Isolation,identification and drug sensitive test of Aeromonas sobria from goldfish

A pathogenic bacterium(3-1-3) was isolated from the diseased goldfish.Its morphological,physiological,biochemical characteristics and 16S rRNA sequence analysis were studied.The isolated strain is gram-negative,with polar single-flagella,glucose fermented without gas production,oxidase-positive,catalase-positive,unrequired sodium ions for growth,no pigment, non-luminescence;It grew slowly on TCBS-plate and insensitive to the vibriostratic agent O/129.The sequence analysis of 16S rRNA gene of 3-1-3 isolation and comparison with that of other related aeromonas showed that 3-1-3 was very close to Aeromonas sobria.According to morphological,physiological,biochemical characteristics and phylogenetic analysis,the isolated strain(3-1-3) is identified as A.sobria.The testing results by paper extension methods for drug sensitive show that,among 20 antibiotics,gentamicin,norfloxacin,chloromycotin,tobramycin,kalamycin,spectinomycin and ceftriaxone have the most inhibitive effect on the strain.