Full Text Available SciELO Venezuela | Language: Spanish 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 relacion [...] a 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 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 invA 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.
Luz, Chacón; Kenia, Barrantes; Cristina, García; Achí, Rosario.
The relatively low concentration of pathogen indicators, such Salmonella, in composting sometimes causes a problem with detection when using the conventional techniques. The presence of viable but non-culturable (VBNC) organisms is also a potential problem with Salmonella detection when using conventional techniques. In this study, the molecular approach for organism recognition, known as Polymerase Chain Reaction (PCR), was used for characterisation the Salmonella spp. used...
Sunar, N. M.; Stentiford, E. I.; Stewart, D. I.; Fletcher, L. A.
Full Text Available Poultry meat has been identified as one of the principal foodborne source of Salmonella. In this preliminary study the prevalence of Salmonella spp. contamination of broiler carcasses, were determined. Sixty samples were collected from poultry carcasses from the commercial broiler slaughtering facility in Namakkal, Tamil Nadu. The presence of Salmonella spp in collected samples was assessed by performing the pre-enrichment and enrichment culture, followed by PCR assay. The primers were selected from the invA gene specific for the detection of Salmonella spp. In this study 8.3% of poultry carcasses were found to be contaminated with Salmonella spp. In order to provide a more accurate profile of the prevalence of Salmonella spp in broiler carcasses, it is pertinent to use inv A gene specific PCR method that could be considered as an appropriate alternative to conventional culture method. [Vet. World 2011; 4(12.000: 562-564
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
Full Text Available SciELO Cuba | Language: Spanish 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 anal [...] izaron 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 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 Car [...] ibbean 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.
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.
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.)
Full Text Available Scientifically based and clinically validated new tools and methods to combat Salmonella infection in poultry, allowing to ensure the safety and health safety products - eggs and poultry meat. The method of selective decontamination involves the use of bivalent bacteriophage that is based on highly selected phages Phagum Salmonella typhimurium and Phagum Salmonella enteritidis, as well as probiotic laktobifadola. The developed tools and methods of selective decontamination followed by immunization with inactivated vaccine associated "Virosalm" allows you to eliminate salmonella infection in poultry.
The standard method for detecting Salmonella generally analyzes food or fecal samples. Salmonella often occur in relatively low concentrations in environmental waters. Therefore, some form of concentration and proliferation may be needed. This study compares three Salmonella analysis methods and develops a new Salmonella detection procedure for use in environmental water samples. The new procedure for Salmonella detection include water concentration, nutrient broth enrichment, selection of Salmonella containing broth by PCR, isolation of Salmonella strains by selective culture plates, detection of possible Salmonella isolate by PCR, and biochemical testing. Serological assay and pulsed-field gel electrophoresis (PFGE) can be used to identify Salmonella serotype and genotype, respectively. This study analyzed 116 raw water samples taken from 18 water plants and belonging to 5 watersheds. Of these 116, 10 water samples (8.6%) taken from 7 water plants and belonging to 4 watersheds were positive for a Salmonella-specific polymerase chain reaction targeting the invA gene. Guided by serological assay results, this study identified 7 cultured Salmonella isolates as Salmonella enterica serovar: Alnaby, Enteritidis, Houten, Montevideo, Newport, Paratyphi B var. Java, and Victoria. These seven Salmonella serovars were identified in clinical cases for the same geographical areas, but only one of them was 100% homologous with clinical cases in the PFGE pattern. - Research highlises in the PFGE pattern. - Research highlights: ? A new Salmonella detecting procedure for environmental water is developed. ? Salmonella isolates are identified by serological assay and PFGE. ? A total of seven Salmonella serovars is isolated from environmental water.
Serious infections with salmonellae remain a threat in many human populations. Despite extensive study of salmonella infections in animals and clinical experience with killed cellular vaccines, there are no vaccines against serotypes other than Salmonella typhi licensed for human use. Serum antibodies to the O-specific polysaccharide (O-SP) of salmonellae protect mice against invasive infection. In order to render it immunogenic, we have conjugated the O-SP of Salmonella typhimurium to carrie...
Watson, D. C.; Robbins, J. B.; Szu, S. C.
The administration of live attenuated Salmonella strains has proven to be an effective way to generate protective immunity against Salmonella infection in humans and mice. Studies in the mouse model have shown that protection requires Salmonella-specific Th1 cells, however the timing and stimulatory requirements for generating optimal Th1 responses have not been carefully examined. We used antibiotic interruption of vaccination with live attenuated Salmonella to examine the requirements for S...
Griffin, Amanda J.; Mcsorley, Stephen J.
Full Text Available Abstract Background Schistosomes are parasitic helminths that infect humans through dermo-invasion while in contaminated water. Salmonella are also a common water-borne human pathogen that infects the gastrointestinal tract via the oral route. Both pathogens eventually enter the systemic circulation as part of their respective disease processes. Concurrent Schistosoma-Salmonella infections are common and are complicated by the bacteria adhering to adult schistosomes present in the mesenteric vasculature. This interaction provides a refuge in which the bacterium can putatively evade antibiotic therapy and anthelmintic monotherapy can lead to a massive release of occult Salmonella. Results Using a novel antibiotic protection assay, our results reveal that Schistosoma-associated Salmonella are refractory to eight different antibiotics commonly used to treat salmonellosis. The efficacy of these antibiotics was decreased by a factor of 4 to 16 due to this association. Salmonella binding to schistosomes occurs via a specific fimbrial protein (FimH present on the surface on the bacterium. This same fimbrial protein confers the ability of Salmonella to bind to mammalian cells. Conclusions Salmonella can evade certain antibiotics by binding to Schistosoma. As a result, effective bactericidal concentrations of antibiotics are unfortunately above the achievable therapeutic levels of the drugs in co-infected individuals. Salmonella-Schistosoma binding is analogous to the adherence of Salmonella to cells lining the mammalian intestine. Perturbing this binding is the key to eliminating Salmonella that complicate schistosomiasis.
Day Tim A
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
Salmonella is a leading cause of waterborne diseases. Salmonella can survive for a long time in aquatic environments, and its persistence in the environment is of great concern to public health. Nonetheless, the presence and diversity of Salmonella in the aquatic environments in most areas remain relatively unknown. In this study, we examined three analytical processes for an optimum Salmonella detection method, and the optimized method was used to evaluate seasonal variations of Salmonella in aquatic environments. In addition, Salmonella strains were isolated by selective culture medium to identify the serotypes by biochemical testing and serological assay, and to identify the genotypes by pulsed-field gel electrophoresis based on the genetic patterns. A total of 136 water samples were collected in the study area in 9 months. Forty-one (30.1%) samples were found to contain Salmonella-specific invA gene, and most (24/41) of the detections occurred in summer. The serovars of Salmonella enterica were identified, including Bareilly, Isangi, Newport, Paratyphi B var. Java, Potsdam and Typhimurium. PMID:24417320
Huang, Kuan-Hao; Hsu, Bing-Mu; Chou, Ming-Yuan; Tsai, Hsien-Lung; Kao, Po-Min; Wang, Hung-Jen; Hsiao, Hsiang-Yu; Su, Ming-Jen; Huang, Yu-Li
In this paper, the antibody titre to Salmonella enteritidis (SE) was examined by the ELISA method in two flocks of laying hens, where during routine bacteriological investigations Salmonellae was never isolated, and in one flock where Colysepticemia was diagnosed and Salmonella isolated accidentally. In the flocks were Salmonellae were not isolated, a titre with a high level of specific antibodies to SE was discovered (15 and 45%), while the flock with accidental findings of SE was poorly pos...
Velhner Maja; Orli? Dušan B.; Potkonjak Dubravka; Kapetanov Miloš; Lazi? Sava
... Salmonella Share Compartir 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 ...
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. PMID:23367664
Münch, Sebastian; Wernery, Ulrich; Kinne, Jörg; Joseph, Marina; Braun, Peggy; Pees, Michael; Flieger, Antje; Fruth, Angelika; Rabsch, Wolfgang
Salmonella is one of the most important pathogens of waterborne diseases with outbreaks from contaminated water reported worldwide. In addition, Salmonella spp. can survive for long periods in aquatic environments. To realize genotypes and serovars of Salmonella in aquatic environments, we isolated the Salmonella strains by selective culture plates to identify the serovars of Salmonella by serological assay, and identify the genotypes by Multilocus sequence typing (MLST) based on the sequence data from University College Cork (UCC), respectively. The results show that 36 stream water samples (30.1%) and 18 drinking water samples (23.3%) were confirmed the existence of Salmonella using culture method combined PCR specific invA gene amplification. In this study, 24 cultured isolates of Salmonella from water samples were classified to fifteen Salmonella enterica serovars. In addition, we construct phylogenetic analysis using phylogenetic tree and Minimum spanning tree (MST) method to analyze the relationship of clinical, environmental, and geographical data. Phylogenetic tree showed that four main clusters and our strains can be distributed in all. The genotypes of isolates from stream water are more biodiversity while comparing the Salmonella strains genotypes from drinking water sources. According to MST data, we can found the positive correlation between serovars and genotypes of Salmonella. Previous studies revealed that the result of Pulsed field gel electrophoresis (PFGE) method can predict the serovars of Salmonella strain. Hence, we used the MLST data combined phylogenetic analysis to identify the serovars of Salmonella strain and achieved effectiveness. While using the geographical data combined phylogenetic analysis, the result showed that the dominant strains were existed in whole stream area in rainy season. Keywords: Salmonella spp., MLST, phylogenetic analysis, PFGE
Kuo, Chun Wei; Hao Huang, Kuan; Hsu, Bing Mu; Tsai, Hsien Lung; Tseng, Shao Feng; Kao, Po Min; Shen, Shu Min; Chou Chiu, Yi; Chen, Jung Sheng
The risks of false-positive responses were examined when using the polymerase chain reaction (PCR) method for the detection of Salmonella in the marine environment (water and shellfish). The degradation rates of DNA, both free and from dead Salmonella, were evaluated in natural seawaters maintained at 10 degrees and 20 degrees C, using PCR with Vir and invA primers. The DNA of dead Salmonella was detected up to 55 d in seawater collected in winter and stored at 10 degrees C. But in summer, the persistence was shorter: 10 d or even 2 d for a smaller inoculum (3 x 10(3) Salmonella ml-1). The role of the planktonic organisms present in spring and summer was pinpointed. For free DNA, the persistence times were shorter: from 2 to 4 d at 20 degrees C, and from 3 to 8 d at 10 degrees C showing that the nuclease activity of marine organisms is higher at warm temperatures. These data led us to recommend careful interpretations of direct PCR results, especially during cold periods and for samples collected close to terrestrial discharges of high concentrations of live, dead or lysed Salmonella. PCR is a rapid, specific and sensitive method, but should be applied with care to marine samples, in order to avoid false-positive responses. PMID:9134724
Dupray, E; Caprais, M P; Derrien, A; Fach, P
Salmonella spp. is a common water-borne pathogens and its genus comprises more than 2,500 serotypes. Major pathogenic genotypes which cause typhoid fever, enteritis and other intestinal-type diseases are S. Typhimurium, S. Enteritidis, S. Stanley, S. Agona, S.Albany, S. Schwarzengrund, S. Newport, S. Choleraesuis, and S. Derby. Hence, the identification of the serotypes of Salmonella spp. is important. In the present study, the analytical procedures include direct concentration method, non-selective pre-enrichment method and selective enrichment method of Salmonella spp.. Both selective enrichment method and cultured bacteria were detected with specific primers of Salmonella spp. by polymerase chain reaction (PCR). At last, the serotypes of Salmonella were confirmed by using MLST (multilocus sequence typing) with aroC, dnaN, hemD, hisD, purE, sucA, thrA housekeeping genes to identify the strains of positive samples. This study contains 121 samples from three different types of water sources including the drinking water (51), streams (45), and swine wastewater (25). Thirteen samples with positive invA gene are separated from culture method. The strains of these positive samples which identified from MLST method are S. Albany, S. Typhimurium, S. Newport, S. Bareilly, and S. Derby. Some of the serotypes, S. Albany, S. Typhimurium and S. Newport, are highly pathogenic which correlated to human diarrhea. In our results, MLST is a useful method to identify the strains of Salmonella spp.. Keywords: Salmonella, PCR, MLST.
Kuo, C.; Hsu, B.; Shen, T.; Tseng, S.; Tsai, J.; Huang, K.; Kao, P.; Chen, J.
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
A multiplex loop-mediated isothermal amplification-RFLP (mLAMP-RFLP) was developed and validated for simultaneous detection of Salmonella strains and Shigella strains in milk. In this system, two sets of LAMP primers were designed to specifically target invA of Salmonella spp. and ipaH of Shigella spp. Under isothermal conditions at 63 °C, ladder pattern of DNA bands could be amplified within 60 min in the presence of genomic DNAs of Salmonella strains and Shigella strains, which could be distinguished between Salmonella spp. and Shigella spp. simultaneously based on the different ladder pattern of DNA bands and subsequent restriction enzyme analysis. The overall analysis time was approximately 20 h including the enrichment of the bacterial cells, which greatly saved detection time. The sensitivity of mLAMP was found to be 100 fg DNA/tube with genomic DNAs of Salmonella strains and Shigella strains, comparatively, multiplex PCR was 1 pg DNA/tube. The mLAMP allowed the detection of milk sample artificially contaminated by Salmonella strains and Shigella strains at initial inoculation levels of approximate 5CFU/10 mL. In conclusion, the mLAMP described here can potentially facilitate simultaneous monitoring of Salmonella and Shigella in a large number of food samples, which could be used as a primary screening method and as a supplement to classical detection method. PMID:21652102
Shao, Yanchun; Zhu, Shengmei; Jin, Cuicui; Chen, Fusheng
In the Danish serological surveillance for Salmonella in poultry (serum and egg yolk) an indirect mix - ELISA is used, based on S. typhimurium and S. enteritidis antigens (Feld et al., 2000). When we evaluated results of the test retrospectively, over the years an unacceptably large fraction of seropositive findings could not be confirmed by the subsequent confirmatory bacteriological sampling in the herd. Therefore we tried to enhance specificity of the ELISA, without losing sensitivity, by refining the antigens used.
Lauritsen, Klara TØlbØl; Klausen, Joan
In the Danish serological surveillance for Salmonella in poultry (serum and egg yolk) a mix-ELISA is used, based on S. typhimurium and S. enteritidis antigens (Feld et al., 2000). When we evaluated results of the test retrospectively, over the years an unacceptably large fraction of seropositive findings could not be confirmed by the subsequent confirmatory bacteriological sampling in the herd. Therefore we tried to enhance specificity of the ELISA, without losing sensitivity, by refining the antigens used.
Lauritsen, Klara TØlbØl; Lind, Peter
Full Text Available In this paper, the antibody titre to Salmonella enteritidis (SE was examined by the ELISA method in two flocks of laying hens, where during routine bacteriological investigations Salmonellae was never isolated, and in one flock where Colysepticemia was diagnosed and Salmonella isolated accidentally. In the flocks were Salmonellae were not isolated, a titre with a high level of specific antibodies to SE was discovered (15 and 45%, while the flock with accidental findings of SE was poorly positive (5%. These results point to the necessity of introducing serological monitoring to SE so that the infection of salmonella may be discovered early and the prevalence in the flock determined, and also for the purpose of applying adequate measures that could reduce the possibility of secretion of SE through eggs.
CD4(+) T cells and B cells are both essential for acquired immunity to Salmonella infection. It is well established that Salmonella inhibit host CD4(+) T-cell responses, but a corresponding inhibitory effect on B cells is less well defined. Here, we utilize an Ag tetramer and pull-down enrichment strategy to directly visualize OVA-specific B cells in mice, as they respond to infection with Salmonella-OVA. Surprisingly, OVA-specific B-cell expansion and germinal center formation was not detected until bacteria were cleared from the host. Furthermore, Salmonella infection also actively inhibited both B- and T-cell responses to the same coinjected Ag but this did not require the presence of iNOS. The Salmonella Pathogenicity Island 2 (SPI2) locus has been shown to be responsible for inhibition of Salmonella-specific CD4(+) T-cell responses, and an examination of SPI2-deficient bacteria demonstrated a recovery in B-cell expansion in infected mice. Together, these data suggest that Salmonella can simultaneously inhibit host B- and T-cell responses using SPI2-dependent mechanisms. PMID:25346524
Nanton, Minelva R; Lee, Seung-Joo; Atif, Shaikh M; Nuccio, Sean-Paul; Taylor, Justin J; Bäumler, Andreas J; Way, Sing Sing; McSorley, Stephen J
Full Text Available One of the most common causes of salmonellosis of man and poultry is Salmonella Enteritidis which is often found in the digestive system of adult birds. The infected birds do not display any evident clinical symptoms and, at the same time, they excrete the bacteria into the surrounding environment. Studies are carried out by standard microbiological procedures which include the isolation of Salmonella spp. in egg yolks and their serologic typization by agglutination on microplates. Along these methods, studies on the possibility to use an enzyme immunoassay, such as cELISA, in order to detect the presence of specific antibodies on Salmonella Enteritidis in egg yolks are carried out intensively. The presence of specific antibodies for Salmonella Enteritidis is detected in egg yolk samples from vaccinated flocks resulted in specific positive for a total of 72.22%. Egg yolk samples originating from hens of an unknown immunologic status were cELISA positive in a total of 1.66%. However, egg yolk samples from non-vaccinated hens were positive on the presence of specific antibodies for Salmonella Enteritidis in 23.07% cases. Bearing in mind that standard bacteriological methods did not confirm the presence of Salmonella Enteritidis in egg yolk samples and that cELISA did establish the presence of specific antibodies in the tested samples it can be concluded that cELISA is a more sensitive test.
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)
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 (p<0.01 and lower concentration of SE cecal colonization (p<0.01. These groups also had a lower isolation of SE from the liver, spleen and ileum. The use of Salmonella 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.
Full Text Available Abstract 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.
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.
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 o...
Grammato Evangelopoulou; Spyridon Kritas; Alexander Govaris; Burriel, Angeliki R.
The pan-genome of a taxonomic group consists of evolutionarily conserved core genes shared by all members and accessory genes that are present only in some members of the group. Group- and subgroup-specific core genes are thought to contribute to shared phenotypes such as virulence and niche specificity. In this study we analyzed 39 Salmonella enterica genomes (16 closed, 23 draft), a species that contains two human-specific serovars that cause typhoid fever, as well as a large number of zoonotic serovars that cause gastroenteritis in humans. Panseq 2.0 was used to define the pan-genome by adjusting the threshold at which group-specific "core" loci are defined. We found the pan-genome to be 9.03 Mbp in size, and that the core genome size decreased, while the number of SNPs/100 bp increased, as the number of strains used to define the core genome increased, suggesting substantial divergence among S. enterica subgroups. Subgroup-specific "core" genes, in contrast, had fewer SNPs/100 bp, likely reflecting their more recent acquisition. Phylogenetic trees were created from the concatenated and aligned pan-genome, the core genome, and multi-locus-sequence typing (MLST) loci. Branch support increased among the trees, and strains of the same serovar grouped closer together as the number of loci used to create the tree increased. Further, high levels of discrimination were achieved even amongst the most closely related strains of S. enterica Typhi, suggesting that the data generated by Panseq may also be of value in short-term epidemiological studies. Panseq provides an easy and fast way of performing pan-genomic analyses, which can include the identification of group-dominant as well as group-specific loci and is available as a web-server and a standalone version at http://lfz.corefacility.ca/panseq/. PMID:22001825
Laing, Chad; Villegas, Andre; Taboada, Eduardo N; Kropinski, Andrew; Thomas, James E; Gannon, Victor P J
Full Text Available SciELO Mexico | Language: Spanish 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 l [...] a 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 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 2 [...] 001. 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 in 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.
Lucía, Morales-Hernández; Ana María, Hernández-Anguiano; Cristóbal, Cháidez-Quiroz; Gilberto, Rendón-Sánchez; Trevor, V. Suslow.
For immediate discrimination among isolated cells we propose a novel device and technique for isolation of cells and sequential detection of specific gene(s) within them by polymerase chain reaction (PCR). In this study, we isolated Salmonella enterica cells and detected the Salmonella-specific invA gene from isolated cells by PCR on a compact disk (CD)-shaped device. This device enabled liquid flow by centrifugal force without a micro pump, and was fabricated from silicon wafer and glass to avoid evaporation of a small amount of reagent. One device has 24 microchannels, and 313 microchambers integrated on each microchannel. One microliter of PCR mixture containing cells was separated into microchambers on the device at 5000 rpm for 30 s. Each microchamber contained approximately 1.5 nL PCR mixture. A Poisson distribution of S. enterica cells was observed for different densities of cell suspension. At 200 cells ?L(-1) of S. enterica or less, isolated single cells could be determined on the device by amplification of DNA of the invA gene; at 400 cells ?L(-1), chambers containing no, one, two, or three cells could be determined on the device. Selective detection of S. enterica was achieved by PCR from a mixture of S. enterica and Escherichia coli on the CD-shaped device. PMID:20865405
Furutani, Shunsuke; Nagai, Hidenori; Takamura, Yuzuru; Kubo, Izumi
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 (...
Abstract Pork meat is one of the major sources for human infections with Salmonella enterica subspecies enterica serovars. Further, zoonoses caused by Salmonella 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 met...
Full Text Available SciELO Brazil | Language: English Abstract in portuguese A presença de três genes de virulência (invA, spvR e spvC) foi determinada em Salmonella Enteritidis isoladas de aves, suínos, humanos e alimentos. Todos os isolados foram positivos para o gene invA, 91,2% também foram positivos para o spvR e 90,2% para o spvC. Não existiu diferença significativa na [...] prevalência dos genes de virulência entre isolados de diferentes origens. Os resultados indicaram que, provavelmente, exista um alto potencial de virulência nos isolados de S. Enteritidis caracterizados. Abstract in english The presence of three virulence genes, invA, spvR, and spvC, was determined in Salmonella Enteritidis isolated from poultry, pigs, humans and food. All isolates were positive for the invA gene, with 91.2% being positive for spvR and 90.2% for spvC. There was no significant difference in the prevalen [...] ce of the virulence genes between isolates from different sources. The results indicate that there is a putative high virulence potential for the S. Enteritidis isolates characterized.
Sílvia Dias de, Oliveira; Carla Rosane, Rodenbusch; Geovana B., Michael; Marisa I.R., Cardoso; Cláudio Wageck, Canal; Adriano, Brandelli.
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.
Paula C. Teixeira
GtgE is an effector protein from Salmonella Typhimurium that modulates trafficking of the Salmonella-containing vacuole. It exerts its function by cleaving the Rab-family GTPases Rab29, Rab32 and Rab38, thereby preventing the delivery of antimicrobial factors to the bacteria-containing vacuole. Here, the crystal structure of GtgE at 1.65?Å resolution is presented, and structure-based mutagenesis and in vivo infection assays are used to identify its catalytic triad. A panel of cysteine protease inhibitors were examined and it was determined that N-ethylmaleimide, antipain and chymostatin inhibit GtgE activity in vitro. These findings provide the basis for the development of novel therapeutic strategies to combat Salmonella infections. PMID:24531472
Kohler, Amanda C; Spanò, Stefania; Galán, Jorge E; Stebbins, C Erec
Isolation of Salmonella from environmental and processing-plant poultry samples requires the sampling of large numbers of areas within the poultry house or plant. Subsequently, the required number of samples necessitates a large volume of work for a microbiology laboratory, especially when the protocol requires the inclusion of a delayed secondary enrichment for the isolation of Salmonella. This study examined the use of the polymerase chain reaction (PCR) to identify those secondary enrichments containing Salmonella. The unique Salmonella virulence gene invA was chosen as the target for the development of a nested PCR because of its uniform distribution among Salmonella serotypes. The use of nested PCR primers increased the sensitivity of detection 100-fold, resulting in the detection of as few as four cells. There was a strong, statistically significant positive correlation between PCR and culture results as determined by chi-square (P costs and manpower required for the surveillance of Salmonella. PMID:12182472
Liu, Tongrui; Liljebjelke, Karen; Bartlett, Elizabeth; Hofacre, Charles; Sanchez, Susan; Maurer, John J
Contamination of retail poultry by Campylobacter spp. and Salmonella enterica is a significant source of human diarrheal disease. Isolation and identification of these microorganisms require a series of biochemical and serological tests. In this study, Campylobacter ceuE and Salmonella invA genes were used to design probes in PCR-enzyme-linked immunosorbent assay (ELISA), as an alternative to conventional bacteriological methodology, for the rapid detection of Campylobacter jejuni, Campylobac...
Hong, Yang; Berrang, Mark E.; Liu, Tongrui; Hofacre, Charles L.; Sanchez, Susan; Wang, Lihua; Maurer, John J.
A polymerase chain reaction based test was developed for the detection of Salmonella spp. in blood specimens. After amplification of a 389 bp-polymerase chain reaction product from the invA gene, a microtiter plate hybridization assay was performed. The protocol described allowed the detection of six to seven copies of the Salmonella typhi genome, as determined by serial dilutions of DNA from S. typhi. Eighteen blood specimens from artificially infected rats and 22 blood specimens fr...
Cocolin, Luca Simone
Full Text Available The anti-Salmonella specific antibodies could be used in food and feedstuffs for thecontrol of the salmonellosis, with large applications. The emphasize of the ”in vitro”effect of the specific anti-Salmonella antibodies on the development of Salmonellagallinarum culture was the aim of our paper. The use of the specific anti-Salmonellaantibodies reduces the bacterial development. Due to the agglutination on theantibodies from the culture media, the bacteria have lower mobility and lowopportunitry to rach the nutrients. It determines the inhibation or reducing thebacteria multiplication. The addition of the specific antibodies inhibates thedevelopment of the salmonella and reduces the risk of salmonellosis, if they are usedas food or feed additives.
Typhoid fever is a life threatening bacterial infection that remains a major global health concern. This continued high burden associated with significant morbidity and mortality rate demands specific and rapid detection technique. This work reports a new sandwich type fluorescence immunoassay format using polymyxin B, a cationic receptor molecule, as a binder agent while anti-Vi antibody served as the capturing agent for specifically detecting Salmonella enterica serovar Typhi. Anti-Vi IgG antibody raised against Vi-BSA conjugate revealed affinity of 7.779nM(-1) signifying immunodominancy of O-acetyls groups in Vi polysaccharide. The detection limit of the developed assay was around 10(1) cellsmL(-1) of Vi expressing Salmonella enterica serovar Typhi with a correlation coefficient (R(2)) equal to 0.97. Positive response obtained for all the tested serovar Typhi clinical isolates as well as the pathogen spiked blood samples recommended specificity and accuracy of Vi antigen as a biomarker during typhoid fever. The intra- and inter-assay precision with Vi spiked samples were satisfactory revealing coefficient of variance (CV%) with a mean of 4.05% and 5.97% respectively. This may be the novel attempt and constructive report on the fluorescence based detection of Vi antigen of serovar Typhi in the epidemic as well as pandemic outbreaks. PMID:25109861
Pandey, Satish K; Vinayaka, Aaydha C; Rishi, Dharam B; Rishi, Praveen; Suri, C Raman
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. PMID:23992511
Cossi, Marcus Vinícius Coutinho; Burin, Raquel Cristina Konrad; Lopes, Danilo Augusto; Dias, Mariane Rezende; Castilho, Natalia Parma Augusto de; de Arruda Pinto, Paulo Sérgiode; Nero, Luís Augusto
A PCR procedure has been developed for routine analysis of viable Salmonella spp. in feed samples. The objective was to develop a simple PCR-compatible enrichment procedure to enable DNA amplification without any sample pretreatment such as DNA extraction or cell lysis. PCR inhibition by 14 different feed samples and natural background flora was circumvented by the use of the DNA polymerase Tth. This DNA polymerase was found to exhibit a high level of resistance to PCR inhibitors present in t...
Lo?fstro?m, Charlotta; Knutsson, Rickard; Axelsson, Ce; Ra?dstro?m, Peter
Genetically modified Salmonella typhimurium VNP20009 (VNP) is a useful vehicle for cancer therapy and vaccine development but exhibits limited tumor targeting in vivo. We engineered a novel VNP derivative that expressed carcinoembryonic antigen (CEA)-specific single chain antibody fragments (scFv) on the cell surface to increase tumor-specific targeting. There was significant scFv cell surface display visualized by flow cytometry and confocal microscopy when cells were probed with fluorescently labeled CEA. Atomic force microscopy (AFM) measurements on whole bacteria confirmed binding of unlabelled CEA to the displayed scFv. The modified VNP strain exhibited increased localization in the upper gastrointestinal tract of CEA transgenic mice and accumulated in CEA-expressing tumors. Furthermore, treatment with a single dose of the VNP derivative inhibited growth of MC38CEA tumors and was associated with local accumulation of CD3+ T cells and CD11b+ macrophages. The display of antibody fragments on the surface of VNP represents a novel strategy for both targeting CEA-expressing tumors and increasing the immunogenicity of Salmonella-based vaccines for cancer. PMID:17399861
Bereta, Michal; Hayhurst, Andrew; Gajda, Mariusz; Chorobik, Paulina; Targosz, Marta; Marcinkiewicz, Janusz; Kaufman, Howard L.
The transthyretin-like protein (TLP) from Salmonella enterica subspecies I is a periplasmic protein with high level structural similarity to a protein found in mammals and fish. In humans, the protein homologue, transthyretin, binds and carries retinol and thyroxine, and a series of other, unrelated aromatic compounds. Here we show that the amino acid sequence of the TLP from different species, subspecies and serovars of the Salmonella genus is highly conserved and demonstrate that the TLP gene is constitutively expressed in S. Typhimurium and that copper and other divalent metal ions severely inhibit enzyme activity of the TLP, a cyclic amidohydrolase that hydrolyses 5-hydroxyisourate (5-HIU). In order to determine the in vivo role of the S. Typhimurium TLP, we constructed a strain of mouse-virulent S. Typhimurium SL1344 bearing a mutation in the TLP gene (SL1344 ?yedX). We assessed the virulence of this strain via oral inoculation of mice and chickens. Whilst SL1344 ?yedX induced a systemic infection in both organisms, the bacterial load detected in the faeces of infected chickens was significantly reduced when compared to the load of S. Typhimurium SL1344. These data demonstrate that the TLP gene is required for survival of S. Typhimurium in a high uric acid environment such as chicken faeces, and that metabolic traits of Salmonellae in natural and contrived hosts may be fundamentally different. Our data also highlight the importance of using appropriate animal models for the study of bacterial pathogenesis especially where host-specific virulence factors or traits are the subject of the study. PMID:23284609
Hennebry, Sarah C; Sait, Leanne C; Mantena, Raju; Humphrey, Thomas J; Yang, Ji; Scott, Timothy; Kupz, Andreas; Richardson, Samantha J; Strugnell, Richard A
This study explores the possibility of simultaneous and specific detection ofSalmonella serovars by surface plasmon resonance (SPR). The PlasmonicÃ‚Â® SPR device wasused to develop this rapid assay. The sandwich immunoassay involves the use of apolyclonal anti-Salmonella antibody to simultaneous capture multiple Salmonella serovarspresent in a sample. This is followed by specific detection of the captured serovars usingO-specific anti-Salmonella antibodies. Milk spiked with Salmonella Ty...
Michael Keusgen; Peter KÃƒÂ¤mpfer; Olga Lezrich; Saikat Datta Mazumdar; Benjamin Barlen
Full Text Available The aims of this study were to isolation of Salmonella from poultry farms of Shiraz province of Iran and determination of their susceptibility against common antibiotics. One hundred and ninety two samples were harvested from intestine and liver of chickens and were aseptically cultured in enrichment and selective media. Out of 192 samples, 30 Salmonella were isolated. Four different serogroups were found among 30 Salmonella isolates. Strains of serogroup D1, which accounted for 70% of total isolates, were the most common isolates. PCR products of all isolated Salmonella showed a predicted 284 bp amplified DNA fragment of invA gene. All of 30 Salmonella strains were susceptible to the antimicrobial effect of Cephalothin, Tylosin, Colistin, Ciprofloxacin, Enrofloxacin, Gentamicin, Chloramphenicol, Cephalotin and Cefotaxime. But 20.7% of Salmonella strains were resistant to Trimethoprim, Nalidixic acid, Flumequine, Tetracycline and Neomycin, 24.2% to Streptomycin, 34.5% to Kanamycin and 13.8% to Amikacin.
T. Zahraei Salehi
Full Text Available Abstract Background The induction of antigen-specific CD8+ T cell cytokine responses against an attenuated, oral recombinant Salmonella enterica serovar Typhimurium vaccine expressing a green fluorescent protein (GFP model antigen was investigated. A GFP expression plasmid was constructed in which the gfp gene was fused in-frame with the 5' domain of the Escherichia coli ?-galactosidase ?-gene fragment with expression under the lac promoter. Groups of mice were orally immunized three times with the bacteria and systemic CD8+ T cell cytokine responses were evaluated. Results High level of the GFP model antigen was expressed by the recombinant Salmonella vaccine vector. Systemic GFP-specific CD8+ T cell cytokine (IFN-? and IL-4 immune responses were detected after mice were orally vaccinated with the bacteria. It was shown that 226 net IFN-? and 132 net IL-4 GFP-specific SFUs/10e6 splenocytes were formed in an ELISPOT assay. The level of IFN-? produced by GFP peptide-stimulated cells was 65.2-fold above background (p Conclusion These results suggested that a high expressing recombinant Salmonella vaccine given orally to mice would elicit antigen-specific CD8+ T cell responses in the spleen. Salmonella bacteria may, therefore, be used as potential mucosal vaccine vectors.
A spent medium antigen was prepared from the avirulent RIA strain of Salmonella typhimurium. Lymph node cells isolated from female BALB/c mice injected subcutaneously with the spent medium antigen exhibited antigen-specific proliferation. By using these cells and T-cell growth factor, continuous spent medium antigen-specific, Thy 1.2-sensitive lines were generated. These cells exhibited antigen-specific proliferation in vitro and were effective in inducing significant (P less than 0.01) host ...
Paul, C.; Shalala, K.; Warren, R.; Smith, R.
Virulent bacteria of the genera Yersinia, Shigella and Salmonella secrete a number of virulence determinants, Yops, Ipas and Sips respectively, by a type III secretion pathway. The IpaB protein of Shigella flexneri was expressed in Yersinia pseudotuberculosis and found to be secreted under the same conditions required for Yop secretion. Likewise, YopE was secreted by the wild-type strain LT2 of Salmonella typhimurium, but YopE was not secreted by the isogenic invA mutant. Secretion of both Ip...
Rosqvist, R.; Ha?kansson, S.; Forsberg, A.; Wolf-watz, H.
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
Full Text Available SciELO Colombia | Language: English 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 arroj [...] ado resultados prometedores, utilizando el indicador bacteriano Escherichia coli (E. coli), con el método recuento en placa. Sin embargo, también se ha demostrado que 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 s [...] ense, 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 m
Sandra Patricia, Rivera; Liliana Janeth, Flórez; Janeth, Sanabria.
An in situ PCR protocol by which we can monitor the presence or absence of lac mRNA in individual cells of a Salmonella typhimurium F' lac(+) strain has been developed. In this protocol, fixed cells are permeabilized with lysozyme and subjected to a seminested reverse transcriptase PCR using reporter molecule-labeled primers, and subsequently, intracellular reporter molecules are detected microscopically at the individual-cell level by use of a horseradish peroxidase-conjugated antifluorescein antibody assay. In order to determine the sensitivity of the in situ PCR assay, the ability to detect lac mRNA in suboptimally isopropyl-beta-D-thiogalactopyranoside-induced cells was investigated. By use of a single-cell beta-galactosidase assay, it was confirmed that homogeneous suboptimally induced cultures of S. typhimurium F' lacY cells could be established, and the number of functional lac mRNAs in individual cells was estimated from standard population level beta-galactosidase assays, Cells estimated to contain asingle lac mRNA were detected as containing lac mRNA by the in situ PCR method. Conclusively, we demonstrate the potential of in situ PCR for detection of even poorly expressed mRNA in individual bacterial cells.
Tolker-Nielsen, Tim; HolmstrØm, Kim
The objective of this study was to analyze the antibiotic resistance phenotype and genotype of Salmonella isolated from broiler production facilities. A total of 193 Salmonella isolates recovered from commercial farms in British Columbia, Canada, were evaluated. Susceptibility to antibiotics was determined with the Sensititre system. Virulence and antibiotic resistance genes were detected by PCR assay. Genetic diversity was determined by pulse-field gel electrophoresis (PFGE) typing. Seventeen serovars of Salmonella were identified. The most prevalent Salmonella serovars were Kentucky (29.0% of isolates), Typhimurium (23.8%), Enteritidis (13.5%), and Hadar (11.9%); serovars Heidelberg, Brandenburg, and Thompson were identified in 7.7, 4.1, and 3.6% of isolates, respectively. More than 43% of the isolates were simultaneously resistant to ampicillin, amoxicillin-clavulanic acid, ceftiofur, cefoxitim, and ceftriaxone. This ?-lactam resistance pattern was observed in 33 (58.9%) of the Salmonella Kentucky isolates; 2 of these isolates were also resistant to chloramphenicol, streptomycin, sulfisoxazole, and tetracycline. Genes associated with resistance to aminoglycosides (aadA1, aadA2, and strA), ?-lactams (blaCMY-2, blaSHV, and blaTEM), tetracycline (tetA and tetB), and sulfonamide (sul1) were detected among corresponding resistant isolates. The invasin gene (invA) and the Salmonella plasmid virulence gene (spvC) were found in 97.9 and 25.9% of the isolates, respectively, with 33 (71.7%) of the 46 Salmonella Typhimurium isolates and 17 (65.4%) of the 26 Salmonella Enteritidis isolates carrying both invA and spvC. PGFE typing revealed that the antibiotic-resistant serovars were genetically diverse. These data confirm that broiler chickens can be colonized by genetically diverse antibiotic-resistant Salmonella isolates harboring virulence determinants. The presence of such strains is highly relevant to food safety and public health. PMID:24405997
Diarra, Moussa Sory; Delaquis, Pascal; Rempel, Heidi; Bach, Susan; Harlton, Colleen; Aslam, Mueen; Pritchard, Jane; Topp, Edward
Colonies of the Salmonella strains usually show a smooth (S) character. Therefore, Salmonella strains producing mucoid colony are very rarely encountered in the literature. Identification of the mucoid Salmonella strains to the species level is difficult via conventional methods, since the mucus layer does not allow the bacterium to respond to the antigenic reactions. In this study we aimed to emphasize the identification of Salmonella serotypes by the polymerase chain reaction (PCR) when rough (R) or mucoid (M) Salmonella isolates are encountered in the laboratory. The urine culture of a 17-year-old female patient revealed growth of 100.000 cfu/mL gram-negative bacilli in mucoid colony morphology. The isolate was identified as Salmonella sp. by biochemical tests and Vitek 2 (bioMérieux, France) automated identification system. Agglutination tests showed negative reaction with the known antiserums. Absence of agglutination was attributed to the mucoid character of the isolate. Identification of the Salmonella sp. was confirmed by Vitek MS MALDI-TOF (bioMérieux, France) analysis method, however, the serotype of the strain could not be identified. In order to verify that the mucoid colony was Salmonella spp., species-specific PCR was performed using invA primers, and Salmonella sp. identification was verified by observing a 284 base-pair (bp) PCR amplicon. Subsequently, serogrouping was done by multiplex-PCR (mPCR), which could identify the O:B (O:4), O:C1 (O:7), O:C2-C3 (O:8), O:D (O:9, O:9,46, O:9,46,27), and O:E (O:3,10, O:3,19) somatic antigens. It was detected that the mucoid Salmonella sp. formed a band of approximately 615 bp in size and took place in group D. Another mPCR directed towards O:D1(O:9) and O:E1(3,10) somatic antigens to detect subgroups of group D mucoid Salmonella spp., revealed that the isolate formed a DNA band of approximately 624 bp in size and took place in group D1 which is usually isolated from human. Modified version of another mPCR was used to determine phase-1 flagellar antigen of common Salmonella serovars, as well as to determine the phase-1 flagellar antigen of mucoid Salmonella spp. in group D1. Thus, the isolate was serotyped as Salmonella Enteritidis (1.9,12:g,m:-). Antibiotic susceptibility test performed by disc diffusion method in line with the recommendations of CLSI, revealed that the isolate was susceptible to ampicillin, ciprofloxacin, ceftriaxone, trimethoprim-sulfamethoxazole and chloramphenicol. In conclusion, PCR is a reliable and rapid alternative method that contributes to the conventional serotyping of Salmonella when rough or mucoid strains that lack somatic and flagellar antigens, are isolated. PMID:24506726
Bay?nd?r Bilman, Fulya; Günayd?n, Elçin; Turhano?lu, Mine; Akkoç, Ali
Salmonella typhimurium possesses two outer membrane receptor proteins, IroN and FepA, which have been implicated in the uptake of enterobactin. To determine whether both receptors have identical substrate specificities, fepA and iroN mutants and a double mutant were characterized. While both receptors transported enterobactin, the uptake of corynebactin and myxochelin C was selectively mediated by IroN and FepA, respectively.
