Investigation of Salmonella spp. in free-range chickens (Gallus gallus domesticus) in Southern Rio Grande do Sul / Pesquisa de Salmonella spp. em galinhas coloniais (Gallus gallus domesticus) no sul do Rio Grande do Sul

Salmonelose é uma doença causada por bactérias do gênero Salmonella, com importância para saúde pública e animal. Dentre os sorotipos hospedeiro-específicos, destaca-se o Gallinarum, que possui os biovares Gallinarum e Pullorum adaptados às aves e amplamente difundidos pelo mundo. Os dados sobre a ocorrência de Salmonella spp. em criações avícolas alternativas no Brasil são escassos. O objetivo deste estudo foi pesquisar a ocorrência de Salmonella spp. em galinhas coloniais encaminhadas para necropsia ao LRD/FV/UFPel. Foram realizadas análises histopatológicas, microbiológicas e moleculares das colônias bacterianas isoladas de 12 amostras de órgãos de galinhas domésticas dos municípios de Pelotas e Piratini, no Rio Grande do Sul. Na análise microbiológica, foram isoladas bactérias do gênero Salmonella sorotipo Gallinarum das 12 amostras, sendo 10/12 bioquimicamente compatíveis com biovar Gallinarum e 2/12 com biovar Pullorum. Na análise molecular PCR 11/12, 91,7% foram identificadas genotipicamente como Salmonella spp. O presente estudo demonstrou uma elevada frequência de isolamento de Salmonella Gallinarum biovar Gallinarum em aves sintomáticas criadas em regime extensivo. Além disso, os dados epidemiológicos das aves analisadas demonstram que a infecção por Salmonella Gallinarum nesses casos está associada ao contato com aves silvestres e falhas de manejo sanitário.(AU)

First report of Escherichia coli O157:H7 in ready-to-eat sushi.

AIMS: The aim of this study was to evaluate the microbiological quality of commercially prepared ready-to-eat (RTE) sushi by enumerating aerobic mesophilic bacteria (AMB) and thermotolerant coliforms (TC) and detecting Escherichia coli and Salmonella ssp. An isolate was identified as E. coli O157:H7 which was evaluated for its virulence and antimicrobial resistance profiling as well as its ability to form biofilms on stainless steel. METHODS AND RESULTS: There were four sampling events in seven establishments, totalling 28 pools of sushi samples. Mean AMB counts ranged between 5·2 and 7·7 log CFU per gram. The enumeration of TC varied between 2·1 and 2·7 log MPN per gram. Salmonella ssp. were not detected, and one sample was positive for E. coli and was identified as E. coli O157:H7. To the best of our knowledge, this is the first report of E. coli O157:H7 in sushi samples in the world literature. This isolate presented virulence genes stx1, stx2, eae and hlyA. It was also susceptible to 14 antimicrobials tested and had the ability to form biofilms on stainless steel. CONCLUSIONS: There is a need to improve the good hygiene practices adopted in establishments selling sushi in the city of Pelotas, Brazil. In addition, the isolated E. coli O157:H7 carries a range of important virulence genes being a potential risk to consumer health, as sushi is a RTE food. This isolate also presents biofilm formation ability, therefore, may trigger a constant source of contamination in the production line of this food. SIGNIFICANCE AND IMPACT OF THE STUDY: The increase in the consumption of sushi worldwide attracts attention regarding the microbiological point of view, since it is a ready-to-eat food. To our knowledge, this was the first time that E. coli O157:H7 was identified in sushi samples.