# Genetic Diversity and Novel Lineages of Anaplasma, Ehrlichia, and Coxiella-like Endosymbionts in Ticks from a Forest Ecosystem in Northeastern China

## TL;DR

This study identifies new bacterial lineages in ticks from a Chinese forest, highlighting the region's rich genetic diversity of tick-borne pathogens.

## Contribution

The discovery of novel Anaplasma and Ehrlichia lineages expands the known genetic diversity of tick-associated bacteria in northeastern China.

## Key findings

- Anaplasma bovis was detected in Hae. concinna with two distinct genotypes.
- A potentially novel Anaplasma lineage was identified in I. persulcatus.
- Two genetically distinct Ehrlichia lineages were found in Hae. japonica and Hae. concinna.

## Abstract

Ticks are important vectors of bacterial pathogens with veterinary and public health significance. However, information on the diversity of tick-associated bacteria in forest ecosystems of northeastern China remains limited. In this study, 821 questing ticks were collected from Huoshankou National Forest Park in Mudanjiang City, Heilongjiang Province, and identified as Haemaphysalis japonica, Hae. concinna, and Ixodes persulcatus. Molecular screening based on rrs gene amplification detected Anaplasma, Ehrlichia, and Coxiella-like endosymbionts (CLE), which were further characterized using multilocus phylogenetic analyses. Anaplasma bovis was detected in Hae. concinna and exhibited two distinct genotypes. In addition, a potentially novel Anaplasma lineage was identified in I. persulcatus. Phylogenetic analyses based on the rrs, gltA, and groEL genes consistently placed this lineage in a separate clade from currently recognized Anaplasma species. Furthermore, two genetically distinct Ehrlichia lineages were detected in Hae. japonica and Hae. concinna. Two lineages of tick-associated CLE were also characterized using five genetic genes. Overall, these findings demonstrate considerable genetic diversity of tick-associated bacteria in forest ecosystems of northeastern China and expand current understanding of their molecular diversity. Further studies incorporating broader sampling and genome-based analyses will be necessary to clarify their taxonomic status and epidemiological relevance.