Resumo

Outbreaks of infections caused by foodborne pathogenic microorganisms become increasingly common, due to any failure in processing, handling or storage of food. The term foodborne illness is used to designate a symptomatology characterized by a set of upset stomach, usually involving vomiting, diarrhea, fever and abdominal pain. Several groups of microorganisms have the capacity of causing such symptoms, however, bacteria, is one the most important microbial group and commonly related to food-borne infections due to its diversity regarding virulence factors; Enterobacteriaceae such as Salmonella sp is the principal agent, due to the ability of production enterotoxins and the Brazilian laws generally determine the absence of Salmonella sp in different food matrices. The present study is focused on the detection of Salmonella sp using molecular techniques, in ready-to-eat raw fish (sashimi, sushi) available at the self-service restaurants in the city of Rio de Janeiro. The raw fish dishes -sushis and sashimis were prepared from three different fishes: salmon, tuna and white fish. Samples were collected at three restaurants (A, B, C), providing a total amount of 16 samples. The following specimens were processed by adding 225 mL of buffered peptone water, homogenized in a stomacher and incubated at 37 °C for 24 h (pre-enrichment step). Subsequently, the samples were submitted to selective enrichment step in tetrathionate broth and DNA was extracted by a commercial kit, DNasy blood and tissue kit (Qiagen) according to the manufacturer recommendations for Gram-negative bacteria. PCR targeting for the invA gene, the first gene in the invABC operon, was performed, resulting in the amplification of a fragment of 596 bp. The occurrence of positive samples for the invA gene was 50% (8/16), in which 100% (4/4) of samples from the establishment C were positive. The adoption of criteria for good practice of manipulation is essential to prevent the contamination of raw fish provide hazard to consumers. Considering the pathogenic potential of many Salmonella species, the findings of this study emphasize the potential risk of consumption of sushi and sashimi for public health.