Qualidade microbiológica de ostras (Crassostrea sp.) e de águas coletadas em cultivos e em bancos naturais da ilha de São Luís, MA

Abstract

This research aimed to evaluate the microbiological quality of water and oysters from natural banks and oyster farms located on the Island of São Luís, MA. For this, 60 samples were analyzed from September 2020 to February 2021, 30 of water and 30 of oysters (Crassostrea sp.) collected directly from shellfish farmers and farm owners in the municipalities of the Island of São Luís, MA. For the determination of total coliforms and E. coli in the water samples, the technique recommended by APHA (2012) was used using the Colilert® rapid method. For the enumeration of total and thermotolerant coliforms in oysters were performed by the Most Probable Number (MPN) method and E. coli by the technique described by Vanderzant and Splittstoesser (1992). Enumeration of coagulase positive Staphylococcus in oyster samples was performed according to SILVA et al., (2017). Surveys for Salmonella sp., Aeromonas sp. and Vibrio sp. in oysters were performed according to the methodologies recommended by APHA (2012), CARNAHAN et al., (1991) and Bacteriological Analytical Manual online ELLIOT, KAYSNER; TAMPLIN (2004). The results in geometric mean count of E. coli in the water samples ranged from 604.29 to 1130.79 NMP/100ml demonstrating unsatisfactory microbiological quality. For the oysters, 8 (26.66%) out of 30 samples were unsuitable for consumption, being 4 samples (13.33%) due to the presence of Salmonella sp. and 4 samples (13.33%) due to E. coli count above the limits of the current legislation. It is recommended the implementation of Good Manufacturing Practices, the use of the purification process and the regular monitoring of the microbiological quality of the water in the oyster production chain in São Luís, MA.