Phylogenesis of the Plague Microbe Yersinia pestis: The Uniqueness of the Evolutionary Model

摘要

The causative agent of plague, the microbe Yersinia pestis, is transmitted by flea bites and therefore occupies a unique position in the Enterobacteriaceae family of intestinal bacteria. There are two approaches to elucidating its origin and evolution (phylogenesis)-molecular genetic (MG) and ecological (ECO), which are based on different evolutionary models and lead to radically different conclusions. The MG approach proclaims the saltation principle of the formation of this pathogen from a clone of the pseudotuberculosis microbe Y. pseudotuberculosis 0:1b, the causative agent of Far East scarlet-like fever (FESLF), by insertion, inactivation, deletions, and, less often, recombination of genes and genetic structures, adopting as a basic evolutionary model the model of neutral evolution of nucleotide marker traits. The MG approach does not reveal the details of the speciation process. According to the evolutionary ECO model, the plague pathogen formed in the process of gradual population genetic transformations almost simultaneously in three geographical populations of the Tarbagan marmot (Marmota sibirica) from three different clones (populations) of the FESLF pathogen in Khentei, Khangai, and the Kharkhiraa-Turgen mountain range (Mongolia). The speciation process was triggered by a well-known abiotic factor-the last (Sartan) maximum cooling of the climate in Central Asia 22-15 ky BP, which caused deep freezing of the soil and a change in the behavior of the marmot flea Oropsylla silantiewi, which, in turn, led to aberrant traumatic infection with FESLF in Tarbagan marmot populations. Ecological factors required that Y. pestis create a unique evolutionary model.