Antimicrobial Activity of Pediococcus pentosaceus PMY2 Against Multidrug-Resistant Pathogens

<b>Background/Objectives</b>: Multidrug-resistant (MDR) pathogens pose a critical challenge in infection treatment. <i>Pediococcus pentosaceus</i> (<i>P. pentosaceus</i>) is known for its antimicrobial activity; however, studies on its effects against MDR pathogens remain limited. This study aimed to evaluate the antimicrobial and biological activities of <i>P. pentosaceus</i> PMY2, isolated from fermented porcine colostrum yogurt, against MDR pathogens, including <i>Staphylococcus aureus</i> (<i>S. aureus</i>), <i>Pseudomonas aeruginosa</i> (<i>P. aeruginosa</i>), and <i>Escherichia coli</i> (<i>E. coli</i>). <b>Methods</b>: The antimicrobial, anti-inflammatory, and cytotoxic effects of <i>P. pentosaceus</i> PMY2 were evaluated in vitro. In addition, IL-6 and TNF-α levels were analyzed using an ELISA kit. <b>Results</b>: The MIC value against <i>S. aureus</i> KCTC 3881 and MRSA (CCARM 3089) was 0.31 mg/mL, while the MBC values were 0.63 mg/mL and 2.5 mg/mL, respectively. At MIC, biofilm formation was inhibited by 62.2% in <i>S. aureus</i> KCTC 3881 and by 51.5% in MRSA. CFS exhibited low cytotoxicity in RAW 264.7 macrophages and significantly reduced NO production, IL-6, and TNF-α levels, indicating strong anti-inflammatory effects. <b>Conclusions</b>: These findings suggest that <i>P. pentosaceus</i> PMY2 exhibited excellent antimicrobial and anti-inflammatory activity against MDR pathogens, demonstrating its potential as a natural antimicrobial agent. These results indicate that PMY2 CFS could be a promising candidate for addressing antibiotic resistance issues.