The clinical effectiveness of central venous catheters treated with anti-infective agents in preventing catheter-related bloodstream infections: a systematic review

Risk factors for multidrug-resistant and extensively drug-resistant Acinetobacter baumannii infection of patients admitted in intensive care unit: a systematic review and meta-analysis

BACKGROUND

Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Acinetobacter baumannii infections pose challenges for clinical treatment and cause high mortality, particularly in intensive care units (ICUs).

AIM

To systematically summarize and analyse the risk factors for MDR/XDR A. baumannii-infected patients admitted to ICUs.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were searched for eligible original studies published in English before October 2023. Meta-analysis was conducted where appropriate, with mean differences (MDs) and odds ratios (ORs) calculated for continuous and nominal scaled data. The quality of included studies was assessed using the Newcastle-Ottawa Scale (NOS).

FINDINGS

Ten studies reporting 1199 ICU patients (604 from general ICUs, 435 from neonatal ICUs, and 160 from paediatric ICUs) from eight countries were included in our analysis. Risk factors associated with MDR A. baumannii infection among patients admitted to general ICUs included high Acute Physiology And Clinical Health II (APACHE Ⅱ) score (mean difference (MD): 7.52; 95% confidence interval (CI): 3.24-11.80; P = 0.0006), invasive procedures (odds ratio (OR): 3.47; 95% CI: 1.70-7.10; P = 0.0006), longer ICU stay (MD: 3.40; 95% CI: 2.94-3.86; P < 0.00001), and use of antibiotics (OR: 2.69; 95% CI: 1.22-5.94; P = 0.01). In the sub-group analysis, longer neonatal ICU stay (MD: 16.88; 95% CI: 9.79-23.97; P < 0.00001) was associated with XDR A. baumannii infection.

CONCLUSION

Close attention should be paid to patients with longer ICU stays, undergoing invasive procedures, using antibiotics, and with high APACHE Ⅱ scores to reduce the risk of MDR and XDR A. baumannii infections.

Healthcare-associated infections in adult intensive care unit patients: Changes in epidemiology, diagnosis, prevention and contributions of new technologies

Patients in intensive care units (ICUs) are at high risk for healthcare-acquired infections (HAI) due to the high prevalence of invasive procedures and devices, induced immunosuppression, comorbidity, frailty and increased age. Over the past decade we have seen a successful reduction in the incidence of HAI related to invasive procedures and devices. However, the rate of ICU-acquired infections remains high. Within this context, the ongoing emergence of new pathogens, further complicates treatment and threatens patient outcomes. Additionally, the SARS-CoV-2 (COVID-19) pandemic highlighted the challenge that an emerging pathogen provides in adapting prevention measures regarding both the risk of exposure to caregivers and the need to maintain quality of care. ICU nurses hold a special place in the prevention and management of HAI as they are involved in basic hygienic care, steering and implementing quality improvement initiatives, correct microbiological sampling, and aspects antibiotic stewardship. The emergence of more sensitive microbiological techniques and our increased knowledge about interactions between critically ill patients and their microbiota are leading us to rethink how we define HAIs and best strategies to diagnose, treat and prevent these infections in the ICU. This multidisciplinary expert review, focused on the ICU setting, will summarise the recent epidemiology of ICU-HAI, discuss the place of modern microbiological techniques in their diagnosis, review operational and epidemiological definitions and redefine the place of several controversial preventive measures including antimicrobial-impregnated medical devices, chlorhexidine-impregnated washcloths, catheter dressings and chlorhexidine-based mouthwashes. Finally, general guidance is suggested that may reduce HAI incidence and especially outbreaks in ICUs.

Reduction of central line-associated bloodstream infections in a large acute care hospital in Midwest United States following implementation of a comprehensive central line insertion and maintenance bundle

BACKGROUND

Central line-associated bloodstream infection (CLABSI) is a preventable medical condition that results in increased patient morbidity and mortality. We describe the impact of various quality improvement interventions on the incidence of CLABSI in an 848-bed community teaching hospital from 1 January 2013 to 31 December 2017.

AIM

To reduce CLABSI rates after implementation of a comprehensive central line insertion and maintenance bundle.

METHODS

A comprehensive bundle of interventions was implemented incorporating the standard US Centers for Disease Control and Prevention bundle with additional measures such as root-cause analysis of all CLABSI cases, use of passive disinfection caps on vascular access ports, standardisation of weekly central venous catheter (CVC) site dressing changes, and use of antithrombotic and antimicrobial-coated CVCs with fewer lumens. A retrospective study evaluated CLABSI rates and time of CLABSI onset after CVC placement in both intensive care unit (ICU) and non-ICU settings.

RESULTS

The annual number of CLABSI cases declined 68% (34 to 11 patients) from 2013 to 2017. There was a 30% decline in CVC days from years 2014 to 2017. Over the same period, CLABSI cases per 1000 CVC days decreased from 0.624 to 0.362: a 42% decline.

CONCLUSION

Following the implementation of a comprehensive bundle of interventions for CVC insertion and maintenance, we found a reduction in rates of CLABSI.

Antimicrobial-impregnated central venous catheters for preventing neonatal bloodstream infection: the PREVAIL RCT

BACKGROUND

Clinical trials show that antimicrobial-impregnated central venous catheters reduce catheter-related bloodstream infection in adults and children receiving intensive care, but there is insufficient evidence for use in newborn babies.

OBJECTIVES

The objectives were (1) to determine clinical effectiveness by conducting a randomised controlled trial comparing antimicrobial-impregnated peripherally inserted central venous catheters with standard peripherally inserted central venous catheters for reducing bloodstream or cerebrospinal fluid infections (referred to as bloodstream infections); (2) to conduct an economic evaluation of the costs, cost-effectiveness and value of conducting additional research; and (3) to conduct a generalisability analysis of trial findings to neonatal care in the NHS.

DESIGN

Three separate studies were undertaken, each addressing one of the three objectives. (1) This was a multicentre, open-label, pragmatic randomised controlled trial; (2) an analysis was undertaken of hospital care costs, lifetime cost-effectiveness and value of information from an NHS perspective; and (3) this was a retrospective cohort study of bloodstream infection rates in neonatal units in England.

SETTING

The randomised controlled trial was conducted in 18 neonatal intensive care units in England.

PARTICIPANTS

Participants were babies who required a peripherally inserted central venous catheter (of 1 French gauge in size).

INTERVENTIONS

The interventions were an antimicrobial-impregnated peripherally inserted central venous catheter (coated with rifampicin-miconazole) or a standard peripherally inserted central venous catheter, allocated randomly (1 : 1) using web randomisation.

