P057

1:Instituto de Investigaciones Científicas y Servicios de Alta Tecnología de Panamá; 2:Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency; 3:CNRS-Université Franche-Comté (UFC); 4:St. Petersburg Pasteur Institute; 5:Université Paris-Saclay; 6:Université Paris-Cité, Université Sorbonne Paris-Nord

Mycobacterium tuberculosis lineage 2 (L2) is often associated with increased drug resistance and rapid transmission.  Panama recently reported an endemic transmission of drug-susceptible M. tuberculosis sublineage L2.2.M3 in Colon.  Here, we aim to perform an in-depth analysis of the whole-genome sequences (WGS) of L2.2.M3 Panama isolates to understand how this endemic transmission is connected in a global context.  We collected WGS data of 90 L2.2.M3 isolates from Colon, Panama, recovered between 2015 and 2023, and analyzed them using the TB-Annotator, as it contains a collection of >112,000 M. tuberculosis strains.  Our results indicate that 96.7% (87/90) were classified as pan-susceptible, 2.2% (2/90) as RR-TB (rifampicin and rifampicin/pyrazinamide-resistant), and 1.1% (1/90) as MDR-TB (rifampicin, isoniazid, and ethionamide resistant). The preliminary assessment revealed that all Colon sublineage L2.2.M3 isolates are very homogeneous and share a unique SNP at position 518748 G>A.  TB-Annotator results show an interesting clonal complex within a larger tree of 1,568 sequence read archives (SRAs) of sublineage L2.2.M3.  Although the Colon sample set does not have enough markers to define it as a sublineage within L2.2.M3, our results suggest that the isolates document a new epidemic branch (internal distance of 35 +/- 17 SNP) that is very endemic in Panama with limited transmission to other countries.  A plausible explanation could be that little time has passed (8 years) since the study population was formed.  However, this might change as more countries are sequencing and sharing information from current and past L2 tuberculosis cases.