Zaporožskij Medicinskij Žurnal (Feb 2020)
Antibacterial properties of a modified magnesium alloy in vitro with clinical strains of non-fermentative gram-negative microorganisms
Abstract
The aim. To determine the antibacterial effect of the products of biodegradation of magnesium alloy ML-10 on the clinical strains of Pseudomonas aeruginosa and Acinetobacter baumannii and, based on the results, substantiate the possibility of this alloy using in orthopedic and traumatological practice as implants with antibacterial activity. Materials and methods. Magnesium alloy extract was prepared on the basis of Mueller-Hinton broth (pH 7.4). The clinical strains of A. baumannii (15) and P. aeruginosa (15) were used in sensitivity testing. The bacteriostatic activity of the alloy extract was estimated by the visual growth presence or absence in test-tubes with microorganisms; bactericidal activity – by the growth of microbial colonies presence or absence on plates with Mueller-Hinton agar after culturing from test tubes for 24, 28 and 72 hours. Results of the study showed that the extract of magnesium alloy ML-10 has a high bacteriostatic and bactericidal activity against the clinical strains of A. baumannii and P. aeruginosa. In test tubes with an extract, the growth of microorganisms was not visually detected, which indicates a significant bacteriostatic activity of the magnesium alloy biodegradation products. The study of bactericidal activity found that the maximum growth of bacteria on agar was observed only after the first culturing from the test tubes (the extract incubation for 24 hours) in which the microorganisms were added in a concentration of 109, 108, 107 CFU/ml the day before. The number of colonies growing on agar after the second culturing (the extract incubation for 48 hours) significantly decreased in the process of thermostating, and after the third culturing (the extract incubation for 72 hours) the microorganism growth was absent on a dense medium in most experiments. High bactericidal activity of the magnesium alloy was found in the experiments with the extract containing 106, 105, 104 CFU/ml. The growth of colonies was absent on the dense medium after culturing from these tubes during the entire experiment. Conclusions. The products of magnesium alloy ML-10 biodegradation have shown high bactericidal activity against the non-fermentative gram-negative microorganisms A. baumannii and P. aeruginosa.
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