Microbial biofilms on needleless connectors for central venous catheters: comparison of standard and silver-coated devices collected from patients in an acute care hospital

Bacterial transfer and biofilm formation in needleless connectors in a clinically simulated in vitro catheter model

OBJECTIVE

Although needleless connectors (NCs) are widely used in clinical practice, they carry significant risk of bloodstream infection (BSI). In this study, we quantified differences in bacterial transfer and biofilm formation between various NCs.

DESIGN

Prospective, clinically simulated in vitro experimental study.

METHODS

We tested 20 NCs in a 5-day clinical simulation of Staphylococcus aureus inoculations onto NC septum surfaces, which were then flushed with saline and cultured for bacterial transfer. Biofilm formation was measured through destructive sampling of the connector-catheter system. Moreover, 8 NC design factors were evaluated for their influence on bacterial transfer and biofilm formation. This study was designed without a disinfection protocol to ascertain the intrinsic risk of each NC.

RESULTS

Clave Neutron and MicroClave had the lowest overall mean log density of bacteria in the flush compared to other NCs (P < .05), except there were no statistically significant differences between Clave Neutron, Microclave, SafeTouch, and SafeAccess (P ≥ .05). The amount of biofilm in the NC was positively associated with bacteria in the flush (P < .0005). Among 8 design factors, flow path was most important, with the internal cannula associated with a statistically significant 1 log reduction (LR) in bacteria in the flush (R2 = 49%) and 0.5-2 LR in the connector (R2 = 34%). All factors together best explained bacteria in the flush (R2 = 65%) and biofilm in the connector (R2 = 48%).

CONCLUSIONS

Bacterial transfer and biofilm formation in the connector-catheter system varied statistically significantly between the 20 NCs, suggesting that NC choice can lower the risk of developing catheter-related BSIs.

Guarding the central venous access device: a new solution for an old problem

HIGHLIGHTS

CLABSIs are a major concern in both the adult and pediatric patient population. Contamination of catheter hubs is a common cause of CLABSI. A novel, transparent line guard protects CVAD hubs from gross contamination. Central line-associated blood stream infections (CLABSIs) are a serious and potentially deadly complication in patients with a central venous access device (CVAD). CVADs play an essential role in modern medicine, serving as lifelines for many patients. To maintain safe and stable venous access, infection prevention bundles are used to help protect patients from complications such as CLABSI. Despite most CLABSIs being preventable, rates have been on the rise, often disproportionately impacting critically ill children. New solutions are needed to strengthen infection prevention bundles and protect CVADs from pathogen entry at catheter hubs and line connections. A novel, Food and Drug Administration-listed device has become available recently to guard CVADs from sources of gross contamination, addressing this apparent gap in infection prevention technology and practice.

Synthesis and Characterization of Durable Antibiofilm and Antiviral Silane-Phosphonium Thin Coatings for Medical and Agricultural Applications

Pathogens such as bacteria and viruses cause disease in a range of hosts, from humans to plants. Bacterial biofilms, communities of bacteria, e.g., Staphylococcus aureusand Escherichia coli, attached to the surface, create a protective layer that enhances their survival in harsh environments and resistance to antibiotics and the host's immune system. Biofilms are commonly associated with food spoilage and chronic infections, posing challenges for treatment and prevention. Tomato brown rugose fruit virus (ToBRFV), a newly discovered tobamovirus, infects tomato plants, causing unique symptoms on the fruit, posing a risk for tomato production. The present study focuses on the effectiveness of silane-phosphonium thin coatings on polymeric films, e.g., polypropylene. Phosphonium has significant antibacterial activity and is less susceptible to antibacterial resistance, making it a safer alternative with a reduced environmental impact. We successfully synthesized silane-phosphonium monomers as confirmed by 31P NMR and mass spectrometry. The chemical composition, thickness, morphology, and wetting properties of the coatings were tested by Fourier-transform infrared spectroscopy with attenuated total reflectance, focused ion beam, atomic force microscopy, environmental scanning electron microscope, and contact angle (CA) measurements. The antibiofilm and antibacterial activities of the coatings were tested against S. aureus and E. coli, while the antiviral activity was evaluated against ToBRFV. The significant antibiofilm and antiviral activity suggests applications in various fields including medicine, agriculture, and the food industry.

