Emerging medical and engineering strategies for the prevention of long-term indwelling catheter blockage

Medical Device-Associated Biofilm Infections and Multidrug-Resistant Pathogens

Medical devices such as venous catheters (VCs) and urinary catheters (UCs) are widely used in the hospital setting. However, the implantation of these devices is often accompanied by complications. About 60 to 70% of nosocomial infections (NIs) are linked to biofilms. The main complication is the ability of microorganisms to adhere to surfaces and form biofilms which protect them and help them to persist in the host. Indeed, by crossing the skin barrier, the insertion of VC inevitably allows skin flora or accidental environmental contaminants to access the underlying tissues and cause fatal complications like bloodstream infections (BSIs). In fact, 80,000 central venous catheters-BSIs (CVC-BSIs)-mainly occur in intensive care units (ICUs) with a death rate of 12 to 25%. Similarly, catheter-associated urinary tract infections (CA-UTIs) are the most commonlyhospital-acquired infections (HAIs) worldwide.These infections represent up to 40% of NIs.In this review, we present a summary of biofilm formation steps. We provide an overview of two main and important infections in clinical settings linked to medical devices, namely the catheter-asociated bloodstream infections (CA-BSIs) and catheter-associated urinary tract infections (CA-UTIs), and highlight also the most multidrug resistant bacteria implicated in these infections. Furthermore, we draw attention toseveral useful prevention strategies, and advanced antimicrobial and antifouling approaches developed to reduce bacterial colonization on catheter surfaces and the incidence of the catheter-related infections.

A comprehensive status update on modification of foley catheter to combat catheter-associated urinary tract infections and microbial biofilms

Present-day healthcare employs several types of invasive devices, including urinary catheters, to improve medical wellness, the clinical outcome of disease, and the quality of patient life. Among urinary catheters, the Foley catheter is most commonly used in patients for bladder drainage and collection of urine. Although such devices are very useful for patients who cannot empty their bladder for various reasons, they also expose patients to catheter-associated urinary tract infections (CAUTIs). Catheter provides an ideal surface for bacterial colonization and biofilm formation, resulting in persistent bacterial infection and severe complications. Hence, rigorous efforts have been made to develop catheters that harbour antimicrobial and anti-fouling properties to resist colonization by bacterial pathogens. In this regard, catheter modification by surface functionalization, impregnation, blending, or coating with antibiotics, bioactive compounds, and nanoformulations have proved to be effective in controlling biofilm formation. This review attempts to illustrate the complications associated with indwelling Foley catheters, primarily focussing on challenges in fighting CAUTI, catheter colonization, and biofilm formation. In this review, we also collate scientific literature on catheter modification using antibiotics, plant bioactive components, bacteriophages, nanoparticles, and studies demonstrating their efficacy through in vitro and in vivo testing.

Temperature and pH Stimuli-Responsive System Delivers Location-Specific Antimicrobial Activity with Natural Products

Smart materials with controlled stimuli-responsive functions are at the forefront of technological development. In this work, we present a generic strategy that combines simple components, physicochemical responses, and easy fabrication methods to achieve a dual stimuli-responsive system capable of location-specific antimicrobial cargo delivery. The encapsulated system is fabricated by combining a biocompatible inert polymeric matrix of poly(dimethylsiloxane) (PDMS) and a bioactive cargo of saturated fatty acids. We demonstrate the effectiveness of our approach to deliver antimicrobial activity for the model bacteria Escherichia coli. The system responds to two control variables, temperature and pH, delivering two levels of antimicrobial response under distinct combinations of stimuli: one response toward the planktonic media and another response directly at the surface for sessile bacteria. Spatially resolved Raman spectroscopy alongside thermal and structural material analysis reveals that the system not only exhibits ON/OFF states but can also control relocation and targeting of the active cargo toward either the surface or the liquid media, leading to different ON/OFF states for the planktonic and sessile bacteria. The approach proposed herein is technologically simple and scalable, facing low regulatory barriers within the food and healthcare sectors by using approved components and relying on fundamental chemical processes. Our results also provide a proof-of-concept platform for the design and easy fabrication of delivery systems capable of operating as Boolean logic gates, delivering different responses under different environmental conditions.

