dual mechanism involved in membrane and nucleic acid disruption of AvBD103b, a new avian defensin from the king penguin, against Salmonella enteritidis CVCC3377.

    Science.gov (United States)

    Teng, Da; Wang, Xiumin; Xi, Di; Mao, Ruoyu; Zhang, Yong; Guan, Qingfeng; Zhang, Jun; Wang, Jianhua

    2014-10-01

    The food-borne bacterial gastrointestinal infection is a serious public health threat. Defensins are evolutionarily conserved innate immune components with broad-spectrum antibacterial activity that do not easily induce resistance. AvBD103b, an avian defensin with potent activity against Salmonella enteritidis, was isolated from the stomach contents of the king penguin (Aptenodytes patagonicus). To elucidate further the antibacterial mechanism of AvBD103b, its effect on the S. enteritidis CVCC3377 cell membrane and intracellular DNA was researched. The cell surface hydrophobicity and a N-phenyl-1-naphthylamine uptake assay demonstrated that AvBD103b treatment increased the cell surface hydrophobicity and outer membrane permeability. Atomic absorption spectrometry, ultraviolet spectrophotometry, flow cytometry, and transmission electron microscopy (TEM) indicated that AvBD103b treatment can lead to the release of the cellular contents and cell death through damage of the membrane. DNA gel retardation and circular dichroism analysis demonstrated that AvBD103b interacted with DNA and intercalated into the DNA base pairs. A cell cycle assay demonstrated that AvBD103b affected cellular functions, such as DNA synthesis. Our results confirmed that AvBD103b exerts its antibacterial activity by damaging the cell membrane and interfering with intracellular DNA, ultimately causing cell death, and suggested that AvBD103b may be a promising candidate as an alternative to antibiotics against S. enteritidis.

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

    DEFF Research Database (Denmark)

    Aabo, Søren; Christensen, J.P.; Chadfield, M.S.

    2002-01-01

    A. Two serotypes demonstrated intracellular log(10) counts that differed significantly from all other serotypes tested: Salmonella Enteritidis PT4 being 1.5 log(10) colony forming units (CFU) ( 31-fold) higher, and Salmonella Tennessee being 0.7 log(10) CFU (fivefold) lower than the reference strain (P......, S. Enteritidis PT6, S. Enteritidis PT8, and Salmonella Berta. The serotypes Salmonella Hadar, Salmonella Virchow, S. 4,12: b:-, S. Typhimurium DT41, and Salmonella Infantis, most of which are considered horizontally transmitted, did not show significantly different intracellular counts from......The aim of the present study was to compare the invasion of selected zoonotic Salmonella serotypes of poultry in an in vivo chicken intestinal loop model and also in vitro in epithelial cell cultures. Invasion was measured relative to a reference strain, Salmonella Typhimurium 4/74 invH201::Tnpho...

  13. Expression profiles of effector proteins SopB, SopD1, SopE1, and AvrA differ with systemic, enteric, and epidemic strains of Salmonella enterica.

    Science.gov (United States)

    Streckel, Wiebke; Wolff, Anne-Christin; Prager, Rita; Tietze, Erhard; Tschäpe, Helmut

    2004-12-01

    The presence and expression of sopB, sopD1, sopE1, and avrA genes encoding virulence associated effector proteins were studied comparatively in 405 Salmonella enterica strains. They belong to different serovars and clonal types (genotypes, phage types) and originated from different clinical (systemic infection, focal enteritis, enterocolitis) and epidemic sources (epidemics, sporadic cases). The sopB and sopD1 determinants were commonly prevalent, but sopE1 and avrA genes only in 55% and 80%, respectively. A correlation of this pattern of absence and presence of the respective genes to the epidemic and clinical origin could not be detected. In contrast, the expression of the respective genes appeared differently: SopB and SopE1 proteins are well produced, but SopD1 and AvrA proteins only rarely under the applied standard culture conditions. However, using a range of different environmental signals (temperature, pH, cations, etc.) some of the S. enterica nonproducer strains (e. g., S. Agona, S. Bovismorbificans, S. Virchow, etc.) begin to produce AvrA and SopD1. They turned now into an expression profile which was found typically for the epidemic strains of S. Typhimurium and S. Enteritidis. Also S. enterica strains from systemic infections could be characterized by their strong SopB and SopE1 expression while SopD1 and AvrA proteins were missing. Although it is premature to outline generally a correlation of these expression profiles and the clinical and epidemiological potency of Salmonellae, the reported results allow a first understanding how a fine tuning of their virulence will take place.

  14. Salmonella Sepsis in African Children

    African Journals Online (AJOL)

    Infection with both Salmonella typhiand non-typhi salmonella. (NTS) is common among children in many African countries. Salmonella typhi predominates among older children and adults with the typical localising features of enteric fever. Nontyphoid salmonellae species are more often reported among children under 5 ...

  15. 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.

  16. Reiter's syndrome after salmonella infection

    Directory of Open Access Journals (Sweden)

    Čanović Predrag S.

    2004-01-01

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

  17. Antiobiotics susceptibility of Salmonella isolates from Wdal Test ...

    African Journals Online (AJOL)

    Antiobiotics susceptibility of Salmonella isolates from Wdal Test Positive Patients at the Federal Medical Center, Gusau. SB Manga, IG Ameh, S Bashir, AG Muazu, B Danjuma, ML Ibrahim, K Abdullahi, J Mawak ...

  18. Salmonella enteritidis ventriculitis

    National Research Council Canada - National Science Library

    Johan, A J; Hung, L C; Norlijah, O

    2013-01-01

    .... We present a case of Salmonella enteritidis meningitis in a six week old female who presented with a one week history of fever, diarrhea and seizures which was unsuccessfully treated with a third...

  19. Cell lines and Salmonella

    NARCIS (Netherlands)

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

    2001-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Priyanka Das

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

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

    DEFF Research Database (Denmark)

    Fashae, Kayode; Hendriksen, Rene S.

    2014-01-01

    ciprofloxacin and gentamicin was low (n = 2; 0.9 %). Multiply resistant isolates included Salmonella Kentucky, the most resistant serovar. qnrB19 was found in two isolates of Salmonella Corvallis and one isolate of Salmonella Larochelle, respectively, while qnrS1 was found in two isolates of Salmonella Derby...... of plasmid-mediated quinolone resistance (PMQR) genes in pigs in Ibadan, Nigeria. Pooled fresh pen floor fecal samples of pigs collected from 31 pig farms were cultured; the Salmonella isolates were serotyped and their antimicrobial susceptibility was determined. PMQR genes were screened by polymerase chain...... Kingston (n = 13; 5.7 %). The most widely distributed serovars among the farms were Salmonella Give (six farms) and Salmonella Elisaberthville (six farms). Resistance to chloramphenicol, sulfonamides, nalidixic acid, streptomycin, and tetracycline ranged from 11.6 % (n = 26) to 22.8 % (n = 51). Resistance...

  2. 92 EAST AFRICAN MEDICAL JOURNAL

    African Journals Online (AJOL)

    2002-02-02

    Feb 2, 2002 ... Objectives: To determine baseline antibody responses to H and O antigens of Salmonella typhi and Salmonella paratyphi (A, B and C) in school aged Nigerian children. Design: Cross-sectional study involving 175 children. Using both rapid slide and tube agglutination techniques in dilutions of sera (1:20 to ...

  3. Anti-typhoid agglutinins in School aged African children | Ibadin ...

    African Journals Online (AJOL)

    Objectives: To determine baseline antibody responses to H and O antigens of Salmonella typhi and Salmonella paratyphi (A, B and C) in school aged Nigerian children. Design: Cross-sectional study involving 175 children. Using both rapid slide and tube agglutination techniques in dilutions of sera (1:20 to 1:320), ...

  4. Cytotoxic mechanism of cytolethal distending toxin in nontyphoidal Salmonella serovar (Salmonella Javiana) during macrophage infection.

    Science.gov (United States)

    Williams, Katherine; Gokulan, Kuppan; Shelman, Diamond; Akiyama, Tatsuya; Khan, Ashraf; Khare, Sangeeta

    2015-02-01

    Cytolethal distending toxin B (cdtB) is a conserved virulence factor in Salmonella enterica serovar Typhi. Here we report the presence and functionality of cdtB in some nontyphoidal Salmonella (NTS) serovars, including Salmonella Javiana (cdtB+wt S. Javiana), isolated from imported food. To understand the role of cdtB in NTS serovars, a deletion mutant (cdtB(-)ΔS. Javiana) was constructed. Macrophages were infected with cdtB+wt S. Javiana (wild type), cdtB(-)Δ S. Javiana (mutant), and cdtB-negative NTS serovar (S. Typhimurium). Cytotoxic activity and transcription level of genes involved in cell death (apoptosis, autophagy, and necrosis) were assessed in infected macrophages. The cdtB+wt S. Javiana caused cellular distension as well as high degree of vacuolization and presence of the autophagosome marker LC3 in infected macrophages as compared with cdtB(-)ΔS. Javiana. The mRNA expression of genes involved in the induction of autophagy in response to toxin (Esr1 and Pik3C3) and coregulators of autophagy and apoptosis (Bax and Cyld) were significantly upregulated in cdtB(+)wt S. Javiana-infected macrophages. As autophagy destroys internalized pathogens in addition to the infected cell, it may reduce the spread of infection.

  5. Salmonella in sesame seed products.

    Science.gov (United States)

    Brockmann, Stefan O; Piechotowski, Isolde; Kimmig, Peter

    2004-01-01

    In the context of an international outbreak of multiresistant Salmonella Typhimurium DT 104 that was correlated to the consumption of halvah ("helva," an Asian candy made from sesame seed), we examined several sesame seed products for the occurrence of Salmonella. Of 117 ready-to-eat food items containing sesame, we isolated salmonellae from 11 (9.4%) samples. In addition to finding Salmonella Typhimurium DT 104 in the halvah involved in the outbreak, we also isolated different Salmonella Typhimurium strains out of halvah from other manufacturers and countries of origin, as well as Salmonella Offa, Salmonella Tennessee, and Salmonella Poona from sesame paste (tahini) and sesame seed, which is sold for raw consumption in cereals.

  6. Two Novel Salmonella Bivalent Vaccines Confer Dual Protection against Two Salmonella Serovars in Mice

    Science.gov (United States)

    Zhao, Xinxin; Dai, Qinlong; Jia, Renyong; Zhu, Dekang; Liu, Mafeng; Wang, Mingshu; Chen, Shun; Sun, Kunfeng; Yang, Qiao; Wu, Ying; Cheng, Anchun

    2017-01-01

    Non-typhoidal Salmonella includes thousands of serovars that are leading causes of foodborne diarrheal illness worldwide. In this study, we constructed three bivalent vaccines for preventing both Salmonella Typhimurium and Salmonella Newport infections by using the aspartate semialdehyde dehydrogenase (Asd)-based balanced-lethal vector-host system. The constructed Asd+ plasmid pCZ11 carrying a subset of the Salmonella Newport O-antigen gene cluster including the wzx-wbaR-wbaL-wbaQ-wzy-wbaW-wbaZ genes was introduced into three Salmonella Typhimurium mutants: SLT19 (Δasd) with a smooth LPS phenotype, SLT20 (Δasd ΔrfbN) with a rough LPS phenotype, and SLT22 (Δasd ΔrfbN ΔpagL::T araC PBAD rfbN) with a smooth LPS phenotype when grown with arabinose. Immunoblotting demonstrated that SLT19 harboring pCZ11 [termed SLT19 (pCZ11)] co-expressed the homologous and heterologous O-antigens; SLT20 (pCZ11) exclusively expressed the heterologous O-antigen; and when arabinose was available, SLT22 (pCZ11) expressed both types of O-antigens, while in the absence of arabinose, SLT22 (pCZ11) expressed only the heterologous O-antigen. Exclusive expression of the heterologous O-antigen in Salmonella Typhimurium decreased the swimming ability of the bacterium and its susceptibility to polymyxin B. Next, the crp gene was deleted from the three recombinant strains for attenuation purposes, generating the three bivalent vaccine strains SLT25 (pCZ11), SLT26 (pCZ11), and SLT27 (pCZ11), respectively. Groups of BALB/c mice (12 mice/group) were orally immunized with 109 CFU of each vaccine strain twice at an interval of 4 weeks. Compared with a mock immunization, immunization with all three vaccine strains induced significant serum IgG responses against both Salmonella Typhimurium and Salmonella Newport LPS. The bacterial loads in the mouse tissues were significantly lower in the three vaccine-strain-immunized groups than in the mock group after either Salmonella Typhimurium or Salmonella

  7. Two Novel Salmonella Bivalent Vaccines Confer Dual Protection against Two Salmonella Serovars in Mice

    Directory of Open Access Journals (Sweden)

    Xinxin Zhao

    2017-09-01

    Full Text Available Non-typhoidal Salmonella includes thousands of serovars that are leading causes of foodborne diarrheal illness worldwide. In this study, we constructed three bivalent vaccines for preventing both Salmonella Typhimurium and Salmonella Newport infections by using the aspartate semialdehyde dehydrogenase (Asd-based balanced-lethal vector-host system. The constructed Asd+ plasmid pCZ11 carrying a subset of the Salmonella Newport O-antigen gene cluster including the wzx-wbaR-wbaL-wbaQ-wzy-wbaW-wbaZ genes was introduced into three Salmonella Typhimurium mutants: SLT19 (Δasd with a smooth LPS phenotype, SLT20 (Δasd ΔrfbN with a rough LPS phenotype, and SLT22 (Δasd ΔrfbN ΔpagL::T araC PBADrfbN with a smooth LPS phenotype when grown with arabinose. Immunoblotting demonstrated that SLT19 harboring pCZ11 [termed SLT19 (pCZ11] co-expressed the homologous and heterologous O-antigens; SLT20 (pCZ11 exclusively expressed the heterologous O-antigen; and when arabinose was available, SLT22 (pCZ11 expressed both types of O-antigens, while in the absence of arabinose, SLT22 (pCZ11 expressed only the heterologous O-antigen. Exclusive expression of the heterologous O-antigen in Salmonella Typhimurium decreased the swimming ability of the bacterium and its susceptibility to polymyxin B. Next, the crp gene was deleted from the three recombinant strains for attenuation purposes, generating the three bivalent vaccine strains SLT25 (pCZ11, SLT26 (pCZ11, and SLT27 (pCZ11, respectively. Groups of BALB/c mice (12 mice/group were orally immunized with 109 CFU of each vaccine strain twice at an interval of 4 weeks. Compared with a mock immunization, immunization with all three vaccine strains induced significant serum IgG responses against both Salmonella Typhimurium and Salmonella Newport LPS. The bacterial loads in the mouse tissues were significantly lower in the three vaccine-strain-immunized groups than in the mock group after either Salmonella Typhimurium or

  8. Salmonella enterica Serotype Napoli is the First Cause of Invasive Nontyphoidal Salmonellosis in Lombardy, Italy (2010-2014), and Belongs to Typhi Subclade.

    Science.gov (United States)

    Huedo, Pol; Gori, Maria; Zolin, Anna; Amato, Ettore; Ciceri, Giulia; Bossi, Anna; Pontello, Mirella

    2017-03-01

    Salmonella enterica serotype Napoli (S. Napoli) is currently emerging in Europe and particularly in Italy, where in 2014 it caused a large outbreak associated with elevated rates of bacteremia. However, no study has yet investigated its invasive ability and phylogenetic classification. Here, we show that between 2010 and 2014, S. Napoli was the first cause of invasive salmonellosis affecting 40 cases out of 687 (invasive index: 5.8%), which is significantly higher than the invasive index of all the other nontyphoidal serotypes (2.0%, p < 0.05). Genomic and phylogenetic analyses of an invasive isolate revealed that S. Napoli belongs to Typhi subclade in clade A, Paratyphi A being the most related serotype and carrying almost identical pattern of typhoid-associated genes. This work presents evidence of invasive capacity of S. Napoli and argues for reconsideration of its nontyphoidal category.

  9. B and T cell crosstalk in anti-bacterial immune responses

    NARCIS (Netherlands)

    de Wit, J.

    2012-01-01

    This thesis shows that phagocytosis of Salmonella by B cells may generate a survival niche and transport vehicle for Salmonella, but that simultaneously Salmonella-infected B cells induce an optimal anti-Salmonella response through activation of multiple arms of the adaptive immune response. The

  10. A DIVA vaccine for cross-protection against Salmonella.

    Science.gov (United States)

    Bearson, Bradley L; Bearson, Shawn M D; Kich, Jalusa D

    2016-03-04

    Swine are often asymptomatic carriers of Salmonella spp., a leading cause of human bacterial foodborne disease. Vaccination against Salmonella is effective for protecting animal health and enhancing food safety. However, with >2500 Salmonella serovars, current vaccines for swine offer limited cross-protection against heterologous serovars. Also, existing vaccines can interfere with surveillance programs that monitor the Salmonella status of swine herds. To overcome Salmonella vaccine limitations, we rationally designed and constructed an attenuated Salmonella enterica serovar Typhimurium vaccine (BBS 866) by deleting multiple small regulatory RNA (sRNA) genes (omrA, omrB, rybB, micA, and invR) in combination with an rfaH mutation. We vaccinated swine intranasally at 3-weeks of age with PBS (mock-vaccinated), BBS 866 or BBS 202 (S. Typhimurium rfaH, Bearson et al., Front Vet Sci 2014;1:9.) and challenged at 7-weeks of age with virulent S. Choleraesuis, a swine pathogen. Vaccination with BBS 866 enhanced protection against S. Choleraesuis by significantly limiting the duration of fever, weight loss, the levels of circulating INFγ, and the total number of swine with S. Choleraesuis septicemia. Vaccination with either BBS 866 or BBS 202 significantly reduced S. Choleraesuis colonization of both systemic (spleen and liver) and gastrointestinal (Peyer's Patch, Ileocecal lymph nodes, and cecum) tissues. Similar to our earlier report for BBS 202, the BBS 866 vaccine strain can be used in swine without compromising the differentiation of infected from vaccinated animals (DIVA). Therefore, the attenuated S. Typhimurium BBS 866 strain, containing mutations in rfaH and multiple sRNAs, addresses the limitations of current Salmonella vaccines by providing cross-protection against Salmonella serovars in swine without interfering with established monitoring programs for Salmonella surveillance. Published by Elsevier Ltd.

  11. Molecular characterization of "inconsistent" variants of Salmonella Typhimurium isolated in Italy

    DEFF Research Database (Denmark)

    Barco, Lisa; Longo, Alessandra; Lettini, Antonia Anna

    2014-01-01

    Salmonella 4,[5],12:i:- is a variant of Salmonella Typhimurium, which lacks the expression of phase-2 flagellar antigen, generally associated with the deletion of the fljB gene. Additional mechanisms involving the fljAB operon ( fljA, fljB, and hin genes) lead to the lack of expression of phase-2...

  12. Salmonella on feces, hides and carcasses in beef slaughter facilities in Venezuela.

    Science.gov (United States)

    Narváez-Bravo, Claudia; Rodas-González, Argenis; Fuenmayor, Yrimar; Flores-Rondon, Carolina; Carruyo, Gabriela; Moreno, Mireya; Perozo-Mena, Armindo; Hoet, Armando E

    2013-09-02

    This study determined Salmonella prevalence at different stages during the slaughtering in three beef slaughter plants (A, B and C) located in the western region of Venezuela (Zulia and Lara states). Each facility was visited three times at monthly intervals, from the months October through December of 2006. Samples were collected from hides (n=80), fecal grabs (n=80) and carcasses (n=80) at the phases of pre-evisceration, after-evisceration and pre-cooler at three sampling sites on the animals (rump, flank and brisket). Salmonella prevalence was higher on hides (36.3%) than on feces (13.8%) (P<0.05). Differences among slaughter plants for overall Salmonella prevalence were observed (P=0.001; A: 3.5%, B: 11.1%, C: 4.4%). From the isolated strains, Salmonella enterica subspecies enterica ser. Saintpaul, Salmonella ser. Javiana and Salmonella ser. Weltevreden were identified. Cattle feces and hides might be considered as important sources of Salmonella for carcass contamination at different slaughter stages. The presence of potentially pathogenic Salmonella serotypes at the slaughtering stages is an evidence of the circulation of this pathogen in the food environment; its presence could increase consumers' risks of infection if proper food handling and preparation techniques are not followed. These data should serve as a baseline for future comparisons in Salmonella prevalence on beef carcasses to be used by the government and industry in order to establish preventive measures and to better address the risks of Salmonella contamination. © 2013.

  13. The risk of salmonellae shedding by dogs fed Salmonella-contaminated commercial raw food diets

    OpenAIRE

    Finley, Rita; Ribble, Carl; Aramini, Jeff; Vandermeer, Meredith; Popa, Maria; Litman, Marcus; Reid-Smith, Richard

    2007-01-01

    Twenty-eight research dogs were enrolled to determine the prevalence of salmonellae shedding after consumption of 1 Salmonella-contaminated commercial raw food diet meal. Sixteen dogs were exposed to Salmonella-contaminated commercial raw food diets and 12 to Salmonella-free commercial raw food diets. Seven of the exposed dogs shed salmonellae 1–7 days after consumption of Salmonella-contaminated raw food diets. None of the dogs fed Salmonella-free diets shed salmonellae. No clinical signs we...

  14. Development of a multiplex polymerase chain reaction protocol for the simultaneous detection of Salmonella enterica serovar Typhi and Class 1 integron

    Directory of Open Access Journals (Sweden)

    Juthika Mandal

    2014-09-01

    Full Text Available Objective: To develop a multiplex polymerase chain reaction (PCR protocol for the simultaneous detection of Salmonella enterica serovar Typhi (S. Typhi and Class 1 integron, so as to aid rapid diagnosis of S. Typhi cases and help in the selection of treatment options based on the presence of the Class 1 integron that can carry resistance cassettes to a range of antibiotics. Methods: PCR for amplification of specific regions was done using fliC-d and intl primers and agarose gel electrophoresis was used for resolution of PCR products. Results: The fliC-d primer (S. Typhi specific amplified a 587 bp region and the intl primer (Class 1 integron specific amplified two bands approximately 500 and 550 bps. The developed method was specific for S. Typhi and did not amplify any products with Salmonella enterica serovar Typhimurium ATCC 14028, Salmonella enterica serovar Paratyphi and Escherichia coli O157:H7. Conclusions: The developed multiplex PCR protocol can be used for rapid diagnosis and aid in proper treatment strategies for patients infected with S. Typhi.

  15. 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.

  16. Salmonella Infections - Multiple Languages

    Science.gov (United States)

    ... to Know - 한국어 (Korean) PDF Centers for Disease Control and Prevention Spanish (español) Expand Section Salmonella Infections: MedlinePlus Health Topic - English Infecciones por salmonela: Tema de salud de MedlinePlus - español ( ...

  17. Antimicrobial susceptibility profile, treatment outcome and serotype distribution of clinical isolates of Salmonella enterica subspecies enterica: a 2-year study from Kerala, South India

    Directory of Open Access Journals (Sweden)

    Harichandran D

    2017-03-01

    Full Text Available Deepa Harichandran, Kavitha Radhakrishnan Dinesh Department of Microbiology, Amrita School of Medicine, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham University, Kochi, Kerala, India Background/purpose: Typhoid and paratyphoid fever continue to be important causes of illness and death in parts of Asia, being associated with poor sanitation and consumption of unsafe food and water. Antimicrobial resistance has emerged to traditional first-line drugs, namely, the fluoroquinolones, as well as to third-generation cephalosporins, posing challenges to treatment. Azithromycin has proven to be an effective alternative for treatment of uncomplicated typhoid fever. The purpose of this study was to determine the antimicrobial susceptibility, clinical outcome and serotype distribution pattern of clinical isolates belonging to Salmonella enterica subspecies enterica. Methodology: All clinical isolates of S. enterica obtained from blood, sterile body fluids, as well as stool and urine samples at Amrita Institute of Medical Sciences and Research Centre, Kerala, India, between August 2011 and July 2013 were included in the study and processed based on standard microbiology protocols. Results: A total of 118 isolates of Salmonella were obtained during the study period. Out of these, 79 were of S. Typhi (66.95%, followed by isolates of S. Paratyphi A (22; 18.64% and S. Typhimurium 12 (10.17%. Five isolates could not be identified further. There was 100% susceptibility to ceftriaxone in all S. enterica subspecies. Ciprofloxacin susceptibility was 32.91% for S. Typhi and 40.90% for S. Paratyphi A as determined by the disk diffusion method. The susceptibility profile of S. Typhi isolates to different antimicrobials was as follows: chloramphenicol (94.93%, ampicillin (77.21%, cotrimoxazole (75.94% and azithromycin (78.48%. For S. Typhi, the minimum inhibitory concentration (MIC of ciprofloxacin required to inhibit the growth

  18. An assessment of soybeans and other vegetable proteins as source of salmonella contamination in pig production

    Directory of Open Access Journals (Sweden)

    Häggblom Per

    2010-02-01

    Full Text Available Abstract Background The impact of salmonella contaminated feed ingredients on the risk for spreading salmonella to pigs was assessed in response to two incidences when salmonella was spread by feed from two feed mills to 78 swine producing herds. Methods The assessment was based on results from the salmonella surveillance of feed ingredients before introduction to feed mills and from HACCP - based surveillance of the feed mills. Results from the mills of the Company (A that produced the salmonella contaminated feed, were by the Chi. Square test compared to the results from all the other (B - E feed producers registered in Sweden. Isolated serovars were compared to serovars from human cases of salmonellosis. Results Salmonella (28 serovars was frequently isolated from imported consignments of soybean meal (14.6% and rape seed meal (10.0%. Company A largely imported soybean meal from crushing plants with a history of unknown or frequent salmonella contamination. The risk for consignments of vegetable proteins to be salmonella contaminated was 2.4 times (P Conclusions Salmonella contaminated feed ingredients are an important source for introducing salmonella into the feed and food chain. Effective HACCP-based control and associated corrective actions are required to prevent salmonella contamination of feed. Efforts should be taken to prevent salmonella contamination already at the crushing plants. This is challenge for the EU - feed industry due to the fact that 98% of the use of soybean/meal, an essential feed ingredient, is imported from crushing plants of third countries usually with an unknown salmonella status.

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

    Science.gov (United States)

    Patel, Jitendra; Sharma, Manan

    2010-04-30

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

  20. Validation of FoodChek™ - Salmonella for Rapid Detection of Salmonella in Eggs, Derivative Products, and the Environment.

    Science.gov (United States)

    Buzinhani, Melissa; Tremblay, Renaud; Martinez, Gabriela; Giuffre, Michael; Hammack, Thomas; Fernandez, Maria Cristina; Ziemer, Wayne

    2016-01-01

    The FoodChek™ - Salmonella assay is an immunomagnetic lateral flow assay for the rapid detection (shorter than 24 h) of the most frequently isolated Salmonella (groups B-E) in eggs, egg-derivative products, and environmental surfaces. The FoodChek - Salmonella assay correctly identified 99.6% (239/240) of the samples tested in the matrix studied, and the statistical analysis of the method comparison study results demonstrated that it performs as well as U.S. culture-based reference methods. Ninety-nine percent of the 103 Salmonella strains tested belonging to serogroups B-E were detected during the inclusivity study. Concerning the exclusivity, 31 nontarget strains were tested. No cross-reactivity was observed in FoodChek - Salmonella assay enrichment conditions. In addition, the assay shows strong robustness, good stability, and consistency among lots. The present study proves that the assay is an effective tool for the rapid detection of Salmonella spp. in whole liquid eggs, liquid egg white (liquid egg albumen), shell eggs, dried whole eggs, dried egg yolks, and environmental surfaces as stainless steel, plastic, rubber, ceramic tiles, and sealed concrete.

  1. 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 ...

  2. The structural model of Salmonella typhimurium ethanolamine ammonia-lyase directs a rational approach to the assembly of the functional [(EutB-EutC)₂]₃ oligomer from isolated subunits.

    Science.gov (United States)

    Bovell, Adonis Miguel; Warncke, Kurt

    2013-02-26

    Ethanolamine ammonia-lyase (EAL) is a 5'-deoxyadenosylcobalamin-dependent bacterial enzyme that catalyzes the deamination of the short-chain vicinal amino alcohols, aminoethanol and (S)- and (R)-2-aminopropanol. The coding sequence for EAL is located within the 17-gene eut operon, which encodes the broad spectrum of proteins that comprise the ethanolamine utilization (eut) metabolosome suborganelle structure. A high-resolution structure of the ∼500 kDa EAL [(EutB-EutC)₂]₃ oligomer from Escherichia coli has been determined by X-ray crystallography, but high-resolution spectroscopic determinations of reactant intermediate-state structures and detailed kinetic and thermodynamic studies of EAL have been conducted for the Salmonella typhimurium enzyme. Therefore, a statistically robust homology model for the S. typhimurium EAL is constructed from the E. coli structure. The model structure is used to describe the hierarchy of EutB and EutC subunit interactions that construct the native EAL oligomer and, specifically, to address the long-standing challenge of reconstitution of the functional oligomer from isolated, purified subunits. Model prediction that the (EutB₂)₃ oligomer assembly will occur from isolated EutB, and that this hexameric structure will template the formation of the complete, native [(EutB-EutC)₂]₃ oligomer, is verified by biochemical methods. Prediction that cysteine residues on the exposed subunit-subunit contact surfaces of isolated EutB and EutC will interfere with assembly by cystine formation is verified by activating effects of disulfide reducing agents. Angstrom-scale congruence of the reconstituted and native EAL in the active site region is shown by electron paramagnetic resonance spectroscopy. Overall, the hierarchy of subunit interactions and microscopic features of the contact surfaces, which are revealed by the homology model, guide and provide a rationale for a refined genetic and biochemical approach to reconstitution of the

  3. Multiple host kinases contribute to Akt activation during Salmonella infection.

    Directory of Open Access Journals (Sweden)

    Bernhard Roppenser

    Full Text Available SopB is a type 3 secreted effector with phosphatase activity that Salmonella employs to manipulate host cellular processes, allowing the bacteria to establish their intracellular niche. One important function of SopB is activation of the pro-survival kinase Akt/protein kinase B in the infected host cell. Here, we examine the mechanism of Akt activation by SopB during Salmonella infection. We show that SopB-mediated Akt activation is only partially sensitive to PI3-kinase inhibitors LY294002 and wortmannin in HeLa cells, suggesting that Class I PI3-kinases play only a minor role in this process. However, depletion of PI(3,4 P2/PI(3-5 P3 by expression of the phosphoinositide 3-phosphatase PTEN inhibits Akt activation during Salmonella invasion. Therefore, production of PI(3,4 P2/PI(3-5 P3 appears to be a necessary event for Akt activation by SopB and suggests that non-canonical kinases mediate production of these phosphoinositides during Salmonella infection. We report that Class II PI3-kinase beta isoform, IPMK and other kinases identified from a kinase screen all contribute to Akt activation during Salmonella infection. In addition, the kinases required for SopB-mediated activation of Akt vary depending on the type of infected host cell. Together, our data suggest that Salmonella has evolved to use a single effector, SopB, to manipulate a remarkably large repertoire of host kinases to activate Akt for the purpose of optimizing bacterial replication in its host.

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

    Science.gov (United States)

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

  5. DNA microarray for tracing Salmonella in the feed chain.

    Science.gov (United States)

    Koyuncu, Sevinc; Andersson, Gunnar; Vos, Pieter; Häggblom, Per

    2011-03-01

    In the present study we investigated if the microarray platforms Premi®Test Salmonella (PTS) and Salmonella array (SA) could be applied for the identification and typing of Salmonella in artificially contaminated animal feed materials. The results were compared to the culture-based MSRV method and serotyping according to Kauffman-White. The SA platform showed a specificity of 100% for the identification of Salmonella compared to 93% with the PTS platform and a sensitivity of 99% or 100%, respectively. Among all identified Salmonella serotypes, 56% with the SA platform and 81% with the PTS platform were correctly identified. The difference in probe signal intensity for each probe was higher between duplicates analyzed with the SA platform than with the PTS platform. Attempts to use the microarray platforms from BPW resulted in many false negative samples and incorrect typing results. The microarray platforms tested were simple to use and might have a potential in tracing studies for Salmonella in the feed chain particularly when rapid information about serotypes are important. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Salmonella contamination of cereal ingredients for animal feeds.

    Science.gov (United States)

    Davies, R H; Wales, A D

    2013-10-25

    Cereal ingredients for animal feedstuffs may become contaminated by Salmonella on their farms of origin. This is often concentrated in multiple foci, owing to contamination by rodents and other wildlife which may be missed by routine sampling, and may involve serovars of particular public health significance, such as Salmonella Typhimurium (STM). The study examined such contamination in domestically-produced cereal ingredients in the United Kingdom. Cereal-producing farms with associated cattle or pig enterprises (43) and feedmills (6) were investigated, following the isolation of STM from their premises (feedmills) or STM DT104 from their livestock (farms) by routine surveillance. Cereal samples from feedmills yielded two STM isolates from the same premises, of the same phage types as were isolated from wild bird faeces at ingredient intake and product loading areas. Farm investigations identified numerous Salmonella serovars, including STM, on grain harvesting and handling equipment, in grain storage areas, and in wildlife samples. Mice were removed from one pig farm and shed Salmonella Derby and Salmonella Bovismorbificans for 10 months afterwards. Grain stores more than one kilometre away from livestock areas were rarely found to be contaminated with STM. The principal issues with Salmonella contamination of cereals appeared to be the use of livestock areas as temporary grain stores on cattle farms, and access to stored grain by wildlife and domestic animals. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  7. Deciphering interplay between Salmonella invasion effectors.

    Directory of Open Access Journals (Sweden)

    Robert J Cain

    2008-04-01

    Full Text Available Bacterial pathogens have evolved a specialized type III secretion system (T3SS to translocate virulence effector proteins directly into eukaryotic target cells. Salmonellae deploy effectors that trigger localized actin reorganization to force their own entry into non-phagocytic host cells. Six effectors (SipC, SipA, SopE/2, SopB, SptP can individually manipulate actin dynamics at the plasma membrane, which acts as a 'signaling hub' during Salmonella invasion. The extent of crosstalk between these spatially coincident effectors remains unknown. Here we describe trans and cisbinary entry effector interplay (BENEFIT screens that systematically examine functional associations between effectors following their delivery into the host cell. The results reveal extensive ordered synergistic and antagonistic relationships and their relative potency, and illuminate an unexpectedly sophisticated signaling network evolved through longstanding pathogen-host interaction.

  8. Waardevermindering pluimveevlees besmet met Salmonella enteritidis en Salmonella typhymurium

    NARCIS (Netherlands)

    Horne, van P.L.M.

    2011-01-01

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

  9. [Current epidemiological status of salmonellosis of humans in Germany].

    Science.gov (United States)

    Kühn, H; Rabsch, W; Liesegang, A

    1994-02-01

    Infections caused by Salmonella typhi and Salmonella paratyphi B have special epidemiological significance. However, the enteritis caused by Salmonella enteritidis and Salmonella typhimurium dominates. A complex typing of these serovars is the prerequisite for both, an effective surveillance of salmonellosis and the detection of occurring replacements and variations of the pathogens. The increasing occurrence of Salmonella in spices since 1993 is epidemiologically remarkable. In this connection, serotypes such as Salmonella javiana, S. rubislaw, and monophasic, KCN-positive serovars dominate. The transmission route man-man is of no special epidemiological importance at present in Germany.

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

    Science.gov (United States)

    Halimi, Hessam A.; Seifi, Hesam A.; Rad, Mehrnaz

    2014-01-01

    Objective To evaluate serovar and antimicrobial resistance patterns of Salmonella spp isolated from healthy, diseased and necropsied cows and calves in this observational study. Methods Nineteen isolates recovered from feces and tissues of salmonellosis-affected animals of two commercial farms in north-east of Iran. In second part of the study, the two farms were sampled 4 times with an interval of 2 month. The samples included calves' feces, adult cows' feces, feeds, water, milk filters, and milk fed to calves. Five Salmonella were isolated from 332 fecal samples collected from calves and peri-parturient cows. No Salmonella was recovered from water, feed, milk filers and milk fed to calves. Results Salmonella Typhimurium was the most frequently isolate among all sero-groups. S. Dublin was only accounted for 8% (two out of 24) of isolates. Isolated Salmonella strains were used for the ERIC PCR DNA fingerprinting assay. Our results grouped Salmonella isolates into 3 clusters, suggesting that specific genotypes were responsible for each sero-group of Salmonella. The results also revealed diversity among Salmonella isolates in cluster III (sero-group B). Eighteen out of 19 Salmonella spp. were resistant to oxytetracycline. Five isolates out of 19 showed more than one drug resistance. Multi-drug resistance was seen only among Salmonella Typhimurium isolates. Enrofloxacin was the most susceptible antibiotic against all isolates in this study. Conclusion The emergence of multiple antibiotic-resistant strains of Salmonella Typhimurium should be of great concern to the public. No correlation between ERIC fingerprinting and resistance patterns of Salmonella isolates was found, which indicates resistance to antimicrobial agents was not related to specific genetic background. PMID:24144122

  11. Inhibition of the metabolism of streptococci and salmonella by specific antisera.

    Science.gov (United States)

    Larson, S M; Charache, P; Chen, M; Wagner, H N

    1974-02-01

    Streptococcal and salmonella antisera inhibited carbohydrate metabolism for groups A, B, C, and D streptococci and group E salmonella, as measured by the formation of [(14)C]dioxide from [(14)C]glucose metabolism. For salmonella, the inhibition was type specific since group E salmonella were inhibited only by salmonella E antisera and not by anti-salmonella A or C(1). For streptococci, quantitative differences were demonstrated, but major cross-reactivity was observed. At high concentrations, the antisera were bactericidal; at more dilute concentrations, for both salmonella and streptococci, carbohydrate metabolism was suppressed, but subculture on chocolate agar showed abundant growth. Cross-reacting antibodies could be absorbed by incubation with either antigen, e.g., streptococcal antisera versus heat-killed salmonella. The results suggest that the radiometric technique can be more sensitive than either capillary flocculation or visual detection of bacterial growth for detecting the inhibition of streptococci and salmonella by specific antibodies. The use of specific antisera may prove useful for bacterial species identification in an automated system for detection of bacterial growth.

