医疗环境凝固酶阴性葡萄球菌耐药性监测及耐药基因研究

Drug resistance and resistant genes of coagulase negative Staphylococcus in medical settings

目的研究医疗环境物体表面及医护人员手凝固酶阴性葡萄球菌(CNS)分布及耐药性,为控制医院感染提供科学依据。方法采用细菌生化鉴定仪WalkaWay-40s1及微量生化管进行CNS的分离与鉴定,K-B纸片扩散法进行药敏试验,同时进行耐药基因mecA的聚合酶链反应(PCR)鉴定。结果采集物体表面标本478份,医护人员手标本363份,共培养分离CNS 63株,检出率7.49%;其中15株CNS分离自物体表面,38株分离自护士手,10株分离自医生手。24株(38.09%)CNS具有mecA基因,为耐甲氧西林CNS(MRCNS),分别为表皮葡萄球菌(12株)、溶血葡萄球菌(6株)、瓦氏葡萄球菌(5株)、头状葡萄球菌头状亚种(1株);药敏结果显示,表皮葡萄球菌、溶血葡萄球菌和瓦氏葡萄球菌分别对青霉素、阿莫西林、氨苄西林/舒巴坦、红霉素、头孢唑林、亚胺培南耐药率达87.50%以上,对复方磺胺甲口恶唑、左氧氟沙星、克林霉素、环丙沙星、四环素、庆大霉素的耐药率达20.83%～45.83%。结论医疗环境物体表面及医护人员手携带的CNS存在多重耐药性,应引起临床警惕。

Objective To study the distribution and drug resistance of coagulase negative Staphylococcus（CNS） isolated from the object surface and hands of healthcare workers in medical settings,and to provide scientific basis for controlling healthcare-associated infection.Methods CNS were isolated and identified with bacterial biochemical identification instrument WalkaWay-40s1 and microbiochemical tube,antimicrobial susceptibility testing was performed with disk diffusion method,drug-resistant gene mecA was detected by polymerase chain reaction method.Results A total of 63 isolates of CNS were isolated from 478 object surface samples and 363 hand samples,the isolation rate was 7.49%,15 CNS isolates were from object surface,38 were from nurses＇ hands and 10 were from doctors＇ hands.24（38.09%） isolates carried mecA gene and were methicillin-resistant CNS（MRCNS）,12 of which were Staphylococcus epidermidis,6 were Staphylococcus haemolyticus,5 were Staphylococcus warneri,and 1 was Staphylococcus capitis subsp.capitis;drug resistant rate of Staphylococcus epidermidis,Staphylococcus haemolyticus,and Staphylococcus warneri to penicillin,amoxicillin,ampicillin/sulbactam,erythromycin,cefazolin,and imipenem was above 87.50% respectively,the resistant rate to trimethoprim/sulfamethoxazole,levofloxacin,clindamycin,ciprofloxacin,tetracycline,and gentamycin were 20.83%-45.83%.Conclusion CNS carried by object surface and hands of healthcare workers in medical settings are multidrug-resistant and should be paid attention.