Mutation Analysis Of Macrolide Resistance In Treponema Pallidum In Shandong, China

Background: Syphilis is a chronic classic sexually transmitted disease (STD) thatcaused by Treponema pallidum(TP). TP may invade the body organs (systemic skin andmucous membranes, cardiovascular, neurological, skeletal, etc.), resulting in multi-systemdamage and a wide variety of signs and symptoms. Syphilis are also called " the greatestimitator." Penicillin is the preferred drug for treatment of syphilis. But there are someproblems in the treatment, penicillin requires intramuscular and can cause severe allergicreactions. Researchers discover that macrolide azithromycin is alternative drug for syphilis. Itonly needs a single oral dose administration, has a long half-life and treatment of othersexually transmitted simultaneously diseases(STD). So macrolide antibiotics be used tocontrol and treatment of syphilis. However, Previous studies reported on azithromycinresistance and they identified two mutation A2058Gand A2059G in the23S ribosomal RNA(rRNA) genes in TP. Several centers have evaluated the rate of macrolide resistance amongsyphilis. So far there are no published data on the geographical variations distribution andprevalence of the A2059G mutation.This is the frst study that has looked for resistancemutations in T. pallidum in Shandong, China.Objective:1. To detecte the mutation of TP23SrRNA gene in Shandong;2. Todetermine the prevalence of the A2058G and A2059G mutations in Shandong;3. To assesswhether macrolide antibiotics are still suitable as alternative drug therapy for syphilis.Methods: DNA was extracted from anogenital lesions presenting with syphilis, and wasdetected by a real-time polymerase chain reaction(PCR) assay that targets the DNApolymerase A gene (polA)of T.pallidum. Positive samples amplify the23SrRNA genes byPCR and direct sequencing of the23S rRNA genes.Results: Two mutations associated with macrolide resistance have been detected, and66specimens contain mutations (100%), of which61specimens containing A2058G mutation and5specimens containing A2059G mutation. This report identifies, for the first time inChina, the existence of strains containing the A2059G mutation.Conclusion: Firstly, high levels of T pallidum macrolide resistance are present inShandong, China, Macrolides cannot be recommended for use in the treatment of syphilis inShandong. Secondly, we found the presence of two mutations indicating the geographicaldistribution and diversity of resistance strains.