Serotype distribution and drug resistance of Streptococcus pneumoniae in hospitalized patients in Yulin, Guangxi

Abstract

Objective To analyze the serotype distribution, drug resistance rate and drug resistance gene carrying of Streptococcus pneumoniae isolates in hospitalized patients, and evaluate the coverage of the vaccine to the serotype of Streptococcus pneumoniae in this area, so as to provide reference for the rational use of antibiotics in clinic.

Methods A total of 150 strains of non-repetitive Streptococcus pneumoniae isolated from inpatients from January 2015 to December 2019 were collected for serotyping and antimicrobial sensitivity test. The carrying rates of pbp2b, ermB and tetM were detected by PCR.

Results The PCR classification rate of 150 strains of Streptococcus pneumoniae was 93.1%, and the classification rate of capsular swelling test was 100%, and a total of 19 serotypes were divided, mainly 19F and 6B. Children’s serotypes were predominantly 19F, 6B, and 15A; adult serotypes were predominantly 19F, 14, and 23F. The coverage rates of the PCV7, PCV10, PCV13 and PPV23 vaccines were 36.8%, 42.1%, 57.9% and 68.4%, respectively. Strains with serotypes of 19F, 6B, 3, and 23F had higher rates of resistance to antimicrobials. The sensitivity of Streptococcus pneumoniae to penicillin was greater than 96.0%. Antimicrobials with significant differences in resistance rates between invasive and non-invasive strains were penicillin, moxifloxacin, and levofloxacin. The percentage of strains carrying both ermB and tetM resistance genes was 96.0%, and the concordance rate between pbp2b, ermB and tetM resistance genes and the resistance phenotype was >98.0%. A total of 10 multi-resistance combinations were detected, with a multi-resistance rate of 62.6%, and the multi-drug resistance pattern of Streptococcus pneumoniae was mainly concentrated in the 19F and 6B serotypes.

Conclusion There are significant age differences in the serotypes of Streptococcus pneumoniae in this area. The vaccine currently used has low coverage in this region and therefore offer limited protection to the population. The drug resistance rates of Streptococcus pneumoniae varied significantly among serotypes. Erythromycin and tetracycline are not recommended for clinical treatment of Streptococcus pneumoniae. Penicillin can still be used as the first choice for clinical treatment of Streptococcus pneumoniae infection.

Abstract

摘要： 目的 分析住院患者肺炎链球菌分离株的血清型分布、耐药率及耐药基因携带, 评估疫苗对本地区肺炎链 球菌血清型的覆盖率, 为临床合理使用抗菌药物提供参考。 方法 收集2015年1月一2019年12月广西玉林市第一人 民医院住院患者送检标本分离的非重复肺炎链球菌150株, 进行血清分型及抗菌药物敏感性试验。用PCR方法检测 pbp2b、ermB、tetM三种耐药基因的携带率。 结果 150株肺炎链球菌经PCR技术分型率为93.1%, 经荚膜肿胀试验分型 率为100%, 共分出19种血清型, 以19F和6B为主。儿童血清型以19F、6B和15A为主; 成人血清型以19F、4和23F为 主。PCV7、PCV10、PCV13和PPV23疫苗的覆盖率依次分别为36.8%、42.1%、57.9%和68.4%。血清型为19F、6B、3和 23F的菌株对抗菌药物的耐药率较高。肺炎链球菌对青霉素的敏感率大于96.0%。侵袭性与非侵袭性菌株中耐药率有 显著差异的抗菌药物为青霉素、莫西沙星和左氧氟沙星。菌株同时携带 ermB和 tetM两种耐药基因占96.0%, pbp2b、 ermB、 tetM三种耐药基因与耐药表型的一致率>98.0%。共检出10种多重耐药组合, 多重耐药率为62.6%, 肺炎链球菌 的多重耐药模式主要集中在19F和6B血清型中。 结论 本地区人群感染肺炎链球菌的血清型存在明显年龄差异。目 前所使用的疫苗在本地区覆盖率低, 对人群的保护作用有限。不同血清型的肺炎链球菌耐药率差异显著。临床治疗 肺炎链球菌不推荐使用红霉素和四环素, 青霉素仍可作为临床治疗肺炎链球菌感染的首选用药。