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Estandarización de una PCR para la detección del gen invA de Salmonella spp. en lechuga/ Standardization of a PRC method for the detection of the Salmonella spp. invA gene in lettuce  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Salmonella spp. es un patógeno bacteriano muy importante causante de diarreas, que es transmitido tanto por la vía fecal-oral, como por alimentos y agua contaminados. En este trabajo se estandarizó una técnica de PCR en lechuga para la detección del gen invA de Salmonella spp.; dicho gen se relaciona con el proceso de invasión al epitelio intestinal. Con la PCR desarrollada en este trabajo se logró estandarizar un método que permite la amplificación del gen invA (more) con una detección de 10² UFC/25 g. Este método acorta los tiempos de respuesta de los resultados presuntivos y brinda información complementaria al cultivo tradicional del patógeno. El estudio del gen invA establece el potencial patógeno del microorganismo presente en la muestra, lo que puede ser de utilidad para la salud pública. Abstract in english Salmonella spp. is a very important bacterial pathogen that causes diarrhea and which is transmitted both through the fecal-oral pathway, as by contaminated food and water. In this study we standardized a PCR method in lettuce for the detection of the Salmonella spp. invA gene. This gene is related to the invasion of the intestinal epithelium process. With the PCR method developed in this study we were able to standardize a method which permits the amplification of the in (more) vA gene with a 10² CFU/25 g detection. This method shortens the response times of the presumptive results and gives complementary information to the traditional culture of the pathogen. The study of the invA gene establishes the pathogenic potential of the microorganism present in the sample, which can be useful for public health purposes.

Chacón, Luz; Barrantes, Kenia; García, Cristina; Rosario, Achí

2010-06-01

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

Science.gov (United States)

Part of the invasion A gene (invA) of slamonellae (Rahn et al., 1992) was amplified and labelled simultaneously with digoxigenin by the polymerase chain reaction (PCR). This was used as gene probe for a colony hybridization assay which included nitrocellulose filter incubation on modified Rambach agar. 312 Salmonella and 268 non-Salmonella strains were hybridized with the invA probe. No false-negative or false-positive results were obtained. In 11 beef samples, which had been contaminated artificially with Salmonella, the test strain was recovered quantitatively with the invA probe. Salmonellae could be detected in 29 samples of 104 further foods of animal origin by means of the gene probe assay in contrast to 27 samples which were positive by the standard method. The invA probe assay allows for the quantitative estimation of Salmonella in fresh meat samples within 48 h. However, with frozen samples a pre-enrichment step is necessary. PMID:7488528

Bülte, M; Jakob, P

1995-08-01

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Presencia del gen de invasividad inv A en cepas de Salmonella spp: aisladas de alimentos del Caribe Colombiano/ Presence of the invasive gene invA in Salmonella spp: strains isolated from food in several cities of the Colombian Caribbean area  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Objetivo: establecer la presencia del gen de invasividad invA en aislamientos de Salmonella spp. obtenidos de alimentos en la región Caribe Colombiana. Métodos: se realizó un estudio microbiológico de control de alimentos en 4 ciudades de la región Caribe entre enero de 2002 y marzo de 2003. Se analizaron 1 300 muestras de alimentos provenientes de mercados y ventas callejeras. Resultados: se recuperaron 74 aislamientos de Salmonella spp. , en carne de res 30 (40,5 % (more) ), embutidos 13 (17,6 %), pollo 12 (16,2 %), queso 9 (12,2 %), cerdo 6 (8,1 %) y otros 4 (5,5 %). Los serotipos más frecuentes fueron: S. anatum 14 (18,9 %), S. uganda 13 (17,6 %), S. newport 9 (12,2 %) y S. typhimurium 7 (9,5 %). El cebador invA amplificó un fragmento de 378 pb, el gen invA se detectó en 72 (97,3 %) aislamientos de Salmonella. Conclusiones: se detectó la presencia del gen invA en los serotipos de Salmonella circulantes en alimentos en la región Caribe Colombiana. Las implicaciones epidemiológicas de estos resultados permiten sugerir a las autoridades sanitarias tomar medidas estrictas en el control, prevención y diagnóstico de la infección por Salmonella en esta región Abstract in english Objective: to establish the presence of invasive gene invA in Salmonella spp. strains obtained from food in several cities of the Colombian Caribbean area. Methods: from January 2002 to March 2003, a microbiological study of quality control of food was carried out in four cities of the Colombian Caribbean area. One thousand and three hundred food samples were analyzed in fast food outlets located in city squares or markets. Results: seventy four isolates of Salmonella wer (more) e recovered: 30 (40.5) in meat; 13 (17.6 %) in sausage; 12 (16.2 %) in chicken; 9 (12.2 %) in cheese; 6 (8.1 %) in pork and 4 (5.5 %) in other types of food. The most frequently isolated serotypes were S.anatum in 14 (18.9 %), S.uganda in 13 (17.6 %), S. newport in 9 (12.2 %) y S. typhimurium in 7 (9.5 %). The invA primer amplified 378 pb fragment, invA gene was detected in 72 (97.3 %) Salmonella isolates. Conclusions: it was possible to detect the invA gene in circulating serotypes of Salmonella isolates obtained from food in the Colombian Caribbean area, the epidemiological implications allow the health authorities to take measure for the prevention, control and diagnosis of Salmonella infection in the Colombian Caribbean area

Espinal Marin, Paula; Prieto Suárez, Edgar; Otero Jiménez, Vanessa; Máttar Velilla, Salim

2006-06-01

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Presencia del gen de invasividad inv A en cepas de Salmonella spp: aisladas de alimentos del Caribe Colombiano Presence of the invasive gene invA in Salmonella spp: strains isolated from food in several cities of the Colombian Caribbean area  

Directory of Open Access Journals (Sweden)

Full Text Available Objetivo: establecer la presencia del gen de invasividad invA en aislamientos de Salmonella spp. obtenidos de alimentos en la región Caribe Colombiana. Métodos: se realizó un estudio microbiológico de control de alimentos en 4 ciudades de la región Caribe entre enero de 2002 y marzo de 2003. Se analizaron 1 300 muestras de alimentos provenientes de mercados y ventas callejeras. Resultados: se recuperaron 74 aislamientos de Salmonella spp. , en carne de res 30 (40,5 %), embutidos 13 (17,6 %), pollo 12 (16,2 %), queso 9 (12,2 %), cerdo 6 (8,1 %) y otros 4 (5,5 %). Los serotipos más frecuentes fueron: S. anatum 14 (18,9 %), S. uganda 13 (17,6 %), S. newport 9 (12,2 %) y S. typhimurium 7 (9,5 %). El cebador invA amplificó un fragmento de 378 pb, el gen invA se detectó en 72 (97,3 %) aislamientos de Salmonella. Conclusiones: se detectó la presencia del gen invA en los serotipos de Salmonella circulantes en alimentos en la región Caribe Colombiana. Las implicaciones epidemiológicas de estos resultados permiten sugerir a las autoridades sanitarias tomar medidas estrictas en el control, prevención y diagnóstico de la infección por Salmonella en esta regiónObjective: to establish the presence of invasive gene invA in Salmonella spp. strains obtained from food in several cities of the Colombian Caribbean area. Methods: from January 2002 to March 2003, a microbiological study of quality control of food was carried out in four cities of the Colombian Caribbean area. One thousand and three hundred food samples were analyzed in fast food outlets located in city squares or markets. Results: seventy four isolates of Salmonella were recovered: 30 (40.5) in meat; 13 (17.6 %) in sausage; 12 (16.2 %) in chicken; 9 (12.2 %) in cheese; 6 (8.1 %) in pork and 4 (5.5 %) in other types of food. The most frequently isolated serotypes were S.anatum in 14 (18.9 %), S.uganda in 13 (17.6 %), S. newport in 9 (12.2 %) y S. typhimurium in 7 (9.5 %). The invA primer amplified 378 pb fragment, invA gene was detected in 72 (97.3 %) Salmonella isolates. Conclusions: it was possible to detect the invA gene in circulating serotypes of Salmonella isolates obtained from food in the Colombian Caribbean area, the epidemiological implications allow the health authorities to take measure for the prevention, control and diagnosis of Salmonella infection in the Colombian Caribbean area

Paula Espinal Marin; Edgar Prieto Suárez; Vanessa Otero Jiménez; Salim Máttar Velilla

2006-01-01

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Development and evaluation of a multiplex real-time PCR (qPCR) assay targeting ttrRSBCA locus and invA gene for accurate detection of Salmonella spp. in fresh produce and eggs  

UK PubMed Central (United Kingdom)

Contamination of foods, especially produce and eggs, with Salmonella spp. is a major concern for public health. Therefore the development of a rapid method for Salmonella detection in those two important food commodities is urgently needed. The main objective of our study was to develop and evaluate a multiplex TaqMan-based real time PCR assay for detection of Salmonella spp. targeting invA gene and ttrRSBCA locus. The detection limit of this assay, 13 copies of genomic invA gene and ttrRSBCA locus, was determined by 10-fold dilutions of DNA from S. Typhimurium (strain SARA9). Inclusivity and exclusivity of the assay were assessed using 101 Salmonella spp. (including all Salmonella species and subspecies) and 48 non-S. enterica strains, respectively. Samples of cilantro (coriander leaves), lettuce, parsley, spinach, tomatoes and jalapeno peppers were seeded with four different Salmonella serovars at levels of 1–20 (low level) and 105 (high level) CFU/25g. The inoculated samples were assayed according to the FDA Salmonella culture method in the Bacteriological Analytical Manual (BAM). Eggs were seeded with two different S. Enteritidis strains at the level used for the produce samples and were assayed according to the USDA Laboratory Guidebook Salmonella culture method. The contaminated samples were analyzed with the multiplex TaqMan-based assay developed in this study. Comparable results were obtained by the qPCR and the two bacteriological methods. Levels as low as 2CFU/25g for produce were detected with the qPCR method according to the BAM and 5CFU/100g for eggs were detected with the qPCR method according to the USDA Laboratory Guidebook. False negatives (inhibition of PCR reaction) were ruled out through the use of a DNA internal amplification control (IAC). The qPCR multiplex assay developed in this study allows rapid and accurate detection of Salmonella spp. in six high-risk produce commodities and eggs, and has the potential to be used with other food matrices.

González-Escalona N; Brown EW; Zhang G

2012-08-01

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objective of this study was the application and evaluation of a loop-mediated isothermal amplification (LAMP) method for the detection of Salmonella spp. strains isolated from food samples. Salmonella specific invA gene sequences (50 strains, 15 serotypes) were amplified at 65oC in 60 min. All ...

Panos G. Ziros; Petros A. Kokkinos; Kostas Papanotas; Apostolos Vantarakis

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

Directory of Open Access Journals (Sweden)

Full Text Available Polymerase chain reaction (PCR) assay had been used to detect Salmonella in food and beverage samples using suitable primers which are based on specific invA gene of Salmonella. Twenty nine samples were collected from street food counters and some canteens in Margonda Street, Depok, West Java, Indonesia. It was found that five of twenty nine samples were detected to contain Salmonella and showed the presence of the amplified product of the size 244 bp. The method of PCR demonstrated the specificity of invA primers for detection of Salmonella as confirmed by biochemical and serological assay. The results of this study revealed that PCR was a rapid and useful tool for detection of Salmonella in food and beverage samples.

Radji, M.; Malik, A.; Widyasmara, A.

2010-01-01

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Psoralen photomutagenic specificity in Salmonella typhimurium  

International Nuclear Information System (INIS)

[en] The cytotoxic and mutagenic specificity of two therapeutically employed psoralens was examined in several Ames Salmonella typhimurium strains with near ultraviolet light activation. Photomutagenic activity of 8-methoxypsoralen (8MOP) and 4,5',8-trimethylpsoralen (TMP) was found to be sequence-specific, and additionally was dependent on the level of DNA-repair proficiency. Phototoxicity was essentially identical in hisC3076, hisD3052 and hisG46 strains; uvrB- excision-repair-deficient bacteria were considerably more susceptible to lethal effects than wild-type parental strains. Finally, the data show that psoralens are potent frameshift photomutagens in Salmonella hisC3076 strains and demonstrate the potential utility of these strains in evaluating photomutagenic and phototoxic activity of new furocoumarin derivatives. (Auth.)

1986-01-01

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

UK PubMed Central (United Kingdom)

Leptospirosis caused by pathogenic species of the genus Leptospira is a re-emerging zoonotic disease, which affects a wide variety of host species and is transmitted by contaminated water. The genomes of several pathogenic Leptospira species contain a gene named invA, which contains a Nudix domain. However, the function of this gene has never been characterized. Here, we demonstrated that the invA gene was highly conserved in protein sequence and present in all tested pathogenic Leptospira species. The recombinant InvA protein of pathogenic L. interrogans strain Lai hydrolyzed several specific dinucleoside oligophosphate substrates, reflecting the enzymatic activity of Nudix in Leptospira species. Pathogenic leptospires did not express this protein in media but temporarily expressed it at early stages (within 60 min) of infection of macrophages and nephric epithelial cells. Comparing with the wild type, the invA-deficient mutant displayed much lower infectivity and a significantly reduced survival rate in macrophages and nephric epithelial cells. Moreover, the invA-deficient leptospires presented an attenuated virulence in hamsters, caused mild histopathological damage, and were transmitted in lower numbers in the urine, compared with the wild-type strain. The invA revertant, made by complementing the invA-deficient mutant with the invA gene, reacquired virulence similar to the wild type in vitro and in vivo. The LD(50) in hamsters was 1000-fold higher for the invA-deficient mutant than for the invA revertant and wild type. These results demonstrate that the InvA protein is a Nudix hydrolase, and the invA gene is essential for virulence in pathogenic Leptospira species.

Luo Y; Liu Y; Sun D; Ojcius DM; Zhao J; Lin X; Wu D; Zhang R; Chen M; Li L; Yan J

2011-10-01

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In vitro selection of RNA aptamer specific to Salmonella typhimurium.  

UK PubMed Central (United Kingdom)

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

Han SR; Lee SW

2013-06-01

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Protective immunity to Salmonella enterica is partially serogroup specific.  

UK PubMed Central (United Kingdom)

Pre-harvest reduction of Salmonella carriage by swine would benefit both animal health and food quality. While vaccination is an attractive pre-harvest intervention to reduce Salmonella levels in swine, the large number of potential Salmonella enterica serovars found in swine makes it critical that vaccines provide broad serotype efficacy. In order to directly compare the relative efficacy of Salmonella vaccines against serogroup-matched and serogroup-unmatched Salmonella, we vaccinated pigs with two commercially available Salmonella vaccines (either serogroup B or serogroup C1) and challenged with serovar-matched, serogroup-matched or serogroup-unmatched challenge strains. We found that while serogroup-matched vaccines provided relatively better efficacy than unmatched vaccines, serotype-unmatched vaccines also provided significant reduction of Salmonella carriage and shed. In addition, by measuring serogroup specific cell mediated (IFN-? ELISPOT) and humoral (anti-LPS ELISA) immunity, we found that this serogroup specific efficacy correlates primarily with humoral immunity, while cell mediated immunity was mostly non-serogroup specific. While the practical relevance to pork quality of this serogroup-specific efficacy remains to be demonstrated, the large predominance of serogroup B Salmonella in swine suggests that a serogroup B Salmonella vaccine for swine would be of value to pre-harvest food safety interventions in swine.

Foss DL; Agin TS; Bade D; Dearwester DA; Jolie R; Keich RL; Lohse RM; Reed M; Rosey EL; Schneider PA; Taylor LP; Willy MS

2013-09-01

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Protective immunity to Salmonella enterica is partially serogroup specific.  

Science.gov (United States)

Pre-harvest reduction of Salmonella carriage by swine would benefit both animal health and food quality. While vaccination is an attractive pre-harvest intervention to reduce Salmonella levels in swine, the large number of potential Salmonella enterica serovars found in swine makes it critical that vaccines provide broad serotype efficacy. In order to directly compare the relative efficacy of Salmonella vaccines against serogroup-matched and serogroup-unmatched Salmonella, we vaccinated pigs with two commercially available Salmonella vaccines (either serogroup B or serogroup C1) and challenged with serovar-matched, serogroup-matched or serogroup-unmatched challenge strains. We found that while serogroup-matched vaccines provided relatively better efficacy than unmatched vaccines, serotype-unmatched vaccines also provided significant reduction of Salmonella carriage and shed. In addition, by measuring serogroup specific cell mediated (IFN-? ELISPOT) and humoral (anti-LPS ELISA) immunity, we found that this serogroup specific efficacy correlates primarily with humoral immunity, while cell mediated immunity was mostly non-serogroup specific. While the practical relevance to pork quality of this serogroup-specific efficacy remains to be demonstrated, the large predominance of serogroup B Salmonella in swine suggests that a serogroup B Salmonella vaccine for swine would be of value to pre-harvest food safety interventions in swine. PMID:23830894

Foss, Dennis L; Agin, Tonia S; Bade, Donald; Dearwester, Don A; Jolie, Rika; Keich, Robin L; Lohse, Robert M; Reed, Maryke; Rosey, Everett L; Schneider, Patricia A; Taylor, Lucas P; Willy, Michael S

2013-06-14

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A polymer coating applied to Salmonella prevents the binding of Salmonella-specific antibodies.  

UK PubMed Central (United Kingdom)

The use of Salmonella as a potential antitumor agent has been investigated, but innate immunity against this bacterium reduces the efficacy of its tumor-targeting and antitumor activities. The purpose of this study was to investigate the modulation of the tumor-targeting efficiency of Salmonella enterica serovar choleraesuis by modifying the immune response to these bacteria by coating them with poly(allylamine hydrochloride) (PAH), designated PAH-S.C. To evaluate this modulation, we used naïve mice and mice immunized with Salmonella to study the role of the preexisting immune response to the antitumor activity of PAH-S.C. When anti-Salmonella antibodies were present, the invasion activity, cytotoxicity, and gene transfer of Salmonella was significantly decreased, both in vitro and in vivo. Treatment with PAH-S.C. resulted in delayed tumor growth and enhanced survival in immunized mice. Furthermore, immunohistochemical studies of the tumors revealed the infiltration of neutrophils and macrophages in immunized mice treated with PAH-S.C. These results indicate that Salmonella encapsulation effectively circumvented the Salmonella-specific immune response.

Lee CH; Lin YH; Hsieh JL; Chen MC; Kuo WL

2013-02-01

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

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The isolation of DNA-free RNA is a crucial step in the reverse transcription PCR (RT-PCR). Every RNA extraction procedure results in RNA samples contaminated with genomic DNA, which can cause false-positive outcomes in highly sensitive applications, including a recently developed quantitative real-time PCR (RT-qPCR) assay that targets invA mRNA for the detection of live Salmonella cells. The assay of this specific mRNA can be used to indicate the presence of live, as opposed to dead, cells of Salmonella enterica in a food matrix. Findings We evaluated the ability of five RNA extraction kits to produce RNA preparations from exponentially growing Salmonella cells. The acceptability of the preparations for use in downstream applications such as RT-qPCR was judged in terms of the total amount of RNA recovered, the integrity of the RNA molecules, and minimal content of DNA. The five kits produced RNA preparations that differed markedly in yield, integrity of the Salmonella RNA and the amount of contaminant DNA. The greatest RNA recovery was achieved with the MasterPure kit; however, the preparation contained high levels of genomic DNA. The UltraClean extraction kit gave a low level of RNA recovery with a poor level of integrity. The RNeasy Mini, RiboPure and PureLink extraction kits produced high-quality, DNA-free RNA suitable for Salmonella detection by RT-qPCR. Conclusions We showed that the RNeasy Mini and PureLink RNA extraction kits were the most suitable for the detection of Salmonella invA mRNA by RT-qPCR. The use of these two kits will greatly reduce the frequency of false-positive results and might allow fast RT-qPCR determination of invA mRNA produced by viable Salmonella in food samples.

Rump Lydia V; Asamoah Benedicta; Gonzalez-Escalona Narjol

2010-01-01

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

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this study was the application and evaluation of a loop-mediated isothermal amplification (LAMP) method for the detection of Salmonella spp. strains isolated from food samples. Salmonella specific invA gene sequences (50 strains, 15 serotypes) were amplified at 65oC in 60 min. All of the strains of Salmonella subsp. Enterica were shown to be positive using the LAMP reaction assay, whereas, all other bacteria, virus and yeasts tested in this study were negative. LAMP products could be visually detected under day light or ultraviolet light, while the specific amplification of the DNA of Salmonella strains generated ladder-like pattern bands on agarose gel. LAMP is suitable for the sensitive, rapid, and inexpensive detection of Salmonella spp. in food analytical laboratories.

Panos G. Ziros; Petros A. Kokkinos; Kostas Papanotas; Apostolos Vantarakis

2012-01-01

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Differentially Evolved Genes of Salmonella Pathogenicity Islands: Insights into the Mechanism of Host Specificity in Salmonella  

Science.gov (United States)

Background The species Salmonella enterica (S. enterica) includes many serovars that cause disease in avian and mammalian hosts. These serovars differ greatly in their host range and their degree of host adaptation. The host specificity of S. enterica serovars appears to be a complex phenomenon governed by multiple factors acting at different stages of the infection process, which makes identification of the cause/s of host specificity solely by experimental methods difficult. Methodology/Principal Findings In this study, we have employed a molecular evolution and phylogenetics based approach to identify genes that might play important roles in conferring host specificity to different serovars of S. enterica. These genes are ‘differentially evolved’ in different S. enterica serovars. This list of ‘differentially evolved’ genes includes genes that encode translocon proteins (SipD, SseC and SseD) of both Salmonella pathogenicity islands 1 and 2 encoded type three secretion systems, sptP, which encodes an effector protein that inhibits the mitogen-activated protein kinase pathway of the host cell, and genes which encode effector proteins (SseF and SifA) that are important in placing the Salmonella-containing vacuole in a juxtanuclear position. Conclusions/Significance Analysis of known functions of these ‘differentially evolved genes’ indicates that the products of these genes directly interact with the host cell and manipulate its functions and thereby confer host specificity, at least in part, to different serovars of S. enterica that are considered in this study.

Eswarappa, Sandeepa M.; Janice, Jessin; Nagarajan, Arvindhan G.; Balasundaram, Sudhagar V.; Karnam, Guruswamy; Dixit, Narendra M.; Chakravortty, Dipshikha

2008-01-01

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Salmonella enterica highly expressed genes are disease specific.  

UK PubMed Central (United Kingdom)

During in vitro broth culture, bacterial gene expression is typically dominated by highly expressed factors involved in protein biosynthesis, maturation, and folding, but it is unclear if this also applies to conditions in natural environments. Here, we used a promoter trap strategy with an unstable green fluorescent protein reporter that can be detected in infected mouse tissues to identify 21 Salmonella enterica promoters with high levels of activity in a mouse enteritis model. We then measured the activities of these and 31 previously identified Salmonella promoters in both the enteritis and a murine typhoid fever model. Surprisingly, the data reveal that instead of protein biosynthesis genes, disease-specific genes such as Salmonella pathogenicity island 1 (SPI-1)-associated genes and genes involved in anaerobic respiration (enteritis) or SPI-2-associated genes and genes of the PhoP regulon (typhoid fever), respectively, dominate Salmonella in vivo gene expression. The overall functional profile of highly expressed genes suggests a marked shift in major transcriptional activities to nutrient utilization during enteritis or to fighting against the host during typhoid fever. The large proportion of known and novel essential virulence factors among the identified genes suggests that high expression levels during infection may correlate with functional relevance.

Rollenhagen C; Bumann D

2006-03-01

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Artificial Salmonella vaccines: Salmonella typhimurium O-antigen-specific oligosaccharide-protein conjugates elicit opsonizing antibodies that enhance phagocytosis.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Outbred NMRI mice and rabbits were vaccinated with different artificial Salmonella typhimurium immunogens and the specificity and activity of elicited antibodies were studied in in vivo and in vitro phagocytosis assays. The Salmonella immunogens used were: (i) the synthetic disaccharide, abequose (f...

Jörbeck, H J; Svenson, S B; Lindberg, A A

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

DEFF Research Database (Denmark)

As part of a major international project for the validation and standardization of PCR for detection of five major food-borne pathogens, four primer sets specific for Salmonella species were evaluated in-house for their analytical accuracy (selectivity and detection limit) in identifying 43 Salmonella spp. and 47 non-Salmonella strains. The most selective primer set was found to be 139-141 (K. Rahn, S. A. De Grandis, R. C. Clarke, S. A. McEwen, J. E. Galan, C. Ginocchio, R. Curtiss 111, and C. L. Gyles, Mol. Cell. Probes 6:271-279, 1992), which targets the invA gene. An extended determination of selectivity by using 364 strains showed that the inclusivity was 99.6% and the exclusivity was 100% for the invA primer set. To indicate possible PCR inhibitors derived from the sample DNA, an internal amplification control (IAC), which was coamplified with the invA target gene, was constructed. In the presence of 300 DNA copies of the IAC, the detection probability for primer set 139-141 was found to be 100% when a cell suspension containing 10(4) CFU/ml was used as the template in the PCR (50 CFU per reaction). The primer set was further validated in an international collaborative study that included 16 participating laboratories. Analysis with 28 coded ("blind") DNA samples revealed an analytical accuracy of 98%. Thus, a simple PCR assay that is specific for Salmonella spp. and amplifies a chromosomal DNA fragment detected by gel electrophoresis was established through extensive validation and is proposed as an international standard. This study addresses the increasing demand of quality assurance laboratories for standard diagnostic methods and presents findings that can facilitate the international comparison and exchange of epidemiological data.

Malorny, B.; Hoorfar, Jeffrey

2003-01-01

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

DEFF Research Database (Denmark)

In a previous study, we reported the performance of a PCR assay amplifying 285-bp of the invA gene of Salmonella spp. through an international ring-trial involving four participating laboratories [Int. J. Food Microbiol. 89 (2003) 241]. Based on the validated set of primers and recent advancements in PCR technology, we have designed two specific PCR assays for detecting Salmonella spp. We have compared PCR-enzyme-linked immunosorbent assay (PCR-ELISA) and LightCycler real-time PCR assay (LC-PCR) with the standard ISO 6579 bacteriological reference method. The two PCR tests incorporated an internal amplification control (IAC) co-amplified with the invA gene of Salmonella to monitor potential PCR inhibitors and ensure successful amplification. The selectivity study involved 84 Salmonella and 44 non-Salmonella strains and the samples tested were represented by 60 artificially-contaminated samples of fish, minced beef and raw milk, and 92 naturally-contaminated milk and meat samples. When using either PCR-ELISA or LC-PCR assays, only Salmonella strains were detected. PCR-ELISA and LC-PCR assays gave with pure Salmonella cultures the same detection limit level of 10(3) CFU/ml, which corresponds respectively to 50 and 10 cells per PCR tube. Data on artificially contaminated samples indicated that both PCR methods were able to detect after enrichment less than five Salmonella cells in 25 g of food, giving 100% concordance with the ISO 6579 reference method. The results on naturally contaminated samples demonstrated that despite certain inhibition problems, LC-PCR and PCR-ELISA assays were highly specific and sensitive, and provide a powerful tool for detection of Salmonella in food samples.

Perelle, Sylvie; Dilasser, Françoise

2004-01-01

 
 
 
 
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A new real-time PCR method for the identification of Salmonella Dublin.  

UK PubMed Central (United Kingdom)

AIMS: Development of a real-time PCR method for the specific detection of Salmonella Dublin. METHODS AND RESULTS: The method was directed towards a Salm. Dublin-specific sequence of the vagC gene on the Salmonella virulence plasmid (pSDV) and towards Salmonella genus-specific sequence of the invA gene, serving as an internal amplification control. The method showed 100% inclusivity and exclusivity when tested on a strain collection containing 50 serotyped S . Dublin strains, 20 strains of other Salmonella serotypes and 10 non- Salmonella strains. The method also showed 100% inclusivity and 99% exclusivity in a collaborative study comprising eight laboratories, where each laboratory received ten different S . Dublin strains and 10 other Salmonella serotypes. CONCLUSIONS: The method showed excellent performance both when validated in the laboratory and in the collaborative study. SIGNIFICANCE AND IMPACT OF THE STUDY: Application of the present method in food control, for example at slaughterhouses, can improve the contamination control of this veterinary and clinically important Salmonella serotype.

Persson S; Jacobsen T; Olsen JE; Olsen KE; Hansen F

2012-09-01

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Comparing the presence of different genes in Salmonella subspecies I-IV and development of a diagnostic multiplex PCR method for identification of Salmonella subspecies.  

UK PubMed Central (United Kingdom)

Reptile-associated salmonellosis in humans has become a growing problem worldwide. Reptiles are frequently asymptomatic carriers of Salmonella and therefore, they are considered as an important reservoir for these bacteria. The classical biochemical method for Salmonella subspecies detection is time consuming, especially in samples from reptiles since they frequently carry more than one Salmonella subspecies. The aim of this study was therefore to develop a multiplex PCR assay for a rapid and accurate differentiation of Salmonella subspecies I, II, IIa, IIIb and IV. In the present study, the occurrence of the genes invA, ttrCA, iroB, STM4075, sciA, STM3690, sadA, gatD, foxA, pagN, fljB, iucD, spvB, lacZ, iutA, mdcA and irp2 was examined in 41 Salmonella strains from Middle Eastern animals (mainly reptiles) by monoplex PCR. According to the results a multiplex PCR assay was developed based on the genes ttrCA, sciA, foxA, iutA. Compared to biochemical analysis this method allowed a fast identification of the subspecies from all the Middle Eastern Salmonella strains (n = 41), as well as 79 strains from German children (n = 18) with reptile associated salmonellosis and other humans and animals (n = 61) with salmonellosis.These results revealed the multiplex PCR as a fast assay for a specific identification of Salmonella subspecies I, II, IIIa, and IIIb.

Münch S; Wernery U; Kinne J; Joseph M; Braun P; Pees M; Flieger A; Fruth A; Rabsch W

2013-01-01

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Simultaneous detection of Salmonella pathogenicity island 2 and its antibiotic resistance genes from seafood.  

Science.gov (United States)

Salmonella enterica serovars are virulent pathogens of humans and animals with many strains possessing multiple drug resistance traits. They have been found to carry resistance to ampicillin, chloramphenicol, florfenicol, streptomycin, sulfonamides, and tetracycline (ACSSuT-resistant). A rapid and sensitive multiplex PCR (mPCR)-based assay was developed for the detection of Salmonella serovars from seafood. Six sets of primers which are one primer pair targeting Salmonella specific gene invA (284 bp), two Salmonella pathogenicity island 2 (SPI-2) genes ssaT (780 bp) and sseF (888 bp) and three antibiotic resistance genes floR (198 bp), sul1 (425 bp), tetG (550 bp) were used for the study. The specificity and sensitivity of the assay were tested by spiking shrimp/fish/clam homogenate with viable cells of Salmonella. This assay allows for the cost effective and reliable detection of pathogenic Salmonella enterica from seafood. The mPCR developed in the present study proved to be a potent analytical tool for the rapid identification of multidrug-resistant Salmonella serovars from seafood. PMID:23545447

Deekshit, Vijaya Kumar; Kumar, Ballamoole Krishna; Rai, Praveen; Rohit, Anusha; Karunasagar, Indrani

2013-03-29

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Simultaneous detection of Salmonella pathogenicity island 2 and its antibiotic resistance genes from seafood.  

UK PubMed Central (United Kingdom)

Salmonella enterica serovars are virulent pathogens of humans and animals with many strains possessing multiple drug resistance traits. They have been found to carry resistance to ampicillin, chloramphenicol, florfenicol, streptomycin, sulfonamides, and tetracycline (ACSSuT-resistant). A rapid and sensitive multiplex PCR (mPCR)-based assay was developed for the detection of Salmonella serovars from seafood. Six sets of primers which are one primer pair targeting Salmonella specific gene invA (284 bp), two Salmonella pathogenicity island 2 (SPI-2) genes ssaT (780 bp) and sseF (888 bp) and three antibiotic resistance genes floR (198 bp), sul1 (425 bp), tetG (550 bp) were used for the study. The specificity and sensitivity of the assay were tested by spiking shrimp/fish/clam homogenate with viable cells of Salmonella. This assay allows for the cost effective and reliable detection of pathogenic Salmonella enterica from seafood. The mPCR developed in the present study proved to be a potent analytical tool for the rapid identification of multidrug-resistant Salmonella serovars from seafood.

Deekshit VK; Kumar BK; Rai P; Rohit A; Karunasagar I

2013-06-01

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Detection of OmpA gene by PCR for specific detection of Salmonella serovars  

Directory of Open Access Journals (Sweden)

Full Text Available Aim: The study was carried out to determine the sensitivity and specificity of OmpA gene in Salmonella serovarsthrough PCR.Materials and Methods: Aset of primers were designed targeting the OmpAgene specific for the Salmonella and polymerasechain reaction was standardized using Salomonella Typhimurium as a positive control and as a negative control 4 nonsalmonella cultures such as Campylobacter coli, Arcobacter butzleri, Brucella abortus and E. coli. Sensitivity of the test wasdetermined by serial dilution of genomic DNAof standard S. Typhimurium. The PCR standardized was used for screening 68strains of different serovars of Salmonella.Results: The PCR developed targeting OmpA specific for Salmonella was highly specific in detection of the salmonellaserovar alone and sensitivity was upto 68.8 fg. Atotal of 68 virulent/ natural strains of different serovars of salmonella takenup for the study were positive by OmpAbased PCR.Conclusions: This study reports that, OmpAgene which is conserved among Salmonella serovars can be used for the detectionof Salmonella in food or clinical samples in further studies, with high sensitivity and specificity.

Joy. L. Kataria; A. Kumar; S. Rajagunalan; L. Jonathan; R.K.Agarwal

2013-01-01

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

Directory of Open Access Journals (Sweden)

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

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

2013-01-01

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Detecting salmonella serovars in shell eggs by loop-mediated isothermal amplification.  

UK PubMed Central (United Kingdom)

Shell eggs contaminated with Salmonella Enteritidis pose serious food safety and public health concerns. More vigilant product testing calls for rapid, accurate, and reliable detection methods for Salmonella. Two loop-mediated isothermal amplification (LAMP) assays targeting different regions of the Salmonella invasion protein (encoded by invA) have been reported. In this study, performance of the two LAMP assays was compared with that of PCR in detecting Salmonella Enteritidis and Salmonella Typhimurium strains in experimentally contaminated egg homogenates. Both LAMP assays were highly specific. The detection limits were approximately 1 CFU per reaction for both Salmonella serovars in pure culture, 100-fold more sensitive than that of PCR. Standard curves generated suggested a good linear relationship between Salmonella cell numbers and LAMP turbidity signals. In spiked egg homogenate, the LAMP assays could detect both Salmonella serovars down to 10(4) CFU/25 ml without enrichment and 10(0) CFU/25 ml with 8-h enrichment. In contrast, PCR was unable to detect either Salmonella serovar in egg homogenates spiked with less than 10(6) CFU/25 ml by direct testing and required at least 12 h of enrichment for samples spiked with 10(1) CFU/25 ml and 24 h for those with 10(0) CFU/25 ml. The complete LAMP assay took about 10 h (including 8 h of enrichment) to complete. In conclusion, the two LAMP assays were rapid, accurate, and reliable methods for detecting Salmonella serovars in shell eggs and may be adopted in routine egg testing for Salmonella to improve egg safety and protect public health.

Yang Q; Chen S; Ge B

2013-10-01

28

Mining and evaluation of new specific molecular targets for the PCR detection of Salmonella spp. genome.  

UK PubMed Central (United Kingdom)

The purpose of this study is to find new molecular targets for the detection of Salmonella. With the online BLAST Program, we compared homology of genomic sequences and specificity in GenBank among Salmonella serovars and non-Salmonella strains and found 98 Salmonella specific target sequences. We selected 33 target sequences of Gene ID from 3335000 to 3337003 for the specificity evaluation, and finally 8 specific fragments screened out, they are 3334138, 3335583, 3335471, 3335211, 3335068, 3336466, 3336736 and 3336998. Primer SC8 of gene 3335583 and SC9 of gene 3335471 were the best in specificity and sensitivity among these primers. The detection sensitivity of Primer SC9 was 1.23 fg/?l for DNA templates and 720 cfu/ml for whole cells, while primer SC8's was 12.3 fg/?l and 720 cfu/ml, respectively. Salmonella could be detected successfully by the PCR method developed in this study after 8 h enrichment when the milk samples were artificially contaminated by this organism at 7 cfu per 10 ml milk.

Kong X; Lu Z; Zhai L; Yao S; Zhang C; Lv F; Bie X

2013-06-01

29

Mining and evaluation of new specific molecular targets for the PCR detection of Salmonella spp. genome.  

Science.gov (United States)

The purpose of this study is to find new molecular targets for the detection of Salmonella. With the online BLAST Program, we compared homology of genomic sequences and specificity in GenBank among Salmonella serovars and non-Salmonella strains and found 98 Salmonella specific target sequences. We selected 33 target sequences of Gene ID from 3335000 to 3337003 for the specificity evaluation, and finally 8 specific fragments screened out, they are 3334138, 3335583, 3335471, 3335211, 3335068, 3336466, 3336736 and 3336998. Primer SC8 of gene 3335583 and SC9 of gene 3335471 were the best in specificity and sensitivity among these primers. The detection sensitivity of Primer SC9 was 1.23 fg/?l for DNA templates and 720 cfu/ml for whole cells, while primer SC8's was 12.3 fg/?l and 720 cfu/ml, respectively. Salmonella could be detected successfully by the PCR method developed in this study after 8 h enrichment when the milk samples were artificially contaminated by this organism at 7 cfu per 10 ml milk. PMID:23771808

Kong, Xiaohan; Lu, Zhaoxin; Zhai, Ligong; Yao, Shulin; Zhang, Chong; Lv, Fengxia; Bie, Xiaomei

2013-06-16

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

Energy Technology Data Exchange (ETDEWEB)

Protein type III secretion systems (T3SSs) are organic nanosyringes that achieve an energy-dependent translocation of bacterial proteins through the two membranes of Gram-negative organisms. Examples include the pathogenic systems of animals, plants and symbiotic bacteria that inject factors into eukaryotic cells, and the flagellar export system that secretes flagellin. T3SSs possess a core of several membrane-associated proteins that are conserved across all known bacterial species that use this system. The Salmonella protein InvA is one of the most highly conserved proteins of this core of critical T3SS components. The crystal structure of a C-terminal domain of InvA reveals an unexpected homology to domains that have been repeatedly found as building blocks of other elements of the T3SS apparatus. This suggests the surprising hypothesis that evolution has produced a significant component of the apparatus structure through a series of gene-duplication and gene-rearrangement events.

Lilic, M.; Quezada, C; Stebbins, C

2010-01-01

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

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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.

Soyer Ye?im; Orsi Renato H; Rodriguez-Rivera Lorraine D; Sun Qi; Wiedmann Martin

2009-01-01

32

[Immunological properties of an artificial antigen possessing the specificity of Salmonella O-factor 3].  

Science.gov (United States)

For the first time the method of obtaining synthetic protein-free antigen with the specificity of Salmonella O-factor by the radical copolymerization of the synthetic trisaccharide 3-0 [4-0-(beta-D-mannopyranosyl)-alpha-L-rhamnopyranosyl]-beta-allyl-D- galactopyranoside with acrylamide was developed. The synthetic antigen thus obtained possessed the narrow specificity of serogroup E Salmonella O-factor 3. The serological activity of the antigen, studied in the precipitation and passive hemagglutination tests, was considerably higher than that of lipopolysaccharides isolated from S. anatum and S. newington. This synthetic antigen proved to be nontoxic and possessed immunogenic properties, inducing the formation of antibodies to Salmonella O-factor 3 in immunized animals. PMID:6191475

Pokrovski?, V I; Tendetnik, Iu Ia; Pokrovski?, V V; Ovcharova, N M; Kochetkov, N K

1983-04-01

33

[Immunological properties of an artificial antigen possessing the specificity of Salmonella O-factor 3  

UK PubMed Central (United Kingdom)

For the first time the method of obtaining synthetic protein-free antigen with the specificity of Salmonella O-factor by the radical copolymerization of the synthetic trisaccharide 3-0 [4-0-(beta-D-mannopyranosyl)-alpha-L-rhamnopyranosyl]-beta-allyl-D- galactopyranoside with acrylamide was developed. The synthetic antigen thus obtained possessed the narrow specificity of serogroup E Salmonella O-factor 3. The serological activity of the antigen, studied in the precipitation and passive hemagglutination tests, was considerably higher than that of lipopolysaccharides isolated from S. anatum and S. newington. This synthetic antigen proved to be nontoxic and possessed immunogenic properties, inducing the formation of antibodies to Salmonella O-factor 3 in immunized animals.

Pokrovski? VI; Tendetnik IuIa; Pokrovski? VV; Ovcharova NM; Kochetkov NK

1983-04-01

34

Host-specificity of Salmonella enterica serovar Gallinarum: insights from comparative genomics.  

Science.gov (United States)

In this study, we have identified the possible genetic factors responsible for fowl-adaptation of Salmonella entericaserovar Gallinarum (S. Gallinarum). By comparing the genes related to Salmonella pathogenicity islands (SPI) of S. Gallinarum with those of Salmonella entericaserovar Enteritidis (S. Enteritidis) we have identified twenty-four positively selected genes. Our results suggest that the genes encoding the structural components of SPI-2 encoded type three secretion apparatus (TTSS) and the effector proteins that are secreted via SPI-1 encoded TTSS have evolved under positive selection pressure in these serovars. We propose that these positively selected genes play important roles in conferring different host-specificities to S. Gallinarum and S. Enteritidis. PMID:19454277

Eswarappa, Sandeepa M; Janice, Jessin; Balasundaram, Sudhagar V; Dixit, Narendra M; Chakravortty, Dipshikha

2009-01-19

35

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

International Nuclear Information System (INIS)

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

2007-01-01

36

Salmonella Diagnosis and Treatment  

Science.gov (United States)

... Digg Google Bookmarks Diagnosis and Treatment How Can Salmonella Infections Be Diagnosed? Many different kinds of illnesses ... testing can determine its specific type. How Can Salmonella Infections Be Treated? Salmonella gastrointestinal infections usually resolve ...

37

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

Directory of Open Access Journals (Sweden)

Full Text Available Introduction: Chlorination is the most widely used disinfection process for drinking water production. The formation of chlorination carcinogenic by-products and chlorine intoxication by direct manipulation in small communities has motivated the study of alternative disinfection processes. In this sense, processes of advanced oxidation (PAOs) have yielded promising results. Escherichia coli (E. coli) is customarily used as faecal bacterial indicator to determine the efficiency of disinfection processes. However, it has been shown that E. coli is less resistant to disinfection than other enteric bacteria such as Shigella spp. and Salmonella spp. Additionally, the viable non-culturable (VNC) state yields bacteria which are not detectable on many culture media.Objective: The main objective is to standardize a method for counting Salmonella spp. and Shigella spp. in specific liquid media to reliably quantify the bacteriological potential risk related to disinfection processes based on PAO.Methods: The study followed a randomized bi-factorial experimental design and the Duncan multiple comparison test. This design allowed the selection of specific liquid media to fittingly standardize the counting of Salmonella spp. and Shigella spp.Results: We found that the best broth for counting Salmonella typhimurium strain at different concentrations in pure and mixed cultures was the Rappaport broth RP, the EE broth also allowed growing the two bacterial species tested in this research. Nonetheless, the latter results suggest the use of additional tests for this particular broth.Discussion: There was a variation in the counting results when pure cultures were used compared to those obtained from mixtures of microorganisms. It was also noted that Salmonella typhimurium and Shigella sonnei, were recovered from minimal concentrations in both RP and EE broths, respectively. To some extent, this suggests an additional confirmative method when using the EE® broth.Conclusion: MPN is a rapid and inexpensive method; easy to apply in water and other contaminated environments where counting of Shigella spp. and Salmonella spp. is needed to estimate potential bacteriological risks. The broths selected were able to recover the two bacterial species from densities as low as 10 cells per 100 ml.

Sandra Patricia Rivera; Liliana Janeth Flórez; Janeth Sanabria

2010-01-01

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Antimicrobial Resistance and Virulence-Associated Genes of Salmonella enterica Subsp. enterica Serotypes Muenster, Florian, Omuna, and Noya Strains Isolated from Clinically Diarrheic Humans in Egypt.  

UK PubMed Central (United Kingdom)

Four serotypes recovered from clinically diarrheic human faecal samples (Salmonella Muenster, Salmonella Florian, Salmonella Omuna and Salmonella Noya) were investigated for the presence of 11 virulence genes (invA, avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, and bcfC) and their association with antibiotic resistance. The 4 Salmonella serotypes lacked virulence genes gipA and spvC. Resistance to 7 of the 14 antimicrobials was detected. The frequency of resistance, to lincomycin and streptomycin (100% of the Salmonella Muenster [2/5], Salmonella Florian [1/5], Salmonella Omuna [1/5], and Salmonella Noya [1/5] isolates), chloramphenicol (100% of the Salmonella Muenster [2/5] and Salmonella Florian [1/5] isolates) and trimethoprim-sulfamethoxazole (100% of the Salmonella Florian [1/5] and Salmonella Omuna [1/5] isolates) was an outstanding feature. With the rest of the antibiotics, the four Salmonella serotypes exhibited a great diversity in their resistance patterns. Overall, the four Salmonella serotypes were resistant to more than one antimicrobial. The antimicrobials to which the Salmonella Muenster, Salmonella Florian, and Salmonella Omuna isolates were resistant, contributed to five different antimicrobial resistance profiles. The virulence associated genes invA, ssaQ, siiD, sopB, and bcfC genes were 100% associated with certain antimicrobial resistance phenotypes (streptomycin and lincosamide) not recorded previously, and secondly, the presence of invA, avrA, ssaQ, mgtC, siiD, sopB, and bcfC was associated with resistance to chloramphenicol. The results of this study will help in understanding the spread of virulence genotypes and antibiotic resistance in Salmonella in the region of study.

Osman KM; Marouf SH; Alatfeehy N

2013-10-01

39

Antimicrobial Resistance and Virulence-Associated Genes of Salmonella enterica Subsp. enterica Serotypes Muenster, Florian, Omuna and Noya Strains Isolated from Clinically Diarrheic Humans in Egypt.  

UK PubMed Central (United Kingdom)

Four serotypes recovered from clinically diarrheic human faecal samples (Salmonella Muenster, Salmonella Florian, Salmonella Omuna and Salmonella Noya) were investigated for the presence of 11 virulence genes (invA, avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, and bcfC) and their association with antibiotic resistance. The 4 Salmonella serotypes lacked virulence genes gipA and spvC. Resistance to 7 of the 14 antimicrobials was detected. The frequency of resistance, to lincomycin and streptomycin (100% of the Salmonella Muenster [2/5], Salmonella Florian [1/5], Salmonella Omuna [1/5], and Salmonella Noya [1/5] isolates), chloramphenicol (100% of the Salmonella Muenster [2/5] and Salmonella Florian [1/5] isolates) and trimethoprim-sulfamethoxazole (100% of the Salmonella Florian [1/5] and Salmonella Omuna [1/5] isolates) was an outstanding feature. With the rest of the antibiotics, the four Salmonella serotypes exhibited a great diversity in their resistance patterns. Overall, the four Salmonella serotypes were resistant to more than one antimicrobial. The antimicrobials to which the Salmonella Muenster, Salmonella Florian, and Salmonella Omuna isolates were resistant, contributed to five different antimicrobial resistance profiles. The virulence associated genes invA, ssaQ, siiD, sopB, and bcfC genes were 100% associated with certain antimicrobial resistance phenotypes (streptomycin and lincosamide) not recorded previously, and secondly, the presence of invA, avrA, ssaQ, mgtC, siiD, sopB, and bcfC was associated with resistance to chloramphenicol. The results of this study will help in understanding the spread of virulence genotypes and antibiotic resistance in Salmonella in the region of study.

Osman KM; Marouf SH; Alatfeehy N

2013-04-01

40

Antimicrobial Resistance and Virulence-Associated Genes of Salmonella enterica Subsp. enterica Serotypes Muenster, Florian, Omuna, and Noya Strains Isolated from Clinically Diarrheic Humans in Egypt.  

Science.gov (United States)

Four serotypes recovered from clinically diarrheic human faecal samples (Salmonella Muenster, Salmonella Florian, Salmonella Omuna and Salmonella Noya) were investigated for the presence of 11 virulence genes (invA, avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, and bcfC) and their association with antibiotic resistance. The 4 Salmonella serotypes lacked virulence genes gipA and spvC. Resistance to 7 of the 14 antimicrobials was detected. The frequency of resistance, to lincomycin and streptomycin (100% of the Salmonella Muenster [2/5], Salmonella Florian [1/5], Salmonella Omuna [1/5], and Salmonella Noya [1/5] isolates), chloramphenicol (100% of the Salmonella Muenster [2/5] and Salmonella Florian [1/5] isolates) and trimethoprim-sulfamethoxazole (100% of the Salmonella Florian [1/5] and Salmonella Omuna [1/5] isolates) was an outstanding feature. With the rest of the antibiotics, the four Salmonella serotypes exhibited a great diversity in their resistance patterns. Overall, the four Salmonella serotypes were resistant to more than one antimicrobial. The antimicrobials to which the Salmonella Muenster, Salmonella Florian, and Salmonella Omuna isolates were resistant, contributed to five different antimicrobial resistance profiles. The virulence associated genes invA, ssaQ, siiD, sopB, and bcfC genes were 100% associated with certain antimicrobial resistance phenotypes (streptomycin and lincosamide) not recorded previously, and secondly, the presence of invA, avrA, ssaQ, mgtC, siiD, sopB, and bcfC was associated with resistance to chloramphenicol. The results of this study will help in understanding the spread of virulence genotypes and antibiotic resistance in Salmonella in the region of study. PMID:23621859

Osman, Kamelia M; Marouf, Sherif H; Alatfeehy, Nayerah

2013-04-26

 
 
 
 
41

Desarrollo y validación de una reacción en cadena de la polimerasa múltiple para la identificación de los serogrupos Salmonella enterica B, C2, D y E de Salmonella enterica/ Development and validation of a multiplex polymerase chain reaction for molecular identification of Salmonella enterica serogroups B, C2, D and E  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Introducción. El esquema Kaufmann-White para la serotipificación de Salmonella, reconoce 46 antígenos O y 119 antígenos H, los cuales han permitido la caracterización de 2.541 serovares. La serotipificación es una herramienta epidemiológica útil en la identificación de serovares circulantes y estudio de brotes, sin embargo, presenta limitaciones técnicas, de interpretación de resultados y alto costo. Objetivo. Desarrollar una prueba de reacción en cadena de la (more) polimerasa múltiple (PCR-M) como alternativa para identificar los serogrupos B, C2, D y E de Salmonella enterica. Materiales y métodos. Se desarrolló una PCR-M para detectar los genes rfbJ de los serogrupos B y C2 y wzx de los serogrupos D y E. Para estandarizar la PCR-M se probaron cepas de referencia de Salmonella pertenecientes a los serogrupos de estudio. Se incluyó el gen invA específico del género Salmonella como control interno de amplificación. La técnica fue validada con un estudio ciego que incluyó 400 aislamientos de Salmonella previamente serotipificados. Resultados. La PCR-M permitió identificar los serogrupos de Salmonella con resultados reproducibles (índice kappa=0,95). La sensibilidad de la prueba estuvo entre 98% y 100% y la especificidad entre 96% y 100%. 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. Abstract in english Introduction. The scheme Kauffman-White (KW) for serotyping of Salmonella recognizes 46 O antigens, and 119 H antigens, thereby permitting the characterization of 2,541 serotypes. The serotyping is a useful epidemiological tool in identifying circulating serotypes and to characterize outbreaks. However, the method presents technical limitations, difficulty in interpretation of results and high costs. Objective. A multiplex polymerase chain reaction test (M-PCR) was develo (more) ped as an alternative method for the identification of serogroups B, C2, D, and E of Salmonella enterica. Materials and methods. The M-PCR detected Salmonella genes rfbJ of serogroups B and C2 and wzx of serogroups D and E. To standardize the M-PCR, reference strains of Salmonella serogroups were compared. Amplification of invA gender-specific gene of Salmonella was included as internal control of amplification. To validate the test, a blind study was conducted to identify by M-PCR 400 isolates that had been previously characterized by serology. Results. The M-PCR detected Salmonella serogroups with reproducible results (Kappa index=0.95). The sensitivity of the test was between 98% to 100% and specificity between 96% to 100%. Conclusions. The polymorphisms in the Salmonella genes rfbJ and wzx permitted the development of a method for molecular typing of Salmonella serogroups that was sensitive, specific and reproducible.

Lavalett, Lelia; Sánchez, Miryan Margot; Múñoz, Nélida; Moreno, Jaime; Cardona-Castro, Nora

2009-06-01

42

Characterisation of epitopes of type 1 fimbriae of Salmonella using monoclonal antibodies specific for SEF21 fimbriae of Salmonella enteritidis.  

Science.gov (United States)

Monoclonal antibodies (mAbs) were used to identify and characterise epitopes of type 1 (SEF21) fimbriae of Salmonella enteritidis. The distribution of the epitopes among salmonellas and other enterobacteria was investigated, as well as the influence of growth media and temperatures on their expression. At least four different epitope clusters were identified on SEF21 fimbriae of S. enteritidis. Two of these clusters were associated with fimbrial haemagglutinins that were either common to all salmonellae tested, or restricted only to S. enteritidis and S. dublin. The four epitope clusters were identified on type 1 fimbriae of most Salmonella serotypes, as well as non-haemagglutinating type 2 fimbriae of S. pullorum and S. gallinarum, and on many other enterobacterial species. The expression of the epitopes was affected by growth conditions. PMID:9549856

Sojka, M G; Carter, M A; Thorns, C J

1998-01-16

43

Prevention of Salmonella Infection in Poultry by Specific Egg-Derived Antibody  

Directory of Open Access Journals (Sweden)

Full Text Available Salmonella enteritidis (SE) colonizes the intestinal tract of poultry and causes food born illness in humans. Reduction of (SE) colonization in the intestinal tract of poultry reduces potential carcass contamination during slaughter. The purpose of this study was to investigate the effect of SE-specific yolk immunoglobulin (IgY) on prevention of SE colonization in orally infected broiler chickens. Commercial Single Comb White Leghorn (SCWL) hens were hyperimmunized with SE whole cell antigens. The presence of anti-Salmonella antibody, IgY and IgG in egg yolk and serum respectively, was monitored by Enzyme Linked Sorbent Assay (ELISA). Two hundred forty male `Ross 308` day old chicks were randomly assigned to 8 groups and 3 replications of 10 birds were grown for 42 days of experiment. Eight experimental groups identified with, S, P, A, SP, SA, AP, SPA, C. Four birds from four challenged groups (S), were orally inoculated with 1 mL of bacterial suspension that contained 1×106 CFU mL-1 S. enteritidis at 3 day of age. The groups that supplemented with antibody (A) received 15 mL of yolk contained antibody mixed per 3.84 mL of drinking water on day 1 and continuing for duration of the experiment. The probiotic treated groups (P) were received probiotic, 0.1% of feed and 0.5% of feed, until day 21 and 56 respectively. One group as control (C) did not received any treatment of probiotic and antibody. A-treated and A-P treated groups had significantly lower fecal shedding (pSalmonella enteritidis-specific IgY combined with probiotic had a beneficial effect in reducing the colonization of Salmonella in market-aged broiler under the condition of this study.