Determination of microbial contamination on the outer surface of needleless connectors before and after disinfection

OBJECTIVES

The aim of this study was to determine bacterial contamination of needleless connectors before and after disinfection to assess the risk for the point of catheter-related bloodstream infections.

RESEARCH METHODOLOGY/DESIGN

Experimental study design.

SETTING

The research was carried out on patients with a central venous catheter hospitalized in the intensive care unit.

MAIN OUTCOMES MEASURES

Bacterial contamination of needleless connectors integrated into central venous catheters was assessed before and after disinfection. Antimicrobial susceptibilities of colonized isolates were investigated. In addition, the compatibility of the isolates with the bacteriological cultures of the patients was determined over a one-month period.

RESULTS

Bacterial contamination varied between 5×10³ and 1×10⁵ colony forming unit was detected before disinfection in 91.7% of needleless connectors. Most common bacteria were coagulase-negative staphylococci; others were Staphylococcus aureus, Enterococcus faecalis, and Corynebacterium species. While most isolates were resistant to penicillin, trimethoprim-sulfamethoxazole, cefoxitin, and linezolid, each was susceptible to vancomycin or teicoplanin. Bacterial survival was not detected on needleless connectors after disinfection. There was no compatibility between the one-month bacteriological culture results of the patients and the bacteria isolated from the needleless connectors.

CONCLUSION

Bacterial contamination was detected on the needleless connectors before disinfection, although they were not rich in bacterial diversity. There was no bacterial growth after disinfection with an alcohol-impregnated swab.

IMPLICATIONS FOR CLINICAL PRACTICE

The majority of needleless connectors had bacterial contamination before disinfection. Needleless connectors should be disinfected for 30 seconds before use, particularly in immunocompromised patients. However, the use of needleless connectors with antiseptic barrier caps may be a more practical and effective solution instead.

How Does Hospital Microbiota Contribute to Healthcare-Associated Infections?

Healthcare-associated infections (HAIs) are still a global public health concern, associated with high mortality and increased by the phenomenon of antimicrobial resistance. Causative agents of HAIs are commonly found in the hospital environment and are monitored in epidemiological surveillance programs; however, the hospital environment is a potential reservoir for pathogenic microbial strains where microorganisms may persist on medical equipment surfaces, on the environment surrounding patients, and on corporal surfaces of patients and healthcare workers (HCWs). The characterization of hospital microbiota may provide knowledge regarding the relatedness between commensal and pathogenic microorganisms, their role in HAIs development, and the environmental conditions that favor its proliferation. This information may contribute to the effective control of the dissemination of pathogens and to improve infection control programs. In this review, we describe evidence of the contribution of hospital microbiota to HAI development and the role of environmental factors, antimicrobial resistance, and virulence factors of the microbial community in persistence on hospital surfaces.

Challenges in reducing the risk of infection when accessing vascular catheters

Injection safety is essential to reduce the risk of healthcare-associated infections (HAIs) when accessing vascular catheters. This general review evaluates the contamination of vascular catheter access ports and associated HAIs in acute care settings, focusing on open lumen stopcocks (OLSs) and disinfectable needleless closed connectors (DNCCs). PubMed was searched from January 2000 to February 2021. OLS intraluminal surfaces are frequently contaminated during patient care, increasing the risk of HAIs, and neither an isopropyl alcohol (IPA) pad nor a port-scrub device can reduce contamination effectively. In contrast, DNCCs can be disinfected, with most studies indicating less intraluminal contamination than OLSs and some studies showing decreased HAIs. While the optimal DNCC design to reduce HAIs needs to be determined, DNCCs alone or stopcocks with a DNCC bonded to the injection port should replace routine use of OLSs, with OLSs restricted to use in sterile fields. Compliance with disinfection is essential immediately before use of a DNCC as use of a non-disinfected DNCC can have equivalent or greater risk of HAIs compared with use of an OLS. The recommendations for access port disinfection in selected national and international guidelines vary. When comparing in-vitro studies, clinical studies and published guidelines, consensus is lacking; therefore, additional studies are needed, including large randomized controlled trials. IPA caps disinfect DNCCs passively, eliminate scrubbing and provide a contamination barrier; however, their use in neonates has been questioned. Further study is needed to determine whether IPA caps are more efficacious than scrubbing with disinfectant to decrease HAIs related to use of central venous, peripheral venous and arterial catheters.

