2009-2014年重庆地区儿童感染肺炎链球菌的耐药性及血清分型研究

Resistance and serotype of Streptococcus pneumoniae isolates from children in Chongqing from 2009 to 2014

目的了解重庆地区儿童2009～2014年肺炎链球菌对常用抗菌药物的耐药性及血清型分布。方法分析2009—2014年从临床感染患者标本中检出的11671株肺炎链球菌的分布特征，采用BD Phoenix 100测定肺炎链球菌对18种抗菌药物的药敏试验，按美国临床实验室标准化委员会（CLSI）标准判断结果。荚膜肿胀试验进行血清学分型，并计算疫苗（PCV7、PCV11、PCV13）覆盖率。结果6年共分离肺炎链球菌11671株，检出率为14．37％；〈2岁组肺炎链球菌分离率为50．7％，2-5岁和〉5岁组的分离率30．8％和18．5％，81．5％的分离株在≤5岁年龄段；未检出耐万古霉素和替考拉宁的肺炎链球菌。肺炎链球菌对利奈唑胺、左氧氟沙星、氧氟沙星、利福平和泰利霉素的耐药率低，分别为：0．02％、0．21％、0．08％、1．13％和3．15％；对四环素、阿奇霉素、红霉素、克林霉素、复方磺胺甲噫唑的耐药率均〉70％以上。2009-2014年肺炎链球菌对美罗培南、左氧氟沙星和利奈唑胺的耐药率无明显改变（P〉0．05），其余受试药物的耐药率均有明显改变（P〈0．05）。600株肺炎链球菌共鉴定出20个血清型，常见的肺炎链球菌血清型为19F、19A、6B、23F，PCV13覆盖率为75．5％。结论肺炎链球菌是导致重庆地区儿童呼吸道感染的重要病原菌，对不同抗生素的耐药性不同，并随着时间而变化，应重视细菌耐药性监测，根据药敏试验结果合理选用抗菌药物。重庆地区肺炎链球菌临床分离株以19F、19A、6B、23F血清型为主，推荐PCV13疫苗预防肺炎链球菌感染。

Objective To investigate antibiotic resistance and the prevalence of serotype o f Streptococcus pneurnoniae isolated from Chongqing＇s children during the period of Jan 2009NDec 2014. Methods Identifications and antibiotic susceptibility tests （AST） of the total 11,671 Streptococcus pneumoniae isolates were performed by BD Phoenix 100 automated system. The AST results were interpreted according to the guidelines of the clinical and Laboratory Standards Institute （CLSI）. The capsular serotypes were identified by Quellung reaction and compared with the spectrum of the pneumococcal conjugate vaccine. Results A total of 11,671 Streptococcus pneumoniae were isolated, accounting for 14.37% （11671 strains）. All the samples were divided into 3 groups： younger than 2 years （group 1）, 2 years to 5 years （group 2） and older than 5 years （group 3）. The positive rate in group 1 （50.7%） is higher than that in group 2 （30.8%） and group 3 （18.5%） statistically. Among all the 11,671 Streptococcus pneumoniae, 81.5% were identified from children no more than 5 years old. No strains of Streptococcus pneumoniae were resistant to vancomycin and teicoplanin. The resistant rates of Streptococcus pneumoniae were determined as 0.02% for linezolid, 0.21% for levofloxacin, 0.08% for ofloxacin, 1.13% for rifampicin, 3.15% for telithromycin. The resistant rates to tetracycline, azithromycin, erythrocin, clindamycin, trimethoprim-sulfamethoxazole were more than 70%. There was no significant change （P〉0.05） of nonsusceptibility rates among meropenem, levofloxacin, linezolid isolates during the investigation period. However, the difference of resistancerates of the rest antibioticswere considered statistically significant （P〈0.05）. Among 600 clinical isolates, 592 Streptococcus pneumoniae were divided into 20 serotypes, the most prevalent serotypes of Streptococcus pneumoniae isolates were 19F, 19A, 6B, 23F and PCV13 was expected to cover 75.5%. Conclusion Streptococcus pneumonia is a common cause of respiratory hospitalizationin young children in Chongqing. The drug resistance of Streptococcus pneumoniae to different antibiotics. It should be paid to the bacterial drug resistance so as to reasonably use a antibiotics based on the result of drug susceptibility testing. The prevalent serotypes are 19F, 19A, 6B, 23F and PCV13 is an effective vaccine to prevent the Streptococcus pneumoniae infections.