Molecular Detection and Genotyping of Coxiella-Like Endosymbionts in Ticks that Infest Horses in South Korea.
Authors: Seo Min-Goo, Lee Seung-Hun, Ouh In-Ohk, Lee Gwang Hyeop, Goo Youn-Kyoung, Kim Seungjoon, Kwon Oh-Deog, Kwak Dongmi
Journal: PloS one
Summary
# Editorial Summary Coxiella-like endosymbionts (CLE) in tick populations represent a potential zoonotic concern for equine professionals and their clients, as these organisms can transition from infected ticks and horses to humans through direct contact. Researchers collected 213 *Haemaphysalis longicornis* ticks from 51 horses across Jeju Island (2009–2013), applying nested PCR and 16S rRNA sequencing to detect both *Coxiella burnetii* and CLE prevalence. More than half the tick population (52.4%) harboured CLE, with phylogenetic analysis confirming high similarity (97.9–100%) to clade B species previously documented in *Haemaphysalis* species, establishing the first confirmed presence of CLE in Korean equine tick populations. The high prevalence of these organisms in horse-infesting ticks underscores the need for enhanced biosecurity protocols when handling parasitised animals, particularly for personnel with compromised immunity, and suggests that regional tick surveillance programmes should extend beyond traditional equine pathogens to encompass zoonotic endosymbionts. Given the documented persistence of CLE in tick populations and their capacity for cross-species transmission, equine professionals should remain alert to emerging evidence regarding the clinical significance of these organisms in their local geographic areas.
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Practical Takeaways
- •Horses on Jeju Island carry ticks with over 50% prevalence of Coxiella-like organisms; implement rigorous tick control and removal protocols to reduce zoonotic transmission risk to handlers
- •Workers handling infested horses should use appropriate personal protective equipment and practice strict hygiene when removing ticks, given the zoonotic potential of Coxiella
- •Monitor for clinical signs of Q fever (caused by Coxiella burnetii) in staff working with horses, particularly those with direct tick exposure
Key Findings
- •Coxiella-like endosymbionts were detected in 52.4% (121/213) of ticks collected from horses on Jeju Island, South Korea
- •All ticks were identified as Haemaphysalis longicornis, the predominant tick species in Korea
- •CLE 16S rRNA sequences were 97.9-100% similar to clade B species previously described in Haemaphysalis spp.
- •This is the first documented report of CLE occurrence in ticks infesting animals in Korea, indicating potential zoonotic transmission risk