27株嗜水气单胞菌致病性及ERIC-PCR指纹图谱分析

Study on the pathogenicity and ERIC- PCR fingerprinting of 27 strains of Aeromonas hydrophila

从福建省淡水养殖鱼类体内分离到27株嗜水气单胞菌,根据嗜水气单胞菌16S rDNA基因和气溶素基因(aerolysin)的保守序列,设计2对引物,对所分离到的27株嗜水气单胞菌进行双重PCR扩增,扩增结果表明,其中18株为含有Aer毒力基因的潜在致病性嗜水气单胞菌,占总菌数的66.67%。应用ERIC—PCR分型技术对27株嗜水气单胞菌菌株进行分析,以相似度54.00%为限,所有菌株可分为Ⅰ和Ⅱ两大聚类,以76.00%相似度为界,27株嗜水气单胞菌可分为11个聚类,同一个聚类中菌株分离区域基本相同。分析结果表明,分离的嗜水气单胞菌基因型的多样性和分离地域具有一定的关联,也表明ERIC—PCR可以有效应用于嗜水气单胞菌分子流行病学调查。

27 strains of Aeromonas hydrophila were isolated from cultured fish in Fujian Province. Based on the 16S rDNA gene sequence and aerolysin gene sequence of A. hydrophila, the synthetic oligonucleotide primers were designed and used to perform duplex PCR amplification of the two conservative genes fragments. The results showed that 18 strains were pathogenic A. hydrophila, which accounted for 66.67% of the strains isolated. Enterobacterial repetitive intergenie consensus sequence PCR （ERIC -PCR） was used to genotype 27 strains of A. hydrophila. By the similarity 54.00% , two special genotypes （ I and II ） from the 27 isolated were identified. However, all the strains could be divided into eleven groups by the similarity 76.00%. There was a tendency that the strains from the same area could be clustered into one group. The results showed that there was a correlation between the genotype and isolating regional among A. hydrophila strains, and ERIC - PCR was of a great significance for molecular epidemiological investigation of A. hydrophila.