Molecular detection of Anaplasma phagocytophilum and Rickettsia monacensis in trombiculid mite pools collected from wild rodents in Korea: Implications for potential mite-borne transmission.

Mite-borne diseases have been extensively studied; however, limited research has focused on the detection of Rickettsia species other than Orientia tsutsugamushi in Korean mites. Polymerase chain reaction (PCR) assays were performed using mites collected from rodents. Nested PCR (N-PCR) targeting the 56 kDa gene of O. tsutsugamushi showed a 0.29 % positivity rate (11/3855) and a 0.1 % minimum infection rate (MIR). The sca1 gene-targeted N-PCR for Rickettsia showed a 1.27 % positivity rate (49/3855) and a 0.005 % MIR, revealing the presence of Rickettsia monacensis. For Anaplasma phagocytophilum detection, N-PCR targeting ankA gene showed a 4.31 % positivity rate (166/3855) and a 0.16 % MIR, while N-PCR targeting the 16S rRNA gene showed a 0.78 % positivity rate (30/3855) and a 0.03 % MIR. Our findings confirm the presence of A. phagocytophilum, R. monacensis, and O. tsutsugamushi DNA in trombiculid mites collected from wild rodents in Korea. Although these pathogens are recognized as human disease agents, the detection of DNA alone does not provide evidence of vector competence. Consequently, further experimental studies are warranted to clarify the potential role of trombiculid mites in the transmission cycles of A. phagocytophilum and R. monacensis. KEYPOINTS: Anaplasma phagocytophilum and Rickettsia monacensis were detected in trombiculid mites collected from wild rodents captured in Korea, suggesting the need for further research on the role of parasitic mites in the human transmission of A. phagocytophilum and R. monacensis.