Feline-Derived Lactiplantibacillus plantarum–Aloe Vera Polysaccharide Hydrogel as a Topical Control Strategy for Staphylococcus pseudintermedius-Infected Wounds

Staphylococcus pseudintermedius (SP) is an important opportunistic pathogen in companion animals, and the increasing prevalence of antimicrobial-resistant strains highlights the need for alternative approaches to local infection control. This study evaluated a topical hydrogel containing feline-derived Lactiplantibacillus plantarum ZYpet-014 and Aloe vera polysaccharides (AVEs) for the treatment of SP-infected wounds. AVEs promoted LP growth and organic-acid production and improved short-term LP viability within the carbomer hydrogel. The LP+AVE-hydrogel inhibited planktonic SP growth and biofilm formation in vitro and caused pronounced morphological disruption of SP cells. Therapeutic efficacy was further evaluated using a full-thickness murine wound model challenged with SP. LP+AVE treatment accelerated wound closure, reaching 95.75% by day 14, while qualitative histological observations suggested improved tissue organization and differences in collagen-associated staining patterns. Treatment was also associated with reduced TNF-α, IL-1β, and IL-6 levels and increased IL-4, IL-10, TGF-β1, and serum VEGF concentrations. In wound tissues, LP+AVE treatment decreased CD80 and increased CD206 immunoreactivity, consistent with a shift in macrophage-associated responses toward a reparative profile. Moreover, 16S rRNA gene sequencing showed reduced relative abundance of Staphylococcus and increased relative abundance of Lactobacillus in treated wounds. Together, these findings demonstrate antibacterial and antibiofilm activities against SP in vitro, accompanied by improved wound healing, modulation of inflammatory responses, and changes in wound microbial composition in vivo, although direct reduction in SP burden in wound tissue remains to be established.