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

作者：Allison F. Messina, K. Katz-Gaynor, Theresa Barton, Naveed Ahmad, Faryal Ghaffar, David A. Rasko, George H. McCracken · 发表于：The Pediatric Infectious Disease Journal · 年份：2007 · DOI：10.1097/inf.0b013e31805cdbeb · 被引用次数：160 · 研究领域：Pneumonia and Respiratory Infections、Respiratory viral infections research、Neonatal and Maternal Infections

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 interm...