Bacterial contamination of a cornea tissue bank: implications for the safety of graft engineering.
OBJECTIVE
To analyze the difficulties involved in managing an episode of bacterial contamination in a cornea bank. We describe (1) the circumstances of bacterial contamination discovery, (2) the methods used to investigate the outbreak, (3) the corrective measures adopted, and (4) the method introduced to improve the reaction capacity in case of bacterial contamination.


METHODS
All the samples collected were cultured in an attempt to identify the environmental reservoir of the contaminated epidemic clone. Bacteria were identified by Gram stain, oxidase test, and biochemical characteristics. The clonality of the strains was assessed by pulsed-field gel electrophoresis.


RESULTS
The bacterial contamination was confirmed for 28 corneas, and 70 additional corneas were discarded. The source of the contamination was identified 17 days after the beginning of the episode. It consisted of a clonal bacterial strain that was found in trypan blue, the dye, used to examine all the tissues. The contaminating bacterium was Burkholderia cepacia, a well-known nosocomial pathogen. A total of 169 grafted corneas had been checked with the contaminated reagent. No cases of post-graft infection were recorded.


CONCLUSIONS
Trypan blue played a major role in this outbreak. The mode and chronology of contamination remain unresolved. This exceptional event emphasizes the risk of bacterial contamination in tissue/cell banks, the necessity to improve methods for its prevention, and procedures to limit its consequences.
Morel
Pascal
P
Unité de Thérapie Tissulaire, Centre Hospitalier Universitaire de Besançon, France. pascal.morel@efs.sante.fr
Roubi
Nora
N
Bertrand
Xavier
X
Lapierre
Valérie
V
Tiberghien
Pierre
P
Talon
Daniel
D
Hervé
Patrick
P
Delbosc
Bernard
B
D019121:Burkholderia Infections / Q000453:epidemiology* / Q000382:microbiology; D016956:Burkholderia cepacia / Q000254:growth & development / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D004396:Coloring Agents; D003315:Cornea / Q000382:microbiology*; D016039:Corneal Transplantation; D015925:Cryopreservation; D004196:Disease Outbreaks; D004340:Drug Contamination; D005125:Eye Banks; D005602:France / Q000453:epidemiology; D006801:Humans; D019188:Organ Preservation Solutions; D012449:Safety; D014343:Trypan Blue
D004396:Coloring Agents; D019188:Organ Preservation Solutions; D014343:Trypan Blue