P0520 HELICOBACTER PYLORI INFECTION IN CHILDREN: UTILITY OF CULTURE IN DIAGNOSIS AND TO STUDIED THE ANTIMICROBIAL SUSCEPTIBILITY:

Introduction: Helicobacter pylori (Hp) causes one of the most widespread infections worldwide: it affects more than 50% of the human population and the acquisition of infection occurs during infancy. Hp infection has been recognized as a cause of chronic gastritis, peptic ulcer, atrophic gastritis and, also, gastric cancer. This infection can be diagnosed by invasive techniques requiring endoscopy and biopsy (histological examination, rapid urease test, culture) and by non invasive tests (serology, urea breath test, detection of Hp antigen stool specimen). The eradication therapy implies an association of a proton pump inhibitor (PPI) and two antibiotics (mainly nitromidazoles, macrolides and betalactames). The bacterial resistance to antibiotics more frequently used represents one of the most important factors of treatment failure. Aims: To determine the accuracy of culture for diagnosis of Hp infection and to evaluate the prevalence of resistance to amoxicillin, metronidazole and clarithromycin in isolates of Hp in children. Methods: 80 biopsies gastric were obtained from paediatric patients (50 Male; age range 3–18 years; mean age 9 years) and processed for histology examination, rapid urease test, culture. 80 faecal specimens were processed for detection of Hp antigen stool. All positive cultures were tested for antimicrobial susceptibility by E-test for amoxicillin, metronidazole and clarithromycin. Results: The results (%) of diagnostics methods are reported in the table. Test Sensitivity (%) Specificity (%) PPV* (%)NPV* (%) Histology 100 100 100 100 Culture 92 100 100 96,5 Rapid urease test72 96,3 90 88,3 Stool test 56 87,3 66,7 81,3 • Positive and negative predictive value The E-test in-vitro antimicrobial susceptibility testing showed that 26% of the isolates were resistant to clarithromycin and 30% to metronidazole. No resistance to amoxicillina was observed. Conclusion: Microbiological isolation of Hp is important to determine the resistance status and the evaluation of antibiotic resistance profiles from paediatric patients can help in optimising therapeutic regimen to prevent treatment failures.