  12. A microfluidic nano-biosensor for the detection of pathogenic Salmonella.

    Science.gov (United States)

    Kim, Giyoung; Moon, Ji-Hea; Moh, Chang-Yeon; Lim, Jong-guk

    2015-05-15

    Rapid detection of pathogenic Salmonella in food products is extremely important for protecting the public from salmonellosis. The objective of the present study was to explore the feasibility of using a microfluidic nano-biosensor to rapidly detect pathogenic Salmonella. Quantum dot nanoparticles were used to detect Salmonella cells. For selective detection of Salmonella, anti-Salmonella polyclonal antibodies were covalently immobilized onto the quantum dot surface. To separate and concentrate the cells from the sample, superparamagnetic particles and a microfluidic chip were used. A portable fluorometer was developed to measure the fluorescence signal from the quantum dot nanoparticles attached to Salmonella in the samples. The sensitivity for detection of pathogenic Salmonella was evaluated using serially diluted Salmonella Typhimurium in borate buffer and chicken extract. The fluorescence response of the nano-biosensor increased with increasing cell concentration. The detection limit of the sensor was 10(3) CFU/mL Salmonella in both borate buffer and food extract. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. 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...

  14. Salmonella onderzoek bij Nederlands pluimvee

    NARCIS (Netherlands)

    van de Giessen AW; Berkers PATA; Peters R; Notermans SHW

    1989-01-01

    Gedurende de eerste helft van 1989 werden 59 pluimveebedrijven uit de leg- en mestsector onderzocht op de aanwezigheid van Salmonella-kiemen. Op 53 bedrijven (90%) kon Salmonella bij pluimvee worden aangetoond. Op 10 bedrijven (17%) bleek S. enteritidis bij pluimvee aanwezig te zijn. Van de 19

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

    Science.gov (United States)

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

    2014-10-17

    Salmonella enterica subsp. enterica serovar 4,[5],12,i:- is a monophasic variant of Salmonella Typhimurium and its occurrence has markedly increased in several European countries in the last ten years. In June 2011, an outbreak of Salmonella 4,[5],12,i:- was reported among attendees of a wedding reception in the North-East of Italy. The source of this outbreak was identified as a cooked pork product served during the wedding reception. All Salmonella isolates from humans and the contaminated pork products were identified as Salmonella 4,[5],12,i:- and phage typed as DT7a. Afterwards, the farm where the pigs were raised was identified and sampled, and Salmonella Typhimurium was isolated from swine fecal samples. Despite the difference in serovar, these Salmonella Typhimurium isolates were also phage typed as DT7a. In the present study, Salmonella isolates from animals, humans and pork products during the outbreak investigation were subtyped by pulsed-field gel electrophoresis (PFGE), Multiple-Locus Variable number tandem repeats Analysis (MLVA), and resistance patterns, aiming to identify the most suitable subtyping methods to characterize isolates associated with this outbreak. In addition, a collection of epidemiologically unrelated strains of Salmonella 4,[5],12,i:- and Salmonella Typhimurium sharing the same phage type (DT7a) was similarly characterized in order to investigate their genetic relationship. This study provides a first snapshot of a rare Salmonella phage type, DT7a, associated with both Salmonella 4,[5],12,i:- and Salmonella Typhimurium. Moreover, the study demonstrated that in this specific context MLVA could be a reliable tool to support outbreak investigations as well as to assess the genetic relatedness among Salmonella isolates. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. 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.

  17. 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

  18. 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

  19. Desarrollo y validación de una reacción en cadena de la polimerasa múltiple para la identificación de los serogrupos B, C2, D y E de Salmonella enterica

    Directory of Open Access Journals (Sweden)

    Nora Cardona-Castro

    2009-06-01

    Conclusiones. El polimorfismo de los genes rfbJ y wzx permitió desarrollar un método de tipificación molecular sensible, específico y reproducible, que podría servir de apoyo a la serotipificación para identificar serogrupos de Salmonella.

  20. Osteomielitis por salmonella

    OpenAIRE

    Alicia Velázquez Pérez; Teresa P. Rodríguez Torres; Orelvis Pérez Duerto

    2014-01-01

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

  1. 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

  2. WGS for surveillance of antimicrobial resistance: a pilot study to detect the prevalence and mechanism of resistance to azithromycin in a UK population of non-typhoidal Salmonella.

    Science.gov (United States)

    Nair, Satheesh; Ashton, Philip; Doumith, Michel; Connell, Steve; Painset, Anais; Mwaigwisya, Solomon; Langridge, Gemma; de Pinna, Elizabeth; Godbole, Gauri; Day, Martin

    2016-12-01

    WGS and phenotypic methods were used to determine the prevalence of azithromycin resistance in Salmonella enterica isolates from the UK and to identify the underlying mechanisms of resistance. WGS by Illumina HiSeq was carried out on 683 Salmonella spp. isolates. Known genes associated with azithromycin resistance were detected by WGS using a mapping-based approach. Macrolide resistance determinants were identified and the genomic context of these elements was assessed by various bioinformatics tools. Susceptibility testing was in accordance with EUCAST methodology (MIC ≤16 mg/L). Fifteen isolates of non-typhoidal Salmonella enterica belonging to serovars Salmonella Blockley, Salmonella Typhimurium, Salmonella Thompson, Salmonella Ridge and Salmonella Kentucky showed resistance or decreased susceptibility to azithromycin (from 6 to >16 mg/L) due to the presence of macrolide resistance genes mphA, mphB or mefB. These genes were either plasmid or chromosomally mediated. Azithromycin-resistant Salmonella Blockley isolates harboured a macrolide inactivation gene cluster, mphA-mrx-mphr(A), within a novel Salmonella azithromycin resistance genomic island (SARGI) determined by MinION sequencing. This is the first known chromosomally mediated mphA gene cluster described in salmonellae. Phylogenetic analysis and epidemiological information showed that mphA Salmonella Blockley isolates were not derived from a single epidemiologically related event. The azithromycin MICs of the 15 Salmonella spp. isolates showed that the presence of the mphA gene was associated with MIC ≥16 mg/L, while the presence of mefB or mphB was not. Azithromycin resistance due to acquisition of known macrolide resistance genes was seen in four different Salmonella serovars and can be either plasmid-encoded or chromosomally encoded. © Crown copyright 2016.

  3. Development of protective immunity to Salmonella, a mucosal pathogen with a systemic agenda

    Science.gov (United States)

    Griffin, Amanda J.; McSorley, Stephen J.

    2014-01-01

    Salmonella infections can cause a range of intestinal and systemic disease in human and animal hosts. While some Salmonella serovars initiate a localized intestinal inflammatory response, others use the intestine as a portal of entry to initiate a systemic infection. Considerable progress has been made in understanding bacterial invasion and dissemination strategies and the nature of the Salmonella-specific immune response to oral infection. Innate and adaptive immunity are rapidly initiated after oral infection but these effector responses can also be hindered by bacterial evasion strategies. Furthermore, although Salmonella resides within intramacrophage phagosomes, recent studies highlight a surprising collaboration of CD4 Th1, Th17, and B cell responses in mediating resistance to Salmonella infection. PMID:21307847

  4. Oral vaccination with attenuated Salmonella choleraesuis C500 ...

    African Journals Online (AJOL)

    user

    Oral vaccination with attenuated Salmonella choleraesuis C500 expressing recombinant UreB and. CagA antigens protects mice against Helicobacter pylori. J. G. Chen1, A. X. .... incubated for 1 h at 37°C. Serum IgG were detected by peroxidase- .... Molecular characterization of the 128-kDa immunodominant antigen.

  5. An assessment of soybeans and other vegetable proteins as source of salmonella contamination in pig production

    Science.gov (United States)

    2010-01-01

    Background The impact of salmonella contaminated feed ingredients on the risk for spreading salmonella to pigs was assessed in response to two incidences when salmonella was spread by feed from two feed mills to 78 swine producing herds. Methods The assessment was based on results from the salmonella surveillance of feed ingredients before introduction to feed mills and from HACCP - based surveillance of the feed mills. Results from the mills of the Company (A) that produced the salmonella contaminated feed, were by the Chi. Square test compared to the results from all the other (B - E) feed producers registered in Sweden. Isolated serovars were compared to serovars from human cases of salmonellosis. Results Salmonella (28 serovars) was frequently isolated from imported consignments of soybean meal (14.6%) and rape seed meal (10.0%). Company A largely imported soybean meal from crushing plants with a history of unknown or frequent salmonella contamination. The risk for consignments of vegetable proteins to be salmonella contaminated was 2.4 times (P salmonella contamination. Also the level of feed mill contamination of salmonella was higher for feed mills belonging to Company A in comparison to the other companies before and also after heat treatment. Four (10.5%) of the 38 serovars isolated from feed ingredients (28) and feed mills (10) were on the EU 2007 top ten list of human cases of salmonellosis and all but eight (78.9%) on a 12 year list (1997-2008) of cases of human salmonellosis in Sweden. Conclusions Salmonella contaminated feed ingredients are an important source for introducing salmonella into the feed and food chain. Effective HACCP-based control and associated corrective actions are required to prevent salmonella contamination of feed. Efforts should be taken to prevent salmonella contamination already at the crushing plants. This is challenge for the EU - feed industry due to the fact that 98% of the use of soybean/meal, an essential feed ingredient

  6. An assessment of soybeans and other vegetable proteins as source of Salmonella contamination in pig production.

    Science.gov (United States)

    Wierup, Martin; Häggblom, Per

    2010-02-17

    The impact of salmonella contaminated feed ingredients on the risk for spreading salmonella to pigs was assessed in response to two incidences when salmonella was spread by feed from two feed mills to 78 swine producing herds. The assessment was based on results from the salmonella surveillance of feed ingredients before introduction to feed mills and from HACCP--based surveillance of the feed mills. Results from the mills of the Company (A) that produced the salmonella contaminated feed, were by the Chi. Square test compared to the results from all the other (B - E) feed producers registered in Sweden. Isolated serovars were compared to serovars from human cases of salmonellosis. Salmonella (28 serovars) was frequently isolated from imported consignments of soybean meal (14.6%) and rape seed meal (10.0%). Company A largely imported soybean meal from crushing plants with a history of unknown or frequent salmonella contamination. The risk for consignments of vegetable proteins to be salmonella contaminated was 2.4 times (P salmonella contamination. Also the level of feed mill contamination of salmonella was higher for feed mills belonging to Company A in comparison to the other companies before and also after heat treatment. Four (10.5%) of the 38 serovars isolated from feed ingredients (28) and feed mills (10) were on the EU 2007 top ten list of human cases of salmonellosis and all but eight (78.9%) on a 12 year list (1997-2008) of cases of human salmonellosis in Sweden. Salmonella contaminated feed ingredients are an important source for introducing salmonella into the feed and food chain. Effective HACCP-based control and associated corrective actions are required to prevent salmonella contamination of feed. Efforts should be taken to prevent salmonella contamination already at the crushing plants. This is challenge for the EU - feed industry due to the fact that 98% of the use of soybean/meal, an essential feed ingredient, is imported from crushing plants of

  7. Salmonella serotypes in reptiles and humans, French Guiana.

    Science.gov (United States)

    Gay, Noellie; Le Hello, Simon; Weill, François-Xavier; de Thoisy, Benoit; Berger, Franck

    2014-05-14

    In French Guiana, a French overseas territory located in the South American northern coast, nearly 50% of Salmonella serotypes isolated from human infections belong to serotypes rarely encountered in metropolitan France. A reptilian source of contamination has been investigated. Between April and June 2011, in the area around Cayenne, 151 reptiles were collected: 38 lizards, 37 snakes, 32 turtles, 23 green iguanas and 21 caimans. Cloacal swab samples were collected and cultured. Isolated Salmonella strains were identified biochemically and serotyped. The overall carriage frequency of carriage was 23.2% (95% confidence interval: 16.7-30.4) with 23 serotyped strains. The frequency of Salmonella carriage was significantly higher for wild reptiles. Near two-thirds of the Salmonella serotypes isolated from reptiles were also isolated from patients in French Guiana. Our results highlight the risk associated with the handling and consumption of reptiles and their role in the spread of Salmonella in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Fate of Salmonella during sesame seeds roasting and storage of tahini.

    Science.gov (United States)

    Torlak, Emrah; Sert, Durmuş; Serin, Pınar

    2013-05-15

    Tahini is usually consumed without further heat treatment, and roasting of sesame seeds is the only Salmonella inactivation step in its traditional production process. This study examined the efficiency of the roasting process in the elimination of Salmonella from sesame seeds and the survival of Salmonella in tahini during storage. Sesame seed and tahini samples were inoculated with a cocktail of three serotypes of Salmonella (S. Typhimurium, S. Newport and S. Montevideo). Complete inactivation of Salmonella in sesame seeds, inoculated with 5.9 log cfu/g, was achieved by roasting at 110 °C for 60 min, 130 °C for 50 min, or 150 °C for 30 min. Salmonella levels in tahini (aw=0.17) inoculated with 5.6 log cfu/g and stored for 16 weeks at 22 or 4 °C decreased by 4.5 and 3.3 log, respectively. Results of this study demonstrated that the standard roasting process is sufficient to inactivate Salmonella in sesame seeds and low water activity of tahini prevents microbial growth, but its composition allows Salmonella to survive for at least 16 weeks. Therefore, prevention of cross-contamination after roasting is crucial for food safety. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. 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....

  10. Salmonella in Sheep in Iceland

    Directory of Open Access Journals (Sweden)

    Gunnarsson E

    2002-03-01

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

  11. Using molecular techniques for rapid detection of Salmonella ...

    African Journals Online (AJOL)

    For this experiment, the whole chicken eggs were negative for Salmonella species by SMT. Salmonella enteritidis was dominating among the recovered Salmonella serovars, followed by. Salmonella typhimurium, while only two strains of Salmonella agona and Salmonella newport were isolated. The PCR assay combined ...

  12. Osteomielitis por salmonella

    Directory of Open Access Journals (Sweden)

    Alicia Velázquez Pérez

    2014-08-01

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

  13. Flagella overexpression attenuates Salmonella pathogenesis.

    Directory of Open Access Journals (Sweden)

    Xinghong Yang

    Full Text Available Flagella are cell surface appendages involved in a number of bacterial behaviors, such as motility, biofilm formation, and chemotaxis. Despite these important functions, flagella can pose a liability to a bacterium when serving as potent immunogens resulting in the stimulation of the innate and adaptive immune systems. Previous work showing appendage overexpression, referred to as attenuating gene expression (AGE, was found to enfeeble wild-type Salmonella. Thus, this approach was adapted to discern whether flagella overexpression could induce similar attenuation. To test its feasibility, flagellar filament subunit FliC and flagellar regulon master regulator FlhDC were overexpressed in Salmonella enterica serovar Typhimurium wild-type strain H71. The results show that the expression of either FliC or FlhDC alone, and co-expression of the two, significantly attenuates Salmonella. The flagellated bacilli were unable to replicate within macrophages and thus were not lethal to mice. In-depth investigation suggests that flagellum-mediated AGE was due to the disruptive effects of flagella on the bacterial membrane, resulting in heightened susceptibilities to hydrogen peroxide and bile. Furthermore, flagellum-attenuated Salmonella elicited elevated immune responses to Salmonella presumably via FliC's adjuvant effect and conferred robust protection against wild-type Salmonella challenge.

  14. Flagella Overexpression Attenuates Salmonella Pathogenesis

    Science.gov (United States)

    Yang, Xinghong; Thornburg, Theresa; Suo, Zhiyong; Jun, SangMu; Robison, Amanda; Li, Jinquan; Lim, Timothy; Cao, Ling; Hoyt, Teri; Avci, Recep; Pascual, David W.

    2012-01-01

    Flagella are cell surface appendages involved in a number of bacterial behaviors, such as motility, biofilm formation, and chemotaxis. Despite these important functions, flagella can pose a liability to a bacterium when serving as potent immunogens resulting in the stimulation of the innate and adaptive immune systems. Previous work showing appendage overexpression, referred to as attenuating gene expression (AGE), was found to enfeeble wild-type Salmonella. Thus, this approach was adapted to discern whether flagella overexpression could induce similar attenuation. To test its feasibility, flagellar filament subunit FliC and flagellar regulon master regulator FlhDC were overexpressed in Salmonella enterica serovar Typhimurium wild-type strain H71. The results show that the expression of either FliC or FlhDC alone, and co-expression of the two, significantly attenuates Salmonella. The flagellated bacilli were unable to replicate within macrophages and thus were not lethal to mice. In-depth investigation suggests that flagellum-mediated AGE was due to the disruptive effects of flagella on the bacterial membrane, resulting in heightened susceptibilities to hydrogen peroxide and bile. Furthermore, flagellum-attenuated Salmonella elicited elevated immune responses to Salmonella presumably via FliC’s adjuvant effect and conferred robust protection against wild-type Salmonella challenge. PMID:23056473

  15. Iron- and Hepcidin-Independent Downregulation of the Iron Exporter Ferroportin in Macrophages during Salmonella Infection

    Directory of Open Access Journals (Sweden)

    François Canonne-Hergaux

    2017-05-01

    Full Text Available Retention of iron in tissue macrophages via upregulation of hepcidin (HAMP and downregulation of the iron exporter ferroportin (FPN is thought to participate in the establishment of anemia of inflammation after infection. However, an upregulation of FPN has been proposed to limit macrophages iron access to intracellular pathogens. Therefore, we studied the iron homeostasis and in particular the regulation of FPN after infection with Salmonella enterica serovar Typhimurium in mice presenting tissue macrophages with high iron (AcB61, basal iron (A/J and wild-type mice, or low iron (Hamp knock out, Hamp−/− levels. The presence of iron in AcB61 macrophages due to extravascular hemolysis and strong erythrophagocytosis activity favored the proliferation of Salmonella in the spleen and liver with a concomitant decrease of FPN protein expression. Despite systemic iron overload, no or slight increase in Salmonella burden was observed in Hamp−/− mice compared to controls. Importantly, FPN expression at both mRNA and protein levels was strongly decreased during Salmonella infection in Hamp−/− mice. The repression of Fpn mRNA was also observed in Salmonella-infected cultured macrophages. In addition, the downregulation of FPN was associated with decreased iron stores in both the liver and spleen in infected mice. Our findings show that during Salmonella infection, FPN is repressed through an iron and hepcidin-independent mechanism. Such regulation likely provides the cellular iron indispensable for the growth of Salmonella inside the macrophages.

  16. Gene co-expression network analysis identifies porcine genes associated with variation in Salmonella shedding.

    Science.gov (United States)

    Kommadath, Arun; Bao, Hua; Arantes, Adriano S; Plastow, Graham S; Tuggle, Christopher K; Bearson, Shawn M D; Guan, Le Luo; Stothard, Paul

    2014-06-09

    Salmonella enterica serovar Typhimurium is a gram-negative bacterium that can colonise the gut of humans and several species of food producing farm animals to cause enteric or septicaemic salmonellosis. While many studies have looked into the host genetic response to Salmonella infection, relatively few have used correlation of shedding traits with gene expression patterns to identify genes whose variable expression among different individuals may be associated with differences in Salmonella clearance and resistance. Here, we aimed to identify porcine genes and gene co-expression networks that differentiate distinct responses to Salmonella challenge with respect to faecal Salmonella shedding. Peripheral blood transcriptome profiles from 16 pigs belonging to extremes of the trait of faecal Salmonella shedding counts recorded up to 20 days post-inoculation (low shedders (LS), n = 8; persistent shedders (PS), n = 8) were generated using RNA-sequencing from samples collected just before (day 0) and two days after (day 2) Salmonella inoculation. Weighted gene co-expression network analysis (WGCNA) of day 0 samples identified four modules of co-expressed genes significantly correlated with Salmonella shedding counts upon future challenge. Two of those modules consisted largely of innate immunity related genes, many of which were significantly up-regulated at day 2 post-inoculation. The connectivity at both days and the mean gene-wise expression levels at day 0 of the genes within these modules were higher in networks constructed using LS samples alone than those using PS alone. Genes within these modules include those previously reported to be involved in Salmonella resistance such as SLC11A1 (formerly NRAMP1), TLR4, CD14 and CCR1 and those for which an association with Salmonella is novel, for example, SIGLEC5, IGSF6 and TNFSF13B. Our analysis integrates gene co-expression network analysis, gene-trait correlations and differential expression to provide new

  17. 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.

  18. 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.

  19. Wild fauna as a carrier of Salmonella in Reunion Island: Impact on pig farms.

    Science.gov (United States)

    Tessier, Claire; Parama Atiana, Laura; Lagadec, Erwan; Le Minter, Gildas; Denis, Martine; Cardinale, Eric

    2016-06-01

    Salmonellosis is an economic burden to the livestock industry in Reunion Island. In this study, we wanted to improve our understanding of Salmonella epidemiology by studying the wild fauna of Reunion Island. We assessed Salmonella diversity in small non-flying mammals, birds and cockroaches in order to evaluate their potential role in the epidemiology of Salmonella. A total of 268 samples were collected from cockroaches, small mammals and birds. The bacteriological analyses revealed that 11.7% of non-flying mammals and 25% of cockroaches tested were Salmonella infected; two wild bird species were also detected positive. The 128 Salmonella isolates were distributed in fifteen serotypes and the most predominant were S. 4,[5],12:i:- (21.9% of positive samples) followed by S. Enteritidis (15.6%), S. Typhimurium (15.6%), S. Infantis (12.5%) and S. Weltevreden (12.5%). A total of 27 XbaI profiles were identified using pulsed-field gel electrophoresis. Comparison of these Salmonella strains with our collection of Salmonella isolated from pigs and pig farm environments at the same period revealed 14 strains in common between wild fauna and pigs, especially for cockroaches. Our results suggest that wild fauna of Reunion Island could be infected by strains of Salmonella also isolated from pigs or pig environment. They may play a role in both persistence and spreading of Salmonella and therefore, could be a source of infection in pig farms. Pest control against cockroaches could be a helpful tool in the reduction of Salmonella infection of pigs, limiting contacts between wild fauna and both pigs and pig environment. Special attention should be paid to S. 4,[5],12:i:- since it was predominant in Reunion Island's wild fauna and pigs and was the third most frequently reported serotype in human salmonellosis in Europe. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. The risk of salmonellae shedding by dogs fed Salmonella-contaminated commercial raw food diets.

    Science.gov (United States)

    Finley, Rita; Ribble, Carl; Aramini, Jeff; Vandermeer, Meredith; Popa, Maria; Litman, Marcus; Reid-Smith, Richard

    2007-01-01

    Twenty-eight research dogs were enrolled to determine the prevalence of salmonellae shedding after consumption of 1 Salmonella-contaminated commercial raw food diet meal. Sixteen dogs were exposed to Salmonella-contaminated commercial raw food diets and 12 to Salmonella-free commercial raw food diets. Seven of the exposed dogs shed salmonellae 1-7 days after consumption of Salmonella-contaminated raw food diets. None of the dogs fed Salmonella-free diets shed salmonellae. No clinical signs were observed in either group. Five of the 7 dogs shed the same serotypes as those recovered from food samples used for feeding. Results showed the same serotypes and antimicrobial resistance pattern in 2 of the 7 shedders. Dogs fed Salmonella-contaminated raw food diets can shed salmonellae and may, therefore, be a source of environmental contamination potentially leading to human or animal illness.

  1. BACTERICIDAL ACTIVITY OF HUMAN SERA AGAINST ...

    African Journals Online (AJOL)

    hi-tech

    2000-12-12

    Dec 12, 2000 ... Individuals of blood group O are likely to be more susceptible to infections caused by Salmonella typhi and paratyphi A,B,C. INTRODUCTION. Human serum is considered an important host defence mechanism against invasive diseases caused by Gram- negative bacteria(1-3). The bactericidal and ...

  2. Efficacy and immunogenicity of a Vi-tetanus toxoid conjugate vaccine in the prevention of typhoid fever using a controlled human infection model of Salmonella Typhi: a randomised controlled, phase 2b trial.

    Science.gov (United States)

    Jin, Celina; Gibani, Malick M; Moore, Maria; Juel, Helene B; Jones, Elizabeth; Meiring, James; Harris, Victoria; Gardner, Jonathan; Nebykova, Anna; Kerridge, Simon A; Hill, Jennifer; Thomaides-Brears, Helena; Blohmke, Christoph J; Yu, Ly-Mee; Angus, Brian; Pollard, Andrew J

    2017-12-02

    Salmonella enterica serovar Typhi (S Typhi) is responsible for an estimated 20 million infections and 200 000 deaths each year in resource poor regions of the world. Capsular Vi-polysaccharide-protein conjugate vaccines (Vi-conjugate vaccines) are immunogenic and can be used from infancy but there are no efficacy data for the leading candidate vaccine being considered for widespread use. To address this knowledge gap, we assessed the efficacy of a Vi-tetanus toxoid conjugate vaccine using an established human infection model of S Typhi. In this single-centre, randomised controlled, phase 2b study, using an established outpatient-based human typhoid infection model, we recruited healthy adult volunteers aged between 18 and 60 years, with no previous history of typhoid vaccination, infection, or prolonged residency in a typhoid-endemic region. Participants were randomly assigned (1:1:1) to receive a single dose of Vi-conjugate (Vi-TT), Vi-polysaccharide (Vi-PS), or control meningococcal vaccine with a computer-generated randomisation schedule (block size 6). Investigators and participants were masked to treatment allocation, and an unmasked team of nurses administered the vaccines. Following oral ingestion of S Typhi, participants were assessed with daily blood culture over a 2-week period and diagnosed with typhoid infection when meeting pre-defined criteria. The primary endpoint was the proportion of participants diagnosed with typhoid infection (ie, attack rate), defined as persistent fever of 38°C or higher for 12 h or longer or S Typhi bacteraemia, following oral challenge administered 1 month after Vi-vaccination (Vi-TT or Vi-PS) compared with control vaccination. Analysis was per protocol. This trial is registered with ClinicalTrials.gov, number NCT02324751, and is ongoing. Between Aug 18, 2015, and Nov 4, 2016, 112 participants were enrolled and randomly assigned; 34 to the control group, 37 to the Vi-PS group, and 41 to the Vi-TT group. 103 participants

  3. 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 ...

  4. Meta-analysis of pulsed-field gel electrophoresis fingerprints based on a constructed Salmonella database.

    Directory of Open Access Journals (Sweden)

    Wen Zou

    Full Text Available A database was constructed consisting of 45,923 Salmonella pulsed-field gel electrophoresis (PFGE patterns. The patterns, randomly selected from all submissions to CDC PulseNet during 2005 to 2010, included the 20 most frequent serotypes and 12 less frequent serotypes. Meta-analysis was applied to all of the PFGE patterns in the database. In the range of 20 to 1100 kb, serotype Enteritidis averaged the fewest bands at 12 bands and Paratyphi A the most with 19, with most serotypes in the 13-15 range among the 32 serptypes. The 10 most frequent bands for each of the 32 serotypes were sorted and distinguished, and the results were in concordance with those from distance matrix and two-way hierarchical cluster analyses of the patterns in the database. The hierarchical cluster analysis divided the 32 serotypes into three major groups according to dissimilarity measures, and revealed for the first time the similarities among the PFGE patterns of serotype Saintpaul to serotypes Typhimurium, Typhimurium var. 5-, and I 4,[5],12:i:-; of serotype Hadar to serotype Infantis; and of serotype Muenchen to serotype Newport. The results of the meta-analysis indicated that the pattern similarities/dissimilarities determined the serotype discrimination of PFGE method, and that the possible PFGE markers may have utility for serotype identification. The presence of distinct, serotype specific patterns may provide useful information to aid in the distribution of serotypes in the population and potentially reduce the need for laborious analyses, such as traditional serotyping.

  5. Salmonella exploits the host endolysosomal tethering factor HOPS complex to promote its intravacuolar replication

    Science.gov (United States)

    Sindhwani, Aastha; Kaur, Harmeet; Tuli, Amit

    2017-01-01

    Salmonella enterica serovar typhimurium extensively remodels the host late endocytic compartments to establish its vacuolar niche within the host cells conducive for its replication, also known as the Salmonella-containing vacuole (SCV). By maintaining a prolonged interaction with late endosomes and lysosomes of the host cells in the form of interconnected network of tubules (Salmonella-induced filaments or SIFs), Salmonella gains access to both membrane and fluid-phase cargo from these compartments. This is essential for maintaining SCV membrane integrity and for bacterial intravacuolar nutrition. Here, we have identified the multisubunit lysosomal tethering factor—HOPS (HOmotypic fusion and Protein Sorting) complex as a crucial host factor facilitating delivery of late endosomal and lysosomal content to SCVs, providing membrane for SIF formation, and nutrients for intravacuolar bacterial replication. Accordingly, depletion of HOPS subunits significantly reduced the bacterial load in non-phagocytic and phagocytic cells as well as in a mouse model of Salmonella infection. We found that Salmonella effector SifA in complex with its binding partner; SKIP, interacts with HOPS subunit Vps39 and mediates recruitment of this tethering factor to SCV compartments. The lysosomal small GTPase Arl8b that binds to, and promotes membrane localization of Vps41 (and other HOPS subunits) was also required for HOPS recruitment to SCVs and SIFs. Our findings suggest that Salmonella recruits the host late endosomal and lysosomal membrane fusion machinery to its vacuolar niche for access to host membrane and nutrients, ensuring its intracellular survival and replication. PMID:29084291

  6. 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 invA 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 invA 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.

  7. Host specific differences alter the requirement for certain Salmonella genes during swine colonization.

    Science.gov (United States)

    Bearson, Bradley L; Bearson, Shawn M D

    2011-06-02

    The pathogenic potential of Salmonella is determined during the complex interaction between pathogen and host, requiring optimal regulation of multiple bacterial genetic systems within variable in vivo environments. The mouse model of systemic disease has been an extremely productive model to investigate the pathogenesis of Salmonella enterica serovar Typhimurium (S. Typhimurium). Although the mouse model is a widely used paradigm for studying the pathogenesis of systemic disease caused by Salmonella, investigations concerning food safety interventions should employ natural hosts to examine gastrointestinal colonization by Salmonella. Recent research has demonstrated specific differences in the attenuation of certain S. Typhimurium mutants in mice compared to swine. This variation in pathogenesis between the mouse model and pigs for the S. Typhimurium mutants is presumably dependent upon either the requirements for specific gene products during systemic disease (mouse) versus gastrointestinal colonization (pig) or host specific differences. In addition, host specific diversity in Salmonella colonization of swine has also been described in comparison to other food-producing animals, including cattle and chickens. Differences in Salmonella colonization and pathogenesis across diverse animal species highlight the importance of species-specific studies of gastrointestinal colonization for the development of Salmonella interventions to enhance pork safety. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Reptiles, amphibians, and human Salmonella infection: a population-based, case-control study.

    Science.gov (United States)

    Mermin, Jonathan; Hutwagner, Lori; Vugia, Duc; Shallow, Sue; Daily, Pamela; Bender, Jeffrey; Koehler, Jane; Marcus, Ruthanne; Angulo, Frederick J

    2004-04-15

    To estimate the burden of reptile- and amphibian-associated Salmonella infections, we conducted 2 case-control studies of human salmonellosis occurring during 1996-1997. The studies took place at 5 Foodborne Diseases Active Surveillance Network (FoodNet) surveillance areas: all of Minnesota and Oregon and selected counties in California, Connecticut, and Georgia. The first study included 463 patients with serogroup B or D Salmonella infection and 7618 population-based controls. The second study involved 38 patients with non-serogroup B or D Salmonella infection and 1429 controls from California only. Patients and controls were interviewed about contact with reptiles and amphibians. Reptile and amphibian contact was associated both with infection with serogroup B or D Salmonella (multivariable odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1-2.2; Preptile or amphibian contact was 6% for all sporadic Salmonella infections and 11% among persons reptile and amphibian exposure is associated with approximately 74,000 Salmonella infections annually in the United States.

  9. Monoclonal antibody-based competitive enzyme-linked immunosorbent assay to detect antibodies to O:4 Salmonella in the sera of livestock and poultry.

    Science.gov (United States)

    Aribam, Swarmistha Devi; Ogawa, Yohsuke; Matsui, Hidenori; Hirota, Jiro; Okamura, Masashi; Akiba, Masato; Shimoji, Yoshihiro; Eguchi, Masahiro

    2015-01-01

    Serotyping is an important element for surveillance of Salmonella. In this study, an anti-O:4 Salmonella monoclonal antibody-based competitive enzyme-linked immunosorbent assay that could identify Salmonella infection in cow, pig, horse, and chicken was developed. This detection system can therefore be useful for a wide range of animals and for humans. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Immunity to intestinal pathogens: lessons learned from Salmonella

    Science.gov (United States)

    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

  11. 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 ...

  12. Development of a Salmonella cross-protective vaccine for food animal production systems.

    Science.gov (United States)

    Heithoff, Douglas M; House, John K; Thomson, Peter C; Mahan, Michael J

    2015-01-01

    Intensive livestock production is associated with increased Salmonella exposure, transmission, animal disease, and contamination of food and water supplies. Modified live Salmonella enterica vaccines that lack a functional DNA adenine methylase (Dam) confer cross-protection to a diversity of salmonellae in experimental models of murine, avian, ovine, and bovine models of salmonellosis. However, the commercial success of any vaccine is dependent upon the therapeutic index, the ratio of safety/efficacy. Herein, secondary virulence-attenuating mutations targeted to genes involved in intracellular and/or systemic survival were introduced into Salmonella dam vaccines to screen for vaccine candidates that were safe in the animal and the environment, while maintaining the capacity to confer cross-protective immunity to pathogenic salmonellae serotypes. Salmonella dam mgtC, dam sifA, and dam spvB vaccine strains exhibited significantly improved vaccine safety as evidenced by the failure to give rise to virulent revertants during the infective process, contrary to the parental Salmonella dam vaccine. Further, these vaccines exhibited a low grade persistence in host tissues that was associated with reduced vaccine shedding, reduced environmental persistence, and induction of cross-protective immunity to pathogenic serotypes derived from infected livestock. These data indicate that Salmonella dam double mutant vaccines are suitable for commercial applications against salmonellosis in livestock production systems. Reducing pre-harvest salmonellae load through vaccination will promote the health and productivity of livestock and reduce contamination of livestock-derived food products, while enhancing overall food safety. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. MALDI-TOF mass spectrometry provides high accuracy in identification of Salmonella at species level but is limited to type or subtype Salmonella serovars.

    Science.gov (United States)

    Kang, Lin; Li, Nan; Li, Ping; Zhou, Yang; Gao, Shan; Gao, Hongwei; Xin, Wenwen; Wang, Jinglin

    2017-04-01

    Salmonella can cause global foodborne illnesses in humans and many animals. The current diagnostic gold standard used for detecting Salmonella infection is microbiological culture followed by serological confirmation tests. However, these methods are complicated and time-consuming. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis offers some advantages in rapid identification, for example, simple and fast sample preparation, fast and automated measurement, and robust and reliable identification up to genus and species levels, possibly even to the strain level. In this study, we established a reference database for species identification using whole-cell MALDI-TOF MS; the database consisted of 12 obtained main spectra of the Salmonella culture collection strains belonged to seven serotypes. Eighty-two clinical isolates of Salmonella were identified using established database, and partial 16S rDNA gene sequencing and serological method were used as comparison. We found that MALDI-TOF mass spectrometry provided high accuracy in identification of Salmonella at species level but was limited to type or subtype Salmonella serovars. We also tried to find serovar-specific biomarkers and failed. Our study demonstrated that (a) MALDI-TOF MS was suitable for identification of Salmonella at species level with high accuracy and (b) that MALDI-TOF MS method presented in this study was not useful for serovar assignment of Salmonella currently, because of its low matching with serological method and (c) MALDI-TOF MS method presented in this study was not suitable to subtype S. typhimurium because of its low discriminatory ability.

  14. Risk assessment of Salmonella in Danish meatballs produced in the catering sector

    DEFF Research Database (Denmark)

    Møller, Cleide Oliveira de Almeida; Nauta, Maarten; Schaffner, Donald W.

    2015-01-01

    observational data and models that were specific for Salmonella spp. in meatballs produced in the catering sector. Danish meatballs are often pan-fried followed by baking in an oven before consumption, in order to reach the core temperature of 75 degrees C recommended by the Danish Food Safety Authority...... of meatballs to core temperatures higher than 70 degrees C, and subsequent holding at room temperatures lower than 20 degrees C, for no longer than 3.5 h, were very effective in Salmonella control. The current Danish Food Safety Authority recommendation of cooking to an internal temperature of 75 degrees C...... is conservative, at least with respect to Salmonella risk. Survival and growth of Salmonella during cooling of meatballs not heat treated in oven had a significant impact on the risk estimates, and therefore, cooling should be considered a critical step during meatball processing. (c) 2014 Published by Elsevier B.V....

  15. Salmonella and raw shell eggs: results of a cross-sectional study of contamination rates and egg safety practices in the United Kingdom catering sector in 2003.

