荚膜肿胀试验阴性肺炎链球菌的菌种鉴定及其抗生素敏感性分析  

Analysis of identification and antibiotic susceptibility of isolates identified as Streptococcus pneumoniae by routine methods with negative quellung reaction results

作　　者：贾举 董方[2] 袁林 高薇 刘丹丹 史伟 姚开虎 Jia Ju;Dong Fang;Yuan Lin;Gao Wei;Liu Dandan;Shi Wei;Yao Kaihu(National Center for Children′s Health,Beijing Children′s Hospital,Capital Medical University,Beijing Pediatric Research Institute,Key Laboratory of Major Diseases in Children,Ministry of Education,Beijing 100045,China;Bacteriology Laboratory,Beijing Children′s Hospital,Capital Medical University,Beijing 100045,China)

机构地区：[1]国家儿童医学中心,首都医科大学附属北京儿童医院,北京市儿科研究所,教育部儿科重大疾病研究重点实验室,北京100045 [2]首都医科大学附属北京儿童医院细菌室,北京100045

出　　处：《中华实用儿科临床杂志》2020年第8期595-599,共5页Chinese Journal of Applied Clinical Pediatrics

基　　金：国家自然科学基金(81371853)。

摘　　要：目的明确临床常规检测为肺炎链球菌,但荚膜肿胀试验阴性的分离菌株中是否存在其他草绿色链球菌,分析其抗生素敏感性,为临床选药提供参考。方法以105株临床分离但荚膜肿胀试验阴性的肺炎链球菌为研究对象,采用草绿色链球菌的多位点序列分析(MLSA)和基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MS)进行菌种鉴定;采用微量肉汤稀释法检测14种抗菌药物的敏感性。结果105株细菌经MLSA确认24株为假肺炎链球菌,其余81株为肺炎链球菌。MALDI-TOF-MS将6株假肺炎链球菌鉴定为肺炎链球菌,3株鉴定为缓症/口腔链球菌;6株肺炎链球菌被鉴定为假肺炎链球菌。全部菌株均对万古霉素、左氧氟沙星和莫西沙星敏感,肺炎链球菌与假肺炎链球菌对头孢呋辛(28.4%和58.4%)、氯霉素(39.5%和4.2%)、红霉素(77.8%和95.8%)和阿奇霉素(75.3%和95.8%)等抗生素不敏感率有明显不同。结论临床常规检测可能将部分假肺炎链球菌鉴定为肺炎链球菌,质谱分析也不能确保正确鉴定;荚膜肿胀试验阴性的肺炎链球菌分离株耐药性情况存在差异,鉴定失误可能影响病原菌及其耐药性的评估。Objective To determine whether these Streptococcus pneumoniae isolates identified by routine cli-nical methods that cannot be serotyped by the quellung reaction contain other species of viridans group streptococci and to determine the antibiotic susceptibility to provide reference for clinical medicine.Methods A total of 105 isolates identified as Streptococcus pneumoniae by routine methods with negative quellung reaction results were enrolled in this study.Multilocus sequence analysis(MLSA)and matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS)were used to identify species of these isolates.Broth microdilution method was used to detect susceptibilities of 14 antibiotics.Results Twenty-four of the 105 isolates were identified as Streptococcus pseudopneumoniae by MLSA,and the remaining 81 were Streptococcus pneumoniae.Six isolates of Streptococcus pseudopneumoniae were misidentified as Streptococcus pneumoniae,and 3 isolates as Streptococcus mitis/oralis by MALDI-TOF-MS;and 6 isolates of Streptococcus pneumoniae were misidentified as Streptococcus pseudopneumoniae.All isolates were susceptible to Vancomycin,Levofloxacin and Moxifloxacin.The non-susceptibility rates between Streptococcus Pneumoniae and Streptococcus pseudopneumoniae against Ceftriaxone(28.4%vs.58.4%),Chloramphenicol(39.5%vs.4.2%),Erythromycin(77.8%vs.95.8%)and Azithromycin(75.3%vs.95.8%)were obviously different.Conclusions Routine clinical methods may misidentify some Streptococcus pseudopneumoniae as Streptococcus pneumoniae,and so does the MALDI-TOF-MS.In addition,Streptococcus pneumoniae isolates with negative results of the quellung reaction showed differences in antimicrobial resistance.And misidentification may affect the evaluation of pathogenic bacteria and antibiotic resistance.

关 键 词：肺炎链球菌 假肺炎链球菌 多位点序列分析 基质辅助激光解析电离飞行时间质谱 药物敏感性 

分 类 号：R446[医药卫生—诊断学]