Antimicrobial Catheters Research Articles

Biomodification Strategies for the Development of Antimicrobial Urinary Catheters: Overview and Advances.

Microbial burden associated with medical devices poses serious health challenges and is accountable for an increased number of deaths leading to enormous medical costs. Catheter‐associated urinary tract infections are the most common hospital‐acquired infections with enhanced patient morbidity. Quite often, catheter‐associated bacteriuria produces apparent adverse outcomes such as urosepsis and even death. Taking this into account, the methods to modify urinary catheters to control microbial infections with relevance to clinical drug resistance are systematically evaluated in this review. Technologies to restrict biofilm formation at initial stages by using functional nanomaterials are elucidated. The conventional methodology of using single therapeutic intervention for developing an antimicrobial catheter lacks clinically meaningful benefit. Therefore, catheter modification using naturally derived antimicrobials such as essential oils, curcumin, enzymes, and antimicrobial peptides in combination with synthetic antibiotics/nanoantibiotics is likely to exert sufficient inhibitory effect on uropathogens and is extensively discussed. Futuristic efforts in this area are projected here that demand clinical studies to address areas of uncertainty to avoid development of bacterial resistance to the new generation therapy with minimum discomfort to the patients.

Nitric oxide releasing vascular catheters for eradicating bacterial infection.

The interaction of blood proteins with an implant surface is not only a fundamental phenomenon but is also key to several important medical complications. Plasma proteins binding on the surface of intravascular catheters can promote bacterial adhesion leading to the risk of local and systemic complications such as catheter-related blood infections (CRBIs). The incidences of CRBIs in the United States amount to more than 250,000 cases/year with an attributable mortality of up to 35% and an annual healthcare expenditure of $2.3 billion approximately. This demands the development of truly nonthrombogenic and antimicrobial catheters. In the present study, catheters were fabricated by incorporating a nitric oxide (NO) donor molecule, S-nitroso-N-acetyl-penicillamine (SNAP) in a hydrophobic medical grade polymer, Elasteon-E2As. NO offers antithrombotic and antibacterial attributes without promoting drug resistance and cytotoxicity. E2As-SNAP catheters were first coated with fibrinogen, a blood plasma protein plays a key role in clot formation and eventual bacterial adhesion to the implant surface. The suitability of the catheters for biomedical applications was tested in vitro for contact angle, NO release kinetics, inhibition of bacteria, and absence of cytotoxicity toward mammalian cells. The highly hydrophobic catheters released NO in the physiological range that inhibited >99% bacterial viability on fibrinogen-coated catheters in a 24 h study. No toxic response of E2As-SNAP catheters leachate was observed using a standard cytotoxicity assay with mouse fibroblast cells. Overall, the results showed that the E2As-SNAP catheters can inhibit viable bacteria even in the presence of blood proteins without causing a cytotoxic response. The fundamentals of this study are applicable to other blood-contacting medical devices as well. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2849-2857, 2018.

Postmarketing experience with Neutrolin\xae (taurolidine, heparin, calcium citrate) catheter lock solution in hemodialysis patients

Catheter-related bloodstream infections (CRBSI) are major complications for patients with life-threatening conditions requiring chronic vascular catheterization. The wide range of etiologic microbes and the ongoing development of resistance to antimicrobials with specific mechanisms of action make this an appropriate target for applying a nonspecific antimicrobial therapeutic. Taurolidine hydrolyzes into two antimicrobial moieties, formaldehyde and methylene glycol, which react with microbial surfaces. Neutrolin® (taurolidine, heparin, calcium citrate) was recently introduced in Germany as an antimicrobial catheter lock solution. This postmarketing experience collected data on 201 patients at 20 centers from January 2014 through September 2016. Likely CRBSI was observed in 13 episodes in 47,118 days (0.2759 per 1000 days [0.1468, 0.4718]). Thrombosed catheter was observed in seven catheters in 47,118 days (0.1486 per 1000 days [0.0595, 0.3061]). No adverse drug reactions that led to the discontinuation of Neutrolin® use were reported. Two patients experienced occasional transient dysgeusia. Neutrolin®, when used in conjunction with guideline-based catheter care, showed reduction in the rate of both CRBSI and catheter thrombosis relative to recent historical controls.

