Application of PCR mrthod by using of 16srRNA and encoding extracellular lipase primer to Aeromonas hydrophila identification and comparison with biochemical tests

Fish disease is the major risk factor in commercial aquaculture with millions of dollars lost annually. Among them, Aeromonas hydrophila as dominant infectious agent in bacterial septicemia in freshwater fish especially Cyprinidae family has been known. A. hydrophila has been associated with tail and fin rot, haemorrhagic septicaemia and epizootic ulcerative syndrome (EUS).In this study 213 isolates were obtained from 200 pieces of patient cultured carp (126 common carp,39 silver carp and 35 grass carp) from Khuzestan province farms with biochemical and molecular tests were investigated. 16srRNA gene was used for Aeromonas sp. Detection and 16srRNA lipase genes was used for Aeromonas hydrophila detection. The result shown 73% of Aeromonas sp. and 52% of Aeromonas hydrophila which were detected by biochemical method were conformed by PCR assay. Also result of this study was shown, the PCR assay compared with biochemical methods, is a rapid and sensitive method for Aeromonas hydrophila detection and has a high sensitivity.