Fig. 1

Heat plots of the antibacterial effects of DOX or TET in combination with carprofen on three methicillin-resistant Staphylococcus pseudintermedius ST71 strains (E104, E032 and E095) and two ST68 strains (E122 and E135). The level of growth inhibition is expressed by colour intensity: the more intense the colour is, the less inhibited the strain was. The Fractional Inhibitory Concentration Index (FICI) was calculated for wells with no visible growth (white colour). Indexes of ΣFICI ≤ 0.5 correspond to synergistic effect, ΣFICI >0.5–4 no effect, ΣFICI > 4 antagonistic. The heat plots show the average of three biological replicates