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

Abstract

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 Borrelia spp. and Rickettsia 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 Rickettsia spp. and Borrelia spp. using molecular methods of which 18.01 % and 10.38 % of tick pools tested positive for Rickettsia or Borrelia DNA, respectively. This is the first Borrelia spp. detection in ticks collected from wild animals in Cameroon. Three species of Rickettsia were found in ticks feeding on domestic animals, namely, Rickettsia africae, Rickettsia aeschlimannii, and Rickettsia massiliae. Borrelia spp. in Cameroon are closely related to Candidatus Borrelia javanensis from China, as well as Candidatus Borrelia africana and Candidatus Borrelia ivorensis from the Ivory Coast. Although the risk this Borrelia species could pose to humans or animals is currently not known, both Rickettsia species are known to cause human disease warranting continuous monitoring and future research to determine the overall public health risk these microorganisms could pose.