Microbial Community Profiling in Intensive Care Units Expose Limitations in Current Sanitary Standards

Hospital-associated infections (HAIs) are a leading cause of morbidity and mortality in intensive care units (ICUs) and neonatal intensive care units (NICUs). Organisms causing these infections are often present on surfaces around the patient. Given that microbiota may vary across different ICUs, the HAI-related microbial signatures within these units remain underexplored. In this study, we use deep-sequencing analyses to explore and compare the structure of bacterial communities at inanimate surfaces of the ICU and NICU wards of The Medical School Clinics Hospital (Brazil). The data revealed that NICU presents higher biodiversity than ICU and surfaces closest to the patient showed a peculiar microbiota, distinguishing one unit from the other. Several facultative anaerobes or obligate anaerobes HAI-related genera were classified as biomarkers for the NICU, whereas Pseudomonas was the main biomarker for ICU. Correlation analyses revealed a distinct pattern of microbe-microbe interactions for each unit, including bacteria able to form multi-genera biofilms. Furthermore, we evaluated the effect of concurrent cleaning over the ICU bacterial community. The results showed that, although some bacterial populations decreased after cleaning, various HAI-related genera were quite stable following sanitization, suggesting being well-adapted to the ICU environment. Overall, these results enabled identification of discrete ICU and NICU reservoirs of potentially pathogenic bacteria and provided evidence for the presence of a set of biomarkers genera that distinguish these units. Moreover, the study exposed the inconsistencies of the routine cleaning to minimize HAI-related genera contamination.

Methods for microbial needleless connector decontamination: A systematic review and meta-analysis

BACKGROUND

The objective of this review was to compare the effectiveness of connector decontamination with 70% alcohol wipes, alcoholic chlorhexidine gluconate wipes, or alcohol impregnated caps to prevent catheter-associated bloodstream infection (CABSI).

METHODS

A systematic search was conducted in CINAHL, Cochrane Central Register of Controlled Trials, Medline, and PubMed. The primary outcome was CABSI, with randomized and observational studies included. The inclusion criteria were: English language, any age group, no date limitations, and reporting connector decontamination interventions to prevent CABSI. The exclusion criteria were: multimodal interventions, letters, and conference abstracts. Quality assessment with the Newcastle-Ottawa Scale, a narrative synthesis, and meta-analysis were conducted. Pooled data used a random effects model for pair-wise comparisons, due to clinical heterogeneity. Statistical heterogeneity was investigated by visual model inspection, χ², and I² statistics.

RESULTS

Ten studies compared 70% alcohol wipes with 70% alcohol-impregnated caps, and 2 studies (n = 1,216) tested an alcoholic chlorhexidine gluconate wipe. Alcoholic chlorhexidine gluconate wipes were associated with significantly less CABSI than 70% alcohol wipes (risk ratio, 0.28; 95% confidence interval, 0.20-0.39). Alcohol-impregnated caps were associated with significantly less CABSI than 70% alcohol wipes (risk ratio, 0.43; 95% confidence interval, 0.28-0.65). Studies were of low to moderate quality.

CONCLUSIONS

Alcohol impregnated caps and alcoholic chlorhexidine gluconate wipes were associated with significantly less CABSI than 70% alcohol wipes. This requires confirmation in randomized controlled trials.

