Format

Send to

Choose Destination
J Antimicrob Chemother. 2018 Nov 26. doi: 10.1093/jac/dky469. [Epub ahead of print]

Role of MIC levels of resistance to clarithromycin and metronidazole in Helicobacter pylori eradication.

Author information

1
Section of Gastroenterology, Department of Medical Sciences, University of Foggia, Foggia, Italy.
2
Gastroenterology and Digestive Endoscopy, 'Nuovo Regina Margherita' Hospital, Rome, Italy.
3
Department of Surgical and Medical Sciences, University of Bologna, Bologna, Italy.

Abstract

Objectives:

Antimicrobial resistance to clarithromycin and metronidazole significantly affects the cure rate of standard therapies for Helicobacter pylori infection. We tested whether different MIC levels of resistance to these antibiotics play a role in therapeutic efficacy.

Methods:

This was a post hoc analysis of data from a therapeutic trial in which patients with antibiotic susceptibility testing (Etest) received first-line sequential therapy. The level of antibiotic resistance was classified according to MIC values into low (MIC from >0.5 to ≤8 for clarithromycin, and from >8 to ≤32 for metronidazole) and high (MIC from >8 to 256 mg/L for clarithromycin, and from >32 to 256 mg/L for metronidazole).

Results:

Data from 1006 patients were included. There were 520 (51.7%) patients with susceptible strains, 136 (13.5%) with clarithromycin-resistant strains, 144 (14.3%) with metronidazole-resistant strains and 206 (20.5%) with clarithromycin-resistant and metronidazole-resistant strains. In the presence of double resistance, the cure rate was still high (38/41, 92.7%) when MIC levels were low and it was reduced (94/112, 83.9%) only when MIC levels of both antibiotics were high. The cure rates did not significantly differ between patients with single antibiotic-resistant strains, irrespective of MIC values, and those with susceptible strains.

Conclusions:

We found that MIC levels of resistance to either clarithromycin or metronidazole play a role in H. pylori therapy outcome and that bacterial resistance becomes relevant in vivo when clarithromycin-resistant and metronidazole-resistant strains have high MIC values for at least one of these antibiotics.

PMID:
30476134
DOI:
10.1093/jac/dky469

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center