Theoretical and experimental investigation of antibacterial activity of lidocaine hydrochloride against clinical resistant gram-negative strains of bacteria

Introduction. Today, antimicrobial resistance is the number one problem worldwide. One of the first mentions of the emergence of antibiotic-resistant strains of bacteria in humans was obtained during military conflicts in Iraq and Afghanistan 20 years ago. In addition, according to the latest data, it has found that Acinetobacter baumani, Pseudomonas aeruginosa, Klebsiela pneumonia and Enterococcus cloacae are predominant among all isolated resistant pathogens. So, the search of new antibacterial drug that can deal with antimicrobial resistance is a task number one. The purpose of the study was to investigate in vitro and in silico antibacterial activity against clinical multidrug-resistant strains of Staphylococcus aureus, P. aeruginosa, A. baumannii, K. pneumonia and E. cloacae. Materials and methods. The object of the study was lidocaine hydrochloride. The molecular docking was performed using AutoDockTools 1.5.6; antibacterial effects were evaluated by the well and "dilution" methods method. Isolates were obtained from clinical samples including tracheal aspirate and broncoalveolar lavage. Results. Lidocaine hydrochloride was shown high selectivity to AHS LasI, Experimental research was demonstrated that against resistant strain of P. aeruginosa lidocaine hydrochloride inhibited growth – from 23.0±0.2 to 16.0±0.2 mm, against A. baumannii – from 24.0±0.1 to 16.0±0.1 mm, against E. cloacea – from 18.0±0.2 to 16.0±0.2 mm, K. pneumonia – from 21.0±0.2 to 16.0±0.2 mm, respectively. The minimum inhibitory concentration (MIC) values of lidocaine hydrochloride for P. aeruginosa, E. cloacea, A. baumannii, K. pneumonia was 0.00075 mmol/L. Conclusion. It has conducted theoretical and experimental studies of antibacterial effect of lidocaine hydrochloride. The theoretical results demonstrated that lidocaine hydrochloride highly selectively inhibited only one enzyme – AHS LasI. According to experimental results, it was shown that lidocaine hydrochloride effectively inhibited resistant strains of P. aeruginosa, E. cloacea, A. baumannii, K. pneumonia. So, lidocaine hydrochloride is a perspective substance for elimination resistance of antibiotics.