Diversity of Rickettsiales bacteria in five species of ticks collected from Jinzhai County, Anhui Province, China in 2021-2022

Front Microbiol. 2023 Apr 28:14:1141217. doi: 10.3389/fmicb.2023.1141217. eCollection 2023.

Abstract

The order Rickettsiales in the class Alphaproteobacteria comprises vector-borne pathogens of both medical and veterinary importance. Ticks, as a group, are second only to mosquitoes as vectors of pathogens to humans, playing a critical role in the transmission of rickettsiosis. In the present study, 880 ticks collected from Jinzhai County, Lu'an City, Anhui Province, China in 2021-2022 were identified as belonging to five species from three genera. DNA extracted from individual ticks was examined using nested polymerase chain reaction targeting the 16S rRNA gene (rrs), and the gene fragments amplified were sequenced to detect and identify Rickettsiales bacteria in the ticks. For further identification, the rrs-positive tick samples were further amplified by PCR targeting the gltA and groEL gene and sequenced. As a result, 13 Rickettsiales species belonging to the genera Rickettsia, Anaplasma, and Ehrlichia were detected, including three tentative species of Ehrlichia. Our results reveal the extensive diversity of Rickettsiales bacteria in ticks from Jinzhai County, Anhui Province. There, emerging rickettsial species may be pathogenic and cause under-recognized diseases. Detection of several pathogens in ticks that are closely related to human diseases may indicate a potential risk of infection in humans. Therefore, additional studies to assess the potential public health risks of the Rickettsiales pathogens identified in the present study are warranted.

Keywords: Anaplasma; Ehrlichia; Jinzhai County; Rickettsia; Rickettsiales; ticks.

Grants and funding

This work was supported by grants from the National Natural Science Foundation of China (grant number 81671985), the Science Foundation for the State Key Laboratory for Infectious Disease Prevention and Control of China (grant numbers 2022SKLID209 and 2019SKLID403), and the Public Health Service Capability Improvement Project of the National Health Commission of the People's Republic of China (grant number 2100409034).