ANTIMICROBIAL EFFECT OF CITRATE BUFFER WITH ANTIBIOTIC

Abstract

Antibiotic resistance of pathogens to medications is an essential problem globally. Thus, new medication compositions are one of the ways to solve this problem. This study aimed to investigate the antimicrobial efficacy of the citrate buffer combined with the antibiotic «Amoxiclav» on standard reference strains of microorganisms. We used standard cultures of C. albicans ATCC10231, E. coli ATCC25922, S. aureus ATCC25923, E. faecalis ATCC29213, M. luteus ATCC4698, S. epidermidis ATCC14990 in the study conducted at the Microbiology, Virology and Immunology Department of the Poltava State Medical University. The sensitivity of standard microorganism strains to the composition was studied with a quantitative method of serial dilutions based on CLSI. ISO/TC 212 «Clinical laboratory testing and in vitro diagnostic test systems. 2021». Thus, the results of this study clearly showed a synergistic effect of citrate buffer and amoxiclav on all the reference strains of microorganisms. Reference strains of Staphylococcus aureus and epidermal staphylococcus showed the highest sensitivity to citrate buffer, which was 4 times (p < 0.05) higher than that shown by micrococci, enterococci and fungi, and 8 times (p < 0.01) higher than that of Escherichia coli, which appeared least sensitive to the test substance. Amoxiclav also inhibited the growth of S. aureus ATCC 25923 and S. epidermidis ATCC 14990 and had the minimal effect on the reference strain of E. coli ATCC 25922, the minimal inhibitory concentration of which was 31.3 times (p < 0.0001) higher than that of staphylococci. The proposed citrate buffer-amoxiclav combination significantly increased the antimicrobial efficacy of its components against all the reference strains of microorganisms. Thus, the sensitivity of E. coli ATCC 25922 and M. lysodeikticus ATCC 4698 to the proposed combination increased 8-fold (p < 0.05) compared to their sensitivity to citrate buffer or amoxiclav alone. The sensitivity of Staphylococcus aureus and enterococcі to the composition increased to the maximum: up to 32-fold (p < 0.001) to the buffer and 4‑fold to the antibiotic (p < 0.01). The effect of a significant increase in the sensitivity of C. albicans ATCC10231 strain to the citrate buffer after adding amoxiclav was gone up 128-fold (p < 0.0001). It was the evidence of a synergistic fungicidal action of the antibiotic-citrate buffer combination.

Keywords

• pathogens, endodontic infections, resistance, citrate buffer, antibiotics, sensitivity, minimal inhibitory concentration, minimal fungicidal concentration