O objetivo deste estudo foi o de avaliar a eficiência da aderência de produtos de exclusão competitiva e de probiótico sobre a tonsila cecal de frangos SPF, com idade de um a doze dias. Através da microscopia eletrônica de varredura, verificou-se a ação destes produtos comerciais com relação a proteção ao epitélio, quando desafiados com Salmonella Enteritidis. O delineamento experimental foi dividido em cinco (05) grupos, sendo o grupo T1 o controle negativo, o grupo T2 recebeu o produto de exclusão competitiva Aviguard, o grupo T3 recebeu o produto de exclusão competitiva Broilact, o grupo T4 recebeu o probiótico Biotop e o grupo T5 o controle positivo. Após 12 horas do tratamento com os produtos de exclusão competitiva ou probiótico as aves foram infectadas, por via oral, com S. Enteritidis. Os resultados obtidos mostraram que os produtos de exclusão competitiva e probiótico apresentaram uma maior eficiência em estabelecer uma microbiota protetora contra S. Enteritidis, e que a adição destes pode produzir um efeito de melhor índice zootécnico, quando comparado com as aves que foram desafiadas com S. Enteritidis e que apresentaram um ganho de peso inferior. / The aim of this study was to evaluate the ultra structure of the cecal tonsil in SPF chicks using scanning electron microscopy, determining the efficacy of competitive exclusion products and probiotic and its protection in cecal epithelium against an oral challenge with Salmonella Enteritidis. The experimental design included five groups: T1 negative control, T2 chicks treated with Aviguard, T3 chicks treated with Broilact, T4 chicks treated with Biotop, and, T5 positive control. After 12 hours of treatment with competitive exclusion products or probiotic the chicks were infected orally with S. Enteritidis. Results showed that treated groups had a protective effect stimulating the establishment of the resident microflora against pathogenic bacteria. Treated chicks showed high weight gain when compared to chicks challenged.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of the commercial poultry keeping is getting high productivity for a low cost and offering to the consumer a product with quality. A pathogenic bacterium that has been worring the avicola section during the last years is the Salmonella. To control this bacterium, it was proposed in this paper the Lactobacillus paracasei, used as probiotic. The Lactobacillus paracasei can be in the future a healthy alternative for the indiscriminate antibiotics use, forbidden for export. This assignment was carried out in the Biotery of Veterinary Preventive Medicine of the Federal University of Santa Maria RS (Biotitic of Medicinal Preventive Veterinaries of Public University of Santa Maria RS). Cutting commercial chicks with a day of living were used. They were remained in wire cages, with a heating system. The feeding was ration (not medicated) and water. The treatments were done in the first day of living of the chicks. It was administrated a probiotic sprayed in the water, and salmonella for endo-esofagic inoculation. The pulverization was done with a manual spray. The endo-esofagic inoculation was done with a probe and syringe with 1ml, with 0,1ml of Salmonella Enteritidis for each chick. For the pulverization and for the water, the inoculo had 1010 UFC/ml of Lactobacillus paracasei and for the endo-esofagic tract 103 UFC/ml of Salmonella Enteritidis. Three groups of twenty chicks were used, distributed as follows: Portion 1- Control; Portion 2- pulverization and addiction of probiotic in the drinking water; Portion 3 addition of probiotic in the drinking water and inoculation of Salmonella Enteritidis; In each week, three chicks from each portion were withdrawn from each group to be weighed, sacrificed and for material collection. The presence in the excrements and the colonization of the cecos of cutting chicks for Salmonella Enteritidis was reduced significantly in the groups treated with Lactobacillus paracasei (P2) for pulverization and addiction in the drinking water. Therefore, we can conclude that the use of probiotics inhibits or reduce the salmonella development, in the intestinal treat of the birds, since we can constact its presence in the Treatment Control (P1) in three samples probably because of the presence of bacterium in the feed, water or environment where the birds were. In the treatment with Addiction of Lactobacillus paracasei in the drinking water + inoculation of Salmonella Enteritidis, we verified three absences of salmonella, in the 0; 32; and 42 