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Helicobacter pylori populations in Peruvian patients

D E Berg1, R H Gilman, J Lelwala-Guruge

  • 1Department of Molecular Microbiology, Washington University Medical School, St. Louis, Missouri 63110, USA. BERG@borcim.wustl@edu

Clinical Infectious Diseases : an Official Publication of the Infectious Diseases Society of America
|December 24, 1997
PubMed

Insights

This study on Helicobacter pylori in Peru found that most patients carried genetically similar bacterial strains, suggesting host selection. Frequent metronidazole use may explain mixed susceptible and resistant strains.

Area of Science:

  • Microbiology
  • Genetics
  • Infectious Diseases

Background:

  • Helicobacter pylori exhibits significant genetic diversity.
  • Understanding strain variation is crucial for elucidating colonization, disease, and evolution.
  • Studying isolates from individual patients offers insights into host-pathogen interactions.

Purpose of the Study:

  • To characterize Helicobacter pylori strains from Peruvian patients.
  • To investigate the relationship between metronidazole resistance and genetic diversity (genotype).
  • To explore factors influencing H. pylori strain selection within hosts.

Main Methods:

  • Analysis of H. pylori isolates from 24 patients at the Japanese-Peruvian Polyclinic in Lima, Peru.
  • Determination of metronidazole susceptibility or resistance.
  • Random Amplified Polymorphic DNA (RAPD) fingerprinting to assess overall bacterial genotype.

Main Results:

  • Both metronidazole-susceptible and -resistant strains were found in 13 out of 24 patients.
  • Strains of more than one RAPD type (genotype) were isolated from only seven patients.
  • Most patients harbored genetically homogeneous H. pylori strains.

Conclusions:

  • Homogeneity in RAPD fingerprints suggests selection for specific H. pylori genotypes during chronic infection.
  • Host factors likely play a role in selecting for advantageous bacterial traits.
  • The co-carriage of related susceptible and resistant strains may result from frequent metronidazole use and alternating selection pressures.

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