Abstract：Bacteria pathogens were isolated from brain tissue of diseased American bullfrog (Lithobates catesbeiana) cultured in farms of Guangdong provinces. One bacteria strain with strong virulence was chosen for identifications. The morphological, biochemical and physiological characteristics, phylogenetic analysis of the isolate was achieved by using conventional method, BD PhoenixTM M50 Automated Microbiology System, 16S rDNA and gyrB genes sequence analysis, the characteristics of the isolated strain were in accordance with those of Elizabethkingia miricola. The virulent tests were carried out by using the pure culture of the isolated strain artificially infected American bullfrog with the concentration of 1×10^8 CFU·mL -1, the result indicated that the isolated strain could infected and caused the same typical wry head symptom as nature infected frog. The morphological and biochemical characteristics of the re-isolated bacteria from the artificially infected diseased frog were the same as those of the original infected bacteria. Antibiotic sensitivity assays showed that among 19 antibiotics tested 4 were sensitive, 8 were tolerant. This experiment successfully isolated a single strain of Elizabethkingia miricola, which provided a scientific basis for the prevention and treatment of American bullfrog infected with Elizabethkingia miricola.
2022, Vol. 35 