    Science.gov (United States)

    Elson, R; Little, C L; Mitchell, R T

    2005-02-01

    This study was prompted by epidemiological investigations of the unusual number of Salmonella Enteritidis outbreaks associated with the use of eggs in catering premises in England and Wales during 2002. The aims of the study, performed between April and May 2003, were to establish the rate of Salmonella contamination in raw shell eggs from catering premises, investigate any correlation between the origin and type of eggs and the presence of particular serotypes or phage types (PTs) of Salmonella, and examine the use of raw shell eggs in catering premises in the United Kingdom. A total of 34,116 eggs (5,686 pooled samples of six eggs) were collected from 2,104 catering premises, most of which were eggs produced in the United Kingdom (88%). Salmonella was isolated from 17 pools (0.3%) of eggs. Of these, 15 were Salmonella Enteritidis, which were further characterized to PTs as follows: PT6 (0.1%), PT4 (0.07%), PT12 (0.04%), PT1 (0.04%), and PT14b (0.02%). Salmonella Livingstone and Salmonella Typhimurium definitive type 7 resistant to ampicillin, streptomycin, sulfonamides, and tetracycline were also isolated. The Salmonella contamination rate of eggs produced in the United Kingdom appears to have decreased significantly since 1995 and 1996. This trend is reflected in the decrease of Salmonella Enteritidis and, in particular, Salmonella Enteritidis PT4. The impact of the United Kingdom Food Standards Agency's advice on the use of eggs, issued in January 2003, is discussed.

  16. The Salmonella Mutagenicity of Sediments from Gediz River (Western Turkey.

    Directory of Open Access Journals (Sweden)

    Meltem Boyacıoğlu

    2015-12-01

    Full Text Available Gediz Nehri sedimentlerinde Salmonella mutajenite testi. Bu çalışmada, Ramsar sitesi olarak koruma altında olan, büyük öneme sahip kuş cennetinin bulunduğu Gediz Nehri deltası sedimentinin, Salmonella typhimurium TA98 ve TA100 suşları kullanılarak yapılan Ames testi ile mutajenik potansiyeli araştırılmıştır. Her iki suşla yapılan mutajenisite testleri sonucunda sediment örneklerinin hiçbirinde mutajenik madde içermediği buna rağmen gözlenen bakteri büyümesinde ki azalmaya bağlı olarak tüm örneklerin toksik olduğu belirlenmiştir

  17. 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

  18. 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.

  19. 'Acute Salmonella typhz' Acalculdus Cholecystitz's

    African Journals Online (AJOL)

    The diagnosis of AACwas established byultrasono graphy and confirmed at lapar otomy: Laboratory cultures grew Salmonella 1377M from bile and citrobacter spp. from the blood. Following surgical intervention, the child had an uneventful recovery andwas discharged three weeks after surgery. 7. Key words: Typhoid fever, ...

  20. EFSA Panel on Biological Hazards; Scientific Opinion on a Quantitative Microbiological Risk Assessment of Salmonella in slaughter and breeder pigs

    DEFF Research Database (Denmark)

    Hald, Tine

    possible (a) by ensuring that breeder pigs are Salmonella-free a reduction of 70-80% in high prevalence MSs and 10-20% in low prevalence MSs can be foreseen; (b) by feeding only Salmonella-free feedstuffs, a reduction of 10-20% in high prevalence MSs and 60-70% in low prevalence MSs can be foreseen; and (c......, followed by control of feed and then control of environmental contamination. Also according to the QMRA, for each MS, a reduction of two logs (99%) of Salmonella numbers on contaminated carcasses would result in more than 90% reduction of the number of human salmonellosis cases attributable to pig meat......This Quantitative Microbiological Risk Assessment (QMRA) represents a major step forward in terms of modelling Salmonella in pigs from farm to consumption as it takes into account the variability between and within EU Member States (MSs). Around 10-20% of human Salmonella infections in EU may...

  1. EU Interlaboratory comparison study VII on bacteriological detection of Salmonella spp

    NARCIS (Netherlands)

    Korver H; Nagelkerke NJD; Giessen AW van de; Mooijman KA; MGB; IMAR

    2005-01-01

    In 2003 a seventh interlaboratory comparison study on bacteriological detection of Salmonella spp. was organised by the Community Reference Laboratory for Salmonella (CRL-Salmonella, Bilthoven, the Netherlands). National Reference Laboratories for Salmonella (NRLs-Salmonella) of the EU Member

  2. Salmonella – A Brief Summary

    Directory of Open Access Journals (Sweden)

    Nurmi Esko

    2002-03-01

    Full Text Available Abstract Salmonellosis is the main cause of human bacterial gastroenteritis in most European countries. Infections with Salmonella is usually subclinical, whereas clinical cases show symptoms with a wide range of severity. Infection is most commonly associated with the consumption of meat, especially poultry or pork, and eggs and their products. Salmonella can enter the food chain at any point throughout its length. The principal reservoir of Salmonellae is the gastrointestinal tract of mammals and birds, but Salmonellae are able to survive and even multiply in many external environments. In Norway, Sweden and Finland cost effective prevention methods have been used for several years to prevent and control Salmonellea infections. In addition, competitive exclusion (CE and vaccination might be relevant as biological methods to prevent colonisation of bird intestines by enteropathogens, especially Salmonella. Antibiotic drug resistance has been a problem since the start of the antibiotic era. The cause for anxiety is that more and more bacteria are becoming resistant, often to a whole range of antibiotics. The debate on the use of antimicrobials in veterinary medicine and animal production dates back almost as long as the use itself. There is a clear evidence to show that antibacterial agents given to animals for growth promotion, prophylactic purposes or treatment induce a rise in the number of antibiotic resistant strains isolated from the animals. These bacteria may be transmitted to humans by several possible routes. There are thus strong arguments for preventive efforts which have to be directed towards identifying real critical control points (HACCP throughout the whole food chain, which starts from the farm and ends at the consumer's table.

  3. Phenotypic characteristics and genotypic correlation between Salmonella isolates from a slaughterhouse and retail markets in Yangzhou, China.

    Science.gov (United States)

    Cai, Yinqiang; Tao, Jing; Jiao, Yang; Fei, Xiao; Zhou, Le; Wang, Yan; Zheng, Huijuan; Pan, Zhiming; Jiao, Xinan

    2016-04-02

    An epidemiological investigation of Salmonella spp. in pig and pork samples from one slaughterhouse and its downstream retail markets in Yangzhou, Jiangsu Province, China, was conducted from October 2013 to March 2014. A total of 71.8% (155/216) and 70.9% (78/110), respectively, of the slaughterhouse and retail market samples were recovered positive for Salmonella. All Salmonella isolates were characterized using serotyping, antimicrobial resistance detection, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Seven serotypes were shared by isolates from the two sources, with the most common serotypes being Salmonella Derby, Typhimurium, and Uganda. Antimicrobial sensitivity testing revealed that the highest antimicrobial resistance rate was against tetracycline (49.7% and 37.2% in isolates from the slaughterhouse and retail market, respectively) with many multidrug-resistant (MDR) isolates in both sources. MLST analysis showed that eight sequence type (ST) patterns were shared, and ST40 occupied an absolute superiority among isolates from both sources. PFGE permitted the resolution of XbaI macrorestriction fragments of the selected 31 Salmonella Derby and 19 Salmonella Typhimurium into 30 and 10 distinct pulsotypes, displaying the high similarity between the isolates from the two sources. Our findings indicated that Salmonella isolates from a slaughterhouse and its downstream retail markets were phenotypically and genetically homologous. Additionally, Salmonella may propagate along the slaughter line and pork production chain from the slaughterhouse to retail markets. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Global regulation by CsrA in Salmonella typhimurium.

    Science.gov (United States)

    Lawhon, Sara D; Frye, Jonathan G; Suyemoto, Mitsu; Porwollik, Steffen; McClelland, Michael; Altier, Craig

    2003-06-01

    CsrA is a regulator of invasion genes in Salmonella enterica serovar Typhimurium. To investigate the wider role of CsrA in gene regulation, we compared the expression of Salmonella genes in a csrA mutant with those in the wild type using a DNA microarray. As expected, we found that expression of Salmonella pathogenicity island 1 (SPI-1) invasion genes was greatly reduced in the csrA mutant, as were genes outside the island that encode proteins translocated into eukaryotic cells by the SPI-1 type III secretion apparatus. The flagellar synthesis operons, flg and fli, were also poorly expressed, and the csrA mutant was aflagellate and non-motile. The genes of two metabolic pathways likely to be used by Salmonella in the intestinal milieu also showed reduced expression: the pdu operon for utilization of 1,2-propanediol and the eut operon for ethanolamine catabolism. Reduced expression of reporter fusions in these two operons confirmed the microarray data. Moreover, csrA was found to regulate co-ordinately the cob operon for synthesis of vitamin B12, required for the metabolism of either 1,2-propanediol or ethanolamine. Additionally, the csrA mutant poorly expressed the genes of the mal operon, required for transport and use of maltose and maltodextrins, and had reduced amounts of maltoporin, normally a dominant protein of the outer membrane. These results show that csrA controls a number of gene classes in addition to those required for invasion, some of them unique to Salmonella, and suggests a co-ordinated bacterial response to conditions that exist at the site of bacterial invasion, the intestinal tract of a host animal.

  5. Modification of Salmonella Typhimurium motility by the probiotic yeast strain Saccharomyces boulardii.

    Directory of Open Access Journals (Sweden)

    Rodolphe Pontier-Bres

    Full Text Available BACKGROUND: Motility is an important component of Salmonella enterica serovar Typhimurium (ST pathogenesis allowing the bacteria to move into appropriate niches, across the mucus layer and invade the intestinal epithelium. In vitro, flagellum-associated motility is closely related to the invasive properties of ST. The probiotic yeast Saccharomyces boulardii BIOCODEX (S.b-B is widely prescribed for the prophylaxis and treatment of diarrheal diseases caused by bacteria or antibiotics. In case of Salmonella infection, S.b-B has been shown to decrease ST invasion of T84 colon cell line. The present study was designed to investigate the impact of S.b-B on ST motility. METHODOLOGY/PRINCIPAL FINDINGS: Experiments were performed on human colonic T84 cells infected by the Salmonella strain 1344 alone or in the presence of S.b-B. The motility of Salmonella was recorded by time-lapse video microscopy. Next, a manual tracking was performed to analyze bacteria dynamics (MTrackJ plugin, NIH image J software. This revealed that the speed of bacterial movement was modified in the presence of S.b-B. The median curvilinear velocity (CLV of Salmonella incubated alone with T84 decreased from 43.3 µm/sec to 31.2 µm/sec in the presence of S.b-B. Measurement of track linearity (TL showed similar trends: S.b-B decreased by 15% the number of bacteria with linear tract (LT and increased by 22% the number of bacteria with rotator tract (RT. Correlation between ST motility and invasion was further established by studying a non-motile flagella-deficient ST strain. Indeed this strain that moved with a CLV of 0.5 µm/sec, presented a majority of RT and a significant decrease in invasion properties. Importantly, we show that S.b-B modified the motility of the pathogenic strain SL1344 and significantly decreased invasion of T84 cells by this strain. CONCLUSIONS: This study reveals that S.b-B modifies Salmonella's motility and trajectory which may account for the modification

  6. Prevalence and Characterization of Monophasic Salmonella Serovar 1,4,[5],12:i:- of Food Origin in China.

    Science.gov (United States)

    Yang, Xiaojuan; Wu, Qingping; Zhang, Jumei; Huang, Jiahui; Guo, Weipeng; Cai, Shuzhen

    2015-01-01

    Salmonella enterica subsp. enterica serovar 1,4,[5],12:i:- is a monophasic variant of Salmonella Typhimurium, which has recently been recognized as an emerging cause of infection worldwide. This bacterium has also ranked among the four most frequent serovars causing human salmonellosis in China. However, there are no reports on its contamination in Chinese food. Serotyping, polymerase chain reaction, antibiotic resistance, virulotyping, and multilocus sequence typing (MLST) assays were used to investigate the prevalence of this serological variant in food products in China, and to determine phenotypic and genotypic difference of monophasic isolates and Salmonella Typhimurium isolated over the same period. Salmonella 1,4,[5],12:i:- was prevalent in various food sources, including beef, pork, chicken, and pigeon. The study also confirmed the high prevalence (53.8%) of resistance to ampicillin, streptomycin, sulfonamides, and tetracycline in Salmonella 1,4,[5],12:i:-, which was higher than that in Salmonella Typhimurium. Moreover, Salmonella 1,4,[5],12:i:- isolates in our study were different from Salmonella Typhimurium isolates by the absence of three plasmid-borne genes (spvC, pefA, and rck) and the presence of gipA in all isolates. All Salmonella 1,4,[5],12:i:- isolates demonstrated MLST pattern ST34. Genomic deletions within the fljBA operon and surrounding genes were only found in Salmonella 1,4,[5],12:i:- isolates, with all isolates containing a deletion of fljB. However, hin and iroB were identified in all Salmonella 1,4,[5],12:i:- isolates. Three different deletion profiles were observed and two of them were different from the reported Salmonella 1,4,[5],12:i:- clones from Spain, America, and Italy, which provided some new evidence on the independent evolution of the multiple successful monophasic clones from Salmonella Typhimurium ancestors. This study is the first report of Salmonella 1,4,[5],12:i:- in food products from China. The data are more

  7. Prevalence and Characterization of Monophasic Salmonella Serovar 1,4,[5],12:i:- of Food Origin in China.

    Directory of Open Access Journals (Sweden)

    Xiaojuan Yang

    Full Text Available Salmonella enterica subsp. enterica serovar 1,4,[5],12:i:- is a monophasic variant of Salmonella Typhimurium, which has recently been recognized as an emerging cause of infection worldwide. This bacterium has also ranked among the four most frequent serovars causing human salmonellosis in China. However, there are no reports on its contamination in Chinese food. Serotyping, polymerase chain reaction, antibiotic resistance, virulotyping, and multilocus sequence typing (MLST assays were used to investigate the prevalence of this serological variant in food products in China, and to determine phenotypic and genotypic difference of monophasic isolates and Salmonella Typhimurium isolated over the same period. Salmonella 1,4,[5],12:i:- was prevalent in various food sources, including beef, pork, chicken, and pigeon. The study also confirmed the high prevalence (53.8% of resistance to ampicillin, streptomycin, sulfonamides, and tetracycline in Salmonella 1,4,[5],12:i:-, which was higher than that in Salmonella Typhimurium. Moreover, Salmonella 1,4,[5],12:i:- isolates in our study were different from Salmonella Typhimurium isolates by the absence of three plasmid-borne genes (spvC, pefA, and rck and the presence of gipA in all isolates. All Salmonella 1,4,[5],12:i:- isolates demonstrated MLST pattern ST34. Genomic deletions within the fljBA operon and surrounding genes were only found in Salmonella 1,4,[5],12:i:- isolates, with all isolates containing a deletion of fljB. However, hin and iroB were identified in all Salmonella 1,4,[5],12:i:- isolates. Three different deletion profiles were observed and two of them were different from the reported Salmonella 1,4,[5],12:i:- clones from Spain, America, and Italy, which provided some new evidence on the independent evolution of the multiple successful monophasic clones from Salmonella Typhimurium ancestors. This study is the first report of Salmonella 1,4,[5],12:i:- in food products from China. The data are

  8. 75 FR 48973 - Draft Guidance for Industry: Prevention of Salmonella

    Science.gov (United States)

    2010-08-12

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry: Prevention of Salmonella... availability of a draft guidance entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During... ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation'' (the...

  9. 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...

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

    NARCIS (Netherlands)

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

    2006-01-01

    The eleventh interlaboratory comparison study on the typing of Salmonella was organised by the Community Reference Laboratory for Salmonella (CRL-Salmonella, Bilthoven, The Netherlands) in collaboration with the Health Protection Agency (HPA, London, United Kingdom) in March 2006. 26 National

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

    Directory of Open Access Journals (Sweden)

    Zihler Annina

    2011-12-01

    Full Text Available Abstract Background Accurate assessment of probiotics with targeted anti-Salmonella activity requires suitable models accounting for both, microbe-microbe and host-microbe interactions in gut environments. Here we report the combination of two original in vitro intestinal models closely mimicking the complex in vivo conditions of the large intestine. Effluents from continuous in vitro three-stage fermentation colonic models of Salmonella Typhimurium infection inoculated with immobilized child microbiota and Salmonella were directly applied to confluent mucus-secreting HT29-MTX cell layers. The effects of Salmonella, addition of two bacteriocinogenic strains, Bifidobacterium thermophilum RBL67 (thermophilicin B67 and Escherichia coli L1000 (microcin B17, and inulin were tested on Salmonella growth and interactions with epithelial cell layers. Salmonella adhesion and invasion were investigated and epithelial integrity assessed by transepithelial electrical resistance (TER measurements and confocal microscopy observation. Data from complex effluents were compared with pure Salmonella cultures. Results Salmonella in effluents of all reactors of the colonic fermentation model stabilized at mean values of 5.3 ± 0.8 log10 cfu/ml effluent. Invasion of cell-associated Salmonella was up to 50-fold lower in complex reactor samples compared to pure Salmonella cultures. It further depended on environmental factors, with 0.2 ± 0.1% being measured with proximal, 0.6 ± 0.2% with transverse and 1.3 ± 0.7% with distal reactor effluents, accompanied by a similar high decrease of TER across cell monolayers (minus 45% and disruption of tight junctions. Subsequent addition of E. coli L1000 stimulated Salmonella growth (6.4 ± 0.6 log10 cfu/ml effluent of all 3 reactors and further decreased TER, but led to 10-fold decreased invasion efficiency when tested with distal reactor samples. In contrast, presence of B. thermophilum RBL67 revealed a protective effect on

  12. 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

  13. Disruption of type III secretion in Salmonella enterica serovar Typhimurium by external guide sequences.

    Science.gov (United States)

    McKinney, Jeffrey S; Zhang, Haifeng; Kubori, Tomoko; Galán, Jorge E; Altman, Sidney

    2004-01-01

    The type III secretion system involved in Salmonella enterica serovar Typhimurium invasion of host cells has been disrupted using inducibly expressed oligonucleotide external guide sequences (EGSs) complementary to invB or invC mRNA. These EGSs direct single site cleavage in these mRNAs by endogenous RNase P, and their expression in Salmonella results in invC mRNA and InvC protein depletion, decreased type III secretion and interference with host cell invasion. Comparison of these effects with those from studies of Salmonella invB and invC mutants suggests that invB EGSs have polar effects on invC mRNA.

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

    Science.gov (United States)

    Kuan, Yu-Diao; Lee, Che-Hsin

    2016-01-01

    Over the past decades, Salmonella has been proven capable of inhibiting tumor growth. It can specifically target tumors and due to its facultative anaerobic property, can be more penetrative than other drug therapies. However, the molecular mechanism by which Salmonella inhibits tumor growth is still incompletely known. The antitumor therapeutic effect mediated by Salmonella is associated with an inflammatory immune response at the tumor site and a T cell-dependent immune response. Many tumors have been proven to have a high expression of indoleamine 2, 3-dioxygenase 1 (IDO), which is a rate-limiting enzyme that catalyzes tryptophan to kynurenine, thus causing immune tolerance within the tumor microenvironment. With decreased expression of IDO, increased immune response can be observed, which might be helpful when developing cancer immunotherapy. The expression of IDO was decreased after tumor cells were infected with Salmonella. In addition, Western blot analysis showed that the expression levels of phospho-protein kinase B (P-AKT), phospho-mammalian targets of rapamycin (P-mTOR), and phospho-p70 ribosomal s6 kinase (P-p70s6K) in tumor cells were decreased after Salmonella infection. In conclusion, our results indicate that Salmonella inhibits IDO expression and plays a crucial role in anti-tumor therapy, which might be a promising strategy combined with other cancer treatments. PMID:26517244

  15. Evaluation of mice infected to Salmonella Spp in Poultry farms of Tehran Province

    Directory of Open Access Journals (Sweden)

    M Hadadian

    2012-08-01

    Full Text Available In this survey, 290 mice and rats fecal samples from commercial layer and broiler poultry houses were tested for Salmonella sp. presence. All samples were cultured on Selenite F broth media and passaged on SS agar and McConkey agar. The suspected colonies were cultured on Urea and TSI agars to be confirmed as Salmonella sp.. Finally, Salmonella isolates were identified genetically and biochemically by PCR and conventional methods, respectively. Serogrouping and Antibiotic resistance profiling were done for further differentiation of isolates. Twenty eight (9.65% Salmonellas were isolated from (out of 290 samples. Eight (28.6%, seven (25%, four (14.3%, and two (7.2% isolates were located in serogroups C, D, B and E, respectively. Seven isolates (25% belonged to Arizona subspecies and just one non-motile serogroup D Salmonella was isolated. All isolates were sensitive to enrofloxacin, difloxacin, norfloxacin, chloramphenicol and florfenicol, but they were resistant to sulfamethoxazole, trimethoprim and neomycin in decreasing order. In addition to former surveys, this study confirmed the role of mice and rats in spreading of Salmonella spp. in poultry farms. In conclusion it is essential to take appropriate measurements (measures for pest management in poultry houses to approach the prevention of some bacterial infection like  (such as salmonellosis.

  16. Validation of the baking process as a kill-step for controlling Salmonella in muffins.

    Science.gov (United States)

    Channaiah, Lakshmikantha H; Michael, Minto; Acuff, Jennifer C; Phebus, Randall K; Thippareddi, Harshavardhan; Olewnik, Maureen; Milliken, George

    2017-06-05

    This research investigates the potential risk of Salmonella in muffins when contamination is introduced via flour, the main ingredient. Flour was inoculated with a 3-strain cocktail of Salmonella serovars (Newport, Typhimurium, and Senftenberg) and re-dried to achieve a target concentration of ~8logCFU/g. The inoculated flour was then used to prepare muffin batter following a standard commercial recipe. The survival of Salmonella during and after baking at 190.6°C for 21min was analyzed by plating samples on selective and injury-recovery media at regular intervals. The thermal inactivation parameters (D and z values) of the 3-strain Salmonella cocktail were determined. A ≥5logCFU/g reduction in Salmonella population was demonstrated by 17min of baking, and a 6.1logCFU/g reduction in Salmonella population by 21min of baking. The D-values of Salmonella serovar cocktail in muffin batter were 62.2±3.0, 40.1±0.9 and 16.5±1.7min at 55, 58 and 61°C, respectively; and the z-value was 10.4±0.6°C. The water activity (a w ) of the muffin crumb (0.928) after baking and 30min of cooling was similar to that of pre-baked muffin batter, whereas the a w of the muffin crust decreased to (0.700). This study validates a typical commercial muffin baking process utilizing an oven temperature of 190.6°C for at least 17min as an effective kill-step in reducing a Salmonella serovar population by ≥5logCFU/g. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  17. Punicalagin inhibits Salmonella virulence factors and has anti-quorum-sensing potential.

    Science.gov (United States)

    Li, Guanghui; Yan, Chunhong; Xu, Yunfeng; Feng, Yuqing; Wu, Qian; Lv, Xiaoying; Yang, Baowei; Wang, Xin; Xia, Xiaodong

    2014-10-01

    Punicalagin, an essential component of pomegranate rind, has been demonstrated to possess antimicrobial activity against several food-borne pathogens, but its activity on the virulence of pathogens and its anti-quorum-sensing (anti-QS) potential have been rarely reported. This study investigated the efficacy of subinhibitory concentrations of punicalagin on Salmonella virulence factors and QS systems. A broth microdilution method was used to determine the MICs of punicalagin for 10 Salmonella strains. Motility assay and quantitative reverse transcription (RT)-PCR were performed to evaluate the effects of punicalagin on the virulence attributes and QS-related genes of Salmonella. The MICs of punicalagin for several Salmonella strains ranged from 250 to 1,000 μg/ml. Motility assays showed that punicalagin, at 1/16× MIC and 1/32× MIC, significantly decreased bacterial swimming and swarming motility, which corresponded to downregulation of the motility-related genes (fliA, fliY, fljB, flhC, and fimD) in RT-PCR assays. RT-PCR also revealed that punicalagin downregulated the expression of most of the selected genes involved in Salmonella virulence. Moreover, a QS inhibition assay indicated that punicalagin dose dependently inhibited the production of violacein by Chromobacterium violaceum and repressed the expression of QS-related genes (sdiA and srgE) in Salmonella. In addition, punicalagin significantly reduced Salmonella invasion of colonic cells (Ppunicalagin has the potential to be developed as an alternative or supplemental agent for prevention of Salmonella infection. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Development of a liposome-based immunochromatographic strip assay for the detection of Salmonella.

    Science.gov (United States)

    Shukla, Shruti; Leem, Hyerim; Kim, Myunghee

    2011-11-01

    Salmonella species are ubiquitous human pathogens which pose a dangerous threat to the elderly and children worldwide. In this study, to develop a more efficient assay procedure for the rapid detection of Salmonella Typhimurium, an immunochromatographic strip assay was developed using immunoliposome (anti-Salmonella IgG-tagged) encapsulated with sulforhodamine B (SRB). The detection sensitivity of the developed immunochromatographic assay was compared with a commercial immunochromatographic test strip using colloidal gold nanoparticles. The liposomes were prepared through a reverse-phase evaporation method by using a lipid and phospholipid mixture and SRB, a fluorescence dye, which was encapsulated in the phospholipid bilayer. Furthermore, the outer surface of the SRB-encapsulated liposome was conjugated with antibody (affinity-purified polyclonal goat anti-Salmonella IgG) to form an immunoliposome (size, 223 nm), used as the analytical reagent in the developed immunoassay. For this strip assay, a plastic-backed nitrocellulose strip was immobilized with two antibody zones. The lower zone of the strip referred to Salmonella antigen capture zone (test line), while the other zone served as a positive control (control line). The lower zone was coated with affinity-purified polyclonal goat anti-Salmonella IgG, while the upper zone was coated with rabbit anti-goat IgG. During capillary migration of the wicking solution (diluted liposome and Salmonella culture, each 50 μl), Salmonella was captured with surface-bound immunoliposomes at the antigen capture zone, while the unbound liposomes migrated upward and bound to another zone. The color density of the antigen capture zone was directly proportional to the amount of S. Typhimurium in the test sample. As a result, the detection limit of the immunochromatographic strip assay developed in this study against S. Typhimurium was found to be 10(2) CFU/ml, which was significantly higher than the detection limit (10(7) CFU

  19. Integrated Stress Responses in Salmonella

    Science.gov (United States)

    Shen, Shu; Fang, Ferric C.

    2011-01-01

    The foodborne gram-negative pathogen Salmonella must adapt to varied environmental conditions encountered within foods, the host gastrointestinal tract and the phagosomes of host macrophages. Adaptation is achieved through the coordinate regulation of gene expression in response to environmental signals such as temperature, pH, osmolarity, redox state, antimicrobial peptides, and nutrient deprivation. This review will examine mechanisms by which the integration of regulatory responses to a broad array of environmental signals can be achieved. First, in the most straightforward case, tandem promoters allow gene expression to respond to multiple signals. Second, versatile sensor proteins may respond to more than one environmental signal. Third, transcriptional silencing and counter-silencing as demonstrated by the H-NS paradigm provides a general mechanism for the convergence of multiple regulatory inputs. Fourth, signaling cascades allow gene activation by independent sensory elements. These mechanisms allow Salmonella to utilize common adaptive stress pathways in response to a diverse range of environmental conditions. PMID:21570144

  20. Flagella Overexpression Attenuates Salmonella Pathogenesis

    OpenAIRE

    Xinghong Yang; Theresa Thornburg; Zhiyong Suo; SangMu Jun; Amanda Robison; Jinquan Li; Timothy Lim; Ling Cao; Teri Hoyt; Recep Avci; Pascual, David W.

    2012-01-01

    Flagella are cell surface appendages involved in a number of bacterial behaviors, such as motility, biofilm formation, and chemotaxis. Despite these important functions, flagella can pose a liability to a bacterium when serving as potent immunogens resulting in the stimulation of the innate and adaptive immune systems. Previous work showing appendage overexpression, referred to as attenuating gene expression (AGE), was found to enfeeble wild-type Salmonella. Thus, this approach was adapted to...

  1. Imported poultry meat as a source of extended-spectrum cephalosporin-resistant CMY-2-producing Salmonella Heidelberg and Salmonella Minnesota in the European Union, 2014-2015.

    Science.gov (United States)

    Campos, Joana; Mourão, Joana; Silveira, Leonor; Saraiva, Margarida; Correia, Cristina Belo; Maçãs, Ana Paula; Peixe, Luísa; Antunes, Patrícia

    2018-01-01

    Extended-spectrum cephalosporin (ESC)-resistant Salmonella have been described at a low level in the EU, nevertheless the increasing importation of poultry meat could be an important source of epidemic strains carrying ESC resistance genes. This study evaluated ESC resistance and its genetic platform among Salmonella isolates from poultry meat products imported into Portugal as well as clonal relatedness of the isolates. All Salmonella isolates recovered from samples of fresh meat destined for import into the EU in the scope of Portuguese official border control (2014-2015) were studied. Antibiotic susceptibility and β-lactamase production was determined by disk diffusion/microdilution. Molecular studies included detection of genes encoding acquired AmpC and extended-spectrum β-lactamases, plasmid-mediated quinolone resistance and other antibiotic resistance genes by PCR/sequencing, and clonality by MLST and XbaI-PFGE. Plasmid characterisation was assessed by conjugation assays, replicon typing (PCR-PBRT/pMLST) and hybridisation experiments (I-CeuI/S1-PFGE nuclease). Isolates belonged to Salmonella Heidelberg (n = 6; ST15/eBG26) and Salmonella Minnesota (n = 1; ST548/eBG77) and presented multidrug-resistant profiles, including to ESCs and/or fluoroquinolones. All but one carried blaCMY-2, located on two epidemic plasmids, IncA/C (ST2, n = 5) or transferable IncI1 (ST12, n = 1). Salmonella Heidelberg was associated with five PFGE types, including one similar to an American epidemic clone. This study reveals imported poultry products as a source of uncommon and/or invasive ESC-resistant Salmonella strains in the EU. The increase of clinically relevant poultry-related serotypes in Europe must be taken into account in the current monitoring of antibiotic resistance trends and in re-evaluation of food regulations. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  2. Lactobacillus bulgaricus, Lactobacillus rhamnosus and Lactobacillus paracasei Attenuate Salmonella Enteritidis, Salmonella Heidelberg and Salmonella Typhimurium Colonization and Virulence Gene Expression In Vitro

    OpenAIRE

    Muyyarikkandy, Muhammed Shafeekh; Amalaradjou, Mary Anne

    2017-01-01

    Salmonella Enteritidis (SE), Salmonella Typhimurium (ST), and Salmonella Heidelberg (SH) have been responsible for numerous outbreaks associated with the consumption of poultry meat and eggs. Salmonella colonization in chicken is characterized by initial attachment to the cecal epithelial cells (CEC) followed by dissemination to the liver, spleen, and oviduct. Since cecal colonization is critical to Salmonella transmission along the food chain continuum, reducing this intestinal association c...

  3. Transmission and control of Salmonella in the pig feed chain: a conceptual model.

    Science.gov (United States)

    Binter, Claudia; Straver, Judith Maria; Häggblom, Per; Bruggeman, Geert; Lindqvist, Per-Anders; Zentek, Jürgen; Andersson, Mats Gunnar

    2011-03-01

    . Prevention of recontamination and control of moisture throughout the chain are thus critical factors for controlling Salmonella in feed production. To verify successful control it is necessary to have monitoring strategies able to detect low levels of Salmonella heterogeneously distributed in large volumes of feed and feed material in bulk. Experience from monitoring programs and research investigations indicates that sampling of dust and sweepings from control points along the production line is an efficient strategy to gain an indication of Salmonella contamination. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Salmonella in chicken meat, eggs and humans; Adelaide, South Australia, 2008.

    Science.gov (United States)

    Fearnley, Emily; Raupach, Jane; Lagala, Fil; Cameron, Scott

    2011-04-29

    allow accurate measurement of interventions taken to reduce rates of Salmonella isolations in animal-based foods. Copyright © 2011. Published by Elsevier B.V.

  5. A questionnaire study of associations between potential risk factors and salmonella status in Swedish dairy herds.

    Science.gov (United States)

    Ågren, Estelle C C; Frössling, Jenny; Wahlström, Helene; Emanuelson, Ulf; Sternberg Lewerin, Susanna

    2017-08-01

    In this study associations between potential risk factors and salmonella status in Swedish dairy herds were investigated. A case-control study design was used, including existing as well as new cases. Herds were assigned a salmonella status on the basis of antibody analysis of bulk milk samples. Information on potential risk factors was collected from registry data and from farmers via a questionnaire. Univariable and multivariable logistic regression analyses were used to investigate associations between salmonella status and potential risk factors. In addition, multivariate analysis with Additive Bayesian Network (ABN) modelling was performed to improve understanding of the complex relationship between all the variables. Because of the difficulty in identifying associations between potential risk factors and infections with low prevalence and a large regional variation, exposure of potential risk factors in the high-prevalence region (Öland) were compared to exposure in other regions in Sweden. In total 483 of 996 (48%) farmers responded to the questionnaire, 69 herds had test-positive bulk milk samples. The strongest association with salmonella status was 'presence of salmonella test-positive herds salmonella status were also seen between 'feeding calves residue milk only' (OR 2.4, 95% CI 1.2-4.6), 'certified organic herds' (OR 2.5, 95% CI 1.2-4.9) and 'frequently seeing signs of rodents' (OR 0.4, 95% CI 0.13-0.97). The ABN model showed associations between Öland and four of the variables: salmonella status, presence of test-positive herds salmonella by other studies. The study confirms the importance of local transmission routes for salmonella, but does not identify specific components in this local spread. Therefore, it supports the use of a broad biosecurity approach in the prevention of salmonella. In Öland, some potential risk factors are more common than in other parts of Sweden. Theoretically these could contribute to the spread of salmonella, but this

  6. Bio-Control of Salmonella Enteritidis in Foods Using Bacteriophages.

    Science.gov (United States)

    Bao, Hongduo; Zhang, Pengyu; Zhang, Hui; Zhou, Yan; Zhang, Lili; Wang, Ran

    2015-08-24

    Two lytic phages, vB_SenM-PA13076 (PA13076) and vB_SenM-PC2184 (PC2184), were isolated from chicken sewage and characterized with host strains Salmonella Enteritidis (SE) ATCC13076 and CVCC2184, respectively. Transmission electron microscopy revealed that they belonged to the family Myoviridae. The lytic abilities of these two phages in liquid culture showed 104 multiplicity of infection (MOI) was the best in inhibiting bacteria, with PC2184 exhibiting more activity than PA13076. The two phages exhibited broad host range within the genus Salmonella. Phage PA13076 and PC2184 had a lytic effect on 222 (71.4%) and 298 (95.8%) of the 311 epidemic Salmonella isolates, respectively. We tested the effectiveness of phage PA13076 and PC2184 as well as a cocktail combination of both in three different foods (chicken breast, pasteurized whole milk and Chinese cabbage) contaminated with SE. Samples were spiked with 1 × 10(4) CFU individual SE or a mixture of strains (ATCC13076 and CVCC2184), then treated with 1 × 10(8) PFU individual phage or a two phage cocktail, and incubated at 4 °C or 25 °C for 5 h. In general, the inhibitory effect of phage and phage cocktail was better at 4 °C than that at 25 °C, whereas the opposite result was observed in Chinese cabbage, and phage cocktail was better than either single phage. A significant reduction in bacterial numbers (1.5-4 log CFU/sample, p Salmonella in foods.

  7. Bio-Control of Salmonella Enteritidis in Foods Using Bacteriophages

    Directory of Open Access Journals (Sweden)

    Hongduo Bao

    2015-08-01

    Full Text Available Two lytic phages, vB_SenM-PA13076 (PA13076 and vB_SenM-PC2184 (PC2184, were isolated from chicken sewage and characterized with host strains Salmonella Enteritidis (SE ATCC13076 and CVCC2184, respectively. Transmission electron microscopy revealed that they belonged to the family Myoviridae. The lytic abilities of these two phages in liquid culture showed 104 multiplicity of infection (MOI was the best in inhibiting bacteria, with PC2184 exhibiting more activity than PA13076. The two phages exhibited broad host range within the genus Salmonella. Phage PA13076 and PC2184 had a lytic effect on 222 (71.4% and 298 (95.8% of the 311 epidemic Salmonella isolates, respectively. We tested the effectiveness of phage PA13076 and PC2184 as well as a cocktail combination of both in three different foods (chicken breast, pasteurized whole milk and Chinese cabbage contaminated with SE. Samples were spiked with 1 × 104 CFU individual SE or a mixture of strains (ATCC13076 and CVCC2184, then treated with 1 × 108 PFU individual phage or a two phage cocktail, and incubated at 4 °C or 25 °C for 5 h. In general, the inhibitory effect of phage and phage cocktail was better at 4 °C than that at 25 °C, whereas the opposite result was observed in Chinese cabbage, and phage cocktail was better than either single phage. A significant reduction in bacterial numbers (1.5–4 log CFU/sample, p < 0.05 was observed in all tested foods. The two phages on the three food samples were relatively stable, especially at 4 ºC, with the phages exhibiting the greatest stability in milk. Our research shows that our phages have potential effectiveness as a bio-control agent of Salmonella in foods.

