Nanoencapsulation and antimicrobial activities of Commiphora swynnertonii resin against multidrug-resistant Staphylococcus aureus strains from mastitis cow patients

Abstract

Bovine mastitis is an inflammatory disease of the mammary gland, largely caused by microbial infections and commonly managed through intramammary administration of antibiotics. However, the extensive and recurrent use of antibiotics has led to the emergence and spread of antibiotic-resistant pathogens, particularly multidrug-resistant (MDR) Staphylococcus aureus, posing significant veterinary and public health challenges. Herein, we investigated the potential of Commiphora swynnertonii resin-loaded nanoparticles as an antibiotic alternative. This study aimed to identify an effective nanocarrier platform for antimicrobial delivery of C. swynnertonii resin. To achieve this, different types of nanocarriers were explored: liposomes, alginate-based nanoparticles, chitosan-based nanoparticles (ChN), solid lipid nanoparticles (SLN), and nanostructured lipid carriers (NLC), each with or without hyaluronic acid-stearylamine conjugate (HAC). Antimicrobial activity was assessed against 13 MDR S. aureus strains isolated from mastitis cow patients. Based on minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) assays, the tested nanocarriers were ranked in ascending order of antimicrobial coverage as follows: liposomes (0% inhibitory and 0% bactericidal), ChN (15.4% inhibitory and 0% bactericidal), NLC (23% inhibitory and 7.6% bactericidal), SLN (69% inhibitory and 46.2% bactericidal), and alginate nanoparticles (100% inhibitory and 53% bactericidal). HAC-containing alginate nanoparticles achieved the strongest activity, with MIC 26-417 µg/ mL and MBC 35-417 µg/mL, followed by HAC-containing SLN with MIC 17-417 µg/mL and MBC 278-417 µg/mL. These findings highlight the potential of alginate-HAC nanoparticles as a promising platform for delivering C. swynnertonii resin constituents, offering a novel strategy to combat MDR mastitis pathogens through plant-based nanotherapeutics.