Development of an Integrated System for Molecular-Genetic Identification of Yersinia pestis Strains

Abstract

The paper describes a developed comprehensive system for molecular-genetic identification of Yersinia pestis strains according to their appurtenance to certain subspecies, biovars, phylo-geographic populations, using realtime PCR (RT-PCR), allele-specific RT-PCR, and multiplex PCR with hybridization fluorescent registration of results on a solid substrate. Application of this system makes it possible to establish the appurtenance of Y. pestis strains to the following phylogenetic branches: 0.ANT1, 0.ANT2, 0.ANT3, 0.ANT5, 3.ANT, 4.ANT of antique biovar of the main subspecies; 2.MED0, 2.MED1, 2.MED2, 2.MED3, 2.MED4 of medieval biovar of the main subspecies; 1.IN1, 1.IN2, 1.IN3 of intermedium biovar of the main subspecies; 1.ORI1, 1.ORI2, 1.ORI3 of oriental biovar of the main subspecies; 0.PE3 (angolica subspecies), 0.PE7 (tibetica subspecies) and 0.PE10 (qinghaica subspecies). The first stage of the studies within the frames of the developed system is indication of plague agent using registered diagnostic drugs. The second stage is the determination of belonging to individual subspecies through RT-PCR or by the method of multiplex PCR system with hybridization-fluorescent registration of results on a solid substrate, which also allows for establishing to which biovars of the main subspecies and the main phylogenetic lines of the ancient biovar the strains belong. The third stage is the identification of strain appurtenance to phylogenetic branches by the AS-RT-PCR method. The designed complex system for molecular-genetic identification of Y. pestis strains can be applied at the regional and federal levels of the laboratory network of the Russian Federation for diagnostics of infectious diseases. Its use will considerably facilitate and increase the efficiency of intraspecific differentiation of Y. pestis strains within the framework of the epidemiological investigation of outbreaks or importation of strains of plague pathogen into the territory of the Russian Federation or during the certification of strains in collection activities.