Anti-infective Efficacy of Duloxetine against Catheter-Associated Urinary Tract Infections Caused by Gram-Positive Bacteria

Catheter-associated urinary tract infections (CAUTIs) frequently occur following the insertion of catheters in hospitalized patients, often leading to severe clinical complications. These complications are exacerbated by biofilm-forming organisms such as Staphylococcus aureus, contributing to the emergence of multidrug-resistant (MDR) strains, which complicates treatment strategies. This study aims to investigate the antibacterial, antibiofilm, and antiadhesive properties of duloxetine against S. aureus in the context of CAUTI. Our findings demonstrate that duloxetine exhibits significant antibacterial activity, as evidenced by the agar diffusion method. A minimal inhibitory concentration (MIC) of 37.5 μg/mL was established using the microdilution method. Notably, duloxetine displayed inhibitory effects against biofilm formation on polystyrene surfaces up to its MIC level, as demonstrated by the crystal violet method. Intriguingly, the study also revealed that duloxetine could prevent biofilm formation at lower concentrations and reduce mature biofilms, as confirmed by scanning electron microscopy (SEM) and quantitative biofilm assays. Furthermore, duloxetine-coated silicone catheter tubes exhibited antibacterial properties against S. aureus in a bladder model, visualized by confocal laser scanning microscopy (CLSM) and corroborated through FDA and PI staining, highlighting noticeable morphological changes in S. aureus post-treatment. In conclusion, this study presents duloxetine as a promising alternative agent with antibacterial and antiadhesive properties against S. aureus in the prevention and management of CAUTI, warranting further exploration in the clinical setting.

Betainization of Polydopamine/Polyethylenimine Coating for Universal Zwitterionization

Biofoulants can adhere to multiple surfaces, degrading the performance of medical devices and industrial facilities and/or causing nosocomial infection. The surface immobilization of zwitterionic materials can prevent the initial attachment of the foulants but lacks extensive implementation. Herein, we propose a facile, universal, two-step surface modification strategy to improve fouling resistance. In the first step, the substrates were immersed in a codeposition solution containing dopamine and branched polyethylenimine (PEI) to form a "primer" layer (PDA/PEI). In the second step, the primer layers were treated with 1,3-propane sultone to betainize primary/secondary/tertiary amine moieties of PEI, generating zwitterions on substrates. After betainization, PS-grafted PDA/PEI (PDA/PEI/S) via a ring-opening alkylation reaction manifested changes in wettability. X-ray photoelectron spectroscopy revealed the presence of zwitterionic moieties on the PDA/PEI/S surfaces. Further investigations using ellipsometry and atomic force microscopy were conducted to scrutinize the relation among the PEI content, film thickness, primer stability, and betainization. As a result, zwitterion-decorated substrates prepared under optimal conditions can exhibit high resistance against bacterial fouling, achieving a 98.5% reduction in bacterial attachment. In addition, the method shows a substrate-independent property, capable of successfully applying it on organic and inorganic substrates. Finally, the newly developed approach shows excellent biocompatibility, displaying no significant difference compared with blank control samples. Overall, we envision that the facile surface modification strategy can further promote the preparation of zwitterion-decorated materials in the future.

Effect of Cluster Nursing Based on Risk Management Strategy on Urinary Tract Infection in Patients With Severe Craniocerebral Injury

Objective

To observe the effect of cluster nursing based on risk management strategy in the management of urinary tract infection in patients with severe craniocerebral injury.

Methods

A total of 116 patients with severe craniocerebral injury who were admitted to our hospital from March 2019 to March 2021 were included. They were divided into the control group (58 patients) and the observation group (58 patients). The control group received routine nursing care and the observation group received cluster nursing based on risk management strategy. The incidence of catheter-associated urinary tract infection (CAUTI), the results of bacterial culture on the surface of the urinary catheter, the incidence of nursing risk events, the duration of placing the urinary catheter, the length of hospital stay, and hospital costs as well as the patient satisfaction score were compared between the two groups. The knowledge, attitude, and practice scale for prevention of catheter infection and the competence evaluation scale of nurses were used to evaluate the sense-control ability and core competence of the interveners.

Results

The total incidence of CAUTI in the observation group was (6.90%) lower than that in the control group (20.69%) (p < 0.05). The bacterial culture results on the catheter surface of patients in the observation group before and after 6 and 12 h of catheter cleaning were better than those of patients in the control group (p < 0.05). The duration of indwelling urinary catheter, hospitalization time, and hospitalization expenses of patients in the observation group were lower than those of patients in the control group (p < 0.05). The incidence rate of nursing risk events in the observation group was (1.72%) lower than that in the control group (11.86%) (p < 0.05). The overall satisfaction score of patients and the control and core ability scores of nursing staff in the observation group were higher than those in the control group (p < 0.05).

