鹤庆新发野鼠鼠疫疫源地中鼠疫噬菌体的分离及其裂解谱测定

Isolation and determination of lysate spectrum of plague bacteriophages in new rodent plague foci Heqing,China

目的查明鹤庆新发野鼠鼠疫疫源地内是否存在鼠疫噬菌体,并对所离分鼠疫噬菌体进行形态鉴定及噬菌谱分析。方法以鹤庆县马厂村为核心,选择5km范围内的自然村为采样点,采用鼠铗法进行捕鼠,实验室中取鼠盲肠置入改良PBS中,采用双层平皿对样本进行筛选、纯化得到噬菌体,观察噬菌斑形态,电镜检查噬菌体形态,并在22℃、24℃、28℃及37℃对21株鼠疫菌与115株非鼠疫菌进行裂解特性分析。结果采集的354份标本,分离到2株鼠疫噬菌体;2株噬菌体在高于24℃温度下可裂解鼠疫菌,低于24℃不能裂解鼠疫菌,而非鼠疫菌在4个温度下均不裂解;电镜形态检测2株噬菌体均属于肌尾噬菌体。结论鹤庆新发野鼠疫疫源地内存在着鼠疫噬菌体,且所分鼠疫噬菌体只有在高于24℃时才裂解鼠疫菌,此特性与鼠疫菌在鹤庆县的长期存在相关,且两株噬菌体存在裂解谱较窄,特异性良好,可用于备用诊断噬菌体的筛选株。

To make clear whether there are Yersinia pestis phages in the new plague focus of Heqing County,and to perform morphological identification and lysate spectrum.When natural villages within 5 km were determined as sampling points,rats were caught by rattan method.The small intestine of mice was taken from the laboratory and put in the modified PBS.The samples were screened and purified by the double-layer plate method.Phage plaques were observed with naked eyes,and the morphology of bacteriophage was examined by electronic microscopy.Pyrolysis characteristics of 21 strains of Yersinia pestis and 115 strains of non-Yersinia pestis at four temperatures of 22℃,24℃,28℃and 37℃respectively.1.A total of 354 specimens were collected and two strains of plague phages were isolated.2.2 strains of bacteriophages could lyse Yersinia pestis at temperatures higher than 24℃,but could not lyse Yersinia pe stis at temperatures lower than 24℃,while all of non-Yersinia pestis did not lyse at four temperatures.3.Electron microscopic examination showed that two phage strains belonged to the family of Myoviridae.There are plague bacteriophages in the new plague focus of Heqing,and the plague bacteriophages can lyse the Yersinia pestis only above 24℃,which is related to their long-term existence in Heqing County.At the same time,the two bacteriophages are of narrow lysis spectrum and well specificity,which can be used for the screening of alternative diagnostic bacteriophages.