Occurrence of Escherichia coli in salmon sashimis commercialized in restaurants from Londrina - PR

Abstract

The population interest for fish consumption has increased, mainly due to several beneficial nutritional properties presented by this food. In this context, oriental culinary also brings different eating habits as consume raw food, such as sashimi. A relevant food contaminant of fecal origin is Escherichia coli, able to become potentially harmful, when it acquires virulence factors, as Shiga toxin-producing E. coli (STEC). This study aimed to evaluate 30 samples of salmon sashimi regarding the presence of E. coli, as well as perform the genotypic characterization of virulence factors associated with STEC. Three samples were collected from 10 different restaurants, specialized in Japanese culinary in the city of Londrina - PR. The E. coli identification was performed using the Colilert® chromogenic substrate technique and biochemical tests, and for the investigation of virulence genes, stx1 and stx2, the polymerase chain reaction (PCR) was used. Among the 30 samples analyzed, 15 (50%) presented contamination by E. coli. However, in no sample were detected virulence factors associated with STEC. Although human diseases associated with STEC are poorly described in Brazil, it is possible to verify that fish, mainly those consumed raw, are potential transmitters of E. coli to humans. This can compromise the food safety of these products and, thus, characterize them as unsuitable for consumption. Therefore, it is necessary the adoption of preventive measures of contamination by E. coli in products intended to human consumption, beyond more research that can verify the potential of STEC as a fish contaminant.