days of treatment. In the positive samples for salmonella, we observed characteristic damages in the liver, typical of the contamination with salmonella, which affects the bloodstream, probably in an intracellular way, and are removed by the river, spleen or bone marrow. During the 32 and 42 days, there were absences of SE, which indicate the inhibitory capacity of the probiotic used. We observed that the inhibition occurs later. The gain of weight of the portion that received sprayed Lactobacilllus paracasei in the drinking water (P2) did not de different of the other treatments. As this same treatment did not accused the presence of SE in the excrements, while the other groups treated with probiotic the rates of SE in the excrements were detected, there is the indication that the presence of Salmonella Enteritidis does not interfere decisively in the cutting chickens productivity. Although it has not occurred significant variation among the groups, related to the body weight, the group treated with Lactobacilllus paracasei sprayed in the drinking water (P2), presented the best performance. / A avicultura comercial tem como objetivo obter alta produtividade a baixo custo e oferecer ao consumidor produto de qualidade. Uma bactéria patogênica que tem preocupado o setor avícola nos últimos tempos é a Salmonela. Para controlar esta bactéria, foi proposto neste trabalho o Lactobacillus paracasei, usado como probiótico. O Lactobacillus paracasei poderá ser uma alternativa saudável para o uso indiscriminado de antibióticos, proibido para exportação. O presente trabalho foi realizado no Biotério da Medicina Veterinária Preventiva da Universidade Federal de Santa Maria RS. Foram utilizados pintos comerciais de corte com um dia de idade, mantidos em gaiolas de arame, sob aquecimento. Para alimentação foi fornecida ração não medicada e água. Os tratamentos foram realizados no primeiro dia de vida das aves. Administrou-se probiótico por pulverização e na água de bebida, e salmonela por inoculação endoesofágica e probiótico na água de bebida. A pulverização foi realizada com auxílio de pulverizador manual. A inoculação via endoesofágica foi realizada com auxílio de uma sonda e seringa graduada de 1ml, com 0,1ml da cultura de Salmonella Enteritidis para cada pintos. Para a pulverização e para a água de bebida, o inóculo continha 1010 UFC/ml, de Lactobacillus paracasei e para a via endoesofágica 103 UFC/ml, de Salmonella Enteritidis. Foram utilizados três grupos de 20 pintos, assim distribuídos: Lote 1- Controle; Lote 2 pulverização e adição de probiótico na água de bebida; Lote 3 - adição de probiótico na água de bebida e inoculação de Salmonella Enteritidis; A cada semana três pintos de cada lote eram retirados de cada grupo para pesagem, sacrifício e colheta do material. A presença nas fezes e a colonização dos cecos de pintos de corte por Salmonella Enteritidis foi acentuadamente reduzida nos grupos tratados com Lactobacillus paracasei (L2) por pulverização e adição na água de bebida. Com isso podemos constatar que o uso de probióticos inibe ou reduz o desenvolvimento de salmonela, no trato intestinal das aves, já que podemos constatar sua presença no Tratamento Controle (L1), em três amostras analisadas, ocorreu possivelmente devido à presença de bactérias na ração, água ou ambiente, onde as aves se encontravam. No tratamento com Adição de Lactobacillus paracasei na água de bebida + inoculação de Salmonella Enteritidis, verificamos três ausências de salmonela, no 0º; 32º; e 42º dias de tratamento. Nas amostras positivas para salmonela observamos lesões características no fígado, típica de contaminação por salmonela, esta atinge a corrente sanguínea, provavelmente de modo intracelular, e são removidas pelo fígado, baço ou medula óssea. Já no 32º e 42º ocorreram ausências de SE o que indica a capacidade inibitória do probiótico utilizado. Observamos que a inibição ocorre tardiamente. O ganho de peso do lote que recebeu Lactobacilllus paracasei pulverizado e na água de bebida (L2) não diferiu dos demais tratamentos. Como esse mesmo tratamento não acusou a presença de SE nas fezes, enquanto nos demais grupos tratados com probiótico os índices de SE nas fezes foram detectáveis, há indicação de que a presença de Salmonella Enteritidis não interfere decisivamente na produtividade de frangos de corte. Embora não tenha ocorrido variação significativa entre os grupos, em relação ao peso corporal, o grupo tratado com Lactobacillus paracasei pulverizado e na água de bebida (L2), apresentou melhor performance.

