A PCR method for the detection of Aphanomyces piscicida

Abstract

We describe a polymerase chain reaction (PCR)-based approach to the detection and identification of Aphanomyces piscicida (=Aphanomyces invadans). Three primer sets were designed based on the sequences of cloned expression genes of A. piscicida NJM 9803 (accession numbers: AB 104634, AB 104635 and AB 104636). They were used to detect the genomic DNA of 42, 18, 10 and 1 isolates of Aphanomyces spp., Saprolegnia spp., Achlya spp. and Dictyuchus sp., respectively. Out of 3 primer sets, a primer set (1APM 1F, 1APM 6R) detected only fish pathogenic A. piscicida but not the other non-fish pathogenic Aphanomyces species. In addition, the PCR revealed sensitivity sufficient for detecting A. piscicida in artificially infected goldfish. From the results, it was demonstrated that the PCR method with the primer set is effective for detection of A. piscicida from infected fishes and diagnosis of mycotic granulomatosis.