不同种属菌株对 3 种食品用消毒剂的抗性比对研究

Comparative study on the resistance of different species strains to 3 kinds of food disinfectants

中文关键词:  消毒剂  指示微生物  种属  抗性  差异

英文关键词:disinfectant  biological indicators  species  resistance  difference

中文摘要:

      目的 比较18种菌株和2种指示微生物对含氯、过氧化氢及季铵盐类消毒剂的抗性差异。方法 选取食品、环境和人体来源的革兰氏阴性菌、革兰氏阳性菌及芽孢菌3类菌株(每类6种), 经基质辅助激光解吸电离飞行时间质谱仪(matrix-assisted laser desorption ionization time of flight mass spectrometry, MALDI-TOF MS)和生化鉴定种属。以金黄色葡萄球菌ATCC6538和大肠杆菌8099 2种指示微生物为参考菌株, 制备2.0×108~10.0×108 CFU/mL菌悬液, 检测其对次氯酸钠(有效氯0.00400%~0.00499%)、过氧化氢(7.5%)及苯扎溴铵(3.996 mg/mL)的耐受性, 作用时间均为3 min。通过计算消毒剂对不同菌株的杀灭对数值(killing log value, KL), 比较不同种属菌株对3种消毒剂抗性差异。结果 消毒剂杀菌效力从强到弱为: 次氯酸钠、过氧化氢、苯扎溴铵; 不同菌种抗性存在显著差异, 且常见的3类菌株(革兰氏阴性菌、革兰氏阳性菌及芽孢菌)中, 均有对消毒剂抗性强于2种指示微生物的菌株。结论 次氯酸钠与过氧化氢的杀菌效果优于苯扎溴铵; 菌株抗性具有种属特异性, 不能单纯通过革兰氏分类预判; 指示微生物应依据实际需求扩大筛选范围。

英文摘要:

      Objective To compare the resistance differences of 18 kinds of bacterial strains and 2 kinds of biological indicators to chlorine-containing disinfectants, hydrogen peroxide and quaternary ammonium compounds. Methods Strains were selected from food, environment and human sources, including gram-negative bacteria, gram-positive bacteria and spore-forming bacteria (6 kinds of strains per category). Species identification was performed using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) and biochemical assays. The 2 kinds of biological indicators, namely Staphylococcus aureus ATCC6538 and Escherichia coli 8099 were used as reference strains. Bacterial suspensions (2.0×108–10.0×108 CFU/mL) were prepared to test their tolerance to sodium hypochlorite (available chlorine 0.00400%–0.00499%), hydrogen peroxide (7.5%), and benzalkonium bromide (3.996 mg/mL). All bacterial strains were treated with disinfectants for 3 minutes. By calculating the killing log value (KL) of disinfectants against different bacterial strains, the differences in resistance of different species of bacterial strains to 3 kinds of disinfectants were compared. Results The bactericidal efficacy ranked as sodium hypochlorite, hydrogen peroxide, benzalkonium bromide. Different species showed significant variations in resistance to disinfectants. Among 3 categories of bacterial strains (gram-negative bacteria, gram-positive bacteria and spore-forming bacteria), there were strains within each category that exhibit ?higher resistance to disinfectants? than 2 kinds of biological indicators?. Conclusion Sodium hypochlorite and hydrogen peroxide exhibit superior bactericidal effects compared to benzalkonium bromide. The resistance to disinfectant of bacteria is species-specific and cannot be predicted solely by gram classification. The screening scope for biological indicators should be expanded based on actual needs.