Mycobacterium tuberculosis spoligotypes circulating in the Lebanese population: a retrospective study.

: Genotyping Mycobacterium tuberculosis in Lebanon on the national level may be beneficial for assessing patients and monitoring the therapeutic response to DOTS. This study aimed to characterize the spoligotypes of clinical isolates of M. tuberculosis patients collected between April 2004 and October 2005 from all Lebanese provinces. Isolates (n = 60) were cultured and identified by their biochemical characteristics. DNA extracts of these samples were amplified by PCR and genotyped by spoligotyping. Thirteen (13) patterns of M. tuberculosis complex family strains were identified: 41.6% of the strains belonged to the T 1 family, 25.0% to LAM 9, 10.0% to Haarlem 3, 3.3% to each of CAS, LAM 8, BCG and Family 36 and 1.7% to each of Haarlem 1, LAM 10, S, M. africanum, X 1 and T 3 families. The noticeable absence of Beijing and East African Indian families was not consistent with the patterns reported in neighbouring countries. A more inclusive study of the Lebanese population is necessary to accurately identify most of the prevailing families in the country.