THE SMALL-SUBUNIT RIBOSOMAL-RNA GENE SEQUENCE OF PLEISTOPHORA-ANGUILLARUM AND THE USE OF PCR PRIMERS FOR DIAGNOSTIC-DETECTION OF THE PARASITE

Using the polymerase chain reaction (PCR) and two primers for conserve d regions of the small subunit ribosomal RNA (SSU-rRNA) of Microsporid ia, a DNA segment about 1,195 base pairs long was amplified from a DNA template prepared from purified spores of the microsporidian species Pleistophora anguillarum. These spores had been isolated from adult ee ls (Anguilla japonica) with ''Beko Disease.'' A comparison of sequence data from other microsporidian species showed P. anguillarum SSU-rRNA to be most similar to Vavraia oncoperae. When juvenile eels were arti ficially infected with P. anguillarum, enzyme-linked immunosorbent ass ay could detect a positive infection only 12 days post-infection. Howe ver, when suitable PCR primers were used, a DNA fragment of about 0.8 kb was detected from these juvenile eels after only 3 days post-infect ion. No PCR product was obtained with templates prepared from clinical ly healthy control animals.