Theoretical confirmation of prospectivity of application of metabolitic complexes of lactobacilli and saccharomycetes in the fight antibiotic resistance of bacteria

Abstract

Introduction. The global problem is the increase in the number of infectious diseases caused by antibiotic–resistant pathogens. Measures to control these microorganisms should be aimed at preventing the formation of antibiotic–resistant populations of microorganisms and at inhibiting already established resistant populations. The aim of the work is to substantiate the perspective of using metabolic complexes of lactobacilli and saccharomycetes to control antibiotic resistance of bacteria. Material & methods. Cellular structures of lactobacilli and saccharomycetes (L / S) were received by irradiation with low–frequency ultrasonic waves (generator G3–109) of suspensions of Lactobacillus rhamnosus GG (from symbiotic PREEMA®, Schonen, Switzerland) and Saccharomyces boulardii (from probiotic drug BULARDI^®, Schonen, Switzerland). The metabolites of L. rhamnosus GG (ML) and S. boulardii (MS) were received in their own cellular structures. The combination of lactobacilli with saccharomycetes (MLS) and metabolites of saccharomycetes (LS) in the cellular structures of lactobacilli. Suspensions of microorganisms (resistant to antibiotics) gram–negative Pseudomonas aeruginosa PR, Acinetobacter baumannii PR, Klebsiella pneumoniae PR, Lelliottia amnigena (Enterobacter amnigenus) PR, gram–positive Staphylococcus aureus PR, Staphylococcus haemoliticus PR, Enterococcus faecalis PR, Corynebacterium xerosis PR, the cultures Corynebacterium spp. tox +, Streptococcus viridans, Streptococcus pneumoniaе with an optical density of 5,0 units on the McFarland scale (Densi–La–Meter (PLIVA–Lachema Diagnostika, (Czech Republic)) was added to L / S / ML / MLS / MS / LS (experimental samples) or to 0.9% sodium chloride solution (control samples) in a ratio of 1: 1. All samples were incubated for 1 hour at a temperature of + 35 ± 1 ° C, then the optical density was adjusted to 0.5 McFarland. Sowing was carried out on Mueller–Hinton medium. After disks with antibiotics (imipenem, vancomycin, cefotaxime, gentamicin, erythromycin, ciprofloxacin, amicil, chloramphenicol, ampicillin, ceftazidime , ceftriaxone, tetracycline, levofloxacin, amoxiclav, azithromycin), incubated (35 ± 1 ° C, 24 hours), measured the zones of growth retardation of microorganisms around the discs with antibiotics. Results & discussion. Potentiation of antimicrobial activity in the combined use of experimental samples with antibacterial drugs occurred in 88% of combinations with ML, 83 % – with MLS, 85 % – with MS, 73 % – with LS. Without increase in activity was substances with gentamicin, amicil, ampicillin, ceftazidime  were administered agains A. baumannii PR and with levofloxacin against S. aureus. Samples of ML over L (P = 0,005) and MLS over L (P = 0,008) had the advantage of a general increase in the diameters of the zones of growth inhibition of all tested pathogens. These results indicate a statistically significantly greater inhibition of growth of selected strains when combining antibiotics with metabolic complexes than with cellular structures. Excellent enhancement was observed when combining different antibacterial drugs with ML (on 5,5 ± 0,7, P <0,05), MLS (on 4,95 ± 0,6, P = 0,01) and MS (on 3,96±0,6, Р=0,001) relative to control. More inhibition of growth was observed of antibiotics with MLS than with MS (P = 0,02). A difference between the efficacies of the metabolic complexes ML and MLS was not found (P = 0,09). The presence of a large number of combinations of metabolic complex – antibiotic with the ability to therapeutically significant indicators to increase the antibacterial activity testifies the effectiveness of the combined use of metabolites L. rhamnosus GG and S. boulardii with different drugs. Conclusion. Theoretically confirmed of perspectivity of application of metabolic complexes of lactobacilli and saccharomycetes in the fight against antibiotic resistance of bacteria. Synergistic combinations of lactobacilli and saccharomycetes with antibiotics have been established. A therapeutically significant increase in their combined antimicrobial activity has been proven. This efficacy for different antibiotic–resistant strains indicates the perspectives of using metabolic complexes of lactobacilli and saccharomycetes to develop multifunctional antimicrobials preparations with consequence the possibility of inhibiting antibiotic resistance to already formed bacterial populations and at preventing the formation of antibiotic–resistant populations of microorganisms.

DOI: 10.5281/zenodo.4382213