Detection of marine Vibrio species from environmental samples with a nested PCR technique

Bacteria of the genus Vibrio are indigenous for the marine environment and temporarily in abundances in the ocean, causing infections to humans and commercially important species of crustaceans, bivalves and fish. These bacteria can therefore cause severe complications for human health and large economic losses to aquaculture. A polymerase chain reaction (PCR) technique was used to detect presence of four different Vibrio species from two different seasons in marine environmental water samples, collected in the south west coast of India. Two species, V. alginolyticus and V. harveyi, were detected in both postand pre-monsoon seasons. However, no difference in presence between the seasons could be statistically determined. V. cholerae was not detected in any of the samples and the results for V. vulnificus were inconclusive due to failure to optimize the PCR technique for this species. The qualitative experiment set up was found to be too weak to detect difference in Vibrio species’ presence between the two seasons. However, using nested PCR to detect pathogenic bacteria from environmental samples is an important tool for risk assessments in the food industry.