ABSTRACT
Enoxacin displayed activity similar to that of norfloxacin against enterobacteria, Pseudomonas aeruginosa, staphylococci, streptococci and Bacteroides spp. The activity of enoxacin against many strains was reduced in acid conditions, but the pH effect was not so marked as that seen with norfloxacin. Nalidixic acid was found to be more active in acid conditions, particularly against staphylococci, Streptococcus faecalis and Ps. aeruginosa. In conditions simulating the treatment of bacterial cystitis, a single dose of enoxacin, achieving a peak concentration of 50 mg/l, suppressed growth of nalidixic acid-sensitive and -resistant Gram-negative bacilli for periods of between 18 and 25 X 5 h. Reduced susceptibility of bacteria surviving exposure to enoxacin was observed in one nalidixic acid-resistant strain of Escherichia coli and in nalidixic acid-sensitive strains exposed to low doses (peak concentration = 5 mg/l) of enoxacin. These results are similar to those obtained with norfloxacin and substantially better than those obtained with nalidixic acid.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Nalidixic Acid/analogs & derivatives , Nalidixic Acid/pharmacology , Naphthyridines/pharmacology , Anti-Bacterial Agents/therapeutic use , Anti-Infective Agents, Urinary/therapeutic use , Drug Evaluation , Enoxacin , Humans , Hydrogen-Ion Concentration , Models, Biological , Naphthyridines/therapeutic use , Norfloxacin , Urinary Bladder/microbiology , Urinary Tract Infections/drug therapyABSTRACT
In conventional in vitro tests and an experimental bladder model ciprofloxacin proved very active against 103 strains of enterobacteria isolated from infected urine. Nalidixic acid-resistant strains were less susceptible to ciprofloxacin than nalidixic acid-sensitive strains, and the activity of the drug was reduced under acid conditions. Nevertheless, all strains were inhibited by 4 mg/l of ciprofloxacin at pH 5.5. Streptococcus spp., Staphylococcus aureus, Pseudomonas aeruginosa and Bacteroides spp. were less susceptible than enterobacteria, although most strains were inhibited by a therapeutically achievable concentration of 2 mg/l. Under conditions simulating the treatment of bacterial cystitis, changing concentrations of ciprofloxacin well within levels achievable in urine inhibited dense bacterial cultures for periods exceeding 24 hours, and surviving bacteria did not exhibit any reduction in susceptibility.
Subject(s)
Anti-Infective Agents, Urinary/therapeutic use , Cystitis/drug therapy , Enterobacteriaceae Infections/drug therapy , Quinolines/therapeutic use , Ciprofloxacin , Dose-Response Relationship, Drug , Drug Resistance, Microbial , Enterobacteriaceae/drug effects , Humans , Nalidixic Acid/therapeutic useABSTRACT
The activity of temocillin was investigated in vitro against 523 clinical isolates of enterobacteria and Pseudomonas aeruginosa. The minimum inhibitory concentration of the new compound for all ampicillin-susceptible enterobacteria and for 90% of ampicillin-resistant enterobacteria was 16 micrograms/ml or less, a concentration readily achieved in plasma. P. aeruginosa strains were uniformly resistant to temocillin. All but 3 of a separate group of 48 enterobacteria exhibiting resistance to the combination of clavulanic acid and amoxicillin were found to be inhibited by 16 micrograms or less of temocillin per ml. The new compound also displayed good activity against a group of laboratory stock cultures selected on the basis of differential resistance to presently available beta-lactam agents. Two of these strains were cefotaxime resistant.
