Resistance problems in gastrointestinal infections

Abstract

A variety of world-wide resistance problems in bacterial gastrointestinal pathogens have emerged within the last decade. Particularly, antibiotics used to treat salmonella, campylobacter and Helicobacter pylori have lost their efficacy in a high proportion of isolates. Of major clinical significance is the resistance of H. pylori to metronidazole and clarithromycin, of Campylobacter spp. to fluoroquinolones and macrolides and of Salmonella spp. to fluoroquinolones and third generation cephalosporins. Of special concern is the spread of multiresistant isolates. Fortunately, in Clostridium difficile the resistance rate against metronidazole or vancomycin appears to be still low. Numerous investigations provided convincing evidence that the major source of emergence and dissemination of bacterial resistance is the use of antibiotics in food animals. This applies in particular to multiresistant strains of salmonella and campylobacter. A restricted use of antibiotics in the livestock is clearly warranted to control the unlimited development of resistance. The following recommendations should be considered in the care of infections with H. pylori, Campylobacter and Salmonella: 1) Treatment of H. pylori should be restricted to ulcer disease and gastric lymphoma. Eradication is not indicated in asymptomatic patients or patients with gastrointestinal pathologies that are not related to H. pylori. 2) Anti-H. pylori antibiotics should include metronidazole, clarithromycin, amoxicillin or tetracycline in combination of two of them. They should be used in short terms and in the recommended dosages together with proton pump inhibitors. If ulcers relapse after the first eradication, the resistance pattern should be determined. 3) In Campylobacter enterocolitis, antibiotics should be reserved for more severe cases. Resistance testing to exclude quinolone resistance is encouraged if antibiotics are considered. 4) In Salmonella gastroenteritis antibiotics do not significantly improve the course of infection. Their use should thus be restricted to patients which are at risk for disseminated disease including infants, elderly and immunosuppressed persons. 5) Since multiresistant Salmonella are common, resistance testing is highly recommended.