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Published on: February 9, 2011
Nasal carriage of methicillin-resistant Staphylococcus pseudintermedius in dogs treated with cephalexin monohydrate
Punpichaya Fungwithaya1, Pattrarat Chanchaithong1, Nathita Phumthanakorn1
1Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand.
Abstract:
This study aimed to investigate the nasal carriage of methicillin-resistant Staphylococcus pseudintermedius (MRSP) in dogs treated with oral cephalexin monohydrate. Ten dogs with superficial pyoderma were monitored longitudinally for carriage of MRSP for up to 1 year after treatment; the strains were typed and antibiograms were determined. Methicillin-susceptible S. pseudintermedius (MSSP) was recovered prior to treatment in all dogs and could be isolated after 12 months in 1 dog. Methicillin-resistant Staphylococcus pseudintermedius was detected within 1 week of treatment in all dogs, and 3 clones represented by ST45, ST112, and ST181 were consistently present for up to 12 months after treatment. All MRSP isolates were resistant to at least 7 common antimicrobials. Oral cephalexin monohydrate treatment selected for strains of multi-resistant MRSP, which were still present after 1 year.
Insights
Cephalexin treatment in dogs with pyoderma selected for multi-resistant methicillin-resistant Staphylococcus pseudintermedius (MRSP) nasal carriage. These MRSP strains persisted for up to one year post-treatment.
Area of Science:
- Veterinary Dermatology
- Antimicrobial Resistance
- Microbiology
Background:
- Superficial pyoderma is a common skin infection in dogs.
- Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is an emerging pathogen.
- Cephalexin is a commonly used antibiotic for canine pyoderma.
Purpose of the Study:
- To investigate the nasal carriage of MRSP in dogs treated with oral cephalexin monohydrate.
- To determine the duration and clonal types of MRSP nasal carriage post-treatment.
- To assess the antimicrobial resistance profiles of MRSP isolates.
Main Methods:
- Longitudinal monitoring of nasal MRSP carriage in ten dogs with superficial pyoderma for up to one year post-cephalexin treatment.
- Bacterial strain typing and determination of antibiograms.
- Detection of methicillin-susceptible S. pseudintermedius (MSSP) and MRSP.
Main Results:
- MRSP was detected in all dogs within one week of cephalexin treatment.
- Three specific MRSP clones (ST45, ST112, ST181) were consistently present for up to 12 months.
- All MRSP isolates exhibited resistance to at least seven common antimicrobials, indicating multi-drug resistance.
Conclusions:
- Oral cephalexin monohydrate treatment selected for and promoted the persistence of multi-resistant MRSP nasal carriage in dogs.
- MRSP nasal carriage can be a long-term consequence of cephalexin therapy for pyoderma.
- The findings highlight the need for careful antibiotic stewardship in veterinary medicine to mitigate the spread of resistant bacteria.
