Screening of Pathogenic Bacteria from the Commercially Important Edible Bivalve Meretrix meretrix

Bacteria widely occur in aquatic environment in marine, estuarine and they are the pathogens to the aquatic organisms.Pathogenic bacteria mainly include Vibrio Species, Pseudomonas, Aeromonas, Staphylococcus etc. Vibrio species are the casual agents of zoonosis, which causes gastrointestinal disorders and septicaemia.The study was carried out for the screening of pathogenic Vibrio species in the edible bivalve Meretrix meretrix and also from its habitat.M.meretrix is the benthic, filter feeding organism by which it will accumulate large groups of bacterial flora from the surrounding environment.The M. meretrix and sediment samples from Kali estuary was screened for the pathogenic Vibrio load on the TCBS Agar medium.The average pathogenic bacterial load was 4.1 Log CFU/g in sediment whereas in M.meretrix it was 4.2 Log CFU/g.The total of 86 Vibrio isolates comprising of Vibrio parahaemolyticus (n = 44), Vibrio alginolyticus (n = 30) and Vibrio navarrensis (n = 12) were found.These Vibrio species were tested for the antibiotic resistance, showed 100% resistant to ampicillin and ceftotaxime, 95% were resistant to ceftazidime and 75% were resistant to cefepime where as 90% were sensitive to chloramphenicol followed by 80% towards tetracycline and 72.5% towards gentamicin.The present findings showed that presence of Vibrio species in estuarine sediments, have affected the M.meretrix of the habitat.The presence of antibiotic resistant Vibrio species causes ill effects in the organisms causing histopathological changes in affected areas and also humans after the consumption.