Detection of Vibrio parahaemolyticus and Aeromonas veronii causing disease in shrimp (Litopenaeus vannamei) by multiplex PCR

Abstract

This study presents the development of a multiplex PCR assay for the simultaneous detection of two major shrimp pathogens. In Vietnam, the co-culture of shrimp and fish in the same pond increases the risk of shrimp infection due to cross-contamination from fish waste, feed, and environmental sources, contributing to disease outbreaks and shrimp mortality rates exceeding 80%. This study aimed to detect Vibrio parahaemolyticus and Aeromonas veronii, two major etiological agents associated with Acute Hepatopancreatic Necrosis Disease (AHPND)/Early Mortality Syndrome (EMS) in Litopenaeus vannamei, using a multiplex polymerase chain reaction (PCR) technique. Two gene fragments, GSTT2 and pepO, were selected as species-specific molecular markers for V. parahaemolyticus and A. veronii, respectively. Multiplex PCR successfully amplified both target genes with clear and specific bands (236 bp for GSTT2, 520 bp for pepO) without cross-reactivity with other bacterial species. These results confirm the reliability and specificity of the method, offering a rapid and accurate diagnostic tool for bacterial diseases in shrimp farming, thereby contributing to improved disease management and sustainable aquaculture development in Vietnam.