MAIN OUTCOME MEASURE

Study 1 - time to first bloodstream infection, sampled between 24 hours after randomisation and 48 hours after peripherally inserted central venous catheter removal. Study 2 - cost-effectiveness of the antimicrobial-impregnated peripherally inserted central venous catheter compared with the standard peripherally inserted central venous catheters. Study 3 - risk-adjusted bloodstream rates in the trial compared with those in neonatal units in England. For study 3, the data used were as follows: (1) case report forms and linked death registrations; (2) case report forms and linked death registrations linked to administrative health records with 6-month follow-up; and (3) neonatal health records linked to infection surveillance data.

RESULTS

Study 1, clinical effectiveness - 861 babies were randomised (antimicrobial-impregnated peripherally inserted central venous catheter, n = 430; standard peripherally inserted central venous catheter, n = 431). Bloodstream infections occurred in 46 babies (10.7%) randomised to antimicrobial-impregnated peripherally inserted central venous catheters and in 44 (10.2%) babies randomised to standard peripherally inserted central venous catheters. No difference in time to bloodstream infection was detected (hazard ratio 1.11, 95% confidence interval 0.73 to 1.67; p = 0.63). Secondary outcomes of rifampicin resistance in positive blood/cerebrospinal fluid cultures, mortality, clinical outcomes at neonatal unit discharge and time to peripherally inserted central venous catheter removal were similar in both groups. Rifampicin resistance in positive peripherally inserted central venous catheter tip cultures was higher in the antimicrobial-impregnated peripherally inserted central venous catheter group (relative risk 3.51, 95% confidence interval 1.16 to 10.57; p = 0.02) than in the standard peripherally inserted central venous catheter group. Adverse events were similar in both groups. Study 2, economic evaluation - the mean cost of babies' hospital care was £83,473. Antimicrobial-impregnated peripherally inserted central venous catheters were not cost-effective. Given the increased price, compared with standard peripherally inserted central venous catheters, the minimum reduction in risk of bloodstream infection for antimicrobial-impregnated peripherally inserted central venous catheters to be cost-effective was 3% and 15% for babies born at 23-27 and 28-32 weeks' gestation, respectively. Study 3, generalisability analysis - risk-adjusted bloodstream infection rates per 1000 peripherally inserted central venous catheter days were similar among babies in the trial and in all neonatal units. Of all bloodstream infections in babies receiving intensive or high-dependency care in neonatal units, 46% occurred during peripherally inserted central venous catheter days.

LIMITATIONS

The trial was open label as antimicrobial-impregnated and standard peripherally inserted central venous catheters are different colours. There was insufficient power to determine differences in rifampicin resistance.

CONCLUSIONS

No evidence of benefit or harm was found of peripherally inserted central venous catheters impregnated with rifampicin-miconazole during neonatal care. Interventions with small effects on bloodstream infections could be cost-effective over a child's life course. Findings were generalisable to neonatal units in England. Future research should focus on other types of antimicrobial impregnation of peripherally inserted central venous catheters and alternative approaches for preventing bloodstream infections in neonatal care.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN81931394.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 57. See the NIHR Journals Library website for further project information.

Reduction of Biofilm Formation on Cooling Tower Heat Exchangers using Nano-silica Coating : Environmentally sustainable antifouling coating demonstrated on stainless steel heat exchanger tubes

Cooling towers are industrial cooling units operating to dissipate heat. As with any surface in contact with aqueous systems, biofilm formation appears on the surface of heat exchangers. Although biofilm formation on plastic tower fill in wet cooling towers has been studied widely, no studies were found regarding biofilm formation on steel heat exchangers in closed-loop systems. In this study, heat exchangers were coated with nano-silica, which is known to reduce the formation of biofilm. Natural biofilm formation was monitored for six months. Biofouling was examined monthly using epifluorescence microscopy by assessing the numbers of live and dead bacteria. It was observed that the biofilm layer formed on the nano-silica coated heat exchanger surfaces was significantly lower than on the control surfaces. 3 log microbial reduction was recorded on coated surfaces in the first month. After six months, total biomass on control surfaces reached 1.28 × 1012 cell cm−2, while the biomass on nano-silica coated surfaces was 6.3 × 104 cell cm−2.

Cost-effectiveness of strategies preventing late-onset infection in preterm infants

OBJECTIVE

Developing a model to analyse the cost-effectiveness of interventions preventing late-onset infection (LOI) in preterm infants and applying it to the evaluation of anti-microbial impregnated peripherally inserted central catheters (AM-PICCs) compared with standard PICCs (S-PICCs).

DESIGN

Model-based cost-effectiveness analysis, using data from the Preventing infection using Antimicrobial Impregnated Long Lines (PREVAIL) randomised controlled trial linked to routine healthcare data, supplemented with published literature. The model assumes that LOI increases the risk of neurodevelopmental impairment (NDI).

SETTING

Neonatal intensive care units in the UK National Health Service (NHS).

PATIENTS

Infants born ≤32 weeks gestational age, requiring a 1 French gauge PICC.

INTERVENTIONS

AM-PICC and S-PICC.

MAIN OUTCOME MEASURES

Life expectancy, quality-adjusted life years (QALYs) and healthcare costs over the infants' expected lifetime.

RESULTS

Severe NDI reduces life expectancy by 14.79 (95% CI 4.43 to 26.68; undiscounted) years, 10.63 (95% CI 7.74 to 14.02; discounted) QALYs and costs £19 057 (95% CI £14 197; £24697; discounted) to the NHS. If LOI causes NDI, the maximum acquisition price of an intervention reducing LOI risk by 5% is £120. AM-PICCs increase costs (£54.85 (95% CI £25.95 to £89.12)) but have negligible impact on health outcomes (-0.01 (95% CI -0.09 to 0.04) QALYs), compared with S-PICCs. The NHS can invest up to £2.4 million in research to confirm that AM-PICCs are not cost-effective.

CONCLUSIONS

The model quantifies health losses and additional healthcare costs caused by NDI and LOI during neonatal care. Given these consequences, interventions preventing LOI, even by a small extent, can be cost-effective. AM-PICCs, being less effective and more costly than S-PICC, are not likely to be cost-effective.

TRIAL REGISTRATION NUMBER

NCT03260517.

Ambulatory Hemodialysis-Technology Landscape and Potential for Patient-Centered Treatment

CKD is a worldwide health problem and the number of patients requiring kidney replacement therapy is rising. In the United States, most patients with ESKD rely on in-center hemodialysis, which is burdensome and does not provide the same long-term benefits as kidney transplantation. Intensive hemodialysis treatments have demonstrated improved clinical outcomes, but its wider adoption is limited by equipment complexity and patient apprehension. Ambulatory devices for hemodialysis offer the potential for self-care treatment outside the clinical setting as well as frequent and prolonged sessions. This article explains the motivation for ambulatory hemodialysis and provides an overview of the necessary features of key technologies that will be the basis for new wearable and implantable devices. Early work by pioneers of hemodialysis is described followed by recent experience using a wearable unit on patients. Finally, ongoing efforts to develop an implantable device for kidney replacement and its potential for implantable hemodialysis are presented.

