A rat model of bacterial keratitis. Effect of antibiotics and corticosteroid
P. R. Badenoch, G. J. Hay, P. J. McDonald and D. J. Coster
A model of bacterial keratitis in rats was developed to quantify the effect
of antibiotics and corticosteroid on the infective process. Corneas were
inoculated with Staphylococcus aureus, Pseudomonas aeruginosa, or
Streptococcus pneumoniae. The natural history of infection with these
organisms was determined. Groups of animals received topical antibiotics
and prednisolone acetate. The effect of treatment on the number of
leukocytes and viable bacteria in the corneas was determined. Prednisolone
did not influence the effect of the antibiotics; however, steroid treatment
alone increased the pseudomonad count as much as 20-fold above the count in
untreated eyes. In general, both the antibiotic and steroid treatments were
more successful when begun eight hours after infection than when begun at
24 hours. a 1% gentamicin sulfate preparation proved effective against each
of the infections, including a pneumococcal strain considered resistant on
the basis of in vitro tests.
