ISOLATION, IDENTIFICATION AND ANTIBIOTIC SENSITIVITY OF CHRYSEOBACTERIUM INDOLOGENES FROM TRIONYX SINENSIS

This study conducted isolation, identification and drugs sensitivity of pathogen from sick Trionyx sinensis to provide a reference for control and prevention disease for Trionyx sinensis. The pathogenic bacteria were isolated and purified from skin, liver, kidney and spleen of Trionyx sinensis. The identification of the isolated pathogen was analyzed by biochemical reactions and 16S rRNA gene sequence. The artificial infection test was performed with intraperitoneal injection, and drugs susceptibility test was conducted by K-B method and double broth dilution method. The results showed that strain J22 was the pathogen of Trionyx sinensis, and the LD₅₀ was 3.30×10⁴ CFU/g. According to morphological and biochemical characteristics as well as 16S rRNA gene sequence analysis, strain J22 was identified as Chryseobacterium indologenes. Strain J22 was susceptible to neomycin, gentamicin and amoxicillin and other 9 antibiotics but resistant to florfenicol and doxycycline, etc. The chlorine dioxide, bleaching powder and potassium ferrate had great antiseptic effect on the isolated pathogeb. These results indicate that Strain J22-induced disease of Trionyx sinensis can be treat by drugs such as neomycin, gentamicin and amoxicillin for oral administration, and that chlorine dioxide, bleaching powder and potassium ferrate are suitable for external use in farming.