  8. Bio-Control of Salmonella Enteritidis in Foods Using Bacteriophages

    Science.gov (United States)

    Bao, Hongduo; Zhang, Pengyu; Zhang, Hui; Zhou, Yan; Zhang, Lili; Wang, Ran

    2015-01-01

    Two lytic phages, vB_SenM-PA13076 (PA13076) and vB_SenM-PC2184 (PC2184), were isolated from chicken sewage and characterized with host strains Salmonella Enteritidis (SE) ATCC13076 and CVCC2184, respectively. Transmission electron microscopy revealed that they belonged to the family Myoviridae. The lytic abilities of these two phages in liquid culture showed 104 multiplicity of infection (MOI) was the best in inhibiting bacteria, with PC2184 exhibiting more activity than PA13076. The two phages exhibited broad host range within the genus Salmonella. Phage PA13076 and PC2184 had a lytic effect on 222 (71.4%) and 298 (95.8%) of the 311 epidemic Salmonella isolates, respectively. We tested the effectiveness of phage PA13076 and PC2184 as well as a cocktail combination of both in three different foods (chicken breast, pasteurized whole milk and Chinese cabbage) contaminated with SE. Samples were spiked with 1 × 104 CFU individual SE or a mixture of strains (ATCC13076 and CVCC2184), then treated with 1 × 108 PFU individual phage or a two phage cocktail, and incubated at 4 °C or 25 °C for 5 h. In general, the inhibitory effect of phage and phage cocktail was better at 4 °C than that at 25 °C, whereas the opposite result was observed in Chinese cabbage, and phage cocktail was better than either single phage. A significant reduction in bacterial numbers (1.5–4 log CFU/sample, p tested foods. The two phages on the three food samples were relatively stable, especially at 4 °C, with the phages exhibiting the greatest stability in milk. Our research shows that our phages have potential effectiveness as a bio-control agent of Salmonella in foods. PMID:26305252

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

    Science.gov (United States)

    Salehi, Sanaz; Howe, Kevin; Lawrence, Mark L; Brooks, John P; Bailey, R Hartford; Karsi, Attila

    2017-01-15

    Nontyphoidal Salmonella strains are the main source of pathogenic bacterial contamination in the poultry industry. Recently, Salmonella enterica serovar Kentucky has been recognized as the most prominent serovar on carcasses in poultry-processing plants. Previous studies showed that flagella are one of the main factors that contribute to bacterial attachment to broiler skin. However, the precise role of flagella and the mechanism of attachment are unknown. There are two different flagellar subunits (fliC and fljB) expressed alternatively in Salmonella enterica serovars using phase variation. Here, by making deletions in genes encoding flagellar structural subunits (flgK, fliC, and fljB), and flagellar motor (motA), we were able to differentiate the role of flagella and their rotary motion in the colonization of broiler skin and cellular attachment. Utilizing a broiler skin assay, we demonstrated that the presence of FliC is necessary for attachment to broiler skin. Expression of the alternative flagellar subunit FljB enables Salmonella motility, but this subunit is unable to mediate tight attachment. Deletion of the flgK gene prevents proper flagellar assembly, making Salmonella significantly less adherent to broiler skin than the wild type. S Kentucky with deletions in all three structural genes, fliC, fljB, and flgK, as well as a flagellar motor mutant (motA), exhibited less adhesion and invasion of Caco-2 cells, while an fljB mutant was as adherent and invasive as the wild-type strain. In this work, we answered clearly the role of flagella in S Kentucky attachment to the chicken skin and Caco-2 cells. We demonstrated that the presence of FliC is necessary for attachment to broiler skin. Expression of the alternative flagellar subunit FljB enables Salmonella motility, but this subunit is unable to mediate strong attachment. Deletion of the flgK gene prevents proper flagellar assembly, making Salmonella significantly less adherent to broiler skin than the wild

  10. A case of reactive arthritis after Salmonella enteritis in a 12-year-old boy

    Directory of Open Access Journals (Sweden)

    Peter Chun

    2011-07-01

    Full Text Available Reactive arthritis comprises a subgroup within infection-associated arthritides in genetically susceptible hosts. Researchers and clinicians recognize two clinical forms of reactive arthritis which occurs after genitourinary tract infection and after gastrointestinal tract infection. Chlamydia infection has been implicated as the most common agent associated with post-venereal reactive arthritis. Studies have proposed Shigella infection, Salmonella infection, or Yersinia infection as the microorganisms responsible for the post-dysenteric form. The human leukocyte antigen (HLA-B27 antigen is the best-known predisposing factor. We report a case of HLA-B27-associated reactive arthritis after Salmonella enteritis at Pusan National University hospital.

  11. Behavior of Salmonella during fermentation, drying and storage of cocoa beans.

    Science.gov (United States)

    do Nascimento, Maristela da Silva; Pena, Pamela Oliveira; Brum, Daniela Merlo; Imazaki, Fabiana Taminato; Tucci, Maria Luiza SantAnna; Efraim, Priscilla

    2013-11-01

    Due to cocoa being considered a possible source of Salmonella contamination in chocolate, the behavior of Salmonella during some cocoa pre-processing stages (fermentation, drying and storage) was investigated. The fermentation process was carried out on a pilot scale (2 kg beans/box) for 7 days. Every day a fermentation box was inoculated with a Salmonella pool (ca. 4 log MPN/g). The results showed that Salmonella did not affect (P>0.05) the growth of the main microorganism groups involved in cocoa fermentation. On the other hand, the pathogen was influenced (PSalmonella showing counts ≤ 1 log MPN/g in the first days, at the end of fermentation it grew in all samples, reaching counts as high as 7.49 log MPN/g. For drying and storage, cocoa beans were inoculated during the fermentation (experiment A) or during the drying (experiment B). In these stages the decline of the water activity affected the pathogen behavior. In experiment A during the drying, Salmonella count increased in most of the samples. In experiment B either a slight growth or no growth in the samples inoculated up to 48 h was observed, whereas the other samples showed reductions from the initial count. After 30 days of storage at room temperature, the water activity decreased to 0.68, and reductions of Salmonella ranged from 0.93 to 2.52 log MPN/g. Despite the reductions observed during the storage, the pathogen was detected even after 120 days. Therefore, the results showed that Salmonella growth or survival depends on when the contamination occurs. © 2013.

  12. 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 ...

  13. 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.

  14. Antimicrobial susceptibility patterns of Salmonella typhi and ...

    African Journals Online (AJOL)

    The aim of this study was to determine antimicrobial susceptibility testing patterns of Candida Albicans and Salmonella typhi isolates. Fifteen isolates of each microorganism were collected from three hospitals located in Dar es Salaam region within a 3-month period in the year 2005. Candida Albicans and Salmonella typhi ...

  15. 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 ...

  16. Quinolone resistance in Salmonella enterica serovar Typhi ...

    African Journals Online (AJOL)

    over Asia and Africa) emerged from Southeast Asia and then spread to other regions of the world [13]. Travellers also played a significant role in spreading the resistant. Salmonella Typhi, especially to the developed world [16,. 17]. The quinolone-resistant Salmonella Typhi is not only prevalent in hospital settings but also in ...

  17. Experimental reproduction of rotavirus and Salmonella pullorum ...

    African Journals Online (AJOL)

    ADEYEYE

    2017-07-10

    Jul 10, 2017 ... 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 ... Significant growth retardation was observed in chicks given either rotavirus or Salmonella pullorum, but this effect was more ... feed and water were provided ad libitum. All the.

  18. Experimental Salmonella-associated conjunctivitis in cats.

    OpenAIRE

    Fox, J G; Beaucage, C M; Murphy, J C; Niemi, S M

    1984-01-01

    Cats were infected experimentally with Salmonella typhimurium via the conjunctiva. Clinical signs consisted of lacrimation, conjunctivitis, blepharospasm, prominent nictitating membrane and scleral injection. These signs were accompanied by an absolute neutrophilia and conjunctival smears indicative of moderate to severe suppurative inflammation. Ocular signs disappeared by day 6 postinfection. Salmonella typhimurium was cultured intermittently from the inoculated conjunctivae and rectal swab...

  19. Antimicrobial susceptibilities of salmonellae isolated from food ...

    African Journals Online (AJOL)

    transmission of typhoid bacilli and other Salmonella spp. This study was conducted to determine the prevalence and antimicrobial resistance patterns of Salmonella spp. from food handlers and cattle and compare the patterns with specimens from patients. Methods: A total of 206 stool samples from apparently healthy food ...

  20. Seroprevalence of Salmonella Gallinarum Infection in Chicken ...

    African Journals Online (AJOL)

    Bheema

    ABSTRACT. Ethiopia owns a large poultry population whose growth is highly constrained by diseases. Fowl typhoid is a serious concern in growing and adult poultry and results from infection by. Salmonella Gallinarum (Salmonella enterica subsp. enterica serovar Gallinarum biovar. Gallinarum). Knowledge of the ...

  1. Experimental reproduction of rotavirus and Salmonella pullorum ...

    African Journals Online (AJOL)

    ADEYEYE

    2017-07-10

    Jul 10, 2017 ... experiment. Body weight. Growth retardation was observed from day 7 P.I. in all infected group till the end of the study. The effects of Rotavirus and ... Table 2: Mean body weights of birds inoculated orally with Rotavirus, Salmonella or Rotavirus/Salmonella .... species and humans (Mettifogo et al., 2014).

  2. 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

  3. Expression of the marA, soxS, acrB and ramA genes related to the AcrAB/TolC efflux pump in Salmonella enterica strains with and without quinolone resistance-determining regions gyrA gene mutations.

    Science.gov (United States)

    Ferrari, Rafaela Gomes; Galiana, Antonio; Cremades, Rosa; Rodríguez, Juan Carlos; Magnani, Marciane; Tognim, Maria Cristina Bronharo; Oliveira, Tereza C R M; Royo, Gloria

    2013-01-01

    Several studies have been conducted in recent years to elucidate the structure, function and significance of AcrB, MarA, SoxS and RamA in Salmonella enterica. In this study, the relative quantification of acrB, soxS, marA and ramA genes expression was evaluated in 14 strains of S. enterica, with or without accompanying mutations in the quinolone resistance-determining regions of the gyrA gene, that were exposed to ciprofloxacin during the exponential growth phase. The presence of ciprofloxacin during the log phase of bacterial growth activated the genes marA, soxS, ramA and acrB in all S. enterica strains analyzed in this study. The highest expression levels for acrB were observed in strains with gyrA mutation, and marA showed the highest expression in the strains without mutation. Considering only the strains with ciprofloxacin minimum inhibitory concentration valuesgene in the strains both with and without mutations was acrB. In the strains with ciprofloxacin minimum inhibitory concentration values ≥ 0.125 μg/mL (low susceptibility), with and without mutations in gyrA, the most expressed gene was marA. In this study, we observed that strains resistant to nalidixic acid may express genes associated with the efflux pump and the expression of the AcrAB-TolC pump genes seems to occur independently of mutations in gyrA. Copyright © 2013 Elsevier Editora Ltda. All rights reserved.

  4. Radiation survival of two nalidixic acid resistant strains of Salmonella typhimurium in various media

    Science.gov (United States)

    Shamsuzzaman, Kazi; Goodwin, Marlene; George, Ian; Singh, Harwant

    Radiation doses required for 90% inactivation, the D10 values, have been determined for two nalidixic acid-resistant strains of Salmonella typhimurium, Nal R ATCC 13311 and K1-2B, in different media. The D10 values were 0.20, 0.57 and 0.53 kGy for the ATCC 13311 strain, and were 0.21, 0.4 and 0.32 kGy for the K1-2B strain, in phosphate buffer, in nutrient broth and on chicken drumsticks, respectively. Since these two strains have radiation sensitivity similar to several Salmonella serotypes reported in the literature, they are good indicator organisms for use in studies on the effect of irradiation on Salmonella in foods that might frequently be contaminated with such organisms.

  5. 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...

  6. 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...

  7. 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...

  8. Report on the fifth workshop organised by CRL-Salmonella

    NARCIS (Netherlands)

    Raes M; Henken AM; MGB

    2001-01-01

    At 18 and 19 September 2000 a workshop was organised by the Community Reference Laboratory for Salmonella (CRL-Salmonella) in Bilthoven, the Netherlands. All National Reference Laboratories for Salmonella (NRLs-Salmonella) of the EU Member States and Norway participated (in total 38 participants).

  9. The Role of the spv Genes in Salmonella Pathogenesis

    Directory of Open Access Journals (Sweden)

    Donald G. Guiney

    2011-06-01

    Full Text Available Salmonella strains cause three main types of diseases in people: gastroenteritis, enteric (typhoid fever, and non-typhoid extra-intestinal disease with bacteremia. Genetic analysis indicates that each clinical syndrome requires distinct sets of virulence genes, and Salmonella isolates differ in their constellation of virulence traits. The spv locus is strongly associated with strains that cause non-typhoid bacteremia, but are not present in typhoid strains. The spv region contains three genes required for the virulence phenotype in mice: the positive transcriptional regulator spvR and two structural genes spvB and spvC. SpvB and SpvC are translocated into the host cell by the SPI-2 type-three secretion system. SpvB prevents actin polymerization by ADP-ribosylation of actin monomers, while SpvC has phosphothreonine lyase activity and has been shown to inhibit MAP kinase signaling. The exact mechanisms by which SpvB and SpvC act in concert to enhance virulence are still unclear. SpvB exhibits a cytotoxic effect on host cells and is required for delayed cell death by apoptosis following intracellular infection. Strains isolated from systemic infections of immune compromised patients, particularly HIV patients, usually carry the spv locus, strongly suggesting that CD4 T cells are required to control disease due to Salmonella that are spv positive. This association is not seen with typhoid fever, indicating that the pathogenesis and immunology of typhoid have fundamental differences from the syndrome of non-typhoid bacteremia.

  10. 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.

  11. 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

  12. Salmonella - at home in the host cell.

    Directory of Open Access Journals (Sweden)

    Preeti eMalik Kale

    2011-06-01

    Full Text Available The Gram-negative bacterium Salmonella enterica has developed an array of sophisticated tools to manipulate the host cell and establish an intracellular niche, for successful propagation as a facultative intracellular pathogen. While Salmonella exerts diverse effects on its host cell, only the cell biology of the classic trigger-mediated invasion process and the subsequent development of the Salmonella-containing vacuole have been investigated extensively. These processes are dependent on cohorts of effector proteins translocated into host cells by two type III secretion systems (T3SS, although T3SS-independent mechanisms of entry may be important for invasion of certain host cell-types. Recent studies into the intracellular lifestyle of Salmonella have provided new insights into the mechanisms used by this pathogen to modulate its intracellular environment. Here we discuss current knowledge of Salmonella-host interactions including invasion and establishment of an intracellular niche within the host.

  13. Pathogenesis of Salmonella-induced enteritis

    Directory of Open Access Journals (Sweden)

    R.L. Santos

    2003-01-01

    Full Text Available Infections with Salmonella serotypes are a major cause of food-borne diseases worldwide. Animal models other than the mouse have been employed for the study of nontyphoidal Salmonella infections because the murine model is not suitable for the study of Salmonella-induced diarrhea. The microbe has developed mechanisms to exploit the host cell machinery to its own purpose. Bacterial proteins delivered directly into the host cell cytosol cause cytoskeletal changes and interfere with host cell signaling pathways, which ultimately enhance disease manifestation. Recently, marked advances have been made in our understanding of the molecular interactions between Salmonella serotypes and their hosts. Here, we discuss the molecular basis of the pathogenesis of Salmonella-induced enteritis.

  14. Salmonella investigation in an Ontario feed mill.

    Science.gov (United States)

    Hacking, W C; Mitchell, W R; Carlson, H C

    1978-01-01

    The frequency of Salmonella contamination of feedstuffs and finished broiler chicken feeds at an Ontario feed mill were investigated over a four-month period. Samples of feed ingredients and finished pelleted feeds were collected at various points during manufacture and cultured in trypticase soy broth prior to selective enrichment for isolation of Salmonella. Salmonella contamination was found in 4.3% of 93 finished pelleted broiler feeds examined. The contamination appeared to result primarily from the incorporation of contaminated animal protein ingredients into the feed. Meatmeal and the broiler, premix, which contained meatmeal as a filler, were most frequently contaminated followed by feather meal. Pelleting failed to eliminate the Salmonellae from the feeds. The methods used failed to detect Salmonella in the environment of the feed mill or its delivery trucks. Recommendations for control are made. PMID:369663

  15. Survival of Salmonella east bourne and Salmonella typhimurium in chocolate.

    Science.gov (United States)

    Tamminga, S K; Beumer, R R; Kampelmacher, E H; van Leusden, F M

    1976-02-01

    Experiments were carried out to assess the reduction rate of two salmonella strains (S. eastbourne and S. typhimurium) in chocolate bars. After artificial contamination of chocolate, after 'conching', with about 10(6) S. eastbourne/g. this organism was still recovered after 9 months storage. The strain of S. typhimurium was less resistant. Both serotypes died off more rapidly in bitter chocolate than in milk chocolate. After contamination with a smaller dose (about 10(3)/g.) with these two serotypes, similar differences were observed.

  16. Evaluation of target sequences for the polymerase chain reaction-based detection of Salmonella in artificially contaminated beef.

    Science.gov (United States)

    de Almeida, Michelle Vieira; Silva, Abelardo; Nero, Luís Augusto

    2014-02-01

    Salmonella is a major cause of foodborne diseases worldwide, which has fueled the demand for the development and evaluation of sensitive, specific, and rapid detection methodologies, such as polymerase chain reaction (PCR). In this study, six primer pairs for the detection of Salmonella were evaluated by PCR with isolates of Salmonella spp. (115) and other bacteria (104). The primers designed for the sifB gene provided the best performance regarding specificity and sensitivity (100%). These primers were selected and used to develop a PCR assay for Salmonella detection during the enrichment steps of the conventional detection method in spiked beef samples. The enrichment steps were: buffered peptone water (BPW), Rappaport-Vassiliadis soya broth (RVS) and at the Müller-Kauffmann tetrathionate novobiocin broth (MKTTn), after 18 h (BPW) and 24 h (RVS and MKTTn) of incubation. The initial concentrations of the Salmonella inocula were 10¹, 10², and 10³ colony-forming units/25 g. The protocol was able to detect Salmonella at all concentrations in the enrichment steps, but not in the nonenriched samples. These results indicated that the proposed protocol was suitable to detect Salmonella in beef during the intermediate stages of the conventional isolation protocol, substantially reducing the time required to obtain the final results.

  17. 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

    . This is due to the fact that antibiotics are not yet commonly used by of the rural population in The Gambia for treatment of NTS infections as well in humans as in the animal production system. Our results do not support the hypothesis that humans and animals in close contact in the same household carry genotypically similar Salmonella serotypes. Nevertheless these findings have stirred up the problem of the transmission of NTS in Africa and have highlighted the poultry population as playing a pivotal role of healthy carriers in the epidemiology of NTS. Based on this study, we suggest other areas to be investigated such as the environment and human-to-human transmission. Little is known on the molecular epidemiology of NTS particularly with respect to their virulence genes. Therefore, to assess their occurrence and contribution to disease in humans and animals in The Gambia and Senegal, we screened all serotypes isolated from humans, animals and food in both countries (chapter 5. A total number of 185 NTS was tested by PCR for the presence of 12 virulence genes. Among these genes, 10 belong to the five described Salmonella Pathogenicity islands thought to be implicated in Salmonella pathogenesis; and the other two genes are carried by plasmids. All genes were present at a level of more than 70% except sopE and pefA which were observed in 33% and 44% of the isolates, respectively. The most prevalent gene was invA (95.5% which is an invasion gene conserved within the Salmonella genus. It has been widely used to diagnose Salmonella in humans and animals. However, the sopE gene associated with outbreaks in human and animals was present in all serotypes isolated in humans with diarrhoea except one. Interestingly, Salmonella Istanbul and Salmonella Javiana isolated from chicken serving restaurants carried all the virulence genes of the five pathogenicity islands. There was a significant association between some virulence genes (sopB, sopE and pipD and resistance to certain

  18. Dual Expression of the Salmonella Effector SrfJ in Mammalian Cells and Plants

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    Julia Aguilera-Herce

    2017-12-01

    Full Text Available SrfJ is an effector of the Salmonella pathogenicity island 2-encoded type III secretion system. Salmonella enterica serovar Typhimurium expresses srfJ under two disparate sets of conditions: media with low Mg2+ and low pH, imitating intravacuolar conditions, and media with myo-inositol (MI, a carbohydrate that can be used by Salmonella as sole carbon source. We investigated the molecular basis for this dual regulation. Here, we provide evidence for the existence of two distinct promoters that control the expression of srfJ. A proximal promoter, PsrfJ, responds to intravacuolar signals and is positively regulated by SsrB and PhoP and negatively regulated by RcsB. A second distant promoter, PiolE, is negatively regulated by the MI island repressor IolR. We also explored the in vivo activity of these promoters in different hosts. Interestingly, our results indicate that the proximal promoter is specifically active inside mammalian cells whereas the distant one is expressed upon Salmonella colonization of plants. Importantly, we also found that inappropriate expression of srfJ leads to reduced proliferation inside macrophages whereas lack of srfJ expression increases survival and decreases activation of defense responses in plants. These observations suggest that SrfJ is a relevant factor in the interplay between Salmonella and hosts of different kingdoms.

  19. Dual Expression of the Salmonella Effector SrfJ in Mammalian Cells and Plants.

    Science.gov (United States)

    Aguilera-Herce, Julia; Zarkani, Azhar A; Schikora, Adam; Ramos-Morales, Francisco

    2017-01-01

    SrfJ is an effector of the Salmonella pathogenicity island 2-encoded type III secretion system. Salmonella enterica serovar Typhimurium expresses srfJ under two disparate sets of conditions: media with low Mg2+ and low pH, imitating intravacuolar conditions, and media with myo-inositol (MI), a carbohydrate that can be used by Salmonella as sole carbon source. We investigated the molecular basis for this dual regulation. Here, we provide evidence for the existence of two distinct promoters that control the expression of srfJ. A proximal promoter, PsrfJ, responds to intravacuolar signals and is positively regulated by SsrB and PhoP and negatively regulated by RcsB. A second distant promoter, PiolE, is negatively regulated by the MI island repressor IolR. We also explored the in vivo activity of these promoters in different hosts. Interestingly, our results indicate that the proximal promoter is specifically active inside mammalian cells whereas the distant one is expressed upon Salmonella colonization of plants. Importantly, we also found that inappropriate expression of srfJ leads to reduced proliferation inside macrophages whereas lack of srfJ expression increases survival and decreases activation of defense responses in plants. These observations suggest that SrfJ is a relevant factor in the interplay between Salmonella and hosts of different kingdoms.

  20. Impact of Hfq on the intrinsic drug resistance of Salmonella enterica serovar Typhimurium

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    Mitsuko eHayashi-Nishino

    2012-06-01

    Full Text Available Salmonella enterica is an important enteric pathogen, and its various serovars cause 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. Hfq is an RNA chaperon that mediates the binding of small RNAs to mRNA and assists in post-transcriptional gene regulation in bacteria. Although Hfq is related to important phenotypes including virulence in Salmonella, its role in the drug resistance of this organism is unknown. The aim of this study was to investigate the role of Hfq in intrinsic drug resistance of S. enterica serovar Typhimurium. hfq mutant was susceptible to acriflavine. Although there is a relationship between the production of the AcrB multidrug efflux pump and Hfq in Escherichia coli, the deletion of the drug efflux acrB did not impair the effect of hfq deletion on Salmonella susceptibility. In contrast, the deletion of another drug efflux gene, smvA, impaired the effect of hfq deletion on acriflavine susceptibility. These results indicate that Hfq regulates the intrinsic drug resistance, and it may influence drug susceptibility by regulating SmvA in Salmonella.

  1. Quantification of Salmonella Typhi in water and sediments by molecular-beacon based qPCR.

    Science.gov (United States)

    Rani, Neetika; Vajpayee, Poornima; Bhatti, Saurabh; Singh, Smriti; Shanker, Rishi; Gupta, Kailash Chand

    2014-10-01

    A molecular-beacon based qPCR assay targeting staG gene was designed for specific detection and quantification of S. Typhi and validated against water and sediment samples collected from the river Ganga, Yamuna and their confluence on two days during Mahakumbha mela 2012-2013 (a) 18 December, 2012: before six major religious holy dips (Makar Sankranti, Paush Poornima, Mauni Amavasya, Basant Panchami, Maghi Poornima and Mahashivratri) (b) 10 February, 2013: after the holy dip was taken by over 3,00,00,000 devotees led by ascetics of Hindu sects at Sangam on 'Mauni Amavasya' (the most auspicious day of ritualistic mass bathing). The assay could detect linearly lowest 1 genomic equivalent per qPCR and is highly sensitive and selective for S. Typhi detection in presence of non specific DNA from other bacterial strains including S. Paratyphi A and S. Typhimurium. It has been observed that water and sediment samples exhibit S. Typhi. The mass holy dip by devotees significantly affected the water and sediment quality by enhancing the number of S. Typhi in the study area. The qPCR developed in the study might be helpful in planning the intervention and prevention strategies for control of enteric fever outbreaks in endemic regions. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Inactivation of Salmonella during cocoa roasting and chocolate conching.

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    Nascimento, Maristela da Silva do; Brum, Daniela Merlo; Pena, Pamela Oliveira; Berto, Maria Isabel; Efraim, Priscilla

    2012-10-15

    The high heat resistance of Salmonella in foods with low water activity raises particular issues for food safety, especially chocolate, where outbreak investigations indicate that few colony-forming units are necessary to cause salmonellosis. This study evaluated the efficiency of cocoa roasting and milk chocolate conching in the inactivation of Salmonella 5-strain suspension. Thermal resistance of Salmonella was greater in nibs compared to cocoa beans upon exposure at 110 to 130°C. The D-values in nibs were 1.8, 2.2 and 1.5-fold higher than those calculated for cocoa beans at 110, 120 and 130°C. There was no significant difference (p>0.05) between the matrices only at 140°C. Since in the conching of milk chocolate the inactivation curves showed rapid death in the first 180 min followed by a lower inactivation rate, and two D-values were calculated. For the first time interval (0-180 min) the D-values were 216.87, 102.27 and 50.99 min at 50, 60 and 70°C, respectively. The other D-values were determined from the second time interval (180-1440 min), 1076.76 min at 50°C, 481.94 min at 60°C and 702.23 min at 70°C. The results demonstrated that the type of matrix, the process temperature and the initial count influenced the Salmonella resistance. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Salmonella proteomics under oxidative stress reveals coordinated regulation of antioxidant defense with iron metabolism and bacterial virulence.

    Science.gov (United States)

    Fu, Jiaqi; Qi, Linlu; Hu, Mo; Liu, Yanhua; Yu, Kaiwen; Liu, Qian; Liu, Xiaoyun

    2017-03-22

    Salmonella Typhimurium is a bacterial pathogen that can cause widespread gastroenteritis. Salmonella encounters reactive oxygen species both under free-living conditions and within their mammalian host during infection. To study its response to oxidative stress, we performed the first large-scale proteomic profiling of Salmonella upon exposure to H 2 O 2 . Among 1600 detected proteins, 83 proteins showed significantly altered abundance. Interestingly, only a subset of known antioxidants was induced, likely due to distinct regulatory mechanisms. In addition, we found elevation of several Salmonella acquired phage products with potential contribution to DNA repair under oxidative stress. Furthermore, we observed robust induction of iron-uptake systems and disruption of these pathways led to bacterial survival defects under H 2 O 2 challenge. Importantly, this work is the first to report that oxidative stress severely repressed the Salmonella type III secretion system (T3SS), reducing its virulence. Biological significance Salmonella, a Gram-negative bacterial pathogen, encounters reactive oxygen species (ROS) both endogenously and exogenously. To better understand its response to oxidative stress, we performed the first large-scale profiling of Salmonella protein expression upon H 2 O 2 treatment. Among 1600 quantified proteins, the abundance of 116 proteins was altered significantly. Notably, iron acquisition systems were induced to promote bacterial survival under oxidative stress. Furthermore, we are the first to report that oxidative stress severely repressed Salmonella type III secretion system and hence reduced its virulence. We believe that these findings will not only help us better understand the molecular mechanisms that Salmonella has evolved to counteract ROS but also the global impact of oxidative stress on bacterial physiology. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. A quantitative approach towards a better understanding of the dynamics of Salmonella spp. in a pork slaughter-line.

    Science.gov (United States)

    van Hoek, Angela H A M; de Jonge, Rob; van Overbeek, Wendy M; Bouw, El; Pielaat, Annemarie; Smid, Joost H; Malorny, Burkhard; Junker, Ernst; Löfström, Charlotta; Pedersen, Karl; Aarts, Henk J M; Heres, Lourens

    2012-02-01

    Pork contributes significantly to the public health disease burden caused by Salmonella infections. During the slaughter process pig carcasses can become contaminated with Salmonella. Contamination at the slaughter-line is initiated by pigs carrying Salmonella on their skin or in their faeces. Another contamination route could be resident flora present on the slaughter equipment. To unravel the contribution of these two potential sources of Salmonella a quantitative study was conducted. Process equipment (belly openers and carcass splitters), faeces and carcasses (skin and cutting surfaces) along the slaughter-line were sampled at 11 sampling days spanning a period of 4 months. Most samples taken directly after killing were positive for Salmonella. On 96.6% of the skin samples Salmonella was identified, whereas a lower number of animals tested positive in their rectum (62.5%). The prevalence of Salmonella clearly declined on the carcasses at the re-work station, either on the cut section or on the skin of the carcass or both (35.9%). Throughout the sampling period of the slaughter-line the total number of Salmonella per animal was almost 2 log lower at the re-work station in comparison to directly after slaughter. Seven different serovars were identified during the study with S. Derby (41%) and S. Typhimurium (29%) as the most prominent types. A recurring S. Rissen contamination of one of the carcass splitters indicated the presence of an endemic 'house flora' in the slaughterhouse studied. On many instances several serotypes per individual sample were found. The enumeration of Salmonella and the genotyping data gave unique insight in the dynamics of transmission of this pathogen in a slaughter-line. The data of the presented study support the hypothesis that resident flora on slaughter equipment was a relevant source for contamination of pork. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Nutrient Composition Promotes Switching between Pellicle and Bottom Biofilm in Salmonella

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    Sonia Paytubi

    2017-11-01

    Full Text Available Salmonella is one of the most frequently reported causes of foodborne illness worldwide. Non-typhoidal serovars cause gastroenteritis in humans. Salmonella can grow on surfaces forming biofilms, contributing to its persistence since biofilms are difficult to eradicate due to the high resistance to antimicrobials and disinfectants. It has been described that there are two crucial biofilm promoting factors in Salmonella: curli and cellulose. The expression of both factors is coordinately regulated by the transcriptional regulator CsgD. Most biofilm studies of Salmonella have been performed by growing bacteria in low osmolarity rich medium and low temperature (25°C. In such conditions, the biofilm is formed at the air–liquid interface (pellicle biofilm. Remarkably, when Salmonella grow in minimal medium, biofilm formation switches from the air–liquid interface to the solid–liquid interface (bottom biofilm. In this report, the switching between pellicle and bottom biofilm has been characterized. Our data indicate that curli, but not cellulose, is crucial for the formation of both kinds of biofilms. In minimal medium, conditions promoting formation of bottom biofilm, a high transcriptional expression of csgD and consequently of the genes involved in the synthesis of curli and cellulose was detected. The nutritional status of the cells seems to be pivotal for the spatial distribution of the biofilms formed. When bacteria is growing in minimal medium the addition of amino acids downregulates the expression of csgB and causes the switch between bottom and pellicle biofilm. The crosstalk between general metabolism and biofilm formation is also highlighted by the fact that the metabolic sensor cAMP modulates the type of biofilm generated by Salmonella. Moreover, cAMP regulates transcriptional expression of csgD and stimulates pellicle biofilm formation, suggesting that the physiological conditions define the type of biofilm formed by Salmonella

  6. Social stress increases fecal shedding of Salmonella typhimurium by early weaned piglets.

    Science.gov (United States)

    Callaway, T R; Morrow, J L; Edrington, T S; Genovese, K J; Dowd, S; Carroll, J; Dailey, J W; Harvey, R B; Poole, T L; Anderson, R C; Nisbet, D J

    2006-09-01

    "Segregated early weaning" (SEW) of pigs reduces exposure to pathogenic bacteria, but upon arrival at grower facilities pigs may be co-mingled regardless of farm of origin. The present study was designed to examine the effect of mixing (social) stress on populations of Salmonella enterica Typhimurium in SEW pigs. Piglets (7 days old; n = 28 in each of 2 replicates) were separated into 2 treatments (control and mixed groups) of 2 pens per treatment (7 piglets/pen). One (n = 1) "seeder" pig/pen was inoculated with 10(9) CFU of S. Typhimurium. Each seeder was placed with non-inoculated "contact" piglets (n = 6). A"contact" piglet was swapped each day between the "mixed" pens for 5 days; pigs in control pens were not exchanged. On day 5, the incidence of fecal Salmonella shedding was higher in the mixed contact pigs (P weaned pigs may increase susceptibility to and/or fecal shedding of Salmonella. Food-borne Salmonella infections in the United States are estimated to cost the economy dollar 2.4 billion annually (ERS/USDA, 2001). Approximately 6-9% of human salmonellosis is associated with the consumption of pork products (Frenzen et al., 1999). Salmonella is relatively common on swine farms and has been isolated from all stages of the pork production chain (Davies et al., 1999; Fedorka-Cray et al., 1997b; Rostagno et al., 2003). Salmonella is a threat to the pork industry not only from a food-safety perspective as a public health concern, but some Salmonella serotypes can cause clinical illnesses in swine, negatively impacting production efficiency and profitability (Schwartz, 1991).

  7. Effects of meat juice on biofilm formation of Campylobacter and Salmonella.

    Science.gov (United States)

    Li, Jiaqi; Feng, Jinsong; Ma, Lina; de la Fuente Núñez, César; Gölz, Greta; Lu, Xiaonan

    2017-07-17

    Campylobacter and Salmonella are leading causes of foodborne illnesses worldwide, vastly harboured by raw meat as their common food reservoir. Both microbes are prevalent in meat processing environments in the form of biofilms that contribute to cross-contamination and foodborne infection. This study applied raw meat juice (chicken juice and pork juice) as a minimally processed food model to study its effects on bacterial biofilm formation. Meat juice was collected during the freeze-thaw process of raw meat and sterilized by filtration. In 96-well polystyrene plates and glass chambers, supplementation of over 25% meat juice (v/v) in laboratory media led to an increase in biofilm formation of Campylobacter and Salmonella. During the initial attachment stage of biofilm development, more bacterial cells were present on surfaces treated with meat juice residues compared to control surfaces. Meat juice particulates on abiotic surfaces facilitated biofilm formation of Campylobacter and Salmonella under both static and flow conditions, with the latter being assessed using a microfluidic platform. Further, the deficiency in biofilm formation of selected Campylobacter and Salmonella mutant strains was restored in the presence of meat juice particulates. These results suggested that meat juice residues on the abiotic surfaces might act as a surface conditioner to support initial attachment and biofilm formation of Campylobacter and Salmonella. This study sheds light on a possible survival mechanism of Campylobacter and Salmonella in meat processing environments, and indicates that thorough cleaning of meat residues during meat production and handling is critical to reduce the bacterial load of Campylobacter and Salmonella. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Wild griffon vultures (Gyps fulvus as a source of Salmonella and Campylobacter in Eastern Spain.

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    Clara Marin

    Full Text Available The existence of Campylobacter and Salmonella reservoirs in wildlife is a potential hazard to animal and human health; however, the prevalence of these species is largely unknown. Until now, only a few studies have evaluated the presence of Campylobacter and Salmonella in wild griffon vultures and based on a small number of birds. The aim of this study was to evaluate the presence of Campylobacter and Salmonella in wild griffon vultures (n = 97 during the normal ringing programme at the Cinctorres Observatory in Eastern Spain. In addition, the effect of ages of individuals (juveniles, subadult and adult on the presence were compared. Campylobacter was isolated from 1 of 97 (1.0% griffon vultures and identified as C. jejuni. Salmonella was isolated from 51 of 97 (52.6% griffon vultures. No significant differences were found between the ages of individuals for the presence of Salmonella. Serotyping revealed 6 different serovars among two Salmonella enterica subspecies; S. enterica subsp. enterica (n = 49, 96.1% and S. enterica subsp. salamae (n = 2, 3.9%. No more than one serovar was isolated per individual. The serovars isolated were S. Typhimurium (n = 42, 82.3%, S. Rissen (n = 4, 7.8%, S. Senftenberg (n = 3, 5.9% and S. 4,12:b[-] (n = 2, 3.9%. Our results imply that wild griffon vultures are a risk factor for Salmonella transmission, but do not seem to be a reservoir for Campylobacter. We therefore rule out vultures as a risk factor for human campylobacteriosis. Nevertheless, further studies should be undertaken in other countries to confirm these results.

  9. Prevalence of antimicrobial resistance of non-typhoidal Salmonella serovars in retail aquaculture products.

    Science.gov (United States)

    Zhang, Jianmin; Yang, Xiaowei; Kuang, Dai; Shi, Xianming; Xiao, Wenjia; Zhang, Jing; Gu, Zhen; Xu, Xuebin; Meng, Jianghong

    2015-10-01

    Aquaculture products can become sources of Salmonella by exposure to contaminated water or through processing practices, thus representing a public health hazard. A study was conducted on Salmonella contamination in aquaculture products sampled from marketplaces and retailers in Shanghai, China. A total of 730 samples (including fish, shellfish, bullfrog, clam, shrimp and others) were obtained from 2006 to 2011. Among them, 217 (29.7%) were positive for Salmonella. Thirty-eight serovars were identified in the 217 Salmonella isolates. The most prevalent were Salmonella Aberdeen (18.4%), S. Wandsworth (12.0%), S. Thompson (9.2%), S. Singapore (5.5%), S. Stanley (4.6%), S. Schwarzengrund (4.6%), S. Hvittingfoss (4.1%) and S. Typhimurium (4.1%). Many resistant isolates were detected, with 69.6% resistant to at least one antimicrobial drug. We observed high resistance to sulfonamides (56.5%), tetracycline (34.1%), streptomycin (28.6%), ampicillin (23.5%) and nalidixic acid (21.2%). Lower levels of resistance were found for gentamicin (3.2%), ciprofloxacin (2.3%), ceftiofur (1.3%), cefotaxime (0.9%), ceftazidime (0.5%) and cefepime (0.5%). A total of 43.3% of the Salmonella isolates were multidrug-resistant and 44 different resistance patterns were found. This study provided data on the prevalence, serovars and antimicrobial resistance of Salmonella from retail aquaculture products in Shanghai, and indicated the need for monitoring programs for microbiologic safety in such projects and for more prudent drug use in aquaculture production in order to reduce the risk of development and spread of antimicrobial resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Molecular methods for serovar determination of Salmonella.

