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Comparison of different selective enrichment steps to isolate Salmonella sp. from feces of finishing swine
Michael, Geovana Brenner;Simoneti, Roselis;Costa, Marisa da;Cardoso, Marisa;
Brazilian Journal of Microbiology , 2003, DOI: 10.1590/S1517-83822003000200009
Abstract: 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.
Comparison of different selective enrichment steps to isolate Salmonella sp. from feces of finishing swine  [cached]
Michael Geovana Brenner,Simoneti Roselis,Costa Marisa da,Cardoso Marisa
Brazilian Journal of Microbiology , 2003,
Abstract: 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.
An rfaH Mutant of Salmonella enterica Serovar Typhimurium is Attenuated in Swine and Reduces Intestinal Colonization, Fecal Shedding, and Disease Severity Due to Virulent Salmonella Typhimurium  [PDF]
Bradley L. Bearson,Shawn M. D. Bearson,Jalusa D. Kich,In Soo Lee
Frontiers in Veterinary Science , 2014, DOI: 10.3389/fvets.2014.00009
Abstract: Swine are often asymptomatic carriers of Salmonella spp., and interventions are needed to limit colonization of swine to enhance food safety and reduce environmental contamination. We evaluated the attenuation and potential vaccine use in pigs of a Salmonella enterica serovar Typhimurium mutant of rfaH, the gene encoding the RfaH antiterminator that prevents premature termination of long mRNA transcripts. Pigs inoculated with wild-type S. Typhimurium exhibited a significant elevation in average body temperature (fever) at 1 and 2 days post-inoculation; rfaH-inoculated pigs did not (n = 5/group). During the 7-day trial, a significant reduction of Salmonella in the feces, tonsils, and cecum were observed in the rfaH-inoculated pigs compared to wild-type inoculated pigs. To determine whether vaccination with the rfaH mutant could provide protection against wild-type S. Typhimurium challenge, two groups of pigs (n = 14/group) were intranasally inoculated with either the rfaH mutant or a PBS placebo at 6 and 8 weeks of age and challenged with the parental, wild-type S. Typhimurium at 11 weeks of age. The average body temperature was significantly elevated in the mock-vaccinated pigs at 1 and 2 days post-challenge, but not in the rfaH-vaccinated pigs. Fecal shedding at 2 and 3 days post-challenge and colonization of intestinal tract tissues at 7 days post-challenge by wild-type S. Typhimurium was significantly reduced in the rfaH-vaccinated pigs compared to mock-vaccinated pigs. Serological analysis using the IDEXX HerdChek Swine Salmonella Test Kit indicated that vaccination with the rfaH mutant did not stimulate an immune response against LPS. These results indicate that vaccination of swine with the attenuated rfaH mutant confers protection against challenge with virulent S. Typhimurium but does not interfere with herd level monitoring for Salmonella spp., thereby allowing for differentiation of infected from vaccinated animals (DIVA).
Compara??o do isolamento microbiológico e da rea??o em cadeia da polimerase no diagnóstico de salmonelose em bezerros infectados experimentalmente com Salmonella Typhimurium
Silva, D.G;ávila, L.G;Berg, R;Silva, D.R;Conde, S.O;Lemos, M.V.F;Fagliari, J.J;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2011, DOI: 10.1590/S0102-09352011000500029
Abstract: the efficiency of microbiological culture and polymerase chain reaction (pcr) for detection of salmonella typhimurium is compared in fecal samples of holstein calves experimentally infected with 109 cfu of salmonella typhimurium. seventy-two fecal samples were analyzed by microbiological culture and pcr associated with selenite cystine (sc) and muller-kauffmann tethrationate (tmk) selective enrichment broths. regardless of the selective enrichment broth, the microbiological culture was significantly better than pcr for detection of positive samples of salmonella typhimurium. the selective enrichment broths sc and tmk had no effect on the efficiency of the microbiological culture. the sc broth was the best option as selective enrichment associated to pcr.
