F. Lorenzo, R. Paul, J. Monteserin, N. Masciotra, E. Mazzeo, I. Wainmayer, L. Perez Lago, M. Matteo, A. Gamberale, H. Fernandez, L. E. Irazu, M. A. Rodriguez, D. Palmero, D. Garcia de Viedma, N. Simboli, B. Lopez, N. K. Yokobori
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 and orphan cases were associated with history of poor adherence to treatment and foreign-born patients. The Euro-American lineage4 was predominant. The most important clusters, M, Ra, Rb and Callao2 strains, comprised 45.9% of the newly diagnosed cases. The historically most important M strain started to decline. The Rb strain was found to be geographically widespread and was strongly associated with transgender women. The Callao2 strain, probably imported from Peru, expanded significantly in the latest years. A preliminary genomic analysis identified several possible local transmission chains. The relatively low proportion of preXDR/XDR cases is encouraging but deserves close monitoring. Collectively, our results constitute important groundwork for the full transition to WGS-based surveillance.