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BioMed Research International
Volume 2014 (2014), Article ID 238532, 12 pages
Research Article

Strain Diversity of Mycobacterium tuberculosis Isolates from Pulmonary Tuberculosis Patients in Afar Pastoral Region of Ethiopia

1Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
2Section for International Health, Department of Community Medicine, Institute for Health and Society, University of Oslo, P.O. Box 1130, Blindern, 0318 Oslo, Norway
3WHO Supranational TB Reference Laboratory, TB & Mycobacteria Unit, Institut Pasteur de la Guadeloupe, 97183 Abymes, France

Received 24 November 2013; Accepted 22 January 2014; Published 6 March 2014

Academic Editor: Tomasz Jagielski

Copyright © 2014 Mulugeta Belay 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.


Data on genotypic diversity of Mycobacterium tuberculosis complex (MTBC) is important to understand its epidemiology, human adaptation, clinical phenotypes, and drug resistance. This study aimed to characterize MTBC clinical isolates circulating in a predominantly pastoralist area in Ethiopia, a country where tuberculosis is the second leading cause of mortality. Culture of sputum samples collected from a total of 325 pulmonary TB suspects was done to isolate MTBC. Spoligotyping was used to characterize 105 isolates from culture positive slopes and the result was compared with an international database. Forty-four spoligotype patterns were observed to correspond to 35 shared-types (SITs) containing 96 isolates and 9 orphan patterns; 27 SITs containing 83 isolates matched a preexisting shared-type in the database, whereas 8 SITs ( isolates) were newly created. A total of 19 SITs containing 80 isolates were clustered within this study (overall clustering of 76.19%). Three dominant lineages (T, CAS, and Manu) accounted for 76.19% of the isolates. SIT149/T3-ETH was one of the two most dominant sublineages. Unlike previous reports, we show that Manu lineage strains not only constitute a dominant lineage, but are also associated with HIV infection in Afar region of Ethiopia. The high level of clustering suggests the presence of recent transmission that should be further studied using additional genotyping markers.