Verklin R M, Mandell G L
J Lab Clin Med. 1977 Jan;89(1):65-71.
In vitro antibiotic susceptibility tests of facultative organisms are routinely performed under aerobic conditions, despite the fact that many infections caused by these organisms occur in anaerobic areas, i.e., intra-abdominal absess. Experiments were performed aerobically and anaerobically to determine the susceptibility of E. coli, P. mirabilis, and K. pneumoniae to gentamicin, tobramycin, cephalothin, cefazolin, and cefamandole. Antibiotic sensitivities were determined by disc and agar dilution techniques in air and in anaerobic jars with CO2 absorbed. Tube dilution studies were performed in air and anaerobically and time-kill studies were done in aerobic and anaerobic broth. The amount of aminoglycoside required to inhibit bacterial growth was increased 4 to 20 times by anaerobiosis in 20 of 25 strains tested. Time-kill curves showed that bacterial killing by aminoglycosides was markedly impaired by anaerobiosis. Anaerobic conditions had no effect on the rate or extent of killing by cephalosporins. These data may have significance in determination of antibiotic susceptibility of facultative organisms under anaerobic tissue conditions. Antibiotic sensitivity testing done on these organisms in air may not reflect the actual state of antibiotic-bacterial interaction under conditions of the infection.
兼性菌的体外抗生素敏感性试验通常在需氧条件下进行，尽管事实上由这些细菌引起的许多感染发生在厌氧区域，即腹腔脓肿。分别在需氧和厌氧条件下进行了实验，以确定大肠杆菌、奇异变形杆菌和肺炎克雷伯菌对庆大霉素、妥布霉素、头孢噻吩、头孢唑林和头孢孟多的敏感性。通过纸片法和琼脂稀释法在空气中以及在吸收了二氧化碳的厌氧罐中测定抗生素敏感性。在空气中以及厌氧条件下进行了试管稀释研究，并在需氧和厌氧肉汤中进行了时间-杀菌研究。在所测试的25株菌株中，有20株在厌氧条件下抑制细菌生长所需的氨基糖苷类药物量增加了4至20倍。时间-杀菌曲线表明，厌氧条件显著损害了氨基糖苷类药物的杀菌作用。厌氧条件对头孢菌素的杀菌速率或程度没有影响。这些数据对于确定厌氧组织条件下兼性菌的抗生素敏感性可能具有重要意义。在空气中对这些细菌进行的抗生素敏感性测试可能无法反映感染条件下抗生素与细菌相互作用的实际情况。
