In vitro synergistic activity of some chinolinic compounds combined with beta-lactam antibiotics against gram-positive and gram-negative clinical isolates.
The antimicrobial activities of nalidixic acid-cephalexin (ratio 1:1) and cinoxacin-cefadroxil (ratio 1:2) combinations have been evaluated against 396 clinical isolates; many of them were nalidixic acid- or cinoxacin-resistant organisms (MIC greater than or equal to 100 micrograms/ml). We have also tested the nalidixic acid-amoxicillin combination (ratio 1:1) against 225 amoxicillin-resistant bacterial strains (MIC greater than or equal to 800 micrograms/ml). Synergy was found for 62-70% of the Enterobacteriaceae and nonfermenter bacilli tested and for 85-92% of the gram-positive bacterial strains. The 225 clinical isolates resistant to amoxicillin (MIC greater than or equal to 800 micrograms/ml) were synergistically inhibited by the nalidixic acid-amoxicillin combination.
D000658:Amoxicillin / Q000494:pharmacology; D002434:Cefadroxil / Q000494:pharmacology*; D002506:Cephalexin / Q000494:pharmacology*; D002937:Cinoxacin / Q000494:pharmacology*; D004357:Drug Synergism; D004755:Enterobacteriaceae / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests; D009268:Nalidixic Acid / Q000494:pharmacology*; D011724:Pyridazines / Q000494:pharmacology*
D011724:Pyridazines; D002434:Cefadroxil; D009268:Nalidixic Acid; D000658:Amoxicillin; D002937:Cinoxacin; D002506:Cephalexin