Diversity of Rickettsiales in Rhipicephalus microplus Ticks Collected in Domestic Ruminants in Guizhou Province, China

Abstract

Rhipicephalus microplus ticks are vectors for multiple pathogens infecting animals and humans. Although the medical importance of R. microplus has been well-recognized and studied in most areas of China, the occurrence of tick-borne Rickettsiales has seldom been investigated in Guizhou Province, Southwest China. In this study, we collected 276 R. microplus ticks from cattle (209 ticks) and goats (67 ticks) in three locations of Guizhou Province. The Rickettsia, Anaplasma, and Ehrlichia were detected by targeting the 16S rRNA gene and were further characterized by amplifying the key genes. One Rickettsia (Ca. Rickettsia jingxinensis), three Ehrlichia (E. canis, E. minasensis, Ehrlichia sp.), and four Anaplasma (A. capra, A. ovis, A. marginale, Ca. Anaplasma boleense) species were detected, and their gltA and groEL genes were recovered. Candidatus Rickettsia jingxinensis, a spotted fever group of Rickettsia, was detected in a high proportion of the tested ticks (88.89%, 100%, and 100% in ticks from the three locations, respectively), suggesting the possibility that animals may be exposed to this type of Rickettsia. All the 16S, gltA, groEL, and ompA sequences of these strains are 100% identical to strains reported in Ngawa, Sichuan Province. E. minasensis, A. marginale, and Candidatus Anaplasma boleense are known to infect livestock such as cattle. The potential effects on local husbandry should be considered. Notably, E. canis, A. ovis, and A. capra have been reported to infect humans. The relatively high positive rates in Qianxinan (20.99%, 9.88%, and 4.94%, respectively) may indicate the potential risk to local populations. Furthermore, the genetic analysis indicated that the E. minasensis strains in this study may represent a variant or recombinant. Our results indicated the extensive diversity of Rickettsiales in R. microplus ticks from Guizhou Province. The possible occurrence of rickettsiosis, ehrlichiosis, and anaplasmosis in humans and domestic animals in this area should be further considered and investigated.

Molecular Detection of Tick-Borne Bacterial and Protozoan Pathogens in Haemaphysalis longicornis (Acari: Ixodidae) Ticks from Free-Ranging Domestic Sheep in Hebei Province, China

“…The following supporting information can be downloaded at: , Table S1. Primers for the amplification of sequences of ticks and tick-borne pathogens [ 13 , 33 , 53 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ]; Supplementary Data. The electrophoretic detection of amplification of tick-borne pathogens PCR products on agarose gel.…”

Detection of bacteria carried by ticks from the mountain areas of Guizhou, Southwestern China

“…In this study, 554 ticks were collected, and only two tick species, R. microplus and H. longicornis, were identi ed. A recent study conducted by Miao Lu found only R. microplus in 3 other cities or autonomous regions (Qianxinan, Liupanshui, and Bijie) in Guizhou [14]. In China, H. longicornis was found to carry the most tick-borne pathogen species, followed by Ixodes persulcatus, Dermacentor nutalli, and R. microplus [13].…”

“…Examples include A. capra, A. ovis, A. marginale, Ca. A. boleense and A. phagocytophilum [14,[40][41]. The threat of human disease cannot be ignored, despite the low abundance of these pathogens in the samples.…”

Pathogenic Rickettsia, Anaplasma, and Ehrlichia in Rhipicephalus microplus ticks collected from cattle and laboratory hatched tick larvae

“…minasensis in Haemaphysalis hystricis ticks from Hainan Island [ 71 ] and the other recently found this pathogen in R . microplus from Guizhou Province [ 72 ]. Our study first reported the E .…”

“…Besides the American continent, it has also been detected in France [65], Ethiopia [67], South Africa [68], Pakistan [69] and Israel [70]. In China, there were only two reports of E. minasensis, one detected E. minasensis in Haemaphysalis hystricis ticks from Hainan Island [71] and the other recently found this pathogen in R. microplus from Guizhou Province [72]. Our study first reported the E. minasensis infection in R. microplus in Hunan Province, China.…”