Abstract
Introduction NHS Blood and Transplant Tissue and Eye Services (TES) is a human multi-tissue, tissue bank supplying tissue for transplant to surgeons throughout the UK. NHSBT has two Eye Banks.
NHSBT investigated all our corneas discard due to contamination with the aim to review for any patterns. NHSBT Eye Banks performs initial Microbiology sampling on all Corneas in Corneas in Organ Culture Media at 7 Days. Corneas undergo a 2nd Microbiology sampling the day after the cornea is transferred into dextran median.
Materials and methods Any Microbiology positive media Identified pre-transplant are sent to NHSBT’s Microbiology Reference Laboratory (MSL) for Identification. Any organisms which are identified post-dispatch are sent to a Referral Laboratory for rapid Identification and Sensitivity/Specificity Testing.
Filton Eye Bank Contaminated Corneas in Organ Media: 2018- 28 (0.91%) 2019 -45 (1.10%), 2020- 27 (1.03%), 2021- 39 (1.41%), 2022- 43 (2.1%) (until 15/08/22)
Most common Identified Organisms: C.Ablicans C. glabrata C.paraphilotis
Contaminated In Dextran Pre-Transplant: 2018- 4 (0.17%) 2019 -6 (0.18%), 2020- 9 (0.46%), 2021- 0 (0%), 2022- 3 (0.3%) (until 15/08/22). Most common Identified Organisms: Bacillus species
Contaminated in Dextran Post Transplant: 2018- 0 (0%) 2019 -8 (0.23%), 2020- 2(0.10%), 2021- 2 (0.08%), 2022- 1 (0.11%) (until 15/08/22). Most common Identified Organisms: Bacillus species
David Lucas Eye Bank: Contaminated Corneas in Organ Media: 2020- 20(1.8%), 2021- 37(1.96%), 2022- 21(1.4%) (until 15/08/22). Most common Identified Organisms: C.Ablicans C. glabrata C.Kefyr
Contaminated In Dextran Pre-Transplant: 2020- 6(0.8%), 2021- 2(0.14%), 2022- 1(0.08%) (until 15/08/22). Most common Identified Organisms: Bacillus species
Contaminated in Dextran Post Transplant: 2020- 2 (0.26%), 2021- 1 (0.07%), 2022- 2 (0.16%) (until 15/08/22). Most common Identified Organisms: Bacillus species
Discussion Processes and facilities are of same standard between the two NHSBT Eye Banks and contamination rates are comparable. contamination is only identified in Approx1% of corneas processed. Corneas where growth is identified in Dextran is less than 1% of corneas Issued. Of the positive Microbiology samples identified post-Transplant, were mostly identified as Environmental Bacteria and had no patient impact on patient and assumed to have been contaminated by the operator.
