Efficacy Profiles of Antimicrobials Evaluated against Staphylococcus Species Isolated from Canine Clinical Specimens

Area of Science:

• Microbiology
• Pharmacology
• Infectious Diseases

Background:

• Cross-resistance among antimicrobials, whether related or unrelated, poses a significant challenge in infectious disease management.
• Understanding antimicrobial efficacy profiles and their associations is crucial for optimizing treatment strategies and diagnostic testing.

Purpose of the Study:

• To investigate the associations between antimicrobial efficacy profiles and the clustering of eleven antimicrobial agents.
• To analyze antimicrobial susceptibility profiles in *Staphylococcus* species using a multivariate approach.

Main Methods:

• A multivariate approach was employed, analyzing susceptibility data from 382 *Staphylococcus* isolates against 15 antimicrobials via disc diffusion.
• Tetrachoric correlation coefficients were computed to assess correlations in antimicrobial efficacy profiles.
• Principal components analysis and factor analysis were utilized to determine the clustering of antimicrobial susceptibility profiles.

Main Results:

• Strong correlations in efficacy profiles were observed among aminoglycosides, penicillins, fluoroquinolones, and lincosamides.
• Three main factors emerged, with Factor 1 linked to enrofloxacin, gentamicin, tylosin, and ampicillin; Factor 2 to clindamycin, lincomycin-spectinomycin, and co-trimoxazole; and Factor 3 to amoxicillin-clavulanic acid and cephalothin.
• Antimicrobials within the same class generally exhibited similar efficacy profiles.

Conclusions:

• Antimicrobial agents tend to cluster based on their efficacy profiles, often aligning with their respective drug classes.
• Laboratories can optimize antimicrobial susceptibility testing by selecting a single representative antimicrobial agent from each identified efficacy group, thereby reducing costs.