Traub W H
Appl Microbiol. 1969 Jul;18(1):51-6. doi: 10.1128/am.18.1.51-56.1969.
One of the drawbacks of the "tube dilution" method for the assay of antibiotics in human serum has been illustrated by utilizing serum-sensitive and serum-resistant strains of Escherichia coli. In the case of serum-sensitive strains, it was found that fresh serum alone may account for the same degree of inhibition and thus yield minimal inhibitory concentrations identical to those obtained with serum combined with antibiotics, that is, "simulated" serum assay specimens. This fallacy of the method is discussed with regard to those instances in which laboratories were merely to utilize the patient's own coliform organism as the test organism, or with respect to the assay of, for example, polymyxins, in which inadvertently a R(ough) and therefore, serum-sensitive strain of E. coli were to be used as the indicator organism. It is recommended that serum-resistant laboratory strains of Staphylococcus aureus or E. coli of known antibiotic susceptibility be employed as the test organisms proper in order to circumvent the inherent bactericidal activity of serum.
利用血清敏感型和血清耐药型大肠杆菌菌株说明了人血清中抗生素“试管稀释”测定法的一个缺点。对于血清敏感型菌株，发现仅新鲜血清可能导致相同程度的抑制，从而产生与血清与抗生素联合使用时相同的最低抑菌浓度，即“模拟”血清测定标本。针对实验室仅使用患者自身的大肠菌作为测试菌的情况，或例如针对多粘菌素的测定（其中无意中使用了粗糙型因而血清敏感型的大肠杆菌菌株作为指示菌），讨论了该方法的这一谬误。建议使用已知抗生素敏感性的血清耐药型金黄色葡萄球菌实验室菌株或大肠杆菌作为合适的测试菌，以规避血清固有的杀菌活性。
