Diagnostic of helicobacter species and resistance to antibiotics

Non-pylori Helicobacter species may occasionally colonize the human stomach causing gastritis, but the prevalence is unknown. They are usually unculturable and may be underdiagnosed. Non-pylori Helicobacter species was found in 9 (1,9%) of 484 patients. Increased resistance in Helicobacter pylori to several antibiotics has been seen worldwide in the last decade. This is a serious problem as half of the world's population is infected with H. pylori, which may cause gastritis, peptic ulcer, gastric cancer, MALT lymphomas and several autoimmune diseases. Antral biopsies from 484 patients were examined for H. pylori by culture and quantitative polymerase chain reaction (qPCR). In addition, the biopsies were examined for Helicobacter spp. by PCR. Susceptibility to amoxicillin, tetracycline, clarithromycin, metronidazole, ciprofloxacin and rifampicin were tested by E-test and for clarithromycin by qPCR. Helicobacter spp. were detected in 68 (14%) of 484 patients. All 68 patients were positive for Helicobacter spp. by PCR and 59 (12%) were positive for H. pylori by qPCR. Thus, 9 (13%) patients with Helicobacter infection had non-pylori Helicobacter spp. H. pylori was cultured from 32 (54%) of 59 patients who were PCR positive for H. pylori. None of the non-pylori Helicobacter spp. were cultured. H. pylori from 3 (9%) of 32 cultured strains were resistant to clarithromycin by E-test. However, 35 (59%) of 59 biopsies were resistant to clarithromycin by qPCR. Also, 17 (49%) of 35 biopsies harbored both clarithromycin sensitive and resistant clones of H. pylori. The prevalence of H. pylori seems to decrease, whereas a relatively high prevalence of non-pylori Helicobacter spp. has been observed. Thus, it is important to include a Helicobacter species specific PCR as they are often non-culturable. H. pylori was detected twice as often by PCR than by culture. A surprisingly high number of patients had both clarithromycin sensitive and resistant H. pylori clones, which will have consequences for the treatment strategy.