rosoxacin and flumequine

The frequency with which Escherichia coli mutated to resist a series of ten 4-quinolone antibacterials was studied. It was found that the mutation frequency could not be predicted from the potency of the drugs against sensitive bacteria. The mutation rates were lowest with ofloxacin, norfloxacin and ciprofloxacin. No mutants were observed with ofloxacin while less mutants were observed with norfloxacin than with ciprofloxacin, despite the latter possessing greatest activity against susceptible bacteria. The mutation frequencies observed with nalidixic acid, cinoxacin, pipemidic acid, flumequine, rosoxacin, oxolinic acid, and enoxacin were much higher than those observed with the three 4-quinolones mentioned earlier. When the sensitivities of the mutants to 4-quinolones were investigated, it was again found that the potency of each 4-quinolone against sensitive bacteria did not correlate with the levels of resistance of mutants to that drug. However, when the relative activities of the 4-quinolones against the mutants were investigated, it was found that no mutant isolated resisted a concentration exceeding the peak serum levels of ciprofloxacin, norfloxacin or ofloxacin. Although some mutants exhibited more resistance than the maximum attainable serum levels of the other 4-quinolones, the sensitivity of all the mutants fell well within the urine levels of pipemidic acid, flumequine, rosoxacin, oxolinic acid, enoxacin, norfloxacin, ofloxacin, and ciprofloxacin.

Topics: 4-Quinolones; Anti-Bacterial Agents; Cinoxacin; Ciprofloxacin; Drug Resistance, Microbial; Enoxacin; Escherichia coli; Fluoroquinolones; Mutation; Nalidixic Acid; Naphthyridines; Norfloxacin; Ofloxacin; Oxazines; Oxolinic Acid; Pipemidic Acid; Quinolines; Quinolizines; Quinolones

The minimal inhibitory concentrations (MICs) of twelve 4-quinolone antimicrobials were determined for Salmonella typhi (25), Salmonella spp. (50), Shigella spp. (50), Campylobacter jejuni (100), Vibrio cholerae (10), Vibrio parahaemolyticus (10), Yersinia enterocolitica (25), Aeromonas hydrophila (25) and Plesiomonas shigelloides (10). MICs were determined using an agar dilution technique in Mueller-Hinton agar (Oxoid, England) supplemented with 10% lysed horse blood. Antibiotic containing plates were inoculated with approximately 10(4) colony forming units of each organism, contained in 10 microliters of Mueller-Hinton broth (Oxoid, England), using a multipoint inoculator. Following inoculation plates were incubated aerobically for 18 hours at 37 degrees C, except for plates inoculated with Campylobacter jejuni which were incubated microaerophilically for 48 hours at 37 degrees C. The MICs of each antimicrobial for each isolate examined, together with the minimum concentrations of each antimicrobial required to inhibit 50% (MIC50) and 90% (MIC90) of the isolates examined, were also determined. The more recently synthesized 4-quinolones showed very good activity against all of the enteric pathogens examined with ciprofloxacin being the most active (MIC90: Salmonella typhi 0.015 microgram/ml, Salmonella spp. 0.015 microgram/ml, Shigella spp. 0.015 microgram/ml, Campylobacter jejuni 0.12 microgram/ml, Vibrio cholerae 0.008 microgram/ml, Vibrio parahaemolyticus 0.06 microgram/ml, Yersinia enterocolitica 0.015 microgram/ml, Aeromonas hydrophila 0.015 microgram/ml and Plesiomonas shigelloides 0.015 microgram/ml. Where considered clinically appropriate these compounds may have a useful role in the treatment and prevention of diarrhoeal disease caused by these enteric pathogens.

Topics: 4-Quinolones; Aeromonas; Anti-Bacterial Agents; Anti-Infective Agents; Campylobacter fetus; Cinoxacin; Ciprofloxacin; Diarrhea; Enoxacin; Fluoroquinolones; Humans; In Vitro Techniques; Intestines; Microbial Sensitivity Tests; Nalidixic Acid; Naphthyridines; Norfloxacin; Ofloxacin; Oxazines; Oxolinic Acid; Pefloxacin; Pipemidic Acid; Quinolines; Quinolizines; Quinolones; Salmonella; Shigella; Vibrio cholerae; Vibrio parahaemolyticus; Yersinia enterocolitica

