A three-phase in-vitro system for studying Pseudomonas aeruginosa adhesion and biofilm formation upon hydrogel contact lenses.
BACKGROUND
Pseudomonas aeruginosa is commonly associated with contact lens (CL) -related eye infections, for which bacterial adhesion and biofilm formation upon hydrogel CLs is a specific risk factor. Whilst P. aeruginosa has been widely used as a model organism for initial biofilm formation on CLs, in-vitro models that closely reproduce in-vivo conditions have rarely been presented.


RESULTS
In the current investigation, a novel in-vitro biofilm model for studying the adherence of P. aeruginosa to hydrogel CLs was established. Nutritional and interfacial conditions similar to those in the eye of a CL wearer were created through the involvement of a solid:liquid and a solid:air interface, shear forces and a complex artificial tear fluid. Bioburdens varied depending on the CL material and biofilm maturation occurred after 72 h incubation. Whilst a range of biofilm morphologies were visualised including dispersed and adherent bacterial cells, aggregates and colonies embedded in extracellular polymer substances (EPS), EPS fibres, mushroom-like formations, and crystalline structures, a compact and heterogeneous biofilm morphology predominated on all CL materials.


CONCLUSIONS
In order to better understand the process of biofilm formation on CLs and to test the efficacy of CL care solutions, representative in-vitro biofilm models are required. Here, we present a three-phase biofilm model that simulates the environment in the eye of a CL wearer and thus generates biofilms which resemble those commonly observed in-situ.
Department of Hygiene and Environmental Medicine, Ernst Moritz Arndt University Greifswald, Greifswald, Germany.
Claudia
C
Rändler
Rutger
R
Matthes
Andrew J
AJ
McBain
Bernd
B
Giese
Martin
M
Fraunholz
Rabea
R
Sietmann
Thomas
T
Kohlmann
Nils-Olaf
NO
Hübner
Axel
A
Kramer
D001422:Bacterial Adhesion; D018441:Biofilms; D003261:Contact Lenses / Q000382:microbiology*; D015818:Eye Infections, Bacterial / Q000382:microbiology*; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000032:analysis; D008954:Models, Biological; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000502:physiology*
D020136:Hydrogel, Polyethylene Glycol Dimethacrylate