Estimation of Full-Length TprK Diversity in Treponema pallidum subsp. <i>pallidum</i>
Amin Addetia, Michelle J. Lin, Quynh Phung, Hong Xie, Meei‐Li Huang, Giulia Ciccarese, Ivano Dal Conte, Marco Cusini, Francesco Drago, Lorenzo Giacani, Alexander L. Greninger
Abstract
Syphilis continues to be a significant public health issue in both low- and high-income countries, including the United States where the rate of syphilis infection has increased over the past 5 years. Treponema pallidum subsp. pallidum , the causative agent of syphilis, carries the outer membrane protein TprK that undergoes segmental gene conversion to constantly create new sequences. We performed full-length deep sequencing of TprK to examine TprK diversity in clinical T. pallidum subsp. pallidum strains. We then combined our results with data from all samples for which TprK deep sequencing results were available. We found almost no overlap in TprK sequences between different patients. Moreover, our data allowed us to estimate the total number of TprK variants that T. pallidum subsp. pallidum can potentially generate. Our results support how the T. pallidum subsp. pallidum TprK antigenic variation system is an equal adversary of the human immune system leading to pathogen persistence in the host.