This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hallander, H O Articles by Karlsson, I Search for Related Content PubMed PubMed Citation Articles by Hallander, H O Articles by Karlsson, I

 Previous Article  |  Next Article 

Antimicrob Agents Chemother. 1982 November; 22(5): 743-752

Synergism between aminoglycosides and cephalosporins with antipseudomonal activity: interaction index and killing curve method.

H O Hallander, K Dornbusch, L Gezelius, K Jacobson and I Karlsson

ABSTRACT

Combinations of gentamicin with cefotaxime, moxalactam, and ceftazidime were tested against 43 bacterial strains, most of them blood isolates. With an interaction index of less than or equal to 0.5 as borderline, synergism was demonstrated against 30 to 40% of the strains by the fractional inhibitory concentration index and against 50 to 70% by the fractional bactericidal concentration index. The reproducibility of the index was within +/- 0.2 for two-thirds of 40 repetitive assays and within +/- 0.4 to 0.5 for all of these assays. Similar results were obtained when netilmicin was substituted for gentamicin. The killing curve system for studying antibiotic synergism was standardized to give results comparable to those obtained with the interaction index. This was achieved when one-half of a previously determined minimum bactericidal concentration was used for single drugs and the amount of antibiotic was at least halved again when drugs were used in combination. An initial bacterial concentration of 10(5) to 10(6) colony-forming units per ml is recommended. Given these conditions, synergism could be defined as a 2-log 10 or more decrease in viable count given by both drugs together, as compared with the more active of the pair after 24 h. Prediction of killing curve results could then be obtained with the fractional bactericidal concentration index. When cephalosporins and gentamicin were combined from the start, the beta-lactam antibiotics were less susceptible to inactivation, as demonstrated in time-killing assays. If one of the antibiotics were added after 24 h, synergism was not demonstrable. The results indicate that the new cephalosporins may be advantageously combined with aminoglycosides.

---

Antimicrob Agents Chemother. 1982 November; 22(5): 743-752

This article has been cited by other articles:

• Serrano-Martin, X., Payares, G., De Lucca, M., Martinez, J. C., Mendoza-Leon, A., Benaim, G. (2009). Amiodarone and Miltefosine Act Synergistically against Leishmania mexicana and Can Induce Parasitological Cure in a Murine Model of Cutaneous Leishmaniasis. Antimicrob. Agents Chemother. 53: 5108-5113 [Abstract] [Full Text]  
• Menez, C., Buyse, M., Besnard, M., Farinotti, R., Loiseau, P. M., Barratt, G. (2006). Interaction between Miltefosine and Amphotericin B: Consequences for Their Activities towards Intestinal Epithelial Cells and Leishmania donovani Promastigotes In Vitro. Antimicrob. Agents Chemother. 50: 3793-3800 [Abstract] [Full Text]  
• Martins-Duarte, E. S., Urbina, J. A., de Souza, W., Vommaro, R. C. (2006). Antiproliferative activities of two novel quinuclidine inhibitors against Toxoplasma gondii tachyzoites in vitro. J Antimicrob Chemother 58: 59-65 [Abstract] [Full Text]  
• Santa-Rita, R. M., Lira, R., Barbosa, H. S., Urbina, J. A., de Castro, S. L. (2005). Anti-proliferative synergy of lysophospholipid analogues and ketoconazole against Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae): cellular and ultrastructural analysis. J Antimicrob Chemother 55: 780-784 [Abstract] [Full Text]  
• Oie, S., Uematsu, T., Sawa, A., Mizuno, H., Tomita, M., Ishida, S., Okano, Y., Kamiya, A. (2003). In vitro effects of combinations of antipseudomonal agents against seven strains of multidrug-resistant Pseudomonas aeruginosa. J Antimicrob Chemother 52: 911-914 [Abstract] [Full Text]  
• Gradelski, E., Valera, L., Bonner, D., Fung-Tomc, J. (2001). Synergistic Activities of Gatifloxacin in Combination with Other Antimicrobial Agents against Pseudomonas aeruginosa and Related Species. Antimicrob. Agents Chemother. 45: 3220-3222 [Abstract] [Full Text]  
• Lira, R., Contreras, L. M., Rita, R. M. S., Urbina, J. A. (2001). Mechanism of action of anti-proliferative lysophospholipid analogues against the protozoan parasite Trypanosoma cruzi: potentiation of in vitro activity by the sterol biosynthesis inhibitor ketoconazole. J Antimicrob Chemother 47: 537-546 [Abstract] [Full Text]  
• Meletiadis, J., Mouton, J. W., Rodriguez-Tudela, J. L., Meis, J. F. G. M., Verweij, P. E. (2000). In Vitro Interaction of Terbinafine with Itraconazole against Clinical Isolates of Scedosporium prolificans. Antimicrob. Agents Chemother. 44: 470-472 [Abstract] [Full Text]  
• Mouton, J. W., van Ogtrop, M. L., Andes, D., Craig, W. A. (1999). Use of Pharmacodynamic Indices To Predict Efficacy of Combination Therapy In Vivo. Antimicrob. Agents Chemother. 43: 2473-2478 [Abstract] [Full Text]  
• Mayer, I., Nagy, E. (1999). Investigation of the synergic effects of aminoglycoside- fluoroquinolone and third-generation cephalosporin combinations against clinical isolates of Pseudomonas spp.. J Antimicrob Chemother 43: 651-657 [Abstract] [Full Text]  
• den Hollander, J. G., Mouton, J. W., Verbrugh, H. A. (1998). Use of Pharmacodynamic Parameters To Predict Efficacy of Combination Therapy by Using Fractional Inhibitory Concentration Kinetics. Antimicrob. Agents Chemother. 42: 744-748 [Abstract] [Full Text]