下口鲇烂尾病病原的分离与鉴定

Isolation and identification of pathogen which caused tail rot disease of Hypostomus plecostomus

对患烂尾病下口鲶(Hypostomus plecostomus)的肝脏、脾脏、肾脏进行病原菌分离,分离到NY635菌株,用NY635菌株人工感染体重在20~30 g的健康鱼,人工感染的下口鲇出现与自然发病鱼相似的症状,并从人工感染的下口鲇病灶中分离出菌落形态相同的细菌。初步证明NY635是引起下口鲇烂尾病的病原。对NY635进行菌落形态观察、生理生化鉴定和16S rDNA基因序列分析,确定菌株NY635为碱性假单胞菌(Pseudomonas alcaligenes),并对其进行了药敏试验。

The characteristics of pathogenic bacteria causing tail rot were isolated from the liver,spleen and the kidney in Hypostomus plecostomus,obtained NY635 strain,and used NY635 strain to infect the Hypostomus plecostomus which weighted at 20~30 g/ind.The infected Hypostomus plecostomus caused symptoms similar to those of naturally occurring,and same bacteria were isolated from infected Hypostomus plecostomus.It can be confirmed that NY635 is the pathogen bacteria of Hypostomus plecostomus rotten tail disease.According to the morphological features,physiological and biochemical characteristics and 16S rDNA gene sequencing,NY635 stain was identified as Pseudomonas alcaligenes,and drug sensitivity test was carried out.