Evaluation of three enrichment broths and five plating media for Salmonella detection in poultry
Rall, Vera Lúcia Mores;Rall, Ricardo;Aragon, Lina Casale;Silva, Márcia Guimar?es da;
Brazilian Journal of Microbiology , 2005, DOI: 10.1590/S1517-83822005000200009
Abstract: we evaluated the effectiveness of selenite cystine (sc), tetrathionate brilliant green (tbg) and rappaport vassiliadis (rv) broths for salmonella isolation. we also tested three classic plating media, salmonella-shigella agar (ss), brilliant green agar (bga), xylose lysine desoxycholate agar (xld) and two chromogenic agars, rambach (ra) and chromagar salmonella (cas). among 100 poultry carcasses, 29 were positive for salmonella using all plating media combined. rv broth (69%) and tt broth (58.6%) were more effective than sc broth (24.1%). the chromogenic media gave better results than the classic ones with less false-positive colonies. the most effective isolation medium was chromagar, where salmonella was identified in 23 (79.3%) of the 29 positive samples, followed by rambach (48%). positivity for salmonella using classic media was 13.8% for bga, 27.6% for ss and 34.5% for xld.
Comparison of methods for mycobacteria isolation from swine feces
Oliveira, Eugenia Márcia de Deus;Rodriguez, César Alejandro Rosales;Rocha, Vivianne Cambuí Mesquita;Ambrosio, Simone Rodriguez;Ohara, Patrícia Miyuki;Amaku, Marcos;Ferreira, Fernando;Dias, Ricardo Augusto;Le?o, Sylvia Cardoso;Ferreira Neto, José Soares;
Brazilian Journal of Microbiology , 2007, DOI: 10.1590/S1517-83822007000400019
Abstract: swine mycobacteriosis is an important cause of carcass condemnation at abattoirs. one of the best ways to recognize the etiologic agent involved, in live animals, is the fecal isolation, as 94% of the lesions are located in the digestive tract. therefore, the goal of the present study was to compare the performance of four decontamination methods followed by inoculation in three different culture media, totalizing twelve procedures of mycobacteria search from swine fecal samples experimentally contaminated. the swine feces were artificially contaminated with 0.02 g of mycobacterium avium, pig-b strain, and subjected to mycobacteria isolation trial. the protocols used were: 1) modified petroff or basic method; 2) modified lowenstein-jensen or acidic method; 3) modified petroff or basic method with re-suspension in amphotericin b; 4) modified lowenstein-jensen or acid method with re-suspension in amphotericin b, followed by inoculation in petragnani, lowenstein-jensen and lowenstein-jensen medium with antibiotics (penicillin g and nalidixic acid). there was a difference (p<0.05) between the mycobacterial recovery percentages from swine feces. the acid method with re-suspension in amphotericin b solution and inoculation in lowenstein-jensen medium with antibiotics showed the best results (87% of mycobacteria recovery).
Compara??o dos caldos selenito cistina, tetrationato Muller-Kauffmann e Rappaport-Vassiliadis no isolamento de Salmonella Typhimurium
ávila, L.G.;Silva, D.G;Fagliari, J.J.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2012, DOI: 10.1590/S0102-09352012000300035
Abstract: three selective enrichment broths - selenite cystine (sc), muller-kauffmann tetrathionate (mkt) and rappaport-vassiliadis (rv) - were compared, for salmonella typhimurium isolation from rectal swabs of a calf experimentally infected. the bacteriological procedure involved pre-enrichment in hajna-gn broth (only for the samples inoculated in rv broth), selective enrichment (sc, mkt and rv broths), culture in modified brilliant green agar (bga), presumptive biochemistry tests (using triple-sugar-iron agar and lysine-agar) and slide agglutination test with poli-o and poli-h salmonella antisera. sc and mkt broths were more efficient in the isolation of salmonella typhimurium (12 positive samples), whereas rv broth had a lower efficiency in the microbiological isolation (ten positive samples).
