环境物体表面不同采样与接种方法在不同材料表面采样结果比较

Comparison of sampling results of different sampling and inoculation methods on the surface of different materials

摘要:

目的 评估不同采样方法检测不同材料表面细菌污染状况的检测效能，寻找一种既符合国家规范又能简便快捷、准确反映物体表面实际微生物污染状况的采样方法。 方法 将灭菌不锈钢板与灭菌无纺布表面均匀涂布腐生葡萄球菌，自然干燥后，分别用三磷酸腺苷（ATP）生物荧光法、棉拭子涂抹法、载体压印法、滤膜法进行物体表面采样并检测菌落总数，比较不同采样方法的差异性。应用SPSS 18.0软件进行数据分析。 结果 不同污染浓度下，不锈钢板和无纺布均是载体压印法检出菌落数最高，其次为滤膜法，棉拭子涂抹法检出菌落数最低。当无纺布染菌量为10⁶ CFU/mL时，载体压印法的检测合格率（30.0%）低于棉拭子涂抹法（80.0%）、滤膜法（80.0%）及ATP生物荧光法（90.0%），差异均有统计学意义（均P < 0.05）。ATP生物荧光法容易出现假阴性结果。在染菌浓度为10⁷ CFU/mL时，棉拭子涂抹法与ATP生物荧光法对无纺布表面采样检测结果的Pearson相关系数为0.838（P=0.002），两种采样方法的检测结果具有良好的相关性。 结论 载体压印法对物体表面污染细菌采样菌落检出数及灵敏度高于棉拭子涂抹法、滤膜法及ATP生物荧光法，载体压印法可用于医疗机构环境物体表面和手表面细菌监测采样；ATP生物荧光法与棉拭子涂抹法对人工污染无纺布表面细菌载量检测结果具有较好的相关性。

Abstract:

Objective To evaluate the detection efficiency of different sampling methods to detect bacterial contamination on the surface of different materials, and explore a sampling method that not only conforms to national standards, but also can simply, quickly and accurately reflect the actual microbial contamination on object surface. Methods Surface of sterilized stainless steel plate and sterilized non-woven fabric were evenly coated with Staphylococcus saprophyticus, after natural drying, object surface were taken samples and detected the total number of bacterial colonies by adenosine triphosphate (ATP) bioluminescence assay, cotton swab smearing method, carrier imprinting method, and membrane filtration method, differences in different sampling methods were compared. Data were analyzed by SPSS 18.0 software. Results Under different contamination concentrations, stainless steel plates and non-woven fabrics had the highest number of bacteria detected by carrier imprinting method, followed by membrane filtration method, while cotton swab smearing method had the lowest number of detected bacteria. When bacterial colonies of non-woven fabric was 10⁶ CFU/mL, the qualified rate of carrier imprinting method (30.0%) was lower than that of cotton swab smearing method (80.0%), membrane filtration method (80.0%) and ATP bioluminescence assay (90.0%), differences were all statistically significant (all P < 0.05). ATP bioluminescence assay was prone to get false negative results. When bacterial concentration was 10⁷ CFU/mL, Pearson correlation coefficient between cotton swab smearing method and ATP bioluminescence assay was 0.838 (P=0.002), detection results of two sampling methods had good correlation. Conclusion Carrier imprinting method is more sensitive than cotton swab smearing method, membrane filtration method and ATP bioluminescence assay for the detection of bacterial colonies contaminated on object surface, carrier imprinting method can be used for the monitoring of bacteria on environmental object surface and hands in medical institutions; ATP bioluminescence assay and cotton swab smearing method have a good correlation to the detection results of bacterial load on artificially contaminated non-woven fabric surface.