ABSTRACT
@#Abstract: Objective To analyze the pathogenic characteristics and epidemiological significance of human plague related strains in Qinghai Province in recent 30 years, so as to provide scientific basis for on-the-spot disposal and prevention and control measures of plague outbreak in Qinghai Province. Methods A total of 35 strains of Yersinia pestis isolated from 29 typical human plague outbreaks in Qinghai Province from 1980 to 2011 were selected and studied by biochemical fermentation experiments. Virulence factors detection of Fraction 1 antigen (Fra1), virulence antigen (VW), pigmentation (Pgm) and Yersinia pestis Ⅰ (PstⅠ), determinants and genotyping of differential regions (DFRs) were used to study the pathogenic characteristics. At the same time, according to the epidemic situation of human and animal plague in Qinghai Province in recent years, the current situation of plague prevention and control and epidemic characteristics were analyzed. Results The biotypes of 35 strains of Yersinia pestis were classical, and the biotypes of 29 strains (82.86%) were of Qinghai-Tibet Plateau type, mainly distributed in southern Qinghai and around lake areas, 2 strains (5.71%) belonged to Qilian Mountains type, mainly distributed in Qilian mountains, and 6 genotypes were identified by DFR. Among them, 16 were type 5, 12 were type 8, 2 were type 10, 1 was type 36, 3 were type 30 and 1 was type 1b, the strains of type 5 and 1b were mainly distributed around the lake and the southern foot of Qilian Mountains, while the strains of type 8, 10, 36 and 30 were mainly distributed in the southern part of Qinghai. Conclusions The pathogen of Yersinia pestis in Qinghai Plateau has complex biochemical types, the epidemic situation among animals is continuous year after year, the situation of prevention and control is serious, the occurrence and prevalence of plague seriously endanger people's health and social development, so it is necessary to do a solid job in the prevention and control of plague to ensure the safety of people's lives.