An approach for the evaluation of synergy between antimicrobials.
Synergy can be assessed by a variety of microbiological techniques. Mathematical modelling of synergy data can accomplish similar results and may provide more information than currently available techniques. In this study a combination of 1/4 MIC of aztreonam (AZTR) and 1 MIC of ciprofloxacin (CIPX) showed synergy against Pseudomonas aeruginosa in killing curve studies (based on the two log different criteria) at the end of 24 h. However, re-growth was always observed even when bactericidal concentrations of antibiotics were present. The surviving organisms showed a two-fold increase of MIC to CIPX after the studies and this resistance was not reversible. A mathematical model to quantitatively describe this observation is proposed.
Wang
Jean Z Y
JZ
Pharmaceutics, School of Pharmacy, University of Connecticut, Storrs, CT 06269, USA.
Nightingale
Charles H
CH
Sweeney
Kevin S
KS
Xi
Nian-Zhu
NZ
Wang
Deng-Ming
DM
D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D001398:Aztreonam / Q000008:administration & dosage*; D002939:Ciprofloxacin / Q000008:administration & dosage*; D024881:Drug Resistance, Bacterial; D004357:Drug Synergism; D006801:Humans; D066298:In Vitro Techniques; D008826:Microbial Sensitivity Tests; D008954:Models, Biological; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000254:growth & development
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D001398:Aztreonam