耐甲氧西林金黄色葡萄球菌在ICU物体表面的生存性研究

Study on the survival of Methicillin-resistant staphylococcus aureus on the surface of medical devices in ICU

目的探讨三级甲等医院ICU里医务人员频繁接触的诊疗器械及物品表面付着的耐甲氧西林金黄色葡萄球菌(MRSA)的生存周期,为选择最佳材质、最有效方法减少MRSA引起的医院感染提供依据,从而更有效地预防与控制感染的发生。方法将ICU医务人员频繁接触的物品分成7种不同材质[棉布、聚氯乙烯树脂塑料(PVC)、橡胶、铜、不锈钢、铬合金、银],采用Kirby-Bauer(K-B)纸片法检测MRSA菌,分离MRSA菌调制菌悬液,用无菌滴管吸菌悬液0.5μL分别滴入7种材质物品表面,并分别放入20℃及35℃培养箱里进行MRSA菌培养。调查7种材质表面付着MRSA的生存周期,分别于付着后1～8h内,干燥后即刻,干燥后第1、2、3、7、15、30天后在2种不同温度下监测MRSA的存活情况。结果研究发现铜片上付着的MRSA无论20℃或35℃均在干燥后即刻死亡;棉布、银片、铬合金上付着的MRSA无论在20℃或35℃下30d后均死亡,而PVC、橡胶、不锈钢附着的MRSA在20℃与35℃下生存周期不同。因此MRSA在不同材质上生存周期明显不同,MRSA最不易生存的材质是铜;相同材质不同温度MRSA菌生存期也不同。结论 MRSA在铜具物品表面不易附着,其物表保持干燥后MRSA立即死亡,这为临床选择有效杀菌材质提供依据,从而防止MRSA在医院内传播。

Objective To explore the life cycle of Methicillin-resistant Staphylococcus aureus(MRSA)on the surface of medical devices and articles frequently contacted by medical staff in ICU of a third-grade hospital,and to provide the basis for selecting the best material and the most effective method to reduce the hospital infection caused by MRSA.Methods The items frequently contacted by medical staff in the ICU were divided into 7 different materials[cotton,polyvinyl chloride resin(PVC),rubber,copper,stainless steel,chrome,silver],and the MRSA was detected and identified by the Kirby-Bauer(KB)method.The suspension of MRSA was prepared and 0.5μL of the suspension was dropped into the surface of 7 kinds of materials,and then placed in an incubator at 20℃and 35℃for cultivation.The survival of MRSA on the surface of 7 kinds of materials was monitored under two temperatures at the time of 8 hours after attachment,immediately after drying,1,2,3,7,15 and 30 days after drying,respectively.Results It was found that the MRSA applied on the copper sheet died immediately after drying at 20℃or 35℃;The MRSA attached to the cotton cloth,silver sheet and chromium alloy died after 30 days at 20℃or 35℃,while the MRSA attached to PVC,rubber,stainless steel has different life cycle at 20℃and 35℃,therefore,the life cycle of MRSA was different on different materials.The most difficult survival material for MRSA was copper.Conclusion The most difficult survival material for MRSA was copper.MRSA applied on the copper sheet died immediately after drying at 20℃or 35℃.This provides a basis for clinical selection of effective bactericidal materials.