Maria Teresa Mascellino
Sapienza University of Rome, Italy
Title: Helicobacter pylori infection: Antibiotic resistance and eradication rate in patients with gastritis showing previous treatment failures
Biography
Biography: Maria Teresa Mascellino
Abstract
Aim of study is to evaluate the antibiotic resistance and the eradication rate in 40 patients with Helicobacter pylori (Hp) infection presenting gastric symptoms that required assessment with diagnostic endoscopy, who failed first line therapy. The patients all positive to urease test, were treated with the quadruple therapy of PPI, bismuth, metronidazole (MZ) and tetracycline (TE) for 14 days consistently to the high clarithromycin (CLA)- resistance level. Eradication status was determined by the 13C-urea breath test. The resistance to CLA and MZ resulted to be very high (50% and 65%, respectively) due to their large use. Amoxicillin, TE and levofloxacin showed 3%, 5% and 25% of resistance respectively. Genetic resistance has been studied for CLA and TE. Mixed Hp infections were demonstrated by the presence of different antimicrobial susceptibility patterns contemporarily. The overall eradication rate resulted as being 82% strictly depending for each patient on the number of gastric districts colonized by Hp. The CLA-resistance levels and mainly the local susceptibility resulted to be crucial in order to establish a correct therapy. The genotypic-resistance is useful in case of absence of live bacteria, contamination and for identifying mixed infections that represent a real problem possibly leading to a resistance underestimation. The real-time PCR detected the resistant population at a very low concentration not detectable by phenotypic tests which primarily show susceptible bacteria. The use of genotypic tests directly on the clinical specimens could predict the antibiotic resistance addressing changes in previous failure treatments. The bismuth quadruple therapy resulted to be effective in the Hp eradication rate.