Abstract:Aeromonas hydrophila can infect an array of animals, including fish, amphibians, reptiles, birds and mammals, and lead to hemorrhagic septicaemia. To develop a rapid and specific quadruple PCR method for the detection of pathogenic Aeromonas hydrophila, four pairs of primers were designed based on the conservative sequences of 16S rRNA gene, serine-protease (ahpA) gene, aerolysin(aerA) gene and hemolysin(hlyA) gene of Aeromonas hydrophila. After optimalizing the reaction conditions, specificity, sensitivity and detection rate of the quadruple PCR method were studied. Results indicated that this method has a high specificity in detecting pathogenic strains of Aeromonas hydrophila but not other irrelative bacteria, and can detect as less as 100fg total DNA. Nine Aeromonas hydrophila strains and fifty-six clinical samples were tested by this quadruple PCR and conventional microbiology methods, and both of the methods can identify these nine Aeromonas hydrophila strains; the detection rate of the fifty-six clinical samples by quadruple PCR was 21.4%, which is higher than that by conventional microbiology methods (16.1%), and their coherence was 94.6%. It could be concluded that the quadruple PCR method which can simultaneously detect 16S rRNA gene and three virulent genes of pathogenic Aeromonas hydrophila was well established, and this method is a reliable and convenient method to detect Aeromonas hydrophila and identify specific type of pathogenic or nonpathogenic strains.