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In vitro comparison of Staphylococcus pseudintermedius susceptibility to common cephalosporins used in dogs

Rebekah R Westermeyer1, Alma F Roy, Maria S Mitchell

  • 1Veterinary Clinical Services, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA, USA.

Veterinary Therapeutics : Research in Applied Veterinary Medicine
|October 21, 2010
PubMed

Insights

This study evaluated cephalosporin antibiotics against Staphylococcus pseudintermedius in dogs. Cephalothin, cefovecin, and cefazolin showed the best in vitro activity, suggesting their potential for treating canine bacterial infections.

Area of Science:

  • Veterinary Microbiology
  • Antimicrobial Resistance
  • Pharmacology

Background:

  • Methicillin-susceptible Staphylococcus pseudintermedius (MSSP) is a common pathogen in canine pyoderma.
  • Cephalosporins are widely used antibiotics in veterinary medicine.
  • Understanding the in vitro activity of different cephalosporins against MSSP is crucial for effective treatment.

Purpose of the Study:

  • To assess the in vitro activity of ten cephalosporin antimicrobial agents against MSSP isolates from dogs.
  • To determine the minimal inhibitory concentration (MIC90) values for each cephalosporin tested.
  • To evaluate potential correlations between susceptibility to different cephalosporins.

Main Methods:

  • Collected 75 MSSP isolates from dogs.
  • Performed in vitro antimicrobial susceptibility testing for 10 cephalosporins.
  • Determined the minimal inhibitory concentration for 90% of strains (MIC90) for each agent.

Main Results:

  • Cephalothin, cefovecin, and cefazolin exhibited the lowest MIC90 values (0.12 ug/mL).
  • Ceftiofur and cefoxitin (0.25 ug/mL), cefpodoxime (0.5 ug/mL), cefaclor and cefadroxil (1 ug/mL) showed moderate activity.
  • Cephalexin and cefixime had the highest MIC90 values (2 ug/mL).
  • Sensitivity to cephalothin indicated cephalexin susceptibility, but not for all cephalosporins.
  • No clear susceptibility trend was observed based on cephalosporin generation.

Conclusions:

  • Cephalothin, cefovecin, and cefazolin demonstrate potent in vitro activity against MSSP in dogs.
  • Cephalexin susceptibility may be inferred from cephalothin sensitivity, but further testing is recommended.
  • Veterinary clinicians should consider specific cephalosporin activity profiles when selecting treatments for canine staphylococcal infections.

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