The Affiliated Weihai Second Municipal Hospital of Qingdao University, Weihai 264200, China.
National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, State Key Laboratory of Infectious Disease Prevention and Control, Beijing 102206, China.
J Glob Antimicrob Resist. 2022 Mar;28:180-184. doi: 10.1016/j.jgar.2022.01.002. Epub 2022 Jan 10.
We analysed the molecular features and antimicrobial susceptibility of Mycoplasma pneumoniae isolates from Weihai, China, in 2019.
Pharyngeal swabs of 160 paediatric patients with pneumonia-related symptoms were collected and were subjected to culture and subsequent characteristic analysis. The characteristics of M. pneumoniae isolates were analysed by real-time PCR and genotyping. Antimicrobial susceptibility testing was performed against four antibiotics. All isolates were amplified for analysis of macrolide (ML) resistance mutations in domain V of the 23S rRNA gene and were genotyped using multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA) and 'AGT' VNTR detection in the p1 gene.
The M. pneumoniae nucleic acid and culture-positive rate of 160 specimens were 88.1% (141/160) and 51.3% (82/160), respectively. Almost all isolates were ML-resistant (81/82). Point mutation at position 2063 in 23S rRNA was identified in all ML-resistant isolates. The ML resistance rate of M. pneumoniae genotype 2 isolates was 97.6% (41/42). MLVA types 4/5/7/2 and 4/5/7/3 belonged to genotype 1, while type 3/5/6/2 belonged to genotype 2. The numbers of 'AGT' VNTR in the p1 gene from all isolates was in the range of 5-15.
This is the first report that the two genotypes of M. pneumoniae were present in a relatively equivalent ratio, with genotype 2 slightly predominant, in paediatric patients in Weihai in 2019, and the overall ML resistance rate was close to 100%. The minimum inhibitory concentration (MIC) of erythromycin in M. pneumoniae with ML resistance mutation A2063T in Weihai was higher than previously reported.
我们分析了 2019 年中国威海分离的肺炎支原体的分子特征和抗菌药物敏感性。
收集 160 例有肺炎相关症状的儿科患者的咽拭子，进行培养和后续特征分析。采用实时 PCR 和基因分型分析肺炎支原体分离株的特征。对四种抗生素进行抗菌药物敏感性试验。所有分离株均扩增分析 23S rRNA 基因 V 区大环内酯（ML）耐药突变，并采用多位点可变数串联重复（VNTR）分析（MLVA）和 p1 基因中的“AGT”VNTR 检测进行基因分型。
160 份标本的肺炎支原体核酸和培养阳性率分别为 88.1%（141/160）和 51.3%（82/160）。几乎所有分离株均为 ML 耐药（81/82）。所有 ML 耐药分离株均在 23S rRNA 2063 位发现点突变。M. pneumoniae 基因型 2 分离株的 ML 耐药率为 97.6%（41/42）。MLVA 类型 4/5/7/2 和 4/5/7/3 属于基因型 1，而类型 3/5/6/2 属于基因型 2。所有分离株 p1 基因中的“AGT”VNTR 数量在 5-15 之间。
这是首次报道 2019 年威海儿童患者中肺炎支原体两种基因型存在比例相当，其中基因型 2 略占优势，整体 ML 耐药率接近 100%。威海 ML 耐药突变 A2063T 肺炎支原体的最低抑菌浓度（MIC）高于以往报道。
