Diversity of Mycobacterium tuberculosis lineages in French Polynesia.

BACKGROUND/PURPOSE: French Polynesia is an overseas territory located in the South Pacific. The incidence of tuberculosis in French Polynesia has been stable since 2000 with an average of 20 cases/y/100,000 inhabitants. Molecular epidemiology of Mycobacterium tuberculosis in French Polynesia is unknown because M. tuberculosis isolates have not been routinely genotyped.

METHODS: From 2009 to 2012, 34 isolates collected from 32 French Polynesian patients were identified as M. tuberculosis by probe hybridization. These isolates were genotyped using spoligotyping and 24-loci mycobacterial interspersed repetitive units (MIRUs)-variable number of tandem repeat (VNTR). Spoligotype patterns obtained using commercial kits were compared with the online international database SITVIT. MIRU-VNTR genotyping was performed using an in-house protocol based on capillary electrophoresis sizing for 24-loci MIRU-VNTR genotyping.

RESULTS: The results of the spoligotyping method revealed that 25 isolates grouped into six previously described spoligotypes [H1, H3, U likely (S), T1, Manu, and Beijing] and nine isolates grouped into six new spoligotypes. Comparison with the international database MIRU-VNTRplus distributed 30 isolates into five lineages (Haarlem, Latin American Mediterranean, S, X, and Beijing) and four as unassigned isolates.

CONCLUSION: Genotyping identified four phylogenetic lineages belonging to the modern Euro-American subgroup, one Beijing genotype responsible for worldwide pandemics, including remote islands in the South Pacific, and one Manu genotype of the ancestral lineage of M. tuberculosis.