Journal: Frontiers in Cellular and Infection Microbiology
Article Title: Different Concentrations of Lactobacillus acidophilus Cell Free Filtrate Have Differing Anti-Biofilm and Immunomodulatory Effects
doi: 10.3389/fcimb.2021.737392
Figure Lengend Snippet: L. acidophilus cell free filtrate (CFF) exhibits bactericidal action on P. aeruginosa planktonic cell growth but not on E. coli growth. Growth curves were conducted by incubating P. aeruginosa or E. coli in a 96-well plate with L. acidophilus 10 8 or 10 6 CFF, 1 µg/mL ciprofloxacin (CPFX), or HCl pH 4 at 37°C with orbital shaking. Absorbance (OD 600 ) was measured every 10 min for 20 h. (A) L. acidophilus 10 8 CFF completely inhibited P. aeruginosa planktonic growth (p < 0.001). 10 6 CFF, HCl pH 4, and 1 µg/mL ciprofloxacin affected P. aeruginosa growth, although significantly less effective than 10 8 CFF. (B) At the end of growth curve studies, bacteria were spread on TSA plates and colonies counted. 10 8 CFF killed > 99.99% P. aeruginosa and therefore was bactericidal. However, all other treatments were not bactericidal. (C) Both concentrations of L. acidophilus CFF and HCl pH 4 did not significantly inhibit E coli growth. However, 1 µg/mL ciprofloxacin inhibited E. coli growth (p < 0.001). (D) Following growth curve studies, E . coli cells were spread on TSA plates and colonies counted. Only 1 µg/mL ciprofloxacin was bactericidal (> 99.99% inhibition). P. aeruginosa growth curves n = 5 independent experiments; P. aeruginosa CFUs n = 3 independent experiments; E. coli growth curves n = 4 independent experiments; E. coli CFUs n = 3 independent experiments.
Article Snippet: Escherichia coli ATCC BAA-1883TM was grown in Tryptic soy broth (TSB; Sigma-Aldrich, St. Louis, MO, USA) for 24 h at 37°C.
Techniques: Bacteria, Inhibition