Rabsch, Wolfgang; Voigt, Wolfgang; Reissbrodt, Rolf; Tsolis, Rene?e M.; Ba?umler, Andreas J.
Salmonella enterica subsp. enterica serovar Enteritidis is a major causative agent of gastroenteritis with contaminated eggs and chicken meat being the major source of infection. Phages are seriously being considered as a safe and cheaper alternative to antibiotics. The intestinal content of chicken was used as source for isolating phages. Phage designated as ?SP-1 was selected for the study. Transmission electron microscopy (TEM) of phage ?SP-1 revealed that it belonged to family Podoviridae. The optimal multiplicity of infection (MOI) was 5 phages/cell. Latent and rise period were calculated to be 30 and 55 minutes respectively, while burst size was 44 phages/bacterial cell. The genome size of ?SP-1 was estimated to be 86?kb from pulsed-field gel electrophoresis analysis (PFGE). The effect of different physical and chemical parameters like temperature, pH, salinity and CaCl? were analyzed to optimize the conditions for large scale production of phages and to check the viability of ?SP-1 under different physiochemical conditions. A temperature of 40?°C, pH 8 and 0.25?M NaCl were found to be optimum for phage adsorption and it was able to survive up to a temperature of 50?°C for 3?min. Capability to survive under hostile environmental conditions, absence of virulence genes in genome and genus specificity suggest suitability of ?SP-1 to be used as a biocontrol agent. PMID:22733367
Augustine, Jeena; Louis, Linda; Varghese, Siju M; Bhat, Sarita G; Kishore, Archana
Essential oils (EO) and short-chain fatty acids have potential antimicrobial activity in broilers. This study aimed to investigate the effect of a specific blend of EO and a combination of this blend of EO with sodium-butyrate on growth performance and Salmonella colonization in broilers. A total of 480 one-day-old male broilers were distributed into 5 treatments (8 pens per treatment and 12 birds per pen) and reared during 42 d in experimental conditions. Dietary treatments consisted of the addition of different doses of EO (0 mg/kg, control; 50 mg/kg, EO50 and 100 mg/kg, EO100) or a combination of EO with 1 g/kg of sodium-butyrate (B; EO50 + B, EOB50 and EO100 + B, EOB100) to a basal diet. All birds were orally infected with 10(8) cfu of Salmonella Enteritidis on d 7 of study. Individual BW and feed intake per pen were measured at arrival and on a weekly basis. The prevalence and enumeration of Salmonella in feces was determined per treatment at 72 h postinfection and on d 23 and 37 of study. At slaughter, cecal content and liver samples from 16 birds per treatment were cultured for Salmonella and cecal pH was measured. No differences were observed on growth performance among treatments. All fecal samples analyzed were positive for Salmonella from d 10 to the end of the rearing period. At slaughter, Salmonella contamination (positive samples) in cecum was lower in birds fed EOB50 compared with the other treatments (P < 0.05), whereas birds fed the control diet showed the highest colonization rates. The pH of the cecal content was not different among treatments. Thus, EO or its combination with sodium-butyrate did not affect growth performance. However, a clear effectiveness of these products was observed in Salmonella control, especially when low doses of EO were combined with sodium-butyrate (EOB50). PMID:24604853
Cerisuelo, A; Marín, C; Sánchez-Vizcaíno, F; Gómez, E A; de la Fuente, J M; Durán, R; Fernández, C
One of the most common causes of salmonellosis of man and poultry is Salmonella Enteritidis which is often found in the digestive system of adult birds. The infected birds do not display any evident clinical symptoms and, at the same time, they excrete the bacteria into the surrounding environment. Studies are carried out by standard microbiological procedures which include the isolation of Salmonella spp. in egg yolks and their serologic typization by aggl...
Radoji?i? Marina; Mili? N.; Nišavi? J.; Markovi? Maja
Peripheral blood lymphocytes collected from calves infected experimentally with Salmonella typhimurium (O antigens 4,5,12) or Salmonella sp. serotype dublin (O 9,12) were stimulated with various bacterial cell envelope components, and their [3H]thymidine incorporation was measured. It was found that peripheral blood lymphocytes from infected calves incorporated significantly more [3H]thymidine than peripheral blood lymphocytes from uninfected controls (P values ranged from less than 0.05 to l...
Robertsson, J. A.; Fossum, C.; Svenson, S. B.; Lindberg, A. A.
Full Text Available The administration of increased doses of antibodies in groups experimentallyinfected with Salmonella gallinarum, in order to record the efficiency of theiradministration in salmonellosis prophylaxis was the aim of our research. When alow infection dose, 1x107 CFU Salmonella gallinarum, was used theadministration of IgY polyclonal antibodies as immunoglobulin extract, or evenyolk administration had a protective effect against germs invasion. This effect wasnot recorded when a 10 folds higher dose was administered (1x108 CFU. Theprophylactic effect of the administration of polyclonal antibodies is demonstrated.
Full Text Available SciELO Brazil | Language: English 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 differe [...] nt 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
IT, Tayeb; P, Nehme; L, Jaber; EK, Barbour.
The Salmonella species Typhimurium and Enteritidis form the most important causes of food poisoning. Immunity to Salmonellae requires innate and specific immune responses. Reported here are the genetic polymorphisms in the genes of Nramp1, Toll-like receptors and CD14 related to the innate immune response to Salmonellae. Salmonella species are typically associated with the intra-cellular pathogens capable of surviving and replicating intra-cellularly in the phagocyte. Co...
Jgc, Amsterdam; Wh, Jong; de Jonge R; Hoebee B
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 presence of viable Salmonella spp.
Bej, A. K.; Mahbubani, M. H.; Boyce, M. J.; Atlas, R. M.
Genes of Salmonella enterica serovar Typhimurium LT2 expected to be specifically present in Salmonella were selected using the Basic Local Alignment Search Tool (BLAST) program. The 152 selected genes were compared with 11 genomic sequences of Salmonella serovars, including Salmonella enterica subsp. I and IIIb and Salmonella bongori (V), and were clustered into 17 groups by their comparison patterns. A total of 38 primer pairs were constructed to represent each of the 17 groups, and PCR was ...
Kim, Hyun-joong; Park, Si-hong; Kim, Hae-yeong
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. PMID:23320420
Li, Liang; Yang, Yu-Rong; Liao, Xiao-Ping; Lei, Chun-Yin; Sun, Jian; Li, Lu-Lu; Liu, Bao-Tao; Yang, Shou-Shen; Liu, Ya-Hong
Background: Typhoid fever is still one of the serious public health problems in many geographic areas and is endemic in most countries. Aim of current study was to evaluate a shortened time –Multiplex PCR for rapid detection of different Sal¬monella enterica serovars. Methods: The PCR primers for three target genes tyv, prt and invA were subjected for amplification by PCR. By using sim¬ple DNA extraction method, rapid PCR cycles and rapid electrophoresis procedure with simple and very che...
Karami, A.; Ranjbar, R.; Ahmadi, Z.; Safiri, Z.
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 tel 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)
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 toxic for bacteria. A SL3261 strain expressing the B subunit of cholera toxin by a similar system (SL3261-CtxB) served as a control in FIV-immunization experiments. Cats immunized once orally or intr...
Tijhaar, E. J.; Siebelink, C. H. J.; Karlas, J. A.; Burger, M. C.; Mooi, F. R.; Osterhaus, A. D. M. E.
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 ...
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.
Full Text Available SciELO Brazil | Language: English 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 d [...] e 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. 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. Necrops [...] y 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.
Terezinha, Knöbl; Leliane T., Rocha; Márcia C., Menão; Cláudia A.S., Igayara; Renata, Paixão; Andréa M., Moreno.
To reduce human exposure to Salmonella spp. in poultry products, broiler chicken flocks have been tested by culture methods. Since the standard techniques may take 3 to 5 days, rapid detection methods have been developed. In this study we tested the performance of three rapid tests originally developed for food samples by using environmental samples obtained from poultry houses. These rapid tests were Reveal, an enzyme-linked immunosorbent assay from Neogen Corp.; BIND, a bacterial ice nucleation detection method from Idetek Corp.; and a filter monitor method from Future Medical Technologies, Inc. For the standard culture, brilliant green with novabiocin and xylose–lysine–tergitol-4 agar were used for presumptive identification, and identities were confirmed by using poly-O antisera. Environmental samples were collected from farms belonging to an integrated poultry company prior to chick placement and 1 week before slaughter. Sensitivities, specificities, and predictive values with 95% confidence intervals were calculated. Statistical differences were determined by using McNemar’s chi square test. The sensitivities of the different tests were not stable, varying widely between sample times, and were affected by freezing of the samples. All of the rapid tests had low sensitivities, which led to many false-negative results. All tests were able to detect Salmonella spp. at a concentration of 10 CFU/ml in at least one of four trials. The BIND and Reveal tests were simple to use with multiple samples and reduced laboratory time by up to 1 day. Based on our results, we do not recommend that any of these rapid tests, in their present state of development, be utilized with environmental samples collected with drag swabs. PMID:10049863
Peplow, Melissa O.; Correa-Prisant, Maria; Stebbins, Martha E.; Jones, Frank; Davies, Peter
Rabbit polyclonal antibodies against the lipopolysaccharide (LPS) of the Rd1P- mutant strain R7 of Salmonella minnesota were serologically characterized using R7 LPS, dephosphorylated LPS, deacylated LPS, deacylated, dephosphorylated and reduced LPS, and synthetic partial structures. The latter comprised partial structures of the core region of Rd1P- LPS bound to the beta 1-->6-linked glucosamine dissacharide with two amide-linked 3-hydroxytetradecanoic acid residues or artificial glycoconjugates comprised of the synthetic oligosaccharides coupled to bovine serum albumin. Using a passive hemolysis and an enzyme immunoassay, absorption and inhibition experiments, the antibody specificites present could be determined. One group of antibodies required components of the core region and the phosphorylated glucosamine disaccharide of the lipid A moiety for binding. The majority of phosphate-independent antibodies was directed against the trisaccharide L-glycero-alpha-D-manno-heptopyranose(1-->3)- L-glycero-alpha-D-manno-heptopyranose(1-->5)3-deoxy-D-manno-oct ulo sonic acid. Antibodies against the 1-->3- and 1-->7-linked heptose disaccharides and against a single heptose were also detected, however, with low titers. No antibodies were found which required the presence of fatty acids. PMID:8275057
Swierzko, A; Brade, L; Höffgen, E C; Brade, H
Full Text Available This study explores the possibility of simultaneous and specific detection ofSalmonella serovars by surface plasmon resonance (SPR. The PlasmonicÃ‚Â® SPR device wasused to develop this rapid assay. The sandwich immunoassay involves the use of apolyclonal anti-Salmonella antibody to simultaneous capture multiple Salmonella serovarspresent in a sample. This is followed by specific detection of the captured serovars usingO-specific anti-Salmonella antibodies. Milk spiked with Salmonella Typhimurium andSalmonella Enteritidis was used as a model system to establish the assay. The assay wasfurther extended to sequentially differentiate between the two Salmonella serovars on asingle SPR chip in a single channel. The assay was proved to work without any additionaldilution or clean-up steps. The sample volume requirement for the assay is only 10 ÃŽÂ¼L. Thelower limits of detection for Salmonella Typhimurium and Salmonella Enteritidis were2.50ÃƒÂ—105 cells mL-1 and 2.50ÃƒÂ—108 cells mL-1, respectively.
Salmonella enterica isolates representing commonly isolated serotypes in Tunisia were analyzed using genotyping and phenotyping methods. ERIC and ITS-PCR applied to 48 Salmonella spp. isolates revealed the presence of 12 and 10 different profiles, respectively. The distribution of profiles among serotypes demonstrated the presence of strains showing an identical fingerprinting pattern. All Salmonella strains used in this study were positive for the sdiA gene. Three Salmonella isolates belonging to serotypes Anatum, Enteritidis and Amsterdam were negative for the invA gene. The spvC gene was detected in thirteen isolates belonging to serotypes Anatum, Typhimurium, Enteritidis, Gallinarum and Montevideo. Antibiotic resistance was frequent among the recovered Salmonella isolates belonging to serotypes Anatum, Typhimurium, Enteritidis, Zanzibar and Derby. The majority of these isolates exhibited resistance to at least two antibiotic families. Four multidrug-resistant isolates were recovered from food animals and poultry products. These isolates exhibited not only resistance to tetracycline, sulphonamides, and ampicillin, but also have shown resistance to fluoroquinolones. Common resistance to nalidixic acid, ciprofloxacin and ofloxacin in two S. Anatum and S. Zanzibar strains isolated from raw meat and poultry was also obtained. Furthermore, wastewater and human isolates exhibited frequent resistance to nalidixic acid and tetracycline. Of all isolates, 33.5% were able to form biofilm. PMID:25273985
Turki, Yousra; Mehr, Ines; Ouzari, Hadda; Khessairi, Amel; Hassen, Abdennaceur
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; )
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In this study, 13% of fresh lettuce (Lactuca sativa) samples collected from markets and supermarkets in two cities of Mexico were contaminated with Salmonella spp. From those samples, amplicons of ?300 base pairs (bp) were amplified, corresponding to the expected size of the invasion (invA) and internal transcribed spacer regions of the 16S and 23S rRNA genes of Salmonella spp. Additionally, Salmonella strains were isolated and harbored plasmids ranging from ?9 to 16 kbp. From these strains, 91% were resistant to ampicillin and nitrofurantoin, whereas 55% were resistant to cephalothin and chloramphenicol. No resistance was detected to amikacin, carbenicillin, cefotaxime, gentamicin, netilmicin, norfloxacin, and sulfamethoxazole-trimethoprim. When Salmonella isolates were tested against novel bacteriocins (morricin 269, kurstacin 287, kenyacin 404, entomocin 420, and tolworthcin 524) produced by five Mexican strains of Bacillus thuringiensis, 50% were susceptible to these antimicrobial peptides. This is the first report showing that Salmonella strains isolated from lettuce are susceptible to bacteriocins produced by the most important bioinsecticide worldwide, suggesting the potential use of these antibacterial peptides as therapeutic agents or food preservatives to reduce or destroy populations of Salmonella spp. PMID:21333148
Castañeda-Ramírez, Cristobal; Cortes-Rodríguez, Viridiana; de la Fuente-Salcido, Norma; Bideshi, Dennis K; del Rincón-Castro, M Cristina; Barboza-Corona, J Eleazar
Salmonella enterica serovar Typhimurium employs two different type III secretion systems (TTSS) encoded within Salmonella pathogenicity islands 1 and 2 (SPI1 and SPI2) for targeting of effector proteins into the cytosol of eukaryotic cells during different stages of the infection cycle. The SPI1 TTSS translocates virulence factors across the plasma membrane when the bacterium initially contacts the host cell. In contrast, the SPI2 TTSS functions to translocate proteins across the membrane of ...
Panthel, Klaus; Meinel, Katrin M.; Dome?nech, Victo?ria E. Sevil; Retzbach, Heike; Igwe, Emeka I.; Hardt, Wolf-dietrich; Ru?ssmann, Holger
Full Text Available In this study, 47 antibiotic-resistant strains of Salmonella enterica subspecies enterica serovar Typhimurium (ST were characterised, including 15 monophasic variants 1, 4, , 12:i:-, (STm isolated from different matrices. They were all selected from 389 Salmonella enterica subspecies enterica strains isolated during 2008-2010 in Abruzzo region (Italy. Thirty-seven strains showed to be resistant to more than 1 antibiotic. Among 47 isolates, phage type U311 and DT104 were identified. The ASSuT resistance pattern was predominant in mST strains and ACSSuT in ST DT104 and U302. A multiplex Polimerase Chain Reaction (PCR method was used to investigate 4 genes: fluorfenicol (floSt, virulence (spvC, invasine (invA and integrase (int. All ST the strain were positive for invA gene and 28,32% of strains were positive for spvC gene. PFGE analysis revealed a large number of small clonal populations, however not ascrivable to outbreaks.
In this study, 47 antibiotic-resistant strains of Salmonella enterica subspecies enterica serovar Typhimurium (ST) were characterised, including 15 monophasic variants 1, 4, , 12:i:-, (STm) isolated from different matrices. They were all selected from 389 Salmonella enterica subspecies enterica strains isolated during 2008-2010 in Abruzzo region (Italy). Thirty-seven strains showed to be resistant to more than 1 antibiotic. Among 47 isolates, phage type U311 and DT104 were identified. The ASSuT resistance pattern was predominant in mST strains and ACSSuT in ST DT104 and U302. A multiplex Polimerase Chain Reaction (PCR) method was used to investigate 4 genes: fluorfenicol (floSt), virulence (spvC), invasine (invA) and integrase (int). All ST the strain were positive for invA gene and 28,32% of strains were positive for spvC gene. PFGE analysis revealed a large number of small clonal populations, however not ascrivable to outbreaks. PMID:24715591
Alessiani, Alessandra; Sacchini, Lorena; Pontieri, Eugenio; Gavini, Jacopo; Di Giannatale, Elisabetta
Full Text Available Abstract Background Recombinant Salmonella vaccine vectors may potentially be used to induce specific CD4+ T cell responses against foreign viral antigens. Such immune responses are required features of vaccines against pathogens such as human immunodeficiency virus type 1 (HIV-1. The aim of this study was to investigate the induction of systemic HIV-1-specific CD4+ T helper (Th responses in mice after oral immunization with a live attenuated Salmonella vaccine vector that expressed HIV-1 subtype C Gag. Groups of BALB/c mice were vaccinated orally three times (4 weeks apart with this recombinant Salmonella. At sacrifice, 28 days after the last immunization, systemic CD4+ Th1 and Th2 cytokine responses were evaluated by enzyme-linked immunospot assay and cytometric bead array. HIV-1 Gag-specific IgG1 and IgG2a humoral responses in the serum were determined by enzyme-linked immunosorbent assay. Results Mice vaccinated with the recombinant Salmonella elicited both HIV-1-specific Th1 (interferon-gamma (IFN-? and tumour necrosis factor-alpha (TNF-? and Th2 (interleukin-4 (IL-4 and interleukin-5 (IL-5 cytokine responses. The vaccine induced 70 (IFN-? spot-forming units (SFUs/10e6 splenocytes and 238 IL-4 SFUs/10e6 splenocytes. Splenocytes from vaccinated mice also produced high levels of Th1 and Th2 cytokines upon stimulation with a Gag CD4 peptide. The levels of IFN-?, TNF-?, IL-4 and IL-5 were 7.5-, 29.1-, 26.2- and 89.3-fold above the background, respectively. Both HIV-1 Gag-specific IgG1 and IgG2a antibodies were detected in the sera of vaccinated mice. Conclusion The study highlights the potential of orally-delivered attenuated Salmonella as mucosal vaccine vectors for HIV-1 Subtype C Gag to induce Gag-specific CD4+ Th1 and Th2 cellular immune responses and antibodies which may be important characteristics required for protection against HIV-1 infection.
Application of a dipstick assay for the detection of Salmonella typhi-specific IgM antibodies on samples collected from S. typhi or S. paratyphi culture-positive patients at the day of admission to the hospital revealed the presence of specific IgM antibodies in 43.5%, 92.9%, and 100% for samples collected 4-6 days, 6-9 days, and > 9 days after the onset of fever, respectively. The mean sensitivity for samples collected an average of 6.6 days after the onset of fever was 65.3%. Culture was positive in 65.9% of the cases with a final clinical diagnosis of typhoid fever. Testing of paired serum samples from culture negative patients with a final clinical diagnosis of typhoid fever resulted in staining of the dipstick in 4.3% of the samples collected at the day of admission to the hospital and in 76.6% of the samples collected one week later, thereby provided strong supporting evidence of typhoid fever by demonstrating seroconversion in a large proportion of the patients. The dipstick assay may thus also be useful for the serodiagnosis of culture-negative patients with clinical signs and symptoms consistent with typhoid fever. The advantages of the dipstick assay are that the result can be obtained on the same day allowing a prompt treatment, that only a small volume of serum is needed, and that no special laboratory equipment is needed to perform the assay. The stability of the reagents of the dipstick and the simplicity of the assay allows its use in places that lack laboratory facilities. PMID:12164298
Hatta, Mochammad; Goris, Marga G A; Heerkens, Evy; Gooskens, Jairo; Smits, Henk L
Contamination of lettuce by Salmonella has caused serious public health problems. Polymerase chain reaction (PCR) allows rapid detection of pathogenic bacteria in food, but it is inaccurate as it might amplify DNA from dead target cells as well. This study aimed to investigate the stability of DNA of dead Salmonella cells in lettuce and to develop an approach to detecting viable Salmonella in lettuce. Salmonella-free lettuce was inoculated with heat-killed Salmonella Typhimurium cells and stored at 4 °C. Bacterial DNA extracted from the sample was amplified by real-time PCR targeting the invA gene. Our results indicate that DNA from the dead cells remained stable in lettuce for at least 8 d. To overcome this limitation, propidium monoazide (PMA), a dye that can selectively penetrate dead bacterial cells and cross-link their DNA upon light exposure, was combined with real-time PCR. Lettuce samples inoculated with different levels of dead or viable S. Typhimurium cells were treated or untreated with PMA before DNA extraction. Real-time PCR suggests that PMA treatment effectively prevented PCR amplification from as high as 10(8) CFU/g dead S. Typhimurium cells in lettuce. The PMA real-time PCR assay could detect viable Salmonella at as low as 10(2) CFU/mL in pure culture and 10(3) CFU/g in lettuce. With 12-h enrichment, S. Typhimurium of 10(1) CFU/g in lettuce was detectable. In conclusion, the PMA real-time PCR assay provides an alternative to real-time PCR assay for accurate detection of Salmonella in food. PMID:22417362
Liang, Ningjian; Dong, Jin; Luo, Laixin; Li, Yong
Salmonella is among the most important food borne pathogens worldwide contaminating a wide range of animal products including meat products. Human illnesses due to this pathogen are attributed to poor biosecurity in production, improper processing and handling of meat and meat products. This is more likely where surveillance and regulatory control is weak. There is however limited information on the occurrence of these pathogens in foods in Nigeria. The extent of contamination of retail-beef and related meat products with Salmonellae in Zaria was evaluated. A total of 435 retailed beef and related meat products consisting of muscle meat, offal and processed meat products were tested for the presence of Salmonella species. Sample types included raw meat, ‘suya’ (roasted meat), ‘balangu’ (barbequed meat), ‘Kilishi’ (spiced sun dried meat) and ‘dambu’ (shredded fried meat). Samples were derived from four major markets and Zango abattoir in Zaria, Nigeria and cultured using selective isolation method with prior enrichment. Suspected isolates were identified and characterised using conventional biochemical methods and Microbact 12E (Oxoid, UK) identification kit. The isolates were serotyped. Confirmed isolates were evaluated in vitro for susceptibilities to 18 commonly used antimicrobial agents. Ten samples (2.3%) were positive for Salmonella. Raw beef samples had the highest isolation rates (2.43%). All the 10 Salmonella isolates were found to carry the invA gene. All the isolates exhibited multiple drug resistance. Simultaneous resistance to up to 8 antibiotics was found amongst the Salmonellae. The isolates exhibited more commonly resistance to members of ?-lactam family and other antibiotic classes including lincosamides, macrolides, aminoglycosides and nitrofurans. Meat and meat products including ready-to-eat meat in Zaria were contaminated with multidrug and virulent Salmonella species. Meat and meat products in Nigeria are thus a hazardous group of foods that can potentially transmit this pathogen to humans.
Tafida, S.Y.; Kabir, J.
Full Text Available Estudos que elucidem a cadeia de transmissão de Salmonella enterica nos sistemas de produção de suínos são importantes para que seja possível implementar programas de controle da infecção. O objetivo deste estudo foi comparar o índice de animais positivos para Salmonella sp. no início da fase de terminação e ao abate e identificar possíveis fontes de contaminação no período. Em três granjas terminadoras, coletaram-se: suabes de superfície nas baias e nos silos durante o vazio sanitário; amostras de fezes e sangue dos animais no dia do alojamento; alíquotas de todos os lotes de ração e amostras de sangue, linfonodos mesentéricos (LM e conteúdo intestinal (CI ao abate. As amostras de sangue foram submetidas a teste de ELISA-LPS para Salmonella Typhimurium. Nas demais amostras, pesquisou-se a presença de Salmonella sp. As amostras de ração foram adicionalmente submetidas à técnica da Reação em Cadeia da Polimerase (PCR amplificando o gene invA. Todos os animais foram negativos para presença de Salmonella sp. nas fezes no início da terminação; entretanto, em duas granjas havia animais soropositivos (12% e 28%, respectivamente. Em duas granjas havia contaminação residual no ambiente e na terceira granja, em um dos lotes de ração, detectou-se a presença de Salmonella sp. pela PCR. Ao abate, acima de 90% dos animais foram positivos no teste de ELISA-LPS, sendo que em todos os lotes encontrou-se um número variável (12-92% de portadores em LM e CI. A partir disso, concluiu-se que a terminação foi a fase crítica para a amplificação da infecção por Salmonella sp., sendo a presença residual do microrganismo na granja e o fornecimento de ração contaminada fontes prováveis de infecção.
PALAVRAS-CHAVES: Abate, isolamento, Salmonella, sorologia, suíno, terminação.
Studies assessing the Salmonella transmission chain in pig herds are the first step to start a control program. The aims of this study were to compare the prevalence of Salmonella positive pigs at the beginning of the finishing phase and at slaughter, and to identify the possible sources of contamination in the farms. In three finishing farms, environmental swabs from the barns and from the feed silos were collected during the sanitary emptiness. Furthermore, samples of feces and blood from the animals on the day of housing; and aliquots from all feed lots were taken. At slaughter, blood, mesenteric lymph nodes (LM and intestinal content (CI were sampled. Blood samples were submitted to a S. Typhimurium ELISA-LPS test. All other samples were submitted to a Salmonella isolation protocol. Feed samples were also submitted to Polymerase Chain Reaction (PCR targeting the invA gene. Feces samples from all pigs were Salmonella negative at the beginning of the finishing phase, in two farms seropositive animals were found. In two farms, residual environmental contamination was detected, and, in the third farm, one of the feed batches was Salmonella positive on the PCR assay. At slaughter, over 90% of the animals were positive on the ELISA-LPS test and, in all cohorts, a variable number (12%-92% of carriers in LM and CI was detected. From this on, it was concluded that the finishing phase was critical for the amplification of Salmonella infection, and the residual environmental contamination in the farms as well as Salmonella positive feed batches were the probable infection sources.
KEY WORDS: Isolation, finishing and slaughter, Salmonella, serology, swine.
Salmonella telaviv, Salmonella tranoroa, and Salmonella illinois were examined for their ability to interact with 15 purified lectins of known sugar specificity. The only interaction observed was between the lectin of Maclura pomifera and S. telaviv. M. pomifera lectin specifically agglutinated suspensions of S. telaviv and precipitated with its purified lipopolysaccharide and isolated lipid A free O polysaccharide. Quantitative inhibition assays showing methyl-alpha-D-galactopyranoside and N...
Allen, P. Z.
Specificity of replicative and SOS-inducible DNA polymerases in frameshift mutagenesis: mutability of Salmonella typhimurium strains overexpressing SOS-inducible DNA polymerases to 30 chemical mutagens.
DNA replication is frequently hindered because of the presence of DNA lesions induced by endogenous and exogenous genotoxic agents. To circumvent the replication block, cells are endowed with multiple specialized DNA polymerases that can bypass a variety of DNA damage. To better understand the specificity of specialized DNA polymerases to bypass lesions, we have constructed a set of derivatives of Salmonella typhimurium TA1538 harboring plasmids carrying the polB, dinB or mucAB genes encoding Escherichia coli DNA polymerase II, DNA polymerase IV or DNA polymerase RI, respectively, and examined the mutability to 30 chemicals. The parent strain TA1538 possesses CGCGCGCG hotspot sequence for -2 frameshift. Interestingly, the chemicals could be classified into four groups based on the mutagenicity to the derivatives: group I whose mutagenicity was highest in strain YG5161 harboring plasmid carrying dinB; group II whose mutagenicity was almost equally high in strain YG5161 and strain TA98 harboring plasmid carrying mucAB; group III whose mutagenicity was highest in strain TA98; group IV whose mutagenicity was not affected by the introduction of any of the plasmids. Introduction of plasmid carrying polB did not enhance the mutagenicity except for benz[a]anthracene. We also introduced a plasmid carrying polA encoding E. coli DNA polymerase I to strain TA1538. Strikingly, the introduction of the plasmid reduced the mutagenicity of chemicals belonging to groups I, II and III, but not the chemicals of group IV, to the levels observed in the derivative whose SOS-inducible DNA polymerases were all deleted. These results suggest that (i) DNA polymerase IV and DNA polymerase RI possess distinct but partly overlapping specificity to bypass lesions leading to -2 frameshift, (ii) the replicative DNA polymerase, i.e., DNA polymerase III, participates in the mutagenesis and (iii) the enhanced expression of E. coli polA may suppress the access of Y-family DNA polymerases to the replication complex. PMID:16455311
Matsui, Keiko; Yamada, Masami; Imai, Masaru; Yamamoto, Kazuo; Nohmi, Takehiko
Salmonella enterica is one of the most common zoonotic pathogens worldwide causing clinical diseases in human and animal hosts. Targeting a reduction of Salmonella prevalence in poultry, the EU set up a microbiological criterion that demands the absence of S. enterica subsp. enterica serovars Enteritidis and Typhimurium including its monophasic variant with seroformula 4,,12:i:- in 25g of poultry neck skin samples and fresh meat according to regulation (EU) no 1086/2011. We developed and in-house validated a method that detects and differentiates these Salmonella serovars based on a 5-plex real-time PCR assay within 24h after sampling. The inclusivity and exclusivity were between 98 and 99% analysing 456 bacterial strains. Validation according to ISO 16140:2003 against the traditional cultural reference method ISO 6579:2002 was performed using 60 artificially contaminated and 31 presumably naturally contaminated chicken neck skin samples resulting in a relative accuracy of 100%. The detection probability reached 100% between 3 and 5CFU/25g sample. We were also able to assign rough and non-motile strains to S. enterica subsp. enterica serovars Enteritidis and Typhimurium. In conclusion, we provide diagnostic laboratories a fast and accurate method to monitor these Salmonella serovars in chicken neck skin samples. Other matrices could be easily adapted. PMID:25462917
Maurischat, Sven; Baumann, Beatrice; Martin, Annett; Malorny, Burkhard
Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A diversificação da produção industrial de alimentos de origem suína e o intercâmbio comercial de animais e seus derivados destinados ao consumo humano podem ser importantes disseminadores de sorovares de Salmonella spp. na cadeia alimentar. Objetivou-se avaliar em 86 cepas de Salmonella spp., isola [...] das em granja de terminação e no abate de suínos, a ocorrência de três genes de virulência (invA, agfA e lpfA), bem como a similaridade genética entre elas. A ocorrência do gene invA foi verificada em 100% das amostras. O gene lpfA foi detectado em 80,23% (69/86) das cepas, não foi detectado em S. Panama e estava presente em todas as cepas de S. Infantis. O gene agfA foi detectado em 63,95% (55/86) das amostras. S. Agona apresentou positividade para todos os genes de virulência estudados. A análise de homologia entre as cepas agrupou os diferentes sorovares em clusters. A similaridade foi independente do local de isolamento, o que demonstra a presença de clones ao longo da cadeia de produção e a existência de multiplicidade de fontes para a infecção dos animais, como a ração, e a contaminação cruzada das carcaças. A pesquisa de genes de virulência e a avaliação da proximidade gênica permitem a caracterização e um maior entendimento sobre cepas de Salmonella circulantes na cadeia produtiva de suínos e, assim, podem subsidiar medidas de controle durante o processo produtivo com o objetivo de garantir a saúde do consumidor. Abstract in english The diversification of industrial food production of swine origin and trade of animals and their derivatives for human consumption may be important disseminators of serovars of Salmonella spp. in the food chain. This study aimed to evaluate 86 strains of Salmonella spp. isolated form in the finishin [...] g and slaughter of pigs, the occurrence of three virulence genes (invA, agfa and lpfA), as well as the genetic similarity between them. The occurrence of gene invA was observed in 100% of the samples. The gene lpfA was detected in 80.23% (69/86) strains and is not detected in S. Panama, but present in all strains of S. Infantis. The gene agfA was detected in 63.95% (55/86). S. Agona was positive for all virulence genes studied. The analysis of homology between the different serovars grouped the isolates in clusters. The similarity was regardless of the location of isolation, demonstrating the presence of clones along the production chain and that there are multiple sources for the infection of animals, such as feed, and cross-contamination of carcasses. A survey of virulence genes and evaluation of gene proximity allow characterization and better understanding of Salmonella strains circulating in the pig production chain, thus being able to support control measures during the production process in order to ensure consumer health.
M.S., Moura; R.P., Oliveira; R.T., Melo; E.P., Mendonça; B.B., Fonseca; D.A., Rossi.
Salmonella enterica serovar Typhimurium is one of the most common serovars isolated from humans and livestock, and over 35% of these isolates are resistant to three or more antibiotics. Multidrug-resistant (MDR) Salmonella is a public health concern as it is associated with increased morbidity in patients compared to antibiotic sensitive strains, though it is unknown how the antibiotic resistant isolates lead to a more severe infection. Cellular invasion is temporally regulated in Salmonella and normally occurs during late-log and stationary growth. However, our previous work determined that a 30 min exposure to a sub-inhibitory concentration of tetracycline can induce the full invasion phenotype during early-log growth in certain MDR S. Typhimurium isolates. The current study examined whether sub-inhibitory concentrations of other antibiotics could also induce the invasiveness in the same set of isolates. Ampicillin and streptomycin had no effect on invasion, but certain concentrations of chloramphenicol were found to induce invasion in a subset of isolates. Two of the isolates induced by chloramphenicol were also inducible by tetracycline. RNA-seq analyses demonstrated that chloramphenicol and tetracycline both down-regulated motility gene expression, while up-regulating genes associated with attachment, invasion, and intracellular survival. Eleven fimbrial operons were up-regulated, which is notable as only three fimbrial operons were thought to be inducible in culture; six of these up-regulated operons have been reported to play a role in Salmonella persistence in mice. Overall, these data show that the normal progression of the genetic pathways that regulate invasion can be expedited to occur within 30 min due to antibiotic exposure. This altered invasion process due to antibiotics may play a role in the increased intensity and duration of infection observed in patients with MDR Salmonella.
Brunelle, Brian W.; Bearson, Bradley L.; Bearson, Shawn M. D.
One hundred chicken carcasses purchased from three markets selling poultry in Ouagadougou, Burkina Faso, between June 2010 and October 2010 were examined for their microbiological quality. The presence of Salmonella was investigated using standard bacteriological procedures, and the isolates obtained were serotyped and tested for antimicrobial susceptibility. The presence of virulence-associated genes of the five main pathogroups of diarrheagenic Escherichia coli-Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli, and enteroinvasive E. coli-was investigated using 16-plex polymerase chain reaction (PCR) on the mixed bacterial cultures from the poultry samples. Of the 100 chicken carcasses studied, 57 were contaminated by Salmonella; 16 different serotypes were identified, the most frequent being Salmonella Derby, found in 28 samples. Four Salmonella strains were resistant to tetracycline, and two were resistant to streptomycin. Based on the PCR detection of the virulence genes, in total, 45 carcasses were contaminated by three pathogroups of E. coli: STEC, EPEC, or EAEC. The STEC and EPEC virulence genes were detected on six and 39 carcasses, respectively. EAEC virulence genes were only detected in combination with those of EPEC (on 11 carcasses) or STEC (on two carcasses). The STEC-positive carcasses contained the genes stx(1), stx(2), eaeA, escV, and ent in different combinations. None of the EPEC-positive carcasses contained the bfp gene, indicating that only atypical EPEC was present. EAEC virulence genes detected were aggR and/or pic. The high proportion of chicken carcasses contaminated by Salmonella and diarrheagenic E. coli indicates a potential food safety risk for consumers and highlights the necessity of public awareness of these pathogens. PMID:22551070
Kagambèga, Assèta; Barro, Nicolas; Traoré, Alfred S; Siitonen, Anja; Haukka, Kaisa
... Lessons? Visit KidsHealth in the Classroom What Other Parents Are Reading Keeping Portions Under Control Recipe: Fruity ... Expect Ebola: What to Know Salmonella Infections KidsHealth > Parents > Infections > Stomach & Intestinal Infections > Salmonella Infections Print A ...
