Intracellular survival of S. aureus subsp. anaerobius strains MVF-84 (●) and RDKA84 (○) in murine macrophage-like cell line J774A.1 (A) and bovine mammary epithelial cell line MAC-T (B). Survival of MVF-84 and RDKA84 was determined using dilutional plate counts. Data of viable intracellular bacteria at 4, 8 and 24 h are expressed as a percentage of internalized bacteria and represent the mean ± S.D. of three independent experiments running in triplicate. Error bars indicate confidence level (95%); p values were determined using the Student’s t-test.