Antibiotic-resistant status and pathogenic clonal complex of canine Streptococcus canis-associated deep pyoderma

Area of Science:

• Veterinary Dermatology
• Microbiology
• Molecular Epidemiology

Background:

• Streptococcus canis is a cause of deep pyoderma in dogs.
• Antibiotic resistance in S. canis isolates from lesions is a growing concern.
• Understanding S. canis pathogenicity and resistance is crucial for effective treatment.

Purpose of the Study:

• To analyze the characteristics of S. canis strains from canine deep pyoderma lesions and oral cavities.
• To determine the antibiotic resistance profiles and molecular types of S. canis isolates.
• To identify potential pathogenic clusters associated with S. canis deep pyoderma.

Main Methods:

• Isolation and antibiotic susceptibility testing of S. canis from canine lesions and oral cavities.
• Molecular typing, including phylogenetic analysis, to identify clonal complexes.
• Detection of beta-lactamase activity in resistant strains.

Main Results:

• Older dogs are more prone to S. canis deep pyoderma.
• A high percentage of S. canis strains (70%) exhibit multidrug resistance.
• Penicillins show high sensitivity (94%) against S. canis, despite some penicillin-resistant strains having beta-lactamase activity.
• Clonal complex 13 (CC13) was exclusively found in lesions and demonstrated high antibiotic resistance, including to vancomycin and linezolid in one isolate.

Conclusions:

• Despite high rates of antibiotic resistance, S. canis deep pyoderma is treatable with beta-lactamase-inhibiting penicillins.
• Clonal complex 13 represents a potentially significant pathogenic cluster associated with high antibiotic resistance in S. canis.