Study protocol for a multicentre, randomised, controlled trial to assess the effectiveness of antimicrobial central venous catheters versus ordinary central venous catheters at reducing catheter related infections in critically ill Chinese patients

IntroductionCatheter use is associated with many complications and is an iatrogenic source of morbidity and mortality in intensive care units (ICU). The catheter being studied (Certofix Protect) was developed to...

Anti-Candida activity of antimicrobial impregnated central venous catheters

BackgroundWhenever the rate of central line-associated bloodstream infections (CLABSIs) remains high even after the implementation of preventive strategies, the use of chlorhexidine/silver sulfadiazine (CSS) or minocycline/rifampin (MR)-impregnated central venous catheters (CVCs) is currently recommended. Nevertheless, the efficacy of such CVCs against Candida albicans and other emerging non-albicans spp. has been insufficiently studied. This study aims to compare the activity of CSS and MR-impregnated CVCs against the yeasts most frequently isolated from CLABSIs.MethodsFor biofilm formation assays, type strains and clinical isolates of C. albicans, C. glabrata and C. parapsilosis sensu stricto were used. Segments of standard polyurethane, MR and second-generation CSS-CVCs were tested. The biofilm metabolic activity was measured by a semi-quantitative XTT reduction assay.ResultsCSS catheter segments significantly reduced the biofilm metabolic activity by all tested Candida spp., with inhibition ranging from 60% to 100%. The MR catheter segments promoted C. albicans and C. parapsilosis biofilm formation and exhibited an inconspicuous effect against C. glabrata.ConclusionsAmong the recommended antimicrobial CVCs, CSS-CVCs proved to be superior in the inhibition of biofilm formation by the most frequent yeasts causing CLABSIs. Data from this in vitro study may suggest that patients at high risk for invasive candidosis could benefit from the use of CSS-CVCs.

Prevention of central venous line associated bloodstream infections in adult intensive care units: A systematic review

BackgroundIn adult Intensive Care Units, the complexity of patient treatment requirements make the use of central venous lines essential. Despite the potential benefits central venous lines can have for patients, there is a high risk of bloodstream infection associated with these catheters. AimIdentify and critique the best available evidence regarding interventions to prevent central venous line associated bloodstream infections in adult intensive care unit patients other than anti-microbial catheters. MethodsA systematic review of studies published from January 2007 to February 2016 was undertaken. A systematic search of seven databases was carried out: MEDLINE; CINAHL Plus; EMBASE; PubMed; Cochrane Library; Scopus and Google Scholar. Studies were critically appraised by three independent reviewers prior to inclusion. ResultsNineteen studies were included. A range of interventions were found to be used for the prevention or reduction of central venous line associated bloodstream infections. These interventions included dressings, closed infusion systems, aseptic skin preparation, central venous line bundles, quality improvement initiatives, education, an extra staff in the Intensive Care Unit and the participation in the ‘On the CUSP: Stop Blood Stream Infections' national programme. ConclusionsCentral venous line associated bloodstream infections can be reduced by a range of interventions including closed infusion systems, aseptic technique during insertion and management of the central venous line, early removal of central venous lines and appropriate site selection.

In Vitro Study of Antimicrobial Percutaneous Nephrostomy Catheters for Prevention of Renal Infections.

Percutaneous nephrostomy (PCN) catheters are the primary method for draining ureters obstructed by malignancy and preventing a decline of renal function. However, PCN catheter-related infections, such as pyelonephritis and urosepsis, remain a significant concern. Currently, no antimicrobial PCN catheters are available for preventing infection complications. Vascular catheters impregnated with minocycline-rifampin (M/R) and M/R with chlorhexidine coating (M/R plus CHD) have previously demonstrated antimicrobial activity. Therefore, in this study, we examined whether these combinations could be applied to PCN catheters and effectively inhibit biofilm formation by common uropathogens. An in vitro biofilm colonization model was used to assess the antimicrobial efficacy of M/R and M/R-plus-CHD PCN catheters against nine common multidrug-resistant Gram-positive and Gram-negative uropathogens as well as Candida glabrata and Candida albicans Experimental catheters were also assessed for durability of antimicrobial activity for up 3 weeks. PCN catheters coated with M/R plus CHD completely inhibited biofilm formation for up to 3 weeks for all the organisms tested. The reduction in colonization compared to uncoated PCN catheters was significant for all Gram-positive, Gram-negative, and fungal organisms (P < 0.05). M/R-plus-CHD PCN catheters also produced significant reductions in biofilm colonization relative to M/R PCN catheters for Enterobacter spp., Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, C. glabrata, and C. albicans (P < 0.05). M/R-plus-CHD PCN catheters proved to be highly efficacious in preventing biofilm colonization when exposed to multidrug-resistant pathogens common in PCN catheter-associated pyelonephritis. M/R-plus-CHD PCN catheters warrant evaluation in a clinical setting to assess their ability to prevent clinically relevant nephrostomy infections.