Shaban Rahimi; Zahra Moghadam Shiraz; Taghi Zahraei Salehi; Mohammad A. Karimi Torshizi; Jesse L. Grimes

2007-01-01

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

Science.gov (United States)

This paper presents two immobilization methods for the intracellular invertase (INVA), from Zymomonas mobilis. In the first method, a chimeric protein containing the invertase INVA, fused through its C-terminus to CBDCex from Cellulomonas fimi was expressed in Escherichia coli strain BL21 (DE3). INVA was purified and immobilized on crystalline cellulose (Avicel) by means of affinity, in a single step. No changes were detected in optimal pH and temperature when INVA-CBD was immobilized on Avicel, where values of 5.5 and 30 degrees C, respectively, were registered. The kinetic parameters of the INVA-CBD fusion protein were determined in both its free form and when immobilized on Avicel. Km and Vmax were affected with immobilization, since both showed an increase of up to threefold. Additionally, we found that subsequent to immobilization, the INVA-CBD fusion protein was 39% more susceptible to substrate inhibition than INVA-CBD in its free form. The second method of immobilization was achieved by the expression of a 6xHis-tagged invertase purified on Ni-NTA resin, which was then immobilized on Nylon-6 by covalent binding. An optimal pH of 5.5 and a temperature of 30 degrees C were maintained, subsequent to immobilization on Nylon-6 as well as with immobilization on crystalline cellulose. The kinetic parameters relating to Vmax increased up to 5.7-fold, following immobilization, whereas Km increased up to 1.7-fold. The two methods were compared showing that when invertase was immobilized on Nylon-6, its activity was 1.9 times that when immobilized on cellulose for substrate concentrations ranging from 30 to 390 mM of sucrose. PMID:18712537

de Los Angeles Calixto-Romo, María; Santiago-Hernández, José Alejandro; Vallejo-Becerra, Vanessa; Amaya-Delgado, Lorena; del Carmen Montes-Horcasitas, María; Hidalgo-Lara, María Eugenia

2008-08-20

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Salmonella Typhimurium-specific bacteriophage ?SH19 and the origins of species specificity in the Vi01-like phage family  

Science.gov (United States)

Background Whole genome sequencing of bacteriophages suitable for biocontrol of pathogens in food products is a pre-requisite to any phage-based intervention procedure. Trials involving the biosanitization of Salmonella Typhimurium in the pig production environment identified one such candidate, ?SH19. Results This phage was sequenced and analysis of its 157,785 bp circular dsDNA genome revealed a number of interesting features. ?SH19 constitutes another member of the recently-proposed Myoviridae Vi01-like family of phages, containing S. Typhi-specific Vi01 and Shigella-specific SboM-AG3. At the nucleotide level ?SH19 is highly similar to phage Vi01 (80-98% pairwise identity over the length of the genome), with the major differences lying in the region associated with host-range determination. Analyses of the proteins encoded within this region by ?SH19 revealed a cluster of three putative tail spikes. Of the three tail spikes, two have protein domains associated with the pectate lyase family of proteins (Tsp2) and P22 tail spike family (Tsp3) with the prospect that these enable Salmonella O antigen degradation. Tail spike proteins of Vi01 and SboM-AG3 are predicted to contain conserved right-handed parallel ?-helical structures but the internal protein domains are varied allowing different host specificities. Conclusions The addition or exchange of tail spike protein modules is a major contributor to host range determination in the Vi01-like phage family.

2011-01-01

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Salmonella Typhimurium-specific bacteriophage ?SH19 and the origins of species specificity in the Vi01-like phage family.  

UK PubMed Central (United Kingdom)

BACKGROUND: Whole genome sequencing of bacteriophages suitable for biocontrol of pathogens in food products is a pre-requisite to any phage-based intervention procedure. Trials involving the biosanitization of Salmonella Typhimurium in the pig production environment identified one such candidate, ?SH19. RESULTS: This phage was sequenced and analysis of its 157,785 bp circular dsDNA genome revealed a number of interesting features. ?SH19 constitutes another member of the recently-proposed Myoviridae Vi01-like family of phages, containing S. Typhi-specific Vi01 and Shigella-specific SboM-AG3. At the nucleotide level ?SH19 is highly similar to phage Vi01 (80-98% pairwise identity over the length of the genome), with the major differences lying in the region associated with host-range determination. Analyses of the proteins encoded within this region by ?SH19 revealed a cluster of three putative tail spikes. Of the three tail spikes, two have protein domains associated with the pectate lyase family of proteins (Tsp2) and P22 tail spike family (Tsp3) with the prospect that these enable Salmonella O antigen degradation. Tail spike proteins of Vi01 and SboM-AG3 are predicted to contain conserved right-handed parallel ?-helical structures but the internal protein domains are varied allowing different host specificities. CONCLUSIONS: The addition or exchange of tail spike protein modules is a major contributor to host range determination in the Vi01-like phage family.

Hooton SP; Timms AR; Rowsell J; Wilson R; Connerton IF

2011-01-01

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Comparison of culture, polymerase chain reaction (PCR), TaqMan Salmonella, and Transia Card Salmonella assays for detection of Salmonella spp. in naturally-contaminated ground chicken, ground turkey, and ground beef.  

Science.gov (United States)

Four types of assays were evaluated for the detection of Salmonella spp. in retail ground chicken (86 packages), ground turkey (104 packages), and ground beef (54 packages). Two 25 g samples from each package were separately subjected to pre-enrichment in buffered peptone water for 20 h at 37 degrees C followed by enrichment in Rappaport Vassiliadis (RV) broth for 20 h at 42 degrees C. The RV enrichments were plated onto Rambach agar, Rainbow Agar Salmonella, and XLT4 agar, and were also tested by a PCR assay targeting the Salmonella invA gene, as well as by the TaqMan Salmonella PCR assay. Additionally, the RV enrichments were tested using the Transia Card Salmonella immunoassay. Results showed that 16.8, 24.0, 28.8, and 26.4% of turkey samples were positive for Salmonella spp. by culture, PCR, TaqMan PCR, and Transia Card Salmonella assays, respectively. Eighteen, 28.5, 35.5, and 34.9% of chicken samples were positive by culture, PCR, TaqMan PCR, and Transia Card Salmonella assays, respectively, and 6.5, 6.5, 6.5, and 18.5% of ground beef samples were positive by the four assays, respectively. Analysis of the data using the kappa statistic showed that there was substantial to excellent agreement between the PCR and TaqMan PCR assays and between the PCR and culture assays (kappa coefficients ranging from 0.67 to 0.87), while there was poor to fair agreement between the results of the Transia Card Salmonella assay and the other methods (kappa coefficients ranging from 0.28 to 0.32). Overall, results showed that the PCR-based assays were more sensitive than the culture method, and the culture and PCR-based assays were more specific than the immunoassay for detection of Salmonella in ground chicken, turkey, and beef due to the occurrence of false positive results using the immunoassay. PMID:14580395

Fratamico, Pina M

2003-10-01

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Effects of feed supplementation with specific hen egg yolk antibody (immunoglobin Y) on Salmonella species cecal colonization and growth performances of challenged broiler chickens.  

UK PubMed Central (United Kingdom)

Anti-Salmonella spp. egg yolk antibodies (IgY) simultaneously directed against Salmonella Enteritidis and Salmonella Typhimurium were tested to determine if their inclusion in feed decreased Salmonella spp. cecal colonization in experimentally infected broiler chickens. Egg yolk powder (EYP) was obtained by freeze-drying egg yolks containing anti-Salmonella spp. Immunoglobin Y was included in feed at 5 levels of concentration (0 to 5%). Feeds were formulated to similar nutrient levels and provided for ad libitum intake from d 1 to 28. Three days after initiation of feed treatments (d 4), chickens were co-challenged with equal numbers of Salmonella Enteritidis and Salmonella Typhimurium (2x10(6) cfu/bird). Cecal samples were recovered weekly over the experimental period (d 7 to 28) to enumerate Salmonella spp. The effect of anti-Salmonella spp. IgY feed supplementation on growth performance of infected chickens was also evaluated during the same period. In comparison with the positive control treatment (PC), treatments involving EYP (T1, T2, T3, T4, and T5), whether containing anti-Salmonella spp. IgY or not, significantly improved (P<0.05) the growth performance of challenged chickens, but without reaching the performance levels of nonchallenged chickens (NC1 and NC2). However, no link can be established between the enhancement in growth performance of challenged birds and their contamination levels by Salmonella because in-feed incorporation of EYP had no significant effect on cecal colonization by Salmonella. Furthermore, the comparison of the 5 anti-Salmonella spp. IgY concentration levels in feed did not reveal any anti-Salmonella spp. IgY concentration effect on growth performance and Salmonella cecal colonization. These results suggest that anti-Salmonella spp. IgY would undergo denaturation and degradation after their passage through the animal gastrointestinal tract and reveal that components of EYP other than specific antibodies have a beneficial effect on growth performance.

Chalghoumi R; Marcq C; Théwis A; Portetelle D; Beckers Y

2009-10-01

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Detección de Salmonella spp. en melón Cantaloupe en unidades de producción y unidad de empaque/ Detection of Salmonella spp. on Cantaloupe melon production units and packaging facility  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El melón Cantaloupe (Cucumis melo L.) grupo reticulatus precortado, proveniente del estado de Guerrero, México, se ha asociado con brotes de salmonelosis en Estados Unidos de América y Canadá, por lo que las exportaciones de melón, a estos países, se suspendieron en 2001. En este trabajo se evaluó la condición sanitaria del melón Cantaloupe, con la detección e identificación de Salmonella, en dos unidades de producción y una unidad de empaque en Zirándaro de (more) los Chávez, Guerrero. Se analizaron 100 melones Cantaloupe (50 de las unidades de producción y 50 de la unidad de empaque), recolectados en enero y abril de 2005, mediante métodos bacteriológicos convencionales y el crecimiento en medios selectivos para la detección de Salmonella, como indicador de contaminación fecal. La proporción de melones con presencia de Salmonella spp. fue 4%, en una de las unidades de producción y 20% en la unidad de empaque. Salmonella se detectó en frutos irrigados con agua de río filtrada pero no clorada y manejados por trabajadores con poca higiene. En pruebas de reacción en cadena de la polimerasa (PCR), dos de seis cepas presuntivas de Salmonella dieron amplificaciones positivas con el par de iniciadores Sal-3 y Sal-4 e invA-1 e invA-2; de las otras cuatro, solo dieron amplificación positiva con invA-1 e invA-2. Estos resultados sugieren que en la región de Zirándaro de los Chávez se tiene más de un serotipo de Salmonella y evidencian la importancia de implementar programas preventivos para asegurar la calidad sanitaria del melón Cantaloupe. Abstract in english Fresh Cantaloupe melons (Cucumis melo L.) group reticulatus coming from the state of Guerrero, Mexico, have been associated with outbreaks of salmonellosis in the United States of America and Canada. These countries suspended the importations of Cantaloupe melon from Mexico due to the outbreaks in 2001. This study evaluated the food safety quality of Cantaloupe melon, with the detection and identification of Salmonella in two production units and a packing facility unit i (more) n Zirándaro de los Chávez, Guerrero. 100 Cantaloupe melons (50 of the production units and 50 of the packaging unit), collected in January and April 2005, were analyzed by conventional bacteriological methods and growth in selective media for detection of Salmonella, as an indicator of fecal contamination. The proportion of melons with presence of Salmonella was 4%, in one of the field production units and 20% in the packing unit. Salmonella was detected in fruits irrigated with filtered but not chlorinated river water and handled by workers with poor hygiene. Characterization by polymerase chain reaction (PCR) demonstrated that, two of six strains of presumptive Salmonella gave positive amplifications with the pair of primers Sal-3 and Sal-4 as with invA-1and invA-2. For four other isolates only two were observed with invA-1 and invA-2. These results suggest that in the region of Zirándaro de los Chávez there are more than one serotype of Salmonella, and demonstrate the importance of implementing prevention programs to ensure the sanitary quality of Cantaloupe melon.

Morales-Hernández, Lucía; Hernández-Anguiano, Ana María; Cháidez-Quiroz, Cristóbal; Rendón-Sánchez, Gilberto; V. Suslow, Trevor

2009-06-01

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A rapid strip immunoblot assay for the specific detection of Salmonella enteritidis infection in chickens.  

Science.gov (United States)

A rapid strip immunoblot assay (RSIA) was developed using recombinant SEF14 antigen. The rSEF14-RSIA was very specific in detecting antibodies to Salmonella enteritidis in chickens. When serum samples obtained from groups of chickens (N = 5) inoculated with six different Salmonella serovars were tested in rSEF14-RSIA, only serum samples obtained from S. enteritidis inoculated birds reacted with rSEF14 antigen except for a group of chickens that had been inoculated with S. dublin. To assess the sensitivity of the rSEF14-RSIA, groups of chickens were inoculated with either 10(4) cfu or 10(10) cfu of S. enteritidis and the serum and egg yolk were analyzed for SEF14 antibodies. By 1 week after infection 66-78% of chickens were found positive for SEF14 antibodies in the serum and the number of positive birds increased subsequently to 89-100%. The S. enteritidis specific antibodies appeared as early as 6 days after infection in the egg yolk of infected chickens. The antibodies to SEF14 in both the serum and egg yolk persisted for at least 7 weeks after infection in a significant proportion of chickens. Our results suggest that rSEF14-RSIA can be a practical and efficient screening test for identifying S. enteritidis infected chickens. PMID:10598114

Rajashekara, G; Wanduragala, D; Halvorson, D A; Nagaraja, K V

1999-12-01

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Importance of the serovar-specific plasmid for virulence of salmonella strains in calves.  

Science.gov (United States)

To evaluate the influence of serovar-specific plasmids on salmonella virulence in calves, experiments were performed involving infection, by the oral route, with mixtures of strains containing equal counts of a plasmid-carrying and a plasmid-free strain of the same serovar. The concentration ratio between the plasmid-carrying and the plasmid-free strain which had developed in the organs of the infected animals was used for a comparative evaluation of virulence and pathogenetic behaviour of the strains. While in the S. typhimurium strains studied, the presence of the plasmid was accompanied by a significantly increased colonization and multiplication of the agent in the host's body, examination of S. enteritidis and S. dublin revealed that the plasmid-free strains exhibited identical or even significantly higher bacterial counts than the plasmid-carrying strains in organs. The fact that plasmid-free salmonella strains with a high virulence for calves have been found demonstrates that the presence of a serovar-specific plasmid is not an indispensable requirement for the development of salmonellosis in calves. PMID:9361383

Steinbach, G; Helmuth, R; Koch, H; Methner, U; Meyer, H

1997-10-01

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

UK PubMed Central (United Kingdom)

Defensins are important antimicrobial effector peptides of the innate immune system, which provides protection against bacterial infections in the intestine. Salmonella Choleraesuis and Salmonella Typhimurium are the most commonly isolated serovars in pig, but disease outcome is dependent on the Salmonella serovar. These infections are a serious problem for the swine industry and are also posing a major threat to public health because of Salmonella-related food-borne illnesses in human. To understand the innate immune response of pigs upon Salmonella infections, we studied the effect of these Salmonella serovars on defensin gene expression in the porcine ileal epithelial cell line IPEC-J2. With the use of scanning electron microscopy, we first visualized the surface characteristics of this cell line, and captured the invasion of Salmonella into the epithelial cell. Gene expression levels of porcine beta-defensin 1 and 2 were both induced upon S. Typhimurium infection but S. Choleraesuis had no effect. Invasion, adhesion and defensin susceptibility of both serovars were similar, which could not explain the observed difference in host response to these Salmonellae. In addition, induction of defensins was dependent on viability of S. Typhimurium, since Salmonella cell- or secreted components had no effect on defensin gene expression. These results provide further insight into the porcine innate immune response towards Salmonella infections, and could partially explain the different epidemiology of Salmonella infections in pig.

Veldhuizen EJ; Koomen I; Ultee T; van Dijk A; Haagsman HP

2009-04-01

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Detection of Salmonella strain by rapid-cycle multiplex PCR  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction and objective: Salmonellosis is responsible for large numbers of infections in both humans and animals. Conventional methods of isolation of Salmonella strains take 4-7 days to complete and are therefore laborious and require substantial manpower. Our main objective was to develop a rapid detection method using shortened PCR cycles in a conventional thermal cyclers and fast electrophoresis for Salmonella.Materials and methods: The PCR primers for tyv (rfbE), prt (rfbS) and invA, genes were used for the rapid identification of S. enterica serovars typhi and paratyphi A, with rapid and short cycles of multiplex PCR. By using very fast and simple DNA extraction method in 10mins, rapid PCR cycles with total times of 35mins and rapid electrophoresis procedure with simple and very cheap buffer in 15mins we were able to separate the PCR products. Results: All references and clinical isolates of Salmonella serovars typhi and paratyphi were accurately identified. Specificity analysis revealed no cross reaction with other enterobacterial strains. The sensitivity of the assay was 1-10 cells. The total time of multiplex PCR from sample preparation to final result is 45 to 50mins.Conclusion: These data indicate that the specificity and sensitivity of optimized rapid cycle multiplex PCR is a potentially valuable tool for rapid diagnosis of S. typhi using a conventional thermal cycler. This method cut the time of a PCR reaction from 3.5h to less than 60mins. These findings could also be applied to other PCR programs detecting various genes allowing researchers to significantly shorten their PCR reaction times.

Ali Karami; Zeynab Ahmadi; Zahra Safiri; Fateme Pourali

2011-01-01

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[Interaction of antibodies of different immunoglobulin classes with specific O-antigens and Salmonella haptens].  

Science.gov (United States)

A study was made of the neutralizing properties of antisalmonella antibodies belonging to different immunoglobulin classes in respect to specific O-antigen (Lipopolysaccharide S. anatum) and haptens of salmonellae. In comparison with IgM-antibodies, IgG-antibodies were more stable bound not only with the univalent trisaccharide determinant, but also with the polysaccharide. However, in regard to the lipopolysaccharide complex the neutralizing activity of IgM- and IgG-antibodies was about the same; IgA-antibodies possessed the greatest neutralizing activity with respect to all the antigenic preparations used. The minimal neutralizing dose of the antigen and haptens increased with the reduction of the size of their molecule. A marked heterogeneity of antibodies of each of the immunoglobulin classes by their antigen-neutralizing properties was revealed in individual sera. PMID:358691

Tendetnik, Iu Ia; Ovcharova, N M

1978-04-01

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[Interaction of antibodies of different immunoglobulin classes with specific O-antigens and Salmonella haptens  

UK PubMed Central (United Kingdom)

A study was made of the neutralizing properties of antisalmonella antibodies belonging to different immunoglobulin classes in respect to specific O-antigen (Lipopolysaccharide S. anatum) and haptens of salmonellae. In comparison with IgM-antibodies, IgG-antibodies were more stable bound not only with the univalent trisaccharide determinant, but also with the polysaccharide. However, in regard to the lipopolysaccharide complex the neutralizing activity of IgM- and IgG-antibodies was about the same; IgA-antibodies possessed the greatest neutralizing activity with respect to all the antigenic preparations used. The minimal neutralizing dose of the antigen and haptens increased with the reduction of the size of their molecule. A marked heterogeneity of antibodies of each of the immunoglobulin classes by their antigen-neutralizing properties was revealed in individual sera.

Tendetnik IuIa; Ovcharova NM

1978-04-01

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Highly Specific and Cost-Efficient Detection of Salmonella Paratyphi A Combining Aptamers with Single-Walled Carbon Nanotubes  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a panel of single-stranded DNA aptamers with high affinity and specificity against Salmonella Paratyphi A was selected from an enriched oligonucleotide pool by a whole-cell-Systematic Evolution of Ligands by Exponential Enrichment (SELEX) procedure, during which four other Salmonella serovars were used as counter-selection targets. It was determined through a fluorescence assay that the selected aptamers had high binding ability and specificity to this pathogen. The dissociation constant of these aptamers were up to nanomolar range, and aptamer Apt22 with the lowest Kd (47 ± 3 nM) was used in cell imaging experiments. To detect this bacteria with high specificity and cost-efficiently, a novel useful detection method was also constructed based on the noncovalent self-assembly of single-walled carbon nanotubes (SWNTs) and DNAzyme-labeled aptamer detection probes. The amounts of target bacteria could be quantified by exploiting chemoluminescence intensity changes at 420 nm and the detection limit of the method was 103 cfu/mL. This study demonstrated the applicability of Salmonella specific aptamers and their potential for use in the detection of Salmonella in food, clinical and environmental samples.

Ming Yang; Zhihui Peng; Yi Ning; Yongzhe Chen; Qin Zhou; Le Deng

2013-01-01

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Highly Specific and Cost-Efficient Detection of Salmonella Paratyphi A Combining Aptamers with Single-Walled Carbon Nanotubes  

Science.gov (United States)

In this paper, a panel of single-stranded DNA aptamers with high affinity and specificity against Salmonella Paratyphi A was selected from an enriched oligonucleotide pool by a whole-cell-Systematic Evolution of Ligands by Exponential Enrichment (SELEX) procedure, during which four other Salmonella serovars were used as counter-selection targets. It was determined through a fluorescence assay that the selected aptamers had high binding ability and specificity to this pathogen. The dissociation constant of these aptamers were up to nanomolar range, and aptamer Apt22 with the lowest Kd (47 ± 3 nM) was used in cell imaging experiments. To detect this bacteria with high specificity and cost-efficiently, a novel useful detection method was also constructed based on the noncovalent self-assembly of single-walled carbon nanotubes (SWNTs) and DNAzyme-labeled aptamer detection probes. The amounts of target bacteria could be quantified by exploiting chemoluminescence intensity changes at 420 nm and the detection limit of the method was 103 cfu/mL. This study demonstrated the applicability of Salmonella specific aptamers and their potential for use in the detection of Salmonella in food, clinical and environmental samples.

Yang, Ming; Peng, Zhihui; Ning, Yi; Chen, Yongzhe; Zhou, Qin; Deng, Le

2013-01-01

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COLONIZATION OF SPECIFIC REGIONS OF THE REPRODUCTIVE TRACT AND DEPOSITION AT DIFFERENT LOCATIONS INSIDE EGGS LAID BY HENS INFECTED WITH SALMONELLA ENTERITIDIS OR SALMONELLA HEIDELBERG  

Science.gov (United States)

Internal contamination of eggs by Salmonella enteritidis has been a significant source of human illness for several decades and is the focus of a recently proposed FDA regulatory plan. Salmonella heidelberg has also been identified as an egg-transmitted human pathogen. The deposition of Salmonella s...

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Interlaboratory diagnostic accuracy of a Salmonella specific PCR-based method  

DEFF Research Database (Denmark)

A collaborative study involving four European laboratories was conducted to investigate the diagnostic accuracy of a Salmonella specific PCR-based method, which was evaluated within the European FOOD-PCR project (http://www.pcr.dk). Each laboratory analysed by the PCR a set of independent obtained presumably naturally contaminated samples and compared the results with the microbiological culture method. The PCR-based method comprised a preenrichment step in buffered peptone water followed by a thermal cell lysis using a closed tube resin-based method. Artificially contaminated minced beef and whole broiler carcass-rinse resulted in a detection limit of less than 5 cells per 25 g meat or 100 ml broiler rinse. A total of 435 samples from four countries, including pig carcass swabs (n = 285), whole broiler carcass-rinse (n = 25), various raw meat (n = 33), and environmental samples (n = 92) were investigated. The interlaboratory diagnostic accuracy, i.e. diagnostic specificity and sensitivity, was shown to be 97.5%. The co-amplification of an internal amplification control indicated possible inhibitory substances derived from the sample. This work can contribute to the quality assurance of PCR-based diagnostic methods and is currently proposed as international standard document.

Malorny, B.; Hoorfar, Jeffrey

2003-01-01

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Molecular characterization of Salmonella strains in individuals with acute diarrhea syndrome in the State of Sucre, Venezuela Caracterização molecular de cepas de Salmonella em indivíduos com síndrome da diarreia aguda no Estado de Sucre, Venezuela  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUCTION:In Venezuela, acute diarrheic syndrome (ADS) is a primary cause of morbi-mortality, often involving the Salmonella genus. Salmonella infections are associated with acute gastroenteritis, one of the most common alimentary intoxications, and caused by the consumption of contaminated water and food, especially meat. METHODS: Conventional and molecular methods were used to detect Salmonella strains from 330 fecal samples from individuals of different ages and both sexes with ADS. Polymerase chain reaction (PCR) was used for the molecular characterization of Salmonella, using invA, sefA, and fliC genes for the identification of this genus and the serotypes Enteritidis and Typhimurium, respectively. RESULTS: The highest frequency of individuals with ADS was found in children 0-2 years old (39.4%), and the overall frequency of positive coprocultures was 76.9%. A total of 14 (4.2%) strains were biochemically and immunologically identified as Salmonella enterica subsp. enterica, of which 7 were classified as belonging to the Enteritidis serotype, 4 to the Typhimurium serotype, and 3 to other serotypes. The S. enterica strains were distributed more frequently in the age groups 3-4 and 9-10 years old. CONCLUSIONS: The molecular characterization method used proved to be highly specific for the typing of S. enterica strains using DNA extracted from both the isolated colonies and selective enrichment broths directly inoculated with fecal samples, thus representing a complementary tool for the detection and identification of ADS-causing bacteria.INTRODUÇÃO: Na Venezuela, síndrome da diarreia aguda (SDA) é a principal causa de mórbi-mortalidade, muitas vezes envolvem o gênero Salmonella. Infecções por Salmonella são associadas com gastroenterite aguda, uma das mais comuns intoxicações alimentares causada pelo consumo de água e alimentos contaminados, principalmente carne. MÉTODOS: Métodos convencionais e moleculares foram usados para detectar cepas de Salmonella em 330 amostras de fezes de indivíduos com SDA de diferentes idades e ambos os sexos. A reação em cadeia da polimerase (PCR) foi utilizada para a caracterização molecular de genes Salmonella invA, sefA e fliC para identificar o gênero e os sorotipos Enteritidis e Typhimurium, respectivamente. RESULTADOS: A maior frequência de indivíduos com SDA foi encontrada em crianças de 0-2 (39,4%) anos, e a frequência total de culturas de fezes positiva foi de 76,9%. Um total de 14 (4,2%) cepas foram bioquímica e imunologicamente identificados como Salmonella enterica subsp. enterica, dos quais 7 foram classificados como pertencentes ao sorotipo Enteritidis, Typhimurium sorotipo 4 e 3 para outros sorotipos. Cepas S. enterica foram distribuídas mais frequentemente em grupos de 3-4 e 9-10 anos de idade. CONCLUSÕES: O método de caracterização molecular usada provou ser altamente específico para tipificar as estirpes dos S. enterica usando tanto DNA extraído de colônias isoladas e direta e caldos de enriquecimento seletivo inoculados com amostras fecais, o que representa uma ferramenta complementar para a detecção e identificação de bactérias que causam a SDA.

Hectorina Rodulfo; Marcos De Donato; Jesús Luiggi; Elvia Michelli; Adriana Millán; Miriam Michelli

2012-01-01

 
 
 
 
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Primers with 5' flaps improve the efficiency and sensitivity of multiplex PCR assays for the detection of Salmonella and Escherichia coli O157:H7.  

UK PubMed Central (United Kingdom)

Foodborne illnesses caused by Salmonella enterica and Escherichia coli O157:H7 are worldwide health concerns. Rapid, sensitive, and robust detection of these pathogens in foods and in clinical and environmental samples is essential for routine food quality testing, effective surveillance, and outbreak investigations. The aim of this study was to evaluate the effect on PCR sensitivity of adding a short, AT-rich overhanging nucleotide sequence (flap) to the 5' end of PCR primers specific for the detection of Salmonella and E. coli O157:H7. Primers targeting the invA gene of Salmonella and the rfbE gene of E. coli O157:H7 were synthesized with or without a 12-bp, AT-rich 5' flap (5'-AATAAATCATAA-3'). Singleplex PCR, multiplex PCR, and real-time PCR sensitivity assays were conducted using purified bacterial genomic DNA and crude cell lysates of bacterial cells. The effect of background flora on detection was evaluated by spiking tomato and jalapeno pepper surface washes with E. coli O157:H7 and Salmonella Saintpaul. When targeting individual pathogens, end-point PCR assays using flap-amended primers were more efficient than nonamended primers, with 20.4 and 23.5% increases in amplicon yield for Salmonella and E. coli O157:H7, respectively. In multiplex PCR assays, a 10- to 100-fold increase in detection sensitivity was observed when the primer flap sequence was incorporated. This improvement in both singleplex and multiplex PCR efficiency and sensitivity can lead to improved Salmonella and E. coli O157:H7 detection.

Timmons C; Dobhal S; Fletcher J; Ma LM

2013-04-01

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

UK PubMed Central (United Kingdom)

Salmonella can contaminate finished products of butcher shops, mainly through cross-contamination of utensils exposed to raw materials. To identify the main sources of contamination with this foodborne pathogen in four butcher shop environments, surface samples were obtained from employees' hands, cutting boards, knives, floor of the refrigeration room, meat grinders, and meat tenderizers (32 samples per area) and analyzed for Salmonella using the International Organization for Standardization method 6579, with modifications. Suspect isolates were identified by PCR (targeting ompC), and confirmed Salmonella isolates were subjected to pulsed-field gel electrophoresis (after treatment with restriction enzyme XbaI), analyzed for the presence of virulence genes (invA, sefA, and spvC), and screened for resistance to 12 antimicrobials. Salmonella isolates was identified only on cutting boards (five samples) from three butcher shops. Fifteen isolates were confirmed as Salmonella belonging to four pulse types (similarity of 71.1 to 100%). The invA gene was detected in 13 isolates, and the sefA was found in 8 isolates; no isolate carried spvC. All tested isolates were resistant to clindamycin and sensitive to amikacin and cefotaxine, and all isolates were resistant to at least 3 of the 12 antimicrobials tested. The results indicate the importance of cutting boards as a source of Salmonella contamination in butcher shops. The presence of multidrug-resistant Salmonella strains possessing virulence genes highlights the health risks for consumers.

Cossi MV; Burin RC; Lopes DA; Dias MR; Castilho NP; de Arruda Pinto PS; Nero LA

2013-09-01

63

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

Science.gov (United States)

The goal of this study was to determine the effects of various levels of gamma irradiation on the phenotypic characteristics of 20 strains of Salmonella Enteritidis inoculated separately into specific-pathogen-free shell eggs. Bacterial strains were inoculated into egg yolks and exposed to (60)Co radiation at doses of 0.49 to 5.0 kGy. The eggs were maintained at 25°C and analyzed for the presence of Salmonella on days 1, 2, 4, and 7, and the recovered Salmonella isolates were characterized biochemically. All strains were resistant to doses of 0.49, 0.54, 0.59, 0.8, and 1 kGy; colony counts were ?10(5) CFU/ml of egg yolk except for one strain, which was detected at 96 h and at 7 days after irradiation at 1 kGy, with a population reduction of 2 log CFU/ml. For the other evaluated doses, 12 strains (60.0%) were resistant at 1.5 kGy and 7 strains (35.0%) were resistant at 3.0 kGy. Among all analyzed strains, 5.0 kGy was more effective for reducing and/or eliminating the inoculated bacteria; only two (10%) strains were resistant to this level of irradiation. Salmonella colony counts were significantly reduced (P hydrogen sulfide production occurred in some strains after irradiation independent of dose and postirradiation storage time. Increases in antibiotic susceptibility also occurred: seven strains became sensitive to ?-lactams, two strains became sensitive to antifolates, and one strain each became sensitive to fluoroquinolone, phenicol, nitrofurans, tetracyclines, and aminoglycosides. The results indicate that up to 5.0 kGy of radiation applied to shell eggs inoculated with Salmonella Enteritidis at 4 log CFU per egg is not sufficient for complete elimination of this pathogen from this food matrix. PMID:22186042

Rodrigues, Elizabeth C P; Souza, Mauro C L; Toledo, Sandro S; Barbosa, Celso G; Reis, Eliane M F; Rodrigues, Dalia P; Lázaro, Norma S

2011-12-01

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

Directory of Open Access Journals (Sweden)

Full Text Available This study was performed to evaluate the adaption of the impedimetric method to detect the lytic infection by Salmonella-specific bacteriophages and to provide a higher selectivity to this rapid method in detecting Salmonella spp. by using specific agents. Three bacteriophages and twelve strains of Salmonella spp. were tested. Each of the twelve strains was used separately to inoculate TSB together with each one of the phages. The inoculum concentration was between 106 and 107?cfu/mL, at a cell: phage ratio of 1 : 100. From the sample analysis, based on conductance (G) measurements (37°C), the infection could be detected, by observation of both detection-time delay and distinct curve trends. The main conclusions were that kinetic detection by impedance microbiology with phage typing constitutes a method of determining whether a test microorganism is sensitive to the bacteriophage and a method to evaluate whether a lytic bacteriophage is present in a sample, by affecting bacterial growth rate/metabolic change.

Lara R. P. Amorim; Joana G. L. Silva; Paul A. Gibbs; Paula C. Teixeira

2009-01-01

65

Production of human rotavirus and Salmonella antigens in plants and elicitation of fljB-specific humoral responses in mice.  

UK PubMed Central (United Kingdom)

A Nicotiana benthamiana transient expression system was used to express single antigen and dimeric combinations of the human rotavirus (HRV) VP7 and a truncated VP4 (VP4?) proteins fused with Salmonella typhimurium's flagellin fljB subunit. Immunoblot analyses using rabbit antibodies generated against these proteins demonstrated that the constructs were successfully expressed with yields ranging from 0.85 to 31.97 ?g of recombinant protein per gram of fresh leaf tissue. Expressing the single and dimeric antigens has no effect on plant growth and development except for VP7 and VP4?::VP7, which show mild necrotic lesions. Immunization of mice with proteins from leaves transformed with constructs bearing the fljB moiety elicited an fljB-specific humoral response. The Nicotiana benthamiana transient system is efficient to express multiple combinations of pathogen proteins and demonstrates the potential of generating a Salmonella typhimurium subunit vaccine in plants.

Bergeron-Sandoval LP; Girard A; Ouellet F; Archambault D; Sarhan F

2011-02-01

66

Human and bovine adenoviruses for the detection of source-specific fecal pollution in coastal waters in Australia.  

UK PubMed Central (United Kingdom)

In this study, the host-specificity and -sensitivity of human- and bovine-specific adenoviruses (HS-AVs and BS-AVs) were evaluated by testing wastewater/fecal samples from various animal species in Southeast, Queensland, Australia. The overall specificity and sensitivity of the HS-AVs marker were 1.0 and 0.78, respectively. These figures for the BS-AVs were 1.0 and 0.73, respectively. Twenty environmental water samples were collected during wet conditions and 20 samples were colleted during dry conditions from the Maroochy Coastal River and tested for the presence of fecal indicator bacteria (FIB), host-specific viral markers, zoonotic bacterial and protozoan pathogens using PCR/qPCR. The concentrations of FIB in water samples collected after wet conditions were generally higher compared to dry conditions. HS-AVs was detected in 20% water samples collected during wet conditions and whereas BS-AVs was detected in both wet (i.e., 10%) and dry (i.e., 10%) conditions. Both Campylobacter jejuni mapA and Salmonella invA genes detected in 10% samples collected during dry conditions. The concentrations of Salmonella invA ranged between 3.5 × 10(2) and 4.3 × 10(2) genomic copies per 500 ml of water Giardia lamblia ?-giardin gene was detected only in one sample (5%) collected during the dry conditions. Weak or significant correlations were observed between FIB with viral markers and zoonotic pathogens. However, during dry conditions, no significant correlations were observed between FIB concentrations with viral markers and zoonotic pathogens. The prevalence of HS-AVs in samples collected from the study river suggests that the quality of water is affected by human fecal pollution and as well as bovine fecal pollution. The results suggest that HS-AVs and BS-AVs detection using PCR could be a useful tool for the identification of human sourced fecal pollution in coastal waters.

Ahmed W; Goonetilleke A; Gardner T

2010-09-01

67

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

UK PubMed Central (United Kingdom)

The goal of this study was to determine the effects of various levels of gamma irradiation on the phenotypic characteristics of 20 strains of Salmonella Enteritidis inoculated separately into specific-pathogen-free shell eggs. Bacterial strains were inoculated into egg yolks and exposed to (60)Co radiation at doses of 0.49 to 5.0 kGy. The eggs were maintained at 25°C and analyzed for the presence of Salmonella on days 1, 2, 4, and 7, and the recovered Salmonella isolates were characterized biochemically. All strains were resistant to doses of 0.49, 0.54, 0.59, 0.8, and 1 kGy; colony counts were ?10(5) CFU/ml of egg yolk except for one strain, which was detected at 96 h and at 7 days after irradiation at 1 kGy, with a population reduction of 2 log CFU/ml. For the other evaluated doses, 12 strains (60.0%) were resistant at 1.5 kGy and 7 strains (35.0%) were resistant at 3.0 kGy. Among all analyzed strains, 5.0 kGy was more effective for reducing and/or eliminating the inoculated bacteria; only two (10%) strains were resistant to this level of irradiation. Salmonella colony counts were significantly reduced (P < 0.01) with increasing doses from the day 1 to 7 of observation, when microbial growth peaked. Loss of mobility, lactose fermentation, citrate utilization, and hydrogen sulfide production occurred in some strains after irradiation independent of dose and postirradiation storage time. Increases in antibiotic susceptibility also occurred: seven strains became sensitive to ?-lactams, two strains became sensitive to antifolates, and one strain each became sensitive to fluoroquinolone, phenicol, nitrofurans, tetracyclines, and aminoglycosides. The results indicate that up to 5.0 kGy of radiation applied to shell eggs inoculated with Salmonella Enteritidis at 4 log CFU per egg is not sufficient for complete elimination of this pathogen from this food matrix.

Rodrigues EC; Souza MC; Toledo SS; Barbosa CG; Reis EM; Rodrigues DP; Lázaro NS

2011-12-01

68

Biomagnetic separation of Salmonella Typhimurium with high affine and specific ligand peptides isolated by phage display technique  

Energy Technology Data Exchange (ETDEWEB)

Analyses of food-borne pathogens are of great importance in order to minimize the health risk for customers. Thus, very sensitive and rapid detection methods are required. Current conventional culture techniques are very time consuming. Modern immunoassays and biochemical analysis also require pre-enrichment steps resulting in a turnaround time of at least 24 h. Biomagnetic separation (BMS) is a promising more rapid method. In this study we describe the isolation of high affine and specific peptides from a phage-peptide library, which combined with BMS allows the detection of Salmonella spp. with a similar sensitivity as that of immunomagnetic separation using antibodies.

Steingroewer, Juliane [Institute of Food Technology and Bioprocess Engineering, Technische Universitaet Dresden, D-01062 Dresden (Germany)]. E-mail: juliane.steingroewer@tu-dresden.de; Bley, Thomas [Institute of Food Technology and Bioprocess Engineering, Technische Universitaet Dresden, D-01062 Dresden (Germany); Bergemann, Christian [Chemicell GmbH, D-10823, Berlin (Germany); Boschke, Elke [Institute of Food Technology and Bioprocess Engineering, Technische Universitaet Dresden, D-01062 Dresden (Germany)

2007-04-15

69

Biomagnetic separation of Salmonella Typhimurium with high affine and specific ligand peptides isolated by phage display technique  

International Nuclear Information System (INIS)

Analyses of food-borne pathogens are of great importance in order to minimize the health risk for customers. Thus, very sensitive and rapid detection methods are required. Current conventional culture techniques are very time consuming. Modern immunoassays and biochemical analysis also require pre-enrichment steps resulting in a turnaround time of at least 24 h. Biomagnetic separation (BMS) is a promising more rapid method. In this study we describe the isolation of high affine and specific peptides from a phage-peptide library, which combined with BMS allows the detection of Salmonella spp. with a similar sensitivity as that of immunomagnetic separation using antibodies.

2007-01-01

70

Isolation of scFv fragments specific to OmpD of Salmonella Typhimurium.  

UK PubMed Central (United Kingdom)

Pork meat is one of the major sources for human infections with Salmonella enterica subspecies enterica serovars. Further, zoonoses caused by S. enterica subspecies enterica serovars are responsible for substantial economical losses in industrial countries. Quick and reliable detection of this infection is urgently needed to improve consumer security. Due to its capability to identify infections independent of the species, a competitive ELISA is the preferable method for the detection of anti-Salmonella antibodies in serum. Recombinant antibody fragments (scFvs) were isolated from the naive human antibody gene library HAL7 by phage display. Recombinant produced outer membrane protein D (OmpD) of Salmonella Typhimurium was used as antigen. The characterization of the isolated single chain Fv (scFv) antibodies was done by enzyme-linked immunosorbent assay (ELISA), immunoblot, sequencing, epitope mapping and size exclusion chromatography (SEC). The detection of anti-OmpD IgGs in swine sera by competitive ELISA was shown in a proof of principle concept. Furthermore, the developed competitive ELISA would be compatible to a recently published DIVA vaccine, allow to distinguish between infected and vaccinated pigs.

Meyer T; Stratmann-Selke J; Meens J; Schirrmann T; Gerlach GF; Frank R; Dübel S; Strutzberg-Minder K; Hust M

2011-01-01

71

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

UK PubMed Central (United Kingdom)

Species belonging to the genus Salmonella are an important cause of enteric fevers, gastroenteritis, and septicemia, and the pathogens are commonly transmitted through contaminated food. In this study, polymerase chain reaction (PCR) amplification of a 287-bp region of the invA gene was compared to a microbiological technique to determine the presence of Salmonella in retail beef and in cantaloupe rinse samples. Both methods showed the same level of sensitivity, detecting 1 CFU/25 g of meat after enrichment for 24 h at 42 degrees C. The presence of Salmonella was determined in 50 commercial top sirloin beef samples that were not artificially inoculated. Three samples were positive by the microbiological method, and these samples and an additional sample were positive by the PCR. Both methods were also used to test surface rinses of cantaloupes collected from 4 farms in Nayarit, Mexico. Salmonella was detected by the microbiological method in 9 of 20 samples (45%), whereas the pathogen was detected by the PCR in 11 samples (55%). This study demonstrates the utility of the PCR targeting the invA gene to determine the presence of Salmonella spp. in beef and cantaloupe samples.

Gallegos-Robles MA; Morales-Loredo A; Alvarez-Ojeda G; Osuna-García JA; Martínez IO; Morales-Ramos LH; Fratamico P

2009-01-01

72

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

Science.gov (United States)

Species belonging to the genus Salmonella are an important cause of enteric fevers, gastroenteritis, and septicemia, and the pathogens are commonly transmitted through contaminated food. In this study, polymerase chain reaction (PCR) amplification of a 287-bp region of the invA gene was compared to a microbiological technique to determine the presence of Salmonella in retail beef and in cantaloupe rinse samples. Both methods showed the same level of sensitivity, detecting 1 CFU/25 g of meat after enrichment for 24 h at 42 degrees C. The presence of Salmonella was determined in 50 commercial top sirloin beef samples that were not artificially inoculated. Three samples were positive by the microbiological method, and these samples and an additional sample were positive by the PCR. Both methods were also used to test surface rinses of cantaloupes collected from 4 farms in Nayarit, Mexico. Salmonella was detected by the microbiological method in 9 of 20 samples (45%), whereas the pathogen was detected by the PCR in 11 samples (55%). This study demonstrates the utility of the PCR targeting the invA gene to determine the presence of Salmonella spp. in beef and cantaloupe samples. PMID:19200105

Gallegos-Robles, M A; Morales-Loredo, A; Alvarez-Ojeda, G; Osuna-García, J A; Martínez, I O; Morales-Ramos, L H; Fratamico, P

73

Long tail fibres of the novel broad-host-range T-even bacteriophage S16 specifically recognize Salmonella OmpC.  

UK PubMed Central (United Kingdom)

We report isolation and characterization of the novel T4-like Salmonella bacteriophage vB_SenM-S16. S16 features a T-even morphology and a highly modified 160?kbp dsDNA genome with 36.9 mol % G+C, containing 269 putative coding sequences and three tRNA genes. S16 is a virulent phage, and exhibits a maximally broad host range within the genus Salmonella, but does not infect other bacteria. Synthesis of functional S16 full-length long tail fibre (LTF) in Escherichia coli was possible by coexpression of gp37 and gp38. Surface plasmon resonance analysis revealed nanomolar equilibrium affinity of the LTF to its receptor on Salmonella cells. We show that OmpC serves as primary binding ligand, and that S16 adsorption can be transferred to E.?coli by substitution of ompC with the Salmonella homologue. S16 also infects 'rough' Salmonella strains which are defective in lipopolysaccharide synthesis and/or its carbohydrate substitution, indicating that this interaction does not require an intact LPS structure. Altogether, its virulent nature, broad host range and apparent lack of host DNA transduction render S16 highly suitable for biocontrol of Salmonella in foods and animal production. The S16 LTF represents a highly specific affinity reagent useful for cell decoration and labelling, as well as bacterial immobilization and separation.

Marti R; Zurfluh K; Hagens S; Pianezzi J; Klumpp J; Loessner MJ

2013-02-01

74

Identification of Salmonella Typhimurium-specific DNA aptamers developed using whole-cell SELEX and FACS analysis.  

UK PubMed Central (United Kingdom)

Conventional methods for detection of infective organisms, such as Salmonella, are complicated and require multiple steps, and the need for rapid detection has increased. Biosensors show great potential for rapid detection of pathogens. In turn, aptamers have great potential for biosensor assay development, given their small size, ease of synthesis and labeling, lack of immunogenicity, a lower cost of production than antibodies, and high target specificity. In this study, ssDNA aptamers specific to Salmonella Typhimurium were obtained by a whole bacterium-based systematic evolution of ligands by exponential enrichment (SELEX) procedure and applied to probing S. Typhimurium. After 10 rounds of selection with S. Typhimurium as the target and S. Enteritidis, E. coli and S. aureus as counter targets, the highly enriched oligonucleic acid pool was sorted using flow cytometry. In total, 12 aptamer candidates from different families were sequenced and grouped. Fluorescent analysis demonstrated that aptamer C4 had particularly high binding affinity and selectivity; this aptamer was then further characterized.

Moon J; Kim G; Lee S; Park S

2013-08-01

75

Evaluation of the specificity of three enzyme-linked immunosorbent assays for detection of antibodies against Salmonella in bovine bulk milk  

Science.gov (United States)

Background The Swedish Salmonella control program has been running for decades and has resulted in a low prevalence of Salmonella in Swedish food producing animals. Routine bacteriology is used to detect Salmonella, however, bacteriology is time consuming, costly and has a low sensitivity. Different enzyme-linked immunosorbent assays (ELISAs) have been developed for detection of antibodies against Salmonella Dublin and S. Typhimurium in bovine bulk milk, individual milk samples as well as in sera. Screening bulk milk for antibodies against Salmonella spp. could improve the cost-effectiveness of the surveillance in Swedish dairy cattle, but as characteristics of tests may vary in different populations, tests should always be evaluated in the specific population where they will be used. Hence, the aim of this study was to evaluate the specificities of three bovine ELISAs when used to analyse bulk milk samples from Swedish dairy cattle. A second aim was to compare the performance of the two Dublin ELISAs tested. Methods Bulk milk samples for analysis were randomly selected from samples collected within the Swedish bulk milk sampling scheme and analyzed with the three ELISAs; a Danish in-house Dublin ELISA, PrioCHECK® Salmonella Ab bovine Dublin ELISA and PrioCHECK® Salmonella Ab bovine ELISA (hereafter named mixed ELISA). The specificities of the ELISAs were calculated assuming a disease-free status in Sweden i.e. that all test positive samples were assumed to be false positive results. This assumption can be used when a disease is known to be infrequent. Results The calculated specificities of the two Dublin ELISAs and the mixed ELISA, when using the producer’s recommended cut-off value of the corrected optic-density percent (ODC%) were 99.4% (95% Confidence Interval (CI): 98.8% -99.8%), 99.4% (95% CI: 98.8% -99.8%) and 97.9% (95% CI: 96.8% -98.7%), respectively. The correlation between the ODC% values of the two Dublin ELISAs was 0.83. Conclusions We conclude that the evaluated ELISAs have sufficiently high specificities to be used as supplement to bacteriological examinations in the Swedish Salmonella control program in cattle as well as a primary screening test in routine surveillance for S. Dublin.

2013-01-01

76

Evaluation of the specificity of three enzyme-linked immunosorbent assays for detection of antibodies against Salmonella in bovine bulk milk.  

UK PubMed Central (United Kingdom)

BACKGROUND: The Swedish Salmonella control program has been running for decades and has resulted in a low prevalence of Salmonella in Swedish food producing animals. Routine bacteriology is used to detect Salmonella, however, bacteriology is time consuming, costly and has a low sensitivity. Different enzyme-linked immunosorbent assays (ELISAs) have been developed for detection of antibodies against Salmonella Dublin and S. Typhimurium in bovine bulk milk, individual milk samples as well as in sera. Screening bulk milk for antibodies against Salmonella spp. could improve the cost-effectiveness of the surveillance in Swedish dairy cattle, but as characteristics of tests may vary in different populations, tests should always be evaluated in the specific population where they will be used. Hence, the aim of this study was to evaluate the specificities of three bovine ELISAs when used to analyse bulk milk samples from Swedish dairy cattle. A second aim was to compare the performance of the two Dublin ELISAs tested. METHODS: Bulk milk samples for analysis were randomly selected from samples collected within the Swedish bulk milk sampling scheme and analyzed with the three ELISAs; a Danish in-house Dublin ELISA, PrioCHECK(®) Salmonella Ab bovine Dublin ELISA and PrioCHECK(®) Salmonella Ab bovine ELISA (hereafter named mixed ELISA). The specificities of the ELISAs were calculated assuming a disease-free status in Sweden i.e. that all test positive samples were assumed to be false positive results. This assumption can be used when a disease is known to be infrequent. RESULTS: The calculated specificities of the two Dublin ELISAs and the mixed ELISA, when using the producer's recommended cut-off value of the corrected optic-density percent (ODC%) were 99.4% (95% Confidence Interval (CI): 98.8% -99.8%), 99.4% (95% CI: 98.8% -99.8%) and 97.9% (95% CI: 96.8% -98.7%), respectively. The correlation between the ODC% values of the two Dublin ELISAs was 0.83. CONCLUSIONS: We conclude that the evaluated ELISAs have sufficiently high specificities to be used as supplement to bacteriological examinations in the Swedish Salmonella control program in cattle as well as a primary screening test in routine surveillance for S. Dublin.

Nyman AK; Ågren EC; Bergström K; Wahlström H

2013-01-01

77

THE MUTATION SPECTRA OF DRINKING WATER SAMPLES USING THE BASE-SPECIFIC TA7000 STRAINS OF SALMONELLA IN THE MICROSUSPENSION ASSAY  

Science.gov (United States)

Previous studies showed that disinfected drinking water samples gave mutagenic spectra typical of halogenated furanones. In this study, we used the TA7000 base-¿specific Salmonella typhimurium tester strains to characterize water samples from two drinking water treatment plants (...

78

Standardization of a quantification method for Salmonella spp. and Shigella spp. in specific liquid media/ Estandarización de un método de recuento para Salmonella spp. y Shigella spp. en medios de cultivo líquidos especializados  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Introducción: La cloración es el método más usado para desinfectar aguas de consumo. La formación de subproductos cancerígenos y las intoxicaciones por manipulación directa en pequeñas comunidades, han motivado el estudio de procesos alternativos. Los procesos de oxidación avanzada (PAOS), han arrojado resultados prometedores, utilizando el indicador bacteriano Escherichia coli (E. coli), con el método recuento en placa. Sin embargo, también se ha demostrado qu (more) e E. coli es menos resistente a la desinfección que otras bacterias entéricas como Shigella y Salmonella y que estos procesos generan bacterias viables que no se cultivan durante el proceso, y no se descubren en medios sólidos. Objetivo: Estandarizar un método de recuento de Salmonella sp. y Shigella sp., en medios de cultivo líquidos especializados, que permita valorar de forma confiable el riesgo bacteriológico en procesos de desinfección PAOS. Métodos: En el presente trabajo se ensayaron y seleccionaron medios líquidos especializados, con los que se estandarizó el recuento de Salmonella sp. y Shigella sp., mediante un diseño experimental aleatorizado bifactorial y la prueba de comparaciones múltiples de Duncan. Resultados: Se encontró que el mejor caldo para recuperar a S. typhimurium a diferentes concentraciones, en cultivos puros y mezclas, fue el caldo Rappaport de Merck (RP). El caldo de enriquecimiento para entero bacterias de Oxoid (EE), permitió un buen crecimiento de las dos especies objeto de esta investigación. Lo cual sugiere el empleo de pruebas adicionales cuando se use caldo EE para NMP. Discusión: Se observó una variación en el recuento cuando se usaron cultivos puros, comparado con la obtenida a partir de mezclas de microorganismos. Sin embargo, S. typhimurium. y Shigella sonnei logran ser recuperadas de concentraciones mínimas en los caldos RP, respectivamente. Conclusión: Se pudo estandarizar un método de fácil aplicación a aguas y otros ambientes contaminados para recuento de Salmonella sp y Shigella sp. Los medios líquidos seleccionados fueron capaces de recuperar concentraciones de menos de 10 bacterias. Abstract in english Introduction: Chlorination is the most widely used disinfection process for drinking water production. The formation of chlorination carcinogenic by-products and chlorine intoxication by direct manipulation in small communities has motivated the study of alternative disinfection processes. In this sense, processes of advanced oxidation (PAOs) have yielded promising results. Escherichia coli (E. coli) is customarily used as faecal bacterial indicator to determine the effic (more) iency of disinfection processes. However, it has been shown that E. coli is less resistant to disinfection than other enteric bacteria such as Shigella spp. and Salmonella spp. Additionally, the viable non-culturable (VNC) state yields bacteria which are not detectable on many culture media. Objective: The main objective is to standardize a method for counting Salmonella spp. and Shigella spp. in specific liquid media to reliably quantify the bacteriological potential risk related to disinfection processes based on PAO. Methods: The study followed a randomized bi-factorial experimental design and the Duncan multiple comparison test. This design allowed the selection of specific liquid media to fittingly standardize the counting of Salmonella spp. and Shigella spp. Results: We found that the best broth for counting Salmonella typhimurium strain at different concentrations in pure and mixed cultures was the Rappaport broth RP, the EE broth also allowed growing the two bacterial species tested in this research. Nonetheless, the latter results suggest the use of additional tests for this particular broth. Discussion: There was a variation in the counting results when pure cultures were used compared to those obtained from mixtures of microorganisms. It was also noted that Salmonella typhimurium and Shigella sonnei, were recovered from minimal concentrations in both RP a

Rivera, Sandra Patricia; Flórez, Liliana Janeth; Sanabria, Janeth

2010-03-01

79

Both Hemolytic Anemia and Malaria Parasite-Specific Factors Increase Susceptibility to Nontyphoidal Salmonella enterica Serovar Typhimurium Infection in Mice?  

