Quantitative Method for Detecting Vibrio parahaemolyticus Using Bio-Theta DOXTM System

Abstract

This is the first report on the quantitative method for detecting Vibrio parahaemolyticus using the Bio-Theta DOXTM system. Seven V. parahaemolyticus strains and 23 non-V. parahaemolyticus strains were assessed. The rate of positive detection of Vibrio in samples of the 7 V. parahaemolyticus strains at high concentration (105 cfu/ml), medium concentration (103 cfu/ml), and low concentration (10 cfu/ml) was 100%. All 7 V. parahaemolyticus strains displayed good linear calibration curves for detection time relative to bacterial count (r > 0.993). The mean negative rate for the high-concentration (106 cfu/ml) non-V. parahaemolyticus samples was 65.2% (15/23) and that for the medium-concentration (103 cfu/ml) samples was 82.6% (19/23). Positive results for detection of the bacteria were obtained for some samples among the 7 V. alginolyticus strains and 1 V. harveyi strain tested; however, the detection times for these species were longer than that for V. parahaemolyticus. A method for measuring total Vibrio counts using the DOX system has previously been developed. Although further detailed field experiments are needed, regular measurement of total Vibrio and V. parahaemolyticus counts in shrimp farm pond water should initially help prevent EMS/AHPNS disease in these shrimp farming systems.