1. Department of Microbial, Cellular and Molecular Biology, College of Natural Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
2. Department of Biology, Debre Birhan University, Debre Birhan, Ethiopia
3. Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
4. Department of Epidemiology, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, USA