The Diversity of Causative Agent Associated with Bacterial Diseases on Catfish (Clarias gariepinus) with Molecular Based from Kendal, Indonesia

Abstract

Bacterial disease is still a big concern in intensive catfish culture in Indonesia. The aim of this research was to find out causative agent on cat fish based on the 16S rDNA gene sequences. This research combined between exploratory in the field and experimental method in Laboratory. Causative agents diversity of bacterial diseases of catfish was isolated from Kendal Regency, Indonesia and based on postulat Koch results. Twenty bacteria (K01–K20) were isolated from external wound and kidney of moribound catfish with TCBS, NA and GSP medium. The postulat results showed that three isolates (K6, K14 and K19) were weaken up to 60% of fishes and caused 10–20% mortality. On the other hand, there were 14 isolates that did not demosntrated their virulence. Based on 16S rDNA sequence analysis, strain K6, K14 and K19 were closely related to Aeromonas sobria (97%.), Pseudomonasplecoglossicida (96%.), Aeromonas caviae (96%.) respectively. Sensitivity test to all isolates showed that these causative agents resistant to some fish drugs.