title: Rapid identification ofHelicobacter pyloriand assessment of clarithromycin susceptibility from clinical specimens using FISH.
abstract: Helicobacter pyloriremains one of the most common bacterial infections worldwide. Clarithromycin resistance is the most important cause ofH. pylorieradication failures. Effective antibiotic therapies inH. pyloriinfection must be rapidly adapted to local resistance patterns. We investigated the prevalence of clarithromycin resistance due to mutations in positions 2142 and 2143 of 23SrRNA gene ofH. pyloriby fluorescencein situhybridisation (FISH), and compared with culture and antimicrobial susceptibility testing in 234 adult patients with dyspepsia who were enrolled. Antrum and corpus biopsy specimens were obtained for rapid urease test, histopathology and culture. Epsilometer test was used to assess clarithromycin susceptibility.H. pyloripresence and clarithromycin susceptibility were determined by FISH in paraffin-embedded biopsy specimens. We found that 164 (70.1%) patients were positive forH. pyloribased on clinical criteria, 114 (69.5% CI 62.5-76.6%) were culture positive, and 137 (83.5% CI 77.8-89.2%) were FISH positive. Thus the sensitivity of FISH was significantly superior to that of culture. However specificity was not significantly different (91.4 versus 100.0%, respectively). The resistance rate to clarithromycin for both antrum and corpus was detected inH. pylori-positive patients; 20.2% by FISH and 28.0% by E-test.The concordance between E-test and FISH was only 89.5% due to the presence of point mutations different from A2143G, A2142G or A2142C. We conclude that FISH is significantly more sensitive than culture and the E-test for the detection ofH. pyloriand for rapid determinination of claritromycin susceptibility. The superior hybridisation efficiency of FISH is becoming an emerging molecular tool as a reliable, rapid and sensitive method for the detection and visualisation ofH. pylori, especially when the management ofH. pylorieradication therapy is necessary. This is particularly important for the treatment of patients withH. pylorieradication failure.
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine Dokuz Eylül University İzmir Turkey.
authors.forename: Ebru
authors.initials: E
authors.lastname: Demiray-Gürbüz
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine Dokuz Eylül University İzmir Turkey.
authors.forename: Özlem
authors.initials: Ö
authors.lastname: Yılmaz
authors.affiliation: Departments of Medicine and Microbiology New York University, School of Medicine, NYUSM New York NY USA.
authors.forename: Asalia Z
authors.initials: AZ
authors.lastname: Olivares
authors.affiliation: Departments of Gastroenterology, Faculty of Medicine Dokuz Eylül University Izmir Turkey.
authors.forename: Can
authors.initials: C
authors.lastname: Gönen
authors.affiliation: Pathology, Faculty of Medicine Dokuz Eylül University Izmir Turkey.
authors.forename: Sülen
authors.initials: S
authors.lastname: Sarıoğlu
authors.affiliation: Departments of Gastroenterology, Faculty of Medicine Dokuz Eylül University Izmir Turkey.
authors.forename: Müjde
authors.initials: M
authors.lastname: Soytürk
authors.affiliation: Medical Biology and Genetics, Faculty of Medicine Dokuz Eylül University İzmir Türkiye.
authors.forename: Sait
authors.initials: S
authors.lastname: Tümer
authors.affiliation: Medical Biology and Genetics, Faculty of Medicine Dokuz Eylül University İzmir Türkiye.
authors.forename: Oğuz
authors.initials: O
authors.lastname: Altungöz
authors.affiliation: Departments of Gastroenterology, Faculty of Medicine Dokuz Eylül University Izmir Turkey.
authors.forename: İlkay
authors.initials: İ
authors.lastname: Şimşek
authors.affiliation: Departments of Medicine and Microbiology New York University, School of Medicine, NYUSM New York NY USA.
authors.forename: Guillermo I
authors.initials: GI
authors.lastname: Perez Perez
keywords: FISH; H. pylori detection; clarithromycin resistance