    Science.gov (United States)

    Shi, Chunlei; Singh, Pranjal; Ranieri, Matthew Louis; Wiedmann, Martin; Moreno Switt, Andrea Isabel

    2015-01-01

    Salmonella is a diverse foodborne pathogen, which has more than 2600 recognized serovars. Classification of Salmonella isolates into serovars is essential for surveillance and epidemiological investigations; however, determination of Salmonella serovars, by traditional serotyping, has some important limitations (e.g. labor intensive, time consuming). To overcome these limitations, multiple methods have been investigated to develop molecular serotyping schemes. Currently, molecular methods to predict Salmonella serovars include (i) molecular subtyping methods (e.g. PFGE, MLST), (ii) classification using serovar-specific genomic markers and (iii) direct methods, which identify genes encoding antigens or biosynthesis of antigens used for serotyping. Here, we reviewed reported methodologies for Salmonella molecular serotyping and determined the "serovar-prediction accuracy", as the percentage of isolates for which the serovar was correctly classified by a given method. Serovar-prediction accuracy ranged from 0 to 100%, 51 to 100% and 33 to 100% for molecular subtyping, serovar-specific genomic markers and direct methods, respectively. Major limitations of available schemes are errors in predicting closely related serovars (e.g. Typhimurium and 4,5,12:i:-), and polyphyletic serovars (e.g. Newport, Saintpaul). The high diversity of Salmonella serovars represents a considerable challenge for molecular serotyping approaches. With the recent improvement in sequencing technologies, full genome sequencing could be developed into a promising molecular approach to serotype Salmonella.

  11. Control of Salmonella enteritidis in Sweden.

    Science.gov (United States)

    Wierup, M; Engström, B; Engvall, A; Wahlström, H

    1995-05-01

    The Swedish control of Salmonella, with special reference to Salmonella enteritidis, in poultry is described. The control is directed at all serotypes of Salmonella and imported grandparent chickens are controlled, which is considered to be the main reason why Sweden so far is not found to be involved in the worldwide spread of different phagetypes of S. enteritidis. However, this spread has initiated a more stringent control of Salmonella in layers as earlier existed in broilers. Since 1990, 90% of the layer flocks are voluntarily tested for Salmonella before slaughter by bacteriological examination of pooled faecal samples. If S. enteritidis is isolated the flock is destroyed. This test, and in addition two similar tests during the production are mandatory as of January 1st, 1994. The voluntary Salmonella control programme has also been extended to all of the layer parents and hatcheries since 1991. Only heat-treated feed is given to all layer chickens during the rearing period and its use is becoming gradually more common also during the production period. Since 1987, four layer flocks have been found to be infected by S. enteritidis phagetype 4 and one flock with phagetype 6. During 1970-1984, 90% of all flocks of broilers were voluntarily tested bacteriologically for Salmonella before slaughter, and since 1984 such a control is mandatory to all flocks. As a result of this and other controls, S. enteritidis has not been isolated from broilers since 1972. Based on a governmental regulation from 1961, introduced as a result of a large Salmonella epidemic in 1953, Sweden runs an active, official control of Salmonella (Wierup et al., 1992).(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Dissemination of Salmonella enteritidis by experimentally-infected pigeons

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    ÁH Albuquerque

    2013-09-01

    Full Text Available Two groups of domestic pigeons (Columba livia were experimentally infected orally with doses of 9.5 x10(7 and 9.5 x10(9 CFU/mL (group A and B, respectively of a Salmonella Enteritidis (SE strain isolated from chickens. None of the used doses caused mortality of the inoculated birds; however, the pathogen was successfully recovered from the liver and spleen of group B birds on day 7 post-inoculation (dpi. Pathogen shedding, as evaluated through cloacal swabs, occurred in both groups until the 14th day of observation (p <0.05. Among all fecal samples collected from group B (n=4, three different birds shed the pathogen in their feces, out of which two were positive on 3 dpi and one on 7 dpi. The same number of fecal samples was evaluated in group A and only one bird shed the pathogen, on 7 and 14 dpi. The concentration of the microorganism in the feces was lower in group A than any sample from Group B. Salmonella Enteritidis isolated from chickens, when inoculated in pigeons, may be recovered from feces, cloacal swabs and organs, and these birds may contaminate poultry causing economic losses as well as posing a risk to the public health.

  13. Identification of a Plasmid-Mediated Quinolone Resistance Gene in Salmonella Isolates from Texas Dairy Farm Environmental Samples.

    Science.gov (United States)

    Cummings, K J; Rodriguez-Rivera, L D; Norman, K N; Ohta, N; Scott, H M

    2017-06-01

    A recent increase in plasmid-mediated quinolone resistance (PMQR) has been detected among Salmonella isolated from humans in the United States, and it is necessary to determine the sources of human infection. We had previously isolated Salmonella from dairy farm environmental samples collected in Texas, and isolates were tested for anti-microbial susceptibility. Two isolates, serotyped as Salmonella Muenster, showed the discordant pattern of nalidixic acid susceptibility and intermediate susceptibility to ciprofloxacin. For this project, whole-genome sequencing of both isolates was performed to detect genes associated with quinolone resistance. The plasmid-mediated qnrB19 gene and IncR plasmid type were identified in both isolates. To our knowledge, this is the first report of PMQR in Salmonella isolated from food animals or agricultural environments in the United States. © 2016 Blackwell Verlag GmbH.

  14. 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.

  15. Trauma Associated Acute Navicular Salmonella Osteomyelitis

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    Soner Sertan Kara

    2014-12-01

    Full Text Available Akut osteomyelit tani ve tedavide gecikme olmasi durumunda yol acabilecegi olasi sekeller ve mortalite nedeniyle tahrip edici olabilecek bir hastaliktir. Navikula nadiren tutulur ve Salmonella turleri de saglikli cocuklarda akut osteomyelite neden olabilir. Burada 4 yasinda, daha once bilinen bir immun yetmezligi, orak hucreli anemisi, hic bir gastrointestinal yakinma ya da supheli besin tuketim oykusu olmayan, ancak ayak bilegi burkulma oykusu olan ve akut navikuler Salmonella osteomiyeliti tanisi konulan bir erkek cocuk olgusu sunulmustur. Hasta cerrahi gecirmeden ve komplikasyon gelismeden iyilesmistir. Travma, altta yatan hastaligi olmayan, saglikli cocuklarda Salmonella osteomyelitini kolaylastirabilmektedir. Uygun tani ve tedavi, akut osteomiyelitin komplikasyonlarini ve gerekebilecek bir cerrahi girisimi engelleyebilir.

  16. EU Interlaboratory comparison study VII on bacteriological detection of Salmonella spp

    NARCIS (Netherlands)

    Korver H; Nagelkerke NJD; van de Giessen AW; Mooijman KA; MGB; IMAR

    2005-01-01

    In 2003 werd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, the Netherlands) het zevende bacteriologische ringonderzoek georganiseerd. Nationale Referentie Laboratoria voor Salmonella (NRL's-Salmonella) van de EU lidstaten (16), van NRL Noorwegen en

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

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    Maria Fookes

    2011-08-01

    Full Text Available The genus Salmonella contains two species, S. bongori and S. enterica. Compared to the well-studied S. enterica there is a marked lack of information regarding the genetic makeup and diversity of S. bongori. S. bongori has been found predominantly associated with cold-blooded animals, but it can infect humans. To define the phylogeny of this species, and compare it to S. enterica, we have sequenced 28 isolates representing most of the known diversity of S. bongori. This cross-species analysis allowed us to confidently differentiate ancestral functions from those acquired following speciation, which include both metabolic and virulence-associated capacities. We show that, although S. bongori inherited a basic set of Salmonella common virulence functions, it has subsequently elaborated on this in a different direction to S. enterica. It is an established feature of S. enterica evolution that the acquisition of the type III secretion systems (T3SS-1 and T3SS-2 has been followed by the sequential acquisition of genes encoding secreted targets, termed effectors proteins. We show that this is also true of S. bongori, which has acquired an array of novel effector proteins (sboA-L. All but two of these effectors have no significant S. enterica homologues and instead are highly similar to those found in enteropathogenic Escherichia coli (EPEC. Remarkably, SboH is found to be a chimeric effector protein, encoded by a fusion of the T3SS-1 effector gene sopA and a gene highly similar to the EPEC effector nleH from enteropathogenic E. coli. We demonstrate that representatives of these new effectors are translocated and that SboH, similarly to NleH, blocks intrinsic apoptotic pathways while being targeted to the mitochondria by the SopA part of the fusion. This work suggests that S. bongori has inherited the ancestral Salmonella virulence gene set, but has adapted by incorporating virulence determinants that resemble those employed by EPEC.

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

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    yesim cekin

    2014-03-01

    Full Text Available Aim: Salmonella infections are the leading cause of food-borne infections and can cause gastroenteritis outbreaks worldwide. Salmonella species is defined as inability to lactose fermentation, using citrate as a carbon source, using lysine as nitrate source and forming Hydrogen sulfide (H2S in TSI agar. However, confirmation of false positive results is time consuming and lead to increased costs. The aim of this study is to evaluate the performance of CHROMagar Salmonella (CHROMagar Microbiology, France which is developed for isolation and detection of Salmonella species. Material and Method: For this purpose, among a total of 148 isolates which were isolated from various clinical specimens and stocked at the Central Laboratory of Akdeniz University Hospital, 65 were Salmonella spp., 10 were Pseudomonas aeruginosa, 10 were E. coli, 10 were Acinetobacter baumannii, 10 were Klebsiella pneumoniae, 18 were Morganella morganii, 11 were Citrobacter spp., 5 were Providencia spp., 4 were Aeromonas spp., 5 were Proteus spp. were included in this study. All of the 65 Salmonella spp. isolates apperared with mauve colonies at the CHROMagar Salmonella. Results: E. coli and Klebsiella pnemoniae species were seen as blue, Providencia species were seen as pale-blue; Morganella morganii species were seen as pale-pink, mauve; and Pseudomonas aeruginosa species were seen as pale. Acinebacter baumannii and Aeromonas spp. species were also seen as mauve colonies. Dicussion: CHROMagar Salmonella medium can detect Salmonella species with %100 sensitivity, however there is a need to biochemical or serological confirmation.

  19. Serovars of Salmonella isolated from Danish turkeys between 1995 and 2000 and their antimicrobial resistance

    DEFF Research Database (Denmark)

    Pedersen, Karl; Hansen, H.C.; Jørgensen, J.C.

    2002-01-01

    ) and Salmonella Anatum (6.8 per cent). in addition, a few rough isolates and isolates belonging to the antigenically incomplete formulae 6.7:-:- and 4,12:b:- were found. The level of antimicrobial resistance was low; the highest resistance was recorded to ampicillin (13.7 per cent) and streptomycin (9.0 per cent...

  20. Disruption of type III secretion in Salmonella enterica serovar Typhimurium by external guide sequences

    OpenAIRE

    McKinney, Jeffrey S.; Zhang, Haifeng; Kubori, Tomoko; Galán, Jorge E.; Altman, Sidney

    2004-01-01

    The type III secretion system involved in Salmonella enterica serovar Typhimurium invasion of host cells has been disrupted using inducibly expressed oligonucleotide external guide sequences (EGSs) complementary to invB or invC mRNA. These EGSs direct single site cleavage in these mRNAs by endogenous RNase P, and their expression in Salmonella results in invC mRNA and InvC protein depletion, decreased type III secretion and interference with host cell invasion. Comparison of these effects wit...

  1. Antimicrobial Effects of Psidium Guajava Extract as One Mechanism of its Antidiarrhoeal Action

    Science.gov (United States)

    Lutterodt, G.D.; Ismail, A.; Basheer, R.H.; Baharudin, H. Mohd.

    1999-01-01

    A morphine-like spasmolytic action (not naloxone reversible; involving the inhibition of acetylcholine release) and also effects on the transmural transport of electrolytes (Na+ and K+) and water have been reported as possible modes of the antidiarrhoeal action of polar fractions of Psidium guajava leaf extractives. The objective for this study was to verify if the reported modes of the antidiarrhoeal action should be broadened to include direct antimicrobial actions on some of the more common bacteria known to cause toxin-induced acute diarrhoea. Serial dilutions of a water-soluble, freeze-dried methanolic extract were tested on 10 such organisms, grown separately on nutrient agar plates, to determine the minimum inhibitory concentration (MIC) for each of these bacteria. These included the causative agents for (i) enteric fever (Salmonella typhi, Salmonella paratyphi A, Salmonella paratyphi B and Salmonella paratyphi C), (ii) food poisoning (Salmonella typhimurium and Staphylococcus aureus), (iii) dysentery (Shigella dysenteriae, Shigella flexneri and Shigella sonnei), and (iv) cholera (Vibrio cholerae). The growth of all these organisms was inhibited at the MIC of 10mg/ml of the extract, which is equivalent to 2.5μg/ml of active extractable flavonoids. The most sensitive organisms (MIC = 1mg/ml) were Staphylococcus aureus, Vibrio cholerae and Shigella flexneri. PMID:22589684

  2. Biocontrol of Salmonella Typhimurium in RTE foods with the virulent bacteriophage FO1-E2.

    Science.gov (United States)

    Guenther, Susanne; Herzig, Oliver; Fieseler, Lars; Klumpp, Jochen; Loessner, Martin J

    2012-03-01

    Foodborne Salmonella infections are a major public health concern worldwide. Bacteriophages offer highly specific and effective biocontrol of such pathogens. We evaluated the broad host range, virulent phage FO1-E2 for reduction of Salmonella Typhimurium in different RTE foods. Samples were spiked with 1×10³ Salmonella cells and treated with 3×10⁸ pfu/g phage, and incubated for 6 days at 8 °C or 15 °C. At 8 °C, no viable cells remained following FO1-E2 application, corresponding to a more than 3 log₁₀ unit reduction. At 15 °C, application of phage lowered S. Typhimurium counts by 5 log units on turkey deli meat and in chocolate milk, and by 3 logs on hot dogs and in seafood. In egg yolk, an effect was observed only after 2 days, but not after 6 days. Phage particles retained their infectivity, although they were readily immobilized by the food matrix, resulting in loss of their ability to diffuse and infect target cells. At the end of the incubation period, phage-resistant Salmonella strains appeared which, however, were not able to compensate for the initial killing effect. Altogether, our data show that virulent phages such as FO1-E2 offer an effective biocontrol measure for Salmonella in foods. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. COORDINATED VIRULENCE FACTORS OF ZOONOTIC PATHOGEN Salmonella Typhimurium ASSOCIATED WITH SYSTEMIC DISEASE

    Directory of Open Access Journals (Sweden)

    Ermin Schadich

    2013-08-01

    Full Text Available  The pivotal virulence factors of foodborne zoonotic pathogen Salmonella enterica serotype Typhimurium associated with pathogenesis of systemic disease of humans and mice are the effectors of type three secretion systems. They are encoded by genes located on two different gene clusters named Salmonella pathogenicity island 1 and 2 (SPI-1 and SPI-2 and Salmonella plasmid virulence locus whose expressions are coordinated by regulatory networks in spatial and temporal manners. Secretion of the SPI-1 effectors required for bacterial internalization into specific compartments called Salmonella- containing vacuole (SCV of infected intestinal epithelial cells, is induced by environmental conditions via Hil transcription factors network. Secretion of SPI-2 and plasmid effectors required for bacterial survival inside of the SCVs of these cells and subsequently infected phagocytic cells, systemic spread, immunosuppression and cytotoxicity, is coordinated by broader regulatory network with the two response regulators, SsrB and SlyA, as the terminal regulators that integrate multiple environmental signals. Key words: Salmonella Typhimurium, effectors, virulence, systemic disease

  4. Molecular detection assay of five Salmonella serotypes of public interest: Typhimurium, Enteritidis, Newport, Heidelberg, and Hadar.

    Science.gov (United States)

    Bugarel, M; Tudor, A; Loneragan, G H; Nightingale, K K

    2017-03-01

    Foodborne illnesses due to Salmonella represent an important public-health concern worldwide. In the United States, a majority of Salmonella infections are associated with a small number of serotypes. Furthermore, some serotypes that are overrepresented among human disease are also associated with multi-drug resistance phenotypes. Rapid detection of serotypes of public-health concern might help reduce the burden of salmonellosis cases and limit exposure to multi-drug resistant Salmonella. We developed a two-step real-time PCR-based rapid method for the identification and detection of five Salmonella serotypes that are either overrepresented in human disease or frequently associated with multi-drug resistance, including serotypes Enteritidis, Typhimurium, Newport, Hadar, and Heidelberg. Two sets of four markers were developed to detect and differentiate the five serotypes. The first set of markers was developed as a screening step to detect the five serotypes; whereas, the second set was used to further distinguish serotypes Heidelberg, Newport and Hadar. The utilization of these markers on a two-step investigation strategy provides a diagnostic specificity of 97% for the detection of Typhimurium, Enteritidis, Heidelberg, Infantis, Newport and Hadar. The diagnostic sensitivity of the detection makers is >96%. The availability of this two-step rapid method will facilitate specific detection of Salmonella serotypes that contribute to a significant proportion of human disease and carry antimicrobial resistance. Published by Elsevier B.V.

  5. Typing of Typhoidal Salmonella Using Extraction of Water Soluble Whole Cell Proteins and Analysing by SDS-PAGE

    Directory of Open Access Journals (Sweden)

    R. Yousefi Mashouf

    2005-10-01

    Full Text Available Introduction & Objective : Salmonella is one of the most important genus of Enterobacteriacea family. The aim of this study was typing of typhoidal Salmonella by SDS-PAGE and comparing the results with those of serotyping method.Materials and Methods: In this study, 4 reference strains of Salmonella species, 5 reference strains of Enterobacteriacea family and 100 clinical isolates of Salmonella that were previously collected from laboratories of Hamadan medical centers were studied. Serotyping of strains were performed by Biomereux and Difco monovalent antisera. Whole-cell proteins of strains were also separated on 10% poly acrylamide gel. Gels were stained by Coomassie Brilliant Blue and analyzed by densitometry. Results: Of 100 cases of Salmonella species, 43 cases (43% were S. typhi, 20 cases (20% were S. typhymurium, 12 cases (12% were S. para typhi B, 10 cases (10% were S. para typhi C, S. para typhi A 1 case (1% and other cases were non-typhoidal Salmonella. The results of serotyping were compared with the results obtained by SDS-PAGE. Many protein bands from 220 KDa to 18.5 KDa were detected by SDS-PAGE and they were used to differentiate the strains. S. typhi serotypes were divided into 5 sub-species and S. para typhi B and C were divided each into 3 sub-species. Protein profiles of the reference strains of Salmonella were compared with protein profiles of Enterobacteriaceae species and showed some differences in major protein bands, however, they had a very similar protein band in 43 KDa area. Conclusion: Since our data was able to divide Salmonella species to sub-types and differentiate them from Enterobacteriacea species, we concluded that analsying SDS-PAGE profile of water soluble whole-cell proteins can be used for typing of these organisms and it is comparble with serotyping, nevertheless, further researches are needed to establish SDS-PAGE method and to replace it with serotyping method.

  6. Immunochemical analyses of serum antibodies from pig herds in a Salmonella non-endemic region

    DEFF Research Database (Denmark)

    Wiuff, Camilla; Thorberg, Britt-Marie; Engvall, Anders

    2002-01-01

    In a large comparative survey of Danish and Swedish slaughter pig herds performed prior to this work, it was unexpectedly found that some Swedish herds harbored seropositive pigs. Serum samples from the Swedish herds had moderate responses in the Salmonella rnix-ELISA (detecting serogroup B and C I...... infections) compared to the Danish herds classifying some of them as seropositive using a cut-off value at 40 OD%. In Sweden, extensive Salmonella control is carried out by bacteriological screening of feces and lymph nodes, and the overall prevalence has been proven to be below 0.1%. The serological...... positive results were therefore unexpected; hence the reactivities of the Swedish sera were studied by a number of immunochemical analyses (Western blot, indirect ELISA, inhibition ELISA, avidity ELISA) and compared to sera from Danish pig herds with verified Salmonella infections ("the reference sera...

  7. Recombinant Salmonella enterica Serovar Typhimurium as a Vaccine Vector for HIV-1 Gag

    Directory of Open Access Journals (Sweden)

    Nyasha Chin'ombe

    2013-08-01

    Full Text Available The HIV/AIDS epidemic remains a global health problem, especially in Sub-Saharan Africa. An effective HIV-1 vaccine is therefore badly required to mitigate this ever-expanding problem. Since HIV-1 infects its host through the mucosal surface, a vaccine for the virus needs to trigger mucosal as well as systemic immune responses. Oral, attenuated recombinant Salmonella vaccines offer this potential of delivering HIV-1 antigens to both the mucosal and systemic compartments of the immune system. So far, a number of pre-clinical studies have been performed, in which HIV-1 Gag, a highly conserved viral antigen possessing both T- and B-cell epitopes, was successfully delivered by recombinant Salmonella vaccines and, in most cases, induced HIV-specific immune responses. In this review, the potential use of Salmonella enterica serovar Typhimurium as a live vaccine vector for HIV-1 Gag is explored.

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    Oliver T. Zishiri

    2016-03-01

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

  10. Division of the Salmonella-Containing Vacuole and Depletion of Acidic Lysosomes in Salmonella-Infected Host Cells Are Novel Strategies of Salmonella enterica To Avoid Lysosomes▿

    OpenAIRE

    Eswarappa, Sandeepa M.; Negi, Vidya Devi; Chakraborty, Sangeeta; Chandrasekhar Sagar, B. K.; Chakravortty, Dipshikha

    2009-01-01

    Salmonella has evolved several strategies to counteract intracellular microbicidal agents like reactive oxygen and nitrogen species. However, it is not yet clear how Salmonella escapes lysosomal degradation. Some studies have demonstrated that Salmonella can inhibit phagolysosomal fusion, whereas other reports have shown that the Salmonella-containing vacuole (SCV) fuses/interacts with lysosomes. Here, we have addressed this issue from a different perspective by investigating if the infected ...

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

    Science.gov (United States)

    Song, Won-Jae; Kang, Dong-Hyun

    2016-02-01

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

  12. Salmonella Enteritidis universal stress protein (usp) gene expression is stimulated by egg white and supports oviduct colonization and egg contamination in laying hens.

    Science.gov (United States)

    Raspoet, R; Gantois, I; Devloo, R; Martel, A; Haesebrouck, F; Pasmans, F; Ducatelle, R; Van Immerseel, F

    2011-11-21

    Salmonella enterica subspecies enterica serovar Enteritidis has caused a worldwide egg-associated pandemic since the mid 1980s. The exact mechanisms causing this egg tropism are still largely unknown, and only a few Salmonella genes have been implicated in the interaction with the oviduct or eggs. A in vivo expression technology screening performed previously, identified the uspA and uspB genes as being highly expressed in the chicken oviduct and in eggs. Here, we demonstrate that uspA and uspB gene expression is indeed induced after contact with egg white. Intra-oviduct inoculation of Salmonella Enteritidis uspB and uspBA mutant strains showed that the mutants had a decreased ability to colonize the magnum and isthmus of the oviduct, the organs that produce the egg white and eggshell membranes, respectively, at 7 days post-inoculation. Intravenous challenge showed that a Salmonella Enteritidis uspBA mutant strain had a decreased ability to contaminate eggs. Analogous to the function of universal stress proteins A and B in other bacterial species, we hypothesize that the Salmonella uspA and uspB genes are involved in long term persistence of Salmonella Enteritidis in harmful environments, such as in the oviduct and eggs, by conferring resistance against compounds that damage the bacterial cell membrane and DNA. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Surveillance and management of salmonella food poisoning.

    Science.gov (United States)

    Hainsworth, Terry

    Reports of Salmonella Montevideo in UK chocolate have put foodborne disease back in the headlines. This article looks at the nature, prevalence and management of this public health problem and highlights the importance of surveillance.

  14. SURVIVAL OF SALMONELLA SPECIES IN RIVER WATER.

    Science.gov (United States)

    The survival of four Salmonella strains in river water microcosms was monitored using culturing techniques, direct counts, whole cell hybridization, scanning electron microscopy, and resuscitation techniques via the direct viable count method and flow cytrometry. Plate counts of...

  15. antimicrobial susceptibility patterns of salmonella species in ...

    African Journals Online (AJOL)

    user

    Empirical treatment for enteric fevers should, therefore, be discouraged while quinolones, cefepime, carbapenem, azithromycin and third generation cephalosporins be given preference. KEY WORDS: Susceptibility, Antimicrobial, Salmonella species, Enteric fever. INTRODUCTION. In the 21st century, enteric fever in the.

  16. A carbon nanotube immunosensor for Salmonella

    Directory of Open Access Journals (Sweden)

    Mitchell B. Lerner

    2011-12-01

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

  17. Epitope tagging of chromosomal genes in Salmonella.

    Science.gov (United States)

    Uzzau, S; Figueroa-Bossi, N; Rubino, S; Bossi, L

    2001-12-18

    We have developed a simple and efficient procedure for adding an epitope-encoding tail to one or more genes of interest in the bacterial chromosome. The procedure is a modification of the gene replacement method of Datsenko and Wanner [Datsenko, K. A. & Wanner, B. L. (2000) Proc. Natl. Acad. Sci. USA 97, 6640-6645]. A DNA module that begins with the epitope-encoding sequence and includes a selectable marker is amplified by PCR with primers that carry extensions (as short as 36 nt) homologous to the last portion of the targeted gene and to a region downstream from it. Transformation of a strain expressing bacteriophage lambda red functions yields recombinants carrying the targeted gene fused to the epitope-encoding sequence. The resulting C-terminal-tagged protein can be identified by standard immuno-detection techniques. In an initial application of the method, we have added the sequences encoding the FLAG and 3xFLAG and influenza virus hemagglutinin epitopes to various genes of Salmonella enterica serovar Typhimurium, including putative and established pathogenic determinants present in prophage genomes. Epitope fusion proteins were detected in bacteria growing in vitro, tissue culture cells, and infected mouse tissues. This work identified a prophage locus specifically expressed in bacteria growing intracellularly. The procedure described here should be applicable to a wide variety of Gram-negative bacteria and is particularly suited for the study of intracellular pathogens.

  18. First detection and characterization of Salmonella spp. in poultry and swine raised in backyard production systems in central Chile.

    Science.gov (United States)

    Alegria-Moran, R; Rivera, D; Toledo, V; Moreno-Switt, A I; Hamilton-West, C

    2017-11-01

    Little is known about Salmonella serovars circulating in backyard poultry and swine populations worldwide. Backyard production systems (BPS) that raise swine and/or poultry are distributed across Chile, but are more heavily concentrated in central Chile, where industrialized systems are in close contact with BPS. This study aims to detect and identify circulating Salmonella serovars in poultry and swine raised in BPS. Bacteriological Salmonella isolation was carried out for 1744 samples collected from 329 BPS in central Chile. Faecal samples were taken from swine, poultry, geese, ducks, turkeys and peacocks, as well as environmental faecal samples. Confirmation of Salmonella spp. was performed using invA-polymerase chain reaction (PCR). Identification of serovars was carried out using a molecular serotyping approach, where serogroups were confirmed by a multiplex PCR of Salmonella serogroup genes for five Salmonella O antigens (i.e., D, B, C1, C2-C3, and E1), along with two PCR amplifications, followed by sequencing of fliC and fljB genes. A total of 25 samples (1·4% of total samples) from 15 BPS (4·6 % of total sampled BPS) were found positive for Salmonella. Positive samples were found in poultry (chickens and ducks), swine and environmental sources. Molecular prediction of serovars on Salmonella isolated showed 52·0% of S. Typhimurium, 16·0% of S. Infantis, 16·0% S. Enteritidis, 8·0% S. Hadar, 4·0% S. Tennessee and 4·0% S. Kentucky. Poor biosecurity measures were found on sampled BPS, where a high percentage of mixed confinement systems (72·8%); and almost half of the sampled BPS with improper management of infected mortalities (e.g. selling the carcasses of infected animals for consumption). Number of birds other than chickens (P = 0·014; OR = 1·04; IC (95%) = 1·01-1·07), mixed productive objective (P = 0·030; OR = 5·35; IC (95%) = 1·24-27·59) and mixed animal replacement origin (P = 0017; OR = 5·19; IC (95%) = 1·35-20·47) were detected as

  19. Conservation of Salmonella infection mechanisms in plants and animals.

    Science.gov (United States)

    Schikora, Adam; Virlogeux-Payant, Isabelle; Bueso, Eduardo; Garcia, Ana V; Nilau, Theodora; Charrier, Amélie; Pelletier, Sandra; Menanteau, Pierrette; Baccarini, Manuela; Velge, Philippe; Hirt, Heribert

    2011-01-01

    Salmonella virulence in animals depends on effectors injected by Type III Secretion Systems (T3SSs). In this report we demonstrate that Salmonella mutants that are unable to deliver effectors are also compromised in infection of Arabidopsis thaliana plants. Transcriptome analysis revealed that in contrast to wild type bacteria, T3SS mutants of Salmonella are compromised in suppressing highly conserved Arabidopsis genes that play a prominent role during Salmonella infection of animals. We also found that Salmonella originating from infected plants are equally virulent for human cells and mice. These results indicate a high degree of conservation in the defense and infection mechanism of animal and plant hosts during Salmonella infection.

  20. Molecular Characterization of Salmonella from Human and Animal Origins in Uganda

    Directory of Open Access Journals (Sweden)

    Atek Atwiine Kagirita

    2017-01-01

    Full Text Available Sporadic Salmonella outbreaks with varying clinical presentations have been on the rise in various parts of Uganda. The sources of outbreaks and factors underlying the different clinical manifestation are curtailed by paucity of information on Salmonella genotypes and the associated virulence genes. This study reports molecular diversity of Salmonella enterica and their genetic virulence profiles among human and animal isolates. Characterization was done using Kauffman-White classification scheme and virulence genes analysis using multiplex PCR. Overall, 52% of the isolates belonged to serogroup D, 16% to serogroup E, 15% to poly F, H-S, and 12% to serogroup B. Serogroups A, C1, and C2 each consisted of only one isolate representing 5%. Virulence genes located on SPI-1 [spaN and sipB] and on SPI-2 [spiA] in addition to pagC and msgA were equally distributed in isolates obtained from all sources. Plasmid encoded virulence gene spvB was found in <5% of isolates from both human epidemic and animal origins whereas it occurred in 80% of clinical isolates. This study reveals that serogroup D is the predominant Salmonella serogroup in circulation and it is widely shared among animals and humans and calls for joint and coordinated surveillance for one health implementation in Uganda.

  1. Interactions of Salmonella enterica with lettuce leaves.

    Science.gov (United States)

    Kroupitski, Y; Pinto, R; Brandl, M T; Belausov, E; Sela, S

    2009-06-01

    To investigate the interactions of Salmonella enterica with abiotic and plant surfaces and their effect on the tolerance of the pathogen to various stressors. Salmonella strains were tested for their ability to form biofilm in various growth media using a polystyrene plate model. Strong biofilm producers were found to attach better to intact Romaine lettuce leaf tissue compared to weak producers. Confocal microscopy and viable count studies revealed preferential attachment of Salmonella to cut-regions of the leaf after 2 h at 25 degrees C, but not for 18 h at 4 degrees C. Storage of intact lettuce pieces contaminated with Salmonella for 9 days at 4 degrees C resulted only in small changes in population size. Exposure of lettuce-associated Salmonella cells to acidic conditions (pH 3.0) revealed increased tolerance of the attached vs planktonic bacteria. Biofilm formation on polystyrene may provide a suitable model to predict the initial interaction of Salmonella with cut Romaine lettuce leaves. Association of the pathogen with lettuce leaves facilitates its persistence during storage and enhances its acid tolerance. Understanding the interactions between foodborne pathogens and lettuce might be useful in developing new approaches to prevent fresh produce-associated outbreaks.

  2. Salmonella Vaccination in Pigs: A Review.

    Science.gov (United States)

    Wales, A D; Davies, R H

    2017-02-01

    The control of Salmonella enterica in pig production is necessary for both public and animal health. The persistent and frequently asymptomatic nature of porcine Salmonella infection and the organism's abilities to colonize other animal species and to survive in the environment mean that effective control generally requires multiple measures. Vaccination is one such measure, and the present review considers its role and its future, drawing on studies in pigs from the 1950s to the present day. Once established in the body as an intracellular infectious agent, Salmonella can evade humoral immunity, which goes some way to explaining the often disappointing performance of inactivated Salmonella vaccines. More recent approaches, using mucosal presentation of antigens, live vaccines and adjuvants to enhance cell-mediated immunity, have met with more success. Vaccination strategies that involve stimulating both passive immunity from the dam plus active immunity in offspring appear to be most efficacious, although either approach alone can yield significant control of Salmonella. Problems that remain include relatively poor control of Salmonella serovars that are dissimilar to the vaccine antigen mix, and difficulties in measuring and predicting the performance of candidate vaccines in ways that are highly relevant to their likely use in commercial production. © 2016 Crown copyright. Zoonoses and Public Health published by Blackwell Verlag GmbH.This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

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

    Science.gov (United States)

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

    2015-07-15

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

  4. NRL Salmonella ringonderzoek II: bacteriologische detectie van Salmonella in aanwezigheid van competitieve flora

    NARCIS (Netherlands)

    Voogt N; in ' t Veld PH; Nagelkerke N; van de Giessen AW; MGB

    1999-01-01

    In april 1998 werd een bacteriologisch ringonderzoek voor de detectie van Salmonella in aanwezigheid van stoorflora georganiseerd door het Nationaal Referentie Laboratorium (NRL) voor Salmonella (RIVM, Bilthoven). Aan het ringonderzoek werd deelgenomen door 23 laboratoria in het kader van het Plan

  5. Impact of litter Salmonella status during feed withdrawal on Salmonella recovery from the broiler crop and ceca.

    Science.gov (United States)

    Buhr, R J; Bourassa, D V; Hinton, A; Fairchild, B D; Ritz, C W

    2017-12-01

    Research was conducted to evaluate the impact of litter Salmonella status during feed withdrawal on Salmonella recovery from the crop and ceca following feed withdrawal. In 4 experiments, pens of broilers in separate rooms were challenged with marker strains of either Salmonella Montevideo or Salmonella Heidelberg. Three d post challenge, a 12-hour feed withdrawal was initiated, and one pen of broilers was switched between rooms for each Salmonella serotype. In experiments 3 and 4, non-challenged broilers also were added to the Salmonella challenge pens. The litter of each pen was sampled before and after the feed withdrawal period, the broilers euthanized, and the crop and ceca aseptically removed for Salmonella isolation. Results showed that only the challenge Salmonella serotype was recovered from the litter in challenge pens where broilers were not moved, while both Salmonella serotypes were recovered from the litter of the switched pens. Salmonella was recovered from 56/80 crops and from 66/80 ceca of challenged broilers that remained in the challenge pens. The challenge Salmonella serotype was recovered from 50/80 crops and from 60/80 ceca, and the switched pens' litter Salmonella serotype was recovered from 19/80 crops but not from the ceca in broilers challenged with Salmonella and then switched between pens. For experiments 3 and 4, Salmonella was recovered from 19/40 crops and from only 2/40 ceca from the non-challenged broilers placed into the Salmonella challenge pens. The results from broilers that were switched between Salmonella challenge pens indicate that the recovery of Salmonella from the crop of broilers following feed withdrawal (on Salmonella-contaminated litter) appears to depend mainly on the initial challenge Salmonella (62%) and less on the litter Salmonella (24%) status during the feed withdrawal period. In contrast, only the initial challenge Salmonella was recovered from the ceca (79%) from broilers that remained in challenge pens or

  6. Salmonella

    Science.gov (United States)

    ... Linked to Raw Meal Organic Shake and Meal Products Recall & Advice to Consumers Case Count Maps Epi Curves ... Infections Associated with a Raw Scraped Ground Tuna Product Recall & Advice to Consumers Case Count Maps Epi Curves ...

