A15 Rapid radiation of treponema pallidum pertenue in wild non-human primates

Abstract

Bacteria of the species Treponema pallidum are causative agentsof venereal syphilis (Treponema pallidum pallidum), Bejel (T. p.endemicum), and yaws (T. p. pertenue) in humans. We documented Treponema pallidum infections associated with diseasein wild sooty mangabeys (Cercocebus atys) in TaïNational Park,Cô te d'Ivoire, and green monkeys (Chlorocebus sabaeus) fromBijilo Forest Park, Gambia and Niokolo-Koba National Park,Senegal. To examine the evolutionary relatedness of these treponemes to those responsible for diseases in humans and forpreviously documented infections in baboons (Papio papio), weconducted a hybridization capture experiment to enrichTreponema pallidum DNA from samples collected from symptomatic individuals. This approach allowed us to sequence thefull genomes of Treponema pallidum strains infecting sooty mangabeys (n = 2) and green monkeys (n = 4). Phylogenomic analyses revealed that all Treponema pallidum strains infecting nonhuman primates are most closely related to the sub-species T.p. pertenue. Strains infecting humans and non-human primatesdo not appear to be reciprocally monophyletic. The star-likephylogenetic branching pattern of the T. p. pertenue clade, withshort basal branches receiving low statistical support, suggestsa rapid initial radiation across humans and non-human primates. These results greatly broaden the known host range ofT.p. pertenue and suggest the existence of a vast zoonotic reservoir that could possibly contribute to the failure of global eradication efforts.