Memoria para optar al Título Profesional de Médico Veterinario / Salmonella enterica es considerada una de las principales causas de enfermedades transmitidas por los alimentos alrededor del mundo, teniendo un amplio rango de hospederos incluyendo los animales silvestres, lo cual ha generado un esfuerzo constante en la vigilancia epidemiológica de la enfermedad. Sin embargo, las aves silvestres presentan un riesgo mayor, ya que pueden recorrer largas distancias, incluso entre países. En este estudio se aisló S. enterica en un 4,95% (46/928) mediante tórula de arrastre, desde aves silvestres acuáticas, principalmente la Gaviota Dominicana (Larus dominicanus), en ocho sitios de muestreo a lo largo del país. Los serovares identificados fueron: S. Enteritidis con un 69,56% (32/46), S. Heildeberg 8,69% (4/46), S. Seftenberg 4,34% (2/46) y por último, otros serovares en menores proporciones como S. Anatum, Havana, Agona, Infantis, Dublin, y una cepa Grupo B (I 4, 5, 12:b:), en donde cada uno presentó una frecuencia de 2,17% (1/46). Además, fueron detectados doce combinaciones de genes asociados a virulencia (virulotipos). Estos resultados sugieren que en Chile, la infección por Salmonella enterica en aves silvestres acuáticas podría tener impacto en la salud pública y animal / Financiamiento: Proyecto Fondecyt 11110398

Memoria para optar al Título Profesional de Médico Veterinario / Las enfermedades transmitidas por alimentos, provocadas por el género Salmonella spp, son un importante problema de salud pública a nivel mundial, siendo el serotipo Salmonella Enteritidis (SE) uno de los principales causantes de gastroenteritis asociadas al consumo de productos de origen aviar. La industria avícola ha implementado diversas medidas para enfrentar esto, tales como probióticos, vacunas y antimicrobianos, pero dado que la enfermedad persiste, las investigaciones actualmente se dirigen, complementariamente, al control del patógeno en el alimento. En este contexto, se está analizando el uso de bacteriófagos líticos en diferentes alimentos como herramienta de biocontrol altamente específica y efectiva. Estos son virus que infectan bacterias, se replican en ellas y las lisan. Son inocuos para las células eucariotas y no alteran la calidad organoléptica de los alimentos. En base a lo anterior, este estudio pretende evaluar la efectividad de una mezcla de cinco bacteriófagos líticos nativos en la reducción del crecimiento de SE en carne fresca de pollo. Para ello, se contaminaron muestras con 5,7x103UFC/mL de SE y se trataron con 107UFP de cada fago/mL, o con 5,7x105UFC/mL y 109UFP/mL, e incubaron durante 10 días a temperatura ambiente controlada (18°C) y de refrigeración (2-8°C), respectivamente. Los resultados demostraron que la mezcla de fagos logró reducciones significativas (p<0,05) de 0,88log10UFC/g a temperatura ambiente y 1,66log10UFC/g a temperatura de refrigeración. Esto evidencia que los bacteriófagos líticos, aplicados con una MOI de 104, pueden controlar eficazmente la presencia de SE en carne fresca de pollo mantenida a distintas temperaturas / Financiamiento: Proyecto Fondecyt 1110038

Aisla el bacteriófago denominado S6 a partir de una muestra de intestinos de pollo. Se evalúa la estabilidad del bacteriófago sometiéndolo a diferentes temperaturas y pH, también se determina la sensibilidad al cloroformo y las características biológicas como multiplicidad de infección, tasa de adsorción y curva de un paso del bacteriófago aislado. Los resultados indican que el bacteriófago S6 es estable a pH entre 6 - 8 y temperaturas de 80°C hasta 60°C. Además, presenta características líticas solo para serovares de Salmonella como Typhimurium, Bispebjerg, Enteritidis mediante la microscopía electrónica de transmisión se determinó que pertenece al orden Caudovirales y a la familia Siphoviridae. / Tesis

