植绒转运拭子联合显色培养基对鼻腔金黄色葡萄球菌定植的快速筛查

目的采用植绒转运拭子联合显色培养基对鼻腔金黄色葡萄球菌(SA)定植进行快速筛查,了解耳鼻喉头颈外科患者SA定植情况,为预防SA感染和医院感染防控提供依据。方法采用eSwab植绒转运拭子采集某院耳鼻喉头颈外科门诊患者鼻前庭标本,以WASPLab微生物自动化系统接种于羊血琼脂培养基和MRSA/SA显色培养基,孵育培养16、40 h,自动拍摄、观察菌落,通过质谱(MALDI-TOF MS)、药敏试验和mecA基因检测对SA进行验证。结果共采集200份鼻前庭标本,检出SA菌株48株,其中MSSA23株(占47.9%),MRSA25株(占比52.1%),鼻腔SA定植率为24.0%,MRSA定植率为12.5%。SA筛查阳性报告平均时间为(17.6±6.1)h。培养与质谱鉴定、耐药表型检测的符合率为100.0%,与mecA基因检测的符合率为97.9%。结论基于植绒转运拭子联合显色培养基的快速检测方法准确度较高,报告时间较短,可以用于SA定植快速筛查。

Rapid screening for Staphylococcus aureus nasal colonization by using eSwab flocked nylon swab transport system and chromogenic culture medium

Objective To rapidly screen Staphylococcus aureus (SA) colonized in nasal cavity by using eSwab flocked nylon swab transport system and chromogenic culture medium, understand SA colonization in outpatients in department of otorhinolaryngology-head and neck surgery (ORL-HNS), and provide basis for prevention and control of SA infection as well as healthcare-associated infection(HAI). Methods eSwab was used to collect nasal vestibule specimens of patients in department of ORL-HNS in a hospital, specimens were inoculated on blood agar medium and methicillin-resistant SA(MRSA)/SA chromogenic culture medium by WASPLab microbial automated system, SA colonies were photographed and observed at 16 and 40 hours respectively, results were verified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS), antimicrobial susceptibility testing and mecA gene detection. Results A total of 200 nasal vestibule specimens were collected, 48 strains of SA were isolated, 23(47.9%) of which were methicillin-sensitive SA(MSSA), and 25(52.1%) were MRSA; nasal colonization rate of SA and MRSA were 24.0% and 12.5% respectively. The average reporting time of SA positive screening was (17.6±6.1) hours. Coincidence rate of screening culture with MALDI-TOF MS identification and drug-resistance phenotype detection were both 100.0%, coincidence rate with mecA gene detection was 97.9%. Conclusion The rapid screening method based on eSwab flocked nylon swab transport system combined with chromogenic culture medium has higher accuracy and shorter reporting time, which can be used for rapid screening of SA colonization.