Bacterial transmission from contact lenses to porcine corneas: an ex vivo study.
OBJECTIVE
To quantify the transmission to ex vivo porcine eyes of Staphylococcus aureus 835 and Pseudomonas aeruginosa 3 from three types of contact lenses-one daily wear and two extended wear-differing in hydrophobicity and roughness.


METHODS
One daily wear lens (etafilcon) and two extended-wear lenses (one lotrafilcon A and one balafilcon A) were inoculated in a bacterial suspension for 30 minutes and then placed on ex vivo porcine eyes. After 16 hours of contact between lens and eye, confocal laser scanning microscopy was used to determine the number of bacteria on the lens and cornea for the calculation of transmission percentages.


RESULTS
Transmission percentages were significantly different for both bacterial strains from an etafilcon A lens and balafilcon A lens (P = 0.006 and 0.04, respectively). Percentages varied from 51% to 68% for the hydrophobic P. aeruginosa and from 54% to 82% for the hydrophilic S. aureus strain, depending on the contact lens involved. Both strains were transferred the least from the most hydrophilic and roughest lens made of lotrafilcon A, although the difference was only statistically significant for S. aureus.


CONCLUSIONS
Bacterial transmission to the porcine cornea differed in the various types of contact lenses and was least in the hydrophilic and rough lens type.
Vermeltfoort
Pit B J
PB
Department of BioMedical Engineering, University Medical Center Groningen, The Netherlands.
van Kooten
Theo G
TG
Bruinsma
Gerda M
GM
Hooymans
Anneke M M
AM
van der Mei
Henny C
HC
Busscher
Henk J
HJ
D000818:Animals; D001422:Bacterial Adhesion; D015169:Colony Count, Microbial; D003261:Contact Lenses / Q000382:microbiology*; D003315:Cornea / Q000382:microbiology*; D018613:Microscopy, Confocal; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D013211:Staphylococcus aureus / Q000502:physiology*; D013552:Swine