Abstract

JURADO-GAMEZ, Henry  and  FAJARDO-ARGOTI, Catalina. DETERMINATION OF THE PROBIOTIC IN VITRO EFFECT OF Lactobacillus gasseri ON A Staphylococcus epidermidis STRAIN. Biosalud [online]. 2017, vol.16, n.2, pp.53-69. ISSN 1657-9550.  https://doi.org/10.17151/biosa.2017.16.2.6.

Due to the characteristic probiotic properties of lactic acid bacteria such as the generation of compounds derived from fermentation, which can inhibit multiple pathogenic organisms to create an unfavorable environment for them and finally to be used as an alternative to the use of drugs to treat and prevent various diseases. The present study sought to assess probiotic characteristics of L. gasseri on S. epidermidis under in vitro conditions. The susceptibility of both strains to different antibiotics, the inhibitory effect of L. gasseri and supernatant on S. epidermidis, and the growth of the lactic strain at different pH, temperature, bile salts and bovine bile were determined. The fermentation kinetics was established, and the count of viable microorganisms in plaque, pH, sugar consumption, consumption of protein and percentage of lactic acid was defined. Finally, peptides and lactic acid were determined using HPLC-DAD for L. gasseri, and in the case of amino acids in the supernatant, these were determined with HPLC-PDA for the two strains. The resistance of both strains to the antibiotics gentamicin and dicloxacillin was found. The lactic strain and the supernatant inhibited the growth of S. epidermidis. The growth was suitable for the different variables with values between 1.8 x 109 and 3.0 x 1012 CFU/150 μl. The exponential phase was observed at 12 hours with a value of 3 x 1011 CFU/150 μl, with values of 4.296, 1.26%, 2.032 mg/l and 0.65 mg/l for pH, lactic acid, sugar consumption and protein consumption, respectively. Finally, the peptide VAL-TIR-VAL with a value of 0.73 mg/ml, 11.7 g/l of lactic acid, and the amino acid tyrosine were identified in the supernatant of L. gasseri by HPLC-DAD. The results show that Lactobacillus gasseri have probiotic characteristics on S. epidermidis under in vitro conditions.

Keywords : Lactic bacteria; inhibition; pathogenic strain; probiotic.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )