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

Abstract

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.