SURFACE PROPERTIES OF LACTOBACILLI AND BIFIDOBACTERIA ARE AFFECTED BY LOSARTAN

MINNAARD, JESSICA; FRAGOMENO, MELISA; PEREZ, PABLO F

Congreso; XVII Congreso Argentino de Microbiología General; 2022

Bifidobacteria and lactobacilli (LB) exert a range of beneficial effects on host health. However, information on the role of medications in the intestinal environment is scarce. Losartan (Ls) is an antihypertensive drug with the ability to affect negative charge of lipid bilayers. As evaluation of cell surface properties is accepted for a preliminary screening of potential probiotic strains, the aim of this work was to study the effect of Ls on these properties in bifidobacteria and LB.Strains were grown in MRS broth (37°C/24 h) with Ls 0.2 mg ml-1 in anaerobic (Bifidobacterium bifidum CIDCA 5310 and B. adolescentis CIDCA 5317) or aerobic conditions (Lactobacillus delbrueckii subsp lactis CIDCA 133 y L. delbreuckii subsp bulgaricus CIDCA 331). Controls without Ls were made. Hydrophobicity was assessed by extraction of bacterial suspensions (in PBS, A0) with hexane, chloroform or ethyl acetate by vortexing. After phases were separated, A600nm of the aqueous phase was measured. H% was calculated as: [(A0 - A)/A0] x100. Contact angle was determined by spreading bacteria on a glass coverslide, putting a drop of distilled water and using a goniometer. To determine zeta potential (ζ-potential), bacteria were suspended in KCl (1 mM) and values were obtained in Horiba Nano- SZ100 analyzer. To evaluate phagocytosis, FITC-labeled bacteria were incubated with THP1 cells (differentiated with phorbol miristate acetate 200 nM) at multiplicity of infection 10 bacteria/cell for 18h at 37ºC/5% CO2. Internalization was determined by flow cytometry by recording FL1(+) cells (%). Trypan blue was used for quenching of non-internalized bacteria. Data presented showed P