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
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. PMID:20338699
Dahshan, Hesham; Shahada, Francis; Chuma, Takehisa; Moriki, Hiraku; Okamoto, Karoku
The objective was to improve efficacy of antisense phosphorodiamidate morpholino oligomers (PMOs) by improving their uptake into bacterial cells. Four different bacterium-permeating peptides, RFFRFFRFFXB, RTRTRFLRRTXB, RXXRXXRXXB, and KFFKFFKFFKXB (X is 6-aminohexanoic acid and B is beta-alanine), were separately coupled to two different PMOs that are complementary to regions near the start codons of a luciferase reporter gene (luc) and a gene required for viability (acpP). Luc peptide-PMOs targeted to luc inhibited luciferase activity 23 to 80% in growing cultures of Escherichia coli. In cell-free translation reactions, Luc RTRTRFLRRTXB-PMO inhibited luciferase synthesis significantly more than the other Luc peptide-PMOs or the Luc PMO not coupled to peptide. AcpP peptide-PMOs targeted to acpP inhibited growth of E. coli or Salmonella enterica serovar Typhimurium to various extents, depending on the strain. The concentrations of AcpP RFFRFFRFFXB-PMO, AcpP RTRTRFLRRTXB-PMO, AcpP KFFKFFKFFKXB-PMO, and ampicillin that reduced CFU/ml by 50% after 8 h of growth (50% inhibitory concentration [IC(50)]) were 3.6, 10.8, 9.5, and 7.5 microM, respectively, in E. coli W3110. Sequence-specific effects of AcpP peptide-PMOs were shown by rescuing growth of a merodiploid strain that expressed acpP with silent mutations in the region targeted by AcpP peptide-PMO. In Caco-2 cultures infected with enteropathogenic E. coli (EPEC), 10 microM AcpP RTRTRFLRRTXB-PMO or AcpP RFFRFFRFFXB-PMO essentially cleared the infection. The IC(50) of either AcpP RTRTRFLRRTXB-PMO or AcpP RFFRFFRFFXB-PMO in EPEC-infected Caco-2 culture was 3 microM. In summary, RFFRFFRFFXB, RTRTRFLRRTXB, or KFFKFFKFFXB, when covalently bonded to PMO, significantly increased inhibition of expression of targeted genes compared to PMOs without attached peptide. PMID:16870773
Tilley, Lucas D; Hine, Orion S; Kellogg, Jill A; Hassinger, Jed N; Weller, Dwight D; Iversen, Patrick L; Geller, Bruce L
A patient with a dual Salmonella infection is described. Salmonella group B was recovered from three blood culture sets but was not detected in seven stool cultures. Salmonella group C2 was isolated from three of seven stool cultures but was not recovered from blood cultures. Specific, non-cross-reactive antibodies to Salmonella groups B and C2 were detected in the sera of the patient by passive hemagglutination assays.
Papasian, C. J.; Bartholomew, W. R.; Neter, E.; Amsterdam, D.
Two colored latex kits (the Wellcolex Colour Salmonella Test [WCT-Salmonella] and the Wellcolex Colour Shigella Test [WCT-Shigella]; Division Diagnostics, Laboratories Wellcome S.A., Paris, France), which allow identification of the most frequently encountered Salmonella serogroups and Shigella species, respectively, were evaluated. WCT-Salmonella and WCT-Shigella yielded sensitivities of 98.4 and 98%, respectively, and a specificity of 100% when they were tested on pure cultures received at ...
Bouvet, P. J.; Jeanjean, S.
To reduce human exposure to Salmonella spp. in poultry products, broiler chicken flocks have been tested by culture methods. Since the standard techniques may take 3 to 5 days, rapid detection methods have been developed. In this study we tested the performance of three rapid tests originally developed for food samples by using environmental samples obtained from poultry houses. These rapid tests were Reveal, an enzyme-linked immunosorbent assay from Neogen Corp.; BIND, a bacterial ice nuclea...
Peplow, Melissa O.; Correa-prisant, Maria; Stebbins, Martha E.; Jones, Frank; Davies, Peter
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):...
Anumolu, V. K.; Lakkineni, V. R.
Multiple drug resistance in Salmonella is an emerging problem in the area of food safety. Depending on the virulence and antibiotic resistance characteristics of the Salmonella strain, infections of varying severity could result. In this study, a multiplex melt curve real-time PCR assay for the detection of virulent and antibiotic resistance strains of Salmonella was developed with two primer sets. The first set targets the virulence gene, invasin (invA), and tetracycline (tetG), streptomycin (aadA2) and sulphonamide (sulI) antibiotic resistance genes, and the second set amplifies ampicillin (blaPSE,blaTEM) and chloramphenicol (floR) resistance genes. The multiplex assay was evaluated using 41 Salmonella strains and was further tested on eight different artificially inoculated food samples. The fluorescent DNA intercalating dye, SYTO9, generated high resolution melt curve peaks and, hence, was used for the development of the assay. This multiplex assay worked efficiently over a DNA concentration range of 20 ng-200 fg and showed a sensitivity of 290 CFU/mL with serially diluted broth cultures. The detection limit for un-enriched artificially inoculated food samples was 10(4) CFU/g, but an enrichment period of 6 h allowed for detection of 10 CFU/g of cells in the samples. PMID:25084639
Singh, Prashant; Mustapha, Azlin
PREVALENCE OF DRUG RESISTANCE AND VIRULENCE FEATURES IN Salmonella spp. ISOLATED FROM FOODS ASSOCIATED OR NOT WITH SALMONELLOSIS IN BRAZIL / Prevalência de resistência antimicrobiana e características de virulência em Salmonella spp. isoladas de alimentos associados ou não com salmonelose no Brasil
Full Text Available SciELO Brazil | Language: English Abstract in portuguese Salmonella é o agente etiológico mais comumente envolvido em casos e surtos de doenças diarréicas de origem alimentar. A preocupação com este patógeno é, ainda, maior quando se verifica o surgimento e a disseminação de cepas multirresistentes e potencialmente mais patogênicas. Neste estudo, 237 cepa [...] s Salmonella spp., associadas ou não com casos ou surtos de salmonelose e pertencentes, principalmente, ao sorovar Enteritidis, foram avaliadas quanto ao perfil de susceptibilidade antimicrobiana e presença dos genes de virulência spvC, invA, sefA e pefA. Entre as cepas avaliadas, 46,8% foram sensíveis a todos os agentes antimicrobianos e 51,9% foram resistentes a pelo menos uma droga. Multirresistência foi observada em 10,5% das cepas. As maiores taxas de resistência foram observadas para estreptomicina (35,9%) e ácido nalidíxico (16,9%). Não foram detectadas cepas resistentes à cefoxitina, cefalotina, cefotaxima, amicacina, ciprofloxaxina e imipenem. O gene invA foi detectado em todas as cepas de Salmonella. Os genes spvC e pefA foram encontrados em 48,1% e 44,3% das cepas, respectivamente. O gene sefA foi detectado em 31,6% das cepas, estando presente somente entre as cepas de S. Enteritidis. Resistência antimicrobiana e marcadores de virulência foram detectados em cepas de Salmonella pertencentes a diversos sorovares. A alta taxa de resistência antimicrobiana verificada em cepas isoladas de frangos e derivados demonstra o potencial risco associado ao consumo destes produtos e a necessidade de se assegurar boas práticas de higiene em toda cadeia produtiva para reduzir a disseminação de patógenos relevantes para a saúde pública. Abstract in english Salmonella is the most common etiological agent of cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread of Salmonella spp., which has become multi-drug resistant and potentially more pathogenic, have increased the concern with this pathogen. In this study, 237 Salmonella sp [...] p., associated or not with foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis, were tested for antimicrobial susceptibility and the presence of the virulence genes spvC, invA, sefA and pefA. Of the isolates, 46.8% were sensitive to all antimicrobials and 51.9% were resistant to at least one antimicrobial agent. Resistance to more than one antimicrobial agent was observed in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%) and nalidixic acid (16.9%). No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxacin and imipenem. The invA gene was detected in all strains. Genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The gene sefA was detected in 31.6% of the strains and only among S. Enteritidis. Resistance and virulence determinants were detected in Salmonella strains belonging to several serotypes. The high rates of antibiotic-resistance in strains isolated from poultry products demonstrate the potential risk associated with the consumption of these products and the need to ensure good food hygiene practices from farm to table to reduce the spread of pathogens relevant to public health.
Ruth Estela Gravato, Rowlands; Christiane Asturiano, Ristori; Alice A., Ikuno; Maria Luisa, Barbosa; Miyoko, Jakabi; Bernadette Dora Gombossy de Melo, Franco.
From the University of Illinois, Professor Stanley Maloy and Assistant Professor Rob Edwards' Web site Salmonella.org is dedicated to the study of the Salmonella bacteria genome. The site offers news and information on the bacteria's various strains, including everything from tips on preventing the infection to links to genomic sequencing data. Any Salmonella researcher or enthusiast will find this uncluttered and straightforward compilation useful.
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
Full Text Available SciELO Brazil | Language: English 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 distribuiç [...] ão 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 crianças 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 study 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.
Mireille Ângela Bernardes, Sousa; Edilberto Nogueira, Mendes; Francisco José, Penna; Luciano Amedée, Péret-Filho; Paula Prazeres, Magalhães.
Overuse of antibiotics in the medical and animal industries is one of the major causes for the development of multi-drug-resistant (MDR) food pathogens that are often difficult to treat. In the past few years, higher incidences of outbreaks caused by MDR Salmonella have been increasingly documented. The objective of this study was to develop a rapid multiplex real-time polymerase chain reaction (PCR) assay for simultaneous detection of pathogenic and MDR Salmonella spp. A multiplex TaqMan®real-time PCR was designed by targeting the invasin virulence gene (invA), and four commonly found antibiotic resistance genes, viz. ampicillin, chloramphenicol, streptomycin and tetracycline. To avoid false negative results and to increase the reliability of the assay, an internal amplification control (IAC) was added which was detected using a locked nucleic acid (LNA) probe. In serially diluted (5 ng-50 fg) DNA samples, the assay was able to detect 100 genomic equivalents of Salmonella, while in a multiplex format, the sensitivity was 1000 genomic equivalents. The assay performed equally well on artificially contaminated samples of beef trim, ground beef of different fat contents (73:27, 80:20, 85:15 and 93:7), chicken rinse, ground chicken, ground turkey, egg, spinach and tomato. While the detection limit for un-enriched inoculated food samples was 10(4) CFU/g, this was improved to 10 CFU/g after a 12-h enrichment in buffered peptone water, with 100% reproducibility. The multiplex real-time assay developed in this study can be used as a valuable tool to detect MDR virulent Salmonella, thus enhancing the safety of food. PMID:23973830
Singh, Prashant; Mustapha, Azlin
Three new Salmonella serotypes belonging to Kauffmann's subgenus I (F. Kauffmann, The Bacteriology of Enterobacteriaceae, 1966) were identified. These serotypes were Salmonella brazos 6,14,18:a:e,n,z15, Salmonella midway 6,14,24:d:1,7, and Salmonella balboa 48a, 48b:z41:monophasic.
Sutch, K. E.; Blackburn, B. O.
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
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
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
Salmonella enterica is a Gram-negative enteropathogen that can cause localized infections, typically resulting in gastroenteritis, or systemic infection, e.g., typhoid fever, in humans and many other animals. Understanding the mechanisms by which Salmonella induces disease has been the focus of intensive research. This has revealed that Salmonella invasion requires dynamic cross-talk between the microbe and host cells, in which bacterial adherence rapidly leads to a complex sequence of cellular responses initiated by proteins translocated into the host cell by a type 3 secretion system. Once these Salmonella-induced responses have resulted in bacterial invasion, proteins translocated by a second type 3 secretion system initiate further modulation of cellular activities to enable survival and replication of the invading pathogen. Elucidation of the complex and highly dynamic pathogen-host interactions ultimately requires analysis at the level of single cells and single infection events. To achieve this goal, researchers have applied a diverse range of microscopy techniques to analyze Salmonella infection in models ranging from whole animal to isolated cells and simple eukaryotic organisms. For example, electron microscopy and high-resolution light microscopy techniques such as confocal microscopy can reveal the precise location of Salmonella and its relationship to cellular components. Widefield light microscopy is a simpler approach with which to study the interaction of bacteria with host cells and often has advantages for live cell imaging, enabling detailed analysis of the dynamics of infection and cellular responses. Here we review the use of imaging techniques in Salmonella research and compare the capabilities of different classes of microscope to address specific types of research question. We also provide protocols and notes on some microscopy techniques used routinely in our own research. PMID:25253256
Malt, Layla M; Perrett, Charlotte A; Humphrey, Suzanne; Jepson, Mark A
This study compared the antimicrobial susceptibility and prevalence of virulence genes in Salmonella enterica Typhimurium isolated from healthy and diseased pigs in Korea. A total of 456 Salmonella Typhimurium isolated from healthy (n = 238) and diseased (n = 218) pigs between 1998 and 2011 were investigated. In total, 93.4% of the Salmonella Typhimurium isolates were resistant to at least one antimicrobial agent tested. The isolates were most often resistant to tetracycline (85.7%), followed by streptomycin (83.6%), nalidixic acid (67.3%), ampicillin (49.3%), chloramphenicol (42.8%), and gentamicin (37.1%). Moreover, multidrug resistance phenotype and resistance to ampicillin, florfenicol, gentamicin, nalidixic acid, neomycin, streptomycin, and tetracycline were significantly higher (P sifA, sitC, and sopB virulence genes. The prevalence of orgA, pagC, and iroN were 50.2, 74.1, and 91.0%, respectively, whereas isolates carrying cdtB (1.5%), pefA (7.0%), and spvB (14.9%) were identified much less frequently. Furthermore, the prevalence of invA, lpfC, orgA, pagC, and iroN was significantly higher (P < 0.01) among the isolates from the diseased pigs than in isolates from the healthy pigs. Our results demonstrated that, among diseased pigs, there was significantly higher resistance to some antimicrobials and greater prevalence of some virulence genes than in healthy pigs, indicating the role these factors play in pathogenesis. Multidrug-resistant Salmonella isolates that carry virulence-associated genes are potentially more dangerous and constitute a public health concern. Thus, continuous surveillance of antimicrobial resistance and virulence characteristics in Salmonella is essential. PMID:25198838
Tamang, Migma Dorji; Gurung, Mamata; Nam, Hyang-Mi; Moon, Dong Chan; Jang, Geum-Chan; Jung, Suk-Chan; Lim, Suk-Kyung
Native DadB and Alr alanine racemases (M/sub r/ 39,000) from Salmonella typhimurium are proteolyzed at homologous positions by ?-chymotrypsin, trypsin, and subtilisin to generate in all cases two nonoverlapping polypeptides of M/sub r/ 28,000 and 11,000. Under nondenaturing conditions, chymotryptic digest results in an associated form of the two fragments which possesses 3% of the original catalytic activity, incorporates 0.76 equiv of the mechanism-based inactivator ?-chloro-[14C]-D-alanine, and exhibits a UV circular dichroism profile identical with that of native enzyme. Protein sequence analysis of the denatured chymotryptic fragments indicates the presence of a tetrapeptide interdomain hinge (DadB, residues 254-257; Alr, residues 256-259) that is attacked at both ends during proteolysis. Under the previously employed digest conditions, NaB3H4-reduced DadB holoenzyme is resistant to ?-chymotrypsin and trypsin and is labile only toward subtilisin. These data suggest that the hinge structure is essential for a catalytically efficient enzyme species and is sensitive to active site geometry. The sequence at the hinge region is also conserved in alanine racemases from Gram-positive bacteria
Full Text Available The infectious intracellular lifestyle of Salmonella enterica relies on the adaptation to nutritional conditions within the Salmonella-containing vacuole (SCV in host cells. We summarize latest results on metabolic requirements for Salmonella during infection. This includes intracellular phenotypes of mutant strains based on metabolic modeling and experimental tests, isotopologue profiling using 13C-compounds in intracellular Salmonella, and complementation of metabolic defects for attenuated mutant strains towards a comprehensive understanding of the metabolic requirements of the intracellular lifestyle of Salmonella. Helpful for this are also genomic comparisons. We outline further recent studies and which analyses of intracellular phenotypes and improved metabolic simulations were done and comment on technical required steps as well as progress involved in the iterative refinement of metabolic flux models, analyses of mutant phenotypes and isotopologue analyses. Salmonella lifestyle is well adapted to the SCV and its specific metabolic requirements. Salmonella metabolism adapts rapidly to SCV conditions, the metabolic generalist Salmonella is quite successful in host infection.
Full Text Available Abstract Background Chicken meat and eggs can be a source of human zoonotic pathogens, especially Salmonella species. These food items contain a potential hazard for humans. Chickens lines differ in susceptibility for Salmonella and can harbor Salmonella pathogens without showing clinical signs of illness. Many investigations including genomic studies have examined the mechanisms how chickens react to infection. Apart from the innate immune response, many physiological mechanisms and pathways are reported to be involved in the chicken host response to Salmonella infection. The objective of this study was to perform a meta-analysis of diverse experiments to identify general and host specific mechanisms to the Salmonella challenge. Results Diverse chicken lines differing in susceptibility to Salmonella infection were challenged with different Salmonella serovars at several time points. Various tissues were sampled at different time points post-infection, and resulting host transcriptional differences investigated using different microarray platforms. The meta-analysis was performed with the R-package metaMA to create lists of differentially regulated genes. These gene lists showed many similarities for different chicken breeds and tissues, and also for different Salmonella serovars measured at different times post infection. Functional biological analysis of these differentially expressed gene lists revealed several common mechanisms for the chicken host response to Salmonella infection. The meta-analysis-specific genes (i.e. genes found differentially expressed only in the meta-analysis confirmed and expanded the biological functional mechanisms. Conclusions The meta-analysis combination of heterogeneous expression profiling data provided useful insights into the common metabolic pathways and functions of different chicken lines infected with different Salmonella serovars.
te Pas Marinus FW
Accurate and fast detection of harmful Salmonella is a major concern of food safety. Common Salmonella serotypes responsible for human associated foodborne outbreaks are S. Enteritidis, S. Hadar, S. Heidelberg, and S. Typhimurium are also commonly isolated from poultry. Serology is commonly used to monitor disease in poultry, therefore application of Salmonella serotype-specific test will have added value in Salmonella surveillance or monitoring vaccine efficacy. Recombinant flagellins were p...
Hofacre, Charles L.; Holt, Peter S.; Lee, Margie D.; Susan Sanchez; Joseph Minicozzi; Maurer, John J.
Abstract Background The EU Regulation No 2160/2003 imposes a reduction in the prevalence of Salmonella in pigs. The efficiency of control programmes for Salmonella in pigs, reported among the EU Member States, varies and definitive eradication seems very difficult. Control measures currently recommended for Salmonella are not serotype-specific. Is it possible that the risk factors for different Salmonella serotypes are different? The aim of...
Correia-Gomes Carla; Economou Theodoros; Mendonça Denisa; Vieira-Pinto Madalena; Niza-Ribeiro João
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
Full Text Available SciELO Brazil | Language: Portuguese 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 presen [...] tes 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 (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 comp [...] aring 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
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.
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 (pdry 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. PMID:23454816
Aviles, Bryan; Klotz, Courtney; Eifert, Joseph; Williams, Robert; Ponder, Monica
Salmonella is one of the most common causes of human gastroenteritis often associated with pork consumption. The aims of this cross-sectional study were to collect preliminary data on the presence of Salmonella enterica in pigs in Piedmont (Italy), through sampling on farm and at slaughter and to gather pilot data on serotypes and phagetypes present in the sampled area and distribution of anti-microbial resistance among isolated strains. Salmonella was detected through culture and identified with Salmonella spp. and Salmonella Typhimurium PCR; positive samples were serotyped, phagetyped and tested for antibiotic susceptibility. Positive samples (from 9% of faeces up to 29% of tonsils) were found in 64% of the herds. Salmonella spp. was retrieved also from scalding water. Most of the isolates were Salmonella Derby, Salmonella Typhimurium and Salmonella 4,5,12:i:-. The results of Salmonella Typhimurium specific PCR suggested that Salmonella 4,5,12:i:- might be unrecognized by serotyping. Anti-microbial resistance was recorded in 75-100% of the isolates. Phagetyping allowed the identification of DT104B and DT46A strains. These results set the bases for further research studies that would aim to estimate the real herd prevalence in Piedmont and the diffusion of serotypes and anti-microbial resistant strains within the same region. PMID:19068072
Lomonaco, S; Decastelli, L; Bianchi, D M; Nucera, D; Grassi, M A; Sperone, V; Civera, T
CONTEXT: Salmonella has been identified as a causative agent of acute pancreatitis. OBJECTIVE: We prospectively evaluated the frequency of acute pancreatitis, pancreatic enzyme elevation and morphological pancreatic abnormalities in patients with Salmonella infection. SUBJECTS: Thirty consecutive patients with salmonellosis (Salmonella enterica serovar Enteritidis: n=25; Salmonella enterica serovar Typhimurium: n=5) and 30 sex- and age-matched healthy subjects were studied. MAIN OUTCOME MEASU...
Pezzilli R; Am, Morselli-labate; Barakat B; Romboli E; Ceciliato R; Piscitelli L; Corinaldesi R
Excreción fecal de Salmonella Albany, su aislamiento en la ración alimenticia y repercusión en el estado de salud de un ocelote (Leopardus pardalis) en cautiverio / Fecal excretion of Salmonella Albany, its isolation in the diet and health repercussion on an ocelot (Leopardus pardalis) in captivity
Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish Los serotipos de Salmonella especie enterica son los responsables del 99% de las salmonelosis en humanos y animales, en particular, Salmonella enterica serovariedad Albany se ha identificado en canales de pollo, por lo que representa un riesgo para la salud humana y animal. Se aisló Salmonella enter [...] ica serovariedad Albany a partir de heces de un ocelote macho (Leopardus pardalis), cautivo en el zoológico de Culiacán, Sinaloa, México, y de pollo crudo (alimento del felino). El patrón por electroforesis en campo pulsado (PFGE) con la enzima Xba I fue idéntico en ambos aislados, lo que indica que la fuente de infección fue el pollo crudo. Cinco meses después de haber aislado las bacterias de las heces, se realizó estudio post mortem del felino anteriormente mencionado, y se observó macroscópicamente: enterocolitis hemorrágica severa y fibrosis renal; y microscópicamente: necrosis de vellosidades y de criptas e infiltrado mononuclear linfocitario severo en íleon, además nefritis intersticial severa multifocal y fibrosis en riñón. A partir de muestras intestinales se amplificó el gen invA que confirma la infección por Salmonella. Los diagnósticos microbiológico, molecular e histopatológico sugieren que la muerte del felino se debió a la infección causada por la ingesta de pollo crudo contaminado con Salmonella enterica serovariedad Albany. Este caso clínico confirma la importancia que tienen los animales que excretan Salmonella vía fecal y describe la relación epidemiológica-molecular de los aislamientos obtenidos de heces y alimento, lo que permitió esclarecer la fuente primaria de infección. Abstract in english Salmonella enterica serotypes are 99% responsible for salmonellosis in human and animals, especially Salmonella enterica serovar Albany that has been identified in chicken carcass representing a risk for human and animal health. Salmonella enterica serovar Albany was isolated from the feces of a mal [...] e ocelot (Leopardus pardalis), at the zoo in Culiacan, Sinaloa, Mexico, and from raw chicken (feline's diet). The pulsed-field gel electrophoresis pattern (PFGE) generated by Xba I enzyme was identical in both isolates, indicating that the source of infection was the raw chicken. Five months after having isolated the bacteria from the feces, a post mortem study was carried out on the feline. Macroscopically, severe hemorrhagic enterocolitis and renal fibrosis was observed and microscopically, there was evidence of severe mononuclear lymphocytic infiltration in the ileum, as well as necrosis of intestinal villi and crypts, besides severe multifocal interstitial nephritis and fibrosis in both kidneys. The invA gene was amplified from intestinal samples confirming an infection by Salmonella. The microbiologic, molecular and histopathology diagnoses suggest that death of the feline was caused by ingestion of raw chicken contaminated with Salmonella enterica serovar Albany. This clinical case highlights the importance of persistent fecal Salmonella shedding animals and describes the molecular epidemiological relationships of isolates from feces and food, which allowed to find the primary source of infection.
Gabriela, Silva-Hidalgo; Héctor Samuel, López-Moreno; Vianney F., Ortiz-Navarrete; Felipe, Juárez-Barranco; Martín, López-Valenzuela.
The aim of this study was to give some insights into the prevalence, serovars, phage types, and antibiotic resistances of Salmonella from animal origin in the United Arab Emirates. Data on diagnostic samples from animals (n = 20,871) examined for Salmonella between 1996 and 2009 were extracted from the databases of the Central Veterinary Research Laboratory in Dubai and from typed strains (n = 1052) from the Robert Koch Institute, Wernigerode Branch in Germany and analyzed for general and animal-specific trends. Salmonella was isolated from 1,928 (9 %) of the 20,871 samples examined. Among the 1,052 typed strains, most were from camels (n = 232), falcons (n = 166), bustards (n = 101), antelopes (n = 66), and horses (n = 63). The predominant serovars were Salmonella Typhimurium (25 %), Salmonella Kentucky (8 %), followed by Salmonella Frintrop (7 %), and Salmonella Hindmarsh (5 %). When analyzed by animal species, the most frequent serovars in camels were Salmonella Frintrop (28 %) and Salmonella Hindmarsh (21 %), in falcons Salmonella Typhimurium (32 %), in bustards Salmonella Kentucky (19 %), in antelopes Salmonella Typhimurium (9 %), and in horses Salmonella Typhimurium (17 %) and S. Kentucky (16 %). Resistance of all typed Salmonella strains (n = 1052) was most often seen to tetracycline (23 %), streptomycin (22 %), nalidixic acid (18 %), and ampicillin (15 %). These data show trends in the epidemiology of Salmonella in different animal species which can be used as a base for future prevention, control, and therapy strategies. PMID:22476789
Münch, Sebastian; Braun, Peggy; Wernery, Ulrich; Kinne, Jörg; Pees, Michael; Flieger, Antje; Tietze, Erhard; Rabsch, Wolfgang
Several outbreaks of Salmonella enterica infections have been linked to tomatoes. One cost-effective way to complement on-farm preventive Good Agricultural Practices is to identify cultivars with inherent decreased susceptibility to Salmonella colonization. Fruit and leaves of 13 tomato cultivars with distinct phenotypes were screened to evaluate their susceptibility to Salmonella epiphytic colonization. Field-grown fruit or gnotobiotically grown seedling leaves were spot inoculated in replicate with either Salmonella Typhimurium LT2 or a tomato outbreak-associated strain of Salmonella Newport. Initial loads of the Salmonella inocula were 2.5 log CFU per fruit and 3.5 or 7.0 log CFU per seedling. Salmonella cells were retrieved and enumerated using direct plating after 24 h of incubation at room temperature for fruit and 72 h at 26°C during the day and 18°C at night for seedling leaves. Epiphytic colonization of fruit by S. enterica was cultivar-dependent and serotype-specific, but did not necessarily correlate with leaf colonization. Fruit of cultivar Heinz-1706 were the least colonized by Salmonella Newport, while the highest populations were retrieved from fruit of Nyagous. By contrast, seedling leaves supporting the lowest populations were Florida 91 VF and the highest were Virginia Sweets for Salmonella Newport. For Salmonella Typhimurium the lowest was Nyagous and the highest was Heinz-1706 and Moneymaker. The tomato outbreak strain of Salmonella Newport attained higher population densities on fruit than did Salmonella Typhimurium, suggesting better adaptation to tomato fruit colonization. Salmonella Newport populations were significantly lower on leaves, but not fruit of the near-isogenic line Movione, compared with the parent cultivar Moneymaker, suggesting the immunity conferring gene Pto could be responding to this outbreak strain. Susceptibility of tomato fruit to Salmonella colonization is highly variable and could be one criterion for cultivar selection for cultivation. PMID:25364916
Han, Sanghyun; Micallef, Shirley Ann
Population genetic studies suggest that Yersinia pestis, the cause of plague, is a clonal pathogen that has recently emerged from Yersinia pseudotuberculosis. Plasmid acquisition is likely to have been a key element in this evolutionary leap from an enteric to a flea-transmitted systemic pathogen. However, the origin of Y. pestis-specific plasmids remains obscure. We demonstrate specific plasmid rearrangements in different Y. pestis strains which distinguish Y. pestis bv. Orientalis strains f...
Prentice, Mb; James, Kd; Parkhill, J.; Baker, Sg; Stevens, K.; Simmonds, Mn; Mungall, Kl; Churcher, C.; Oyston, Pc; Titball, Rw; Wren, BW; Wain, J.; Pickard, D.; Hien, Tt; Farrar, Jj
The type III secretion system (T3SS) encoded by the Salmonella pathogenicity island 2 (SPI2) has a central role in systemic infections by Salmonella enterica and for the intracellular phenotype. Intracellular S. enterica uses the SPI2-encoded T3SS to translocate a set of effector proteins into the host cell, which modify host cell functions, enabling intracellular survival and replication of the bacteria. We sought to determine whether specific functions of the SPI2-encoded T3SS can be transf...
Hansen-wester, Imke; Chakravortty, Dipshikha; Hensel, Michael
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.)
Full Text Available Lack of specificity of the therapeutic agent is a primary limitation in the treatment of a tumor. The use of preferentially replicating bacteria as therapeutic agents is an innovative approach to tumor treatment. This is based on the observation that certain obligate or facultative anaerobic bacteria are capable of multiplying selectively in tumors and inhibiting their growth. Bacteria have been employed as antitumor agents that are capable of preferentially amplifying within tumors and inhibiting their growth. Moreover, bacteria-derived factors have an immune-stimulation effect. Therefore, bacteria are able to transfer therapeutic genes into the tumor cells using their infective ability. Herein, we introduce the application of bacteria for tumor therapy and focus on Salmonella, which have been widely used for tumor therapy. Salmonella have mainly been applied as gene-delivery vectors, antitumor immune activators and tumor cell death inducers. This study will not only evaluate the therapeutic efficacy of Salmonella for the treatment of tumor but will also elucidate the mechanisms underlying the antitumor activities mediated by Salmonella, which involve host immune responses and cellular molecular responses.
The host-pathogen interactions occurring in the gallbladder during Salmonella Typhi colonization contribute to typhoid fever pathogenesis during the acute and chronic stages of disease. The gallbladder is the primary reservoir during chronic typhoid carriage. In this organ, Salmonella encounters host-barriers including bile, immunoglobulins, and mucus. However, the bacterium possesses mechanisms to resist and persist in this environment, in part by its ability to attach to and invade into the gallbladder epithelium. Such persistence in the gallbladder epithelium contributes to chronic carriage. In addition, patients harboring gallstones in their gallbladders have increased risk of becoming carriers because these abnormalities serve as a substrate for Salmonella biofilm formation. Our laboratory has studied the Salmonella interactions in this specific environment by developing in vitro methods that closely mimic the gallbladder and gallstones niches. These methods are reproducible and provide a platform for future studies of acute and chronic bacterial infections in the gallbladder. PMID:25253258
Gonzalez-Escobedo, Geoffrey; Gunn, John S
Salmonella is one of the most dangerous and common food-borne pathogens. The overuse of antibiotics for disease prevention has led to the development of multidrug resistant Salmonella. Now, more than ever, there is a need for new antimicrobial drugs to combat these resistant bacteria. Aptamers have grown in popularity since their discovery, and their properties make them attractive candidates for therapeutic use. In this work, we describe the selection of highly specific DNA aptamers to S. enteritidis and S. typhimurium. To evolve species-specific aptamers, twelve rounds of selection to live S. enteritidis and S. typhimurium were performed, alternating with a negative selection against a mixture of related pathogens. Studies have shown that synthetic pools combined from individual aptamers have the capacity to inhibit growth of S. enteritidis and S. typhimurium in bacterial cultures; this was the result of a decrease in their membrane potential. PMID:23387511
Kolovskaya, Olga S; Savitskaya, Anna G; Zamay, Tatiana N; Reshetneva, Irina T; Zamay, Galina S; Erkaev, Evgeny N; Wang, Xiaoyan; Wehbe, Mohamed; Salmina, Alla B; Perianova, Olga V; Zubkova, Olga A; Spivak, Ekaterina A; Mezko, Vasily S; Glazyrin, Yury E; Titova, Nadezhda M; Berezovski, Maxim V; Zamay, Anna S
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®
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
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
Dry heat was used to inactivate Salmonella newington, Salmonella typhimurium, Salmonella anatum, Salmonella kentucky, Salmonella cubana, Salmonella seftenberg, Salmonella thompson, and Salmonella tennessee in corn flour at 10 and 15% moisture. The flour was spray inoculated at 10(5) Salmonella cells per g and then stored at 49 degrees C (120 degrees F); viable Salmonella cells were counted on Trypticase (BBL Microbiology Systems) soy agar plates every 30 min for the first 4 h and then at 4-h ...
Vancauwenberge, J. E.; Bothast, R. J.; Kwolek, W. F.
Data indicate that prevalence of specific serovars of Salmonella enterica in human foodborne illness is not correlated with their prevalence in feed. Given that feed is a suboptimal environment for S. enterica, it appears that survival in poultry feed may be an independent factor unrelated to virulence of specific serovars of Salmonella. Additionally, S. enterica serovars appear to have different host specificity and the ability to cause disease in those hosts is also serovar dependent. These differences among the serovars may be related to gene presence or absence and expression levels of those genes. With a better understanding of serovar specificity, mitigation methods can be implemented to control Salmonella at preharvest and postharvest levels. PMID:25664339
Andino, A.; Hanning, I.
Salmonella enterica is divided into four subspecies containing a large number of different serovars, several of which are important zoonotic pathogens and some show a high degree of host specificity or host preference. We compare 45 sequenced S. enterica genomes that are publicly available (22 complete and 23 draft genome sequences). Of these, 35 were found to be of sufficiently good quality to allow a detailed analysis, along with two Escherichia coli strains (K-12 su...
Jacobsen, Annika; Hendriksen, Rene S.; Aarestrup, Frank Møller; Ussery, David; Friis, Carsten
Full Text Available Abstract Salmonellosis is the main cause of human bacterial gastroenteritis in most European countries. Infections with Salmonella is usually subclinical, whereas clinical cases show symptoms with a wide range of severity. Infection is most commonly associated with the consumption of meat, especially poultry or pork, and eggs and their products. Salmonella can enter the food chain at any point throughout its length. The principal reservoir of Salmonellae is the gastrointestinal tract of mammals and birds, but Salmonellae are able to survive and even multiply in many external environments. In Norway, Sweden and Finland cost effective prevention methods have been used for several years to prevent and control Salmonellea infections. In addition, competitive exclusion (CE and vaccination might be relevant as biological methods to prevent colonisation of bird intestines by enteropathogens, especially Salmonella. Antibiotic drug resistance has been a problem since the start of the antibiotic era. The cause for anxiety is that more and more bacteria are becoming resistant, often to a whole range of antibiotics. The debate on the use of antimicrobials in veterinary medicine and animal production dates back almost as long as the use itself. There is a clear evidence to show that antibacterial agents given to animals for growth promotion, prophylactic purposes or treatment induce a rise in the number of antibiotic resistant strains isolated from the animals. These bacteria may be transmitted to humans by several possible routes. There are thus strong arguments for preventive efforts which have to be directed towards identifying real critical control points (HACCP throughout the whole food chain, which starts from the farm and ends at the consumer's table.
Full Text Available Background: Typhoid fever is still one of the serious public health problems in many geographic areas and is endemic in most countries. Aim of current study was to evaluate a shortened time –Multiplex PCR for rapid detection of different Sal¬monella enterica serovars. Methods: The PCR primers for three target genes tyv, prt and invA were subjected for amplification by PCR. By using sim¬ple DNA extraction method, rapid PCR cycles and rapid electrophoresis procedure with simple and very cheap buffer were utilized in 200 to 300 volts for 15 minutes to separate the PCR products. Results: The results showed that all reference and clinical isolates of S. enterica were accurately identified by this as¬say with no cross reaction with other enterobacterial strains tested. Detection limit of the reaction was to be fewer than 10-1 colony forming unit. Conclusion: These data indicate that the optimized rapid cycle multiplex PCR is a potentially valuable tool for rapid diagno¬sis of S. enterica using a conventional thermal cycler. This method reduced the reaction time of PCR from 3.5 h to less than 1 h.
Sickle cell disease is a rare condition in italian patients and even rarer are its complications, in particular Salmonella osteomyelitis. We describe a case of a Ghanaian child with sickle cell disease who developed osteomyelitis due to Salmonella panama, treated successfully with surgical debridement, followed by a prolonged period of specific antibiotic therapy. PMID:12494543
Busetti, M; Longo, B; Colonna, F; Dibello, D; Barbi, E; Campello, C
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)
Salmonella is one of the most important food-borne pathogens that can be transmitted through the consumption of contaminated milk and milk products. Early detection of Salmonella in food is important for food safety. Two selective media, brilliant green agar (BGA) and xylose lysine desoxycholate (XLD) agar are commonly used in diagnostic laboratories for the isolation of Salmonella, often after enrichment of the samples in a broth before plating on the solid medium. Recently, a new medium called CHROmagar Salmonella (CAS) has become available for the rapid detection of Salmonella. In the present study, we compared this new medium with BGA and XLD for the isolation of Salmonella from 160 dairy products samples (80 ice cream and 80 kariesh cheese samples) with enrichment in Rappaport- Vassiliadis (RV) and tetrathionate (TT) broth. TECRA Unique Salmonella ELISA test was used. Only one sample was positive for Salmonella, which appeared on each of CAS and XLD agars, after enrichment using RV but not TT. This was associated with a sensitivity and specificity of (100 %, 92.45%), (100%, 93.71%) and (0 %, 100%) for each of CHROmagar Salmonella, XLD and BGA respectively. TECRA Unique Salmonella test yielded the highest sensitivity and specificity among all used methods; it had 100% sensitivity with 100% specificity. PMID:18992207
El Shamy, Hoda A; Bakr, Wafaa M; Gomaa, Naglaa F; Barheem, Omar H
We have developed a rapid and sensitive method for immunomagnetic separation (IMS) of Salmonella along with their real time detection via PCR. Silica-coated magnetic nanoparticles were functionalized with carboxy groups to which anti-Salmonella antibody raised against heat-inactivated whole cells of Salmonella were covalently attached. The immuno-captured target cells were detected in beverages like milk and lemon juice by multiplex PCR and real time PCR with a detection limit of 104 cfu.mL?1 and 103 cfu.mL?1, respectively. We demonstrate that IMS can be used for selective concentration of target bacteria from beverages for subsequent use in PCR detection. PCR also enables differentiation of Salmonella typhi and Salmonella paratyphi A using a set of four specific primers. In addition, IMS—PCR can be used as a screening tool in the food and beverage industry for the detection of Salmonella within 3–4 h which compares favorably to the time of several days that is needed in case of conventional detection based on culture and biochemical methods. (author)
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.
Arun K. Bhunia
Leafy greens are occasionally involved in outbreaks of enteric pathogens. In order to control the plant contamination it is necessary to understand the factors that influence enteric pathogen-plant interactions. Attachment of Salmonella enterica serovar typhimurium to lettuce leaves has been demonstrated before; however, only limited information is available regarding the localization and distribution of immigrant Salmonella on the leaf surface. To extend our knowledge regarding initial pathogen-leaf interactions, the distribution of green-fluorescent protein-labeled Salmonella typhimurium on artificially contaminated romaine lettuce leaves was analyzed. We demonstrate that attachment of Salmonella to different leaf regions is highly variable; yet a higher attachment level was observed on leaf regions localized close to the petiole (7.7 log CFU g(-1)) compared to surfaces at the far-end region of the leaf blade (6.2 log CFU g(-1)). Attachment to surfaces located at a central leaf region demonstrated intermediate attachment level (7.0 log CFU g(-1)). Salmonella displayed higher affinity toward the abaxial side compared to the adaxial side of the same leaf region. Rarely, Salmonella cells were also visualized underneath stomata within the parenchymal tissue, supporting the notion that this pathogen can also internalize romaine lettuce leaves. Comparison of attachment to leaves of different ages showed that Salmonella displayed higher affinity to older compared to younger leaves (1.5 log). Scanning electron microscopy revealed a more complex topography on the surface of older leaves, as well as on the abaxial side of the examined leaf tissue supporting the notion that a higher attachment level might be correlated with a more composite leaf landscape. Our findings indicate that initial attachment of Salmonella to romaine lettuce leaf depends on multiple plant factors pertaining to the specific localization on the leaf tissue and to the developmental stage of the leaf. PMID:21569943
Kroupitski, Yulia; Pinto, Riky; Belausov, Eduard; Sela, Shlomo
Full Text Available CONTEXT: Salmonella has been identified as a causative agent of acute pancreatitis. OBJECTIVE: We prospectively evaluated the frequency of acute pancreatitis, pancreatic enzyme elevation and morphological pancreatic abnormalities in patients with Salmonella infection. SUBJECTS: Thirty consecutive patients with salmonellosis (Salmonella enterica serovar Enteritidis: n=25; Salmonella enterica serovar Typhimurium: n=5 and 30 sex- and age-matched healthy subjects were studied. MAIN OUTCOME MEASURES: All subjects underwent serum amylase and lipase determination and ultrasonography. RESULTS: None of the subjects developed acute pancreatitis. Two patients (6.7% and two controls showed serum amylase activity above the upper reference limit whereas, in five patients (16.7% and one control subject (3.3%, the serum lipase activity appeared above the upper reference limit. Salmonella infection significantly increased serum activity of lipase (P less than 0.001 while it did not significantly affect serum amylase levels (P=0.204. Serum lipase activity was significantly higher in patients infected by Salmonella enterica serovar Typhimurium than in those infected by Salmonella enterica serovar Enteritidis (P=0.012. Ultrasonography did not show pancreatic abnormalities in any of the subjects. CONCLUSIONS: Our data demonstrated an elevation of serum lipase activity in gastroenteritis due to Salmonella infection, but this elevation does not seem to have clinical significance. The elevation of serum lipase seems to be particularly related to infection from Salmonella enterica serovar Typhimurium.
