N-乙酰半胱氨酸联合头孢西丁对金黄色葡萄球菌的体外药敏试验研究  

Effect of N-acetylcysteine combined with cefoxitin on Staphylococcus aureus in vitro drug susceptibility tests

作　　者：吴桐[1] 谷海瀛 WU Tong;GU Haiying(Health Science Center,Ningbo University,Ningbo 315211,Zhejiang,China;Laboratory of Gastroenterology,the Affiliated Hospital of Medical School of Ningbo University,Ningbo 315020,Zhejiang,China)

机构地区：[1]宁波大学医学部,浙江宁波315211 [2]宁波大学医学院附属医院消化病实验室,浙江宁波315020

出　　处：《中国现代医生》2023年第27期99-104,共6页China Modern Doctor

摘　　要：目的使用头孢西丁(cefoxitin,FOX)分别与未处理的N-乙酰半胱氨酸(N-acetylcysteine,NAC)和酸碱度调节至中性的NAC对金黄色葡萄球菌(Staphylococcus aureus,S.aureus)ATCC29213、ATCC43300进行体外联合药敏试验,检测FOX与NAC联合应用对S.aureus的作用,评估NAC的酸性特性在发挥药物效果中的影响。方法微量肉汤稀释法测定药物最小抑菌浓度(minimal inhibitory concentration,MIC);棋盘法进行联合药物敏感性试验,结晶紫染色法测定生物被膜(biofilm,BF)形成量,激光共聚焦显微镜观察菌落成分变化。调节NAC至中性再次进行上述试验。结果FOX对S.aureus ATCC29213和ATCC43300的MIC分别为2μg/ml和32μg/ml,NAC对2菌株的MIC均为4mg/ml。酸度调节至中性的NAC对ATCC29213和ATCC43300的MIC均>64mg/ml。保持弱酸性的NAC与FOX间存在相加作用,BF含量、细菌数量、BF多糖成分均有所下降;中性的NAC与FOX联合应用时药物间作用效果为无关甚至拮抗,未出现上述作用效果。结论NAC的存在一定程度上可增加S.aureus体外条件下对FOX的敏感性,降低细菌数量和BF的形成量,且不因菌株耐药性的不同而存在明显差异,但这种作用依赖于NAC自身的酸性。Objective To conduct a combination susceptibility test of cefoxitin(FOX)with N-acetylcysteine(NAC)or NAC adjusted to neutral pH on Staphylococcus aureus(S.aureus)ATCC29213 and ATCC43300,aiming to evaluate the drugs effect and the acidic properties of NAC on S.aureus.Methods Minimal inhibitory concentration(MIC)of FOX and NAC were tested by broth microdilution method;Combining drug susceptibility experiment was tested by the checkerboard method.The biofilm biomass quantification was determined by crystal violet staining.Biofilm(BF)composition changes were visualized using confocal laser scanning microscopy.The experiment was performed again by using neutral NAC.Results MIC of FOX against S.aureus ATCC29213 and ATCC43300 were 2μg/ml and 32μg/ml.MIC of NAC was 4mg/ml for both strains,while the MIC of neutral NAC was greater than 64mg/ml.Both strains show an additive effect between NAC and FOX when the pH was low,where the content of BF,the number of bacteria,and the polysaccharide component of BF decreased.However,the drug’s effects were shown as irrelevant or antagonistic when the pH was adjusted to neutral.Conclusion NAC is able to increase the sensitivity of S.aureus to FOX and significantly destroys BF formation,and the acidity of NAC might be the key to its effects.

关 键 词：金黄色葡萄球菌 生物被膜 N-乙酰半胱氨酸 抗生物被膜 

分 类 号：R37[医药卫生—病原生物学]