1. Department of Veterinary Science, University for Development Studies, P.O. Box TL 1882, Tamale, Ghana
2. Department of Animal Science, University for Development Studies, P.O. Box TL 1882, Tamale, Ghana
3. Antimicrobial Research Unit, University of KwaZulu-Natal, Durban 4000, South Africa
4. Discipline of Medical Biochemistry, University of KwaZulu-Natal, Durban, South Africa