Canine pyoderma: mecA persists autogenous bacterin formulation from meticillin-resistant Staphylococcus pseudintermedius (MRSP) and S. aureus (MRSA)

Loeffler, Anette; Scott, Claire; Frosini, Sian Marie

Abstract

Objective Autogenous Staphylococcus pseudintermedius bacterins can reduce prescribing of antimicrobials in the management of canine recurrent pyoderma. However, increasing prevalence of meticillin-resistant, mecA-positive S. pseudintermedius (MRSP) raises concern over dispersal of mecA through bacterin therapy. We investigated the presence and integrity of mecA in bacterin formulations after manufacturing. Material and methods Twenty clinical isolates (12 MRSP, 7 MR-S. aureus, 1 meticillin-susceptible SP) were investigated. Pellets from overnight growth were washed 3 times with 0.5% phenol saline, followed by addition of 0.1 ml 10% formal-saline to 10 ml phenol-saline. Sterility was confirmed, and DNA extracted using both a standard genomic extraction kit and one recommended for formalin-fixed tissue samples (FFPE). The presence of mecA was determined after PCR and its integrity examined in 5 randomly selected samples after sequencing. Results In all bacterins from meticillin-resistant isolates, mecA was detected following FFPE extraction; products aligned fully to a reported mecA sequence. After standard DNA extraction, mecA was seen in 16/19 samples. Conclusion Persistence of mecA in MRSP bacterins suggests that dispersal of this important resistance mediator through therapy may be possible. While the ability of skin bacteria to uptake naked DNA remains unclear, it seems prudent to only formulate autogenous bacterins from mecA-negative S. pseudintermedius to avoid unnecessary spread of mecA.

Citation

Loeffler, A., Scott, C., & Frosini, S. M. (2021). Canine pyoderma: mecA persists autogenous bacterin formulation from meticillin-resistant Staphylococcus pseudintermedius (MRSP) and S. aureus (MRSA). Tierärztliche Praxis Ausgabe K: Kleintiere / Heimtiere, 49(06), 437-440. https://doi.org/10.1055/a-1624-0951

• Journal Article Type: Article
• Acceptance Date: May 18, 2021
• Publication Date: Dec 3, 2021
• Deposit Date: Jul 15, 2022
• Publicly Available Date: Dec 3, 2022
• Print ISSN: 1434-1239
• Publisher: Schattauer
• Peer Reviewed: Peer Reviewed
• Volume: 49
• Issue: 06
• Pages: 437-440
• DOI: https://doi.org/10.1055/a-1624-0951
• Keywords: Antimicrobial resistance; superficial pyodermie; recurrent; phenol; formalin; DNA; METHICILLIN-RESISTANT; EVOLUTION; INSIGHTS; DNA