Study of Crystal Formation and Nitric Oxide (NO) Release Mechanism from S-Nitroso-N-acetylpenicillamine (SNAP)-Doped CarboSil Polymer Composites for Potential Antimicrobial Applications.

Stable and long-term nitric oxide (NO) releasing polymeric materials have many potential biomedical applications. Herein, we report the real-time observation of the crystallization process of the NO donor, S-nitroso-N-acetylpenicillamine (SNAP), within a thermoplastic silicone-polycarbonate-urethane biomedical polymer, CarboSil 20 80A. It is demonstrated that the NO release rate from this composite material is directly correlated with the surface area that the CarboSil polymer film is exposed to when in contact with aqueous solution. The decomposition of SNAP in solution (e.g. PBS, ethanol, THF, etc.) is a pseudo-first-order reaction proportional to the SNAP concentration. Further, catheters fabricated with this novel NO releasing composite material are shown to exhibit significant effects on preventing biofilm formation on catheter surface by Pseudomonas aeruginosa and Proteus mirabilis grown in CDC bioreactor over 14 days, with a 2 and 3 log-unit reduction in number of live bacteria on their surfaces, respectively. Therefore, the SNAP-CarboSil composite is a promising new material to develop antimicrobial catheters, as well as other biomedical devices.

Taurolidine-citrate-heparin lock reduces catheter-related bloodstream infections in intestinal failure patients dependent on home parenteral support: a randomized, placebo-controlled trial

Background: In patients with intestinal failure who are receiving home parenteral support (HPS), catheter-related bloodstream infections (CRBSIs) inflict health impairment and high costs.Objective: This study investigates the efficacy and safety of the antimicrobial catheter lock solution, taurolidine-citrate-heparin, compared with heparin 100 IE/mL on CRBSI occurrence.Design: Forty-one high-risk patients receiving HPS followed in a tertiary HPS unit were randomly assigned in a double-blinded, placebo-controlled trial. External, stratified randomization was performed according to age, sex, and prior CRBSI incidence. The prior CRBSI incidence in the study population was 2.4 episodes/1000 central venous catheter (CVC) days [95% Poisson confidence limits (CLs): 2.12, 2.71 episodes/1000 CVC days]. The maximum treatment period was 2 y or until occurrence of a CRBSI or right-censoring because of CVC removal. The exact permutation tests were used to calculate P values for the log-rank tests.Results: Twenty patients received the taurolidine-citrate-heparin lock and 21 received the heparin lock, with 9622 and 6956 treatment days, respectively. In the taurolidine-citrate-heparin arm, no CRBSIs occurred, whereas 7 CRBSIs occurred in the heparin arm, with an incidence of 1.0/1000 CVC days (95% Poisson CLs: 0.4, 2.07/1000 CVC days; P = 0.005). The CVC removal rates were 0.52/1000 CVC days (95% Poisson CLs: 0.17, 1.21/1000 CVC days) and 1.72/1000 CVC days (95% Poisson CLs: 0.89, 3.0/1000 CVC days) in the taurolidine-citrate-heparin and heparin arm, respectively, tending to prolong CVC survival in the taurolidine arm (P = 0.06). Costs per treatment year were lower in the taurolidine arm (€2348) than in the heparin arm (€6744) owing to fewer admission days related to treating CVC-related complications (P = 0.02).Conclusions: In patients with intestinal failure who are life dependent on HPS, the taurolidine-citrate-heparin catheter lock demonstrates a clinically substantial and cost-beneficial reduction of CRBSI occurrence in a high-risk population compared with heparin. This trial was registered at clinicaltrials.gov as NCT01948245.

Comparative Efficacies of Antimicrobial Catheter Lock Solutions for Fungal Biofilm Eradication in an in Vitro Model of Catheter-Related Fungemia.

Fungal catheter-related bloodstream infections (CRBSIs)—primarily due to Candida species—account for over 12% of all CRBSIs, and have been progressively increasing in prevalence. They present significant health and economic burdens, and high mortality rates. Antimicrobial catheter lock solutions are an important prophylactic option for preventing fungal CRBSIs. In this study, we compared the effectiveness of two FDA-approved catheter lock solutions (heparin and saline) and three experimental antimicrobial catheter lock solutions—30% citrate, taurolidine-citrate-heparin (TCH), and nitroglycerin-citrate-ethanol (NiCE)—in an in vitro model of catheters colonized by fungi. The fungi tested were five different strains of Candida clinical isolates from cancer patients who contracted CRBSIs. Time-to-biofilm-eradication was assessed in the model with 15, 30, and 60 min exposures to the lock solutions. Only the NiCE lock solution was able to fully eradicate all fungal biofilms within 60 min. Neither 30% citrate nor TCH was able to fully eradicate any of the Candida biofilms in this time frame. The NiCE lock solution was significantly superior to TCH in eradicating biofilms of five different Candida species (p = 0.002 for all).

口腔癌に対する逆行性動注化学放射線療法のカテーテル関連血流感染症に関する検討

Catheter-related bloodstream infection (CRBSI) is one of the serious complications of chemotherapy in various cancer treatments and often causes cessation or temporary withdrawal of treatment. We investigated CRBSIs associated with retrograde superselective intra-arterial chemoradiotherapy for oral cancer. A total of 160 patients with oral cancer who had received catheterization from the superficial temporal or occipital arteries to the tumor-feeding arteries in our institution between January 2010 and December 2014 were studied retrospectively. All intra-arterial catheter tips were sent for culture, and catheter bacterial cultures were positive in 67 patients (41.9%). Blood culture tests were performed in 50 patients who had fever with a temperature of 38℃ or higher, and blood cultures were positive in 20 patients (12.5%). Both catheter cultures and blood cultures were positive in 12 patients. The same bacteria were detected in 7 patients (4.4%), fulfilling the criteria for CRBSI. The incidence ratio of CRBSI was 0.83 per 1,000 catheter days. All CRBSIs were eventually controlled by appropriate antimicrobial therapy and catheter replacement or decannulation.

Comparative efficacies of Antimicrobial Catheter Lock Solutions for Fungal Biofilm Eradication in an in vitro model of Catheter-Related Fungemia

Fungal catheter-related bloodstream infections (CRBSIs), primarily due to Candidaspecies, account for over 12% of all CRBSIs and have been progressively increasing in prevalence. They present significant health and economic burdens and high rates of mortality. Antimicrobial catheter lock solutions are an important prophylactic option for preventing fungal CRBSIs. In this study we compared the effectiveness of two FDA-approved catheter lock solutions (heparin and saline) and three experimental antimicrobial catheter lock solutions, 30% Citrate, Taurolidine-Citrate-Heparin (TCH), and Nitroglycerin-Citrate-Ethanol (NiCE). All solutions were tested in an in vitro model of yeast biofilm eradication. The yeast tested were five different strains of Candidaclinical isolates from cancer patients who contracted CRBSIs. Time-to-biofilm-eradication was assessed in the model with 15, 30 and 60 minute exposures to the lock solutions. Only the NiCE lock solution was able to fully eradicate all fungal biofilms within 60 minutes. Neither 30% citrate nor TCH was able to fully eradicate any of the Candida biofilms in this time frame. The NiCE lock solution was significantly superior to TCH in eradicating biofilms of five different Candidaspecies (P = 0.002 for all). NiCE lock showed significant efficacy compared with all solutions tested indicating NiCE has the potential to be used as an antifungal lock solution in high-risk settings where CRBSI caused by Candida is predominant. J. Rosenblatt, Infective Technologies, LLC: Co-Inventor of the Nitroglycerin-Citrate-Ethanol catheter lock solution technology which is owned by the University of Texas MD Anderson Cancer Center (UTMDACC) and has been licensed by Novel Anti-Infective Technologies, LLC in which Dr. Rosenblatt is a and Shareholder, Licensing agreement or royalty; UT MD Anderson Cancer Center: Co-Inventor of the Nitroglycerin-Citrate-Ethanol catheter lock solution technology which is owned by the University of Texas MD Anderson Cancer Center (UTMDACC) and has been licensed by Novel Anti-Infective Technologies, LLC in which Dr. Rosenblatt is a s and Scientific Advisor, Licensing agreement or royalty; I. Raad, Merck: Grant Investigator, Research grant; Allergan: Grant Investigator, Research grant; Infective Technologies, LLC: Co-Inventor of the Nitroglycerin-Citrate-Ethanol catheter lock solution technology which is owned by the University of Texas MD Anderson Cancer Center (UTMDACC) and has been licensed by Novel Anti-Infective Technologies, LLC in which Dr. Raad is a s and Shareholder, Licensing agreement or royalty