The minimal inhibitory concentrations (MICs) of twelve 4-quinolone antimicrobials were determined for 100 isolates of Haemophilus influenzae (including 30 beta-lactamase producing strains) and 100 isolates of Streptococcus pneumoniae. MICs were determined using an agar dilution technique in Mueller-Hinton agar supplemented with 10% lysed horse blood. The inoculum used was approximately 10(4) colony-forming units, contained in 10 microliters of Mueller-Hinton broth, which was applied to the agar plates using a multipoint inoculator. Following inoculation, plates were incubated at 37 degrees C for 18 h in an atmosphere enriched to 10% carbon dioxide. The MIC of each antimicrobial for each isolate examined was determined as the lowest concentration of the antimicrobial which completely inhibited growth of the inoculum. The minimum concentrations required to inhibit the growth of 50% (MIC50) and 90% (MIC90) of the organisms examined were also determined. The more recently synthesised 4-quinolones showed considerably greater activity than nalidixic acid and pipemidic acid against clinical isolates of Haemophilus influenzae and Streptococcus pneumoniae. There was no apparent difference between the MICs observed for beta-lactamase producing and non-beta-lactamase producing strains of Haemophilus influenzae. Ciprofloxacin was the most active 4-quinolone examined (MIC90 for Haemophilus influenzae 0.008 microgram/ml; Streptococcus pneumoniae 2 micrograms/ml). Clinical studies on a possible role for some of the more recently synthesised 4-quinolones in the management of patients with respiratory infection are indicated.

Topics: 4-Quinolones; Anti-Infective Agents; Cinoxacin; Ciprofloxacin; Enoxacin; Fluoroquinolones; Haemophilus influenzae; Humans; Microbial Sensitivity Tests; Nalidixic Acid; Naphthyridines; Norfloxacin; Ofloxacin; Oxazines; Oxolinic Acid; Pefloxacin; Pipemidic Acid; Quinolines; Quinolizines; Quinolones; Streptococcus pneumoniae

The minimal inhibitory concentrations (MICs) of nalidixic acid, pipemidic acid, cinoxacin, oxolinic acid, flumequine, pefloxacin, acrosoxacin, amifloxacin, norfloxacin, enoxacin, ofloxacin and ciprofloxacin were determined for a range of clinical isolates. MICs were determined using an agar dilution technique in Mueller-Hinton agar supplemented with 10% lysed horse blood. The inoculum used was approximately 10(4) colony forming units, contained in 10 microliters Mueller-Hinton broth, which was applied to the agar plates using a multipoint inoculator. Following inoculation, plates were incubated in conditions appropriate for the organisms under investigation. The MIC of each antimicrobial for each isolate examined was determined as the lowest concentration of the antimicrobial which completely inhibited growth of the inoculum. The minimum concentrations required to inhibit the growth of 50% (MIC50) and 90% (MIC90) of the organisms examined were also determined. All of the more recently synthesised 4-quinolones showed considerably greater activity than the parent compounds, nalidixic acid, pipemidic acid and cinoxacin, against the range of organisms used in this study. Ciprofloxacin and ofloxacin were the two most active of the 4-quinolones examined.

Topics: 4-Quinolones; Anti-Infective Agents; Bacteria; Cinoxacin; Ciprofloxacin; Enoxacin; Fluoroquinolones; Humans; Microbial Sensitivity Tests; Nalidixic Acid; Naphthyridines; Norfloxacin; Ofloxacin; Oxazines; Oxolinic Acid; Pefloxacin; Pipemidic Acid; Quinolines; Quinolizines; Quinolones

Some new quinolones may be used for the treatment of gonococcal urethritis. U. urealyticum is considered as a potential agent of urethritis. This report describes the in vitro antimicrobial activity of seven quinolones against 45 clinical isolates of U. urealyticum. The MIC's geometric mean is (microgram/ml): rosoxacin (1,74), pefloxacin (4,6), oxolinic acid (9), flumequin (12,12), norfloxacin (15,75), nalidixic acid (27). Pipemidic acid is constantly inactive (greater than 128 micrograms/ml). The results of these susceptibility studies provide support for undertaking clinical evaluations of new quinolones against infections with U. urealyticum.

Topics: 4-Quinolones; Anti-Bacterial Agents; Fluoroquinolones; Nalidixic Acid; Norfloxacin; Oxolinic Acid; Pefloxacin; Pipemidic Acid; Quinolines; Quinolizines; Quinolones; Ureaplasma