The presence of subAB was investigated for 3,453 Escherichia coli strains of various pathogenic categories. The occurrence of other virulence genes in subAB-positive strains was investigated. The subAB operon was detected among some Shiga toxin-producing E. coli (STEC) serotypes devoid of eae and carrying ehxA. Most subAB-positive strains also harbored stx 2 , iha, saa, and lpfA O113 .Subtilase cytotoxin, a new member of the AB 5 toxin family, was identified for the first time in 2004 in a virulent O113:H21 Shiga toxin-producing Escherichia coli (STEC) strain that caused an outbreak of hemolytic-uremic syndrome in South Australia (16,18). The presence of subAB genes was further detected in other STEC strains belonging to different serotypes (19). Subsequently, subAB genes were identified among STEC strains isolated in other countries (3,8,9,14,25).To evaluate how widely distributed the subAB operon is, we studied a large collection of STEC serotypes from nonhuman sources and E. coli strains of different pathogenic categories associated with human infections. The subAB-positive strains were further characterized regarding the presence of other virulence genes.A total of 2,255 E. coli strains isolated from humans and belonging to enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), extraintestinal pathogenic E. coli (ExPEC), and E. coli strains not belonging to the diarrheagenic categories described so far were randomly selected. STEC strains isolated in Brazil from humans have previously been tested for the presence of subAB by our group (3). The 1,198 STEC strains from nonhuman sources were isolated from dairy cattle, beef cattle, buffaloes, and goats. Overall, 109 different STEC serotypes were tested. An STEC strain of serotype O113:H21 (3) was used as a reference strain for subAB, cdt-V, and lpfA O113 , and E. coli strain DH5␣ was used as a negative control.The strains were screened for the presence of the subAB operon (encoding subtilase cytotoxin) using colony hybridization assays (21). The 1,823-bp subAB-specific DNA probe was derived from the STEC serotype O113:H21 (3) strain by PCR as previously described (19). Hybridization assays were performed under stringent conditions, and the probe was labeled with [␣-32 P]dCTP (Amersham), using the Ready-To-Go DNA labeling kit (Amersham). All strains which yielded a positive or weak signal in hybridization assays with the subAB probe were retested by PCR (18,19), and only those confirmed by PCR were considered to be carrying this sequence.The genetic profiles of the subAB-positive strains were determined using our previously reported data for the same strains (6,7,12,13,20,24) regarding the presence of the ehxA, eae, stx 1 , stx 2 , and adhesin-encoding genes (1,10,11,15,17,22,23).A total of 130 STEC strains carrying the subAB operon, representative of each serotype and isolated from different animals, were analyzed by PCR for the presence of genes encoding Lpf O113 and cytolethal distendi...

Aims:  To determine the prevalence of Shiga toxin‐producing Escherichia coli (STEC) and serotypes and virulence markers of the STEC isolates from beef and dairy cattle in Rio Grande do Sul, Brazil. Methods and Results:  Faecal samples from beef cattle were collected at slaughterhouses. The isolates were submitted to colony hybridization assay with specific DNA probes for stx1, stx2 and eae genes, and serotyped for the identification of O and H antigens. Thirty‐nine per cent of beef cattle surveyed harboured at least one STEC strain. Among the distinct serotypes identified, 10 were shared by both beef and dairy cattle. Most of the strains isolated harboured stx2. Genotypic and phenotypic profiles allowed the identification of 34 and 31 STEC strains, isolated from beef and dairy cattle, respectively. Serotypes O10:H14, O15:H21, O96:H21, O119:H4, O124:H11, O128:H21, O137:H‐, O141:H19, O159:H42, O160:H2 and O177:H11, identified in this study, have not been previously reported as STEC isolated from cattle. Conclusions:  Cattle are an important reservoir of STEC strains associated with human diseases in South America. Significance and Impact of the Study:  Determining the prevalence, genotypic profile and serotypes of STEC strains isolated from cattle enables the prediction of possible risk for public health.