Science.gov (United States)

Severe pediatric malaria is an important risk factor for developing disseminated infections with nontyphoidal Salmonella serotypes (NTS). While recent animal studies on this subject are lacking, early work suggests that an increased risk for developing systemic NTS infection during malaria is caused by hemolytic anemia, which leads to reduced macrophage microbicidal activity. Here we established a model for oral Salmonella enterica serotype Typhimurium challenge in mice infected with Plasmodium yoelii nigeriensis. Initial characterization of this model showed that 5 days after coinoculation, P. yoelii nigeriensis infection increased the recovery of S. Typhimurium from liver and spleen by approximately 1,000-fold. The increased bacterial burden could be only partially recapitulated by antibody-mediated hemolysis, which increased the recovery of S. Typhimurium from liver and spleen by 10-fold. These data suggested that both hemolysis and P. yoelii nigeriensis-specific factors contributed to the increased susceptibility to S. Typhimurium. The mechanism by which hemolysis impaired resistance to S. Typhimurium was further investigated. In vitro, S. Typhimurium was recovered 24 h after infection of hemophagocytic macrophages in 2-fold-higher numbers than after infection of mock-treated macrophages, making it unlikely that reduced macrophage microbicidal activity was solely responsible for hemolysis-induced immunosuppression during malaria. Infection with P. yoelii nigeriensis, but not antibody-mediated hemolysis, reduced serum levels of interleukin-12p70 (IL-12p70) in response to S. Typhimurium challenge. Collectively, studies establishing a mouse model for this coinfection suggest that multiple distinct malaria-induced immune defects contribute to increased susceptibility to S. Typhimurium.

Roux, Christelle M.; Butler, Brian P.; Chau, Jennifer Y.; Paixao, Tatiane A.; Cheung, Kong Wai; Santos, Renato L.; Luckhart, Shirley; Tsolis, Renee M.

2010-01-01

80

Studies on the substrate specificity of a GDP-mannose pyrophosphorylase from Salmonella enterica  

Directory of Open Access Journals (Sweden)

Full Text Available A series of methoxy and deoxy derivatives of mannopyranose-1-phosphate (Manp-1P) were chemically synthesized, and their ability to be converted into the corresponding guanosine diphosphate mannopyranose (GDP-Manp) analogues by a pyrophosphorylase (GDP-ManPP) from Salmonella enterica was studied. Evaluation of methoxy analogues demonstrated that GDP-ManPP is intolerant of bulky substituents at the C-2, C-3, and C-4 positions, in turn suggesting that these positions are buried inside the enzyme active site. Additionally, both the 6-methoxy and 6-deoxy Manp-1P derivatives are good or moderate substrates for GDP-ManPP, thus indicating that the C-6 hydroxy group of the Manp-1P substrate is not required for binding to the enzyme. When taken into consideration with other previously published work, it appears that this enzyme has potential utility for the chemoenzymatic synthesis of GDP-Manp analogues, which are useful probes for studying enzymes that employ this sugar nucleotide as a substrate.

Lu Zou; Ruixiang Blake Zheng; Todd L. Lowary

2012-01-01

 
 
 
 
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THE USE OF THE ANTI-SALLMONELA SPECIFIC POLYCLONAL ANTIBODIES ISOLATED FROM HEN EGGS FOR INIBITING THE GROWING OF THE SALMONELLA GENUS BACTERIA  

Directory of Open Access Journals (Sweden)

Full Text Available The anti-Salmonella specific antibodies could be used in food andfeedstuffs for the control of the salmonellosis, with large applications.The emphasize of the ”in vitro” effect of the specific anti-Salmonellaantibodies on the development of Salmonella gallinarum culture wasthe aim of our paper. The use of the specific anti-Salmonellaantibodies reduces the bacterial development. Due to theagglutination on the antibodies from the culture media, the bacteriahave lower mobility and low opportunitry to rach the nutrients. Itdetermines the inhibation or reducing the bacteria multiplication. Theaddition of the specific antibodies inhibates the development of thesalmonella and reduces the risk of salmonellosis, if they are used asfood or feed additives.

CRISTE ADRIANA; CRISTE F.; NEGREA O.; DINEA MARIANA; PETRESCU I.

2007-01-01

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Analysis of expression of flagella by Salmonella enterica serotype typhimurium by monoclonal antibodies recognising both phase specific and common epitopes.  

Science.gov (United States)

Monoclonal antibodies specific for phase 1 ("i" antigen), phase 2 ("1,2" antigen) and common epitopes of the flagellins of Salmonella enterica serotype Typhimurium were raised. Having confirmed their specificity, the monoclonal antibodies were used to develop semi-quantitative ELISAs in order to assess the relative expression of the two phases by strains of Typhimurium. The majority of Typhimurium strains representative of a wide cross-section of definitive types from animal and environmental sources preferentially expressed phase 1 antigen in vitro. DT40 strains were unique in expressing phase 2 preferentially. The ratio of phase 1 to phase 2 expressed by strains tended to be constant for any one strain when strains were grown on a number of conventional laboratory media. However, the ratio of phases was shown to be modulated by incubation at 42 degrees C and buffering media at pH values, notably 4.5, other than neutral. Selenite broth and Rambach media repressed flagellation. PMID:11118742

Sojka, M; Sayers, A R; Woodward, M J

2001-01-01

83

Multiplex real-time PCR for detection of campylobacter, salmonella, and Shigella.  

UK PubMed Central (United Kingdom)

Infectious diarrhea can be classified based on its clinical presentation as noninflammatory or inflammatory disease. In developing countries, among inflammatory diarrhea cases, Shigella is the most common cause, followed by Campylobacter and Salmonella. Because the time frame in which treatment choices must be made is short and conventional stool cultures lack good sensitivity, there is a need for a rapid, sensitive, and inexpensive detection technique. The purpose of our study was to develop a multiplex real-time PCR procedure to simultaneously identify Campylobacter spp., Salmonella spp., and Shigella spp. Primers were designed to amplify the invA, ipaH, and 16S rRNA genes simultaneously in a single reaction to detect Salmonella, Shigella, and Campylobacter, respectively. Using this approach, we correctly identified 102 of 103 strains of the targeted enteropathogens and 34 of 34 other pathogens. The melting temperatures were 82.96 ± 0.05°C for invA, 85.56 ± 0.28°C for ipaH, and 89.21 ± 0.24°C for 16S rRNA. The limit of accurate quantification for the assay in stool samples was 10(4) CFU g(-1); however, the limit of detection was 10(3) CFU g(-1). This assay is a simple, rapid, inexpensive, and reliable system for the practical detection of these three enteropathogens in clinical specimens.

Barletta F; Mercado EH; Lluque A; Ruiz J; Cleary TG; Ochoa TJ

2013-09-01

84

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

UK PubMed Central (United Kingdom)

Development of antibiotic resistance may alter the virulence properties of bacterial organisms. In this study, nine clinical ceftriaxone-susceptible Salmonella enterica serotype Typhimurium strains were subjected to stepwise selection with increasing concentrations of ceftriaxone in culture media. Mutations in virulence-associated genes and antibiotic efflux genes were analyzed by polymerase chain reaction (PCR) and DNA sequencing. The expression levels of virulence genes invA and stn as well as efflux pump genes tolC, arcA, and arcB before and after the selection were measured by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The stepwise selection resulted in the development of Salmonella strains that were highly resistant to ceftriaxone. Sequence analysis did not reveal any mutations or deletions in the examined virulence genes and regulatory gene, but a silent mutation (T423C) in acrR (encoding a repressor for the efflux pump) was detected in most of the ceftriaxone-resistant strains. The qRT-PCR revealed increased expression of the AcrAB-TolC efflux pump and decreased expression of invA and stn in the ceftriaxone-resistant strains. Moreover, decreased invasion into cultured epithelial cells and reduced growth rates were observed with the resistant strains. These results suggest that acquisition of ceftriaxone resistance is associated with the overexpression of the AcrAB-TolC efflux pump and leads to reduced virulence in Salmonella Typhimurium.

Li L; Yang YR; Liao XP; Lei CY; Sun J; Li LL; Liu BT; Yang SS; Liu YH

2013-01-01

85

Molecular characterization of a new serovar of Salmonella bongori 13,22:z39:- isolated from a lizard.  

Science.gov (United States)

Three Salmonella strains isolated from a lizard (Gallotia simoni) in the "Isla del Hierro" (Canary Islands, Spain) were serotyped as Salmonella bongori serotype 13,22:z39:-, which has not been described in the Kauffmann-White scheme of Salmonella serovars. In order to shed light on the assignment of those strains to the S. bongori species, several genes were amplified and/or sequenced. The iroB gene has been reported to be present only in S. enterica, while the invA gene has been described as being a helpful tool in distinguishing Salmonella from other bacterial species. Both genes were amplified and, as expected, only invA could be amplified. The fliC gene, encoding the phase 1 flagellin fljB gene, encoding phase 2 flagellin, and the gapA gene, which is believed to present polymorphic alleles among different subspecies, were amplified and sequenced. The sequence obtained from fliC(z39) matched with the sequences fliC(z39) obtained from other serovars. The sequence obtained from gapA clustered into the S. bongori group when it was compared to others previously described. We conclude that these three isolates are members of the S. bongori species representing a new serovar that will be described in the next supplement to the Kauffmann-White scheme. PMID:15862460

Herrera-León, Silvia; Saco, Montserrat; Martínez Silvestre, Albert; Silveira, Luis; Echeita, Aurora; Usera, Miguel Angel

2005-02-12

86

Detection of Salmonella enteritidis in pooled poultry environmental samples using a serotype-specific real-time-polymerase chain reaction assay.  

UK PubMed Central (United Kingdom)

While real-time-polymerase chain reaction (RT PCR) has been used as a rapid test for detection of Salmonella Enteritidis in recent years, little research has been done to assess the feasibility of pooling poultry environmental samples with a Salmonella Enteritidis-specific RT PCR assay. Therefore the objective of this study was to compare RT PCR Salmonella Enteritidis detection in individual and pooled (in groups of two, three, and four) poultry environmental drag swab samples to traditional cultural methods. The drag swabs were collected from poultry facilities previously confirmed positive for Salmonella Enteritidis and were cultured according to National Poultry Improvement Plan guidelines. Initial, Salmonella Enteritidis-specific RT PCR assay threshold cycle cutoff values of < or = 36, < or = 30, and < or = 28 were evaluated in comparison to culture. The average limit of detection of the RT PCR assay was 2.4 x 10(3) colony-forming units (CFUs)/ml, which corresponded to an average threshold cycle value of 36.6. Before enrichment, samples inoculated with concentrations from 10(2) to 10(5) CFUs/ml were detected by RT PCR, while after enrichment, samples inoculated from 10(0) to 10(5) CFUs/ml were detected by RT PCR. Threshold cycle cutoff values were used in the subsequent field trial from which Salmonella Enteritidis was cultured in 7 of 208 environmental samples (3.4%). Individual samples were 99.0%, 100%, and 100% in agreement with the RT PCR at threshold cycle (C(t)) cutoff values of < or = 36, < or = 30, and < or = 28 respectively. The agreement for pooled samples also followed the same trend with highest agreement at C(t) < or = 28 (pool of 2 = 100.0%, pool of 3 = 100.0%, pool of 4 = 100.0%), midrange agreement at C(t) < or = 30 (pool of 2 = 99.0%, pool of 3 = 100.0%, pool of 4 = 100.0%), and lowest agreement at C(t) < or = 36 (pool of 2 = 98.1%, pool of 3 = 97.1%, pool of 4 = 98.1%). In conclusion, regardless of the level of pooling after tetrathionate enrichment, sensitivity was very good, and results would be comparable to what would have been found with individual culture or individual RT PCR at C(t) < or = 36.

Adams DR; Stensland WR; Wang CH; O'Connor AM; Trampel DW; Harmon KM; Strait EL; Frana TS

2013-03-01

87

[Salmonella pathogenicity islands].  

UK PubMed Central (United Kingdom)

Salmonella species are facultative intracellular pathogenic bacteria. They can invade macrophages, dendritic and epithelial cells. The responsible virulence genes for invasion, survival, and extraintestinal spread are located in Salmonella pathogenicity islands (SPIs). SPIs are thought to be acquired by horizontal gene transfer. Some of the SPIs are conserved throughout the Salmonella genus, and some of them are specific for certain serovars. There are differences between Salmonella serotypes in terms of adaptation to host cell, virulence factors and the resulting infection according to SPA presence and characteristics. The most important Salmonella virulence gene clusters are located in 12 pathogenicity islands. Virulence genes that are involved in the intestinal phase of infection are located in SPI-1 and SPI-2 and the remaining SPIs are required for intracellular survival, fimbrial expression, magnesium and iron uptake, multiple antibiotic resistance and the development of systemic infections. In addition SPIs, Sigma ss (RpoS) factors and adaptive acid tolerance response (ATR) are the other two important virulence factors. RpoS and ATR found in virulent Salmonella strains help the bacteria to survive under inappropriate conditions such as gastric acidity, bile salts, inadequate oxygen concentration, lack of nutrients, antimicrobial peptides, mucus and natural microbiota and also to live in phagosomes or phagolysosomes. This review article summarizes the data related to pathogenicity islands in Salmonella serotypes and some factors which play role in the regulation of virulence genes.

S?r?ken B

2013-01-01

88

TRANSCIPTIONAL SUPPRESSION OF SPECIFIC PORCINE IMMUNE PATHWAYS DURING INFECTION WITH SALMONELLA ENTERICA SEROTYPE TYPHIMURIUM COMPARED TO CHOLERAESUIS  

Science.gov (United States)

Salmonellosis is prevalent worldwide and is both a food safety issue and production problem. Classic salmonellae of pigs are S. enterica serotype Choleraesuis (SC) and Typhimurium (ST). To understand the host transcriptional response to infection, total RNA was collected from the mesenteric lymph ...

89

Both Hemolytic Anemia and Malaria Parasite-Specific Factors Increase Susceptibility to Nontyphoidal Salmonella enterica Serovar Typhimurium Infection in Mice?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Severe pediatric malaria is an important risk factor for developing disseminated infections with nontyphoidal Salmonella serotypes (NTS). While recent animal studies on this subject are lacking, early work suggests that an increased risk for developing systemic NTS infection during malaria is caused...

Roux, Christelle M.; Butler, Brian P.; Chau, Jennifer Y.; Paixao, Tatiane A.; Cheung, Kong Wai; Santos, Renato L.

90

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Salmonella typhimurium aroA strains (SL3261), expressing high levels of the Gag protein of feline immunodeficiency virus (FIV) fused with maltose binding protein (SL3261-MFG), were constructed using an invertible promoter system that allows the stable expression of heterologous antigens at levels to...

Tijhaar, E.J.; Siebelink, C.H.J.; Karlas, J.A.; Burger, M.C.; Mooi, F.R.; Osterhaus, A.D.M.E.

91

Differential early interactions between Salmonella enterica serovar Typhi and two other pathogenic Salmonella serovars with intestinal epithelial cells.  

Science.gov (United States)

Salmonella enterica serovar Typhi (hereafter referred to as S. typhi) is a host-restricted pathogen that adheres to and invades the distal ileum and subsequently disseminates to cause typhoid fever in humans. However, S. typhi appears to be avirulent in small animals. In contrast, other pathogenic salmonellae, such as S. enterica serovars Typhimurium and Dublin (S. typhimurium and S. dublin, respectively), typically cause localized gastroenteritis in humans but have been used as models for typhoid fever because these organisms cause a disease in susceptible rodents that resembles human typhoid. In vivo, S. typhi has been demonstrated to attach to and invade murine M cells but is rapidly cleared from the Peyer's patches without destruction of the M cells. In contrast, invasion of M cells by S. typhimurium is accompanied by destruction of these M cells and subsequently sloughing of the epithelium. These data have furthered our view that the early steps in the pathogenesis of typhoidal and nontyphoidal Salmonella serovars are distinct. To extend this concept, we have utilized an in vitro model to evaluate three parameters of initial host-pathogen interactions: adherence of three Salmonella serovars to human and murine small intestinal epithelial cell (IEC) lines, the capacity of these salmonellae to invade IECs, and the ability of the bacteria to induce interleukin-6 (IL-6) in these cell lines as a measure of host cell activation and the host acute-phase response. The results demonstrate that S. typhi adheres to and invades human small IECs better than either S. typhimurium or S. dublin. Interestingly, invA and invE null mutants of S. typhi are able neither to adhere to nor to invade IECs, unlike S. typhimurium invA and invE mutants, which adhere to but cannot invade IECs. S. typhi also induces significantly greater quantities of IL-6 in human small IEC lines than either of the other two Salmonella serovars. These findings suggest that differential host cytokine responses to bacterial pathogens may play an important role in the pathological sequelae that follow infection. Importantly, S. typhimurium did not induce IL-6 in murine IECs. Since S. typhimurium infection in mice is often used as a model of typhoid fever, these findings suggest that, at least in this case, the mouse model does not reflect the human disease. Taken together, our studies indicate that (i) marked differences occur in the initial steps of S. typhi, S. typhimurium, and S. dublin pathogenesis, and (ii) conclusions about S. typhi pathogenesis that have been drawn from the mouse model of typhoid fever should be interpreted conservatively. PMID:9573122

Weinstein, D L; O'Neill, B L; Hone, D M; Metcalf, E S

1998-05-01

92

Development of an enzyme-linked immunosorbent assay for quantification of Salmonella enteritidis-specific antibodies in egg yolk  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The present study aims at developing an indirect ELISA to quantify yolk antibodies specific to all surface proteins of the invasive Salmonella Enteritidis (SE), which acquired the 1.8, 14.1, and ~ 50 Kb plasmids. An ELISA checkerboard was used in four different experiments to account for the different parameters included in the preliminary ELISA procedure, and consequently to maximize the difference in Optical Density (OD) values between control positive and negative yolk (more) samples. The first experiment aimed at studying the impact of 5% Bovine Serum Albumin (BSA) dissolved in distilled water as a blocking reagent on a 28 µg/well SE antigen-coated plate, while applying the positive and negative control yolk samples to different concentrations of Phosphate-Buffered Saline (PBS).Conjugate application was maintained constant at a dilution of 1:500 in PBS. The second experiment was similar to the first one, but the positive and negative control yolk samples were diluted in PBS-Tween 20, and the conjugate dilution was changed to 1:1500 in PBS-Tween 20. In the third experiment, the conjugate was diluted at 1:1500 in 5% BSA/PBS-Tween 20 diluent or PBS-Tween 20 diluent with no 5% BSA. The objective of the fourth experiment was to study the impact of four different concentrations of SE-coated antigen levels (28µg/well, 56µg/well, 84µg/well, and 112µg/well), while fixing the blocking step with 5% BSA in distilled water, and the conjugate dilution set at 1:1000 in 5% BSA/PBSTween 20, and fixing the control yolk samples dilution at 1% in PBS-Tween 20. This last experimental procedure allowed the highest difference in mean absorbance OD values of the positive control minus the negative control samples, which was equivalent to 0.381. In addition, the final protocol for this ELISA was applied on individual egg yolk samples of two groups of chicken layers: one challenged in the esophagus at 11 days with 5.4 x 10(10) CFU/ml/bird of SE, and the second group was not challenged. The mean OD values of the egg yolk of antibodies specific against SE of the two groups were significantly different (0.8578 versus 0.5250; p

Tayeb, IT; Nehme, P; Jaber, L; Barbour, EK

2006-12-01

93

Development of an enzyme-linked immunosorbent assay for quantification of Salmonella enteritidis-specific antibodies in egg yolk  

Directory of Open Access Journals (Sweden)

Full Text Available The present study aims at developing an indirect ELISA to quantify yolk antibodies specific to all surface proteins of the invasive Salmonella Enteritidis (SE), which acquired the 1.8, 14.1, and ~ 50 Kb plasmids. An ELISA checkerboard was used in four different experiments to account for the different parameters included in the preliminary ELISA procedure, and consequently to maximize the difference in Optical Density (OD) values between control positive and negative yolk samples. The first experiment aimed at studying the impact of 5% Bovine Serum Albumin (BSA) dissolved in distilled water as a blocking reagent on a 28 µg/well SE antigen-coated plate, while applying the positive and negative control yolk samples to different concentrations of Phosphate-Buffered Saline (PBS).Conjugate application was maintained constant at a dilution of 1:500 in PBS. The second experiment was similar to the first one, but the positive and negative control yolk samples were diluted in PBS-Tween 20, and the conjugate dilution was changed to 1:1500 in PBS-Tween 20. In the third experiment, the conjugate was diluted at 1:1500 in 5% BSA/PBS-Tween 20 diluent or PBS-Tween 20 diluent with no 5% BSA. The objective of the fourth experiment was to study the impact of four different concentrations of SE-coated antigen levels (28µg/well, 56µg/well, 84µg/well, and 112µg/well), while fixing the blocking step with 5% BSA in distilled water, and the conjugate dilution set at 1:1000 in 5% BSA/PBSTween 20, and fixing the control yolk samples dilution at 1% in PBS-Tween 20. This last experimental procedure allowed the highest difference in mean absorbance OD values of the positive control minus the negative control samples, which was equivalent to 0.381. In addition, the final protocol for this ELISA was applied on individual egg yolk samples of two groups of chicken layers: one challenged in the esophagus at 11 days with 5.4 x 10(10) CFU/ml/bird of SE, and the second group was not challenged. The mean OD values of the egg yolk of antibodies specific against SE of the two groups were significantly different (0.8578 versus 0.5250; p<0.05), which indicates the possible application of the developed ELISA for screening SE infection by examining egg yolks produced by commercial layers.

IT Tayeb; P Nehme; L Jaber; EK Barbour

2006-01-01

94

Inhibition of polymerase chain reaction for the detection of Escherichia coli O157:H7 and Salmonella enterica on walnut kernels.  

UK PubMed Central (United Kingdom)

The aim of this study was to determine whether Escherichia coli O157:H7 can be reliably detected and isolated from walnut kernels using standard methods of analysis. The limit of detection approached 1 cell per analytical unit (25 g) for E. coli O157:H7 on walnut kernels enriched in modified tryptic soy broth with 20 ?g/ml novobiocin and plating onto selective agar media. The presence of PCR inhibitors in walnut kernels was indicated by the failure to detect E. coli O157:H7 from culture positive enrichment broths analysed by PCR, with two separate polymerase and reagent compositions (Dupont BAX E. coli O157:H7 MP system, Promega GoTaq Green for stx) and three methods of template preparation (DuPont BAX, Qiagen DNeasy, Bio-Rad InstaGene). PCR inhibition was overcome by 1:100 dilution in TE buffer of the DNeasy or InstaGene template. PCR inhibition was not relieved by dilution of the BAX template. Similar results were observed for walnut kernels inoculated with Salmonella enterica and analysed for invA, indicating that PCR inhibition is not specific to the organism or primer/template. These results indicate that analysis of walnut kernels for pathogens should be with culture based methods or use protocols for DNA template preparation modified to remove or dilute inhibitors and the need for internal amplification controls in PCR methods.

Ganz K; Gill A

2013-08-01

95

Inhibition of polymerase chain reaction for the detection of Escherichia coli O157:H7 and Salmonella enterica on walnut kernels.  

Science.gov (United States)

The aim of this study was to determine whether Escherichia coli O157:H7 can be reliably detected and isolated from walnut kernels using standard methods of analysis. The limit of detection approached 1 cell per analytical unit (25 g) for E. coli O157:H7 on walnut kernels enriched in modified tryptic soy broth with 20 ?g/ml novobiocin and plating onto selective agar media. The presence of PCR inhibitors in walnut kernels was indicated by the failure to detect E. coli O157:H7 from culture positive enrichment broths analysed by PCR, with two separate polymerase and reagent compositions (Dupont BAX E. coli O157:H7 MP system, Promega GoTaq Green for stx) and three methods of template preparation (DuPont BAX, Qiagen DNeasy, Bio-Rad InstaGene). PCR inhibition was overcome by 1:100 dilution in TE buffer of the DNeasy or InstaGene template. PCR inhibition was not relieved by dilution of the BAX template. Similar results were observed for walnut kernels inoculated with Salmonella enterica and analysed for invA, indicating that PCR inhibition is not specific to the organism or primer/template. These results indicate that analysis of walnut kernels for pathogens should be with culture based methods or use protocols for DNA template preparation modified to remove or dilute inhibitors and the need for internal amplification controls in PCR methods. PMID:23628609

Ganz, Kyle; Gill, Alex

2013-02-26

96

Salmonella Yoruba infection in white-tufted-ear marmoset (Callithrix jacchus) Infecção por Salmonella Yoruba em sagui-de-tufo-branco (Callithrix jacchus)  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study was to describe a fatal salmonellosis case in a non-human female primate (Callithrix jacchus), found in the illegal pet trade in Brazil. The marmoset was sent to the quarantine section of the Guarulhos City Zoo and died in the sequence of an episode of profuse diarrhea. Necropsy findings included mucous enteritis, and liver enlargement and necrosis. Feces and liver fragments were collected for bacteriological tests, which indicated the presence of Salmonella sp.; it was subsequently characterized as pertaining to the Yoruba serotype. The susceptibility profile demonstrated resistance to tetracycline only. The strain was positive for genes that encoded the virulence factors investigated (invA, sefC, pefA and spvC). The results indicated the risk of introduction of Salmonella pathogenic serotypes in primates in captivity.O objetivo deste trabalho foi descrever um caso fatal de salmonelose em uma fêmea primata não humana (Callithrix jacchus), originária de tráfico ilegal no Brasil. O sagui foi enviado para seção de quarentena do Zoológico Municipal de Guarulhos e morreu após um episódio de diarréia profusa. Achados de necropsia incluíram enterite mucosa, hepatomegalia e necrose do fígado. Fezes e fragmentos do fígado foram coletados para testes bacteriológicos e indicaram a presença de Salmonella sp.; subsequentemente caracterizada como sorotipo Yoruba. O perfil de suscetibilidade mostrou resistência somente à tetraciclina. A cepa foi positiva para os genes que codificam os fatores de virulência investigados (invA, sefC, pefA and spvC). Os resultados indicaram o risco de introdução de sorotipos patogênicos de Salmonella por primatas em cativeiro.

Terezinha Knöbl; Leliane T. Rocha; Márcia C. Menão; Cláudia A.S. Igayara; Renata Paixão; Andréa M. Moreno

2011-01-01

97

BAM: Salmonella  

Science.gov (United States)

... Salmonella Spicer-Edwards flagellar (H) antisera. Return to Chapter Contents. Preparation ... antisera. Spicer-Edwards serological test. ... More results from www.fda.gov/food/foodscienceresearch/laboratorymethods

98

Allotypic and idiotypic specificities of anti-Salmonella abortus-equi antibodies produced by rabbits subjected to successive irradiations  

International Nuclear Information System (INIS)

[en] Three out of five rabbits subjected to successive irradiations and immunized against Salmonella abortus-equi produced IgG which, transiently, were not precipitated by anti-a3 anti-allotypic sera, although they carried all the determinants of the a3 allotypic pattern. As a3 IgG from normal rabbits are precipitated by anti-a3 sera, it appeared that the molecular distribution of the a3 allotypic determinants was different on the IgG produced by these irradiated rabbits compared to IgG produced by normal rabbits. After a second irradiation, one of these rabbits produced a high level (50 mg per ml) of anti-Salmonella antibodies of restricted heterogeneity. An anti-idiotypic serum prepared against anti-Salmonella antibodies produced by this rabbit after the first irradiation precipitated the idiotypes it recognised in the serum collected after the first irradiation, while it did not precipitate the idiotypes it recognised in the serum collected after the second irradiation, although they carried all the determinants of the idiotypes of the serum collected after the first irradiation. That probably means that there is a different molecular distribution of the idiotypic determinants between antibodies produced after the first irradiation and antibodies produced after the second irradiation. An antiidiotypic serum prepared against anti-Salmonella antibodies produced after the second irradiation did not distinguish by precipitation in gel medium or by radioimmunoassay between the idiotypes it recognised in antibodies produced after the first irradiation and those in antibodies produced after the second irradiation. The idiotypic similarity thus detected, and the fact that unexpected allotypes were not detected, is in better agreement with the expression of the potentiality of radiation-resistant cells than with the expression of new antibody producing cell clones arising from virgin stem cells. (author)

1978-01-01

99

The structure of the linkage between the O-specific polysaccharide and the core region of the lipopolysaccharide from Salmonella enterica serovar Typhimurium revisited.  

Science.gov (United States)

Salmonella enterica sv. Typhimurium strain 1135 possesses smooth(S)-form lipopolysaccharide (LPS). Although the structures of the core region and the O-specific polysaccharide were investigated intensively between the 1960s and the 1980s, the structure of the linkage region between the O-chain and the core was not elucidated unequivocally. By using modern MS and high-field NMR spectroscopy for analysis of the isolated carbohydrate backbone of the LPS, it has been shown that it is a beta-D-Galp residue that links the first repeating unit of the O-specific polysaccharide to O-4 of the last D-Glcp residue of the core region. Interestingly, this particular D-Galp residue is alpha-linked in all following repeating units. The data are discussed with regard to the ligation of O-specific polysaccharide and core region during LPS biosynthesis. PMID:10727941

Olsthoorn, M M; Petersen, B O; Duus, J; Haverkamp, J; Thomas-Oates, J E; Bock, K; Holst, O

2000-04-01

100

Biofilm formation, virulence gene and multi-drug resistance in Salmonella Kentucky isolated in Tunisia  

UK PubMed Central (United Kingdom)

Food-borne diseases caused by Salmonella enterica are a significant public health concern around the world. Since 2002, S. enterica serovar Kentucky has shown an increase in several countries with the concurrent emergence of multidrug-resistant isolates. The spread of such strains in the environment poses a major public health problem. A total of 57 Salmonella Kentucky strains isolated from different sources during the period 2005 to 2008 in Tunisia, were characterized by their antimicrobial and mercury resistance profiles; ability to form a biofilm; virulence invA/spvC genes and quorum sensing sdiA gene. A total of 10.6% of the isolates demonstrated multidrug-resistance against 3 to 13 antibiotics with ciprofloxacin resistance occurring in 33% of human isolates. In addition, 37% of the isolates exhibited minimum inhibitory concentrations value to mercuric chloride, ranging from 8 to 32?gml?1 and were considered as resistant strains. The majority of strains tested were able to form a biofilm, especially for environmental and animal derived isolates. Therefore, the biofilm seems to comprise a normal and favorable capability in the life of Salmonella Kentucky in the environment. Interestingly, all the isolates possessed the sdiA gene, 87.7% of isolates possessed the invA gene, and no isolate harbored the spvC gene. The emergence of resistance to ciprofloxacin in human Salmonella Kentucky isolates, added to the presence of invA and sdiA genes, and the production of biofilm could be the decisive factors in the dissemination of S. Kentucky strains on a large scale.

Turki Y; Ouzari H; Mehri I; Ben Aissa R; Hassen A

2012-03-01

 
 
 
 
101

Pathogenicity of Salmonella enteritidis Phage Type 1 Isolate of Malaysia in 21 Day Old Specific-Pathogen Free Chickens  

Directory of Open Access Journals (Sweden)

Full Text Available Salmonella enteritidis (SE) has always been related to subclinical infection in the chickens infected after 2 weeks of hatching. However, few pathogenic phage types were proven for their ability to manifest systemic infection and cause the organism to be shed into the surrounding environment. It was the objective of the study to determine the pathogenicity of SE Phage Type (PT) 1 in Specific-Pathogen-Free (SPF) chickens. About 93, 21 day old SPF chickens where divided into 3 groups namely the Control, SE and Mortality groups. The chickens were raised separately in caging system and given free access to antibiotic-free ration and water. The SE and Mortality groups were inoculated orally (1.0 mL) with SE PT 1 (1x108 cfu mL-1). The chickens in the SE and Control groups were sacrificed at various intervals throughout the trial. Samples were collected for bacterial isolation and histological examination. The mortality percentage of the chickens in the Mortality group was recorded. The study showed that no mortality was recorded throughout the trial in the mortality as well as the SE group. Body weight was lower in the SE group when compared to the Control group throughout the trial except at days 2, 3 and 5 post inoculation (pi) reaching its peak at day 14 pi when the SE group body weight was 26% lower than the controls. Clinical signs observed in the SE and Mortality group were represented by diarrhoea, inappetance, ruffled feather and stunted chickens while no abnormal clinical signs where recorded in the Control group. Grossly mild airsacculitis, mild peritonitis and hepatic congestion where recorded in the SE group at day 2 pi until day 5 pi while no gross lesions where recorded in the Control group. SE was first isolated in the caecum (66%) at 12 h pi. At day 1 pi SE was isolated from the caecum and spleen (33%) whilst at day 2, SE was isolated from the caecum (100%) and caecal tonsil (66%). No SE was isolated from the cloacal swabs throughout the trial. The villi height was generally lower in the SE group when compared to the Controls, however it was significantly lower (p<0.05) in the duodenum at 12 h, days 1, 3, 5, 10, 14 and 21 pi; in the jejunum at 6 h, days 2, 14 and 21 pi while in the ileum at days 1, 3 and 5 pi. The crypts depth measurement was fluctuating however it ended up by being higher in the SE group, nevertheless it was significantly lower (p<0.05) in the SE group when compared to the Control group in the duodenum at 6 h and day 14 pi in the jejunum at day 10 pi; in the ileum at 12 h pi. Histopathological changes recorded included hepatitis, congestion and focal areas of necrosis; splenitis, congestion and oedema in the adenoid sheathed arteries; congestion and areas of necrosis in the lymphoi follicles of the bursa of Fabricius; enteritis, congestion and sloughing of necrotic enterocytes in the intestinal villi with presence of bacterial clusters in the villi surface and intestinal lumen. SE rods present in the caecal tonsils were seen to be engulfed by macrophages at days 1 and 2 pi, necrosis of the enterocytes on the villi surface and infiltration of the bacteria was recorded at day 2 pi while at days 5 pi the bacteria multiplication were seen and often located upon the M-like M cells however, no actual engulfment was recorded.

S. Ahmad; M. Hair-Bejo; Z. Zunita; S. Khairani-Bejo

2011-01-01

102

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

UK PubMed Central (United Kingdom)

BACKGROUND: Multidrug-resistant (MDR) Salmonella isolates are associated with increased morbidity compared to antibiotic-sensitive strains and are an important health and safety concern in both humans and animals. Salmonella enterica serovar Typhimurium is a prevalent cause of foodborne disease, and a considerable number of S. Typhimurium isolates from humans and livestock are resistant to three or more antibiotics. The majority of these MDR S. Typhimurium isolates are resistant to tetracycline, a commonly used and clinically and agriculturally relevant antibiotic. Because exposure of drug-resistant bacteria to antibiotics can affect cellular processes associated with virulence, such as invasion, we investigated the effect tetracycline had on the invasiveness of tetracycline-resistant MDR S. Typhimurium isolates. RESULTS: The isolates selected and tested were from two common definitive phage types of S. Typhimurium, DT104 and DT193, and were resistant to tetracycline and at least three other antibiotics. Although Salmonella invasiveness is temporally regulated and normally occurs during late-log growth phase, tetracycline exposure induced the full invasive phenotype in a cell culture assay during early-log growth in several DT193 isolates. No changes in invasiveness due to tetracycline exposure occurred in the DT104 isolates during early-log growth or in any of the isolates during late-log growth. Real-time PCR was used to test expression of the virulence genes hilA, prgH, and invF, and these genes were significantly up-regulated during early-log growth in most isolates due to tetracycline exposure; however, increased virulence gene expression did not always correspond with increased invasion, and therefore was not an accurate indicator of elevated invasiveness. This is the first report to assess DT193 isolates, as well as the early-log growth phase, in response to tetracycline exposure, and it was the combination of both parameters that was necessary to observe the induced invasion phenotype. CONCLUSIONS: In this report, we demonstrate that the invasiveness of MDR S. Typhimurium can be modulated in the presence of tetracycline, and this effect is dependent on growth phase, antibiotic concentration, and strain background. Identifying the conditions necessary to establish an invasive phenotype is important to elucidate the underlying factors associated with increased virulence of MDR Salmonella.

Brunelle BW; Bearson SM; Bearson BL

2013-09-01

103

Evaluation of a cocktail of three bacteriophages for the biocontrol of Salmonella of wastewater  

UK PubMed Central (United Kingdom)

Salmonella serovars are increasing in importance as significant pathogens of both human and animals. Although water and wastewater are treated to eliminate pathogenic microorganisms, they still play an important role in the transmission of Salmonella spp. In this study, bacteriophages infecting Salmonella spp. were isolated from wastewater and evaluated; for their potential to lyse environmental Salmonella strains in vitro at different MOIs and temperatures; and to control the wastewater bacterial community. Three distinct phages designated sww65, sww275, and sww297; as defined by plaque morphology, electron microscopy and host range; were obtained from wastewater. Challenge tests were performed at 37, and 30°C with the infection of the Salmonella cultures with individual phage, a mixture of two phages, and cocktail of three phages at MOIs of 100, 102, and 104 PFU/CFU. At 30, and 37°C, a cocktail of three phages reduced all of the Salmonella cultures tested. These results required a high multiplicity of infection. However, when infected with only one phage or a mixture of two phages at MOIs of 100 or 10 2 PFU/CFU, an emergence of bacterial resistance was observed. The dynamic monitoring of wastewater enterobacterial community was conducted using Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR). The number of bands decreased gradually with the use of individual phage or phage cocktails. Moreover, the dynamic monitoring of Salmonella community during wastewater treatment was performed using PCR detection of virulence gene invA. The results correlated with the ERIC-PCR fingerprints, and suggested that Salmonella community was affected by the phage treatment. Indeed, in wastewater, bacteriophages are reducing Salmonella and other members of the Enterobacteriaceae. These results indicated that dynamic changes are closely related with the process of treatment. The introduction of wide host range bacteriophages in wastewater can have a potential impact on the dynamics of the microbial communities, manifested by the reduction or the elimination of microbial species.

Turki Y; Ouzari H; Mehri I; Ammar AB; Hassen A

2012-03-01

104

Salmonella Yoruba infection in white-tufted-ear marmoset (Callithrix jacchus)/ Infecção por Salmonella Yoruba em sagui-de-tufo-branco (Callithrix jacchus)  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O objetivo deste trabalho foi descrever um caso fatal de salmonelose em uma fêmea primata não humana (Callithrix jacchus), originária de tráfico ilegal no Brasil. O sagui foi enviado para seção de quarentena do Zoológico Municipal de Guarulhos e morreu após um episódio de diarréia profusa. Achados de necropsia incluíram enterite mucosa, hepatomegalia e necrose do fígado. Fezes e fragmentos do fígado foram coletados para testes bacteriológicos e indicaram a p (more) resença de Salmonella sp.; subsequentemente caracterizada como sorotipo Yoruba. O perfil de suscetibilidade mostrou resistência somente à tetraciclina. A cepa foi positiva para os genes que codificam os fatores de virulência investigados (invA, sefC, pefA and spvC). Os resultados indicaram o risco de introdução de sorotipos patogênicos de Salmonella por primatas em cativeiro. Abstract in english The aim of this study was to describe a fatal salmonellosis case in a non-human female primate (Callithrix jacchus), found in the illegal pet trade in Brazil. The marmoset was sent to the quarantine section of the Guarulhos City Zoo and died in the sequence of an episode of profuse diarrhea. Necropsy findings included mucous enteritis, and liver enlargement and necrosis. Feces and liver fragments were collected for bacteriological tests, which indicated the presence of Sa (more) lmonella sp.; it was subsequently characterized as pertaining to the Yoruba serotype. The susceptibility profile demonstrated resistance to tetracycline only. The strain was positive for genes that encoded the virulence factors investigated (invA, sefC, pefA and spvC). The results indicated the risk of introduction of Salmonella pathogenic serotypes in primates in captivity.

Knöbl, Terezinha; Rocha, Leliane T.; Menão, Márcia C.; Igayara, Cláudia A.S.; Paixão, Renata; Moreno, Andréa M.

2011-08-01

105

Salmonella Serotype Enteritidis  

Science.gov (United States)

Salmonella serotype Enteritidis General Information Frequently Asked Questions Salmonella serotype Enteritidis infection Egg and chicken contamination Who ... Pages in this Report General Information Additional Information Salmonella serotype Enteritidis infection Salmonella serotype Enteritidis (SE) is ...

106

Salmonella Infection (Salmonellosis) and Animals  

Science.gov (United States)

... Salmonella Infantis, Salmonella Newport, and Salmonella Lille Dry Dog Food - Salmonella Infantis Chicks and Ducklings - Salmonella Altona and ... Field: Human Salmonella Infantis Infections Linked to Dry Dog Food — United States and Canada, 2012 Update: Recall of ...

107

Salmonella Infection  

Science.gov (United States)

... valves (endocarditis) Your bones or bone marrow (osteomyelitis) Reactive arthritis People who have had salmonella are at higher risk of developing reactive arthritis. Also known as Reiter's syndrome, reactive arthritis typically ...

108

Phenotypic analysis of Salmonella enterica serovar Typhimurium rpoE mutants encoding RNA polymerase extracytoplasmic stress response sigma factors ?(E) with altered promoter specificity.  

UK PubMed Central (United Kingdom)

We previously identified mutants in the rpoE gene of Salmonella enterica serovar Typhimurium (S. Typhimurium) encoding RNA polymerase extracytoplasmic stress response sigma factors ?(E) with altered promoter specificity. The replacement of the conserved R171 residue in the conserved region 4.2 of ?(E) by different amino acid residues exhibited different phenotypes. While R171A almost completely abolished sigma factor activity, R171G and R171C mutant changes imparted a relaxed recognition phenotype to the sigma factor. In the present study, we introduced these mutations into the S. Typhimurium chromosome to investigate their phenotype during ethanol stress and in promoter recognition. Both relaxed sigma factors were found to initiate transcription from a high number of artificial promoters in the S. Typhimurium genome. Both mutants had substantially decreased activity under stress conditions. However, this decreased activity and also the recognition of atypical promoters had no significant effect upon growth, even in stressful conditions.

Rezuchova B; Homerova D; Sevcikova B; Novakova R; Feckova L; Roberts M; Kormanec J

2013-01-01

109

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

DEFF Research Database (Denmark)

The aim of this work was the validation of a rapid, real-time PCR assay based on TaqMan((R)) technology for the unequivocal identification of Salmonella spp. to be used directly on an agar-grown colony. A real-time PCR system targeting at the Salmonella spp. invA gene was optimized and validated through a four times repeated blind experiment performed in two different laboratories including 50 Salmonella spp. with representative strains from each of the 5 different Salmonella subgenera and 30 non-Salmonella strains. Both parameters DeltaR(n) (fluorescence intensity of template through a normalized reporter value) and C-T (cycle at which the fluorescence intensity achieved a pre-established threshold) were analyzed. Overall mean DeltaR(n) and C-T values for Salmonella strains (2.14 +/- 0.87 and 15.30 +/- 0.90, respectively) were statistically different from values for non-Salmonella strains, allowing the establishment of cut-off DeltaR(n) and C-T values based on 95% confidence intervals that allowed the correct identification of all strains tested in each independent experiment. The accuracy of this assay in terms of inclusivity and exclusivity was 100%. Moreover, the PCR system proved to be especially convenient because the pre-mix containing all PCR reagents except for the bacterial cells could be kept at -20 degreesC for at least I month before its use. The optimized TaqMan((R)) real-time PCR assay is a useful, simple and rapid method for routine identification of Salmonella spp., irrespective of the particular subgenus.

Rodriguez-Lazaro, D.; Hernández, Marta

2003-01-01

110

Development of a Novel Hexa-plex PCR Method for Identification and Serotyping of Salmonella Species.  

UK PubMed Central (United Kingdom)

Abstract 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.

Li R; Wang Y; Shen J; Wu C

2013-09-01

111

Do Salmonella carry spare tyres?  

Science.gov (United States)

Salmonellae are enterobacteria that have the unique ability to change their flagellar composition by switching expression among two loci that encode the major flagellin protein. This property is not available to all Salmonella, but is species, subspecies and serotype specific. Curiously, the subsequent loss of the second locus in some lineages of Salmonella has apparently been tolerated and, indeed, has led to considerable success for some lineages. We discuss here an evolutionary model for maintenance of this unique function and the possible evolutionary advantages of loss or preservation of this mechanism. We hypothesize that the second flagellin locus is a genetic 'spare tyre' used in particular environmental circumstances. PMID:18375124

McQuiston, John R; Fields, Patricia I; Tauxe, Robert V; Logsdon, John M

2008-03-28

112

Visiting the cell biology of Salmonella infection.  

UK PubMed Central (United Kingdom)

Salmonella, a Gram-negative facultative intracellular pathogen is capable of infecting vast array of hosts. The striking ability of Salmonella to overcome every hurdle encountered in the host proves that they are true survivors. In the host, Salmonella infects various cell types and needs to survive and replicate by countering the defense mechanism of the specific cell. In this review, we will summarize the recent insights into the cell biology of Salmonella infection. Here, we will focus on the findings that deal with the specific mechanism of various cell types to control Salmonella infection. Further, the survival strategies of the pathogen in response to the host immunity will also be discussed in detail. Better understanding of the mechanisms by which Salmonella evade the host defense system and establish pathogenesis will be critical in disease management.

Lahiri A; Lahiri A; Iyer N; Das P; Chakravortty D

2010-10-01

113

Salmonella Susceptibility  

Science.gov (United States)

Nontyphoidal Salmonella (NTS) are a group of enteric bacteria can lead to life-threatening bacteremia in those with weakened immune systems. MacLennan et al. identify an immune response that may have important implications for the development of a vaccine against NTS.

Susan Moir (National Institutes of Health;); Anthony Fauci (National Institutes of Health;)

2010-04-23

114

Salmonella from Pocket Pets  

Science.gov (United States)

... Professionals Glossary Resources Outbreak Response and Prevention Branch Salmonella from Pocket Pets The Salmonella germ is actually ... has been cleaned and disinfected. Tips for Preventing Salmonella from Rodents Washing hands with soap and water ...

115

Reptiles, Amphibians, and Salmonella  

Science.gov (United States)

... Favorites Delicious Digg Google Bookmarks Reptiles, Amphibians, and Salmonella Reptiles, Amphibians, and Salmonella Did you know that ... aquariums where they live. How do people get Salmonella infections from reptiles and amphibians? Reptiles and amphibians ...

116

78 FR 42526 - Salmonella  

Science.gov (United States)

...Docket No. FDA-2013-D-0254] Salmonella Contamination of Dry Dog Food; Withdrawal...CPG) entitled ``Sec. 690.700 Salmonella Contamination of Dry Dog Food...the CGP entitled ``Sec. 690.700 Salmonella Contamination of Dry Dog Food...

2013-07-16

117

Salmonella: Annual Summary, 2005.  

Science.gov (United States)

This Annual Summary of the National Salmonella Surveillance System contains surveillance data on reported laboratory-confirmed Salmonella isolates in the United States for the year 2005. The National Salmonella Surveillance System collects reports of isol...

2005-01-01

118

Detection of Salmonella spp. in oysters by PCR.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

PCR DNA amplification of a region of the himA gene of Salmonella typhimurium specifically detected Salmonella spp. In oysters, 1 to 10 cells of Salmonella spp. were rapidly detected by the PCR following a pre-enrichment step to increase sensitivity and to ensure that detection was based on the prese...

Bej, A K; Mahbubani, M H; Boyce, M J; Atlas, R M

119

Detection of Salmonella by Surface Plasmon Resonance  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study explores the possibility of simultaneous and specific detection ofSalmonella serovars by surface plasmon resonance (SPR). The Plasmonic® SPR device wasused to develop this rapid assay. The sandwich immunoassay involves the use of apolyclonal anti-Salmonella antibody to simultaneous cap...

Benjamin Barlen; Saikat Datta Mazumdar; Olga Lezrich; Peter Kämpfer; Michael Keusgen

120

Comparison of Salmonella serovar isolation and antimicrobial resistance patterns from porcine samples between 2003 and 2008.  

UK PubMed Central (United Kingdom)

Food-borne Salmonella infections can produce symptoms from mild gastroenteritis to severe systemic disease and death, representing an important public health issue in U.S. livestock and livestock products, which have been implicated as frequent sources of Salmonella contamination. Concerns have been raised about the spread of antibiotic resistance in Salmonella strains, particularly those that originate from food animal sources, as a result of prophylactic and therapeutic antimicrobial use in these species. Longitudinal comparisons of Salmonella serovars isolated from porcine tissues submitted to the Iowa State University Veterinary Diagnostic Laboratory in 2003 and 2008 were conducted to evaluate changes in serovar dynamics and antimicrobial resistance. Incidence of recovered group C Salmonella enterica serovar Choleraesuis var. Kunzendorf decreased between 2003 and 2008, while recovery of group B strains Salmonella Typhimurium var. 5-(formerly, Copenhagen), Salmonella Agona, Salmonella Derby, Salmonella Heidelberg, and Salmonella Typhimurium increased. Significant changes in resistance interpretation were seen in Salmonella Derby with regard to spectinomycin and sulfadimethoxine; in Salmonella Heidelberg with regard to florfenicol, spectinomycin, and sulfadimethoxine; and in Salmonella Choleraesuis var. Kunzendorf, Salmonella Typhimurium, Salmonella Typhimurium var. 5-, and Salmonella Agona with regard to spectinomycin. Only 2 of 293 isolates in 2003 and 5 of 395 isolates in 2008 were resistant to enrofloxacin. Utilizing antibiotics approved for use in food animals to evaluate antimicrobial resistance provides more specific information on the selection pressure exerted on Salmonella populations through the use of these drugs.

Clothier KA; Kinyon JM; Frana TS

2010-07-01

 
 
 
 
121

Salmonella Enteritidis is superior in egg white survival compared with other Salmonella serotypes.  

UK PubMed Central (United Kingdom)

Salmonella enterica subspecies enterica serotype Enteritidis is a major cause of egg-borne human salmonellosis. The ability to survive in egg albumen at chicken body temperature was hypothesized to be an important factor involved in the predominant contamination of eggs by this specific serotype. Eighty-nine Salmonella strains from different serotypes, belonging to 5 serogroups, were incubated for 24 h in egg white at 42°C. The number of Salmonella Enteritidis strains that were able to survive in egg white was significantly higher compared with strains belonging to other serotypes and serogroups that were tested in this study. These data add evidence to the hypothesis that egg white survival is one of the reasons why Salmonella Enteritidis is more predominantly isolated from contaminated eggs, and helps explaining why most reported egg-borne Salmonella outbreaks in humans are caused by Salmonella Enteritidis.

De Vylder J; Raspoet R; Dewulf J; Haesebrouck F; Ducatelle R; Van Immerseel F

2013-03-01

122

Genetic analysis of multidrug-resistant Salmonella enterica serovars Stanley and Typhimurium from cattle.  

UK PubMed Central (United Kingdom)

During 2005-2008, a longitudinal study was conducted in southern Japan to detect and characterize multidrug-resistant Salmonella enterica serovars recovered from cattle diagnostic specimens. Determination of antimicrobial resistance phenotypes and genotypes, identification of Salmonella genomic island 1 (SGI1), detection of virulence genes, plasmid analysis, conjugal transfer experiments, and sequencing of class 1 integrons were conducted. Multidrug-resistant Salmonella detected were serovars Stanley, Typhimurium, and O4:d. Salmonella Stanley isolates exhibited resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, oxytetracycline, trimethoprim, and kanamycin (ACSSuT+) encoded by bla(TEM), catA, aadA2, tetA, sul1, dfrA12, and aphA1 genes, respectively. Sequencing analysis revealed that aadA2 and dfrA12 were integrated as gene cassettes within the class 1 integrons of 1.5kb size. Importantly, the isolates harboured easily transferable plasmids of ca. 210kb with the potential of transmitting resistance phenotype and genotype detected in the donor isolates. Moreover, Salmonella Typhimurium DT104 isolates with typical SGI1 were detected and presented ACSSuT+ resistance phenotype encoded by bla(PSE-1) and bla(TEM); floR; aadA1; sul1; and tetA and tetG, respectively. Salmonella Typhimurium isolates carried plasmids of variable sizes ranging from 3.5 to 100 kb with DT104 isolates harbouring plasmids of ca. 90 kb. Salmonella serovar O4:d had ACSSuT+ resistance phenotype mediated by bla(TEM), catA, aadA1, sul1, tetA, and aphA1 genes. A virulence gene invA was found in all multidrug-resistant Salmonella Typhimurium, Stanley and O4:d clinical isolates. In conclusion, this is the first report describing the occurrence of multidrug-resistant Salmonella Stanley from bovine species. The emergence of Salmonella Stanley isolates exhibiting plasmid-encoded high-level multidrug resistance is an important health concern because this new pathogenecity was associated with mortality in cattle.

Dahshan H; Shahada F; Chuma T; Moriki H; Okamoto K

2010-09-01

123

Mutagenicity and antimutagenicity testing of six chemicals associated with the pungent properties of specific spices as revealed by the Ames Salmonella/microsomal assay.  

UK PubMed Central (United Kingdom)

Three compounds, capsaicin, thymol and borneol, were initially screened for mutagenic activity using Salmonella typhimurium strains TA97, TA98 and TA100, with and without S9 metabolic activation, and 20 min standard preincubation time. Three other compounds, allyl isothiocyanate, eugenol and cinnamaldehyde, were screened for mutagenic activity as above, but with a prolonged, nonstandard preincubation time of up to 120 minutes. All six test compounds used in the assays are associated with the pungent properties of some specific spices in which the test compounds can be found to exist naturally. The first objective of this study was to observe if mutagenic activity can be correlated to the pungent properties of these six test compounds. However, due to toxicity and the observation that only capsaicin was mutagenic, using strain TA100 in the presence of S9 metabolic activation, it was not possible to deduce any relationship between mutagenicity and the test chemicals' pungent properties. Naturally occurring capsaicin, found in the spice Capsicum annum, was detected and quantified using thin layer and gas chromatographic techniques. The final objective was to detect the presence of antimutagenic factor(s) in C. annum that would suppress the mutagenicity of capsaicin. When the mutagenic capsaicin and 2-aminoanthracene were assayed in the presence of C. annum acetone extract, using strain TA100 with S9 metabolic activation, the mutagenic response of both the mutagens were reduced by approximately 50%. Assaying capsaicin and 2-aminoanthracene in the presence of chlorophyll, the mutagenic response of the two mutagens was reduced by less than 40%. From this observation it was inferred that chlorophyll can successfully suppress the mutagenicity activities of capsaicin and 2-aminoanthracene, together with other antimutagenic factors that were present in the acetone extract of C. annum.