Contaminant-Activated Visible Light Photocatalysis

Pristine titanium dioxide (TiO₂) absorbs ultraviolet light and reflects the entire visible spectrum. This optical response of TiO₂ has found widespread application as white pigments in paper, paints, pharmaceuticals, foods and plastic industries; and as a UV absorber in cosmetics and photocatalysis. However, pristine TiO₂ is considered to be inert under visible light for these applications. Here we show for the first time that a bacterial contaminant (Staphylococcus aureus—a MRSA surrogate) in contact with TiO₂ activates its own photocatalytic degradation under visible light. The present study delineates the critical role of visible light absorption by contaminants and electronic interactions with anatase in photocatalytic degradation using two azo dyes (Mordant Orange and Procion Red) that are highly stable because of their aromaticity. An auxiliary light harvester, polyhydroxy fullerenes, was successfully used to accelerate photocatalytic degradation of contaminants. We designed a contaminant-activated, transparent, photocatalytic coating for common indoor surfaces and conducted a 12-month study that proved the efficacy of the coating in killing bacteria and holding bacterial concentrations generally below the benign threshold. Data collected in parallel with this study showed a substantial reduction in the incidence of infections.

Antimicrobial activity of Ti-ZrN/Ag coatings for use in biomaterial applications

Severely broken bones often require external bone fixation pins to provide support but they can become infected. In order to reduce such infections, novel solutions are required. Titanium zirconium nitride (Ti-ZrN) and Ti-ZrN silver (Ti-ZrN/Ag) coatings were deposited onto stainless steel. Surface microtopography demonstrated that on the silver containing surfaces, S_a and S_v values demonstrated similar trends whilst the R_a, average height and RMS value and S_p values increased with increasing silver concentration. On the Ti-ZrN/Ag coatings, surface hydrophobicity followed the same trend as the S_a and S_v values. An increase in dead Staphylococcus aureus and Staphylococcus epidermidis cells was observed on the coatings with a higher silver concentration. Using CTC staining, a significant increase in S. aureus respiration on the silver containing surfaces was observed in comparison to the stainless steel control whilst against S. epidermidis, no significant difference in viable cells was observed across the surfaces. Cytotoxicity testing revealed that the TiZrN coatings, both with and without varying silver concentrations, did not possess a detrimental effect to a human monocyte cell line U937. This work demonstrated that such coatings have the potential to reduce the viability of bacteria that result in pin tract infections.

Comparative Analysis of Bacterial Community Composition and Structure in Clinically Symptomatic and Asymptomatic Central Venous Catheters

Totally implanted venous access ports (TIVAPs) are commonly used catheters for the management of acute or chronic pathologies. Although these devices improve health care, repeated use of this type of device for venous access over long periods of time is also associated with risk of colonization and infection by pathogenic bacteria, often originating from skin. However, although the skin microbiota is composed of both pathogenic and nonpathogenic bacteria, the extent and the consequences of TIVAP colonization by nonpathogenic bacteria have rarely been studied. Here, we used culture-dependent and 16S rRNA gene-based culture-independent approaches to identify differences in bacterial colonization of TIVAPs obtained from two French hospitals. To explore the relationships between nonpathogenic organisms colonizing TIVAPs and the potential risk of infection, we analyzed the bacterial community parameters between TIVAPs suspected (symptomatic) or not (asymptomatic) of infection. Although we did not find a particular species assemblage or community marker to distinguish infection risk on an individual sample level, we identified differences in bacterial community composition, diversity, and structure between clinically symptomatic and asymptomatic TIVAPs that could be explored further. This study therefore provides a new view of bacterial communities and colonization patterns in intravascular TIVAPs and suggests that microbial ecology approaches could improve our understanding of device-associated infections and could be a prognostic tool to monitor the evolution of bacterial communities in implants and their potential susceptibility to infections. IMPORTANCE Totally implanted venous access ports (TIVAPs) are commonly used implants for the management of acute or chronic pathologies. Although their use improves the patient's health care and quality of life, they are associated with a risk of infection and subsequent clinical complications, often leading to implant removal. While all TIVAPs appear to be colonized, only a fraction become infected, and the relationship between nonpathogenic organisms colonizing TIVAPs and the potential risk of infection is unknown. We explored bacteria present on TIVAPs implanted in patients with or without signs of TIVAP infection and identified differences in phylum composition and community structure. Our data suggest that the microbial ecology of intravascular devices could be predictive of TIVAP infection status and that ultimately a microbial ecological signature could be identified as a tool to predict TIVAP infection susceptibility and improve clinical management.

Microbially and phytofabricated AgNPs with different mode of bactericidal action were identified to have comparable potential for surface fabrication of central venous catheters to combat Staphylococcus aureus biofilm

In spite of newer innovations and process improvements, catheter related infections still pose serious threat to hospitalized patients. Silver nanoparticles (AgNPs) are well demonstrated to have antibacterial properties and also have been implemented for surface fabrication of many indwelling medical devices. So, herein we sought to compare the performance of AgNPs generated through biogenic routes using bacteria and plant extract for their antibacterial and antibiofilm potential against biofilm forming Staphylococcus aureus. The biosynthesized AgNPs were characterized by UV- Visible spectroscopy, HR-TEM and EDS analysis. The antibacterial efficiency of the nanoparticles was detected by Disc diffusion assay, MIC and MBC analysis. The antibiofilm properties of the nanoparticles were also investigated. The antibacterial mode of interaction of both nanoparticles on the bacterium was analyzed by HR-TEM. Insight into mode of interaction and mechanism of antibacterial activity of both AgNPs showed them to have promises for surface fabrication of central venous catheters. No study has been conducted so far to compare the efficiency of two different biogenic AgNPs and this highlights the novelty of the current work. Though both AgNPs were observed to exhibit comparable activity in terms of bactericidal and antibiofilm, the mode of bacterial interaction and degree of damage caused was entirely different.

Microbiologic contamination of a positive- and a neutral- displacement needleless intravenous access device in clinical use

The use of a positive-displacement needleless intravenous access device was associated with lower microbial contamination rates compared with a neutral-displacement device when used on central venous catheters in hemato-oncology patients. In addition, rates of central line-associated bloodstream infection did not differ when either device was used.

Graft polymerization of styryl bisphosphonate monomer onto polypropylene films for inhibition of biofilm formation

There has been increased concern during the past few decades over the role bacterial biofilms play in causing a variety of health problems, especially since they exhibit a high degree of resistance to antibiotics and are able to survive in hostile environments. Biofilms consist of bacterial aggregates enveloped by a self-produced matrix attached to the surface. Ca(2+) ions promote the formation of biofilms, and enhance their stability, viscosity, and strength. Bisphosphonates exhibit a high affinity for Ca(2+) ions, and may inhibit the formation of biofilms by acting as sequestering agents for Ca(2+) ions. Although the antibacterial activity of bisphosphonates is well known, research into their anti-biofilm behavior is still in its early stages. In this study, we describe the synthesis of a new thin coating composed of poly(styryl bisphosphonate) grafted onto oxidized polypropylene films for anti-biofilm applications. This grafting process was performed by graft polymerization of styryl bisphosphonate vinylic monomer onto O2 plasma-treated polypropylene films. The surface modification of the polypropylene films was confirmed using surface measurements, including X-ray photoelectron spectroscopy, atomic force microscopy, and water contact angle goniometry. Significant inhibition of biofilm formation was achieved for both Gram-negative and Gram-positive bacteria.

Microorganisms in Confined Habitats: Microbial Monitoring and Control of Intensive Care Units, Operating Rooms, Cleanrooms and the International Space Station

Indoor environments, where people spend most of their time, are characterized by a specific microbial community, the indoor microbiome. Most indoor environments are connected to the natural environment by high ventilation, but some habitats are more confined: intensive care units, operating rooms, cleanrooms and the international space station (ISS) are extraordinary living and working areas for humans, with a limited exchange with the environment. The purposes for confinement are different: a patient has to be protected from infections (intensive care unit, operating room), product quality has to be assured (cleanrooms), or confinement is necessary due to extreme, health-threatening outer conditions, as on the ISS. The ISS represents the most secluded man-made habitat, constantly inhabited by humans since November 2000 – and, inevitably, also by microorganisms. All of these man-made confined habitats need to be microbiologically monitored and controlled, by e.g., microbial cleaning and disinfection. However, these measures apply constant selective pressures, which support microbes with resistance capacities against antibiotics or chemical and physical stresses and thus facilitate the rise of survival specialists and multi-resistant strains. In this article, we summarize the available data on the microbiome of aforementioned confined habitats. By comparing the different operating, maintenance and monitoring procedures as well as microbial communities therein, we emphasize the importance to properly understand the effects of confinement on the microbial diversity, the possible risks represented by some of these microorganisms and by the evolution of (antibiotic) resistances in such environments – and the need to reassess the current hygiene standards.