Conclusion

Cluster nursing based on risk management strategy can effectively reduce the incidence of nursing risk events and the probability of UTI in patients with severe craniocerebral injury, shorten the duration of indwelling urinary catheter and hospitalization.

Sonochemically engineered nano-enabled zinc oxide/amylase coatings prevent the occurrence of catheter-associated urinary tract infections

Catheter-associated urinary tract infections (CAUTIs), caused by biofilms, are the most frequent health-care associated infections. Novel antibiofilm coatings are needed to increase the urinary catheters' life-span, decrease the prevalence of CAUTIs and reduce the development of antimicrobial resistance. Herein, antibacterial zinc oxide nanoparticles (ZnO NPs) were decorated with a biofilm matrix-degrading enzyme amylase (AM) and simultaneously deposited onto silicone urinary catheters in a one-step sonochemical process. The obtained nano-enabled coatings inhibited the biofilm formation of Escherichia coli and Staphylococcus aureus by 80% and 60%, respectively, for up to 7 days in vitro in a model of catheterized bladder with recirculation of artificial urine due to the complementary mode of antibacterial and antibiofilm action provided by the NPs and the enzyme. Over this period, the coatings did not induce toxicity to mammalian cell lines. In vivo, the nano-engineered ZnO@AM coated catheters demonstrated lower incidence of bacteriuria and prevent the early onset of CAUTIs in a rabbit model, compared to the animals treated with pristine silicone devices. The nano-functionalization of catheters with hybrid ZnO@AM coatings appears as a promising strategy for prevention and control of CAUTIs in the clinic.

Simultaneous Ultrasound-Assisted Hybrid Polyzwitterion/Antimicrobial Peptide Nanoparticles Synthesis and Deposition on Silicone Urinary Catheters for Prevention of Biofilm-Associated Infections

Nosocomial infections caused by antibiotic-resistant bacteria are constantly growing healthcare threats, as they are the reason for the increased mortality, morbidity, and considerable financial burden due to the poor infection outcomes. Indwelling medical devices, such as urinary catheters, are frequently colonized by bacteria in the form of biofilms that cause dysfunction of the device and severe chronic infections. The current treatment strategies of such device-associated infections are impaired by the resistant pathogens but also by a risk of prompting the appearance of new antibiotic-resistant bacterial mechanisms. Herein, the one-step sonochemical synthesis of hybrid poly(sulfobetaine) methacrylate/Polymyxin B nanoparticles (pSBMA@PM NPs) coating was employed to engineer novel nanoenabled silicone catheters with improved antifouling, antibacterial, and antibiofilm efficiencies. The synergistic mode of action of nanohybridized zwitterionic polymer and antimicrobial peptide led to complete inhibition of the nonspecific protein adsorption and up to 97% reduction in Pseudomonas aeruginosa biofilm formation, in comparison with the pristine silicone. Additionally, the bactericidal activity in the hybrid coating reduced the free-floating and surface-attached bacterial growth by 8 logs, minimizing the probability for further P. aeruginosa spreading and host invasion. This coating was stable for up to 7 days under conditions simulating the real scenario of catheter usage and inhibited by 80% P. aeruginosa biofilms. For the same time of use, the pSBMA@PM NPs coating did not affect the metabolic activity and morphology of mammalian cells, demonstrating their capacity to control antibiotic-resistant biofilm-associated bacterial infections.

Transvaginal closure of urinary bladder opening and Mitrofanoff technique in a neurologically impaired female with chronic indwelling catheter: a case presentation

Background

Chronic catheterization remains the only attractive option in specific circumstances, especially in neurologically impaired patients. Complications produced by the indwelling catheters, like patulous urethra and bladder neck destruction, usually lead to severe incontinence and significant nursing difficulties. Here, we describe a rare case, a urinary bladder opening representing massive and extensive destruction of the urethra and bladder sphincter due to an indwelling catheter.

Case presentation

We present a 46-year-old paraplegic woman complaining of recurrent febrile urinary tract infections and severe urinary incontinence. She suffered from persistent malodorous urine and skin breakdowns from constant urine leakage. The vaginal examination revealed extensive destruction of the urethra and a 10 cm opening permitting the urinary bladder wall to prolapse into the vagina. The patient underwent a combined surgical approach; a transvaginal bladder closure with anterior colporrhaphy and a Mitrofanoff procedure to ensure a continent stoma for future clean intermittent self-catheterization (CISC). The patient is compliant with CISC and, remains continent twelve years after surgery.

