AUTHOR=Penchuk Yurii , Savytska Maryana , Kobyliak Nazarii , Ostapchenko Danylo , Kolodiy Igor , Onysenko Svitlana , Tsyryuk Olena , Korotkyi Oleksandr , Grygoriev Fedir , Falalyeyeva Tetyana 

TITLE=Antimicrobial activity of dietary supplements based on bacterial lysate of Lactobacillus rhamnosus DV

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2023.1211952

DOI=10.3389/fcimb.2023.1211952

ISSN=2235-2988

ABSTRACT=<sec><title>Introduction</title><p>According to WHO, antibiotic resistance is increasing to hazardous levels worldwide. Candidiasis often occurs after taking antibiotics. Therefore, antibiotic resistance is a global problem and searching for antibacterial agents is necessary.</p></sec><sec><title>Aim</title><p>To determine the antimicrobial activity of bacterial lysate of <italic>Lactobacillus (L.) rhamnosus</italic> DV separately and with plant extracts against bacterial and yeast test cultures.</p></sec><sec><title>Material and methods</title><p>Antimicrobial activity of Del-Immune V<sup>®</sup> (cell wall and DNA fragments from a <italic>L. rhamnosus</italic> DV) separately and with cinnamon, beetroot, and blackcurrant extracts was determined by the minimum inhibitory concentration (MIC). Twofold serial dilutions determined the MIC in previously prepared meat-peptone broth (MPB) for bacteria and liquid wort for yeast. In the study, gram-negative (<italic>Escherichia coli</italic> IEM-1, <italic>Proteus vulgaris</italic> PА-12, <italic>Pseudomonas</italic> sp. MI-2, <italic>L. rhamnosus</italic> 13/2) and gram-positive (<italic>Bacillus (B.) subtilis</italic> BТ-2, <italic>Staphylococcus aureus</italic> BМС-1) bacteria, as well as yeast (<italic>Candida (C.) albicans</italic> D-6, <italic>C. tropicalis</italic> PE-2, <italic>C. utilis</italic> BVS-65) were used as test cultures.</p></sec><sec><title>Results</title><p>The MIC for the studied bacterial test cultures after application of <italic>L. rhamnosus</italic> DV bacterial lysates was from 1.0 ± 0.05 mg/mL to 12.5 ± 0.63 mg/mL, which was significantly less than that of the thermally inactivated control (MIC from 125.0 ± 6.25 mg/mL to 250.0 ± 12.5 mg/mL). <italic>B. subtilis</italic> BT-2 culture was the least sensitive to the action of the bacterial lysate (MIC—12.5 ± 0.63 mg/mL). It showed the best antibacterial and antifungal effect bacterial lysate with the phytonutrient blackcurrant.</p></sec><sec><title>Conclusions</title><p>It was demonstrated that bacterial lysate of lactic acid bacteria <italic>L. rhamnosus</italic> DV exhibits antibacterial and antifungal properties during direct contact with pathogenic agents.</p></sec>