Ciprofloxacin, a quinolone carboxylic acid compound active against aerobic and anaerobic bacteria

Abstract

The in vitro activity of ciprofloxacin, a quinolone-carboxylic acid derivative, was compared with those of norfloxacin, cefotaxime, cephalexin, ceftazidime, moxalactam, amoxicillin, and methicillin and other agents, as appropriate. The MICs of ciprofloxacin for 90% of members of the family Enterobacteriaceae and for Pseudomonas aeruginosa, Neisseria spp., and Bacteroides fragilis were between 0.005 and 0.8 ,ug/ml, whereas streptococci and staphylococci were all inhibited by c6.3 p,g/ml. Ciprofloxacin was 4-to 32-fold more active than norfloxacin and inhibited gentamicin-, ameikacin-, cefotaxime-, and moxalactam-resistant members of the family Enterobacteriaceae and P. aeruginosa and methicillin-resistant Staphylococcus aureus. The activity of ciprofloxacin wkas not affected by serum but decreased in the presence of acid urine.The frequency of resistance to ciprofloxacin was between 10-7 and 10-9.Nalidixic acid, a pyridone-carboxylic acid compound, was introduced into medical use in 1963. It was not used clinically to any great extent because of the rapid development of resistance to the compound (5). In the 1970s, pipemidic acid was synthesized in Japan (6). This compoqnd, which provided reasonable concentrations in tissue, was used to treat infections other than urinary tract infections, as was nalidixic acid and other compounds of this class, such as oxolinic acid and cinoxacin.The development of norfloxacin, a pyridone-carboxylic acid derivative, showed that it was possible to develop compounds of this class which, by virtue of their broad spectrum of activity and the low incidence of resistance to them, would be clinically useful (2, 4). Although the expanded-spectrum cephalosporins inhibit many clinically important bacteria, resistance has already been encountered among Enterobacter and Pseudomonas spp. (3). For this reason, we sought to study cirprofloxacin, a novel quinolone compound, and to compare its activity with those of other agents currently in use. MATERIALS AND METHODSCompounds. All compounds were obtained from their respective manufacturers. Ciprofloxacin was a gift of Bayer; norfloxacin was obtained from Merck Sharp & Dohme.Fresh dilutions of each compound were prepared daily in sterile medium. Bacterial isolates were obtained from patients treated at The Columbia-Presbyterian Medical Center, New York. Both recent isolates and isolates that are multiply resistant to antibiotics had been saved over the past 5 years and were tested. Only one isolate from a patients was tested to avoid multiple copies of the same strain.Susceptibility testing. Antimicrobial susceptibility tests were performed by an agar dilution method with MuellerHinton agar, except where otherwise specified. A final inoculum of 105 CFUs, prepared by dilution of a fresh overnight broth culture, was applied to agar with a replicating spot device. Broth dilutions were performed with 105 CFU in tubes each having a volume of 1 ml. Agar plates and tubes were incubated at 35°C for 18 h. RESULTSCiprofloxacin had an extremely broad rang...

Carriage of Class 1 and 2 Integrons in Quinolone, Extended-Spectrum-β-Lactamase-Producing and Multi Drug Resistant E.coli and K.pneumoniae: High Burden of Antibiotic Resistance

“…Several reports are available on the mechanism of quinolone resistance in either E.coli or K.pneumoniae or even both or quinolone resistance in ESBL producing bacteria; however, no report is available on the actual resistance of nalidixic acid and ciprofloxacin in these two isolates [29][30][31][32][33][34][35] , except few published studies on urinary isolates, [36][37][38][39][40] whereby low prevalence has been reported as compared to our study. Study performed in our neighboring country reported 17% and 38% of E. coli isolates obtained from uncomplicated and complicated UTI respectively, were found resistant to ciprofloxacin.…”

Bioequivalence of Two Oral Extended Release Formulations of Ciprofloxacin Tablets in HealthyMale Volunteers under Fed and Fasting Conditions

“…Chemically it is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid] [3,5,11]. It was found to be more active against enterobacteriaceae than the older drugs of this class, such as nalidixic acid, with minimum inhibitory concentrations ranging from 0.008 to 2.0 mg/l [3,4].…”

Activities of pefloxacin and ciprofloxacin in experimentally induced Pseudomonas pneumonia in neutropenic guinea pigs

“…Both drugs are well absorbed orally, have serum half-lives of 8.6 and 3.9 h, respectively, and reach concentrations in serum well above the MIC for many bacterial species (3, 6). Extensive in vitro studies have shown that ciprofloxacin has a MIC90 of -1 g/ml, whereas pefloxacin has a MIC90 of .2 ,ug/ml for many of the above-mentioned bacteria (2,5,14). It is of special interest that both of these antimicrobial agents are highly active against Pseudomonas aeruginosa, including multiply drug-resistant strains (2, 11).…”