  7. Production and caracterization of monoclonal antibodies for the detection of Salmonella enterica in chicken meat Produção e caracterização de anticorpos monoclonais para a detecção de Salmonella enterica em carne de frango

    Directory of Open Access Journals (Sweden)

    Andréa dos Santos Schneid

    2005-06-01

    Full Text Available A panel of 13 monoclonal antibodies (MAbs that react against outer membrane proteins of Salmonella Enteritidis was obtained. Two MAbs were classified as IgM, six were IgG2a, three were IgG3 and one was of the IgG2b isotype. The reactivity of the MAbs against different serovars of Salmonella enterica and other bacteria was investigated using an indirect ELISA. Five MAbs reacted only against Salmonella Enteritidis. Two MAbs presented crossed reactions with thermo-extracted antigens of Klebsiella pneumoniae, Citrobacter freundii and Enterobacter aerogenes. MAb 424H presented wide spectrum of reactivity, detecting antigens of Salmonella belonging to serogroups B, C, D, E and G. The detection limit of different serovars of Salmonella in a indirect ELISA with MAb 424H varied from 1.0 x 10(4 CFU/mL for Salmonella London to 1.4 x 10(6 CFU/mL for Salmonella Gallinarum and Salmonella Typhimurium. Evaluation of the performance of the ELISA with MAb 424H in the detection of Salmonella in samples of chicken meat artificially contaminated revealed that the ELISA was able to detect all serovars after sample enrichment using two levels of contamination. Samples of chicken meat not artificially contaminated analysed in parallel were negative for Salmonella in both the conventional and the ELISA methods.Foi obtido um painel de 13 anticorpos monoclonais que reagem com proteínas de membrana externa de Salmonella Enteritidis. Dois MAbs foram classificados como IgM, 6 foram do isotipo IgG2a, três foram do isotipo IgG3 e um do isotipo IgG2b. A reatividade dos anticorpos monoclonais (MAbs com diferentes sorovares de Salmonella e outras bactérias foi investigada através de um ELISA indireto. Cinco MAbs reagiram apenas com Salmonella Enteritidis. Dois MAbs apresentaram reação cruzada com antígenos termoextraídos de Klebsiella pneumoniae, Citrobacter freundii e Enterobacter aerogenes. O MAb 424H apresentou amplo espectro de reatividade, detectando antígenos de

  8. Effects of egg shell quality and washing on Salmonella Infantis penetration.

    Science.gov (United States)

    Samiullah; Chousalkar, K K; Roberts, J R; Sexton, M; May, D; Kiermeier, A

    2013-07-15

    The vast majority of eggs in Australia are washed prior to packing to remove dirt and fecal material and to reduce the microbial contamination of the egg shell. The egg contents can be an ideal growth medium for microorganisms which can result in human illness if eggs are stored improperly and eaten raw or undercooked, and it is estimated that egg-related salmonellosis is costing Australia $44 million per year. Egg shell characteristics such as shell thickness, amount of cuticle present, and thickness of individual egg shell layers can affect the ease with which bacteria can penetrate the egg shell and washing could partially or completely remove the cuticle layer. The current study was conducted to investigate the effects of egg washing on cuticle cover and effects of egg shell quality and cuticle cover on Salmonella Infantis penetration of the egg shell. A higher incidence of unfavorable ultrastructural variables of the mammillary layer such as late fusion, type B bodies, type A bodies, poor cap quality, alignment, depression, erosion and cubics were recorded in Salmonella penetrated areas of egg shells. The influence of egg washing on the ability of Salmonella Infantis on the egg shell surface to enter the egg internal contents was also investigated using culture-based agar egg penetration and real-time qPCR based experiments. The results from the current study indicate that washing affected cuticle cover. There were no significant differences in Salmonella Infantis penetration of washed or unwashed eggs. Egg shell translucency may have effects on Salmonella Infantis penetration of the egg shell. The qPCR assay was more sensitive for detection of Salmonella Infantis from egg shell wash and internal contents than traditional microbiological methods. The agar egg and whole egg inoculation experiments indicated that Salmonella Infantis penetrated the egg shells. Egg washing not only can be highly effective at removing Salmonella Infantis from the egg shell surface

  9. Investigation of in-feed organic acids as a low cost strategy to combat Salmonella in grower pigs.

    Science.gov (United States)

    Lynch, H; Leonard, F C; Walia, K; Lawlor, P G; Duffy, G; Fanning, S; Markey, B K; Brady, C; Gardiner, G E; Argüello, H

    2017-04-01

    Salmonella carriage in pigs is a significant food safety issue. Dietary supplementation with organic acids has previously been shown to reduce shedding and transmission of Salmonella. Therefore, this study aimed to examine the effect of three commercially available organic acid-based products on Salmonella levels in grower pigs, using a model of experimental infection that closely mimics natural exposure to the organism. Seven week old trial pigs (n=40) with a mean weight of 14.7kg were placed in one of four pens with 10 pigs/pen. Pens had previously been contaminated with Salmonella Typhimurium 4,[5],12;i;- via seeder pigs. Trial pigs received one of four diets for 28days: 1, control diet; 2, sodium butyrate supplemented diet; 3, benzoic acid supplemented diet and 4, formic-citric acid supplemented diet. A further 10 pigs were placed in a Salmonella-free pen receiving the control diet. Pigs were weighed and blood sampled on days 0 and 28. Faeces was collected on day 0, 2, 3, 5, 7, 14, 21 and 28 and examined for Salmonella. On day 28, 5 pigs/group were euthanised and ileocaecal lymph nodes (ILN) and caecal contents sampled for culture. The remaining 5 pigs/pen were then fed the control diet and faeces were collected on days 35 and 42. On day 42 pigs were euthanised and ILN and caecal contents tested for Salmonella levels. The trial was repeated once. Within the first two days of exposure to the contaminated environment, 96% (77/80) of pigs became infected. Most pigs shed Salmonella at levels of between 100-103 CFU/g faeces for at least 7days post-exposure. A significant reduction in Salmonella faecal concentration was observed after supplementation with sodium butyrate (p=0.001) and a formic citric acid blend (pfeed when compared to the positive control group. The use of sodium butyrate or a blend of formic and citric acid in feed could be considered a cost-effective control measure to reduce Salmonella faecal shedding and improve ADWG in Salmonella infected herds

  10. Tips to Reduce Your Risk of Salmonella from Eggs

    Science.gov (United States)

    ... this? Submit What's this? Submit Button Past Emails Salmonella and Eggs Language: English (US) Español (Spanish) Recommend ... can I reduce my chance of getting a Salmonella infection? Consider buying and using pasteurized eggs and ...

  11. 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

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

    Science.gov (United States)

    ... Enjoying Homemade Ice Cream without the Risk of Salmonella Infection Share Tweet Linkedin Pin it More sharing ... year homemade ice cream causes several outbreaks of Salmonella infection with up to several hundred victims at ...

  13. Epidemiological Investigation of Salmonella enterica Serovar Kedougou in Thailand

    DEFF Research Database (Denmark)

    Pornruangwong, Srirat; Hendriksen, Rene S.; Pulsrikarn, Chaiwat

    2011-01-01

    Objective: Salmonella enterica serovar Kedougou is among the top 10 serovars reported in northern Thailand. The objective of this study was to identify risk factors associated with Salmonella Kedougou infection in Thailand and to compare the molecular types and antimicrobial resistance with Salmo......Objective: Salmonella enterica serovar Kedougou is among the top 10 serovars reported in northern Thailand. The objective of this study was to identify risk factors associated with Salmonella Kedougou infection in Thailand and to compare the molecular types and antimicrobial resistance.......023), region (northern Thailand; p factors associated with Salmonella Kedougou infection compared to other nontyphoid Salmonella. Of the Salmonella Kedougou isolates of human origin, 84% exhibited resistance to at least three antimicrobial classes...... association, whereas the majority of the animal isolates from United Kingdom clustered separately. Conclusions: This study reveals Salmonella Kedougou as a major cause of human infections in northern Thailand especially during the hot period and suggests a global spread probably due to travel. The clonal...

  14. Prevalence and antimicrobial profiles of Salmonella serovars from ...

    African Journals Online (AJOL)

    Prevalence and antimicrobial profiles of Salmonella serovars from ... Antimicrobial susceptibility test was performed with 17 antimicrobial agents ... for specific Salmonella control program to be instituted as part of a national food safety strategy.

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

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    USDA), Athens, USA. Accepted 6 ... Salmonella enterica serovar Enteritidis is a food borne pathogen of humans causing food-poisoning .... Comparison of percent sero-positive hens per group and means of Salmonella.

  16. Test results of Salmonella typing by the NRLs-Salmonella in the Member States of the EU and the EnterNet Laboratories - Collaborative study VI on typing of Salmonella

    NARCIS (Netherlands)

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

    2002-01-01

    Test resultaten van Salmonella sero- en faagtypering en antimicrobiele gevoeligheidsbepalingen door de Nationale Referentie Laboratoria voor Salmonella in de Lidstaten van de Europese Unie en EnterNet Laboratoria: Ringonderzoek VI (2001) voor Salmonella. Een zesde ringonderzoek betreffende de

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  18. Composite IS1-tetracycline resistance elements in aerobactin-encoding FIme plasmids from epidemic Salmonella wien.

    OpenAIRE

    Casalino, M.; Nicoletti, M; Junakovic, N; Maimone, F

    1988-01-01

    Class B tetracycline resistance determinants have been identified in two aerobactin-encoding FIme plasmids representative of those isolated from epidemic Salmonella wien. Genetic data, restriction enzyme analysis of recombinant and mutant plasmids, and Southern blot hybridizations indicate that in both plasmids the class B determinant so far found and described only on Tn10-like transposons is part of a different genetic element. This composite insertion sequence element is about 7 kilobases ...

  19. 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.

  20. 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.

  1. Reduced particle size wheat bran is butyrogenic and lowers Salmonella colonization, when added to poultry feed.

    Science.gov (United States)

    Vermeulen, K; Verspreet, J; Courtin, C M; Haesebrouck, F; Ducatelle, R; Van Immerseel, F

    2017-01-01

    Feed additives, including prebiotics, are commonly used alternatives to antimicrobial growth promoters to improve gut health and performance in broilers. Wheat bran is a highly concentrated source of (in)soluble fiber which is partly degraded by the gut microbiota. The aim of the present study was to investigate the potential of wheat bran as such to reduce colonization of the cecum and shedding of Salmonella bacteria in vivo. Also, the effect of particle size was evaluated. Bran with an average reduced particle size of 280μm decreased levels of cecal Salmonella colonization and shedding shortly after infection when compared to control groups and groups receiving bran with larger particle sizes. In vitro fermentation experiments revealed that bran with smaller particle size was fermented more efficiently, with a significantly higher production of butyric and propionic acid, compared to the control fermentation and fermentation of a larger fraction. Fermentation products derived from bran with an average particle size of 280μm downregulated the expression of hilA, an important invasion-related gene of Salmonella. This downregulation was reflected in an actual lowered invasive potential when Salmonella bacteria were pretreated with the fermentation products derived from the smaller bran fraction. These data suggest that wheat bran with reduced particle size can be a suitable feed additive to help control Salmonella infections in broilers. The mechanism of action most probably relies on a more efficient fermentation of this bran fraction and the consequent increased production of short chain fatty acids (SCFA). Among these SCFA, butyric and propionic acid are known to reduce the invasion potential of Salmonella bacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Survey of the prevalence of Salmonella species on laying hen farms in Kosovo.

    Science.gov (United States)

    Hulaj, B; Çabeli, P; Goga, I; Taylor, N; Hess, C; Hess, M L

    2016-09-01

    A survey on the prevalence of Salmonella (S) species was carried out on 39 layer farms in Kosovo between April and September 2012. In total 367 samples, comprising feces, dust, eggs, and internal organs from dead birds, were investigated using bacteriological culture methods. Additionally, data on the location of the farm, the total number of birds on the farm, age of birds, and laying performance were collected. Salmonella were isolated from 38 samples obtained from 19 (49%) farms. The most common serovar identified was Salmonella enteritidis, found on 18 farms. The most common S. enteritidis phage type was PT29 followed by PT6, PT7, PT21, PT13a, PT8, PT14b, and PT4. One S. enteritidis isolate was not typable. Six farms had more than one phage type. Furthermore, serovar S. Bovismorbificans also was found in samples from 3 farms. Flock size or production stage was not associated with the probability of isolating Salmonella. The only flock factor found to be significantly associated was percent hen/day production: It was 2.8 times more likely to isolate Salmonella from flocks with production above 80% hen/day production compared to flocks producing at a lower level. Analysis of antimicrobial resistance patterns of 30 isolates revealed that all isolates were sensitive to gentamicin, ampicillin, sulphamethoxazole trimethoprim, and oxytetracycline, and 29 (97%) were sensitive to ciprofloxacin. All isolates showed intermediate resistance or were resistant to minocycline and cloxacillin. Twenty-six isolates (86%) had intermediate resistance to amoxicillin and 27 isolates (90%) were fully resistant to streptomycin. The present survey revealed a high prevalence of Salmonella enteritidis in layer flocks in Kosovo, indicating that table eggs have to be suspected as an important source of human salmone-llosis. © 2016 Poultry Science Association Inc.

  3. Evaluation of VIDAS Salmonella (SLM) easy Salmonella method for the detection of Salmonella in a variety of foods: collaborative study.

    Science.gov (United States)

    Crowley, Erin; Bird, Patrick; Fisher, Kiel; Goetz, Katherine; Benzinger, M Joseph; Agin, James; Goins, David; Johnson, Ronald L

    2011-01-01

    The VIDAS Salmonella (SLM) Easy Salmonella method is a specific enzyme-linked fluorescent immunoassay performed in the automated VIDAS instrument. The VIDAS Easy Salmonella method is a simple 2-step enrichment procedure, using pre-enrichment followed by selective enrichment in a newly formulated broth, SX2 broth. This new method was compared in a multilaboratory collaborative study to the U.S. Food and Drug Administration's Bacteriological Analytical Manual, Chapter 5 method for five food matrixes (liquid egg, vanilla ice cream, spinach, raw shrimp, and peanut butter) and the U.S. Department of Agriculture's Microbiology Laboratory Guidebook 4.04 method for deli turkey. Each food type was artificially contaminated with Salmonella at three inoculation levels. A total of 15 laboratories representing government, academia, and industry, throughout the United States, participated. In this study, 1583 samples were analyzed, of which 792 were paired replicates and 791 were unpaired replicates. Of the 792 paired replicates, 285 were positive by both the VIDAS and reference methods. Of the 791 unpaired replicates, 341 were positive by the VIDAS method and 325 were positive by the cultural reference method. A Chi-square analysis of each of the six food types was performed at the three inoculation levels tested. For all foods evaluated, the VIDAS Easy SLM method demonstrated results comparable to those of the reference methods for the detection of Salmonella.

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

    Science.gov (United States)

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

    2014-01-01

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

  5. Virulence and antimicrobial resistance of Salmonella spp. and Escherichia coli in the beef jerky production line.

    Science.gov (United States)

    Fernandes, Fernanda Pereira; Voloski, Flávia Liége Schütz; Ramires, Tassiana; Haubert, Louise; Reta, Giulia Giugliani; Mondadori, Rafael Gianella; Silva, Wladimir Padilha da; Conceição, Rita de Cássia Dos Santos da; Duval, Eduarda Hallal

    2017-05-01

    Intense manipulation during beef jerky production increases the possibility of contamination with pathogenic microorganisms. This study evaluated the contamination by thermotolerant coliforms, Escherichia coli and Salmonella spp., on processing surfaces and raw materials during beef jerky production, as well as in the final product. Thermotolerant coliforms were found on all surfaces tested and in the raw material. Escherichia coli was identified in 6.7% of the surface samples, while Salmonella spp. was found in 3.3% of the surface samples and 8.6% of raw material samples. Virulence genes were detected in Salmonella spp. isolates. One Salmonella spp. isolate was resistant to sulfonamide, while one E. coli isolate was multiresistant, including the presence of resistance genes sul2, strA, strB, tetA and tetB. The presence of coliforms demonstrates failings in hygienic-sanitary procedures. The presence of pathogenic microorganisms causing foodborne diseases in the production line indicates persistent contamination in the production plant. Although the drying process applied to beef jerky should guarantee the safety of the final product, the presence of multiresistant pathogenic microorganisms, presenting virulence genes, should be a matter of concern. Because beef jerky is a ready-to-eat product, a failure in the production process may cause such microorganisms to pose a public health risk. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Science.gov (United States)

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

  7. A trans-acting leader RNA from a Salmonella virulence gene.

    Science.gov (United States)

    Choi, Eunna; Han, Yoontak; Cho, Yong-Joon; Nam, Daesil; Lee, Eun-Jin

    2017-09-19

    Bacteria use flagella to move toward nutrients, find its host, or retract from toxic substances. Because bacterial flagellum is one of the ligands that activate the host innate immune system, its synthesis should be tightly regulated during host infection, which is largely unknown. Here, we report that a bacterial leader mRNA from the mgtCBR virulence operon in the intracellular pathogen Salmonella enterica serovar Typhimurium binds to the fljB coding region of mRNAs in the fljBA operon encoding the FljB phase 2 flagellin, a main component of bacterial flagella and the FljA repressor for the FliC phase 1 flagellin, and degrades fljBA mRNAs in an RNase E-dependent fashion during infection. A nucleotide substitution of the fljB flagellin gene that prevents the mgtC leader RNA-mediated down-regulation increases the fljB-encoded flagellin synthesis, leading to a hypermotile phenotype inside macrophages. Moreover, the fljB nucleotide substitution renders Salmonella hypervirulent, indicating that FljB-based motility must be compromised in the phagosomal compartment where Salmonella resides. This suggests that this pathogen promotes pathogenicity by producing a virulence protein and limits locomotion by a trans-acting leader RNA from the same virulence gene during infection.

  8. Extended Spectrum Beta-lactam Resistance among Salmonella

    Science.gov (United States)

    Salmonella is an important food bourn pathogen capable of infecting both humans and animals. One of the most effective treatments for Salmonella infections is beta-lactam antibiotics, particularly extended spectrum beta-lactams; however, Salmonella resistant to these antibiotics have been recovered ...

  9. 21 CFR 866.3550 - Salmonella spp. serological reagents.

    Science.gov (United States)

    2010-04-01

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

  10. 76 FR 16425 - Draft Guidance for Industry: Testing for Salmonella

    Science.gov (United States)

    2011-03-23

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry: Testing for Salmonella Species... availability of a draft guidance for industry entitled ``Testing for Salmonella Species in Human Foods and... and other persons who are covered by FDA's final rule ``Prevention of Salmonella Enteritidis in Shell...

  11. 76 FR 81513 - Guidance for Industry: Prevention of Salmonella

    Science.gov (United States)

    2011-12-28

    ... HUMAN SERVICES Food and Drug Administration Guidance for Industry: Prevention of Salmonella Enteritidis... availability of a guidance for industry entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During... with certain provisions contained in FDA's final rule ``Prevention of Salmonella Enteritidis in Shell...

  12. 9 CFR 113.30 - Detection of Salmonella contamination.

    Science.gov (United States)

    2010-01-01

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

  13. 78 FR 42451 - Animal Feeds Contaminated With Salmonella Microorganisms

    Science.gov (United States)

    2013-07-16

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 500 Animal Feeds Contaminated With Salmonella... Administration (FDA or Agency) is revoking an advisory opinion on animal feeds contaminated with Salmonella... enforcement strategy articulated in a final compliance policy guide (CPG) on Salmonella in food for animals...

  14. Characterization of a multidrug resistant Salmonella enterica give ...

    African Journals Online (AJOL)

    Salmonella enterica Give is one of the serotypes that have been incriminated in Salmonella infections; sometimes associated with hospitalization and mortalities in humans and animals in some parts of the world. In this work, we characterized one Salmonella Give isolated from cloaca swab of an Agama agama lizard ...

  15. Biofilm formation of Salmonella species isolated from fresh cabbage ...

    African Journals Online (AJOL)

    The aim of the study was to isolate Salmonella from fresh cabbage and spinach vegetables, determine antimicrobial resistance and biofilm formation of the isolates. Spinach and cabbage farm vegetables were found to harbour Salmonella. A total of eighty-two Salmonella isolates were recovered from both vegetables and ...

  16. Mechanism of Salmonella reduction in fermented pig feed

    NARCIS (Netherlands)

    Winsen, van R.L.; Lipman, L.J.A.; Biesterveld, S.; Urlings, B.A.P.; Snijders, J.M.A.; Knapen, van F.

    2001-01-01

    To protect consumers from Salmonella infection acquired through the consumption of pork meat, it is necessary to eradicate Salmonella from pork. In order to achieve this, the whole pork production chain should be free from Salmonella, including the pigs at the farm. In epidemiological studies it was

  17. Salmonella in raccoons (Procyon lotor) in southern Ontario, Canada.

    Science.gov (United States)

    Jardine, Claire; Reid-Smith, Richard J; Janecko, Nicol; Allan, Mike; McEwen, Scott A

    2011-04-01

    Numerous serotypes of Salmonella have been detected in a variety of wild animals, including raccoons (Procyon lotor). Raccoons are common, mid-size omnivores that live in close association with people in urban and rural areas in Ontario. Although raccoons are known to shed Salmonella, little is known about their potential long-term role in maintaining Salmonella infections. We sampled feces from raccoons in three areas of Ontario: one primarily urban site around Niagara, one primarily rural site north of Guelph, and the grounds of the Toronto Zoo, in 2007 to identify which serotypes of Salmonella were commonly shed by raccoons in southern Ontario. In addition, we conducted a longitudinal study at the Toronto Zoo site to determine if raccoons remain persistently infected with Salmonella. Salmonella was found in 45% of samples. The prevalence of Salmonella in raccoon feces ranged from 27% at the rural site to 65% at the urban site. We detected 16 serotypes of Salmonella in 83 positive samples. The most common serotype detected in raccoons from the rural and zoo sites was Salmonella enterica serotype Typhimurium, whereas Salmonella Newport was detected most commonly in the urban site. Only one raccoon of 11 that were captured in four or more consecutive trapping sessions shed the same Salmonella serotype for two consecutive months, suggesting that raccoons regularly acquire new Salmonella serotypes from the environment.

  18. 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 Nigerian setting. ... This finding shows that virulent Salmonella strains pose a major health hazard and public health concern to the affected population. Our study shows that there is a high prevalence rate of virulent Salmonella ...

  19. Resistance of broiler outbred lines to infection with Salmonella enteritidis

    NARCIS (Netherlands)

    Bolder, N.M.; Janss, L.L.G.; Putirulan, F.F.; Wagenaar, J.A.

    2002-01-01

    Salmonella infections originating from poultry are one of the major causes of food-borne disease. For the control of salmonella in poultry a multifactorial approach is more likely to be effective, and the genetic resistance of poultry breeds to salmonella infections may be a valuable contribution.

  20. Salmonella serovars in the herpetofauna of Indiana County, Pennsylvania.

    Science.gov (United States)

    Chambers, David L; Hulse, Arthur C

    2006-05-01

    Herpetofaunal Salmonella enterica serovars have not been fully examined in any U.S. region. Thirty-three Salmonella serovars were isolated from 156 samples from 34 species, all within Indiana County, Pennsylvania. Results suggest that herpetofaunas could potentially pose a threat to humans. Further understanding of Salmonella in herpetofaunas may prevent future human cases.

  1. Salmonella surrogate reduction using industrial peanut dry roasting parameters

    Science.gov (United States)

    Studies were conducted to evaluate the effectiveness of industrial peanut dry roasting parameters in Salmonella reduction using a Salmonella surrogate, Enterococcus faecium, which is slightly more heat tolerant than Salmonella. Runner-type peanuts were inoculated with E. faecium and roasted in a lab...

  2. Characterization of a Multidrug Resistant Salmonella Enterica Give ...

    African Journals Online (AJOL)

    Dr Olaleye

    ABSTRACT. Salmonella enterica Give is one of the serotypes that have been incriminated in Salmonella infections; sometimes associated with hospitalization and mortalities in humans and animals in some parts of the world. In this work, we characterized one. Salmonella Give isolated from cloaca swab of an Agama ...

  3. Characterizing Salmonella Contamination in Two Rendering Processing Plants.

    Science.gov (United States)

    Gong, Chao; Jiang, Xiuping

    2017-02-01

    A microbiological investigation on Salmonella contamination was conducted in two U.S. rendering plants to investigate the potential cross-contamination of Salmonella in the rendering processing environment. Sampling locations were predetermined at the areas where Salmonella contamination may potentially occur, including raw materials receiving, crax (rendered materials before grinding process) grinding, and finished meal loading-out areas. Salmonella was either enumerated directly on xylose lysine Tergitol 4 agar plates or enriched in Rappaport-Vassiliadis and tetrathionate broths. The presumptive Salmonella isolates were confirmed using CHROMagar plating and latex agglutination testing and then characterized using pulsed-field gel electrophoresis, serotyping, and biofilm-forming determination. Among 108 samples analyzed, 79 (73%) samples were Salmonella positive after enrichment. Selected Salmonella isolates (n = 65) were assigned to 31 unique pulsed-field gel electrophoresis patterns, with 16 Salmonella serotypes, including Typhimurium and Mbandaka, identified as predominant serotypes and 10 Salmonella strains determined as strong biofilm formers. Our results indicated that the raw materials receiving area was the primary source of Salmonella and that the surfaces surrounding crax grinding and finished meal loading-out areas harbor Salmonella in biofilms that may recontaminate the finished meals. The same Salmonella serotypes found in both raw materials receiving and the finished meal loading-out areas suggested a potential of cross-contamination between different areas in the rendering processing environment.

  4. PhoP-Induced Genes within Salmonella Pathogenicity Island 1

    Science.gov (United States)

    Aguirre, Andrés; Cabeza, María Laura; Spinelli, Silvana V.; McClelland, Michael; García Véscovi, Eleonora; Soncini, Fernando C.

    2006-01-01

    The invasive pathogen Salmonella enterica has evolved a sophisticated device that allows it to enter nonphagocytic host cells. This process requires the expression of Salmonella pathogenicity island 1 (SPI-1), which encodes a specialized type III protein secretion system (TTSS). This TTSS delivers a set of effectors that produce a marked rearrangement of the host cytoskeleton, generating a profuse membrane ruffling at the site of interaction, driving bacterial entry. It has been shown that the PhoP/PhoQ two-component system represses the expression of the SPI-1 machinery by down-regulating the transcription of its master regulator, HilA. In this work, we reveal the presence of a PhoP-activated operon within SPI-1. This operon is composed of the orgB and orgC genes, which encode a protein that interacts with the InvC ATPase and a putative effector protein of the TTSS, respectively. Under PhoP-inducing conditions, expression of this operon is directly activated by the phosphorylated form of the response regulator, which recognizes a PhoP box located at the −35 region relative to the transcription start site. Additionally, under invasion-inducing conditions, orgBC expression is driven both by the prgH promoter, induced by the SPI-1 master regulator HilA, and by the directly controlled PhoP/PhoQ promoter. Together, these results indicate that in contrast to the rest of the genes encompassed in the SPI-1 locus, orgBC is expressed during and after Salmonella entry into its host cell, and they suggest a role for the products of this operon after host cell internalization. PMID:16980492

  5. Clinical features of children with nontyphoidal Salmonella bacteremia: A single institution survey in rural Japan.

    Directory of Open Access Journals (Sweden)

    Yoshihiro Aoki

    Full Text Available Nontyphoidal Salmonella (NTS can cause bacterial enterocolitis. Although some children with NTS infection develop bacteremia, its clinical manifestations have not been discussed adequately. Therefore, we examined children with NTS bacteremia. We retrospectively examined the medical records of 15 patients aged less than 15 years. Salmonella spp. were detected in the blood cultures of these patients between 1991 and 2014. We divided an additional sample group of 34 patients diagnosed with an NTS infection between 2005 and 2014, into 2 groups. Group bacteremia (B included patients in whose blood cultures Salmonella spp. were detected, and group non-bacteremia (NB included patients in whom Salmonella infection was not detected. We compared each group using Wilcoxon test and Fisher's exact test. The number of patients with fever, diarrhea, or abdominal pain was 15 (100%, 13 (87%, and 9 (60%, respectively, in the first sample of patients. However, vomiting and bloody stool were observed in only 5 patients (33%. More than 70% of patients exhibited a reduced white blood cell count, while C-reactive protein levels were variable in the patients. Salmonella spp. were detected via stool culture in 10 patients (67%. Diarrhea persisted for more than 4 days more frequently in group B than group NB (p = 0.004. The number of patients whose fever persisted for more than 4 days was significantly higher in group B than group NB (p = 0.030. Therefore, if NTS bacteremia is suspected, blood cultures should be collected and antibiotics should be initiated in cases with diarrhea or fever for more than 4 days. Furthermore, a negative stool culture result does not preclude the possibility of NTS bacteremia.

  6. Frequency and correlation of some enteric indicator bacteria and Salmonella in ready-to-eat raw vegetable salads from Mexican restaurants.

    Science.gov (United States)

    Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Castro-Rosas, Javier

    2013-08-01

    Data about Salmonella presence in ready-to-eat raw vegetable salads (REVS) consumed in restaurants or sold as REVS in México is not available. The objective of the study was to measure the frequency of coliform bacteria (CB), fecal coliform (FC), Escherichia coli, and Salmonella in REVS from different types of restaurants and determine the correlations of CB, FC, and E. coli versus Salmonella from frequencies and concentration data. The REVS were purchased from 3 types of restaurants: national chain restaurants (A1 , A2 ); local restaurants (B1 , B2 ); and small restaurants in local markets (C1 , C2 , C3 ). Two restaurants for each A and B, and 3 for C, were included. Forty REVS were purchased at each A and B restaurant, and 20 at each C restaurant. CB were tested by plate count using violet red bile agar, FC and E. coli were detected by the most probable number method and E. coli confirmed using IMViC test; conventional method of culture was used for Salmonella. Of 220 analyzed samples, 100% had CB, 95.5% had FC, 83.2% had E. coli, and 6.8% had Salmonella. E. coli frequency was equal to or exceeded 75% in all the cases: 75% (A1 , C1 , C2 ), 80% (B2 ), 85% (B1 , C3 ), and 100% (A2 ). Salmonella frequency was equal to or exceeded 2.5% in all cases: 2.5% (A1 ), 5% (B2 , C2 ), 7.5% (B1 ), and 10% (A2 , C1 , C3 ). No correlation was observed between FC or E. coli versus Salmonella in the analyzed salads. All the tested salads were of poor quality microbiologically, and microbiological quality did not differ between the restaurants types. © 2013 Institute of Food Technologists®

  7. Effects of broiler feed medications on Salmonella.

    Science.gov (United States)

    Volkova, Victoriya V; Hubbard, Sue Ann; Magee, Danny L; Byrd, J Allen; Bailey, Richard H; Wills, Robert W

    2013-09-01

    This pilot analysis was conducted with data from 52 conventional grow-out broiler flocks in a prospective field observational study in the southeastern United States during 2003-2006. Each flock was sampled for Salmonella 1 wk before the end of grow-out, upon arrival at the processing plant, and during processing (prior to and immediately after carcass chilling). The broiler litter was sampled on the day of bird harvest. The grow-out feeding programs, including the medications delivered in feed, were surveyed with questionnaires completed by the broiler managers and feedmill managers. Each detail of the feeding program was tested for statistical association with the frequency of Salmonella in the flock at each sampling point, after accounting for variation in Salmonella frequency between the farms, broiler complexes, and companies. Significant associations were found between Salmonella frequency in the broiler flock pre- and postharvest and the inclusion of feeds containing individual coccidiostats and other antimicrobial growth promoters, days on feed, and total consumption of feeds containing these products, as well as with practices such as a mash feed and a nonmedicated withdrawal feed. The analysis provided testable hypotheses for how broiler feed medications impact the frequency of Salmonella in the flocks.

  8. Salmonella and Eggs: From Production to Plate

    Directory of Open Access Journals (Sweden)

    Harriet Whiley

    2015-02-01

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

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

    NARCIS (Netherlands)

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

    1998-01-01

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

  10. The detection of antibodies against Salmonella Enteritidis in reference materials using a LPS ELISA ; A collaborative study amongst the National Reference Laboratories for Salmonella

    NARCIS (Netherlands)

    Voogt N; Dufrenne JB; Nagelkerke N; Veld PH in' t; Henken AM; MGB

    1997-01-01

    Het Communautair Referentie Laboratorium voor Salmonella (CRL) heeft een ringonderzoek georganiseerd waarin een immunologische methode voor het aantonen van antilichamen tegen Salmonella Enteritidis (SE) werd uitgevoerd en waaraan alle Nationale Referentie Laboratoria voor Salmonella (NRLs)

  11. Impact of litter salmonella status during feed withdrawal on salmonella recovery from the broiler crop and ceca

    Science.gov (United States)

    Research was conducted to evaluate the impact of litter Salmonella status during feed withdrawal on Salmonella recovery from the crop and ceca following feed withdrawal. In 4 experiments, pens of broilers in separate rooms were challenged with marker strains of either Salmonella Montevideo or Salmon...

  12. An allele of an ancestral transcription factor dependent on a horizontally acquired gene product.

    Directory of Open Access Journals (Sweden)

    H Deborah Chen

    Full Text Available Changes in gene regulatory circuits often give rise to phenotypic differences among closely related organisms. In bacteria, these changes can result from alterations in the ancestral genome and/or be brought about by genes acquired by horizontal transfer. Here, we identify an allele of the ancestral transcription factor PmrA that requires the horizontally acquired pmrD gene product to promote gene expression. We determined that a single amino acid difference between the PmrA proteins from the human adapted Salmonella enterica serovar Paratyphi B and the broad host range S. enterica serovar Typhimurium rendered transcription of PmrA-activated genes dependent on the PmrD protein in the former but not the latter serovar. Bacteria harboring the serovar Typhimurium allele exhibited polymyxin B resistance under PmrA- or under PmrA- and PmrD-inducing conditions. By contrast, isogenic strains with the serovar Paratyphi B allele displayed PmrA-regulated polymyxin B resistance only when experiencing activating conditions for both PmrA and PmrD. We establish that the two PmrA orthologs display quantitative differences in several biochemical properties. Strains harboring the serovar Paratyphi B allele showed enhanced biofilm formation, a property that might promote serovar Paratyphi B's chronic infection of the gallbladder. Our findings illustrate how subtle differences in ancestral genes can impact the ability of horizontally acquired genes to confer new properties.

  13. Control of Salmonella enterica serovar Enteritidis in laying hens by inactivated Salmonella Enteritidis vaccines

    Science.gov (United States)

    de Freitas Neto, Oliveiro Caetano; Mesquita, Aline Lopes; de Paiva, Jaqueline Boldrin; Zotesso, Fábio; Berchieri Júnior, Angelo

    2008-01-01

    Salmonella Enteritidis is one of the agents that is responsible for outbreaks of human foodborne salmonellosis caused by Salmonella Enteritidis and is generally associated with the consumption of poultry products. Inactivated Salmonella Enteritidis cell vaccine is one of the available methods to control Salmonella Enteritidis in breeders and laying hens, however results in terms of efficacy vary. This vaccine has never been tested in Brazil, therefore, the present work was carried out to assess three commercial inactivated Salmonella Enteritidis vaccines allowed in Brazil. Four hundred white light variety commercial laying hens were obtained at one-day-of age. At eight weeks old, the birds were divided into four groups with one hundred animals each. Birds from three groups (V1, V2 and V3) received different intramuscular vaccines, followed by a booster dose at 16 weeks of age. Birds from another group (CG) were not vaccinated. When the laying hens were 20, 25 and 31 weeks old, 13 from each group were transferred to another room and were challenged by inoculating 2 mL neat culture of Salmonella Enteritidis. On the second day after each challenge, the caecal contents, spleen, liver and ovary of three birds from each group were analyzed for the presence of Salmonella Enteritidis. Twice a week a cloacal swab of each bird was taken and all eggs laid were examined for the presence of Salmonella Enteritidis. After four consecutive negative cloacal swabs in all the groups, the birds were sacrificed so as to examine the liver, caecal contents and ovaries. Overall, the inactivated vaccine used in group V3 reduced Salmonella Enteritidis in the feces and eggs. A very small amount of Salmonella was found in the spleen, liver, ovary and caeca of the birds in the four groups during the whole experiment. In general, inactivated Salmonella Enteritidis vaccines was able to decrease the presence of Salmonella Enteritidis in the birds and in the eggs as well. Nevertheless, they must

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

    Directory of Open Access Journals (Sweden)

    Parthasarathi Behera

    2015-05-01

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

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

    Science.gov (United States)

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

    2014-02-01

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

  16. Plants as alternative hosts for Salmonella.

    Science.gov (United States)

    Schikora, Adam; Garcia, Ana V; Hirt, Heribert

    2012-05-01

    Recent findings show that many human pathogenic bacteria can use multiple host organisms. For example, Salmonella Typhimurium can use plants as alternative hosts to humans and other animals. These bacteria are able to adhere to plant surfaces and actively infect the interior of plants. Similarly to the infection of animal cells, S. Typhimurium suppresses plant defense responses by a type III secretion mechanism, indicating that these bacteria possess a dedicated multi-kingdom infection strategy, raising the question of host specificity. In addition, evidence is accumulating that the interaction of Salmonella with plants is an active process with different levels of specificity, because different Salmonella serovars show variations in pathogenicity, and different plant species reveal various levels of resistance towards these bacteria. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Exploiting host immunity: the Salmonella paradigm

    Science.gov (United States)

    Behnsen, Judith; Perez-Lopez, Araceli; Nuccio, Sean-Paul; Raffatellu, Manuela

    2014-01-01

    Pathogens have evolved clever strategies to evade and in some cases exploit the attacks of an activated immune system. Salmonella enterica is one such pathogen, exploiting multiple aspects of host defense to promote its replication in the host. Here we review recent findings on the mechanisms by which Salmonella establishes systemic and chronic infection, including strategies involving manipulation of innate immune signaling and inflammatory forms of cell death, as well as immune evasion by establishing residency in M2 macrophages. We also examine recent evidence showing that the oxidative environment and the high levels of antimicrobial proteins produced in response to localized Salmonella gastrointestinal infection enable the pathogen to successfully outcompete the resident gut microbiota. PMID:25582038

  18. Salmonella-infektion kompliceret med akut nyreinsufficiens

    DEFF Research Database (Denmark)

    Thøgersen, Thøger; Jensen, Jørgen Erik; Jespersen, Bente

    2003-01-01

    Acute renal failure is a known complication to Salmonella gastroenteritis, and patients with chronic renal failure or impaired host defence are at increased risk. In the two presented cases there had been a few days of gastroenteritis before the hospitalisation, but the only symptoms...... at the admission were fatigue and dyspnoea. In both cases severe uraemia had developed and the patients and their physicians did not expect the episode of gastroenteritis to be the only etiology of acute renal failure. Both patients had normal renal histology and Salmonella was grown in their faeces. Subsequently......, their renal function was normalised. In these patients dialysis and renal biopsies would have been unnecessary if the ability of even a moderate Salmonella infection to cause acute renal failure in a healthy subject had been realised and prompt rehydration had been initiated....

