Ren Fei, Liu Yiping, Niu Jingrong, Song Yang, Cheng Hongbing, Zhao Chao, Cui Jia, Chen Yunxia, Bai Yuzan, Rao Huaxiang, Yu Juan
Department of Laboratory Animal Center, Changzhi Medical College, Changzhi, 046000, China.
Department of Basic Medical Sciences, Changzhi Medical College, Changzhi, 046000, China.
Parasit Vectors. 2025 Jun 22;18(1):236. doi: 10.1186/s13071-025-06898-6.
Babesiosis, a globally emerging tick-borne zoonosis caused by intraerythrocytic protozoan Babesia species, poses a significant threat to both animal and human health. This study investigated the prevalence and genetic diversity of Babesia sp. in small rodents in central and southern Shanxi Province, China.
Rodents were captured from central and southern Shanxi Province, China. Liver, spleen, and kidney specimens were collected and screened for Babesia sp. based on 18S rRNA gene amplification and sequencing. For genetic and evolutionary analysis of Babesia sp. sequences based on the 18S rRNA gene, a phylogenetic tree was created using MEGA 11. Genetic diversity was analyzed using DNASP 6.12.03, and haplotype networks in Babesia microti from different regions and hosts were constructed using PopART software.
Three hundred and one rodents were captured; PCR screening revealed a 6.64% (20/301) prevalence of Babesia sp. infection, detected in Niviventer confucianus (16.87%, 14/83) and Apodemus agrarius (3.85%, 6/156). Detection rates did not differ significantly according to sex, tissue, or habitat type. Geographically, central Shanxi exhibited significantly higher detection rates than southern Shanxi (9.74% vs. 0.94%, χ = 8.573, P = 0.003). Phylogenetic analysis of the partial 18S rRNA gene (1083 bp) confirmed that all sequences obtained in this study were the B. microti Kobe type, closely related to sequences from southeastern Shanxi obtained in our previous study (with 99.7-100% identity), with the ability to infect humans. Genetic diversity analysis of 65 B. microti sequences from China (20 sequences from the present study and 45 from GenBank) identified 21 haplotypes with host- and geography-specific patterns. Host-specific analysis of 18S rRNA gene polymorphisms revealed higher genetic diversity in tick-derived sequences than in rodent- or human-derived sequences. Haplotype network analysis suggested that Shanxi sequences (Hap-1, Hap-10, and Hap-11) exhibited close genetic proximity of 1-3 nucleotide substitutions with rodent-derived sequences from Yunnan and Fujian provinces and human-derived sequences from Yunnan and Zhejiang provinces.
This study found a high prevalence and low genetic diversity of B. microti infection in wild rodents in central Shanxi, which could provide a basis for local corresponding prevention and control strategies.
巴贝斯虫病是一种全球范围内新出现的蜱传播人畜共患病，由红细胞内原生动物巴贝斯虫属物种引起，对动物和人类健康构成重大威胁。本研究调查了中国山西省中部和南部小型啮齿动物中巴贝斯虫属的流行情况和遗传多样性。
在中国山西省中部和南部捕获啮齿动物。采集肝脏、脾脏和肾脏标本，基于18S rRNA基因扩增和测序筛选巴贝斯虫属。为了基于18S rRNA基因对巴贝斯虫属序列进行遗传和进化分析，使用MEGA 11创建了系统发育树。使用DNASP 6.12.03分析遗传多样性，并使用PopART软件构建来自不同地区和宿主的微小巴贝斯虫的单倍型网络。
共捕获301只啮齿动物；PCR筛选显示巴贝斯虫属感染率为6.64%（20/301），在社鼠（16.87%，14/83）和黑线姬鼠（3.85%，6/156）中检测到。根据性别、组织或栖息地类型，检测率无显著差异。在地理上，山西中部的检测率显著高于山西南部（9.74%对0.94%，χ = 8.573，P = 0.003）。对部分18S rRNA基因（1083 bp）的系统发育分析证实，本研究获得的所有序列均为微小巴贝斯虫神户型，与我们之前研究中从山西东南部获得的序列密切相关（同一性为99.7 - 100%），具有感染人类的能力。对来自中国的65条微小巴贝斯虫序列（本研究的20条序列和来自GenBank的45条序列）的遗传多样性分析确定了21种具有宿主和地理特异性模式的单倍型。对18S rRNA基因多态性的宿主特异性分析表明，蜱源序列的遗传多样性高于啮齿动物或人类源序列。单倍型网络分析表明，山西的序列（Hap - 1、Hap - 10和Hap - 11）与来自云南和福建的啮齿动物源序列以及来自云南和浙江的人类源序列在1 - 3个核苷酸替换上表现出密切的遗传接近性。
本研究发现山西中部野生啮齿动物中微小巴贝斯虫感染率高且遗传多样性低，可为当地相应的预防和控制策略提供依据。