Selective Enrichment Media Bias the Types of Salmonella enterica Strains Isolated from Mixed Strain Cultures and Complex Enrichment Broths  [PDF]
Lisa Gorski
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0034722
Abstract: For foodborne outbreak investigations it can be difficult to isolate the relevant strain from food and/or environmental sources. If the sample is contaminated by more than one strain of the pathogen the relevant strain might be missed. In this study mixed cultures of Salmonella enterica were grown in one set of standard enrichment media to see if culture bias patterns emerged. Nineteen strains representing four serogroups and ten serotypes were compared in four-strain mixtures in Salmonella-only and in cattle fecal culture enrichment backgrounds using Salmonella enrichment media. One or more strain(s) emerged as dominant in each mixture. No serotype was most fit, but strains of serogroups C2 and E were more likely to dominate enrichment culture mixtures than strains of serogroups B or C1. Different versions of Rappaport-Vassiliadis (RV) medium gave different patterns of strain dominance in both Salmonella-only and fecal enrichment culture backgrounds. The fittest strains belonged to serogroups C1, C2, and E, and included strains of S. Infantis, S. Thompson S. Newport, S. 6,8:d:-, and S. Give. Strains of serogroup B, which included serotypes often seen in outbreaks such as S. Typhimurium, S. Saintpaul, and S. Schwarzengrund were less likely to emerge as dominant strains in the mixtures when using standard RV as part of the enrichment. Using a more nutrient-rich version of RV as part of the protocol led to a different pattern of strains emerging, however some were still present in very low numbers in the resulting population. These results indicate that outbreak investigations of food and/or other environmental samples should include multiple enrichment protocols to ensure isolation of target strains of Salmonella.
Rosecler Alves Pereirara,Mararisa Macagnan,Patricia Schwarz,C laudio Wageck Canal
Ciência Animal Brasileira , 2010,
Abstract: Salmonella Typhimurium is an important agent isolated from cases of human food poisoning in Brazil. Animal-origin products are the main source of infection, and pork has been implicated in Salmonella transmission to humans. Programs to salmonella monitoring in swine have been carried out, using bacteriologicaland serological tests like ELISA. However, these tests are time-consuming and expensive. The rapid agglutination test (RAT) is cheaper, faster and easier. Aiming to standardize RAT to detect anti-salmonella antibodies in swine serum, 60 samples of swine serum were tested. They had previously displayed positive (30) or negative (30) results in the ELISA test. The results showed that RAT had sensitivity, specificity, predictive positive value and predictive negative value equal to 96.7% when non-diluted serum was tested. Thus, this test can be applied to detect antibodies against S. Typhimurium in swine serum.
Efficiency of Plating Media and Enrichment Broths for Isolating Salmonella Species from Human Stool Samples: A Comparison Study  [PDF]
Apichai Srijan, Boonchai Wongstitwilairoong, Ladaporn Bodhidatta, Carl Mason
Open Journal of Medical Microbiology (OJMM) , 2015, DOI: 10.4236/ojmm.2015.54028
Abstract: A comparative study was performed to evaluate best practice culture media and enrichment broths for recovering Salmonella species from human stool samples. A total of 1297 human stools were collected and processed in this study. Evaluation of agar media was carried out by direct plating (DP), 1096 stool samples were inoculated on Modified Semisolid Rappaport-Vassiliadis (MSRV), Xylose-Lysine-Deoxycolate (XLD), MacConkey (MAC), and Hektoen Enteric (HE) agars. Evaluation of enrichment broths were carried out by enrichment all 1297 stool samples in Selenite broth (SB), Rappaport-Vassiliadis (RV) broth, and Buffered Peptone Water (BPW), followed by plating on MSRV, MAC, and HE agars. A total of 102 Salmonella-positive stools by DP, 85.3% (87/102) were recovered utilizing MSRV while recovery from XLD, MAC, and HE agars were 34.3% (35/102), 34.3% (35/102), and 29.4% (30/102) respectively. A total 299/1297 stools samples were Salmonella-positive on at least one plating medium after enrichment procedure were 77.3% (177/299) for SB, 86.0% (197/299) and 78.6% (180/299) for RV and BPW respectively. All Salmonella isolated in this study was nontyphi Salmonella. Presently, the data suggest that the use of MSRV over MAC, HE, and XLD agars for isolation nontyphi Salmonella species from human stools is more efficacious. Additionally, use of MSRV in combination with MAC and HE agars following enrichment in RV broth enhances recovery of nontyphi Salmonella species. However, RV broth is inhibitory to typhi Salmonella, thus use of MSRV medium in combination with MAC, HE or XLD agars in direct plating following enrichment in non-selective BPW is an alternate method for recovery of both typhi and nontyphi Salmonella species contaminated in human stool samples.
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