  19. Quinolones in the treatment of Salmonella carriers.

    Science.gov (United States)

    Rodríguez-Noriega, E; Andrade-Villanueva, J; Amaya-Tapia, G

    1989-01-01

    Infections caused by Salmonella typhi are commonly followed by a chronic carrier state despite positive clinical and initial bacteriologic responses. The use of primary antibiotics like chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole has several major drawbacks, including in some instances the failure to prevent the carrier state. The appearance worldwide of strains with multiple resistance to the most commonly used regimens has prompted the search for new forms of therapy. Among the agents studied have been third-generation cephalosporins and quinolones, which are active in vitro against bacterial enteropathogens like S. typhi. Resolution of chronic carriage of S. typhi and other salmonellae is difficult, and regimens commonly fail (including those that combine antibiotic administration with removal of the gallbladder). In addition to being active in vitro against Salmonella species, the newer quinolones adequately penetrate the intestinal lumen, liver, bile, and gallbladder. Initial experience with norfloxacin and ciprofloxacin in oral treatment of the chronic S. typhi carrier state in adults has been promising.

  20. Presence of indicator bacteria, diarrhoeagenic Escherichia coli pathotypes and Salmonella in fresh carrot juice from Mexican restaurants.

    Science.gov (United States)

    Torres-Vitela, M D R; Gómez Aldapa, C A; Cerna-Cortes, J F; Villarruel-López, A; Rangel-Vargas, E; Castro-Rosas, J

    2013-03-01

    Coliform bacteria (CB), faecal coliforms (FC), Escherichia coli, diarrhoeagenic E. coli pathotypes (DEP) and Salmonella frequencies were determined for fresh carrot juice from restaurants in Pachuca city, Mexico. Two hundred and eighty carrot juice samples were purchased in three types of restaurants: (A), national chain restaurants; (B), local restaurants; and (C), very small restaurants. Two restaurants for each A and B, and three for C, were included. Forty juice samples were purchased at each restaurant. All tested juice samples had poor microbiological quality. Of these samples, 100, 96·8, 54·3, 8·9 and 8·6% had CB, FC, E. coli, DEP and Salmonella, respectively. CB were present in all juice samples regardless of source, with limits ranging from 3·6 × 10² to 8·5 × 10⁷ CFU ml⁻¹, and the limits for FC and E. coli were restaurants at levels of 5% or above: DEP, 5% (A₁, B₂, 10% (A₂, B₁, C₁, C₂) and 12·5% (C₃); Salmonella, 5% (A₁, A₂, B₂), 7·5% (C₂), 10% (C₁, 12·5% (B₁) and 15% (C₃). This is the first report of microbiological quality and Salmonella, enteroinvasive E. coli (EIEC), enterotoxigenic E. coli (ETEC) and Shiga toxin-producing E. coli (STEC) isolation from fresh carrot juice in Mexico. Fresh carrot juice from restaurants could be an important factor contributing to the endemicity of EIEC-, ETEC- and STEC- and Salmonella-caused gastroenteritis in Mexico. © 2012 The Society for Applied Microbiology.

  1. Isolation and characterization of lactobacillus and bacillus producing ...

    African Journals Online (AJOL)

    The biosurfactants were investigated for potential antimicrobial activity using disk diffusion method against causal organisms of food borne illnesses. These food borne pathogens include Salmonella typhi, Escherichia coli, Staphylococcus aureus, Salmonella paratyphi and Shigella dysentrae. Biosurfactant producing ...

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

    LENUS (Irish Health Repository)

    Dineen, Patrick F

    2011-06-01

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

  3. Influence of the treatment of Listeria monocytogenes and Salmonella enterica serovar Typhimurium with citral on the efficacy of various antibiotics.

    Science.gov (United States)

    Zanini, Surama F; Silva-Angulo, Angela B; Rosenthal, Amauri; Aliaga, Dolores Rodrigo; Martínez, Antonio

    2014-04-01

    The main goal of this work was to study the bacterial adaptive responses to antibiotics induced by sublethal concentration of citral on first-and second-generation cells of Listeria monocytogenes serovar 4b (CECT 4032) and Salmonella enterica serovar Typhimurium (CECT 443). The first-generation cells were not pretreated with citral, while the second-generation cells were obtained from cells previously exposed to citral during 5 h. The trials were conducted at 37°C. The presence of citral in the culture medium and the antibiotic strips resulted in a reduced minimum inhibitory concentration (MIC) for the first-generation cells of Listeria monocytogenes serovar 4b and Salmonella Typhimurium. This result was observed for almost all the antibiotics, compared with the same microorganisms of the control group (without citral), which could represent an additive effect. For Listeria serovar 4b, the second-generation cells of the test group maintained the same susceptibility to antibiotics compared with cells in the control group and in the test group of the first generation. The second-generation cells of the control group indicated that the Salmonella Typhimurium maintained the same sensitivity to the antibiotics tested compared with the first generation of this group, except in the case of erythromycin, which exhibited an increased MIC value. With respect to the second-generation cells of Salmonella Typhimurium, the presence of citral determined a decrease in the antibiotic susceptibility for almost all of the antibiotics, except colistin, compared with the first-generation of the test group, which can be seen by increase of MIC values. In conclusion, the presence of citral in the culture medium of Listeria 4b and Salmonella Typhimurium increased the antibiotic susceptibility of the first generations, while we observed an increase in antibiotic resistance in the second generation of Salmonella Typhimurium.

  4. Phenotypic and genetic characterization of antimicrobial resistance in Salmonella serovars isolated from retail meats in Alberta, Canada.

    Science.gov (United States)

    Aslam, Mueen; Checkley, Sylvia; Avery, Brent; Chalmers, Gabhan; Bohaychuk, Valerie; Gensler, Gary; Reid-Smith, Richard; Boerlin, Patrick

    2012-10-01

    This study determined the prevalence of Salmonella serovars, antimicrobial resistance (AMR) and resistance genes in Salmonella isolated from retail meats purchased in Alberta, Canada. Samples were collected during one year period (May 2007-April 2008) on weekly basis from 19 census divisions in Alberta. A total of 564 samples including chicken (n = 206), turkey (n = 91), beef (n = 134) and pork (n = 133) were purchased. Salmonella were recovered from chicken (40%), turkey (27%) and pork (2%) samples and was not found in ground beef. A total of 21, 8, and 3 different serovars were recovered from chicken, turkey and pork meats, respectively. Salmonella Hadar was most common in chicken whereas S. Heidelberg was common in turkey meat. Overall 29% (32/110) of isolates were susceptible to tested antimicrobials and resistance to ciprofloxacin, amikacin and nalidixic acid was not found in any isolate. Multiresistance (≥2 antimicrobials) was found in 56% of isolates. Resistance to amoxicillin-clavulanic acid (AMC), ceftiofur (TIO), and ceftriaxone (CRO) was found in about 21% of chicken and 25% of turkey isolates. Resistance to either of tetracycline (TET), streptomycin (STR) or ampicillin (AMP) was unconditionally associated with S. Hadar but resistance to either of TET, AMP, AMC, TIO, CRO or cefoxitin was associated with S. Heidelberg. The strA/B (42% isolates), tet(A) (28% isolates), bla(CMY-2) (21% isolates) and bla(TEM) (17% isolates) were the most common resistance genes found. The bla(CMY-2) and bla(TEM) genes were unconditionally associated with S. Heidelberg; tet(A) and strA/B with S. Hadar and tet(B) gene with S. Kentucky. The strA/B genes were not associated with S. Heidelberg. Our data suggests that the prevalence of Salmonella serovars varied by the meat type and that AMR and resistance genes varied by the Salmonella serovars. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  5. Prevalence of Salmonella spp. in reptiles

    OpenAIRE

    加藤, 行男; 村上, 賢

    2007-01-01

    A total of 291 fecal samples from 252 wild reptiles and 39 pet reptiles were examined for the prevalence of Salmonella spp. in Japan. Salmonella spp. were isolated from 29 (11.5%) of 252 wild reptiles and 22 (55.6%) of 39 pet reptiles. The isolates were identified into subspecies I to IV. The majority of isolates (43.6%) belonged to subspecies I and these isolates could be identified into 9 serovars. The serovars isolated were found to be S. Newport, S. Litchifield and S. Thompson which cause...

  6. Quantitative proteomic analysis of the Salmonella-lettuce interaction.

    Science.gov (United States)

    Zhang, Yuping; Nandakumar, Renu; Bartelt-Hunt, Shannon L; Snow, Daniel D; Hodges, Laurie; Li, Xu

    2014-11-01

    Human pathogens can internalize food crops through root and surface uptake and persist inside crop plants. The goal of the study was to elucidate the global modulation of bacteria and plant protein expression after Salmonella internalizes lettuce. A quantitative proteomic approach was used to analyse the protein expression of Salmonella enterica serovar Infantis and lettuce cultivar Green Salad Bowl 24 h after infiltrating S. Infantis into lettuce leaves. Among the 50 differentially expressed proteins identified by comparing internalized S. Infantis against S. Infantis grown in Luria Broth, proteins involved in glycolysis were down-regulated, while one protein involved in ascorbate uptake was up-regulated. Stress response proteins, especially antioxidant proteins, were up-regulated. The modulation in protein expression suggested that internalized S. Infantis might utilize ascorbate as a carbon source and require multiple stress response proteins to cope with stresses encountered in plants. On the other hand, among the 20 differentially expressed lettuce proteins, proteins involved in defense response to bacteria were up-regulated. Moreover, the secreted effector PipB2 of S. Infantis and R proteins of lettuce were induced after bacterial internalization into lettuce leaves, indicating human pathogen S. Infantis triggered the defense mechanisms of lettuce, which normally responds to plant pathogens. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  7. Modeling the influence of temperature, water activity and water mobility on the persistence of Salmonella in low-moisture foods.

    Science.gov (United States)

    Farakos, S M Santillana; Frank, J F; Schaffner, D W

    2013-09-02

    survival in non-fat food systems as compared to foods containing low-fat levels (12% fat). The models developed in this study represent the first predictive models for survival of Salmonella in low-moisture foods. These models provide baseline information to be used for research on risk mitigation strategies for low-moisture foods. © 2013. Published by Elsevier B.V. All rights reserved.

  8. InstantLabs® Salmonella species detection method: matrix extension.

    Science.gov (United States)

    Sharma, Neil; Bambusch, Lauren; Le, Thu; Morey, Amit; Hayman, Melinda; Montez, Sergio J

    2014-01-01

    The performance of InstantLabs® Salmonella Species Food Safety Kit to detect Salmonella in four food matrixes was validated against the International Organization for Standardization (ISO) reference method 6579:2002. The matrixes (raw ground beef, raw chicken breast, raw ground chicken, and lettuce) were inoculated with low levels of Salmonella (Salmonella. Samples were validated using 375 g (meat) or 25 g (lettuce and poultry) test portions enriched in FASTGRO TM SE at 42±1 °C for 12 h and 10 h, respectively. All samples were confirmed using the ISO reference method, regardless of initial-screen result. The InstantLabs test method was shown to perform as well as or better than the reference method for the detection of Salmonella species in ground beef, chicken breast, ground chicken, and lettuce. Inclusivity and exclusivity testing revealed no false negatives among the 100 Salmonella serovars and no false positives among the 30 non-Salmonella species examined, respectively.

  9. Source attribution of human Salmonella cases in Sweden

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  10. Presence of Salmonella pathogenicity island 2 genes in seafood-associated Salmonella serovars and the role of the sseC gene in survival of Salmonella enterica serovar Weltevreden in epithelial cells.

    Science.gov (United States)

    Bhowmick, Patit P; Devegowda, Devananda; Ruwandeepika, H A Darshanee; Karunasagar, Iddya; Karunasagar, Indrani

    2011-01-01

    The type III secretion system encoded by the Salmonella pathogenicity island 2 (SPI-2) has a central role in the pathogenesis of systemic infections by Salmonella. Sixteen genes (ssaU, ssaB, ssaR, ssaQ, ssaO, ssaS, ssaP, ssaT, sscB, sseF, sseG, sseE, sseD, sseC, ssaD and sscA) of SPI-2 were targeted for PCR amplification in 57 seafood-associated serovars of Salmonella. The sseC gene of SPI-2 was found to be absent in two isolates of Salmonella enterica serovar Weltevreden, SW13 and SW39. Absence of sseC was confirmed by sequencing using flanking primers. SW13 had only 66 bp sequence of the sseC gene and SW39 had 58 bp sequence of this gene. A clinical isolate, S. Weltevreden--SW3, 10:r:z6--was used to construct a deletion mutant for the sseC gene. Significant reduction in the survival of SW3, 10:r:z6 ΔsseC and natural mutants SW13 and SW39 in HeLa cells suggests that sseC has a crucial role in the intracellular survival of S. Weltevreden. Expression of sseC was upregulated during the intracellular phase of both S. enterica serovar Typhimurium and clinical isolate S. Weltevreden SW3, 10:r:z6, suggesting a crucial role for this gene in the survival of S. Weltevreden inside host cells.

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

    Science.gov (United States)

    Jasson, Vicky; Baert, Leen; Uyttendaele, Mieke

    2011-02-28

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

  12. 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.

  13. 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.

  14. Low molecular weight thiol-dependent antioxidant and antinitrosative defenses in Salmonella pathogenesis

    Science.gov (United States)

    Song, Miryoung; Husain, Maroof; Jones-Carson, Jessica; Liu, Lin; Henard, Calvin A.; Vázquez-Torres, Andrés

    2012-01-01

    We found herein that the intracytoplasmic pool of the low-molecular weight (LMW) thiol glutathione (GSH) is readily oxidized in Salmonella exposed to nitric oxide (NO). The hypersusceptibility of gshA and gshB mutants lacking γ-glutamylcysteine and glutathione synthetases to NO and S-nitrosoglutathione indicates that GSH antagonizes the bacteriostatic activity of reactive nitrogen species. Metabolites of the GSH biosynthetic pathway do not affect the enzymatic activity of classical NO targets such as quinol oxidases. In contrast, LMW thiols diminish the nitrosative stress experienced by enzymes, such as glutamine oxoglutarate amidotransferase, that contain redox active cysteines. LMW thiols also preserve the transcription of Salmonella pathogenicity island 2 gene targets from the inhibitory activity of nitrogen oxides. These findings are consistent with the idea that GSH scavenges reactive nitrogen species (RNS) other than NO. Compared to the adaptive response afforded by inducible systems such as the hmp-encoded flavohemoprotein, gshA, encoding the first step of GSH biosynthesis, is constitutively expressed in Salmonella. An acute model of salmonellosis has revealed that the antioxidant and antinitrosative properties associated with the GSH biosynthetic pathway represent a first line of Salmonella resistance against reactive oxygen and nitrogen species engendered in the context of a functional NRAMP1R divalent metal transporter. PMID:23217033

  15. Salmonella and antimicrobial resistance in an animal-based agriculture river system.

    Science.gov (United States)

    Palhares, Julio Cesar Pascale; Kich, Jalusa D; Bessa, Marjo C; Biesus, Luiza L; Berno, Lais G; Triques, Nelise J

    2014-02-15

    The aim of this study was to examine the Salmonella serovars and antimicrobial resistance within an animal-based agriculture river system. The study area consisted of a 1,345 ha upper part of Pinhal catchment. A total of 384 samples were collected in four years of monitoring. Salmonella was isolated from 241 samples (62.7%), resulting in 324 isolates. The highest number of Salmonella sp. occurred in samples associated with sites with high stoking density animal unit per hectare. It was possible to demonstrate the variability of serovars in the study area: 30 different serovars were found and at least 11 per monitoring site. Thirty-three potentially related isolates were genotyped by PFGE, one major clone was observed in serovar Typhimurium, which occurred in animal feces (swine and bovine), and different sites and samplings proving the cross-contamination and persistence of this specific clone. Among 180 isolates submitted to an antimicrobial susceptibility test, 50.5% were susceptible to all 21 antimicrobials tested and 54 different profiles were found. In the current study, 49.5% of the tested isolates were resistant to at least one antimicrobial, and multi-resistance occurred in 18% of isolates. Results indicate a close interaction between animal-based agriculture, Salmonella, and antimicrobial resistance. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Temperature effects on the antimicrobial efficacy of condensed smoke and lauric arginate against Listeria and Salmonella.

    Science.gov (United States)

    Lingbeck, Jody M; Cordero, Paola; O'Bryan, Corliss A; Johnson, Michael G; Ricke, Steven C; Crandall, Philip G

    2014-06-01

    Condensed smoke or liquid smoke (LS) and lauric arginate (LAE) are antimicrobials used in food preservation. They have demonstrated abilities to reduce or inhibit pathogenic and spoilage organisms. Few studies, however, have reported on the effectiveness of LS or LAE over the range of temperatures typically encountered in food marketing channels. Therefore, the effects of temperature on the antimicrobial properties of two commercial LS fractions, an LS derived from pecan shells, and LAE against two common foodborne pathogens, Listeria and Salmonella, were investigated. The MICs of the three LS samples and LAE were measured at 4, 10, and 37°C for Listeria monocytogenes strains 2045 (Scott A, serotype 4b) and 10403S (serotype 1/2a) and two strains of Listeria innocua, a well-established surrogate, and at 10, 25, and 37°C for Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Heidelberg. The MICs for LS against Listeria ranged from 3 to 48% (vol/vol), with higher MICs seen with lower temperatures. The MICs for LS on Salmonella ranged from 3 to 24%. Values for LAE ranged between 0.004 and 0.07% for both pathogens, and like LS, higher MICs were always associated with lower incubation temperatures. Understanding how storage temperature affects the efficacy of antimicrobials is an important factor that can contribute to lowering the hurdles of use levels and costs of antimicrobials and ultimately improve food safety for the consumer.

  17. InduciblespyTranscription Acts as a Sensor for Envelope Stress ofSalmonella typhimurium.

    Science.gov (United States)

    Jeong, Seon Mi; Lee, Hwa Jeong; Park, Yoon Mee; Kim, Jin Seok; Lee, Sang Dae; Bang, Iel Soo

    2017-01-01

    Salmonella enterica infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target Salmonella envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for Salmonella envelope stress, we examined the transcription of the S. enterica serovar typhimurium spy gene, the ortholog of which in Escherichia coli encodes Spy (spheroplast protein y). Spy is a chaperone protein expressed and localized in the periplasm of E. coli during spheroplast formation, or by exposure to protein denaturing conditions. spy expression in S. typhimurium was examined by constructing a spy-gfp transcriptional fusion. S. typhimurium spy transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, spy induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring spy transcription may be useful to determine whether a molecule particularly cause envelope stress in Salmonella .

  18. Antibiotic resistance of prevalent Salmonella and Shigella strains in northwest Ethiopia.

    Science.gov (United States)

    Aseffa, A; Gedlu, E; Asmelash, T

    1997-11-01

    Salmonella and Shigella strains were isolated prospectively from in- and outpatient specimens of the Gondar College teaching hospital over a two year period, from June 1994 to May 1996. Of 7993 miscellaneous specimens cultured, 80 yielded Salmonella and 147 Shigella. Serogroup B dominated among the salmonella, accounting for 61% of isolates, followed by S. typhi (21%). S. flexneri (58.5%) and S. dysenteriae (36.7%) were the most frequently isolated species among the Shigella. Results of sensitivity testing to five commonly used antibiotics in the area: ampicillin, chloramphenicol, gentamicin, tetracycline and cotrimoxazole, showed multiple drug resistance among the isolates of both salmonella and shigella. Only 4% of shigella were sensitive to all five antibiotics screened for in the study. Overall sensitive of shigella isolates to individual antibiotics was 8.8% to tetracycline, 10% to ampicillin, 28% to co-trimoxazole and 98% to gentamicin. No resistance was observed to nalidixic acid among 108 shigella strains tested for this antibiotic. The continued sensitivity of S. typhi to chloramphenicol, cotrimoxazole, ampicillin and the other commonly used antibiotics is noted. It is recommended that nalidixic acid be introduced into the area under strict regulation for treatment of severe cases of shigella dysentery, an illness which is highly endemic in the region and the cause of occasional epidemics with high mortality.

  19. Evaluation of YadC protein delivered by live attenuated Salmonella as a vaccine against plague.

    Science.gov (United States)

    Sun, Wei; Olinzock, Joseph; Wang, Shifeng; Sanapala, Shilpa; Curtiss, Roy

    2014-03-01

    Yersinia pestis YadB and YadC are two new outer membrane proteins related to its pathogenicity. Here, codon-optimized yadC, yadC810 (aa 32-551), or yadBC antigen genes delivered by live attenuated Salmonella strains are evaluated in mice for induction of protective immune responses against Y. pestis CO92 through subcutaneous or intranasal challenge. Our findings indicate that mice immunized with Salmonella synthesizing YadC, YadC810, or YadBC develop significant serum IgG responses to purified recombinant YadC protein. For subcutaneous challenge (approximately 230 LD50 of Y. pestis CO92), mice immunized with Salmonella synthesizing YadC or YadC810 are afforded 50% protection, but no protection by immunization with the Salmonella strain synthesizing YadBC. None of these antigens provided protection against intranasal challenge (approximately 31 LD50 of Y. pestis CO92). In addition, subcutaneous immunization with purified YadC810 protein emulsified with alum adjuvant does not elicit a protective response against Y. pestis administered by either challenge route. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  20. Rapid DNA transformation in Salmonella Typhimurium by the hydrogel exposure method.

    Science.gov (United States)

    Elabed, Hamouda; Hamza, Rim; Bakhrouf, Amina; Gaddour, Kamel

    2016-07-01

    Even with advances in molecular cloning and DNA transformation, new or alternative methods that permit DNA penetration in Salmonella enterica subspecies enterica serovar Typhimurium are required in order to use this pathogen in biotechnological or medical applications. In this work, an adapted protocol of bacterial transformation with plasmid DNA based on the "Yoshida effect" was applied and optimized on Salmonella enterica serovar Typhimurium LT2 reference strain. The plasmid transference based on the use of sepiolite as acicular materials to promote cell piercing via friction forces produced by spreading on the surface of a hydrogel. The transforming mixture containing sepiolite nanofibers, bacterial cells to be transformed and plasmid DNA were plated directly on selective medium containing 2% agar. In order to improve the procedure, three variables were tested and the transformation of Salmonella cells was accomplished using plasmids pUC19 and pBR322. Using the optimized protocol on Salmonella LT2 strain, the efficiency was about 10(5) transformed cells per 10(9) subjected to transformation with 0.2μg plasmid DNA. In summary, the procedure is fast, offers opportune efficiency and promises to become one of the widely used transformation methods in laboratories. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Iron acquisition pathways and colonization of the inflamed intestine by Salmonella enterica serovar Typhimurium

    OpenAIRE

    Costa, Luciana F.; Mol, Juliana P. S.; Silva, Ana Patricia C.; Macêdo,Auricélio A.; Silva, Teane M. A.; Alves, Geraldo E.S.; Winter, Sebastian; Winter, Maria G.; Velazquez, Eric M; Byndloss, Mariana X.; Bäumler, Andreas J.; Tsolis, Renée M.; Paixão, Tatiane A.; Renato L Santos

    2016-01-01

    Salmonella enterica serotype Typhimurium is able to expand in the lumen of the inflamed intestine through mechanisms that have not been fully resolved. Here we utilized streptomycin-pretreated mice and dextran sodium sulfate (DSS)-treated mice to investigate how pathways for S. Typhimurium iron acquisition contribute to pathogen expansion in the inflamed intestine. Competitive infection with an iron uptake-proficient S. Typhimurium strain and mutant strains lacking tonB feoB, feoB, tonB or ir...

  2. The differential effects of 1,25-dihydroxyvitamin D3 on Salmonella-induced interleukin-8 and human beta-defensin-2 in intestinal epithelial cells.

    Science.gov (United States)

    Huang, F-C

    2016-07-01

    Salmonellosis or Salmonella, one of the most common food-borne diseases, remains a major public health problem worldwide. Intestinal epithelial cells (IECs) play an essential role in the mucosal innate immunity of the host to defend against the invasion of Salmonella by interleukin (IL)-8 and human β-defensin-2 (hBD-2). Accumulated research has unravelled important roles of vitamin D in the regulation of innate immunity. Therefore, we investigated the effects of 1,25-dihydroxyvitamin D3 (1,25D3) on Salmonella-induced innate immunity in IECs. We demonstrate that pretreatment of 1,25D3 results in suppression of Salmonella-induced IL-8 but enhancement of hBD-2, either protein secretion and mRNA expression, in IECs. Furthermore, 1,25D3 enhanced Salmonella-induced membranous recruitment of nucleotide oligomerization domain (NOD2) and its mRNA expression and activation of protein kinase B (Akt), a downstream effector of phosphoinositide 3-kinase (PI3K). Inhibition of the PI3K/Akt signal counteracted the suppressive effect of 1,25D3 on Salmonella-induced IL-8 expression, while knock-down of NOD2 by siRNA diminished the enhanced hBD-2 expression. These data suggest differential regulation of 1,25D3 on Salmonella-induced IL-8 and hBD-2 expression in IECs via PI3K/Akt signal and NOD2 protein expression, respectively. Active vitamin D-enhanced anti-microbial peptide in Salmonella-infected IECs protected the host against infection, while modulation of proinflammatory responses by active vitamin D prevented the host from the detrimental effects of overwhelming inflammation. Thus, active vitamin D-induced innate immunity in IECs enhances the host's protective mechanism, which may provide an alternative therapy for invasive Salmonella infection. © 2016 British Society for Immunology.

  3. Evaluation of the respiratory route as a viable portal of entry for Salmonella in poultry via intratracheal challenge of Salmonella Enteritidis and Salmonella Typhimurium.

    Science.gov (United States)

    Kallapura, G; Morgan, M J; Pumford, N R; Bielke, L R; Wolfenden, A D; Faulkner, O B; Latorre, J D; Menconi, A; Hernandez-Velasco, X; Kuttappan, V A; Hargis, B M; Tellez, G

    2014-02-01

    Experimental and epidemiological evidence suggests that primary infection of Salmonella is by the oral-fecal route for poultry. However, the airborne transmission of Salmonella and similar enteric zoonotic pathogens has been historically neglected. Increasing evidence of Salmonella bioaerosol generation in production facilities and studies suggesting the vulnerabilities of the avian respiratory architecture together have indicated the possibility of the respiratory system being a potential portal of entry for Salmonella in poultry. Presently, we evaluated this hypothesis through intratracheal (IT) administration of Salmonella Enteritidis and Salmonella Typhimurium, as separate challenges, in a total of 4 independent trials, followed by enumeration of cfu recovery in ceca-cecal tonsils and recovery incidence in liver and spleen. In all trials, both Salmonella Enteritidis and Salmonella Typhimurium, challenged IT colonized cecae to a similar or greater extent than oral administration at identical challenge levels. In most trials, chickens cultured for cfu enumeration from IT-challenged chicks at same dose as orally challenged, resulted in an increase of 1.5 log higher Salmonella Enteritidis from ceca-cecal tonsils and a much lower dose IT of Salmonella Enteritidis could colonize ceca to the same extent than a higher oral challenge. This trend of increased cecal colonization due to IT challenge was observed with all trails involving week-old birds (experiment 2 and 3), which are widely considered to be more difficult to infect via the oral route. Liver-spleen incidence data showed 33% of liver and spleen samples to be positive for Salmonella Enteritidis administered IT (10(6) cfu/chick), compared with 0% when administered orally (experiment 2, trial 1). Collectively, these data suggest that the respiratory tract may be a largely overlooked portal of entry for Salmonella infections in chickens.

  4. Ultraviolet (UV-C) inactivation of Enterococcus faecium, Salmonella choleraesuis and Salmonella typhimurium in porcine plasma

    OpenAIRE

    Bl?zquez, Elena; Rodr?guez, Carmen; R?denas, Jes?s; P?rez de Rozas, Ana; Segal?s, Joaquim; Pujols, Joan; Polo, Javier

    2017-01-01

    The objective of this study was to assess the effectiveness of an ultraviolet (UV-C, 254 nm) irradiation system on reducing the load of Salmonella typhimurium (S. typhimurium), Salmonella choleraesuis (S. choleraesuis) resistant to streptomycin and Enterococcus faecium (E. faecium) inoculated in sterile porcine plasma and then subjected to different UV-C irradiation doses (750, 1500, 3000, 6000 and 9000 J/L) using a pilot plant UV-C device working under turbulent flow. Results indicated that ...

  5. Salmonella-TEK, a rapid screening method for Salmonella species in food.

    OpenAIRE

    Van Poucke, L S

    1990-01-01

    A micro-enzyme-linked immunosorbent assay (micro-ELISA) using the Salmonella-TEK screen kit was tested for the detection of Salmonella spp. in pure cultures as well as in 30 artificially contaminated food samples and in 45 naturally contaminated food samples. Different raw, fleshy foods and processed foods were used as test products. The artificially contaminated minced meat samples were preenriched in buffered peptone water, and after incubation, different selective enrichment broths were te...

  6. Bacteriophage-based enrichment coupled to immunochromatographic strip-based detection for the determination of Salmonella in meat and poultry.

    Science.gov (United States)

    Muldoon, Mark T; Teaney, George; Li, Jingkun; Onisk, Dale V; Stave, James W

    2007-10-01

    Immunochemical-based methods for the detection of Salmonella in food can be complicated by the presence of closely related, immunocrossreactive non-Salmonella species in the sample that may cause false-positive results. To circumvent this problem, specific bacteriophages against immunocrossreactive, non-Salmonella bacteria were used in the sample enrichment step to suppress their growth and improve the performance of an immunochromatographic strip-based detection method for Salmonella. Cross-reactive bacteria were isolated from various food sources and were characterized with a panel of Salmonella somatic O antigen-specific monoclonal antibodies. These cross-reactive bacteria were primarily Citrobacter spp. and Escherichia coli with serology shared with Salmonella serogroups B, D, and F. These bacteria were used as hosts for the isolation of specific lytic bacteriophages. When formulated with the primary enrichment, the bacteriophage cocktail significantly reduced false positives with a broadly reactive immunochromatographic test strip. This was demonstrated in both artificially and naturally contaminated meat. False positives in naturally contaminated beef samples were reduced from 32 of 115 samples tested to zero. In raw meat and poultry with a relatively high bioburden (>10(5) CFU/g), the use of the bacteriophage-based enrichment procedure gave improved recovery of Salmonella compared with the conventional culture-based reference method. This was observed when coupled to either test strip-based or selective agar-based detection. The use of specific bacteriophages for the control of immunocrossreactive and competitive microflora during the food sample enrichment step provides a new approach for enhancing the performance of both immunological- and cultural-based detection methods.

  7. Salmonella bacteriuria in a cat fed a Salmonella-contaminated diet.

    Science.gov (United States)

    Fauth, Erika; Freeman, Lisa M; Cornjeo, Lilian; Markovich, Jessica E; Janecko, Nicol; Weese, J Scott

    2015-09-01

    A 9-year-old castrated male domestic shorthair cat was evaluated because of hematuria and weight loss after an 8-year history of intermittent signs of feline lower urinary tract disease (FLUTD). A complete diet history revealed that the cat was eating a commercial diet that does not undergo the same processing procedures as most pet foods and so might be at increased risk for bacterial contamination owing to a nonstandard industry cooking procedure. The cat had a history consistent with FLUTD, but bacteriologic culture of the urine revealed Salmonella organisms. Additional analysis revealed Salmonella enterica serotype I:ROUGH-O:g,m,s:- in samples of urine and feces as well as Salmonella enterica serotype Johannesburg and Salmonella enterica serotype Senftenberg in the diet. The cat responded positively to antimicrobial treatment for the Salmonella bacteriuria as well as to dietary and environmental management for the clinical signs associated with FLUTD. Findings in this case highlighted an additional health consequence associated with ingestion of Salmonella-contaminated food. Such contamination is of particular concern with raw meat-based diets or diets that have not undergone standard industry cooking practices. Veterinarians should obtain a diet history for every companion animal during every evaluation to help with diagnosis and optimal treatment.

  8. First identification of Salmonella Urbana and Salmonella Ouakam in humans in Africa.

    Science.gov (United States)

    Saba, Courage Kosi Setsoafia; Escudero, Jose Antonio; Herrera-Leon, Silvia; Porrero, Maria Concepcion; Suarez, Monica; Dominguez, Lucas; Demuyakor, Bawa; Gonzalez-Zorn, Bruno

    2013-10-15

    Salmonella infections are increasing worldwide, but there are few reports on Salmonella surveillance in African countries and other developing countries. This has made it difficult to estimate the actual burden of salmonellosis, especially in Africa. This study was conducted in a neglected Northern Region of Ghana where there are no previous data on Salmonella serotypes. Standard microbiological tests were used for isolation, identification, and serotyping. Micro-dilution was used for the antimicrobial susceptibility tests. Four serotypes of Salmonella were identified: S. Urbana, S. Ouakam, S. Senftenberg, and S. Stanleyville. All the serotypes were susceptible to the 20 antibiotics used in the susceptibility test. S. Urbana and S. Ouakam were identified in humans for the first time in Africa. This study may serve as a baseline study for future investigations on Salmonella in the region and may assist public health officials to take the appropriate measures in case of a disease outbreak caused by Salmonella in the area. The article may also give health officials a fair idea of the resistance level of these serotypes in the region.

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

    Science.gov (United States)

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

    1992-01-01

    Seven Canadian layer flocks with Salmonella enteritidis in their environment were investigated to determine the numbers of hens infected with S. enteritidis, the localization of S. enteritidis in organs of infected hens and the numbers of S. enteritidis-infected eggs produced by two affected flocks. By a microagglutination test (MAT) using S. pullorum antigens, these flocks had more seropositive hens (mean 51.9 +/- 16.9%) than two Salmonella-free flocks (mean 13.0 +/- 4.2%). Culture of tissues of 580 hens (433 seropositive) from the seven flocks detected 26 (4.5%) S. enteritidis-infected hens from two flocks. In one flock, 2/150 hens were infected with S. enteritidis phage type (PT) 8, which was confined to the ceca, and no Salmonella spp. were isolated from 2520 eggs (one day's lay). In the second flock, where 24/150 hens were infected with S. enteritidis PT13, extraintestinal infection was found in nine hens and involved the ovaries and/or oviduct in two hens. Salmonella enteritidis PT13 was isolated from one sample of egg contents and from one sample of cracked shells from among 14,040 eggs (one day's lay) from this flock. The overall prevalence of S. enteritidis-contaminated eggs from the two flocks with infected hens was less than 0.06%. Other Salmonella spp. isolated were S. heidelberg from 58 hens (10%), and S. hadar, S. mbandaka and S. typhimurium from one hen (0.2%) each. The MAT with antigens of S. pullorum had a sensitivity of 81% and a specificity of 24% for detecting S. enteritidis-infected hens.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1423059

  10. Salmonella-induced changes in the gut microbiota and immune response genes transcriptome during administration of vancomycin and Bacteroides fragilis

    Directory of Open Access Journals (Sweden)

    Yu. V. Bukina

    2017-04-01

    Full Text Available The aim. To study Salmonella-induced changes in the intestinal wall microbiota, the expression of Salmonella effector proteins SipA, SopB, SopE2 and transcriptional activity of genes FFAR2, Foxp3, RORγt in rat GALT during administration of vancomycin and B.fragilis. Methods. Investigations of qualitative and quantitative composition of the microbiota of the wall of the small intestine were carried out, and the expression level of rat genes Foxp3, Rorc (Royt, FFAR2 and Salmonella effector proteins SipA, SopB and SopE2 were determined by RT-PCR, the relationship between groups of microorganisms was established. Results. Administration of B.fragilis against the background pre-treatment with vancomycin and Salmonella infection alters the quantitative composition of the microbiota in the wall of the small intestine contents: a decrease in Salmonella spp., E.coli, P.aeruginosa, Proteus spp., Enterobacter spp., Klebsiella spp. and Shigella spp., as well as increasing Bacteroides spp., E.faecalis, E.faecium and Peptostreptococcus anaerobius. The level of expression of Salmonella effector proteins in animals with the combined administration of vancomycin and S.enteritidis (I group, S.typhimurium (II group increased: SopB – 101 and 20 times; SopE2 - 80 and 2 times; SipA - 613 times (II group, and also 5-fold decrease was noted in the I group. Relative normalized number of mRNA of genes FFAR2, Foxp3, RORγt in GALT of rats in groups III and IV increased: FFAR2 - 2.7 and 5.4 times; Foxp3 - 2.5 and 85 times, RORγt level decreased by 70% and only in IV group. Conclusions. Using B.fragilis creates conditions for the correction of Salmonella-induced changes of the intestinal microbiome. Pretreatment of animals with vancomycin causes increased transcriptional activity of genes SipA, SopB and SopE2, except SipA after administration of S.enteritidis. Administration of B.fragilis increases the level of mRNA of genes FFAR2 and Foxp3 in GALT and reduces ROR

  11. Effects of dietary clays on performance and intestinal mucus barrier of broiler chicks challenged with Salmonella enterica serovar Typhimurium and on goblet cell function in vitro.

