Downs J T, Andriole V T, Ryan J L
Yale J Biol Med. 1986 Jan-Feb;59(1):11-6.
Fifty-three clinical isolates of Klebsiella and fifty-one clinical isolates of Pseudomonas aeruginosa, twenty-six of which were carbenicillin-(CARB) resistant, were tested for susceptibility to mezlocillin (MEZ), azlocillin (AZL), and piperacillin (PIP), both alone and in combination with tobramycin (TOB) using the microtiter broth diluent method and an inoculum density of 10(6) CFU/ml. The Klebsiella were highly resistant to TOB, MEZ, and PIP (MIC90: 8, greater than 256, greater than 128 micrograms/ml, respectively). Synergy was demonstrated in 53 percent (PIP/TOB) and 51 percent (MEZ/TOB). An indifferent response was observed in 47 percent (PIP/TOB) and 49 percent MEZ/TOB of the Klebsiella. PIP, MEZ, and AZL in combination with TOB showed synergism against CARB-resistant Pseudomonas in less than 10 percent of the strains tested. Synergy could be demonstrated against CARB-susceptible Pseudomonas with the combinations PIP/TOB, AZL/TOB, and MEZ/TOB in 12 percent, 12 percent, and 24 percent, respectively, of the twenty-five strains tested. Indifferent effects were observed in 84 percent, 88 percent, and 76 percent, respectively, of these same CARB-susceptible strains. These data suggest that there is no significant difference in the incidence of synergy with these new penicillins and tobramycin against either Pseudomonas or Klebsiella.
采用微量肉汤稀释法，接种密度为10(6)CFU/ml，对53株克雷伯菌临床分离株和51株铜绿假单胞菌临床分离株（其中26株对羧苄西林耐药）进行了美洛西林（MEZ）、阿洛西林（AZL）和哌拉西林（PIP）单独及与妥布霉素（TOB）联合使用时的药敏试验。克雷伯菌对妥布霉素、美洛西林和哌拉西林高度耐药（MIC90分别为8、大于256、大于128μg/ml）。在53%（哌拉西林/妥布霉素）和51%（美洛西林/妥布霉素）的试验中显示出协同作用。在47%（哌拉西林/妥布霉素）和49%（美洛西林/妥布霉素）的克雷伯菌中观察到无差异反应。哌拉西林、美洛西林和阿洛西林与妥布霉素联合使用时，对测试的不到10%的耐羧苄西林铜绿假单胞菌菌株显示出协同作用。在测试的25株对羧苄西林敏感的铜绿假单胞菌菌株中，哌拉西林/妥布霉素、阿洛西林/妥布霉素和美洛西林/妥布霉素联合使用时，分别在12%、12%和24%的菌株中显示出协同作用。在这些相同的对羧苄西林敏感的菌株中，分别有84%、88%和76%观察到无差异作用。这些数据表明，这些新型青霉素与妥布霉素联合使用时，对铜绿假单胞菌或克雷伯菌产生协同作用的发生率没有显著差异。