Dialysis catheters in the ICU: selection, insertion and maintenance

PURPOSE OF REVIEW

Choosing the best catheter for renal replacement therapy (RRT) is not an easy task. Beyond catheter length, many of its properties can influence effectiveness of the RRT session. Maintenance between sessions, particularly the locking solution, also impacts catheter lifespan and infection rates.

RECENT FINDINGS

Many innovations in dialysis catheters have been proposed by the industry over the past decade, including the material used, the shape of the lumens and the position of the inflow and outflow holes. Impregnated catheters have also been developed to prevent catheter-related infections. Many locking solutions are available, either for maintaining catheter patency or for preventing infections.

SUMMARY

Although studies conducted in the specific context of the ICU are still scarce, some conclusions can be drawn. Catheter length must be adapted to the insertion site to reach an area of high blood flow. Kidney-shape lumens appear to be less thrombogenic and seem to prevent catheter dysfunction. Catheter tip and lumen holes also affect catheter function. For catheter locking, 4% citrate appears nowadays as one of the best options, but taurolidine-based solutions are also interesting.

A state of the art review on optimal practices to prevent, recognize, and manage complications associated with intravascular devices in the critically ill

Intravascular catheters are inserted into almost all critically ill patients. This review provides up-to-date insight into available knowledge on epidemiology and diagnosis of complications of central vein and arterial catheters in ICU. It discusses the optimal therapy of catheter-related infections and thrombosis. Prevention of complications is a multidisciplinary task that combines both improvement of the process of care and introduction of new technologies. We emphasize the main component of the prevention strategies that should be used in critical care and propose areas of future investigation in this field.

Antibacterial and antibiofouling clay nanotube-silicone composite

Introduction

Invasive medical devices are used in treating millions of patients each day. Bacterial adherence to their surface is an early step in biofilm formation that may lead to infection, health complications, longer hospital stays, and death. Prevention of bacterial adherence and biofilm development continues to be a major healthcare challenge. Accordingly, there is a pressing need to improve the anti-microbial properties of medical devices.

Materials and Methods

Polydimethylsiloxane (PDMS) was doped with halloysite nanotubes (HNTs), and the PDMS-HNT composite surfaces were coated with PDMS-b-polyethylene oxide (PEO) and antibacterials. The composite material properties were examined using SEM, energy dispersive spectroscopy, water contact angle measurements, tensile testing, UV-Vis spectroscopy, and thermal gravimetric analysis. The antibacterial potential of the PDMS-HNT composites was compared to commercial urinary catheters using cultures of E. coli and S. aureus. Fibrinogen adsorption studies were also performed on the PDMS-HNT-PEO composites.

Results

HNT addition increased drug load during solvent swelling without reducing material strength. The hydrophilic properties provided by PEO were maintained after HNT addition, and the composites displayed protein-repelling properties. Additionally, composites showed superiority over commercial catheters at inhibiting bacterial growth.

Conclusion

PDMS-HNT composites showed superiority regarding their efficacy at inhibiting bacterial growth, in comparison to commercial antibacterial catheters. Our data suggest that PDMS-HNT composites have potential as a coating material for anti-bacterial invasive devices and in the prevention of institutional-acquired infections.

Analyzing the antiseptic capacity of silver-functionalized poly(ethylene glycol)–heparin hydrogels after human whole blood exposure

Advanced blood contacting biomaterials are designed to combine antiseptic and anticoagulant functionalities.

Prevention and care of respiratory failure in obese patients

With the increase in the global prevalence of obesity, there is a parallel rise in the proportion of obese patients admitted to intensive care units, referred for major surgery or requiring long-term non-invasive ventilation (NIV) at home for chronic respiratory failure. We describe the physiological effect of obesity on the respiratory system mainly in terms of respiratory mechanics, respiratory drive, and patency of the upper airways. Particular attention is given to the prevention and the clinical management of respiratory failure in obese patients with a main focus on invasive and NIV in intensive care during the perioperative period and long-term use of NIV on return home. We also address other aspects of care of obese patients, including antibiotic dosing and catheter-related infections.

A Tick Antivirulence Protein Potentiates Antibiotics against Staphylococcus aureus

New strategies are needed to combat antibiotic resistance, especially against pathogens such as methicillin-resistant Staphylococcus aureus A tick antifreeze glycoprotein, IAFGP, possesses potent antibiofilm properties against a variety of clinical pathogens, including S. aureus Synergy between IAFGP, or a peptide (P1) representative of a repeat region of the protein, with different antibiotics was assessed in vitro Antibiotics that synergized with either IAFPG or P1 were further evaluated in vivo using vertebrate and invertebrate infection models. IAFGP readily enhanced the efficacy of antibiotics against S. aureus Synergy with daptomycin, an antibiotic used to treat methicillin-resistant S. aureus, was observed in vitro and in vivo using iafgp-transgenic mice and flies. Furthermore, synergy with ciprofloxacin or gentamicin, antibiotics not generally used to treat S. aureus, was also perceived. The combined effect of the antibiotic and IAFGP was associated with improved permeation of the antibiotic into the cell. Our results highlight that synergy of IAFGP with antibiotics traditionally used to treat this pathogen, and enhancement of the potency of antibiotics not commonly used against this microbe, can provide novel alternative therapeutic strategies to combat bacterial infections.

Cumulative Evidence of Randomized Controlled and Observational Studies on Catheter-Related Infection Risk of Central Venous Catheter Insertion Site in ICU Patients: A Pairwise and Network Meta-Analysis

BACKGROUND

Selection of central venous catheter insertion site in ICU patients could help reduce catheter-related infections. Although subclavian was considered the most appropriate site, its preferential use in ICU patients is not generalized and questioned by contradicted meta-analysis results. In addition, conflicting data exist on alternative site selection whenever subclavian is contraindicated.

OBJECTIVE

To compare catheter-related bloodstream infection and colonization risk between the three sites (subclavian, internal jugular, and femoral) in adult ICU patients.

DATA SOURCE

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled trials, CINAHL, and ClinicalTrials.gov.

STUDY SELECTION

Eligible studies were randomized controlled trials and observational ones.

DATA EXTRACTION

Extracted data were analyzed by pairwise and network meta-analysis.

