J Med Microbiol 58 (2009), 1309-1313; DOI: 10.1099/jmm.0.010876-0
© 2009 Society for General Microbiology
ISSN 0022-2615
Proton motive force-dependent efflux of tetracycline in clinical isolates of Helicobacter pylori
Mona Anoushiravani1,
Tahereh Falsafi1 and
Vahid Niknam2
1 Department of Biology, Alzahra University, Tehran, Iran
2 Department of Biology, Tehran University, Tehran, Iran
Correspondence
Tahereh Falsafi
tfalsafi{at}yahoo.com
Received March 6, 2009
Accepted June 25, 2009
The aim of this study was to evaluate the role of proton motive force (PMF)-dependent efflux in resistance of Helicobacter pylori to tetracycline (Tet). Tet MIC was determined by agar dilution in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP), an inhibitor of PMF. Antibiotic accumulation was conducted in the presence or absence of CCCP and the fluorescence of the accumulated antibiotic was measured by spectrofluorometry. In the presence of CCCP, antibiotic accumulation was increased by 2–17-fold in 17/20 Tetr isolates and by 3–10-fold in four of five high-level-resistant mutants. Correlation was observed between this increase and diminution of MIC with CCCP. PMF-dependent efflux mechanisms therefore appear to play an important role in the resistance of clinical isolates of H. pylori to Tet.
Copyright © 2009 Society for General Microbiology.