In vitro antibacterial and antibiofilm effects of mupirocin spray against Staphylococcus pseudintermedius

Area of Science:

• Veterinary Dermatology
• Microbiology
• Pharmacology

Background:

• Mupirocin is an effective topical antibiotic for skin infections.
• Ointment formulations of mupirocin present application challenges in canine systemic pyoderma.
• Clinicians frequently reformulate mupirocin ointment into sprays for off-label use.

Purpose of the Study:

• To evaluate the antibacterial and antibiofilm effects of varying mupirocin spray concentrations (0.5%, 1%, 2%) against Staphylococcus pseudintermedius.
• To assess the stability of these effects over a 21-day period.
• To determine the optimal concentration for clinical application in canine pyoderma.

Main Methods:

• Mupirocin spray was prepared by mixing mupirocin ointment with distilled water.
• Antibacterial activity was assessed using broth microdilution assays and live/dead staining.
• Antibiofilm activity was quantified via crystal violet staining.

Main Results:

• All tested concentrations of mupirocin spray inhibited Staphylococcus pseudintermedius growth.
• Mupirocin spray demonstrated dose-dependent inhibition of biofilm formation.
• Significant antibacterial and antibiofilm efficacy was observed with 2% and 1% mupirocin sprays compared to 0.5%.
• The observed effects remained stable for 21 days.

Conclusions:

• Mupirocin spray formulations, particularly at 1-2% concentrations, are effective against Staphylococcus pseudintermedius.
• Mupirocin spray offers a convenient and effective alternative for treating canine systemic pyoderma.
• The study supports the clinical utility of mupirocin spray for veterinary dermatological applications.