Antimicrobial Metabolites from Pig Nasal Microbiota

Objective: Isolation of bacteria and fungi from porcine nasal microbiome and evaluation of antibioticproducing potential among them. Methods: Conventional isolation using Sabouraud and Mueller-Hinton nutrient media was carried out for collected samples. The isolated strains were subjected to antibiotic susceptibility testing and antimicrobial activity screening. Results and Discussion: Taxonomy positions of the 20 isolated strains (18 bacteria, 1 yeast, 1 fungus) were determined by phylogenetic analysis, morphological study and a substrate utilization assay. Pseudomonas aeruginosa SM-11 was found to produce 4 known antibacterial molecules (pyocyanine, pyochelin, pyoluteorin, monorhamnolipid). Production of pyocyanine was induced by cocultivation with test microorganisms. Conclusions: The mammal microbiota might serve as a valuable source of antimicrobialproducing strains, including those of rare taxa. Cocultivation techniques are a promising approach to exploring antimicrobials from silent biosynthetic gene clusters.