National Laboratory for Meningitis and Pneumococcal Infections, Center of Bacteriology, Adolfo Lutz Institute, São Paulo, State of São Paulo, Brazil.
Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiania, State of Goiás, Brazil.
PLoS One. 2018 Nov 29;13(11):e0208211. doi: 10.1371/journal.pone.0208211. eCollection 2018.
In 2010, a ten-valent pneumococcal conjugate vaccine (PCV10) was introduced in the routine infant national immunization program in Brazil. Invasive pneumococcal disease (IPD) caused by serotype 19A (Spn19A) increased after the introduction of PCVs in several countries. We compared the frequency, antimicrobial resistance and molecular patterns of invasive Spn19A strains before and after PCV10 introduction in Brazil using data from the national laboratory-based surveillance.
We analyzed invasive Spn19A strains isolated from 2005-2009 (pre-PCV10 period), 2011-2015 and 2016-2017 (post-PCV10 periods). Antimicrobial susceptibility was performed for all Spn19A strains, and multilocus sequence typing (MLST) was performed for strains isolated in the age groups <5 years and ≥50 years.
Among the study period, a total of 9,852 invasive Spn strains were analyzed, and 673 (6.8%) belonged to serotype 19A. Overall, the proportion of Spn19A among the total number of IPD strains increased from 2.8% in 2005-2009 to 7.0% and 16.4% in 2011-2015 and 2016-2017, respectively. The relative increase in Spn19A was observed especially in children <5 years old (2005-2009: 3.2%; 2011-2015: 15.5%; 2016-2017: 31.2%). The percentage of penicillin resistance (MIC 2.0-4.0 μg/mL), erythromycin resistance and multidrug resistance (MDR) increased after PCV10 introduction due to the expansion of the MDR clonal complex CC320 (2005-2009: 8.6%; 2011-2015: 56.1%; 2016-2017: 66.5%).
We observed an expansion of MDR-CC320 among invasive Spn19A strains after PCV10 introduction in Brazil, probably related to a combination of factors, such as vaccination and antimicrobial pressure. Continued surveillance of Spn19A strains is necessary to monitor the sustainability of this clonal complex in the Brazilian population.
2010 年，巴西将一种十价肺炎球菌结合疫苗（PCV10）纳入国家常规婴儿免疫计划。在几个国家推出肺炎球菌结合疫苗（PCV）后，血清型 19A（Spn19A）引起的侵袭性肺炎球菌病（IPD）有所增加。我们使用国家实验室监测数据比较了巴西 PCV10 引入前后侵袭性 Spn19A 菌株的频率、抗菌药物耐药性和分子模式。
我们分析了 2005-2009 年（PCV10 引入前）、2011-2015 年和 2016-2017 年（PCV10 引入后）分离的侵袭性 Spn19A 菌株。对所有 Spn19A 菌株进行抗菌药物敏感性检测，对年龄<5 岁和≥50 岁组分离的菌株进行多位点序列分型（MLST）。
在研究期间，共分析了 9852 株侵袭性 Spn 菌株，其中 673 株（6.8%）属于血清型 19A。总体而言，Spn19A 占 IPD 菌株总数的比例从 2005-2009 年的 2.8%分别增加到 2011-2015 年和 2016-2017 年的 7.0%和 16.4%。Spn19A 在<5 岁儿童中的相对增加尤其明显（2005-2009 年：3.2%；2011-2015 年：15.5%；2016-2017 年：31.2%）。由于多药耐药克隆复合体 CC320 的扩展（2005-2009 年：8.6%；2011-2015 年：56.1%；2016-2017 年：66.5%），青霉素（MIC 2.0-4.0 μg/mL）耐药率、红霉素耐药率和多重耐药率（MDR）在 PCV10 引入后有所增加。
我们观察到巴西 PCV10 引入后侵袭性 Spn19A 菌株中 MDR-CC320 的扩展，这可能与疫苗接种和抗菌药物压力等多种因素有关。需要继续监测 Spn19A 菌株，以监测该克隆复合体在巴西人群中的可持续性。