Manifiesta que el cuy es una especie de producción que se ve afectada principalmente por Salmonella Typhimurium, la cual expresa factores de virulencia codificados por diferentes genes, que, en conjunto, cumplen funciones coordinadas para llevar a cabo la patogenia y desarrollar la enfermedad. Por ello, el presente estudio evaluó la presencia de 10 genes codificantes de diversos factores de virulencia de importancia biológica de un total de 100 aislados de Salmonella Typhimurium, compuestos por 90 cepas procedentes de cuyes enfermos y 10 cepas procedentes de cuyes aparentemente sanos, confirmados en estudios previos. El ADN de los aislados fue extraído y analizado mediante la técnica de PCR múltiple, para evaluar la presencia de los genes spvB, spiA, cdtB, sipB, tolC, sitC, lpfC, sifA, sopB y pefA, obteniéndose un patrón genético similar, con frecuencias de detección variables mayores al 60%, tanto en aislados de cuyes sanos como enfermos, excepto el gen cdtB, el cual no fue detectado; concluyéndose que no existe diferencia entre los factores de virulencia presentes en cepas de Salmonella Typhimurium aisladas de cuyes enfermos y cuyes aparentemente sanos; sin embargo, debe tenerse en cuenta el potencial peligro que representan los animales portadores dentro de la producción. / Universidad Nacional Mayor de San Marcos (Lima). Vicerrectorado de Investigación y Posgrado Perú. Ministerio de la Producción. Programa Nacional de Innovación para la Competitividad y Productividad (Innóvate Perú) / Tesis

Orientador: Angelo Berchieri Junior / Coorientador: Hélio José Montassier / Banca: Rosângela Zacarias Machado / Banca: Luiz Felipe Caron / Banca: Raphael Lucio Andreatti Filho / Banca: Marcelo Brocchi / Resumo: Salmonella Enteritidis (SE) causa doença transmitida por alimentos (DTA) em humanos. Carne de frango e ovos frequentemente estão associados a esses casos. O controle da infecção em aves, baseia-se em medidas de biossegurança, incluindo-se a vacinação. Tem sido comum a utilização de vacinas vivas (VV) e inativadas (Bacterinas - BA), porém pouco se sabe sobre os mecanismos imunes desencadeados pelas vacinas contra SE. Neste estudo, utilizaram-se quatroprogramas vacinais (VV; VV+VV; BA; VV+BA) em galinhas leves de variedade branca para postura de ovos de mesa, vacinadas com 5 e/ou 25 dias de vida, e desafiadas aos 45 dias de vida com SE. No dia anterior à infecção (1 DAI) e 1, 6 e 9 dias pós-infecção (DPI), cinco aves/grupo foram sacrificadas para amostragem. A população de linfócitos CD4+ e CD8+ foi avaliada por imuno-histoquímica em tonsilas cecais e fígado; citocinas foram quantificadas por RT-qPCR em tempo real em tonsilas cecais e baço; níveis de IgG e IgM foram mensurados por ELISA no soro e IgA em lavado intestinal. Os níveis de imunoglobulina (IgG, IgM e IgA) estavam significativamente mais altos em aves vacinadas com BA, do 1 DAI ao 9 DPI, em comparação aos grupos vacinados somente com VV. Os níveis de IFN-γ, na tonsila cecal, eram similares em todos os grupos após o desafio. Antes do desafio (1 DAI), IL-10 foi altamente expressa em baço de aves que receberam somente BA (25 dias de vida), sugerindo o desenvolvimento de resposta por linfócitos T CD4+ auxiliar 2 (Ta2), reforçado pelos altos níveis de IgG encontrados neste grupo (p<0.05). Os níveis de TGF-β4 e das citocinas pró-inflamatórias IL-6 e TNFSF15 eram bastante elevados no grupo que recebeu VV+VV. A vacinação por via oral com VV aumentou significativamente o fluxo de linfócitos T CD8+ para as tonsilas cecais após o desafio. Isso poderia... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Salmonella Enteritidis (SE) causes foodborne infection in humans. Poultry meat and eggs are frequently associated with these cases. The control of this bacterium is based on sanitary measures and mainly, vaccination of chicken flocks. Vaccine programs are used worldwide to control SE in poultry flocks. Live (LV) and killed vaccines (KV) are often combined, although few studies regarding immune mechanisms developed by SE vaccines are available. In this work, four vaccine programs were studied (LV; LV+LV; KV; LV+KV) in white layer-hens vaccinated at 5 and/or 25 days-old and challenged at 45 days-old with SE. At 1 day before (dbi) and 1, 6 and 9 days post-infection (DPI), five birds/group were