Eldholm Vegard, Pettersson John H-O, Brynildsrud Ola B, Kitchen Andrew, Rasmussen Erik Michael, Lillebaek Troels, Rønning Janne O, Crudu Valeriu, Mengshoel Anne Torunn, Debech Nadia, Alfsnes Kristian, Bohlin Jon, Pepperell Caitlin S, Balloux Francois
Infection Control and Environmental Health, Norwegian Institute of Public Health, 0456 Oslo, Norway;
Infection Control and Environmental Health, Norwegian Institute of Public Health, 0456 Oslo, Norway.
Proc Natl Acad Sci U S A. 2016 Nov 29;113(48):13881-13886. doi: 10.1073/pnas.1611283113. Epub 2016 Nov 21.
The "Beijing" Mycobacterium tuberculosis (Mtb) lineage 2 (L2) is spreading globally and has been associated with accelerated disease progression and increased antibiotic resistance. Here we performed a phylodynamic reconstruction of one of the L2 sublineages, the central Asian clade (CAC), which has recently spread to western Europe. We find that recent historical events have contributed to the evolution and dispersal of the CAC. Our timing estimates indicate that the clade was likely introduced to Afghanistan during the 1979-1989 Soviet-Afghan war and spread further after population displacement in the wake of the American invasion in 2001. We also find that drug resistance mutations accumulated on a massive scale in Mtb isolates from former Soviet republics after the fall of the Soviet Union, a pattern that was not observed in CAC isolates from Afghanistan. Our results underscore the detrimental effects of political instability and population displacement on tuberculosis control and demonstrate the power of phylodynamic methods in exploring bacterial evolution in space and time.
“北京” 型结核分枝杆菌（Mtb）谱系2（L2）正在全球传播，并与疾病进展加速和抗生素耐药性增加有关。在此，我们对L2亚谱系之一的中亚分支（CAC）进行了系统发育动力学重建，该分支最近已传播到西欧。我们发现，近期的历史事件推动了CAC的进化和传播。我们的时间估计表明，该分支可能在1979 - 1989年苏联 - 阿富汗战争期间传入阿富汗，并在2001年美国入侵后人口流离失所的情况下进一步传播。我们还发现，苏联解体后，前苏联各共和国的Mtb分离株中大规模积累了耐药性突变，而在阿富汗的CAC分离株中未观察到这种模式。我们的结果强调了政治不稳定和人口流离失所对结核病控制的有害影响，并证明了系统发育动力学方法在探索细菌时空进化方面的作用。
