Identification of a Novel Yersinia enterocolitica Strain from Bats in Association with a Bat Die-Off That Occurred in Georgia (Caucasus)

Abstract

<jats:p>Yersinia entercolitica is a bacterial species within the genus Yersinia, mostly known as a human enteric pathogen, but also recognized as a zoonotic agent widespread in domestic pigs. Findings of this bacterium in wild animals are very limited. The current report presents results of the identification of cultures of Y. entercolitica from dead bats after a massive bat die-off in a cave in western Georgia. The growth of bacterial colonies morphologically suspected as Yersinia was observed from three intestine tissues of 11 bats belonging to the Miniopterus schreibersii species. These three isolates were identified as Y. enterocolitica based on the API29 assay. No growth of Brucella or Francisella bacteria was observed from tissues of dead bats. Full genomes (a size between 4.6–4.7 Mbp) of the Yersinia strains isolated from bats were analyzed. The phylogenetic sequence analyses of the genomes demonstrated that all strains were nearly identical and formed a distinct cluster with the closest similarity to the environmental isolate O:36/1A. The bat isolates represent low-pathogenicity Biotype 1A strains lacking the genes for the Ail, Yst-a, Ysa, and virulence plasmid pYV, while containing the genes for Inv, YstB, and MyfA. Further characterization of the novel strains cultured from bats can provide a clue for the determination of the pathogenic properties of those strains.</jats:p>

Evidence of Extensive Circulation of Yersinia enterocolitica in Rodents and Shrews in Natural Habitats from Retrospective and Perspective Studies in South Caucasus

“…There was only one strain in the entire EnteroBase, which belonged to the same cluster as the Dedoplistskaro strains, the strain Y18EE025 of an undetermined biogroup and serotype. Interestingly, the SNP-type of the strain 18ENCDC AsAtc Rint-11-12 isolated from R. norvegicus was identical to the Y. enterocolitica strains obtained from dead bats described in Georgia [ 26 ].…”

“…To define genetic relationships among the small mammal Y. enterocolitica isolates from Georgia and worldwide isolates of Y. enterocolitica strains, 125 core genome SNP-typing was performed using the EnteroBase platform. We included the isolates of Y. enterocolitica obtained from bats in Georgia [ 26 ] in this analysis. The results of the SNP-typing are shown in Supplementary Figure S4 .…”

“…This Georgian isolate was phylogenetically close to the strain YE13/03, serotype O:6,30 isolated in the United Kingdom from human feces in 2003. Interestingly, the strain 18ENCDC AsAtc Rint–11-12 isolated from Rattus norvegicus formed a distinct and unique cluster with Y. enterocolitica isolates from dead bats in Georgia [ 26 ]. Despite the distance between the two sites of isolation being only about 100 kilometers ( Figure 1 ), the two places are separated by mountains, likely preventing a direct communication of the rat and bat populations between the areas.…”

“…The role of ongoing outbreaks of Y. pestis in this area for the selection of these unique Y. enterocolitica variants will need further investigation. Overall, the reported observations contribute to a better understanding of the potential public health importance of Yersinia species of small mammals beyond plague [ 10 , 18 , 26 , 32 ].…”

“…The plasmid profile of Y. enterocolitica isolates was determined by the phenol method [ 25 ] as described by us previously [ 26 ]. The vaccine strain of Y. pestis , EV76, containing three plasmids of known molecular weight (101 kb, 70.5 kb, and 9.5 kb), was used as the plasmid size standard.…”