ExcludeMRSA-trial. ExcludeMRSA-trial

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) forms a zoonotic risk. This study investigated whether probiotics could reduce LA-MRSA colonization in piglets. Three Lactococcus lactis strains, selected for their negative association with S. aureus, were intra-nasally administered as cocktail to piglets within 24 hours of birth in a placebo-controlled field trial on six farms in Ireland and the Netherlands. LA-MRSA presence was monitored via qPCR of swabs and dust samples. Results showed no significant differences in LA-MRSA colonization or 16S rDNA nasal microbiome composition between cocktail treatment and placebo groups. The L. lactis strains were rarely detected in the nasal microbiota, suggesting poor colonization. Factors like treatment timing, single-dose administration, and microbial competition may have contributed to the lack of efficacy, highlighting the need for more knowledge on effective probiotic strategies for farm LA-MRSA decolonization.