Different strains of Pseudomonas aeruginosa isolated from ocular infections or inflammation display distinct corneal pathologies in an animal model.
OBJECTIVE
The present investigation sought to define the responses of mouse eyes to challenge with three different strains of P. aeruginosa isolated from human corneas or contact lenses: two different strains produced an ulcerative keratitis, and one strain produced contact lens-induced acute red eye (CLARE).


METHODS
The corneas of BALB/c mice were inoculated with three different strains of P aeruginosa. The strains were allowed to interact with the corneas for up to 24 h. In addition, strain Paerl, isolated from CLARE, was subjected to in vitro assays to measure its ability to invade corneal epithelial cells, or to produce cytotoxicity in these cells. Both these assays used cultured rabbit corneal epithelial cells.


RESULTS
Both MK isolates were able to infect the corneas of mice, but the CLARE isolate was non-infective. The predominant response to infection with the cytotoxic strain was severe corneal edema and infiltration of the corneal stroma with polymorphonuclear leukocytes (PMNs). The predominant response with the invasive MK isolate was corneal ulceration and infiltration with PMNs. The CLARE strain produced only low levels of PMN infiltration. In in vitro assays the CLARE strain was non-invasive and non-cytotoxic.


CONCLUSIONS
This study has identified that P. aeruginosa produces at least three different types of corneal pathology and that not all strains are able to infect mouse corneas.
Cole
N
N
The Cooperative Research Centre for Eye Research and Technology, University of New South Wales, Sydney, Australia.
Willcox
M D
MD
Fleiszig
S M
SM
Stapleton
F
F
Bao
B
B
Tout
S
S
Husband
A
A
D000818:Animals; D003315:Cornea / Q000382:microbiology* / Q000473:pathology*; D004847:Epithelial Cells / Q000502:physiology / Q000821:virology; D005128:Eye Diseases / Q000382:microbiology; D015817:Eye Infections / Q000382:microbiology*; D006801:Humans; D007249:Inflammation / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D011552:Pseudomonas Infections / Q000473:pathology*; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000302:isolation & purification* / Q000502:physiology; D011817:Rabbits; D013045:Species Specificity