Impact of the pneumococcal conjugate vaccine on serotype distribution and antimicrobial resistance of invasive Streptococcus pneumoniae isolates in Dallas, TX, children from 1999 through 2005
Impact of the pneumococcal conjugate vaccine on serotype distribution and antimicrobial resistance of invasive Streptococcus pneumoniae isolates in Dallas, TX, children from 1999 through 2005
复制标题
DOI：
10.1097/inf.0b013e31805cdbeb
复制
发表时间：
2007-06-01
影响因子：
3.6
通讯作者：
McCracken, George H., Jr.
中科院分区：
文献类型：
--
作者：
Messina, Allison F.;Katz-Gaynor, Kathy;McCracken, George H., Jr.
背景：由于七价肺炎球菌结合疫苗减少了儿童中疫苗型侵袭性肺炎球菌病（IPD），因此现在更大比例的IPD是由非疫苗（NVT）血清型引起的。我们分析了达拉斯儿童医疗中心导致 IPD 的肺炎链球菌的血清型、抗菌药物耐药性和遗传相关性。方法：收集 1999 年 1 月 1 日至 2005 年 12 月 31 日期间的肺炎链球菌分离株。以达拉斯儿童医疗中心的住院和急诊中心入院人数作为分母来计算 IPD 的发病率。对分离株进行血清分型，并测定其青霉素和头孢噻肟敏感性。通过脉冲场凝胶电泳、多位点序列分型以及青霉素结合蛋白以及mef和erm基因的测定对19A分离株进行了进一步表征。结果：IPD的发病率从1999年的93.6例/10万患者下降到2003年的最低点41例/10万患者（P < 0.001）。 19A血清型引起的IPD病例数有所增加，占2005年IPD病例的40%。IPD分离株对青霉素和头孢噻肟的敏感性从1999年到2005年没有变化（P = 0.687）。从 1999 年到 2005 年，NVT 血清型中青霉素 (P < 0.001) 和头孢噻肟 (P = 0.034) 的敏感性下降。19A 分离株的分子特征显示 ST-199 占优势 (62%)。 2004年和2005年出现了几种高度青霉素耐药和中度头孢噻肟耐药菌株。结论：在达拉斯，七价肺炎球菌结合疫苗从1999年到2005年通过降低疫苗型疾病的发病率而降低了IPD的发病率。 NVT 血清型，特别是 19A，在 2004 年和 2005 年很流行，并且对抗菌药物具有更强的耐药性。
Background: Because the heptavalent pneumococcal conjugate vaccine has reduced vaccine-type invasive pneumococcal disease (IPD) in children, a greater proportion of IPD is now caused by nonvaccine (NVT) serotypes. We analyzed the serotypes, antimicrobial resistance profiles and genetic relatedness of Streptococcus pneumoniae responsible for IPD at Children's Medical Center of Dallas.Methods: S. pneumoniae isolates were collected from January 1, 1999 through December 31, 2005. Incidence of IPD was calculated using inpatient and emergency center admissions to Children's Medical Center of Dallas as the denominator. Isolates were serotyped, and their penicillin and cefotaxime susceptibility determined. The 19A isolates were further characterized by pulsed-field gel electrophoresis, multilocus sequence typing and determination of penicillin-binding proteins and mef and erm genes.Results: The incidence of IPD decreased from 93.6 cases/100,000 patients in 1999 to a nadir of 41 cases/100,000 patients in 2003 (P < 0.001). The number of IPD cases caused by serotype 19A increased, accounting for 40% of the cases of IPD in 2005. Penicillin and cefotaxime susceptibility of IPD isolates did not change from 1999 through 2005 (P = 0.687). There was a decrease in penicillin (P < 0.001) and cefotaxime (P = 0.034) susceptibility in NVT serotypes from 1999 to 2005. Molecular characterization of 19A isolates revealed a predominance of ST-199 (62%). Several highly penicillin-resistant and intermediately cefotaxime-resistant strains emerged in 2004 and 2005.Conclusions: In Dallas, heptavalent pneumococcal conjugate vaccine reduced the incidence of IPD from 1999 to 2005 by reducing the incidence of vaccine-type disease. NVT serotypes, particularly 19A, were prevalent and more resistant to antimicrobials in 2004 and 2005.