Effects of multipurpose contact-lens care solutions on adhesion of Pseudomonas aeruginosa to corneal epithelial cells.
OBJECTIVE
To study the adhesion of Pseudomonas aeruginosa (PA) to human corneal epithelial cells treated with multipurpose contact-lens care solutions (MPSs).


METHODS
SV40-immortalized human corneal epithelial cells (svHCET cells) were cultured on collagen-coated culture slides for 7 days. The svHCET cells were exposed to three MPSs: MPS-A (polyhexamethylene biguanide, macrogolglycerol hydroxystearate), MPS-B (polyhexamethylene biguanide, Poloxamer, and boric acid) or MPS-C (Polyquad, Poloxamine, and boric acid) for 60 min. PA cells (ATCC27853) were inoculated onto cultured svHCET cells and adhesion was observed with a PKH67 fluorescent dye-labeling method using a confocal laser scanning microscope. The number of adherent PA was assessed by 16S-rDNA quantification using real-time polymerase chain reaction and confocal laser scanning microscope imaging. PA adhesion and inter- and intracellular invasion into svHCET cells were also observed with scanning electron microscopy and transmission electron microscopy.


RESULTS
PA adhesion was more than three times higher in MPS-B-treated cells and six times higher in MPS-C-treated cells compared with control estimated by real-time polymerase chain reaction (P < 0.05). MPS-A-treated cells showed no significant increase in PA adhesion. With scanning electron microscopy and transmission electron microscopy, PA were observed to enter opened cell-cell borders between adjacent svHCET cells treated with MPS-B and C, but not with MPS-A.


CONCLUSIONS
Taken together, these results support the possibility that chronic use of MPS containing boric acid (MPS-B and MPS-C) by hydrogel contact lens wearers may lead to increased risk for associated microbial corneal infection with PA.
Imayasu
Masaki
M
Department of Anatomy, Nagoya City University Medical School, Nagoya, Aichi, Japan. imayasu-m@menicon-net.co.jp
Shimizu
Hideo
H
Shimada
Shoichi
S
Suzuki
Takashi
T
Cavanagh
H Dwight
HD
D001422:Bacterial Adhesion / Q000187:drug effects*; D002461:Cell Line, Transformed; D003199:Computer Systems; D018639:Contact Lens Solutions / Q000009:adverse effects*; D004338:Drug Combinations; D019573:Epithelium, Corneal / Q000382:microbiology*; D005456:Fluorescent Dyes; D006801:Humans; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009930:Organic Chemicals; D016133:Polymerase Chain Reaction; D011550:Pseudomonas aeruginosa / Q000502:physiology*
D018639:Contact Lens Solutions; D004338:Drug Combinations; D005456:Fluorescent Dyes; D009930:Organic Chemicals; C451241:PKH67