Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan.
Sapporo Clinical Laboratory, Inc., Sapporo, Japan.
J Infect Public Health. 2020 Aug;13(8):1094-1100. doi: 10.1016/j.jiph.2020.04.012. Epub 2020 May 21.
Multidrug resistance (MDR) in non-vaccine serotypes (NVTs)-Streptococcus pneumoniae is a global public health concern after the widespread use of pneumococcal conjugate vaccines (PCVs). The present study aimed to analyze the prevalence of serotypes and antimicrobial susceptibilities of non-invasive/colonization isolates of S. pneumoniae eight years after the introduction of PCV in Japan.
A total of 545 non-invasive pneumococcal isolates (460 children, 85 adults) obtained from July 2018 to January 2019 were studied. All isolates were tested for susceptibility to ten antimicrobials and were characterized for serotypes, penicillin binding protein (PBP) genotypes, and macrolide resistance genes.
Among children, 95.0% of isolates belonged to non-13-valent pneumococcal conjugate vaccine (PCV13) serotypes (NVTs), with 15A (15.0%) being dominant, followed by 35B (12.2%), 23A (11.1%), 15B (9.8%), and 15C (9.6%). In contrast, serotype 3 (18.8%) was the most prevalent in adults, while 15A, 10A, and 23A were also common. Serotypes covered by PCV13 and 23-valent pneumococcal polysaccharide vaccine (PPSV23) in all the adult isolates were 25.9% and 48.2%, respectively. High resistance rates were observed against erythromycin, tetracycline, and clindamycin (≥62.4% children, ≥58.8% adults). Penicillin-resistant and penicillin-intermediate isolates represented 2.2% and 33.8% of all isolates, respectively. Most isolates of the three dominant NVTs 15A, 35B, and 23A were non-susceptible to penicillin. Overall, multiple drug resistance (MDR) was detected in 69.0% of all isolates, including dominant NVTs 15A, 35B, 23A, 15B, and 15C. Among all the isolates, 81.8% harbored at least one altered PBP genes, and erm(B), mef(A/E) and both these genes were found in 68.2%, 23.3%, and 6.8%, respectively. High prevalence (>90%) of erm(B) was observed in serogroup 15, and serotypes 23A, 33F, and 12F.
The present study revealed the high prevalence of NVTs 15 and 23A, and 35B showing MDR, suggesting their spread after introduction of routine PCV immunization.
在广泛使用肺炎球菌结合疫苗（PCV）后，非疫苗血清型（NVT）-肺炎链球菌的多药耐药性（MDR）成为全球公共卫生关注的问题。本研究旨在分析日本引入 PCV 八年后非侵袭性/定植分离株肺炎链球菌血清型和抗菌药物敏感性的流行情况。
本研究共检测了 2018 年 7 月至 2019 年 1 月期间获得的 545 株非侵袭性肺炎链球菌分离株（460 例儿童，85 例成人）。所有分离株均进行了十种抗菌药物的药敏试验，并对血清型、青霉素结合蛋白（PBP）基因型和大环内酯类耐药基因进行了鉴定。
在儿童中，95.0%的分离株属于非 13 价肺炎球菌结合疫苗（PCV13）血清型（NVTs），其中 15A（15.0%）最为常见，其次是 35B（12.2%）、23A（11.1%）、15B（9.8%）和 15C（9.6%）。相比之下，血清型 3（18.8%）在成人中最为常见，而 15A、10A 和 23A 也很常见。所有成人分离株中，PCV13 和 23 价肺炎球菌多糖疫苗（PPSV23）覆盖的血清型分别为 25.9%和 48.2%。对红霉素、四环素和克林霉素的耐药率较高（儿童≥62.4%，成人≥58.8%）。青霉素耐药和中介分离株分别占所有分离株的 2.2%和 33.8%。三种主要 NVTs 15A、35B 和 23A 的大多数分离株对青霉素均不敏感。总体而言，所有分离株中，69.0%为多重耐药（MDR），包括主要的 NVTs 15A、35B、23A、15B 和 15C。所有分离株中，81.8%至少携带一种改变的 PBP 基因，erm(B)、mef(A/E)和这两种基因的检出率分别为 68.2%、23.3%和 6.8%。15 组血清型中 erm(B)的高流行率（>90%），而血清型 23A、33F 和 12F 则发现了 mef(A/E)。
本研究表明，15 型和 23A 型 NVT 以及 35B 型 MDR 的高流行率表明，它们在常规 PCV 免疫接种后已经传播。