Salmonella Typhimurium est un pathogène intracellulaire dont la virulence repose sur l'expression de protéines effectrices qui sont transportées dans les cellules hôtes infectées. Dans la cellule cette bactérie réside dans un compartiment appelé SCV (Salmonella-containing vacuole). Au cours de l'infection, la protéine effectrice SifA est transportée du cytosol bactérien à celui de la cellule infectée. Après sa translocation SifA est retrouvée à la surface de la SCV et des tubules. Cette protéine est constituée de deux domaines distincts. Le domaine N-terminal interagit avec la protéine hôte SKIP. Le domaine C-terminal a une structure similaire à d'autres protéines bactériennes possédant une activité d'échange de nucléotide guanine (GEF). Cependant on ignore si le domaine C-terminal contribue aux fonctions de SifA dans la virulence de Salmonella et, si c'est le cas, si il exerce une activité GEF sur une protéine de l'hôte. Nous avons utilisé un modèle de souris invalidée pour SKIP pour montrer que SKIP est un médiateur du rôle de SifA dans la virulence de Salmonella et que SifA à également un rôle qui est indépendant de son interaction avec SKIP. Ce dernier est porté par le domaine C-terminal de SifA. Nous avons montré que ce domaine de SifA se lie à la petite GTPase Arl8b, une protéine lysosomale. Le domaine C-terminal de SifA et Arl8b sont importants pour le recrutement de LAMP1 sur les SCVs et les tubules associés. L'utilisation d'une lignée cellulaire invalidée pour l'expression d'Arl8b a montré une prolifération réduite de Salmonella. Ces résultats nous permettent de proposer un modèle pour le rôle du domaine C-terminal de SifA dans la virulence de Salmonella. / The virulence of the intracellular pathogen Salmonella Typhimurium relies on the expression of bacterial effector proteins that are translocated into infected host cells. This bacterium resides and proliferates in a host-cell compartment named the Salmonel-la-containing vacuole (SCV). Following translocation in the infected host cells, the effector protein SifA localizes onto the SCV and SCV-associated membrane tubules. This protein is made of two distinct domains. The SifA N-terminal domain interacts with the host-cell protein SKIP. The SifA C-terminus has a fold similar to other bacterial effector proteins having a guanine nucleotide exchange factor (GEF) activity. Indeed, SifA binds preferentially a GDP-bound form of RhoA but does not stimulate GDP disso-ciation. Therefore it remains unknown whether the SifA C-terminus contributes to the functions of SifA in Salmonella virulence and, if it does, whether it has a GEF activity towards a host protein. We used a model of SKIP knockout mice to show that SKIP mediates susceptibility to Salmonellosis and to establish that SifA also contributes to Salmonella virulence independently of its interaction with SKIP. We next identified that the SifA C-terminal domain supports this contribution. We have further showed that the SifA C-terminus binds the small GTPase Arl8b and that both SifA C-terminus and activated Arl8b are important for the recruitment of LAMP1 on SCVs and associated tubules. Using an Arl8b knock down cell line, we observed that the absence of Arl8b results in a reduced proliferation of wild-type Salmonella. Finally, we proposed a model for the role of the SifA C-terminus in Salmonella virulence.

