Minimal inhibitory concentration of Azithromycin and Erythromycin against 288 clinical strains of Mycoplasma pneumoniae and their resistance gene mutations
10.3760/cma.j.cn101070-20250514-00350
- VernacularTitle:肺炎支原体288株对阿奇霉素和红霉素的最小抑菌浓度及其耐药基因变异研究
- Author:
Zhengrong YANG
1
;
Haiwei DOU
;
Yuang CAI
;
Dawei SHI
;
Deli XIN
;
Wenjie QI
Author Information
1. 首都医科大学附属北京友谊医院感染科，北京 100050
- Publication Type:Journal Article
- Keywords:
Mycoplasma pneumoniae;
Gene mutation;
Macrolides;
Drug resistance;
Minimal inhibitory concentration
- From:
Chinese Journal of Applied Clinical Pediatrics
2025;40(10):771-774
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To characterize the minimal inhibitory concentration (MIC) of macrolides against clinical Mycoplasma pneumoniae (MP) isolates and to investigate the significance of 23S rRNA mutations. Methods:Cross-sectional study.A total of 288 clinical MP strains preserved in the laboratory from 2016 to 2021 were taken for macrolide resistance gene testing and the evaluation of in vitro susceptibility to Azithromycin and Erythromycin.MIC 50 and MIC 90 values were calculated separately for macrolide-susceptible and -resistant strains. Results:All 288 MP strains underwent the test of in vitro susceptibility to Azithromycin, while 86 of them were additionally tested for Erythromycin.Among these strains, 22 strains were Azithromycin-sensitive, and 266 strains were Azithromycin-resistant.A2063G mutations were detected in 260 (97.7%) strains, while A2064G mutations were detected in 6 (2.3%) strains.Azithromycin-resistant strains had an MIC 50 of 128.000 μg/mL and an MIC 90 of 512.000 μg/mL, with the MIC ranging between 16.000 and 512.000 μg/mL.Seven strains were sensitive and 79 strains were resistant to Erythromycin.Among Erythromycin-resistant strains, A2063G mutations were detected in 73 (92.4%) strains, while A2064G mutations were detected in 6 (7.6%) strains.Erythromycin-resistant strains had an MIC 50 of 256.000 μg/mL and an MIC 90 of 512.000 μg/mL, with the MIC ranging between 64.000 and 1 024.000 μg/mL. Conclusions:A2063G and A2064G mutations in the 23S rRNA gene of MP are associated with high-level in vitro resistance to Azithromycin and Erythromycin, significantly limiting the clinical effectiveness of these antibiotics.Early resistance gene testing is recommended for suspected MP patients, which can help optimize the treatment, improve prognosis, and prevent resistance spread.
