In vitro assessment of bacterial colonisation rates of goat umbilical cord segments using three embodiments of a novel neonatal umbilical catheter protection device

Abstract

IntroductionCentral line-associated bloodstream infections (CLABSIs) in neonates with umbilical catheters occur at a rate that is 5 times higher than CLABSIs in adults with central catheters. No device currently exists tailored to the unique constraints umbilical catheters pose. The current study examined the natural progression of bacterial colonisation in goat umbilical cords and the relationship between embodiments of a novel neonatal umbilical catheter protection device and bacterial colonisation rates. The authors hypothesise that device venting is required to minimise bacterial colonisation in the unique umbilical stump environment.MethodsThe natural progression of bacterial colonisation in goat umbilical cord segments was studied by examining bacterial colonisation rates each day over 7 days. To understand the relationship between protection and bacterial colonisation, umbilical catheters were placed in goat umbilical cord segments and secured with 1 of 3 embodiments of a novel umbilical catheter protection device, which offered varying degrees of venting. After a 7-day period of incubation, colony counts were compared.ResultsBacterial load was largest when umbilical cord segments were fresh and subsequently decreased over time. Further, bacterial colonisation rates showed a statistically significant difference between device embodiments (F(2,9)=4.26, p<0.05), with the non-vented embodiment showing the highest bacterial colonisation rate.ConclusionsA device to better stabilise and protect umbilical catheters in order to reduce bloodstream infections in neonates is greatly needed. The current experiments confirm the hypothesis that completely enclosed, or non-vented, protection device will have increased bacterial growth.

Novel Neonatal Umbilical Catheter Protection and Stabilization Device in In vitro Model of Catheterized Human Umbilical Cords: Effect of Material and Venting on Bacterial Colonization

“…Furthermore, a prototype without venting (0%) led to an increase in bacterial colonization rates, a finding consistent with previous testing with goat umbilical cord segments. 26 As previously suggested by these authors, a nonvented (or completely enclosed) dome may lead to a more hospitable environment for bacterial growth, as it likely traps moisture and warmth surrounding a necrosing umbilical stump. 26 Therefore, some venting is necessary to counteract this phenomenon.…”

“…26 As previously suggested by these authors, a nonvented (or completely enclosed) dome may lead to a more hospitable environment for bacterial growth, as it likely traps moisture and warmth surrounding a necrosing umbilical stump. 26 Therefore, some venting is necessary to counteract this phenomenon. Our in vitro experimental setup mimics a NICU "worst-case" scenario for maximal bacterial incubation: a warmed, humidified incubator typically utilized for very premature neonates.…”

“…This study represents the first to test the effect of physical protection on bacterial colonization of the UC insertion site in human umbilical cords, and builds upon the work previously done by this group in bacterial colonization of goat umbilical cords. 26 In addition, this current study is the first to test a novel neonatal UC and stabilization device in vitro using human umbilical cord segments. We demonstrate that there is no increased bacterial colonization rate of catheterized umbilical cords when adequately vented or using a vented silicone prototype.…”

“…An in vitro study by Dambkowski et al used goat umbilical cord segments and demonstrated that the use of a vented protective device led to less bacterial colonization than a completely enclosed device. 26 This current study expands upon this prior work by determining the minimum venting to reduce bacterial colonization, testing bacterial colonization with various materials (i.e., plastic and silicone), and comparing bacterial colonization rates to the "goal post" standard of care. The first aim of this study is to identify a minimum amount of venting that leads to comparable colonization rates to the "goal post" method of securement; the second aim of this study is to develop and test a silicone prototype with appropriate venting and compare bacterial colonization rates of the prototype to those of the "goal post.…”