Abstracts Category : Other

Occurence andgenetic diversity of Anaplasma marginale in cattle from twodiptanks in Zambezia Province Mozambique

by SizanobuhleLotshonaphi Nyoni-Phili

Anaplasmosis is a tick-borne disease that can resultin serious loss of production and even loss of livestock. It iscaused by the most globally prevalent vector-borne pathogen oflivestock, Anaplasma marginale, with endemic regions in all sixpermanently inhabited continents. This study examined theoccurrence and diversity of A. marginale in cattle (n= 100)opportunistically sampled at two diptanks (Botao, n=50, andNamitangurine, n=50) in Zambezia Province, Mozambique. A duplexquantitative real-time PCR was used to detect A. marginale and A.marginale subsp. centrale in cattle samples from the two diptanks.The overall prevalence of A. marginale was 87% (95% CI: 80, 93%).There was no significant difference (p>0.05) between theprevalence of A. marginale in cattle at Namitangurine diptank(88.0%, n=42) and Botao diptank (86.0%, n=43). The overallprevalence of A. marginale subsp. centrale was 6.0% (95% CI: 2.0,11%). Only 2.0% (n=1) of cattle sampled from Botao diptank werepositive for A. marginale subsp. centrale, while 10% (n=5) werepositive for A. marginale subsp. centrale at Namitangurime diptank.There was no significant association (p>0.05) between A.marginale subsp. centrale presence in cattle and diptank. In orderto assess the genetic variability in A. marginale, msp1 ampliconswere sequenced from 27 samples from the two diptanks. Fourteennovel MSP1a repeat sequences were identified. Most samples hadmixed infections with one to eight msp1 genotypes identified inindividual animals. A total of 47 different msp1 genotypes werefound from 76 msp1 sequences generated from the 27 samples. Thisconsiderable genetic diversity contributes to the understanding ofthe regional diversity of A. marginale and will be important forthe development of appropriate and effective vaccines in thefuture. In future research, the gene sequences of eight highlypromising vaccine candidates will be examined from these samples.In addition, the results will be compared to equivalent resultsfrom cattle samples from an area in the Limpopo National Park wherecattle are grazed alongside wildlife, to see if the presence ofwildlife affects the diversity of the A. marginale population incattle.Advisors/Committee Members: Collins, Nicola E. (advisor), Chaisi, Mamohale E. (coadvisor).