A review of the recent advances in antimicrobial coatings for urinary catheters.

This review article intends to provide an expansive insight into the various antimicrobial agents currently being researched for urinary catheter coatings. According to CDC, approximately 75% of urinary tract infections are caused by urinary catheters and 15-25% of hospitalized patients undergo catheterization. In addition to these alarming statistics, the increasing cost and health related complications associated with catheter associated UTIs make the research for antimicrobial urinary catheter coatings even more pertinent. This review provides a comprehensive summary of the history, the latest progress in development of the coatings and a brief conjecture on what the future entails for each of the antimicrobial agents discussed.

PMD24 - The Economic Impact of Using Antimicrobial Catheters Impregnated with Rifampin and Clindamycin to Reduce Infection Rates in External Ventricular Drainage: A Budget Impact Analysis

PMD24 - The Economic Impact of Using Antimicrobial Catheters Impregnated with Rifampin and Clindamycin to Reduce Infection Rates in External Ventricular Drainage: A Budget Impact Analysis

The potential of photo-deposited silver coatings on Foley catheters to prevent urinary tract infections

Catheter-associated urinary tract infection (CAUTI) represents one of the most common causes of morbidity and mortality. The resistance demonstrated by many microorganisms to conventional antibiotic therapies and the increasing health-care costs have recently encouraged the definition of alternative preventive strategies, which can have a positive effect in the management of infections. Antimicrobial urinary catheters have been developed through the photo-chemical deposition of silver coatings on the external and luminal surfaces. The substrates are exposed to ultraviolet radiation after impregnation into a silver-based solution, thus inducing the in situ synthesis of silver particles. The effect of the surface treatment on the material was investigated through scanning electron microscopy (SEM) and silver ion release measurements. The ability of microorganisms commonly associated with urinary tract infections was investigated in terms of bacterial viability, proliferation and biofilm development, using Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis as target organisms. The silver coatings demonstrated good distribution of silver particles to the substrate, and proved an effective antibacterial capability in simulated biological conditions. The low values of silver ion release demonstrated the optimum adhesion of the coating. The results indicated a good potential of silver-based antimicrobial materials for prevention of catheter-associated urinary tract infection.

Implementation of the updated 2015 Commission for Hospital Hygiene and Infection Prevention (KRINKO) recommendations "Prevention and control of catheter-associated urinary tract infections" in the hospitals in Frankfurt/Main, Germany.

