在美国引入7价肺炎球菌疫苗后，儿科人群中肺炎链球菌非疫苗血清型的抗菌药物耐药性增加。

Increased antimicrobial resistance among nonvaccine serotypes of Streptococcus pneumoniae in the pediatric population after the introduction of 7-valent pneumococcal vaccine in the United States.

作者信息

Farrell David J, Klugman Keith P, Pichichero Michael

机构信息

G. R. Micro Ltd, London, UK.

出版信息

Pediatr Infect Dis J. 2007 Feb;26(2):123-8. doi: 10.1097/01.inf.0000253059.84602.c3.

DOI:10.1097/01.inf.0000253059.84602.c3

PMID:17259873

Abstract

BACKGROUND

The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in the United States in February 2000. The PROTEKT US study evaluated serotype distribution, PCV7 coverage and antimicrobial susceptibility among Streptococcus pneumoniae isolates collected from children aged 0 to 14 years in 2000 through 2001 (year 1; n = 2033), 2002 through 2003 (year 3; n = 1740) and 2003 through 2004 (year 4; n = 1591).

METHODS

Serotyping was performed by Neufeld Quellung reaction. Antimicrobial susceptibilities were determined centrally according to Clinical Laboratory Standards Institute methodology and interpretive breakpoints.

RESULTS

The proportion of isolates covered by PCV7 (vaccine serotypes) decreased from 65.5% (year 1) to 34.7% (year 3) and to 27.0% (year 4) (P < 0.0001) with similar changes seen at regional and state levels. The most common serotypes in year 4 were nonvaccine serotypes (NVS) 19A (19.0% of all isolates), 6A (7.8%), 3 (7.6%), 15 (6.3%) and 35B (5.8%) and vaccine serotype 19F (12.7%). NVS 19A increased relative to vaccine serotype 19F among isolates expressing the erm(B) + mef(A) macrolide-resistant genotype (P < 0.0001) between year 1 (7.8% [19A] versus 86.7% [19F]) and year 4 (45.5% [19A] versus 51.7% [19F]). Antimicrobial resistance rates (year 1 versus year 4) among NVS from nonblood (respiratory tract) sources increased for penicillin (resistant: 12.7-16.1% [P = 0.0857]; intermediate susceptibility: 20.1-31.5% [P < 0.0001]), erythromycin (21.2-31.6% [P < 0.0001]), amoxicillin-clavulanate (1.4-5.8% [P < 0.0001]) and multidrug resistance (resistance to > or =2 antimicrobial classes) (24.6-31.6% [P = 0.0034]).

CONCLUSIONS

The proportion of S. pneumoniae isolates from U.S. pediatric patients covered by PCV7 decreased substantially in the 4 years after vaccine introduction. However, resistance to commonly used antimicrobials, including beta-lactams and macrolides, as well as multidrug-resistant strains increased significantly among respiratory tract isolates of NVS.

摘要

背景

7价肺炎球菌结合疫苗（PCV7）于2000年2月在美国推出。PROTEKT美国研究评估了2000年至2001年（第1年；n = 2033）、2002年至2003年（第3年；n = 1740）和2003年至2004年（第4年；n = 1591）从0至14岁儿童中分离出的肺炎链球菌菌株的血清型分布、PCV7覆盖率及抗菌药物敏感性。

方法

通过纽费尔德荚膜肿胀反应进行血清分型。根据临床实验室标准协会的方法和解释性断点集中测定抗菌药物敏感性。

结果

PCV7覆盖的菌株比例（疫苗血清型）从65.5%（第1年）降至34.7%（第3年），再降至27.0%（第4年）（P < 0.0001），在区域和州层面也有类似变化。第4年最常见的血清型为非疫苗血清型（NVS）19A（占所有分离株的19.0%）、6A（7.8%）、3（7.6%）、15（6.3%）和35B（5.8%）以及疫苗血清型19F（12.7%）。在表达erm(B)+mef(A)大环内酯耐药基因型的分离株中，NVS 19A相对于疫苗血清型19F有所增加（第1年[19A为7.8%，19F为86.7%]与第4年[19A为45.5%，19F为51.7%]之间，P < 0.0001）。非血液（呼吸道）来源的NVS中，青霉素（耐药：12.7 - 16.1%[P = 0.0857]；中介敏感性：20.1 - 31.5%[P < 0.0001]）、红霉素（21.2 - 31.6%[P < 0.0001]）、阿莫西林 - 克拉维酸（1.4 - 5.8%[P < 0.0001]）和多重耐药（对≥2类抗菌药物耐药）（24.6 - 31.6%[P = 0.0034]）的抗菌药物耐药率（第1年与第4年相比）有所增加。