Master of Science / Department of Animal Sciences and Industry / J. Ernest Minton / Enteric pathogens are responsible for major economic losses in the swine industry. In the U.S., Salmonella enterica subspecies enterica serovar Typhimurium (ST) and serovar Choleraesuis (SC) account for essentially all cases of salmonellosis in swine. Previous studies documented that oral ST eroded growth and produced unmistakable changes in the endocrine stress and somatotropic axis of young growing pigs. However, these effects occurred in the absence of elevated systemic inflammatory cytokines that were previously thought to accompany disease-associated growth retardation. In the current study, it was hypothesized that SC would produce very different systemic inflammatory cytokine responses compared to ST given the likelihood of SC to produce systemic disease in pigs. Weaned pigs were housed two per pen with free access to feed and water during a 14 d experiment. On d 0, pigs were fed either 108 CFU SC or 108 ST, and bacteria were re-fed twice weekly through the course of the experiment. Control pigs were fed dough without bacteria. Serum was collected on d 0, 7, and 14 for determination of tumor necrosis factor alpha (TNFα), interleukin-1beta (IL-1β), and insulin-like growth factor-I (IGF-I) were determined. Rectal temperatures (RT) were monitored daily beginning 2 d prior to challenge with bacteria and until 7 d following the first bacterial feeding. Pigs were weighed initially, and at the conclusion of the study. Daily body weight gain was reduced by 25.4% in pigs fed SC (P<.0001) compared to control, while growth was similar between control pigs and those fed ST. Pigs fed SC had increased RT beginning on d 2 and continuing though d 7 (P < 0.05) with the greatest elevation spike on d 3 (P < 0.001) when compared to controls. On d 7, pigs fed SC had reduced IGF-I when compared to both control (P < 0.01) and ST pigs (P = 0.01). Despite the obvious febrile response, and the reductions in body weight gain and serum IGF-I, circulating TNFα and IL-1β were not affected by treatment. It was concluded that elevated TNFα and IL-1β are not obligatory correlates of SC-induced pathology and growth retardation in weaned pigs.

The genotoxicity of energetic compounds (i.e., explosives) that are known to be present in contaminated soils at military training sites has not been extensively investigated. Thus, the Salmonella mutagenicity and Muta(TM)Mouse assays were employed as in vitro assays to examine the mutagenic activity of twelve explosive compounds, as well as three soil samples from Canadian Forces Base Petawawa. Salmonella analyses employed strains TA98 (frameshift mutations) and TA100 (base-pair substitution mutations), as well as the metabolically-enhanced YG1041 (TA98 background) and YG1042 (TA100 background), with and without exogenous metabolic activation (S9). For Salmonella analyses, the results indicate that ten of the explosive compounds were mutagenic, and consistently elicited direct-acting, base-pair substitution activity. All three soil samples were also observed to be mutagenic, eliciting direct-acting, frameshift activity. Mutagenic potencies were significantly higher on the metabolically-enhanced strains for all compounds and soil samples. For Muta(TM)Mouse analyses on FE1 cells, the results indicate that the majority of explosive compounds did not exhibit mutagenic activity. All three soil samples elicited significant positive responses (PET 1 and PET 3 without S9, and PET 2 with S9), and although there is some evidence of a concentration-related trend, the responses were weak. Correspondence of the mutagenic activity observed with the two assay systems, for both the explosive compounds and soil samples, was negligible. The differential response is likely due to differences in metabolic capacity between the two assay systems. Furthermore, it is likely that there are unidentified compounds present in these soil samples that are, at least in part, responsible for the observed mutagenic activity. Additional testing of other explosive compounds, as well as soil samples from other military training sites, using a variety of in vitro and in vivo assays, is warranted in order to reliably estimate mutagenic hazard and subsequently assess risk to human health.