    Science.gov (United States)

    Almeida, J A S; Ponnuraj, N P; Lee, J J; Utterback, P; Gaskins, H R; Dilger, R N; Pettigrew, J E

    2014-04-01

    In vivo and in vitro experiments were conducted to test for beneficial effects of dietary clays on broiler chicks challenged with Salmonella enterica serovar Typhimurium and to explore potential mechanisms. First, two hundred forty 1-d-old male broilers (initial BW: 41.6 ± 0.4 g) were allotted in a 2 × 4 factorial arrangement in a randomized complete block design. There were 2 infection treatments (with or without Salmonella) and 4 diets: basal (BAS), 0.3% smectite A (SMA), 0.3% smectite B, and 0.3% zeolite. The Salmonella reduced (P clay largely restored it (challenge × diet interaction, P clays (P clays restored the growth depression caused by Salmonella, and changes in goblet cell function may contribute to the benefits of one of the clays, specifically SMA.

  12. Enzyme immunoassay for detection of Salmonella in low-moisture foods: collaborative study.

    Science.gov (United States)

    Flowers, R S; Klatt, M J; Robison, B J; Mattingly, J A; Gabis, D A; Silliker, J H

    1987-01-01

    A collaborative study was performed in 15 laboratories to evaluate a modification of the enzyme immunoassay (EIA) method for detection of Salmonella in foods (46.B21-46.B29). The modified EIA requires 18-24 h pre-enrichment, 6-8 h selective enrichment, and 14-18 h M-broth post-enrichment prior to performing the assay, which requires 1-2 h. Total assay time is 40-52 h. The modified method was compared with the standard culture method for detection of Salmonella in 5 low-moisture foods: nonfat dry milk, milk chocolate, meat and bone meal, dry whole egg, and ground pepper. The modified method has been adopted official first action for use with low-moisture foods.

  13. The Salmonella enterica Pan-genome

    NARCIS (Netherlands)

    Jacobsen, A.; Hendriksen, R. S.; Aaresturp, F. M.; Ussery, D. W.; Friis, C.

    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

  14. 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...

  15. Attachment of Salmonella spp. to pork meat

    DEFF Research Database (Denmark)

    Hansen, Trine; Riber, Leise; Löfström, Charlotta

    2011-01-01

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

  16. Thirteenth CRL-Salmonella interlaboratory comparison study on typing of Salmonella spp. : Dertiende CRL-Salmonella ringonderzoek voor de typering van Salmonella spp.

    NARCIS (Netherlands)

    Berk PA; Maas HME; de Pinna E; Mooijman KA; LZO; cib

    2010-01-01

    De Nationale Referentie Laboratoria (NRL's) van de 27 Europese lidstaten scoorden goed bij de kwaliteitscontrole op Salmonella-typering in 2008. Vier laboratoria hadden hiervoor een herkansing nodig. Daarnaast is een analyse van alle NRL's als groep uitgevoerd, waaruit bleek dat zij 97 %

  17. Incidence and antimicrobial susceptibility pattern of salmonella ...

    African Journals Online (AJOL)

    A study was carried out to investigate the incidence of Salmonella species among 300 children using stool samples from six hospitals in the metropolitan Kano. The organisms were investigated using cultural, serological biochemical characterization and sensitivity to some antimicrobial agents. The incidence of the bacteria ...

  18. Colicinogeny in Salmonella serovars isolated in Brazil

    Directory of Open Access Journals (Sweden)

    Leila Carvalho Campos

    1988-06-01

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

  19. Sixteenth EURL-Salmonella interlaboratory comparison study on typing of Salmonella spp. : Zestiende EURL-Salmonella ringonderzoek voor de typering van Salmonella spp.

    NARCIS (Netherlands)

    Jacobs-Reitsma WF; Pol-Hofstad IE; Maas HME; de Pinna E; Mooijman KA; LZO; cib

    2012-01-01

    De 28 Nationale Referentie Laboratoria (NRL's) van de 27 Europese lidstaten scoorden in 2011 goed bij de kwaliteitscontrole om Salmonella te typeren. Twee laboratoria hadden hiervoor een herkansing nodig. Alle NRL's samen konden gemiddeld genomen aan 97 procent van de geteste stammen de juiste naam

  20. Experimental Salmonella typhimurium infections in rats. I

    DEFF Research Database (Denmark)

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

    1989-01-01

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

  1. Salmonella typhi time to change empiric treatment

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  2. Antimicrobial susceptibility of Salmonella enterica strains isolated ...

    African Journals Online (AJOL)

    SARAH

    2015-11-30

    Nov 30, 2015 ... ABSTRACT. Objectives: The aim of this study was to determine the prevalence and antibiotic resistance profile of. Salmonella enterica isolated from raw beef, mutton and intestines sold in Ouagadougou; Burkina Faso. Methodology and Results: A total of 450 samples from raw meat of beef (n=175), mutton ...

  3. 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 ...

  4. Quinolone resistance in Salmonella enterica serovar Typhi ...

    African Journals Online (AJOL)

    Introduction. The human restricted bacteria, Salmonella enterica serovar. Typhi is the major cause of typhoid fever (or enteric fever), a characteristic severe systemic illness [1]. In 2010, typhoid fever accounted for an estimated global burden of. 27 million new cases and 200,000 deaths [2]. For over two decades, S. enterica ...

  5. Effect of Salmonella thyphymurium Infection on the ...

    African Journals Online (AJOL)

    Danfodiyo University Sokoto. They were fed on wheat bran, bean offal, cowpea hay, while water was provided ad libitum. Before the commencement of the experiment, .... Agerso H., Friis C., and Nielsen J.P. (2000). Pharmacokinetics and tissue distribution of amoxicillin in healthy and salmonella typhimurium infected pigs.

  6. 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...

  7. Persistence of salmonella typhimurium in nopal cladodes

    Science.gov (United States)

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

  8. Virulence factors of Salmonella enterica serovar Enteritidis

    NARCIS (Netherlands)

    Zhao, Y.

    2002-01-01

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

  9. Swiss Army Pathogen: The Salmonella Entry Toolkit

    Directory of Open Access Journals (Sweden)

    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.

  10. Salmonella osteomyelitis by sickle cell anemia

    Energy Technology Data Exchange (ETDEWEB)

    Rausch, H.; Tran, V.T.; Boeckmann, U.

    1985-10-01

    Case report of a 28 year old black sickle cell anemia patient with salmonella osteomyelitis of the radius. Aside from sickle cell anemia patients this skeletal complication of enteric salmonellosis is an extreme rarity. Description of the typical roentgenological features includes intracortical fissures and sequestration.

  11. Salmonella virulence plasmid: pathogenesis and ecology.

    Science.gov (United States)

    Silva, Claudia; Puente, José Luis; Calva, Edmundo

    2017-06-22

    A current view on the role of the Salmonella virulence plasmid in the pathogenesis of animal and human hosts is discussed; including the possible relevance in secondary ecological niches. Various strategies towards further studies in this respect are proposed within the One Health Concept. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Centers for Disease Control (CDC) Podcasts

    2009-12-09

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

  13. Sixteenth EURL-Salmonella interlaboratory comparison study on typing of Salmonella spp. : Zestiende EURL-Salmonella ringonderzoek voor de typering van Salmonella spp.

    NARCIS (Netherlands)

    Jacobs-Reitsma WF; Pol-Hofstad IE; Maas HME; de Pinna E; Mooijman KA; LZO; cib

    2012-01-01

    De 28 Nationale Referentie Laboratoria (NRL's) van de 27 Europese lidstaten scoorden in 2011 goed bij de kwaliteitscontrole om Salmonella te typeren. Twee laboratoria hadden hiervoor een herkansing nodig. Alle NRL's samen konden gemiddeld genomen aan 97 procent van de geteste stammen de

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

    Science.gov (United States)

    Broilers may carry Salmonella and Campylobacter on inner and outer surfaces upon arrival at the slaughter plant and carcasses can be further contaminated during commercial processing. A sensitive, non-destructive, repeatable sampling method would be useful to test carcasses for levels of bacteria b...

  15. Distribution of prophages and SGI-1 antibiotic-resistance genes among different Salmonella enterica serovar Typhimurium isolates

    NARCIS (Netherlands)

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

    2006-01-01

    Recently, the authors identified Salmonella enterica serovar Typhimurium (S. Typhimurium) definitive type (DT)104-specific sequences of mainly prophage origin by genomic subtractive hybridization. In the present study, the distribution of the prophages identified, ST104 and ST64B, and the novel

  16. Nontyphoid Salmonella Infection: Microbiology, Clinical Features, and Antimicrobial Therapy

    Directory of Open Access Journals (Sweden)

    Hung-Ming Chen

    2013-06-01

    Full Text Available Nontyphoid Salmonella is the most common bacterial pathogen causing gastrointestinal infection worldwide. Most nontyphoid Salmonella infection is limited to uncomplicated gastroenteritis that seldom requires antimicrobial treatment. Nevertheless, invasive infections, such as bacteremia, osteomyelitis, and meningitis, may occur and require antimicrobial therapy. Continuous genetic and genomic evolution in Salmonella leading to increased virulence and resistance to multiple drugs are of significant public health concern. Two major changes in the epidemiology of nontyphoid salmonellosis in Europe and in the USA occurred in the second half of the 20th century: the emergence of foodborne human infections caused by Salmonella enterica serotype Enteriditis and by multidrug-resistant strains of Salmonella enterica serotype Typhimurium. In the 21st century, a worsening situation is the increasing resistance to fluoroquinolones and third-generation cephalosporins in nontyphoid Salmonella. Clinical isolates showing carbapenem resistance also have been identified. Although antimicrobial therapy is usually not indicated for uncomplicated Salmonella gastroenteritis, recent studies indicated that a short-course ceftriaxone therapy (3–5 days for patients with severe gastroenteritis would lead to a faster clinical recovery. Continuous surveillance of Salmonella in both humans and animals is mandatory. A better understanding of the mechanisms that lead to the emergence of antimicrobial resistance in Salmonella may help in the devising of better interventional strategies to reduce the spread of resistant Salmonella between humans and reservoirs along the food chain.

  17. Effect of strategic administration of an encapsulated blend of formic acid, citric acid, and essential oils on Salmonella carriage, seroprevalence, and growth of finishing pigs.

    Science.gov (United States)

    Walia, Kavita; Argüello, Hector; Lynch, Helen; Leonard, Finola C; Grant, Jim; Yearsley, Dermot; Kelly, Sinead; Duffy, Geraldine; Gardiner, Gillian E; Lawlor, Peadar G

    2017-02-01

    the diet with FormaXOL™ for 28days increased the feed cost per kg of live-weight gain by €0.08. Overall, results suggest that strategic administration of an encapsulated blend of formic acid, citric acid, and essential oils, to finishing pigs for 28days prior to slaughter has potential to prevent increased Salmonella shedding at certain time points as well as seroprevalence. However, this additive did not lower intestinal carriage, nor did it reduce seroprevalence to below the cut-off used for the high Salmonella risk category in Ireland (50%) or improve growth performance. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. CHROMOSOME TRANSFER KINETICS OF SALMONELLA HFR STRAINS.

    Science.gov (United States)

    JOHNSON, E M; FALKOW, S; BARON, L S

    1964-08-01

    Johnson, E. M. (Walter Reed Army Institute of Research, Washington, D.C.), Stanley Falkow, and L. S. Baron. Chromosome transfer kinetics of Salmonella Hfr strains. J. Bacteriol. 88:395-400. 1964.-The kinetics of chromosome transfer of an Hfr strain of Salmonella typhosa and an Hfr strain of S. typhimurium were examined in interrupted matings with multiply auxotrophic S. typhimurium recipients. The S. typhosa Hfr, TD-7, was found to transfer the pro-A, met-A, arg (A, C, F, or H), and ile markers at 8, 32, 36, and 51 min, respectively, after contact with the recipient strain. Comparison of these entry times with those of the analogous Escherichia coli Hfr P4X-6 for the same markers showed the gene order to be identical. However, the TD-7 entry times were considerably extended over those of P4X-6, which transfers these markers of E. coli F(-) strains at, respectively, 5, 20, 22.5, and 28 min. A similar extension of the entry times was noted with the S. typhimurium Hfr, SR-305, which transfers the markers in the reverse order, ile-met-A-pro-A, at 3 to 4, 18, and 46 min, respectively. Examination of P4X-6/Salmonella Hfr entry time ratios showed them to be constant at 0.63 for the earlier markers transferred by both TD-7 and SR-305. These data suggest that the physical length of the Salmonella chromosome is the same as that of E. coli, and that the rate of chromosome transfer of the Salmonella Hfr strains to S. typhimurium recipients is only 0.63 that of P4X-6 to E. coli F(-) strains under the same physical conditions.

  19. Salmonella collected from nest run cart shelves in commercial shell egg processing facilities.

    Science.gov (United States)

    Musgrove, M T; Shaw, J D; Harrison, M A

    2012-09-01

    Salmonella, a member of the bacterial family Enterobacteriaceae, may be recovered from foods and processing facilities. High levels of Enterobacteriaceae in the processing plant environment can be an indication of inadequate sanitation. This experiment was designed to determine if nest run egg carts serve as reservoirs for Salmonella. Eggs that are produced by hens not housed in buildings connected to the processing plant are referred to as nest run. Many of these eggs are transported to a central processing facility before they are washed, graded, and packed. Two plants in the Southeastern United States were sampled; one was a mixed operation and the other was an off-line operation. On each of 3 visits, 5 shelves on each of 5 carts were sampled (n = 25/visit). A 12 × 12 cm area on each shelf was swabbed with a sterile gauze pad moistened with PBS and transported on ice back to the laboratory. Each swab was preenriched in buffered peptone at 37°C for 24 h, selectively enriched using TT and Rappaport-Vassiliadis broth at 42°C overnight, then plated onto brilliant green sulfa and XLT-4 incubated at 37°C for 24 h. Presumptive colonies were transferred to lysine iron agar and triple sugar iron slants for 24 h at 37°C. Isolates with presumptive reactions were confirmed using commercial polyclonal antisera. After initial confirmation, serogrouping was performed using commercial antisera. Mixed-operation swab samples were 12% positive for Salmonella, whereas off-line samples were 36% positive for Salmonella; isolates were confirmed as serogroups B, C1, and C2. Kauffman-White serotyping was performed by a contract laboratory. Serotypes (n = 30) recovered were Anatum, Heidelberg, Infantis, Kentucky, Mbandanka, and Typhimurium. This work demonstrated that nest run egg carts may serve as reservoirs for Salmonella in the shell egg processing environment.

  20. DksA-dependent transcriptional regulation in Salmonella experiencing nitrosative stress

    Directory of Open Access Journals (Sweden)

    Matthew A Crawford

    2016-03-01

    Full Text Available Redox-based signaling is fundamental to the capacity of bacteria to sense, and respond to, nitrosative and oxidative stress encountered in natural and host environments. The conserved RNA polymerase regulatory protein DksA is a thiol-based sensor of reactive nitrogen and oxygen species. DksA-dependent transcriptional control promotes antinitrosative and antioxidative defenses that contribute to Salmonella pathogenesis. The specific adaptive changes mediated by DksA in response to reactive species, however, have not been elucidated. Herein, we characterize DksA-dependent changes in gene expression in Salmonella enterica experiencing nitrosative stress. Genome-wide expression analysis of wild-type and delta-dksA Salmonella exposed to the nitric oxide (•NO donor DETA NONOate demonstrated •NO- and DksA-dependent regulatory control of 427 target genes. Transcriptional changes centered primarily on genes encoding aspects of cellular metabolism. Several antioxidants and oxidoreductases important in redox buffering, •NO detoxification, and damage repair were also observed to be up-regulated in an •NO- and DksA-dependent manner. Compared to wild-type bacteria, •NO-treated delta-dksA Salmonella exhibited a de-repression of genes encoding components of iron homeostasis and failed to activate sulfur assimilation and cysteine biosynthetic operons. As cysteine is integral to efficient antinitrosative and antioxidative defense and repair programs, we further examined the redox-responsive transcriptional control of cysteine biosynthesis by DksA. These investigations revealed that the activation of genes comprising cysteine biosynthesis also occurs in response to hydrogen peroxide, is dependent upon the redox-sensing zinc finger domain of DksA, and requires the transcriptional regulator CysB. Our observations demonstrate that DksA mediates global adaptation to nitrosative stress in Salmonella and provide unique insight into a novel regulatory mechanism

  1. Trg-deficient Salmonella colonize quiescent tumor regions by exclusively penetrating or proliferating.

    Science.gov (United States)

    Zhang, Miaomin; Forbes, Neil S

    2015-02-10

    Chemotherapeutics fail to effectively treat tumors because they cannot reach quiescent regions far from blood vessels. Motile Salmonella are an attractive delivery system that could break this therapeutic barrier. However, little is known about the dissemination and tissue penetration of individual bacteria in tumors after intravenous administration. We hypothesized that eliminating the Trg receptor would improve accumulation in tumor quiescence. To test this hypothesis, we deleted the trg gene from nonpathogenic Salmonella. To quantify individual bacterial behavior, we measured tissue penetration in a tumor-on-a-chip device and measured colony localization in mouse tumors using immunofluorescence. In tumors in vitro and in mice, trg(-) Salmonella penetrated farther into tissue than control bacteria. This difference in localization was caused by the inability to sense sugars in well perfused tissue. Three distinct bacterial phenotypes were observed: proliferating, penetrating, and inactive. Large proliferating colonies, containing more than 40% of individual bacteria, only formed less than 60μm from blood vessels. Small colonies, in comparison, were present both near (inactive) and far (penetrating) from vessels. The farthest was 361.2μm from a vessel, demonstrating the ability to target avascular regions. In addition, colonization was most pronounced in poorly vascularized tumor regions. We show that deletion of trg amplifies Salmonella accumulation in quiescent tumor regions, and, for the first time, identify biological processes that control bacterial distribution in tumors. Understanding how Salmonella penetrate tissue, target quiescence and specifically replicate in tumors are essential steps toward creating a tightly controlled, tunable bacterial therapy. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Risk assessment of Salmonella in Danish meatballs produced in the catering sector.

    Science.gov (United States)

    Møller, Cleide O de A; Nauta, Maarten J; Schaffner, Donald W; Dalgaard, Paw; Christensen, Bjarke B; Hansen, Tina B

    2015-03-02

    A modular process risk model approach was used to assess health risks associated with Salmonella spp. after consumption of the Danish meatball product (frikadeller) produced with fresh pork in a catering unit. Meatball production and consumption were described as a series of processes (modules), starting from 1.3kg meat pieces through conversion to 70g meatballs, followed by a dose response model to assess the risk of illness from consumption of these meatballs. Changes in bacterial prevalence, concentration, and unit size were modelled within each module. The risk assessment was built using observational data and models that were specific for Salmonella spp. in meatballs produced in the catering sector. Danish meatballs are often pan-fried followed by baking in an oven before consumption, in order to reach the core temperature of 75°C recommended by the Danish Food Safety Authority. However, in practice this terminal heat treatment in the oven may be accidentally omitted. Eleven production scenarios were evaluated with the model, to test the impact of heat treatments and cooling rates at different room temperatures. The risk estimates revealed that a process comprising heat treatment of meatballs to core temperatures higher than 70°C, and subsequent holding at room temperatures lower than 20°C, for no longer than 3.5h, were very effective in Salmonella control. The current Danish Food Safety Authority recommendation of cooking to an internal temperature of 75°C is conservative, at least with respect to Salmonella risk. Survival and growth of Salmonella during cooling of meatballs not heat treated in oven had a significant impact on the risk estimates, and therefore, cooling should be considered a critical step during meatball processing. Copyright © 2014. Published by Elsevier B.V.

  3. Prevalence and characterization of Salmonella species isolated from pigs, ducks and chickens in Sichuan Province, China.

    Science.gov (United States)

    Li, Ruichao; Lai, Jing; Wang, Yang; Liu, Shuliang; Li, Yun; Liu, Kunyao; Shen, Jianzhong; Wu, Congming

    2013-04-15

    This study aimed to analyze the prevalence of Salmonella isolated from different parts of the food production chain, and to characterize these isolates. A total of 165 Salmonella enterica isolates were identified from 1382 samples taken from conventional farms, abattoirs and retail markets from 2010 to 2011 in Sichuan, China. The Salmonella isolates were assayed for serotype, antimicrobial susceptibility, prevalence of class 1 integrons and β-lactamase genes, and subtyped using pulsed-field gel electrophoresis. Among these isolates, S. enterica serotypes Derby (76 isolates, 46%) and Typhimurium (16 isolates, 10%) were the most prevalent, and high antimicrobial resistance rates were observed for tetracycline (77%), sulfamethoxazole/trimethoprim (43%), nalidixic acid (41%) and spectinomycin (41%). Class 1 integrons were detected in 21% of these isolates, and contained gene cassettes dfrA12-aadA2, dfrA1-aadA1, dfrA1, blaPSE-1 and dfrA1/aadA2. blaOXA-1 was the most commonly identified β-lactamase gene (n=14), followed by blaTEM-1 (n=6), blaPSE-1 (n=4) and blaCMY-2 (n=1). A S. enterica serotype Indiana isolate derived from chicken from a market was positive for both blaOXA-1 and blaCMY-2, and resistant to nine tested antibiotics. The PFGE patterns were diverse. Our findings indicated that most isolates from different sampling sites were phenotypically and genetically diverse, and Salmonella was widespread and may transmit along the food production chain from farm to market. Isolates with decreased susceptibility to fluoroquinolones and extended-spectrum cephalosporins, which are used to fight foodborne Salmonella, pose a serious threat to public health. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Quantitative transfer of Salmonella Typhimurium LT2 during mechanical slicing of tomatoes as impacted by multiple processing variables.

    Science.gov (United States)

    Wang, Haiqiang; Ryser, Elliot T

    2016-10-03

    Slicing of fresh produce can readily lead to pathogen cross-contamination with pre-sliced tomatoes having been linked to multistate outbreaks of salmonellosis in the United States. This study aimed to assess the impact of multiple processing variables on quantitative transfer of Salmonella during simulated commercial slicing of tomatoes. One red round tomato was inoculated with Salmonella Typhimurium LT2 at ~5logCFU/g and sliced using a manual or electric slicer, followed by 20 uninoculated tomatoes. Thereafter, the distribution of Salmonella on inoculated and uninoculated tomato slices was evaluated along with the transfer of Salmonella from different parts of the slicer. The impact of multiple processing variables including post-contamination hold time (0 and 30min), tomato wetness (dry and wet), processing room temperature (23, 10 and 4°C), slice thickness (0.48, 0.64, and 0.95cm), tomato variety (Torero, Rebelski, and Bigdena) and pre-wash treatment (no wash, tap water, and chlorine) was also investigated. The data were fitted to a two-parameter exponential decay model (Y=A⋅exp(BX)) with the percentage of Salmonella transferred to 20 uninoculated tomatoes then calculated. Salmonella populations on nine inoculated tomato slices ranged from 4.6±0.2 to 5.5±0.3logCFU/g, with higher populations on slices from the blossom and stem scar ends. However, Salmonella transfer to the previously uninoculated slices was similar (P>0.05), ranging from 2.1±0.2 to 3.4±0.2logCFU/g. Significantly fewer salmonellae transferred from the blade (3.4±0.4 log CFU, P≤0.05) than from the back and bottom plates (4.7±0.3 log CFU) or the whole manual slicer (5.2±0.2 log CFU) to the 20 uninoculated tomatoes. However, the blade was the primary contributor to Salmonella transfer for the electric slicer. Post-contamination hold time, processing temperature and tomato slice thickness did not significantly impact (P>0.05) the Salmonella transfer rate (parameter B) or the overall

  5. Modeling the survival kinetics of Salmonella in tree nuts for use in risk assessment.

    Science.gov (United States)

    Santillana Farakos, Sofia M; Pouillot, Régis; Anderson, Nathan; Johnson, Rhoma; Son, Insook; Van Doren, Jane

    2016-06-16

    Salmonella has been shown to survive in tree nuts over long periods of time. This survival capacity and its variability are key elements for risk assessment of Salmonella in tree nuts. The aim of this study was to develop a mathematical model to predict survival of Salmonella in tree nuts at ambient storage temperatures that considers variability and uncertainty separately and can easily be incorporated into a risk assessment model. Data on Salmonella survival on raw almonds, pecans, pistachios and walnuts were collected from the peer reviewed literature. The Weibull model was chosen as the baseline model and various fixed effect and mixed effect models were fit to the data. The best model identified through statistical analysis testing was then used to develop a hierarchical Bayesian model. Salmonella in tree nuts showed slow declines at temperatures ranging from 21°C to 24°C. A high degree of variability in survival was observed across tree nut studies reported in the literature. Statistical analysis results indicated that the best applicable model was a mixed effect model that included a fixed and random variation of δ per tree nut (which is the time it takes for the first log10 reduction) and a fixed variation of ρ per tree nut (parameter which defines the shape of the curve). Higher estimated survival rates (δ) were obtained for Salmonella on pistachios, followed in decreasing order by pecans, almonds and walnuts. The posterior distributions obtained from Bayesian inference were used to estimate the variability in the log10 decrease levels in survival for each tree nut, and the uncertainty of these estimates. These modeled uncertainty and variability distributions of the estimates can be used to obtain a complete exposure assessment of Salmonella in tree nuts when including time-temperature parameters for storage and consumption data. The statistical approach presented in this study may be applied to any studies that aim to develop predictive models to be

  6. Study of the cross-contamination and survival of Salmonella in fresh apples.

    Science.gov (United States)

    Perez-Rodriguez, F; Begum, M; Johannessen, G S

    2014-08-01

    The present work aimed at studying the cross contamination of apples by Salmonella during the processing of commercial fresh apples and its survival capacity on apple at room temperature. For the first study, the typical process of fresh apples was simulated at laboratory scale in which an apple that was artificially contaminated by Salmonella at different concentration levels (8, 6 and 5 log cfu/apple) was introduced in one batch and processed including a simulated transport/washing step and drying step using sponges to simulate the porous material used in the industry. Results indicated that at 8 log cfu/apple, 50% fresh apples were contaminated after processing, with all analysed environmental samples being positive for the pathogen, consisting of washing water and sponges. However, at lower inoculum levels (5-6 log cfu/apple) no cross contamination was detected in apples, and only environmental samples showed contamination by Salmonella after processing including both water and sponges. Experiments on the survival of Salmonella on apple showed that the pathogen was capable to survive for 12 days, only showing a significant drop at the end of the experiment. Finally, two-class attribute sampling plans were assessed as tool to detect Salmonella in different contamination scenarios in fresh apple. This analysis indicated that with the highest inoculum level, a total of 16 apples would be needed to reach 95% of detecting Salmonella (i.e. lot rejection). In turn, when low levels were assessed (5-6 log cfu/apple), a large number of apples (n=1021) would have to be sampled to obtain the same confidence level (95%). If the environment is sampled (i.e. water and sponges), a lower number of samples would be needed to detect the pathogen. However, the feasibility of environmental sampling has not been assessed from a practical point of view. Overall, the results in this study evidenced that cross contamination by Salmonella might occur during processing of fresh apples

  7. Validation of a Salmonella loop-mediated isothermal amplification assay in animal food.

    Science.gov (United States)

    Domesle, Kelly J; Yang, Qianru; Hammack, Thomas S; Ge, Beilei

    2018-01-02

    Loop-mediated isothermal amplification (LAMP) has emerged as a promising alternative to PCR for pathogen detection in food testing and clinical diagnostics. This study aimed to validate a Salmonella LAMP method run on both turbidimetry (LAMP I) and fluorescence (LAMP II) platforms in representative animal food commodities. The U.S. Food and Drug Administration (FDA)'s culture-based Bacteriological Analytical Manual (BAM) method was used as the reference method and a real-time quantitative PCR (qPCR) assay was also performed. The method comparison study followed the FDA's microbiological methods validation guidelines, which align well with those from the AOAC International and ISO. Both LAMP assays were 100% specific among 300 strains (247 Salmonella of 185 serovars and 53 non-Salmonella) tested. The detection limits ranged from 1.3 to 28 cells for six Salmonella strains of various serovars. Six commodities consisting of four animal feed items (cattle feed, chicken feed, horse feed, and swine feed) and two pet food items (dry cat food and dry dog food) all yielded satisfactory results. Compared to the BAM method, the relative levels of detection (RLODs) for LAMP I ranged from 0.317 to 1 with a combined value of 0.610, while those for LAMP II ranged from 0.394 to 1.152 with a combined value of 0.783, which all fell within the acceptability limit (2.5) for an unpaired study. This also suggests that LAMP was more sensitive than the BAM method at detecting low-level Salmonella contamination in animal food and results were available 3days sooner. The performance of LAMP on both platforms was comparable to that of qPCR but notably faster, particularly LAMP II. Given the importance of Salmonella in animal food safety, the LAMP assays validated in this study holds great promise as a rapid, reliable, and robust method for routine screening of Salmonella in these commodities. Published by Elsevier B.V.

  8. Detection and characterization of Salmonella in lairage, on pig carcasses and intestines in five slaughterhouses.

    Science.gov (United States)

    De Busser, E V; Maes, D; Houf, K; Dewulf, J; Imberechts, H; Bertrand, S; De Zutter, L

    2011-01-31

    In this study, conducted at five slaughterhouses, individual pigs were sampled and followed up from stunning to cooling down of the carcasses. In this way, Salmonella prevalence and possible risk points were described. At the lairage area, pens were sampled using overshoes. At stunning and bleeding, pigs were individually identified and subsequently swabs were taken of the oral cavity and the carcass after polishing, splitting and forced chilling. Additionally, duodenum, ileum, rectum and mesenteric lymph nodes were extracted and samples were taken of the scalding water. All samples were submitted to Salmonella isolation and Salmonella isolates were serotyped and genotyped by pulsed-field gel electrophoresis (PFGE). Of all samples taken (n = 1953), 14.1% were Salmonella positive. The prevalence of S. in the lairage area varied widely (from 0 to 100%) between the slaughterhouses. Of the sampled pigs (n = 226), 48.2% were positive in at least one sample. Statistical analysis revealed that the contamination of the lairage area was related to a higher amount of positive carcasses after polishing. Furthermore, the contamination of the carcasses after splitting and forced chilling was related to the contamination level of the carcass after polishing. A relation between the outer (carcass) contamination and the inner (gut content and lymph nodes) contamination of a pig could not be established. The predominant serotypes were S. Typhimurium (58.7%) and S. Derby (17.4%). Genotyping revealed 46 different PFGE profiles among the 276 Salmonella isolates. The same genotype at the lairage area as in the oral cavity of the pigs was found in 95%. The results indicate that the lairage area is a primary source of Salmonella in slaughter pigs and that carcass contamination originates from the environment rather than from the pig (inner contamination) itself. It further shows that slaughterhouses vary in their capability of dealing with Salmonella positive pigs. A slaughterhouse

  9. 76 FR 41157 - Guidance for Industry: Questions and Answers Regarding the Final Rule, Prevention of Salmonella...

    Science.gov (United States)

    2011-07-13

    ... Answers Regarding the Final Rule, Prevention of Salmonella Enteritidis in Shell Eggs During Production... Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation'' (the draft guidance... rule entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and...

  10. Development of a novel hexa-plex PCR method for identification and serotyping of Salmonella species.

    Science.gov (United States)

    Li, Ruichao; Wang, Yang; Shen, Jianzhong; Wu, Congming

    2014-01-01

    Salmonella is one of the most important foodborne pathogens, which causes a huge economic burden worldwide. To detect Salmonella rapidly is very meaningful in preventing salmonellosis and decreasing economic losses. Currently, isolation of Salmonella is confirmed by biochemical and serobased serotyping methods, which are time consuming, labor intensive, and complicated. To solve this problem, a hexa-plex polymerase chain reaction (PCR) method was developed using comparative genomics analysis and multiplex PCR technology to detect Salmonella and Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Agona, Salmonella Choleraesuis, and Salmonella Pullorum simultaneously. The accuracy of this method was tested by a collection of 142 Salmonella. Furthermore, the strategy described in this article to mine serovar-specific fragments for Salmonella could be used to find specific fragments for other Salmonella serotypes and bacteria. The combination of this strategy and multiplex PCR is promising in the rapid identification of foodborne pathogens.

  11. 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.

  12. 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.

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

    Science.gov (United States)

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

    2015-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Roopa Rajashekar

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

  15. A defective mutant of Salmonella enterica Serovar Gallinarum in cobalamin biosynthesis is avirulent in chickens Mutante de Salmonella enterica serovar Gallinarum duplo defectivo na biossíntese de cobalamina é avirulento para aves

    Directory of Open Access Journals (Sweden)

    Jacqueline Boldrin de Paiva

    2009-09-01

    Full Text Available Salmonella enterica serovar Gallinarum (SG is a fowl typhoid agent in chickens and is a severe disease with worldwide economic impact as its mortality may reach up to 80%. It is one of a small group of serovars that typically produces typhoid-like infections in a narrow range of host species and which therefore represents a good model for human typhoid. The survival mechanisms are not considered to be virulent mechanisms but are essential for the life of the bacterium. Mutants of Salmonella Gallinarum containing defective genes, related to cobalamin biosynthesis and which Salmonella spp. has to be produced to survive when it is in an anaerobic environment, were produced in this study. Salmonella Gallinarum is an intracellular parasite. Therefore, this study could provide information about whether vitamin B12 biosynthesis might be essential to its survival in the host. The results showed that the singular deletion in cbiA or cobS genes did not interfere in the life of Salmonella Gallinarum in the host, perhaps because single deletion is not enough to impede vitamin B12 biosynthesis. It was noticed that diluted SG mutants with single deletion produced higher mortality than the wild strain of SG. When double mutation was carried out, the Salmonella Gallinarum mutant was unable to provoke mortality in susceptible chickens. This work showed that B12 biosynthesis is a very important step in the metabolism of Salmonella Gallinarum during the infection of the chickens. Further research on bacterium physiology should be carried out to elucidate the events described in this research and to assess the mutant as a vaccine strain.Salmonella enterica serovar Gallinarum (SG é o agente do tifo aviário, doença severa que provoca mortalidade em até 80% do plantel de aves. SG encontra-se entre os poucos sorotipos de Salmonella que são agentes etiológicos de enfermidade específica, à semelhança de Salmonella Typhi em seres humanos podendo, portanto, servir

  16. The prevalence of Salmonella enterica in Spanish feed mills and potential feed-related risk factors for contamination.

    Science.gov (United States)

    Torres, Gregorio J; Piquer, F Javier; Algarra, Leonor; de Frutos, Cristina; Sobrino, Odón J

    2011-02-01

    preclude Salmonella control measures from including all stages of feed production and they should have a risk-based approach according to the findings of this study. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Salmonella occurrence and Enterobacteriaceae counts in pig feed ingredients and compound feed from feed mills in Ireland.

    Science.gov (United States)

    Burns, Anne Marie; Lawlor, Peadar G; Gardiner, Gillian E; McCabe, Evonne M; Walsh, Des; Mohammed, Manal; Grant, Jim; Duffy, Geraldine

    2015-10-01

    ingredients in the present study was low, even minor Salmonella contamination in feed has the potential to affect many herds and may subsequently cause human infection. Furthermore, the recovery of a recently emerged serovar with multi-antibiotic resistance is a potential cause for concern. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Conservation of Salmonella infection mechanisms in plants and animals.

    Directory of Open Access Journals (Sweden)

    Adam Schikora

    Full Text Available Salmonella virulence in animals depends on effectors injected by Type III Secretion Systems (T3SSs. In this report we demonstrate that Salmonella mutants that are unable to deliver effectors are also compromised in infection of Arabidopsis thaliana plants. Transcriptome analysis revealed that in contrast to wild type bacteria, T3SS mutants of Salmonella are compromised in suppressing highly conserved Arabidopsis genes that play a prominent role during Salmonella infection of animals. We also found that Salmonella originating from infected plants are equally virulent for human cells and mice. These results indicate a high degree of conservation in the defense and infection mechanism of animal and plant hosts during Salmonella infection.

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

    DEFF Research Database (Denmark)

    Kudahl, Anne Braad

    2010-01-01

    Infection with Salmonella Dublin in the dairy herd and effects of the infection and relevant control measures are currently being modeled into the dairy herd simulation model called Simherd. The aim is to compare the effects of different control strategies against Salmonella Dublin on both within...... of the simulations will therefore be used for decision support in the national surveillance and eradication program against Salmonella Dublin. Basic structures of the model are programmed and will be presented at the workshop. The model is in a phase of face-validation by a group of Salmonella......-herd- prevalence and economy by simulations. The project Dublin on both within-herd- prevalence and economy by simulations. The project is a part of a larger national project "Salmonella 2007 - 2011" with the main objective to reduce the prevalence of Salmonella Dublin in Danish Dairy herds. Results...

  20. Coordinated regulation of virulence during systemic infection of Salmonella enterica serovar Typhimurium.

    Directory of Open Access Journals (Sweden)

    Hyunjin Yoon

    2009-02-01

    Full Text Available To cause a systemic infection, Salmonella must respond to many environmental cues during mouse infection and express specific subsets of genes in a temporal and spatial manner, but the 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 83 regulators inferred to play a role in Salmonella enteriditis Typhimurium (STM virulence and tested them in three virulence assays (intraperitoneal [i.p.], and intragastric [i.g.] infection in BALB/c mice, and persistence in 129X1/SvJ mice. Overall, 35 regulators were identified whose absence attenuated virulence in at least one assay, and of those, 14 regulators were required for systemic mouse infection, the most stringent virulence assay. As a first step towards understanding the interplay between a pathogen and its host from a systems biology standpoint, we focused on these 14 genes. Transcriptional profiles were obtained for deletions of each of these 14 regulators 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 14 regulators control the same 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 the response regulator SsrB and the MarR type regulator, SlyA, are the terminal regulators in a cascade that integrates multiple signals. Furthermore, experiments to demonstrate epistatic relationships showed that SsrB can replace SlyA and, in some cases, SlyA can replace SsrB for expression of SPI-2 encoded