中国实用儿科杂志

中国实用儿科杂志

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百日咳致病菌株的药物敏感性和疫苗相关基因型研究

  

  1. 国家儿童医学中心  首都医科大学附属北京儿童医院  北京市儿科研究所微生物研究室  儿科重大疾病研究教育部重点实验室  国家呼吸系统疾病临床医学研究中心  儿童呼吸道感染性疾病研究北京市重点实验室， 北京  100045
  • 出版日期:2019-08-06 发布日期:2019-09-04

Distribution of vaccine-related genotypes and antimicrobial susceptibility among the Bordetella pertussis isolates

  1. National Center for Children’s Health；Beijing Children’s Hospital，Capital Medical University；Beijing Pediatric Research Institute；Key Laboratory of Major Diseases in Children，Ministry of Education；National Clinical Research Center for Respiratory Diseases；Beijing Key Laboratory of Pediatric Respiratory Infection Diseases，Beijing  100045，China
  • Online:2019-08-06 Published:2019-09-04

摘要：

目的　了解百日咳确诊患儿的临床特征、致病菌株的毒力基因分型及抗菌药物敏感性状况。 方法　收集2015—2016年首都医科大学附属北京儿童医院细菌培养确诊的224例百日咳患儿的临床信息，采用E-test法及KB纸片法检测分离的百日咳鲍特菌对抗菌药物的敏感性，并检测菌株的23S rDNA基因耐药突变及其抗原基因型。结果　224例患儿分别来自全国14个省份，其中150例（67.0%）患儿＜6月龄，176例（78.6%）例患儿未接种或未完成全程百日咳疫苗接种。224株百日咳鲍特菌的主要抗原基因型为ptxA1/ptxC1/ptxP1/prn1/fim2-1/fim3-1/tcfA2，占90.6%（203/224）。所有红霉素耐药菌株均为ptxP1基因型，且23S rDNA基因均检测到A2047G位点突变。分离到18株ptxP3基因型高毒力株，对大环内酯类药物均敏感。全部分离株对磺胺甲基异噁唑/甲氧苄啶（SMZ）最小抑菌浓度（MIC）值分布范围为0.004～0.500 mg/L。结论　当前培养确诊的百日咳患儿以未接种疫苗的小婴儿为主，致病菌株的抗原基因型主要为ptxA1/ptxC1/ptxP1/prn1/fim2-1/fim3-1/tcfA2，该型菌株普遍对大环内酯类耐药。高毒力的ptxP3型致病菌株较少见，均对大环内酯类敏感。体外药物敏感性试验提示SMZ可用于百日咳的经验治疗。

关键词: 百日咳鲍特菌, 毒力基因, 抗菌药物敏感性

Abstract:

Objective　To summarize the clinical characteristics of children with pertussis and investigate the distribution of virulence-related genotypes and antimicrobial susceptibility among the Bordetella pertussis isolates. Methods　The clinical information of 224 culture-positive pertussis cases in Beijing Children’s Hospital，Capital Medical University from 2015 to 2016 was collected. Antimicrobial susceptibility was determined by E-test and Kirby-Bauer（KB） disk diffusion methods. A fragment of the 23S rDNA genes was detected for drug-resistance mutation and antigen genotypes. Results　The 224 culture-positive pertussis cases were from 14 provinces or municipalities. Among the 224 subjects，150 patients（67.0%） were younger than 6 months old and 176 patients（78.6%） were unvaccinated or not fully vaccinated individuals. The commonest virulence-associated genotype was ptxA1/ptxC1/ptxP1/prn1/fim2-1/fim3-1/tcfA2，with frequencies of 90.6%（203/224）. All erythromycin-resistant strains were determined A2047G mutation in 23S rDNA sequences，and the strains were the ptxP1 genotype（203/224）. Eighteen ptxP3 strains were identified in the present study and all ptxP3 strains were sensitive to erythromycin. All isolates were determined low MIC against sulphamethoxazole/trimethoprim（0.004-0.500 mg/L）. Conclusion　The culture-positive pertussis cases are mostly infants and young children unvaccinated or not-fully vaccinated. The isolates genotyped as ptxA1/ptxC1/ptxP1/prn1/fim2-1/fim3-1/tcfA2 are widespread，which are highly resistant to erythromycin. The high-virulent strains harboring ptxP3 are rare，and are sensitive to erythromycin. Sulphamethoxazole/trimethoprim is effective to treat pertussis caused by erythromycin-resistant isolates.

Key words: Bordetella pertussis, virulence-related gene, antimicrobial susceptibility