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Tuberculosis Research and Treatment
Volume 2012 (2012), Article ID 892079, 7 pages
Clinical Study

Diversity of Mycobacterium tuberculosis Isolates from New Pulmonary Tuberculosis Cases in Addis Ababa, Ethiopia

1Immunology Unit, Armauer Hansen Research Institute, P.O. Box 1005, Addis Ababa, Ethiopia
2Department of Microbiology, Immunology and Parasitology, School of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
3Division of Molecular Biology and Human Genetics, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, MRC Centre for Molecular and Cellular Biology, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 19063, Francie van Zijl Drive, Tygerberg 7505, South Africa

Received 15 July 2012; Accepted 18 October 2012

Academic Editor: Edward A. Graviss

Copyright © 2012 Adane Mihret et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Understanding the genetic diversity of Mycobacterium tuberculosis is needed for a better understanding of the epidemiology of TB and could have implications for the development of new diagnostics, drugs, and vaccines. M. tuberculosis isolates were characterized using spoligotyping and were compared with the SpoIDB4 database of the Pasteur Institute of Guadeloupe. A total of 53 different patterns were identified among 192 isolates examined. 169 of the isolates were classified into one of the 33 shared SITs, whereas the remaining 23 corresponded to 20 orphan patterns. 54% of the isolates were ascribed to the T family, a family which has not been well defined to date. Other prominent families were CAS, Haarlem, LAM, Beijing, and Unknown comprising 26%, 13%, 2.6%, 0.5%, and 2.1%, respectively. Among HIV-positive patients, 10 patterns were observed among 25 isolates. The T (38.5%), H (26.9%), and CAS (23.1%) families were the most common among HIV-positive individuals. The diversity of the M. tuberculosis strains found in this study is very high, and there was no difference in the distribution of families in HIV-positive and HIV-negative TB patients except the H family. Tuberculosis transmission in Addis Ababa is due to only the modern M. tuberculosis families (CAS, LAM, T, Beijing, Haarlem, and U).