Molecular Comparison of Bacterial Communities on Peripheral Intravenous Catheters and Matched Skin Swabs

Skin bacteria at peripheral intravenous catheter (PIVC) insertion sites pose a serious risk of microbial migration and subsequent colonisation of PIVCs, and the development of catheter related bloodstream infections (CRBSIs). Common skin bacteria are often associated with CRBSIs, therefore the bacterial communities at PIVC skin sites are likely to have major implications for PIVC colonisation. This study aimed to determine the bacterial community structures on skin at PIVC insertion sites and to compare the diversity with associated PIVCs. A total of 10 PIVC skin site swabs and matching PIVC tips were collected by a research nurse from 10 hospitalised medical/surgical patients at catheter removal. All swabs and PIVCs underwent traditional culture and high-throughput sequencing. The bacterial communities on PIVC skin swabs and matching PIVCs were diverse and significantly associated (correlation coefficient = 0.7, p<0.001). Methylobacterium spp. was the dominant genus in all PIVC tip samples, but not so for skin swabs. Sixty-one percent of all reads from the PIVC tips and 36% of all reads from the skin swabs belonged to this genus. Staphylococcus spp., (26%), Pseudomonas spp., (10%) and Acinetobacter spp. (10%) were detected from skin swabs but not from PIVC tips. Most skin associated bacteria commonly associated with CRBSIs were observed on skin sites, but not on PIVCs. Diverse bacterial communities were observed at skin sites despite skin decolonization at PIVC insertion. The positive association of skin and PIVC tip communities provides further evidence that skin is a major source of PIVC colonisation via bacterial migration but microbes present may be different to those traditionally identified via culture methods. The results provide new insights into the colonisation of catheters and potential pathogenesis of bacteria associated with CRBSI, and may assist in developing new strategies designed to reduce the risk of CRBSI.

Comparison of a silver-coated needleless connector and a standard needleless connector for the prevention of central line-associated bloodstream infections

OBJECTIVE

To assess the impact of a novel, silver-coated needleless connectors (NCs) on central-line-associated bloodstream infection (CLABSI) rates compared with a mechanically identical NCs without a silver coating.

DESIGN

Prospective longitudinal observation study SETTING Two 500-bed university hospitals

PATIENTS

All hospitalized adults from November 2009 to June 2011 with non-hemodialysis central lines

INTERVENTIONS

Hospital A started with silver-coated NCs and switched to standard NCs in September 2010; hospital B started with standard NCs and switched to silver-coated NCs. The primary outcome was the difference revealed by Poisson multivariate regression in CLABSI rate using standard Centers for Disease Control and Prevention surveillance definitions. The secondary outcome was a comparison of organism-specific CLABSI rates by NC type.

RESULTS

Among 15,845 hospital admissions, 140,186 central-line days and 221 CLABSIs were recorded during the study period. In a multivariate model, the CLABSI rate per 1,000 central-line days was lower with silver-coated NCs than with standard NCs (1.21 vs 1.79; incidence rate ratio=0.68 [95% CI: 0.52-0.89], P=.005). A lower CLABSI rate per 1,000 central-line days for the silver-coated NCs versus the standard NCs was observed with S. aureus (0.11 vs 0.30, P=.02), enterococci (0.10 vs 0.27, P=.03), and Gram-negative organisms (0.28 vs 0.63, P=.003) but not with coagulase-negative staphylococci (0.31 vs 0.36) or Candida spp. (0.42 vs 0.40).

CONCLUSIONS

The use of silver-coated NCs decreased the CLABSI rate by 32%. CLABSI reduction efforts should include efforts to minimize contamination of NCs.

