Introduction

AUTHOR=Castro-Rodriguez Bernardo , Franco-Sotomayor Greta , Benitez-Medina Jose Manuel , Cardenas-Franco Greta , Jiménez-Pizarro Natalia , Cardenas-Franco Camilo , Aguirre-Martinez Juan Luis , Orlando Solon Alberto , Hermoso de Mendoza Javier , Garcia-Bereguiain Miguel Angel TITLE=Prevalence, drug resistance, and genotypic diversity of the RDRio subfamily of Mycobacterium tuberculosis in Ecuador: a retrospective analysis for years 2012–2016 JOURNAL=Frontiers in Public Health VOLUME=12 YEAR=2024 URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1337357 DOI=10.3389/fpubh.2024.1337357 ISSN=2296-2565 ABSTRACT=Introduction

A major sublineage within the Mycobacterium tuberculosis (MTB) LAM family characterized by a new in-frame fusion gene Rv3346c/55c was discovered in Rio de Janeiro (Brazil) in 2007, called RD^Rio, associated to drug resistance. The few studies about prevalence of MTB RD^Rio strains in Latin America reported values ranging from 3% in Chile to 69.8% in Venezuela, although no information is available for countries like Ecuador.

Methods

A total of 814 MTB isolates from years 2012 to 2016 were screened by multiplex PCR for RD^Rio identification, followed by 24-loci MIRU-VNTR and spoligotyping.

Results

A total number of 17 MTB RD^Rio strains were identified, representing an overall prevalence of 2.09% among MTB strains in Ecuador. While 10.9% of the MTB isolates included in the study were multidrug resistance (MDR), 29.4% (5/17) of the RD^Rio strains were MDR.

Discussion

This is the first report of the prevalence of MTB RD^Rio in Ecuador, where a strong association with MDR was found, but also a very low prevalence compared to other countries in Latin America. It is important to improve molecular epidemiology tools as a part of MTB surveillance programs in Latin America to track the transmission of potentially dangerous MTB stains associated to MDR TB like MTB RD^Rio.