Azizan A; Blevins RD

1995-02-01

124

Mutagenicity and antimutagenicity testing of six chemicals associated with the pungent properties of specific spices as revealed by the Ames Salmonella/microsomal assay.  

Science.gov (United States)

Three compounds, capsaicin, thymol and borneol, were initially screened for mutagenic activity using Salmonella typhimurium strains TA97, TA98 and TA100, with and without S9 metabolic activation, and 20 min standard preincubation time. Three other compounds, allyl isothiocyanate, eugenol and cinnamaldehyde, were screened for mutagenic activity as above, but with a prolonged, nonstandard preincubation time of up to 120 minutes. All six test compounds used in the assays are associated with the pungent properties of some specific spices in which the test compounds can be found to exist naturally. The first objective of this study was to observe if mutagenic activity can be correlated to the pungent properties of these six test compounds. However, due to toxicity and the observation that only capsaicin was mutagenic, using strain TA100 in the presence of S9 metabolic activation, it was not possible to deduce any relationship between mutagenicity and the test chemicals' pungent properties. Naturally occurring capsaicin, found in the spice Capsicum annum, was detected and quantified using thin layer and gas chromatographic techniques. The final objective was to detect the presence of antimutagenic factor(s) in C. annum that would suppress the mutagenicity of capsaicin. When the mutagenic capsaicin and 2-aminoanthracene were assayed in the presence of C. annum acetone extract, using strain TA100 with S9 metabolic activation, the mutagenic response of both the mutagens were reduced by approximately 50%. Assaying capsaicin and 2-aminoanthracene in the presence of chlorophyll, the mutagenic response of the two mutagens was reduced by less than 40%. From this observation it was inferred that chlorophyll can successfully suppress the mutagenicity activities of capsaicin and 2-aminoanthracene, together with other antimutagenic factors that were present in the acetone extract of C. annum. PMID:7710293

Azizan, A; Blevins, R D

1995-02-01

125

Conservation and divergence among Salmonella enterica subspecies.  

UK PubMed Central (United Kingdom)

Genome sequencing efforts of taxonomically proximate organisms successfully divulged proteomic diversity embedded within closely related organisms. The Salmonella enterica subspecies represents a group of enterobacteric pathogens known to share similar genomic content yet possess diverse host specificity and distinct disease symptoms. Study of Salmonella enterica subspecies proteomes reports an overestimation of the proximity among the subspecies. Interestingly, orthology comparison among Salmonella typhi and Salmonella typhimurium across the proteome suggested the metabolic proteins possessed the highest propensity of the divergence, while proteins involved in environment information processing and genetic information processing are least susceptible to evolution. Consistent with earlier reports, transporter proteins and transcription factors are the most populated protein families in the Salmonellae. Several of the unique domains present in Salmonella typhi and Salmonella typhimurium genomes were introduced into the genome through phage invasion and eventually selected. Redundancy and divergence is observed among the metabolic pathway proteins. Though complying with essentiality of their function, the metabolic proteins possess the highest propensity of sampling sequence space for imbibing new function. The detailed cross-genome analysis of the subspecies provides an understanding of diversity and unique attributes defined in the individual Salmonella enterica genomes.

Bhaduri A; Kalaimathy S; Sowdhamini R

2009-06-01

126

Molecular divergence of the serotype-specific plasmid (pSLT) among strains of Salmonella typhimurium of human and veterinary origin and comparison of pSLT with the serotype specific plasmids of S. enteritidis and S. dublin.  

UK PubMed Central (United Kingdom)

Molecular variants of the serotype-specific plasmid (SSP) of Salmonella typhimurium (pSLT) were recognised in clinical and veterinary isolates by restriction enzyme fingerprinting. Three had undergone minor DNA rearrangements, whereas two had acquired resistance determinants to a wide range of antimicrobial agents including gentamicin, trimethoprim, tetracycline, streptomycin, ampicillin (Ap) and kanamycin (Km). One of the latter was the result of co-integrate formation with an IncX, conjugative R-plasmid that specified ApKm resistance. The co-integrate plasmid (pOG669) was incompatible with, and displaced, pSLT and its molecular variants. The restriction fingerprints of SSPs of S. enteritidis and S. dublin were compared with pSLT. All were related at the 35% level on the basis of a Dice coefficient of similarity. The SSPs of S. enteritidis and S. dublin were incompatible with the co-integrate plasmid pOG669. Whereas in S. enteritidis this resulted from incompatibility with the pSLT component (the SSP was compatible with the IncX component), the converse was found with S. dublin.

Platt DJ; Taggart J; Heraghty KA

1988-12-01

127

Secreted Effector Proteins of Salmonella enterica Serotype Typhimurium Elicit Host-Specific Chemokine Profiles in Animal Models of Typhoid Fever and Enterocolitis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Infection of bovine ligated loops with the Salmonella enterica serotype Typhimurium wild type but not a sipA sopABDE2 mutant resulted in fluid accumulation, polymorphonuclear cell infiltration, and expression of CXC chemokines, particularly GRO?. None of these sipA sopABDE2-dependent responses was o...

Zhang, Shuping; Adams, L. Garry; Nunes, Jairo; Khare, Sangeeta; Tsolis, Renée M.; Bäumler, Andreas J.

128

Acute diarrhea associated with Salmonella enterica in Belo Horizonte-MG: prevalence and characterization of isolates/ Diarreia aguda associada a Salmonella enterica em Belo Horizonte-MG: prevalência e caracterização das amostras isoladas  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese INTRODUÇÃO: A diarreia infecciosa aguda é considerada um problema de saúde pública associado a uma ampla gama de agentes etiológicos, entre os quais destaca-se Salmonella enterica, causa importante de diarreia inflamatória em países desenvolvidos e em desenvolvimento. OBJETIVOS: Avaliar a distribuição de S. enterica em crianças com diarreia aguda em Belo Horizonte e caracterizar as amostras isoladas. MATERIAL E MÉTODO: O grupo de estudo consistiu de 157 crian? (more) ?as de nível socioeconômico baixo. Espécimes fecais foram empregados para pesquisa de leucóc itos e cultivo de Salmonella. As amostras isoladas foram sorotipadas e submetidas à avaliação do perfil de suscetibilidade a antimicrobianos, da produção de betalactamases de amplo espectro (ESBL) e da presença de marcadores de virulência (invA, iroB e spvC). RESULTADOS: Cinco/3,2% crianças apresentaram-se infectadas por S. enterica; três/60%, por S. enterica Typhimurium; uma/20%, por S. enterica Enteritidis; e uma/20%, por S. enterica subsp. enterica sorotipo 8,20:z4,z23:-. Leucócitos fecais foram detectados em dois dos cinco espécimes positivos para S. enterica. As amostras isoladas de três crianças apresentaram resistência a ácido nalidíxico, ácido nalidíxico + cloranfenicol e ácido nalidíxico + cloranfenicol + ampicilina. Nenhuma amostra produziu ESBL. Todas as amostras albergavam os genes invA e iroB. O marcador spvC foi observado em amostras isoladas de duas crianças infectadas por S. Typhimurium e S. Enteritidis. CONCLUSÃO: Os resultados demonstram que diarreia associada a S. enterica é raramente observada entre crianças da nossa região e indicam a necessidade de avaliação periódica do perfil de suscetibilidade a antimicrobianos da bactéria para orientar o estabelecimento de antibioticoterapia, quando indicada. Abstract in english Introduction: Acute infectious diarrhea is still regarded as a public health problem associated with a wide range of etiologic agents, from which Salmonella enterica is particularly worth mentioning inasmuch as it is a major cause of inflammatory diarrhea in both developed and developing countries. Objective: To assess the distribution of S. enterica among children with acute diarrhea in Belo Horizonte and to characterize bacterium isolates. Material and methods: The stud (more) y group comprised a total of 157 children from low socioeconomic background. Stool samples were collected for leukocyte analysis and Salmonella bacterial culture. The isolates were serotyped and evaluated as to antimicrobial susceptibility profile, extended-spectrum ?-lactamases (ESBL) production, and presence of virulence markers (invA, iroB, and spvC). RESULTS: A total of 5/3.2% children were infected by S. enterica, 3/60% by S. enterica Typhimurium, 1/20% by S. enterica Enteritidis and 1/20% S. enterica subsp. enterica serotype 8.20:z4,z23:-. Fecal leucocytes were detected in two out of five fecal specimens positive for S. enterica. Isolates from three children were resistant to nalidixic acid, nalidixic acid + chloramphenicol, and nalidixic acid + chloramphenicol + ampicillin. ESBL production was not detected. All samples presented invA and iroB genes. spvC marker was observed in isolates from two children infected by S. Typhimurium and S. Enteritidis. Conclusion: The results demonstrate that S. enterica infection is uncommon among children from our region. Furthermore, they indicate the need for periodic monitoring of bacterial antimicrobial susceptibility profile in order to establish suitable antimicrobial therapy when required.

Sousa, Mireille Ângela Bernardes; Mendes, Edilberto Nogueira; Penna, Francisco José; Péret-Filho, Luciano Amedée; Magalhães, Paula Prazeres

2013-02-01

129

Peroxide-shunt substrate-specificity for the Salmonella typhimurium O2-dependent tRNA modifying monooxygenase (MiaE).  

UK PubMed Central (United Kingdom)

Post-transcriptional modifications of transfer RNA (tRNA)1 are made to structurally diversify tRNA. These modifications alter non-covalent interactions within the ribosomal machinery, resulting in phenotypic changes related to cell metabolism, growth, and virulence. MiaE is a carboxylate bridged, non-heme diiron monooxygenase, which catalyzes the O2-dependent hydroxylation of a hypermodified-tRNA nucleoside at position 37 (2-methylthio-N6-isopentenyl-adenosine(37)-tRNA) [designated ms2i6A37]. In this work, recombinant MiaE was cloned from Salmonella typhimurium, purified to homogeneity, and characterized by UV-visible and dual-mode X-band EPR spectroscopy for comparison to other non-heme diiron enzymes. Additionally, three nucleoside substrate-surrogates (i6A, Cl2i6A, and ms2i6A) and their corresponding hydroxylated products (io6A, Cl2io6A, and ms2io6A) were synthesized to investigate the chemo- and stereospecificity of this enzyme. In the absence of the native electron transport chain, the peroxide-shunt was utilized to monitor the rate of substrate hydroxylation. Remarkably, regardless of the substrate (i6A, Cl2i6A, and ms2i6A) used in peroxide-shunt assays, hydroxylation of the terminal isopentenyl-C4-position was observed with > 97% E-stereoselectivity. No other non-specific hydroxylation products were observed in enzymatic assays. Steady-state kinetic experiments also demonstrate that the initial rate of MiaE hydroxylation is highly influenced by the substituent at the C2-position of the nucleoside base (v0/[E] for ms2i6A > i6A > Cl2i6A]. Indeed, the > 3-fold rate enhancement exhibited by MiaE for the hydroxylation of the free ms2i6A nucleoside relative to i6A is consistent with previous whole cell assays reporting the io6A and ms2io6A product distribution within native tRNA-substrates. This observation suggests that the nucleoside C2-substituent is a key point of interaction regulating MiaE substrate specificity.

Corder AL; Subedi BP; Zhang S; Dark AM; Foss FW; Pierce BS

2013-08-01

130

Genomic characterization provides new insight into Salmonella phage diversity.  

UK PubMed Central (United Kingdom)

BACKGROUND: Salmonella is a widely distributed foodborne pathogen that causes tens of millions of salmonellosis cases globally every year. While the genomic diversity of Salmonella is increasingly well studied, our knowledge of Salmonella phage genomic diversity is still rather limited, despite the contributions of both lysogenic and lytic phages to Salmonella virulence, diversity and ecology (e.g., through horizontal gene transfer and Salmonella lysis). To gain a better understanding of phage diversity in a specific ecological niche, we sequenced 22 Salmonella phages isolated from a number of dairy farms from New York State (United States) and analyzed them using a comparative genomics approach. RESULTS: Classification of the 22 phages according to the presence/absence of orthologous genes allowed for classification into 8 well supported clusters. In addition to two phage clusters that represent novel virulent Salmonella phages, we also identified four phage clusters that each contained previously characterized phages from multiple continents. Our analyses also identified two clusters of phages that carry putative virulence (e.g., adhesins) and antimicrobial resistance (tellurite and bicyclomycin) genes as well as virulent and temperate transducing phages. Insights into phage evolution from our analyses include (i) identification of DNA metabolism genes that may facilitate nucleotide synthesis in phages with a G+C % distinct from Salmonella, and (ii) evidence of Salmonella phage tailspike and fiber diversity due to both single nucleotide polymorphisms and major re-arrangements, which may affect the host specificity of Salmonella phages. CONCLUSIONS: Genomics-based characterization of 22 Salmonella phages isolated from dairy farms allowed for identification of a number of novel Salmonella phages. While the comparative genomics analyses of these phages provide a number of new insights in the evolution and diversity of Salmonella phages, they only represent a first glimpse into the diversity of Salmonella phages that is likely to be discovered when phages from different environments are characterized.

Moreno Switt AI; Orsi RH; den Bakker HC; Vongkamjan K; Altier C; Wiedmann M

2013-01-01

131

Tentative Colistin Epidemiological Cut-Off Value for Salmonella spp.  

DEFF Research Database (Denmark)

The objective of this research was to determine minimal inhibitory concentration (MIC) population distributions for colistin for Salmonella on subtype level. Furthermore, we wanted to determine if differences in MIC for colistin could be explained by mutations in pmrA or pmrB encoding proteins involved in processes that influence the binding of colistin to the cell membrane. During 2008–2011, 6,583 Salmonella enterica subsp. enterica isolates of human origin and 1931 isolates of animal/meat origin were collected. The isolates were serotyped, and susceptibility was tested towards colistin (range 1–16 mg/L). Moreover, 37 isolates were tested for mutations in pmrA and pmrB by polymerase chain reaction (PCR) and DNA sequencing. MIC distribution for colistin at serotype level showed that Salmonella Dublin (n=198) followed by Salmonella Enteritidis (n=1247) were less susceptible than “other” Salmonella serotypes originating from humans (n=5,274) and Salmonella Typhimurium of animal/meat origin (n=1794). MIC was ?1 mg/L for 98.9% of “other” Salmonella serotypes originating from humans, 99.4% of Salmonella Typhimurium, 61.3% of Salmonella Enteritidis, and 12.1% of Salmonella Dublin isolates. 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 Reading and in pmrB in one Salmonella Concord isolate, both with MIC of ?1 for colistin. In conclusion, our study indicates that missense mutations are not necessarily involved in increased MICs for colistin. Increased MICs for colistin seemed to be linked to specific serotypes (Salmonella Dublin and Salmonella Enteritidis). We recommend that Salmonella with MIC of >2 mg/L for colistin be evaluated on the serovar level.

AgersØ, Yvonne; Torpdahl, Mia

2012-01-01

132

A carbon nanotube immunosensor for Salmonella  

Science.gov (United States)

Antibody-functionalized carbon nanotube devices have been suggested for use as bacterial detectors for monitoring of food purity in transit from the farm to the kitchen. Here we report progress towards that goal by demonstrating specific detection of Salmonella in complex nutrient broth solutions using nanotube transistors functionalized with covalently-bound anti-Salmonella antibodies. The small size of the active device region makes them compatible with integration in large-scale arrays. We find that the on-state current of the transistor is sensitive specifically to the Salmonella concentration and saturates at low concentration (Salmonella and other bacteria types, with no sign of saturation even at much larger concentrations (10^8 cfu/ml).

Lerner, Mitchell B.; Goldsmith, Brett R.; McMillon, Ronald; Dailey, Jennifer; Pillai, Shreekumar; Singh, Shree R.; Johnson, A. T. Charlie

133

MÉTODOS DE EXTRAÇÃO DE DNA PARA A DETECÇÃO DE Salmonella EM OVOS DE GALINHAS, COM E SEM CASCA, ATRAVÉS DA REAÇÃO EM CADEIA PELA POLIMERASE DNA EXTRACTION METHODS FOR Salmonella DETECTION IN CHICKEN EGGS, INSHELL AND OUTSHELL, BY POLIMERASE CHAIN REACTION  

Directory of Open Access Journals (Sweden)

Full Text Available O diagnóstico microbiológico de Salmonella sp em amostras de alimentos é demorado, com cinco diferentes etapas, levando cerca de 120 horas até o resultado final. A utilização da técnica da Reação em Cadeia pela Polimerase (PCR) pode diminuir esse período, porém sofre influência de substâncias presentes na amostra que afetam a reação. O objetivo deste trabalho foi comparar dois métodos de extração de DNA, a extração por tratamento térmico e a pelo fenol-clorofórmio, em amostras de 100 ovos de galinhas domésticas artificialmente contaminados com uma cepa de Salmonella enterica sorovar typhimurium em fase estacionária. O material obtido com as extrações foi submetido à PCR, utilizando-se um par de iniciadores que amplificam um fragmento de 284pb do gene InvA de Salmonella sp. Comparando os métodos de extração, observou-se uma diferença na capacidade de detecção de 12% a favor do método do fenol-clorofórmio, quando a extração foi realizada a partir do ovo com casca. No momento em que a mesma metodologia foi usada apenas com a parte interna dos ovos, essa diferença subiu para 26% o que foi significativo (PThe Salmonella sp detection in feed samples is time consuming, it has five stages and requires 120 hours for final results. The use of polimerase chain reaction technique can reduce this time considerably, however it can be affected by substances from the sample. This study had the objective of comparing two methods of DNA extraction, by heating process and by phenol-chloroform in samples of 100 chicken eggs experimentally infected with a sample of Salmonella enterica sorovar typhimurium in stationary phase. After the two extraction methods a PCR was done using a pair of oligonucleotides that amplifies a fragment of 284pb in the InvA gene de Salmonella sp. Comparing the extraction methods it was noted a difference of 12% favorably to the phenol-chloroform method when the extraction was done from eggs with shell. The same method using just the egg internal part resulted in a difference of 26% with high significance (P<0.003), showing that the method used was determinant to improve the technique efficiency. However, comparing the positive percentage independent of the DNA extraction method a significant difference (P<0.047) was noted for outshell eggs. This fact suggests that for Salmonella egg analysis, only the egg internal part should be used because the shell can determine interference in technique.

Maristela Lovato Flôres; Vladimir Pinheiro do Nascimento; Ivonyr Irene Troglio Abdel Kader; Luciana Ruschel dos Santos; Alexandre Pontes Pontes; Carlos Tadeu Pippi Salle; Rui Fernando Felix Lopes

2001-01-01

134

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

UK PubMed Central (United Kingdom)

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

Singh P; Mustapha A

2013-09-01

135

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

Science.gov (United States)

Overuse of antibiotics in the medical and animal industries is one of the major causes for the development of multi-drug-resistant (MDR) food pathogens that are often difficult to treat. In the past few years, higher incidences of outbreaks caused by MDR Salmonella have been increasingly documented. The objective of this study was to develop a rapid multiplex real-time polymerase chain reaction (PCR) assay for simultaneous detection of pathogenic and MDR Salmonella spp. A multiplex TaqMan®real-time PCR was designed by targeting the invasin virulence gene (invA), and four commonly found antibiotic resistance genes, viz. ampicillin, chloramphenicol, streptomycin and tetracycline. To avoid false negative results and to increase the reliability of the assay, an internal amplification control (IAC) was added which was detected using a locked nucleic acid (LNA) probe. In serially diluted (5ng-50fg) DNA samples, the assay was able to detect 100 genomic equivalents of Salmonella, while in a multiplex format, the sensitivity was 1000 genomic equivalents. The assay performed equally well on artificially contaminated samples of beef trim, ground beef of different fat contents (73:27, 80:20, 85:15 and 93:7), chicken rinse, ground chicken, ground turkey, egg, spinach and tomato. While the detection limit for un-enriched inoculated food samples was 10(4)CFU/g, this was improved to 10CFU/g after a 12-h enrichment in buffered peptone water, with 100% reproducibility. The multiplex real-time assay developed in this study can be used as a valuable tool to detect MDR virulent Salmonella, thus enhancing the safety of food. PMID:23973830

Singh, Prashant; Mustapha, Azlin

2013-08-02

136

SALMATcor: microagglutination for Salmonella flagella serotyping.  

UK PubMed Central (United Kingdom)

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

Duarte Martínez F; Sánchez-Salazar LM; Acuña-Calvo MT; Bolaños-Acuña HM; Dittel-Dittel I; Campos-Chacón E

2010-08-01

137

Definition of the redox states of cobalt-precorrinoids: investigation of the substrate and redox specificity of CbiL from Salmonella typhimurium.  

UK PubMed Central (United Kingdom)

The enzyme CbiL from the facultative anaerobe Salmonella typhimurium exhibits a high degree of homology to CobI from the aerobe Pseudomonas denitrificans (29% identity; 51% conservation obtained by a Blastp search of the ncbi database). As CobI catalyzes the third methylation in the aerobic pathway to vitamin B12 it is proposed that CbiL catalyzes the analogous step in the anaerobic pathway. Potential metallo and metal-free substrates were characterized and their redox states defined by a combination of physicochemical techniques (MALDI-MS, NMR, UV/vis, IR, and EPR) and then used to investigate the function of CbiL. CbiL exhibited an absolute requirement for the presence of a metal ion (Co(II), Ni(II), or Zn(II)) within the tetrapyrrole substrate. CbiL had no preference for the redox state of its cobalt tetrapyrrole substrate, methylating both the reduced form, Co(II) 2, 7-dimethyl-dipyrrocorphin (Co(II)-precorrin-2), and the oxidized form, Co(III) 2,7-dimethyl-isobacterioclorin (Co(III)-factor-II). In contrast CbiL had a marked preference for the oxidized Ni(II) and Zn(II)-2,7-dimethyl-isobacteriochlorin (Ni(II) and Zn(II)-factor-II). Removal of the metal ion from a product of CbiL (Zn(II)-factor-III) allowed characterization by 13C NMR, identifying the tetrapyrrole as 2,7,20-trimethyl-isobacteriochlorin (factor-3), indicating that CbiL methylates at C20, the same site as that methylated by CobI. Competition experiments, utilizing isotopic labeling to distinguish otherwise identical mass substrates and products, revealed that oxidized Co(III) or Ni(II)-factor-II were equally good substrates, whereas Co(II)-precorrin-2 was much preferred over Ni(II)-precorrin-2. Excess Ni(II)-precorrin-2 did not decrease CbiL methylation of Co(II)-precorrin-2, implying that CbiL has a low affinity for Ni(II)-precorrin-2. These results are interpreted on the basis of tetrapyrrole ruffling occurring on the optimization of the metallo-N bond distances. The greater flexibility of the reduced precorrin-2 ring system allows greater deformation on accommodating the bound metal ion, the distortions imposed by bound Ni(II) or Zn(II) ions being larger than Co(II). The resulting distortions imposed on the precorrin ring could then decrease catalysis by causing a departure from the optimal substrate conformation required for CbiL. On oxidation of the Ni(II) or Zn(II)-precorrin-2, the increased stiffness of the ring could then constrain the metallo-factor-II conformation toward that of the usual substrate, allowing greater methylation by CbiL. In contrast to its counterpart CobI in the aerobic pathway of B12 biosynthesis, which methylates the metal-free precorrin-2, these studies show CbiL to be the first methylase unique to the anaerobic pathway, methylating a metallo-precorrin-2 substrate. Implications of CbiL specificity for the mechanism of the anaerobic B12 pathway are discussed.

Spencer P; Stolowich NJ; Sumner LW; Scott AI

1998-10-01

138

Definition of the redox states of cobalt-precorrinoids: investigation of the substrate and redox specificity of CbiL from Salmonella typhimurium.  

Science.gov (United States)

The enzyme CbiL from the facultative anaerobe Salmonella typhimurium exhibits a high degree of homology to CobI from the aerobe Pseudomonas denitrificans (29% identity; 51% conservation obtained by a Blastp search of the ncbi database). As CobI catalyzes the third methylation in the aerobic pathway to vitamin B12 it is proposed that CbiL catalyzes the analogous step in the anaerobic pathway. Potential metallo and metal-free substrates were characterized and their redox states defined by a combination of physicochemical techniques (MALDI-MS, NMR, UV/vis, IR, and EPR) and then used to investigate the function of CbiL. CbiL exhibited an absolute requirement for the presence of a metal ion (Co(II), Ni(II), or Zn(II)) within the tetrapyrrole substrate. CbiL had no preference for the redox state of its cobalt tetrapyrrole substrate, methylating both the reduced form, Co(II) 2, 7-dimethyl-dipyrrocorphin (Co(II)-precorrin-2), and the oxidized form, Co(III) 2,7-dimethyl-isobacterioclorin (Co(III)-factor-II). In contrast CbiL had a marked preference for the oxidized Ni(II) and Zn(II)-2,7-dimethyl-isobacteriochlorin (Ni(II) and Zn(II)-factor-II). Removal of the metal ion from a product of CbiL (Zn(II)-factor-III) allowed characterization by 13C NMR, identifying the tetrapyrrole as 2,7,20-trimethyl-isobacteriochlorin (factor-3), indicating that CbiL methylates at C20, the same site as that methylated by CobI. Competition experiments, utilizing isotopic labeling to distinguish otherwise identical mass substrates and products, revealed that oxidized Co(III) or Ni(II)-factor-II were equally good substrates, whereas Co(II)-precorrin-2 was much preferred over Ni(II)-precorrin-2. Excess Ni(II)-precorrin-2 did not decrease CbiL methylation of Co(II)-precorrin-2, implying that CbiL has a low affinity for Ni(II)-precorrin-2. These results are interpreted on the basis of tetrapyrrole ruffling occurring on the optimization of the metallo-N bond distances. The greater flexibility of the reduced precorrin-2 ring system allows greater deformation on accommodating the bound metal ion, the distortions imposed by bound Ni(II) or Zn(II) ions being larger than Co(II). The resulting distortions imposed on the precorrin ring could then decrease catalysis by causing a departure from the optimal substrate conformation required for CbiL. On oxidation of the Ni(II) or Zn(II)-precorrin-2, the increased stiffness of the ring could then constrain the metallo-factor-II conformation toward that of the usual substrate, allowing greater methylation by CbiL. In contrast to its counterpart CobI in the aerobic pathway of B12 biosynthesis, which methylates the metal-free precorrin-2, these studies show CbiL to be the first methylase unique to the anaerobic pathway, methylating a metallo-precorrin-2 substrate. Implications of CbiL specificity for the mechanism of the anaerobic B12 pathway are discussed. PMID:9778368

Spencer, P; Stolowich, N J; Sumner, L W; Scott, A I

1998-10-20

139

Salmonella enhance chemosensitivity in tumor through connexin 43 upregulation.  

UK PubMed Central (United Kingdom)

The use of preferentially replicating bacteria as oncolytic agents is one of the innovative approaches for the treatment of cancer. The capability of Salmonella to disperse within tumors and hence to delay tumor growth was augmented when combined with chemotherapy. This work is warranted to elucidate the underlying mechanism of antitumor effects by the combination therapy of Salmonella and cisplatin. The presence of functional gap junctions is highly relevant for the success of chemotherapy. Following Salmonella treatment, dose- and time-dependent upregulation of connexin 43 (Cx43) expressions were observed. Moreover, Salmonella significantly enhanced gap intercellular communication (GJIC), as revealed by the fluorescent dye scrape loading assay. To study the pathway underlying these Salmonella-induced effects, we found that Salmonella induced a significant increase in mitogen-activated protein kinases (MAPK) signaling pathways. The Salmonella-induced upregulation of Cx43 was prevented by treatment of cells with the phosphorylated p38 inhibitor, but not phosphorylated extracellular signal-regulated kinase (pERK) inhibitor or phosphorylated c-jun N terminal kinase (pJNK) inhibitor. Specific knockdown of Cx43 had an inhibitory effect on GJIC and resulted in a reduction of cell death after Salmonella and cisplatin treatment. Our results suggest that accumulation of Salmonella in tumor sites leads to increase Cx43 gap junction communication and enhances the combination of Salmonella and cisplatin therapeutic effects.

Chang WW; Lai CH; Chen MC; Liu CF; Kuan YD; Lin ST; Lee CH

2013-10-01

140

Salmonella enhance chemosensitivity in tumor through connexin 43 upregulation.  

Science.gov (United States)

The use of preferentially replicating bacteria as oncolytic agents is one of the innovative approaches for the treatment of cancer. The capability of Salmonella to disperse within tumors and hence to delay tumor growth was augmented when combined with chemotherapy. This work is warranted to elucidate the underlying mechanism of antitumor effects by the combination therapy of Salmonella and cisplatin. The presence of functional gap junctions is highly relevant for the success of chemotherapy. Following Salmonella treatment, dose- and time-dependent upregulation of connexin 43 (Cx43) expressions were observed. Moreover, Salmonella significantly enhanced gap intercellular communication (GJIC), as revealed by the fluorescent dye scrape loading assay. To study the pathway underlying these Salmonella-induced effects, we found that Salmonella induced a significant increase in mitogen-activated protein kinases (MAPK) signaling pathways. The Salmonella-induced upregulation of Cx43 was prevented by treatment of cells with the phosphorylated p38 inhibitor, but not phosphorylated extracellular signal-regulated kinase (pERK) inhibitor or phosphorylated c-jun N terminal kinase (pJNK) inhibitor. Specific knockdown of Cx43 had an inhibitory effect on GJIC and resulted in a reduction of cell death after Salmonella and cisplatin treatment. Our results suggest that accumulation of Salmonella in tumor sites leads to increase Cx43 gap junction communication and enhances the combination of Salmonella and cisplatin therapeutic effects. PMID:23558669

Chang, Wen-Wei; Lai, Chih-Ho; Chen, Man-Chin; Liu, Chi-Fan; Kuan, Yu-Diao; Lin, Song-Tao; Lee, Che-Hsin

2013-04-05

 
 
 
 
141

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

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi produzir e purificar anticorpos policlonais específicos para Salmonella Enteritidis (Enterobacteriaceae). O anti-soro foi produzido em coelhos, empregando-se flagelina purificada. O título e a especificidade foram determinados através do ensaio imunoenzimático - ELISA e a purificação por cromatografia de afinidade com sepharose Proteína A. As suspensões bacterianas foram cultivadas em cinco diferentes meios de cultura (infusão de cérebro coração - BHI, caldo tripticase soja, caldo lactosado, caldo nutriente - CN e água peptonada). Observou-se que dependendo do meio o título do anti-soro pode variar e os melhores resultados foram obtidos com BHI e CN. O anti-soro foi específico para Salmonella Enteritidis, apresentando porcentagens de reações cruzadas com Salmonella Typhimurium, Salmonella Infantis e Salmonella Newport de 16,0, 11,9 e 6,4%, respectivamente. Menores porcentagens foram obtidas com outras enterobactérias testadas. Esses resultados indicam a possibilidade da utilização desses anticorpos na padronização de ensaios imunológicos para a detecção de Salmonella EnteritidisThe purpose of this study was to produce and to purify specific polyclonal antibodies for Salmonella Enteritidis (Enterobacteriaceae). The anti-serum was raised in rabbits using purified flagelin. Anti-serum titer and specificity were determined by an immunoassay - ELISA and its purification was performed by sepharose protein A affinity chromatography. The bacteria suspensions were cultivated in five different media (brain heart infusion - BHI, tripticase soy broth, nutrient broth - NB, peptone water). Results have showed that anti-serum titers varied depending on which media type was used and BHI and NB media yielded the most significant results. The anti-serum produced was specific for Salmonella Enteritidis. Its cross-reactivity with Salmonella Thyphimurium, Salmonella Infantis and Salmonella Newport were 16.0, 11.9 and 6.4% respectively and lower percentages than those were observed in other Enterobacteriaceae species tested. Results indicate that these polyclonal antibodies may be used in standardization of immunological assays for Salmonella Enteritidis detection

Iliana Alcocer; Eiko Itano; Mario Augusto Ono; Tereza Cristina R.M. de Oliveira

2002-01-01

142

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

Directory of Open Access Journals (Sweden)

Full Text Available Aim: To study the incidence of S.enteritidis in poultry and meat samples by cultural and PCR methods. Materials and Methods: A total of 130 samples (25 each of chicken, mutton, poultry faeces, cloacal samples and 10 each of liver, spleen and kidney) collected from different sources were subjected to cultural and PCR methods for the presence of Salmonella and Salmonella enteritidis. Primers for invA and sefA gene were used for Salmonella and S.enteritidis respectively. Results: Out of 130 samples, 87 were positive for Salmonella spp. i.e. chicken-16(64%), mutton-12(48%), faeces-23(92%), cloacal swabs-23(92%), liver-5(50%), spleen and kidney samples-4(40%) each by PCR methods, whereas 77 were positive by cultural method i.e. chicken-14(56%), mutton-10(40%), faeces-22(88%), cloacal swabs-21(84%), liver-4(40%), spleen and kidney-3(30% each). Out of 87 positive for Salmonella by PCR method, 59(chicken-12, mutton-7, faeces-17, cloacal swabs-15, liver-3, spleen-2, kidney-3) were positive for S.enteritidis. High incidence of S.enteritidis (68%) in all the above samples are indicative of unhygienic conditions in poultry farms. Selective enrichment with Rappaport-Vassilidias (RV) broths and Tetrathionate (TT) broths were superior over Selenite-F (SF) and Selenite cysteine (SC) broths. Conclusions: High incidence of S.enteritidis was seen in most of poultry samples like chicken, kidney, liver and it's faeces than mutton, which was indicative of contamination of S.enteritidis is more prevalent in poultry farms. [Vet World 2012; 5(9.000): 541-545

Putturu Ramya; Thirtham Madhavarao; Lakkineni Venkateswara Rao

2012-01-01

143

MÉTODOS DE EXTRAÇÃO DE DNA PARA A DETECÇÃO DE Salmonella EM OVOS DE GALINHAS, COM E SEM CASCA, ATRAVÉS DA REAÇÃO EM CADEIA PELA POLIMERASE/ DNA EXTRACTION METHODS FOR Salmonella DETECTION IN CHICKEN EGGS, INSHELL AND OUTSHELL, BY POLIMERASE CHAIN REACTION  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O diagnóstico microbiológico de Salmonella sp em amostras de alimentos é demorado, com cinco diferentes etapas, levando cerca de 120 horas até o resultado final. A utilização da técnica da Reação em Cadeia pela Polimerase (PCR) pode diminuir esse período, porém sofre influência de substâncias presentes na amostra que afetam a reação. O objetivo deste trabalho foi comparar dois métodos de extração de DNA, a extração por tratamento térmico e a pelo feno (more) l-clorofórmio, em amostras de 100 ovos de galinhas domésticas artificialmente contaminados com uma cepa de Salmonella enterica sorovar typhimurium em fase estacionária. O material obtido com as extrações foi submetido à PCR, utilizando-se um par de iniciadores que amplificam um fragmento de 284pb do gene InvA de Salmonella sp. Comparando os métodos de extração, observou-se uma diferença na capacidade de detecção de 12% a favor do método do fenol-clorofórmio, quando a extração foi realizada a partir do ovo com casca. No momento em que a mesma metodologia foi usada apenas com a parte interna dos ovos, essa diferença subiu para 26% o que foi significativo (P Abstract in english The Salmonella sp detection in feed samples is time consuming, it has five stages and requires 120 hours for final results. The use of polimerase chain reaction technique can reduce this time considerably, however it can be affected by substances from the sample. This study had the objective of comparing two methods of DNA extraction, by heating process and by phenol-chloroform in samples of 100 chicken eggs experimentally infected with a sample of Salmonella enterica sor (more) ovar typhimurium in stationary phase. After the two extraction methods a PCR was done using a pair of oligonucleotides that amplifies a fragment of 284pb in the InvA gene de Salmonella sp. Comparing the extraction methods it was noted a difference of 12% favorably to the phenol-chloroform method when the extraction was done from eggs with shell. The same method using just the egg internal part resulted in a difference of 26% with high significance (P

Flôres, Maristela Lovato; Nascimento, Vladimir Pinheiro do; Kader, Ivonyr Irene Troglio Abdel; Santos, Luciana Ruschel dos; Pontes, Alexandre Pontes; Salle, Carlos Tadeu Pippi; Lopes, Rui Fernando Felix

2001-04-01

144

[Cloning and identification of ipaJ gene in Salmonella pullorum].  

UK PubMed Central (United Kingdom)

OBJECTIVE: Cloning of ipaJ gene from Salmonella pullorum C79-13, and identification of expressed IpaJ protein as an immunogen of the pathogen. METHODS: With suppression subtractive hybridization (SSH) between Salmonella pullorum strain C79-13 (tester) and Salmonella enteritidis strain 50041 (driver), three subtracted fragments PEA3, PE31 and PE44 showed high homology with ipaJ in plasmid pSFD10 of Salmonella choleraesuis C500. The three subtracted sequences were spliced together into the whole sequence of ipaJ in Salmonella pullorum. Then the ipaJ gene was amplified from Salmonella pullorum by polymerase chain reaction (PCR) and cloned into prokaryotic expressive vector pET-30a(+). Western-blot was used to identify it as an immunogen. The distribution of the gene was also detected in Salmonella pullorum isolates. RESULTS: The ipaJ gene cloned from Salmonella pullorum was 840 bp, and the expressed fusion protein was 37 kDa. Specific reaction was found between Salmonella pullorum positive serum and expressed protein by Western-blot assay, confirming its identification as an immunogen of Salmonella pullorum. The PCR results showed that the gene exists in all Salmonella pullorum strains. CONCLUSION: The ipaJ gene from Salmonella pullorum was first reported and cloned, and the expressed IpaJ protein was confirmed as an immunogen of Salmonella pullorum.

Li Q; Xu Y; Huang J; Jiao X

2010-11-01

145

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The presence of Salmonella in the intestinal tract, on the chickens skin and among their feathers, may cause carcasses contamination during slaughtering and processing and possibly it is responsible by the introduction of this microorganism in the slaughterhouses. A rapid method to identify and monitor Salmonella and their sorovars in farm is becoming necessary. A pre-enriched multiplex polymerase chain reaction (m-PCR) assay employing specific primers was developed and u (more) sed to detect Salmonella at the genus level and to identify the Salmonella enterica serovar Enteritidis (S. Enteritidis) and Salmonella enterica serovar Typhimurium (S. Typhimurium) in broiler chicken swab samples. The method was validated by testing DNA extract from 90 fresh culture cloacal swab samples from poultry chicken cultured in phosphate buffer peptone water at 37 ºC for 18 h. The final results showed the presence of Salmonella spp. in 25% of samples, S. Enteritidis was present in 12% of the Salmonella-positive samples and S. Typhimurium in 3% of the samples. The m-PCR assay developed in this study is a specific and rapid alternative method for the identification of Salmonella spp. and allowed the observation of specific serovar contamination in the field conditions within the locations where these chickens are typically raised.

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

2013-01-01

146

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The presence of Salmonella in the intestinal tract, on the chickens skin and among their feathers, may cause carcasses contamination during slaughtering and processing and possibly it is responsible by the introduction of this microorganism in the slaughterhouses. A rapid method to identify and monitor Salmonella and their sorovars in farm is becoming necessary. A pre-enriched multiplex polymerase chain reaction (m-PCR) assay employing specific primers was developed and u (more) sed to detect Salmonella at the genus level and to identify the Salmonella enterica serovar Enteritidis (S. Enteritidis) and Salmonella enterica serovar Typhimurium (S. Typhimurium) in broiler chicken swab samples. The method was validated by testing DNA extract from 90 fresh culture cloacal swab samples from poultry chicken cultured in phosphate buffer peptone water at 37 ºC for 18 h. The final results showed the presence of Salmonella spp. in 25% of samples, S. Enteritidis was present in 12% of the Salmonella-positive samples and S. Typhimurium in 3% of the samples. The m-PCR assay developed in this study is a specific and rapid alternative method for the identification of Salmonella spp. and allowed the observation of specific serovar contamination in the field conditions within the locations where these chickens are typically raised.

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

2013-03-01

147

Salmonella mutagenicity assay: reproducibility  

Energy Technology Data Exchange (ETDEWEB)

This letter to the editor presents an interlaboratory comparison of data from the Ames Salmonella mutagenicity assay from 2 different laboratories. They suggest that the variation seen with various strains of Salmonella are intrinsic variations due to the complexity of the processes of mutation rather than to laboratory conditions. (KRM)

1980-01-01

148

Genomics of Salmonella Species  

Science.gov (United States)

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.

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

149

Peroxidase-antiperoxidase and immunogold labeling of Salmonella typhimurium and Salmonella choleraesuis var kunzendorf in tissues of experimentally infected swine.  

UK PubMed Central (United Kingdom)

Peroxidase-antiperoxidase immunoenzymatic labeling and immunogold labeling techniques were evaluated for microscopic detection and location of Salmonella organisms in tissues of experimentally infected swine. Salmonella typhimurium and Salmonella choleraesuis var kunzendorf were labeled specifically by the peroxidase-antiperoxidase technique in paraffin-embedded tissues of infected swine for conventional light microscopy and by postembedding immunogold labeling on ultrathin sections for electron microscopy. Salmonella typhimurium had a low tendency to invade the enteric mucosa and did not reveal any predilection for a specific intestinal location. Salmonella choleraesuis var kunzendorf, however, was located preferentially in colon and on the luminal surface of ileal M cells of Peyer patches and had a tendency to invade the enteric mucosa there.

Pospischil A; Wood RL; Anderson TD

1990-04-01

150

Systemic administration of attenuated Salmonella choleraesuis carrying thrombospondin-1 gene leads to tumor-specific transgene expression, delayed tumor growth and prolonged survival in the murine melanoma model.  

Science.gov (United States)

Some anaerobic and facultative anaerobic bacteria have been used experimentally as anticancer agents because of their selective growth in the hypoxia regions of solid tumors after systemic administration. We have previously shown the feasibility of using attenuated Salmonella choleraesuis as a gene delivery vector. In this study, we exploited S. choleraesuis carrying thrombospondin-1 (TSP-1) gene for treating primary melanoma and experimental pulmonary metastasis in the syngeneic murine B16F10 melanoma model. Systemic administration of S. choleraesuis allowed targeted gene delivery to tumors. The bacteria accumulated preferentially in tumors over livers and spleens at ratios ranging from 1000:1 to 10,000:1. The level of transgene expression via S. choleraesuis-mediated gene transfer in tumors could reach more than 1800-fold higher than in livers and spleens. Notably, bacterial accumulation was also observed in the lungs with metastatic nodules, but not in healthy lungs. When administered into mice bearing subcutaneous or pulmonary metastatic melanomas, S. choleraesuis carrying TSP-1 gene significantly inhibited tumor growth and enhanced survival of the mice. Immunohistochemical studies in the tumors from these mice displayed decreased intratumoral microvessel density. Taken together, these findings suggest that TSP-1 gene therapy delivered by S. choleraesuis may be effective for the treatment of primary as well as metastatic melanomas. PMID:15375381

Lee, Che-Hsin; Wu, Chao-Liang; Shiau, Ai-Li

2005-02-01

151

Application of bioinformatics on the detection of pathogens by Pcr  

International Nuclear Information System (INIS)

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

2007-01-01

152

Evaluation of an indirect ELISA for the detection of Salmonella in chicken meat Avaliação de um ELISA indireto para detecção de Salmonella em carne de frango  

Directory of Open Access Journals (Sweden)

Full Text Available In this work, an indirect ELISA based on a monoclonal antibody (MAb) specific for an outer membrane protein of Salmonellaenterica serovar Enteritidis was used for detection of Salmonella in 154 samples of chicken meat. Its efficiency was determined through comparison with the results obtained from the conventional method. The prevalence of samples contaminated with Salmonella was 23% with the conventional culture method, and 26% with the ELISA. From thirty-five samples positive for Salmonella by the conventional method, 33 were also positive by ELISA. Seven other samples were only positive in the ELISA. Comparison of the results obtained in the two methods showed an ELISA sensitivity and specificity of 94%, and positive and negative predictive values of 82% and 98% respectively. The serotyping of the isolates revealed 31 Salmonella enterica serovar Enteritidis, 2 Salmonella enterica serovar Heidelberg, 1 Salmonella enterica serovar Choleraesuis and 1 Salmonella enterica sorovar 6,7:-:-.Neste trabalho, um ELISA indireto baseado em um anticorpo monoclonal (MAb) especifico para proteína de membrane externa de Salmonellaenterica serovar Enteritidis foi usado para detecção de Salmonella em 154 amostras de carne de frango. Sua eficiência foi determinada através de comparação com os resultados obtidos pela metodologia convencional. A prevalência de amostras contaminadas com Salmonella foi de 23% pelo método de cultivo convencional, e 26% pelo ELISA. De 35 amostras positivas para Salmonella pela metodologia convencional, 32 também foram positivas no ELISA. Outras sete amostras foram positivas somente no ELISA. Comparando os resultados obtidos nos dois métodos, o ELISA demonstrou sensibilidade e especificidade de 94%, e valor preditivo positivo e negativo de 82% e 98% respectivamente. A sorotipagem dos isolados revelou 31 Salmonella enterica serovar Enteritidis, 2 Salmonella enterica serovar Heidelberg, 1 Salmonella enterica serovar Choleraesuis e 1 Salmonella enterica sorovar 6,7:-:-.

Andréa dos Santos Schneid; Kelly Lameiro Rodrigues; Davi Chemello; Eduardo Cesar Tondo; Marco Antônio Zacchia Ayub; José Antonio Guimarães Aleixo

2006-01-01

153

Evaluation of an indirect ELISA for the detection of Salmonella in chicken meat/ Avaliação de um ELISA indireto para detecção de Salmonella em carne de frango  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Neste trabalho, um ELISA indireto baseado em um anticorpo monoclonal (MAb) especifico para proteína de membrane externa de Salmonellaenterica serovar Enteritidis foi usado para detecção de Salmonella em 154 amostras de carne de frango. Sua eficiência foi determinada através de comparação com os resultados obtidos pela metodologia convencional. A prevalência de amostras contaminadas com Salmonella foi de 23% pelo método de cultivo convencional, e 26% pelo ELISA. D (more) e 35 amostras positivas para Salmonella pela metodologia convencional, 32 também foram positivas no ELISA. Outras sete amostras foram positivas somente no ELISA. Comparando os resultados obtidos nos dois métodos, o ELISA demonstrou sensibilidade e especificidade de 94%, e valor preditivo positivo e negativo de 82% e 98% respectivamente. A sorotipagem dos isolados revelou 31 Salmonella enterica serovar Enteritidis, 2 Salmonella enterica serovar Heidelberg, 1 Salmonella enterica serovar Choleraesuis e 1 Salmonella enterica sorovar 6,7:-:-. Abstract in english In this work, an indirect ELISA based on a monoclonal antibody (MAb) specific for an outer membrane protein of Salmonellaenterica serovar Enteritidis was used for detection of Salmonella in 154 samples of chicken meat. Its efficiency was determined through comparison with the results obtained from the conventional method. The prevalence of samples contaminated with Salmonella was 23% with the conventional culture method, and 26% with the ELISA. From thirty-five samples po (more) sitive for Salmonella by the conventional method, 33 were also positive by ELISA. Seven other samples were only positive in the ELISA. Comparison of the results obtained in the two methods showed an ELISA sensitivity and specificity of 94%, and positive and negative predictive values of 82% and 98% respectively. The serotyping of the isolates revealed 31 Salmonella enterica serovar Enteritidis, 2 Salmonella enterica serovar Heidelberg, 1 Salmonella enterica serovar Choleraesuis and 1 Salmonella enterica sorovar 6,7:-:-.

Schneid, Andréa dos Santos; Rodrigues, Kelly Lameiro; Chemello, Davi; Tondo, Eduardo Cesar; Ayub, Marco Antônio Zacchia; Aleixo, José Antonio Guimarães

2006-09-01

154

Evaluation of VIDAS Salmonella (SLM) easy Salmonella method for the detection of Salmonella in a variety of foods: collaborative study.  

UK PubMed Central (United Kingdom)

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.

Crowley E; Bird P; Fisher K; Goetz K; Benzinger MJ Jr; Agin J; Goins D; Johnson RL

2011-11-01

155

Is it safe to eat raw seafood? Prevalence of Salmonella in some seafood products sold in Alexandria markets.  

UK PubMed Central (United Kingdom)

BACKGROUND: Salmonella is a significant microbial hazard in seafood. Salmonella-contaminated seafood usually looks and smells normal; it is therefore essential that every effort is made toward the rapid detection of Salmonella as an important criterion in quality control of seafood. AIMS: This study aims to determine the percentage of Salmonella in some Egyptian seafood sold in Alexandria markets and to study the validity of Chromagar Salmonella Plus (CASP) agar versus xylose lysine desoxycholate and Salmonella-Shigella agar for the isolation and identification of Salmonella in seafood. MATERIALS AND METHODS: Two hundred and twenty-five samples of three seafood types, shrimp, gandofli, and river mussel (om-elkhloul) were studied. Samples were selectively enriched in Rappaport-Vassiliadis and tetrathionate broth, and then plated onto the aforementioned plating media for the detection of Salmonella. RESULTS: In total, Salmonella was detected in 9.8% of the samples. The sensitivity and specificity of the media used varied according to the media and enrichment broth combinations used. The CASP and Rappaport-Vassiliadis combination yielded the best sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 95.45, 100, 100, 99.5, and 99.5%, respectively. CONCLUSION AND RECOMMENDATION: CASP was more accurate than xylose lysine desoxycholate and Salmonella-Shigella in the detection of Salmonella from seafood samples. We recommend that CASP medium should be tested against more Salmonella-positive samples before it is used as a screening plating medium for Salmonella in seafood.

Bakr WM; El Sayed AM; El Shamy HA; Amine AE

2013-08-01

156

Rapid Detection of Salmonella spp. by Using Felix-O1 Bacteriophage and High-Performance Liquid Chromatography  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A method is described whereby the presence of Salmonella spp. can be detected within 8 to 24 h of sample collection. The method depends upon the interaction of Salmonella spp. with the Salmonella-specific Felix-O1 bacteriophage. This interaction results in an increase in concentration of the bacteri...

Hirsh, Dwight C.; Martin, Lori D.

157

Sips, Sops, and SPIs but not stn influence Salmonella enteropathogenesis.  

Science.gov (United States)

The virulence factors influencing Salmonella-induced enteropathogenesis remain poorly characterised. The interactions of different serotypes of Salmonella with bovine ileal mucosa have been characterised in the ligated ileal loop model. In a quantitative intestinal invasion assay Salmonella dublin, S. choleraesuis, S. gallinarum, and S. abortusovis strains were all recovered from ileal mucosa, either with or without Peyer's patches in similar numbers. This observation suggests that the magnitude and route of intestinal invasion does not mediate Salmonella serotype host specificity. Despite being equally invasive there was a clear hierarchy in the enteropathogenicity of these serotypes. The magnitude of the enteropathogenic responses did not correlate to serotype host specificity. These observations implicate undefined serotype specific factors in influencing enteropathogenicity independently of intestinal invasion. Disruption of genes in Salmonella Pathogenicity Island (SPI) 1 of S. typhimurium and S. dublin blocked the secretion of Salmonella Invasion Proteins (Sips) and Salmonella Outer Proteins (Sops). These mutants were significantly less invasive and enteropathogenic then the wild type strain in ligated ileal loops. Disruption of sopB and sopD significantly reduced enteropathogenesis, but without influencing intestinal invasion. These two genes appear to act in concert. Surprisingly, disruption of stn, the Salmonella enterotoxin gene cloned on the basis of its homology to cholera toxin, did not influence enteropathogenesis. SopB was mapped to the 20 centisome of S. typhimurium and is flanked by 5 genes that are organised in a manner typical of a pathogenicity island, which we have termed SPI-5. Mutation of the other genes in SPI-5 also attenuated enteropathogenesis but not virulence for mice, suggesting SPI-5 is a key locus specifically influencing Salmonella enteropathogenesis. PMID:10659368

Wallis, T S; Wood, M; Watson, P; Paulin, S; Jones, M; Galyov, E

1999-01-01

158

A mutant of Salmonella enterica serovar Typhimurium RNA polymerase extracytoplasmic stress response sigma factor sigma(E) with altered promoter specificity.  

UK PubMed Central (United Kingdom)

The alternative sigma factor sigma(E) is critical for envelope stress response and plays a role in pathogenicity of a variety of different bacteria. We previously identified several critical nucleotides in the Salmonella enterica serovar Typhimurium (S. Typhimurium) sigma(E)-dependent rpoEp3 promoter that corresponded to the most conserved nucleotides in the sigma(E) consensus sequence of the -10 and -35 promoter elements. In the present study, we exploited a previously established Escherichia coli (E. coli) two-plasmid system with an error-prone PCR mutagenesis to identify mutants in the rpoE gene that suppress the mutation of the most conserved residue A-30G of the rpoEp3 promoter. This analysis identified amino-acid changes in the conserved arginine residue (R171G, R171C) located in the conserved region 4.2 of sigma(E) that enabled efficient recognition of the mutated rpoEp3 promoter. However, the change of this conserved arginine to alanine (R171A) resulted in an almost complete loss of sigma(E) activity. The activity of the mutant sigma(E) factors in directing transcription of the wild-type (WT) and the A-30G mutated rpoEp3 promoters was investigated by S1-nuclease mapping using RNA isolated from the E. coli two-plasmid system. In addition to suppression of the A-30G mutated rpoEp3 promoter, both mutant sigma factors (R171G, R171C) also efficiently directed transcription from the WT rpoEp3 promoter and from the rpoEp3 promoter with other mutations in the -35 element, indicating relaxed recognition of the sigma(E)-dependent promoters by both mutants. The activity of both mutant sigma(E) factors was confirmed in vivo in S. Typhimurium. In conclusion, replacement of the conserved R171 residue in sigma(E) by different amino-acid residues exhibited intriguingly different phenotypes; R171A almost completely abolished sigma factor activity, whereas R171G and R171C impart a relaxed recognition phenotype to sigma(E).