sacrificed for sampling. The population of CD4+ and CD8+ T cells was evaluated by immunohistochemistry in caecal tonsils and liver, cytokines were quantified by real time RT-qPCR in caecal tonsils and spleen; IgG, IgM and IgA levels were measured by ELISA in serum and the latter in intestinal washes. The immunoglobulin levels (IgG, IgM and IgA) were significantly higher in birds vaccinated with KV, from 1 dbi to 9 DPI, than in groups that received only LV. In caecal tonsils, IFN-γ levels were similar in all groups after challenge. Before challenge (1 dbi), IL-10 was highly expressed in spleen of birds that received only KV (25 days-old), suggesting the development of the T CD4+ helper 2 (Th2) type of immune response, reinforced by high IgG levels against SE seen in this group (p<0.05). TGF-β4 and the proinflammatory cytokines IL-6 and TNFSF15 were higher in caecal tonsils in the group that received LV+LV. Vaccination by oral route with LV clearly increased the influx of CD8+ T cells in caecal tonsils after challenge. This could be correlated with the better control of SE noticed in groups that received at least one dose of LV, including... (Complete abstract click electronic access below) / Doutor

A total of 842 single patient isolates of Salmonella spp. from the New Territories East Cluster hospitals, Hong Kong, were collected during 2002 and 2004. The most common Salmonella enterica serotype isolated was S. Enteritidis (29.7%, 250 of 842) followed by S. Typhimurium (13.7%, 115 of 842). The remaining 29.6% (249 of 842) belonged to 44 serotypes and 27.1% (228 of 842) were non-typeable. The majority of isolates were from patients aged two years or younger and were isolated during June to October of each of the three years. The susceptibilities to 19 antimicrobial agents of the 834 isolates that survived were tested. Resistant strains were investigated for [1] the mechanisms of resistance to fluoroquinolones and the third generation cephalosporins; [2] the genetic mechanisms of emergence of antibiotic-resistant salmonellae; and [3] their molecular epidemiology. / Less than half (46.9%, 391 of 834) of the isolates were susceptible to all the antimicrobial agents tested and 21.3% (178 of 834) were resistant to three and up to 14 in a total of 75 resistance patterns. Resistance to nalidixic acid increased from 18.9% (53 of 280) in 2002 to 36.6% (94 of 259) in 2004 (p &lt;0.001) while reduced susceptibility and resistance to ciprofloxacin increased from 17.9% (50 of 280) to 39.4% (102 of 259) (p &lt;0.001). All salmonellae remained susceptible to the third generation cephalosporins until 2003 when we isolated the first resistant isolate and two more in 2004. / No mutations in the quinolone resistance-determining region of target genes gyrA, gyrB, parC and parE were detectable in six of the 59 isolates that were resistant to 0.03 mg/l of ciprofloxacin and 14 that were susceptible to 0.03 mg/l of ciprofloxacin, all isolates being obtained in 2002. Forty-two isolates harboured one mutation, and one to eight harboured two to four mutations with those in positions Ser83 and/or Asp87 of the gyrA gene being the most common (89.8%, 53 of 59). No mutation was detected in the gyrB gene. A parC mutation at Ser80 was present only in strains with one or two gyrA mutation(s) while that at Thr57 could be present in strains without any other target gene mutations. A parE mutation (Ser458&rarr;Pro) was detected together with two gyrA and one parC mutations in only one isolate which was resistant to high concentrations of fluoroquinolones. Complementation experiments using a wild-type gyrA gene performed on isolates with gyrA gene mutations showed that mutations in gyrA contributed to fluoroquinolone-resistance. Only two among the 349 isolates that were obtained during 2002-2004 and resistant to 0.03 mg/l of ciprofloxacin harboured the qnr gene. / Of the three isolates that were resistant to the third generation cephalosporins, one, a S. Typhimurium, produced a beta-lactamase, CTX-M-9, of pI 8.1, and two, a S. Typhimurium and a