RESUMEN
Antimicrobial susceptibility of 50 local isolates of Helicobacter pylori from patients with acid peptic diseases was investigated to commonly used antibiotics. The maximum resistance was (66%) detected to metronidazole (MIC > 8 micrograms/ml). The frequency of resistance to ampicillin, erythromycin, ciprofloxacin was in the range of 20-28 per cent; least resistance was observed to tetracycline (10%). The gradient disc diffusion method was found to give reproducible results and also correlated with agar dilution method for minimum inhibitory concentration (MIC). Study of the enzymatic activity of H. pylori isolates showed that all isolates had urease, catalase, oxidase, esterase-lipase, and naphthol-AS-beta-1-phosphohydrolase enzymes and were consistently negative for ten other enzymes tested. Majority of the isolates expressed alkaline phosphatase (17/18), esterase (17/18) and acid phosphatase (14/18). The acid phosphatase had the maximum mean enzymatic activity. There was no difference in enzymatic activity between H. pylori isolates from ulcer and gastritis patients. H. pylori isolates could be typed into five biotypes. Type III was found to be more common (44.4%). This study supports the existence of the strain variations among H. pylori on the basis of the enzyme profiles.