Rezuchova B; Skovierova H; Homerova D; Roberts M; Kormanec J

2009-08-01

159

Thermal inactivation of eight Salmonella serotypes on dry corn flour.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

160

Screening of poultry samples for Salmonella Typhimurium by PCR assay  

Directory of Open Access Journals (Sweden)

Full Text Available Poultry samples viz., cloacal swabs, egg swabs, poultry faeces and feed were screened for Salmonella Typhimurium. A set of primers derived from fli C gene were employed to standardize PCR for detection of Salmonella Typhimurium from poultry samples, which gave specific amplification of a 620 bp fragment. Boiling and snap chilling method used for template preparation. Screening of 112 samples revealed that 12 samples positive for Salmonella Typhimurium by PCR assay. [Vet. World 2012; 5(3.000): 169-172

V K Anumolu; V R Lakkineni

2012-01-01

 
 
 
 
161

Transcriptional regulation of the assT-dsbL-dsbI gene cluster in Salmonella enterica serovar Typhi IMSS-1 depends on LeuO, H-NS, and specific growth conditions.  

UK PubMed Central (United Kingdom)

The assT gene encodes an arylsulfate sulfotransferase, an enzyme that catalyzes sulfuryl transfer from phenolic sulfate to a phenolic acceptor. In Salmonella enterica serovar Typhi IMSS-1, the assT gene is located upstream of the dsbL and dsbI genes, which are involved in a disulfide bond formation required for its activation. The assT-dsbL-dsbI gene cluster forms an operon transcribed by a LeuO-dependent promoter, in rich medium A (MA). Interestingly, in the absence of cloned leuO and in a ?leuO background, two transcription start sites were detected for assT and two for dsbL-dsbI in minimal medium. The H-NS nucleoid protein repressed the expression of the assT-dsbL-dsbI LeuO-dependent operon, as well as of the assT transcriptional units. Thus, the expression of the assT-dsbL-dsbI gene cluster depends on the global regulatory proteins LeuO and H-NS, as well as on specific growth conditions.

Gallego-Hernández AL; Hernández-Lucas I; De la Cruz MA; Olvera L; Morett E; Medina-Aparicio L; Ramírez-Trujillo JA; Vázquez A; Fernández-Mora M; Calva E

2012-05-01

162

Evaluation of two new chromogenic media for detection of Salmonella in stools.  

Science.gov (United States)

A clinical collaborative study was conducted to compare two new chromogenic agar media, Rambach agar and the Salmonella Detection and Identification Medium (SMID) (bioMérieux, France), with two conventional media, Salmonella-Shigella agar and Hektoen agar. Thirty-nine Salmonella strains involving 14 serotypes were isolated from 1,454 stool specimens. After enrichment in a selective broth, 100% sensitivity was obtained with each medium. The SMID and Rambach agars are considerably more specific than the conventional media. Although SMID agar detects all Salmonella serotypes, it is not as specific as Rambach agar, which requires a complementary test (C8 esterase test) to detect all serotypes. PMID:8050441

Monnery, I; Freydiere, A M; Baron, C; Rousset, A M; Tigaud, S; Boude-Chevalier, M; de Montclos, H; Gille, Y

1994-03-01

163

Evaluation of two new chromogenic media for detection of Salmonella in stools.  

UK PubMed Central (United Kingdom)

A clinical collaborative study was conducted to compare two new chromogenic agar media, Rambach agar and the Salmonella Detection and Identification Medium (SMID) (bioMérieux, France), with two conventional media, Salmonella-Shigella agar and Hektoen agar. Thirty-nine Salmonella strains involving 14 serotypes were isolated from 1,454 stool specimens. After enrichment in a selective broth, 100% sensitivity was obtained with each medium. The SMID and Rambach agars are considerably more specific than the conventional media. Although SMID agar detects all Salmonella serotypes, it is not as specific as Rambach agar, which requires a complementary test (C8 esterase test) to detect all serotypes.

Monnery I; Freydiere AM; Baron C; Rousset AM; Tigaud S; Boude-Chevalier M; de Montclos H; Gille Y

1994-03-01

164

Rapid Detection of Salmonella in Chicken Meat Using Immunomagnetic Separation, CHROMagar, ELISA and Real-time Polymerase Chain Reaction (RT-PCR)  

Directory of Open Access Journals (Sweden)

Full Text Available The main objective of this study was to standardize and compare rapid methods for the detection of Salmonella in meat samples using Immuno-Magnetic Separation (IMS) followed by culturing in CHROMagar Plus media, Enzyme-Linked Immunosorbent Assay (ELISA) and Real-Time Polymerase Chain Reaction (RT-PCR). Ten-fold dilutions of bacterial suspension (S. typhymurium, ATCC13311) were prepared from the original concentration of 1.6 x 106cfu/ml. Chicken wing samples of 25 g each negative for Salmonella were spiked with six different concentrations of bacteria ranging from 106 to 101. These samples were incubated in buffered peptone water for 4 h as pre-enrichment step and were tested repeatedly. The IMS technique involved the use of paramagnetic polystyrene microscopic beads coated with purified antibodies against Salmonella. The CHROMagar Plus media containing chromomeric substrate facilitated detection of Salmonella species from other flora. The Assurance EIA Salmonella Kit with polyclonal antibodies directed against Salmonella facilitated easy and rapid detection. In the RT-PCR primers targeting invA gene was used which amplified a 378 bp fragment. Comparing to conventional culture method (4 days), CHROMagar plate culture following IMS showed light mauve to mauve-colored colonies of Salmonella in 23 h with high sensitivity (99%) at 1.6 cfu/ml. IMS-ELISA combination also showed high sensitivity (75%) at 1.6 x 103 cfu/ml in 8 h and minimized cross-reactivity with many Enterobacteraceae. The combination of IMS with RT-PCR took less than 7 h and was even more sensitive (100%) at 1.6 cfu/ml. Sensitivities of IMS-RT-PCR and IMS-CHROMagar were higher compared to IMS-ELISA. IMS-CHROMagar was easier to perform and detects only living Salmonella. These methods will be highly suitable for routine detection and may significantly assist the processing industry in avoiding costly recalls and the timely investigation of outbreaks.

Ensaf G. Taha; A. Mohamed; K.K. Srivastava; P.G. Reddy

2010-01-01

165

Epidemic increase in Salmonella bloodstream infection in children, Bwamanda, the Democratic Republic of Congo.  

UK PubMed Central (United Kingdom)

Salmonella enterica is the leading cause of bloodstream infection in children in sub-Saharan Africa, but few data are available from Central-Africa. We documented during the period November 2011 to May 2012 an epidemic increase in invasive Salmonella bloodstream infections in HGR Bwamanda, a referral hospital in Equateur Province, DR Congo. Salmonella spp. represented 90.4 % (103 out of 114) of clinically significant blood culture isolates and comprised Salmonella Typhimurium (54.4 %, 56 out of 103), Salmonella Enteritidis (28.2 %, 29 out of 103) and Salmonella Typhi (17.5 %, 18 out of 103), with Salmonella Enteritidis accounting for most of the increase. Most (82 out of 103, 79.6 %) isolates were obtained from children < 5 years old. Median ages of patients infected with Salmonella Typhimurium and Salmonella Enteritidis were 14 months (14 days to 64 years) and 19 months (3 months to 8 years) respectively. Clinical presentation was non-specific; the in-hospital case fatality rate was 11.1 %. More than two thirds (69.7 %, 53 out of 76) of children < 5 years for whom laboratory data were available had Plasmodium falciparum infection. Most (83/85, 97.6 %) non-typhoid Salmonella isolates as well as 6/18 (33.3 %) Salmonella Typhi isolates were multidrug resistant (i.e. resistant to the first-line oral antibiotics amoxicillin, trimethoprim-sulfamethoxazole and chloramphenicol), one (1.0 %) Salmonella Typhimurium had decreased ciprofloxacin susceptibility owing to a point mutation in the gyrA gene (Gly81Cys). Multilocus variable-number tandem-repeat (MLVA) analysis of the Salmonella Enteritidis isolates revealed closely related patterns comprising three major and four minor profiles, with differences limited to one out of five loci. These data show an epidemic increase in clonally related multidrug-resistant Salmonella bloodstream infection in children in DR Congo.

Phoba MF; De Boeck H; Ifeka BB; Dawili J; Lunguya O; Vanhoof R; Muyembe JJ; Van Geet C; Bertrand S; Jacobs J

2013-08-01

166

Antigenic relationships within the genus Salmonella as revealed by anti-Salmonella enteritidis monoclonal antibodies.  

Science.gov (United States)

A panel of 38 monoclonal antibodies (MAbs) that react with outer membrane proteins (OMPs) of Salmonella enteritidis was produced. On the basis of their binding pattern in ELISA, the MAbs were divided into three groups. The first group, consisting of 15 MAbs, was found to be Salmonella-specific as they did not cross-react with Escherichia coli or Pasteurella multocida. The second group of 15 MAbs cross-reacted with E. coli but not with P. multocida, reflecting the closer antigenic relationship of E. coli with Salmonella. The third group of 8 MAbs cross-reacted with both E. coli and P. multocida, indicating that the antigenic determinants identified by these MAbs are conserved in all the three genera. The antigenic relationship of the Salmonella serovars (S. enteritidis, S. gallinarum, S. typhimurium, S. dublin, S. agona, S. indiana and S. choleraesuis) was studied using OMPs prepared from them and the anti-S. enteritidis MAbs. Three MAbs appeared to be specific for S. enteritidis as they did not cross-react with any of the other Salmonella serovars. Twelve of the 38 MAbs cross-reacted with all the serovars tested. Six of these were specific to the Salmonella genus as they did not cross-react with any of the other Gram-negative bacteria tested. The reactivity pattern of the other MAbs indicated that S. gallinarum was antigenically close to S. enteritidis, followed in order by S. dublin, S. agona, S. typhimurium and S. indiana, whereas S. choleraesuis seemed to be antigenically quite distant from S. enteritidis. PMID:12090290

Malik, M; Butchaiah, G; Bansal, M P; Siddiqui, M Z; Bakshi, C S; Singh, R K

2002-04-01

167

Arguments against the replacement of type species of the genus Salmonella from Salmonella choleraesuis to 'Salmonella enterica' and the creation of the term 'neotype species', and for conservation of Salmonella choleraesuis.  

UK PubMed Central (United Kingdom)

The proposals of Le Minor and Popoff in 1987 and again of Euzéby in 1999 on the type species of the genus Salmonella are in violation of Rule 20a of the Bacteriological Code (1990 Revision) and should be rejected. The introduction of the term 'neotype species' should be rejected. The specific epithet choleraesuis in the binary combination Salmonella choleraesuis should be conserved. The serovar name Choleraesuis should be changed to Hogcholera.

Yabuuchi E; Ezaki T

2000-07-01

168

Salmonella radicidation of poultry carcasses  

International Nuclear Information System (INIS)

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

1982-01-01

169

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

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Full Text Available The invasive capacity and persistence of this pathogen, crop and ceca in apparently healthy birds of two broiler lines raised without growth promoter antibiotics in ration and originated from eggs inoculated eggshell and in allantoidal cavity with Salmonella Enteritidis. Histological and bacteriological exams from cecal and crop were performed with one, seven, 14 and 21 days of age after hatch in broilers of fast and slow growing rate. Bacterio-logical exams were performed fecal excretion with one, eigth, 22 and 35 days. The Salmonella Enteritidis invaded and colonizated the gastrointestinal tract of the two lines tested, but the the infection reduced with age, and was more persistant in Ross broilers. The results were different for two lines. The pathogen was excreted from just one chick of ISA Label at 22 days of age and four Ross chicks until 35 days of age. In order, Salmonella was detected in 87.5% (14/16) and 38,1% (5/16) of ceca; in 81.2% (13/16) and 12.5% (2/16) of crops; in fast and slow growing rate lines, respectively. In apparent healthy organs, excepted the crop, an inflammatory process with predominance of macrophage and lymphocytes. The slow growing rate line was effective to eliminate bacteria in the organism. Key-words: Ceca, crop, fecal excretion, inflammation. Avaliaram-se, neste estudo, a capacidade inva-siva, a persistência e a freqüência de excreção fecal da Salmonella Enteritidis em aves aparentemente saudáveis de duas linhagens de frango de corte, criadas sem antibióticos promotores de crescimento na ração e oriundas de ovos inoculados na casca ou na cavidade alantóide com Salmonella Enteritidis fagotipo 4. Realizaram-se exames bacteriológicos das excretas com um, oito, 22 e 35 dias, e histológicos e bacteriológicos do inglúvio e ceco, com um, sete, quatorze e 21 dias pós-eclosão em frangos de crescimento rápido e lento. Salmonella Enteritidis invadiu e colonizou o trato gastrintestinal das duas linhagens, mas a infecção declinou com a idade, sendo mais persistente na linhagem Ross. O patógeno foi excretado de uma única ave ISA Label até 22 dias de vida e em quatro aves da linhagem Ross até 35 dias. Constatou a Salmonella em ordem de colonização, em 87,5% (14/16) e 38,1% (5/16) dos cecos; em 81,2% (13/16) e 12,5% (2/16) dos inglúvios das linhagens Ross e ISA Label, respectivamente. Nos cecos aparentemente saudáveis, evidenciou-se um processo inflamatório com predominância de macrófagos e ou linfócitos, enquanto no inglúvio não se detectaram alterações microscópicas. A linhagem de ISA Label foi mais hábil em eliminar a bactéria do seu organismo. Palavras-chaves: Ceco, excreção fecal, inflamação, inglúvio.

Maria Auxiliadora Andrade; Albenones José de Mesquita; José Henrique Stringhini; Leandro da Silva Chaves; Maíra Silva Mattos; Adson Santa Cruz Oliveira; Dunya Mara Cardoso Moraes

2007-01-01

170

Cytokine gene expression in lymph node and spleen of sheep in response to Salmonella infection by two serotypes displaying different host specificity.  

UK PubMed Central (United Kingdom)

In order to investigate the determinism of the host specificity and to better understand the host resistance mechanisms, infections of sheep were performed with either S. abortusovis, serotype specific for ovine species, or with S. dublin, serotype adapted to cattle and accidentally transmissible to human. Following a subcutaneous challenge, S. dublin disseminated more rapidly towards lymphoid tissues than S. abortusovis. However, S. abortusovis tended to persist in spleen more efficiently than S. dublin. Using a quantitative RT-PCR method, the expression level of ovine cytokines genes was measured in the draining lymph node and in the spleen, in the course of infection. Inflammatory cytokine response was characterised by an early and strong increase of IL-1beta and TNFalpha mRNA in both lymphoid organs following S. dublin infection, while S. abortusovis challenge only induced IL-1beta mRNA increase in the spleen at day 3 post-inoculation. Likewise, S. dublin infection provoked a marked increase of IL-12 mRNA and a slight up-regulation of IFNgamma gene transcription in the local lymphoid site, in contrast to S. abortusovis infection. Elsewhere, both serotypes induced a strong and early IL-10 mRNA production and had no effect on IL-4 gene expression. Finally, taken together, these data suggest that the intensity of inflammatory and anti-infectious cytokine responses, but not the type 2 cytokine response, is serotype-dependent. They also suggest that the host-specific serotype, by limiting the host cytokine-mediated defence, could favour its persistence within lymphoid organs.

Montagne A; Menanteau P; Boivin R; Bernard S; Lantier F; Lalmanach AC

2001-10-01

171

Cytokine gene expression in lymph node and spleen of sheep in response to Salmonella infection by two serotypes displaying different host specificity.  

Science.gov (United States)

In order to investigate the determinism of the host specificity and to better understand the host resistance mechanisms, infections of sheep were performed with either S. abortusovis, serotype specific for ovine species, or with S. dublin, serotype adapted to cattle and accidentally transmissible to human. Following a subcutaneous challenge, S. dublin disseminated more rapidly towards lymphoid tissues than S. abortusovis. However, S. abortusovis tended to persist in spleen more efficiently than S. dublin. Using a quantitative RT-PCR method, the expression level of ovine cytokines genes was measured in the draining lymph node and in the spleen, in the course of infection. Inflammatory cytokine response was characterised by an early and strong increase of IL-1beta and TNFalpha mRNA in both lymphoid organs following S. dublin infection, while S. abortusovis challenge only induced IL-1beta mRNA increase in the spleen at day 3 post-inoculation. Likewise, S. dublin infection provoked a marked increase of IL-12 mRNA and a slight up-regulation of IFNgamma gene transcription in the local lymphoid site, in contrast to S. abortusovis infection. Elsewhere, both serotypes induced a strong and early IL-10 mRNA production and had no effect on IL-4 gene expression. Finally, taken together, these data suggest that the intensity of inflammatory and anti-infectious cytokine responses, but not the type 2 cytokine response, is serotype-dependent. They also suggest that the host-specific serotype, by limiting the host cytokine-mediated defence, could favour its persistence within lymphoid organs. PMID:11587739

Montagne, A; Menanteau, P; Boivin, R; Bernard, S; Lantier, F; Lalmanach, A C

2001-10-01

172

Use of bacteriophages as biocontrol agents to control Salmonella associated with seed sprouts.  

UK PubMed Central (United Kingdom)

Two Salmonella bacteriophages (SSP5 and SSP6) were isolated and characterized based on their morphology and host range, and evaluated for their potential to control Salmonella Oranienburg in vitro and on experimentally contaminated alfalfa seeds. Phages SSP5 and SSP6 were classified as members of the Myoviridae and Siphoviridae families, respectively. Both phages had a broad host range of over 65% of the 41 Salmonella strains tested. During in vitro trials, the phages resulted in incomplete lysis of Salmonella cultures, in spite of high levels of phage remaining in the system. Phage SSP5 was more effective in reducing Salmonella populations. Addition of phage SSP6 to alfalfa seeds previously contaminated with S. Oranienburg caused an approximately 1 log(10) CFU g(-1) reduction of viable Salmonella, which was achieved 3 h after phage application. Thereafter the phage had no inhibitory effect on Salmonella population growth. A second addition of the same (SSP6) or different (SSP5) phage to a Salmonella culture treated with phage SSP6, did not affect Salmonella populations. It was further shown that development of Salmonella permanently resistant to phage was not evident in either seed or in vitro challenge trials, suggesting the existence of a temporary, acquired, non-specific phage resistance phenomenon. These factors may complicate the use of phages for biocontrol.

Kocharunchitt C; Ross T; McNeil DL

2009-01-01

173

One-Step Triplex High-Resolution Melting Analysis for Rapid Identification and Simultaneous Subtyping of Frequently Isolated Salmonella Serovars  

Science.gov (United States)

Salmonellosis is one of the most important food-borne diseases worldwide. For outbreak investigation and infection control, accurate and fast subtyping methods are essential. A triplex gene-scanning assay was developed and evaluated for serotype-specific subtyping of Salmonella enterica isolates based on specific single-nucleotide polymorphisms in fragments of fljB, gyrB, and ycfQ. Simultaneous gene scanning of fljB, gyrB, and ycfQ by high-resolution melting-curve analysis of 417 Salmonella isolates comprising 46 different serotypes allowed the unequivocal, simple, and fast identification of 37 serotypes. Identical melting-curve profiles were obtained in some cases from Salmonella enterica serotype Enteritidis and Salmonella enterica serotype Dublin, in all cases from Salmonella enterica serotype Ohio and Salmonella enterica serotype Rissen, from Salmonella enterica serotype Mbandaka and Salmonella enterica serotype Kentucky, and from Salmonella enterica serotype Bredeney, Salmonella enterica serotype Give, and Salmonella enterica serotype Schwarzengrund. To differentiate the most frequent Salmonella serotype, Enteritidis, from some S. Dublin isolates, an additional single PCR assay was developed for specific identification of S. Enteritidis. The closed-tube triplex high-resolution melting-curve assay developed, in combination with an S. Enteritidis-specific PCR, represents an improved protocol for accurate, cost-effective, simple, and fast subtyping of 39 Salmonella serotypes. These 39 serotypes represent more than 94% of all human and more than 85% of all nonhuman Salmonella isolates (including isolates from veterinary, food, and environmental samples) obtained in the years 2008 and 2009 in Austria.

Zeinzinger, Josef; Stoger, Anna; Kornschober, Christian; Kunert, Renate; Allerberger, Franz; Mach, Robert; Ruppitsch, Werner

2012-01-01

174

One-step triplex high-resolution melting analysis for rapid identification and simultaneous subtyping of frequently isolated Salmonella serovars.  

UK PubMed Central (United Kingdom)

Salmonellosis is one of the most important food-borne diseases worldwide. For outbreak investigation and infection control, accurate and fast subtyping methods are essential. A triplex gene-scanning assay was developed and evaluated for serotype-specific subtyping of Salmonella enterica isolates based on specific single-nucleotide polymorphisms in fragments of fljB, gyrB, and ycfQ. Simultaneous gene scanning of fljB, gyrB, and ycfQ by high-resolution melting-curve analysis of 417 Salmonella isolates comprising 46 different serotypes allowed the unequivocal, simple, and fast identification of 37 serotypes. Identical melting-curve profiles were obtained in some cases from Salmonella enterica serotype Enteritidis and Salmonella enterica serotype Dublin, in all cases from Salmonella enterica serotype Ohio and Salmonella enterica serotype Rissen, from Salmonella enterica serotype Mbandaka and Salmonella enterica serotype Kentucky, and from Salmonella enterica serotype Bredeney, Salmonella enterica serotype Give, and Salmonella enterica serotype Schwarzengrund. To differentiate the most frequent Salmonella serotype, Enteritidis, from some S. Dublin isolates, an additional single PCR assay was developed for specific identification of S. Enteritidis. The closed-tube triplex high-resolution melting-curve assay developed, in combination with an S. Enteritidis-specific PCR, represents an improved protocol for accurate, cost-effective, simple, and fast subtyping of 39 Salmonella serotypes. These 39 serotypes represent more than 94% of all human and more than 85% of all nonhuman Salmonella isolates (including isolates from veterinary, food, and environmental samples) obtained in the years 2008 and 2009 in Austria.

Zeinzinger J; Pietzka AT; Stöger A; Kornschober C; Kunert R; Allerberger F; Mach R; Ruppitsch W

2012-05-01

175

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

Directory of Open Access Journals (Sweden)

Full Text Available A new procedure for rapid detection of Salmonella in foods, based on the combination of SPRINT TM, MSRV TM and Salmonella Latex TestTM, was evaluated. SPRINT TM is a system to reduce the preenrichment and selective enrichment steps to 24 hours. MSRV TM is a semi-solid selective media for detection of motile Salmonella. Salmonella Latex TestTM is a rapid latex agglutination test for Salmonella. Using the three systems in combination, the total time for detection of Salmonella in a food sample is 48h. Evaluations were performed in artificially contaminated ready-to-eat baby-foods and raw Brazilian sausages (lingüiça) containing no added microorganisms. The BAM conventional culture procedure was used as reference method. The study with baby foods indicated that the new procedure had good sensitivity (89%) and specificity (100%), without cross-reactions with Enterobacteriaceae. However, when applied to naturally contaminated foods, the performance was poor: chi square (x² = 5.062, ?> 0. 05) and Kappa-Cohen agreement (K = 0.171, p=0.089) indexes indicated that the differences between results given by the two procedures were significant and the correlation between them was low.Avaliou-se um novo procedimento para detecção rápida de Salmonella em alimentos, baseado na combinação entre SPRINT®, MSRV® e Salmonella Latex Test® . SPRINT® é um sistema para reduzir as etapas de pré-enriquecimento e enriquecimento seletivo para 24 h. MSRV® é um meio seletivo semi-sólido para detecção de salmonelas móveis. Salmonella Latex Test® é um teste rápido de aglutinação de látex. A combinação dos três sistemas permite que a detecção de Salmonella em alimentos possa ser feita em apenas 48 h. O procedimento foi avaliado em alimentos infantis prontos para consumo, experimentalmente contaminados com Salmonella exclusivamente e com uma mistura de Salmonella e várias espécies de Enterobacteriaceae e também em cem amostras de lingüiças de porco e de frango sem adição artificial de microrganismos. O método convencional de cultura foi empregado como método de referência. A avaliação em alimentos infantis indicou que o procedimento proposto apresentava boa sensibilidade (80%) e especificidade (100%), sem reação cruzada com outras Enterobacteriaceae. Entretanto, quando aplicado a lingüiças, seu desempenho não foi adequado: os valores de x² (5,062, ? > 0,05) e do índice de concordância de Kappa (0,171, p=0,089) indicaram que as diferenças entre os resultados obtidos pelos dois métodos foram estatisticamente significantes e a correlação entre eles foi baixa.

Jane Maria Lafayette Neves Gelinski; Gunnar Martin; Maria Teresa Destro; Mariza Landgraf; Bernadette Dora Gombossy de Melo Franco

2002-01-01

176

Tenth CRL-Salmonella interlaboratory comparison study (2005) on typing of Salmonella spp. Tiende CRL-Salmonella ringonderzoek (2005) voor de typering van Salmonella spp.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 Instit...

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

177

Eleventh CRL-Salmonella interlaboratory comparison study (2006) on typing of Salmonella spp. Elfde CRL-Salmonella ringonderzoek (2006) voor de typering van Salmonella spp.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 Referenti...

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

178

Substitution of glutamic acid 109 by aspartic acid alters the substrate specificity and catalytic activity of the beta-subunit in the tryptophan synthase bienzyme complex from Salmonella typhimurium.  

UK PubMed Central (United Kingdom)

In an effort to understand the catalytic mechanism of the tryptophan synthase beta-subunit from Salmonella typhimurium, possible functional active site residues have been identified (on the basis of the 3-D crystal structure of the bienzyme complex) and targeted for analysis utilizing site-directed mutagenesis. The chromophoric properties of the pyridoxal 5'-phosphate cofactor provide a particularly convenient and sensitive spectral probe to directly investigate changes in catalytic events which occur upon modification of the beta-subunit. Substitution of Asp for Glu 109 in the beta-subunit was found to alter both the catalytic activity and the substrate specificity of the beta-reaction. Steady-state kinetic data reveal that the beta-reaction catalyzed by the beta E109D alpha 2 beta 2 mutant enzyme complex is reduced 27-fold compared to the wild-type enzyme. Rapid-scanning stopped-flow (RSSF) UV-visible spectroscopy shows that the mutation does not seriously affect the pre-steady-state reaction of the beta E109D mutant with L-serine to form the alpha-aminoacrylate intermediate, E(A-A). Binding of the alpha-subunit specific ligand, alpha-glycerol phosphate (GP) to the alpha 2 beta 2 complex exerts the same allosteric effects on the beta-subunit as observed with the wild-type enzyme. However, the pre-steady-state spectral changes for the reaction of indole with E(A-A) show that the formation of the L-tryptophan quinonoid, E(Q3), is drastically altered. Discrimination against E(Q3) formation is also observed for the binding of L-tryptophan to the mutant alpha 2 beta 2 complex in the reverse reaction. In contrast, substitution of Asp for Glu 109 increases the apparent affinity of the beta E109D alpha-aminoacrylate complex for the indole analogue indoline and results in the increased rate of synthesis of the amino acid product dihydroiso-L-tryptophan. Thus, the mutation affects the covalent bond forming addition reactions and the nucleophile specificity of the beta-reaction catalyzed by the bienzyme complex.

Brzovi? PS; Kayastha AM; Miles EW; Dunn MF

1992-02-01

179

Biofilms promote survival and virulence of Salmonella enterica sv. Tennessee during prolonged dry storage and after passage through an in vitro digestion system.  

UK PubMed Central (United Kingdom)

Salmonella enterica serotypes have been linked to outbreaks associated with low water activity foods. While the biofilm-forming abilities of Salmonella improve its survival during thermal processing and sanitation it is unclear whether biofilms enhance survival to desiccation and gastric stresses. The purpose of this study was to quantify the effect of physiological state (planktonic versus biofilm) and prior exposure to desiccation and storage in dry milk powder on Salmonella survival and gene expression after passage through an in vitro digestion model. Planktonic cells of Salmonella enterica serotype Tennessee were deposited onto membranes while biofilms were formed on glass beads. The cells were subsequently dried at room temperature and stored in dried milk powder (a(w)=0.3) for up to 30 days. Salmonella survival was quantified by serial dilution onto Brilliant Green Agar before desiccation, after desiccation, after 1-day storage and after 30-day storage. At each sampling period both physiological states were tested for survival through a simulated gastrointestinal system. RNA was extracted at the identical time points and Quantitative Real-Time PCR was used to determine relative expression for genes associated with stress response (rpoS, otsB), virulence (hilA, invA, sipC) and a housekeeping gene 16S rRNA. The physiological state and length of storage affected the survival and gene expression of Salmonella within the desiccated milk powder environment and after passage through an in vitro digestion system (p<0.05). Larger numbers of S. Tennessee were recovered by plate counts for biofilms compared to planktonic, however, the numbers of Salmonella genomes detected by qPCR were not significantly different suggesting entry of the planktonic cells of S. Tennessee into a viable but non-culturable state. The increased expression of stress response genes rpoS and otsB correlated with survival, indicating cross-protection to low water activity and acid stress. Increased expression of virulence-associated genes was seen in cells exposed to dry storage for short periods, however the largest amount of expression occurred in biofilm cells stored for 30 days at aw 0.3, suggesting increased virulence potential.

Aviles B; Klotz C; Eifert J; Williams R; Ponder M

2013-04-01

180

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

UK PubMed Central (United Kingdom)

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.

Halimi HA; Seifi HA; Rad M

2014-01-01

 
 
 
 
181

Direct detection of Salmonella spp. in estuaries by using a DNA probe.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A method for direct detection of Salmonella spp. in water was developed by using a commercially available DNA probe. Particulate DNA was extracted from 500- to 1,500-ml water samples collected from New York Harbor and Chesapeake Bay and used as a substrate for a salmonella-specific DNA probe in dot ...

Knight, I T; Shults, S; Kaspar, C W; Colwell, R R

182

Development of a transdermal Salmonella challenge model in calves.  

UK PubMed Central (United Kingdom)

Recent investigations have found that Salmonella can be routinely recovered from peripheral lymph nodes (PLNs) of cattle presented for harvest. When contained within the PLNs, this foodborne pathogen is protected from currently used postharvest, inplant intervention strategies and, therefore, PLNs harboring Salmonella may be a potential contaminant of ground beef. The objective of this work was to develop a challenge model that effectively and repeatedly results in Salmonella -positive PLNs. A 10-lancet skin-allergy instrument was inoculated with Salmonella, and calves were inoculated intra- and/or transdermally by applying the device over various ventral regions of the skin. Salmonella was successfully and predictably recovered from regionspecific PLNs up to 8 days postchallenge. Furthermore, serotypes inoculated within specific regions were only recovered from the PLNs draining those regions. This model provides a method to predictably infect PLNs with Salmonella. Further, this model makes it possible to determine the duration of infection and to evaluate candidate interventions that may shorten the duration of infection.

Edrington TS; Loneragan GH; Hill J; Genovese KJ; He H; Callaway TR; Anderson RC; Brichta-Harhay DM; Nisbet DJ

2013-07-01

183

Evanescent Wave Fiber Optic Biosensor for Salmonella Detection in Food  

Directory of Open Access Journals (Sweden)

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

Angela M. Valadez; Carlos A. Lana; Shu-I Tu; Mark T. Morgan; Arun K. Bhunia

2009-01-01

184

Salmonella serotype diversity and seasonality in urban and rural streams.  

UK PubMed Central (United Kingdom)

AIMS: To investigate the prevalence, seasonality and genetic diversity of Salmonella enterica serotypes, particularly those of human and veterinary health significance, in urban and rural streams. METHODS AND RESULTS: Using a swab collection technique and multiple culture media for isolation, Salmonella were detected in 78.4% of water samples (November 2003 to July 2005) taken from urban and rural/agricultural streams in the Grand River watershed (Ontario, Canada). Among 235 isolates, there were 38 serotypes, with the predominant serotypes and phagetypes (PT) being Salmonella Typhimurium PT 104 and Salmonella Heidelberg PT 19. These are also the most common Salmonella serotypes found in humans and farm animals locally and across Canada, a trend not commonly reported. The urban stream had more frequent Salmonella occurrence, greater serotype diversity and greater genetic variability (based on pulsed field gel electrophoresis) of specific strains compared with the rural/agricultural streams. Distinct seasonality in serotypes of health significance was observed only in the rural/agricultural streams, which is likely a reflection of seasonal source inputs in these watersheds. Despite the lower occurrence of these strains in stream water in the colder months, laboratory studies did not support reduced survival of Salm. Typhimurium and Salm. Heidelberg at lower temperatures, although survival differences were observed with other serotypes. CONCLUSIONS: A diverse range of Salmonella serotypes and PT were obtained from both urban and rural/agricultural streams, with the predominant strains being those most frequently associated with human and veterinary disease in Canada. SIGNIFICANCE AND IMPACT OF THE STUDY: The ubiquitous nature of Salmonella in water and the predominance of serotypes/PT of human or veterinary health significance suggest that the aquatic environment is a reservoir for this bacterium and could be involved in the transport and dissemination of this pathogen between hosts.

Thomas JL; Slawson RM; Taylor WD

2013-03-01

185

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Avaliou-se um novo procedimento para detecção rápida de Salmonella em alimentos, baseado na combinação entre SPRINT®, MSRV® e Salmonella Latex Test® . SPRINT® é um sistema para reduzir as etapas de pré-enriquecimento e enriquecimento seletivo para 24 h. MSRV® é um meio seletivo semi-sólido para detecção de salmonelas móveis. Salmonella Latex Test® é um teste rápido de aglutinação de látex. A combinação dos três sistemas permite que a detecção d (more) e Salmonella em alimentos possa ser feita em apenas 48 h. O procedimento foi avaliado em alimentos infantis prontos para consumo, experimentalmente contaminados com Salmonella exclusivamente e com uma mistura de Salmonella e várias espécies de Enterobacteriaceae e também em cem amostras de lingüiças de porco e de frango sem adição artificial de microrganismos. O método convencional de cultura foi empregado como método de referência. A avaliação em alimentos infantis indicou que o procedimento proposto apresentava boa sensibilidade (80%) e especificidade (100%), sem reação cruzada com outras Enterobacteriaceae. Entretanto, quando aplicado a lingüiças, seu desempenho não foi adequado: os valores de x² (5,062, ? > 0,05) e do índice de concordância de Kappa (0,171, p=0,089) indicaram que as diferenças entre os resultados obtidos pelos dois métodos foram estatisticamente significantes e a correlação entre eles foi baixa. Abstract in english A new procedure for rapid detection of Salmonella in foods, based on the combination of SPRINT TM, MSRV TM and Salmonella Latex TestTM, was evaluated. SPRINT TM is a system to reduce the preenrichment and selective enrichment steps to 24 hours. MSRV TM is a semi-solid selective media for detection of motile Salmonella. Salmonella Latex TestTM is a rapid latex agglutination test for Salmonella. Using the three systems in combination, the total time for detection of Salmone (more) lla in a food sample is 48h. Evaluations were performed in artificially contaminated ready-to-eat baby-foods and raw Brazilian sausages (lingüiça) containing no added microorganisms. The BAM conventional culture procedure was used as reference method. The study with baby foods indicated that the new procedure had good sensitivity (89%) and specificity (100%), without cross-reactions with Enterobacteriaceae. However, when applied to naturally contaminated foods, the performance was poor: chi square (x² = 5.062, ?> 0. 05) and Kappa-Cohen agreement (K = 0.171, p=0.089) indexes indicated that the differences between results given by the two procedures were significant and the correlation between them was low.

Gelinski, Jane Maria Lafayette Neves; Martin, Gunnar; Destro, Maria Teresa; Landgraf, Mariza; Franco, Bernadette Dora Gombossy de Melo

2002-09-01

186

A novel chromogenic ester agar medium for detection of Salmonellae.  

Science.gov (United States)

A novel agar medium, chromogenic Salmonella esterase (CSE) agar, for the differentiation of salmonellae is described. The agar contains peptones and nutrient extracts together with the following (grams per liter unless otherwise specified): 4-[2-(4-octanoyloxy-3, 5-dimethoxyphenyl)-vinyl]-quinolinium-1-(propan-3-yl carboxylic acid) bromide (SLPA-octanoate; bromide form), 0.3223; lactose, 14. 65; trisodium citrate dihydrate, 0.5; Tween 20, 3.0; ethyl 4-dimethylaminobenzoate, 0.035% (wt/vol), novobiocin, 70 mg liter-1. The key component of the medium is SLPA-octanoate, a newly synthesized ester formed from a C8 fatty acid and a phenolic chromophore. In CSE agar, the ester is hydrolyzed by Salmonella spp. to yield a brightly colored phenol which remains tightly bound within colonies. After 24 h of incubation at 37 or 42 degreesC, colonies of typical Salmonella spp. were burgundy colored on a transparent yellow background, whereas non-Salmonella spp. were white, cream, yellow or transparent. CSE agar was evaluated by using a panel of strains including a high proportion of Salmonella and non-Salmonella strains giving atypical reactions on other differential agars. The sensitivity (93.1%) of CSE agar for non-typhi salmonellae compared favorably with those of Rambach (82. 8%), xylose-lysine-deoxycholate (XLD; 91.4%), Hektoen-enteric (89.7%), and SM ID (91.4%) agars. The specificity (93.9%) was also comparable to those of other Salmonella media (SM ID agar, 95.9%; Rambach agar, 91.8%; XLD agar, 91.8%; Hektoen-enteric agar, 87.8%). Strains of Citrobacter freundii and Proteus spp. giving false-positive reactions with other media gave a negative color reaction on CSE agar. CSE agar enabled the detection of >30 Salmonella serotypes, including agona, anatum, enteritidis, hadar, heidelberg, infantis, montevideo, thompson, typhimurium, and virchow, which accounted for 91.8% of the salmonella isolates recorded by the Public Health Laboratory Service (Colindale, London, England) for 1997. PMID:9925620

Cooke, V M; Miles, R J; Price, R G; Richardson, A C

1999-02-01

187

[The detection of salmonellas using Rambach agar].  

Science.gov (United States)

Selective enrichment in Rappaport-Vassiliadis medium of 1595 animal fed samples and of 82 feedstuff and carcass meal was streaked simultaneously onto water-blue-metachrome-yellow-lactose-agar acc. to Gassner, onto brilliant-green-phenol-red-lactose-agar acc. to Kauffmann and onto Rambach agar. Salmonellae were isolated in 34 cases with Rambach agar (sensitivity 94.4%), in 33 cases with water-blue-metachrome-yellow-lactose-agar acc. to Gassner (sensitivity 91.7%) and in 31 cases with brilliant-green-phenol-red-lactose-agar acc. to Kauffmann (sensitivity 86.1%). The high specificity (99.87%) recommends the use of Rambach agar for isolation of Salmonellae from selective enrichment. PMID:7993335

Weber, A; Wachowitz, R

1994-02-01

188

[The detection of salmonellas using Rambach agar  

UK PubMed Central (United Kingdom)

Selective enrichment in Rappaport-Vassiliadis medium of 1595 animal fed samples and of 82 feedstuff and carcass meal was streaked simultaneously onto water-blue-metachrome-yellow-lactose-agar acc. to Gassner, onto brilliant-green-phenol-red-lactose-agar acc. to Kauffmann and onto Rambach agar. Salmonellae were isolated in 34 cases with Rambach agar (sensitivity 94.4%), in 33 cases with water-blue-metachrome-yellow-lactose-agar acc. to Gassner (sensitivity 91.7%) and in 31 cases with brilliant-green-phenol-red-lactose-agar acc. to Kauffmann (sensitivity 86.1%). The high specificity (99.87%) recommends the use of Rambach agar for isolation of Salmonellae from selective enrichment.

Weber A; Wachowitz R

1994-02-01

189

Antibiotic susceptibility of Salmonella spp.: a comparison of two surveys with a 5 years interval  

Directory of Open Access Journals (Sweden)

Full Text Available Salmonella infections are one of the major global public health problems. During the last decade, antibiotic resistance and multiresistance of Salmonella spp. have increased a great deal, especially in developing countries with an increased and indiscriminate use of antibiotics in the treatment of humans and animals. This study aims to investigate and compare antimicrobial susceptibility patterns of Salmonella during 2005 and 2010.A total of 186 Salmonella strain during 2005 and 140 Salmonella strain during 2010 were isolated from stool specimens using standard methods. The isolates were confirmed as Salmonella by using a battery of biochemical reactions. Specific antisera were used for serologic characterization of Salmonella strain. Antimicrobial susceptibility testing was performed by standard disk diffusion method using ampicillin, trimethoprim-sulfamethoxasole, ceftriaxon, chloramphenicol, nalidixic acid and ciprofloxacin.One hundred eighty (96.8%) of 186 isolated Salmonella strains in 2005, and 133 (95%) of 140 isolated Salmonella strain in 2010 are recognized as Salmonella Enteritidis. Sensitivity of Salmonella isolates during 2005 and 2010 were 91.9% and 92.9% to ampicillin, 95.7% and 97.1% to trimethoprim-sulfamethoxasole, 99.5% and 100% to chloramphenicol, 99.5% and 100% to ciprofloxacin, 98.9% and 97.1% to ceftriaxon, 73.1% and 95.7% to nalidixic acid, respectively.Sensitivity of Salmonella isolates to all tested antimicrobial agents except to ceftriaxon was been slightly improved over testing period. Resistance rate to ceftriaxon was higher in 2010 than in 2005, and this fact deserves attention. Significantly increase susceptibility rate to nalidixic acid was observed between the two surveys

Gordana Mijovi?; Bogdanka Andri?; Dragica Terzi?; Milena Lopi?i?; Brankica Dupanovi?

2012-01-01

190

Detection of Salmonella spp. Using a Generic and Differential FRET-PCR.  

UK PubMed Central (United Kingdom)

To facilitate the detection of Salmonella and to be able to rapidly and conveniently determine the species/subspecies present, we developed and tested a generic and differential FRET-PCR targeting their tetrathionate reductase response regulator gene. The differential pan-Salmonella FRET-PCR we developed successfully detected seven plasmids that contained partial sequences of S. bongori and the six S. enterica subspecies. The detection limit varied from ?5 copies of target gene/per PCR reaction for S. enterica enterica to ?200 for S. bongori. Melting curve analysis demonstrated a T m of ?68°C for S. enterica enterica, ?62.5°C for S. enterica houtenae and S. enterica diarizonae, ?57°C for S. enterica indica, and ?54°C for S. bongori, S. enterica salamae and S. enterica arizonae. The differential pan-Salmonella FRET-PCR also detected and determined the subspecies of 4 reference strains and 47 Salmonella isolated from clinically ill birds or pigs. Finally, we found it could directly detect and differentiate Salmonella in feline (5/50 positive; 10%; one S. enterica salamae and 4 S. enterica enterica) and canine feces (15/114 positive; 13.2%; all S. enterica enterica). The differential pan-Salmonella FRET-PCR failed to react with 96 non-Salmonella bacterial strains. Our experiments show the differential pan-Salmonella FRET-PCR we developed is a rapid, sensitive and specific method to detect and differentiate Salmonella.

Zhang J; Wei L; Kelly P; Freeman M; Jaegerson K; Gong J; Xu B; Pan Z; Xu C; Wang C

2013-01-01

191

Detection of Salmonella spp. Using a Generic and Differential FRET-PCR.  

Science.gov (United States)

To facilitate the detection of Salmonella and to be able to rapidly and conveniently determine the species/subspecies present, we developed and tested a generic and differential FRET-PCR targeting their tetrathionate reductase response regulator gene. The differential pan-Salmonella FRET-PCR we developed successfully detected seven plasmids that contained partial sequences of S. bongori and the six S. enterica subspecies. The detection limit varied from ?5 copies of target gene/per PCR reaction for S. enterica enterica to ?200 for S. bongori. Melting curve analysis demonstrated a T m of ?68°C for S. enterica enterica, ?62.5°C for S. enterica houtenae and S. enterica diarizonae, ?57°C for S. enterica indica, and ?54°C for S. bongori, S. enterica salamae and S. enterica arizonae. The differential pan-Salmonella FRET-PCR also detected and determined the subspecies of 4 reference strains and 47 Salmonella isolated from clinically ill birds or pigs. Finally, we found it could directly detect and differentiate Salmonella in feline (5/50 positive; 10%; one S. enterica salamae and 4 S. enterica enterica) and canine feces (15/114 positive; 13.2%; all S. enterica enterica). The differential pan-Salmonella FRET-PCR failed to react with 96 non-Salmonella bacterial strains. Our experiments show the differential pan-Salmonella FRET-PCR we developed is a rapid, sensitive and specific method to detect and differentiate Salmonella. PMID:24146814

Zhang, Jilei; Wei, Lanjing; Kelly, Patrick; Freeman, Mark; Jaegerson, Kirsten; Gong, Jiansen; Xu, Bu; Pan, Zhiming; Xu, Chuanling; Wang, Chengming

2013-10-16

192

Detection of Salmonella spp. Using a Generic and Differential FRET-PCR  

Science.gov (United States)

To facilitate the detection of Salmonella and to be able to rapidly and conveniently determine the species/subspecies present, we developed and tested a generic and differential FRET-PCR targeting their tetrathionate reductase response regulator gene. The differential pan-Salmonella FRET-PCR we developed successfully detected seven plasmids that contained partial sequences of S. bongori and the six S. enterica subspecies. The detection limit varied from ?5 copies of target gene/per PCR reaction for S. enterica enterica to ?200 for S. bongori. Melting curve analysis demonstrated a Tm of ?68°C for S. enterica enterica, ?62.5°C for S. enterica houtenae and S. enterica diarizonae, ?57°C for S. enterica indica, and ?54°C for S. bongori, S. enterica salamae and S. enterica arizonae. The differential pan-Salmonella FRET-PCR also detected and determined the subspecies of 4 reference strains and 47 Salmonella isolated from clinically ill birds or pigs. Finally, we found it could directly detect and differentiate Salmonella in feline (5/50 positive; 10%; one S. enterica salamae and 4 S. enterica enterica) and canine feces (15/114 positive; 13.2%; all S. enterica enterica). The differential pan-Salmonella FRET-PCR failed to react with 96 non-Salmonella bacterial strains. Our experiments show the differential pan-Salmonella FRET-PCR we developed is a rapid, sensitive and specific method to detect and differentiate Salmonella.

Zhang, Jilei; Wei, Lanjing; Kelly, Patrick; Freeman, Mark; Jaegerson, Kirsten; Gong, Jiansen; Xu, Bu; Pan, Zhiming; Xu, Chuanling; Wang, Chengming

2013-01-01

193

Nitric oxide and salmonella pathogenesis.  

UK PubMed Central (United Kingdom)

Nitric oxide (NO) and its congeners contribute to the innate immune response to Salmonella. This enteric pathogen is exposed to reactive nitrogen species (RNS) in the environment and at different anatomical locations during its infectious cycle in vertebrate hosts. Chemical generation of RNS enhances the gastric barrier to enteropathogenic bacteria, while products of the Salmonella pathogenicity island 1 type III secretion system and Salmonella-associated molecular patterns stimulate transcription of inducible NO synthase (iNOS) by cells of the mononuclear phagocytic cell lineage. The resulting NO, or products that arise from its interactions with oxygen (O(2)) or iron and low-molecular weight thiols, are preferentially bacteriostatic against Salmonella, while reaction of NO and superoxide ([Formula: see text]) generates the bactericidal compound peroxynitrite (ONOO-). The anti-Salmonella activity of RNS emanates from the modification of redox active thiols and metal prosthetic groups of key molecular targets of the electron transport chain, central metabolic enzymes, transcription factors, and DNA and DNA-associated proteins. In turn, Salmonella display a plethora of defenses that modulate the delivery of iNOS-containing vesicles to phagosomes, scavenge and detoxify RNS, and repair biomolecules damaged by these toxic species. Traditionally, RNS have been recognized as important mediators of host defense against Salmonella. However, exciting new findings indicate that Salmonella can exploit the RNS produced during the infection to foster virulence. More knowledge of the primary RNS produced in response to Salmonella infection, the bacterial processes affected by these toxic species, and the adaptive bacterial responses that protect Salmonella from nitrosative and oxidative stress associated with NO will increase our understanding of Salmonella pathogenesis. This information may assist in the development of novel therapeutics against this common enteropathogen.

Henard CA; Vázquez-Torres A

2011-01-01

194

Nitric oxide and salmonella pathogenesis.  

Science.gov (United States)

Nitric oxide (NO) and its congeners contribute to the innate immune response to Salmonella. This enteric pathogen is exposed to reactive nitrogen species (RNS) in the environment and at different anatomical locations during its infectious cycle in vertebrate hosts. Chemical generation of RNS enhances the gastric barrier to enteropathogenic bacteria, while products of the Salmonella pathogenicity island 1 type III secretion system and Salmonella-associated molecular patterns stimulate transcription of inducible NO synthase (iNOS) by cells of the mononuclear phagocytic cell lineage. The resulting NO, or products that arise from its interactions with oxygen (O(2)) or iron and low-molecular weight thiols, are preferentially bacteriostatic against Salmonella, while reaction of NO and superoxide ([Formula: see text]) generates the bactericidal compound peroxynitrite (ONOO-). The anti-Salmonella activity of RNS emanates from the modification of redox active thiols and metal prosthetic groups of key molecular targets of the electron transport chain, central metabolic enzymes, transcription factors, and DNA and DNA-associated proteins. In turn, Salmonella display a plethora of defenses that modulate the delivery of iNOS-containing vesicles to phagosomes, scavenge and detoxify RNS, and repair biomolecules damaged by these toxic species. Traditionally, RNS have been recognized as important mediators of host defense against Salmonella. However, exciting new findings indicate that Salmonella can exploit the RNS produced during the infection to foster virulence. More knowledge of the primary RNS produced in response to Salmonella infection, the bacterial processes affected by these toxic species, and the adaptive bacterial responses that protect Salmonella from nitrosative and oxidative stress associated with NO will increase our understanding of Salmonella pathogenesis. This information may assist in the development of novel therapeutics against this common enteropathogen. PMID:21833325

Henard, Calvin A; Vázquez-Torres, Andrés

2011-04-20

195

Microencapsulated sorbic acid and nature-identical compounds reduced Salmonella Hadar and Salmonella Enteritidis colonization in experimentally infected chickens.  

Science.gov (United States)

The reduction of Salmonella prevalence in broilers is a priority in European Union agricultural policies because treatment with antibiotics is forbidden by Regulation (EC) 2160/2003. Two trials were conducted to evaluate the efficacy of a microencapsulated blend of sorbic acid and nature-identical compounds (i.e., chemically synthesized botanicals; SAB) on the reduction of the cecal prevalence and contents of Salmonella enterica serovars Hadar and Enteritidis in experimentally infected chickens. In the first trial, 125 one-day-old Lohmann specific-pathogen-free chickens were assigned to one of the following treatments: negative control (not challenged and not treated), positive control (challenged and not treated), SAB0.3, SAB1, or SAB5 (challenged and treated with the microencapsulated blend included in the feed at 0.03, 0.1, or 0.5%, respectively). At 30 d of age, birds were infected with 10(6) cfu of Salmonella Hadar, and after 5, 10, or 20 d postinfection, 5, 10, and 10 birds per treatment, respectively, were killed and the cecal contents and liver and spleen samples were analyzed for Salmonella Hadar. In the second trial, 100 one-day-old Ross 708 chickens were assigned to 1 of 5 treatments: control (not treated), SAB0.3, SAB1, SAB2, or SAB5 (treated with the blend included in the feed at 0.03, 0.1, 0.2, or 0.5%, respectively). At 7 d of age, the birds were challenged with 10(5) cfu of Salmonella Enteritidis, and after 7, 14, or 24 d after challenge, 5, 5, and 10 birds per treatment, respectively, were killed and cecal contents were analyzed for Salmonella Enteritidis. Results showed that in the early stage of infection Salmonella prevalence was high in both studies, whereas at the end of the observation periods, the blends at 0.03, 0.1, and 0.5 in the challenge with Salmonella Hadar and at 0.2 and 0.5% in the challenge with Salmonella Enteritidis significantly reduced (by 2 log(10) cfu) the cecal content of Salmonella. This study showed that intestinal delivery of microencapsulated sorbic acid and nature-identical compounds can result in a 100-fold reduction of Salmonella at the intestinal level in broilers at slaughter age. PMID:21753203

Grilli, E; Tugnoli, B; Formigoni, A; Massi, P; Fantinati, P; Tosi, G; Piva, A

2011-08-01

196

Microencapsulated sorbic acid and nature-identical compounds reduced Salmonella Hadar and Salmonella Enteritidis colonization in experimentally infected chickens.  

UK PubMed Central (United Kingdom)

The reduction of Salmonella prevalence in broilers is a priority in European Union agricultural policies because treatment with antibiotics is forbidden by Regulation (EC) 2160/2003. Two trials were conducted to evaluate the efficacy of a microencapsulated blend of sorbic acid and nature-identical compounds (i.e., chemically synthesized botanicals; SAB) on the reduction of the cecal prevalence and contents of Salmonella enterica serovars Hadar and Enteritidis in experimentally infected chickens. In the first trial, 125 one-day-old Lohmann specific-pathogen-free chickens were assigned to one of the following treatments: negative control (not challenged and not treated), positive control (challenged and not treated), SAB0.3, SAB1, or SAB5 (challenged and treated with the microencapsulated blend included in the feed at 0.03, 0.1, or 0.5%, respectively). At 30 d of age, birds were infected with 10(6) cfu of Salmonella Hadar, and after 5, 10, or 20 d postinfection, 5, 10, and 10 birds per treatment, respectively, were killed and the cecal contents and liver and spleen samples were analyzed for Salmonella Hadar. In the second trial, 100 one-day-old Ross 708 chickens were assigned to 1 of 5 treatments: control (not treated), SAB0.3, SAB1, SAB2, or SAB5 (treated with the blend included in the feed at 0.03, 0.1, 0.2, or 0.5%, respectively). At 7 d of age, the birds were challenged with 10(5) cfu of Salmonella Enteritidis, and after 7, 14, or 24 d after challenge, 5, 5, and 10 birds per treatment, respectively, were killed and cecal contents were analyzed for Salmonella Enteritidis. Results showed that in the early stage of infection Salmonella prevalence was high in both studies, whereas at the end of the observation periods, the blends at 0.03, 0.1, and 0.5 in the challenge with Salmonella Hadar and at 0.2 and 0.5% in the challenge with Salmonella Enteritidis significantly reduced (by 2 log(10) cfu) the cecal content of Salmonella. This study showed that intestinal delivery of microencapsulated sorbic acid and nature-identical compounds can result in a 100-fold reduction of Salmonella at the intestinal level in broilers at slaughter age.

Grilli E; Tugnoli B; Formigoni A; Massi P; Fantinati P; Tosi G; Piva A

2011-08-01

197

Evaluation of Virulence and Antimicrobial Resistance in Salmonella enterica Serovar Enteritidis Isolates from Humans and Chicken- and Egg-Associated Sources.  

