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In Vitro Assay of Bacterial Adhesion onto Mammalian Epithelial Cells
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In Vitro Assay of Bacterial Adhesion onto Mammalian Epithelial Cells

Published on: May 16, 2011

Trimethoprim, sulphamethoxazole, bacterial adhesion and polymorphonuclear leucocyte function

C E Emmanouilides1, P E Lianou, H P Bassaris

  • 1Department of Microbiology, Medical School of Athens, Goudi, Greece.

The Journal of Antimicrobial Chemotherapy
|December 1, 1990
PubMed

Insights

Subinhibitory antibiotic concentrations reduced bacterial adherence and enhanced immune cell activity. This suggests antibiotics may modulate host-pathogen interactions beyond direct bacterial killing, impacting bacterial infection outcomes.

Area of Science:

  • Microbiology
  • Immunology
  • Pharmacology

Background:

  • Antibiotic resistance is a growing global health concern.
  • Understanding sub-antimicrobial dose effects is crucial for novel therapeutic strategies.
  • Bacterial adherence and host immune responses are key factors in infection pathogenesis.

Purpose of the Study:

  • To investigate the impact of subinhibitory concentrations of trimethoprim and sulphamethoxazole on bacterial adherence and host immune cell function.
  • To evaluate the effects of these antibiotics on the interaction between common uropathogens and human immune cells.

Main Methods:

  • Culturing of Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae.
  • Exposure to subinhibitory concentrations (1/4 Minimum Inhibitory Concentration) of trimethoprim, sulphamethoxazole, or their combination.
  • Assessment of bacterial adherence to host cells.
  • Evaluation of phagocytosis and bactericidal activity of polymorphonuclear leucocytes (PMNs).
  • Analysis of the chemotactic response of human PMNs to bacterial filtrates.

Main Results:

  • Subinhibitory antibiotic concentrations significantly reduced the adherence of all tested bacterial strains.
  • No significant change in the number of phagocytosed bacteria was observed.
  • A significant increase in the bactericidal activity of PMNs against pre-exposed bacteria was noted.
  • Filtrates from bacteria grown with antibiotics enhanced the chemotactic response of human PMNs.

Conclusions:

  • Subinhibitory antibiotic concentrations can modulate bacterial virulence factors, specifically reducing adherence.
  • These antibiotic concentrations enhance the host immune response by increasing PMN bactericidal activity and chemotaxis.
  • This suggests a potential role for sub-antimicrobial antibiotic dosing in modulating host-pathogen interactions and improving infection outcomes.

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