Shifting Genetic Structure of Invasive Serotype 19A Pneumococci in the United States
Shifting Genetic Structure of Invasive Serotype 19A Pneumococci in the United States
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DOI：
10.1093/infdis/jir052
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发表时间：
2011-05-15
影响因子：
6.4
通讯作者：
Brueggemann, Angela B.
中科院分区：
文献类型：
--
作者：
Beall, Bernard W.;Gertz, Robert E.;Brueggemann, Angela B.
背景。自2000年美国引入7价结合疫苗以来，侵袭性血清型（血清19a）肺炎球菌病（IPD）迅速出现。血清19a IPD发病率在2005-2008年期间略有增加（从每10万人2.3例增加到2.5例），而血清19a青霉素耐药性（定义为最小抑制剂浓度[MIC] >= 2 μ g/mL）显著增加（从28.7%增加到43.7%）。为了更好地了解变化，我们对2004-2008年间恢复的血清19a分离株进行了特征分析。我们对2004-2008年通过疾病控制中心活性细菌核心监测发现的所有2767株血清19a IPD分离株进行了抗菌药物敏感性试验。我们对2005-2007年间恢复的1874株血清19a分离株中的1804株（96.3%）和2008年全部148株5岁以下儿童血清19a分离株进行了基因分型。2005-2007年期间，IPD分离株的耐药克隆复合物（CC） 320/271（19A）从20.9%（550株中115株）上升到32.9%（633株中208株），与血清19A青霉素耐药性上升（从28.7%（567株中163株）上升到39.5%（661株中261株），P < 0.001）相对应。2005-2007年期间，320/271（19A）导致的IPD总数有所增加，2005-2008年期间，5岁以下儿童的IPD从每10万人2.1例增加到3.6例。2005-2007年间，血清19A分离株中青霉素敏感/中间推定疫苗逃逸CC695（19A）从7.5%（550例中的41例）增加到13.6%（633例中的85例）（P = 0.002）。血清19a率可能已趋于稳定；然而，克隆转移正在增加阻力。CC320/271（19A）和CC695（19A）引起的IPD增加可能反映了除了抗性之外的其他选择优势。
Background. Following 7-valent conjugate vaccine introduction in the United States in 2000, invasive serotype (sero19A) pneumococcal disease (IPD) emerged rapidly. Sero19A IPD incidence increased slightly during 2005-2008 (from 2.3 cases to 2.5 cases per 100,000 population), whereas sero19A penicillin resistance (defined as a minimum inhibitor concentration [MIC] >= 2 mu g/mL) increased significantly (from 28.7% to 43.7%). To better understand changes, we characterized sero19A isolates recovered during 2004-2008.Methods. We performed antimicrobial susceptibility testing on all 2767 sero19A IPD isolates identified through the Centers for Disease Control Active Bacterial Core surveillance during 2004-2008. We genotyped 1804 (96.3%) of 1874 sero19A isolates recovered during 2005-2007 and all 148 year 2008 sero19A isolates from children < 5 years of age.Results. Resistant clonal complex (CC) 320/271(19A) increased from 20.9% (115 of 550) to 32.9% (208 of 633; P < .001) of IPD isolates during 2005-2007, which paralleled increased sero19A penicillin resistance (from 28.7% [163 of 567 isolates] to 39.5% [261 of 661 isolates]; P < .001). Total IPD due to 320/271(19A) increased during 2005-2007 and increased from 2.1 to 3.6 cases per 100,000 population during 2005-2008 in children < 5 years of age. The penicillin-susceptible/intermediate, putative vaccine-escape CC695(19A) increased from 7.5% (41 of 550) to 13.6% (85 of 633) of sero19A isolates during 2005-2007 (P = .002).Conclusions. Sero19A rates may have plateaued; however, clonal shifts are increasing resistance. Increased IPD caused by CC320/271(19A) and CC695(19A) could reflect additional selective advantages in addition to resistance.