UK PubMed Central (United Kingdom)

Abstract Salmonella enterica serovar Enteritidis is a leading cause of salmonellosis throughout the world and is most commonly associated with the consumption of contaminated poultry and egg products. Salmonella Enteritidis has enhanced ability to colonize and persist in extraintestinal sites within chickens. In this study, 54 Salmonella Enteritidis isolates from human patients (n=28), retail chicken (n=9), broiler farms (n=9), and egg production facilities (n=8) were characterized by antimicrobial susceptibility testing, plasmid analysis, genetic relatedness using XbaI and AvrII pulsed-field gel electrophoresis (PFGE), and the presence of putative virulence genes. Nine isolates were evaluated for their abilities to invade and survive in intestinal epithelial and macrophage cell lines. Overall, 56% (n=30) of isolates were resistant to at least one antimicrobial agent tested, yet no isolates showed resistance to more than three antimicrobials. All isolates carried a common ?55-kb plasmid, with some strains containing additional plasmids ranging from 3 to 50?kb. PFGE analysis revealed five XbaI and AvrII clusters. There were significant overlaps in the PFGE patterns of the isolates from human, chicken, and egg houses. All isolates tested PCR positive for iacP, purR, ttrB, spi4H, rmbA, sopE, invA, sopB, spvB, pagC, msgA, spaN, orgA, tolC, and sifA, and negative for iss, virB4, and sipB. Of the isolates selected for virulence testing, those containing the iron acquisition genes, iutA, sitA, and iucA, and ?50-kb plasmids demonstrated among the highest levels of macrophage and epithelial cell invasion, which may indicate their importance in pathogenesis.

Han J; Gokulan K; Barnette D; Khare S; Rooney AW; Deck J; Nayak R; Stefanova R; Hart ME; Foley SL

2013-10-01

198

Induction of seroconversion and persistence of Salmonella Typhimurium in pigs are strain dependent.  

UK PubMed Central (United Kingdom)

Foodborne salmonellosis is one of the most important bacterial zoonotic diseases worldwide. Salmonella Typhimurium is the serovar most frequently isolated from persistently infected slaughter pigs in Europe. Salmonella Typhimurium pathogenesis is host species specific. In addition, differences in in vitro behaviour of Salmonella Typhimurium strains have also been described, which may be reflected by a different course of infection within a host species. We compared the course of a Salmonella Typhimurium infection in pigs, using two Salmonella Typhimurium strains that were able to interfere with MHC II expression on porcine macrophages to a different extent in vitro. After experimental inoculation, blood and faecal samples from all pigs were collected at regular time points. At 40 days post inoculation (pi), animals were euthanized and tissue samples were bacteriologically analysed. The proportion of serologically positive piglets at 33 days pi was significantly higher in pigs that were inoculated with the strain that did not downregulate MHC II expression in vitro. Furthermore, this strain was less frequently shed and isolated in lower numbers from tonsils and ileocaecal lymph nodes than the strain that was able to markedly downregulate MHC II expression in vitro. We thus found that the delayed onset of seroconversion after oral inoculation of piglets with a particular Salmonella Typhimurium strain coincided with higher faecal shedding and increased persistence. Strain specific differences in Salmonella pathogenesis might thus have repercussions on the serological detection of Salmonella Typhimurium infections in pigs.

Van Parys A; Boyen F; Leyman B; Verbrugghe E; Maes D; Haesebrouck F; Pasmans F

2013-09-01

199

Development of challenge models to evaluate the efficacy of a vaccine to reduce carriage of Salmonella in peripheral lymph nodes of cattle.  

UK PubMed Central (United Kingdom)

Because challenge models to infect peripheral lymph nodes (PLNs) with Salmonella have not been reported, we performed a series of experiments to develop and refine challenge models to evaluate an intervention applied at the animal level and to provide initial estimates of efficacy of an intervention (i.e., a vaccine) to aid in the design of future studies. In each of four experiments, steers (control or vaccinated) were inoculated with Salmonella strains Montevideo or Newport, and in experiment IV, Salmonella Senftenberg was also used. Calves were euthanized 14 to 42 days postinoculation, and PLNs were collected. In the first experiment, calves were challenged with ?10¹? Salmonella cells, and few treatment differences were observed 14 days postchallenge. However, by day 21, Salmonella Newport was recovered from fewer vaccinated calves than control calves (P < 0.05). In experiment II, calves were challenged with ?10? Salmonella cells and, after two necropsies (14 and 28 days postchallenge), only one lymph node was Salmonella positive; therefore, the study was terminated. In experiment III, calves were again challenged with ?10¹? Salmonella cells, and no significant effect of vaccine was observed in calves challenged with Montevideo or Newport strains. A transdermal route of challenge was explored in experiment IV, using a 10-lancet, allergy testing instrument. Sixteen steers were challenged with either Salmonella Newport or Salmonella Montevideo (Salmonella Newport right legs; Salmonella Montevideo left legs), and all steers were challenged on the lower abdomen with Salmonella Senftenberg. Transdermal inoculation resulted in predictably Salmonella-positive PLNs, and a modest vaccine effect was detected. Because it is well tolerated by the calves and results in predictable and regionally specific Salmonella recovery from PLNs, the transdermal route of challenge may be preferred by researchers wishing to evaluate the impact of interventions designed to reduce the carriage of Salmonella in PLNs.

Edrington TS; Loneragan GH; Hill J; Genovese KJ; Brichta-Harhay DM; Farrow RL; Krueger NA; Callaway TR; Anderson RC; Nisbet DJ

2013-07-01

200

Detection of salmonellae by using Rambach agar and by a C8 esterase spot test.  

UK PubMed Central (United Kingdom)

In food microbiology, Rambach agar facilitates the differentiation of non-typhi Salmonella through a specific red pigmentation of the colonies. The usefulness of Rambach agar was examined relative to its usefulness to the field of clinical microbiology. Of 170 non-typhi Salmonella strains, 92 and 97% gave bright red colonies after 24 and 48 h of incubation, respectively, while 100% of 112 other members of the family Enterobacteriaceae were of a different color (blue, green, beige, or colorless). Red colonies were also found with five of five Acinetobacter isolates and one of three Pseudomonas isolates. To further detect Salmonella typhi and the rare beige or colorless colonies atypical of Salmonella isolates, a C8 esterase detection spot test was carried out. With UV light, that test revealed fluorescent colonies for all Salmonella isolates tested.

Freydiere AM; Gille Y

1991-10-01

 
 
 
 
201

Detection of salmonellae by using Rambach agar and by a C8 esterase spot test.  

Science.gov (United States)

In food microbiology, Rambach agar facilitates the differentiation of non-typhi Salmonella through a specific red pigmentation of the colonies. The usefulness of Rambach agar was examined relative to its usefulness to the field of clinical microbiology. Of 170 non-typhi Salmonella strains, 92 and 97% gave bright red colonies after 24 and 48 h of incubation, respectively, while 100% of 112 other members of the family Enterobacteriaceae were of a different color (blue, green, beige, or colorless). Red colonies were also found with five of five Acinetobacter isolates and one of three Pseudomonas isolates. To further detect Salmonella typhi and the rare beige or colorless colonies atypical of Salmonella isolates, a C8 esterase detection spot test was carried out. With UV light, that test revealed fluorescent colonies for all Salmonella isolates tested. PMID:1939599

Freydiere, A M; Gille, Y

1991-10-01

202

Salmonella AvrA Coordinates Suppression of Host Immune and Apoptotic Defenses via JNK Pathway Blockade.  

Science.gov (United States)

Salmonellae are bacterial pathogens that have evolved sophisticated strategies to evade host immune defenses. These strategies include the secretion of effector proteins into mammalian cells so as to subvert innate immune and apoptotic signaling pathways, thereby allowing Salmonella to avoid elimination. Here, we show that the secreted Salmonella typhimurium effector protein AvrA possesses acetyltransferase activity toward specific mitogen-activated protein kinase kinases (MAPKKs) and potently inhibits c-Jun N-terminal kinase (JNK) and NF-kappaB signaling pathways in both transgenic Drosophila and murine models. Furthermore, we show that AvrA dampens the proapoptotic innate immune response to Salmonella at the mouse intestinal mucosa. This activity is consistent with the natural history of Salmonella in mammalian hosts, where the bacteria elicit transient inflammation but do not destroy epithelial cells. Our findings suggest that targeting JNK signaling to dampen apoptosis may be a conserved strategy for intracellular pathogens. PMID:18407067

Jones, Rheinallt M; Wu, Huixia; Wentworth, Christy; Luo, Liping; Collier-Hyams, Lauren; Neish, Andrew S

2008-04-17

203

Salmonella interactions with plants and their associated microbiota.  

Science.gov (United States)

The increase in the incidence of gastroenteritis outbreaks linked to the consumption of foods of plant origin has ignited public concern and scientific interest in understanding interactions of human enteric pathogens with plants. Enteric disease caused by nontyphoidal Salmonella is a major public health burden, with the number of cases of illness linked to fresh produce, spices, and nuts surpassing those linked to foods of animal origin. Mounting evidence supports the hypothesis that colonization of plants is an important part of the life cycle of this human pathogen. Although plant responses to human pathogens are distinct from the more specific responses to phytopathogens, plants appear to recognize Salmonella, likely by detecting conserved microbial patterns, which subsequently activates basal defenses. Numerous Salmonella genes have been identified as playing a role in its colonization of plant surfaces and tissues, and in its various interactions with other members of the phyto-microbial community. Importantly, Salmonella utilizes diverse and overlapping strategies to interact with plants and their microflora, and to successfully colonize its vertebrate hosts. This review provides insight into the complex behavior of Salmonella on plants and the apparent remarkable adaptation of this human pathogen to a potentially secondary host. PMID:23506360

Brandl, Maria T; Cox, Clayton E; Teplitski, Max

2013-04-01

204

Salmonella fecal shedding and immune responses are dose- and serotype- dependent in pigs.  

Science.gov (United States)

Despite the public health importance of Salmonella infection in pigs, little is known about the associated dynamics of fecal shedding and immunity. In this study, we investigated the transitions of pigs through the states of Salmonella fecal shedding and immune response post-Salmonella inoculation as affected by the challenge dose and serotype. Continuous-time multistate Markov models were developed using published experimental data. The model for shedding had four transient states, of which two were shedding (continuous and intermittent shedding) and two non-shedding (latency and intermittent non-shedding), and one absorbing state representing permanent cessation of shedding. The immune response model had two transient states representing responses below and above the seroconversion level. The effects of two doses [low (0.65×10(6) CFU/pig) and high (0.65×10(9) CFU/pig)] and four serotypes (Salmonella Yoruba, Salmonella Cubana, Salmonella Typhimurium, and Salmonella Derby) on the models' transition intensities were evaluated using a proportional intensities model. Results indicated statistically significant effects of the challenge dose and serotype on the dynamics of shedding and immune response. The time spent in the specific states was also estimated. Continuous shedding was on average 10-26 days longer, while intermittent non-shedding was 2-4 days shorter, in pigs challenged with the high compared to low dose. Interestingly, among pigs challenged with the high dose, the continuous and intermittent shedding states were on average up to 10-17 and 3-4 days longer, respectively, in pigs infected with S. Cubana compared to the other three serotypes. Pigs challenged with the high dose of S. Typhimurium or S. Derby seroconverted on average up to 8-11 days faster compared to the low dose. These findings highlight that Salmonella fecal shedding and immune response following Salmonella challenge are dose- and serotype-dependent and that the detection of specific Salmonella strains and immune responses in pigs are time-sensitive. PMID:22523553

Ivanek, Renata; Österberg, Julia; Gautam, Raju; Sternberg Lewerin, Susanna

2012-04-16

205

Salmonella fecal shedding and immune responses are dose- and serotype- dependent in pigs.  

UK PubMed Central (United Kingdom)

Despite the public health importance of Salmonella infection in pigs, little is known about the associated dynamics of fecal shedding and immunity. In this study, we investigated the transitions of pigs through the states of Salmonella fecal shedding and immune response post-Salmonella inoculation as affected by the challenge dose and serotype. Continuous-time multistate Markov models were developed using published experimental data. The model for shedding had four transient states, of which two were shedding (continuous and intermittent shedding) and two non-shedding (latency and intermittent non-shedding), and one absorbing state representing permanent cessation of shedding. The immune response model had two transient states representing responses below and above the seroconversion level. The effects of two doses [low (0.65×10(6) CFU/pig) and high (0.65×10(9) CFU/pig)] and four serotypes (Salmonella Yoruba, Salmonella Cubana, Salmonella Typhimurium, and Salmonella Derby) on the models' transition intensities were evaluated using a proportional intensities model. Results indicated statistically significant effects of the challenge dose and serotype on the dynamics of shedding and immune response. The time spent in the specific states was also estimated. Continuous shedding was on average 10-26 days longer, while intermittent non-shedding was 2-4 days shorter, in pigs challenged with the high compared to low dose. Interestingly, among pigs challenged with the high dose, the continuous and intermittent shedding states were on average up to 10-17 and 3-4 days longer, respectively, in pigs infected with S. Cubana compared to the other three serotypes. Pigs challenged with the high dose of S. Typhimurium or S. Derby seroconverted on average up to 8-11 days faster compared to the low dose. These findings highlight that Salmonella fecal shedding and immune response following Salmonella challenge are dose- and serotype-dependent and that the detection of specific Salmonella strains and immune responses in pigs are time-sensitive.

Ivanek R; Österberg J; Gautam R; Sternberg Lewerin S

2012-01-01

206

Molecular insights into farm animal and zoonotic Salmonella infections  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Salmonella enterica is a facultative intracellular pathogen of worldwide importance. Infections may present in a variety of ways, from asymptomatic colonization to inflammatory diarrhoea or typhoid fever depending on serovar- and host-specific factors. Human diarrhoeal infections are frequently acqu...

Stevens, Mark P.; Humphrey, Tom J.; Maskell, Duncan J.

207

Phosphorylation of the autophagy receptor optineurin restricts Salmonella growth  

DEFF Research Database (Denmark)

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

Wild, Philipp; Farhan, Hesso

2011-01-01

208

Phosphorylation of the autophagy receptor optineurin restricts Salmonella growth.  

UK PubMed Central (United Kingdom)

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

Wild P; Farhan H; McEwan DG; Wagner S; Rogov VV; Brady NR; Richter B; Korac J; Waidmann O; Choudhary C; Dötsch V; Bumann D; Dikic I

2011-07-01

209

Prevalence of Salmonella in vegetables from Mexico.  

UK PubMed Central (United Kingdom)

The present study is an overview of the role of vegetables as a transmission vehicle of Salmonella in Mexico. One hundred samples of each of 17 different vegetables were analyzed during a period of 18 months. Salmonella was isolated from 98 samples. Salmonella enterica serovar Typhimurium was isolated from the highest percentage of samples with typeable Salmonella isolates (23.9%), followed by S. enterica subsp. arizonae and Salmonella Choleraesuis each from 16.9%, Salmonella Gallinarum from 11.1%, Salmonella Anatum and S. enterica subsp. houtenae each from 9.7%, Salmonella Agona and Salmonella Edinburg each from 4.22%, Salmonella Enteritidis and S. enterica subsp. salamae each from 2.81%, and Salmonella Bongor, Salmonella Pullorum, Salmonella Typhi, and Salmonella C1 flagellar b each from 1.4%. Of the isolated bacteria, 27.6% were nontypeable strains. Salmonella was isolated from 12% of parsley samples, 11% of cilantro samples, 9% of broccoli samples, 9% of cauliflower samples, 9% of "papaloquelite" (Porophyllum ruderale) samples, 9% of purslane (Portulaca oleracea) samples, 7% of long lettuce samples, 7% of spinach samples, 7% of watercress samples, 6% of Chinese parsley samples, 4% of beet samples, 3% of celery samples, 3% of Romaine lettuce samples, 1% of cabbage samples, and 1% of potato samples. The presence of Salmonella Typhi in parsley is noteworthy. No Salmonella isolates were obtained from zucchini and onion. These results indicate that raw or minimally processed vegetables can be contaminated with Salmonella, leading to direct infection of consumers or cross-contamination of other foodstuffs. These contaminated vegetables can represent a severe health risk for the Mexican consumer.

Quiroz-Santiago C; Rodas-Suárez OR; Carlos R V; Fernández FJ; Quiñones-Ramírez EI; Vázquez-Salinas C

2009-06-01

210

Prevalence of Salmonella in vegetables from Mexico.  

Science.gov (United States)

The present study is an overview of the role of vegetables as a transmission vehicle of Salmonella in Mexico. One hundred samples of each of 17 different vegetables were analyzed during a period of 18 months. Salmonella was isolated from 98 samples. Salmonella enterica serovar Typhimurium was isolated from the highest percentage of samples with typeable Salmonella isolates (23.9%), followed by S. enterica subsp. arizonae and Salmonella Choleraesuis each from 16.9%, Salmonella Gallinarum from 11.1%, Salmonella Anatum and S. enterica subsp. houtenae each from 9.7%, Salmonella Agona and Salmonella Edinburg each from 4.22%, Salmonella Enteritidis and S. enterica subsp. salamae each from 2.81%, and Salmonella Bongor, Salmonella Pullorum, Salmonella Typhi, and Salmonella C1 flagellar b each from 1.4%. Of the isolated bacteria, 27.6% were nontypeable strains. Salmonella was isolated from 12% of parsley samples, 11% of cilantro samples, 9% of broccoli samples, 9% of cauliflower samples, 9% of "papaloquelite" (Porophyllum ruderale) samples, 9% of purslane (Portulaca oleracea) samples, 7% of long lettuce samples, 7% of spinach samples, 7% of watercress samples, 6% of Chinese parsley samples, 4% of beet samples, 3% of celery samples, 3% of Romaine lettuce samples, 1% of cabbage samples, and 1% of potato samples. The presence of Salmonella Typhi in parsley is noteworthy. No Salmonella isolates were obtained from zucchini and onion. These results indicate that raw or minimally processed vegetables can be contaminated with Salmonella, leading to direct infection of consumers or cross-contamination of other foodstuffs. These contaminated vegetables can represent a severe health risk for the Mexican consumer. PMID:19610340

Quiroz-Santiago, Carolina; Rodas-Suárez, Oscar R; Carlos R, Vázquez; Fernández, Francisco J; Quiñones-Ramírez, Elsa Irma; Vázquez-Salinas, Carlos

2009-06-01

211

Effect of Low Dose of Fumonisins on Pig Health: Immune Status, Intestinal Microbiota and Sensitivity to Salmonella  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this study was to measure the effects of chronic exposure to fumonisins via the ingestion of feed containing naturally contaminated corn in growing pigs infected or not with Salmonella spp. This exposure to a moderate dietary concentration of fumonisins (11.8 ppm) was sufficient to induce a biological effect in pigs (Sa/So ratio), but no mortality or pathology was observed over 63 days of exposure. No mortality or related clinical signs, even in cases of inoculation with Salmonella (5 × 104 CFU), were observed either. Fumonisins, at these concentrations, did not affect the ability of lymphocytes to proliferate in the presence of mitogens, but after seven days post-inoculation they led to inhibition of the ability of specific Salmonella lymphocytes to proliferate following exposure to a specific Salmonella antigen. However, the ingestion of fumonisins had no impact on Salmonella translocation or seroconversion in inoculated pigs. The inoculation of Salmonella did not affect faecal microbiota profiles, but exposure to moderate concentrations of fumonisins transiently affected the digestive microbiota balance. In cases of co-infection with fumonisins and Salmonella, the microbiota profiles were rapidly and clearly modified as early as 48 h post-Salmonella inoculation. Therefore under these experimental conditions, exposure to an average concentration of fumonisins in naturally contaminated feed had no effect on pig health but did affect the digestive microbiota balance, with Salmonella exposure amplifying this phenomenon.

Christine Burel; Mael Tanguy; Philippe Guerre; Eric Boilletot; Roland Cariolet; Marilyne Queguiner; Gilbert Postollec; Philippe Pinton; Gilles Salvat; Isabelle P. Oswald; Philippe Fravalo

2013-01-01

212

Salmonella in Sheep in Iceland  

Directory of Open Access Journals (Sweden)

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.

Hjartardóttir S; Gunnarsson E; Sigvaldadóttir J

2002-01-01

213

Meningoencefalitis letal por Salmonella B  

Directory of Open Access Journals (Sweden)

Full Text Available La meningoencefalitis por bacilos gramnegativos ha ido incrementándose desde la década de los 70, con una mayor incidencia en niños pequeños, aunque existe una tendencia a aumentar en pacientes de la 3ra. edad. Dentro de este grupo de microorganismos, la causada por Salmonella sp, por su poca frecuencia, resulta una rareza. En este caso se presenta a una paciente de 80 años de edad con cuadro clínico de meningoencefalitis, que en el estudio del líquido cefalorraquídeo se aisló Salmonella grupo B serotipo typhimurium; la paciente fallece a los 5 días de su ingreso. La meningoencefalitis por Salmonella sp debe tenerse en cuenta en pacientes menores de 2 años de edad y ancianos, por la severidad del cuadro clínico y elevada mortalidad.Meningoencephalitis caused by gram-negative bacilli has increased since the 1970s, with a higher incidence in little children , although there is a a trend to rise in the elderly. Within this group of micororganisms, the meningoencephalitis caused by Salmonella sp is rare, since it is not very common. The case of an 80-year-old female patient with a clinical picture of meningoencephalitis is reported. Salmonella typhimurium serogroup B was isolated from the cerebrospinal fluid. The patient died 5 days after being admitted in the hospital. The meningoencephalitis caused by Salmonella sp should be taken into consideration in children under 2 and in the elederly because of the severity of the clinical picture and the elevated mortality.

Nilda E. Herrera Valdés; Ma. Elena Fuerte Calvo; Ma. Elena Díaz García; Daysi Rodríguez Larrinaga; Martha Sandoval Acosta; Mario Santiago Puga Torres

2001-01-01

214

Evaluation of the Wellcolex Colour Salmonella Test for detection of Salmonella spp. in enrichment broths.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Wellcolex Colour Salmonella Test was evaluated for detection of Salmonella spp. in enrichment broths of 1,010 stool samples. In 39 specimens, Salmonella spp. could be isolated from the selenite F broth (SF). Wellcolex agglutination indicative of the presence of Salmonella spp. was noted with the...

Rohner, P; Dharan, S; Auckenthaler, R

215

The ninth workshop organised by CRL-Salmonella De negende workshop georganiseerd door CRL-Salmonella  

Digital Repository Infrastructure Vision for European Research (DRIVER)

De negende workshop georganiseerd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella) werd gehouden op 13 en 14 mei 2004 in Bilthoven, Nederland. De vertegenwoordigers van de Nationale Referentie Laboratoria voor Salmonella (NRLs-Salmonella) van de lidstaten van de Eur...

Korver H; Mooijman KA

216

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

UK PubMed Central (United Kingdom)

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

Yue M; Rankin SC; Blanchet RT; Nulton JD; Edwards RA; Schifferli DM

2012-01-01

217

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

Science.gov (United States)

Bacteria of the genus Salmonella comprise a large and evolutionary related population of zoonotic pathogens that can infect mammals, including humans and domestic animals, birds, reptiles and amphibians. Salmonella carries a plethora of virulence genes, including fimbrial adhesins, some of them known to participate in mammalian or avian host colonization. Each type of fimbria has its structural subunit and biogenesis genes encoded by one fimbrial gene cluster (FGC). The accumulation of new genomic information offered a timely opportunity to better evaluate the number and types of FGCs in the Salmonella pangenome, to test the use of current classifications based on phylogeny, and to infer potential correlations between FGC evolution in various Salmonella serovars and host niches. This study focused on the FGCs of the currently deciphered 90 genomes and 60 plasmids of Salmonella. The analysis highlighted a fimbriome consisting of 35 different FGCs, of which 16 were new, each strain carrying between 5 and 14 FGCs. The Salmonella fimbriome was extremely diverse with FGC representatives in 8 out of 9 previously categorized fimbrial clades and subclades. Phylogenetic analysis of Salmonella suggested macroevolutionary shifts detectable by extensive FGC deletion and acquisition. In addition, microevolutionary drifts were best depicted by the high level of allelic variation in predicted or known adhesins, such as the type 1 fimbrial adhesin FimH for which 67 different natural alleles were identified in S. enterica subsp. I. Together with strain-specific collections of FGCs, allelic variation among adhesins attested to the pathoadaptive evolution of Salmonella towards specific hosts and tissues, potentially modulating host range, strain virulence, disease progression, and transmission efficiency. Further understanding of how each Salmonella strain utilizes its panel of FGCs and specific adhesin alleles for survival and infection will support the development of new approaches for the control of Salmonellosis. PMID:22701679

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

2012-06-12

218

Development of a DNA microarray for molecular identification of all 46 Salmonella O serogroups.  

UK PubMed Central (United Kingdom)

Salmonella is a major cause of food-borne disease in many countries. Serotype determination of Salmonella is important for disease assessment, infection control, and epidemiological surveillance. In this study, a microarray system that targets the O antigen-specific genes was developed for simultaneously detecting and identifying all 46 Salmonella O serogroups. Of these, 40 serogroups can be confidently identified, and the remaining 6, in three pairs (serogroups O67 and B, E1 and E4, and A and D1), need to be further distinguished from each other using PCR methods or conventional serotyping methods. The microarray was shown to be highly specific when evaluated against 293 Salmonella strains, 186 Shigella strains, representative Escherichia coli strains, and 10 strains of other bacterial species. The assay correctly identified 288 (98%) of the Salmonella strains. The detection sensitivity was determined to be 50 ng genomic DNA per sample. By testing simulated samples in a tomato background, 2 to 8 CFU per gram inoculated could be detected after enrichment. This newly developed microarray assay is the first molecular protocol that can be used for the comprehensive detection and identification of all 46 Salmonella O serogroups. Compared to the traditional serogrouping method, the microarray provides a reliable, high-throughput, and sensitive approach that can be used for rapid identification of multiple Salmonella O serogroups simultaneously.

Guo D; Liu B; Liu F; Cao B; Chen M; Hao X; Feng L; Wang L

2013-06-01

219

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

Science.gov (United States)

Based on a data set on Campylobacter and Salmonella prevalence in the broiler supply chain, collected during the period 2002 through 2005 in the Netherlands, farm- and slaughterhouse-specific characteristics were tested for their effect on Campylobacter and Salmonella prevalence at different stages of the broiler supply chain. Three different sampling points were considered: departure from the farm, arrival at the slaughterhouse, and the end of the slaughterline. Strong associations were found between Salmonella and Campylobacter prevalence at a particular sampling point and their prevalence at the preceding point of the chain. Statistical analyses showed that the country of origin of the broiler farm had a significant effect on the prevalence of Salmonella and Campylobacter at slaughterhouse arrival. The feeding company delivering to the farm also showed a significant effect on the occurrence of both pathogens at departure from the broiler farm. The prevalence of Campylobacter decreased with an increasing number of birds per flock, whereas the prevalence of Salmonella increased with an increasing number of birds per flock. The number of flocks processed within a specific slaughterhouse was not associated with an increased or decreased prevalence of Campylobacter and Salmonella. The results provide more insight into factors related to the occurrence of both pathogens and in understanding their epidemiology. The results can be supportive in decision making on measures to reduce the contamination of broiler products with Salmonella and Campylobacter. PMID:22912476

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

2012-09-01

220

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

Directory of Open Access Journals (Sweden)

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

Mahdi Dilmaghani; Malahat Ahmadi; Taghi Zahraei-Salehi; Alireza Talebi

2011-01-01

 
 
 
 
221

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

UK PubMed Central (United Kingdom)

Based on a data set on Campylobacter and Salmonella prevalence in the broiler supply chain, collected during the period 2002 through 2005 in the Netherlands, farm- and slaughterhouse-specific characteristics were tested for their effect on Campylobacter and Salmonella prevalence at different stages of the broiler supply chain. Three different sampling points were considered: departure from the farm, arrival at the slaughterhouse, and the end of the slaughterline. Strong associations were found between Salmonella and Campylobacter prevalence at a particular sampling point and their prevalence at the preceding point of the chain. Statistical analyses showed that the country of origin of the broiler farm had a significant effect on the prevalence of Salmonella and Campylobacter at slaughterhouse arrival. The feeding company delivering to the farm also showed a significant effect on the occurrence of both pathogens at departure from the broiler farm. The prevalence of Campylobacter decreased with an increasing number of birds per flock, whereas the prevalence of Salmonella increased with an increasing number of birds per flock. The number of flocks processed within a specific slaughterhouse was not associated with an increased or decreased prevalence of Campylobacter and Salmonella. The results provide more insight into factors related to the occurrence of both pathogens and in understanding their epidemiology. The results can be supportive in decision making on measures to reduce the contamination of broiler products with Salmonella and Campylobacter.

Franz E; van der Fels-Klerx HJ; Thissen J; van Asselt ED

2012-09-01

222

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)

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.

Jorge Hernández; Peter Lindberg; Jonas Waldenström; Mirva Drobni; Björn Olsen

2012-01-01

223

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

UK PubMed Central (United Kingdom)

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.

Hernández J; Lindberg P; Waldenström J; Drobni M; Olsen B

2012-01-01

224

Pet Turtles: Cute but Contaminated with Salmonella  

Science.gov (United States)

... Radiation-Emitting Products Tobacco Products Vaccines, Blood & Biologics Pet Turtles: Cute But Contaminated with Salmonella Search the ... But disturbingly, Salmonella infections still occur because some pet shops, flea markets, street vendors, and online stores ...

225

Salmonella Outbreak Sickens 307 in 37 States  

Science.gov (United States)

... sharing features on this page, please enable JavaScript. Salmonella Outbreak Sickens 307 in 37 States CDC says ... August 9, 2013 Related MedlinePlus Pages Health Statistics Salmonella Infections FRIDAY, Aug. 9 (HealthDay News) ---- More than ...

226

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

Directory of Open Access Journals (Sweden)

Full Text Available Background and Objectives: The significant rise in food borne infections is mainly caused by Campylobacter spp., Salmonella serovars and Verotoxigenic Escherichia coli. As the emerging food borne pathogens cause disease, more studies have been conducted for rapid detection of these pathogens. The combination of immunomagnetic separation and polymerase chain reaction (IMS-PCR) is the most accurate and rapid test preferred by almost every researcher. Fourier Transform Infrared Spectroscopy (FTIR) is preferred for being a new, user friendly and rapid technique in microbiological analyses. The main aim of this study is to detect application of IMS-FTIR for Salmonella identification from foods in a short time with a higher sensitivity.Materials and Methods: Conventional Culture Technique (CC), IMS-CC, IMS-PCR and IMS-FTIR techniques were compared with each other for rapid detection in artificially contaminated minced beef with Salmonella Typhimurium, as of the 2nd, 4th and 8th hours of contamination. The method was evaluated in different food matrices and sensitivity, specifity and overall recovery was calculated.Results: The results indicate that IMS-FTIR can detect S. Typhimurium as of the 8th hour with sensitivity of 95.6667, accuracy of 91.69329, false positive ratio of 0.04333 and overall recovery of 95.66%.Conclusion: It can be suggested that the IMS-FTIR method is capable of detecting S.Typhimurium in a short time with lower cost.

A Koluman; G CeliK; T Unlu

2012-01-01

227

Elisa indireto na detecção de Salmonella spp. em lingüiça suína An indirect Elisa for detection of salmonella spp. in swine sausage  

Directory of Open Access Journals (Sweden)

Full Text Available Um teste ELISA, baseado em um anticorpo monoclonal (MAb) específico para uma proteína de membrana externa de Salmonella enterica serovar Enteritidis foi comparado com o método de cultivo tradicional na detecção de Salmonella spp. em 110 amostras de lingüiça suína frescal. A prevalência do patógeno nas amostras foi de 11,82% de acordo com o cultivo tradicional. O teste ELISA revelou sensibilidade, especificidade, valores preditivos positivos e negativos de 100%, 98%, 87% e 100%, respectivamente. Tais achados indicam que, comparado ao sistema tradicional, o teste imunológico foi bastante eficaz na determinação de Salmonella spp. em amostras de lingüiças naturalmente contaminadas.The performance of an ELISA test based on a monoclonal antibody (MAb) specific to Salmonella enterica serovar Enteritidis was compared with standard culture method for detection of Salmonella spp. in 110 samples of swine fresh sausages. The prevalence was of 11.82%, according the standard method. Comparison of ELISA and the culture method revealed the sensitivity, specificity, and positive and negative predictive values of 100%, 98%, 87% and 100%, respectively. Results indicate that compared with standard culture method the ELISA test was effective in detection of Salmonella in swine sausages naturally contaminated.

Andrea Pinto Loguercio; José Antonio Guimarães Aleixo; Agueda Castagna de Vargas; Mateus Matiuzzi da Costa

2002-01-01

228

Splenic abscess due to Salmonella enteritidis  

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Full Text Available Splenic abscess is a very rare complication of non-typhoidal Salmonella infections. We report a case of splenic abscess caused by Salmonella enteritidis. The patient is a 63-year-old woman with diabetes mellitus and underwent splenectomy. This case suggests that the patients with comorbities are at increased risk for invasive infections in non-typhoidal Salmonella infections.

Hatice Çabadak; Ay?e Erbay; Kerem Karaman; Süha ?en; Yasemin Tezer Tekçe

2012-01-01

229

Mixed salmonella infection - A case report  

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Full Text Available Mixed infection with multiple Salmonella serotypes in the same patient is an unusual finding. We present a case of enteric fever in which the blood culture was sterile and Widal test was negative. The culture of the bone marrow yielded Salmonella typhi and Salmonella paratyphi A.

Joshi S; Wattal C; Sharma A; Prasad K

2002-01-01

230

Ninth CRL-Salmonella interlaboratory comparison study (2004) on typing of Salmonella spp Negende CRL-Salmonella ringonderzoek (2004) voor de typering van Salmonella spp  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Het negende ringonderzoek voor de typering van Salmonella werd in de lente van 2004 georganiseerd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) in samenwerking met Health Protection Agency (HPA, Londen, Verenigd Koninkrijk) en het Centraal I...

Korver H; Maas HME; Ward LR; Mevius DJ; Wannet WJB; Mooijman KA

231

Establishment of a real-time PCR-based approach for accurate quantification of bacterial RNA targets in water, using Salmonella as a model organism.  

UK PubMed Central (United Kingdom)

Quantitative PCR (Q-PCR) is a fast and efficient tool to quantify target genes. In eukaryotic cells, quantitative reverse transcription-PCR (Q-RT-PCR) is also used to quantify gene expression, with stably expressed housekeeping genes as standards. In bacteria, such stable expression of housekeeping genes does not occur, and the use of DNA standards leads to a broad underestimation. Therefore, an accurate quantification of RNA is feasible only by using appropriate RNA standards. We established and validated a Q-PCR method which enables the quantification of not only the number of copies of target genes (i.e., the number of bacterial cells) but also the number of RNA copies. The genes coding for InvA and the 16S rRNA of Salmonella enterica serovar Typhimurium were selected for the evaluation of the method. As DNA standards, amplified fragments of the target genes were used, whereas the same DNA standards were transcribed in vitro for the development of appropriate RNA standards. Salmonella cultures and environmental water samples inoculated with bacteria were then employed for the final testing. Both experimental approaches led to a sensitive, accurate, and reproducible quantification of the selected target genes and RNA molecules by Q-PCR and Q-RT-PCR. It is the first time that RNA standards have been successfully used for a precise quantification of the number of RNA molecules in prokaryotes. This demonstrates the potential of this approach for determining the presence and metabolic activity of pathogenic bacteria in environmental samples.

Fey A; Eichler S; Flavier S; Christen R; Höfle MG; Guzmán CA

2004-06-01

232

Salmonella detection using 16S ribosomal DNA/RNA probe-gold nanoparticles and lateral flow immunoassay.  

UK PubMed Central (United Kingdom)

An ultrasensitive, simple, and fast lateral flow immunoassay for Salmonella detection using gold nanoparticles conjugated with a DNA probe, which is complementary to the 16S ribosomal RNA and DNA of Salmonella, has been developed. The detection limit is 5 fmol for the synthetic single-stranded DNA. For the Salmonella cultured samples, the nucleic acids from 10(7) bacteria were rapidly detected in 30 min. After silver enhancement, the detection limit was as low as 10(4) cells which is lower than 10(5) bacteria cells, the human infective dose of food-borne Salmonella. Furthermore, the probes used in this study are specific to Salmonella compared to several other Enterobacteriaceae. This approach would be a useful tool for microbial detection regarding food safety or clinical diagnosis. It is also suitable for large-scale screening in developing countries because it is low-cost, sensitive, specific and convenient.

Liu CC; Yeung CY; Chen PH; Yeh MK; Hou SY

2013-12-01

233

Salmonella detection using 16S ribosomal DNA/RNA probe-gold nanoparticles and lateral flow immunoassay.  

Science.gov (United States)

An ultrasensitive, simple, and fast lateral flow immunoassay for Salmonella detection using gold nanoparticles conjugated with a DNA probe, which is complementary to the 16S ribosomal RNA and DNA of Salmonella, has been developed. The detection limit is 5 fmol for the synthetic single-stranded DNA. For the Salmonella cultured samples, the nucleic acids from 10(7) bacteria were rapidly detected in 30 min. After silver enhancement, the detection limit was as low as 10(4) cells which is lower than 10(5) bacteria cells, the human infective dose of food-borne Salmonella. Furthermore, the probes used in this study are specific to Salmonella compared to several other Enterobacteriaceae. This approach would be a useful tool for microbial detection regarding food safety or clinical diagnosis. It is also suitable for large-scale screening in developing countries because it is low-cost, sensitive, specific and convenient. PMID:23870991

Liu, Cheng-Che; Yeung, Chun-Yan; Chen, Po-Hao; Yeh, Ming-Kung; Hou, Shao-Yi

2013-05-24

234

Evaluation of antibacterial activity against Salmonella Enteritidis.  

UK PubMed Central (United Kingdom)

Salmonella enterica serovar Enteritidis is a well-known pathogenic bacterium responsible for human gastrointestinal enteritis mainly due to the consumption of eggs and egg-products. The first aim of this work was to study several virulence factors of a strain isolated from egg content: SEovo. First, bacterial growth was studied at several temperatures and cell morphology was observed by scanning electronic microscopy. These experiments showed Salmonella's ability to grow at low temperatures and to produce exoproducts. Next, Salmonella motility was observed performing swimming, twitching, and swarming tests. Results indicated a positive flagellar activity and the cell ability to differentiate and become hyperflagellated under specific conditions. Moreover, SEovo adherence and biofilm formation was carried out. All of these tests enabled us to conclude that SEovo is a potential pathogen, thus it can be used as a model to perform antibacterial experiments. The second part of the study was dedicated to the evaluation of the antibacterial activity of different molecules using several methods. The antibacterial effect of silver and copper aluminosilicates was tested by two different kinds of methods. On the one hand, the effect of these two antibacterial agents was determined using microbiological methods: viable cell count and agar-well diffusion. And on the other hand, the antibacterial activity was evaluated using CLSM and SYTO Red/SYTOX Green dyeing. CLSM allowed for the evaluation of the biocide on sessile cells, whereas the first methods did not. Results showed that adhered bacteria were more resistant than planktonic counterparts and that CLSM was a good alternative to evaluate antibacterial activity on fixed bacteria without having to carry out a removing step.

Legendre G; Faÿ F; Linossier I; Vallée-Réhel K

2011-06-01

235

Retlig beskyttelse mod salmonella i et EU- og WTO-retligt perspektiv  

DEFF Research Database (Denmark)

This article addresses the legal approach to the risk of salmonella infections on the complex interaction between EU Law and international law. It is examined how the latitude of individual states to adopt national food safety measures is restricted by both EU Law and WTO Law. The specific issue of protection against salmonella also serves as illustration of the difficult balancing of the interests of high level of food safety and the free movement of goods.

Edinger, Wieke Huizing; Andersen, Lars Bracht

2011-01-01

236

Seroprevalence of Salmonella and Mycoplasma gallisepticum infection in chickens in Rajshahi and surrounding districts of Bangladesh  

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Full Text Available A serological survey on the prevalence of antibodies against Salmonella and Mycoplasma gallisepticum (MG) was carried out in layer chickens in Rajshahi and surrounding districts of Bangladesh. A total of 605 sera samples were examined by rapid plate agglutination (RPA) test using commercial Salmonella and MG antigens to determine the Salmonella and MG specific antibodies. Out of 605 sera samples 14.05% had single Salmonella, 45.12% had single MG and 11.24% had their concurrent infection. Prevalence of Salmonella was recorded the highest (37.60%) in adult compared to young (16.66%). On the contrary, MG and their concurrent infections were recorded the highest (71.66% and 13.33%) in young compared to adult (50.40% and 10.40%). The prevalence of Salmonella, MG and their concurrent infections were recorded the highest (34.28%, 68.57% and 17.14%) in large flocks compared to small flocks (21.25%, 50% and 8.75%). The prevalence of Salmonella infection was the highest (30.37%) in summer followed by winter (23.69%), rainy (25%) and autumn (23.33%). The prevalence of MG infection was the highest (61.58%) in winter followed by autumn (56.88%), rainy (55%) and summer (49.63%). Whereas, their concurrent infection was the highest (12.11%) in winter followed by summer (11.85%), rainy (10.83%) and autumn (10%).

Khandoker Mohammad Mozaffor Hossain; Md. Takabbar Hossain; Ichiro Yamato

2010-01-01

237

[Fatal septicemia caused by Salmonella dublin  

UK PubMed Central (United Kingdom)

A case of Salmonella Dublin infection which ran a lethal course in a woman aged 49 years is described. Salmonella Dublin was first isolated in Denmark in recent years and appears to be associated with more serious clinical pictures than the other zoonotic Salmonella serotypes. The incidence of S. Dublin is increasing particularly in France and Belgium. It was first isolated from human cases in Denmark in recent years. In the clinical microbiological department in the County of Copenhagen, S. Dublin constitutes approximately 1% of the zoonotic Salmonella serotypes which are isolated from faeces while it is one of the commonest Salmonella serotypes isolated from blood.

Eriksen NH; Jakobsen TJ

1989-03-01

238

Production and evaluation of the utility of novel phage display-derived peptide ligands to Salmonella spp. for magnetic separation.  

UK PubMed Central (United Kingdom)

AIMS: The objectives of this study were to produce Salmonella-specific peptide ligands by phage display biopanning and evaluate their use for magnetic separation (MS). METHODS AND RESULTS: Four-phage display biopanning rounds were performed, and the peptides expressed by the two most Salmonella-specific (on the basis of phage-binding ELISA results) phage clones, MSal020401 and MSal020417, were chemically synthesized and coupled to MyOne™ tosylactivated Dynabeads(®). Peptide capture capability for whole Salmonella cells from nonenriched broth cultures was quantified by MS + plate counts and MS + Greenlight™ detection and compared to capture capability of anti-Salmonella (antibody-coated) Dynabeads(®). MS + Greenlight™ gave a more comprehensive picture of capture capability than MS + plate counts and showed that Peptide MSal020417-coated beads exhibited at least similar, if not better, capture capability to anti-Salmonella Dynabeads(®) (mean capture values of 36·0 ± 18·2 and 31·2 ± 20·1%, respectively, over Salmonella spp. concentration range 3 × 10(1) -3 × 10(6) CFU ml(-1)) with cross-reactivity of ?1·9% to three other foodborne pathogens: Escherichia coli, Listeria monocytogenes and Campylobacter jejuni. CONCLUSIONS: One of the phage display-derived peptide ligands was demonstrated by MS + Greenlight™ to be a viable antibody alternative for MS of Salmonella spp. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates an antibody-free approach to Salmonella detection and opens substantial possibilities for more rapid tests for this bacterium.

Morton J; Karoonuthaisiri N; Stewart LD; Oplatowska M; Elliott CT; Grant IR

2013-07-01

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Development of a cell culture method to isolate and enrich Salmonella enterica serotype enteritidis from shell eggs for subsequent detection by real-time PCR.  

UK PubMed Central (United Kingdom)

Salmonella enterica serotype Enteritidis is a major cause of nontyphoidal salmonellosis from ingestion of contaminated raw or undercooked shell eggs. Current techniques used to identify Salmonella serotype Enteritidis in eggs are extremely laborious and time-consuming. In this study, a novel eukaryotic cell culture system was combined with real-time PCR analysis to rapidly identify Salmonella serotype Enteritidis in raw shell eggs. The system was compared to the standard microbiological method of the International Organization for Standardization (Anonymous, Microbiology of food and animal feeding stuffs-horizontal method for the detection of Salmonella, 2002). The novel technique utilizes a mouse macrophage cell line (RAW 264.7) as the host for the isolation and intracellular replication of Salmonella serotype Enteritidis. Exposure of macrophages to Salmonella serotype Enteritidis-contaminated eggs results in uptake and intracellular replication of the bacterium, which can subsequently be detected by real-time PCR analysis of the DNA released after disruption of infected macrophages. Macrophage monolayers were exposed to eggs contaminated with various quantities of Salmonella serotype Enteritidis. As few as 10 CFU/ml was detected in cell lysates from infected macrophages after 10 h by real-time PCR using primer and probe sets specific for DNA segments located on the Salmonella serotype Enteritidis genes sefA and orgC. Salmonella serotype Enteritidis could also be distinguished from other non-serogroup D Salmonella serotypes by using the sefA- and orgC-specific primer and probe sets. Confirmatory identification of Salmonella serotype Enteritidis in eggs was also achieved by isolation of intracellular bacteria from lysates of infected macrophages on xylose lysine deoxycholate medium. This method identifies Salmonella serotype Enteritidis from eggs in less than 10 h compared to the more than 5 days required for the standard reference microbiological method of the International Organization for Standardization (Microbiology of food and animal feeding stuffs-horizontal method for the detection of Salmonella, 2002).

Day JB; Basavanna U; Sharma SK

2009-08-01

240

Development of a Cell Culture Method To Isolate and Enrich Salmonella enterica Serotype Enteritidis from Shell Eggs for Subsequent Detection by Real-Time PCR?  

Science.gov (United States)

Salmonella enterica serotype Enteritidis is a major cause of nontyphoidal salmonellosis from ingestion of contaminated raw or undercooked shell eggs. Current techniques used to identify Salmonella serotype Enteritidis in eggs are extremely laborious and time-consuming. In this study, a novel eukaryotic cell culture system was combined with real-time PCR analysis to rapidly identify Salmonella serotype Enteritidis in raw shell eggs. The system was compared to the standard microbiological method of the International Organization for Standardization (Anonymous, Microbiology of food and animal feeding stuffs—horizontal method for the detection of Salmonella, 2002). The novel technique utilizes a mouse macrophage cell line (RAW 264.7) as the host for the isolation and intracellular replication of Salmonella serotype Enteritidis. Exposure of macrophages to Salmonella serotype Enteritidis-contaminated eggs results in uptake and intracellular replication of the bacterium, which can subsequently be detected by real-time PCR analysis of the DNA released after disruption of infected macrophages. Macrophage monolayers were exposed to eggs contaminated with various quantities of Salmonella serotype Enteritidis. As few as 10 CFU/ml was detected in cell lysates from infected macrophages after 10 h by real-time PCR using primer and probe sets specific for DNA segments located on the Salmonella serotype Enteritidis genes sefA and orgC. Salmonella serotype Enteritidis could also be distinguished from other non-serogroup D Salmonella serotypes by using the sefA- and orgC-specific primer and probe sets. Confirmatory identification of Salmonella serotype Enteritidis in eggs was also achieved by isolation of intracellular bacteria from lysates of infected macrophages on xylose lysine deoxycholate medium. This method identifies Salmonella serotype Enteritidis from eggs in less than 10 h compared to the more than 5 days required for the standard reference microbiological method of the International Organization for Standardization (Microbiology of food and animal feeding stuffs—horizontal method for the detection of Salmonella, 2002).

Day, J. B.; Basavanna, U.; Sharma, S. K.

2009-01-01

 
 
 
 
241

Development of a cell culture method to isolate and enrich Salmonella enterica serotype enteritidis from shell eggs for subsequent detection by real-time PCR.  

Science.gov (United States)

Salmonella enterica serotype Enteritidis is a major cause of nontyphoidal salmonellosis from ingestion of contaminated raw or undercooked shell eggs. Current techniques used to identify Salmonella serotype Enteritidis in eggs are extremely laborious and time-consuming. In this study, a novel eukaryotic cell culture system was combined with real-time PCR analysis to rapidly identify Salmonella serotype Enteritidis in raw shell eggs. The system was compared to the standard microbiological method of the International Organization for Standardization (Anonymous, Microbiology of food and animal feeding stuffs-horizontal method for the detection of Salmonella, 2002). The novel technique utilizes a mouse macrophage cell line (RAW 264.7) as the host for the isolation and intracellular replication of Salmonella serotype Enteritidis. Exposure of macrophages to Salmonella serotype Enteritidis-contaminated eggs results in uptake and intracellular replication of the bacterium, which can subsequently be detected by real-time PCR analysis of the DNA released after disruption of infected macrophages. Macrophage monolayers were exposed to eggs contaminated with various quantities of Salmonella serotype Enteritidis. As few as 10 CFU/ml was detected in cell lysates from infected macrophages after 10 h by real-time PCR using primer and probe sets specific for DNA segments located on the Salmonella serotype Enteritidis genes sefA and orgC. Salmonella serotype Enteritidis could also be distinguished from other non-serogroup D Salmonella serotypes by using the sefA- and orgC-specific primer and probe sets. Confirmatory identification of Salmonella serotype Enteritidis in eggs was also achieved by isolation of intracellular bacteria from lysates of infected macrophages on xylose lysine deoxycholate medium. This method identifies Salmonella serotype Enteritidis from eggs in less than 10 h compared to the more than 5 days required for the standard reference microbiological method of the International Organization for Standardization (Microbiology of food and animal feeding stuffs-horizontal method for the detection of Salmonella, 2002). PMID:19561188

Day, J B; Basavanna, U; Sharma, S K

2009-06-26

242

Adhesion and growth inhibitory effect of chicken egg yolk antibody (IgY) on Salmonella enterica serovars Enteritidis and Typhimurium in vitro.  

UK PubMed Central (United Kingdom)

The protective effects of powder preparation of egg yolk immunoglobulin Y (IgY), specific to Salmonella Enteritidis and Salmonella Typhimurium outer membrane proteins (OMP), against these two Salmonella sp. serovars were investigated in vitro in two different assays: adhesion-prevention and growth-inhibition. The adhesion-prevention assay was conducted using polarized monolayers of the human intestinal epithelial Caco-2 cell line. First, the conditions of Salmonella adherence to Caco-2 cells were optimized, and interferences of bacteria with the transepithelial electrical resistance (TER) of fully differentiated Caco-2 cell monolayers and the lactate dehydrogenase release upon exposure of the cells to Salmonella were evaluated. Both Salmonella sp. serovars were able to adhere to Caco-2 cells and decreased TER. Results from the adhesion-prevention assay demonstrated that specific IgY reduced the decrease in TER of the infected Caco-2 cell monolayers and blocked the Salmonella sp. adhesion in a concentration-dependent manner (p < 0.05). Nonspecific IgY also exhibited an inhibitory effect on these two parameters, but to a lesser extent than that of the specific IgY (p < 0.05). The protective effect of nonspecific IgY could be attributed to the low-density lipoprotein component of the water-soluble fraction of egg yolks that may not have been eliminated during ultrafiltration. The growth-inhibition assay revealed that specific IgY had an inhibitory effect on the bacterial growth, markedly during the late exponential phase, whereas nonspecific IgY failed to do so. Taken together, these results suggest that the in vitro growth inhibitory effect of specific IgY on Salmonella spp. resulted from the specific binding activity of these IgY to Salmonella sp. OMP. Passive immunization with Salmonella sp. OMP-specific IgY could thus be useful to prevent Salmonella colonization in broiler chickens and the subsequent carcass contamination during processing.

Chalghoumi R; Théwis A; Beckers Y; Marcq C; Portetelle D; Schneider YJ

2009-06-01

243

Use of bacteriophages in combination with competitive exclusion to reduce Salmonella from infected chickens.  

UK PubMed Central (United Kingdom)

Salmonella-spedfic bacteriophages (BP) and competitive exclusion (CE) were used to reduce Salmonella colonization in experimentally infected chickens. A "cocktail" of distinct phage (i.e., phage showing different host ranges and inducing different types of plaques on Salmonella Typhimurium [ST] cultures) was developed. The killing activity of the selected BPs on ST cultures differed significantly, as determined in in vitro killing assays. BPs were administered orally to the chickens several days prior and after ST challenge but not simultaneously. BPs were readily isolated from the feces of the BP-treated chickens approximately 48 hr after administration. A CE product consisting of a defined culture of seven different microbial species was used either alone or in combination with BP treatment. CE was administered orally at hatch. Salmonella counts in intestine, ceca, and a pool of liver/spleen were evaluated in Salmonella-challenged chickens treated with BP or with BP and CE. In both trials 1 and 2, a beneficial effect of the phage treatment on weight gain performance was evident. A reduction in Salmonella counts was detected in cecum and ileum of BP-, CE-, and BP+CE-treated chickens as compared with nontreated birds. In trial 1, BP treatment reduced ST counts to marginal levels in the ileum and reduced counts sixfold in the ceca. A reduction of Salmonella counts with BP, CE, and BP+CE treatments was evident in chickens from trial 2. Both CE and BP treatments showed differences in the reduction of Salmonella counts after challenge between spedmens obtained at days 4 and 14 postchallenge in ceca, liver/spleen, and ileum. The preliminary data presented in this report show that isolation and characterization of Salmonella-specific BP is uncomplicated and feasible on a larger scale. Results indicate a protective effect of both Salmonella-specific BPs and a defined competitive exclusion product against Salmonella colonization of experimentally infected chickens. These results are encouraging for further work on the use of BP as an effective alternative to antibiotics to reduce Salmonella infections in poultry.

Toro H; Price SB; McKee AS; Hoerr FJ; Krehling J; Perdue M; Bauermeister L

2005-03-01

244

Use of bacteriophages in combination with competitive exclusion to reduce Salmonella from infected chickens.  

