Microbial Biofilms on Needleless Connectors for Central Venous Catheters: Comparison of Standard and Silver-Coated Devices Collected from Patients in an Acute Care Hospital

Abstract

e 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 the associations between NC usage and biofilm characteristics. Viable microorganisms were detected by plate counts from 46% of standard NCs and 59% of silver-coated NCs (P ‫؍‬ 0.11). There were no significant associations (P > 0.05, chi-square test) between catheter type, side of catheter placement, number of catheter lumens, site of catheter placement, or NC placement duration and positive NC findings. There was an association (P ‫؍‬ 0.04, chi-square test) between infusion type and positive findings for 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 rRNA gene from selected NCs provided a substantially larger number of operational taxonomic units per NC than did plate counts (26 to 43 versus 1 to 4 operational taxonomic units/NC, respectively), 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 also may contain organisms from the health care 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.

Microbial communities profiling in intensive care units expose limitations in current sanitary standards

“…However, all these clusters revealed a strong negative correlation with Bacillus , Sphingobium , Hydrogenophaga , Thauera , Thermomonas , and Gemmobacter . It is important to note that most of these bacterial genera are known players in biofilms formation, including synergic multi-genera biofilms, on various hospital dry surfaces [36,37]. Biofilms matrix is a resistance mechanism that could stabilize a bacteria community in a selective environment such as (N)ICUs [38].…”

Flebitis infecciosa o no infecciosa: lecciones de un programa intervencional sobre flebitis asociada a catéter venoso periférico

“…En nuestro hospital, sólo se usan CVP de poliuretano que se asocian a menos flebitis que otros materiales 22 , no aplicamos gel antiinflamatorio local y el lumen del catéter es uniforme 20 , de un diámetro no asociado a un mayor riesgo de flebitis 33,34 . Por otra parte, sólo se autorizan conectores sin aguja específicos, descartando aquellos de diseño interior con intrincado, los que se asocian a una alta tasa de bacteriemias [11][12][13][14][15]35 . Este trabajo tiene varias limitaciones que deben ser mencionadas.…”

“…Los conectores sin aguja permitidos requerían la presencia de un tabique interno septado, que no impidiera el flujo laminar y superficies lisas que permitieran una desinfección eficiente y transparentes para la observación de residuo sanguíneo en su interior. Estas características se han asociado a una reducción en el riesgo de complicaciones infecciosas [11][12][13][14][15] .…”

Comparison of a Silver-Coated Needleless Connector and a Standard Needleless Connector for the Prevention of Central Line-Associated Bloodstream Infections

“…32 From a convenience sample of 62 patients enrolled in the current study, 151 NCs were prospectively obtained for biofilm analysis; biofilm was observed on the luminal surface of >90% of both silvercoated and standard NCs. 33 Microorganisms were recovered by culture from~50% of both NC types, substantially less than those with biofilm burden, but none of the patients from whom these NC cultures were obtained developed a CLABSI. Thus, the relationship between biofilm formation within a NC and subsequent bloodstream infection remains unclear.…”