DATA SYNTHESIS

Twenty studies were included; 11 were observational, seven were randomized controlled trials for other outcomes, and two were randomized controlled trials for sites. We evaluated 18,554 central venous catheters: 9,331 from observational studies, 5,482 from randomized controlled trials for other outcomes, and 3,741 from randomized controlled trials for sites. Colonization risk was higher for internal jugular (relative risk, 2.25 [95% CI, 1.84-2.75]; I = 0%) and femoral (relative risk, 2.92 [95% CI, 2.11-4.04]; I = 24%), compared with subclavian. Catheter-related bloodstream infection risk was comparable for internal jugular and subclavian, higher for femoral than subclavian (relative risk, 2.44 [95% CI, 1.25-4.75]; I = 61%), and lower for internal jugular than femoral (relative risk, 0.55 [95% CI, 0.34-0.89]; I = 61%). When observational studies that did not control for baseline characteristics were excluded, catheter-related bloodstream infection risk was comparable between the sites.

CONCLUSIONS

In ICU patients, internal jugular and subclavian may, similarly, decrease catheter-related bloodstream infection risk, when compared with femoral. Subclavian could be suggested as the most appropriate site, whenever colonization risk is considered and not, otherwise, contraindicated. Current evidence on catheter-related bloodstream infection femoral risk, compared with the other sites, is inconclusive.

Are antimicrobial peripherally inserted central catheters associated with reduction in central line-associated bloodstream infection? A systematic review and meta-analysis

BACKGROUND

Antimicrobial peripherally inserted central catheters (PICCs) may reduce the risk of central line-associated bloodstream infection (CLABSI). However, data regarding efficacy are limited. We aimed to evaluate whether antimicrobial PICCs are associated with CLABSI reduction.

METHODS

MEDLINE, EMBASE, CINHAL, and Web of Science were searched from inception to July 2016; conference proceedings were searched to identify additional studies. Study selection and data extraction were performed independently by 2 authors.

RESULTS

Of 597 citations identified, 8 studies involving 12,879 patients met eligibility criteria. Studies included adult and pediatric patients from intensive care, long-term care, and general ward settings. The incidence of CLABSI in patients with antimicrobial PICCs was 0.2% (95% confidence interval [CI], 0.0%-0.5%), and the incidence among nonantimicrobial catheters was 5.3% (95% CI, 2.6%-8.8%). Compared with noncoated PICCs, antimicrobial PICCs were associated with a significant reduction in CLABSI (relative risk [RR], 0.29; 95% CI, 0.10-0.78). Statistical heterogeneity (I², 71.6%; T2 = 1.07) was resolved by publication type, with peer-reviewed articles showing greater reduction in CLABSI (RR, 0.21; 95% CI, 0.06-0.74). Twenty-six patients (95% CI, 21-75) need to be treated with antimicrobial PICCs to prevent 1 CLABSI. Studies of adults at greater baseline risk of CLABSI experienced greater reduction in CLABSI (RR, 0.20; P = .003).

CONCLUSIONS

Available evidence suggests that antimicrobial PICCs may reduce CLABSI, especially in high-risk subgroups. Randomized trials are needed to assess efficacy across patient populations.

An assessment of the future impact of alternative technologies on antibiotics markets

BACKGROUND

The increasing threat of antimicrobial resistance combined with the paucity of new classes of antibiotics represents a serious public health challenge. New treatment technologies could, in theory, have a significant impact on the future use of traditional antibiotics, be it by facilitating rational and responsible use or by product substitution in the existing antibiotics markets, including by reducing the incidence of bacterial infections through preventative approaches. The aim of this paper is to assess the potential of alternative technologies in reducing clinical use of and demand for antibiotics, and to briefly indicate which segments of the antibiotics market that might be impacted by these technologies.

METHODS

An initial mapping exercise to identify the alternative technologies was followed by a review of relevant published and grey literature (n = 52). We also carried out stakeholder engagement activities by a round-table discussion with infectious disease specialists and a multi-criteria decision analysis exercise with pharmaceutical industry experts.

RESULTS

Ten alternative technologies were identified and analyzed for their potential impact on the antibiotics market. Of these, rapid point-of-care diagnostics, vaccines, fecal microbiota transplantation, and probiotics were considered to have a "high" or "medium" potential impact over a 10-20 year horizon. Therapeutic antibodies, antibiotic biomaterials, bacteriophages, antimicrobial nanoparticles, antimicrobial peptides, and anti-virulence materials were rated as having "low" potential impact.

CONCLUSION

Despite the apparent potential of the most promising alternative technologies to reduce demand, that reduction will likely only happen in limited segments of the antibiotics market or, in the case of preventing community acquired streptococcal infections by vaccination, in a low-price generics market segment. Thus, alternative technologies are not expected to represent any disincentive to antibiotics developers. Finally, it is unlikely that alternative technologies will displace the need for new classes, and sub-classes, of antibiotics in the short and medium terms.

Anti-biofilm Activity as a Health Issue

The formation and persistence of surface-attached microbial communities, known as biofilms, are responsible for 75% of human microbial infections (National Institutes of Health). Biofilm lifestyle confers several advantages to the pathogens, notably during the colonization process of medical devices and/or patients’ organs. In addition, sessile bacteria have a high tolerance to exogenous stress including anti-infectious agents. Biofilms are highly competitive communities and some microorganisms exhibit anti-biofilm capacities such as bacterial growth inhibition, exclusion or competition, which enable them to acquire advantages and become dominant. The deciphering and control of anti-biofilm properties represent future challenges in human infection control. The aim of this review is to compare and discuss the mechanisms of natural bacterial anti-biofilm strategies/mechanisms recently identified in pathogenic, commensal and probiotic bacteria and the main synthetic strategies used in clinical practice, particularly for catheter-related infections.

Catheter impregnation, coating or bonding for reducing central venous catheter-related infections in adults

BACKGROUND

The central venous catheter (CVC) is essential in managing acutely ill patients in hospitals. Bloodstream infection is a major complication in patients with a CVC. Several infection control measures have been developed to reduce bloodstream infections, one of which is impregnation of CVCs with various forms of antimicrobials (either with an antiseptic or with antibiotics). This review was originally published in June 2013 and updated in 2016.

OBJECTIVES

Our main objective was to assess the effectiveness of antimicrobial impregnation, coating or bonding on CVCs in reducing clinically-diagnosed sepsis, catheter-related blood stream infection (CRBSI), all-cause mortality, catheter colonization and other catheter-related infections in adult participants who required central venous catheterization, along with their safety and cost effectiveness where data were available. We undertook the following comparisons: 1) catheters with antimicrobial modifications in the form of antimicrobial impregnation, coating or bonding, against catheters without antimicrobial modifications and 2) catheters with one type of antimicrobial impregnation against catheters with another type of antimicrobial impregnation. We planned to analyse the comparison of catheters with any type of antimicrobial impregnation against catheters with other antimicrobial modifications, e.g. antiseptic dressings, hubs, tunnelling, needleless connectors or antiseptic lock solutions, but did not find any relevant studies. Additionally, we planned to conduct subgroup analyses based on the length of catheter use, settings or levels of care (e.g. intensive care unit, standard ward and oncology unit), baseline risks, definition of sepsis, presence or absence of co-interventions and cost-effectiveness in different currencies.

