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.
