Department of Ophthalmology, Université de Montréal, Montréal, Québec, Canada.
Medical Affairs, Héma-Québec, Québec, Québec, Canada.
Cornea. 2020 Jul;39(7):827-833. doi: 10.1097/ICO.0000000000002267.
To assess the efficacy of the prestorage corneal swab (PCS) culture to screen for corneal graft contamination after storage in Optisol-GS.
A retrospective analysis of all PCS cultures was performed at the Eye Bank of Québec in Hôpital Maisonneuve-Rosemont from September 2013 to June 2016. Whole corneal culture was performed on rejected grafts because of a positive PCS, and a contamination rate was calculated. In addition, contamination rates of corneoscleral rims were compared between corneas tested with PCS and those of imported corneas which did not have PCS.
Among the 1966 PCS cultures performed, 814 (41.4%) were positive for growth. Pathogenic bacteria were present in 144 (7.3%) corneas, including Staphylococcus aureus (n = 96, 11.8% of all positive cultures), Enterobacteriaceae (n = 14, 1.7%), and Pseudomonas aeruginosa (n = 6, 0.7%). After preservation in Optisol-GS, only 7 (6.9%) corneas remained contaminated (95% confidence interval 5.1-9.3). The sensitivity of the PCS culture was 87.5% (95% confidence interval 47.4-99.7). There was no significant difference in corneoscleral rim contamination between corneas tested with PCS (1/388; 0.2%) compared with imported, nonswabbed corneas (3/214; 1.4%) (P = 0.131). Therefore, the cost to recover the loss of tissue rejected because of false-positive PCS by purchasing corneal tissue was calculated to be $142,884 (CAD) per year.
Despite the high sensitivity of PCS cultures, there was no significant reduction of infection after corneal transplantation using this technique. In consequence, 93% of the corneas possibly suitable for transplantation were rejected. This suggests that the PCS culture alone is a poor test for detecting clinically relevant corneal contamination.
评估储存于 Optisol-GS 中的供体角膜预存拭子（PCS）培养物在筛选角膜移植物污染方面的效果。
对 2013 年 9 月至 2016 年 6 月在魁北克眼库的 Maisonneuve-Rosemont 医院进行的所有 PCS 培养物进行回顾性分析。对因 PCS 阳性而被拒绝的移植物进行全角膜培养，并计算污染率。此外，还比较了进行 PCS 检测的角膜和未进行 PCS 检测的进口角膜的角膜缘环的污染率。
在进行的 1966 次 PCS 培养中，814 次（41.4%）培养物呈阳性生长。144 个角膜中存在病原菌，包括金黄色葡萄球菌（n = 96，所有阳性培养物的 11.8%）、肠杆菌科（n = 14，1.7%）和铜绿假单胞菌（n = 6，0.7%）。在 Optisol-GS 中保存后，仅 7 个（6.9%）角膜仍受到污染（95%置信区间 5.1-9.3）。PCS 培养的灵敏度为 87.5%（95%置信区间 47.4-99.7）。与进口未拭子的角膜（3/214；1.4%）相比，进行 PCS 检测的角膜缘环污染率无显著差异（1/388；0.2%）（P = 0.131）。因此，每年因假阳性 PCS 导致的组织损失而购买角膜组织的费用为 142884 美元（加元）。
尽管 PCS 培养的灵敏度很高，但使用该技术进行角膜移植后，感染率并没有显著降低。因此，93%的可能适合移植的角膜被拒绝。这表明 PCS 培养物本身是一种检测临床相关角膜污染的不良检测方法。
