Suller M T, Russell A D
Pharmaceutical Microbiology, Welsh School of Pharmacy, Cardiff University.
J Hosp Infect. 1999 Dec;43(4):281-91. doi: 10.1016/s0195-6701(99)90424-3.
Concern has been growing regarding the potential of antibiotic and disinfectant co-resistance in clinically important bacteria. In this study, the susceptibilities of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) to chlorhexidine (CHX), the quaternary ammonium compounds cetylpyridinium chloride (CPC) and benzalkonium chloride (BC), triclosan, dibromopropamidine isethionate (DBPI) and triclocarban were compared. MRSA exhibited low-level resistance to CHX and the QACs, with MICs of 1.5 to 3-fold (CHX), and 2 to 4-fold (QACs) higher than MSSA. However, the MIC values for MRSA ranged between 0.025 (the MIC of MSSA) and 1 microg/mL with triclosan, and between <5 (the MIC of MSSA) and 75 microg/mL with DPBI. Nevertheless, these strains remain relatively sensitive to most of these antimicrobial agents. The bactericidal efficacy of CHX, CPC and DBPI (with the exception of one strain) correlated with their MIC value. This was not observed using triclosan; MRSA and MSSA strains were equally susceptible to its killing effect, regardless of MIC. The permeabilizing agent, ethylenediamine tetraacetic acid (EDTA) was unable to potentiate the antibacterial activities of the biocides against any of the strains tested. Attempts to select for staphylococcal strains with increased resistance to triclosan, CPC or CHX, using disc diffusion, step-wise broth, or repeated exposure/recovery technique, were only partially successful, and resistance was found to be unstable. The susceptibilities of vancomycin-resistant enterococcus (VRE) and vancomycin-sensitive enterococcus (VSE) to the biocides were also compared and found to be similar both in terms of MIC testing and time-kill studies.
人们越来越关注临床上重要细菌中抗生素和消毒剂共同耐药的可能性。在本研究中，比较了耐甲氧西林金黄色葡萄球菌（MRSA）和甲氧西林敏感金黄色葡萄球菌（MSSA）对洗必泰（CHX）、季铵化合物西吡氯铵（CPC）和苯扎氯铵（BC）、三氯生、乙磺酸盐二溴丙脒（DBPI）和三氯卡班的敏感性。MRSA对CHX和季铵化合物表现出低水平耐药，其MIC比MSSA高1.5至3倍（CHX）和2至4倍（季铵化合物）。然而，MRSA对三氯生的MIC值介于0.025（MSSA的MIC）和1μg/mL之间，对DBPI的MIC值介于<5（MSSA的MIC）和75μg/mL之间。尽管如此，这些菌株对大多数这些抗菌剂仍相对敏感。CHX、CPC和DBPI（除一株外）的杀菌效力与其MIC值相关。使用三氯生未观察到这种情况；MRSA和MSSA菌株对其杀菌作用同样敏感，无论MIC如何。通透剂乙二胺四乙酸（EDTA）无法增强杀菌剂对任何测试菌株的抗菌活性。使用纸片扩散法、逐步肉汤法或重复暴露/复苏技术筛选对三氯生、CPC或CHX耐药性增加的葡萄球菌菌株的尝试仅部分成功，且发现耐药性不稳定。还比较了耐万古霉素肠球菌（VRE）和万古霉素敏感肠球菌（VSE）对杀菌剂的敏感性，发现无论是MIC测试还是时间杀菌研究，两者均相似。
