Previous Article | Next Article ![]()
Antimicrobial Agents and Chemotherapy, November 1999, p. 2657-2662, Vol. 43, No. 11
Department of Medical Microbiology and
Infection Control, Faculty of Medicine, Vrije Universiteit, Amsterdam,
The Netherlands1; Department of
Molecular Microbiology, Washington University, St. Louis,
Missouri3; and Department of
Microbiology and Immunology, Faculty of Medicine, Dalhousie University,
Halifax, Canada2
Received 19 January 1999/Returned for modification 19 April
1999/Accepted 27 August 1999
We found that NCTC11637, the type strain of Helicobacter
pylori, the causative agent of peptic ulcer disease and an early risk factor for gastric cancer, is metronidazole resistant. DNA transformation, PCR-based restriction analysis, and DNA sequencing collectively showed that the metronidazole resistance of this strain
was due to mutation in rdxA (gene HP0954 in the full genome sequence of H. pylori 26695) and that resistance did not
depend on mutation in any of the other genes that had previously been suggested: catalase (katA), ferredoxin (fdx),
flavodoxin (fldA), pyruvate:flavodoxin oxidoreductase
(por
0066-4804/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Insertion of Mini-IS605 and Deletion of
Adjacent Sequences in the Nitroreductase (rdxA) Gene Cause
Metronidazole Resistance in Helicobacter pylori
NCTC11637



), RecA (recA), or superoxide
dismutase (sodB). This is in accord with another recent study that attributed metronidazole resistance to point mutations in
rdxA. However, the mechanism of rdxA
inactivation that we found in NCTC11637 is itself also novel: insertion
of mini-IS605, one of the endogenous transposable elements
of H. pylori, and deletion of adjacent DNA sequences
including 462 bp of the 851-bp-long rdxA gene.
*
Corresponding author. Mailing address: Department of
Medical Microbiology and Infection Control, Vrije Universiteit
Amsterdam, Van der Boechorststraat 7, 1081 BT Amsterdam, The
Netherlands. Phone: 31-20-4448319. Fax: 31-20-4448318. E-mail:
JG.Kusters.mm{at}med.vu.nl.
This article has been cited by other articles:
| Clin. Vaccine Immunol. | Clin. Microbiol. Rev. |
|---|---|
| J. Clin. Microbiol. | ALL ASM JOURNALS |