Interference of probiotic bacteria isolated from yoghurt with Pseudomonas aeruginosa in vitro

This study evaluated the ability of the probiotic organisms isolated from yoghurt to inhibit the pathogenic activity of Pseudomonas aeruginosa in vitro. A total of 8 bacterial strains isolated from samples were tested for antimicrobial activity. The antibacterial activity of the one strain was more potent than the other isolated strains that this isolate was identified as Enterococcus faeciumstrain by morphological, biochemical and 16S rDNA gene sequencing analysis. The various preparations (Enterococcus whole- cell culture containing 106 CFU/ml, acid filtrate, neutralized filtrate and cells washed and resuspended in phosphate buffered saline) were tested in vitro for their effects on the production of the P. aeruginosabiofilm. No viable P. aeruginosacells were detected after culture in the whole-cell culture and acid filtrate E. faeciumpreparations. Compared to P. aeruginosagrown in LB medium, the whole-cell culture and acid filtrate had a significant inhibitory effect on biofilm production.