Identification of bacterial communities and tick-borne pathogens in the fowl ticks (Argas persicus) from Almaty Oblast, Turkistan Oblast, and Shymkent City of Kazakhstan

Argas persicus (the fowl tick) is native to Central Asia. In this study, a total of 671 soft ticks were collected from chickens in three sampling sites (Bakanas District, Almaty Oblast; Sayram District, Turkistan Oblast; Shymkent City), Kazakhstan. A total of 16 tick pools (10 ticks per pool) were used for 16 S rRNA gene-based microbiome profiling by sequencing the V3-V4 region. Subsequently, seven genetic markers were amplified for molecular detection of Anaplasma, Rickettsia and Coxiella. Alpha and beta diversity analyses revealed that A. persicus ticks in Bakanas District had the highest microbial richness and diversity, while the ticks in Shymkent City and Sayram District exhibited highly similar microbial community compositions. The microbiome was predominated by Proteobacteria, specifically the genera Rickettsia and Coxiella, especially in Sayram District and Shymkent City, and the relative abundance of the top 30 bacterial components differed among sampling sites. Three pathogens including unclassified Anaplasma sp., Rickettsia hoogstraalii and Coxiella burnetii were detected for the first time in A. persicus ticks in Kazakhstan. The unclassified Anaplasma sp. was prevalent in ticks associated with domestic poultry and migratory birds, while Rickettsia hoogstraalii tended to parasitize seabird-related ticks with high prevalence. In addition, Coxiella burnetii infection prevalence was higher in pastoral areas than in urban areas, and birds act as secondary transmission vectors. These findings reveal that tick-borne pathogens harbored by avian soft ticks deserve close attention, especially in Central Asia.