Trypanosome Infection and Genetic Variation in Major Histocompatibility Complex DRB3 Gene in Cattle in Ghana

Abstract

The accurate diagnosis of trypanosome infection and control of trypanosomosis remain challenging problems to cattle production in Ghana and other countries in sub-Saharan Africa. In this study, two PCR methods, based on ITS primers and Trypanosoma vivax-specific primers, were evaluated for the diagnosis of trypanosome infection in 110 each of four breeds of cattle in Ghana, namely, N'Dama, Zebu, WASH and Sanga. Whereas ITS primers did not detect any infection in all 440 animals, T. vivax-specific primers detected 4 positives in WASH and 7 positives in N'Dama. Haematological studies showed that mean PCV values for T. vivax-infected WASH and N'Dama were lower in infected compared to uninfected animals with the difference being highly significant (p < 0.01) in N'Dama. Using HRM analysis followed by sequencing, MHC DRB3 gene in 51 N'Dama and 52 WASH were genotyped. Seventeen alleles were found in each breed, indicating that this gene was highly polymorphic in the two breeds. Alleles 2101 and 2002 were significantly associated (OR = 40.45, RR = 28.13, p = 0.02 and OR = 41.57, RR = 29.40, p = 0.03) with susceptibility to T. vivax infection in N'Dama and WASH, respectively. The study, using West African cattle breeds, demonstrated that ITS primers are less sensitive than T. vivax-specific primers in the diagnosis of trypanosome infection. This study is the first to use HRM analysis in genotyping MHC in cattle, from available literature. Also from available literature, this is the first study to determine MHC allelic variants associated with susceptibility to T. vivax infection in cattle.