10.22376/ijpbs.2019.10.1.p1-12 Volume 2 Issue 4 2011 (October - December) A total of 105 shell fish samples (35 each of prawn, shrimp and crab) collected from local markets were subjected to cultural methods and PCR for the presence of lessThan i greaterThan V. parahaemolyticus lessThan /i greaterThan and their toxins using primers for lessThan i greaterThan toxR lessThan /i greaterThan , lessThan i greaterThan tdh lessThan /i greaterThan and lessThan i greaterThan trh lessThan /i greaterThan genes respectively. Out of total 105 samples, positive isolates of lessThan i greaterThan V. parahaemolyticus lessThan /i greaterThan were found in 17 prawn samples, 25 shrimp and 19 crab samples by cultural method where as by PCR assay the organism was found in 24 samples of prawn, 33 shrimp and 27 crab samples. Out of 84 positive isolates of lessThan i greaterThan V. parahaemolyticus lessThan /i greaterThan by PCR method, 11 showed presence of lessThan i greaterThan tdh lessThan /i greaterThan , 37 had lessThan i greaterThan trh lessThan /i greaterThan and 6 had both lessThan i greaterThan tdh lessThan /i greaterThan and lessThan i greaterThan trh lessThan /i greaterThan . Selective broths (Alkaline PeptoneWater and Salt Polymyxin Broth) were more efficient than non-selective broths (Brain Heart Infusion and Tryptic Soy Broth) and Salt Polymyxin Broth (SPB) was superior over Alkaline Peptone Water (APW) in selective broths for isolation of this organism by both cultural and PCR methods. The sensitivity of PCR method for this organism was 2.5cfu. N. Subhashini, N. Krishnaiah And Ch. Bindu Kiranmayi Vibrio parahaemolyticus, PCR, Cultural method, Prevalence, Shell fish 335-341