Vibrio parahaemolyticus is a gram negative bacterium and causes gastrointestinal illness in humans. In this study, twenty five out of fifty cockle samples from Padang, Indonesia produced purple colonies when they were grown on selective medium, CHROMagarTM Vibrio. Specific–PCR for toxR gene detection gave positive results in which a band with 368 base pairs size appeared on the gel for all the isolates that confirmed the presence of V. parahaemolyticus. In the virulence properties test, all the isolates showed negative results for tdh and trh genes detection. The results indicate that the isolates under this study do not contain virulence properties that correlate to the ability of infection and diseases, which means that they are nonpathogenic.
In this study, RAPD-PCR and ERIC-PCR were used to study the epidemiology of V. parahaemolyticus isolated from cockles in Padang, Indonesia. The Gold Oligo OPAR3 primer produced bands ranged from 1-8 with sizes from 0.2 – 5.0 kb and the Gold Oligo OPAR8 primer produced 1-7 bands with sizes 0.7 – 1.5 kb. Both primers produced twenty five RAPD patterns with a few isolates failed to produce any products. Based on phylogenetic dendrogram, all the isolates can be divided into 6 major clusters with similarity between 0 to 52%. For the ERIC primer, it produced bands ranged from 3-15 with sizes from 0.1 – 5.0 kb and twenty seven different ERIC patterns. Construction of the phylogenetic dendogram showed the isolates can be divided into 4 major clusters with similarity between 56 to 86%. The high diversity of both processes may be due to the multiple contamination sources of V. parahaemolyticus.
Vibrio parahaemolyticus is one of the most widely recognized pathogenic Vibrio species due to numerous outbreaks and its’ wide occurrence in marine environment. In this study, 32 isolates of V. parahaemolyticus isolated from cockles were tested for sensitivity to 16 antibiotics and the presence of plasmids. All the isolates were multi-resistance, defined as resistant to atleast three different antibiotics with multiple antibiotic resistance indexes ranging from 0.31 to 0.69, indicating the isolates originate from high risk sources of contamination where antibiotics are often used. In the plasmid profiling test, only 15 isolates (47%) harbored plasmid DNA, which ranged in size from 2.7 to 56.2 kb, separating the isolates into 14 plasmid profiles. Hence, food contaminated with antibiotic resistant V. parahaemolyticus could be a major threat to public health due to the distinct possibility that they can be a significant reservoir of genes encoding antibiotic resistance determinants that can be transferred intra or interspecies. As in many developing countries, raw food hygiene and antimicrobial resistance epidemiology is still in the infancy stage in the locality of the study and thus our data provide a current baseline profile of antimicrobial resistance and plasmid of V. parahaemolyticusfrom cockles in Padang, Indonesia.