Fig. 1. Global and Indian core gene phylogenies of Corynebacterium diphtheriae and tox gene variants by decade.

A Maximum likelihood phylogenetic tree based on the core gene single nucleotide polymorphisms from the 502 global Corynebacterium diphtheriae genome collection. The country of isolation (1), decade of isolation (2), and AMR gene presence/absence heatmap made using ARIBA⁵⁰ (3), are all annotated. Most monophyletic groups within the tree represent only one country and decade, with the major exception of the large Belarussian/German dominated group, marked with a blue star. Both the blue and orange stars highlight groups used for BEAST analysis. B The core gene maximum likelihood phylogeny of only the 122 Indian isolates, coloured by state (1) and year of isolation (2). C The proportion of the 18 tox gene variants found across 291 tox⁺ and 211 non-toxigenic isolates per decade, with the number of isolates per decade shown.