Science.gov (United States)

Salmonella-spedfic bacteriophages (BP) and competitive exclusion (CE) were used to reduce Salmonella colonization in experimentally infected chickens. A "cocktail" of distinct phage (i.e., phage showing different host ranges and inducing different types of plaques on Salmonella Typhimurium [ST] cultures) was developed. The killing activity of the selected BPs on ST cultures differed significantly, as determined in in vitro killing assays. BPs were administered orally to the chickens several days prior and after ST challenge but not simultaneously. BPs were readily isolated from the feces of the BP-treated chickens approximately 48 hr after administration. A CE product consisting of a defined culture of seven different microbial species was used either alone or in combination with BP treatment. CE was administered orally at hatch. Salmonella counts in intestine, ceca, and a pool of liver/spleen were evaluated in Salmonella-challenged chickens treated with BP or with BP and CE. In both trials 1 and 2, a beneficial effect of the phage treatment on weight gain performance was evident. A reduction in Salmonella counts was detected in cecum and ileum of BP-, CE-, and BP+CE-treated chickens as compared with nontreated birds. In trial 1, BP treatment reduced ST counts to marginal levels in the ileum and reduced counts sixfold in the ceca. A reduction of Salmonella counts with BP, CE, and BP+CE treatments was evident in chickens from trial 2. Both CE and BP treatments showed differences in the reduction of Salmonella counts after challenge between spedmens obtained at days 4 and 14 postchallenge in ceca, liver/spleen, and ileum. The preliminary data presented in this report show that isolation and characterization of Salmonella-specific BP is uncomplicated and feasible on a larger scale. Results indicate a protective effect of both Salmonella-specific BPs and a defined competitive exclusion product against Salmonella colonization of experimentally infected chickens. These results are encouraging for further work on the use of BP as an effective alternative to antibiotics to reduce Salmonella infections in poultry. PMID:15839424

Toro, H; Price, S B; McKee, A S; Hoerr, F J; Krehling, J; Perdue, M; Bauermeister, L

2005-03-01

245

Eukaryotic signaling pathways targeted by Salmonella effector protein AvrA in intestinal infection in vivo  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The Salmonella AvrA gene is present in 80% of Salmonella enterica serovar strains. AvrA protein mimics the activities of some eukaryotic proteins and uses these activities to the pathogen's advantage by debilitating the target cells, such as intestinal epithelial cells. Therefore, it is important to understand how AvrA works in targeting eukaryotic signaling pathways in intestinal infection in vivo. In this study, we hypothesized that AvrA interacts with multiple stress pathways in eukaryotic cells to manipulate the host defense system. A whole genome approach combined with bioinformatics assays was used to investigate the in vivo genetic responses of the mouse colon to Salmonella with or without AvrA protein expression in the early stage (8 hours) and late stage (4 days). Specifically, we examined the gene expression profiles in mouse colon as it responded to pathogenic Salmonella stain SL1344 (with AvrA expression) or SB1117 (without AvrA expression). Results We identified the eukaryotic targets of AvrA and the cell signaling pathways regulated by AvrA in vivo. We found that pathways, such as mTOR, NF-kappaB, platelet-derived growth factors, vascular endothelial growth factor, oxidative phosphorylation, and mitogen-activated protein kinase signaling are specifically regulated by AvrA in vivo and are associated with inflammation, anti-apoptosis, and proliferation. At the early stage of Salmonella infection, AvrA mainly targeted pathways related to nuclear receptor signaling and oxidative phosphorylation. At the late stage of Salmonella infection, AvrA is associated with interferon-gamma responses. Conclusion Both early and late phases of the host response exhibit remarkable specificity for the AvrA+ Salmonella. Our studies provide new insights into the eukaryotic molecular cascade that combats Salmonella-associated intestinal infection in vivo.

Liu Xingyin; Lu Rong; Xia Yinglin; Wu Shaoping; Sun Jun

2010-01-01

246

Production and Kinetics of Salmonella enterica serovar enteritidis in Vibrofermentor  

Directory of Open Access Journals (Sweden)

Full Text Available Food-borne human Salmonellosis caused by Salmonella enterica serovar enteritidis has given a rise to many of economic losses in terms of both poultry and food industries. Salmonella has a great importance among the major bacterial pathogens of poultry. In Turkey as well as all over the world prevention of Salmonella infection can be achieved by good monitoring and screening programs. More recently immunological test systems are used for diagnosis based on the detection of surface antigens such as lipopolysaccharide (LPS), flagellin etc. As to its production some different methods are used practically. In this work, the lab-scale production of Salmonella enterica serovar enteritidis was achieved both in shake-flask and vibrofermentor cultures and a comparative optimization of the process yield and production kinetics was carried out. The microorganisms were cultivated in brain heart infusion broth, at 37°C for 5 h. Specific growth rates and doubling times for both vibrofermentör and shake-flask were estimated as 0.509 and 0.709 h-1 and 75.0 and 58.6 min, respectively. LPS and flagella were extracted from lyophilized cultures.

A. Nalbantsoy; O. Akpolat; I. Karaboz; S.I. Deliloglu-Gurhan

2007-01-01

247

Survival of Salmonella east bourne and Salmonella typhimurium in chocolate.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 str...

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

248

Salmonella bongori Provides Insights into the Evolution of the Salmonellae  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 inf...

Fookes, Maria; Schroeder, Gunnar N.; Langridge, Gemma C.; Blondel, Carlos J.; Mammina, Caterina; Connor, Thomas R.

249

Abscesso esplênico causado por Salmonella Splenic abscess due to Salmonella  

Directory of Open Access Journals (Sweden)

Full Text Available OBJETIVO: Relatar as características demográficas, clínicas, diagnóstica e terapêutica de pacientes com abscesso esplênico (AE) causado por Salmonella. MÉTODO: Análise retrospectiva de dados de pacientes atendidos no Serviço de Cirurgia Geral e Aparelho Digestivo do Hospital Universitário Gaffrée-Guinle no período de janeiro de 2001 a dezembro de 2005, a estes se incluiu um caso tratado em outro hospital em época anterior. RESULTADOS: Dentre 4823 pacientes recentemente atendidos, dois apresentaram AE causado por Salmonella enteritidis, enquanto o caso mais antigo o agente responsável foi a Salmonella typhi. Todos eram homens, com idade média de 45 anos. Em nenhum deles foi identificada condição predisponente à formação do abscesso; os exames de imagem foram capazes de diagnosticar o AE. Todos foram tratados por esplenectomia e antibioticoterapia e evoluíram para cura. CONCLUSÕES: A Salmonella, apesar de infrequente, pode ser o agente causal do AE. Caracteristicamente os abscessos eram grandes e apresentavam material necrótico em seu interior. Nesta condição, a esplenectomia associada a antibioticoterapia mostrou-se eficaz no tratamento.BACKGROUND: Splenic abscess is a uncommon disease and remains a diagnostic challenge. Outcome is fatal when the condition is not promptly recognized and treated. The aim of this study was to analyze the demographic, clinical, diagnostic methods and management characteristic of patients with salmonelal splenic abscess. METHODS: Retrospective study at General and Digestive Surgery Service - Hospital Universitário Gaffrée-Guinle of the Universidade Federal do Estado do Rio de Janeiro - UNIRIO from January 2001 to December 2005 resulting in a total number of 4823 patients has been performed. An additional case treated by one author was added. RESULTS: During the studied period two cases of splenic abscess due to Salmonella enteritidis was treated; a third older case was due to Salmonella typhi. All patients were man; the mean age was 45 years, all were immunocompetent and had large solitary lesion. All patients underwent splenectomy and antibiotic therapy; the outcome was favorable for all patients. CONCLUSION: Nowadays still is possible that splenic abscess is due to Salmonella species etiology; typically, all patients are immunocompetents adult males and large solitary lesions within necrotic material. In this condition, splenectomy and intravenous antibiotic administration appear to constitute the most convenient therapy.

Bruno von Glen Herkenhoff; Ludmila Godoy dos Santos Ferreira; Maristela Cavedagne; Renato Manganelli Salomão; Acyolli Moreira Maia; Antonio Carlos Iglesias

2006-01-01

250

Salmonella engineered to express CD20-targeting antibodies and a drug-converting enzyme can eradicate human lymphomas.  

UK PubMed Central (United Kingdom)

Escape from immune detection favors both tumor survival and progression, and new approaches to circumvent this are essential to combat cancers. Nonvirulent, tumor-tropic bacteria, such as Salmonella typhimurium, can unmask a tumor by transforming it into a site of inflammation; however, the nonspecific invasiveness of Salmonella leads to off-target effects diluting its therapeutic efficacy and making its use in human patients inherently risky. Here, we demonstrate that Salmonella tumor specificity can be significantly improved via a surface-expressed single-domain antibody directed to a tumor-associated antigen (CD20). Antibody-dependent bacterial targeting specifies the infection of CD20+ lymphoma cells in vitro and in vivo, while significantly diminishing nonspecific cell invasion. Indeed, CD20-targeted Salmonella was less generally invasive, even in organs that normally serve as physiological reservoirs. Furthermore, tumor-specific Salmonella engineered to carry the herpes simplex virus thymidine kinase prodrug-converting enzyme effectively treats human lymphoma xenografts when coadministered intratumorally or intravenously with ganciclovir in mice lacking a functional adaptive immune system. Therefore, tumor-targeted Salmonella could prove effective even in those patients displaying a debilitated immune system, which is often the case with late-stage cancers. Altogether, antibody-displaying Salmonella vectors can mediate a tumor-specific response and rejection with few detectable adverse effects while specifically delivering cytotoxic payloads.

Massa PE; Paniccia A; Monegal A; de Marco A; Rescigno M

2013-08-01

251

Epidemiological investigations of surveillance strategies of zoonotic Salmonella.  

UK PubMed Central (United Kingdom)

This thesis is concerned with the application of recently developed epidemiological and statistical tools to inform the optimisation of a national surveillance strategy of considerable importance to human health. The results of a series of epidemiological investigations of surveillance strategies for zoonotic Salmonella are presented. Salmonella are one of the most common and serious zoonotic foodborne pathogenic bacteria globally. These studies were motivated by the increasing focus on the cost-effectiveness of surveillance while maintaining consumer confidence in food supply. Although data from the Danish Salmonella surveillance and control programme has been used in these investigations, the techniques may be readily applied to other surveillance data of similar quality. The first study describes the spatial epidemiological features of Danish Salmonella surveillance and control programme data from 1995 to 2004, using a novel method of spatially adaptive smoothing. The conditional probability of a farm being a case was consistently high in the the south-west of Sonderjylland on the Jutland peninsula, identifying this area for further investigation and targeted surveillance. The identification of clustering of case farms led into the next study, which closely examines one year of data, 2003, for patterns of spatial dependency. K-function analyses provided evidence for aggregation of Salmonella case farms over that of all farms at distances of up to six kilometres. Visual semivariogram analyses of random farm-level effects from a Bayesian logistic regression model (adjusted for herd size) of Salmonella seropositivity, revealed spatial dependency between pairs of farms up to a distance of four kilometres apart. The strength of the spatial dependency was positively associated with slaughter pig farm density. We describe how this might inform the surveillance programme by potentially targeting herds within a four kilometre radius of those with high levels of Salmonella infection. In the third study, farm location details, routinely recorded surveillance information, and industry survey data from 1995 were combined to build a logistic seroprevalence model. This identified wet-feeding and specific pathogen free herd health status as protective factors for Salmonella seropositivity, while purchasing feed was a risk factor. Once adjusting for these covariates, we identified pockets of unexplained risk for Salmonella seropositivity and found spatial dependency at distances of up to six km (95% CI: 2–35 km) between farms. A generalised linear spatial model was fitted to the Jutland data allowing formal estimation of the range of spatial correlation and a measure of the uncertainty about it. There was a large within-farm component to the variance, suggesting that gathering more farm level information would be advantageous if this approach was to be used to target surveillance strategy. The fourth study again considers data from the whole study period, 1995 to 2004. A detailed temporal analysis of the data revealed there was no consistent seasonal pattern and correspondingly no benefit in targeting sampling to particular times of the year. Spatiotemporal analyses suggested a local epidemic of increased seroprevalence occured in west Jutland in late 2000. Lorelogram analyses showed a defined period of statistically significant temporal dependency, suggesting that there is little value in sampling more frequently than every 10 weeks on the average farm. The final study uses findings from the preceding chapters to develop a zero-inflated binomial model which predicts which farms are most at risk of Salmonella, and then preferentially samples these high-risk farms. This type of modelling allows assessment of similarities and differences between factors that affect herd infection status (introduction) and those that affect the seroprevalence in infected herds (persistence and spread). The model suggested that many of the herds where Salmonella was not detected were infected but at a low prevalence. Using cost and sensitivity, we compa

Benschop J

252

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

Energy Technology Data Exchange (ETDEWEB)

The Ames/Salmonella assay, developed by Professor Bruce Ames at the University of California, Berkeley, is a rapid and sensitive assay for detecting mutagenicity of various chemical compounds (Maron and Ames, 1983). It is a widely accepted short-term assay for detecting chemicals that induce mutations in the histidine (his) gene of Salmonella typhimurium. This is a reverse mutation assay that detects the mutational reversion of his-dependent Salmonella to the his-independent counterpart. Thereby, mutagenic compounds will increase the frequency of occurrence of his-independent bacterial colonies. The assay utilizes the specific genetically constructed strains of bacteria either with or without mammalian metabolic activation enzymes (S9), Aroclor induced rat liver homogenate to assess the mutagenicity of different compounds. In this study, we will use the Ames/Salmonella assay to investigate the mutagenicity of Hexanitrostilbene (HNS) from both Bofors and Pantex, and Dipicryethane (DPE).

Wu, R; Felton, J

2007-10-12

253

Cellulitis Due to Salmonella infantis.  

Directory of Open Access Journals (Sweden)

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.

Satish R Patil; Kshirsagar AY; Ghorpade MV; Shinde RV

2013-01-01

254

Salmonella-secreted Virulence Factors  

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-05-01

255

Nitric Oxide and Salmonella Pathogenesis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Nitric oxide (NO) and its congeners contribute to the innate immune response to Salmonella. This enteric pathogen is exposed to reactive nitrogen species (RNS) in the environment and at different anatomical locations during its infectious cycle in vertebrate hosts. Chemical generation of RNS enhance...

Henard, Calvin A.; Vázquez-Torres, Andrés

256

Salmonella Infection and Water Frogs  

Centers for Disease Control (CDC) Podcasts

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.

2010-01-12

257

Salmonella enteritidis isolation from broiler chickens infected with low doses  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper we present the possibilities for detection of Salmonella enteritidis (SE) by bacteriological and serological technics. Also, we studied which tissue is the most suitable sample for Salmonella isolation. One day old and three weeks old broiler chickens were experimentally infected with low doses of SE. For the isolation of SE we used Rappaport Vassiliadis media. Specific antibodies in sera were detected using ELISA. According to our results, broiler chickens were susceptible to infection with low doses of SE. However, specific antibodies could not been found. SE was isolated from caeca, but not from livers of infected chickens when tested at the end of the experiment (at 6 weeks). Our results revealed that bacterial cultures are still the method of choice for detection of SE in broilers flocks.

Velhner Maja; Stojanov I.; Potkonjak Dubravka; Kapetanov M.; Orli? Dušan; Raši? Z.

2005-01-01

258

A real-time multiplex SYBR Green I polymerase chain reaction assay for rapid screening of salmonella serotypes prevalent in the European Union.  

UK PubMed Central (United Kingdom)

A two-step real-time SYBR Green I multiplex polymerase chain reaction (PCR) assay with melting curve analysis was developed for rapid detection of 19 Salmonella serotypes frequently encountered in humans, animals, and animal-associated meat products within the European Union. The first-step single-tube reaction (Multiplex PCR I), consisting of five primer pairs, classified an initial test panel of eight Salmonella serotypes into five groups on the basis of characteristic amplicon melting temperatures produced by each strain. Following designation into groups, two subsequent triplex reactions (Multiplex PCR II-G1 and II-G3) allowed for further identification of five Salmonella serotypes by their melting peak temperatures. Primers for serotype differentiation were designed to target the genes encoding either phase 1 and 2 flagellar antigens fliC and fljB or unique serotype-specific loci. In addition, the assay simultaneously screened for the presence of the ampicilin-amoxicillin, chloramphenicol-florfenicol, streptomycin-spectinomycin, sulfanomides, and tetracycline (ACSSuT)-type multidrug resistance pattern, indicated by the floR gene, and for the Salmonella virulence plasmid encoded by the svp operon in Salmonella serotype Typhimurium. The established multiplex assays were successfully tested on 97 isolates, comprising 37 distinct Salmonella serotypes and 12 non-Salmonella strains. The two-step assay correctly detected 19 of 37 Salmonella serotypes and all non-Salmonella strains produced negative results. Of the 19 serotypes detected in the assays, 7 serotypes, including Salmonella serotypes Ohio, Goldcoast, Livingstone, Kedougou, Enteritidis, Kentucky, ACSSuT-type Salmonella serotype Typhimurium DT104 and DT104b, as well as non-ACSSuT-type Salmonella serotype Typhimurium strains, were definitively identified. The developed multiplex real-time SYBR Green I PCR assay represents a more rapid and reliable method for identification of large numbers of Salmonella serotypes prevalent throughout the European Union than assays using phenotypic serotyping methods.

Rajtak U; Leonard N; Bolton D; Fanning S

2011-07-01

259

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

Science.gov (United States)

The ability to detect a specific organism from a complex environment is vitally important to many fields of public health, including food safety. For example, tomatoes have been implicated numerous times as vehicles of foodborne outbreaks due to strains of Salmonella but few studies have ever recovered Salmonella from a tomato phyllosphere environment. Precision of culturing techniques that target agents associated with outbreaks depend on numerous factors. One important factor to better understand is which species co-enrich during enrichment procedures and how microbial dynamics may impede or enhance detection of target pathogens. We used a shotgun sequence approach to describe taxa associated with samples pre-enrichment and throughout the enrichment steps of the Bacteriological Analytical Manual's (BAM) protocol for detection of Salmonella from environmental tomato samples. Recent work has shown that during efforts to enrich Salmonella (Proteobacteria) from tomato field samples, Firmicute genera are also co-enriched and at least one co-enriching Firmicute genus (Paenibacillus sp.) can inhibit and even kills strains of Salmonella. Here we provide a baseline description of microflora that co-culture during detection efforts and the utility of a bioinformatic approach to detect specific taxa from metagenomic sequence data. We observed that uncultured samples clustered together with distinct taxonomic profiles relative to the three cultured treatments (Universal Pre-enrichment broth (UPB), Tetrathionate (TT), and Rappaport-Vassiliadis (RV)). There was little consistency among samples exposed to the same culturing medias, suggesting significant microbial differences in starting matrices or stochasticity associated with enrichment processes. Interestingly, Paenibacillus sp. (Salmonella inhibitor) was significantly enriched from uncultured to cultured (UPB) samples. Also of interest was the sequence based identification of a number of sequences as Salmonella despite indication by all media, that samples were culture negative for Salmonella. Our results substantiate the nascent utility of metagenomic methods to improve both biological and bioinformatic pathogen detection methods. PMID:24039862

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

2013-09-09

260

Bacteriological detection of Salmonella in the presence of competitive micro-organisms (A collaborative study amongst the National Reference Laboratories for Salmonella) Bacteriologische detectie van Salmonella in aanwezigheid van storingsflora (Een ringonderzoek met de Nationale Referentie Laboratoria voor Salmonella)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Het Communautair Referentie Laboratorium voor Salmonella heeft een tweede bacteriologisch ringonderzoek georganiseerd met deelname van de Nationale Referentie Laboratoria voor Salmonella. Het belangrijkste doel van dit onderzoek was verschillen tussen de NRLs in de resultaten van Salmonella dete...

Voogt N; Veld PH in 't; Nagelkerke N; Henken AM

 
 
 
 
261

9 CFR 113.122 - Salmonella Choleraesuis Bacterin.  

Science.gov (United States)

...2009-01-01 2009-01-01 false Salmonella Choleraesuis Bacterin. 113.122 Section 113...Bacterial Products § 113.122 Salmonella Choleraesuis Bacterin. Salmonella Choleraesuis Bacterin shall be prepared from a...

2009-01-01

262

METHOD FOR PREVENTING AND TREATING INFECTION CAUSED BY SALMONELLA CHOLERAESUIS OR SALMONELLA DUBLIN  

UK PubMed Central (United Kingdom)

The present invention relates to a method which can be used to prevent infection caused by Salmonella Choleraesuis bacteria and infection caused by Salmonella Dublin bacteria, and which can treat disease caused by infection caused by Salmonella Choleraesuis bacteria and Salmonella Dublin bacteria and relates more particularly to a composition comprising a bacteriophage having a genome represented by sequence ID number 1, a bacteriophage having a genome represented by a partial genetic sequence of sequence ID number 2 to sequence ID number 22, or a mixture of the two bacteriophages as an effective ingredient and relates to a method for using the composition to prevent infection caused by Salmonella Choleraesuis bacteria or Salmonella Dublin bacteria or treat disease caused by infection caused by Salmonella Choleraesuis bacteria or Salmonella Dublin bacteria.

YOON SEONG JUN; JUN SOO YOUN; PAIK HYOUN ROK; KANG SANG HYEON

263

Interaction of Salmonella choleraesuis, Salmonella dublin and Salmonella typhimurium with porcine and bovine terminal ileum in vivo.  

UK PubMed Central (United Kingdom)

Quantitative experiments on the interaction of Salmonella choleraesuis and Salmonella dublin with porcine and bovine intestinal epithelia yielded no evidence to suggest that host restriction of S. choleraesuis and S. dublin for pigs and calves respectively could be explained in terms of the patterns of intestinal invasion observed in ligated ileal loops in vivo, at 3 h after challenge. No evidence was found to support the idea that Peyer's patches, or specifically M cells, are the major route of entry for these serotypes in vivo. Three hours after loop inoculation, each serotype was recovered in comparable numbers from either absorptive or Peyer's patch mucosae present in the same ileal loop, indicating that both types of tissue are involved in the early stages of the enteropathogenic process induced by both serotypes. More detailed transmission electron microscopic (TEM) analyses of follicle-associated epithelia (FAE) challenged with S. choleraesuis showed that in the same region of FAE, organisms invaded both M cells and enterocytes directly; comparable detailed TEM studies with S. dublin could not be carried out because of the tissue-destructive properties of this serotype. S. dublin was clearly more histotoxic than S. choleraesuis as had previously been found in rabbits: this difference is almost certainly due to a tissue-damaging toxin which is neither host nor gut-tissue specific. The tissue-destructive potential of S. dublin has profound implications for the measurement of and the assignment of significance to the invasiveness of S. dublin. S. dublin was nearly always seen entering gut cells in micro-colonies whereas S. choleraesuis entered mainly as single organisms or small groups of two or three.

Bolton AJ; Osborne MP; Wallis TS; Stephen J

1999-09-01

264

Interaction of Salmonella choleraesuis, Salmonella dublin and Salmonella typhimurium with porcine and bovine terminal ileum in vivo.  

Science.gov (United States)

Quantitative experiments on the interaction of Salmonella choleraesuis and Salmonella dublin with porcine and bovine intestinal epithelia yielded no evidence to suggest that host restriction of S. choleraesuis and S. dublin for pigs and calves respectively could be explained in terms of the patterns of intestinal invasion observed in ligated ileal loops in vivo, at 3 h after challenge. No evidence was found to support the idea that Peyer's patches, or specifically M cells, are the major route of entry for these serotypes in vivo. Three hours after loop inoculation, each serotype was recovered in comparable numbers from either absorptive or Peyer's patch mucosae present in the same ileal loop, indicating that both types of tissue are involved in the early stages of the enteropathogenic process induced by both serotypes. More detailed transmission electron microscopic (TEM) analyses of follicle-associated epithelia (FAE) challenged with S. choleraesuis showed that in the same region of FAE, organisms invaded both M cells and enterocytes directly; comparable detailed TEM studies with S. dublin could not be carried out because of the tissue-destructive properties of this serotype. S. dublin was clearly more histotoxic than S. choleraesuis as had previously been found in rabbits: this difference is almost certainly due to a tissue-damaging toxin which is neither host nor gut-tissue specific. The tissue-destructive potential of S. dublin has profound implications for the measurement of and the assignment of significance to the invasiveness of S. dublin. S. dublin was nearly always seen entering gut cells in micro-colonies whereas S. choleraesuis entered mainly as single organisms or small groups of two or three. PMID:10517596

Bolton, A J; Osborne, M P; Wallis, T S; Stephen, J

1999-09-01

265

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

UK PubMed Central (United Kingdom)

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.

Liu WQ; Feng Y; Wang Y; Zou QH; Chen F; Guo JT; Peng YH; Jin Y; Li YG; Hu SN; Johnston RN; Liu GR; Liu SL

2009-01-01

266

Contribution of the Type VI Secretion System Encoded in SPI-19 to Chicken Colonization by Salmonella enterica Serotypes Gallinarum and Enteritidis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Salmonella Gallinarum is a pathogen with a host range specific to poultry, while Salmonella Enteritidis is a broad host range pathogen that colonizes poultry sub-clinically but is a leading cause of gastrointestinal salmonellosis in humans and many other species. Despite recent advances in our under...

Blondel, Carlos J.; Yang, Hee-Jeong; Castro, Benjamín; Chiang, Sebastián; Toro, Cecilia S.; Zaldívar, Mercedes

267

Interaction of Salmonella serotypes with porcine macrophages in vitro does not correlate with virulence.  

Science.gov (United States)

The interaction between Salmonella serotypes and macrophages is potentially instrumental in determining the outcome of infection. The nature of this interaction was characterized with respect to virulence and serotype-host specificity using pigs as the infection model. Experimental infection with Salmonella typhimurium, Salmonella choleraesuis or Salmonella dublin resulted in enteric, systemic or asymptomatic infection, respectively, which correlates well with the association of S. choleraesuis with systemic disease in pigs in epidemiological studies. Persistence within porcine alveolar macrophages in vitro did not directly correlate with virulence since S. typhimurium persisted in the highest numbers, and S. choleraesuis in the lowest. Comparison to other studies revealed that the relatively high persistence of S. typhimurium in macrophages correlates with its virulence in a broad range of animals: this could be a virulence mechanism for broad-host-range serotypes. There were little or no significant differences in the induction of pro-inflammatory cytokines by macrophages infected with the three serotypes. S. typhimurium and S. dublin, but not S. choleraesuis, damaged porcine macrophages, and the mechanism of damage did not resemble apoptosis. In conclusion, the virulence of Salmonella serotypes in pigs did not directly correlate with their interaction with porcine macrophages in vitro. The interaction of Salmonella and macrophages in vitro may not accurately model their interaction in vivo, and this will form the basis of further study. PMID:10878128

Watson, P R; Paulin, S M; Jones, P W; Wallis, T S

2000-07-01

268

Application of a novel biopolymer for removal of Salmonella from poultry wastewater.  

UK PubMed Central (United Kingdom)

This study evaluated the potential of an extracellular, novel biopolymeric flocculant produced by a strain of Klebsiella terrigena for removal of Salmonella, a potent pathogen prevalent in poultry wastewater. The purified biopolymer was applied to poultry wastewater containing 3 log CFU cells of Salmonella. An optimized dosage of 2 mg L(-1) of the purified bioflocculant was sufficient to remove 80.3% Salmonella spp. within 30 min, at ambient temperature. Also this bioflocculant showed high flocculating activity (90%) against kaolin particles and proved to be far more effective than the other synthetic flocculants used in this study. Fluorescent in situ hybridization (FISH) with the genus specific Sal3 probe hybridized with the Salmonella present in the agglomerated matrix of the bioflocculant. Confocal laser scanning micrographs (CLSM) allowed a clear visualization of the spatial distribution of the total flocculated bacterial population (with DAPI and Eub338 probe) as well as Salmonella (with the Sal3 probe), indicating that the removed Salmonella remained bound and embedded within the flocculant matrix. Scanning electron microscopic (SEM) analysis exhibited a porous surface morphology. The bioflocculant was characterized to be a polysaccharide by FTIR, HPLC, CHN and chemical analysis. A viable alternative treatment technology of poultry wastewater using this novel bioflocculant is suggested.

Ghosh M; Ganguli A; Pathak S

2009-04-01

269

Application of a novel biopolymer for removal of Salmonella from poultry wastewater.  

Science.gov (United States)

This study evaluated the potential of an extracellular, novel biopolymeric flocculant produced by a strain of Klebsiella terrigena for removal of Salmonella, a potent pathogen prevalent in poultry wastewater. The purified biopolymer was applied to poultry wastewater containing 3 log CFU cells of Salmonella. An optimized dosage of 2 mg L(-1) of the purified bioflocculant was sufficient to remove 80.3% Salmonella spp. within 30 min, at ambient temperature. Also this bioflocculant showed high flocculating activity (90%) against kaolin particles and proved to be far more effective than the other synthetic flocculants used in this study. Fluorescent in situ hybridization (FISH) with the genus specific Sal3 probe hybridized with the Salmonella present in the agglomerated matrix of the bioflocculant. Confocal laser scanning micrographs (CLSM) allowed a clear visualization of the spatial distribution of the total flocculated bacterial population (with DAPI and Eub338 probe) as well as Salmonella (with the Sal3 probe), indicating that the removed Salmonella remained bound and embedded within the flocculant matrix. Scanning electron microscopic (SEM) analysis exhibited a porous surface morphology. The bioflocculant was characterized to be a polysaccharide by FTIR, HPLC, CHN and chemical analysis. A viable alternative treatment technology of poultry wastewater using this novel bioflocculant is suggested. PMID:19492545

Ghosh, Moushumi; Ganguli, Abhijit; Pathak, Santosh

2009-04-01

270

[Salmonella choleraesuis C500 delivering DNA immunization against classical swine fever virus].  

Science.gov (United States)

Classical Swine Fever Virus (CSFV) E2 protein eukaryotic expression plasmid pVAXE2 was constructed. The plasmid pVAXE2 was transformed into Salmonella choleraesuis C500 (S. C500) attenuated vaccine strain by electroporation to generate Salmonella choleraesuis engineering strain S. C500/pVAXE2. The characterization of S. C500/pVAXE2 in morphology, growth, biochemistry and serology indicated that it retained the same properties as its original strain S. C500 with exception of kanamycin resistance originated from the plasmid pVAXE2. The plasmid stable in the bacteria after 15 passages. Kunming mice and rabbits were vaccinated three times at two weeks interval with S. C500/pVAXE2 in oral and intramuscular routes at the dosage of 1 x 10(8) CFU for mice and 2 x 10(9) CFU for rabbits each time. The specific antibody response against CSFV and Salmonella choleraesuis was detected by ELISA. Two weeks after the third boost the immunized rabbits were challenged with 20 ID50 of hog cholera lapinized virus (HCLV), followed by a virulent strain of Salmonella choleraesuis two week later than HCLV challenge. The results showed that all immunized mice and rabbits produced significant antibodies against CSFV and Salmonella choleraesuis, and the immunized rabbits demonstrated the effective protection against the challenge of HCLV and virulent Salmonella choleraesuis. These results indicated the potential of developing multiplex swine DNA vaccine by using this bacteria as the vector. PMID:16468338

Qiao, Hong-Wei; Sun, Jin-Fu; Han, Wen-Yu; Li, Zuo-Sheng; Yu, Xing-Long; Tu, Chang-Chun

2005-11-01

271

[Salmonella choleraesuis C500 delivering DNA immunization against classical swine fever virus].  

UK PubMed Central (United Kingdom)

Classical Swine Fever Virus (CSFV) E2 protein eukaryotic expression plasmid pVAXE2 was constructed. The plasmid pVAXE2 was transformed into Salmonella choleraesuis C500 (S. C500) attenuated vaccine strain by electroporation to generate Salmonella choleraesuis engineering strain S. C500/pVAXE2. The characterization of S. C500/pVAXE2 in morphology, growth, biochemistry and serology indicated that it retained the same properties as its original strain S. C500 with exception of kanamycin resistance originated from the plasmid pVAXE2. The plasmid stable in the bacteria after 15 passages. Kunming mice and rabbits were vaccinated three times at two weeks interval with S. C500/pVAXE2 in oral and intramuscular routes at the dosage of 1 x 10(8) CFU for mice and 2 x 10(9) CFU for rabbits each time. The specific antibody response against CSFV and Salmonella choleraesuis was detected by ELISA. Two weeks after the third boost the immunized rabbits were challenged with 20 ID50 of hog cholera lapinized virus (HCLV), followed by a virulent strain of Salmonella choleraesuis two week later than HCLV challenge. The results showed that all immunized mice and rabbits produced significant antibodies against CSFV and Salmonella choleraesuis, and the immunized rabbits demonstrated the effective protection against the challenge of HCLV and virulent Salmonella choleraesuis. These results indicated the potential of developing multiplex swine DNA vaccine by using this bacteria as the vector.

Qiao HW; Sun JF; Han WY; Li ZS; Yu XL; Tu CC

2005-11-01

272

Evaluation of Target Sequences for the Polymerase Chain Reaction-Based Detection of Salmonella in Artificially Contaminated Beef.  

UK PubMed Central (United Kingdom)

Abstract 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 10(1), 10(2), and 10(3) 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.

de Almeida MV; Silva A Jr; Nero LA

2013-10-01

273

Evaluation of five new plating media for isolation of Salmonella species.  

Science.gov (United States)

A three-phase study was conducted to compare Hektoen enteric agar (HE), Rambach agar (Ra), SM-ID medium (SM), xylose-lysine-Tergitol 4 agar (XLT4), novobiocin-brilliant green-glycerol-lactose agar (NBGL), and modified semisolid Rappaport-Vassiliadis medium (MSRV) for the recovery of nontyphoid salmonellae from stool specimens. After evaluation of the first two phases, which resulted in the elimination of Ra, SM, and NBGL, 593 consecutive stool samples were investigated by plating them directly and after tetrathionate enrichment at 37 degrees C on HE, XLT4, and MSRV. A total of 82 Salmonella-positive stool specimens were detected (positivity rate, 13.8%). Sensitivities for direct plating and after tetrathionate enrichment were 32.9 and 86.6%, respectively, for XLT4, 63.4 and 100.0%, respectively, for MSRV, and 34.1 and 79.3%, respectively, for HE. Specificities (percentage of morphologically suspicious colonies that were indeed salmonellae) were 100.0 and 99.8%, respectively, for XLT4, 99.0 and 98.8%, respectively, for MSRV, and 67.9 and 75.0%, respectively, for HE. The use of MSRV instead of HE increased the isolation rate of salmonellae by 26.2% (65 versus 82 strains isolated from HE and MSRV, respectively). We conclude that MSRV is the most sensitive medium tested and is a very specific medium for the isolation of nontyphoid salmonellae from stool specimens. However, its semisolid nature is a disadvantage and requires careful handling in the laboratory, especially when salmonellae are present. XLT4 had a sensitivity comparable to that of HE and a nearly 100% specificity and can be regarded as an alternative for the isolation of nontyphoid salmonellae from stool samples. PMID:7790441

Dusch, H; Altwegg, M

1995-04-01

274

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

DEFF Research Database (Denmark)

The effect of Salmonella on milk production is not well established in cattle. The objective of this study was to investigate whether introduction of Salmonella into dairy cattle herds was associated with reduced milk yield and determine the duration of any such effect. Longitudinal data from 2005 through 2009 were used, with data from 12 mo before until 18 mo after the estimated date of infection. Twenty-eight case herds were selected based on an increase in the level of Salmonella-specific antibodies in bulk-tank milk from

Nielsen, T D; Green, L E

2012-01-01

275

Direct visual detection of Salmonella genomic DNA using gold nanoparticles.  

UK PubMed Central (United Kingdom)

Gold nanoparticles (AuNPs) are well recognized tools for visual DNA detection. Most reports on their use have however been restricted to synthetic or PCR amplified DNA sequences. Herein, we describe a visual DNA detection method that can detect unamplified genomic DNA sequences specifically, using simple reagents and AuNPs, without the need for PCR. This strategy applies thiolated probes and AuNPs to detect genomic DNA. The thiolated probes, in the presence of target Salmonella genomic sequences, cause the AuNPs to aggregate irreversibly, producing a red to purple colorimetric change. As little as 608?000 copies (at 37 fM) of the Salmonella genome were thus detected visually, by eye, without the need for a power source or sophisticated instrumentation. This method thus opens in-roads to direct visual detection, bringing sophisticated DNA analysis capabilities to the point of need.

Kalidasan K; Neo JL; Uttamchandani M

2013-04-01

276

EU Interlaboratory comparison study VIII (2004) on bacteriological detection of Salmonella spp. EU Ringonderzoek VIII (2004) voor bacteriologische detectie van Salmonella spp.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In 2004 werd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) het achtste bacteriologische ringonderzoek georganiseerd. Deelnemers van de studie waren de Nationale Referentie Laboratoria voor Salmonella (NRL's-Salmonella) van de EU lidstat...

Korver H; Heisterkamp SH; Veenman C; Mooijman KA

277

EU Interlaboratory comparison study IX (2005) on bacteriological detection of Salmonella spp. EU Ringonderzoek IX (2005) voor bacteriologische detectie van Salmonella spp.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In 2005 werd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) het negende bacteriologische ringonderzoek georganiseerd. Deelnemers van de studie waren de Nationale Referentie Laboratoria voor Salmonella (NRL's-Salmonella) van de EU lidstat...

Berk PA; Veenman C; Mooijman KA

278

Reveal Salmonella 2.0 test for detection of Salmonella spp. in foods and environmental samples. Performance Tested Method 960801.  

UK PubMed Central (United Kingdom)

Reveal Salmonella 2.0 is an improved version of the original Reveal Salmonella lateral flow immunoassay and is applicable to the detection of Salmonella enterica serogroups A-E in a variety of food and environmental samples. A Performance Tested Method validation study was conducted to compare performance of the Reveal 2.0 method with that of the U.S. Department of Agriculture-Food Safety and Inspection Service or U.S. Food and Drug Administration/Bacteriological Analytical Manual reference culture methods for detection of Salmonella spp. in chicken carcass rinse, raw ground turkey, raw ground beef, hot dogs, raw shrimp, a ready-to-eat meal product, dry pet food, ice cream, spinach, cantaloupe, peanut butter, stainless steel surface, and sprout irrigation water. In a total of 17 trials performed internally and four trials performed in an independent laboratory, there were no statistically significant differences in performance of the Reveal 2.0 and reference culture procedures as determined by Chi-square analysis, with the exception of one trial with stainless steel surface and one trial with sprout irrigation water where there were significantly more positive results by the Reveal 2.0 method. Considering all data generated in testing food samples using enrichment procedures specifically designed for the Reveal method, overall sensitivity of the Reveal method relative to the reference culture methods was 99%. In testing environmental samples, sensitivity of the Reveal method relative to the reference culture method was 164%. For select foods, use of the Reveal test in conjunction with reference method enrichment resulted in overall sensitivity of 92%. There were no unconfirmed positive results on uninoculated control samples in any trials for specificity of 100%. In inclusivity testing, 102 different Salmonella serovars belonging to serogroups A-E were tested and 99 were consistently positive in the Reveal test. In exclusivity testing of 33 strains of non-salmonellae representing 14 genera, 32 were negative when tested with Reveal following nonselective enrichment, and the remaining strain was found to be substantially inhibited by the enrichment media used with the Reveal method. Results of ruggedness testing showed that the Reveal test produces accurate results even with substantial deviation in sample volume or device development time.

Hoerner R; Feldpausch J; Gray RL; Curry S; Islam Z; Goldy T; Klein F; Tadese T; Rice J; Mozola M

2011-09-01

279

Reveal Salmonella 2.0 test for detection of Salmonella spp. in foods and environmental samples. Performance Tested Method 960801.  

Science.gov (United States)

Reveal Salmonella 2.0 is an improved version of the original Reveal Salmonella lateral flow immunoassay and is applicable to the detection of Salmonella enterica serogroups A-E in a variety of food and environmental samples. A Performance Tested Method validation study was conducted to compare performance of the Reveal 2.0 method with that of the U.S. Department of Agriculture-Food Safety and Inspection Service or U.S. Food and Drug Administration/Bacteriological Analytical Manual reference culture methods for detection of Salmonella spp. in chicken carcass rinse, raw ground turkey, raw ground beef, hot dogs, raw shrimp, a ready-to-eat meal product, dry pet food, ice cream, spinach, cantaloupe, peanut butter, stainless steel surface, and sprout irrigation water. In a total of 17 trials performed internally and four trials performed in an independent laboratory, there were no statistically significant differences in performance of the Reveal 2.0 and reference culture procedures as determined by Chi-square analysis, with the exception of one trial with stainless steel surface and one trial with sprout irrigation water where there were significantly more positive results by the Reveal 2.0 method. Considering all data generated in testing food samples using enrichment procedures specifically designed for the Reveal method, overall sensitivity of the Reveal method relative to the reference culture methods was 99%. In testing environmental samples, sensitivity of the Reveal method relative to the reference culture method was 164%. For select foods, use of the Reveal test in conjunction with reference method enrichment resulted in overall sensitivity of 92%. There were no unconfirmed positive results on uninoculated control samples in any trials for specificity of 100%. In inclusivity testing, 102 different Salmonella serovars belonging to serogroups A-E were tested and 99 were consistently positive in the Reveal test. In exclusivity testing of 33 strains of non-salmonellae representing 14 genera, 32 were negative when tested with Reveal following nonselective enrichment, and the remaining strain was found to be substantially inhibited by the enrichment media used with the Reveal method. Results of ruggedness testing showed that the Reveal test produces accurate results even with substantial deviation in sample volume or device development time. PMID:22165011

Hoerner, Rebecca; Feldpausch, Jill; Gray, R Lucas; Curry, Stephanie; Islam, Zahidul; Goldy, Tim; Klein, Frank; Tadese, Theodros; Rice, Jennifer; Mozola, Mark

280

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Hernández, Jorge; Lindberg, Peter; Waldenström, Jonas; Drobni, Mirva; Olsen, Björn

 
 
 
 
281

Feeding a diet containing a fructooligosaccharide mix can enhance Salmonella vaccine efficacy in mice.  

Science.gov (United States)

Fructooligosaccharides (FOS) are considered prebiotics because of their ability to promote growth of specific beneficial gut bacteria, such as bifidobacteria. Some studies reported potential immune-modulating properties. The aim of this study was to investigate the effect of FOS:inulin mix on murine response to Salmonella vaccine and evaluate the relevance toward protection against Salmonella infection. Balb/c mice were fed a diet containing 5% FOS:inulin mix or a control diet 1 wk before oral immunization with a suboptimal dose of live attenuated Salmonella typhimurium vaccine. Four weeks after vaccination, mice were infected with LD100 of virulent S. typhimurium. Specific blood Salmonella immunoglobulin G and fecal immunoglobulin A significantly increased in mice fed the diet containing prebiotics compared with control mice 4 wk postimmunization. Peritoneal macrophage phagocytic activity also significantly increased in FOS:inulin-fed mice at 1 wk postimmunization compared with control mice. No detectable effects were observed on the percentage of lymphoid cell subsets in the spleen. However, production of cytokines, interferon-gamma, interleukin-12, and tumor necrosis factor alpha, was numerically increased in spleen cell cultures stimulated with mitogens from FOS:inulin-fed mice 1 and 4 wk postimmunization. Salmonella translocation to lymphoid organs was not affected by feeding FOS:inulin. However, the improved response to Salmonella vaccine was concomitant with an increase in the survival rate of FOS:inulin-fed mice upon challenge with virulent Salmonella. No detectable effects were observed on the composition or the metabolic activity of the microbiota. Overall, the data suggest that a diet supplemented with FOS:inulin mix stimulates mucosal immunity and seems to improve efficacy of an oral vaccine. PMID:18156414

Benyacoub, Jalil; Rochat, Florence; Saudan, Kim-Yen; Rochat, Isabelle; Antille, Nicolas; Cherbut, Christine; von der Weid, Thierry; Schiffrin, Eduardo J; Blum, Stephanie

2008-01-01

282

Prevalence, incidence and geographical distribution of serovars of Salmonella on dairy farms in England and Wales.  

Science.gov (United States)

A study of randomly selected dairy farms in England and Wales was made between October 1999 and February 2001 to estimate the prevalence and incidence of Salmonella serovars. The farms were enrolled through five milk-buying companies, which represented 63 per cent of the dairy farms in England and Wales, and they were sampled on up to four occasions (449 farms at visit 1, 272 farms at visit 2, 251 farms at visit 3 and 243 farms at visit 4). In total, 19,296 samples of pooled faecal pats and slurry were collected. The farm-specific prevalence of all serovars of Salmonella ranged from 12.1 per cent (95 per cent confidence interval [CI] 8.2 to 16.0 per cent) to 24.7 per cent (95 per cent CI 19.4 to 30.1 per cent) at each visit. The most common serovars identified were Salmonella Dublin (3.7 to 6.6 per cent farm-specific prevalence at each visit), Salmonella Agama (1.8 to 7.6 per cent) and Salmonella Typhimurium (2.6 to 4.1 per cent) The prevalence varied by region and month of sampling and increased in late summer. The incidence rate of all serovars of Salmonella was 0.43 (95 per cent CI 0.34 to 0.54) cases per farm-year at risk. There was no significant difference between the incidence rates of the common serovars S Typhimurium (0.07), S Dublin (0.06) and S Agama (0.13). A total of 29 Salmonella serovars were isolated. Few of the isolates were resistant to the 16 antimicrobial agents tested, except the isolates of S Typhimurium dt104, of which 67.9 per cent were resistant to at least five of them. PMID:16311384

Davison, H C; Smith, R P; Pascoe, S J S; Sayers, A R; Davies, R H; Weaver, J P; Kidd, S A; Dalziel, R W; Evans, S J

2005-11-26

283

APPLICATION OF MICROARRAY TECHNOLOGY TO INVESTIGATE SALMONELLA  

Science.gov (United States)

Microarrays have been developed for the study of Salmonella at the molecular level, which is a model system for investigating pathogenesis. Microarrays were used to analyze the gene expression of Salmonella in various environments that mimic the host environment and these studies have helped to eluc...

284

DETECTION OF SALMONELLA SPECIES IN FOODSTUFFS  

Science.gov (United States)

Conventional methods to detect Salmonella spp. in foodstuffs may take up to one week. Considering the limited shelf life of ready-to-eat foods as well as fresh produce, rapid methods for pathogen detection are required. Real-time detection of Salmonella spp. will broaden our ability to screen larg...

285

Epitope mapping in Salmonella flagellar protein.  

UK PubMed Central (United Kingdom)

The flagellar filaments of bacteria of the genus Salmonella are highly immunopotent and antigenically diverse. It is proposed to develop vaccines by replacing the flagella of live attenuated Salmonella strains with engineered flagellar filament proteins containing foreign epitopes of medical and agricultural importance. As an initial step in this process, the major linear epitope regions of one filament protein have been identified.

Joys TM

1991-01-01

286

Salmonella paratyphi B meningitis in an infant.  

UK PubMed Central (United Kingdom)

We report a case of Salmonella paratyphi B meningitis in a 90 day-old male infant who was admitted with complaints of fever, vomiting and one episode of vacant stare. Clinically, the infant was found to be toxic and dull with a bulging anterior fontanelle. Subsequently, blood and cerebrospinal fluid cultures demonstrated the presence of Salmonella Paratyphi B organism.

Mahalakshmi R; Rajeshbabu B; Mohan R; Balakumaran D; Venkataraman P; Ponnurangam Nagarajan V

2013-01-01

287

FRUCTOSE-6-PHOSPHATE REDUCTASE FROM SALMONELLA GALLINARUM  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Zancan, Glaci T. (Universidade do Paraná, Curitiba, Paraná, Brazil), and Metry Bacila. Fructose-6-phosphate reductase from Salmonella gallinarum. J. Bacteriol. 87:614–618. 1964.—A fructose-6-phosphate reductase present in cell-free extracts of Salmonella gallinarum was purified approximately 42 time...

Zancan, Glaci T.; Bacila, Metry

288

Survival of Salmonella Heidelberg in hummus  

Science.gov (United States)

Salmonella Heidelberg is the fourth-most commonly reported Salmonella serotype to cause human illness. There have been several outbreaks and recalls caused by S. Heidelberg in ready to eat foods. Recently, 700 people became ill from ingesting hummus shirazi contaminated with S. Heidelberg. This stud...

289

Evolution of Salmonella enterica virulence via point mutations in the fimbrial adhesin.  

UK PubMed Central (United Kingdom)

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

Kisiela DI; Chattopadhyay S; Libby SJ; Karlinsey JE; Fang FC; Tchesnokova V; Kramer JJ; Beskhlebnaya V; Samadpour M; Grzymajlo K; Ugorski M; Lankau EW; Mackie RI; Clegg S; Sokurenko EV

2012-01-01

290

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

Science.gov (United States)

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

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

2012-01-01

291

Non-Typhoidal Salmonella Aortitis in a transplant patient  

International Nuclear Information System (INIS)

Non-typhoidal salmonella bacteremia may result in extra gastrointestinallocalization of infection. Aortitis due to non-typhoidal salmonella wasreported to be the cause of 38-42% of all infected abdominal aortitis.Underlying atherosclerosis is a frequent site for salmonella aortitis. Wedescribe here a case of possible salmonella aortitis in a renal transplantpatient. (author)

2002-01-01

292

Significance of salmonella in pork production chain  

Directory of Open Access Journals (Sweden)

Full Text Available Animals, feed, meat and meat products are often transported across long distances, being an important part of international trade, which enables a dissemination of salmonella, including even of some resistant strains. Pigs are animals which are difficult to manipulate because of their temperament, build, sharp teeth, irritability, good sense of smell, bad sight and their sensitivity to stress. Animals coming from different farms should be separated in stock yards to prevent both contamination with pathogens such as salmonella and their irritation and aggressiveness caused by contacts with other pigs. These animals are usually a significant reservoir of salmonella which are 'inside' the gastrointestinal tract and gut associated lymph tissue. In contrast to our country, in the EU, even countries which have always had low salmonella prevalence, e.g. Finland, have a control program. The program has to be based on a guarantee that all relevant factors will participate in the prevention of salmonella contamination.

Karabasil Ne?eljko; Dimitrijevi? Mirjana; Kilibarda Nataša; Teodorovi? Vlado; Balti? Milan Ž.

2008-01-01

293

Pathogenesis of Salmonella-induced enteritis  

Directory of Open Access Journals (Sweden)

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.

Santos R.L.; Tsolis R.M.; Bäumler A.J.; Adams L.G.

2003-01-01

294

Salmonella investigation in an Ontario feed mill.  

Science.gov (United States)

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.

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

1978-01-01

295

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

UK PubMed Central (United Kingdom)

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).

Tennant SM; Zhang Y; Galen JE; Geddes CD; Levine MM

2011-01-01

296

Identification of an outer membrane protein of Salmonella enterica serovar Typhimurium as a potential vaccine candidate for Salmonellosis in mice.  

UK PubMed Central (United Kingdom)

We report our investigation of the functions of PagN in Salmonella pathogenesis and its potential as a vaccine candidate. Further investigation conducted in this study indicates that the outer membrane protein PagN is important for Salmonella adhesion/invasion of epithelial cells as well as bacterial virulence. When pagN was deleted from Salmonella enterica serovar Typhimurium (S. Typhimurium), the adhesion and invasion of HT-29 epithelial cells was significantly decreased compared with the wild type strain. Mice infected with the pagN mutant strain exhibited less pathological signs in the intestine and survived longer than the wild-type-infected mice. PagN is widely distributed and conserved among clinical isolates of different Salmonella serovars, making PagN a potential vaccine candidate for Salmonella infection. To elucidate the potential of PagN as a vaccine, we expressed and purified recombinant PagN (rPagN). When rPagN was tested in mice, it provided significant protection against Salmonella infection in vivo. In vitro, anti-PagN serum enhanced clearance of Salmonella, indicating a contribution of PagN-specific antibodies to the killing process. This correlates well with the observed protection of mice immunized with rPagN. Our preliminary results indicate more functions of PagN in S. Typhimurium virulence as well as its potential as a protective vaccine.

Yang Y; Wan C; Xu H; Aguilar ZP; Tan Q; Xu F; Lai W; Xiong Y; Wei H

2013-05-01

297

Simultaneous Detection of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in Raw Salad Vegetables and Vegetarian Burger Patties  

Directory of Open Access Journals (Sweden)

Full Text Available The health risks posed by Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium through the consumption of raw vegetables and vegetarian burger patties necessitates the needs for the optimization of analytical approach for their detection and enumeration in the raw vegetables, which served as potential vehicles for transmission of these pathogenic microorganisms. We sought to establish a rapid, economic and sensitive method to detect and determine the load of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium using the most probable numbers (MPN) in combination with the multiplex polymerase chain reaction (MPCR). From the naturally contaminated one hundred and seventy five samples tested (n = 175), the overall prevalence of Salmonella spp. was 28%, Salmonella Enteritidis was 20% and Salmonella Typhimurium was 14.3%, respectively. The MPN-MPCR is a quantitative method to determine the density of cell concentration of Salmonella in all the samples (Salmonella spp. ranged from <3 to 53 MPN/g; S. Enteritidis ranged from <3 to 24 MPN/g; and S. Typhimurium ranged from <3 to 15 MPN/g). The combination of the MPN-MPCR is an efficient, simple, fast analytical method for the detection and enumeration of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in vegetables and the vegetarian burger patties since it can significantly reduce time and labour with analysis completed within 2 days, as opposed to the traditional confirmation method that can take up to 5 days for unequivocal identification of species.

Elexson Nillian; Chai Lay Ching; Pui Chai Fung; Tunung Robin; Ubong Anyi; Tuan Zainazor Tuan Chilek; Son Radu; Mitsuaki Nishibuchi

2011-01-01

298

An evaluation of certain Salmonella detection methods in surface water.  

Science.gov (United States)

Two different procedures were employed for detecting Salmonella spp. in environmental water samples: a rapid method (enrichment in Salmosyst Broth and plating in Rambach Agar-Merck) and a longer assay (pre-enrichment in Buffered Peptone Water, enrichment in Selenite-Cistyne Broth and plating in Brilliant Green Agar-Difco). The efficiency of microbiological tests was measured by the following criteria: recovery, sensitivity and specificity. The results analysed by the Kendall concordance coefficients demonstrated that the rapid method appeared more effective even if poorly specific. PMID:9353547

Bernagozzi, M; Sacchetti, R; Polenta, L

1996-11-01

299

Salmonella bongori provides insights into the evolution of the Salmonellae.  

UK PubMed Central (United Kingdom)

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.

Fookes M; Schroeder GN; Langridge GC; Blondel CJ; Mammina C; Connor TR; Seth-Smith H; Vernikos GS; Robinson KS; Sanders M; Petty NK; Kingsley RA; Bäumler AJ; Nuccio SP; Contreras I; Santiviago CA; Maskell D; Barrow P; Humphrey T; Nastasi A; Roberts M; Frankel G; Parkhill J; Dougan G; Thomson NR

2011-08-01

300

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

UK PubMed Central (United Kingdom)

Vaccination with purified capsular polysaccharide Vi Ag from Salmonella typhi can protect against typhoid fever, although the mechanism for its efficacy is not clearly established. In this study, we have characterized the B cell response to this vaccine in wild-type and T cell-deficient mice. We show that immunization with typhoid Vi polysaccharide vaccine rapidly induces proliferation in B1b peritoneal cells, but not in B1a cells or marginal zone B cells. This induction of B1b proliferation is concomitant with the detection of splenic Vi-specific Ab-secreting cells and protective Ab in Rag1-deficient B1b cell chimeras generated by adoptive transfer-induced specific Ab after Vi immunization. Furthermore, Ab derived from peritoneal B cells is sufficient to confer protection against Salmonella that express Vi Ag. Expression of Vi by Salmonella during infection did not inhibit the development of early Ab responses to non-Vi Ags. Despite this, the protection conferred by immunization of mice with porin proteins from Salmonella, which induce Ab-mediated protection, was reduced postinfection with Vi-expressing Salmonella, although protection was not totally abrogated. This work therefore suggests that, in mice, B1b cells contribute to the protection induced by Vi Ag, and targeting non-Vi Ags as subunit vaccines may offer an attractive strategy to augment current Vi-based vaccine strategies.

