Aim: In this study, it was aimed to establish an infection model with Klebsiella pneumoniae on A549 Lung cancer cell line and to evaluate the effect of additional vitamins on the antibacterial effect of ampicillin sulbactam in the treatment. Cell culture and pathology results were determined in parallel with microbial analysis. Methods: Minimal inhibitory concentration (MIC), fractional inhibitory concentration (FIC), biofilm optical density of ampicillin sulbactam, vitamins E, K1 and P on Klebicella pneumoniae ATCC 700603 strain were determined. Cytotoxic activity on A549 cancer cell line in parallel with microbial analysis and pathology results were determined. Results: Ampicillin Sulbactam MIC dose range used in the treatment of Klebsiella pneumoniae infection is 16 mg/L. Looking at the FIC dose ranges, Vitamin K1+Ampicillin sulbactam, Vitamin P+Ampicillin sulbactam 2.5mg/ml+0.5µg/ml, Vitamin E+Ampicillin sulbactam 5mg/ml+0.5µg/ml, K1+P+E+Ampicillin sulbactam 2,5mg/ml+2.5mg/ml+5mg/ml+0.5µg/ml it was determined that it was. It was determined that it has a synergistic effect in combination with vitamins K1 and P antibiotics. In addition, in the presence of biofilm below 570 nm, the OD values of K1, P, E and K1+P+E+ antibiotic combinations were found to be 1.006, 0.969, 1.096 and 1.015, respectively. As a result of cell culture studies and evaluation of pathology results, it was determined that increasing the dose of Ampicillin sulbactam to 8 µg/ml increased the antibacterial effect and the vitamin combination was more effective. Conclusions: Antibiotic and vitamin combination was found to be more effective in Klebsiella pneumoniae infection in our study. This situation contributes to the search for alternative antimicrobials.