Com o aumento, a cada ano, dos alojamentos na cadeia de produção avícola, a disseminação de doenças ficou facilitada. Nos lotes de aves, a fase inicial tem principal importância no que tange à contaminação por Salmonella Enteritidis, devido a maior sensibilidade às infecções pela ausência de uma flora intestinal completa e a imaturidade do sistema imune. Avaliaram-se, neste estudo, os benefícios na progênie do uso de uma vacina inativada em adjuvante oleoso para Salmonella Enteritidis, em matrizes pesadas, através de coleta de ovos bicados e pintos natimortos no incubatório, bem como suabes de arrasto nos aviários de frangos de corte. Observou-se que a imunização das matrizes conferiu uma proteção para suas progênies, tanto em ovos bicados, pintos natimortos coletados no incubatório no dia do nascimento, bem como em granjas de frango de corte, onde foram coletados suabes de arrasto entre 21 e 30 dias. Em ovos bicados foram analisadas 850 amostras, sendo que nos lotes vacinados tiveram 10 amostras (1,18%) positivas, e, nos lotes não vacinados tiveram 288 amostras (33,88%) positivas. Em pintos natimortos foram analisados 850 amostras, sendo os lotes vacinados tiveram 16 amostras (1,88%) positivas e nos lotes não vacinados tiveram 210 amostras positivas (24,70%). Em suabe de arrasto, nas granjas de frangos de corte, foram analisadas 502 amostras para lotes não vacinados; sendo 22 amostras positivas (4,38%). Nos lotes vacinados foram analisados 475 amostras, sendo 6 amostras positivas (1,26%). Os resultados obtidos nos levam a concluir que a vacina de Salmonella Enteritidis inativada em adjuvante oleoso, propicia uma imunidade passiva para as progênies das matrizes de corte que foram vacinadas, proporcionando uma redução significativa a infecções precoces pela bactéria. / With the increase of households in the poultry production chain each year, the spread of diseases was facilitated. In lots of birds, the initial phase has primary importance regarding to contamination by Salmonella Enteritidis, due to a bigger sensitivity to the infections by the absence of a complete gut and the immaturity of the immune system. In this study it was evaluated, the benefits of using the progeny of an inactivated vaccine in oil adjuvant for Salmonella Enteritidis in the main weighted broilers, through collection of eggs pecked and hatchery stillbirth chicks, as well as drag swabs on poultry broiler. It was observed that immunization of matrices gave a protection to their progeny, both egg pecked, hatchery stillborn chicks collected on the day of birth, and in broiler farms, where the drag swabs were collected between 21 and 30 days. In pecked eggs were analyzed 850 samples, being that in the vaccinated lots 10 samples (1.18%) were positive and in non-vaccinated lots 288 samples (33.88%) were positive. In stillbirths chicks were analyzed 850 samples, and in the vaccinated lots were 16 samples (1.88%) positive and in the unvaccinated lots, 210 were positives samples (24.70%). In the drag swab in broiler farms, 502 samples were analyzed for non-vaccinated lots, with 22 positive samples (4.38%). In the vaccinated lots were analyzed 475 samples and six positive samples (1.26%). The results lead us to conclude that the Salmonella Enteritidis inactivated vaccine in oil adjuvant, provides passive immunity to the progeny of broiler breeder flocks were vaccinated, providing a significant reduction in early infections by bacteria.

A leptospirose é uma zoonose mundial causada por bactéria do gênero Leptospira. O desenvolvimento de uma vacina de subunidade eficaz seria de grande interesse em saúde pública. Propusemos investigar 4 antigenos de Leptospira interrogans srv Copenhageni, genes LIC12659, LIC12660, LIC12631 e LIC10868, os quais foram amplificados e clonados nos vetores de expressão pAE e pAEsox. As proteínas VapB, VapC, VapBC e Sph2 foram expressas em E. coli e em salmonela SL3261 e purificadas por cromatografia de afinidade a metal. As atividades hemolítica de Sph2 e ribonucleásica de VapC não foram evidenciadas, possivelmente devido a diferenças estruturais entre as proteínas recombinantes e as nativas. Os clones de E. coli com os genes do módulo toxina-antitoxina vapBC sofreram os efeitos de inibição (vapC) e recuperação (vapBC) de crescimento, como descrito. As proteínas recombinantes, VapB purificada ou em salmonlea e Sph2, mostraram-se imunogênicas em camundongos e em hamsters. A imunização com Salmonela-VapB determinou a melhor proteção no teste de desafio. / Leptospirosis is a zoonosis worldwide distributed, caused by bacteria from the genus Leptospira. The development of an efficient vaccine of sub-unities would be of major interest for public health. We proposed to investigate 4 antigens from Leptospira interrogans srv Copenhageni, genes LIC12659, LIC12660, LIC12631 and LIC10868, which were amplified and cloned into expression vectors pAE and pAEsox. The proteins VapB, VapC, VapBC and Sph2 were expressed in E. coli and in salmonella SL3261, and purified by metal-affinity chromatography. The activities hemolytic of Sph2 and ribonuclease of VapC were not confirmed, possibly due to differences between native and recombinant proteins. The clones of E. coli with genes of the toxin-antitoxin module vapBC suffered inhibition (vapC) and recovery (vapBC) of growth rate as described. The recombinant proteins VapB purified or in salmonella and purified Sph2, showed to be immunogenic in mice and in hamsters. The immunization with Salmonella-VapB determined better protection on challenge assay.

