梁河家鼠鼠疫疫源地鼠疫噬菌体的分离及其流行病学意义

目的调查梁河县家鼠鼠疫疫源地宿主动物中是否携带鼠疫噬菌体,并探讨其流行病学意义。方法2017年采集梁河家鼠鼠疫疫源地4个曾流行过鼠疫乡镇的鼠类标本,以鼠疫疫苗株EV76为饲养菌,采用双层平板法分离鼠疫噬菌体,同时挑取部分噬菌体进行电镜扫描。结果共获得338份标本(黄胸鼠234只,臭鼩鼱43只,其余61只),分离到29株鼠疫噬菌体,总分离率为8.58%(29/338),其中19株分离自黄胸鼠,分离率为8.12%(19/234),8株分离自臭鼩鼱,分离率为18.6%(8/43);4个乡镇全部有分离到鼠疫噬菌体,其中遮岛镇分离率最高为16.13%(5/31);初次分离这些鼠疫噬菌体时,其噬斑在双层平板上表现为大(直径≥2.0 mm)、中(≥1.0 mm,≤2.0 mm)及小(≤1.0 mm)3种噬斑;2株有代表性噬菌体皆为肌尾病毒科噬菌体。结论梁河家鼠鼠疫疫源地中普遍存在鼠疫噬菌体,黄胸鼠是主要的携带宿主,所分鼠疫噬菌体为肌尾病毒科噬菌体且具有多态性,值得进一步研究。

Isolation of Yersinia pestis phage from the Lianghe plague foci of Domestic rats and its epidemiological significance

To investigate whether the host animals of the plague foci in Lianghe County carry the Yersinia pestis phage, and to explore its epidemiological significance. In 2017, samples from four epidemic towns were collected in Lianghe plague foci. Vaccine strain of EV76 were used as feeding bacteria, and used double-layer plate method were used to isolate Yersinia pestis phages. At the same time, some phages were selected for electron microscopy scanning. 29 of Yersinia pestis phages were isolated from 338 samples (234 of Rattus flavipectus, 43 of Suncus murinus and 61 of the remaining), with total isolation rate of 8.58%(29/338). Among them, 19 were isolated from Rattus flavipectus, with a separation rate of 8.12%(19/234), and 8 were isolated from Suncus murinus, with a separation rate of 18.6%(8/43). The Yersinia pestis phages were isolated in all 4 villages, and the highest rate was 16.13% (5/31) in Zhedao Town. The plaque of the phages is divided into three appearance of big (≥2.0 mm), middle (≥1.0 mm,≤2.0 mm) and small (≤1.0 mm). Two phages are identified as the Myoviridae family. The Yersinia pestis phages are common in the plague foci in Lianghe County, and Rattus flavipectus is the main carrier. These Yersinia pestis phages are polymorphic phages of the Myoviridae family, and it is worth further study.