Long-Term Population-Based Genotyping Study of Mycobacterium tuberculosis Complex Isolates in the French Departments of the Americas

Abstract

The three French overseas departments of the Americas are characterized both by insular (Guadeloupe and Martinique) and continental (French Guiana) settings with a tuberculosis case detection rate that varies from less than 10 per 100,000 per year in insular areas to an estimated incidence of more than 55 per 100,000 in French Guiana. Under a long-term genotyping program, more than three-fourths of all the Mycobacterium tuberculosis isolates (n ‫؍‬ 744) received from the three settings were fingerprinted over a 10-year period (1994 to 2003) by spoligotyping and variable number of tandem DNA repeats (VNTRs) in order to understand the current trends in their detection rates, drug resistance, and groups and subpopulations at risk of contracting the disease and to pinpoint the circulating phylogeographical clades of the bacilli. The major difference in the study populations was the nationality of the patients, with a high percentage of immigrants from highincidence neighboring countries in French Guiana and a low but increasing percentage in the French Caribbean. The rate of recent transmission was calculated to be 49.3% in French Guiana, compared to 27.2% and 16.9% in Guadeloupe and Martinique, respectively. At the phylogeographic level, 77.9% of the isolates studied belonged to four major clades (Haarlem, Latin-American and Mediterranean, T, and X) which are already reported from neighboring Caribbean islands in an international database and may underline potential interregional transmission events.

Discovery of a Novel Mycobacterium tuberculosis Lineage That Is a Major Cause of Tuberculosis in Rio de Janeiro, Brazil

“…Of particular interest was the observation that all RD Rio strains belonged exclusively to the LAM family (P Յ 0.0001 by a two-sided Fisher exact test). The LAM spoligotype signature is characterized by the simultaneous absence of at least spacers 21 to 24 and 33 to 36, and the LAM family is one of the most prevalent and widely distributed strain families in the world (8,9). Indeed, 58% of all Rio de Janeiro spoligotype patterns were LAM types.…”

“…By comparison, the rich diversity in fingerprint patterns of LAM strains in Rio de Janeiro observed in this study leads to the hypothesis that the LAM family has had a relatively long history of circulation in Brazil. Given the prevalence of the LAM family in Southern Europe and around the Mediterranean basin, it has been suggested that the presence of the LAM lineage in South America and the Caribbean may be linked to early post-Columbus European colonial history, particularly that of the Spanish Empire (8). For the RD Rio strains, significant microevolution has occurred in direct-repeat, MIRU-VNTR, and IS6110-RFLP patterns as well, indicating that the RD Rio LSP arose as a temporally distant genetic event in an ancestral M. tuberculosis clone now endemic in Rio de Janeiro.…”

Finer Snapshot of Circulating Mycobacterium tuberculosis Genotypes in Guadeloupe, Martinique, and French Guiana

“…It also aimed to estimate the benefit of 12-locus mycobacterial interspersed repetitive-unit (MIRU) typing coupled to spoligotyping and to select a reduced MIRU locus typing scheme for an efficient subtyping of clusters belonging to LAM and Haarlem lineages that predominate in South America and the Caribbean (1,(3)(4)(5)13).…”

Automated Extraction and Amplification for Direct Detection of Mycobacterium tuberculosis Complex in Various Clinical Samples

“…With the incidence of culture-positive tuberculosis (TB) cases at 25.3 per 100,000 and a 25% rate of TB/HIV coinfection, the TB incidence in French Guiana is the highest of all French regions (3,5). In this context, there is an urgent need for simple, automated systems for molecular diagnosis of TB that can be adapted to small laboratories.…”