A comparison of genotyping tool in Treponema pallidum: Review and meta-analysis

Background: To decipher the molecular epidemiology of the Treponema pallidum subspecies, pallidum, researchers have developed different molecular typing schemes which identify strains type from clinical specimens. However, the results of these studies show remarkable diversity.

Methods: We searched for literature in PubMed, MEDLINE, Web of Sciences, and OVID from January 1998 to January 2019, in order to compare the efficiency of typing schemes using published evidence for systematic reviews and meta-analyses.

Results: From the 43 studies included, the overall typing efficiency of Treponema pallidum was 71.4% (95% CI: 63.2-78.9%). Subgroup analyses indicated that the typing efficiency of CDC-typing (CDCT, 68.2%, 95% CI: 53.6-81.2%) was worse than those of enhanced CDC-typing (ECDCT, 72.3%, 95% CI: 60-83.1%), CDC-rspA (81.6%, 95% CI: 76.1-86.6%), multi-locus sequence typing (MLST, 67.1%, 95% CI: 61.1-72.7), and sequencing-based molecular typing (SBMT, 71.6%, 95% CI: 50-89.2%). A limitation of this review is that the studies included employed different criteria to collect and investigate samples of Treponema pallidum, which could contribute to heterogeneity.

Conclusions: This analysis suggests that CDCT is an inferior scheme in molecular typing, the discriminatory power was very similar for ECDCT and SBMT. Other factors contributing to the heterogeneity between typing studies warrants further study.