Detection of A2058G and A2059G on the 23S rRNA Gene by Multiplex Nested PCR to Identify Treponema pallidum Resistance to Azithromycin in Indonesia.

Azithromycin is an antibiotic used to treat syphilis, especially in the context of penicillin allergy. Although resistance to azithromycin has been widely reported to be associated with one- and/or two-point mutations on the 23S rRNA gene, it has yet to be described in Indonesia. Specimens were collected from 220 patients diagnosed with secondary syphilis. A multiplex nested polymerase chain reaction (PCR) testing system using the 23S rRNA target gene of Treponema pallidum was designed using three primer pairs. The first step involved the use of PCR primer pairs to detect T. pallidum. In the second step, two PCR primer pairs were constructed to identify azithromycin-resistant T. pallidum based on A2058G and A2059G point mutations. T. pallidum detected in samples from Jakarta or Bandung were not resistant to azithromycin. However, azithromycin-resistant T. pallidum were found in samples from Makassar, Medan, and Bali. Specimens from heterosexual males and patients with HIV accounted for the majority of azithromycin resistance noted in the study. This study demonstrated that the azithromycin-resistant T. pallidum detected in Indonesia appear to be a novel variant of resistance, containing both the A2058G and A2059G mutations found in Medan and Makassar.