Putland R A, Guinness M D
J Clin Microbiol. 1985 Nov;22(5):822-7. doi: 10.1128/jcm.22.5.822-827.1985.
Semiautomated rapid broth elution (Autobac Multi-Test System; General Diagnostics, Div. Warner-Lambert Co., Morris Plains, N.J.) and disk diffusion tests were compared with an agar dilution breakpoint method to determine the antibiotic susceptibility of 147 methicillin-resistant Staphylococcus aureus isolates from our hospital. Although the disk diffusion method, in general, correlated well with the agar dilution tests, the overall agreement of the Autobac tests with agar dilution tests was only 79%, with many very major discrepancies occurring with clindamycin (88%), gentamicin (33%), and methicillin (15%). When we used a 10-fold higher inoculum for the Autobac tests, all isolates were shown to be resistant to methicillin, but significant numbers of major and minor discrepancies occurred with chloramphenicol, fusidic acid, and neomycin. The majority of isolates were shown to belong to three biotypes, distinguishable by lactose fermentation, lipolysis, hemolysis, and pigment production. The antibiotic susceptibility profile of one biotype was found to be markedly different from those of the other biotypes and contained a high incidence of clindamycin susceptibility and neomycin, gentamicin, and kanamycin resistance. In contrast, the other two biotypes had a high incidence of clindamycin, gentamicin, and kanamycin resistance and neomycin susceptibility and accounted for most of the very major discrepancies in the clindamycin and aminoglycoside tests. In these methicillin-resistant S. aureus strains, discrepancies possibly may arise from partial expression of methicillin resistance, dissociated or inducible clindamycin resistance, and instability of gentamicin resistance.
采用半自动快速肉汤洗脱法（自动细菌多重检测系统；通用诊断公司，华纳-兰伯特公司分部，新泽西州莫里斯平原）和纸片扩散法，并与琼脂稀释断点法进行比较，以确定我院147株耐甲氧西林金黄色葡萄球菌分离株的抗生素敏感性。虽然纸片扩散法总体上与琼脂稀释试验相关性良好，但自动细菌检测法与琼脂稀释试验的总体一致性仅为79%，在克林霉素（88%）、庆大霉素（33%）和甲氧西林（15%）检测中出现了许多非常大的差异。当我们将自动细菌检测法的接种量提高10倍时，所有分离株均显示对甲氧西林耐药，但在氯霉素、夫西地酸和新霉素检测中出现了大量的主要和次要差异。大多数分离株显示属于三种生物型，可通过乳糖发酵、脂解、溶血和色素产生来区分。发现其中一种生物型的抗生素敏感性谱与其他生物型明显不同，克林霉素敏感性以及对新霉素、庆大霉素和卡那霉素耐药的发生率较高。相比之下，其他两种生物型对克林霉素、庆大霉素和卡那霉素耐药以及对新霉素敏感的发生率较高，并且在克林霉素和氨基糖苷类检测中占了大部分非常大的差异。在这些耐甲氧西林金黄色葡萄球菌菌株中，差异可能源于甲氧西林耐药的部分表达、解离或诱导性克林霉素耐药以及庆大霉素耐药的不稳定性。
