关键词: 黄金鲫鱼, 病原菌分离鉴定, 药敏试验, 复感染试验, 同源分析

Abstract: In recent years, sarcoidosis is one of the frequent outbreak disease in freshwater fishery. In order to effectively prevent and control this disease, the experiment separated the dominant pathogens (named AH strain) from the dying gold crucian carp at a fish farm of Hefei outskirts and carried out identification. The morphological characteristics, physiological and biochemical characteristics of the strain, and the sensitivity of common drugs were determined by traditional bacteria classification method, and molecular biology method was also used to clone and sequence the specific fragment of 16S rRNA. The AH strain was consistent with the control Edwards strain on the morphological characteristics and physiological biochemical characteristics. The result of sequence analysis on AH strain and catfish Edward siella strains (AB050826, NR_024769) showed that the homology to each other was over 99.9%, and they were assigned to the same strains family. After artificial infection test, similar natural incidence of visceral sarcoidosis symptoms were appeared. The results of drug sensitivity test showed that AH strain was sensitive to ofloxacin and the other 10 kinds of drugs; moderately sensitive to the sulfa drugs, such as sulfamethoxazole; and resistant to 4 kinds of antibiotics. Comprehensive analysis indicated that Edward bacteria was a virulent pathogen of gold crucian carp visceral sarcoidosis. This study provided a useful reference for the effective prevention and control of golden crucian carp offal sarcoidosis.

Key words: gold crucian carp, isolation and identification of pathogenic bacteria, drug sensitivity test, multiple infection test, phylogenetic tree analysis