SEARCH METHODS

We used the standard search strategy of the Cochrane Anaesthesia, Critical and Emergency Care Review Group (ACE). In the updated review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 3), MEDLINE (OVID SP; 1950 to March 2015), EMBASE (1980 to March 2015), CINAHL (1982 to March 2015), and other Internet resources using a combination of keywords and MeSH headings. The original search was run in March 2012.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that assessed any type of impregnated catheter against either non-impregnated catheters or catheters with another type of impregnation in adult patients cared for in the hospital setting who required CVCs. We planned to include quasi-RCT and cluster-RCTs, but we identified none. We excluded cross-over studies.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methodological procedures expected by Cochrane. Two authors independently assessed the relevance and risk of bias of the retrieved records. We expressed our results using risk ratio (RR), absolute risk reduction (ARR) and number need to treat to benefit (NNTB) for categorical data and mean difference (MD) for continuous data, where appropriate, with their 95% confidence intervals (CIs).

MAIN RESULTS

We included one new study (338 participants/catheters) in this update, which brought the total included to 57 studies with 16,784 catheters and 11 types of impregnations. The total number of participants enrolled was unclear, as some studies did not provide this information. Most studies enrolled participants from the age of 18, including patients in intensive care units (ICU), oncology units and patients receiving long-term total parenteral nutrition. There were low or unclear risks of bias in the included studies, except for blinding, which was impossible in most studies due to the catheters that were being assessed having different appearances. Overall, catheter impregnation significantly reduced catheter-related blood stream infection (CRBSI), with an ARR of 2% (95% CI 3% to 1%), RR of 0.62 (95% CI 0.52 to 0.74) and NNTB of 50 (high-quality evidence). Catheter impregnation also reduced catheter colonization, with an ARR of 9% (95% CI 12% to 7%), RR of 0.67 (95% CI 0.59 to 0.76) and NNTB of 11 (moderate-quality evidence, downgraded due to substantial heterogeneity). However, catheter impregnation made no significant difference to the rates of clinically diagnosed sepsis (RR 1.0, 95% CI 0.88 to 1.13; moderate-quality evidence, downgraded due to a suspicion of publication bias), all-cause mortality (RR 0.92, 95% CI 0.80 to 1.07; high-quality evidence) and catheter-related local infections (RR 0.84, 95% CI 0.66 to 1.07; 2688 catheters, moderate quality evidence, downgraded due to wide 95% CI).In our subgroup analyses, we found that the magnitudes of benefits for impregnated CVCs varied between studies that enrolled different types of participants. For the outcome of catheter colonization, catheter impregnation conferred significant benefit in studies conducted in ICUs (RR 0.70;95% CI 0.61 to 0.80) but not in studies conducted in haematological and oncological units (RR 0.75; 95% CI 0.51 to 1.11) or studies that assessed predominantly patients who required CVCs for long-term total parenteral nutrition (RR 0.99; 95% CI 0.74 to 1.34). However, there was no such variation for the outcome of CRBSI. The magnitude of the effects was also not affected by the participants' baseline risks.There were no significant differences between the impregnated and non-impregnated groups in the rates of adverse effects, including thrombosis/thrombophlebitis, bleeding, erythema and/or tenderness at the insertion site.

AUTHORS' CONCLUSIONS

This review confirms the effectiveness of antimicrobial CVCs in reducing rates of CRBSI and catheter colonization. However, the magnitude of benefits regarding catheter colonization varied according to setting, with significant benefits only in studies conducted in ICUs. A comparatively smaller body of evidence suggests that antimicrobial CVCs do not appear to reduce clinically diagnosed sepsis or mortality significantly. Our findings call for caution in routinely recommending the use of antimicrobial-impregnated CVCs across all settings. Further randomized controlled trials assessing antimicrobial CVCs should include important clinical outcomes like the overall rates of sepsis and mortality.

Nanoscale Plasma Coating Inhibits Formation of Staphylococcus aureus Biofilm

Staphylococcus aureus commonly infects medical implants or devices, with devastating consequences for the patient. The infection begins with bacterial attachment to the device, followed by bacterial multiplication over the surface of the device, generating an adherent sheet of bacteria known as a biofilm. Biofilms resist antimicrobial therapy and promote persistent infection, making management difficult to futile. Infections might be prevented by engineering the surface of the device to discourage bacterial attachment and multiplication; however, progress in this area has been limited. We have developed a novel nanoscale plasma coating technology to inhibit the formation of Staphylococcus aureus biofilms. We used monomeric trimethylsilane (TMS) and oxygen to coat the surfaces of silicone rubber, a material often used in the fabrication of implantable medical devices. By quantitative and qualitative analysis, the TMS/O2 coating significantly decreased the in vitro formation of S. aureus biofilms; it also significantly decreased in vivo biofilm formation in a mouse model of foreign-body infection. Further analysis demonstrated TMS/O2 coating significantly changed the protein adsorption, which could lead to reduced bacterial adhesion and biofilm formation. These results suggest that TMS/O2 coating can be used to effectively prevent medical implant-related infections.

New Technology: Heparin and Antimicrobial-Coated Catheters

Although tunneled hemodialysis catheter must be considered the last option for vascular access, it is necessary in some circumstances in the dialysis patient. Thrombosis and infections are the main causes of catheter-related comorbidity. Fibrin sheath, intimately related with the biofilm, is the precipitating factor of this environment, determining catheter patency and patient morbidity. Its association with bacterial overgrowth and thrombosis has led to the search of multiple preventive measures. Among them is the development of catheter coatings to prevent thrombosis and infections. There are two kinds of treatments to cover the catheter surface: antithrombotic and antimicrobial coatings. In nondialysis-related settings, mainly in intensive care units, both have been shown to be efficient in the prevention of catheter-related infection. This includes heparin, silver, chlorhexidine, rifampicine and minocycline. In hemodialysis population, however, few studies on surface-treated catheters have been made and they do not provide evidence that shows complication reduction. The higher effectiveness of coatings in nontunneled catheters may depend on the short average life of these devices. Hemodialysis catheters need to be used over long periods of time and require clinical trials to show effectiveness of coatings over long periods. This also means greater knowledge of biofilm etiopathogeny and fibrin sheath development.

[Technical criteria of central venous catheters: Anaesthesiologist/intensivist and pharmacist opinions]

INTRODUCTION

The lack of technical information from suppliers and from the literature, a wide variety of features and the absence of medical device reference document explain the difficulty for medical and pharmaceutical staffs to choose a central venous catheter (CVC). The aim of this study was to establish the specifications to choose a CVC according to the clinician needs.

