This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by DeLoney, C. R.
Right arrow Articles by Schiller, N. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by DeLoney, C. R.
Right arrow Articles by Schiller, N. L.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, December 2000, p. 3368-3373, Vol. 44, No. 12
0066-4804/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Characterization of an In Vitro-Selected Amoxicillin-Resistant Strain of Helicobacter pylori

Cindy R. DeLoney and Neal L. Schiller*

Division of Biomedical Sciences, University of California, Riverside, Riverside, California 92521

Received 31 January 2000/Returned for modification 25 April 2000/Accepted 5 September 2000

An amoxicillin-resistant (Amoxr) strain of Helicobacter pylori was selected for by culturing an amoxicillin-sensitive (Amoxs) strain in increasingly higher concentrations of amoxicillin, resulting in a 133-fold increase in MIC, from 0.03 to 0.06 µg/ml to 4 to 8 µg/ml. This resistance was stable upon freezing for at least 6 months and conferred cross-resistance to seven other beta -lactam antibiotics. beta -Lactamase activity was not detected in this Amoxr strain; however, analysis of the penicillin-binding protein (PBP) profiles generated from isolated bacterial membranes of the Amoxs parental strain and the Amoxr strain revealed a significant decrease in labeling of PBP 1 by biotinylated amoxicillin (bio-Amox) in the Amoxr strain. Comparative binding studies of PBP 1 for several beta -lactams demonstrated that PBP 1 in the Amoxr strain had decreased affinity for mezlocillin but not significantly decreased affinity for penicillin G. In addition, PBP profiles prepared from whole bacterial cells showed decreased labeling of PBP 1 and PBP 2 in the Amoxr strain at all bio-Amox concentrations tested, suggesting a diffusional barrier to bio-Amox or a possible antibiotic efflux mechanism. Uptake analysis of 14C-labeled penicillin G showed a significant decrease in uptake of the labeled antibiotic by the Amoxr strain compared to the Amoxs strain, which was not affected by pretreatment with carbonyl cyanide m-chlorophenylhydrazone, eliminating the possibility of an efflux mechanism in the resistant strain. These results demonstrate that alterations in PBP 1 and in the uptake of beta -lactam antibiotics in H. pylori can be selected for by prolonged exposure to amoxicillin, resulting in increased resistance to this antibiotic.

* Corresponding author. Mailing address: Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521. Phone: (909) 787-4569. Fax: (909) 787-5504. E-mail: neal.schiller{at}ucr.edu.

Antimicrobial Agents and Chemotherapy, December 2000, p. 3368-3373, Vol. 44, No. 12
0066-4804/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Megraud, F., Lehours, P. (2007). Helicobacter pylori Detection and Antimicrobial Susceptibility Testing. Clin. Microbiol. Rev. 20: 280-322 [Abstract] [Full Text]  
  • Co, E.-M. A., Schiller, N. L. (2006). Resistance Mechanisms in an In Vitro-Selected Amoxicillin-Resistant Strain of Helicobacter pylori. Antimicrob. Agents Chemother. 50: 4174-4176 [Abstract] [Full Text]  
  • Boyanova, L., Nikolov, R., Lazarova, E., Gergova, G., Katsarov, N., Kamburov, V., Spassova, Z., Derejian, S., Jelev, C., Mitov, I., Krastev, Z. (2006). Antibacterial resistance in Helicobacter pylori strains isolated from Bulgarian children and adult patients over 9 years. J Med Microbiol 55: 65-68 [Abstract] [Full Text]  
  • Nahar, S., Mukhopadhyay, A. K., Khan, R., Ahmad, M. M., Datta, S., Chattopadhyay, S., Dhar, S. C., Sarker, S. A., Engstrand, L., Berg, D. E., Nair, G. B., Rahman, M. (2004). Antimicrobial Susceptibility of Helicobacter pylori Strains Isolated in Bangladesh. J. Clin. Microbiol. 42: 4856-4858 [Abstract] [Full Text]  
  • Megraud, F (2004). H pylori antibiotic resistance: prevalence, importance, and advances in testing. Gut 53: 1374-1384 [Full Text]  
  • Shin, J.-H., Roe, I.-H., Kim, H.-G. (2004). Production of anti-Helicobacter pylori urease-specific immunoglobulin in egg yolk using an antigenic epitope of H. pylori urease. J Med Microbiol 53: 31-34 [Abstract] [Full Text]  
  • Kwon, D. H., Dore, M. P., Kim, J. J., Kato, M., Lee, M., Wu, J. Y., Graham, D. Y. (2003). High-Level {beta}-Lactam Resistance Associated with Acquired Multidrug Resistance in Helicobacter pylori. Antimicrob. Agents Chemother. 47: 2169-2178 [Abstract] [Full Text]  
  • Okamoto, T., Yoshiyama, H., Nakazawa, T., Park, I.-D., Chang, M.-W., Yanai, H., Okita, K., Shirai, M. (2002). A change in PBP1 is involved in amoxicillin resistance of clinical isolates of Helicobacter pylori. J Antimicrob Chemother 50: 849-856 [Abstract] [Full Text]  
  • Shin, J.-H., Yang, M., Nam, S. W., Kim, J. T., Myung, N. H., Bang, W.-G., Roe, I. H. (2002). Use of Egg Yolk-Derived Immunoglobulin as an Alternative to Antibiotic Treatment for Control of Helicobacter pylori Infection. CVI 9: 1061-1066 [Abstract] [Full Text]  
  • Gerrits, M. M., Schuijffel, D., van Zwet, A. A., Kuipers, E. J., Vandenbroucke-Grauls, C. M. J. E., Kusters, J. G. (2002). Alterations in Penicillin-Binding Protein 1A Confer Resistance to {beta}-Lactam Antibiotics in Helicobacter pylori. Antimicrob. Agents Chemother. 46: 2229-2233 [Abstract] [Full Text]  
  • Torres, J., Camorlinga-Ponce, M., Perez-Perez, G., Madrazo-De la Garza, A., Dehesa, M., Gonzalez-Valencia, G., Munoz, O. (2001). Increasing Multidrug Resistance in Helicobacter pylori Strains Isolated from Children and Adults in Mexico. J. Clin. Microbiol. 39: 2677-2680 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»