No abstract

Ocorrência de RESUMOForam coletadas 100 amostras de conteúdo fecal de aves de corte, 100 de produtos de frango (coxa, sobrecoxa, asa, dorso, carne moída e fígado) e 100 de fezes de humanos, e analisadas para pesquisa de Campylobacter. Realizou-se a determinação da espécie e da presença dos genes cdt, responsáveis pela codificação da toxina citoletal distensiva (CDT), através da técnica da PCR. A bactéria foi isolada de 61% das amostras de fezes de frango, 20% de produtos de frango e 3% de fezes de humanos. A maioria dos isolados foi determinada como C. jejuni. Destes, 93,5% apresentaram os genes para a toxina CDT. Apesar de a ocorrência de Campylobacter em fezes de humanos ter sido baixa, a prevalência em frangos de corte e produtos de frango foi elevada, fato que, aliado à presença dos genes cdt na maioria dos isolados, representa risco potencial para os consumidores. Esses resultados são indicativos da necessidade de medidas preventivas no sistema de produção e de boas práticas de fabricação na indústria, de forma a minimizar a contaminação dos produtos e diminuir o risco para os consumidores.

No abstract

No abstract

ResumoO objetivo deste trabalho foi verificar o padrão microbiológico de queijo mussarela comercializado em estabelecimentos varejistas de Pelotas, Rio Grande do Sul. Foram analisadas 40 amostras de queijo mussarela, compreendendo 20 de queijo em peça e 20 de queijo fatiado, as quais foram submetidas a contagem de coliformes termotolerantes e de estafilococos coagulase positiva, e a pesquisa de Salmonella spp. e de Listeria monocytogenes. Observou-se que 12,5% das amostras de queijo fatiado e 5% de queijo em peça estavam em desacordo com os padrões estabelecidos pela legislação brasileira. Estes resultados indicam a necessidade de maior monitoramento desses produtos e maior cuidado higiênico-sanitário durante o processamento por parte das indústrias. Palavras-chave: Segurança de alimentos, micro-organismos indicadores, micro-organismos patogênicos AbstractThe aim of this study was to verify the microbiological quality of mozzarella cheese sold in retail markets of Pelotas, Rio Grande do Sul, Brazil. Forty samples of mozzarella cheese were analyzed, comprising 20 samples of block cheese and 20 of sliced cheese. The cheese samples were analyzed for thermotolerant coliform counts and coagulase positive staphylococci counts, and presence of Salmonella spp and Listeria monocytogenes. The percentage of 12,5% and 5% of the sliced and block cheese samples analyzed, respectively, exceeded the microbiological standards accepted by Brazilian legislation. These results indicate the need for a better product monitoring and more concern with hygiene and sanitary practices during industrial process.

RESUMO: As bactérias do gênero Vibrio habitam ambiente tipicamente marinho e estuarino, sendo comumente isoladas de pescados. As principais espécies de Vibrio reportadas como agentes de infecções em humanos são V. vulnificus , V. parahaemolyticus , V. cholerae e V. mimicus . V. vulnificus é considerado o mais perigoso, podendo causar septicemia e levar à morte. V. parahaemolyticus é um patógeno importante nas regiões costeiras de clima temperado e tropical em todo o mundo e tem sido responsável por casos de gastroenterites associadas ao consumo de peixes, moluscos e crustáceos marinhos. V. cholerae causa surtos, epidemias e pandemias relacionados com ambientes estuarinos. V. mimicus pode causar episódios esporádicos de gastroenterite aguda e infecções de ouvido. A patogenicidade das bactérias está ligada à habilidade do micro-organismo em iniciar uma doença (incluindo entrada, colonização e multiplicação no corpo humano). Para que isso ocorra, os micro-organismos fazem uso de diversos fatores. O objetivo desta revisão foi sintetizar o conhecimento disponível na literatura sobre os fatores de patogenicidade de V. vulnificus , V. parahaemolyticus , V. cholerae e V. mimicus .