Evaluation of anti-microbial activity of filtrates of Lactobacillus rhamnosus and Saccharomyces boulardii against antibiotic-resistant gram-negative bacteria

Abstract

The article presents the results of the first study on the influence of biologically active substances Lactobacillus rhamnosus GG ATCC 53103 and Saccharomyces boulardii, obtained according to the author`s method, on growth of gram-negative bacteria with broad medical resistance: Pseudomonas aeruginosa PR, Klebsiella pneumoniae PR, Lelliottia amnigena (Enterobacter amnigenus) PR using the spectrophotometric method. Disintegrates of L. rhamnosus GG and S. boulardii were obtained using low-frequency ultrasound processing of suspension of probiotic strains, and metabolites – through cultivation of lactobacteria and saccharomycetes in disintegrates of probiotic microorganisms. To samples of test-cultures with studied filtrates of disintegrates or metabolites we added growth medium and cultivated them (period of monitoring was 5- and 24-hours). Results of the studies were expressed as the percentage of inhibition of increment in polyresistant gram-negative bacteria under the impact of biologically active substances of probiotic microorganisms. Five-hour incubation of test-strains with the studied samples of lactobacteria led to inhibition of their growth properties by 85.6–96.7%. Growth of bacteria under the impact of substances of saccharomycetes was inhibted by 45.1–92.5%. Twenty-four hour exposure of the test-cultures in filtrates of L. rhamnosus GG and S. boulardii caused 100% inhibition of P. aeruginosa and L. amnigena polyresistant strains. Temporal interval of cultivation directly proportionally affected the extent of inhibition of growth of microorganisms: we determined direct correlation dependence within 0.789–0.991. Maximum inhibition of increment of the studied pathogens was observed under the influence of metabolites of lactobacteria, obtained by cultivating primary producers in their disintegrate. We determined a high level of anti-microbial activity of metabolites from L. rhamnosus GG and S. boulardii obtained by cultivation of probiotics in disintegrates against bacteria resistant to a broad range of preparations, which allows us to consider these substances as promising for development of anti-microbial preparations of a new generation against etiologically significant antibiotic-resistant gram-negative microorganisms.

Minimum Inhibitory and Bactericidal Concentrations of Antibacterial Drugs Separately and Together With Metabolic Complexes of Lactobacillus Rhamnosus Gg and Saccharomyces Boulardii

“…It was difficult to isolate these pathogens during bacteriological studies (S. aureus was isolated predominantly) 22,23 . These results prove the potential for constructing based on metabolic complexes of lactobacilli and saccharomycetes of "accompaniments-preparations" to antibiotics for the treatment of wound infections 24,25,26 . Resistant to ciprofloxacin E. faecalis showed moderate resistance to the combined use of the antibiotic with the metabolite complex ML, despite a decrease in MIC by only half.…”

Producing metabolic complexes of probiotic microorganisms with significant antimicrobial properties

“…Він дає змогу раціонально використовувати виробничі ресурси шляхом поєднання послідовних етапів отримання структурних компонентів і продуктів метаболізму; спростити технологію отримання комбінованих біологічно активних речовин завдяки спільному культивуванню різних видів мікроорганізмів; підвищити протидифтерійні властивості метаболітних речовин. Отже, цим способом можна отримувати комбінацію метаболітних комплексів різних пробіотичних мікроорганізмів із високими антибактеріальними властивостями, результати наведені в попередніх публікаціях [4,13,14].…”