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Resistance of veillonella to hydrosoluble pristinamycins: a possible outer membrane barrier effect

M Reig1, C Calderón, F Baquero

  • 1Department of Microbiology, Hospital Ramón y Cajal, National Institute of Health (INSALUD), Madrid, Spain.

Anaerobe
|April 1, 1995
PubMed

Insights

Veillonella bacteria show consistent susceptibility to clindamycin but resistance to pristinamycins. Polymyxin B nonapeptide reduced pristinamycin MICs, suggesting the outer membrane acts as a barrier.

Area of Science:

  • Microbiology
  • Bacterial Outer Membrane Permeability
  • Antimicrobial Resistance

Background:

  • Veillonella species are Gram-negative bacteria.
  • Understanding their antimicrobial susceptibility is crucial for clinical management.
  • The outer membrane of Gram-negative bacteria can influence antibiotic efficacy.

Purpose of the Study:

  • To investigate the in vitro antimicrobial susceptibility of Veillonella strains.
  • To explore the role of the outer membrane in resistance to specific antibiotics.
  • To assess the impact of polymyxin B nonapeptide on antibiotic efficacy.

Main Methods:

  • In vitro susceptibility testing of 25 Veillonella strains.
  • Antimicrobial susceptibility testing against clindamycin, erythromycin, quinupristin, and dalfopristin.
  • Evaluation of polymyxin B nonapeptide's effect on antibiotic Minimum Inhibitory Concentrations (MICs).

Main Results:

  • Consistent susceptibility to clindamycin observed across all strains.
  • Resistance to erythromycin and hydrosoluble pristinamycins (quinupristin, dalfopristin) was noted.
  • Polymyxin B nonapeptide significantly reduced quinupristin and dalfopristin MICs in most strains.

Conclusions:

  • Veillonella exhibits a distinct antibiotic susceptibility profile, including clindamycin sensitivity.
  • The bacterial outer membrane likely contributes to reduced susceptibility to pristinamycins.
  • Targeting the outer membrane may enhance the efficacy of certain antibiotics against Veillonella.

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