[Antibiotic resistance of Helicobacter pylori in children and macrolide-resistant genotypes in Helicobacter pylori].

OBJECTIVE

To explore the antibiotic resistance of Helicobacter pylori (H.pylori ) in children and identify 23 S rRNA gene mutations in macrolide-resistant strains.

METHODS

From December 2008 to December 2010, a total of 73 H.pylori strains were isolated from 120 gastric mucosa specimens obtained from children of gastrointestinal symptoms with a diagnosis of gastritis or peptic ulcer underwent gastroscopy. The antibiotic resistance to 9 antibiotics of 73 H.pylori strains isolated from gastric biopsies was detected by E-test method. Mutations in 23 S rRNA gene of macrolide-resistant of isolated H.pylori strains were examined by polymerase chain reaction (PCR).

RESULTS

Seventy-three H.pylori strains (60.8%) were isolated from gastric biopsies.Seventy were drug resistance strains and only 3 sensitive strains.No resistance to amoxicillin, gentamicin and tetracycline was observed. The resistance rate to azithromycin, clarithromycin, metronidazole, rifampicin, levofloxacin and moxifloxacin was 79.5% (58/73), 80.8% (59/73), 58.9% (43/73), 6.8% (5/73), 12.3% (9/73) and 13.7% (10/73) respectively. The dual, triple and quadruple antibacterial resistant percentage was 47.9% (35/73), 8.2% (6/73) and 1.4% (1/73) respectively. And the multi-drug resistance rate to clarithromycin, azithromycin and metronidazole was 43.8% (32/73). The gene mutation rate of A2142C,A2142G, and A2143G in 23 S rRNA gene was 1.6% (1/64), 6.3% (4/64) and 85.9% (55/64) respectively.

CONCLUSIONS

There is a high rate of multi-drug resistance to clarithromycin, azithromycin and metronidazole in H.pylori strains isolated from children at our hospital. Therefore amoxicillin and rifampicin sensitive to H.pylori strains should be considered for H.pylori eradication. A2143G is the most populated mutation in macrolide-resistant strains.