Analysis of Treponema pallidum Strains From China Using Improved Methods for Whole-Genome Sequencing From Primary Syphilis Chancres

Background. Whole-genome sequencing (WGS) of lreponema pallidum subspecies pallidum (TPA) has been constrained by the lack of in vitro cultivation methods for isolating spirochetes from patient samples. Methods. We built upon recently developed enrichment methods to sequence TPA directly from primary syphilis chancre swabs collected in Guangzhou, China. Results. By combining parallel, pooled whole-genome amplification with hybrid selection, we generated high-quality genomes from 4 of 8 chancre-swab samples and 2 of 2 rabbit-passaged isolates, all subjected to challenging storage conditions. Conclusions. This approach enabled the first WGS of Chinese samples without rabbit passage and provided insights into TPA genetic diversity in China.

Automated summary

This study successfully developed a new method for direct TPA whole-genome sequencing from patient samples, overcoming previous limitations due to in vitro cultivation methods. Using this approach, researchers obtained high-quality genome data from Chinese samples and gained insights into the genetic diversity of TPA in China.