Insights into the Phylogeny and Evolution of Cold Shock Proteins: From Enteropathogenic Yersinia and Escherichia coli to Eubacteria

Psychrotrophic foodborne pathogens, such as enteropathogenic Yersinia, which are able to survive and multiply at low temperatures, require cold shock proteins (Csps). The Csp superfamily consists of a diverse group of homologous proteins, which have been found throughout the eubacteria. They are related to cold shock tolerance and other cellular processes. Csps are mainly named following the convention of those in Escherichia coli. However, the nomenclature of certain Csps reflects neither their sequences nor functions, which can be confusing. Here, we performed phylogenetic analyses on Csp sequences in psychrotrophic enteropathogenic Yersinia and E. coli. We found that representative Csps in enteropathogenic Yersinia and E. coli can be clustered into six phylogenetic groups. When we extended the analysis to cover Enterobacteriales, the same major groups formed. Moreover, we investigated the evolutionary and structural relationships and the origin time of Csp superfamily members in eubacteria using nucleotide-level comparisons. Csps in eubacteria were classified into five clades and 12 subclades. The most recent common ancestor of Csp genes was estimated to have existed 3585 million years ago, indicating that Csps have been important since the beginning of evolution and have enabled bacterial growth in unfavorable conditions.

ANALYSIS OF THE EPIDEMIOLOGICAL SITUATION ON PSEUDOTUBERCULOSIS AND INTESTINAL YERSINIOSIS IN RUSSIA AND FORECAST OF THE INCIDENCE RATE IN THE MEDIUM-TERM PERSPECTIVE

The article presents an analysis of epidemiological situation on pseudotuberculosis and intestinal yersiniosis in the Russian Federation in 2004-2016, as well as the forecast of incidence rate for the medium term. Retrospective analysis of microbiological researches for enteropathogenic Yersinia performed by the Centers of Hygiene and Epidemiology of Rospotrebnadzor of Siberian and Far Eastern Regions is presented. The territories in Siberian Federal, North Western and Far Eastern Federal Districts with stably high level of morbidity were revealed. Insufficient usage of genetic diagnostic, the most effective and operative method (PCR) in practical laboratories of Rospotrebnadzor was determined. Various serotype and biotype spectra of Y. enterocolitica strains from different sources and the dominating Y. pseudotuberculosis genotype О:1b were detected.

INFLUENCE OF BACTERIAL DIVERSITY AND INTERSPECIES INTERACTIONS ON DRINKING WATER-ASSOCIATED BIOFILMS OF YЕRSINIA ЕNTEROCOLITICA

The capability of the enteropathogenic Yersinia enterocolitica 8081 bio/serotype 1B/O:8 to form binary and multi-species biofilms with defined bacterial strains was studied. The interspecies interactions in the binary biofilms of the enteropathogen with three bacterial isolates from drinking water and water-associated biofilms were assessed. The effect of each individual partner strain for the Y. enterocolitica involvement in the four-species bacterial biofilm was evaluated by excluding one by one the isolates from the sessile community. It was found out that Y. enterocolitica and the tested bacterial strains interact each other in the binary biofilm formation. Moreover, the Y. enterocolitica involvement in the biofilms depends on the partner strain. In the multi-species biofilms, a synergetic effect of one of the bacterial partner strains on the Y. enterocolitica attachment was detected in contrast to the weak inhibitory effect of another one.