儿童肺炎金黄色葡萄球菌分离株的分子生物学特征及耐药性研究  

Molecular biological characteristics and antimicrobial resistance of Staphylococcus aureus isolated from children with pneumonia

作　　者：孔黎明 杨鑫[1] 钱素云[1] 董方[2] 刘颖超[1] 王丽娟[1] 姚开虎 宋文琪[2] Kong Liming;Yang Xin;Qian Suyun;Dong Fang;Liu Yingchao;Wang Lijuan;Yao Kaihu;Song Wenqi(Pediatric Intensive Care Unit,Beijing Children′s Hospital,Capital Medical University,National Center for Children′s Health,Beijing 100045,China;Bacteriology Laboratory,Beijing Children′s Hospital,Capital Medical University,Natio-nal Center for Children′s Health,Beijing 100045,China;Key Laboratory of Major Diseases in Children,Ministry of Education,National Key Discipline of Pediatrics(Capital Medical University),National Clinical Research Center for Respiratory Diseases,Beijing Key Laboratory of Pediatric Respiratory Infection Diseases,Beijing Pediatric Research Institute,Beijing Children′s Hospital,Capital Medical University,National Center for Children′s Health,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重症医学科,北京100045 [2]国家儿童医学中心,首都医科大学附属北京儿童医院检验科,北京100045 [3]国家儿童医学中心,首都医科大学附属北京儿童医院,北京市儿科研究所皮肤疾病研究室,北京100045

出　　处：《中华实用儿科临床杂志》2020年第4期268-273,共6页Chinese Journal of Applied Clinical Pediatrics

基　　金：国家自然科学基金(81571948);北京市自然科学基金(7172075)。

摘　　要：目的了解儿童金黄色葡萄球菌(金葡菌)肺炎致病株分子特征及耐药性,供临床诊治参考。方法收集2016年1月至2017年3月首都医科大学附属北京儿童医院确诊为金葡菌肺炎患者分离株,采用头孢西丁纸片法和mecA检测鉴定耐甲氧西林金葡菌(MRSA)或甲氧西林敏感金葡菌(MSSA);对所有菌株进行多位点序列分型(MLST)和葡萄球菌蛋白A(spa)分型,并对MRSA菌株进行葡萄球菌盒氏染色体(SCCmec)分型;采用PCR方法检测21种超抗原(SAgs)基因、杀白细胞素(PVL)基因、黏附基因fnbB、cna;采用琼脂稀释法、E-test检测14种抗生素体外药物敏感性。结果共收集42株金葡菌,其中MRSA、MSSA各21株。MRSA的优势克隆为ST59-SCCmecⅣa-t437(71.4%);MSSA的分型较为分散,以ST25-t078(14.2%)最多见。42株金葡菌中有36株(85.7%)至少携带1种超抗原基因,最常见的超抗原基因型为sek-seq(21.4%);MRSA pvl基因携带率(52.3%)明显高于MSSA(14.2%),而MSSA fnbB及cna基因携带率(42.8%和47.6%)明显高于MRSA(均为9.5%),差异均有统计学意义(均P<0.05)。本组金葡菌多重耐药率达90.4%(38/42株)。结论MRSA在儿童金葡菌肺炎致病株中检出率高,其主要克隆型为ST59-SCCmecⅣa-t437。儿童肺炎金葡菌分离株的超抗原基因携带率和多重耐药率较高,MRSA菌株常携带pvl基因,而MSSA菌株携带fnbB、cna更常见。Objective To investigate the molecular characteristic and antimicrobial resistance of Staphyloco-ccus aureus(S.aureus)isolated from children with pneumonia,in order to provide the evidence for clinical diagnosis and treatment.Method s The S.aureus strains isolated from children diagnosed as S.aureus pneumonia in the Beijing Children′s Hospital,Capital Medical University,between January 2016 and March 2017 were collected.Methicillin-resistant S.aureus(MRSA)and Methicillin-susceptible S.aureus(MSSA)were identified using the cefoxitin disc method and the detection of the mecA gene.S.aureus isolates were characterized by multilocus sequence typing(MLST)and Staphylococcal protein A(spa)typing,and MRSA strains were characterized by Staphylococcal chromosome cassette(SCCmec)typing.Besides,21 superantigens(SAgs)genes,panton-valentine leucocidin(PVL)genes,adhesion genes fnbb and cna were detected by PCR;E-test was used to detect in vitro drug sensitivity of 14 antibiotics.Result s A total of 42 S.aureus were collected,and 21 isolates were MSSA,the same to MRSA,while MSSA strains had relatively dispersed typing,with ST25-t078(14.2%)as the most common one.ST59-SCCmecⅣa-t437(71.4%)were the most predominant clones of MRSA.Of the 42 isolates,36 strains(85.7%)had at least 1 superantigen gene,and sek-seq(21.4%)was the main virulence genotype.The ratio of pvl in MRSA strains(52.3%)was significantly higher than that in MSSA strains(14.2%),while the detection rate of fnbB and cna in MRSA(9.5%,9.5%)was significantly lower than that in MSSA(42.8%,47.6%),and the differences were statistically significant(all P<0.05).Ninety point four percent(38/42 strains)of the S.aureus isolates were multidrug resistant.Conclusions In children with S.aureus pneumonia,MRSA has a high detection rate,and its dominant clonotype is ST59-SCCmecⅣa-t437.The pre-valence of superantigen genes and the multidrug resistant rate of S.aureus are relatively high.MRSA strains often carry pvl,while MSSA strains usually carry fnbB and cna gene.

关 键 词：肺炎 儿童 金黄色葡萄球菌 分子分型 毒力因子 多重耐药 

分 类 号：R72[医药卫生—儿科] R446[医药卫生—临床医学]