Comparison of ESCHERICHIA COLI levels in shellfish from Mediterranean coast, Morocco

Abstract

Monitoring of ESCHERICHIA COLI levels in commercial bivalve shellfish is intended to protect consumer health from foodborne diseases. This study aims to identify if one species can be used as indicator for microbiological contamination of other species present. During 2012, 168 samples of shellfish (clams, cockles and mussels) were analysed for E. COLI by MPN technique. 62.5% of samples complied with regulatory threshold ≤230 MPN and geometric mean were higher in cockles than in clams or mussels in each site. Statistical significance was observed between sites. Seasonally, the highest levels were recorded in wet weather (winter and spring) due to runoff of waters from rainfall and lowest levels were recorded in dry weather (summer) when high temperatures show bactericidal effect. Our findings show cockles could be as sentinel specie for burrowing shellfish, but for non burrowing (mussels), monitoring should be done on this specie.