Azimi P H, Dunphy M G
Division of Infectious Diseases, Children's Hospital Oakland, California.
Antimicrob Agents Chemother. 1989 Sep;33(9):1620-1. doi: 10.1128/AAC.33.9.1620.
Seventy-five strains of Haemophilus influenzae type b, including 45 beta-lactamase-positive strains, were tested by MIC and time kill studies for susceptibility to ampicillin-sulbactam at various ratios. beta-Lactamase-negative strains were inhibited by lower concentrations of ampicillin-sulbactam than beta-lactamase-positive organisms. beta-Lactamase-negative strains showed a decrease in CFU per milliliter by a factor of 10(4) after a 24-h incubation with ampicillin-sulbactam. beta-Lactamase-positive isolates showed an initial decrease by a factor of up to 10(2) CFU per milliliter, but by the end of incubation these isolates grew to approximately the same cell density as the antibiotic-free control regardless of ampicillin-sulbactam ratios. Caution should be exercised in the use of this combination in treatment of meningitis, in which a high bacterial density is commonly encountered.
对75株b型流感嗜血杆菌（其中包括45株β-内酰胺酶阳性菌株）进行了最低抑菌浓度（MIC）和时间杀菌研究，以检测其对不同比例的氨苄西林-舒巴坦的敏感性。β-内酰胺酶阴性菌株比β-内酰胺酶阳性菌株对更低浓度的氨苄西林-舒巴坦敏感。β-内酰胺酶阴性菌株在与氨苄西林-舒巴坦孵育24小时后，每毫升菌落形成单位（CFU）减少了10⁴倍。β-内酰胺酶阳性分离株最初每毫升CFU最多减少10²倍，但孵育结束时，无论氨苄西林-舒巴坦的比例如何，这些分离株的细胞密度都增长到与无抗生素对照大致相同的水平。在治疗通常会遇到高细菌密度的脑膜炎时，使用这种联合用药应谨慎。
