There is a major problem with the rising occurrence of highly virulent and multiply-resistant strains, including methicillin-resistant Staphylococcus aureus (MRSA), because of their difficult treatment. This study aimed to evaluate the antibacterial and antibiofilm effect of new enterocins (Ent) against potential pathogenic MRSA strains isolated from rabbits. Staphylococci (n =110) were identified with PCR and screened for methicillin/oxacillin/cefoxitin resistance (MR) using the disk diffusion method and the PBP2' Latex Agglutination Test Kit. Enzyme production, hemolysis, DNase activity, slime production, and biofilm formation were tested in MRSA strains. The susceptibility of MRSA to eight partially-purified enterocins (Ent) produced by E. faecium and E. durans strains was checked using agar spot tests. The antibiofilm activity of Ents was tested using a quantitative plate assay. Out of 14 MRSA, PBP testing confirmed MR in 8 strains. The majority of MRSA showed DNase activity and β-hemolysis. Slime production and moderate biofilm formation were observed in all strains. MRSA were susceptible to tested Ents (100–12800 AU/mL; except Ent4231). The antibiofilm effect of Ents (except Ent4231) was noted in the high range (64.9-97.0%). These results indicate that enterocins offer a promising option for the prevention and treatment of bacterial infections caused by biofilm-forming MRSA.

The species Lactococcus lactis is the bacterium extensively used in dairy industry. This bacterium is generally recognized as safe which was added to the European Food Safety Authority Qualified Presumption of Safety list. The major functions of this species in dairy fermentation are production of lactic acid from lactose, citric acid fermentation and hydrolysis of casein. But the representatives of this species producing bacteriocin substances can exert an inhibitory effect against spoilage bacteria. The aim of this study was to test three lactococcal strains isolated from raw goat milk for their postbiotic activity and to test their stability in goat milk yogurts in encapsulated form for further application. To reach the aims, validated methods were used. Three postbiotic active Lactococcus lactis subsp. lactis strains (identified by Blastn 16S rRNA analysis) from raw goat milk produced bacteriocin substances which in their concentrated form inhibited the growth of indicator enterococci and staphylococci up to 97.8 % with inhibitory activity up to 800 AU/mL. The encapsulated (freeze dried) lactococci fortified goat milk yogurts showed sufficient stability and survival in yogurts. The highest amount was reached using the strain MK2/8 (8.1 ± 0.0 cfu/g log 10) not influencing yogurt pH.