Fig. 1.

Agglomerative clustering of MTB isolates by genetic similarity. We used known lineage-defining mutations to calculate isolate-isolate Euclidean distances, which is shown in the heat map. Using these distances of the lineage-defining mutation vectors between isolates, we applied Ward's method of hierarchical clustering to construct the dendrogram and determine the five lineage clusters. The dendrogram is colored by the corresponding isolate genetic lineage. Green: East Asian, Purple: Euro-American (Latin America Mediterranean-LAM sublineage), Orange: Euro-American (other sublineages than LAM), Yellow: Central Asian, Blue: Indo-oceanic & M. africanum. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)