Molecular Characterization Based on MLST and ECDC Typing Schemes and Antibiotic Resistance Analyses of Treponema pallidum subsp. pallidum in Xiamen, China

Frontiers in Cellular and Infection Microbiology

Xiao-Zhen Zhu¹  Li-Li Liu¹  Jian-Jun Niu¹  Li-Rong Lin¹  Shu-Min He²  Dan Liu²  Tian-Ci Yang² 

[1] Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China;Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China;Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China;

关键词: syphilis;    Treponema pallidum;    strain typing;    ECDC;    MLST, antibiotic resistance;   

DOI  :  10.3389/fcimb.2020.618747

来源: Frontiers

【 摘 要 】

In total, 49 clinical samples were analyzed using two typing schemes, Enhanced Centers for Disease Control and Prevention(ECDC) and multilocus sequence typing (MLST), to describe the molecular characteristics of circulating Treponema pallidum isolates in Xiamen between 2016 and 2017. In addition, genetic mutations potentially related to antibiotic resistance of T. pallidum were also analyzed. Forty five samples were fully typed by ECDC, and 14 different subtypes were detected. The most common subtype was 16d/f (24.4%), followed by 14d/f (20.0%). All forty nine samples were successfully typed by MLST, while only four allelic profiles were identified, including three SS14-like profiles and one Nichols-like profile. Among them, the major allelic profile was 1.1.8 (85.7%). Interestingly, the allelic profile 1.3.1 widespread in Europe and North America was not detected in this region. Additionally, A2058G mutation in 23S rRNA was found in all detectable samples (38/38), and no mutation in 16S rRNA was observed (36/36). Four non-synonymous single-nucleotide polymorphisms in penicillin-binding protein genes were found in the 35 samples eligible for Sanger sequencing. Among them, the variant in tp0500 (P564I) can only be found in the SS14-like isolates. Homoplastic changes in tp0760 (I415F/I415M) and tp0705 (A506V/A506T) were found. Moreover, the variant tp0705 A506V and the variant tp0705 A506T separately appeared in the SS14-like isolates and Nichols-like isolates, respectively. This study showed that the genotypes of T. pallidum isolates in Xiamen between 2016 and 2017 were different from those in other geographic areas. The resistance-related variants of T. pallidum isolates identified in this study could provide awareness for clinicians in the treatment of syphilis.

【 授权许可】

CC BY