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.
Full Text Available Aims: Salmonella enterica serovar Typhi is the major causative agent for typhoidial fever around the globe among human population reported till date. Present research work was carried out for detection and molecular characterisation of Salmonella enterica serovar Typhi isolated from humans with Typhoidial fever by biochemical, phenotypical and virulence gene based polymerase chain reaction (PCR techniques. The isolated strains were also investigated for antibiotic susceptibility patterns as a control measure. Methodology and Results: A total of 16 clinical samples were collected from the same numbers of patients (7 males and 9 females from Coimbatore, Erode and Salem districts of Tamil Nadu and were processed via broth enrichment methods for isolation and identification of the causative agent S. enterica serovar Typhi. Microbiological and biochemical investigations revealed the presence of S. Typhi from 16 samples. The biotyping of the isolates showed that all the isolates belonged to biotype IV. The PCR analysis confirmed the presence of invA (Invasion gene, 244bp, tyv (Tyveloseepimerase gene, 615 bp, fliC-d (Phage-1 flagellin gene for d-antigen, 750 bp and viaB (Vi antigen gene, 439bp in all 16 clinical samples. The antibiotic susceptibility test that was carried out among the isolates against 12 antimicrobial agents, showed 100 % resistance to only ampicillin and 100 % sensitivity to carbenicillin, chloramphenicol, clindamycin, gentamycin, kanamycin and tetracycline.Conclusion, significance and impact of study: This study confirmed the association of virulent strains of S. enterica serovar Typhi from Typhoidial fever among human population and suggested that PCR based diagnostic could be very useful for the rapid detection of S. Typhi isolates. Present study emphasized the use of antibiotic like chloramphenicol or in combination with other antibiotics for the effective control of S. Typhi.
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
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...
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.
Full Text Available Con el objetivo de determinar la inocuidad bacteriológica de los quesos frescos y semimadurados que se venden en algunos ?mercados sobre ruedas? en la ciudad de México, se realizó la detección simultánea de Salmonella spp y de Listeria monocytogenes, mediante la técnica de reacción en cadena de la polimerasa (PCR, así como con los métodos bacteriológicos convencionales, según la normatividad correspondiente para cada microorganismo; es decir, la NOM-114-SSA1-1994 mexicana, que constituye un método para la determinación de Salmonella en alimentos; de igual manera la NOM-143-SSA1-1995 mexicana, que representa un método de prueba microbiológica para alimentos y determinación de L. monocytogenes. Se analizaron 120 muestras seleccionadas al azar, provenientes de cuatro ?mercados sobre ruedas? de una zona del sur de la ciudad de México. La metodología propuesta para la PCR múltiple se basó en la amplifi cación simultánea de los genes InvA e Iap procedentes de los genomas de Salmonella spp y de L. monocytogenes, respectivamente; de igual forma, la metodología para la extracción de ADN bacteriano a partir de las muestras se desarrolló con el fi n de eliminar o disminuir la posible interferencia de inhibidores propios del alimento mediante centrifugación previa de las muestras y se comprobó que la amplifi cación de ambos resultó positiva, aun cuando los patógenos se encuentren presentes en las muestras a una concentración de por lo menos 30 UFC/g. Del total de muestras analizadas con la técnica de PCR, sólo tres resultaron positivas a la presencia de Salmonella spp, en ninguna estuvo presente L. monocytogenes, en contraste con los resultados de los métodos bacteriológicos, por medio de los cuales no se obtuvo ningún resultado positivo.
Claudia D. Alc\\u00E1zar Monta\\u00F1ez
Salmonella enterica subsp. enterica serovar 4,,12,i:- is a monophasic variant of Salmonella Typhimurium and its occurrence has markedly increased in several European countries in the last ten years. In June 2011, an outbreak of Salmonella 4,,12,i:- was reported among attendees of a wedding reception in the North-East of Italy. The source of this outbreak was identified as a cooked pork product served during the wedding reception. All Salmonella isolates from humans and the contaminated pork products were identified as Salmonella 4,,12,i:- and phage typed as DT7a. Afterwards, the farm where the pigs were raised was identified and sampled, and Salmonella Typhimurium was isolated from swine fecal samples. Despite the difference in serovar, these Salmonella Typhimurium isolates were also phage typed as DT7a. In the present study, Salmonella isolates from animals, humans and pork products during the outbreak investigation were subtyped by pulsed-field gel electrophoresis (PFGE), Multiple-Locus Variable number tandem repeats Analysis (MLVA), and resistance patterns, aiming to identify the most suitable subtyping methods to characterize isolates associated with this outbreak. In addition, a collection of epidemiologically unrelated strains of Salmonella 4,,12,i:- and Salmonella Typhimurium sharing the same phage type (DT7a) was similarly characterized in order to investigate their genetic relationship. This study provides a first snapshot of a rare Salmonella phage type, DT7a, associated with both Salmonella 4,,12,i:- and Salmonella Typhimurium. Moreover, the study demonstrated that in this specific context MLVA could be a reliable tool to support outbreak investigations as well as to assess the genetic relatedness among Salmonella isolates. PMID:25108760
Lettini, A A; Saccardin, C; Ramon, E; Longo, A; Cortini, E; Dalla Pozza, M C; Barco, L; Guerra, B; Luzzi, I; Ricci, A
In an earlier study with Salmonella typhimurium L1388 (ST) and Salmonella enteritidis L1225 (SE) isolated from diseased chickens, we found that SE formed more biofilm than ST on abiotic surfaces in a time-dependent manner. Since the ability of salmonellae to survive extreme environment is related to their virulence, the present study examined the survival of Salmonella typhimurium L1388 and Salmonella nteritidis L1225 under the usual stresses that salmonellae encounter during their life cycle...
Yb, Ngwai; Wambebe C; Adachi Y
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 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. PMID:23834803
Edrington, T S; Loneragan, G H; Hill, J; Genovese, K J; Brichta-Harhay, D M; Farrow, R L; Krueger, N A; Callaway, T R; Anderson, R C; Nisbet, D J
Full Text Available Salmonella is a leading cause of foodborne illness in the United States, with poultry and poultry products being a primary source of infection to humans. Poultry may carry some Salmonella serovars without any signs or symptoms of disease and without causing any adverse effects to the health of the bird. Salmonella may be introduced to a flock by multiple environmental sources, but poultry feed is suspected to be a leading source. Detecting Salmonella in feed can be challenging because low levels of the bacteria may not be recovered using traditional culturing techniques. Numerous detection methodologies have been examined over the years for quantifying Salmonella in feeds and many have proven to be effective for Salmonella isolation and detection in a variety of feeds. However, given the potential need for increased detection sensitivity, molecular detection technologies may the best candidate for developing rapid sensitive methods for identifying small numbers of Salmonella in the background of large volumes of feed. Several studies have been done using polymerase chain reaction (PCR assays and commercial kits to detect Salmonella spp. in a wide variety of feed sources. In addition, DNA array technology has recently been utilized to track the dissemination of a specific Salmonella serotype in feed mills. This review will discuss the processing of feeds and potential points in the process that may introduce Salmonella contamination to the feed. Detection methods currently used and the need for advances in these methods also will be discussed. Finally, implementation of rapid detection for optimizing control methods to prevent and remove any Salmonella contamination of feeds will be considered.
Steven C. Ricke
This paper presents the direct detection of Salmonella typhimurium on shell eggs using a phage-based magnetoelastic (ME) biosensor. The ME biosensor consists of a ME resonator as the sensor platform and E2 phage as the biorecognition element that is genetically engineered to specifically bind with Salmonella typhimurium. The ME biosensor, which is a wireless sensor, vibrates with a characteristic resonant frequency under an externally applied magnetic field. Multiple sensors can easily be remotely monitored. Multiple measurement and control sensors were placed on the shell eggs contaminated by Salmonella typhimurium solutions with different known concentrations. The resonant frequency of sensors before and after the exposure to the spiked shell eggs was measured. The frequency shift of the measurement sensors was significantly different than the control sensors indicating Salmonella contamination. Scanning electron microscopy was used to confirm binding of Salmonella to the sensor surface and the resulting frequency shift results.
Chai, Yating; Li, Suiqiong; Horikawa, Shin; Shen, Wen; Park, Mi-Kyung; Vodyanoy, Vitaly J.; Chin, Bryan A.
... Risk of Human Salmonella Infections from Live Baby Poultry Share Compartir Risk of Human Salmonella Infections from ... do people get Salmonella infections from live baby poultry? Live poultry may have Salmonella germs in their ...
We demonstrated that an exogenous conjugate consisting of a ?-lactamase and a monoclonal antibody against a surface antigen of Salmonella is capable of conferring selective penicillin resistance on bacteria. This immunoenzymatic approach allows the rapid growth and detection of specific bacteria and may find other applications when temporary and nongenetic antibiotic resistance is required.
Ponsard, Isabelle; Soumillion, Patrice
We evaluated the TaqMan Salmonella amplification/detection kit from PE Applied Biosystems, which uses a polymerase chain reaction (PCR) assay for rapid detection of Salmonella in food samples. This system uses the 5' nuclease activity of Taq DNA polymerase, which digests an internal fluorogenic probe to monitor the amplification of the target gene. The system's sensitivity and specificity were evaluated using 42 serotypes of 68 Salmonella strains isolated from fecal samples from patients in Tokyo, Japan, and 39 non-Salmonella strains in 22 genera. There were no false-negative or false-positive results. This PCR assay can detect 3 CFU per PCR tube of Salmonella in pure culture (120 CFU/ml of TSB culture). PCR signals were attenuated with artificially contaminated shrimp, but a similar detection limit was obtained. TaqMan's performance was tested with 100 meat and chicken samples purchased from stores in Tokyo. Overall, two of the DNA extraction protocols (the Chelex and EnviroAmp methods) worked equally well, with some exceptions. Of the 100 samples analyzed, 10 were positive for Salmonella with both conventional culture methods and the kit and 89 were negative with both. One sample was negative by the culture method but positive by the kit assay. These results indicate that TaqMan is a reliable and rapid method for Salmonella analysis in the food industry. With this system, food samples can be analyzed for Salmonella in less than 20 h. PMID:10419204
Kimura, B; Kawasaki, S; Fujii, T; Kusunoki, J; Itoh, T; Flood, S J
Full Text Available Background and Objective: Salmonellosis is one of the most important food-borne bacterial zoonotic diseases worldwide, and poultry and its products are the major sources for salmonella transmission to human. Isolation of Salmonella enterica from poultry needs bacteriologic enrichment and selected cultures of fecal samples. In this study, different culture methods for the isolation of salmonella from fecal samples were compared. Material and Methods: Forty- five positive samples from infected farms and 45 negative samples from normal farms were processed using enrichment media including tetrathionate broth, selenite cistine and Rappaport-Vassiliadis. Then the samples were incubated in selective cultures, and after 24 h, their results were compared with standard method. Results: Specificity of all methods for salmonella isolation was 100%, and salmonella was not isolated from the negative samples. The highest susceptibility was related to the method in which the sample first in Selenite cistine and later in Rappaport-Vassiliadis was enriched (100%. Enrichment in Rappaport-Vassiliadis could isolate 41 salmonella from 45 positive samples (91% while the result of enrichment in tetrathionate was 6 isolates (13.3%. Conclusion: This study shows that enrichment in selenite cistine and then in Rappaport-Vassiliadis is currently the best method for isolating salmonella from fecal samples of poultry. Key words: Salmonella; Bacteriologic Culture; Diagnosis; Isolation; Enrichment; Poultry
Morshed, R. (PhD
The innate immune system provides the first line of defense against invading microorganisms by inducing a variety of inflammatory and antimicrobial responses. These responses are particularly important in the gastrointestinal tract, where the needs for efficient nutrient uptake and host defense collide. Many pathogens have evolved to specifically colonize the intestine, causing millions of cases of enteric infections a year. A paradigm of an enteric pathogen is Salmonella enterica, a gram-negative bacterium that causes a wide range of gastrointestinal and systemic diseases. Infections with Salmonella enterica serovar Typhimurium (S. typhimurium) lead to an acute intestinal inflammation in human and animal hosts, as a result of the bacterium invading the mucosa. A distinctive feature of Salmonella is that it has not only adapted to survive in a strong inflammatory environment, but it also uses this adaptation as a strategy to gain a growth advantage over the intestinal microbiota. We will use the model organism S. typhimurium to discuss the innate immune mechanisms employed by the mammalian gastrointestinal system and how the pathogen responds and subverts these mechanisms. In particular, we focus on the recognition of extra- and intra-cellular Salmonellae by germline-encoded pattern recognition receptors of the TLR and NLR families, and how Salmonella might profit from the activation of these receptors. PMID:22198618
Broz, Petr; Ohlson, Maikke B; Monack, Denise M
In this study we considered the influence of phage addition on the fate of Salmonella enterica serovar Typhimurium in different foods. Phage P22 was applied to the following: liquid eggs, energy drinks, whole and skimmed milk, apple juice, chicken breast and chicken mince all spiked with its host, whose growth was monitored for 24 and 48h at 4°C. Appreciable host inactivation, generally in the order of 2 log cycles, was achieved compared to phage-free controls in all food matrices when 10(4)UFC/g host inoculum was used. Furthermore, wild food strains belonging to the serotypes Typhimurium, Enteritidis, Derby Give, Newport, Muenchen and Muenster were assayed towards phage P22. Only isolates of Salmonella Typhimurium as well as Salmonella Derby and Salmonella Enteritidis was inhibited by the presence of P22 phage. Additional challenge experiments were carried out by spiking liquid-eggs, chicken breast and chicken mince with mixes of wild Salmonella Typhimurium (at concentration of about 10(4)UFC/g) strains along with their relative phage P22. The results showed a reduction of 2-3 log cycles after 48h at 4°C depending on both mix of strains and the specific food. Overall, the results indicate that phages may be useful in the control of food-borne pathogens. The food matrices considered, the liquid more than the solid, do not seem to affect the phage ability of infection compared to similar tests performed in vitro. PMID:25240138
Zinno, Paola; Devirgiliis, Chiara; Ercolini, Danilo; Ongeng, Duncan; Mauriello, Gianluigi
Full Text Available The study was undertaken to elucidate the recent epidemiological status of salmonellosis in India. A total of 23 Salmonella isolates were recovered from different disease outbreaks in different geographical locations. The phenotypic analysis by serotyping, transmission electron microscopy and antibiogram profiles were able to classify the Salmonella isolates based on different serovars. The S. Gallinarum isolates were also classified into different strains based on the resistance pattern to different antimicrobials used. The plasmid profiles of the Salmonella isolates were also found to be serovar specific and the S. Gallinarum isolates were subdivided into different strains based on the geographical origin. There was a positive correlation between the antibiotic resistance pattern and the presence of plasmid within different serovars.
A recombinant strain, isolated following the transduction of an Escherichia coli recipient carrying the Salmonella typhimurium (SB) specificity genes with DNA from a donor having the Salmonella potsdam (SP) specificity, was shown [Bullas, L.R., Colson, C. & Van Pel, A. (1976) J. Gen. Microbiol. 95, 166-172] to have neither SB nor SP specificity but to encode a novel restriction specificity, SQ. The heteroduplex analysis of the hsdS (specificity) genes of the SB and SP restriction and modifica...
Fuller-pace, F. V.; Bullas, L. R.; Delius, H.; Murray, N. E.
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.
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
Salmonella (S.) Typhimurium and S. Enteritidis are the major causative agents of food-borne illnesses worldwide. Currently, a rapid detection system using multiplex real-time polymerase chain reaction (PCR) has been applied for other food-borne pathogens such as Escherichia coli, Staphylococcus aureus and Streptococcus spp. A multiplex real-time PCR was developed for the simultaneous detection of Salmonella spp., especially S. Typhimurium and S. Enteritidis, in beef and pork. For the specific...
Lee, Su Hwa; Jung, Byeong Yeal; Rayamahji, Nabin; Lee, Hee Soo; Jeon, Woo Jin; Choi, Kang Seuk; Kweon, Chang Hee; Yoo, Han Sang
We describe Salmonella control programs of broiler chickens, layer hens, and pigs in Denmark. Major reductions in the incidence of foodborne human salmonellosis have occurred by integrated control of farms and food processing plants. Disease control has been achieved by monitoring the herds and flocks, eliminating infected animals, and diversifying animals (animals and products are processed differently depending on Salmonella status) and animal food products according to the determined risk. In 2001, the Danish society saved U.S.$25.5 million by controlling Salmonella. The total annual Salmonella control costs in year 2001 were U.S.$14.1 million (U.S.$0.075/kg of pork and U.S.$0.02/kg of broiler or egg). These costs are paid almost exclusively by the industry. The control principles described are applicable to most industrialized countries with modern intensive farming systems.
Wegener, Henrik Caspar; Hald, Tine
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.
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 sal...
Patil, Satish R.; Ay, Kshirsagar; Mv, Ghorpade; Rv, Shinde
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 th...
Gunnarsson E; Hjartardóttir S; Sigvaldadóttir J
We evaluated which chromogenic agar medium for Salmonella detection in stool would be most sensitive and specific in our culture protocol. The use of BBL CHROMagar Salmonella chromogenic medium combined with xylose-lysine-deoxycholate agar yielded a sensitivity of 100% and also reduced workload and costs.
Dijk, Saskia; Bruins, Marjan J.; Ruijs, Gijs J. H. M.
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
Het Communautair Referentie Laboratorium voor Salmonella heeft een ringonderzoek voor de serotypering van Salmonella georganiseerd met deelname van alle Nationale Referentie Laboratoria (NRLs) voor Salmonella. Het doel van dit ringonderzoek was meer informatie te krijgen over de resultaten van de serotypering van Salmonella enterica in de NRLs. De deelnemende laboratoria moesten de stammen identificeren volgens de serotyperingsmethode die routinematig in hun laboratori...
Voogt N; Hme, Maas; Wj, Leeuwen; Am, Henken
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.
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.
Ndez, Jorge Hern X. E.; Peter Lindberg; Jonas Waldenström; Mirva Drobni; Rn Olsen, Bj X. F.
The MgtC is a virulence factor in Salmonella Typhimurium that is required for growth at low-Mg2+ concentrations and intramacrophage survival. This gene is codified in a conserved region of the Salmonella pathogenicity island 3 (SPI-3), and is also present in the chromosome of other Salmonella serovars. In this study we characterized the MgtC factor in S. Typhi, a human specific pathogen, by using mgtC and SPI-3 mutant strains. We found that MgtC is the most important factor codified in the SP...
Retamal, Patricio; Castillo-ruiz, Mario; Mora, Guido C.
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.
The eleventh interlaboratory comparison study on the typing of Salmonella was organised by the Community Reference Laboratory for Salmonella (CRL-Salmonella, Bilthoven, The Netherlands) in collaboration with the Health Protection Agency (HPA, London, United Kingdom) in March 2006. 26 National Reference Laboratories for Salmonella (NRLs-Salmonella), including Norway, and 31 Enter-Net Laboratories (ENLs), three of which also NRLs, participated in the study. In total, 20 strain...
Pa, Berk; Hme, Maas; Pinna E de; Ka, Mooijman
A nation-wide survey was conducted to estimate the prevalence of Salmonella enteritidis and other salmonellas among Canadian commercial broiler flocks. Environmental (litter and/or water) samples from 226 of 294 (76.9%) randomly selected flocks were contaminated with salmonellas. Litter samples were more often contaminated with salmonellas than water samples (47.4 v. 12.3%). Fifty different salmonella serovars were isolated. The most prevalent serovars were S. hadar, S. infantis, and S. schwa...
Poppe, C.; Irwin, R. J.; Messier, S.; Finley, G. G.; Oggel, J.
Field laboratories of the U.S. Food and Drug Administration collected and tested 11,312 import and 768 domestic seafood samples over a 9-year period (1990 to 1998) for the presence of Salmonella. The overall incidence of Salmonella was 7.2% for import and 1.3% for domestic seafood. Nearly 10% of import and 2.8% of domestic raw seafood were positive for Salmonella. The overall incidence of Salmonella in ready-to-eat seafood and shellfish eaten raw was 0.47% for domestic--one shucked oyster and one shark cartilage powder. The incidence in the 2,734 ready-to-eat import seafood was 2.6%--cooked shrimp, shellfish or fish paste, smoked fish, salted/dried fish, and caviar. The incidence in import shellfish consumed raw was 1% in oyster, 3.4% in clams, and 0% in mussels. The incidence in raw, import fish was 12.2%. Distribution of Salmonella in seafood on a regional basis indicated the incidence to be highest in central Pacific and Africa and lowest in Europe/Russia and North America (12% versus 1.6%). Data on a country basis indicated Vietnam to have the highest (30%) and Republic of Korea the lowest (0.7%). While the most frequent serotypes in import seafood were Salmonella Weltevreden (1st), Salmonella Senftenberg (2nd), Salmonella Lexington, and Salmonella Paratyphi-B (3rd, equal numbers for each serotype), the top 20 list included Salmonella enteritidis (5th), Salmonella Newport (6th), Salmonella Thompson (7th), Salmonella typhimurium (12th), and Salmonella anatum (13th), commonly involved in foodborne illness in the United States. Because the incidence in the present study is based on only a small fraction of the seafood imported into the United States, efforts should be directed toward implementation of hazard analysis and critical control points to reduce the incidence of Salmonella in seafood without relying on testing for Salmonella. PMID:10826714
Heinitz, M L; Ruble, R D; Wagner, D E; Tatini, S R
The sums propose to evaluate the bacterial contamination of certain food taken randomly by two pathogenic bacteria (Salmonella and Listeria) considering the evolution of the diseases of food oignon. For that 78 food samples of different origins were analysed. 2 stocks of the Listeria kind and 3 stocks of the salmonella kind were insulated and identified by biochemical and molecular tests. The pathogenic isolates were identified by coloration gram, test catalase, insulation on specific culture media and Api (20 E for Salmonella and Api listeria. At the end, the PCR were realized to amplify the gene iap which codes for the protein p60 at listeria as well as a sequence clonee randomly specific of Salmonella.
Full Text Available A total of 400 hatchery samples comprised of yolk interior (100, paper pad (100, shell membrane (100 and fecal swab of newly hatched chicks (100 were tested to detect the presence of Salmonella organism by bacteriological agar plate test. Positive cases recorded in this study were 37 (37, 12 (12, 3 (3 and 19 (19% from each sample (100 of yolk interior, paper pad, shell membrane and fecal swab of newly hatched chicks, respectively. A representative numbers of 50 isolates were used for the identification of serogoups of Salmonella prevailing in selected area by using polyvalent antisera. The result indicated that the test isolates 45(90% were typed to a specific serogroup of "O". All 45 isolated Salmonella serogroup ?O? were then characterized by different specific biochemical media. Based on these tests, the selective isolates were identified as Salmonella gallinarum.
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
Sensibilidad y especificidad del recuento de leucocitos en las materias fecales para predecir la presencia de Salmonella o Shigellaen pacientes con enfermedad diarreica aguda / Sensitivity and specificity of leukocyte count in feces as a predictor of stool culture positivity for Samonella or Shigella
Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish En la mayoría de los estudios que evalúan la presencia de leucocitos en las materias fecales no se determinan la sensibilidad y especificidad del examen de acuerdo con el recuento de dichas células. Objetivo: evaluar el recuento de leucocitos en las materias fecales como prueba diagnóstica para pred [...] ecir la presencia de Salmonella o Shigella. Diseño: estudio descriptivo de corte transversal en el Hospital Pablo Tobón Uribe, de Medellín, Colombia, en 905 coprocultivos hechos a pacientes hospitalizados con enfermedad diarreica aguda. Métodos: se registraron el recuento de leucocitos y el resultado del coprocultivo. Este último se tomó como el estándar de oro para evaluar el rendimiento de los diferentes valores del recuento. Resultados: los porcentajes de sensibilidad y especificidad de la prueba, de acuerdo con el recuento de leucocitos fueron, respectivamente: 1-5: 89,2% y 57,1%; 6-10: 86,2% y 52,8%; 11-20: 77,7% y 62,7%; 21-30: 63,9% y 76,3%; 31-50: 45,2% y 85,5%; más de 50: 28,3% y 90,9%. El área bajo la curva fue de 0,7699 (IC 95%: 0,7275-0,8123). Conclusiones: la sensibilidad de la prueba descendió y su especificidad aumentó en la medida en que se incrementaba el recuento de leucocitos en la materia fecal. La baja especificidad con los valores inferiores del recuento de leucocitos puede deberse a la presencia de otros agentes enteroinvasores o a enfermedades diarreicas de causas no infecciosas. Abstract in english In most studies of fecal leukocyte counts as predictors of the result of stool cultures the sensitivity and specificity were not determined. Objective: to evaluate fecal leukocyte counts as a predictor of the presence of Salmonella and Shigella. Design: a descriptive, cross section study was carried [...] out in 905 stool cultures at a university hospital in Medellín, Colombia. Results for Salmonella and Shigella were taken as the gold standard to evaluate the sensitivity and specificity of fecal leukocyte counts. Results: sensitivity and specificity, according to the level of the count, were, respectively: 1-5 leukocytes: 89.2% and 57.1%; 6-10 leukocytes: 86.2% and 52.8%; 11-20 leukocytes: 77.7% and 62.7%; 21-30 leukocytes: 63.9% and 76.3%; 31-50 leukocytes: 45.2% and 85.5%; more than 50 leukocytes: 28.3% and 90.9%. The area under the curve was 0.7699 (CI 95%: 0.7275-0.8123). Conclusions: sensitivity decreased and specificity increased with higher counts of fecal leukocytes. Low specificity with the lesser values of leukocyte counts may be due to either the presence of enteroinvasive pathogens other than Salmonella and Shigella, or to non-infectious diarrheal disease.
Mónica Cecilia, Cuartas Trujillo; Olga Lucía, Molina Upegui; Ana Cristina, Restrepo Ceballos; Claudia Yarely, Maya Carmona; Sergio, Jaramillo Veláquez; Jorge Hernando, Donado Gómez; John Jairo, Zuleta Tobón; Jaime Aberto, López Vargas.
A 33 year old woman with recurrent Salmonella enteritidis sepsis is described. Penicillins, ceftriaxone, ciprofloxacin, and chloramphenicol could not eradicate the salmonellas but a combination of high dose ciprofloxacin and ceftriaxone for the eighth episode successfully cured the infection. The combination of ciprofloxacin and ceftriaxone may be a valuable therapeutic regimen in patients with recurrent salmonella sepsis. Prolonged intrahepatic cholestasis resulting from granulomatous hepati...
Trauner, M.; Grasmug, E.; Stauber, R. E.; Hammer, H. F.; Hoefler, G.; Reisinger, E. C.
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.
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.
A total of 39 Salmonella enterica serovar Saintpaul strains from imported seafood, pepper and from environmental and clinical samples were analyzed for the presence of virulence genes, antibiotic resistance, plasmid and plasmid replicon types. Pulsed-field gel electrophoresis (PFGE) fingerprinting using the XbaI restriction enzyme and plasmid profiling were performed to assess genetic diversity. None of the isolates showed resistance to ampicillin, chloramphenicol, gentamicin, kanamycin, streptomycin, sulfisoxazole, and tetracycline. Seventeen virulence genes were screened for by PCR. All strains were positive for 14 genes (spiA, sifA, invA, spaN, sopE, sipB, iroN, msgA, pagC, orgA, prgH, lpfC, sitC, and tolC) and negative for three genes (spvB, pefA, and cdtB). Twelve strains, including six from clinical samples and six from seafood, carried one or more plasmids. Large plasmids, sized greater than 50 kb were detected in one clinical and three food isolates. One plasmid was able to be typed as IncI1 by PCR-based replicon typing. There were 25 distinct PFGE-XbaI patterns, clustered to two groups. Cluster A, with 68.5% similarity mainly consists of clinical isolates, while Cluster C, with 67.6% similarity, mainly consisted of shrimp isolates from India. Our findings indicated the genetic diversity of S. Saintpaul in clinical samples, imported seafood, and the environment and that this serotype possesses several virulent genes and plasmids which can cause salmonellosis. PMID:21645810
Akiyama, Tatsuya; Khan, Ashraf A; Cheng, Chorng-Ming; Stefanova, Rossina
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 colorles...
Freydiere, A. M.; Gille, Y.
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 relatedness and revealed 20 distinct genetic patterns among the 42 isolates. However, all DT104 isolates fell within 2 closely related genetic clusters. Other Salmonella isolates were genetically group...
White, David G.; Zhao, Shaohua; Mcdermott, Patrick F.; Ayers, Sherry; Friedman, Sharon; Sherwood, Julie; Breider-foley, Missy; Nolan, Lisa K.
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 Javia...
Jackson, Brendan R.; Griffin, Patricia M.; Cole, Dana; Walsh, Kelly A.; Chai, Shua J.
Abstract Salmonella is a human pathogen that is commonly found in poultry products. It is possible to decrease chicken carcass and egg contaminations by adding organic acids to the feed or drinking water at appropriate times. Medium chain fatty acids are be more antibacterial against Salmonella than short-chain fatty acids. The antibacterial effect of these acids is species specific. Bacteria that are unable to decrease intracellular pH accumulate organic acid anions in accordance...
Immerseel, Filip; Russell, James; Flythe, Michael; Gantois, Inne; Timbermont, Leen; Pasmans, Frank; Haesebrouck, Freddy; Ducatelle, Richard
In this study the feasibility of 50- and 60-mer oligonucleotides in microarray analysis for the detection and identification of antibiotic resistance genes in various Salmonella strains was assessed. The specificity of the designed oligonucleotides was evaluated, furthermore the optimal spotting concentration was determined. The oligonucleotide microarray was used to screen two sets of Salmonella strains for the presence of several antibiotic resistance genes. Set 1 consisted of strains with ...
Hoek, A. H. A. M.; Scholtens-toma, I. M. J.; Cloekaert, A.; Aarts, H. J. M.
Salmonellae are of major importance as causes of food borne disease. Classical diagnostic methods that rely on cultivation, Widal slide agglutination tests and biochemical tests for detecting Salmonella are time-consuming. More rapid identification is highly desirable for clinical and epidemiological reasons. This obstacle can be overcome by Fluorescence in situ Hybridization (FISH). FISH uses fluorescently labelled probes that hybridize specifically to complementary target sequences on the b...
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. Moreover, it can be easily performed within a maximum of 12 h from food sampling, thus allowing prompt detection of Salmonella spp. in the food stocks analyzed.
Ferretti, R.; Mannazzu, I.; Cocolin, L.; Comi, G.; Clementi, F.
Consumption of contaminated poultry meat is still an important cause of Salmonella infections in humans and there is a need for control methods that protect broilers from day-of-hatch until slaughter age against infection with Salmonella. Colonisation-inhibition, a concept in which a live Salmonella strain is orally administered to day-old chickens and protects against subsequent challenge, can potentially be used as control method. In this study, the efficacy of a Salmonella Typhimurium ?hilAssrAfliG strain as a colonisation-inhibition strain for protection of broilers against Salmonella Typhimurium was evaluated. Administration of a Salmonella Typhimurium ?hilAssrAfliG strain to day-old broiler chickens decreased faecal shedding and strongly reduced caecal and internal organ colonisation of a Salmonella Typhimurium challenge strain administered one day later using a seeder bird model. In addition, it was verified whether a colonisation-inhibition culture could be developed that protects against both Salmonella Enteritidis and Typhimurium. Therefore, the Salmonella Typhimurium ?hilAssrAfliG strain was orally administered simultaneously with a Salmonella Enteritidis ?hilAssrAfliG strain to day-old broiler chickens, which resulted in a decreased caecal and internal organ colonisation for both a Salmonella Enteritidis and a Salmonella Typhimurium challenge strain short after hatching, using a seeder bird model. The combined culture was not protective against Salmonella Paratyphi B varietas Java challenge, indicating serotype-specific protection mechanisms. The data suggest that colonisation-inhibition can potentially be used as a versatile control method to protect poultry against several Salmonella serotypes. PMID:24975814
De Cort, W; Mot, D; Haesebrouck, F; Ducatelle, R; Van Immerseel, F
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
Bacterial flagellins are important virulence-associated factors and strong inducers of inflammatory responses in mammalian hosts. Flagellins have also been investigated as potential vaccine adjuvants, either for induction of humoral or cellular immune responses, to different target antigens. In this study we investigated the adjuvant properties of three Salmonella enterica flagellins types (FliCd, FliCi and FljB) to an ovalbumin-derived CD8+ T cell-restricted epitope (OVA257–264). Although mice immunized with the three tested flagellins elicited antigen-specific activated CD8+ T cells, only animals immunized with FliCi and FliCd flagellins admixed with ovalbumin mounted specific in vivo cytotoxic responses to peptide-pulsed target cells. The present results indicate that Salmonella flagellins are endowed with type-specific adjuvant effects toward murine CD8+ T cells, a feature that may impact their use as adjuvants for prophylatic or therapeutic vaccines. PMID:24031176
Braga, Catarina J.M.; Massis, Liliana M.; Alencar, Bruna C.G.; Rodrigues, Maurício M.; Sbrogio-Almeida, M.E.; Ferreira, Luís C.S.
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 understanding of the complex interplay between Salmonella and their hosts, the molecular basis of host range restriction and unique pathobiology of Gallinarum remain largely unknown. Type VI Secretion S...
Blondel, Carlos J.; Yang, Hee-jeong; Castro, Benjami?n; Chiang, Sebastia?n; Toro, Cecilia S.; Zaldi?var, Mercedes; Contreras, Ine?s; Andrews-polymenis, Helene L.; Santiviago, Carlos A.
Many of the most virulent strains of Salmonella enterica produce two distinct Cu,Zn-superoxide dismutases (SodCI and SodCII). The bacteriophage-encoded SodCI enzyme makes the greater contribution to Salmonella virulence. We have performed a detailed comparison of the functional, structural, and regulatory properties of the Salmonella SodC enzymes. Here we demonstrate that SodCI and SodCII differ with regard to specific activity, protease resistance, metal affinity, and peroxidative activity, ...
Ammendola, Serena; Pasquali, Paolo; Pacello, Francesca; Rotilio, Giuseppe; Castor, Margaret; Libby, Stephen J.; Figueroa-bossi, Nara; Bossi, Lionello; Fang, Ferric C.; Battistoni, Andrea
Salmonella enterica, a leading cause of food-borne gastroenteritis worldwide, may be found in any raw food of animal, vegetable, or fruit origin. Salmonella serovars differ in distribution, virulence, and host specificity. Salmonella enterica serovar Kentucky, though often found in the food supply, is less commonly isolated from ill humans. The multidrug-resistant isolate S. Kentucky CVM29188, isolated from a chicken breast sample in 2003, contains three plasmids (146,811 bp, 101,461 bp, and ...
Fricke, W. Florian; Mcdermott, Patrick F.; Mammel, Mark K.; Zhao, Shaohua; Johnson, Timothy J.; Rasko, David A.; Fedorka-cray, Paula J.; Pedroso, Adriana; Whichard, Jean M.; Leclerc, J. Eugene; White, David G.; Cebula, Thomas A.; Ravel, Jacques
Full Text Available The present study was undertaken to know the seroprevalence of Salmonella and Mycoplasma gallisepticum (MG infection in six model breeder poultry farms (MBPFs located at kalapara Upazilla under Patuakhali district, Bangladesh. A total of 364 sera samples were collected from chickens belonging to six MBPFs. All sera samples were examined by rapid serum plate agglutination (SPA test using commercial Salmonella (SP and MG antigens to determine the presence of Salmonella and MG specific antibodies in different age and sex of birds belonging to MBPFs. In addition to that prevalence of Salmonella and Mycoplasma infection in MBPFs during rainy and winter seasons were also recorded. The results of serological tests were analyzed statistically. The overall prevalence of Salmonella and Mycoplasma infection in six MBPFs were recorded as 23.46% and 46.88% respectively. Prevalence of salmonella was recorded highest in rainy season (25.00% than the winter season (21.88. On the contrary, Mycoplasma infection was recorded highest in winter season (61.45% than the rainy season (51.74%. Both Salmonella and Mycoplasma infections were recorded highest in female birds (24.10% than the male birds (15.62%. The prevalence of MG infection decreased with the increase of age. MG infection recorded highest 71.42% at 18 weeks of age and lowest 50% at 22 weeks of age. On the other hand, the prevalence Salmonella infection was increased with the increase age. Salmonella infection was found highest 30.76% at 39 weeks of age and lowest 13.33% at 32 weeks of age. It was concluded from the present study that both Salmonella and MG infection were significantly present in all six MBPFs and SPA test could be used as a tool for quick detection of Salmonella and MG infection.
