Prevalencia de la resistencia a metrodinazol, claritromicina y tetraciclina en Helicobacter pylori aislado de pacientes de la Región Metropolitana / Prevalence of metronidazole, clarithromycin and tetracycline resistance in Helicobacter pylori isolated from Chilean patients

Background: Helicobacter pylori is a pathogenic bacterium that infects a significant number of individuals. At present, therapeutic strategies to eradicate this bacterium depend on our knowledge of its resistance to antimicrobials. Aims: To evaluate the primary resistance of H pylori to metronidazole (Mtz), clarithromycin (Cla), and tetracycline (Tet) in symptomatic out-patients. Material and Methods: Fifty independent isolates of H pylori were obtained by endoscopy-assisted gastric biopsy from patients attending the University of Chile Clinical Hospital, that previously had not been treated with an eradication regime against this bacterium. The minimal inhibitory concentration of each antimicrobial was determined by agar dilution method. Results: Forty five and 27 percent of the isolates were found to be resistant to Mtz and Tet, respectively; the majority of these resistant isolates were from patients older than 21 years. Twenty percent of isolates were resistant to Cla; these were distributed evenly among different ages. Thirty two percent of the isolates were resistant to two or more of the antimicrobials. Conclusions: The high frequency of naturally occurring, antimicrobial-resistant strains of H pylori poses a national and world-wide problem for public health.

Prevalencia de la infección por helicobacter pylori según ensayo de la ureasa en pacientes derivados a la Unidad de Endoscopía del Hospital Clínico de la Universidad de Chile / Prevalence of infection by helicobacter pylori by urease test in patients derivates to the endoscopic section of Hospital Clínico de la Universidad de Chile

Helicobacter pylori is a pathogenic bacterium that infects a significant number of individuals. In Chile about 79 percent of the population is colonized. Aims: This study evaluate the prevalence of the H. pylori infection in symptomatic outpatients. Materials and Methods: 276 non selected patients were enrolled from Endoscopic Unit of Clinical Hospital of the University of Chile. The bacterium was detected by urease test. Results: H. pylori infection was found in 44,9 percent patients. Infection was higher in younger patients, 53,8 percent between 21-60 years, and was lower in older patients, 25,6 percent in older than 60 years. The risk of being H. pylori carrier is twofold higher in persons younger than 60 years as compared to those older than 60 years. Conclusion: The age would be modifier factors for H. pylori infection risk.

Resistencia antimicrobiana en Helicobacter pylori: aspectos clínicos y moleculares / Antimicrobial resistance of Helicobacter pylori: clinical and molecular aspects

Helicobacter pylori is a relevant pathogen for gastroduodenal diseases in human beings. Although its eradication often improves gastroduodenal diseases, H pylori is acquiring an elevated rate of resistance to various antimicrobials, such as metronidazole, clarithromycin, tetracycline and amoxicillin. Multi-drug resistance is a major problem to select the appropriate treatment of infectious diseases. To improve our understanding on the com-plexity of the problem, in this article we review the resistance mechanisms and give an update on H pylori antimicrobial resistance (Rev Méd Chile 2003; 131: 1313-20).