Effects of vitamin C in enhancing the activities of antibiotics against multi-drug resistant bacteria

Abstract

The emergence and proliferation of antibiotic-resistant pathogens have become a global threat. A large number of the pathogens are becoming resistant even to the last resort of antibiotics. The project aimed to study the antimicrobial effect of adjuvants against multi-drug-resistant bacteria by using Vitamin C in three different concentrations. The concentrations are 1.66 mg/ml, 3.33 mg/ml, and 6.66mg/ml. Six isolates of Klebsiella pneumonia were taken. Among them five isolates (KPJANCH1, KPFEBNCH6, KPMARDSH4, H1NONCH, KPFEBDSH2) became susceptible to Amikacin in all three concentrations, among them one isolate H1NONCH became susceptible to Imipenem in all three concentrations, one isolate KPJANCH1 to Amoxicillin + Clavulanic acid (1.66mg/ml, 6.66mg/ml) but KPFEBDSH2 showed susceptibility to Cefixime (1.66 mg/ml and 3.33 mg/ml), two isolates (KPFEBNCH6, KPFEBDSH2) showed susceptibility to Azithromycin, KPFEBDSH2 in all the concentration but KPFEBNCH6 remained resistant in 3.33 mg/ml. KPFEBDSH2 also became susceptible to Ciprofloxacin and Cefixime (1.66mg/ml, 3.33mg/ml). KPFEBNCH6, KPMARDSH4, and KBFEBDSH2 became sensitive to Co-trimoxazole only in all the concentrations and KPMARDSH4 to Ceftriaxone (1.66 mg/ml). Four multi-drug-resistant E. coli isolates were treated with Vitamin C along with antibiotics, one of them remained resistant in all the concentrations by ten antibiotics and the rest of them showed susceptibility in the mentioned concentrations of Vitamin C, two isolates, E213 (6.66 mg/ml) and E238 (3.33 mg/ml) showed susceptibility to Imipenem, E238 also became susceptible to Amoxicillin + Clavulanic acid (6.66 mg/ml). Another isolate 254 by Azithromycin (3.33 mg/ml). From 6 Multi-drug resistant isolates of Staphylococcus aureus, 4 isolates showed susceptibility. Among them, three isolates (JUDNCH, SA-OTDSH-12, SEPNCW1-1) became susceptible to Amikacin in the first concentration but JUDNCH and SA-OTDSH-12 showed susceptibility at a Vitamin C concentration of 3.33 mg/ml and 6.66 mg/ml as well. For Gentamycin, SA-OTDSH-12 became susceptible in all the concentrations of Vitamin C, and SEPNCW1-1 showed sensitivity at 1.66 mg/ml. Two isolates (SEPDNCW3-15, SEPNCW1-1) became susceptible to Ciprofloxacin in all three concentrations of vitamin C. Lastly, one isolate (NONCW2-15) became susceptible to Amoxicillin + Clavulanic acid in the last two concentration. SA-SEPCNW-2 showed susceptibility to Ceftriaxone when combined with Vitamin C at a concentration of 6.66mg/ml. However, the result of remnant isolates of Klebsiella pneumonia, E. coli, 6 and Staphylococcus aureus remained indifferent. Further research is needed to understand the underlying effect of vitamin C as an adjuvant.