Microbial biofilms associated with intravascular catheter-related bloodstream infections in adult intensive care patients

Catheter-related bloodstream infection (CRBSI) is one of the most serious complications in hospitalised patients, leading to increased hospitalisation, intensive care admissions, extensive antibiotic treatment and mortality. A greater understanding of these bacterial infections is needed to improve the prevention and the management of CRBSIs. We describe here the systematic culture-independent evaluation of intravascular catheter (IVC) bacteriology. Twelve IVCs (6 central venous catheters and 6 arterial catheters) were collected from 6 patients. By using traditional culture methods, 3 patients were diagnosed with catheter colonisation including 1 patient who also had CRBSI, and 3 had no colonisation. From a total of 839,539 high-quality sequence reads from high-throughput sequencing, 8 microbial phyla and 76 diverse microbial genera were detected. All IVCs examined in this study were colonised with complex microbial communities including "non-colonised IVCs," as defined using traditional culture methods. Two main community types were observed: Enterobacteriaceae spp., dominant in patients without colonisation or CRBSI; and Staphylococcus spp., dominant in patients with colonisation and CRBSI. More diverse pathogens and a higher microbial diversity were present in patients with IVC colonisation and CRBSI. Community composition did not appear to be affected by patients' antibiotic treatment or IVC type. Characterisation of these communities is the first step in elucidating roles of these pathogens in disease progression, and to ultimately facilitate the improved prevention, refined diagnosis and management of CRBSI.

Microbial diversity on intravascular catheters from paediatric patients

Microorganisms play important roles in intravascular catheter (IVC)-related infections, which are the most serious complications in children with IVCs, leading to increased hospitalisation, intensive care admissions, extensive antibiotic treatment and mortality. A greater understanding of bacterial communities is needed in order to improve the management of infections. We describe here the systematic culture-independent evaluation of IVC bacteriology in IVC biofilms. Twenty-four IVC samples (six peripherally inserted central catheters, eight central venous catheters and ten arterial catheters) were collected from 24 paediatric patients aged 0 to 14 years old. Barcoded amplicon libraries produced from genes coding 16S rRNA and roll-plate culture methods were used to determine the microbial composition of these samples. From a total of 1,043,406 high-quality sequence reads, eight microbial phyla and 136 diverse microbial genera were detected, separated into 12,224 operational taxonomic units (OTUs). Three phyla (Actinobacteria, Firmicutes and Proteobacteria) predominate the microorganism on the IVC surfaces, with Firmicutes representing nearly half of the OTUs found. Among the Firmicutes, Staphylococcus (15.0% of 16S rRNA reads), Streptococcus (9.6%) and Bacillus (6.1%) were the most common. Community composition did not appear to be affected by patients' age, gender, antibiotic treatment or IVC type. Differences in IVC microbiota were more likely associated with events arising from catheter dwell time, rather than the type of IVC used.

Disinfection of Needleless Connector Hubs: Clinical Evidence Systematic Review

Background. Needleless connectors (NC) are used on virtually all intravascular devices, providing an easy access point for infusion connection. Colonization of NC is considered the cause of 50% of postinsertion catheter-related infections. Breaks in aseptic technique, from failure to disinfect, result in contamination and subsequent biofilm formation within NC and catheters increasing the potential for infection of central and peripheral catheters. Methods. This systematic review evaluated 140 studies and 34 abstracts on NC disinfection practices, the impact of hub contamination on infection, and measures of education and compliance. Results. The greatest risk for contamination of the catheter after insertion is the NC with 33-45% contaminated, and compliance with disinfection as low as 10%. The optimal technique or disinfection time has not been identified, although scrubbing with 70% alcohol for 5-60 seconds is recommended. Studies have reported statistically significant results in infection reduction when passive alcohol disinfection caps are used (48-86% reduction). Clinical Implications. It is critical for healthcare facilities and clinicians to take responsibility for compliance with basic principles of asepsis compliance, to involve frontline staff in strategies, to facilitate education that promotes understanding of the consequences of failure, and to comply with the standard of care for hub disinfection.