Abstract
African animal trypanosomosis is a complex infectious disease responsible for production
losses in livestock herds. The severity of the disease has been associated with different
species and strains of trypanosomes which have not been characterized molecularly in
Nigeria. Many of the previous studies conducted in Nigeria were based on microscopy and
serology. This study accessed the prevalence of trypanosomes in the forest (Ogun State)
and Savannah (Kaduna State) zones, being major ecological belts of tsetse flies infestation
in Nigeria and also carried out molecular characterization and phylogenetic analysis of
identified trypanosomes.
Blood samples were collected from the jugular veins of 411 cattle (129 males and 282
females), studied between May and October 2010 using systematic random sampling
method. These included Muturu (112), N’dama (31), Sokoto Gudali (68) and White Fulani
(200) breeds of ages 6 months to 3 years. Trypanosomes were detected by microscopy and
species-specific Polymerase Chain Reaction (PCR) techniques. Sequencing of the ITS-1
region of ribosomal DNA gene were carried out for phylogenetic analysis using Molecular
Evolutionary and Genetic Analysis software. Data were analyzed using descriptive
statistics and Chi-square test at P = 0.05.
The overall prevalence of trypanosomes in cattle were 15.1% and 63.7% for microscopy
and PCR, respectively. By microscopy, T. brucei (3.6%), T. congolense (5.2%) and T.
vivax (6.3%) were detected, while PCR detected T. congolense savannah (48.7%), T.
congolense forest (0.5%), T. vivax (26.0%), T. brucei (4.4%) and T. evansi (0.5%).
Prevalence by microscopy and PCR was significantly higher in Ogun State (18.1% and
75.1%) than in Kaduna State (8.9% and 35.6%). Trypanosoma congolense savannah and
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forest types were detected in Ogun State but only T. congolense savannah was detected in
Kaduna State. The strains of T. brucei in Kaduna were different from those in Ogun State
due to common nucleotide deletion points at loci 186, 279, 280, 281 and 325 of the
sequences from Ogun State and nucleotide alterations from G ⇢ T, C ⇢ T and G ⇢ A at
loci 124, 197 and 201, respectively. Sequence polymorphism of the ITS-1 region was
highest in T. brucei brucei compared to T. congolense and T. vivax. Phylogenetic analysis
revealed that T. vivax from cattle in Kaduna and Ogun States clustered together and had
100% and 96% homology to those detected in cattle in Venezuela and Zambia,
respectively. However, T. brucei from Kaduna and Ogun States clustered into two separate
clades and both had 98% and 95% homology respectively, to those detected in cattle in
Zambia.
This is the first report of the molecular characterization of T. congolense savannah and
forest types in Nigeria. The genetic relatedness of trypanosomes from Nigeria to that of
Venezuela and Zambia implies that the treatment regime known to be successful in the two
countries can be adopted in Nigeria. It is recommended that regular surveillance and
screening for new strains of trypanosomes be conducted on Nigerian cattle for effective
prevention and control of the disease.
TAKEET, M (2021). Prevalence And Molecular Characterisation Of Trypanosomes Of Cattle In Ogun And Kaduna States, Nigeria. Afribary. Retrieved from https://tracking.afribary.com/works/prevalence-and-molecular-characterisation-of-trypanosomes-of-cattle-in-ogun-and-kaduna-states-nigeria
TAKEET, MICHAEL "Prevalence And Molecular Characterisation Of Trypanosomes Of Cattle In Ogun And Kaduna States, Nigeria" Afribary. Afribary, 22 Apr. 2021, https://tracking.afribary.com/works/prevalence-and-molecular-characterisation-of-trypanosomes-of-cattle-in-ogun-and-kaduna-states-nigeria. Accessed 23 Nov. 2024.
TAKEET, MICHAEL . "Prevalence And Molecular Characterisation Of Trypanosomes Of Cattle In Ogun And Kaduna States, Nigeria". Afribary, Afribary, 22 Apr. 2021. Web. 23 Nov. 2024. < https://tracking.afribary.com/works/prevalence-and-molecular-characterisation-of-trypanosomes-of-cattle-in-ogun-and-kaduna-states-nigeria >.
TAKEET, MICHAEL . "Prevalence And Molecular Characterisation Of Trypanosomes Of Cattle In Ogun And Kaduna States, Nigeria" Afribary (2021). Accessed November 23, 2024. https://tracking.afribary.com/works/prevalence-and-molecular-characterisation-of-trypanosomes-of-cattle-in-ogun-and-kaduna-states-nigeria