Molecular surveillance of multidrug-resistant tuberculosis at the dawn of the genomic era, Argentina, 2013-2022

We genotyped 1189 multidrug-resistant Mycobacterium tuberculosis isolates identified during 2013-2022 in Argentina, through a mixed strategy using PCR-based methods and whole-genome sequencing. Epidemiological, geographic distribution and microbiological data were integrated. Most cases belonged to a cluster (75.7%). The proportion of orphan and clustered cases varied across regions. The Euro-American lineage4 was virtually predominant. The most important clusters, M, Ra, Rb and Callao2 strains, comprised 45.9% of the newly diagnosed cases, and their relative importance varied over time. A preliminary genomic analysis showed that several local transmission chains due to the Callao2 strain, imported from Peru, were active, including a superspreading event that occurred circa 2020. A good performance of the current second-line regimes can be expected for most of the cases. Heightening suspicion of drug-resistance and enhancing timely and active surveillance in specific risk groups could contribute to the tuberculosis management in Argentina, tackling transmission and resistance amplification. BiosketchBiochemist Federico Lorenzo is a professional of the Servicio de Micobacterias, Departamento de Bacteriologia, INEI, ANLIS "C. G. Malbran" and is specialized in the microbiological diagnosis of mycobacterial diseases using next-generation sequencing technologies. His research interests are drug-resistant tuberculosis, non-tuberculous mycobacteria and bioinformatic analysis applied to diagnostics. One-sentence summaryWe evaluated the genotypes associated with multidrug-resistant tuberculosis in Argentina, 2013-2022.