Marshall JL; Flores-Langarica A; Kingsley RA; Hitchcock JR; Ross EA; López-Macías C; Lakey J; Martin LB; Toellner KM; MacLennan CA; MacLennan IC; Henderson IR; Dougan G; Cunningham AF

2012-12-01

 
 
 
 
301

Salmonella Biofilm Formation on Aspergillus niger Involves Cellulose - Chitin Interactions  

Science.gov (United States)

Salmonella cycles between host and nonhost environments, where it can become an active member of complex microbial communities. The role of fungi in the environmental adaptation of enteric pathogens remains relatively unexplored. We have discovered that S. enterica Typhimurium rapidly attaches to and forms biofilms on the hyphae of the common fungus, Aspergillus niger. Several Salmonella enterica serovars displayed a similar interaction, whereas other bacterial species were unable to bind to the fungus. Bacterial attachment to chitin, a major constituent of fungal cell walls, mirrored this specificity. Pre-incubation of S. Typhimurium with N-acetylglucosamine, the monomeric component of chitin, reduced binding to chitin beads by as much as 727-fold and inhibited attachment to A. niger hyphae considerably. A cellulose-deficient mutant of S. Typhimurium failed to attach to chitin beads and to the fungus. Complementation of this mutant with the cellulose operon restored binding to chitin beads to 79% of that of the parental strain and allowed for attachment and biofilm formation on A. niger, indicating that cellulose is involved in bacterial attachment to the fungus via the chitin component of its cell wall. In contrast to cellulose, S. Typhimurium curli fimbriae were not required for attachment and biofilm development on the hyphae but were critical for its stability. Our results suggest that cellulose–chitin interactions are required for the production of mixed Salmonella-A. niger biofilms, and support the hypothesis that encounters with chitinaceous alternate hosts may contribute to the ecological success of human pathogens.

Brandl, Maria T.; Carter, Michelle Q.; Parker, Craig T.; Chapman, Matthew R.; Huynh, Steven; Zhou, Yaguang

2011-01-01

302

Molecular insights into farm animal and zoonotic Salmonella infections.  

UK PubMed Central (United Kingdom)

Salmonella enterica is a facultative intracellular pathogen of worldwide importance. Infections may present in a variety of ways, from asymptomatic colonization to inflammatory diarrhoea or typhoid fever depending on serovar- and host-specific factors. Human diarrhoeal infections are frequently acquired via the food chain and farm environment by virtue of the ability of selected non-typhoidal serovars to colonize the intestines of food-producing animals and contaminate the avian reproductive tract and egg. Colonization of reservoir hosts often occurs in the absence of clinical symptoms; however, some S. enterica serovars threaten animal health owing to their ability to cause acute enteritis or translocate from the intestines to other organs causing fever, septicaemia and abortion. Despite the availability of complete genome sequences of isolates representing several serovars, the molecular mechanisms underlying Salmonella colonization, pathogenesis and transmission in reservoir hosts remain ill-defined. Here we review current knowledge of the bacterial factors influencing colonization of food-producing animals by Salmonella and the basis of host range, differential virulence and zoonotic potential.

Stevens MP; Humphrey TJ; Maskell DJ

2009-09-01

303

Molecular characterization of Salmonella enterica serotype Enteritidis isolates from humans by antimicrobial resistance, virulence genes, and pulsed-field gel electrophoresis.  

UK PubMed Central (United Kingdom)

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a major serovar associated with human salmonellosis. A total of 425 clinical S. Enteritidis isolates of human origin were collected between June 2009 and September 2010 from North Carolina. The isolates were further characterized for antimicrobial susceptibility, antimicrobial resistance coding determinants, virulence genes, and fingerprint profiles to determine whether they were similar or different to the S. Enteritidis strain responsible for the human outbreak due to consumption of contaminated eggs. Ten different antimicrobial resistance phenotypes were observed with the highest frequency of resistance exhibited to ampicillin (n=10; 2.35%). The isolates were predominantly pansusceptible (n=409; 96.23%); however, seven isolates were multidrug resistant (MDR; i.e., resistant to three or more antimicrobials). Extended spectrum ?-lactamase (ESBL) coding genes (bla(TEM) and bla(PSE)) were detected in the ampicillin-resistant isolates, whereas a single MDR isolate tested positive for class 1 integron (1 kb). The majority of the isolates (n=422; 99.3%) carried the invA, mgtC, stn, sopB, sopE1, and sefA virulence genes. However, 37 (8.7%) and 46 (10.82%) S. Enteritidis isolates tested negative for the plasmid encoded genes spvC and rck, respectively. Pulsed-field gel electrophoresis (PFGE) typing of 118 S. Enteritidis isolates by restriction enzymes XbaI and BlnI resulted in seven clusters, each with a discriminatory index (DI) of 0.715 and 0.785, respectively. The combination of XbaI-BlnI patterns generated a dendrogram with 14 clusters and a higher DI of 0.914. The PFGE profile of 80 isolates matched 100% with the S. Enteritidis strain that has been cited for the recent outbreak in the United States due to consumption of contaminated eggs. In conclusion, we identified a genotypic similar S. Enteritidis population in our study based on antimicrobial susceptibility, virulence gene, and PFGE fingerprint profiles.

Zou M; Keelara S; Thakur S

2012-03-01

304

Salmonella penetration through eggshells of chickens of different genetic backgrounds.  

Science.gov (United States)

Eggs have been identified as a source of salmonellosis, making the transmission of Salmonella to eggs of great concern to the poultry industry. The goal of this experiment was to determine the ability of Salmonella to penetrate the eggshell of 5 different breeds of noncommercial chicken, Barred Plymouth Rock, White Leghorn, Brown Leghorn, Fayoumi, and Light Sussex, and 1 commercial Lohmann LSL-Lite. Egg weight, breaking force, shell weight, and shell thickness measurements were taken for 30 eggs per breed. A 1 cm in diameter hole was cut out from the narrow end of 30 additional eggs per breed. The shells were filled with plate count agar containing tetracycline and 0.1% 2,3,5-triphenyl terazolium chloride and sealed with paraffin wax. Agar-filled eggs were submerged for 1 min in an overnight culture of tetracycline-resistant Salmonella Heidelberg and incubated at 37°C for 40 h. Eggs were candled and visual colonies were counted and reported as cfu per egg and cfu per gram of shell. The SAS mixed model was used to evaluate differences between breeds for egg quality characteristics and the number of cfu per egg and per gram of shell. Commercial layers (62.6 g) and Barred Plymouth Rock (61.5 g) produced the largest eggs, whereas Fayoumi (47.1 g) produced the smallest (P Sussex (27.7 cfu/g) and Brown Leghorn (27.2 cfu/g), with other breeds intermediate. These results indicate that there are breed-specific influences on the ability of an egg to resist Salmonella, which cannot be explained by shell quality measurements. Further investigations are warranted to determine the contributing factors to shell penetration by bacteria. This study highlights the value in maintaining heritage chicken breeds as a genetic resource for the future. PMID:23960130

Rathgeber, Bruce M; McCarron, Paige; Budgell, Krista L

2013-09-01

305

SopB of Salmonella enterica serovar Typhimurium is a potential DNA vaccine candidate in conjugation with live attenuated bacteria.  

Science.gov (United States)

The immune response against Salmonella is multi-faceted involving both the innate and the adaptive immune system. The characterization of specific Salmonella antigens inducing immune response could critically contribute to the development of epitope based vaccines for Salmonella. We have tried to identify a protective T cell epitope(s) of Salmonella, as cell mediated immunity conferred by CD8+ T cells is the most crucial subset conferring protective immunity against Salmonella. It being a proven fact that secreted proteins are better in inducing cell mediated immunity than cell surface and cytosolic antigens, we have analyzed all the genbank annotated Salmonella pathogenicity island 1 and 2 secreted proteins of Salmonella enterica serovar Typhimurium (S. typhimurium) and S. enterica serovar Typhi (S. typhi). They were subjected to BIMAS and SYFPEITHI analysis to map MHC-I and MHC-II binding epitopes. The huge profile of possible T cell epitopes obtained from the two classes of secreted proteins were tabulated and using a scoring system that considers the binding affinity and promiscuity of binding to more than one allele, SopB and SifB were chosen for experimental confirmation in murine immunization model. The entire SopB and SifB genes were cloned into DNA vaccine vectors and were administered along with live attenuated Salmonella and it was found that SopB vaccination reduced the bacterial burden of organs by about 5-fold on day 4 and day 8 after challenge with virulent Salmonella and proved to be a more efficient vaccination strategy than live attenuated bacteria alone. PMID:19428891

Nagarajan, Arvindhan G; Balasundaram, Sudhagar V; Janice, Jessin; Karnam, Guruswamy; Eswarappa, Sandeepa M; Chakravortty, Dipshikha

2009-03-11

306

[Concurrent leptospirosis and salmonella infection].  

UK PubMed Central (United Kingdom)

We report a case of a 56-year-old man who was admitted with septicaemia of unknown origin after working in a henhouse. The patient had beginning liver and kidney failure. Salmonella Typhimurium was cultured from the stool, and DNA from Leptospira spp. was demonstrated by PCR in the urine and blood culture. Leptospirosis is a rare condition that should be remembered as a differential diagnosis in patients with relevant exposure. Leptospirosis may be diagnosed with polymerase chain reaction at an early stage of infection. Later development of antibodies will confirm the diagnosis.

Rönsholt FF; Seidelin JB; Villumsen S

2009-05-01

307

Abscesos esplénicos por Salmonella Splenic abscesses from Salmonella infection  

Directory of Open Access Journals (Sweden)

Full Text Available Los abscesos esplénicos son infrecuentes. Describimos el caso de un paciente de 56 años, quien consultó por diarrea, fiebre, vómito y pérdida de peso; al examen físico presentaba ictericia, hepatomegalia y ascitis. Se demostró por medio de imágenes diagnosticas la presencia de abscesos esplénicos, causados por Salmonella species. Considerando el tipo de abscesos se dio manejo medico sin necesidad de ser intervenido, presentando evolución adecuada. No se encontró ningún factor de riesgo diferente al foco gastrointestinal como precursor de la formación de los abscesos esplénicos.Spleen abscesses are uncommon. We describe the case of a 56 year-old man who presented with diarrhea, fever, vomiting and weight loss. On physical examination, the main findings included jaundice, hepatomegaly and ascites. Diagnostic imaging showed the presence of spleen abscesses, due to Salmonella species. Considering the type of abscess, medical treatment was given without the need for interventional treatment, resulting in a satisfactory outcome. No other risk factor was found, other than the gastrointestinal focus as the precursor of the splenic abscess.

Carmen Cecilia Gómez; Eduardo Zuñiga

2005-01-01

308

IgG keeps virulent Salmonella from evading dendritic cell uptake  

Science.gov (United States)

Dendritic cells (DCs) are phagocytic professional antigen-presenting cells that can prime naive T cells and initiate anti-bacterial immunity. However, several pathogenic bacteria have developed virulence mechanisms to impair DC function. For instance, Salmonella enterica serovar Typhimurium can prevent DCs from activating antigen-specific T cells. In addition, it has been described that the Salmonella Pathogenicity Island 1 (SPI-1), which promotes phagocytosis of bacteria in non-phagocytic cells, can suppress this process in DCs in a phosphatidylinositol 3-kinase (PI3K) -dependent manner. Both mechanisms allow Salmonella to evade host adaptive immunity. Recent studies have shown that IgG-opsonization of Salmonella can restore the capacity of DCs to present antigenic peptide–MHC complexes and prime T cells. Interestingly, T-cell activation requires Fc? receptor III (Fc?RIII) expression over the DC surface, suggesting that this receptor could counteract both antigen presentation and phagocytosis evasion by bacteria. We show that, despite IgG-coated Salmonella retaining its capacity to secrete anti-capture proteins, DCs are efficiently capable of engulfing a large number of IgG-coated bacteria. These results suggest that DCs employ another mechanism to engulf IgG-coated Salmonella, different from that used for free bacteria. In this context, we noted that DCs do not employ PI3K, actin cytoskeleton or dynamin to capture IgG-coated bacteria. Likewise, we observed that the capture is an Fc?R-independent mechanism. Interestingly, these internalized bacteria were rapidly targeted for degradation within lysosomal compartments. Hence, our results suggest a novel mechanism in DCs that does not employ PI3K/actin cytoskeleton/dynamin/Fc?Rs to engulf IgG-coated Salmonella, is not affected by anti-capture SPI-1-derived effectors and enhances DC immunogenicity, bacterial degradation and antigen presentation.

Riquelme, Sebastian A; Bueno, Susan M; Kalergis, Alexis M

2012-01-01

309

FimH adhesin from host unrestricted Salmonella Enteritidis binds to different glycoprotein ligands expressed by enterocytes from sheep, pig and cattle than FimH adhesins from host restricted Salmonella Abortus-ovis, Salmonella Choleraesuis and Salmonella Dublin.  

UK PubMed Central (United Kingdom)

Adhesion to gut tissues and colonization of the alimentary tract, two important stages in the pathogenesis of Salmonella, are mediated by FimH adhesin of type 1 fimbriae. It was suggested that minor differences in the structure of FimH are most likely associated with differences in adhesion specificities, and may determine the tropism of various Salmonella serovars to different species and tissues. We investigated this hypothesis by comparing the binding properties of FimH proteins from three Salmonella enterica serovars with limited (Choleraesuis, Dublin) or restricted (Abortusovis) host ranges to FimH from broad host range S. Enteritidis and mannose inactive FimH from S. Gallinarum. Although all active variants of FimH protein were able to bind mannose-rich glycoproteins (RNase B, HRP and Man-BSA) with comparable affinity measured by surface plasmon resonance, there were significant differences in the binding profiles of the FimH proteins from host restricted serovars and host unrestricted serovar Enteritidis, to glycoproteins from enterocyte cell lines established in vitro and derived from sheep, pig and cattle. When low-binding FimH adhesin from S. Enteritidis was subjected to Western blot analysis, it bound to surface membrane protein of about 130 kDa, and high-binding FimH adhesins from S. Abortusovis, S. Choleraesuis and S. Dublin bound to surface membrane protein of about 55 kDa present in each cell line. Differential binding of FimH proteins from host-restricted and broad-host-range Salmonella to intestinal receptors was confirmed using mutant FimH adhesins obtained by site-directed mutagenesis. It was found that the low-binding variant of FimH from S. Choleraesuis with mutation Leu57Pro lost the ability to bind protein band of 55 kDa, but instead interacted with glycoprotein of about 130 kDa. On the other hand, the high-binding variant of FimH adhesin from S. Enteritids with mutation Asn101Ser did not bind to its receptor of 130 kDa, but instead it interacted with glycoprotein ligand of 55 kDa. These results suggest that FimH adhesins of type 1 fimbriae are one of the factors responsible for different host-specificities of these Salmonella serovars.

Grzymaj?o K; Ugorski M; Kolenda R; K?dzierska A; Ku?mi?ska-Bajor M; Wieliczko A

2013-10-01

310

FimH adhesin from host unrestricted Salmonella Enteritidis binds to different glycoprotein ligands expressed by enterocytes from sheep, pig and cattle than FimH adhesins from host restricted Salmonella Abortus-ovis, Salmonella Choleraesuis and Salmonella Dublin.  

Science.gov (United States)

Adhesion to gut tissues and colonization of the alimentary tract, two important stages in the pathogenesis of Salmonella, are mediated by FimH adhesin of type 1 fimbriae. It was suggested that minor differences in the structure of FimH are most likely associated with differences in adhesion specificities, and may determine the tropism of various Salmonella serovars to different species and tissues. We investigated this hypothesis by comparing the binding properties of FimH proteins from three Salmonella enterica serovars with limited (Choleraesuis, Dublin) or restricted (Abortusovis) host ranges to FimH from broad host range S. Enteritidis and mannose inactive FimH from S. Gallinarum. Although all active variants of FimH protein were able to bind mannose-rich glycoproteins (RNase B, HRP and Man-BSA) with comparable affinity measured by surface plasmon resonance, there were significant differences in the binding profiles of the FimH proteins from host restricted serovars and host unrestricted serovar Enteritidis, to glycoproteins from enterocyte cell lines established in vitro and derived from sheep, pig and cattle. When low-binding FimH adhesin from S. Enteritidis was subjected to Western blot analysis, it bound to surface membrane protein of about 130kDa, and high-binding FimH adhesins from S. Abortusovis, S. Choleraesuis and S. Dublin bound to surface membrane protein of about 55kDa present in each cell line. Differential binding of FimH proteins from host-restricted and broad-host-range Salmonella to intestinal receptors was confirmed using mutant FimH adhesins obtained by site-directed mutagenesis. It was found that the low-binding variant of FimH from S. Choleraesuis with mutation Leu57Pro lost the ability to bind protein band of 55kDa, but instead interacted with glycoprotein of about 130kDa. On the other hand, the high-binding variant of FimH adhesin from S. Enteritids with mutation Asn101Ser did not bind to its receptor of 130kDa, but instead it interacted with glycoprotein ligand of 55kDa. These results suggest that FimH adhesins of type 1 fimbriae are one of the factors responsible for different host-specificities of these Salmonella serovars. PMID:23910950

Grzymaj?o, Krzysztof; Ugorski, Maciej; Kolenda, Rafa?; K?dzierska, Anna; Ku?mi?ska-Bajor, Marta; Wieliczko, Alina

2013-07-17

311

Phage-Coupled Piezoelectric Biodetector for Salmonella  

Canada Institute for Scientific and Technical Information (Canada)

Salmonella typhimurium is a leading cause of foodborne illness and a critical threat agent for potential bioterrorism. Current rapid detection initiatives include biosensors that routinely incorporate antibodies for biorecognition. However, antibodies are costly and may degrade under unfavorable environmental conditions. A stable, Inexpensive substitute may be filamentous bacteriophage affinity selected from a phage display library for specificity to S. typhimurium. We immobilized affinity-selected phage to a quartz crystal microbalance for detection of S. typhimurium in solution. An ELISA procedure, precipitation assay, and flow cytometry were employed to confirm phage specificity and selectivity. The phage was up to 22,000 times more specific for S. typhimurium than controls and up to 1,000 times more selective in comparison to other bacteria. For recognition of the phage targeted bacterial outer membrane structure, biotinylated S. typhimurium surface proteins from lysate were reacted with phage cross- linked to water-soluble resin to prepare a protein eluate for Western blot, which revealed a single 60-70 kD band. Three immobilization methods (physical adsorption, biotin-streptavidin-phage self-assembly, and Langmuir-Blodgett) using two phage forms (filamentous and phage coat proteins) were evaluated for proof of concept sensor preparation. Specific binding between phage and target on the biosensor resulted in concentration dependent resonance frequency changes. Best results were obtained when 10(exp 10) - 10(exp 11) filamentous phage particles converted to spherical forms (spheroids) by chloroform denaturation were immobilized as phage coat proteins using Langmuir-Blodgett technique. In summary, filamentous phage selected from a phage library can be used for the preparation of rapid, specific, and selective biodetectors that may ultimately be suitable for continuous food and environmental monitoring devices, diagnostic assays, and biosorbents.

2005-01-01

312

Determination of salmonellae from municipal wastewaters.  

Science.gov (United States)

This study compared the efficiency of culture methods for salmonellae detection in wastewaters collected from three Finnish municipal treatment plants and from one laboratory-scale plant. The performance of one-step enrichment in Preuss tetrathionate broth was better than that of two-step enrichment (buffered peptone water pre-enrichment (BPW) and selective enrichment in Rappaport-Vassiliadis (RV) medium. The best combinations for Salmonella isolation were xylose-lysine-deoxycholate (XLD) and Rambach (RB) agars after Preuss enrichment and did not differ when brilliant green-magnesium chloride (BM) or brilliant green phenol red (BP) agars were used. The two-step enrichment inhibited the growth of both salmonellae and interfering accompanying flora. Salmonella-positive plates were generally easier to read when inoculated from RV than from Preuss medium because of less growth of competing flora. XLD and BM agars supported growth of salmonellae and inhibited growth of competing flora better than BP and Rambach agars. XLD and BM agars gave the highest numbers of salmonellae isolations but XLD and Rambach agars gave the best differentiation. Salmonella levels were 1100 MPN/100 mL. PMID:11464761

Koivunen, J; Lanki, E; Rajala, R L; Siitonen, A; Heinonen-Tanski, H

2001-01-01

313

Functional and phenotypic profiling of innate immunity during Salmonella infection  

DEFF Research Database (Denmark)

Salmonellae are food borne pathogens, typically acquired by the oral ingestion of contaminated food or water, causing disease in both healthy and immunocompromised individuals. To gain insight into early immune regulation events caused by Salmonella as well as inflammatory signatures induced by Salmonella and other bacteria in human monocyte-derived dendritic cells (DC), we examined these properties using in vivo and in vitro experimental settings. The outcome of infection with Salmonella depends on the host as well as the infecting serovar. Understanding the relative risks associated with and within different serovars is of major importance for public health. Using an established mouse model, we compared the pathogenicity of two S. Typhimurium strains (SL1344 and DT120) and found that the passage through and the ability to proliferate within the host gastrointestinal system determined the pathogenicity of these strains. Salmonella is a mucosal pathogen, gaining access to host systemic circulation by crossing the gut epithelial barrier and residing intracellularly in DC and M?. Until recently focus has been centred on the involvement of M? and the conventional antigen-presenting DC (mDC) in bacterial infections, whereas the other major dendritic cell subset, plasmacytoid DC (pDC), plays an important part in antiviral responses, and is less well characterised in regard to antibacterial immunity. Using multi-parametric flow cytometry, we were able to show for the first time that pDC accumulated in Peyer’s patches 24 hours after murine oral Salmonella challenge and while M? and mDC exhibited dose-related cellular atrophy, pDC were less susceptible to bacteria-induced cell death, suggesting a role for pDC in early stage Salmonella containment. Furthermore, we identified a number of both DC and M? subsets, two of which following infection, accumulated in Peyer’s patches and lamina propria, respectively. Generally, we tend to set apart pathogenic bacteria from opportunistic pathogens and commensal bacteria based on their abilities to induce disease in different hosts, however, the nature of the inflammatory response they induce in DC that set them apart from commensal bacteria remains largely unclear. In the present study, we developed a system by which we were able to compare the bacteria-induced imprint of important regulatory proteins in DC to bacterial-encoded ligands. We observed that DC responded to six different bacteria in a phyla-specific manner giving rise to similar inflammatory signatures within the groups of proteobacteria, firmicutes and actinobacteria, hence being independent on pathogenic versus non-pathogenic properties, and also on the bacteria-to-cell ratio for most bacteria. The results presented in this thesis add to the current knowledge about innate immunity to Salmonella, suggest new host immune cell subsets important for bacterial containment and provide a basic understanding of bacteria-induced DC inflammatory programs. The two latter could prove important in regard to treatment regimes, as targeted modulation of DC profiles for instance by probiotics, could lead to improved therapy for a number of gut related diseases.

SØrensen, Rikke Brandt; Pedersen, Susanne Brix

2012-01-01

314

Occurrence of Salmonella sp in laying hens  

Directory of Open Access Journals (Sweden)

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.

Gama NMSQ; Berchieri Jr A; Fernandes SA

2003-01-01

315

Evaluation of new culture media for rapid detection and isolation of salmonellae in foods.  

UK PubMed Central (United Kingdom)

Conventional methods for Salmonella detection in foods can require up to 6 and at least 4 days. We have observed that the total analysis time can be reduced to 48 h by using Salmosyst broth as a liquid medium for both preenrichment and selective enrichment and Rambach agar (RA), a new selective plate medium. In samples of artificially contaminated ground beef Salmonella enteritidis was detected at a concentration of 0.4 CFU/g (10 CFU/25 g) by both a conventional method and the new method. Of 519 samples of foods for sale, 38 were Salmonella positive by both methods while 471 were negative. Nine samples which were negative by the conventional method were positive by the Salmosyst-RA method, while one sample positive by the first method was negative by the last. Therefore, the Salmosyst-RA method showed 97.9% sensitivity compared with the 81.2% sensitivity of the conventional method. The new method was also highly specific (98% specificity) in presumptive identification of Salmonella colonies. Furthermore, a 6-h preenrichment in Salmosyst broth has been proved sufficient for the repair of heat-injured Salmonella cells and for subsequent recovery by selective enrichment. In conclusion, the Salmosyst-RA method shows several advantages over both conventional and rapid noncultural methods: (i) only two media are required instead of the five media for conventional methods; (ii) in real time it is comparable to other rapid noncultural methods, which require 30 to 31 h; (iii) it is highly sensitive and specific; and (iv) it allows the isolation of Salmonella strains which can be characterized by appropriate phenotypic and genotypic typing methods for epidemiological investigations.

Pignato S; Marino AM; Emanuele MC; Iannotta V; Caracappa S; Giammanco G

1995-05-01

316

Evaluation of new culture media for rapid detection and isolation of salmonellae in foods.  

Science.gov (United States)

Conventional methods for Salmonella detection in foods can require up to 6 and at least 4 days. We have observed that the total analysis time can be reduced to 48 h by using Salmosyst broth as a liquid medium for both preenrichment and selective enrichment and Rambach agar (RA), a new selective plate medium. In samples of artificially contaminated ground beef Salmonella enteritidis was detected at a concentration of 0.4 CFU/g (10 CFU/25 g) by both a conventional method and the new method. Of 519 samples of foods for sale, 38 were Salmonella positive by both methods while 471 were negative. Nine samples which were negative by the conventional method were positive by the Salmosyst-RA method, while one sample positive by the first method was negative by the last. Therefore, the Salmosyst-RA method showed 97.9% sensitivity compared with the 81.2% sensitivity of the conventional method. The new method was also highly specific (98% specificity) in presumptive identification of Salmonella colonies. Furthermore, a 6-h preenrichment in Salmosyst broth has been proved sufficient for the repair of heat-injured Salmonella cells and for subsequent recovery by selective enrichment. In conclusion, the Salmosyst-RA method shows several advantages over both conventional and rapid noncultural methods: (i) only two media are required instead of the five media for conventional methods; (ii) in real time it is comparable to other rapid noncultural methods, which require 30 to 31 h; (iii) it is highly sensitive and specific; and (iv) it allows the isolation of Salmonella strains which can be characterized by appropriate phenotypic and genotypic typing methods for epidemiological investigations. PMID:7646035

Pignato, S; Marino, A M; Emanuele, M C; Iannotta, V; Caracappa, S; Giammanco, G

1995-05-01

317

Influence of acid adaptation on the survival of Salmonella enteritidis and Salmonella typhimurium in simulated gastric fluid and in Rattus norvegicus intestine infection  

UK PubMed Central (United Kingdom)

The aim of this study was to investigate the influence of acid adaptation in the survival of Salmonella Enteritidis (SE86) and Salmonella Typhimurium (ST99) during exposure to simulated gastric fluid (SGF) and in intestinal infection of Rattus norvegicus. Acid-adapted and nonadapted Salmonella strains were exposed to SGF (pH 1.5) and were inoculated by gavage in adult rats. Results indicated that acid-adapted SE86 survived significantly better (P < 0.05) than nonadapted SE86, nonadapted ST99 and acid-adapted ST99 in SGF. Nonadapted microorganisms were observed in higher counts in feces than acid-adapted strains, while acid-adapted microorganisms demonstrated higher counts in intestine samples, suggesting intestinal invasion capacity. Acid-adapted SE86 was recovered in higher counts from ileum-cecum junction than the other microorganisms. Salmonella Enteritidis has been identified as the most frequent serovar involved with the foodborne outbreaks in Brazil. In Southern Brazil, a specific strain of Salmonella Enteritidis (SE86) has been involved with more than 90% of the salmonellosis occurring in the last years, and the main food vehicle is home-made mayonnaise frequently added with different quantities of vinegar, which can cause acid adaptation in Salmonella cells. The results of this work indicate that SE86 presented higher acid adaptation, which contributed to higher survival rates in simulated gastric fluid and better intestinal colonization. These results could be related to human virulence and the frequent involvement of this strain with foodborne outbreaks in southern Brazil.

Perez KarlaJoseane; Ceccon RaquelValim; Malheiros PatriciadaSilva; Jong ErnaVogt; Tondo EduardoCesar

2010-05-01

318

Molecular Typing of Salmonella paratyphi B and Salmonella paratyphi C Isolates from Clinical Samples in Iran  

Directory of Open Access Journals (Sweden)

Full Text Available Background & Objective: Molecular typing is an important tool in surveillance and outbreak investigations of human Salmonella infections. In this study, Subtyping of Salmonella Paratyphi B and C isolates derived from Iranian patients was carried out by RAPD-PCR to assess the extent of genetic diversity of these isolates. Materials & Methods: Fourteen Salmonella isolates including 6 strains of Salmonella paratyphi B and 8 strains of Salmonella paratyphi C were characterized using RAPD-PCR. Two arbitrary primers, namely OPP-16 and P1254 were used for RAPD analysis and the dendrograms were constructed with NTsys 2.0 computer software. Results: Both primers showed high discriminatory power in differentiating of the related strains of Salmonella. The dendrograms constructed based on RAPD-PCR profiles (with both primers) involving 14 salmonella strains revealed 4 distinct patterns, indicating that these isolates are genetically heterogeneous. Furthermore, a good correlation was not observed between the serotype and the molecular profiles obtained from RAPD data of the Salmonella isolates. Conclusion: The findings of the present study verify the usefulness of RAPD-PCR in characterizing and comparing strains of Salmonella Paratyphi B and C.

Fahimeh Baghbani-arani; Mercedeh Tajbakhsh; Atiyeh Hashemi Soltaniyeh; Bahareh Rajaei; Seyed Davar Siadat; Mohamahreza Aghasadeghi; Seyed Mehdi Sadat

2012-01-01

319

Effect of natural microbiota on growth of Salmonella spp. in fresh pork – A predictive microbiology approach  

DEFF Research Database (Denmark)

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

MØller, Cleide; Ilg, Y.

2013-01-01

320

Confirmation of presumptive Salmonella colonies contaminated with Proteus swarming using the polymerase chain reaction (PCR) method.  

Science.gov (United States)

In Mexico, zero tolerance regulation is practiced regarding Salmonella in food products. the presence of which is verified by the procedure described in NOM 114-SSA-1994. During the period between August 2002 and March 2003, 245 food samples were tested using this procedure in the Central Laboratories of the Department of Health for the State of Jalisco (CEESLAB). Of these 245 samples, 35 showed presumptive colonies contaminated with Proteus swarm cells even after selective isolation. These swarm cells make Salmonella recovery and biochemical identification difficult due to the occurance of atypical biochemical profiles which generally correspond to that of Proteus. Out of the 35 samples contaminated with Proteus, 65 presumptive colonies were isolated. These colonies were analyzed using both normative microbiological method and Polymerase Chain Reaction (PCR). The PCR method detected two positive samples while normative microbiological method was not able to identify. In order to determine the extent of interference of Proteus swarming on the Salmonella-specific PCR band amplification, Salmonella ser. Typhimurium was grown in the presence of Proteus swarming. These results show that Proteus swarming did not interfere with Salmonella PCR-amplification, although the appearance of Sanlmonella was altered such that the black precipitate was no observed in the presence of Proteus swarming. Ours result indicate that the PCR method used in this study may be successfully applied to confirm presumptive Salmnonella colonies contaminated with Proteus swarming. PMID:18693548

Gutiérrez Rojo, Rosalba; Torres Chavolla, Edith

 
 
 
 
321

Characterization of Escherichia coli and Salmonella enterica from cattle feed ingredients.  

Science.gov (United States)

The objectives of this study were (1) to evaluate the frequency with which feed ingredients or mixed feeds in cattle feedlots were contaminated with Escherichia coli and Salmonella spp. and (2) to evaluate the antimicrobial susceptibility patterns of non-type-specific Escherichia coli and Salmonella spp. recovered from feed ingredients or mixed feeds. Approximately 30 individual samples were collected from each of several feed commodities present on two cattle feedlots each month for 1 year. Half of the samples were cultured for Escherichia coli, and the other half were cultured for Salmonella spp. E. coli was recovered from 48.2% (516/1070) of the samples and from all feed ingredient types at least once. Salmonella spp. were recovered from 5.3% (57/1070) of samples. Overall, 40.3% (207/514) of E. coli isolates and 54.4% (31/57) of Salmonella spp. isolates were susceptible to all antimicrobials tested in the panel. Bacterial contamination of feed ingredients used at cattle feedlots with enteric bacteria is relatively common. In some cases, the enteric organisms are resistant to one or more antimicrobials. Feed ingredients may be a source of genetic elements associated with antimicrobial resistance for feedlot cattle. To be successful in minimizing foodborne pathogens and antimicrobial resistance in the cattle feedlot setting, it is important to consider the myriad of potential sources of these organisms or genetic elements. PMID:16366856

Dargatz, David A; Strohmeyer, Rachel A; Morley, Paul S; Hyatt, Doreene R; Salman, Mo D

2005-01-01

322

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

UK PubMed Central (United Kingdom)

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 3×10? 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 log?? 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.

Guenther S; Herzig O; Fieseler L; Klumpp J; Loessner MJ

2012-03-01

323

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

Science.gov (United States)

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

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

2013-01-01

324

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

UK PubMed Central (United Kingdom)

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

Jackson BR; Griffin PM; Cole D; Walsh KA; Chai SJ

2013-08-01

325

Competitive enzyme-linked immunosorbent assay for cholera-related enterotoxins in Salmonella typhimurium.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report a rapid competitive enzyme-linked immunosorbent assay to screen Salmonella typhimurium strains for cholera-related enterotoxin antigens. Polymyxin B extracts of bacterial cells from syncase-glucose broth cultures of 7 of 15 strains gave positive results. The specificity of the test was con...

Hariharan, H; Booth, B A; Brickman, T J; Katt, W C; Boesman-Finkelstein, M; Finkelstein, R A

326

Identification of Two Phylogenetically Related Organisms from Feces by PCR for Detection of Salmonella spp.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two previously reported PCR methods were evaluated to determine whether they are as sensitive and specific as conventional culture methods in detecting Salmonella spp. from feces. Bovine and equine feces were enriched overnight in brain heart infusion broth and assayed using PCR methods and primer s...

Gentry-Weeks, Claudia; Hutcheson, H. Joel; Kim, Lisa Marie; Bolte, Denise; Traub-Dargatz, Josie; Morley, Paul; Powers, Barbara

327

Twelve-Hour PCR-Based Method for Detection of Salmonella spp. in Food  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A PCR-based method for the detection of Salmonella spp. in food was developed. The method, set up on typical salami from the Italian region of Marche, is sensitive and specific and shows excellent correlation with the conventional method of reference when naturally contaminated foods are analyzed. M...

Ferretti, R.; Mannazzu, I.; Cocolin, L.; Comi, G.; Clementi, F.

328

[Detection of Salmonella, Shigella and Staphylococcus aureus based on quantum dots and immunomagnetic beads].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To establish a detecting method of Salmonella, Shigella and Staphylococcus aureus by using quantum dots and immunomagnetic beads. METHODS: The polychrome colour CdSe quantum dots were synthetized by water phase process. Triad colour quantum dots were conjugated with specific anti-Salmonella, anti-Shigella and anti-Staphylococcus aureus antibody by covalent cross-linking reaction, and then the coupled product was confirmed by SDS-PAGE and ultraviolet absorption spectrum. Using immunomagnetic enrichment and quantum dots labeling specific antibody, the fluorescence intensity of Salmonella, Shigella and Staphylococcus aureus were observed by fluorescence microscope. RESULTS: The coupled reaction was successful by SDS-PAGE and ultraviolet absorption spectrum. Using immunomagnetic enrichment and quantum dots with different color and different wavelength labeling specific antibody, the detection time was less than 2h in the same reaction system. The samples infection with target bacteria were detected directly. The detection limit was 10 CFU/ml. CONCLUSION: This method can detect Salmonella, Shigella and Staphylococcus aureus quickly and specificly.

Li Q; Chen P; Wang J; Zhang S; Yan J

2013-07-01

329

Characterization of integron mediated antimicrobial resistance in Salmonella isolated from diseased swine  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Forty-two Salmonella isolates obtained from diseased swine were genetically characterized for the presence of specific antimicrobial resistance mechanisms. Twenty of these isolates were characterized as S. Typhimurium DT104 strains. Pulsed-field gel electrophoresis was used to determine genetic rela...

White, David G.; Zhao, Shaohua; McDermott, Patrick F.; Ayers, Sherry; Friedman, Sharon; Sherwood, Julie; Breider-Foley, Missy

330

Simultaneous Detection of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in Raw Salad Vegetables and Vegetarian Burger Patties  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The health risks posed by Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium through the consumption of raw vegetables and vegetarian burger patties necessitates the needs for the optimization of analytical approach for their detection and enumeration in the raw vegetables, which ser...

Elexson Nillian; Chai Lay Ching; Pui Chai Fung; Tunung Robin; Ubong Anyi; Tuan Zainazor Tuan Chilek; Son Radu; Mitsuaki Nishibuchi

331

Sensibilidad a los antimicrobianos de cepas de salmonella aisladas en granjas porcinas del estado Zulia/ Antimicrobial susceptibility of salmonella strains isolated from pig herds in Zulia state  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El objetivo de este estudio fue determinar los patrones de resistencia a los antimicrobianos de diferentes cepas de Salmonella aisladas en granjas de cerdos del estado Zulia. Para este fin se evaluaron mediante la técnica de Bauer-Kirby, 126 cepas de Salmonella aisladas de heces de cerdos portadores asintomáticos. Las pruebas de sensibilidad antimicrobiana demostraron que los más altos niveles de resistencia fueron frente a la sulfamida (54%), tetraciclina (40%), ácid (more) o nalidíxico (29%) y ampicilina (23%). Sin embargo, sensibilidad superior al 95% fue encontrada frente a la ceftriaxona, gentamicina, apramicina y colistina. El treinta por ciento de las cepas mostraron multirresistencia (MR) a los antimicrobianos, siendo el patrón de resistencia ASuT (7,14%) el más frecuente. Los resultados obtenidos indican que la proporción de cepas de Salmonella de origen porcino con características de multirresistencia a los agentes antimicrobianos es medianamente elevada (30%) y esta multirresistencia puede afectar a cualquier serotipo. Desde ese punto de vista, la infección de las personas por cepas de Salmonella de origen porcino conlleva a un riesgo potencial de presentar dificultades en el tratamiento específico. Abstract in english The aim of this study was to determine antimicrobial resintance paterns of different strains of Salmonella isolated in pig farms of the Zulia State. To achieve these goals 126 strain Salmonella were screened by Kirby-Bauer method, colleted from heces of pigs asymptomatic. Antimicrobial susceptibility tests showed that the highest level of resistance was against Sulphonamides (54%), Tetracycline (40%), Nalidixic acid (29%) and Amplicillin (23%). However, susceptibility sup (more) erior to 95% was found to Ceftriaxone, Gentamycin, Apramycin and Colistin. Thrity percent of the strains showed multirresitance, being the patterns resistance ASuT (7.14%) the most frequent. The results indicate the proportion of strain of Salmonella of pig origin with characteristics of multiresistance to the antimicrobial agents is elevated (30%) and this multiresistance could affect to anyone serotype. From this point of view, the infection of the people by isolates of Salmonella from swine origin entails a potential risk to present difficulties in the specific treatment.

Mejia, Willian; Calatayud Marquez, Derwin; Zapata, Denice; Quintero, Armando; Sánchez, Damarys; Mateu, Enric

2008-12-01

332

Salmonella enteritidis meningitis - A case report  

Directory of Open Access Journals (Sweden)

Full Text Available A male infant admitted with pyogenic meningitis with protein energy malnutrition developed fatal infection due to Salmonella enteritidis. The same organism was isolated from CSF and blood cultures.

Varaiya A; Saraswathi K; Tendolkar U; De A; Shah S; Mathur M

2001-01-01

333

Acalculous cholecystitis due to Salmonella enteritidis  

Directory of Open Access Journals (Sweden)

Full Text Available Acute acalculous cholecystitis (AAC) is defined as an acute inflammation of the gallbladder in the absence of stones. We herein report a case of a young man who developed AAC after a Salmonella enteritidis gastrointestinal infection.

Maria Lourdes Ruiz-Rebollo, Gloria Sánchez-Antolín, Félix García-Pajares, Maria Antonia Vallecillo-Sande, Pilar Fernández-Orcajo, Rosario Velicia-Llames, Agustín Caro-Patón

2008-01-01

334

Elimination of Salmonellae from Animal Glandular Products  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Methods for the elimination of salmonellae from selected powdered pharmaceuticals of animal glandular origin were studied. Terminal heat treatment under carefully controlled conditions was effective for pancreatin—a powder containing proteolytic, amylolytic, and lipolytic enzymes prepared from hog p...

De Fiebre, Conrad W.; Burck, Kenneth T.; Feldman, David

335

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

Centers for Disease Control (CDC) Podcasts

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.

2009-12-09

336

Acalculous cholecystitis due to Salmonella enteritidis  

Science.gov (United States)

Acute acalculous cholecystitis (AAC) is defined as an acute inflammation of the gallbladder in the absence of stones. We herein report a case of a young man who developed AAC after a Salmonella enteritidis gastrointestinal infection.

Ruiz-Rebollo, Maria Lourdes; Sanchez-Antolin, Gloria; Garcia-Pajares, Felix; Vallecillo-Sande, Maria Antonia; Fernandez-Orcajo, Pilar; Velicia-Llames, Rosario; Caro-Paton, Agustin

2008-01-01

337

Acalculous cholecystitis due to Salmonella enteritidis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Acute acalculous cholecystitis (AAC) is defined as an acute inflammation of the gallbladder in the absence of stones. We herein report a case of a young man who developed AAC after a Salmonella enteritidis gastrointestinal infection.

Ruiz-Rebollo, Maria Lourdes; Sánchez-Antolín, Gloria; García-Pajares, Félix; Vallecillo-Sande, Maria Antonia

338

Draft Guidance for Industry: Testing for Salmonella ...  

Science.gov (United States)

... FDA. 1995. Compliance Policy Guide Sec. 690.700, Salmonella Contamination of Dry Dog Food (CPG 7126.17). FDA. 2010. ... More results from www.fda.gov/food/guidanceregulation/guidancedocumentsregulatoryinformation

339

SALMONELLA: WHERE DOES IT COME FROM?  

Science.gov (United States)

This session will provide insight into foodborne transmission and direct transmission of salmonella from a variety of sources to humans. An understanding of the various modes of transmission will enable a more effective intervention strategy to be developed....

340

Salmonella Paratyphi B septicemia in a Neonate.  

UK PubMed Central (United Kingdom)

Septicemia is a major cause of death in neonates especially in developing countries. We report a case of septicemia in a neonate due to Salmonella Paratyphi B. The baby responded well to therapy and recovered completely.

Bhat P; Dias M; Hegde R; Pinto H

2013-04-01

 
 
 
 
341

Detection of Salmonella species in foodstuffs.  

UK PubMed Central (United Kingdom)

Conventional methods to detect Salmonella spp. in foodstuffs may take up to 1 wk. Methods for pathogen detection are required. Real-time detection of Salmonella spp. will broaden our ability to screen large number of samples in a short time. This chapter describes a step-by-step procedure using an oligonucleotide probe that becomes fluorescent upon hybridization to the target DNA (Molecular Beacon; MB) in a real-time polymerase chain reaction (PCR) assay. The capability of the assay to detect Salmonella species from artificially inoculated fresh- and fresh-cut produce as well as ready-to-eat meats is demonstrated. The method uses internal positive and negative controls which enable researchers to detect false-negative PCR results. The procedure uses the buffered peptone water for the enrichment of Salmonella spp. and successfully detects the pathogen at low level of contamination (2-4 cells/25 g) in <24 h.

Bhagwat AA; Patel J; Chua T; Chan A; Cruz SR; Aguilar GA

2008-01-01

342

Salmonella as a vaccine delivery vehicle.  

UK PubMed Central (United Kingdom)

Attenuated Salmonella vaccines can be administered orally to deliver recombinant antigens to mucosal surfaces inducing a protective immune response against a variety of targeted pathogens. A number of exciting new approaches and technologies for attenuated Salmonella vaccines have been developed recently. However, a disconnect remains between results obtained with mice in preclinical studies and results obtained in human clinical trials. This is due to an incomplete understanding of Salmonella Typhi interactions with human hosts and inadequate animal models available for study. In this review, the authors describe recent progress in identifying important differences underlying S. Typhi-host interactions, the development of novel approaches to vaccine design and six recent clinical trials evaluating Salmonella-vectored vaccines.

Roland KL; Brenneman KE

2013-09-01

343

Factors influencing phagocytosis of Salmonella typhimurium by macrophages in murine schistosomiasis  

Directory of Open Access Journals (Sweden)

Full Text Available We investigated the influence of Salmonella typhimurium load and specific antibodies on phagocytosis in schistosomiasis. Macrophages from Schistosoma mansoni-infected mice showed depressed capacity to increase the phagocytosis in the presence of a high bacterial load, due to a reduced involvement of these cells in phagocytosis and to a deficient ability to increase the number of phagocytosed bacteria. Normal and Salmonella-infected mice increased their phagocytic capacity when exposed to a high bacterial load. Antibody to Salmonella increased the phagocytic capacity of macrophages from Schistosoma-infected mice due to an increase in the number of bacteria phagocytosed but caused no modification in the number of macrophages engaged in phagocytosis. Our data indicate that macrophages from Schistosoma-infected mice work close to their functional limit, since no increase in phagocytosis was observed after increasing the bacterial load. Specific antibodies can improve their phagocytic capacity and, therefore, could help clearing concurrent infection.Investigamos a influência da carga bacteriana e de anticorpos específicos sobre a fagocitose na esquistossomose. Macrófagos de camundongos esquistossomóticos mostraram uma menor capacidade para aumentar a fagocitose mesmo na presença de alta carga bacteriana, devido a um reduzido envolvimento destas células na fagocitose e a uma incapacidade para aumentar o número de bactérias fagocitadas por macrófago. Camundongos normais e infectados por Salmonella typhimurium aumentaram sua capacidade fagocitária quando expostos a uma alta carga bacteriana. Anticorpos para Salmonella typhimurium significantemente aumentaram a capacidade fagocitária de macrófagos de camundongos esquistossomóticos devido ao aumento do número de bactérias ingeridas mas não causaram nenhuma modificação no número de macrófagos envolvidos na fagocitose. Nossos dados indicam que macrófagos de camundongos esquistossomóticos trabalham próximo ao seu limite funcional, desde que nenhum aumento significante na fagocitose foi observado após aumentar a carga bacteriana. Anticorpos específicos podem melhorar sua capacidade fagocitária e, portanto, poderiam auxiliar na eliminação da infecção concomitante por Salmonella.

Maria Imaculada Muniz-Junqueira; Aluízio Prata; Carlos Eduardo Tosta

1997-01-01

344

Factors influencing phagocytosis of Salmonella typhimurium by macrophages in murine schistosomiasis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Investigamos a influência da carga bacteriana e de anticorpos específicos sobre a fagocitose na esquistossomose. Macrófagos de camundongos esquistossomóticos mostraram uma menor capacidade para aumentar a fagocitose mesmo na presença de alta carga bacteriana, devido a um reduzido envolvimento destas células na fagocitose e a uma incapacidade para aumentar o número de bactérias fagocitadas por macrófago. Camundongos normais e infectados por Salmonella typhimurium (more) aumentaram sua capacidade fagocitária quando expostos a uma alta carga bacteriana. Anticorpos para Salmonella typhimurium significantemente aumentaram a capacidade fagocitária de macrófagos de camundongos esquistossomóticos devido ao aumento do número de bactérias ingeridas mas não causaram nenhuma modificação no número de macrófagos envolvidos na fagocitose. Nossos dados indicam que macrófagos de camundongos esquistossomóticos trabalham próximo ao seu limite funcional, desde que nenhum aumento significante na fagocitose foi observado após aumentar a carga bacteriana. Anticorpos específicos podem melhorar sua capacidade fagocitária e, portanto, poderiam auxiliar na eliminação da infecção concomitante por Salmonella. Abstract in english We investigated the influence of Salmonella typhimurium load and specific antibodies on phagocytosis in schistosomiasis. Macrophages from Schistosoma mansoni-infected mice showed depressed capacity to increase the phagocytosis in the presence of a high bacterial load, due to a reduced involvement of these cells in phagocytosis and to a deficient ability to increase the number of phagocytosed bacteria. Normal and Salmonella-infected mice increased their phagocytic capacity (more) when exposed to a high bacterial load. Antibody to Salmonella increased the phagocytic capacity of macrophages from Schistosoma-infected mice due to an increase in the number of bacteria phagocytosed but caused no modification in the number of macrophages engaged in phagocytosis. Our data indicate that macrophages from Schistosoma-infected mice work close to their functional limit, since no increase in phagocytosis was observed after increasing the bacterial load. Specific antibodies can improve their phagocytic capacity and, therefore, could help clearing concurrent infection.

Muniz-Junqueira, Maria Imaculada; Prata, Aluízio; Tosta, Carlos Eduardo

1997-04-01

345

A comparative study of culture methods and PCR assay for Salmonella detection in poultry drinking water.  

UK PubMed Central (United Kingdom)

The present work compared 2 culture methods and PCR assays for motile and nonmotile Salmonella detection using artificially contaminated poultry drinking water. The specificity was 1 for all methods studied. The accuracy and sensitivity were 1 for all motile strains, whereas these parameters were between 0 and 0.7 for nonmotile Salmonella strains. The positive predictive value and negative predictive value were 1 for all motile Salmonella strains in the 3 methods used. Nonmotile Salmonella strains showed a positive predictive value of 1 in the PCR method. However, the positive predictive value was indeterminate in the tetrathionate (TT) methods for both strains tested and in the modified semisolid Rappaport-Vassiliadis (MSRV) method for Salmonella Pullorum. On the other hand, the negative predictive value was between 0.20 and 0.43 for the 3 methods. The detection level of motile strains was 4 to 7 cfu/25 mL for all methods. Nonmotile Salmonella strains could not be detected in the TT method, whereas only Salmonella Gallinarum could be recovered from 1.1 × 10(1) cfu/25 mL in the MSRV method. In relation to the molecular methods, PCR could detect these strains from 1.1 × 10(4) cfu/25 mL. Extending incubation time of the enrichment medium to 6 d in the TT method did not improve the isolation rates. In general, all selective plating media did not show any statistical differences in the parameters of performance studied. The kappa coefficient showed that there was an excellent agreement between the 3 methods for motile strains. For nonmotile strains, the agreement was poor between the MSRV and the PCR; there was no agreement when the TT method was compared with the MSRV and the PCR methods. The difference in detection levels obtained with the methods used for motile and nonmotile Salmonella strains and the difficulty in detecting these last strains represents a potential problem when a poultry water sample is considered negative for the presence of Salmonella.

Soria MC; Soria MA; Bueno DJ

2013-01-01

346

Salmonella spp. are cytotoxic for cultured macrophages.  

Science.gov (United States)

We have shown by a variety of microscopical and biochemical techniques that Salmonella spp. are cytotoxic for cultured J774A.1 and bone marrow-derived murine macrophages. The cytotoxicity is initially manifested by inhibition of membrane ruffling and macropinocytosis in infected macrophages, and is followed by cell death. Macrophages killed by Salmonella spp. exhibited features of apoptosis such as condensation and fragmentation of chromatin, membrane blebbing, and the presence of cytoplasmic nucleosomes and apoptotic bodies. Cytotoxicity does not require bacterial internalization as cytochalasin D, a drug that prevents bacterial uptake, did not prevent Salmonella-induced macrophage cell death. However, the cytotoxic effects are strictly dependent upon the expression of the invasion-associated Type III protein-secretion system encoded at centisome 63 of the Salmonella chromosome. Wild-type Salmonella typhimurium grown under conditions that do not allow optical expression of this system or strains of Salmonella carrying mutations in genes that encode components of this protein-secretion system were devoid of macrophage cytotoxicity. In addition, mutations in invJ, spaO, sipB, sipC and sipD, which encode proteins that are secreted via this secretion apparatus and are required for bacterial entry into non-phagocytic cells, also abolished the toxicity. In contrast, mutations in sipA and sptP, which encode secreted proteins that are not required for bacterial invasion, had no effect on macrophage cytotoxicity. These results indicate a close correlation between the mechanisms of bacterial internalization into non-phagocytic cells and those that lead to macrophage cytotoxicity. Host-adapted serotypes of Salmonella such as S. typhi, S. gallinarum and S. dublin were also toxic for murine macrophages, indicating that this virulence property is probably present in most Salmonella spp. and is not associated with the mechanisms responsible for host range. PMID:8885278

Chen, L M; Kaniga, K; Galán, J E

1996-09-01

347

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)

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-level demonstrated a strong positive association between the prevalence of Salmonella-positive breeding holdings and the prevalence of Salmonella-positive production holdings, suggesting a vertical dissemination of Salmonella between the holdings. Based on the combined results from breeding and production holdings, multivariable regression analysis showed that the odds of Salmonella-positive pens with pigs increased with the number of breeding pigs in the holding and with the following pen-level factors: flooring systems other than slatted floors or solid floors with straw, presence of maiden gilts, number of pigs per pen, 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 holdings. However, many other serovars were relatively prevalent in Western EU Member States. A complementary within-holding prevalence study indicated that, due to a non-perfect diagnostic test sensitivity, the observed EU-level prevalence of Salmonella-positive holdings with breeding pigs was roughly 80% of the estimated true EU-level prevalence. But this proportion varied between Member States.

Hald, Tine

2011-01-01

348

SALMONELLA ENTERITIDIS – PHENOTYPIC AND GENOTYPIC  

Directory of Open Access Journals (Sweden)

Full Text Available Today, Salmonella enterica subspecies enterica serovar Enteritidis (S. Enteritidis) represents one of the most common serotypes that causes enterocolitis. Since S. enteritidis identification methods are advanced permanently, the following phenotyping methods could be applied for this purpose: biotyping, phagotyping (phage typing – PT), and resistotyping. From methods for genotyping of S. Enteritidis, plasmid profile analysis (PP), restriction analysis of the virulence plasmid, ribotyping, pulsed field gel electroph