Probable long-term prevalence for a predominant Mycobacterium tuberculosis clone of a Beijing genotype in Colon, Panama.

Beijing genotype Mycobacterium tuberculosis strains associate with increased virulence, resistance and/or higher transmission rates. This study describes a specific Beijing strain predominantly identified in the Panamanian province of Colon with one of the highest incidences of tuberculosis in the country. Retrospective mycobacterial interspersed repetitive unit/variable number of tandem repeats analysis of 42 isolates collected between January and August 2018 allowed to identify a cluster (Beijing A) with 17 (40.5%) Beijing isolates. Subsequent prospective strain-specific PCR-based surveillance from September 2019 to March 2020 confirmed the predominance of the Beijing A strain (44.1%) in this province. Whole-genome sequencing revealed higher-than-expected diversity within the cluster, suggesting long-term prevalence of this strain and low number of cases caused by recent transmission. The Beijing A strain belongs to the Asian African 3 (Bmyc13, L2.2.5) branch of the modern Beijing sublineage, with their closest isolates corresponding to cases from Vietnam, probably introduced in Panama between 2000 and 2012.