A total of 50 Salmonella enterica serovar Javiana isolates, isolated from food, environmental and clinical samples, were analyzed for antibiotic resistance, presence of virulence genes, plasmids and plasmid replicon types. To assess the genetic diversity, pulsed-field gel electrophoresis (PFGE) fingerprinting and plasmid profiles were performed. All of the isolates were sensitive to chloramphenicol, nalidixic acid, and sulfisoxazole, and four isolates showed intermediate resistance to gentamicin or kanamycin. Eleven isolates, including representatives from each of the source types, were resistant to ampicillin. Four isolates from either clinical or environmental sources were resistant to tetracycline, while an additional 20 isolates showed intermediate resistance to this drug. Fourteen isolates, primarily from food sources, showed intermediate resistance to streptomycin. The S. Javiana isolates were screened by PCR for 17 virulence genes (spvB, spiA, pagC, msgA, invA, sipB, prgH, spaN, orgA, tolC, iroN, sitC, IpfC, sifA, sopB, cdtB, and pefA). All isolates were positive for nine to fourteen of these genes, but none were positive for pefA, spvB and lpfC, which are typically present on the Salmonella virulence plasmid. Seven of the virulence genes including cdtB were found in all 50 isolates, suggesting that S. Javiana from food and environmental sources had virulence similar to clinical isolates. Four clinical isolates and two food isolates carried one or more plasmids of approximately 30, 38, and 58 kb, with the 58 kb plasmids belonging to incompatibility group IncFIIA. Two clinical isolates carried IncI1 type mega plasmid (80 kb), and one clinical isolate carried plasmids of 4.5 and 7 kb. The PFGE profiles resulted 34 patterns in five clusters at a 90% similarity threshold. Our results indicate that S. Javiana isolates have a diverse clonal population among the clinical, food and environmental samples and this serotype possesses several virulent genes and plasmids that can contribute to the development of salmonellosis in human. This study provides data that support the potential transmission of S. Javiana virulence factors from food and environmental sources to cause infections in humans. PMID:23628778
Mezal, Ezat H; Stefanova, Rossina; Khan, Ashraf A
The identification of Salmonella spp. from poultry meat was studied by comparing bacterial detection using the Gene-Trak colorimetric hybridization method, a PCR amplification kit and an Enzyme Linked Immunosorbent Assay (ELISA), and these methods were compared with the conventional methodology proposed by the United States Food and Drug Administration (US FDA) for detection of Salmonella in food samples. Forty positive and negative samples were studied. The three methods yielded similar results with levels of Salmonella greater than 10 CFU per sample, even when the samples were highly contaminated with competing bacteria. In contrast, 20 CFU of seed inoculum per sample was the lowest level of Salmonella detectable with all three methods and the standard culture method. The detection limits of the PCR and ELISA assays were 5 CFU/g after enrichment at 37 deg. C for 6 and 9 hours, respectively. Compared with conventional bacteriology, all three methods here demonstrated high sensitivity and specificity for Salmonella. (author)
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
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.
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. PMID:21381925
Rajtak, Ursula; Leonard, Nola; Bolton, Declan; Fanning, Séamus
In order to estimate the number of human Salmonella infections attributable to each of major animal-food source, and help identifying the best Salmonella intervention strategies, a microbial subtyping approach for source attribution was applied. We adapted a Bayesian model that attributes illnesses to specific sources and allows for the estimation of the differences in the ability of Salmonella subtypes and food types to result in reported salmonellosis. The number of human cases caused by different Salmonella subtypes is estimated as a function of the prevalence of these subtypes in the animal-food sources, subtype-related factors, and source-related factors. National-surveillance serotyping data from 1998 to 2007 were applied to the model. Results suggested that the relative contribution of the sources to salmonellosis varied during the 10 year period, and that eggs are the most important source of disease, being responsible for over 50 % of the cases in most years. Broilers followed in importance in 1999, 2000, 2001, 2002 and 2005, while swine was the second most important source in 2000, 2004 and 2007. Salmonella was seldom isolated from cattle and few cases were attributed to this source. The proportion of cases attributed to an unknown source varied substantially between years. We conclude that this is valid approach to attribute salmonellosis in Japan, and that and improved dataset would substantially improve results. This is the first indication of the relative contribution of different foods for human salmonellosis, and results may be used for further research, risk management and public health strategies.
Toyofuku, Hajime; Pires, Sara Monteiro
...Guidance for Industry: Prevention of Salmonella Enteritidis in Shell Eggs During Production...guidance entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During Production...FDA's final rule ``Prevention of Salmonella Enteritidis in Shell Eggs During...
...Guidance for Industry: Prevention of Salmonella Enteritidis in Shell Eggs During Production...industry entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During Production...FDA's final rule ``Prevention of Salmonella Enteritidis in Shell Eggs During...
A new Salmonella serotype, Salmonella enteritidis serotype Grandhaven (30(1):r:1,2), was isolated from the stool of a 35-year-old man with mild gastroenteritis. He had just returned from Sudan, Africa.
Mcdougal, D. L.; Treleaven, B. E.; Renshaw, E. C.
We have tested 750 Salmonella strains and 130 strains of other species of the family Enterbacteriaceae with the 4-methylumbelliferyl caprilate reagent (MUCAP) test. The MUCAP test is a fluorescence test for rapid identification of Salmonella strains. The non-Salmonella strains were strains sent for identification as suspected Salmonella strains and thus have phenotypes similar to those of Salmonella strains. All 748 tested Salmonella strains of subgroups I, II, III, and IV were positive in th...
Olsson, M.; Syk, A.; Wollin, R.
In many countries the incidence of human salmonella infections has markedly increased in recent years. To discuss recent developments and current understanding on the control of salmonella infections in animals, WHO organized a Consultation on the Control of Salmonella Infections in Animals: Prevention of Foodborne Salmonella Infections in Humans, held in Jena, Germany, on 21-26 November 1993. The present article summarizes the recommendations made by the participants on the pathoimmunogenesi...
Recently a chromosomal locus possibly specific for Salmonella enterica serovar Typhimurium DT104 has been reported that contains a multiple antibiotic resistance gene cluster. Evidence is provided that Salmonella enterica serovar Agona strains isolated from poultry harbor a similar gene cluster including the newly described floR gene, conferring cross-resistance to chloramphenicol and florfenicol.
Cloeckaert, Axel; Sidi Boumedine, Karim; Flaujac, Geraldine; Imberechts, Hein; D Hooghe, Inge; Chaslus-dancla, Elisabeth
In small scale poultry Salmonella colonization research, experiments are typically conducted using multiple adjacent floor pens within a single room or building. The spread of Salmonella among the pens and the presence of preexisting Salmonella may complicate the experimental design and influence t...
Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Se analizó la calidad microbiológica en 37 muestras de lechuga variedad criolla (Lactuca sativa var. Capitata L.) de distintos intermediarios en las provincias de San José y Cartago, en Costa Rica. Las muestras se recolectaron mediante muestreo no probabilístico por selección intencional. Se cuantif [...] icó Escherichia coli (NMP/g) como indicador de contaminación fecal y se determinó la presencia de patógenos específicos (Shigella y Salmonella), por cultivo y por PCR-Múltiple. En el 65% de las muestras analizadas se detectó E. coli, aunque no se encontró Shigella ni Salmonella por PCR-Múltiple o cultivo. Una posible explicación es que los niveles de contaminación de Shigella y Salmonella están por debajo de los límites de detección de ambos métodos (menos de 10(4) UFC/g para Shigella y menos de 10² UFC/g para Salmonella). Estos resultados establecen una base importante para continuar con este tema de investigación y analizar otras fuentes de transmisión de Shigella y Salmonella, dado que ambos patógenos son frecuentes en la región. Abstract in english The microbiological quality of 37 lettuce samples of the creole variety (Lactuca sativa var. Capitata L.) obtained from different intermediaries at the provinces of San José and Cartago, in Costa Rica was analyzed. The samples were collected through a non-probabilistic sampling with intentional sele [...] ction. Escherichia coli (NMP/g) was quantified as indicator of fecal contamination and the presence of specific pathogens (Shigella and Salmonella) was determined by culture and Multiplex-PCR. In 65% of the samples analyzed we detected E. coli, even though we did not find Shigella or Salmonella by Multiplex-PCR or culture. A possible explanation is that the Shigella or Salmonella contamination levels may have been under the detection limits for both methods (less than 10(4) CFU/g for Shigella, and less than 10² CFU/g for Salmonella). These results establish an important basis for continuing with this research subject and analyzing other sources of transmission of Shigella and Salmonella contamination, since both pathogens are frequent in the region.
Kenia, Barrantes; Rosario, Achí.
Poly D,L-lactide-co-glycolide (PLGA) nanoparticle-encapsulated honeybee (Apis melifera) venom promotes clearance of Salmonella enterica serovar Typhimurium infection in experimentally challenged pigs through the up-regulation of T helper type 1 specific immune responses.
Honeybee (Apis melifera) venom (HBV), which includes melittin and lipid-soluble ingredients (chrysin and pinocembrin), elicited increases in the CD4(+)/CD8(+) T lymphocyte ratio, relative mRNA expression levels of the T helper type 1 (Th 1) cytokines (interferon-? and IL-12) and reinforced viral clearance of an experimental porcine reproductive and respiratory syndrome (PRRS) virus infection in our previous study. On the basis of that previous study, we have now developed poly-d,l-lactide-co-glycolide (PLGA)-encapsulated HBV nanoparticles (P-HBV) for longer sustained release of HBV. We administered P-HBV to pigs via the rectal route, and then evaluated the potential immune-enhancing and bacterial clearance effects of P-HBV against Salmonella enterica serovar Typhimurium. The CD4(+)/CD8(+) lymphocyte ratio, proliferative capacity of peripheral blood lymphocytes and relative mRNA expression levels of IFN-? and IL-12 (produced mainly by Th1 lymphocytes) were significantly increased in the P-HBV group up to 2 weeks post-administration of P-HBV. After S. Typhimurium infection, the P-HBV group showed a marked reduction in microbial burden in feces and all tissue samples (including the ileum, cecum, colon, and mesenteric lymph node (MLN)), a significant increase in Th 1 cytokines (IFN-?, IL-2, and IL-12) and a marked decrease in a Th 2 cytokine (IL-4) in all tissue samples and peripheral blood lymphocytes. Thus, P-HBV may be a promising strategy for immune enhancement and prevention of S. Typhimurium or other bacterial infections. PMID:25193467
Lee, Jin-A; Jung, Bock-Gie; Kim, Tae-Hoon; Kim, Yun-Mi; Park, Min-Ho; Hyun, Pung-mi; Jeon, Jong-woon; Park, Jin-kyu; Cho, Cheong-Weon; Suh, Guk-Hyun; Lee, Bong-Joo
Salmonella Enteritidis emerged as a major egg-associated pathogen in the late 20th century. Epidemiologic data from England, Wales, and the United States indicate that S. Enteritidis filled the ecologic niche vacated by eradication of S. Gallinarum from poultry, leading to an epidemic increase in human infections. We tested this hypothesis by retrospective analysis of epidemiologic surveys in Germany and demonstrated that the number of human S. Enteritidis cases is inversely related to the pr...
Rabsch, W.; Hargis, B. M.; Tsolis, R. M.; Kingsley, R. A.; Hinz, K. H.; Tscha?pe, H.; Ba?umler, A. J.
Purpose: Rapid development of nanotechnology has recently brought significant attention to the extraordinary biological features of nanomaterials. The objective of the present investigation was to evaluate morphological characteristics of the assembles of gold and platinum nanoparticles (nano-Au and nano-Pt respectively), with Salmonella Enteritidis (Gram-negative) and Listeria monocytogenes (Gram-positive), to reveal possibilities of constructing bacteria-nanoparticle vehicles. Methods: Hydrocolloids of nano-Au or nano-Pt were added to two bacteria suspensions in the following order: nano-Au + Salmonella Enteritidis; nano-Au + Listeria monocytogenes; nano-Pt + Salmonella Enteritidis; nano-Pt + Listeria monocytogenes. Samples were inspected by transmission electron microscope. Results: Visualization of morphological interaction between nano-Au and Salmonella Enteritidis and Listeria monocytogenes, showed that nano-Au were aggregated within flagella or biofilm network and did not penetrate the bacterialcell. The analysis of morphological effects of interaction of nano-Pt with bacteria revealed that nano-Pt entered cells of Listeria monocytogenes and were removed from the cells. In the case of Salmonella Enteritidis, nano-Pt were seen inside bacteria cells, probably bound to DNA and partly left bacterial cells. After washing and centrifugation, some of the nano-Pt-DNA complexes were observed within Salmonella Enteritidis. Conclusion: The results indicate that the bacteria could be used as a vehicle to deliver nano-Pt to specific points in the body.
Sawosz, Ewa; Chwalibog, André
Lysogenic bacteriophages are a significant source of variability in closely related Salmonella strains. In this study, screening for diversity of 152 Salmonella Typhimurium strains was performed using PCR detection of selected prophage regions derived from phages P22, Gifsy-1, Gifsy-2, Fels-1, ST104 and SopEPhi. A high degree of variability was observed in the presence of specific genes. Based on the presence of particular prophage genes, we divided strains into 37 different PCR-prophage profiles; 20 of them were represented by only a single strain. Using multilocus variable number tandem repeats analysis (MLVA), 152 Salmonella strains were separated into 82 MLVA strings. Similar grouping of Salmonella strains was observed in the case of PCR-prophage detection and MLVA and the results corresponded well with the phage type of strains. However, several Salmonella strains were detected, which were closely related according to MLVA; yet, they differed in PCR phage profiles. The observations support a view that integration/excision of bacteriophages in Salmonella strains are frequent events shaping the bacterial genome. PMID:17355601
Drahovská, Hana; Mikasová, Eva; Szemes, Tomás; Ficek, Andrej; Sásik, Milan; Majtán, Viktor; Turna, Ján
Full Text Available Accurate and fast detection of harmful Salmonella is a major concern of food safety. Common Salmonella serotypes responsible for human associated foodborne outbreaks are S. Enteritidis, S. Hadar, S. Heidelberg, and S. Typhimurium are also commonly isolated from poultry. Serology is commonly used to monitor disease in poultry, therefore application of Salmonella serotype-specific test will have added value in Salmonella surveillance or monitoring vaccine efficacy. Recombinant flagellins were purified to be used as antigens in an ELISA. In this study, an ELISA was developed for the serological detection of S. Enteritidis. Once optimized, 500 ng of purified recombinant S. Enteritidis flagellin and a 1:64 dilution were determined to be optimal for testing sera. A negative baseline cutoff was calculated to be an optical density (OD of 0.35. All sera from birds with history of S. Enteritidis exposure tested positive and all sera from chickens with no exposure tested negative to this Salmonella serotype. Current ELISA for serological detection of Salmonella suffers from cross reactivity inherent in lipopolysaccharide (LPS or whole cell antigen based serological tests. This new ELISA eliminates common cross reactivity by focusing specifically on the flagellins of the Salmonella serotypes common in poultry and associated with foodborne outbreaks.
Charles L. Hofacre
Chronic infections caused by persistent pathogens represent an important health problem. Here, we establish a simple practical mouse Salmonella infection model for identifying bacterial maintenance functions that are essential for persistency. In this model, a substantial fraction of Salmonella survived even several days of treatment with a potent fluoroquinolone antibiotic indicating stringency of the model. Evaluation of twelve metabolic defects revealed dramatically different requirements for Salmonella during persistency as compared to acute infections. Disrupted synthesis of unsaturated/cyclopropane fatty acids was the only defect that resulted in rapid Salmonella clearance suggesting that this pathway might contain suitable targets for antimicrobial chemotherapy of chronic infection. PMID:22911873
Barat, Somedutta; Steeb, Benjamin; Mazé, Alain; Bumann, Dirk
Full Text Available Salmonella is an important pathogen for both humans andanimals. Although the organism has been intensively studiedduring the last century, much remains to be learned about thispathogen. The complicated nomenclature system of Salmonellahas long been a subject of discussion. In 2005, “Salmonellaenterica” finally gained official approval as the type species ofthe genus Salmonella. The genus Salmonella also contains thespecies “Salmonella bongori” in addition to a new species,“Salmonella subterranean”, which was recognized in 2005.Unlike other bacterial genera, Salmonella organisms are differentiatedby serotyping analysis. Presently, new serotypes(serovars are still being discovered each year, adding to thecomplexity of this large bacterial population. Despite the conservedgenetic background, molecular analysis has indicatedsuccessful evolution of the Salmonella genome in response tothe environment, particularly to the selective pressure from antimicrobial agents.Mechanisms of fluoroquinolone resistance in Salmonella are similar to the complex systemreported for other members of the family Enterobacteriaceae. On the other hand, resistanceto extended-spectrum cephalosporins is more likely to be mediated by blaCTX-M or ampCgenes that are carried on plasmids. Plasmid-borne genes have increased efficacy in the disseminationof resistance determinants, resulting in increased antimicrobial resistance. Toprovide clinicians with up-to-date information on this important pathogen, the evolvingnomenclature and clinical importance of Salmonella are reviewed.
The objective of this study was to identify risk factors associated with persistence of Salmonella shedding in finishing swine. A longitudinal study was conducted in 18 cohorts of pigs from three finishing sites of one swine production company. Among the 446 Salmonella isolates (isolated from 187 pigs), there were 18 distinct serovars. The six most common serovars were S. enterica serovar Derby (47.3%), S. Agona (27.4%), S. Johannesburg (10.5%), S. Schwarzengrund (2.7%), S. Litchfield (2.5%) and S. Mbandaka (2.2%). Survival analysis techniques, Kaplan-Meier methods and Log-rank test were used to estimate the duration of Salmonella shedding in days and to evaluate differences in shedding associated with risk factors at different organizational levels: isolate (serovar), pig, cohort and site. The risk factors at the pig-level were: sex, age and individual health status; and the risk factors at the cohort-level were: health risk, treatment and "at risk pigs" proportions, nursery and barn environment Salmonella status and prior exposure to the same serovar in the nursery or barn environment. Survival analysis using acceleration failure time models, with a log-normal distribution, was applied to investigate risk factors associated with Salmonella persistence (175 pigs) and serovar-specific persistence (151 pigs) during the study period. Pigs detected Salmonella positive for the first time at 10 weeks of age had a longer duration of shedding, than pigs first detected at an older age. The duration of shedding was shorter among pigs infected with S. Derby, S. Johannesburg and other serovars as compared to pigs infected with S. Agona. A significant difference was observed among sites. Cohorts with pig treatment proportions greater than the median were more likely to have a shorter duration of Salmonella shedding. Pigs from cohorts with nursery positive pools greater than the overall mean had a longer duration of Salmonella shedding as compared to pigs from cohorts with nursery pools less than or equal to the mean. These results suggest that the duration of Salmonella shedding may depend on Salmonella serovar, pig age at the time of infection, farm site and cohort-level risk factors. Identification of risk factors associated with the duration of shedding may allow more targeted interventions for the control Salmonella by evaluation of control measures not only for prevalence reduction, but also to decrease the duration of shedding. Such measures may decrease the risk of contamination of pork and subsequent risk of foodborne illness. PMID:25005468
Pires, A F A; Funk, J A; Bolin, C
The growth and appearance of 115 stock Salmonella isolates on a new formulation of CHROMagar Salmonella (CAS) medium were compared to those on xylose-lysine-desoxycholate agar (XLD), Salmonella-Shigella agar (SS), and Hektoen enteric agar (HEA) media. CAS medium was then compared prospectively to XLD and SS for the detection and presumptive identification of Salmonella strains in 500 consecutive clinical stool samples. All stock Salmonella isolates produced typical mauve colonies on CAS mediu...
Maddocks, Susan; Olma, Tom; Chen, Sharon
A Salmonella live vaccine causing both O4- and O9-specific immune responses would be of use, but no reported Salmonella serotype has both of these O antigens. Constructed Salmonella typhimurium strains with an rfb (O-antigen-specifying) gene cluster of type D in the chromosome and one of type B in an F'-rfb+ factor, and those with the reverse combination reacted strongly with both anti-O4 (and anti-O5) and anti-O9 sera and, if they carried recA, could be maintained in this state by growth con...
Johnson, B. N.; Weintraub, A.; Lindberg, A. A.; Stocker, B. A.
This study evaluates the usefulness of spatio-temporal statistical tools to detect outbreaks using routine surveillance data where limited epidemiological information is available. A dataset from 2002 to 2007 containing information regarding date, origin, source and serotype of 29 586 Salmonella isolates from Thailand was analysed. Data was grouped into human and non-human categories and the analysis was performed for the top five occurring serovars for each year of the study period. A total 91 human and 39 non-human significant spatio-temporal clusters were observed, accounting for 11% and 16% of the isolates, respectively. Serovar-specific associations between human and non-human clusters were also evaluated. Results show that these statistical tools can provide information for use in outbreak prevention and detection, in countries where only limited data is available. Moreover, it is suggested that monitoring non-human reservoirs can be relevant in predicting future Salmonella human cases.
Coutinho Calado Domingues, Ana Rita; Vieira, Antonio
Flagella are cell surface appendages involved in a number of bacterial behaviors, such as motility, biofilm formation, and chemotaxis. Despite these important functions, flagella can pose a liability to a bacterium when serving as potent immunogens resulting in the stimulation of the innate and adaptive immune systems. Previous work showing appendage overexpression, referred to as attenuating gene expression (AGE), was found to enfeeble wild-type Salmonella. Thus, this approach was adapted to...
Yang, Xinghong; Thornburg, Theresa; Suo, Zhiyong; Jun, Sangmu; Robison, Amanda; Li, Jinquan; Lim, Timothy; Cao, Ling; Hoyt, Teri; Avci, Recep; Pascual, David W.
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 Salmon...
Herrera Valde?s, Nilda E.; Ma. Elena Fuerte Calvo; Ma. Elena Díaz García; Daysi Rodríguez Larrinaga; Martha Sandoval Acosta; Mario Santiago Puga Torres
Test resultaten van Salmonella sero- en faagtypering en antimicrobiele gevoeligheidsbepalingen door de Nationale Referentie Laboratoria voor Salmonella in de Lidstaten van de Europese Unie en EnterNet Laboratoria: Ringonderzoek VI (2001) voor Salmonella. Een zesde ringonderzoek betreffende de typering van Salmonella werd georganiseerd door het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella, Bilthoven, Nederland) in samenwerking met Public Health L...
Korver H; Raes M; Hme, Maas; Lr, Ward; Wjb, Wannet; Am, Henken
Full Text Available Two patients with Reiter's syndrome, after Salmonella infection were treated on the Infections disease ward at Clinical hospital center in Kragujevac. In the first patient, ten days after the onset of Salmonella infection, signs of edema and pain in the right ankle occurred, accompanied by expressed conjunctivitis. Within next two months consecutive metatarsophalanges changes joint of the right foot have appeared. In the second patient, two weeks after the onset of Salmonella infection, edema of the left hand joints and a week later edema of the right hand and right ankle joints appeared. In both patients inflammatory syndrome was expressed (high erythrocyte sedimentation rates, fibrinogen, C-reactive protein along with negative rheumatoid factors and positive antigen HLA-B27. Outcome of the disease in both cases was favorable upon receiving nonsteroid antirheumatic therapy. Signs of arthritis disappeared after three months. No signs of recurrent arthritis have been seen during the next four years in the first and next two years in the second patient.
?anovi? Predrag S.
The host–pathogen interactions induced by Salmonella Typhi and Salmonella Paratyphi A during enteric fever are poorly understood. This knowledge gap, and the human restricted nature of these bacteria, limit our understanding of the disease and impede the development of new diagnostic approaches. To investigate metabolite signals associated with enteric fever we performed two dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC/TOFMS) on plasma from patients with S. Typhi and S. Paratyphi A infections and asymptomatic controls, identifying 695 individual metabolite peaks. Applying supervised pattern recognition, we found highly significant and reproducible metabolite profiles separating S. Typhi cases, S. Paratyphi A cases, and controls, calculating that a combination of six metabolites could accurately define the etiological agent. For the first time we show that reproducible and serovar specific systemic biomarkers can be detected during enteric fever. Our work defines several biologically plausible metabolites that can be used to detect enteric fever, and unlocks the potential of this method in diagnosing other systemic bacterial infections. DOI: http://dx.doi.org/10.7554/eLife.03100.001 PMID:24902583
Näsström, Elin; Vu Thieu, Nga Tran; Dongol, Sabina; Karkey, Abhilasha; Voong Vinh, Phat; Ha Thanh, Tuyen; Johansson, Anders; Arjyal, Amit; Thwaites, Guy; Dolecek, Christiane; Basnyat, Buddha; Baker, Stephen; Antti, Henrik
Full Text Available Salmonella is one of the major pathogenic bacteria present in contaminated water. 16-23S rRNA spacer region has been reported to be polymorphic at serovar level in Salmonella. Salmonella isolates obtained from Ganges river water were studied for 16-23S rRNA spacer region polymorphism. Thirty three isolates belonging to eight serovars (S. Typhimurium, S. Abuja, S. Pantypridd, S. Lagos, S. Chinkual, S. Zwickau, S. Goldenberg and S. Oritamerin were studied for the polymorphism. Out of 33 isolates, 15 different profiles were observed no serovar specific profile. Our findings indicate that 16-23S rRNA spacer region is not specific at serovar level, but can be used for differentiation of different Salmonella isolates.
Salmonella enterica subspecies 1 serovar Typhimurium encodes a type III secretion system (TTSS) within Salmonella pathogenicity island 1 (SPI-1). This TTSS injects effector proteins into host cells to trigger invasion and inflammatory responses. Effector proteins are recognized by the TTSS via signals encoded in their N termini. Specific chaperones can be involved in this process. The chaperones InvB, SicA, and SicP are encoded in SPI-1 and are required for transport of SPI-1-encoded effector...
Ehrbar, Kristin; Friebel, Andrea; Miller, Samuel I.; Hardt, Wolf-dietrich
Chronic infections caused by persistent pathogens represent an important health problem. Here, we establish a simple practical mouse Salmonella infection model for identifying bacterial maintenance functions that are essential for persistency. In this model, a substantial fraction of Salmonella survived even several days of treatment with a potent fluoroquinolone antibiotic indicating stringency of the model. Evaluation of twelve metabolic defects revealed dramatically different requirements ...
Barat, Somedutta; Steeb, Benjamin; Maze?, Alain; Bumann, Dirk
Swarming behavior among 167 Salmonella sp. isolates, representing all eight groups, was assessed. Only eight strains failed to swarm under standard conditions. Four of the defective strains swarmed on alternate carbon sources, and four harbored general defects in motility or lipopolysaccharide. Thus, swarming may represent an evolutionarily conserved behavior in Salmonella spp.
Kim, Wook; Surette, Michael G.
Full Text Available Brain abscess is an uncommon and serious life-threatening infection in children. Focal intracranial infections caused by Salmonella spp. in this age group are also rare. We report the case of a 4-month-old male infant with a frontoparietal brain abscess caused by Salmonella typhimurium , the presence of which was not suspected clinically.
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)
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.
Muniz-Junqueira Maria Imaculada
Colanic acid (CA) is a common exopolysaccharide produced by many genera in the Enterobacteriaceae. It is critical for biofilm formation on HEp-2 cells and on chicken intestinal tissue by Salmonella. In this study, we generated different CA synthesis gene mutants and evaluated the immune responses induced by these mutants. One of these mutations, ?(wza-wcaM)8, which deleted the whole operon for CA synthesis, was introduced into two Salmonella vaccine strains attenuated by auxotrophic traits or by the regulated delayed attenuation strategy (RDAS). The mice immunized with the auxotrophic Salmonella vaccine strain with the deletion mutation ?(wza-wcaM)8 developed higher vaginal IgA titers against the heterologous protective antigen and higher levels of antigen-specific IgA secretion cells in lungs. In Salmonella vaccine strains with RDAS, the strain with the ?(wza-wcaM)8 mutation resulted in higher levels of protective antigen production during in vitro growth. Mice immunized with this strain developed higher serum IgG and mucosal IgA antibody responses at 2 weeks. This strain also resulted in better gamma interferon (IFN-?) responses than the strain without this deletion at doses of 10(8) and 10(9) CFU. Thus, the mutation ?(wza-wcaM)8 will be included in various recombinant attenuated Salmonella vaccine (RASV) strains with RDAS derived from Salmonella enterica serovar Paratyphi A and Salmonella enterica serovar Typhi to induce protective immunity against bacterial pathogens. PMID:23774599
Wang, Shifeng; Shi, Huoying; Li, Yuhua; Shi, Zhaoxing; Zhang, Xin; Baek, Chang-Ho; Mothershead, Tabor; Curtiss, Roy
Full Text Available Abstract Background Accurate assessment of probiotics with targeted anti-Salmonella activity requires suitable models accounting for both, microbe-microbe and host-microbe interactions in gut environments. Here we report the combination of two original in vitro intestinal models closely mimicking the complex in vivo conditions of the large intestine. Effluents from continuous in vitro three-stage fermentation colonic models of Salmonella Typhimurium infection inoculated with immobilized child microbiota and Salmonella were directly applied to confluent mucus-secreting HT29-MTX cell layers. The effects of Salmonella, addition of two bacteriocinogenic strains, Bifidobacterium thermophilum RBL67 (thermophilicin B67 and Escherichia coli L1000 (microcin B17, and inulin were tested on Salmonella growth and interactions with epithelial cell layers. Salmonella adhesion and invasion were investigated and epithelial integrity assessed by transepithelial electrical resistance (TER measurements and confocal microscopy observation. Data from complex effluents were compared with pure Salmonella cultures. Results Salmonella in effluents of all reactors of the colonic fermentation model stabilized at mean values of 5.3 ± 0.8 log10 cfu/ml effluent. Invasion of cell-associated Salmonella was up to 50-fold lower in complex reactor samples compared to pure Salmonella cultures. It further depended on environmental factors, with 0.2 ± 0.1% being measured with proximal, 0.6 ± 0.2% with transverse and 1.3 ± 0.7% with distal reactor effluents, accompanied by a similar high decrease of TER across cell monolayers (minus 45% and disruption of tight junctions. Subsequent addition of E. coli L1000 stimulated Salmonella growth (6.4 ± 0.6 log10 cfu/ml effluent of all 3 reactors and further decreased TER, but led to 10-fold decreased invasion efficiency when tested with distal reactor samples. In contrast, presence of B. thermophilum RBL67 revealed a protective effect on epithelial integrity compared to previous E. coli L1000 periods, as reflected by a significant mean increase of TER by 58% in all reactors. Inulin addition enhanced Salmonella growth and invasion when tested with distal and proximal reactor samples, respectively, but induced a limited decrease of TER (minus 18% in all reactors. Conclusions Our results highlight the benefits of combining suitable cellular and colonic fermentation models to assess strain-specific first-level host protection properties of probiotics during Salmonella infection, providing an efficient system biology tool for preclinical development of new antimicrobials.
Full Text Available Abstract Background The EU Regulation No 2160/2003 imposes a reduction in the prevalence of Salmonella in pigs. The efficiency of control programmes for Salmonella in pigs, reported among the EU Member States, varies and definitive eradication seems very difficult. Control measures currently recommended for Salmonella are not serotype-specific. Is it possible that the risk factors for different Salmonella serotypes are different? The aim of this study was to investigate potential risk factors for two groups of Salmonella sp serotypes using pen faecal samples from breeding pig holdings representative of the Portuguese pig sector. Methods The data used come from the Baseline Survey for the Prevalence of Salmonella in breeding pigs in Portugal. A total of 1670 pen faecal samples from 167 herds were tested, and 170 samples were positive for Salmonella. The presence of Salmonella in each sample (outcome variable was classified in three categories: i no Salmonella, ii Salmonella Typhimurium or S. Typhimurium-like strains with the antigenic formula: 1,4,5,12:i:-, , and iii other serotypes. Along with the sample collection, a questionnaire concerning herd management and potential risk factors was utilised. The data have a “natural” hierarchical structure so a categorical multilevel analysis of the dataset was carried out using a Bayesian hierarchical model. The model was estimated using Markov Chain Monte Carlo methods, implemented in the software WinBUGS. Results The significant associations found (when compared to category “no Salmonella”, for category “serotype Typhimurium or S. Typhimurium-like strains with the antigenic formula: 1,4,5,12:i:-” were: age of breeding sows, size of the herd, number of pigs/pen and source of semen. For the category “other serotypes” the significant associations found were: control of rodents, region of the country, source of semen, breeding sector room and source of feed. Conclusions The risk factors significantly associated with Salmonella shedding from the category “serotype Typhimurium or serotype 1,4,5,12:i:-“ were more related to animal factors, whereas those associated with “other serotypes” were more related to environmental factors. Our findings suggest that different control measures could be used to control different Salmonella serotypes in breeding pigs.
Salmonella enterica species are Gram-negative bacteria, which are responsible for a wide range of food- and water-borne diseases in both humans and animals, thereby posing a major threat to public health. Recently, there has been an increasing number of reports, linking Salmonella contaminated raw vegetables and fruits with food poisoning. Many studies have shown that an essential feature of the pathogenicity of Salmonella is its capacity to cross a number of barriers requiring invasion of a large variety of cells and that the extent of internalization may be influenced by numerous factors. However, it is poorly understood how Salmonella successfully infects hosts as diversified as animals or plants. The aim of this review is to describe the different stages required for Salmonella interaction with its hosts: (i) attachment to host surfaces; (ii) entry processes; (iii) multiplication; (iv) suppression of host defense mechanisms; and to point out similarities and differences between animal and plant infections. PMID:25653644
Wiedemann, Agnès; Virlogeux-Payant, Isabelle; Chaussé, Anne-Marie; Schikora, Adam; Velge, Philippe
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.
Listeria monocytogenes and Salmonella are two major foodborne pathogens of significant concern. Two optical evanescent wave immunosensors were evaluated for detection: Antibody-coupled fiber-optic biosensor and a surface plasmon resonant (SPR) immunosensor. In the fiber-optic sensor, polyclonal antibodies for the test organisms were immobilized on polystyrene fiber wave -guides using streptavidin - biotin chemistry. Cyanine 5 -labeled monoclonal antibodies C11E9 (for L. monocytogenes) and SF-11 (for Salmonella Enteritidis) were used to generate a specific fluorescent signal. Signal acquisition was performed by launching a laser-light (635 nm) from an Analyte-2000. This immunosensor was able to detect 103 - 109 cfu/ml of L. monocytogenes or 106-109 cfu/ml of Salmonella Enteritidis and the assays were conducted at near real-time with results obtained within one hour of sampling. The assays were specific and showed signal even in the presence of other microorganisms such as E. coli, Enterococcus faecalis or Salmonella Typhimurium. In the SPR system, IAsys instrument (resonant mirror sensor) was used. Monoclonal antibody-C11E9 was directly immobilized onto a carboxylate cuvette. Whole Listeria cells at various concentrations did not yield any signal while surface protein extracts did. Crude protein extracts from L. monocytogenes and L. innocua had average binding responses of around 150 arc sec (0.25 ng/mm2), which was significantly different from L. grayi, L. ivanovii, or L. welshimeri with average responses of monocytogenes and Salmonella Enteritidis.
Bhunia, Arun K.; Geng, Tao; Lathrop, Amanda; Valadez, Angela; Morgan, Mark T.
The diversity of 55 Salmonella-specific bacteriophages isolated from 191 fecal samples of poultry and swine from farms located in diverse geographic areas of Spain was determined using lysis profiling, DNA restriction and random amplification of polymorphic DNA (RAPD-PCR). Among them, lysis profiling and RAPD-PCR exhibited 100% typeability and DNA restriction 96%, with discriminatory power of 0.978 (± 0.016), 0.938 (± 0.028) and 0.982 (± 0.013), respectively. The highest concordance (0.974) was that between RAPD-PCR and lysis profiling. None of the bacteriophages isolated from poultry and swine shared any DNA restriction or RAPD-PCR patterns and only two lysis profiles were common to bacteriophages isolated from poultry and swine. The major part of the lysis and RAPD-PCR profiles from the bacteriophages isolated from poultry included only one or two bacteriophages, while those obtained from swine contained more than two bacteriophages. Overall, our results provide evidence of the remarkable diversity exhibited by bacteriophages of Salmonella in farm animals. Moreover, they also show that RAPD-PCR may also be suitable for the pre-screening of the diversity of Salmonella bacteriophages for further use in biocontrol and therapeutic strategies. PMID:25670704
Cortés, Pilar; Spricigo, Denis A; Bardina, Carlota; Llagostera, Montserrat
Transovarian passage of salmonella was evaluated in snakes by cesarean delivery and subsequent bacteriological examination of fetuses. In all cases, the same Salmonella serotype was isolated from the feces of gravid females and their fetuses. The visceral distribution of salmonella in normal snakes was found to involve almost all visceral organs. Of nonenteric organs examined, salmonella was recovered most often from the livers and ureters. Experimental infections with Salmonella typhimurium ...
Chiodini, R. J.
Salmonella spp. in raw broiler parts: occurrence, antimicrobial resistance profile and phage typing of the Salmonella Enteritidis isolates Salmonella spp. em cortes de frango: ocorrência, resistência antimicrobiana e fagotipificação dos isolados de Salmonella Enteritidis
The present study was carried out to evaluate the occurrence of Salmonellae in raw broiler parts and to determine the antimicrobial resistance profile of the isolated strains. Twenty-four (39.3%) broiler parts samples were positive for Salmonella and twenty-five Salmonella strains were isolated, since two different serovars were detected in one single positive sample. Salmonella Enteritidis was the most prevalent serovar. Among Salmonella Enteritidis isolates, 95.2% belonged to Phage Type 4 (...
Aldemir Reginato Ribeiro; Aline Kellermann; Luciana Ruschel dos Santos; Marjo Cadó Bessa; Vladimir Pinheiro do Nascimento
To protect consumers from Salmonella infection acquired through the consumption of pork meat, it is necessary to eradicate Salmonella from pork. In order to achieve this, the whole pork production chain should be free from Salmonella, including the pigs at the farm. In epidemiological studies it was concluded that the use of fermented feed plays a significant role in the reduction of Salmonella prevalence in pig farms. However, the mechanism of Salmonella reduction in fermented feed is not kn...
Winsen, R. L.; Lipman, L. J. A.; Biesterveld, S.; Urlings, B. A. P.; Snijders, J. M. A.; Knapen, F.
Of eight Salmonella, serB-linked hsd genes for the restriction and modification of DNA transferred to Escherichia coli/Salmonella hybrids, only two--those with SM and ST (S. muenchen and S. thompson, respectively) specificities--may have weakly complemented rSB- and none complemented rK-. An A-specific DNA probe failed to hybridize to HindIII-restricted fragments of each of the hybrids, but an SB (S. typhimurium)-specific probe hybridized to DNA from the hybrid with ST specificity. These results indicate that additional families of the type I hsd genes may exist. PMID:3056913
Ryu, J; Rajadas, P T; Bullas, L R
The serum and whey agglutination test were compared on paired samples from thirty-five cases of bovine abortion associated with Salmonella dublin infection. The whey test proved nearly as useful as the serum test for confirming an active infection though it was only practicable to examine the whey for flagellar antibodies. S. dublin was isolated from nearly half of the milk samples obtained within the first week of abortion but none of those collected after the fourth week. The whey test proved of no value in retrospective identification of abortion cases. The trial using the milk ring test was disappointing. PMID:4518346
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.
Validity of methodsExperiments were carried out In which it was assessed which Salmonella isolation method is the most productive one In the examination of broiler carcasses. Refrigerated, refrigerated and radiated (2.50 kGy), frozen and frozen and radiated (2.50 kGy) samples of broilers were examined. After evaluation of all results It was concluded that the following method was the most productive one:1. pre-enrichment in buffered peptone water at 37 °C for 20 hours2. enrichm...
Mulder, R. W. A. W.
Aims: To monitor if a temperature-humidity-time treatment found to be effective in eliminating Salmonella in laboratory trials (Gradel et al. 2003) was efficient against Salmonella in naturally infected layer houses. Methods and Results: Six layer houses with natural Salmonella infections were steam treated in a download period, aiming at greater than or equal to60degreesC and 100% relative humidity (RH) during a 24-h period, with or without the addition of 30 ppm formaldehyde. In addition, two control layer houses were disinfected chemically. Salmonella samples taken from predetermined sites before and after treatment were tested qualitatively for Salmonella and coliforms. Samples with indicator bacteria (feed inoculated with Escherichia coli or Enterococcus faecalis and faeces with naturally occurring E. coli and enterococci) were placed during steam-treatment at 12 sites in each house (where the temperature was logged at 5-min intervals) and tested for surviving bacteria. Generally, the field test results confirmed the results of laboratory tests, especially when 30 ppm formaldehyde was added to the steam. In well-sealed houses, the recommended temperature-humidity-time scheme was accomplished at a minimum of 10 cm above floor level within 1 h. Conclusions: A steam treatment of greater than or equal to60degreesC and 100% RH during a 24-h period with the addition of 30 ppm formaldehyde at the beginning of the process is recommended for eliminating Salmonella from naturally infected poultry layer houses. Significance and Impact of the Study: A specific recommendation for the elimination of Salmonella in poultry houses can be given.
