Prevalence and antibiotic resistance of pathogenic Vibrios in shellfishes from Cochin market

Abstract

Shellfish samples obtained from four retail markets in Cochin were examined for the presence of pathogenic <i>Vibrios</i>. A total of 110 samples collected during the period between September 2010 and March 2011 included shrimp, crab and clams. <i>Vibrio </i>species was detected in 65.5% of the samples. Six potentially pathogenic <i>Vibrio </i>species such as <i>V. parahaemolyticus </i>(68.1%), <i>V. alginolyticus </i>(18.1%), <i>V. vulnificus </i>(2%), <i>V. cholerae </i>(1%), <i>V. harveyi </i>(1%) and <i>V</i>.

<i>mimicus </i>(1%) were detected. Overall percentage of incidence was highest in clams (84.2%) followed by shrimps (63.8%) and crabs (37.5%). When isolates were tested for their susceptibility to various antibiotics, highest incidence of antibiotic resistance was evident against ampicillin and colistin followed by amoxycillin, carbenicillin, ceftazidime and cephalothin and lowest against chloramphenicol, tetracycline and nalidixic acid. Multiple drug resistance was prevalent among the isolates. Results indicate that the various seafood markets at the retail level in Cochin are contaminated with potentially pathogenic <i>Vibrio </i>species. If they survive insufficient processing/cooking conditions they would have an impact on safety of processed/cooked ready-to-eat food.