Streptococcal endophthalmitis from contaminated donor corneas after keratoplasty. Clinical and Laboratory investigations

We report thee cases of Streptococcus viridans endophthalmitis following penetrating keratoplasty in which S viridans was cultured from the recipient eye, McCarey-Kaufman (M-K) media, and corneoscleral rims. As a laboratory correlation, we investigated the ability of S viridans to survive in M-K medium supplemented with gentamicin. After M-K medium was inoculated with S viridans, it was stored overnight at 4°C, after which the temperature was raised to 23°C. Periodic colony counts were performed for up to 24 hours after warming. No killing occurred in the cold. Ten hours passed before there was one log reduction in the bacterial colony count. Organisms could still be cultured at 24 hours. We conclude that gentamicin alone may be inadequate prophylaxis against S viridans contamination of donor corneas.