Gradel, K.O.; JØrgensen, J.C.
Finishing pigs infected with Salmonella pose significant food safety risks by carrying the pathogen into abattoirs. This study was conducted to determine the dynamics of Salmonella infection in finishing pigs, and associated immunological, physiological, and behavioral alterations, by longitudinally comparing infected to noninfected pigs during 6 weeks postinfection (p.i.). Bacteriological data revealed that all inoculated pigs started shedding Salmonella within 2?h p.i., and persistently shed the bacteria up to the end of the study. Ileal and cecal contents, as well as mesenteric lymph node samples, were all positive throughout the study, containing 3-4 log(10) cfu/g of Salmonella at 24?h p.i., and 4-5 log(10) cfu/g of Salmonella up to 4 weeks p.i. Levels of Salmonella dropped markedly (p?lymph nodes by 48?h p.i.; (2) at 24?h and 3 weeks p.i. in the ileum; and (3) in the cecum and spleen at 3 weeks p.i. Interleukin-12, interleukin-1 and its antagonist, and a porcine-specific antimicrobial peptide RNA expression in tissues changed over time, but were not different between groups. Infected pigs spent more time in ventral recumbency, standing, and sitting than controls (p??0.10). This study shows that finishing pigs can carry high levels of Salmonella for up to 4 weeks p.i. in the gastrointestinal contents and mesenteric lymph nodes, shedding high levels of the bacteria without developing clinical symptoms, but developing an immune response throughout the intestinal tract. Moreover, subtle behavioral changes measured as postures were detected, and therefore warrant additional investigation. PMID:21254892
Rostagno, Marcos H; Eicher, Susan D; Lay, Donald C
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.
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. PMID:23910950
Grzymaj?o, Krzysztof; Ugorski, Maciej; Kolenda, Rafa?; K?dzierska, Anna; Ku?mi?ska-Bajor, Marta; Wieliczko, Alina
Het Communautair Referentie Laboratorium (CRL) voor Salmonella heeft een ringonderzoek voor de serotypering van Salmonella georganiseerd. De Nationale Referentie Laboratoria (NRLs) voor Salmonella uit 14 van de 15 lidstaten van de Europese Unie deden aan het onderzoek mee. Het doel was te onderzoeken of de NRLs serotypen van Salmonella enterica subsp. enterica correct konden identificeren. Twintig serotypen van Salmonella enterica subsp. enterica werden door het CRL g...
Voogt N; Hme, Maas; Wj, Leeuwen; Am, Henken
Salmonella is a major foodborne pathogen and porcine products are an important source. With this in mind, pork sausages were surveyed for Salmonella prevalence. Sausages were sampled during August-December 2008, none of which were positive for Salmonella. As an alternative porcine source of salmonella, 102 pig ear pet treats were surveyed from October 2008 to September 2009. Salmonella was detected in 24.5% of treats using a culture detection method and 28.4% using peR. As dogs...
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
The aim of this study was to evaluate the phenotypic and genotypic properties of nonlysogenic Salmonella Typhimurium (ST(P22-)) and lysogenic Salmonella Typhimurium (ST(P22+)) in the presence of sublethal concentrations (SLC2D) of citrus essential oils (CEOs), which were used to evaluate antimicrobial susceptibility, cell surface hydrophobicity, autoaggregation ability, bacterial motility, lysogenic conversion, gene expression patterns, and antibiofilm formation. The SLC2D values of non-heat-treated (N-CEO) and heat-treated (H-CEO) CEO in an autoclave at 121°C for 20 min were 2.0 to 2.1 mg/ml against ST(P22-) and 1.7 to 1.9 mg/ml against STP(22+). The rates of injured ST(P22-) and ST(P22+) cells treated with SLC2D of N-CEO and H-CEO ranged from 67 to 83%. The hydrophobicity and autoaggregation were decreased to 2.5 and 19.5% for ST(P22-) and 4.7 and 21.7% for ST(P22+), respectively, in the presence of N-CEO. A noticeable reduction in the swarming motility was observed in ST(P22-) with N-CEO (14.5%) and H-CEO (13.3%). The numbers of CEO-induced P22 were 5.40 log PFU/ml for N-CEO and 5.65 log PFU/ml for H-CEO. The relative expression of hilA, hilC, hilD, invA, invC, invE, invF, sirA, and sirB was down-regulated in ST(P22-) and ST(P22+) with N-CEO and H-CEO. The numbers of adherent ST(P22-) and ST(P22+) were effectively reduced by more than 1 log in the presence of CEO. These results suggest that CEO has potential to be used to control bacterial attachment, colonization, and invasion. PMID:24780330
Ahn, Juhee; Almario, Jose Alejandro; Salaheen, Serajus; Biswas, Debabrata
EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on a review on the European Union Summary reports on trends and sources zoonoses, zoonotic agents and food-borne outbreaks in 2009 and 2010 – specifically for the data on Salmonella, Campylobacter, verotoxigenic Escherichia coli, Listeria monocytogenes and foodborne outbreaks
The European Union (EU) Summary Reports on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2009 and 2010 – specifically for the data on Salmonella, Campylobacter, verotoxigenic Escherichia coli, Listeria monocytogenes and foodborne outbreaks was reviewed. The main conclusions and recommendations are reported. Comparison between EU Member States (MSs) was found to be difficult due to the differences of the methods used, sampling schemes and reporting systems. Methods, sampling schemes and reporting systems among MSs should therefore be harmonised. When comparing MS-specific trends, the impact of sample sizes, weight of samples and methodologies should be considered, as these variables could otherwise lead to misinterpretation of the data. Incidence data alone do not provide a full picture of the public health burden of zoonotic diseases. Fatalities provide another important insight. Ultimately, summary measures of public health such as disability adjusted life years (DALYs) and cost-of-illness estimates should be presented. Travel information was found to be still incomplete in many MSs. For many pathogens this hampers source attribution. To better understand the public health problems related to food and animal sources in the EU, it is desirable to differentiate between travel within and outside the EU. This would also be useful to better evaluate the public health impact of EU-wide food safety measures. Whenever possible the data/results should be analysed using proper statistical tools. When data do not allow for this, the text should be kept to presenting the data without implying any patterns or trends.
In this study, 151 (18.6%) of 814 ceca obtained during in-line processing of 28 broiler (Hybro G, Avian, Arbor acres, and Cobb breeds) and 5 layer (Ross, Tetra SL, Isa Brown, and Brown Nick breeds) flocks in Turkey were found to be contaminated with four different Salmonella serovars. Only Salmonella enterica subsp. enterica Serovar Enteritidis (Salmonella Enteritidis) was recovered from layer birds, whereas Salmonella Enteritidis (81.5%). Salmonella Agona (7.6%), Salmonella Thompson (10.1%), and Salmonella Sarajane (0.8%) were isolated from broiler birds. Isolations of Salmonella Agona and Salmonella Thompson from poultry are reported for the first time in Turkey. The isolation of Salmonella Sarajane from chickens is the first report in the world. The standard method of National Poultry Improvement Plan, U.S. Department of Agriculture, was used to detect Salmonella from chicken cecal samples. Primary and delayed secondary enrichments (PE and DSE) were done in tetrathionate-Hajna broth (TTHB). Two different agar media, xylose lysine tergitol 4 (XLT4) and brilliant green with novobiocin (BGN) were used to observe, and compared for their isolation and selective differentiation of, Salmonella-suspected colonies. Isolated salmonellae were then biotyped and serotyped. Ninety-one and 151 salmonellae were isolated with XLT4 agar after PE and DSE, respectively. From the same samples, BGN agar was able to detect only 50 and 131 Salmonella after PE and DSE, respectively. The isolation rate with XLT4 was 11.2% (P broiler flocks and from 60.0% (3 of 5) of the layers. The detection sensitivity of the isolation method was determined as 1 CFU g(-1) experimentally. These data demonstrate the presence of Salmonella Enteritidis, Salmonella Thompson, Salmonella Agona, and Salmonella Sarajane in chicken flocks in Turkey. PMID:11726169
Carli, K T; Eyigor, A; Caner, V
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.
Salmonella enteritidis es un microorganismo que raramente afecta al componente muscular. Recogemos el caso de un paciente varón con Síndrome de Inmunodeficiencia Adquirida (SIDA), que tras un episodio de gastroenteritis aguda debida a Salmonella enteritidis presenta, varios meses después, una necrosis muscular masiva en los miembros inferiores, que le llevó al shock séptico y posteriormente a la muerte.Salmonella enteritidis is a microorganism which rarely affects muscles. We report ...
Baeta, P.; Ferna?ndez Palacios, J.; Marrero, T.; Sua?rez, O.
Salmonellosis caused by Salmonella bacteria is a food-borne disease and worldwide health threat causing millions of infections and thousands of deaths every year. This pathogen infects an usually broad range of host organisms including human and plants. A better understanding of the mechanisms of communication between Salmonella and its hosts requires identifying the interactions between Salmonella and host proteins. Protein-protein interactions (PPIs) are the fundamental building blocks of c...
Schleker, Sylvia; Garcia-garcia, Javier; Klein-seetharaman, Judith; Oliva, Baldo
A microtitration plate, antibody-capture, enzyme-linked immunosorbent assay was developed for detection of Salmonella typhimurium. The assay utilizes a monoclonal detector antibody which shows no cross-reactions with non-Salmonella species and only a slight cross-reaction with one other Salmonella serotype. By using only one cultural stage (in a nonselective, chemically defined medium) prior to the enzyme-linked immunosorbent assay, low numbers of cells in food (10 cells 25 g-1) were detected...
Lee, H. A.; Wyatt, G. M.; Bramham, S.; Morgan, M. R.
The Salmonella dublin virulence plasmid mediates systemic infection in mice and cattle. Here, we analyze the interaction between wild-type and plasmid-cured Salmonella strains with phagocytes in vitro and in vivo. The intracellular recovery of S. dublin from murine peritoneal and bovine alveolar macrophages cultured in the presence of gentamicin in vitro was not related to virulence plasmid carriage. However, the virulence plasmid increased the lytic activity of S. dublin, Salmonella typhimur...
Guilloteau, L. A.; Wallis, T. S.; Gautier, A. V.; Macintyre, S.; Platt, D. J.; Lax, A. J.
An investigation was carried out to establish the occurrence of Salmonellae in household wall lizards (Gecko gecko and Hemidactylus sp.) in Nsukka, Nigeria. Twentyseven out of 90 geckos examined yielded positive Salmonella isolations, giving a carrier-rate of 30 per cent. While 2 isolates were non-typable, the other 25 strains belonged to 6 serotypes: Salmonella weltevreden (8 strains), Salmonella typhimurium, Salmonella enteritidis, Salmonella hvittingfos, Salmonella saintpaul, and Salmonella agama. Two serotypes, Salmonella weltevreden and Salmonella hvittingfoss are reported for the first time in Nigeria. The role of Geckonidae in the epidemiology of salmonellosis and the public health implications of geckoborn Salmonellae are highlighted. PMID:3833829
Oboegbulem, S I; Iseghohimhen, A U
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.
The beneficial effects of probiotic Enterococcus spp. in different hosts, such as mice and humans, have previously been reported in several studies. However, studies of large domestic animals, as well as challenge studies with pathogenic microorganisms, are very rare. Here, we investigated the influence of oral treatment of pigs with the probiotic bacterium Enterococcus faecium NCIMB 10415 on Salmonella enterica serovar Typhimurium DT104 infections in weaning piglets. Clinical symptoms, fecal excretion, the organ distribution of Salmonella, and the humoral immune response (immunoglobulin G [IgG], IgM, and IgA levels) in serum were examined. A pool of 89 piglets was randomly divided into probiotic and control groups. The probiotic group received a feed supplement containing E. faecium starting on day 14 postpartum prior to challenge with Salmonella serovar Typhimurium DT104 at 28 days postpartum. After challenge with Salmonella serovar Typhimurium DT104, piglets in both groups showed no severe clinical signs of salmonellosis. However, fecal excretion and colonization of Salmonella in organs were significantly greater in piglets fed E. faecium. Likewise, the humoral immune response against Salmonella (serum IgM and IgA levels) was significantly greater in the probiotic group animals than in control animals. The results of this study suggest that E. faecium NCIMB 10415 treatment enhanced the course of infection in weaning piglets challenged with Salmonella serovar Typhimurium DT104. However, the probiotic treatment also appeared to result in greater production of specific antibodies against Salmonella serovar Typhimurium DT104. PMID:19270131
Szabó, István; Wieler, Lothar H; Tedin, Karsten; Scharek-Tedin, Lydia; Taras, David; Hensel, Andreas; Appel, Bernd; Nöckler, Karsten
The 24 most frequently isolated paratyphoids from poultry, along with Salmonella gallinarum and Salmonella pullorum, plus strains of Arizona, Citrobacter, Edwardsiella, Escherichia, Klebsiella, Prteus, Pseudomonas, Serratia and Shigella were inoculated into triple sugar iron (TSI) and lysine iron (LI) slants and into six fermentation broths which were numbered: 1 (dextrose), 2 (lactose), 3 (sucrose), 4 (mannitol), 5 (maltose), 6 (dulcitol). All the salmonella cultures (except S. pullorum) gave a 1, 4, 5, 6 code which means they produced acid, and in most cases gas, in dextrose, mannitol, maltose and dulcitol, but no acid or gas in lactose and sucrose. S. pullorum gave a 1, 4 code. All non-salmonella cultures gave a fermentation pattern different from the 1, 4, 5, 6 pattern of paratyphoids and S. gallinarum. Therefore, this six sugar system can be successfully used in the selection of suspect salmonella cultures for specific typing. Results from a miniaturized system (Minitek) were the same as those from the standard tube method for the carbohydrate fermentation tests for all cultures tested. PMID:995819
Cox, N A; Williams, J E
Chemotherapeutics fail to effectively treat tumors because they cannot reach quiescent regions far from blood vessels. Motile Salmonella are an attractive delivery system that could break this therapeutic barrier. However, little is known about the dissemination and tissue penetration of individual bacteria in tumors after intravenous administration. We hypothesized that eliminating the Trg receptor would improve accumulation in tumor quiescence. To test this hypothesis, we deleted the trg gene from nonpathogenic Salmonella. To quantify individual bacterial behavior, we measured tissue penetration in a tumor-on-a-chip device and measured colony localization in mouse tumors using immunofluorescence. In tumors in vitro and in mice, trg(-) Salmonella penetrated farther into tissue than control bacteria. This difference in localization was caused by the inability to sense sugars in well perfused tissue. Three distinct bacterial phenotypes were observed: proliferating, penetrating, and inactive. Large proliferating colonies, containing more than 40% of individual bacteria, only formed less than 60?m from blood vessels. Small colonies, in comparison, were present both near (inactive) and far (penetrating) from vessels. The farthest was 361.2?m from a vessel, demonstrating the ability to target avascular regions. In addition, colonization was most pronounced in poorly vascularized tumor regions. We show that deletion of trg amplifies Salmonella accumulation in quiescent tumor regions, and, for the first time, identify biological processes that control bacterial distribution in tumors. Understanding how Salmonella penetrate tissue, target quiescence and specifically replicate in tumors are essential steps toward creating a tightly controlled, tunable bacterial therapy. PMID:25523033
Zhang, Miaomin; Forbes, Neil S
A potential source of pathogenic bacteria in ground beef is the lymphatic system, specifically the lymph nodes. Bacteria have been isolated from the lymph nodes of cattle at slaughter; however, most studies have dealt with mesenteric lymph nodes, which are not normally incorporated into ground beef. The objective of the current study was to determine the prevalence and multidrug-resistance status of Salmonella in bovine lymph nodes associated with lean and fat trimmings that might be utilized in ground beef production. Bovine lymph nodes (n = 1,140) were collected from commercial beef processing plants. Half of the lymph nodes sampled were obtained from cull cow and bull processing plants, and the remainder were obtained from fed beef processing plants. Lymph nodes located in chuck and flank adipose tissue were collected for this study. Salmonella prevalence in the lymph node samples was low, with an overall prevalence of 1.6% and a 95% confidence interval of 0.85 to 2.3%. Lymph nodes from cull cattle carcasses had a higher prevalence of Salmonella than did those from fed cattle carcasses. Lymph nodes from the flanks of cow and bull carcasses had the highest prevalence at 3.86%, whereas lymph nodes from the chuck region of fed cattle carcasses had the lowest prevalence at 0.35%. Three of the 18 Salmonella-positive lymph node samples contained multidrug-resistant Salmonella, and all 3 samples were from cull cattle. PMID:18724765
Arthur, Terrance M; Brichta-Harhay, Dayna M; Bosilevac, Joseph M; Guerini, Michael N; Kalchayanand, Norasak; Wells, James E; Shackelford, Steven D; Wheeler, Tommy L; Koohmaraie, Mohammad
The MgtC is a virulence factor in Salmonella Typhimurium that is required for growth at low-Mg2+ concentrations and intramacrophage survival. This gene is codified in a conserved region of the Salmonella pathogenicity island 3 (SPI-3), and is also present in the chromosome of other Salmonella serovars. In this study we characterized the MgtC factor in S. Typhi, a human specific pathogen, by using mgtC and SPI-3 mutant strains. We found that MgtC is the most important factor codified in the SPI-3 of S. Typhi for growth in low-Mg2+ media and survival within human cells. In addition, by using reporter genes we determined that the low-Mg2+ concentration, acidic media and PhoP regulator induce mgtC expression in S. Typhi. We suggest that MgtC is the most important virulence factor codified in the SPI-3 of S. Typhi. PMID:19436747
Retamal, Patricio; Castillo-Ruiz, Mario; Mora, Guido C
Signal transduction through protein-protein interactions and protein modifications are the main mechanisms controlling many biological processes. Here we described the implementation of MedScan information extraction technology and Pathway Studio software (Ariadne Genomics Inc.) to create a Salmonella specific molecular interaction database. Using the database, we have constructed several signal transduction pathways in Salmonella enterica serovar Typhi which causes Typhoid Fever, a major health threat especially in developing countries. S. Typhi has several pathogenicity islands that control rapid switching between different phenotypes including adhesion and colonization, invasion, intracellular survival, proliferation, and biofilm formation in response to environmental changes. Understanding of the detailed mechanism for S. Typhi survival in host cells is necessary for development of efficient detection and treatment of this pathogen. The constructed pathways were validated using publically available gene expression microarray data for Salmonella. PMID:20861532
Ong, Su Yean; Ng, Fui Ling; Badai, Siti Suriawati; Yuryev, Anton; Alam, Maqsudul
Salmonella has evolved several strategies to counteract intracellular microbicidal agents like reactive oxygen and nitrogen species. However, it is not yet clear how Salmonella escapes lysosomal degradation. Some studies have demonstrated that Salmonella can inhibit phagolysosomal fusion, whereas other reports have shown that the Salmonella-containing vacuole (SCV) fuses/interacts with lysosomes. Here, we have addressed this issue from a different perspective by investigating if the infected ...
Eswarappa, Sandeepa M.; Negi, Vidya Devi; Chakraborty, Sangeeta; Chandrasekhar Sagar, B. K.; Chakravortty, Dipshikha
Ten monoclonal antibodies (6 immunoglobulin G1 kappa [IgG1 kappa] and 4 IgG2b kappa) from six hybrid clones specific for Salmonella typhi antigen were produced by immunizing BALB/cJ mice with affinity-purified S. typhi proteins (Bp). The latter were prepared by passing crude S. typhi Bp through an affinity column made from Sepharose conjugated to IgG antibodies against partially purified S. typhi Bp. The eluent was subsequently used as the immunogen for the production of monoclonal antibody. ...
Ekpo, P.; Sarasombath, S.; Banchuin, N.; Sirisinha, S.
Full Text Available SciELO Venezuela | Language: Spanish 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%), ácido 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 susceptibilit [...] y tests showed that the highest level of resistance was against Sulphonamides (54%), Tetracycline (40%), Nalidixic acid (29%) and Amplicillin (23%). However, susceptibility superior 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.
Willian, Mejia; Derwin, Calatayud Marquez; Denice, Zapata; Armando, Quintero; Damarys, Sánchez; Enric, Mateu.
One of the applications of ionizing radiations in food is the inactivation of vegetative phatogenic bacteria (radicidation) such as Salmonella, Shigella, Campylobacter, Vibro and Listeria. These bacteria are associated with the diseases transmitted by food (ETA). Fresh and frozen farmyard fowls can be contaminated with pathogenic microorganisms, between them Salmonella. In Argentine, between years 1987-1990, Salmonella enteritidis was the main cause of salmonellosis. In food irradiation, with the aim of improving and assuring its hygienic quality, it is important to know the radiosensitivity of microorganisms to be inactivated. Inactivation of a determined microorganism shall depend, between others factors, of the species, strain, number and of the irradiation conditions (temperature, media, etc.). D10 value is a very useful data in order to compare radiosensitivities between the microorganisms and the influence of different factors in their sensitivities. In this paper, it was determined the sensitivity to the gamma radiation of Salmonella enteritidis in fresh and frozen chickens
...HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 118 [Docket No. FDA-2000-N-0190] Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation; Change of Registration Date, Address, and...
... Vaccines, Blood & Biologics Articulos en Espanol Pet Turtles: Cute But Contaminated with Salmonella Search the Consumer Updates ... Consumers The little glassy-eyed creatures may look cute and harmless, but small turtles can make people ...
Background: Extended-spectrum *-lactamases (ESBLs) are important resistance mechanisms which affect *-lactam antibiotics, including cephalosporins. Extended-spectrum 3rd generation cephalosporins are considered drugs of choice for serious Salmonella infections. The emergence of ESBL-producing orga...
Current federal regulations required monitoring for fecal coliforms or Salmonella in biosolids destined for land application. Standard protocols designed to quantify these organisms in water or wastewater were identified and specified in these regulations. However, proto...
Previous studies have shown that Peyer's patches (PP) are not required for intestinal immunoglobulin A (IgA) responses to orally administered soluble protein. However, the roles of PP in regulation of mucosal immune responses against bacterial antigen remain to be clarified. In the present study, we generated several gut-associated lymphoreticular tissue-null mice by treatment with anti-interleukin-7 receptor antibody, the fusion protein of lymphotoxin beta receptor and IgG Fc, and/or tumor necrosis factor receptor p55 and IgG Fc. These mice were then immunized with recombinant Salmonella expressing the C fragment of the tetanus toxin (rSalmonella-Tox C). Orally immunized PP-null mice as well as isolated lymphoid follicle (ILF)-null, PP/ILF-null, and PP/ILF/mesenteric lymph node-null mice induced identical levels of tetanus toxoid (TT)-specific systemic IgG responses to those of control mice. However, PP-null mice, but not ILF-null mice, failed to induce TT-specific intestinal IgA antibodies. Analysis of TT-specific CD4+ T-cell responses showed a reduction of gamma interferon (IFN-gamma) synthesis in the intestinal lamina propriae of PP-null mice given oral rSalmonella-Tox C. In contrast, TT-specific IFN-gamma responses in the spleen and delayed-type hypersensitivity responses were intact in those immunized mice. Interestingly, Salmonella lipopolysaccharide (LPS)-specific fecal IgA responses were not elicited in PP-null mice, while serum IgG anti-LPS antibodies were identical to those of control mice. These results suggest that while none of the gut-associated lymphoreticular tissues are required for the induction of systemic immune responses, PP are an essential lymphoid tissue for induction and regulation of intestinal IgA immunity against orally administered rSalmonella. PMID:18086815
Hashizume, Tomomi; Togawa, Atsushi; Nochi, Tomonori; Igarashi, Osamu; Kweon, Mi-Na; Kiyono, Hiroshi; Yamamoto, Masafumi
The repopulation potential and recovery of Salmonella sp. and their close relatives Arizona spp. and Citrobacter spp. in sewage sludge which had been composted was examined. Salmonellae growth in previously composted sludge was found to occur in the mesophilic temperature range (20 to 40 degrees c), require a moisture content of greater than or equal to 20%, and require a carbon/nitrogen ratio in excess of 15:1.
Russ, C. F.; Yanko, W. A.
Infections with Salmonella are an important public health problem worldwide. Salmonella are one of the most common causes of food-borne illness in humans. There are many types of Salmonella but they can be divided into two broad categories: those that cause typhoid and those that do not. The typhoidal Salmonella (TS), such as S. enterica subsp. enterica serovars Typhi and S. Paratyphi only colonize humans and are usually acquired by the consumption of food or water contaminated with human fecal material. The much broader group of non-typhoidal Salmonella (NTS) usually results from improperly handled food that has been contaminated by animal or human fecal material. Antimicrobials are critical to the successful outcome of invasive Salmonella infections and enteric fever. Due to resistance to the older antimicrobials, ciprofloxacin [fluoroquinolone (FQ)] has become the first-line drug for treatment. Nevertheless, switch to FQ has led to a subsequent increase in the occurrence of salmonellae resistant to this antimicrobial agent. The exact mechanism of this FQ resistance is not fully understood. FQ resistance has driven the use of third-generation cephalosporins and azithromycin. However, there are sporadic worldwide reports of high level resistance to expanded-spectrum cephalosporins (such as ceftriaxone) in TS and in NTS it has been recognized since 1988 and are increasing in prevalence worldwide. Already there are rare reports of azithromycin resistance leading to treatment failure. Spread of such resistance would further greatly limit the available therapeutic options, and leave us with only the reserve antimicrobials such as carbapenem and tigecycline as possible treatment options. Here, we describe the methods involved in the genotypic characterization of antimicrobial resistance in clinical isolates of salmonellae. PMID:25253247
Harish, Belgode N; Menezes, Godfred A
Two eight week old purebred female Bull Terrier puppies died within 24 hours of each other as a result of a septicemia caused by Salmonella dublin. The salient clinical features were: temperature of 41°C; rapid breathing; fluid, blood-stained stools; prostration and death. Pathological findings included embolic pneumonia, splenitis, myocarditis, nephritis and meningoencephalitis. Salmonella dublin was isolated from the spleen, lung and kidneys of both puppies.
Nation, P. N.
Nine immunoglobulin G and nine immunoglobulin M murine monoclonal antibody-producing hybridomas reactive with live Salmonella bacteria were obtained from several fusions of immune spleen cells and Sp2/0 myeloma cells. The antibodies were selected by the magnetic immunoluminescence assay. The monoclonal antibodies were reactive with serogroups A, B, C1, C2, D, E, and K and Salmonella choleraesuis subsp. diarizonae. Each monoclonal antibody proved to be reactive with a distinct serotype. Clinic...
Torensma, R.; Visser, M. J.; Aarsman, C. J.; Poppelier, M. J.; Beurden, R.; Fluit, A. C.; Verhoef, J.
We evaluated the performances of a newly designed real-time polymerase chain reaction (PCR) assay using TaqMan® probes to detect Salmonella Typhi. TaqMan® real-time PCR assays were performed by designed primers and probe based on the staG gene for detecting S. Typhi. The specificity of the assay was evaluated on 15 Salmonella serovars. The analytical specificity was evaluated on 20 non-Salmonella microorganisms. The analytical sensitivity was assessed using decreasing DNA quantities of S. Typhi ATCC 19430. Finally the detection capability of the TaqMan® real-time PCR assay on isolates recovered from patients with Salmonella infections was compared to the conventional PCR assay. Only S. Typhi strain had positive results when subjected to the assay using Typhi-specific real-time PCR. No amplification products were observed in real-time PCR with any of the non-Salmonella microorganisms tested. The TaqMan® real-time PCR was more sensitive than the conventional PCR. In conclusion, we found that the easy-to-use real-time PCR assays were faster than conventional PCR systems. The staG-based TaqMan® real-time PCR assay showed to be specific and sensitive method for the safe and rapid detection of the S. Typhi. PMID:24939681
Ranjbar, Reza; Naghoni, Ali; Farshad, Shohreh; Lashini, Hadi; Najafi, Ali; Sadeghifard, Nourkhoda; Mammina, Caterina
Full Text Available Abstract Background PCR amplification for the detection of pathogens in biological material is generally considered a rapid and informative diagnostic technique. Invasive Salmonella serovars, which cause enteric fever, can be commonly cultured from the blood of infected patients. Yet, the isolation of invasive Salmonella serovars from blood is protracted and potentially insensitive. Methods We developed and optimised a novel multiplex three colour real-time PCR assay to detect specific target sequences in the genomes of Salmonella serovars Typhi and Paratyphi A. We performed the assay on DNA extracted from blood and bone marrow samples from culture positive and negative enteric fever patients. Results The assay was validated and demonstrated a high level of specificity and reproducibility under experimental conditions. All bone marrow samples tested positive for Salmonella, however, the sensitivity on blood samples was limited. The assay demonstrated an overall specificity of 100% (75/75 and sensitivity of 53.9% (69/128 on all biological samples. We then tested the PCR detection limit by performing bacterial counts after inoculation into blood culture bottles. Conclusions Our findings corroborate previous clinical findings, whereby the bacterial load of S. Typhi in peripheral blood is low, often below detection by culture and, consequently, below detection by PCR. Whilst the assay may be utilised for environmental sampling or on differing biological samples, our data suggest that PCR performed directly on blood samples may be an unsuitable methodology and a potentially unachievable target for the routine diagnosis of enteric fever.
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
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.
A survey was conducted to estimate the prevalence of Salmonella enteritidis and other salmonellas among Canadian commercial egg producing flocks. Environmental (faecal and eggbelt) samples from 152 of 295 (52.9%) randomly selected flocks were contaminated with salmonellas. Thirty-five different salmonella serovars were isolated. Eggbelt samples were more often contaminated with salmonellas than faecal samples (25.7 v. 10.1%). The most prevalent serovars were S. heidelberg, S. infantis, S. hadar, and S. schwarzengrund; they were isolated from samples of 59/295 (20%), 18/295 (6.1%), 17/295 (5.8%), and 15/295 (5.1%) flocks, respectively. Feed samples of 21/295 (7.2%) flocks were contaminated with salmonellas. Salmonella enteritidis was isolated from the environmental samples of 8/295 (2.7%) flocks. Salmonella enteritidis phage type (PT) 8 was isolated from 5 flocks, PT 13a from 2 flocks, and PT 13 from 1 flock. PMID:2019297
Poppe, C; Irwin, R J; Forsberg, C M; Clarke, R C; Oggel, J
Identification of environmental reservoirs of nontyphoidal salmonellosis: aptamer-assisted bioconcentration and subsequent detection of salmonella typhimurium by quantitative polymerase chain reaction.
In this study, identification of environmental reservoirs of Salmonella enterica subsp. enterica serovar Typhimurium (abbreviated as Salmonella Typhimurium) in sediments, water, and aquatic flora collected from the Ganges River (Ganges riverine material) was carried out by adopting a two-step strategy. Step 1 comprised a selective serovar-specific capture of Salmonella Typhimurium from potential reservoirs. Step 2 involved culture-free detection of selectively captured Salmonella Typhimurium by ttr gene-specific molecular beacon (MB) based quantitative polymerase chain reaction (q-PCR). The ttr gene-specific MB designed in this study could detect 1 colony-forming unit (cfu)/PCR captured by serovar-specific DNA aptamer. Sediments, water, and aquatic flora collected from the Ganges River were highly contaminated with Salmonella Typhimurium. The preanalytical step in the form of serovar-specific DNA aptamer-based biocapture of bacterial cells was found to enhance the sensitivity of the fluorescent probe in the presence of nonspecific DNA . Information about the presence of environmental reservoirs of Salmonella Typhimurium in the Ganges River region may pave the way for forecasting and management of nontyphoidal salmonellosis in south Asia. PMID:21875107
Jyoti, Anurag; Vajpayee, Poornima; Singh, Gulshan; Patel, Chandra Bali; Gupta, Kailash Chand; Shanker, Rishi
In the Danish Salmonella Control Program, eggs from broiler parent flocks are surveyed by serologic analysis every 4 wk for antibodies against Salmonella lipopolysaccharide O-antigens 1, 4, 5, 9, and 12 (Mix-enzyme-linked immunosorbent assay [ELISA]) and 6 and 7 (Infantis-ELISA). The antibody response is measured in percentage optical density (OD%) of a strong positive reaction, and the cutoff value has been determined to be 40 OD%. Two or more reactors above 40 OD% will place the parent flock under suspicion. There has been concern about possible cross-reactions between Salmonella spp. and other Enterobacteriaceae, e.g., Escherichia coli, because a high specificity of a Salmonella antibody test is desirable. Moreover, false-positive Salmonella results have economic consequences and impede planning the production. A case-control study based on cases of clinical E. coli infections (colibacillosis) from two Danish hatcheries, supplying about 62% of the Danish broiler production, is described. In order to eliminate a possible bias from age and season, the controls were matched on age of the birds and on time of submitting the samples. This study shows that flocks with preceding colibacillosis did nor have higher salmonella reactions than matched flocks without a preceding colibacillosis. This observation was confirmed in longitudinal studies.
Gradel, K.O.; Feld, Niels Christian
Rapid, reliable, and robust detection of Salmonella in produce remains a challenge. In this study, loop-mediated isothermal amplification (LAMP) was comprehensively evaluated against real-time quantitative PCR (qPCR) for detecting diverse Salmonella serovars in various produce items (cantaloupe, pepper, and several varieties of lettuce, sprouts, and tomato). To mimic real-world contamination events, produce samples were surface-inoculated with low concentrations (1.1-2.9 CFU/25 g) of individual Salmonella strains representing ten serovars and tested after aging at 4 °C for 48 h. Four DNA extraction methods were also compared using produce enrichment broths. False-positive or false-negative results were not observed among 178 strains (151 Salmonella and 27 non-Salmonella) used to evaluate assay specificity. The detection limits for LAMP were 1.8-4 CFU per reaction in pure culture and 10(4)-10(6) CFU per 25 g (i.e., 10(2)-10(4) CFU per g) in produce without enrichment, comparable to those obtained by qPCR. After 6-8 h of enrichment, both LAMP and qPCR consistently detected these low concentrations of Salmonella of diverse serovars in all produce items except sprouts. The PrepMan Ultra sample preparation reagent yielded the best results among the four DNA extraction methods. Upon further validation, LAMP may be a valuable tool for routine Salmonella testing in produce. The difficulty of detecting Salmonella in sprouts, whether using LAMP or qPCR, warrants further study. PMID:25475319
Yang, Qianru; Wang, Fei; Jones, Kelly L; Meng, Jianghong; Prinyawiwatkul, Witoon; Ge, Beilei
Salmonella is a globally widespread food-borne pathogen having major impact on public health. All motile serovars of Salmonella enterica of poultry origin are zoonotic, and contaminated meat and raw eggs are an important source to human infections. Information on the prevalence of Salmonella at farm/holding level, and the zoonotic serovars circulating in layer poultry in the South and South-East Asian countries including Bangladesh, where small-scale commercial farms are predominant, is limited. To investigate the prevalence of Salmonella at layer farm level, and to identify the prevalent serovars we conducted a cross-sectional survey by randomly selecting 500 commercial layer poultry farms in Bangladesh. Faecal samples from the selected farms were collected following standard procedure, and examined for the presence of Salmonella using conventional bacteriological procedures. Thirty isolates were randomly selected, from the ninety obtained from the survey, for serotyping and characterized further by plasmid profiling and pulsed-field gel electrophoresis (PFGE). Results of the survey showed that the prevalence of motile Salmonella at layer farm level was 18% (95% confidence interval 15-21%), and Salmonella Kentucky was identified to be the only serovar circulating in the study population. Plasmid analysis of the S. Kentucky and non-serotyped isolates revealed two distinct profiles with a variation of two different sizes (2.7 and 4.8 kb). PFGE of the 30 S. Kentucky and 30 non-serotyped isolates showed that all of them were clonally related because only one genotype and three subtypes were determined based on the variation in two or three bands. This is also the first report on the presence of any specific serovar of Salmonella enterica in poultry in Bangladesh.
Barua, Himel; Biswas, Paritosh K.
Bacteriologische detectie van Salmonella in aanwezigheid van stoorflora. Bacteriologisch ringonderzoek IV voor de Nationale Referentie Laboratoria voor Salmonella, het gebruik van MSRV als selectieve ophoping
Het Communautair Referentie Laboratorium voor Salmonella heeft een vierde bacteriologisch ringonderzoek georganiseerd betreffende de detectie van Salmonella. De deelnemers waren de Nationale Referentie Laboratoria (NRLs) voor Salmonella uit de lidstaten van de Europese Unie. Dit ringonderzoek had twee doelen: 1) Evaluatie van de resultaten van verschillende besmettingsniveaus van Salmonella Enteritidis (100 en 1000 kve) en Salmonella Typhimurium (10 en 100 kve) in de ...
Raes M; Nagelkerke N; Am, Henken
...TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS...Inactivated Bacterial Products § 113.122 Salmonella...nontoxic. Each serial of biological product containing Salmonella...by or acceptable to Veterinary Services....
...TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS...Inactivated Bacterial Products § 113.123 Salmonella...nontoxic. Each serial of biological product containing Salmonella...by or acceptable to Veterinary Services....
...and Drugs 2 2010-04-01 2010-04-01 false Salmonella Enteritidis (SE) prevention measures. 118.4 Section...STORAGE, AND TRANSPORTATION OF SHELL EGGS § 118.4 Salmonella Enteritidis (SE) prevention measures. You...
... this? Submit What's this? Submit Button CDC Features Salmonella is a Sneaky Germ: Seven Tips for Safer Eating Language: English Español (Spanish) Share Compartir Salmonella can contaminate more than poultry and eggs. It ...
... Literature Reviews Market Research Statistics Reference Guides Reports Salmonella: Dry Pet Foods and Pet Treats (FAQ) Originally ... 2008, there was a prolonged multistate outbreak of Salmonella enterica serotype Schwarzengrund infections in humans. A total ...
...draft guidance addresses testing procedures for Salmonella...direct-human-contact animal foods, and the interpretation...SUPPLEMENTARY INFORMATION: I. Background FDA is announcing the...industry entitled ``Testing for Salmonella Species...Direct- Human-Contact Animal Foods.'' The...
Full Text Available A two-phase study was conducted to compare the efficacy of several enrichment selective-broth steps associated to different plating media for recovery of Salmonella sp. from finishing swine feces. In a first phase, Rappaport-Vassiliadis broth (RV incubated at 42ºC, Tetrathionate Müller-Kauffmann broth at 37ºC (TMK37 and 42ºC (TMK42, and Selenite Cystine broth (SC at 37ºC, in combination with three selective plating media Rambach agar (RA, Xylose-Lysine-Tergitol 4 agar (XLT4, and Brilliant-Green Phenol-Red Lactose Sucrose agar (VB were compared for recovery of Salmonella from artificially contaminated swine feces. In a second phase, RV, TMK37, and TMK42, associated with XLT4 and VB , were tested with naturally contaminated swine feces. In this study RV, TMK42 and TMK37 were superior to SC for isolating Salmonella sp. from artificially contaminated feces. TMK42 and RV were more productive than TMK37 for recovery of Salmonella from naturally contaminated feces samples. Selectivity and indication capability of the plating media were remarkably affected by the selective enrichment step effectiveness. The TMK42/XLT4 association was the most sensitive and RV/XLT4 the most specific. The use of VB agar is also recommended to increase the likelihood of isolating atypical H2S-late producing/ non-producing Salmonella. In this study RV and TMK42 were the most efficient selective enrichment for recovery of Salmonella sp. from swine feces.
