Subinhibitory concentrations of moxifloxacin decrease adhesion and biofilm formation of Stenotrophomonas maltophilia

A Pompilio1,2, C Catavitello3, C Picciani1,2

  • 1Center for Excellence on Aging, 'G. D'Annunzio' University Foundation, Chieti, Italy.

Insights

Sub-inhibitory concentrations of moxifloxacin significantly reduced adhesion and biofilm formation in Stenotrophomonas maltophilia, a common airway pathogen in cystic fibrosis (CF) patients. This suggests moxifloxacin

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Pharmacology

Background:

  • Stenotrophomonas maltophilia is an emerging nosocomial pathogen increasingly found in cystic fibrosis (CF) patients' airways.
  • Bacterial adhesion and biofilm formation contribute to persistent infections, particularly in CF.
  • Understanding the impact of sub-minimum inhibitory concentrations (subMICs) of antibiotics on bacterial virulence factors is crucial.

Purpose of the Study:

  • To evaluate the effect of subMICs of moxifloxacin on the adhesion, biofilm formation, and cell-surface hydrophobicity of S. maltophilia strains from CF patients.
  • To assess the potential of moxifloxacin in managing S. maltophilia infections, especially those involving biofilms.

Main Methods:

  • Two S. maltophilia strains isolated from CF patients were exposed to subMICs (0.03x and 0.06x MIC) of moxifloxacin.
  • Adhesion and biofilm formation assays were performed on polystyrene surfaces and quantified by colony counts.
  • Cell-surface hydrophobicity was determined using a standard n-hexadecane adhesion test.

Main Results:

  • Moxifloxacin at subMICs significantly decreased both adhesion and biofilm formation in both tested S. maltophilia strains.
  • A significant reduction in cell-surface hydrophobicity was observed in one of the two strains after exposure to moxifloxacin subMICs.
  • These findings indicate that moxifloxacin can impair key S. maltophilia virulence factors.

Conclusions:

  • Sub-inhibitory concentrations of moxifloxacin effectively reduce S. maltophilia adhesion and biofilm formation.
  • Moxifloxacin demonstrates potential as a therapeutic agent for CF patients and other biofilm-related S. maltophilia infections.
  • Further investigation into moxifloxacin's role in combating biofilm-associated bacterial infections is warranted.

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