Figure 9

Synergistic activity of KS16 to antibiotics. (A) Information on antibiotics and the working concentration. Sensititre Gram-positive MIC plate (Cat. No. EUST) with final concentration of individual antibiotics shown. CHL, Chloramphenicol; CIP, Ciprofloxacin; CLI, Clindamycin; ERY, Erythromycin; FOX, Cefoxitin; FUS, Fusidate; GEN, Gentamicin; KAN, Kanamycin; LZD, Linezolid; MUP, Mupirocin; PEN, Penicillin; RIF, Rifampin; SMX, Sulfamethoxazole; STR, Streptomycin; SYN, Quinupristin/Dalfopristin; TET, Tetracycline; TIA, Tiamulin; TMP, Trimethoprim; VAN, Vancomycin; NEG and POS indicate the negative and positive control, respectively. The antibiotics induced by KS16 are indicated in yellow. (B,C) Effect of KS16 on the susceptibility to antibiotics. ATCC 25923 cells were cultured in a Sensititre Gram positive MIC plate (Cat. No. EUST) with (B) or without (C) KS16 (2.5 μg/mL). Yellow circle of the plate was indicated MIC for each antibiotic. (D) Checkerboard assays for gentamicin, kanamycin, and methicillin. Different concentrations of KS16 and antibiotics were used to determine the susceptibility of ATCC 25923 cells. The yellow circles indicate the concentrations showing FICI = 0.5. One of representative from n = 3 was shown. All images of (B–D) were photographed and processed in Adobe Illustrator CS6 (v16.0.0, Adobe Systems Inc., USA).