A utilização de vacinas destaca-se como medida preventiva contra a leptospirose. Sete potenciais antígenos vacinais de L. interrogans sorovar Copenhageni foram estudados: LipL32, LipL23 e LipL22 (lipoproteínas), SphH e Sph4 (hemolisinas), AnkB (domínio anquirina) e OmpA76 (domínio OmpA). Os genes foram amplificados, clonados e as proteínas expressas em E.coli e Salmonella enterica para ensaios de imunização e desafio. As sete proteínas foram purificadas. No primeiro desafio, hamsters foram imunizados com a salmonela recombinante para expressar a OmpA76 e desafiados com sorovar Pomona. Sobreviveu 30% do grupo salmonela recombinante, 100% da vacina comercial e 10% dos controles. No segundo desafio, hamsters foram imunizados com pool das sete proteínas e desafiados com sorovar Copenhageni. Sobreviveram 30% do grupo pool de proteínas, 90% da vacina comercial, 100% da bacterina e 0% do grupo PBS. A LipL32, OmpA76, LipL23 e LipL22 reagiram com soros de hamsters infectados. Extratos de leptospiras foram reconhecidos pelos soros específicos contra LipL32, OmpA76 e LipL23. / Preventive measures as vaccines are the best strategies to combat leptospirosis. Seven potential vaccine candidates from L. iInterrogans serovar Copenhageni were studied: LipL32, LipL23 and LipL22 (lipoproteins), SphH e Sph4 (hemolysins), AnkB (ankyrin domain) and OmpA76 (OmpA domain). The genes were amplified, cloned and the proteins expressed in E. Coli e Salmonella enteric for challenge assays. In the first assay, hamsters were immunized with the recombinant salmonella to express OmpA76 in vivo, and challenged with serovar Pomona. The survival was 30% of the recombinant salmonella group, 100% of the commercial vaccine and 10% of the control groups. In the second assay, hamsters were immunized with a pool of the purified proteins and challenged with serovar Copenhageni. The survival was 30% of the group pool of proteins, 90% of the commercial vaccine, 100% of the bacterin and 0% of the PBS group. LipL32, OmpA76, LipL23 and LipL22 reacted with hamsters infected sera. Leptospiral extracts were recognized by specific sera against LipL32, OmpA76 and LipL23.

Salmonella spp é um dos microrganismos patogênicos de relevância em alimentos. Sua detecção em alimentos por metodologia de cultura é trabalhosa e demorada, o que explica a grande variedade de sistemas automatizados e kits para detecção rápida desse patógeno existentes no mercado. Muitos desses métodos alternativos são validados por organizações internacionalmente reconhecidas, mas tais validações têm sido efetuadas em condições laboratoriais artificiais e com matrizes alimentares experimentalmente contaminadas, dificilmente refletindo a realidade de um laboratório de rotina de análises microbiológicas de alimentos. Nesse trabalho, avaliou-se o desempenho de sete métodos rápidos alternativos genotípicos e imunológicos, usados simultaneamente para detecção de Salmonella spp em 244 amostras de alimentos sem contaminação experimental, empregando o método de cultura ISO 6579:2002 como método de referência. Os métodos avaliados foram BAX Salmonella,VIDAS Salmonella (SLM),Transia Plate Salmonella Gold,VIP Salmonella,TECRA UNQUIQUE SALMONELLA,Singlepath Salmonella e 1-2 Test. O nível de detecção para cada método também foi determinado, trabalhando-se com três matrizes alimentares diferentes, experimentalmente contaminadas com cinco níveis de inóculo. O método de referência detectou 50 amostras (20,5%) positivas para Salmonella spp. Nas condições em que o trabalho foi realizado, a porcentagem de concordância dos resultados positivos obtidos pelos métodos alternativos avaliados em relação aos resultados positivos obtidos pelo método ISO 6579:2002 variou de 42,3% a 100% nas amostras sem contaminação experimental e de 75% a 100% nas amostras artificialmente contaminadas, dependendo do método avaliado e da matriz alimentar analisada. Todos os métodos rápidos avaliados apresentaram resultados falso-positivos e falso-negativos, em freqüências dependentes também do método avaliado e da matriz alimentar analisada. Os resultados obtidos evidenciaram que os métodos rápidos avaliados devem ser utilizados unicamente para fins de triagem, podendo haver um risco intrínseco na escolha de um método rápido para detectar Salmonella spp em determinada matriz alimentar. A seleção de um método rápido, em particular, só deve ser feita