tetracycline and trovafloxacin

Oral Fusobacterium nucleatum populations from 20 young, healthy children were examined for beta-lactamase production. Ten children (50%) harbored, altogether, 25 beta-lactamase-positive F. nucleatum isolates that were identified as F. nucleatum subsp. polymorphum, F. nucleatum subsp. nucleatum, and F. nucleatum subsp. vincentii (J. L. Dzink, M. T. Sheenan, and S. S. Socransky, Int. J. Syst. Bacteriol. 40:74-78, 1990). In vitro susceptibility of these beta-lactamase-producing and 26 non-beta-lactamase-producing F. nucleatum isolates was tested with penicillin G, amoxicillin-clavulanic acid, tetracycline hydrochloride, metronidazole, trovafloxacin, and azithromycin. Except for penicillin G, the antimicrobials exhibited good activity against all F. nucleatum isolates.

Topics: Amoxicillin-Potassium Clavulanate Combination; Anti-Bacterial Agents; Azithromycin; beta-Lactamases; Child, Preschool; Female; Fluoroquinolones; Fusobacterium nucleatum; Humans; Male; Metronidazole; Microbial Sensitivity Tests; Naphthyridines; Penicillin G; Tetracycline

Successful treatment of Helicobacter pylori infection is becoming compromised by emerging resistance. We report the prevalence rates of H. pylori resistance to metronidazole, clarithromycin, amoxycillin, tetracycline and trovafloxacin in The Netherlands. A total of 231 H. pylori clinical isolates were collected throughout the country over a period of 6 months during 1997-1998. The MICs of the above-mentioned antibiotics were determined in a single laboratory. The overall percentage of resistance for clarithromycin and metronidazole was 1.7% and 21.2%, respectively. None of the strains was resistant to amoxycillin or tetracycline. The primary resistance rate of trovafloxacin was as high as 4.7%. Since trovafloxacin has not yet been introduced on to the Dutch market, the resistance is probably induced by the use of other quinolones. Our data indicate that treatment outcome would benefit from susceptibility testing before starting therapy, especially when prescribing metronidazole.

Topics: Amoxicillin; Anti-Bacterial Agents; Clarithromycin; Drug Resistance, Microbial; Drug Resistance, Multiple; Drug Utilization; Fluoroquinolones; Helicobacter Infections; Helicobacter pylori; Humans; Metronidazole; Microbial Sensitivity Tests; Naphthyridines; Netherlands; Tetracycline

The activities of ampicillin, amoxycillin-clavulanic acid, gentamicin, tetracycline, nalidixic acid, ciprofloxacin, pefloxacin and trovafloxacin against 207 consecutive clinical isolates of Escherichia coli were determined. Fifty-six (27.3%) isolates were haemolytic. The percentages of resistance to quinolones and tetracycline, but not to other agents, among haemolytic isolates were significantly lower (P < 0.05) than among non-haemolytic isolates. Ciprofloxacin-resistant mutants obtained from ciprofloxacin-susceptible haemolytic isolates still produced haemolysis. It is concluded that most quinolone-resistant clinical isolates of E. coli are non-haemolytic, although haemolysis is produced by quinolone-resistant mutants derived from haemolytic quinolone-susceptible strains.

Topics: Amoxicillin; Ampicillin; Animals; Anti-Infective Agents; Ciprofloxacin; Clavulanic Acid; Drug Resistance, Microbial; Escherichia coli; Fluoroquinolones; Gentamicins; Hemolysin Proteins; Hemolysis; Humans; Microbial Sensitivity Tests; Nalidixic Acid; Naphthyridines; Pefloxacin; Tetracycline