Carlson College of Veterinary Medicine

Bovine anaplasmosis is a tick-borne disease, mainly caused by Anaplasma marginale and A. centrale and is distributed in tropical and sub-tropical areas. This study aimed to characterise A. marginale and A. centrale from African buffaloes in Kruger National Park (KNP), South Africa, using the DNA sequences of the genes coding for major surface protein (msp1β) and heat shock protein (groEL), respectively. A total of 747 blood samples were collected from February 2014 to August 2016 from African buffaloes kept in KNP, and DNAs were tested using a molecular-phylogenetic approach. Out of 747 samples tested, 129 (17.3%) and 98 (13.1%) were positive for single infection with A. marginale and A. centrale, respectively; whereas 113 (15.1%) were positive for both Anaplasma spp. Pairwise difference of 1.6-8.5% was observed in msp1β sequences of A. marginale whereas that was only 0.3-2.4% for groEL sequences of A. centrale. Separate phylogenetic analyses of msp1β and groEL sequences of A. marginale and A. centrale, respectively, revealed that sequences of Anaplasma spp. from African buffaloes were unique and they grouped separately when compared with previously published sequences of both species. This is the first study to characterise A. marginale and A. centrale from African buffalo using species specific molecular markers. This study will pave the way for future studies to assess genetic variation among Anaplasma spp. from wild ruminants using molecular markers that are better at differentiating between species and strains than the more commonly used 16S rRNA gene, and help to undertake health and fitness studies and host-parasite dynamics using quantitative molecular tools.