Detection of Novel Spotted Fever Group Rickettsiae (Rickettsiales: Rickettsiaceae) in Ticks (Acari: Ixodidae) in Southwestern China

Abstract Spotted fever group rickettsiae, mainly maintained and transmitted by ticks, are important etiological agents of (re)emerging zoonotic diseases worldwide. It is great significance to investigate spotted rickettsiae in ticks different areas for the prevention control rickettsioses. In this study, a total 305 were collected from wild domestic animals Chongqing, Guizhou, Yunnan, Guangxi provinces southwestern China during 2017–2019 examined presence PCR with primers targeting partial gltA, ompA, rrs, htrA genes. Results showed that two species, including pathogenic Candidatus Rickettsia jingxinensis (Rickettsiales: Rickettsiaceae) potential novel species sp. sw Rickettsiaceae), identified. The Ca. R. sequences recovered Rhipicephalus microplus (Ixodida: Ixodidae) Haemaphysalis longicornis phylogenetically clustered previous jingxinensis, longicornii XY118 strains. was detected Amblyomma geoemydae Rh. microplus. Interestingly, as far we know, first report A. geoemydae. Phylogenetic analyses indicated closely related aeschlimannii gltA ompA genes grouped cluster composed montanensis raoultii aeschlimannii, massiliae rhipicephali htrA, while formed separate clade rrs. pathogenicity should be further confirmed. These results expand knowledge geographical distribution vector useful assessing public health risk.