Michael Geovana Brenner
Full Text Available Ewa Sawosz1, André Chwalibog2, Jacek Szeliga3, Filip Sawosz2, Marta Grodzik1, Marlena Rupiewicz1, Tomasz Niemiec1, Katarzyna Kacprzyk11Division of Biotechnology and Biochemistry of Nutrition, Warsaw University of Life Sciences, Warsaw, Poland; 2Department of Basic Animal and Veterinary Sciences, University of Copenhagen, Copenhagen, Denmark; 3Division of Microbiology of Analytical Centre, Warsaw University of Life Sciences, Warsaw, PolandPurpose: Rapid development of nanotechnology has recently brought significant attention to the extraordinary biological features of nanomaterials. The objective of the present investigation was to evaluate morphological characteristics of the assembles of gold and platinum nanoparticles (nano-Au and nano-Pt respectively, with Salmonella Enteritidis (Gram-negative and Listeria monocytogenes (Gram-positive, to reveal possibilities of constructing bacteria-nanoparticle vehicles.Methods: Hydrocolloids of nano-Au or nano-Pt were added to two bacteria suspensions in the following order: nano-Au + Salmonella Enteritidis; nano-Au + Listeria monocytogenes; nano-Pt + Salmonella Enteritidis; nano-Pt + Listeria monocytogenes. Samples were inspected by transmission electron microscope.Results: Visualization of morphological interaction between nano-Au and Salmonella Enteritidis and Listeria monocytogenes, showed that nano-Au were aggregated within flagella or biofilm network and did not penetrate the bacterial cell. The analysis of morphological effects of interaction of nano-Pt with bacteria revealed that nano-Pt entered cells of Listeria monocytogenes and were removed from the cells. In the case of Salmonella Enteritidis, nano-Pt were seen inside bacteria cells, probably bound to DNA and partly left bacterial cells. After washing and centrifugation, some of the nano-Pt-DNA complexes were observed within Salmonella Enteritidis.Conclusion: The results indicate that the bacteria could be used as a vehicle to deliver nano-Pt to specific points in the body.Keywords: morphology, nanoparticles, gold, platinum, bacteria
Salmonella enterica, the cause of food poisoning and typhoid fever, has evolved sophisticated mechanisms to modulate Rho family guanosine triphosphatases (GTPases) to mediate specific cellular responses such as actin remodeling, macropinocytosis, and nuclear responses. These responses are largely the result of the activity of a set of bacterial proteins (SopE, SopE2, and SopB) that, upon delivery into host cells via a type III secretion system, activate specific Rho family GTPases either dire...
Patel, Jayesh C.; Gala?n, Jorge E.
Tartronate semialdehyde reductases (TSRs), also known as 2-hydroxy-3-oxopropionate reductases, catalyze the reduction of tartronate semialdehyde using NAD as cofactor in the final stage of D-glycerate biosynthesis. These enzymes belong to family of structurally and mechanically related ?-hydroxyacid dehydrogenases which differ in substrate specificity and catalyze reactions in specific metabolic pathways. Here, we present the crystal structure of GarR a TSR from Salmonella typhimurium determ...
Osipiuk, J.; Zhou, M.; Moy, S.; Collart, F.; Joachimiak, A.
Nontyphoidal Salmonella species cause gastrointestinal disease worldwide. The prevailing theory of Salmonella enteropathogenesis is that bacterial invasion of the intestinal epithelium is essential for virulence and that this requires the virulence-associated genomic region Salmonella pathogenicity island 1 (SPI-1). Recent studies of Salmonella enterica infection models have demonstrated that enterocolitis and diarrhea in mice and cows can occur independently of SPI-1. In this study, we sough...
Hu, Qinghua; Coburn, Bryan; Deng, Wanyin; Li, Yuling; Shi, Xiaolu; Lan, Quanxue; Wang, Bing; Coombes, Brian K.; Finlay, B. Brett
De Salmonella referentiemonsters werden getest in 31 laboratoria. De laboratoria onderzochten elk 25 monsters, 20 Salmonella referentiemonsters en 5 Salmonella negatieve monsters. De werkwijze was gebaseerd op het ISO-voorschrift voor de aantoning van Salmonella. Er werden 3 selectieve ophopingsmedia gebruikt: - tetrathionaat briljant-groen gal bouillon (TBB) - malachiet-groen magnesium-chloride bouillon (RV) - Een op het deelnemende laboratorium gebruikelijk medium (O...
Ph, Veld In Apos T.; Ja, Hoekstra; Hj, Beckers
Type-1 fimbriae are associated with most Salmonella enterica serovars and are an essential factor for host colonization. Mannanoligosaccharides (MOS), a prebiotic that is agglutinated by type-1 fimbriae, are proposed for the control of enterobacteria colonization and may be an alternative to Salmonella control in pigs. The aim of this study was to evaluate the capability of porcine Salmonella strains to adhere to MOS in vitro. A total of 108 strains of Salmonella sp. isolated from carrier pig...
Borowsky, Luciane; Corc?a?o, Gertrudes; Cardoso, Marisa
Salmonella infections originating from poultry are one of the major causes of food-borne disease. For the control of salmonella in poultry a multifactorial approach is more likely to be effective, and the genetic resistance of poultry breeds to salmonella infections may be a valuable contribution. Experimental Salmonella enteritidis infections were examined in three different broiler outbred lines: the FC line, which had been selected for feed conversion efficiency; the R line, which had been...
Bolder, N. M.; Janss, L. L. G.; Putirulan, F. F.; Wagenaar, J. A.
Een van de taken van het Communautair Referentie Laboratorium voor Salmonella (CRL-Salmonella) is het verbeteren van detectie methoden voor Salmonella. Hiertoe werd onderzoek uitgevoerd om de isolatie van Salmonella uit kippenfaeces te verbeteren. In vergelijking met de standaard ISO methode werden de volgende effecten bestudeerd: (i) de invloed van de incubatietijd van de voorophoping in gebufferd pepton water (BPw); (ii) het gebruik van Modified Semi-Solid Rappaport Vassiliadis Medium Ba...
Cj, Heuvelman; Veld Ph, In Apos T.
Antimicrobial resistance levels were examined for 365 Salmonella isolates recovered from the lymph nodes (n = 224) and cecal contents (n = 141) of market-age swine at slaughter. Antimicrobial resistance testing was performed by disk diffusion using 13 antibiotics common in the treatment of disease in human and veterinary medicine. Although none of the antibiotics tested were used subtherapeutically within the last 5 years on the farms sampled, resistance to chlortetracycline, penicillin G, streptomycin, and sulfisoxazole was common. Penicillin G resistance was significantly more frequent (P = 0.03) and sulfisoxazole resistance was significantly less frequent (P lymph node versus cecal isolates. Multidrug resistance was observed among 94.7% of the lymph node isolates and 93.5% of the cecal isolates. The most frequent multidrug resistance pattern included three antibiotics-penicillin G, streptomycin, and chlortetracycline. Isolates in somatic serogroup B, and more specifically, Salmonella Agona and Salmonella Schwarzengrund isolates, were often resistant to a greater number of antibiotics than were isolates in the other serogroups. Streptomycin, sulfisoxazole, ampicillin (lymph node isolates), and nitrofurantoin (cecal isolates) resistance levels differed significantly between somatic serogroups. The prevalence of penicillin G-, streptomycin-, and sulfisoxazole-resistant isolates differed significantly between serovars for both lymph node and cecal isolates. Results of this study suggest that a correlation exists between the somatic serogroup or serovar of a Salmonella isolate and its antimicrobial resistance status, which is specific to the antibiotic of interest and the source of the isolate (lymph node versus cecal contents). PMID:11601696
Farrington, L A; Harvey, R B; Buckley, S A; Droleskey, R E; Nisbet, D J; Inskip, P D
Two pediatric patients with salmonella infections (one with typhoid fever and the second with salmonella C2 gastroenteritis), had a diffuse abdominal uptake of Ga-67 citrate. The possible explanation for this finding is discussed. Salmonella infection should be included as a cause in the differential diagnosis of diffuse accumulation of Ga-67 citrate
Two pediatric patients with salmonella infections (one with typhoid fever and the second with salmonella C2 gastroenteritis), had a diffuse abdominal uptake of Ga-67 citrate. The possible explanation for this finding is discussed. Salmonella infection should be included as a cause in the differential diagnosis of diffuse accumulation of Ga-67 citrate.
Garty, I.; Koren, A.
Salmonella and Vibrio species were isolated and identified from Litopenaeus vannamei cultured in shrimp farms. Shrimp samples showed occurrence of 3.3% of Salmonella and 48.3% of Vibrio. The isolates were also screened for antibiotic resistance to oxolinic acid, sulphonamides, tetracycline, sulfamethoxazole/trimethoprim, norfloxacin, ampicillin, doxycycline hydrochloride, erythromycin, chloramphenicol, and nitrofurantoin. Salmonella enterica serovar Corvallis isolated from shrimp showed indiv...
Banerjee, Sanjoy; Ooi, Mei Chen; Shariff, Mohamed; Khatoon, Helena
Few studies have evaluated the health consequences of antimicrobial-resistant Salmonella strains associated with outbreaks. Among 32 outbreaks occurring in the United States from 1984 to 2002, 22% of 13,286 persons in 10 Salmonella-resistant outbreaks were hospitalized, compared with 8% of 2,194 persons in 22 outbreaks caused by pansusceptible Salmonella strains (p<0.01).
Varma, Jay K.; Greene, Katherine D.; Ovitt, Jessa; Barrett, Timothy J.; Medalla, Felicita; Angulo, Frederick J.
Salmonella is an important pathogen of humans and animals. One of the most effective treatments for Salmonella infections are beta -lactam antibiotics. However, Salmonella resistant to these antibiotics has been increasing in clinical isolates. To investigate if this increase is also occurring in a...
Salmonella is an important food bourn pathogen capable of infecting both humans and animals. One of the most effective treatments for Salmonella infections is beta-lactam antibiotics, particularly extended spectrum beta-lactams; however, Salmonella resistant to these antibiotics have been recovered ...
Peanut butter spiked with Salmonella enterica ser. Typhimurium was prepared by an independent laboratory and sent to Applied Biosystems to determine the sensitivity and specificity of the TaqMan Salmonella enterica Detection Kit for detecting Salmonella in peanut butter. The samples were spiked at three levels: five no-spike (0 CFU/25 g); 20 low-spike (0.2 CFU/25 g); and 20 high-spike (2 CFU/25 g). They were coded to create a blind set of 45 samples. The samples were processed based on an unpaired test design that included enrichment in buffered peptone water for the candidate method and lactose broth for the reference method. In the candidate method, a 1 mL aliquot of enriched sample was extracted using PrepMan Ultra Sample Preparation Reagent; the sample was amplified on the Applied Biosystems 7500 real-time PCR system, and analyzed for detection of Salmonella using RapidFinder Version 1.0 software. All samples processed by the candidate method were confirmed by culture according to the U.S. Food and Drug Administration's Bacteriological Analytical Manual procedures. Sensitivity, specificity, and Chi-square analysis were calculated by combining candidate method results with those of the reference method that were collected by the independent laboratory. The TaqMan Salmonella enterica Detection Kit showed 40% sensitivity, 100% specificity, and a Chi-square value equal to 1.52. Chi-square analysis indicated the candidate method and the reference method were comparable. Although the candidate method sensitivity was only 40% when compared with the reference method (unpaired samples), the sensitivity was > 100% when the candidate method results were compared with those of the confirmation method (same sample enrichment). PMID:20166614
Tebbs, Robert S; Cao, Yan Y; Balachandran, Priva; Petrauskene, Olga
Genotyping is becoming an increasingly important tool to improve risk assessments of Salmonella. DNA microarray technology is a promising diagnostic tool that can provide high resolution genomic profile of many genes simultaneously. However, standardization of DNA microarray analysis is needed before it can be used as a tool in source attribution models for comparable characterization of isolates across laboratories and countries. The reproducibility of data was evaluated for a simple and single-dye DNA microarray (Huehn et al., Appl Environ Microbiol, 2009, 75:1011-1020) for genotyping of Salmonella at two different laboratories. The low-density array contained 281 of 57-60-mer oligonucleotide probes for detecting a wide range of specific genomic markers associated with antibiotic resistance, cell envelope structures, mobile genetic elements and pathogenicity. Several test parameters that differed between the two labs were identified: printing facilities and equipment, choice of hybridization buffer, wash buffers used following hybridization and the choice of procedure for purifying genomic DNA. These critical parameters were randomized in a four-factorial experiment and statistical measures of inter-lab consistency and agreement were performed based on the kappa coefficient. A high level of agreement (kappa = 0.7-1.0) was obtained even when using different printing and hybridization facilities, different procedures for purifying genomic DNA and different wash buffers. However, less agreement (Kappa = 0.2-0.6) between microarray results were observed when using different hybridization buffers, indicating this as the most critical factor for standardization between laboratories. In conclusion, this study indicates that it is possible to set up an international standard for a decentralized and simple-to-implement DNA microarray as part of a pan-European source-attribution model for risk assessment of Salmonella.
Löfström, Charlotta; GrØnlund, Hugo Ahlm
Het Communautair Referentie Laboratorium (CRL) voor Salmonella heeft een derde ringonderzoek voor de serotypering van Salmonella georganiseerd. Alle Nationale Referentie Laboratoria (NRLs) voor Salmonella van de Europese Unie deden aan het onderzoek mee. Het belangrijkste doel was het vergelijken van de serotyperingsresultaten van de NRLs. In totaal werden er door het CRL 20 serotypen van Salmonella enterica subsp. enterica geselecteerd. Deze moesten door de NRLs met d...
Voogt N; Hme, Maas; Wj, Leeuwen; Am, Henken
Salmonella enterica serotype Gallinarum is the causative agent of fowl typhoid, a disease characterized by high morbidity and mortality that causes major economic losses in poultry production. We have reported that S. Gallinarum harbors a type VI secretion system (T6SS) encoded in Salmonella pathogenicity island 19 (SPI-19) that is required for efficient colonization of chicks. In the present study, we aimed to characterize the SPI-19 T6SS functionality and to investigate the mechanisms behind the phenotypes previously observed in vivo. Expression analyses revealed that SPI-19 T6SS core components are expressed and produced under in vitro bacterial growth conditions. However, secretion of the structural/secreted components Hcp1, Hcp2, and VgrG to the culture medium could not be determined, suggesting that additional signals are required for T6SS-dependent secretion of these proteins. In vitro bacterial competition assays failed to demonstrate a role for SPI-19 T6SS in interbacterial killing. In contrast, cell culture experiments with murine and avian macrophages (RAW264.7 and HD11, respectively) revealed production of a green fluorescent protein-tagged version of VgrG soon after Salmonella uptake. Furthermore, infection of RAW264.7 and HD11 macrophages with deletion mutants of SPI-19 or strains with genes encoding specific T6SS core components (clpV and vgrG) revealed that SPI-19 T6SS contributes to S. Gallinarum survival within macrophages at 20 h postuptake. SPI-19 T6SS function was not linked to Salmonella-induced cytotoxicity or cell death of infected macrophages, as has been described for other T6SS. Our data indicate that SPI-19 T6SS corresponds to a novel tool used by Salmonella to survive within host cells. PMID:23357385
Blondel, Carlos J; Jiménez, Juan C; Leiva, Lorenzo E; Alvarez, Sergio A; Pinto, Bernardo I; Contreras, Francisca; Pezoa, David; Santiviago, Carlos A; Contreras, Inés
Salmonella is an important food-borne pathogen causing disease in humans and animals worldwide. Salmonellosis may be caused by any one of over 2,500 serovars of Salmonella. Nonetheless, Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Agona are the second most prevalent serovars isolated from humans and livestock products respectively. Limited knowledge is available about the virulence mechanisms responsible for diarrheal disease caused by them. To investigate the contribution of sopB, sopD and pipD as virulence factors in intracellular infections and the uniqueness of these bacteria becoming far more prevalent than other serovars, the infection model of Caenorhabditis elegans and phenotypic microarray were used to characterize their mutants. The strains containing the mutation in sopB, sopD and pipD genes were constructed by using latest site-specific group II intron mutagenesis approach to reveal the pathogenicity of the virulence factors. Overall, we observed that the mutations in sopB, sopD and pipD genes of both serovars did not exhibit significant decrease in virulence towards the nematode. This may indicate that these virulence effectors may not be universal virulence factors involved in conserved innate immunity. There are significant phenotypic differences amongst strains carrying sopB, sopD and pipD gene mutations via the analysis of biochemical profiles of the bacteria. Interestingly, mutant strains displayed different susceptibility to chemical stressors from several distinct pharmacological and structural classes when compared to its isogenic parental strains. These metabolic and chemosensitivity assays also revealed multiple roles of Salmonella virulence factors in nutrient metabolism and antibiotic resistance. PMID:25312847
Khoo, Chai-Hoon; Sim, Jiun-Horng; Salleh, Noorzaleha Awang; Cheah, Yoke-Kqueen
Definitive diagnosis of infectious diseases, including food poisoning, requires culture and identification of the infectious agent. We described how antibodies could be used to shorten this cumbersome process. Specifically, we employed an anti-Salmonella lipopolysaccharide O12 monoclonal antibody in an epitope-inhibition 10-min test (TUBEX TP) to detect O12+Salmonella organisms directly from routine blood culture broths. The aim is to obviate the need to subculture the broth and subsequently ...
Nugraha, Jusak; Marpaung, Ferdy R.; Tam, Frankie C. H.; Lim, Pak Leong
An antigen-capture, monoclonal-antibody-based enzyme-linked immunoassay (ELISA) that detects a broad range of Salmonella serovars in various serogroups was developed and compared with standard culture procedures for detection of Salmonella in 1055 field samples collected from poultry-hatchery environments. The diagnostic sensitivity of the ELISA relative to culture was 99.9% and the diagnostic specificity 99.6%. The extensive culture procedure included nonselective enrichment (NSE) as well as...
Brooks, Brian W.; Lutze-wallace, Cheryl L.; Devenish, John; Elmufti, Mohamed; Burke, Teresa
Salmonella enterica is a human pathogen with over 2,500 serovars characterized. S. enterica serovars Choleraesuis and Paratyphi C are two globally distributed serovars. We have developed a rapid molecular-typing method to detect serovars Choleraesuis and Paratyphi C in food samples by using a comparative-genomics approach to identify regions unique to each serovar from the sequenced genomes. A Salmonella-specific primer pair based on oriC was designed as an internal control to establish accur...
Woods, David F.; Reen, F. Jerry; Gilroy, Deirdre; Buckley, Jim; Frye, Jonathan G.; Boyd, E. Fidelma
A disposable immunosensor for Salmonella enterica subsp. enterica serovar Typhimurium LT2 (S) detection using a magneto-immunoassay and gold nanoparticles (AuNPs) as label for electrochemical detection is developed. The immunosensor is based on the use of a screen-printed carbon electrode (SPCE) that incorporates a permanent magnet underneath. Salmonella containing samples (i.e. skimmed milk) have been tested by using anti-Salmonella magnetic beads (MBs-pSAb) as capture phase and sandwiching afterwards with AuNPs modified antibodies (sSAb-AuNPs) detected using differential pulse voltammetry (DPV). A detection limit of 143 cells mL(-1) and a linear range from 10(3) to 10(6) cells mL(-1) of Salmonella was obtained, with a coefficient of variation of about 2.4%. Recoveries of the sensor by spiking skimmed milk with different quantities of Salmonella of about 83% and 94% for 1.5×10(3) and 1.5×10(5) cells mL(-1) were obtained, respectively. This AuNPs detection technology combined with magnetic field application reports a limit of detection lower than the conventional commercial method carried out for comparison purposes in skimmed milk samples. PMID:22884647
Afonso, André S; Pérez-López, Briza; Faria, Ronaldo C; Mattoso, Luiz H C; Hernández-Herrero, Manuela; Roig-Sagués, Artur Xavier; Maltez-da Costa, Marisa; Merkoçi, Arben
This pilot analysis was conducted with data from 52 conventional grow-out broiler flocks in a prospective field observational study in the southeastern United States during 2003-2006. Each flock was sampled for Salmonella 1 wk before the end of grow-out, upon arrival at the processing plant, and during processing (prior to and immediately after carcass chilling). The broiler litter was sampled on the day of bird harvest. The grow-out feeding programs, including the medications delivered in feed, were surveyed with questionnaires completed by the broiler managers and feedmill managers. Each detail of the feeding program was tested for statistical association with the frequency of Salmonella in the flock at each sampling point, after accounting for variation in Salmonella frequency between the farms, broiler complexes, and companies. Significant associations were found between Salmonella frequency in the broiler flock pre- and postharvest and the inclusion of feeds containing individual coccidiostats and other antimicrobial growth promoters, days on feed, and total consumption of feeds containing these products, as well as with practices such as a mash feed and a nonmedicated withdrawal feed. The analysis provided testable hypotheses for how broiler feed medications impact the frequency of Salmonella in the flocks. PMID:24283130
Volkova, Victoriya V; Hubbard, Sue Ann; Magee, Danny L; Byrd, J Allen; Bailey, Richard H; Wills, Robert W
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 detectie in aanwezigheid van storingsflora te evalueren. Hiervoor werden de ISO 6579 methode (voorgestelde referentiemethode) en, facultatief, de eigen methode van een laboratorium ...
Voogt N; Ph, Veld In Apos T.; Nagelkerke N; Am, Henken
Het Communautair Referentie Laboratorium (CRL) voor Salmonella heeft een bacteriologisch ringonderzoek georganiseerd waaraan alle Nationale Referentie Laboratoria (NRLs) voor Salmonella deelnamen. Doel van het ringonderzoek was om de resultaten te vergelijken van de voorgestelde referentiemethode voor de detectie van Salmonella (ISO 6579 methode) tussen en binnen de laboratoria en om de resultaten van de referentie en eigen methode binnen een laboratorium te vergelijk...
Voogt N; Ph, Veld In T.; Shw, Notermans; Am, Henken
A total of 200 samples of milk and dairy products as well as 120 samples of dairy handlers were randomly collected from different dairy farms and supermarkets in Dakahlia Governorate, Egypt. The conventional cultural and serotyping methods for detection of Salmonella in dairy products were applied and the results were compared with those obtained by molecular screening assay using (ttr sequence). The obtained results revealed that 21% of milk and dairy products (42/200) were positive for Salmonella species using enrichment culture-based PCR method, while 12% of different dairy samples (24/200) were found to be positive for Salmonella species by using the conventional culture methods. Two stool specimens out of 40 apparently healthy dairy handlers were positive by the PCR method. Serotyping of Salmonella isolates revealed that 58.3% (14/24) from different dairy products were contaminated with Salmonella Typhimurium. We conclude that the enrichment culture-based PCR assay has high sensitivity and specificity for detection of Salmonella species in dairy products and handlers. High incidence of Salmonella Typhimurium in the examined dairy samples highlights the important role played by milk and dairy products as a vehicle in disease prevalence. Great effort should be applied for reducing foodborne risk for consumers. PMID:24808971
Gwida, Mayada M; Al-Ashmawy, Maha A M
Salmonella septic arthritis in healthy, immunocompetent patients is extremely rare. We present the case of a 70-year-old man who presented with a one-day history of painful swelling of his ankle from which was aspirated pus which subsequently grew Salmonella enteritidis. There was no history of trauma or symptoms consistent with Salmonella enterocolitis. Our patient recovered fully after two weeks on intravenous ceftriaxone and six weeks on oral ciprofloxacin. Salmonella is a notifiable disease in the European Union and the United States of America, and is associated with outbreaks as a result of food contamination. The nature of Salmonella arthritis and its appropriate management are outlined.
Dineen, Patrick F
There are over 2500 Salmonella enterica serovars that circulate globally. Of these, serovars those classified into subspecies I are the most common cause of human salmonellosis. Many subspecies I Salmonella serovars are routinely isolated from egg farm environments but are not frequently associated with causing disease in humans. In this study, virulence profiles were generated for 10 strains of Salmonella enterica isolated directly from egg farm environments to investigate their potential public health risk. Three virulence parameters were assessed including in vitro invasion, in vivo pathogenicity and characterization of genomic variation within five specific pathogenicity islands. These 10 Salmonella strains exhibited significant differences in invasion into the human intestinal epithelial cell line, Caco2. Low, moderate, and high invasion patterns were observed and the degree of invasion was dependent on bacterial growth in a nutritive environment. Interestingly, two Salmonella strains, S. Adelaide and S. Bredeney had consistently low invasion. The S. Typhimurium definitive types and S. Virchow exhibited the greatest cell invasion following growth in Luria Bertani broth. Only the S. Typhimurium strains caused disease in BALB/c mice, yet the majority of serovars were consistently detected in feces over the 21 day experiment. Genomic comparison of the five specific pathogenicity islands has shown that variation in virulence is likely multifactorial. Sequence variability was observed primarily in strains with low virulence. In particular, genes involved in forming the structures of the SPI-1 and SPI-2 type 3 secretion systems as well as multiple effector proteins were among the most variable. This variability suggest that serovars with low virulence are likely to have both invasion and within host replication defects that ultimately limit their pathogenicity. PMID:25667583
McWhorter, Andrea R.; Chousalkar, Kapil K.
Salmonella spp. are able to form biofilms on abiotic and biotic surfaces. In vivo studies in our laboratory have shown that Salmonella can form biofilms on the surfaces of cholesterol gallstones in the gallbladders of mice and human carriers. Biofilm formation on gallstones has been demonstrated to be a mechanism of persistence. The purpose of this work was to identify and evaluate Salmonella sp. cholesterol-dependent biofilm factors. Differential gene expression analysis between biofilms on glass or cholesterol-coated surfaces and subsequent quantitative real-time PCR (qRT-PCR) revealed that type 1 fimbria structural genes and a gene encoding a putative outer membrane protein (ycfR) were specifically upregulated in Salmonella enterica serovar Typhimurium biofilms grown on cholesterol-coated surfaces. Spatiotemporal expression of ycfR and FimA verified their regulation during biofilm development on cholesterol-coated surfaces. Surprisingly, confocal and scanning electron microscopy demonstrated that a mutant of type 1 fimbria structural genes (?fimAICDHF) and a ycfR mutant showed increased biofilm formation on cholesterol-coated surfaces. In vivo experiments using Nramp1(+/+) mice harboring gallstones showed that only the ?ycfR mutant formed extensive biofilms on mouse gallstones at 7 and 21 days postinfection; ?fimAICDHF was not observed on gallstone surfaces after the 7-day-postinfection time point. These data suggest that in Salmonella spp., wild-type type 1 fimbriae are important for attachment to and/or persistence on gallstones at later points of chronic infection, whereas YcfR may represent a specific potential natural inhibitor of initial biofilm formation on gallstones. PMID:23897604
Gonzalez-Escobedo, Geoffrey; Gunn, John S
Approximately 2.7% of a collection of Salmonella enterica var. Typhimurium promoter-lux reporter strains showed altered transcriptional patterns when exposed to low concentrations of nine different fluoroquinolones (FQs). Even at the subinhibitory concentrations employed, all nine FQs upregulated genes involved in the SOS response, umuD, lexA, sbmC and dinP. In addition, transcriptional regulators, genes putatively associated with membrane integrity (spr), virulence (sicA) and metabolism (plsB) were affected. Using the Ames test with Salmonella strain TA102, increased mutagenicity was demonstrated in response to all the FQs tested: ciprofloxacin, moxifloxacin, levofloxacin and gatifloxacin. Transcriptional effects were largely specific to the FQ antimicrobials. Such responses are consistent with the primary mechanism of action of this class of inhibitor, namely, the introduction of DNA damage. This work provides support for the notion that small molecules can have functions other than growth inhibition that may affect the establishment and maintenance of community dynamics in complex environments. PMID:21102598
Yim, Grace; McClure, JoAnn; Surette, Michael G; Davies, Julian E
Three esterases (Est-) hydrolysing alpha-naphthyl acetate: Est-E1, Est-E3 and Est-E4 produced by Salmonella enterica serovar Typhimurium, strain LT2 were separated by DEAE chromatography and gel filtration. Est-E3, the major component of this set of enzymes, clearly differed from the two other esterases by its apparent molecular weight, titration curve, substrate specificity and inactivation. Immunoglobulins raised against Est-E3 completely neutralized the activity of Est-E3 but did not react with Est-E1 or Est-E4; it showed no cross reaction with carboxylesterase B of Escherichia coli or with carboxylesterases from other enterobacteria. Est-E3 showed electrophoretic variants which were biochemically and immunologically detected in the seven subspecies of the genus Salmonella. These findings suggest that variants of Est-E3 are the products of very closely related loci originating from a common ancestral gene. The esterase could be a phylogenetic marker of the genus and a suitable molecular tool for taxonomy and epidemiology. PMID:8407677
Brisabois, A; Goullet, P
Increasing antimicrobial resistance in nontyphoid Salmonella species has been a serious problem for public health worldwide. The high rate of resistance is hampering the use of conventional antibiotics, and growing resistance to newer antimicrobial agents is aggravating the situation. The circumstances of occurrence and spread of antimicrobial resistance are complex; however, a major cause is the widespread use of antimicrobial agents in food animals, particularly in animal feed. Genetic analysis has indicated that the source of resistance is frequently a transferable plasmid. Recent studies have revealed that some serotype-specific virulence plasmids form hybrid plasmids through recombination with resistance plasmids or acquire gene cassettes consisting of multiple resistance genes. Such evolutionary events provide a virulent strain the advantage of survival in an unfavorable drug environment. In view of the serious implications associated with drug-resistant Salmonella species, a more deliberate use of antibiotics in both human medicine and animal industry is warranted. Continued surveillance of antimicrobial resistance and use of antimicrobial agents in food animals is also indispensable. PMID:15356819
Su, Lin-Hui; Chiu, Cheng-Hsun; Chu, Chishih; Ou, Jonathan T
A radiometric method for the detection of Salmonella in foods has been developed which is based on Salmonella poly H agglutinating serum preventing Salmonella from producing 14CO2 from [14C] dulcitol. The method will detect the presence or absence of Salmonella in a product within 30 h compared to 4 to 5 days by routine culture methods. The method has been evaluated against a routine culture method using 58 samples of food. The overall agreement was 91%. Five samples negative for Salmonella by the routine method were positive by the radiometric method. These may have been false positives. However, the routine method may have failed to detect Salmonella due to the presence of large numbers of lactose-fermenting bacteria which hindered isolation of Salmonella colonies on the selective agar plates
In recent years, Salmonella enteritidis has become an increasingly important public health problem in Italy. In some parts of the country, the fraction of total human salmonella isolates accounted for by S. enteritidis has risen from 3-4% in the mid-1980s to more than 30% in 1990. Between 1990 and 1991, the number of reported S. enteritidis outbreaks increased more than sixfold. The 33 outbreaks reported in 1991 occurred in seven contiguous regions in northern and central Italy and were clust...
Binkin, N.; Scuderi, G.; Novaco, F.; Giovanardi, G. L.; Paganelli, G.; Ferrari, G.; Cappelli, O.; Ravaglia, L.; Zilioli, F.; Amadei, V.; Magliani, W.; Viani, I.; Ricco?, D.; Borrini, B.; Magri, M.
Following a buffet meal served to six guests at a private domestic function, five of the guests and the host developed symptoms of food poisoning. Salmonella enteritidis phage type 4 (PT4) was isolated from all four individuals who submitted faecal samples for investigation. Leftover samples of a savoury rice dish consumed by all six ill persons contained 6 x 10(3)/gm Salmonella enteritidis PT4. The rice salad comprised boiled rice, raw carrots, eggs, cheese and curry powder. The curry powder...
Evans, M. R.; Parry, S. M.; Ribeiro, C. D.
After the problem of Salmonella infections in foods and feeding stuffs is emphasized, an account is given of the current ways of manufacturing bone meal, meat meal, blood meal, fish meal, fish flour, egg products and coconut. The effectiveness in eliminating salmonellae and the chance and possible sources of recontamination are described for each production method. Besides heat treatment, fumigation by ethylene oxide and irradiation with gamma rays are considered. The bacteriological tests required to establish the effectiveness of treatment are also discussed, as well as the effect of the treatment on the nutritive value of the product. (author). 50 refs, 4 tabs
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. Salmo...
Nmsq, Gama; Berchieri Jr A; Sa, Fernandes
Serotyping has been the gold standard for identifying Salmonella, but it requires large amounts of standard antisera. Multilocus sequence typing (MLST) has been applied to identify Salmonella serovars, but the recombination of 4-7 housekeeping genes and multiple analytic steps diminish its applicability. In the present study, we determined the complete sequences of the RNA polymerase beta subunit gene (rpoB) and 7 housekeeping genes (aroC, dnaN, hemD, hisD, purE, sucA, and thrA) for 76 strains of 33 Salmonella enterica serovars and conducted phylogenetic analyses together with the corresponding gene sequences of 24 reference strains registered in the GenBank database. Based on the phylogenetic analyses, 100 strains from 40 serovars and 91 strains from 37 serovars were classified into 60 rpoB (RST) and 49 multilocus sequence types (ST), respectively. The nucleotide similarities were 98.8-100% and 96.9-100% for the complete rpoB gene and the seven concatenated housekeeping genes, respectively. The strains of 35 and 30 serovars formed serovar-specific branches or clusters in the rpoB and housekeeping gene phylogenetic trees, respectively. Therefore, complete rpoB gene sequencing and phylogenetic analysis may be a useful method for identifying Salmonella serovars that is a simpler, more cost-effective, and less time-consuming alternative or complementary method to MLST and conventional serotyping. PMID:23274983
Seong, Won-Jin; Kwon, Hyuk-Joon; Kim, Tae-Eun; Lee, Deog-Yong; Park, Mi-Sun; Kim, Jae-Hong
To determine patterns of cross-contamination and antibiotic susceptibility of microorganisms commonly associated with cattle, 60 cattle shipped to a commercial abattoir (20 in each of three separate trial periods) were followed through processing. Samples for bacterial isolation were collected from the feces and hides immediately before shipping, from the hides at the abattoir after exsanguination, and from the carcasses before evisceration and in the cooler. Samples were cultured for Salmonella and non-type-specific Escherichia coli. Salmonella was identified in 33.9% (n = 20) of the fecal samples and on 37.3% (n = 22) of the hides before shipment. At the abattoir, the proportion of hides from which Salmonella was isolated increased (P hotbox carcass samples. Isolates were tested for antimicrobial drug susceptibility. For nonspecific E. coli, 80.3% (n = 270) of the isolates were resistant to at least one antimicrobial drug. For Salmonella, 97% (n = 101) of the isolates were resistant to at least one antimicrobial drug; however, only 4.0% were resistant to two or more. The most common resistance was to sulfamethoxazole. These results indicate that the presence of microorganisms resistant to antimicrobial drugs is common in cattle and beef. Further studies are needed to identify the sources and causes of this drug resistance. PMID:17388041
Fluckey, W M; Loneragan, W G H; Warner, R; Brashears, M M
Full Text Available A serological survey of the prevalence of antibodies to Salmonella gallinarum among chickens under two different management systems around Jos, Plateau State, Nigeria was carried out using the standard plate agglutination test. The objective of this study was to determine serologically the prevalence of antibodies against Salmonella gallinarum among apparently healthy chickens around Jos. A total of 700 serum samples made up of 450 exotic and 250 local breed of chickens were used for this study with 37.9% seropositvity. In the free range system (19.3% of the flocks sampled were seropositive for Salmonella gallinarium antibodies while in the semi intensive, 18.6% of the flock tested positive. The serum agglutination test (SAT was adapted to the microtitre format used to determine somatic and flagella titres. The antigen used for this study was specific for S. gallinarum, hence differentiation between species infection was assessed in this study. Perhaps the most feasible way to eradicate the disease is to encourage farmers (both small and large scale to break the disease cycle at their levels by embarking on prompt and regular vaccination programmes. It is thus concluded that Salmonella gallinarum (fowl typhoid is present in the area investigated. Fowl typhoid may continue to have a negative effect on the economy of poultry production in Nigeria if not controlled. A statistical analysis was precluded due to inadequate data sets.
A Mix-ELISA using lipopolysaccharide antigens from Salmonella enterica serotype Enteritidis and Typhimurium? was evaluated using samples collected over time in the Danish salmonella surveillance programme for poultry. Serological samples (n = 42813) taken from broiler-breeder flocks after a year of bacteriological monitoring with negative results were used for calculating the flock and individual test specificities, which were 0.997 and 0.999, respectively. Layer flocks from the table egg sector were used for calculation of positive predictive values. In the survey, flocks were examined for salmonella by Mix-ELISA and by faecal culture, and in case of a positive result in either of these a repeated, serological testing was performed, and 60 animals were organ-cultured. If one of these samplings was positive, the flock was declared salmonella infected. In a period of 3 months, 35 flocks were found to be positive in the routine samples. Of these, 32 were serologically positive, 2 both serologically and faecallypositive and 1 flock only faecally positive. For flocks serologically positive in the surveillance programme, a positive-predictive value of 0.62 for organ culture positivity was found, and while considering serological follow-up samples, the value was 0.95.
Feld, Niels Christian; Ekeroth, Lars
The aim of this study was to examine the Salmonella serovars and antimicrobial resistance within an animal-based agriculture river system. The study area consisted of a 1,345 ha upper part of Pinhal catchment. A total of 384 samples were collected in four years of monitoring. Salmonella was isolated from 241 samples (62.7%), resulting in 324 isolates. The highest number of Salmonella sp. occurred in samples associated with sites with high stoking density animal unit per hectare. It was possible to demonstrate the variability of serovars in the study area: 30 different serovars were found and at least 11 per monitoring site. Thirty-three potentially related isolates were genotyped by PFGE, one major clone was observed in serovar Typhimurium, which occurred in animal feces (swine and bovine), and different sites and samplings proving the cross-contamination and persistence of this specific clone. Among 180 isolates submitted to an antimicrobial susceptibility test, 50.5% were susceptible to all 21 antimicrobials tested and 54 different profiles were found. In the current study, 49.5% of the tested isolates were resistant to at least one antimicrobial, and multi-resistance occurred in 18% of isolates. Results indicate a close interaction between animal-based agriculture, Salmonella, and antimicrobial resistance. PMID:24317171
Palhares, Julio Cesar Pascale; Kich, Jalusa D; Bessa, Marjo C; Biesus, Luiza L; Berno, Lais G; Triques, Nelise J
Cystic meningiomas are rare tumors. There is no clear prevalence between cystic meningiomas and histologic type. MRI has allowed a correct diagnosis of cystic meningiomas as much as 80%. However, the differentiation is not easy pre-operatively in some cases. In this study, 3 patient who had cystic meningiomas with dural invasion were discussed from radiological, operatively and histopathologically.
Avci, Emel; Ozturk, Adil; Ozardali, Ilyas; Bereket, Murat; Karabag, Hamza; Yucetas, Seyho; Cakir, Ahmet
Full Text Available Cystic meningiomas are rare tumors. There is no clear prevalence between cystic meningiomas and histologic type. MRI has allowed a correct diagnosis of cystic meningiomas as much as 80%. However, the differentiation is not easy pre-operatively in some cases. In this study, 3 patient who had cystic meningiomas with dural invasion were discussed from radiological, operatively and histopathologically.
