The combined effects of ciprofloxacin and vitamin C on the multi drug resistant Gram-negative bacteria

Abstract

Antibiotic resistance has become a major cause of superinfection and mortality globally. Combination therapy can be used to treat multi-drug-resistant Gram-negative bacteria. Vitamin C can be used in combination with antibiotics. In this study, the effects of combination of an antibiotic and Vitamin C, whether it be synergistic, antagonistic, or additive on multi-drug resistant Gam-negative bacteria were investigated. It was observed that the combination of Ciprofloxacin and Vitamin C showed a synergistic effect on the inhibition of bacterial growth. For Pseudomonas koreensis, the mean MIC of the combination was 30 μg/mL (CIP:15 μg/mL, Vitamin C:15 μg/ml) and the mean FICI was 0.47. For Escherichia fergusonii, the mean MIC of the combination was 22.5 μg/mL (CIP:7.5 μg/Ml, Vitamin C:15 μg/mL) and the mean FICI was 0.48. For another strain of P.koreensis, the mean MIC of the combination was 55 μg/mL (CIP:22.5 μg/Ml, Vitamin C:32.5 μg/mL) and the mean FICI was 0.49 Lastly for Enterobacter sichuanensis mean MIC of the combination was 50 μg/mL (CIP:17.5 μg/Ml, Vitamin C:32.5 μg/mL) and the mean FICI was 0.41. Since all the mean FICIs were within 0.5, the combination was found synergistic on these bacteria.