METHODS

An analysis of suppliers' technical documentation and a literature review was performed to identify criteria and to collect them in a questionnaire to conduct semi-structured interviews between 1 pharmacist and 5 anaesthesiologists/intensivists. With these interviews, the technical criteria were classified according to their importance in 3 levels.

RESULTS

Thirteen technical criteria were identified after reading the technical documents and the literature. Among them, 8 were classified as "essential criteria" (level I) by the physicians: J-shaped guide, one clamp on each way, identified lumen, radiopacity, graduation every centimeter by 5 to 20 cm from the distal extremity, a length of 15 to 25 cm, a single-lumen catheter with a 14 to 16G way and a three-lumen catheter with 14 to 18G way. Finally, three criteria were classified as "intermediate criteria" (level II) and two as "optional criteria" (level III).

CONCLUSIONS

This collaborative approach allowed to reference new medical devices according to the clinicians needs. These CVC are a mean to respect guidelines for physicians and nurses and to secure the patient's care.

Electrically conductive catheter inhibits bacterial colonization

PURPOSE

To design, prototype, and assess a custom vascular access catheter for its ability to inhibit bacterial colonization in vitro and to optimize electric parameters for efficacy and safe translation.

MATERIALS AND METHODS

A vascular access catheter with conductive elements was designed and custom fabricated with two electrodes at the tip, separated by a nonconductive segment. The catheter was colonized with Staphylococcus aureus and incubated at predetermined current levels (4-8 µA) and durations (4-24 h). Catheters were compared using bacterial counts and scanning electron microscopy (SEM).

RESULTS

Bacteria colony-forming units were reduced significantly (P < .05) by > 90% (91.7%-100%) in all uninterrupted treatment arms that included electric current (4 µA or 8 µA) of at least 8 hours' duration. Qualitative analysis using SEM revealed that the treated catheter exposed to electric current had markedly less bacteria compared with the untreated catheter.

CONCLUSIONS

This catheter with conductive elements inhibits bacterial colonization in vitro when very small electric current (4-8 µA) is applied across the tip for 8-24 hours. In vivo validation is requisite to future translation to the clinical setting.

Comparative effectiveness of two catheter locking solutions to reduce catheter-related bloodstream infection in hemodialysis patients

BACKGROUND AND OBJECTIVES

Infection is the second leading cause of death in hemodialysis patients. Catheter-related bloodstream infection and infection-related mortality have not improved in this population over the past two decades. This study evaluated the impact of a prophylactic antibiotic lock solution on the incidence of catheter-related bloodstream infection and mortality.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This prospective, multicenter, observational cohort study compared the effectiveness of two catheter locking solutions (gentamicin/citrate versus heparin) in 555 hemodialysis patients dialyzing with a tunneled cuffed catheter between 2008 and 2011. The groups were not mutually exclusive. Rates of catheter-related bloodstream infection and mortality hazards were compared between groups.

RESULTS

The study population (n=555 and 1350 catheters) had a median age of 62 years (interquartile range=41-83 years), with 50% men and 71% black. There were 427 patients evaluable in the heparin period (84,326 days) and 322 patients evaluable in the antibiotic lock period (71,192 days). Catheter-related bloodstream infection in the antibiotic lock period (0.45/1000 catheter days) was 73% lower than the heparin period (1.68/1000 catheter days; P=0.001). Antibiotic lock use was associated with a decreased risk of catheter-related bloodstream infection compared with heparin (risk ratio, 0.23; 95% confidence interval, 0.13 to 0.38 after multivariate adjustment). Cox proportional hazards modeling found that antibiotic lock was associated with a reduction in mortality (hazard ratio, 0.36; 95% confidence interval, 0.22 to 0.58 in unadjusted analyses; hazard ratio, 0.32; 95% confidence interval, 0.14 to 0.75 after multivariate adjustment). The rate of gentamicin-resistant organisms decreased (0.40/1000 person-years to 0.22/1000 person-years) in the antibiotic lock period (P=0.01).

CONCLUSIONS

The results of this study show that the use of a prophylactic, gentamicin/citrate lock was associated with a substantial reduction in catheter-related bloodstream infection and is the first to report a survival advantage of antibiotic lock in a population at high risk of infection-related morbidity and mortality.

Dialysis Central Venous Catheter Types and Performance

The choice of both short-term (nontunneled) and long-term (tunneled) central venous catheters (CVCs) for hemodialysis is a difficult one, due to the large number of available catheters, with very different characteristics and cost.

CVC-related complications (in particular infections, thrombosis and inefficient dialysis) can determine ominous consequences and death, with extremely elevated costs due to prolonged hospitalization and expensive procedures. Thus, the correct balance between cost and quality of CVC is required when deciding which kind of CVC should be adopted.

In this regard, the design of CVCs has become a very active area of industrial and clinical research, with the ultimate goal of improving the long-term function of the catheter and of reducing complication rates, because even small improvements in the complication or reintervention rates have a positive impact on individual patient care and cost to society. In this article we review the general features of CVCs, including differences between tunneled and nontunneled CVCs, materials and their compatibility with lock solutions, the implications of straight versus precurved design in nontunneled CVCs, lumen and tip features with their clinical implications, catheter coatings and their effect on infection and thrombosis.

Prevention of biofilm colonization by Gram-negative bacteria on minocycline-rifampin-impregnated catheters sequentially coated with chlorhexidine

Resistant Gram-negative bacteria are increasing central-line-associated bloodstream infection threats. To better combat this, chlorhexidine (CHX) was added to minocycline-rifampin (M/R) catheters. The in vitro antimicrobial activity of CHX-M/R catheters against multidrug resistant, Gram-negative Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia was tested. M/R and CHX-silver sulfadiazine (CHX/SS) catheters were used as comparators. The novel CHX-M/R catheters were significantly more effective (P < 0.0001) than CHX/SS or M/R catheters in preventing biofilm colonization and showed better antimicrobial durability.

New cost-effective treatment strategies for acute emergency situations

In an era of ever-increasing healthcare costs, new treatments must not only improve outcomes and quality of care but also be cost-effective. This is most challenging for emergency and critical care. Bigger and better has been the mantra of Western medical care for decades, leading to costlier but not necessarily better care. Recent advances focused on new implementation processes for evidence-based best practices such as checklists and bundles have transformed medical care. We outline recent advances in medical practice that have positively affected both the quality of care and its cost-effectiveness. Future medical care must be smarter and more effective if we are to meet the increasing demands of an aging patient population in the context of ever more limited resources.

Effect of Intrafix® SafeSet infusion apparatus on phlebitis in a neurological intensive care unit: a case-control study

OBJECTIVE

To investigate the effect of the Intrafix(®) SafeSet infusion apparatus on the incidence of phlebitis in patients being intravenously infused in a neurological intensive care unit (ICU).

