Emerging Mycobacterium bovis in Lebanon: a snapshot based on whole-genome sequencing

Background Tuberculosis is a pressing public health issue in Lebanon, a country of approximately five million people, including around 1.5 million refugees from Palestine and Syria. Prior research has revealed uncontrolled animal sources of Mycobacterium bovis , emphasizing the necessity for a comprehensive approach to combat tuberculosis in the region. Methods 48 clinical Mycobacterium tuberculosis complex isolates were identified through whole genome sequence. Also, 43 animal fecal samples were collected from various farms across Lebanon to investigate the presence of the M. tuberculosis complex using CRISPR-csm4 PCR. Results Genomic analysis revealed that 39/48 (81.25%) of isolates were M. tuberculosis and 9/48 (18.75%) were M. bovis. M. tuberculosis was distributed over four lineages, Indo-Oceanic L1 (n = 3/39)(7.6%), East-Asian L2 (n = 1/39)(2.5%), East-African Indian L3 (n = 5/39)(12.8%) and Euro-American L4 (n = 30/39)(76.9%). Sub-lineage L4.8 (Euro-American (mainly T), comprising 8/39 of the isolates (20.5%) was predominant, followed by sub-lineages L3 (East-African Indian, n = 5/39 isolates)(12.8%), L4.2.2.2 (Euro-American (Ural), n= 4/39 isolates)(10.2%) and L4.6.5 (Euro American, n=4/39 isolates)(10.2%). Nine M. bovis were classified into two clades, designated as unknown2 (n=2/9; 22.2%) and unknown3 (n=7/9; 77.8%). Interestingly, none of the clades or others were detected in the 48 faecal samples using CRISPR standard PCR and qPCR. Conclusions This study offers insights into human and bovine tuberculosis in Lebanon, emphasizing M. tuberculosis lineages prevalence and M. bovis distribution into two clades, aiding the fight against tuberculosis, especially bovine tuberculosis, and renewing our understanding of tuberculosis dynamics in Lebanon. ### Competing Interest Statement The authors have declared no competing interest.