Introduction
The Mycobacterium tuberculosis (MTB) complex may be subdivided into seven lineages (Comas et al., 2013) with unequal geographic distribution. Among them, the Beijing lineage (Lineage 2), has received greater attention because of its successful global distribution, increased transmissibility and virulence, and involvement in major outbreaks in some settings (Bifani, Mathema, Kurepina, & Kreiswirth, 2002; Borrell et al., 2009; Iwamoto et al., 2012; Yang et al., 2012). Certain Beijing clones have been associated to resistance and higher ability to compensate for the loss of fitness linked to the acquisition of drug resistance.
The Beijing lineage constitutes around 13% of the global MTB complex population (Parwati, van Crevel, & van Soolingen, 2010). Since its discovery in East Asia in 1995 (van Soolingen et al., 1995), many studies have documented its endemic prevalence in Asia (~50% of the circulating strains in East Asia) (Parwati et al., 2010), as well as its presence in South Africa (27%) (Gandhi et al., 2014) and northern Eurasia (40-60%) (Mokrousov, 2013). However, limited information is available on its representativeness in other geographic areas worldwide, e.g., the Caribbean and Central America, were an average of 3.5 % of total tuberculosis (TB) cases in the area associated to the Beijing lineage have been reported (Millet, Baboolal, Streit, Akpaka, & Rastogi, 2014) and some more specific data about its presence (2.1%) in Guatemala, where the Beijing lineage was involved in a severe outbreak (Saelens et al., 2015) .
The purpose of this study was to complete a preliminary information (Dominguez et al., 2019) on the presence of this lineage in Panama. We focused our efforts on Colon, a Panamanian province with the highest TB incidence rate (MINSA, 2018). Based on a modular strategy that combined Mycobacterial Interspersed Repetitive-Unit/Variable-Number of Tandem Repeats (MIRU-VNTR)-based typing (Supply et al., 2006), strain-specific PCRs, and whole genome sequencing (WGS) we aim to i) update the data on Beijing strains in Colon, ii) evaluate the role of Beijing strains in recent transmission active events, and iii) explore the Beijing phylogeny and history in Panama.