P71
Recent history of MDR Mycobacterium tuberculosis complex strains of Lineage 2 and Lineage 4 in Central Asia
E Rousseau(1) M Merker(2) . Central Asia study group(3) U Antonenka(4) H Hoffmann(4,5) T Wirth(6,7) S Niemann(1,8)
1:Molecular and Experimental Mycobacteriology, Research Center Borstel, Germany; 2:Evolution of the Resistome, Research Center Borstel, Germany; 3:Diverse; 4:IMLred; WHO Supranational TB-Reference Laboratory, Gauting, Germany; 5:SYNLAB Gauting, SYNLAB Dachau, Germany; 6:EPHE, PSL University, Paris, France; 7:Institut de Systématique, Evolution, Biodiversité, ISYEB, Muséum national d’Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France; 8:German Center for Infection Research, Partner site Hamburg-Lübeck-Borstel-Riems, Germany
Central Asia is a hotspot for drug resistant tuberculosis (TB) and faced several recent outbreaks of multidrug resistant (MDR) Mycobacterium tuberculosis (Mtbc) strains, linked to the emergence and rapid expansion of modern Lineage 2 “Beijing” outbreak strains. Those strains are characterized by high resistance rates and fast spread when compared to strains of other major Mtbc lineages such as lineage 4 strains.
Here, we present an overview of recent spread and evolution of MDR Mtbc strains, based on 20 years of genomic transmission analysis of Mtbc strains obtained in the five Central Asian Republics Uzbekistan, Turkmenistan, Tajikistan, Kazakhstan and Kyrgyzstan. The dataset comprises 2247 high quality whole genome sequences from 2001 to 2019. Out of these, 1001 strains were MDR, 229 strains were pre-XDR, and 15 were XDR. Phylogenetic strain classification showed L2 strains are dominant (n=1611), followed by strains of L4 (n=592). Bayesian effective population reconstructions correlate recent crisis such as the 1992 - 1997 Tajikistani Civil War and the 2008 Central Asia energy crisis with rapid expansion of modern L2 epidemic clones e.g. “W148” and "Central Asian Outbreak”, in 3 stacking waves. Ancestral geographical states inferences reveal that L2 experimented more inter-countries movements than L4, which is consistent with a most recent local implementation and efficient spreading of the former.
While sampling bias must be accounted for, the results obtained draw a recent history of recent replacement of Lineage 4 tuberculosis strains with most epidemically successful Lineage 2 modern clones in Central Asia.