Simultaneous detection of pathogens causing francisellosis,furunculosis and vibriosis in Atlantic cod by multiplex polymerase chain reaction

An assay for the simultaneous detection of three major bacterial pathogens of Atlantic cod with multiplex polymerase chain reaction (mPCR) was developed. Primers targeting the flanking regions of genes groEL, gyrB and amiB were standardized to diagnose francisellosis, furunculosis and vibriosis respectively. The detection limit of Francisella piscicida, Aeromonas salmonicida and Vibrio anguillarum in the mPCR assay ranged from 10 ng to 100 pg of bacterial DNA mL^?1, 10 μg to 50 ng of bacterial DNA mL^?1 and 1 μg to 100 ng of bacterial DNA mL^?1 respectively. These primers were found to be specific in the determination of the respective genes in the individual pathogen without cross‐reaction, thus making the assay an efficient tool to detect the presence of these pathogens simultaneously or individually.