Detection of Helicobacter pylori and the genotypes of resistance to clarithromycin and the heterogeneous genotype to this antibiotic in biopsies obtained from symptomatic children

- 81.6% of biopsies from symptomatic children were H. pylori positive by PCR.
- Clarithromycin genotype: 42.3% wild-type, 47.7% resistant and 9.9% heterogeneous.
- Mutations detected: A2143G (87.5%), A2142G (7.5%) and double A2142C-A2143G (5%)
- Heterogeneous genotypes showed wild-type genotype plus mutation, A2143G or A2142G

The aim of this study was to use a commercially available kit (GenoType® HelicoDR; Hain Life Science, Germany) to detect Helicobacter pylori infection and clarithromycin resistance genotype in biopsies obtained from symptomatic children. Results: 111 out of 136 (81.6%) biopsies were H. pylori positive by genotype: 47 (42.3%) showed wild-type genotype, 53 resistant genotype (47.7%) and 11 heterogeneous genotype (9.9%). Culture was negative in 27 out of the 111 genotyped biopsies. Mutation A2143G (87.5%), followed by A2142G (7.5%) and double mutant A2142C-A2143G (5%) were found. The 11 heterogeneous genotype biopsies showed wild-type plus A2143G in 9 and plus A2142G in 2. Conclusions: This kit is a rapid, culture-independent method for routine application in biopsies from the pediatric population that allows detection of clarithromycin resistance and heterogeneous genotypes. It is important to know the clinical impact of infection with this type of strains as well as the role in treatment success.