Antagonistic activity of monocultures and consortia of lactobacilli against multidrug-resistant isolates of opportunistic bacteria as a screening of their probiotic potential

Abstract

Background. In recent years, special attention has been paid to the studying the consortia of probiotic bacteria. In these associations, the properties of individual microorganisms can be enhanced, in particular, their antagonistic activity which is an effective indicator for screening of probiotic potential. The development of probiotics based on such consortia with antibacterial properties is critical in the light of the growing problem of drug resistance in microorganisms.The aim of the work. To study the antagonistic activity of monocultures and consortia of lactobacilli against multidrug-resistant isolates of opportunistic bacteria. Materials and methods. The antagonistic activity of lactobacilli monocultures and their consortia was assessed simultaneously by two methods: the cross streak method and the well diffusion method.Results. All strains of lactobacilli and their consortia, depending on the research method, had varying degrees of antagonistic activity. Five consortia had stronger antagonism to test cultures as compared to monocultures, while in one consortium, the effect of antagonistic activity was reduced compared to monocultures. The results of studying the antagonistic activity of two consortia (Limosilactobacillus fermentum 44/1 and Lacticaseibacillus rhamnosus 12L, Latilactobacillus curvatus LCR-111-1 and Lactiplantibacillus plantarum 8PAZ) contradict data on the biocompatibility of strains in these consortia. Differences in the degree of antagonistic effects of lactobacilli on gram-positive and gram-negative species of opportunistic bacteria were revealed.Conclusion. The study showed that both the biocompatibility of the probiotic strains and the antagonistic activity of the consortium are the important requirements for creating a probiotic consortium with effective probiotic potential. To study the antagonistic properties of lactobacilli, the number of isolates of target gram-positive and gram-negative bacteria and normobiota should be increased. This will allow us to determine effective strategies for using probiotics in conditions of the spread of drug resistance of microorganisms.

Keywords

• lactobacilli, probiotic consortia, probiotic potential, antagonistic activity, opportunistic bacteria, multidrug-resistant isolates