The history of Helicobacter pylori: from phylogeography to paleomicrobiology  F. Mégraud, P. Lehours, F.F. Vale  Clinical Microbiology and Infection  Volume 22, Issue 11, Pages 922-927 (November 2016) DOI: 10.1016/j.cmi.2016.07.013 Copyright © 2016 Terms and Conditions

Fig. 1 Relationships between modern populations (a), modern subpopulations (b), and ancestral populations (c) of Helicobacter pylori (Falush D, Wirth T, Linz B, Pritchard JK, Stephens M, Kidd M, et al. Traces of human migrations in Helicobacter pylori populations. Science 2003;299:1582–5). The black lines show neighbour-joining population trees as measured by δˆ, the net nucleotide distance between populations. The circle diameters indicate their genetic diversity, measured as the average genetic distance between random pairs of individuals. The larger circles in (a) versus (c) reflect the effects of admixture between ancestral populations. Filled arcs reflect the number of isolates (a and b) or nucleotides (c) in each population. Colour coding is consistent in different parts of the figure, except for modern hpEurope, which is an admixture between the ancestral AE1 and AE2 populations. Scales are at lower right. Clinical Microbiology and Infection 2016 22, 922-927DOI: (10.1016/j.cmi.2016.07.013) Copyright © 2016 Terms and Conditions

Fig. 2 Chronological reconstruction of the major population events occurring during the intimate human-Helicobacter pylori association. (Moodley Y, Linz B, Bond RP, Nieuwoudt M, Soodyall H, Schlebusch CM, et al. Age of the association between Helicobacter pylori and man. PLoS Pathog 2012;8:e1002693). Black lines indicate undifferentiated populations and all other lines are color-coded according to population. The sequence of events is as follows: (1) initial acquisition of H. pylori by a human ancestor; (2) divergence of H. pylori into two super-lineages; (3) first successful migration of modern humans Out of Africa via the southern route; (4) H. pylori divergence into hpAfrica1 and hpNEAfrica with migration eastwards (hpNEAfrica) and westwards (hpAfrica1); (5) divergence of H. pylori out of Africa into hpSahul and (6) hpAsia2 and hpEastAsia; (7) host jump from San to large felines giving rise to H. acinonychis; (8) southward migration of San carrying the ancestor of hpAfrica2; (9) second successful migration Out of Africa via the Levant; (10) hybridization of AE1 from central and south-west Asia and AE2 from north-east Africa in the Middle East or western Asia resulting in hpEurope; (11) spread of hpEurope bacteria to Europe; (12) back migration from the Middle East and Spain spreading hpEurope into North Africa. Dates in italics represent estimates obtained from sources other than H. pylori. kya: thousand years ago. Clinical Microbiology and Infection 2016 22, 922-927DOI: (10.1016/j.cmi.2016.07.013) Copyright © 2016 Terms and Conditions