Effect of microampere current on clinical strains of acinetobacter baumannii with multiple drug resistance and the manifestation of the bioelectric effect

Abstract

There is an urgent need to develop new effective strategies to combat resistant bacteria. The aim was to investigate the effect of microampere current on resistant A. baumannii strains and its impact on bacterial susceptibility to antibiotics. The study of the effect of low-intensity currents on the reference and clinical strains of A. baumannii (n=15) was conducted in isotonic solution and meat-peptone broth (MPB), followed by measuring the optical density (OD) after 24 and 48 hours of incubation. The change in microorganism susceptibility to ceftazidime was also evaluated. The OD values after current exposure on the reference strain A. baumannii in isotonic solution significantly (p≤0.05) differed from the values without current exposure by 1.7 and 1.55 times at 24 and 48 hours, respectively. The effect of currents on clinical strains led to a significant decrease (p≤0.05) in OD values (1.9±0.4 – without current exposure; 1.2±0.2 – after current exposure) by 1.58 times at 48 hours. Under the influence of currents, the cell concentration of clinical A. baumannii strains in MPB at 48 hours significantly decreased by 1.18 times (p≤0.05). A statistically significant bioelectric effect was also observed after prior exposure to microampere currents on A. baumannii strains, manifested by the reduction of bacterial resistance to ceftazidime. The average values of the minimum inhibitory concentrations of ceftazidime significantly (p≤0.001) decreased approximately 3.38 times, and the bactericidal ones – 4.18 times. Low-intensity currents exhibit a significant bactericidal effect on clinically relevant multidrug-resistant A. baumannii strains and enhance their susceptibility to antibiotics.