Primary resistance of Helicobacter pylori is still low in Southern Austria

Abstract

Objectives: We determined primary and secondary resistance rates of H. pylori in different regions of Austria and potential bacterial and host factors associated with resistance.

Methods: In a prospective multicentre study H. pylori was cultivated from biopsies and susceptibility testing was performed according to EUCAST. Resistance to clarithromycin and levofloxacin was determined by sequencing of the resistance-determining regions of 23S rRNA and gyrA genes. cagA, vacA and babA2 genotypes were determined.

Results: A total of 1266 patients were included. 178 isolates were cultured: 128 from patients without prior eradication therapy, 50 from patients after failed eradication. Primary resistance to clarithromycin, levofloxacin and metronidazole were 17.2%, 9.4% and 10.2%, respectively. Secondary resistance to clarithromycin, levofloxacin and metronidazole were 64%, 18% and 44%, respectively. Prior eradication was associated with a higher risk of clarithromycin as well as metronidazole resistance (OR=8.1; 95% CI 3.8-17.1 and OR 5.7; 95% CI 2.5-13, respectively).

Conclusion: Primary resistance to both clarithromycin and levofloxacin was markedly lower in Southern Austria than recently reported.

Keywords: Clarithromycin resistance; Helicobacter pylori; Mutations 23S rRNA; Primary resistance; Virulence factors.