Christophe Bernard Louizette, Mott Mariana, da Cunha Gabriela, Caierão Juliana, D Azevedo Pedro, Dias Cícero
Basic Health Sciences Department, Federal University of Health Sciences of Porto Alegre, Porto Alegre, Brazil.
Hospital Moinhos de Vento, Porto Alegre, Brazil.
J Med Microbiol. 2018 May;67(5):687-694. doi: 10.1099/jmm.0.000717.
Invasive pneumococcal disease (IPD) in the elderly is an important public health issue due to the increased proportion of this population in many countries including Brazil. We aimed to characterise pneumococci isolates in adults >50 years with IPD, following the introduction of the 10-valent pneumococcal conjugate vaccine (PCV10) as part of the National Childhood Immunisation Program for children ≤2 years in March 2010. Between 2013 and 2015, pneumococcal isolates were collected and serotypes were determined using multiplex PCR and/or Quellung reaction. Antimicrobial susceptibility was defined by E-test (bioMérieux); genetic diversity was determined using Multiple-Locus Variable Number Tandem Repeat Analysis (MLVA) and, in selected isolates, Multi Locus Sequence Typing (MLST) was performed. Among 102 pneumococcal isolates, the most frequent serotypes were 19A, 13 of 102 (12.7 %) and 22F, 10 of 102 (9.8 %). Ninety-eight isolates were tested for antimicrobial susceptibility. Intermediate resistance to penicillin was present in 2/98 (2.0 %), ceftriaxone in 7/98 (7.1 %) and meropenem in 7/95 (7.4 %) of the isolates (non-meningitis breakpoint: 4 µg ml/2 µg ml/0.5 µg ml, respectively). Resistance to penicillin (meningitis breakpoint ≥0.12 µg ml) was observed in 31/98 (31.6 %) of the isolates. Genetic analysis presented two relevant clonal groups, belonging to non-PCV10 serotypes: 19A (ST320, linked to non-susceptibility) and 22F (ST6403). Our data suggest a predominance of non-PCV10 serotypes among IPD in the elderly population in circulating strains ca. 3 to 5 years after the introduction of PCV10 in Brazil.
由于包括巴西在内的许多国家老年人口比例不断增加，老年人侵袭性肺炎球菌病（IPD）成为一个重要的公共卫生问题。2010年3月，10价肺炎球菌结合疫苗（PCV10）作为国家2岁及以下儿童免疫规划的一部分引入后，我们旨在对50岁以上患有IPD的成年人中的肺炎球菌分离株进行特征分析。2013年至2015年期间，收集肺炎球菌分离株，并使用多重PCR和/或荚膜肿胀反应确定血清型。通过E试验（生物梅里埃公司）确定抗菌药物敏感性；使用多位点可变数目串联重复分析（MLVA）确定遗传多样性，并对选定的分离株进行多位点序列分型（MLST）。在102株肺炎球菌分离株中，最常见的血清型是19A，102株中有13株（12.7%），以及22F，102株中有10株（9.8%）。对98株分离株进行了抗菌药物敏感性测试。2/98（2.0%）的分离株对青霉素呈中度耐药，7/98（7.1%）对头孢曲松呈中度耐药，7/95（7.4%）的分离株对美罗培南呈中度耐药（非脑膜炎折点分别为4 µg/ml/2 µg/ml/0.5 µg/ml）。98株分离株中有31/98（31.6%）对青霉素耐药（脑膜炎折点≥0.12 µg/ml）。遗传分析显示有两个相关的克隆群，属于非PCV10血清型：19A（ST320，与不敏感性有关）和22F（ST6403）。我们的数据表明，在巴西引入PCV10约3至5年后，老年人群IPD的流行菌株中，非PCV10血清型占主导地位。
