Muhvich K H, Park M K, Myers R A, Marzella L
Department of Pathology, University of Maryland School of Medicine, Baltimore.
Antimicrob Agents Chemother. 1989 Sep;33(9):1526-30. doi: 10.1128/AAC.33.9.1526.
We have tested the ability of hyperoxia (98% O2-2% CO2 at 2.8 atmospheres absolute [ca. 284.6 kPa]) to enhance killing of Escherichia coli (serotype O18 or ATCC 25922) by nitrofurantoin, sulfamethoxazole, trimethoprim, gentamicin, and tobramycin. We have also looked for interactions between hyperoxia and the aminoglycosides against Pseudomonas aeruginosa ATCC 27853. Hyperoxia significantly enhanced bacteriostatic activity of nitrofurantoin and trimethoprim as measured by MIC testing. The possibility exists that these effects might be due to the method required to tests MICs under hyperoxic conditions rather than to the effect of hyperoxia itself. In addition, hyperoxia enhanced killing of bacteria by trimethoprim as measured by MBC testing. Hyperoxia decreased numbers of E. coli by 1.3 log10 and P. aeruginosa by 2.7 log10 in cation-supplemented Mueller-Hinton broth medium. The bacteriostatic effects of hyperoxia did not affect MICs of gentamicin or tobramycin. The lack of interaction between hyperoxia and gentamicin or tobramycin was confirmed by determining the number of viable bacteria remaining after 24 h of exposure to hyperoxia by using a pour plate method. We conclude that hyperoxia potentiates the antimicrobial activity of the reduction-oxidation-cycling antibiotic tested (nitrofurantoin) and of one of the antimetabolites tested (trimethoprim). Hyperoxia does not enhance the bactericidal effects of gentamicin and tobramycin, which require oxidative metabolism for transport into bacterial cells.
我们测试了高氧环境（2.8个绝对大气压[约284.6千帕]下98%氧气-2%二氧化碳）增强呋喃妥因、磺胺甲恶唑、甲氧苄啶、庆大霉素和妥布霉素对大肠杆菌（O18血清型或美国典型培养物保藏中心25922）杀灭作用的能力。我们还研究了高氧环境与氨基糖苷类药物对铜绿假单胞菌美国典型培养物保藏中心27853的相互作用。通过最小抑菌浓度（MIC）测试发现，高氧环境显著增强了呋喃妥因和甲氧苄啶的抑菌活性。这些作用可能是由于在高氧条件下测试MIC所需的方法，而非高氧本身的作用。此外，通过最低杀菌浓度（MBC）测试发现，高氧环境增强了甲氧苄啶对细菌的杀灭作用。在补充阳离子的穆勒-欣顿肉汤培养基中，高氧环境使大肠杆菌数量减少1.3个对数10，铜绿假单胞菌数量减少2.7个对数10。高氧环境的抑菌作用并未影响庆大霉素或妥布霉素的MIC。通过倾注平板法测定暴露于高氧环境24小时后剩余的活菌数量，证实了高氧环境与庆大霉素或妥布霉素之间不存在相互作用。我们得出结论，高氧环境增强了所测试的氧化还原循环抗生素（呋喃妥因）和所测试的一种抗代谢物（甲氧苄啶）的抗菌活性。高氧环境并未增强庆大霉素和妥布霉素的杀菌作用，这两种药物需要氧化代谢才能转运进入细菌细胞。
