PREVALENCE AND GENETIC CHARACTERISATION OF NEMATODES IN RURAL POULTRY IN THE NORTHERN REGION, GHANA

Abstract

Rural poultry production in Ghana is predominantly done under the extensive system. Extensive system of production exposes birds to parasites infection mostly nematode species. The prevalence of nematodes in rural chicken from Kumbugu, Savelugu and Tolon Districts in the Northern Region of Ghana was investigated and the genetics of Ascaridia galli characterised. A total of 86 village chickens were dissected and screened for parasitic nematodes and the DNA of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene (475 bp) of 20 A. galli isolates were sequenced. The nematode species Ascaridia galli and Heterakis spp. were found at the following prevalence; A. galli in Savelugu District was 9/25 (36.0 %), Tolon and Kumbungu Districts recorded 14/25 (56.0 %) and 9/36 (25.0 %), respectively. Heterakis spp. prevalence rate in Savelugu District was 7/25 (28.0 %), Tolon and Kumbugu Districts also recorded 5/25 (20.0 %) and 6/36 (16.67 %), respectively Chi-square test showed a significant association of A. galli prevalence to the Districts of origin of birds (x2 = 6.0907, p < 0.048). From 20 DNA analysed (Savelugu n=7, Tolon n=7 and Kumbungu n=6), two haplotypes were seen, namely, GHA1 and GHA2 with a single nucleotide variable site. Haplotype GHA1 was found to have wide distribution globally compared with GenBank deposits, whereas GHA2 appeared novel in the present study. These DNA sequences presented rather very low haplotype diversity of 0.100, but having negative Tajima’s D and Fu’s Fs indices which indicate population expansion. An AMOVA revealed that A. galli populations in the three Districts not to have differentiated from each other. The data generated by the present study revealed the importance of Ascaridia galli and Heterakis spp. infection in rural chicken in Ghana and pave way for further epidemiological study and population genetics characterisation of avian nematodes.