Use of a pair of blood culture bottles for sterility testing of corneal organ culture media

AIMS To test the effectiveness and rapidity of a pair of blood culture bottles in the diagnosis of bacterial and fungal contamination of corneal organ culture media. METHODS 761 microbiological analyses of storage media (Inosol and Exosol, Opsia, Toulouse, France), sampled in all phases of the organ culture at 31°C of 410 consecutive corneas, were analysed. Each medium was inoculated in a pair of Bactec Plus Aerobic/F and Bactec Lytic/10 Anaerobic/F blood bottles and placed in a Bactec 9240 incubator for 14 days at 37°C and in a Sabouraud broth at 20°C. Changes in colour or turbidity of storage media were evaluated daily at the corneal bank. Recipients were screened post-graft for infectious signs. RESULTS Overall contamination rate was 2.4% (18/761). Contamination was detected in less than 1 day in 78% (14/18) and less than 2 days in 94% (17/18). Positivity of the microbiological controls of starting media preceded changes medium colour in 10 out of 14 cases. Bactec blood bottles allowed detection of bacteria as well as yeasts. CONCLUSION The use of a pair of Bactec blood culture bottles appears reliable for the rapid diagnosis of a wide range of microbiological contaminations of organ cultured corneas during banking.