Barry A, Pfaller M, Fuchs P, Gerlach E, Hardy D, McLaughlin J
Clinical Microbiology Institute, Tualatin, Oregon 97062.
Eur J Clin Microbiol Infect Dis. 1993 Jun;12(6):469-72. doi: 10.1007/BF01967446.
In vitro studies in five different medical centers documented the susceptibility of 2,440 consecutive isolates of the Enterobacteriaceae against ampicillin-sulbactam disks of different potencies. For determination of MICs, both 2:1 or 1:1 ratios were used as long as the concentrations of sulbactam at the breakpoints remained the same, i.e. MIC < or = 16/8.0 micrograms/ml or < or = 8.0/8.0 micrograms/ml for the susceptible category. Disks containing 10 micrograms of ampicillin and 10 micrograms of sulbactam are still to be preferred with interpretive criteria of > or = 15 mm for susceptible and < or = 11 mm for resistant (MIC > or = 64/32 micrograms/ml or > or = 32/32 micrograms/ml). The reliability of the disk test actually diminished when the amount of sulbactam in the disk was increased.
五个不同医学中心的体外研究记录了2440株连续分离的肠杆菌科细菌对不同效力的氨苄西林-舒巴坦纸片的敏感性。为了测定最低抑菌浓度（MIC），只要舒巴坦在断点处的浓度保持不变，即敏感类别为MIC≤16/8.0微克/毫升或≤8.0/8.0微克/毫升，就使用2:1或1:1的比例。含10微克氨苄西林和10微克舒巴坦的纸片仍为首选，其解释标准为敏感时≥15毫米，耐药时≤11毫米（MIC≥64/32微克/毫升或≥32/32微克/毫升）。当纸片中舒巴坦的量增加时，纸片试验的可靠性实际上会降低。
