Infection by a previously uncharacterized Ehrlichia species in rodents from Inner Mongolia, Northern China

Abstract

Ehrlichia are intracellular bacteria of medical importance to both humans and domestic animals. They are mainly vectored by ticks and harbored by domestic and wild animals such as rodents. In this study, we investigated the prevalence and genetic diversity of Ehrlichia in rodents from Inner Mongolia Autonomous Region, Northern China. In 2021, a total of 359 rodents representing 10 species were captured in two locations of Inner Mongolia: Siziwang Banner and Ar Horqin Banner. Subsequently, an Ehrlichia was detected and characterized in three Spermophilus dauricus and one Meriones unguiculatus. Its rrs, gltA, and groEL sequences have the highest identities of 100%, 87.9%, and 99.7% to known Ehrlichia species, respectively, and they form distinct clades in the phylogenetic trees. Ehrlichia strains mostly related to this species have been detected in ticks from Russia, suggesting that it may be exposed to humans and animals through tick bites. The pathogenicity of this Ehrlichia should be further studied.

Keywords: Inner Mongolia; Meriones unguiculatus; Rodents; Spermophilus dauricus.