Journal: Advanced Science

Article Title: Alzheimer's Progenitor Amyloid‐β Targets and Dissolves Microbial Amyloids and Impairs Biofilm Function

doi: 10.1002/advs.202301423

Figure Lengend Snippet: Aβ dissolved the biofilms made by the live culture of P. aeruginosa (PAO1) and E. coli (K‐12). A) Schematic illustration of Aβ dissolving microbial biofilms. B,C) K‐12, PAO1, CsgA mutant (MC4100), and FapC mutant (Pseudomonas UK4) cultures (optical density OD 0.3) were grown for 48 h in the wells of 96‐well plates with peg lid and biofilms were formed on the pegs. The biofilms were incubated with Aβ (0–7.5 µ m ) and stained with crystal violet dye ( n = 3). Aβ at 3.5 µ m significantly reduced biofilm synthesis (*, p < 0.05). D) PAO1 and K‐12 microbial cultures were grown overnight on small (100 mm) glass petri dishes. Biofilms formed at the glass surfaces were gently washed with PBS and treated with Aβ (3.5 µ m ) for 24 h (37 °C). After incubation with Aβ, biofilms were treated with 0.1% crystal violet stain for 15 min and images were taken by a stereomicroscope and brightfield channel (scale bar: 100 µm). Biofilms treated with Aβ were disintegrated in contrast to PBS control. ThT (100 µ m , 15 min) labelled biofilms showed similar biofilm breakage into smaller fragments with Aβ (scale bar: 100 µm). Similarly, TEM was used to examine the fragmented morphology of disintegrated microbial biofilms treated with Aβ. K‐12 showed 400–500 nm and for PAO1 100–200 nm biofilm chunks were observed (scale bar: 200 nm).

Article Snippet: Microbial culture of K12 and PAO1 were added to 96‐well plates at OD 0.3 and incubated overnight at the static condition at 37 °C with Minimum Biofilm Eradication Concentration (MBEC) peg lids (Innovotech, Edmonton, Canada) where biofilms were formed on the pegs.

Techniques: Mutagenesis, Incubation, Staining, Control

Journal: Advanced Science

Article Title: Alzheimer's Progenitor Amyloid‐β Targets and Dissolves Microbial Amyloids and Impairs Biofilm Function

doi: 10.1002/advs.202301423

Figure Lengend Snippet: SEM imaging of PAO1 and K‐12 biofilms after treatment with Aβ. Microbial cultures treated with Aβ were further examined in SEM. K‐12 and PAO1 cultures treated with Aβ (3.5 µ m ) both revealed substantial reduction in fimbriae‐like biofilm structures in Aβ treated samples, as compared to PBS‐treated samples.

Article Snippet: Microbial culture of K12 and PAO1 were added to 96‐well plates at OD 0.3 and incubated overnight at the static condition at 37 °C with Minimum Biofilm Eradication Concentration (MBEC) peg lids (Innovotech, Edmonton, Canada) where biofilms were formed on the pegs.

Techniques: Imaging

Journal: Advanced Science

Article Title: Alzheimer's Progenitor Amyloid‐β Targets and Dissolves Microbial Amyloids and Impairs Biofilm Function

doi: 10.1002/advs.202301423

Figure Lengend Snippet: A) Aβ increases the anti‐microbial susceptibility of P. aeruginosa and E. coli . Microbial cultures of PAO1 and K‐12 were grown overnight (OD 0.3, at 37 °C) and subjected to series of dilutions of Aβ (0–1 µ m ) and Pen (0–5 × 10 −2 U mL −1 ) Strep (0–5 × 10 −2 µg mL −1 ) in LB media ( n = 6). Biofilm swabs form pegs were streaked on LB agar plate and number of surviving colonies were counted. B) Concentration‐dependent antimicrobial effect with Pen, Strep effect was evident, C) whereas Aβ antimicrobial effect was diminished at higher concentrations. To examine the anti‐microbial susceptibility of PAO1 and K‐12, microbial cultures were treated overnight with selected concentrations of Aβ (0.05 µ m ) mixed with Pen (5 × 10 −6 U mL −1 ) Strep (5 × 10 −6 µg mL −1 ) in LB media. Biofilm swabs were streaked on LB agar plate (D) that presented a significant reduction in the number of surviving colonies (E) (*, p < 0.05).

Article Snippet: Microbial culture of K12 and PAO1 were added to 96‐well plates at OD 0.3 and incubated overnight at the static condition at 37 °C with Minimum Biofilm Eradication Concentration (MBEC) peg lids (Innovotech, Edmonton, Canada) where biofilms were formed on the pegs.

Techniques: Concentration Assay