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Inhibition of bacterial adhesion by subinhibitory concentrations of antibiotics

K C Vidya1, P S Mallya, P S Rao

  • 1Department of Microbiology, Kasturba Medical College, Manipal, India.

Indian Journal of Medical Microbiology
|June 2, 2005
PubMed
Abstract

Insights

Sub-inhibitory concentrations of antibiotics can reduce Escherichia coli adhesion, a key factor in urinary tract infections (UTIs). Co-trimoxazole demonstrated the most significant reduction in E. coli adhesion, suggesting its effectiveness in treating UTIs.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Pharmacology

Background:

  • Urinary Tract Infections (UTIs) are common, with Escherichia coli being a primary causative agent.
  • Bacterial adhesion is a critical virulence factor for E. coli in UTIs.
  • Sub-inhibitory concentrations (sub-MICs) of antibiotics can modulate bacterial functions without causing cell death.

Purpose of the Study:

  • To investigate the impact of sub-MIC antibiotic concentrations on E. coli adhesion.
  • To evaluate the efficacy of various antibiotics in preventing bacterial adhesion to human vaginal epithelial cells.

Main Methods:

  • Three strains of E. coli (ATCC 25922, MTCC 729, U 105) were used.
  • Sub-MICs (1/2, 1/4, 1/8 MIC) of ciprofloxacin, ceftazidime, gentamicin, ampicillin, and co-trimoxazole were tested.
  • Bacterial adhesion to human vaginal epithelial cells was quantified.

Main Results:

  • The 1/2 MIC of all tested antibiotics significantly inhibited E. coli adhesion.
  • Co-trimoxazole exhibited the greatest suppression of adhesion in E. coli strain MTCC 729.
  • Antibiotics like ciprofloxacin, ceftazidime, and ampicillin induced morphological changes in bacteria at sub-MIC levels.

Conclusions:

  • Co-trimoxazole is a highly effective antibiotic for treating UTIs caused by uropathogenic E. coli.
  • Sub-MIC antibiotic treatment can be a viable strategy to reduce bacterial virulence factors like adhesion.
  • Antibiotic choice is crucial for managing E. coli-related UTIs.

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