S. Enteritidis, produced CTX-M-14, of pI 7.9. The blaCTX-M-9 gene was located on a class 1 integron on a 62 kb transferable plasmid and the blaCTX-M-14 gene was associated with the insertion sequence ISEcp1 and present on a 70 kb and a 92 kb transferable plasmid, respectively. This is the first report of a CTX-M-9 enzyme in S. Typhimurium in Hong Kong. (Abstract shortened by UMI.) / The MICs of nalidixic acid in the presence of 20 mg/l of Phe-Arg beta-naphthylamide (PAbetaN) for the 73 isolates that were tested for the presence of target gene mutations and S. Typhimurium ATCC 13311 were at least 4-fold lower than those of nalidixic acid in the absence of PAbetaN, indicating presence of an efflux system that could be inhibited by PAbetaN and of which nalidixic acid was a substrate. / Twenty-one isolates with different target gene mutations and fluoroquinolone susceptibilities were selected to investigate the effect of active efflux system, outer membrane permeability and target gene expression on fluoroquinolone-susceptibility. The amount of ciprofloxacin accumulated in the presence of carbonyl cyanide m-chloro-phenylhydrazone (CCCP) was significantly more than that in the absence of CCCP in 15 of these 21 strains, indicating presence of an efflux system that used proton motive force as energy. The amount of ciprofloxacin accumulated in 15 strains was significantly less than that in the standard strain (ATCC 13311) after the addition of CCCP, indicating that these strains were less permeable to ciprofloxacin than the standard strain. Real-time PCR experiments revealed that there were strains with overexpression of target genes as well as the acrB gene that codes for AcrB in the AcrAB-TolC efflux system. No aac(6')-Ib-cr was detected in our strains. / Jin, Yujuan. / "January 2008." / Adviser: M. L. Ling. / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4543. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (p. 195-219). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

by Koo Ching Irene. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 105-118). / Abstract also in Chinese. / Acknowledgments --- p.i / Abstract --- p.ii / Content --- p.iv / List of tables --- p.viii / List of figures --- p.x / Chapter Chapter 1: --- Introduction --- p.1 / Chapter A. --- Classification of salmonellae --- p.1 / Chapter B. --- Salmonellae enterica ser Enteritidis --- p.4 / Chapter C. --- Global increase in the prevalence of S. Enteritidis --- p.6 / Chapter D. --- Susceptibility of S. Enteritidis to antimicrobial agents --- p.13 / Chapter E. --- Methods for the epidemiological typing of S. Enteritidis --- p.17 / Chapter 1. --- Phenotypic methods --- p.17 / Chapter (1) --- Biotyping --- p.17 / Chapter (2) --- Antibiotic resistance pattern --- p.18 / Chapter (3) --- Phage typing --- p.18 / Chapter (4) --- Characterization of plasmids --- p.19 / Chapter a. --- Resistance plasmids --- p.20 / Chapter b. --- Transferability of plasmids --- p.20 / Chapter c. --- Incompatibility --- p.21 / Chapter 2. --- Molecular methods --- p.21 / Chapter (1) --- Plasmid analysis --- p.21 / Chapter a. --- Plasmid profile --- p.22 / Chapter b. --- Plasmid fingerprinting --- p.22 / Chapter (2) --- Chromosomal DNA fingerprinting --- p.24 / Chapter a. --- Restriction fragment length polymorphism (RFLP) of chromosomal DNA --- p.25 / Chapter b. --- Pulsed-field gel electrophoresis (PFGE) --- p.25 / Chapter c. --- Hybridization with specific gene probes --- p.26 / Chapter d. --- Ribotyping --- p.27 / Chapter e. --- Insertion sequence IS200 fingerprinting --- p.29 / Chapter (3) --- Polymerase chain reaction (PCR) --- p.30 / Chapter 3. --- Other --- p.32 / Chapter (1) --- Lipopoly saccharide (LPS) analysis --- p.32 / Chapter (2) --- "Whole cell protein profile analysis, fatty acid profile analysis, multilocus enzyme electrophoresis and Fourier-transform injfrared spectroscopy" --- p.33 / Chapter F. --- Epidemiology of S. Enteritidis in different parts of the world --- p.34 / Chapter G. --- Objectives --- p.35 / Chapter Chapter 2: --- Materials and Methods --- p.36 / Materials --- p.36 / Methods --- p.38 / Chapter A. --- Identification --- p.38 / Chapter 1. --- Biochemical tests --- p.38 / Chapter 2. --- Serotyping --- p.38 / Chapter B. --- Antimicrobial susceptibility testing --- p.39 / Chapter C. --- Characterization of β-lactamases --- p.39 / Chapter 1. --- Extraction of β-lactamases --- p.39 / Chapter 2. --- Determination of isoelectric points (pIs) --- p.41 / Chapter D. --- Characterization ofplasmids --- p.42 / Chapter 1. --- Genetic studies --- p.42 / Chapter (1) --- Transferability of resistance plasmids --- p.42 / Chapter (2) --- Mobilization of resistances --- p.43 / Chapter 2. --- Molecular studies --- p.44 / Chapter (1) --- Plasmid profile analysis --- p.44 / Chapter a. --- Plasmid extraction --- p.44 / Chapter b. --- Agarose gel electrophoresis --- p.45 / Chapter (2) --- Plasmid DNA fingerprinting --- p.45 / Chapter a. --- Preparation of pure plasmid DNA --- p.46 / Chapter b. --- Preparation of individual plasmid from strains harbouring more than one plasmid --- p.46 / Chapter c. --- Restriction endonuclease digestion of plasmid DNA --- p.47 / Chapter E. --- Total DNA fingerprinting --- p.47 / Chapter 1. --- Total DNA preparation --- p.48 / Chapter 2. --- Restriction endonuclease digestion of total DNA --- p.48 / Chapter 3. --- Ribotyping --- p.49 / Chapter (1) --- Restriction enzyme digestion of total DNA --- p.49 / Chapter (2) --- Transfer of DNA fragments to solid support --- p.49 / Chapter (3) --- Reverse transcription of rRNA into cDNA and labelling of cDNA --- p.50 / Chapter (4) --- Hybridization --- p.50 / Chapter (5) --- Detection of hybridized fragments --- p.51 / Chapter 4. --- AP-PCR (Arbitrary primed-PCR) --- p.51 / Chapter F. --- Experimental design --- p.52 / Chapter Chapter 3: --- Results --- p.54 / Chapter A. --- Prevalence of S. Enteritidis in the Prince of Wales Hospital --- p.54 / Chapter B. --- Antimicrobial susceptibilities --- p.58 / Chapter C. --- β-lactamases produced by β-lactam-resistant S. Enteritidis --- p.66 / Chapter D. --- Plasmid profile analysis --- p.66 / Chapter E. --- Characterization of resistance plasmids --- p.69 / Chapter F. --- Plasmid fingerprinting --- p.72 / Chapter G. --- Total DNA fingerprinting --- p.76 / Chapter H. --- Ribotyping --- p.82 / Chapter I. --- AP-PCR --- p.85 / Chapter J. --- "Correlation of plasmid analysis, total DNA fingerprinting, ribotyping and AP-PCR results" --- p.88 / Chapter Chapter 4: --- Discussion --- p.91 / Chapter A. --- Prevalence of S. Enteritidis --- p.91 / Chapter B. --- Susceptibilities of S. Enteritidis to antimicrobial agents --- p.92 / Chapter C. --- Evaluation of methods for epidemiological typing of S. Enteritidis --- p.94 / Chapter D. --- Molecular epidemiology of S. Enteritidis in Hong Kong --- p.99 / Chapter E. --- Areas for future research --- p.102 / References --- p.105 / Appendix --- p.119

Salmonella enteritidis has recently emerged as a potential pathogen in poultry products. The growth of S. enteritidis in poultry is affected by several factors such as storage temperature, pH, water activity, modified atmosphere and the presence of preservatives. All of these factors may act alone or in combination with each other resulting in a synergistic, antimicrobial effect. / In this research, initial storage studies were done to determine the effect of various atmospheres (air, vacuum, oxygen absorbent and gas packaging) on the microbial changes of packaged chicken thighs followed by challenge studies with a strain of S. enteritidis$ sp{ rm{NAST}}$. Chicken thighs were packaged in Cryovac bags and stored at 4 and 12$ sp circ$C for up to 28d. Changes in headspace gas composition, pH, drip loss, color and odor were monitored at each sampling day. / The effect of various packaging treatments, dipping solutions (chitosan (0.2%w/v) and potassium sorbate (0.2%w/v)) and low dose irradiation (1.5 & 3.0 kGy) on the growth of S. enteritidis$ sp{ rm NAST}$ and on the shelf-life of chicken thighs stored at 4 and 12$ sp circ$C was also investigated. (Abstract shortened by UMI.)

