UCL School of Pharmacy, University College London, London, UK.
Pharmacy Department, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
J Antimicrob Chemother. 2022 Jul 28;77(8):2191-2198. doi: 10.1093/jac/dkac181.
Patients requiring long-term intravenous access are at risk of intraluminal catheter bloodstream infection. 'Prophylactic' locks aim to limit this risk but there is uncertainty regarding the most effective lock.
To develop a novel technique intended to replicate clinical procedures to compare the effectiveness of various 'prophylactic' locks against biofilm biomass ('biomass') formation and biofilm viability ('viability') of Escherichia coli and Staphylococcus epidermidis in intravenous catheters.
For 10 consecutive days 106 cfu/mL E. coli NCTC 10418 and S. epidermidis ATCC 12228 were separately cultured in single lumen 9.6 French silicone tunnelled and cuffed catheters. These were flushed with 0.9% w/v sodium chloride using a push-pause technique before and after instillation of seven 'prophylactic' locks (water, ethanol, sodium chloride, heparinized sodium chloride, citrate, taurolidine plus citrate, and taurolidine; each in triplicate) for 6 h daily. Intraluminal 'biomass' and 'viability' were quantified using crystal violet staining and flush culture, respectively.
The reduction of 'biomass' and 'viability' depended on both agent and species. Citrate was least effective against E. coli 'viability' and 'biomass' but most effective against S. epidermidis 'viability', and taurolidine was most effective against E. coli 'biomass' and 'viability' but least effective against S. epidermidis 'viability'. 'Biomass' and 'viability' were significantly correlated in E. coli between (r = 0.997, P < 0.001) and within (r = 0.754, P = 0.001) interventions, but not in S. epidermidis.
A novel technique found the effect of 'prophylactic' agents in reducing 'biomass' and 'viability' varied by species. The choice of agent depends on the most likely infecting organism.
需要长期静脉通路的患者存在管腔内导管血流感染的风险。“预防”锁旨在限制这种风险，但对于最有效的锁仍存在不确定性。
开发一种新的技术，旨在复制临床操作，以比较各种“预防”锁对大肠杆菌和表皮葡萄球菌在静脉导管中生物膜生物量（“生物量”）形成和生物膜活力（“活力”）的有效性。
连续 10 天，将 106 cfu/mL 的大肠杆菌 NCTC 10418 和表皮葡萄球菌 ATCC 12228 分别培养在单腔 9.6 法国硅酮隧道和带袖套的导管中。在每天 6 小时内，使用推停技术在注入七种“预防”锁（水、乙醇、氯化钠、肝素化氯化钠、柠檬酸盐、牛磺胆酸钠加柠檬酸盐、牛磺胆酸钠；每种均重复三次）前后冲洗 0.9% w/v 氯化钠。分别使用结晶紫染色和冲洗培养来定量管内“生物量”和“活力”。
“生物量”和“活力”的减少取决于药物和物种。柠檬酸盐对大肠杆菌“活力”和“生物量”的作用最小，但对表皮葡萄球菌“活力”的作用最大，牛磺胆酸钠对大肠杆菌“生物量”和“活力”的作用最大，但对表皮葡萄球菌“活力”的作用最小。在大肠杆菌中，“生物量”和“活力”之间（r = 0.997，P < 0.001）和干预内（r = 0.754，P = 0.001）具有显著相关性，但在表皮葡萄球菌中则没有。
一种新的技术发现，“预防”剂在减少“生物量”和“活力”方面的效果因物种而异。药物的选择取决于最有可能感染的生物体。
