Frequency and molecular characteristics of ciprofloxacin- and rifampicin-resistant Helicobacter pylori from gastric infections in the UK

Gastrointestinal, Emerging and Zoonotic Infections Department, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5HT, UK Correspondence Robert J. Owen robert.owen{at}hpa.org.uk Received March 20, 2009 Accepted July 6, 2009 Treatment failure with standard Helicobacter pylori eradication regimes may require the use of ‘rescue’ therapies containing fluoroquinolones or rifamycins. The susceptibilities of H. pylori in the UK to such antimicrobials are unknown; therefore, this study aimed to determine the frequencies and molecular markers of resistance. Ciprofloxacin and rifampicin susceptibilities were determined by Etest and/or disc diffusion for 255 isolates of H. pylori , including 171 isolates from adult dyspeptic patients with refractive infections. Mutations in known resistance-determining regions of gyrA and rpoB were determined. The ciprofloxacin resistance rate was 7.5 %, and gyrA mutations, predominantly at codon position 91, were identified in most resistant isolates. One isolate (