após a determinação do grau de risco que se queira assumir. / Salmonella spp is an important foodborne pathogen. The detection in foods by the cultural methodology takes at least five days to be completed and several automated systems and kits are available in the market for rapid detection of this pathogen. Most rapid methods are validated by internationally recognized organizations, but most validations have been conducted in artificial laboratory conditions, working with inoculated food samples, hardly reflecting the real conditions of a routine testing laboratory. In this study, seven immunological and genotypic rapid methods were used simultaneously for the detection of Salmonella spp in 244 non-inoculated food samples, and compared to the ISO 6754:2002 cultural method, used as reference. The rapid methods evaluated were BAX Salmonella, VIDAS Salmonella (SLM), Transia Plate Salmonella Gold, TECRA UNIQUE SALMONELLA, VIP Salmonella, Singlepath Salmonella and 1-2 Test. The lowest detection level for each method was also determined using three different food matrices experimentally contaminated with five levels of inoculum. Based on results obtained by the ISO 6754:2002 method, 50 (20.5%) samples were positive for Salmonella spp. In the conditions of the study, the agreement percentage of positive results obtained by each rapid method when compared to the positive results of the reference method varied between 42.3% and 100% in the non-inoculated food samples and between 75% and 100% in the experimentally contaminated samples, depending on the method and the tested food matrix. All rapid methods presented false-positive and false-negative results, and their frequency varied according to the method and the tested food matrix. Results confirmed that these rapids methods should be used for screening exclusively, and the selection of a rapid method for detection of Salmonella spp in foods may have an intrinsic risk. The degree of this risk needs to be determined before a particular method is selected.

A presença de Salmonella em 200 amostras de alimentos crus de origem animal foi investigada empregando-se os dois ensaios imunoenzimáticos rápidos TECRA&#8482; Salmonella VIA e TECRA&#8482; Salmonella UNIQUE (TECRA Diagnostics, Rosewille, NSW, Australia) e o método de cultura convencional empregado rotineiramente no Instituto Adolfo Lutz, São Paulo, SP. Quarenta e cinco amostras (22.5%) foram Salmonella positivas por pelo menos um dos três métodos. O número de amostras positivas de acordo com o método analítico foi 34 (75,6%) para o método de cultura convencional, 29 (64,4%) para TECRA&#8482; Salmonella VIA e 27 (60.0%) para TECRA&#8482; Salmonella UNIQUE. O método de cultura convencional detectou quatro amostras positivas não detectadas por nenhum dos outros dois métodos rápidos. TECRA&#8482; Salmonella UNIQUE detectou sete amostras positivas não detectadas pelos demais métodos. Uma amostra foi positiva apenas pelo método TECRA&#8482; Salmonella VIA. Considerando todos os resultados (positivos e negativos) o teste de qui quadrado de McNemar indicou que as diferenças entre os resultados obtidos pelos métodos rápidos, quando comparados aos obtidos pelo método convencional, não foram estatisticamente significativas (p>0.05). / The presence of Salmonella in 200 raw food samples of animal origin was investigated by means of rapid immunoassays TECRA&#8482; Salmonella VIA and TECRA&#8482; Salmonella UNIQUE (TECRA Diagnostics, Rosewille, NSW, Australia) and the cultural procedure used routinely in Instituto Adolfo Lutz, Sao Paulo, SP. Forty-five samples (22.5%) were Salmonella positive by at least one of the three methods. The number of positive samples according to the analytical method was 34 (75.6%) for the cultural procedure, 29 (64.4%) for TECRA&#8482; Salmonella VIA and 27 (60.0%) for TECRA&#8482; Salmonella UNIQUE. The cultural method detected four positive samples that both rapid methods were unable to detect. TECRA&#8482; Salmonella UNIQUE detected seven positive samples that were not detected by the two other methods. One sample was positive by the TECRA&#8482; Salmonella VIA exclusively. Considering overall results (positive and negative) McNemar\'s chi square tests indicated that the differences between results given by the rapid immunoassays when compared to those of the cultural method were not significant (p>0.05).