Primary resistance to clarithromycin in clinical strains of Helicobacter pylori isolated from children in Poland

Helicobacter pylori resistance to clarithromycin is an important factor in the failure of eradication therapy. The resistance results from point mutat ions in the 23S rRNA gene of H. pylori. The prevalence of primary resistanc e of H. pylori to clarithromycin in children and mutations associated with resistance were studied and it was found that 23.5% (23/98) of H. pylori st rains isolated in our hospital during 1998-2000 were resistant to clarithro mycin. The primary resistance was mainly caused by an A2143G mutation, but the isolates with an A2142G mutation had higher MICs for clarithromycin com pared with those with an A2143G mutation: median MIC 256 versus 16 mg/l. Co mparison of our data with previous results showed that the prevalence of H. pylori resistance to clarithromycin in children has increased in Poland ov er the last three years, however the difference was not significant (23.5 v s. 17%, P = 0.22). (C) 2001 Elsevier Science B.V. and International Society of Chemotherapy. All rights reserved.