Microbial quality of oysters and waters from culture and natural banks in Cananeia (SP)

Abstract

The consumption of marine organisms, especially bivalve molluscs, might affect the human health, once that they concentrate in their tissues, suspended particles, including pathogenic microorganisms. Cananeia region is the largest oyster producer in the state of São Paulo, and in 1999 was founded the Cooperostra (Cooperative), which promotes the oysters depuration process in sterile tanks, leading to reduce and/or eliminate retained substances in their tissues. This study aims (i) evaluate the water quality in the adjacencies of the natural oysters’ beds and during the steps of the depuration process, through the determination of Escherichia coli, total coliforms and thermotolerant coliforms, and (ii)evaluate the contamination of Crassostreasp by Salmonella sp., total coliforms, thermotolerant coliforms and Staphylococcuscoagulase positive, in samples collected at Cooperostra and in natural oysters’beds, assessing the contamination level of the organisms and the efficiency of the depuration process. The results show a reduce of Salmonella sp and coliforms densities in the oysters’ tissues after the depuration process. However, Staphylococcus coagulase positive shown high levels, which may be indicative of handling contamination. The Salmonella sp results were in agreement with RDC n12.