Molecular identification of Borrelia and Rickettsia in hard ticks infesting domestic and wild animals in Cameroon

Ticks are blood-sucking arthropods which can vector various, pathogenic microorganisms between humans and domestic or wild animal hosts. In Cameroon, little is still known about the diversity of ticks and tick-borne pathogens found feeding on these various hosts. This study investigates the frequency of positive pools of <i>Borrelia</i> spp. and <i>Rickettsia</i> spp. in 415 DNA pools arising from 1148 collected ticks belonging to five genera and twenty-five tick species collected from both domestic and wild animals in Cameroon. Tick species were identified morphologically and confirmed molecularly when necessary. All tick pools were tested for <i>Rickettsia</i> spp. and <i>Borrelia</i> spp. using molecular methods of which 18.01 % and 10.38 % of tick pools tested positive for <i>Rickettsia</i> or <i>Borrelia</i> DNA, respectively. This is the first <i>Borrelia</i> spp. detection in ticks collected from wild animals in Cameroon. Three species of <i>Rickettsia</i> were found in ticks feeding on domestic animals, namely, <i>Rickettsia africae, Rickettsia aeschlimannii</i>, and <i>Rickettsia massiliae. Borrelia</i> spp. in Cameroon are closely related to <i>Candidatus</i> Borrelia javanensis from China, as well as <i>Candidatus</i> Borrelia africana and <i>Candidatus</i> Borrelia ivorensis from the Ivory Coast. Although the risk this <i>Borrelia</i> species could pose to humans or animals is currently not known, both <i>Rickettsia</i> species are known to cause human disease warranting continuous monitoring and future research to determine the overall public health risk these microorganisms could pose.