Abstract:
Ticks and tick-borne pathogens constitute a great threat to livestock production and are a potential health hazard
to humans. Grasscutters (Thryonomys swinderianus) are widely hunted for meat in Ghana and many other West
and Central African countries. However, tick-borne zoonotic risks posed by wild grasscutters have not been
assessed. The objective of this study was to investigate bacterial and protozoan pathogens in ticks infecting wild
grasscutters. A total of 81 ticks were collected from three hunted grasscutters purchased from Kantamanto, the
central bushmeat market in Accra. Ticks were identified as Ixodes aulacodi and Rhipicephalus sp. based on
morphological keys, which were further confirmed by sequencing mitochondrial 16S ribosomal DNA (rDNA) and
cytochrome oxidase I (COI) genes of specimens. Protozoan infections were tested by PCR amplifying 18S rDNA
of Babesia/Theileria/Hepatozoon, while bacterial infections were evaluated by PCRs or real-time PCRs targeting
Anaplasmataceae, Borrelia, spotted fever group rickettsiae, chlamydiae and Candidatus Midichloria mitochondrii.
The results of PCR screening showed that 35.5% (27 out of 76) of I. aulacodi were positive for parasite infections.
Sequencing analysis of the amplified products gave one identical sequence showing similarity with Babesia spp.
reported from Africa. The Ca. M. mitochondrii endosymbiont was present in 85.5% (65 out of 76) of I. aulacodi
but not in the five Rhipicephalus ticks. Two Anaplasmataceae bacteria genetically related to Ehrlichia muris and
Anaplasma phagocytophilum were also detected in two I. aulacodi. None of the ticks were positive for Borrelia spp.,
spotted fever group rickettsiae and chlamydiae. Since I. aulacodi on wild grasscutters are potential carriers of
tick-borne pathogens, some of which could be of zoonotic potential, rigorous tick control and pathogen analyses
should be instituted especially when wild caught grasscutters are being used as foundation stock for breeding.