一株宽宿主谱裂解性大肠杆菌噬菌体的进化分析

PHYLOGENETIC ANALYSIS OF A BROAD-HOST-RANGE LYTIC COLIPHAGE

裂解性噬菌体能够特异性裂解细菌,本研究分析了一株从自然界中分离的宽宿主谱裂解性大肠杆菌噬菌体的种属和进化关系。前期用Adams双层平板琼脂法从猪场污水中分离纯化出一株裂解性噬菌体v B_Eco M_JS09,裂解谱分析能够裂解禽致病性大肠杆菌和产肠毒素大肠杆菌。扩增分析gene18、gene 23序列,并根据gp18和gp23氨基酸序列构建系统进化树,分析JS09的遗传进化关系。结果表明噬菌体v B_Eco M_JS09基因组为ds DNA,属于有尾噬菌体目、肌尾噬菌体科、T4-like噬菌体、T-evens亚群。其gp18氨基酸序列与大肠杆菌噬菌体RB69同源性最高,为100%;gp23氨基酸序列与大肠杆菌T4噬菌体同源性最高为96%。该结果为禽致病性大肠杆菌和产肠毒素大肠杆菌的防控提供了生物学基础。

Lytic bacteriophage (phage) can kill bacteria. This study analyzed the classification and phylogeny of a broad-host-range lytic coliphage isolated from the nature. In a previous study, a strain of phage vB_EcoM_JS09 was isolated by using Adams double-layer agar plate method and purified from the sewage of a swine farm. The genome was extracted through phenol chloroform isopropanol method, then treated with DNase I, RNase A and Mung Bean Nuclease. The conserved tail sheath gene 18 and major capsid protein gene 23 of T4-like phages were amplified using the reported primers and JS09 as a template and their deduced amino acid sequences were used for phylogenetic tree analysis. Results showed that lytic coliphage JS09 had the genome of double stranded DNA, belonging to the Caudovirales, Myoviridae, T4-like phage, T-even subgroups. The homology of amino acid sequence of gp18 was 100%with E.coli phage RB69 while that of gp23 shared 96%identity to E.coli T4 phage. The results provide a good foundation for the biology of Avian pathogenic Escherichiacoli and enterotoxigenic Escherichiacoli prevertion Cuel control.