Introduction Syphilis is a globally occurring sexually transmitted disease caused by Treponema pallidum, a non-cultured in vitro bacterium. Molecular typing of Treponema pallidum strains isolated from patients are useful for investigating the molecular epidemiologic patterns, diversity of strains and antimicrobial resistance patterns.To date, there was no data on the circulating or prevalent subtype in Brazil. In this study we aimed to determine T. pallidum strain diversity and analyse for the mutation associated with macrolide resistance from patients with primary syphilis attended at CSEGPS.
Methods We analysed 24 samples of primary lesion collected from patients attended at CSEGPS between 2013 and 2015. DNA was extracted with DNeasy kit (Qiagen). Standard PCR targeting tpp47 and polA genes was used for screening. Molecular typing was performed by CDC established methods, by determination of the 60 bp repeats within the arp gene, and RFLP analysis of tpr subfamily II genes (E, G and J). Completed by sequence analysis of a variable region of the tp0548 gene. The 23S rDNA mutation was analysed by DNA sequencing of PCR product.
Results: T. pallidum DNA was detected in samples from 15 patients. Among 12 specimes typed, subtype found were 14d/g (6), 14d/d (5) and 12b/d (1). From 10 samples analysed for 23 rDNA mutation, all showed A2058-G, no mutation was detected at A2059. One case presented a different subtype in re-infection. The first was 14d/g and the second was 14d/d.
Conclusion: T. pallidum detected in the samples of patients with primary syphilis are of subtypes 14d/g, 14d/d and 12b/d. The macrolide resistance mutation A2058-G was detected in all samples analysed. T. pallidum subtyping discriminated re-infection.