gemifloxacin and Helicobacter-Infections

Helicobacter pylori (H pylori) is a common gastric pathogen which is associated with chronic gastritis, peptic ulcer, and gastric cancer. It has worldwide distribution with higher incidence in developing countries. Gemifloxacin is a fluoroquinolone antibiotic with documented in vitro activity against H pylori. Considering that there is no clinical data to verify gemifloxacin efficacy in H pylori eradication, this pilot clinical trial was designed.. This prospective pilot study was performed during February 2014 to February 2015. A regimen of gemifloxacin (320 mg single dose) plus twice daily doses of amoxicillin1g, bismuth 240 mg, and omeprazole 20 mg for 14 days were prescribed for H pylori infected patients in whom a first-line standard quadruple therapy (clarithromycin-amoxicillin-bismuth-omeprazole) had failed. To confirm H pylori eradication a 13C-urea breath test was performed 4 weeks after treatment.Compliance and incidence of adverse effects were evaluated by questionnaires.. A total of 120 patients were enrolled consecutively; out of which 106 patients achieved H pylori eradication; per-protocol and intention-to-treat eradication rates were 91.4% (95% CI: 85.5-97.6) and 88.3% (95% CI: 75.4-92.4) respectively. Three patients (2.5%) failed to take at least 80% of the drugs and excluded from the final analysis. Adverse effects were reported in 42% of patients, most commonly including nausea (15%) and diarrhea (13.3%), which was intense in 1 patient and led to the discontinuation of treatment. In total, 96.7% (116/120) of the patients took the medications correctly.. This study revealed that gemifloxacin-containing quadruple therapy provides high H pylori eradication rate (≥90% PP cure rate), and this agent can be included in the list of second-line H pylori therapeutic regimens.

Topics: Adult; Amoxicillin; Anti-Bacterial Agents; Dose-Response Relationship, Drug; Drug Therapy, Combination; Female; Fluoroquinolones; Follow-Up Studies; Gastric Mucosa; Gastroscopy; Gemifloxacin; Helicobacter Infections; Helicobacter pylori; Humans; Male; Naphthyridines; Omeprazole; Pilot Projects; Prospective Studies; Proton Pump Inhibitors; Stomach Diseases; Treatment Outcome

The levofloxacin resistance caused by gyrA gene mutation is rising rapidly to limit wide application for Helicobacter pylori eradication. We investigated whether gemifloxacin has a superior antimicrobial activity to levofloxacin against H. pylori..  Forty-four consecutive clinical H. pylori isolates with levofloxacin resistance and 80 randomly selected levofloxacin-sensitive controls were tested for gemifloxacin sensitivity by E-test. The resistance to levofloxacin or gemifloxacin was defined as minimal inhibitory concentration (MIC) > 1 mg/L. The clinical features and GyrA mutation patterns checked by direct sequencing were also analyzed to assess its association with the H. pylori gemifloxacin resistance..  All levofloxacin-sensitive H. pylori isolates were sensitive to gemifloxacin. Eight strains (18.2%) resistant to levofloxacin could be still sensitive to gemifloxacin. Gemifloxacin achieved a 5-time lower in MIC levels against levofloxacin-resistant isolates. Nearly all levofloxacin-resistant isolates (97.7%, 43/44) had GyrA mutation at amino acid position 87 or 91. Double mutation sites may play dual roles in quinolone resistance, as N87K plus H57Y or D91N plus V77A mutations showed high-level resistance to both quinolones; whereas D91Y plus A97V or D91N plus A97V mutations showed low level levofloxacin resistance to become sensitive to gemifloxacin. In H. pylori isolates with single N87K, D91Y or D91N mutation, near 20% was gemifloxacin-sensitive and levofloxacin-resistant. The gemifloxacin-resistant rate of H. pylori was higher in patients with gastric ulcer than in those without (p <.05)..  Gemifloxacin is superior to levofloxacin in antimicrobial activity against clinical H. pylori isolates, and even overcome some levofloxacin resistance.

Topics: Anti-Bacterial Agents; Bacterial Proteins; DNA Gyrase; Drug Resistance, Bacterial; Fluoroquinolones; Gemifloxacin; Helicobacter Infections; Helicobacter pylori; Humans; Microbial Sensitivity Tests; Mutation; Naphthyridines; Quinolones; Taiwan

The minimum inhibitory concentrations (MICs) of 330 nonduplicate Helicobacter pylori isolates to nemonoxacin, tigecycline, and eight other antimicrobial agents were determined by using the agar dilution method. Sequencing the quinolone resistance-determining regions (QRDRs) in the gyrA gene of these isolates was also performed. Resistance to clarithromycin showed an increasing trend during the ten-year study period and was highest (38%) in 2005. Tigecycline had potent in vitro activities against all isolates, with an MIC(90) of 0.06 μg/ml. Among the quinolones tested, nemonoxacin (MIC(50) of 0.12 μg/ml and MIC(90) of 0.25 μg/ml) and gemifloxacin had one to two-fold better in vitro activities than ciprofloxacin, levofloxacin, and moxifloxacin. Among the nine isolates (2.7%) with levofloxacin resistance, four (44.4%) were also resistant to metronidazole, three (33.3%) to clarithromycin, and two (22.2%) to amoxicillin. Isolates with levofloxacin resistance exhibited one or two of three amino acid alterations (Ser-70, Asn-87, and Asp-91) involved in QRDRs in the gyrA gene. A double mutation at Ser70Cys and Asn87Ile had a higher level of resistance. The results of this study suggest a potentially useful role of nemonoxacin and tigecycline in the treatment of infections caused by H. pylori. The gyrA mutation at Ser-70 is a novel finding and has an impact on levofloxacin resistance.

Topics: Amino Acid Substitution; Amoxicillin; Anti-Bacterial Agents; Aza Compounds; Ciprofloxacin; Clarithromycin; DNA Gyrase; Drug Resistance, Multiple, Bacterial; Fluoroquinolones; Gemifloxacin; Helicobacter Infections; Helicobacter pylori; Humans; Levofloxacin; Metronidazole; Microbial Sensitivity Tests; Minocycline; Moxifloxacin; Mutation; Naphthyridines; Ofloxacin; Quinolines; Quinolones; Sequence Analysis, Protein; Taiwan; Tetracyclines; Tigecycline