乙酰吉他霉素干混悬剂对肺炎支原体的体外抗菌作用

Antibacterial effect of acetylkitasamycin dry suspension on Mycoplasma pneumoniae in vitro

目的:探讨乙酰吉他霉素干混悬剂对肺炎支原体(MP)的体外抗菌作用。方法:选择2016—2019年本实验室保存的呼吸系统感染患者的MP临床分离株51株,以阿奇霉素、红霉素对照药物,采用微量倍比稀释法测定乙酰吉他霉素干混悬剂对MP的体外最低抑菌浓度(MIC)。结果:51株临床分离株中,43例耐药株,含23SrRNA 2063位点突变,8例敏感株,无耐药相关位点突变。微量倍比稀释法的结果显示:乙酰吉他霉素干混悬剂对MP标准株FH和M129的MIC值均为0.125 mg·L^(-1),对MP临床耐药株的MIC值为8~32 mg·L^(-1),MIC_(50)为16 mg·L^(-1),MIC_(90)为32 mg·L^(-1);对MP临床敏感株的MIC值为0.063~0.125 mg·L^(-1),MIC_(50)和MIC_(90)均为0.125 mg·L^(-1)。红霉素对MP临床耐药株MIC范围为256~1024 mg·L^(-1),MIC_(50)和MIC_(90)分别为512和1024 mg·L^(-1);阿奇霉素对MP临床耐药株MIC范围为64~512 mg·L^(-1),MIC_(50)和MIC_(90)分别为256和512 mg·L^(-1);红霉素和阿奇霉素对MP临床敏感株的MIC值均<0.5 mg·L^(-1)。结论:肺炎支原体对大环内酯类抗生素呈不同程度的耐药,乙酰吉他霉素干混悬剂体外对MP敏感株有较好的抑菌活性,对MP耐药株的MIC值水平较低,临床上对肺炎支原体感染的作用需要进一步研究。

Objective:To investigate the antibacterial effect of acetylkitasamycin dry suspension on Mycoplasma pneumoniae(MP)in vitro.Methods:51 clinical isolates and 2 standard strains of MP from patients with respiratory tract infection stored in our laboratory from 2016 to 2019 were randomly selected for the research.Taking azithromycin and erythromycin as control drugs,the minimum inhibitory concentration(MIC)of acetylkitasamycin dry suspension against MP was determined using broth microdilution method.Results:Of all the 51 clinical isolates,there were 43 drug-resistant strains that contained the point mutations A2063G in V region of 23S rRNA domain,and there were 8 susceptible strains which had no mutations related to drug resistance.The MIC values of the acetyljithamycin dry suspension were 0.125 mg·L^(-1)for the standard MP strains FH and M129;for the clinically resistant MP strains,the MIC was 8~32 mg·L^(-1),the MIC_(50) was 16 mg·L^(-1),and the MIC_(90) was 32 mg·L^(-1);for clinically sensitive MP strains,the MIC was 0.063~0.125 mg·L^(-1),and both MIC_(50) and MIC_(90) were 0.125 mg·L^(-1).Erythromycin had a MIC range of 256~1024 mg·L^(-1)for clinically resistant MP strains,the MIC_(50) was 512 mg·L^(-1),and the MIC_(90) was 1024 mg·L^(-1);azithromycin had a MIC range of 64~512 mg·L^(-1) for clinically resistant MP strains,the MIC_(50) was 256 mg·L^(-1),and the MIC_(90) was 512 mg·L^(-1).The MIC values of erythromycin and azithromycin for clinically sensitive MP strains were<O.5 mg·L^(-1).Conclusion:MP showed different degrees of resistance to macrolide antibiotics.Acetylkitasamycin dry suspension had good bacteriostatic activity against sensitive MP strains in vitro,and the MIC value against resistant MP strains was low,and the clinical effect on MP infection need to be further studied.