四川省木里县牦牛体表寄生蜱携带无形体和斑点热群立克次体的分子流行病学调查OA

To investigate the tick species parasitizing yaks in Muli County,Sichuan Province,China,and to assess the prevalence of Anaplasma spp.and spotted fever group Rickettsia(SFGR)harbored by these ticks,a total of 650 ticks were collected from the body surface of yaks.Ticks were preliminarily identified based on morphological characteristics,and polymerase chain reaction(PCR),sequence analysis,and phylogenetic analysis were performed to detect ticks(16S rRNA),and its carried Anaplasma(16S rRNA)and SFGR(ompB).The results showed that two tick species were identified:Rhipicephalus microplus and Ixodes ovatus,accounting for 74.5%(484/650)and 25.5%(166/650)of the total samples,respectively.The overall infection rate of Anaplasma was 27.1%(176/650),and two Anaplasma species were detected,namely A.ovis and A.marginale.The overall infection rate of SFGR was 26.0%(169/650),with four SFGR species identified:R.felis,R.massiliae,R.aeschlimannii,and Candidatus R.longicornii.Mixed infections with Anaplasma and SFGR were detected in both R.microplus and I.ovatus,with an overall co-infection rate of 6.0%(39/650).These findings indicate that R.microplus is likely the dominant tick species in this region,and that ticks parasitizing yaks in Muli County exhibit relatively high infection rates of Anaplasma and SFGR.Enhanced surveillance and control measures targeting tick-borne pathogens are therefore warranted in this area.