Helicobacter pylori, a Gram-negative microaerophilic bacterium, a prevalent human pathogen in the gastric mucosa, is responsible for gastric and duodenal ulcers (1). In H. pylori infections the therapeutic aim is complete eradication of H. pylori in the stomach. The current therapy of choice is a triple combination that consists of an acid inhibitor, for example a proton pump inhibitor such as omeprazole, and two antibiotics, such as clarithromycin and amoxicillin. This triple therapy is, however, associated with disadvantages (2). As a result of differing diffusion properties, the three different substances, which should act together, do not reach uniformly the inflammatory foci caused by H. pylori. Thus, in order to achieve good healing results, very high doses, which are accompanied by serious side effects, are necessary. It is obvious that a triple therapy has also other great disadvantages in comparison with administration of only one medicament or even of two medicaments (3). Novel organometallic compounds have been prepared by complexing the fluoroquinolones, norfloxacin, ofloxacin, ciprofloxacin, sparfloxacin, lomefloxacin, pefloxacin and gatifloxacin, with bismuth. The complexes were characterized by UV, IR, atomic absorption spectroscopy, elemental analysis, differential scanning calorimetry, thermogravimetric analysis and mass spectrometry. Their antibacterial potential against Helicobacter pylori and other microorganisms was investigated. These compounds were found to possess strong activity against Helicobacter pylori with a minimum inhibitory concentration of 0.5 mg L -l . They also exhibited moderate activity against Escherichia coli, Staphylococcus aureus, Bacillus pumilus and Staphylococcus epidermidis. These bismuth-fluoroquinolone complexes have the potential to be developed as drugs against H. pylori related ailments.
