Molecular detection of in engorged ablyomma variegatum and cattle in Ogun State, Nigeria.

Early diagnosis of in cattle is a recipe for effective control of heartwater in ruminants. Hence, we assessed the presence of in the blood of cattle and the engorged by nested PCR. The electrophoresed PCR products obtained after primary and secondary amplifications revealed amplicon sizes of about350 bp and 280 bp respectively, which corresponded with the partial region of pSC20 gene amplified. Sequences obtained had 95-99% homology with those sequences available in GenBank. The prevalence of the in ticks (50%; 126/252) was significantly ( < 0.05) higher than that in cattle blood 23.55% (61/259). The prevalence was significantly ( < 0.05) higher in ticks from adult cattle 51.47% (133/259) than those from the young cattle 44.86% (116/259) and in tick from females 54.55% (141/259) than in ticks from the males 41.38% (107/259). Alignment of autochthonous sequences revealed that the three sequences were polymorphic with two sequences showing similar nucleotides deletion at points 87-91 and 107-108. The phylogenetic trees inferred by ML showed topologies with two autochthonous sequences, one each from cattle blood and tick, clustering together in one clade and the other clustering within those sequences from South Africa and Zimbabwe in another clade. In conclusion, this study revealed a higher prevalence of in engorged than in the blood of infected cattle. Hence, it is suggested that the amplification that targets the pCS20 gene in engorged ticks may be more suitable to determine the carrier status of cattle.