Les salmonelles, responsables de fièvres typhoïdes et gastro-entérites, sont un problème majeur de santé publique. Les systèmes de sécrétion de type III (TTSS) sont des facteurs de virulence cruciaux de Salmonella. Nos travaux ont montré que délétion du cadre ouvert de lecture yfgL conduit à une faible transcription des gènes codant les 3 TTSS conduisant à une baisse importante de la virulence de Salmonella Enteritidis. Or, la délétion de ce gène, dont la protéine chez E.coli est en complexe avec les protéines YaeT, YfiO, NlpB et SmpA, conduit à une altération de la membrane externe. Chez S. Enteritidis, nous avons montré que le rôle du complexe « YaeT » dans l’assemblage des protéines de membrane externe est conservé. Or, seule l’inactivation d’yfiO, conduit une diminution de l’expression des TTSS. Nos travaux ont toutefois suggéré que le défaut d’assemblage des protéines de membrane externe n’est pas la cause de ce défaut d’expression des TTSS observés chez les mutants yfgL et yfiO. / Salmonella, responsible for typhoid fever and gastroenteritis, is a worldwide health problem. Type three secretion system (TTSS) are crucial virulence factors in Salmonella. Our work showed that deletion of the open reading frame yfgL led to a transcriptional down-regulation of the genes encoding the proteins involved in the biosynthesis of the 3 TTSS in Salmonella Enteritidis. It was shown that inactivation of yfgL whose encoded protein is in complex with YaeT, YfiO, NlpB and SmpA in E. coli, causes an outer membrane alteration. In S. Enteritidis, we observed that the role of the “YaeT” complex in outer membrane protein assembly is conserved in S. Enteritidis. In addition, only yfiO inactivation resulted in a down-expression of the TTSS. However, we presented elements suggesting that the outer membrane protein targeting defect was not responsible for the TTSS down-expression observed in the yfgL and yfiO mutants.

No Rio Grande do Sul (RS), uma cepa de Salmonella (S.) Enteritidis (SE86) foi identificada como o principal microrganismo causador de Doenças Transmitidas por Alimentos (DTA), nos últimos anos. O objetivo deste trabalho foi avaliar a multiplicação e a recuperação da S. Enteritidis SE86 em diluentes, meios de cultura e métodos de semeadura, após a exposição ao Dicloroisocianurato de sódio (NaDCC). Em um primeiro momento, o microrganismo foi ativado em caldo BHI e exposto a 200ppm de NaDCC, por cinco minutos. Em seguida, ele foi diluído em diferentes soluções, as quais foram armazenadas a 7º C e 30º C, separadamente, sendo amostradas e analisadas microbiologicamente, a cada hora, durante seis horas. Em um segundo momento, foi avaliada a recuperação do microrganismo, antes e após exposição ao NaDCC, através de semeadura em superfície e pelo método da Camada Fina de Ágar (Thin Agar Layer - TAL), em cinco diferentes meios de cultura [Agar Triptona de Soja (TSA), Agar Verde Brilhante Manitol Lisina Cristal de Violeta (MLCB), Agar Verde Brilhante (BGA), Agar Salmonella Shigella (SS) e Agar Xilose Lisina Desoxicolato (XLD)]. Na terceira fase do estudo, foram avaliadas a multiplicação e a recuperação de dois outros sorovares de Salmonella, além da S. Enteritidis SE86, utilizando o diluente, o meio de cultura e o método de semeadura que demonstraram os melhores resultados nas fases antecedentes. Os resultados demonstraram que houve multiplicação significativa (P < 0,05) da S. Enteritidis SE86 não exposta ao NaDCC, armazenada a 30º C, nos diluentes Água peptonada (P), Água peptonada + Tween 80, Lecitina e Tiossulfato de sódio (P + N), Solução salina + Tween 80, Lecitina e Tiossulfato de sódio (SaS + N) e Água peptonada + Solução salina (P + SaS). O diluente Solução salina (SaS) não propiciou multiplicação