Full Text Available Salmonella enteritidis es un microorganismo que raramente afecta al componente muscular. Recogemos el caso de un paciente varón con Síndrome de Inmunodeficiencia Adquirida (SIDA, que tras un episodio de gastroenteritis aguda debida a Salmonella enteritidis presenta, varios meses después, una necrosis muscular masiva en los miembros inferiores, que le llevó al shock séptico y posteriormente a la muerte.Salmonella enteritidis is a microorganism which rarely affects muscles. We report a case of a male patient with AIDS, who suffered an episode of acute gastroenteritis due to Salmonella enteritidis, months ago. After this incident, the patient presented massive muscular necrosis in the lower limbs which led to septic shock and subsequent death.
Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Salmonella enteritidis es un microorganismo que raramente afecta al componente muscular. Recogemos el caso de un paciente varón con Síndrome de Inmunodeficiencia Adquirida (SIDA), que tras un episodio de gastroenteritis aguda debida a Salmonella enteritidis presenta, varios meses después, una necros [...] is muscular masiva en los miembros inferiores, que le llevó al shock séptico y posteriormente a la muerte. Abstract in english Salmonella enteritidis is a microorganism which rarely affects muscles. We report a case of a male patient with AIDS, who suffered an episode of acute gastroenteritis due to Salmonella enteritidis, months ago. After this incident, the patient presented massive muscular necrosis in the lower limbs wh [...] ich led to septic shock and subsequent death.
P., Baeta; J., Fernández Palacios; T., Marrero; O., Suárez.
Full Text Available The immunomagnetic separation (IMS is a technique that has been used to increase sensitivity and specificity and to decrease the time required for detection of Salmonella in foods through different methodologies. In this work we report on the development of a method for detection of Salmonella in chicken cuts using in house antibody-sensitized microspheres associated to conventional plating in selective agar (IMS-plating. First, protein A-coated microspheres were sensitized with polyclonal antibodies against lipopolysacharide and flagella from salmonellae and used to standardize a procedure for capturing Salmonella Enteritidis from pure cultures and detection in selective agar. Subsequently, samples of chicken meat experimentally contaminated with S. Enteritidis were analyzed immediately after contamination and after 24h of refrigeration using three enrichment protocols. The detection limit of the IMS-plating procedure after standardization with pure culture was about 2x10 CFU/mL. The protocol using non-selective enrichment for 6-8h, selective enrichment for 16-18h and a post-enrichment for 4h gave the best results of S. Enteritidis detection by IMS-plating in experimentally contaminated meat. IMS-plating using this protocol was compared to the standard culture method for salmonellae detection in naturally contaminated chicken cuts and yielded 100% sensitivity and 94% specificity. The method developed using in house prepared magnetic microespheres for IMS and plating in selective agar was able to diminish by at least one day the time required for detection of Salmonella in chicken products by the conventional culture method.A separação imunomagnética (IMS é uma técnica que tem sido associada a diferentes métodos de detecção de Salmonella em alimentos para aumentar a sensibilidade e a especificidade e diminuir o tempo de análise. Neste trabalho é comunicada a obtenção de microesferas magnéticas sensibilizadas com anticorpos anti-Salmonella e seu uso em associação com a metodologia de cultivo convencional para desenvolver um método de detecção de salmonelas em cortes de frango (IMS-plaqueamento. Inicialmente, microesferas cobertas com proteína A foram sensibilizadas com anticorpos policlonais contra lipopolissacarídeo e flagelo de salmonelas e usadas na padronização de um procedimento que captura Salmonella Enteritidis em cultivo puro e faz posterior detecção em ágar seletivo. A seguir, amostras de carne de frango experimentalmente contaminadas com S. Enteritidis foram analisadas imediatamente após a contaminação e após 24h de refrigeração utilizando três protocolos de enriquecimento. O limite de detecção foi cerca de 2x10 UFC/mL. O protocolo que incluiu enriquecimento não-seletivo por 6-8h, enriquecimento seletivo por 16-18h e pós-enriquecimento por 4h foi o que proporcionou melhor resultado na detecção de S. Enteritidis em carne de frango experimentalmente contaminada. Este protocolo foi comparado à metodologia convencional em estudo de detecção de salmonelas em cortes de frango naturalmente contaminados e obteve 100% de sensibilidade e 94% de especificidade. O método desenvolvido foi capaz de diminuir em pelo menos um dia o tempo de detecção de salmonelas em cortes de frango pela metodologia convencional.
Rita de Cássia dos Santos da Conceição
Full Text Available SciELO Brazil | Language: English Abstract in portuguese A separação imunomagnética (IMS) é uma técnica que tem sido associada a diferentes métodos de detecção de Salmonella em alimentos para aumentar a sensibilidade e a especificidade e diminuir o tempo de análise. Neste trabalho é comunicada a obtenção de microesferas magnéticas sensibilizadas com antic [...] orpos anti-Salmonella e seu uso em associação com a metodologia de cultivo convencional para desenvolver um método de detecção de salmonelas em cortes de frango (IMS-plaqueamento). Inicialmente, microesferas cobertas com proteína A foram sensibilizadas com anticorpos policlonais contra lipopolissacarídeo e flagelo de salmonelas e usadas na padronização de um procedimento que captura Salmonella Enteritidis em cultivo puro e faz posterior detecção em ágar seletivo. A seguir, amostras de carne de frango experimentalmente contaminadas com S. Enteritidis foram analisadas imediatamente após a contaminação e após 24h de refrigeração utilizando três protocolos de enriquecimento. O limite de detecção foi cerca de 2x10 UFC/mL. O protocolo que incluiu enriquecimento não-seletivo por 6-8h, enriquecimento seletivo por 16-18h e pós-enriquecimento por 4h foi o que proporcionou melhor resultado na detecção de S. Enteritidis em carne de frango experimentalmente contaminada. Este protocolo foi comparado à metodologia convencional em estudo de detecção de salmonelas em cortes de frango naturalmente contaminados e obteve 100% de sensibilidade e 94% de especificidade. O método desenvolvido foi capaz de diminuir em pelo menos um dia o tempo de detecção de salmonelas em cortes de frango pela metodologia convencional. Abstract in english The immunomagnetic separation (IMS) is a technique that has been used to increase sensitivity and specificity and to decrease the time required for detection of Salmonella in foods through different methodologies. In this work we report on the development of a method for detection of Salmonella in c [...] hicken cuts using in house antibody-sensitized microspheres associated to conventional plating in selective agar (IMS-plating). First, protein A-coated microspheres were sensitized with polyclonal antibodies against lipopolysacharide and flagella from salmonellae and used to standardize a procedure for capturing Salmonella Enteritidis from pure cultures and detection in selective agar. Subsequently, samples of chicken meat experimentally contaminated with S. Enteritidis were analyzed immediately after contamination and after 24h of refrigeration using three enrichment protocols. The detection limit of the IMS-plating procedure after standardization with pure culture was about 2x10 CFU/mL. The protocol using non-selective enrichment for 6-8h, selective enrichment for 16-18h and a post-enrichment for 4h gave the best results of S. Enteritidis detection by IMS-plating in experimentally contaminated meat. IMS-plating using this protocol was compared to the standard culture method for salmonellae detection in naturally contaminated chicken cuts and yielded 100% sensitivity and 94% specificity. The method developed using in house prepared magnetic microespheres for IMS and plating in selective agar was able to diminish by at least one day the time required for detection of Salmonella in chicken products by the conventional culture method.
Rita de Cássia dos Santos da, Conceição; Ângela Nunes, Moreira; Roberta Juliano, Ramos; Fabiana Lemos, Goularte; José Beiro, Carvalhal; José Antonio Guimarães, Aleixo.
We demonstrated previously that expression of a single trans-membrane region of the ?(12) -desaturase gene of Synechocystis sp. PCC 6803 in Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) altered the membrane physical state of this pathogen, induced a significant change in the pattern of mRNA transcription of major heat shock genes, and inhibited pathogen growth inside murine macrophages. In this study, we demonstrate that injection of the modified Salmonella strain [Stm(pBAD200)] into C57Bl6j mice is safe. Survival of mice was associated with bacterial clearance, an increased number of splenic leukocytes, and high levels of interleukin-12, interferon ? and tumor necrosis factor ? in spleens as well as in sera. Furthermore, Stm(pBAD200)-injected mice developed a Salmonella-specific antibody and Th1-like responses. Mice challenged with Stm(pBAD200) are protected from systemic infection with Salmonella wild-type. Similarly, mice infected with Stm(pBAD200) by the oral route survived when challenged with an oral lethal dose of Salmonella wild-type. The avirulent Stm(pBAD200) phenotype is associated with a remarkable change in the expression of the hilC, hilD, hilA, invF and phoP genes, among others, whose products are required for invasion and replication of Salmonella inside phagocytic cells. These data demonstrate the use of trans-membrane peptides to generate attenuated strains, providing a potential novel strategy to develop vaccines for both animal and human use. PMID:25208333
Porta, Amalia; Morello, Silvana; Granata, Ilaria; Iannone, Raffaella; Maresca, Bruno
Salmonella enterica causes substantial morbidity and mortality in humans and animals. Infection and intestinal colonization by S. enterica require virulence factors that mediate bacterial binding and invasion of enterocytes and innate immune cells. Some S. enterica colonization factors and their alleles are host restricted, suggesting a potential role in regulation of host specificity. Recent data also suggest that colonization factors promote horizontal gene transfer of antimicrobial resistance genes by increasing the local density of Salmonella in colonized intestines. Although a profusion of genes are involved in Salmonella pathogenesis, the relative importance of their allelic variation has only been studied intensely in the type 1 fimbrial adhesin FimH. Although other Salmonella virulence factors demonstrate allelic variation, their association with specific metadata (e.g., host species, disease or carrier state, time and geographic place of isolation, antibiotic resistance profile, etc.) remains to be interrogated. To date, genome-wide association studies (GWAS) in bacteriology have been limited by the paucity of relevant metadata. In addition, due to the many variables amid metadata categories, a very large number of strains must be assessed to attain statistically significant results. However, targeted approaches in which genes of interest (e.g., virulence factors) are specifically sequenced alleviates the time-consuming and costly statistical GWAS analysis and increases statistical power, as larger numbers of strains can be screened for non-synonymous single nucleotide polymorphisms (SNPs) that are associated with available metadata. Congruence of specific allelic variants with specific metadata from strains that have a relevant clinical and epidemiological history will help to prioritize functional wet-lab and animal studies aimed at determining cause-effect relationships. Such an approach should be applicable to other pathogens that are being collected in well-curated repositories. PMID:24454310
Yue, Min; Schifferli, Dieter M
MarA and its homologue, RamA, have been implicated in multidrug resistance (MDR). RamA overexpression in Salmonella enterica serovar Typhimurium and Escherichia coli conferred MDR independently of marA. Inactivation of ramA did not affect the antibiotic susceptibilities of wild-type S. enterica serovar Typhimurium or 15 unrelated clinical MDR isolates. Thus, ramA overexpression is not a common MDR mechanism in Salmonella.
Straaten, T.; Janssen, R.; Mevius, D. J.; Dissel, J. T.
The Paradigm Diagnostics Salmonella Indicator Broth (PDX-SIB) is intended as a single-step selective enrichment indicator broth to be used as a simple screening test for the presence of Salmonella spp. in environmental samples. This method permits the end user to avoid multistep sample processing to identify presumptively positive samples, as exemplified by standard U.S. reference methods. PDX-SIB permits the outgrowth of Salmonella while inhibiting the growth of competitive Gram-negative and -positive microflora. Growth of Salmonella-positive cultures results in a visual color change of the medium from purple to yellow when the sample is grown at 37 +/- 1 degree C. Performance of PDX-SIB has been evaluated in five different categories: inclusivity-exclusivity, methods comparison, ruggedness, lot-to-lot variability, and shelf stability. The inclusivity panel included 100 different Salmonella serovars, 98 of which were SIB-positive during the 30 to 48 h incubation period. The exclusivity panel included 33 different non-Salmonella microorganisms, 31 of which were SIB-negative during the incubation period. Methods comparison studies included four different surfaces: S. Newport on plastic, S. Anatum on sealed concrete, S. Abaetetuba on ceramic tile, and S. Typhimurium in the presence of 1 log excess of Citrobacter freundii. Results of the methods comparison studies demonstrated no statistical difference between the SIB method and the U.S. Food and Drug Administration-Bacteriological Analytical Manual reference method, as measured by the Mantel-Haenszel Chi-square test. Ruggedness studies demonstrated little variation in test results when SIB incubation temperatures were varied over a 34-40 degrees C range. Lot-to-lot consistency results suggest no detectable differences in manufactured goods using two reference Salmonella serovars and one non-Salmonella microorganism. PMID:23767367
Olstein, Alan; Griffith, Leena; Feirtag, Joellen; Pearson, Nicole
Fifty-four epidemiologically unrelated multidrug-resistant Salmonella enterica serovar Typhimurium isolates, collected between 1992 and 2000 in Italy, were analyzed for the presence of integrons. Strains were also tested for Salmonella genomic island 1 (SGI1), carrying antibiotic resistance genes in DT104 strains. A complete SGI1 was found in the majority of the DT104 strains. Two DT104 strains, showing resistance to streptomycin-spectinomycin and sulfonamides, carried a partially deleted SGI...
Carattoli, Alessandra; Filetici, Emma; Villa, Laura; Dionisi, Anna Maria; Ricci, Antonia; Luzzi, Ida
The study was conducted for the comparative evaluation of the vaccine potential of Salmonella Enteritidis (S. Enteritidis, SE) ghost, SE ghost carrying Escherichia coli heat labile enterotoxin B subunit (LTB) protein, and a commercial vaccine. Group A chickens were used as a non-vaccinated control, group B chickens were immunized with the ghost carrying LTB protein, group C chickens were immunized with the ghost and, group D chickens were immunized with a commercial vaccine. Group D chickens showed the swelling at the injection site, while no adverse reactions were observed at injection sites of the group B and C chickens. Chickens from the immunized groups B, C, and D demonstrated significant increases in plasma IgG, intestinal secretory IgA levels, and antigen-specific lymphocyte proliferative responses. After challenge with a virulent SE strain via intravenous route, groups B, C, and D showed significantly higher egg production and lower internal egg contamination and lower recovery of the challenge strain from internal organs compared to non-immunized-challenged control group A. In conclusion, these data indicate that immunization of chickens with the ghost and ghost carrying LTB is safe, without causing any adverse reaction, and is effective as the commercial vaccine in terms of reduction in internal egg contamination and internal organ colonization of Salmonella. PMID:25218296
Jawale, Chetan V; Lee, John Hwa
Vaccination against Salmonella enteritidis in Dutch commercial layer flocks with a vaccine based on a live Salmonella gallinarum 9R strain: evaluation of efficacy, safety, and performance of serologic Salmonella tests.
This study describes a field trial in which 80 commercial layer flocks, with an increased risk of Salmonella enteritidis (SE) infection and placed on farms with a certified Standardized Biosecurity Programme (SBP) or a request for a SBP certificate, were vaccinated with a vaccine based on a live attenuated Salmonella gallinarum (SG) 9R strain. An evaluation is presented of the efficacy of the vaccine against SE infections, the effect on the performance of serologic Salmonella tests, and the spread of the vaccine strain to the egg content. For the efficacy study, assessment of the flock level occurrence of SE infections in the vaccinated group of 80 flocks was compared with that of a nonvaccinated group of 1854 flocks hatched in the same period. This control group was examined according to the compulsory control programme in The Netherlands. An evaluation was done of the performance of serologic Salmonella tests and the spread of the vaccine strain to the inner egg content of five of the vaccinated flocks. Findings demonstrated the flock level occurrence of SE infections in the vaccinated group (2/80 = 2.5%) to be significantly (P = 0.01) lower than that of the nonvaccinated group (214/1854 = 11.5%). Vaccination resulted in 59.0% positive test results in lipopolysaccharide BD enzyme-linked immunosorbent assay (ELISA) for detecting antibodies against Salmonella serogroups B and D and 0% positive test results in the rapid plate agglutination test for detecting antibodies against S. pullorum (SP)/SG. The mean specificities of two blocking ELISAs (gm- and i-double antibody sandwich ELISAs) based on the flagellar antigen of SE and Salmonella typhimurium (ST) on the same sera were 99.6% and 96.1%, respectively. The vaccine strain could not be isolated from any of the 450 pools of 10 eggs. On the basis of these results, we concluded that vaccination with a vaccine based on an attenuated SG 9R strain contributes to the reduction of SE infections in commercial layer flocks. Furthermore, serologic monitoring of SE, ST, and SP/SG can still be carried out on flocks vaccinated with an attenuated SG 9R strain. Additionally, we found no indication of the spread of the vaccine strain to the egg content. PMID:11332503
Feberwee, A; de Vries, T S; Hartman, E G; de Wit, J J; Elbers, A R; de Jong, W A
The host interferon (IFN) system plays an important role in protection against microbial infections. Salmonella enterica serovar Typhimurium is highly virulent in the mouse model, whereas mutants that lack DNA adenine methylase (Dam(-)) are highly attenuated and elicit fully protective immune responses against murine typhoid fever. We examined the expression of IFN-responsive genes in several mouse tissues following infection with Dam(+) or Dam(-) Salmonella. Infection of mice with Dam(+) Salmonella resulted in the induction of host genes known to be indicators of IFN bioactivity and regulated by either IFN-alpha/beta (Mx1) or IFN-gamma (class II transactivator protein [CIITA] and inducible nitric oxide synthase [iNOS]) or by both IFN-alpha/beta and IFN-gamma (RNA-specific adenosine deaminase [ADAR1] and RNA-dependent protein kinase [PKR]) in a tissue-specific manner compared to uninfected animals. Since the Mx1 promoter is IFN-alpha/beta specific and the Mx1 gene is not inducible directly by IFN-gamma, these data suggest a role of IFN-alpha/beta in the host response to Salmonella infection. Mice infected with Dam(-) Salmonella showed reduced expression of the same set of IFN-stimulated genes (ISGs) as that observed after infection with wild-type Salmonella. The reduced capacity to induce ISGs persisted in Dam(-)-vaccinated mice after challenge with the virulent (Dam(+)) strain. Finally, although no Dam(-) organisms were recovered from the liver or spleen after oral infection of mice, ADAR, PKR, Mx, and CIITA expression levels were elevated in these tissues relative to those in uninfected mice, suggestive of the distant action of a signaling molecule(s) in the activation of ISG expression. PMID:12228285
Shtrichman, Ronit; Heithoff, Douglas M; Mahan, Michael J; Samuel, Charles E
The host interferon (IFN) system plays an important role in protection against microbial infections. Salmonella enterica serovar Typhimurium is highly virulent in the mouse model, whereas mutants that lack DNA adenine methylase (Dam?) are highly attenuated and elicit fully protective immune responses against murine typhoid fever. We examined the expression of IFN-responsive genes in several mouse tissues following infection with Dam+ or Dam? Salmonella. Infection of mice with Dam+ Salmonella resulted in the induction of host genes known to be indicators of IFN bioactivity and regulated by either IFN-?/? (Mx1) or IFN-? (class II transactivator protein [CIITA] and inducible nitric oxide synthase [iNOS]) or by both IFN-?/? and IFN-? (RNA-specific adenosine deaminase [ADAR1] and RNA-dependent protein kinase [PKR]) in a tissue-specific manner compared to uninfected animals. Since the Mx1 promoter is IFN-?/? specific and the Mx1 gene is not inducible directly by IFN-?, these data suggest a role of IFN-?/? in the host response to Salmonella infection. Mice infected with Dam? Salmonella showed reduced expression of the same set of IFN-stimulated genes (ISGs) as that observed after infection with wild-type Salmonella. The reduced capacity to induce ISGs persisted in Dam?-vaccinated mice after challenge with the virulent (Dam+) strain. Finally, although no Dam? organisms were recovered from the liver or spleen after oral infection of mice, ADAR, PKR, Mx, and CIITA expression levels were elevated in these tissues relative to those in uninfected mice, suggestive of the distant action of a signaling molecule(s) in the activation of ISG expression. PMID:12228285
Shtrichman, Ronit; Heithoff, Douglas M.; Mahan, Michael J.; Samuel, Charles E.
A total of 60 Salmonella enterica serovar (ser.) Enteritidis isolates, 28 from poultry houses and 32 from clinical samples, were isolated during 2010. These isolates were subjected to testing and analyzed for antibiotic resistance, virulence genes, plasmids and plasmid replicon types. To assess genetic diversity, pulsed-field gel electrophoresis (PFGE) fingerprinting, using the XbaI restriction enzyme, Multiple-Locus Variable-Number Tandem Repeat Analysis (MLVA) and plasmid profiles were performed. All isolates from poultry, and 10 out of 32 clinical isolates were sensitive to ampicillin, chloramphenicol, gentamicin, kanamycin, nalidixic acid, sulfisoxazole, streptomycin, and tetracycline. Twenty-one of thirty-two clinical isolates were resistant to ampicillin and tetracycline, and one isolate was resistant to nalidixic acid. PFGE typing of sixty ser. Enteritidis isolates by XbaI resulted in 10-12 bands and grouped into six clusters each with similarity from 95% to 81%. The MLVA analysis of sixty isolates gave 18 allele profiles with the majority of isolates displayed in three groups, and two clinical isolates found to be new in the PulseNet national MLVA database. All isolates were positive for 12 or more of the 17 virulence genes mostly found in S. enterica (spvB, spiA, pagC, msgA, invA, sipB, prgH, spaN, orgA, tolC, iroN, sitC, IpfC, sifA, sopB, and pefA) and negative for one gene (cdtB). All isolates carried a typical 58 kb plasmid, type Inc/FIIA. Three poultry isolates and one clinical isolate carried small plasmids with 3.8, 6, 7.6 and 11.5 kb. Ten of the clinical isolates carried plasmids, with sizes 36 and 38 kb, types IncL/M and IncN, and one isolate carried an 81 kb plasmid, type IncI. Southern hybridization of a plasmid with an Inc/FIIA gene probe hybridized one large 58 kb plasmid in all isolates. Several large and small plasmids from poultry isolates were not typed by our PCR-based method. These results confirmed that PFGE fingerprinting has limited discriminatory power for ser. Enteritidis in both poultry and clinical sources. However, the plasmid and MLVA allele profiles were a useful and important epidemiology tool to discriminate outbreak strains of ser. Enteritidis from poultry and clinical samples. PMID:24290628
Mezal, Ezat H; Sabol, Ashley; Khan, Mariam A; Ali, Nawab; Stefanova, Rossina; Khan, Ashraf A
Bacterial flagellin is recognized by Toll-like receptor (TLR5) and activates NF-?B which leads to the induction of proinflammatory gene expression. Salmonella expresses two flagellin proteins, FliC and FljB. We purified FliC and FljB and examined the ability of the Salmonella flagellins to activate the NF-?B transcription factor in human embryonic kidney cells. We found that FliC and FljB as purified proteins possessed a comparable specific activity for activation of NF-?B-dependent gene e...
Simon, Raphael; Samuel, Charles E.
Store besætninger lider størst økonomisk tab ved infektion med Salmonella Dublin. Selv i en veldrevet besætning kan tabet løbe op i mellem 1,3 og 3,3 millioner kr. over en tiårs periode. Ved uhensigtsmæssige hygiejne- og managementrutiner kan tabet nemt blive meget højere.
Nielsen, Torben Dahl; Nielsen, Liza Rosenbaum
Full Text Available A study of colicinogeny was made in 748 strains of Salmonella (97 serovars isolated from different sources; human (291, animal (119, environmental (141, food (102 and animal feed (95. Colicin production was detected in 64 strains (8.6%, particularly isolated from foods (30.4%. Col. E1 (53 and Ia (44 were the most frequently observed, especially in S. agona for environment and food sources. Col V production was identified in 5 strains of S. typhimurium within 8 producer cultures isolated from humans. Its relationship with the sources and serovars of Salmonella are discussed.Investigou-se a produção de colicina em 748 amostras de Salmonella (97 sorovares advindas de díferentes fontes: humana (291, animal (119, ambiental (141, de alimentos (102 e rações (95. Detectaram-se 64 amostras (8,6% colicinogênicas, particularmente isoladas de alimentos (30,4%. ColE1 (53 e Ia (44 foram as mais freqüentes, especialmente no sorovar S, agona, de origem ambiental e de alimentos. Identificou-se também a produção de col V em 5 amostras de S. typhimurium dentre 8 culturas produtoras de origem humana. Discute-se a relação entre a capacidade colicinogênica e as fontes e sorovares de Salmonella.
Leila Carvalho Campos
Citrate lyase, the key enzyme of anaerobic citrate catabolism, could not be deleted from Salmonella typhimurium. The only class of mutants found had a mode of covalent regulation that strongly resembled the Escherichia coli system: citrate lyase was only active, i.e., acetylated, when a cosubstrate was present.
Kulla, Hans G.
Many of the most virulent strains of Salmonella enterica produce two distinct Cu,Zn-superoxide dismutases (SodCI and SodCII). The bacteriophage-encoded SodCI enzyme makes the greater contribution to Salmonella virulence. We have performed a detailed comparison of the functional, structural, and regulatory properties of the Salmonella SodC enzymes. Here we demonstrate that SodCI and SodCII differ with regard to specific activity, protease resistance, metal affinity, and peroxidative activity, with dimeric SodCI exhibiting superior stability and activity. In particular, monomeric SodCII is unable to retain its catalytic copper ion in the absence of zinc. We have also found that SodCI and SodCII are differentially affected by oxygen, zinc availability, and the transcriptional regulator FNR. SodCII is strongly down-regulated under anaerobic conditions and dependent on the high affinity ZnuABC zinc transport system, whereas SodCI accumulation in vitro and within macrophages is FNR-dependent. We have confirmed earlier findings that SodCII accumulation in intracellular Salmonella is negligible, whereas SodCI is strongly up-regulated in macrophages. Our observations demonstrate that differences in expression, activity, and stability help to account for the unique contribution of the bacteriophage-encoded SodCI enzyme to Salmonella virulence. PMID:18362154
Ammendola, Serena; Pasquali, Paolo; Pacello, Francesca; Rotilio, Giuseppe; Castor, Margaret; Libby, Stephen J; Figueroa-Bossi, Nara; Bossi, Lionello; Fang, Ferric C; Battistoni, Andrea
Full Text Available Abstract Background Salmonella paratyphi C, like S. typhi, is adapted to humans and causes typhoid fever. Previously we reported different genome structures between two strains of S. paratyphi C, which suggests that S. paratyphi C might have a plastic genome (large DNA segments being organized in different orders or orientations on the genome. As many but not all host-adapted Salmonella pathogens have large genomic insertions as well as the supposedly resultant genomic rearrangements, bacterial genome plasticity presents an extraordinary evolutionary phenomenon. Events contributing to genomic plasticity, especially large insertions, may be associated with the formation of particular Salmonella pathogens. Results We constructed a high resolution genome map in S. paratyphi C strain RKS4594 and located four insertions totaling 176 kb (including the 90 kb SPI7 and seven deletions totaling 165 kb relative to S. typhimurium LT2. Two rearrangements were revealed, including an inversion of 1602 kb covering the ter region and the translocation of the 43 kb I-CeuI F fragment. The 23 wild type strains analyzed in this study exhibited diverse genome structures, mostly as a result of recombination between rrn genes. In at least two cases, the rearrangements involved recombination between genomic sites other than the rrn genes, possibly homologous genes in prophages. Two strains had a 20 kb deletion between rrlA and rrlB, which is a highly conservative region and no deletion has been reported in this region in any other Salmonella lineages. Conclusion S. paratyphi C has diverse genome structures among different isolates, possibly as a result of large genomic insertions, e.g., SPI7. Although the Salmonella typhoid agents may not be more closely related among them than each of them to other Salmonella lineages, they may have evolved in similar ways, i.e., acquiring typhoid-associated genes followed by genome structure rearrangements. Comparison of multiple Salmonella typhoid agents at both single sequenced genome and population levels will facilitate the studies on the evolutionary process of typhoid pathogenesis, especially the identification of typhoid-associated genes.
Multidrug-resistant Salmonella enterica serovar Typhimurium ST313 has emerged in sub-Saharan Africa causing severe infections in humans. Therefore, it has been speculated that this specific sequence type, ST313, carries factors associated with increased pathogenicity. We assessed the role in virulence of a gene with a yet unknown function, st313-td, detected in ST313 through comparative genomics. Additionally, the structure of the genomic island ST313-GI, harbouring the gene was determined. T...
Herrero-fresno, Ana; Wallrodt, Inke; Leekitcharoenphon, Pimlapas; Olsen, John Elmerdahl; Aarestrup, Frank M.; Hendriksen, Rene S.
Paradoxically, nitric oxide (NO) has been found to exhibit cytotoxic, antiproliferative, or cytoprotective activity under different conditions. We have utilized Salmonella mutants deficient in antioxidant defenses or peptide transport to gain insights into NO actions. Comparison of three NO donor compounds reveals distinct and independent cellular responses associated with specific redox forms of NO. The peroxynitrite (OONO-) generator 3-morpholinosydnonimine hydrochloride mediates oxygen-dep...
Groote, M. A.; Granger, D.; Xu, Y.; Campbell, G.; Prince, R.; Fang, F. C.
Recognition of typhoid hepatitis is important since it has to be differentiated from other common ailments in our country such as viral, malarial or amoebic hepatitis. Early institution of specific therapy in cases of typhoid hepatitis carries a good prognosis. In our study, 107 patients with positive blood or bone marrow cultures for Salmonella typhi, were evaluated for hepatomegaly and abnormal serum liver enzymes, PT and alkaline phosphatase. The clinical features of typhoid fever with hep...
Rasoolinejad, M.; Mogbel Alhosein, N. Esmailpoor Bazaz B.
Four bacteriophages, P22, P27, 9NA, and KB1, active on smooth Salmonella strains belonging to serogroups A, B, and D1 were investigated for endoglycosidase activity and specificity in enzyme hydrolysis assays. Purified phage was incubated with phenol-water-extracted lipopolysaccharide preparations which had been partially delipidated. Dialyzable oligosaccharides, released by phage glycosidase activity, were analyzed by sugar and methylation analyses. Phages P27, 9NA, and KB1, as well as P22 a...
Wollin, Ralfh; Eriksson, Ulla; Lindberg, Alf A.
Phenotypic differences among closely related bacteria have been largely ascribed to species-specific genes, such as those residing in pathogenicity islands. However, we now report that the differential regulation of homologous genes is the mechanism responsible for the divergence of the enteric bacteria Salmonella enterica and Escherichia coli in their ability to make LPS modifications mediating resistance to the antibiotic polymyxin B. In S. enterica serovar Typhimurium, the PmrA/PmrB two-co...
Winfield, Mollie D.; Groisman, Eduardo A.
Problem statement: Poultry industry is intensive and consistently applies an all-in, all-out system with the aim of minimizing infection pressure and targeting specific pathogens like Salmonella which remains one of the leading causes of food-borne illness, many questions regarding the introduction and persistence in animal production still remain. Therefore disinfection during production break is a routine part of the biosecurity programs of poultry houses. The correct usage of disinf...
Soliman, Essam S.; Taha, E. G.; Sobieh, M. A. A.; Reddy, P. G.
Bone-in and boneless parts, such as drumsticks, are used in ground chicken production. In addition, neck skin is used as a source of fat in ground products. Contaminated chicken neck skin and bones containing internalized Salmonella are potential sources of this pathogen in ground chicken. This study determined the prevalence of Salmonella and serotype distribution in drumstick bones and neck skin of postchill chicken carcasses. One week prior to slaughter, chicken houses (n = 26) at nine farms were tested for the presence of Salmonella, using the boot sock method. Chicken flocks from these houses originated from Salmonella-positive breeders. Eight Salmonella-positive chicken flocks and one flock with undetermined Salmonella status were monitored through processing. Three hundred postchill drumsticks and 299 neck skin samples were analyzed for Salmonella prevalence. Skin samples were rinsed and stomached prior to analysis. Bones were extracted from the drumsticks, external surfaces were sterilized, and bones were crushed for analysis. One Salmonella isolate from each positive sample was serogrouped. Half of the isolates representing different sample types were serotyped. Overall, Salmonella was found in 0.8, 21.4, and 80.1% of bone marrow, neck skin, and farms, respectively. Prevalence of Salmonella on rinsed skin samples (2.3%) and stomached skin samples (20.7%) differed significantly (P ? 0.05). Serogroups B, C2, D, and E were found at 23.4, 31.9, 11.7, and 29.8%, respectively. Six Salmonella serotypes were identified: Liverpool (37.9%), Kentucky (27.6%), and Typhimurium (27.6%) were isolated most frequently from neck skin; the two bone isolates were Kentucky; and more than 50% of the farm isolates were Kentucky and Ouakam. Salmonella-contaminated neck skin might be a more significant source of this contamination in ground chicken than Salmonella internalized in bones. PMID:24988028
Wu, Diezhang; Alali, W Q; Harrison, M A; Hofacre, C L
A modular process risk model approach was used to assess health risks associated with Salmonella spp. after consumption of the Danish meatball product (frikadeller) produced with fresh pork in a catering unit. Meatball production and consumption were described as a series of processes (modules), starting from 1.3kg meat pieces through conversion to 70g meatballs, followed by a dose response model to assess the risk of illness from consumption of these meatballs. Changes in bacterial prevalence, concentration, and unit size were modelled within each module. The risk assessment was built using observational data and models that were specific for Salmonella spp. in meatballs produced in the catering sector. Danish meatballs are often pan-fried followed by baking in an oven before consumption, in order to reach the core temperature of 75°C recommended by the Danish Food Safety Authority. However, in practice this terminal heat treatment in the oven may be accidentally omitted. Eleven production scenarios were evaluated with the model, to test the impact of heat treatments and cooling rates at different room temperatures. The risk estimates revealed that a process comprising heat treatment of meatballs to core temperatures higher than 70°C, and subsequent holding at room temperatures lower than 20°C, for no longer than 3.5h, were very effective in Salmonella control. The current Danish Food Safety Authority recommendation of cooking to an internal temperature of 75°C is conservative, at least with respect to Salmonella risk. Survival and growth of Salmonella during cooling of meatballs not heat treated in oven had a significant impact on the risk estimates, and therefore, cooling should be considered a critical step during meatball processing. PMID:25540860
Møller, Cleide O de A; Nauta, Maarten J; Schaffner, Donald W; Dalgaard, Paw; Christensen, Bjarke B; Hansen, Tina B
...Regarding the Final Rule, Prevention of Salmonella Enteritidis in Shell Eggs During Production...Regarding the Final Rule, Prevention of Salmonella Enteritidis in Shell Eggs During Production...final rule entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During...
...for the bacteriological examination of salmonella. 147.11 Section 147.11 Animals...for the bacteriological examination of salmonella. (a) For egg- and meat-type...tests, up to 25 birds, and birds from Salmonella enteritidis (SE) positive...
...Regarding the Final Rule, Prevention of Salmonella Enteritidis in Shell Eggs During Production...Regarding the Final Rule, Prevention of Salmonella Enteritidis in Shell Eggs During Production...producers to implement measures to prevent Salmonella Enteritidis (SE) from...
...feeds contaminated with Salmonella microorganisms...processed fish meal, poultry meal, meat meal...be contaminated with Salmonella bacteria, an organism...be contaminated with Salmonella microorganisms: Bone...solubles, meat scraps, poultry meat meal,...
When grown on Rambach Propylene Glycol Containing Agar (Rambach agar), 216 of 230 (93.9%) Salmonella organisms isolated from patients and 54 of 62 (87.1%) Salmonella stock cultures produced a crimson-colored growth. Of the 14 clinical Salmonella isolates which displayed colors other than crimson, 8 were Salmonella typhi, 2 were Salmonella paratyphi A, and 4 belonged to other commonly isolated serotypes. All eight Salmonella stock cultures which failed to produce a crimson color belonged to ra...
Gruenewald, R.; Henderson, R. W.; Yappow, S.
Poultry products are an important source of Salmonella enterica. An effective way to reduce food poisoning due to Salmonella would be to breed chickens more resistant to Salmonella. Unfortunately host responses to Salmonella are complex with many factors involved. To learn more about responses to Salmonella in young chickens, a cDNA microarray analysis was performed to compare gene expression profiles between two chicken lines under control and Salmonella infected conditions. Newly hatched ch...
Hemert, S.; Hoekman, A. J. W.; Smits, M. A.; Rebel, J. M. J.
An outbreak of Salmonella Typhimurium phage type U292 has been ongoing in Denmark since 1 April, with 1,054 cases registered until 23 October 2008. Extensive investigations including hypothesis-generating interviews, matched case-control studies, cohort studies in embedded outbreaks, shopping list analyses, analyses of food samples from patient's homes, trace-back analyses and extensive microbiological analysis of products have not provided clear indications of a specific source of infection but the main hypothesis is that the vehicle of the outbreak are different pork products. In addition to the large U292 outbreak, at least four other S. Typhimurium outbreaks (caused by phage types U288, DT120, DT3 and DT135) have been investigated in Denmark in 2008.
Ethelberg, S.; Wingstrand, Anne
Salmonellosis is the most frequent foodborne disease worldwide and can be transmitted to humans by a variety of routes, especially via animal and plant products. Salmonella bacteria are believed to use not only animal and human but also plant hosts despite their evolutionary distance. This raises the question if Salmonella employs similar mechanisms in infection of these diverse hosts. Given that most of our understanding comes from its interaction with human hosts, we investigate here to what degree knowledge of Salmonella–human interactions can be transferred to the Salmonella–plant system. Reviewed are recent publications on analysis and prediction of Salmonella–host interactomes. Putative protein–protein interactions (PPIs) between Salmonella and its human and Arabidopsis hosts were retrieved utilizing purely interolog-based approaches in which predictions were inferred based on available sequence and domain information of known PPIs, and machine learning approaches that integrate a larger set of useful information from different sources. Transfer learning is an especially suitable machine learning technique to predict plant host targets from the knowledge of human host targets. A comparison of the prediction results with transcriptomic data shows a clear overlap between the host proteins predicted to be targeted by PPIs and their gene ontology enrichment in both host species and regulation of gene expression. In particular, the cellular processes Salmonella interferes with in plants and humans are catabolic processes. The details of how these processes are targeted, however, are quite different between the two organisms, as expected based on their evolutionary and habitat differences. Possible implications of this observation on evolution of host–pathogen communication are discussed. PMID:25674082
Schleker, Sylvia; Kshirsagar, Meghana; Klein-Seetharaman, Judith
Salmonella infections can manifest themselves as acute abdominal problems and lead to emergency surgery. Some examples are: salmonella-related intestinal perforations, gallbladder involments, salpingitis, and peritonitis. Mesenteric lymphadenitis associated with salmonella mimics acute appendicitis and it is often difficult to establish a timely and tempestive diagnosis in children with right lower abdominal pain. Because of the difficult diagnostic process, a significant number of patients with salmonella infections present acute abdomen and undergo needless operations. Instead, in our case of salmonella-related acute abdomen, laparotomy was the right therapeutic choice. The conclusion is drawn that, even if there is not a precise diagnosis, in salmonella-related acute abdomen the surgical approach is the right choice, considering the high morbidity and mortality associated with untreated appendicitis and intestinal perforations. PMID:16835580
Manganaro, A; Impellizzeri, P; Manganaro, A; Cutrupi, A; Formica, I; Zuccarello, B