1. Faculty of Dentistry, Obafemi Awolowo University, Ile-Ife, Nigeria
2. Division of Oral Microbiology, Clinical Microbiology and Infectious Diseases, School of Pathology, National Health Laboratory Services and Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa
3. School of Oral Health Sciences, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa