Molecular detection of concurrent infections of Anaplasma sp Omatjenne, Theileria mutans, Babesia bigemina and Anaplasma marginale in calves and yearlings in a tick endemic Guinea savannah ecosystem in Cameroon

Abstract

Ticks play a major role in limiting profitable livestock production in sub-Sahara Africa and the region is beleaguered by a paucity of data on diseases implicated in high young stock morbidity and mortality. In a tick endemic high Guinea savannah ecosystem 20 calves were raised in a traditional grazing system and blood collected from them during their first eighteen months of life. PCR, Restriction Fragment Length Polymorphism (RFLP) and sequencing were applied on DNA of tick-borne pathogens in animal blood buffy coat to amplify and characterize the 16S rRNA genes of Anaplasma, Ehrlichia and 18S rRNA gene for Babesia spp. All animals had different combinations of mixed infections of these haemoparasites. Anaplasma sp. Omatjenne (reported for the first time in this region) and T. mutans infected all and four of these animals, respectively. Babesia bigemina, and Anaplasma sp. Omatjenne concurrently occurred in all 20 experimental animals; A marginale in 15 while no Ehrlichia ruminantium was detected. The presence of Anaplasma marginale and Anaplasma sp. Omatjenne in the blood significantly reduced haematocrit (p<0.0001) while Babesia bigemina and Theileria mutans had no such effect (P>0.05). The mean first-time contact periods (in weeks) for B. bigemina, T. mutans, Anaplasma sp. Omatjenne and A. marginale were 15 (3-37), 30(9-43), 21(5-55) and 25(7-55) respectively; and they were not significantly different (P>0.05). The sequences for new pathogens we found in the region: Theileria mutans and Ehrlichia Bom Pastor or (Anaplasma sp. Omatjenne) have been deposited in the GenBank database with accession numbers MN719893.1 and MN719091.1. The absence of disease states during the study demonstrates an endemically stable situation in the region for these infections. With no clinical data on A. sp. Omatjenne and T. mutans infections in this area, further insights into their epizootiology should be of interest.