Microbial biofilms on needleless connectors for central venous catheters


#IVTEAM #Intravenous literature: Perez, E., Williams, M., Jacob, J.T., Reyes, M.D., Chernetsky Tejedor, S., Steinberg, J.P., Rowe, L., Ganakammal, S.R., Changayil, S., Weil, M.R. and Donlan, R.M. (2013) Microbial biofilms on needleless connectors for central venous catheters: a comparison of standard and silver-coated devices collected from patients in an acute care hospital. Journal of Clinical Microbiology. December 26th. .


Microorganisms may colonize needleless connectors (NCs) on intravascular catheters, forming biofilms and predisposing patients to catheter- associated infection (CAI). Standard and silver-coated NCs were collected from catheterized intensive care unit patients to characterize biofilm formation using culture-dependent and culture-independent methods and to investigate association between NC usage and biofilm characteristics. Viable microorganisms were detected by plate count (PC) from 46% of standard and 59% of silver-coated NCs (p=0.11). There were no significant associations (p>0.05, chi-squared test) between catheter type, side of catheter placement, number of catheter lumens, site of catheter placement, or NC duration, and positive NC. There was an association (p=0.04, chi-squared test) between infusion type and positive standard NCs. Viable microorganisms exhibiting intracellular esterase activity were detected on >90% of both NC types (p=0.751), suggesting that a large percentage of organisms were not culturable using the conditions provided in this study. Amplification of the 16S ribosomal RNA gene from selected NCs provided a substantially larger number of operational taxonomic units per NC than PC (26-43 vs 1-4), suggesting that culture-dependent methods may substantially underestimate microbial diversity on NCs. NC bacterial communities were clustered by patient and venous access type and may reflect the composition of the patient’s local microbiome but may also contain organisms from the healthcare environment. NCs provide a portal of entry for a wide diversity of opportunistic pathogens to colonize the catheter lumen, forming a biofilm and increasing the potential for CAI, highlighting the importance of catheter maintenance practices to reduce microbial contamination.

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