METHODS

Patients aged > 12 years, with no history of diabetes mellitus and no existing phlebitis, requiring a daily peripheral intravenous infusion of ≥ 8 h with the total period lasting ≥ 3 days, were enrolled. Infusions were performed using the Intrafix(®) SafeSet or normal infusion apparatus. Incidence of phlebitis (scored according to the Infusion Nursing Standards of Practice of the American Infusion Nurses Society) was analysed.

RESULTS

Patients (n = 1545) were allocated to Intrafix(®) SafeSet (n = 709) or normal infusion (n = 836) groups, matched for age, gender and preliminary diagnosis. Incidence of phlebitis was significantly higher using normal infusion apparatus compared with the Intrafix(®) SafeSet (23.4% versus 17.9%, respectively).

CONCLUSION

Intrafix(®) SafeSet infusion apparatus significantly reduced the incidence of phlebitis in patients in the neurological ICU, compared with normal infusion apparatus, and may be suitable for use in routine clinical practice.

Novel strategies for the prevention and treatment of biofilm related infections

Biofilm formation by human bacterial pathogens on implanted medical devices causes major morbidity and mortality among patients, and leads to billions of dollars in healthcare cost. Biofilm is a complex bacterial community that is highly resistant to antibiotics and human immunity. As a result, novel therapeutic solutions other than the conventional antibiotic therapies are in urgent need. In this review, we will discuss the recent research in discovery of alternative approaches to prevent or treat biofilms. Current anti-biofilm technologies could be divided into two groups. The first group focuses on targeting the biofilm forming process of bacteria based on our understanding of the molecular mechanism of biofilm formation. Small molecules and enzymes have been developed to inhibit or disrupt biofilm formation. Another group of anti-biofilm technologies focuses on modifying the biomaterials used in medical devices to make them resistant to biofilm formation. While these novel anti-biofilm approaches are still in nascent phases of development, efforts devoted to these technologies could eventually lead to anti-biofilm therapies that are superior to the current antibiotic treatment.

Bench-to-bedside review: Challenges of diagnosis, care and prevention of central catheter-related bloodstream infections in children

Central venous catheters (CVCs) are indispensable in modern pediatric medicine. CVCs provide secure vascular access, but are associated with a risk of severe complications, in particular bloodstream infection. We provide a review of the recent literature about the diagnostic and therapeutic challenges of catheter-related bloodstream infection (CRBSI) in children and its prevention. Variations in blood sampling and limitations in blood culturing interfere with accurate and timely diagnosis of CRBSI. Although novel molecular testing methods appear promising in overcoming some of the present diagnostic limitations of conventional blood sampling in children, they still need to solidly prove their accuracy and reliability in clinical practice. Standardized practices of catheter insertion and care remain the cornerstone of CRBSI prevention although their implementation in daily practice may be difficult. Technology such as CVC impregnation or catheter locking with antimicrobial substances has been shown less effective than anticipated. Despite encouraging results in CRBSI prevention among adults, the goal of zero infection in children is still not in range. More high-quality research is needed in the field of prevention, accurate and reliable diagnostic measures and effective treatment of CRBSI in children.

Catheter impregnation, coating or bonding for reducing central venous catheter-related infections in adults

BACKGROUND

The central venous catheter (CVC) is a commonly used device in managing acutely ill patients in the hospital. Bloodstream infections are major complications in patients who require a CVC. Several infection control measures have been developed to reduce bloodstream infections, one of which is CVC impregnated with various forms of antimicrobials (either with an antiseptic or with antibiotics).

OBJECTIVES

We aimed to assess the effects of antimicrobial CVCs in reducing clinically diagnosed sepsis, established catheter-related bloodstream infection (CRBSI) and mortality.

SEARCH METHODS

We used the standard search strategy of the Cochrane Anaesthesia Review Group (CARG). We searched MEDLINE (OVID SP) (1950 to March 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 3, 2012), EMBASE (1980 to March 2012), CINAHL (1982 to March 2012) and other Internet resources using a combination of keywords and MeSH headings.

SELECTION CRITERIA

We included randomized controlled trials that assessed any type of impregnated catheter against either non-impregnated catheters or catheters with another impregnation. We excluded cross-over studies.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the CARG. Two authors independently assessed the relevance and risk of bias of the retrieved records. We expressed our results using risk ratio (RR), absolute risk reduction (ARR) and number need to treat to benefit (NNTB) for categorical data and mean difference (MD) for continuous data where appropriate with their 95% confidence intervals (CIs).

MAIN RESULTS

We included 56 studies with 16,512 catheters and 11 types of antimicrobial impregnations. The total number of participants enrolled was unclear as some studies did not provide this information. There were low or unclear risks of bias in the included studies, except for blinding, which was impossible in most studies due to different appearances between the catheters assessed. Overall, catheter impregnation significantly reduced CRBSI, with an ARR of 2% (95% CI 3% to 1%), RR of 0.61 (95% CI 0.51 to 0.73) and NNTB of 50. Catheter impregnation also reduced catheter colonization, with an ARR of 10% (95% CI 13% to 7%), RR of 0.66 (95% CI 0.58 to 0.75) and NNTB of 10. However, catheter impregnation made no significant difference to the rates of clinically diagnosed sepsis (RR 1.0 (95% CI 0.88 to 1.13)) and all-cause mortality (RR 0.88 (95% CI 0.75 to 1.05)).In our subgroup analyses, we found that the magnitudes of benefits for impregnated CVCs varied in studies that enrolled different types of participants. For the outcome of catheter colonization, catheter impregnation conferred significant benefit in studies conducted in intensive care units (ICUs) (RR 0.68 (95% CI 0.59 to 0.78)) but not in studies conducted in haematological and oncological units (RR 0.75 (95% CI 0.51 to 1.11)) or studies that assessed predominantly patients who required CVCs for long-term total parenteral nutrition (TPN)(RR 0.99 (95% CI 0.74 to 1.34)). However, there was no such variation for the outcome of CRBSI. The magnitude of the effects was also not affected by the participants' baseline risks.There were no significant differences between the impregnated and non-impregnated groups in the rates of adverse effects, including thrombosis/thrombophlebitis, bleeding, erythema and/or tenderness at the insertion site.

AUTHORS' CONCLUSIONS

This review confirms the effectiveness of antimicrobial CVCs in improving such outcomes as CRBSI and catheter colonization. However, the magnitude of benefits in catheter colonization varied according to the setting, with significant benefits only in studies conducted in ICUs. Limited evidence suggests that antimicrobial CVCs do not appear to significantly reduce clinically diagnosed sepsis or mortality. Our findings call for caution in routinely recommending the use of antimicrobial-impregnated CVCs across all settings. Further randomized controlled trials assessing antimicrobial CVCs should include important clinical outcomes like the overall rates of sepsis and mortality.

