Molecular detection of Coxiella species from Rhipicephalus evertsi evertsi infesting sheep in Potchefstroom, South Africa.

Coxiella species are emerging infectious bacteria of different animal hosts in South Africa, but knowledge regarding their occurrence and prevalence is limited. Hence, the aim of this study was to examine both the presence of non-pathogenic Coxiella spp. as well as its pathogenic relative Coxiella burnetti from ticks infesting sheep from small communal Matlwang village of Potchefstroom in South Africa. A total of 192 ticks (39 individual females and 38 pools of 153 males) were collected from sheep hosts. Morphologically identified ticks were confirmed by obtaining their cytochrome C oxidase subunit 1 (CO1) gene sequences and they were genetically screened for the presence of non-pathogenic Coxiella spp. as well as Coxiella burnetti by PCR and sequencing of the bacterial 16S rRNA and IS1111 gene fragments, respectively. Collected ticks were identified as Rhipicephalus evertsi evertsi and the phylogenetic analysis using the CO1 gene supported the respective taxon in comparison to reference sequences from the NCBI GenBank database. The overall prevalence of Coxiella species was 66.23 % (51/77) for Coxiella-like endosymbionts and 10.39 % (8/77) for C. burnetii based on 16S rRNA and IS1111 PCR results, respectively. Although the primary transmission route of Coxiella spp. is through the inhalation of contaminated aerosols, its presence in ticks may suggest a health risk among animals. Moreover, the detection of C. burnetti in this study suggests that ticks may play a significant role in maintaining the bacterium within domestic farming reservoirs and serve as a potential source of environmental contamination, thereby, potentially contributing to occupational pathogen exposure among livestock herders, owners, veterinarians and villagers through an increased risk of aerosol transmission.