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.
Unit of Typing and Genetics of Mycobacteria, Institut Pasteur de Tunis (Tunisia), 13 Place Pasteur, BP 74, Tunis, Tunisia.
Amine
A
Namouchi
Unit of Typing and Genetics of Mycobacteria, Institut Pasteur de Tunis (Tunisia), 13 Place Pasteur, BP 74, Tunis, Tunisia.
Anis
A
Karboul
Unit of Typing and Genetics of Mycobacteria, Institut Pasteur de Tunis (Tunisia), 13 Place Pasteur, BP 74, Tunis, Tunisia.
Besma
B
Mhenni
Unit of Typing and Genetics of Mycobacteria, Institut Pasteur de Tunis (Tunisia), 13 Place Pasteur, BP 74, Tunis, Tunisia.
Neila
N
Khabouchi
Hôpital Régional de Menzel-Bourguiba, Menzel-Bourguiba, Tunisia.
Raja
R
Haltiti
Hôpital Régional de Zaghouan, Zaghouan, Tunisia.
Ridha
R
Ben Hassine
Hôpital la Rabta, Tunis, Tunisia.
Béchir
B
Louzir
Hôpital Abderrahman Mami de Pneumo-Phtisiologie, Ariana, Tunisia.
Abdellatif
A
Chabbou
Unit of Typing and Genetics of Mycobacteria, Institut Pasteur de Tunis (Tunisia), 13 Place Pasteur, BP 74, Tunis, Tunisia.
Helmi
H
Mardassi
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