Self-disinfecting surfaces: review of current methodologies and future prospects

Methods to improve disinfection of environmental surfaces in hospital rooms include improving cleaning/disinfection by environmental service workers through education and feedback on cleaning effectiveness (eg, use of fluorescent dyes), "no-touch" methods (eg, UV-C light), and self-disinfecting surfaces. Self-disinfecting surfaces can be created by impregnating or coating surfaces with heavy metals (eg, silver or copper), germicides (eg, triclosan), or miscellaneous methods (eg, light-activated antimicrobials). These methods are under active investigation but to date have not been assessed for their ability to reduce health care-associated infections.

Modern trends in infection control practices in intensive care units

Hospital-acquired infections (HAIs) are common in intensive care unit (ICU) patients and are associated with increased morbidity and mortality. There has been an increasing effort to prevent HAIs, and infection control practices are paramount in avoiding these complications. In the last several years, numerous developments have been seen in the infection prevention strategies in various health care settings. This article reviews the modern trends in infection control practices to prevent HAIs in ICUs with a focus on methods for monitoring hand hygiene, updates in isolation precautions, new methods for environmental cleaning, antimicrobial bathing, prevention of ventilator-associated pneumonia, central line-associated bloodstream infections, catheter-associated urinary tract infections, and Clostridium difficile infection.

A review of epidural catheter-related infections

Spinal drug delivery is a generally safe and effective therapy for the treatment of both acute and chronic pain. However, it can be occasionally associated with significant complications, including neurologic injury, as a result of bleeding and infection in a confined space. This article focuses on risk factors for developing epidural catheter-related infections as well as strategies to minimize risks. Additionally, the diagnosis and management of epidural catheter-related infections, both superficial and deep, are discussed.

Prevention and management of central line-associated bloodstream infections in hospital practice

In this article aimed at hospitalists, we examine the literature on preventive measures for central line-associated bloodstream infections (CLABSIs) and optimal management once a CLABSI has been established. We focus on a number of core preventive measures and the contemporary approach of bundling these measures for maximal impact in reducing infection rates. We then discuss empiric and pathogen-specific antibiotic therapy, including the role of newer antimicrobial agents, as well as the management of an infected central venous catheter.

Improved antibiotic-impregnated catheters with extended-spectrum activity against resistant bacteria and fungi

Minocycline-rifampin-impregnated central venous catheters (M/R CVCs) have been shown to be efficacious in reducing catheter-related bloodstream infections (CRBSI) and inhibiting the biofilm adherence of resistant Gram-positive and Gram-negative pathogens, with the exception of Pseudomonas aeruginosa and Candida spp. To expand the spectrum of antimicrobial activity, a novel second-generation M/R catheter was developed by adding chlorhexidine (CHX-M/R). CVCs and peripherally inserted central catheters (PICCs) were impregnated with CHX-M/R and compared with first-generation M/R catheters, CHX-silver sulfadiazine-treated CVCs (CHX/SS-CVCs), chlorhexidine-treated PICCs, and uncoated catheters. A biofilm catheter colonization model was used to assess the efficacy of catheters against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), P. aeruginosa, Candida albicans, and Candida glabrata. CHX-M/R-impregnated CVCs were the only antimicrobial catheters that completely inhibited the biofilm colonization of all resistant bacterial and fungal organisms tested at all time intervals, and they were significantly superior to uncoated catheters (all P values were ≤0.003). Furthermore, CHX-M/R-coated CVCs had a significantly more effective and prolonged (up to 3 weeks) antimicrobial activity against MRSA and P. aeruginosa than M/R, CHX/SS, and uncoated CVCs (P < 0.0001). Similarly, CHX-M/R-coated PICCs were also superior to M/R-coated and CHX-coated PICCs in preventing biofilms of MRSA, VRE, P. aeruginosa, and Candida species (P value = 0.003 for all). Our study shows that novel CHX-M/R-coated catheters have unique properties in completely inhibiting biofilm colonization of MRSA, VRE, P. aeruginosa, and fungi in a manner superior to that of M/R- and chlorhexidine-treated catheters.

Candida biofilms and the host: models and new concepts for eradication

Biofilms define mono- or multispecies communities embedded in a self-produced protective matrix, which is strongly attached to surfaces. They often are considered a general threat not only in industry but also in medicine. They constitute a permanent source of contamination, and they can disturb the proper usage of the material onto which they develop. This paper relates to some of the most recent approaches that have been elaborated to eradicate Candida biofilms, based on the vast effort put in ever-improving models of biofilm formation in vitro and in vivo, including novel flow systems, high-throughput techniques and mucosal models. Mixed biofilms, sustaining antagonist or beneficial cooperation between species, and their interplay with the host immune system are also prevalent topics. Alternative strategies against biofilms include the lock therapy and immunotherapy approaches, and material coating and improvements. The host-biofilm interactions are also discussed, together with their potential applications in Candida biofilm elimination.

New materials and devices for preventing catheter-related infections

Catheters are the leading source of bloodstream infections for patients in the intensive care unit (ICU). Comprehensive unit-based programs have proven to be effective in decreasing catheter-related bloodstream infections (CR-BSIs). ICU rates of CR-BSI higher than 2 per 1,000 catheter-days are no longer acceptable. The locally adapted list of preventive measures should include skin antisepsis with an alcoholic preparation, maximal barrier precautions, a strict catheter maintenance policy, and removal of unnecessary catheters. The development of new technologies capable of further decreasing the now low CR-BSI rate is a major challenge. Recently, new materials that decrease the risk of skin-to-vein bacterial migration, such as new antiseptic dressings, were extensively tested. Antimicrobial-coated catheters can prevent CR-BSI but have a theoretical risk of selecting resistant bacteria. An antimicrobial or antiseptic lock may prevent bacterial migration from the hub to the bloodstream. This review discusses the available knowledge about these new technologies.

Combating bacterial colonization on metals via polymer coatings: relevance to marine and medical applications

Metals are widely used in engineering as well as medical applications. However, their surfaces are easily colonized by bacteria that form biofilms. Among the numerous concerns with biofilm formation, biocorrosion is of particular importance in industry, because structural integrity may be compromised, leading to technical failures. In the food industry and medical field, biofilms also pose health risks. To inhibit bacterial colonization, the surfaces of metals can be coated with a polymeric layer which is antiadhesive and/or bactericidal. This article describes polymers that have these desired properties and the methodologies for immobilizing them on metal surfaces of relevance to the marine and medical fields. The focus is on polymer coatings that have a high degree of stability in aqueous medium and do not leach out. The efficacies of the different polymer coatings against bacteria commonly encountered in marine (Desulfovibrio desulfuricans) and medical applications (Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli) are demonstrated.