Prevalence and Molecular Characterization of Babesia ovis Infecting Sheep in Nigeria

Abstract

Babesiosis is a significant tick-borne disease that causes varying degrees of losses to animals and humans, as well as a severe economic impact. In Nigeria, there have been several reports on the prevalence of Babesia infection in sheep; however, to date, there is no documented report on the molecular characterization of Babesia ovis in sheep. Here, we determined the prevalence of Babesia infection in sheep using microscopy and PCR and further characterized Babesia ovis in sheep in Nigeria. In this study, 198 blood samples were collected from Abuja and Abeokuta, Nigeria. Microscopic and polymerase chain reactions were used to detect the presence of B. ovis in sheep. Genomic DNA was extracted from blood samples, and generic RLB forward and reverse primers were used to amplify the 18S rRNA segment of B. ovis. Sequence analysis of the generic molecular marker was used to determine the genetic characteristics of B. ovis in sheep in Nigeria. The prevalence of B. ovis infection using microscopy and PCR was 61.1% and 36.9%, respectively. There was a higher prevalence of Babesia infection in Abeokuta (38.4%) than in Abuja. Study animals of one and half years to three years had the highest percentage (45.8%) of Babesia infection, and higher infection of B. ovis was recorded in male animals (37.5%), balami breeds (40.0%), white coat colors (44.4%), emaciated animals (75.0%), and polycythaemic animals (57.1%). Sequencing analysis indicated that B. ovis 18S rRNA from southwestern Abeokuta and north-central Abuja, Nigeria, showed 90–95% identity of documented isolates from other countries. BioEdit and MEGAX software was used to clean sequences and construct a phylogenetic tree to show evolutionary relationships. In conclusion, the findings from this study offer significant information on the molecular characteristics of B. ovis infection for the first time in Nigeria, as well as its present prevalence status. Furthermore, sheep have been identified as a potential reservoir for this tick-borne pathogen; thus, the information from this study can serve as a basis to formulate effective control strategies for tick-borne pathogens circulating amongst the ruminant population in Nigeria and Africa by extension.