健康6月龄内儿童肺炎链球菌携带状况及耐药特征分析

Carriage of Streptococcus pneumoniae and its drug resistance characteristics in healthy children under 6 months of age

目的 了解济南地区健康6月龄内儿童鼻咽部肺炎链球菌携带血清型及耐药特征,为肺炎球菌疫苗推广接种提供数据。方法 2019年11月—2020年4月采集济南地区216例健康6月龄内儿童鼻咽拭子,经分离培养获得疑似肺炎链球菌菌株;利用基质辅助激光解吸电离飞行时间质谱和奥普托欣敏感试验鉴定后,采用多重PCR方法明确肺炎链球菌血清型;进一步采用微生物药敏分析仪进行药物敏感性检测。结果 216例健康6月龄内儿童肺炎链球菌携带率为5.1%(11/216),共携带7种血清型:15B、23F、6B、8、18C、19F和13。13价肺炎球菌多糖结合疫苗血清型覆盖率为54.5%,23价肺炎球菌多糖疫苗覆盖率为90.9%。19种抗生素中红霉素和阿奇霉素耐药率为100.0%;耐药率80.0%以上的有四环素、克林霉素、甲氧苄胺嘧啶/磺胺甲噁唑;头孢呋辛和青霉素(口服)的耐药率超过50.0%。万古霉素、利奈唑胺、左氧氟沙星、氯霉素和莫西沙星未发现耐药菌株。11例儿童鼻咽部肺炎链球菌分离株显示多重耐药,耐药种类3~6种。结论 济南地区健康6月龄内儿童鼻咽部定植的肺炎链球菌具有多种血清型,且抗生素耐药现象较严重。

Objective To analyze nasopharyngeal carriage of Streptococcus pneumoniae serotypes and characteristics of drug resistance in healthy children under 6 months of age in Jinan, and to provide reliable data for pneumococcal vaccination. Methods Two hundred and sixteen nasopharyngeal swabs were collected from healthy infants younger than 6 months in Jinan from November 2019 to April 2020. Streptococcus pneumoniae was cultured and isolated. Matrix assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF MS) and optochin susceptibility were performed. Multiplex PCR was used to determine Streptococcus pneumoniae serotypes. Antibiotic susceptibility was evaluated by antimicrobial susceptibility analyzer. Results The carriage rate of Streptococcus pneumoniae in the 216 healthy children under 6 months of age was 5.1%(11/216), including seven pneumococcal serotypes, 15B, 23F, 6B, 8, 18C, 19F and 13. The vaccine coverage of the 13-valent pneumococcal polysaccharide conjugate vaccine was 54.5%, and that of the 23-valent pneumococcal polysaccharide vaccine was 90.9%. Among 19 antibiotics, the drug resistance rates of erythromycin and azithromycin were 100.0%, those of tetracycline, clindamycin and trimethoprim/sulfamethoxazole were over 80.0%, and those of cefuroxime and penicillin(oral) were over 50.0%. No drug resistant strains were found for vancomycin, linezolid, levofloxacin, chloramphenicol and moxifloxacin. Streptococcus pneumoniae isolated from eleven children’s nasopharynx showed multi-drug resistance with 3-6 kinds of drugs. Conclusion Streptococcus pneumoniae colonized in nasopharynx of the healthy children under 6 months of age in Jinan has multiple serotypes and serious antimicrobial resistance.