Genetic profiling of Mycobacterium tuberculosis in Tunisia: predominance and evidence for the establishment of a few genotypes.
Typing analyses of 378 Mycobacterium tuberculosis isolates collected between the years 2001 and 2005 from three northern representative regions of Tunisia revealed a highly homogeneous population. Indeed, 84.9 % of all tuberculosis (TB) cases were attributed to the Haarlem, LAM or T families. Strikingly, within each family, more than 60 % of TB cases were due to a single genotype. ST50 (Haarlem3) and ST42 (LAM9) genotypes were exceptionally predominant, representing 46.3 % of all typed isolates. ST50 showed an increased tendency for clustering and was more predominant in the extreme north of the country. By contrast, the more widespread ST42, which was apparently prevalent 17 years ago, displayed weak cluster individualization and a low transmission rate, consistent with its stable association with the Tunisian population. It is believed that both mass BCG vaccination, strictly applied for four decades, and the high endogamy rate that characterizes the Tunisian population could have profoundly shaped the population structure of M. tuberculosis by concurrently favouring the selection and accommodation of particular genotypes.
Namouchi
Amine
A
Unit of Typing and Genetics of Mycobacteria, Institut Pasteur de Tunis (Tunisia), 13 Place Pasteur, BP 74, Tunis, Tunisia.
Karboul
Anis
A
Unit of Typing and Genetics of Mycobacteria, Institut Pasteur de Tunis (Tunisia), 13 Place Pasteur, BP 74, Tunis, Tunisia.
Mhenni
Besma
B
Unit of Typing and Genetics of Mycobacteria, Institut Pasteur de Tunis (Tunisia), 13 Place Pasteur, BP 74, Tunis, Tunisia.
Khabouchi
Neila
N
Unit of Typing and Genetics of Mycobacteria, Institut Pasteur de Tunis (Tunisia), 13 Place Pasteur, BP 74, Tunis, Tunisia.
Haltiti
Raja
R
Hôpital Régional de Menzel-Bourguiba, Menzel-Bourguiba, Tunisia.
Ben Hassine
Ridha
R
Hôpital Régional de Zaghouan, Zaghouan, Tunisia.
Louzir
Béchir
B
Hôpital la Rabta, Tunis, Tunisia.
Chabbou
Abdellatif
A
Hôpital Abderrahman Mami de Pneumo-Phtisiologie, Ariana, Tunisia.
Mardassi
Helmi
H
Unit of Typing and Genetics of Mycobacteria, Institut Pasteur de Tunis (Tunisia), 13 Place Pasteur, BP 74, Tunis, Tunisia.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000995:Antitubercular Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D024881:Drug Resistance, Bacterial; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000382:microbiology; D014416:Tunisia / Q000453:epidemiology
D000995:Antitubercular Agents