Aim: The Commission for Hospital Hygiene and Infection Prevention (KRINKO) updated the recommendations for the prevention of catheter-associated urinary tract infections in 2015. This article will describe the implementation of these recommendations in Frankfurt’s hospitals in autumn, 2015.Material and methods: In two non-ICU wards of each of Frankfurt’s 17 hospitals, inspections were performed using a checklist based on the new KRINKO recommendations. In one large hospital, a total of 5 wards were inspected. The inspections covered the structure and process quality (operating instructions, training, indication, the placement and maintenance of catheters) and the demonstration of the preparation for insertion of a catheter using an empty bed and an imaginary patient, or insertion in a model.Results: Operating instructions were available in all hospital wards; approximately half of the wards regularly performed training sessions. The indications were largely in line with the recommendations of the KRINKO. Alternatives to urinary tract catheters were available and were used more often than the urinary tract catheters themselves (15.9% vs. 13.5%). In accordance with the recommendations, catheters were placed without antibiotic prophylaxis or the instillation of antiseptic or antimicrobial substances or catheter flushing solutions. The demonstration of catheter placement was conscientiously performed. Need for improvement was seen in the daily documentation and the regular verification of continuing indication for a urinary catheter, as well as the omission of regular catheter change.Conclusion: Overall, the recommendations of the KRINKO on the prevention of catheter-associated urinary tract infections were adequately implemented. However, it cannot be ruled out that in situations with time pressure and staff shortage, the handling of urinary tract catheters may be of lower quality than that observed during the inspections, when catheter insertion was done by two nurses. Against this background, a sufficient number of qualified staff and regular ward rounds by the hygiene staff appear recommendable.

In Vitro Assessment of the Antimicrobial Efficacy of Optimized Nitroglycerin-Citrate-Ethanol as a Nonantibiotic, Antimicrobial Catheter Lock Solution for Prevention of Central Line-Associated Bloodstream Infections.

The rapid, broad-spectrum, biofilm-eradicating activity of the combination of 0.01% nitroglycerin, 7% citrate, and 20% ethanol and its potential as a nonantibiotic, antimicrobial catheter lock solution (ACLS) were previously reported. Here, a nitroglycerin-citrate-ethanol (NiCE) ACLS optimized for clinical assessment was developed by reducing the nitroglycerin and citrate concentrations and increasing the ethanol concentration. Biofilm-eradicating activity was sustained when the ethanol concentration was increased from 20 to 22% which fully compensated for reducing the citrate concentration from 7% to 4% as well as the nitroglycerin concentration from 0.01% to 0.0015% or 0.003%. The optimized formulations demonstrated complete and rapid (2 h) eradication of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-intermediate Staphylococcus aureus (VISA), methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant enterococci (VRE), multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Klebsiella pneumoniae, MDR Enterobacter cloacae, MDR Acinetobacter baumannii, MDR Escherichia coli, MDR Stenotrophomonas maltophilia, Candida albicans, and Candida glabrata biofilms. The optimized NiCE lock solutions demonstrated anticoagulant activities comparable to those of heparin lock solutions. NiCE lock solution was significantly more effective than taurolidine-citrate-heparin lock solution in eradicating biofilms of Staphylococcus aureus and Candida glabrata The optimized, nonantibiotic, heparin-free NiCE lock solution demonstrates rapid broad-spectrum biofilm eradication as well as effective anticoagulant activity, making NiCE a high-quality ACLS candidate for clinical assessment.

Surface modification of a polyethylene film for anticoagulant and antimicrobial catheter

A functional anticoagulant and antibacterial coating for polyethylene (PE) films is described. The stepwise preparation of this nanocomposite surface coating involves O2 plasma etching of PE film, carbodiimide coupling of cysteamine to the etched PE film, binding of Ag to sulfhydryl groups of cysteamine, and assembly of heparin capped AgNPs on the PE film. The nanocomposite film and its components were characterized by 1H-nuclear magnetic resonance spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and field emission-scanning electron microscopy. The resulting PE films demonstrate anticoagulant activity using a hemoglobin whole blood clotting assay, and anti-bacterial activity against Bacillus cereus 3551 (Gram-positive) and Escherichia coli BL21 (Gram-negative) bacteria. The hydrophilicity of the heparin coated PE was determined by contact angle measurements; and the stability of the nanocomposite film, with respect to Ag leaching, was assessed by atomic absorption spectroscopy.