Conclusion

This case demonstrates that in the era of CISC, there are still neurologically impaired females suffering from rare but critical adverse effects of indwelling catheters. The urethra and bladder neck erosion represent a demanding treatment assignment. The Mitrofanoff procedure for continent stoma and the transvaginal closure of urinary bladder opening produced a lifesaving potential treatment.

The recent advances in surface antibacterial strategies for biomedical catheters

As one of the most common hospital-acquired infections, catheter-related infections (CRIs) which are caused by microbial colonization lead to increasing morbidity and mortality of patients and life threat for medical staffs. In this case, a variety of efforts have been made to design functional materials to limit bacterial colonization and biofilm formation. In this review, we focus on the recent advances in surface modification strategies of biomedical catheters used to prevent CRIs. The tests for the evaluation of the performances of modified catheters are listed. Future prospects of surface antibacterial strategies for biomedical catheters are also outlined.

Marine Microbial-Derived Antibiotics and Biosurfactants as Potential New Agents against Catheter-Associated Urinary Tract Infections

Catheter-associated urinary tract infections (CAUTIs) are among the leading nosocomial infections in the world and have led to the extensive study of various strategies to prevent infection. However, despite an abundance of anti-infection materials having been studied over the last forty-five years, only a few types have come into clinical use, providing an insignificant reduction in CAUTIs. In recent decades, marine resources have emerged as an unexplored area of opportunity offering huge potential in discovering novel bioactive materials to combat human diseases. Some of these materials, such as antimicrobial compounds and biosurfactants synthesized by marine microorganisms, exhibit potent antimicrobial, antiadhesive and antibiofilm activity against a broad spectrum of uropathogens (including multidrug-resistant pathogens) that could be potentially used in urinary catheters to eradicate CAUTIs. This paper summarizes information on the most relevant materials that have been obtained from marine-derived microorganisms over the last decade and discusses their potential as new agents against CAUTIs, providing a prospective proposal for researchers.

Staff and patient perceptions of a community urinary catheter service

Introduction

Urinary catheters are used extensively throughout healthcare for various reasons including management of urinary tract dysfunction. The purpose of this study was to simultaneously explore both catheter user experience and staff perception of catheter services within community urinary catheter care.

Methods

A questionnaire was conducted to investigate the views of community nursing staff. During the same time period, patients were interviewed about i) catheter-care standards and adherence to guidelines ii) patients' feelings towards their catheter and iii) potential improvements to catheter practices and design.

Results

Sixty-nine staff were surveyed. Although 97% of staff indicated they used local guidelines, in up to 62% of cases findings suggested practices in sending urine samples for culture did not comply with guidelines. Seventy-five percent of staff were satisfied with catheter care, but weaknesses were identified in handover processes, communication between staff and patients, and excessive documentation. Staff results were compared with the findings from interviews of 29 long-term urinary catheter users, demonstrating a higher level of satisfaction with catheter care amongst patients (86%). Patients and staff agreed that generally the impacts of their catheter on personal hygiene, sense of independence, sense of dignity and of patient happiness, were neutral (neither positive nor negative). However, regarding improvements to catheter practices and catheter design; 73% of staff but only 45% of patients suggested improvements in service, while 76% of patients but only 49% of staff suggested improvement in design.

Conclusion

The study reveals general satisfaction with community catheter care, but indicates areas of potential improvements regarding communication, documentation and catheter design. When compared to patient responses, staff overall had a less positive view of patients perception of their relationship with their catheter.

Innovations in indwelling urethral catheterisation

The indwelling urethral catheter remains an integral part of contemporary medical care, despite its significant design shortcomings. Urethral catheterisation is responsible for well-recognised complications including catheter-associated urinary tract infection (CAUTI), catheter-associated urethral injury (CAUI), catheter blockage, and bladder mucosal irritation. In this narrative review, we provide an update on current innovations in urethral catheter design, aimed at safeguarding against these complications. There is an obvious need to improve catheter technology and urologists should support the translation of innovations into clinical practice.

Prevention and management of urinary catheter blockages in community settings

Self-management of long-term urinary catheters can be challenging for patients, and recurrent catheter blockages may cause concern among patients, carers and healthcare professionals. Catheter blockages are a significant challenge for nurses practising in community settings, because frequent and unplanned catheter changes can be costly to healthcare services in terms of time and resources. This article details evidence-based recommendations for the assessment and diagnosis of catheter blockages, as well as the identification of risk factors. It also explains the interventions that can be used to prevent and manage catheter blockages and describes the role of the nurse in supporting patients with a long-term catheter in situ in community settings.