Isolation and biological characteristics of a wild Yersinia pestis phage / 中华地方病学杂志

ABSTRACT

Objective:A strain of Yersinia pestis phage was isolated from the cecum of Meriones unguiculatus, and its biological characteristics were studied. Methods:The phage was isolated from the cecum of a Meriones unguiculatus which died in the Meriones unguiculatus natural foci of plague in Inner Mongolia. Phage morphology was observed by transmission electron microscopy (TEM). The optimal multiplicity of infection (MOI), one-step growth curve, stability of the phage to temperature and acidity and alkalinity, sensitivity to chloroform, ethanol, isopropanol and ultraviolet rays, host range of phage lysis and lysis of the phage to wild strains of Yersinia pestis were analyzed. Results:The diameter of the phage plaque was about 10.00 mm. The head of the phage showed icosahedral symmetry under TEM, and the head was composed of a head with a diameter of 51.72 nm and a tail with a length of 10.00 nm. The MOI was 0.01, the incubation period was about 20 min, the outbreak period was 20-100 min and the outbreak amount was 200 PFU/cell. Under the condition of pH 5-12, it could maintain high activity, not sensitive to chloroform, 10% ethanol and isopropanol. Ultraviolet irradiation for 2 min could kill most of the phages. The host spectrum of the phage was narrow, and with strong specificity. It could lyse wild strains of Yersinia pestis exclusively. Conclusions:The phage is classified as family Podoviridae, which has a potential to assist the diagnosis of Yersinia pestis, enriches the database of Yersinia pestis phages and lays a foundation for the research and application of Yersinia pestis phages.