Antimicrobial activity of enrofloxacin against Staphylococcus intermedius strains isolated from canine pyodermas

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Published on: September 8, 2021

J P Ganière1, C Médaille, A Limet

  • 1Unité de Pathologie Infectieuse, Ecole Nationale Vétérinaire, BP 40706, 44307 Nantes, France. ganiere@vet-nantes.fr

Veterinary Dermatology
|June 26, 2001
PubMed

Insights

Enrofloxacin resistance in Staphylococcus intermedius strains from canine pyoderma is rare in France. However, laboratory studies show that inappropriate antibiotic use could promote the development of resistant strains in vivo.

Area of Science:

  • Veterinary Microbiology
  • Antimicrobial Resistance
  • Canine Dermatology

Background:

  • Staphylococcus intermedius is a common cause of canine pyoderma.
  • Enrofloxacin is a fluoroquinolone antibiotic frequently used in veterinary medicine.
  • Monitoring antimicrobial resistance is crucial for effective treatment strategies.

Purpose of the Study:

  • To determine the minimal inhibition concentrations (MICs) of enrofloxacin against Staphylococcus intermedius strains isolated from canine pyodermas in France.
  • To assess the prevalence of enrofloxacin resistance in these strains over time.
  • To investigate the potential for in vitro selection of enrofloxacin-resistant variants.

Main Methods:

  • Collection and isolation of 393 Staphylococcus intermedius strains from canine pyodermas in France between 1995 and 1999.
  • Determination of enrofloxacin MICs using standard microbiological methods.
  • In vitro serial passage experiments in subinhibitory enrofloxacin concentrations.

Main Results:

  • Enrofloxacin MICs ranged from 0.063 to 64 mg L-1.
  • MIC50 and MIC90 values were 0.125 and 0.25 mg L-1, respectively.
  • Two resistant strains were identified exclusively in 1999 isolates; in vitro passages showed a 4-16 fold increase in MICs.

Conclusions:

  • Enrofloxacin resistance in Staphylococcus intermedius remains uncommon in French canine pyoderma cases.
  • The in vitro selection of resistant variants suggests a potential risk of resistance development with inappropriate enrofloxacin use.
  • Continued surveillance and judicious antibiotic use are recommended to preserve enrofloxacin efficacy.

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