Efficacy of antimicrobial impregnated urinary catheter in thwarting foreign body associated urinary tract infections caused by Pseudomonas aeruginosa

Event Abstract Back to Event Efficacy of antimicrobial impregnated urinary catheter in thwarting foreign body associated urinary tract infections caused by Pseudomonas aeruginosa Hina Saini1, Sanjay Chhibber1 and Kusum Harjai1 1 Panjab University, Microbiology, India Introduction: Catheter associated urinary tract infections (CAUTIs) are rising exponentially around the globe; especially in intensive care units. The formation of biofilm on the surface of an indwelling urinary catheter (UC) marks the onset of CAUTI. Treatment of CAUTI/eradication of biofilm poses an intricate challenge to clinicians and researchers since bacteria within biofilm have increased protection against host immune response and resistance to antimicrobials. Biofilm-associated bacteria on the surface of UC produce quorum sensing (QS) signal molecules which regulate the expression of genes required for biofilm formation. Attenuation of QS, which in turn regulates biofilm production, seems to be a novel approach to curb CAUTI. The present study was thus designed with a preventive strategy to generate a biomaterial by impregnating a silicone UC with combination of azithromycin (AZM) and ciprofloxacin (CIP) and testing its efficacy in-vitro against Pseudomonas aeruginosa. Materials and Methods: Medical grade silicone tubing (0.30mm X 0.64mm) was impregnated with antimicrobials: 3% CIP and 6% AZM. In-vitro efficacy was assessed for control and AZM-CIP impregnated UC against P. aeruginosa standard strain PAO1 using serial plate transfer test (SPTT), in-vitro biofilm colonization, durability test, scanning electron microscopy (SEM) to visualise biofilm and shelf-life test. Results and Discussion: SPTT of AZM-CIP impregnated UC revealed prominent zones of inhibition (> 30mm) against P. aeruginosa PAO1 during testing period of one month and no bacterial growth was observed around or under the UC. These results indicate prolonged antimicrobial activity of these catheters with sustained diffusion of drugs and absence of resistance development since no bacteria was found attached to catheters following continuous exposure to heavy inoculum of P. aeruginosa. AZM-CIP impregnated UC showed complete inhibition of bacterial colonization and biofilm formation after 24h exposure to P. aeruginosa PAO1. These findings suggest anti-adherence activity of catheters. AZM-CIP impregnated UC were tested for durability by dipping in sterile human urine for 4 weeks simulating biological conditions. The results showed significant decline in biofilm formation over 4 weeks suggesting longer durability. These findings were further confirmed by SEM which showed limited bacterial cells within disrupted biofilm on the surface of antimicrobial impregnated UC as compared with fully grown intact biofilm on the surface of control catheters. Additionally, AZM-CIP impregnated UC showed complete inhibition of biofilm formation at quarterly intervals displaying stable real-time shelf life for one year. Conclusion: AZM-CIP impregnated UC demonstrated prolonged duration of antimicrobial and antibiofilm activity. The present study bring out the fact that synergistic combination of currently available antibiotics AZM and CIP may be usefully applied to generate a biomaterial by impregnating these drugs into a UC to prevent bacterial colonization and biofilm formation. Such a catheter would be beneficial in clinical situations, especially in long-term foreign body associated urinary tract infections. This work was funded by University Grants Commission (UGC), New Delhi, India (F1-17.1/2013-14/MANF-2013-14-SIK-CHA-22060/(SA-III/Website). We thank Sophisticated Analytical Instrumentation Facility (SAIF), Panjab University, Chandigarh for their kind support in Scanning Electron Microscopy

Antimicrobial-impregnated catheters for the prevention of catheter-related bloodstream infections.

Central venous catheters are commonly used in critically ill patients. Such catheterization may entail mechanical and infectious complications. The interest in catheter-related infection lies in the morbidity, mortality and costs that it involved. Numerous contributions have been made in the prevention of catheter-related infection and the current review focuses on the possible current role of antimicrobial impregnated catheters to reduce catheter-related bloodstream infections (CRBSI). There is evidence that the use of chlorhexidine-silver sulfadiazine (CHSS), rifampicin-minocycline, or rifampicin-miconazol impregnated catheters reduce the incidence of CRBSI and costs. In addition, there are some clinical circumstances associated with higher risk of CRBSI, such as the venous catheter access and the presence of tracheostomy. Current guidelines for the prevention of CRBSI recommended the use of a CHSS or rifampicin-minocycline impregnated catheter in patients whose catheter is expected to remain in place > 5 d and if the CRBSI rate has not decreased after implementation of a comprehensive strategy to reduce it.