Mycobacterium tuberculosis belonging to family LAM and sublineage RD Rio: common strains in Southern Brazil for over 10 years

Abstract

A sublineage of Mycobacterium tuberculosis called RDRio was described in 2007. Although only recently described, this strain may have been present previously in the population, and its identification in clinical isolates will elucidate bacterial transmission dynamics and host-pathogen interactions. This study evaluated the clonal diversity of the RDRio sublineage in clinical isolates from Rio Grande-RS obtained between 1998 and 2001. Among the 45 samples analyzed by the MIRU-VNTR method, there were six clusters with two samples each and 33 orphan strains with unique pattern. The strains were distributed across several different lineages including LAM (34.04%), × (14.89%), Haarlem (12.77%), UgandaI (10.64%), S (4.26%), NEW-1 (2.13%) and Cameroon (2.13%); 14.89% of the strains matched to multiple lineages. RDRio strains were present in 28.9% of the samples and 81.25% of the identified strains belonged to the LAM family. The high clonal diversity observed in this study is a constant feature in this region. The RDRio sublineage has been in Rio Grande-RS since 1998. The continued monitoring of RDRio in clinical isolates will enhance the understanding of its epidemiological significance.

Population structure and genetic diversity of Mycobacterium tuberculosis in Ecuador

“…Only some countries in Latin America like Paraguay 21 , Chile [22][23][24] , Honduras 25 , Colombia [26][27][28][29] and French Guiana 30 have reported a nationwide analysis of the distribution of genotypes. Other countries with genotype reports like Peru [31][32][33] , Bolivia 34 , Venezuela 35,36 , Mexico 37 and Brazil [38][39][40][41] have concentrated their studies in densely populated urban areas, or strains with special characteristics like LAM Rio (Argentina 42 , Brazil [43][44][45][46] ) and/or isolates with drug resistance (Argentina Peru and an earlier study from Ecuador [47][48][49] ) or isolates from patients at high risk for drug resistance (Bolivia 34 ). Also, most of the previous studies were done with spoligotyping or a combination of spoligotyping and MIRU-VNTR.…”

Tuberculosis Genetic Epidemiology: A Latin American Perspective

“…Despite this, whole-genome sequencing has revealed substantial genetic diversity between strains, leading to an improved phylogenetic SNP-based strain classification [28]. Studies in Peru [25,29,30], Argentina [31], Mexico [32,33], and Brazil [34,35,36,37] have all examined the genetic diversity of MTB in Latin America and have established that the predominant strains have evolved from the Euro-American lineage 4. This domination of lineage 4 in South America, alongside its worldwide distribution, supports the hypothesis that it was introduced and dispersed by European colonialists in the mid-sixteenth to nineteenth centuries, as discussed above [38,39,40,41].…”

Exploring the “Latin American Mediterranean” family and the RDRio lineage in Mycobacterium tuberculosis isolates from Paraguay, Argentina and Venezuela

“…Later on, an 11% frequency of RD Rio (mostly LAM9 and LAM2) was reported amongst 186 patients diagnosed between 2008 and 2009 [30]. In Rio Grande do Sul , the southernmost Brazilian state, a frequency of 28.9% was detected amongst 45 clinical isolates obtained between 1998 and 2001 [53]. In the same state, amongst 237 isolates collected between 2004 and 2006, a total of 38% was RD Rio [29].…”