durante as seis horas de incubação, mas manteve as células viáveis, sendo, portanto, escolhido para os demais experimentos. Células expostas e não expostas ao NaDCC não foram capazes de se multiplicar em nenhum dos diluentes testados, a 7º C. Da mesma forma, após exposição ao NaDCC, nenhuma multiplicação significativa foi observada nos diluentes armazenados a 30º C. Não houve diferença significativa (P < 0,05) nas contagens de S. Enteritidis SE86 exposta ao NaDCC quando semeada em TSA, meios seletivos ou meios seletivos adicionados de sobre camada de TSA (TAL). O meio XLD foi escolhido para os demais experimentos, uma vez que permitiu praticamente a mesma multiplicação que o meio TSA. Quando foram avaliadas a multiplicação e a recuperação de S. Enteritidis SE86, S. Typhimurium e S. Bredeney, expostas e não expostas ao NaDCC, diluídas em SaS e semeadas em TSA, XLD e XLD + sobre camada de TSA (TAL), não houve diferença significativa entre as contagens de células obtidas nos meios e no TAL, sugerindo que a semeadura direta em XLD pode ser um método adequado para a quantificação de Salmonella exposta ao NaDCC, em condições laboratoriais. / In Rio Grande do Sul State (RS), a strain of Salmonella (S.) Enteritidis (SE86) was identified as the main causative microorganism of foodborne diseases, in recent years. The aim of this study was to evaluate diluents, media and plating methods for growth and recovery of this pathogen, after exposure to Sodium dichloroisocyanurate (NaDCC). At first, the microorganism was exposed to 200 mg kg-1 NaDCC by five minutes. Then it was diluted in different diluent solutions, which were stored at 7º C and 30° C, separately, being sampled and microbiologically analyzed for six hours. In a second step, the recovery of the microorganism before and after exposed by NaDCC was evaluated, through surface plating method and Thin Layer Agar (TAL) method, in five different culture media [Tryptic Soy Agar (TSA), Mannitol Lysine Crystal Violet Brilliant Green Agar (MLCB); Brilliant Green Agar (BGA), Salmonella Shigella Agar (SS) and Xylose Lysine Desoxychole Agar (XLD)]. In the third phase of this study, the growth and recovery of S. Enteritidis SE86 and two other serovars of Salmonella were evaluated, using the diluent, the culture medium and plating method that showed the best results in previous phases. The results showed significant multiplication (P < 0.05) of S. Enteritidis SE86 not exposed to NaDCC, stored at 30 °C, in diluents Peptone water (P), Peptone water + Tween 80, Lecithin and Sodium thiosulfate (P + N), Saline solution + Tween 80, Lecithin and Sodium thiosulfate (SaS + N) and Peptone water + Saline solution (P + SaS). Saline solution (SaS) did not sustain bacterial multiplication, but maintained viable cells, being chosen for the next experiments. Exposed and not exposed cells were not able to multiply in any of the diluents at 7º C during six hours of storage. After NaDCC exposure, no significant multiplication was observed in any of the diluents stored at 30º C. No significant difference (P < 0,05) in growth of S. Enteritidis SE86 exposed to NaDCC was observed on TSA, selective medium or on selective media overlayed with TSA (TAL). The XLD medium was chosen for the next experiments, since it allowed the same multiplication that TSA. When the multiplication and recovery of exposed and not exposed S. Enteritidis SE86, S. Typhimurium, and S. Bredeney were evaluated after dilution in SaS and plating on TSA, XLD, and XLD overlayed with TSA, there was no significant difference in counts obtained on media and TAL, suggesting that direct plating on XLD could be an adequate method for the quantification of Salmonella exposed to NaDCC, under laboratory conditions.