The efficacy of noble metal alloy urinary catheters in reducing catheter-associated urinary tract infection

Prevention of urinary tract infection using a silver alloy hydrogel-coated catheter in critically ill patients: A single-center prospective randomized controlled study

Background

A new type of silver alloy hydrogel-coated (SAH) catheter has been shown to prevent bacterial adhesion and colonization by generating a microcurrent, and to block the retrograde infection pathway. However, these have only been confirmed in ordinary patients. This study aims to evaluate the effectiveness of a SAH catheter for preventing urinary tract infections in critically ill patients.

Methods

This was a prospective single-center, single-blind, randomized, controlled study. A total of 132 patients requiring indwelling catheterization in the intensive care unit (ICU) of the First Affiliated Hospital of the University of Science and Technology of China between October 2022 and February 2023 and who met the study inclusion/exclusion criteria were randomly divided into two groups. Patients in the SAH catheter group received a SAH catheter, while patients in the conventional catheter group received a conventional siliconized latex Foley catheter. The main outcome measure was the incidence of catheter-associated urinary tract infections (CAUTIs). Secondary outcome indicators included urine positivity for white blood cells and positive urine cultures on 3 days, 7 days, 10 days, and 14 days after catheterization, number of viable bacteria in the catheter biofilm on day 14, pathogenic characteristics of positive urine cultures, length of ICU stay, overall hospital stay, ICU mortality, and 28-day mortality. All the data were compared between the two groups.

Results

A total of 68 patients in the conventional catheter group and 64 patients in the SAH catheter group were included in the study. On day 7 after catheter placement, the positivity rate for urinary white blood cells was significantly higher in the conventional catheter group than in the SAH catheter group (33.8% vs. 15.6%, P=0.016). On day 10, the rates of positive urine cultures (27.9% vs. 10.9%, P=0.014) and CAUTIs (22.1% vs. 7.8%, P=0.023) were significantly higher in the conventional catheter group than in the SAH catheter group. On day 14, the numbers of viable bacteria isolated from the catheter tip ([3.21±1.91]×106 colony-forming units [cfu]/mL vs. [7.44±2.22]×104 cfu/mL, P <0.001), balloon segment ([7.30±1.99]×107 cfu/mL vs. [3.48±2.38]×105 cfu/mL, P <0.001), and tail section ([6.41±2.07]×105 cfu/mL vs. [8.50±1.46]×103 cfu/mL, P <0.001) were significantly higher in the conventional catheter group than in the SAH catheter group. The most common bacteria in the urine of patients in both groups were Escherichia coli (n=13) and Pseudomonas aeruginosa (n=6), with only one case of Candida in each group. There were no significant differences between the two groups in terms of ICU hospitalization time, total hospitalization time, ICU mortality, and 28-day mortality.

Conclusion

SAH catheters can effectively inhibit the formation of catheter-related bacterial biofilms in critically ill patients and reduce the incidence of CAUTIs, compared with conventional siliconized latex Foley catheters; however, regular replacement of the catheter is still necessary.

Fabrication of antibacterial polydopamine-carboxymethyl cellulose-Ag nanoparticle hydrogel coating for urinary catheters

Urinary tract infections caused by catheter insertion are prevalent in hospital clinics, which can induce serious complications such as bacteriuria and sepsis, and even lead to patient death. The disposable catheters currently used in clinical practice suffer from poor biocompatibility and high infection rate. In this paper, we developed a polydopamine (PDA)-carboxymethylcellulose (CMC)-Ag nanoparticles (AgNPs) coating with both good antibacterial and anti-adhesion properties to bacteria on the surfaces of a disposable medical latex catheter by a simple dipping method. The antibacterial efficiency of the coated catheters against Gram-negative E. coli and Gram-positive S. aureus bacteria was evaluated with both inhibition zone tests and fluorescence microscopy. Compared with the untreated catheter, the PDA-CMC-AgNPs coated catheters showed both good antibacterial and anti-adhesion properties to bacteria, which inhibited the adhesion of live bacteria and dead bacteria by 99.0% and 86.6%, respectively. This novel PDA-CMC-AgNPs composite hydrogel coating has great potential in applications in catheters and other biomedical devices to reduce infections.

Evaluating the Potential of a New Low-Profile Urinary Catheter in Preventing Catheter-Associated Urinary Tract Infections: A Prospective Randomized Blinded Clinical Trial

Aim

To investigate the efficacy of a new low-profile catheter on incidence of the catheter-associated urinary tract infections (CAUTI) in comatose patients admitted to the intensive care unit.

Background

Catheter-induced urothelial injury is a key component in the development of urinary tract infections in catheterized patients.

Methods

In this prospective randomized blinded clinical trial, 80 patients requiring indwelling urinary catheterization were equally randomized to either the standard Foley catheter (control) or the low-profile catheter (experimental) group. The signs of urinary tract infection for comatose patients were considered (ie, ≥105 of colony-forming unit/milliliter of urine, hematuria, serum leukocytes, and body temperature) and recorded at baseline and on days 3 and 5 after catheterization. The analysis of covariance was applied by the SPSS-20 software at a 95% confidence level.

Results

An increasing proportion of patients with elevated urinary colony counts were seen in the Foley catheter group compared with the low-profile catheter group (12.5% vs 5%). However, there were no between-group differences in the urinary colony counts and body temperature after controlling for antibiotic doses and fluid intake. Patients in the low-profile catheter group had significantly lower rates of hematuria and serum leukocytes than those in the Foley catheter group.

Conclusion

A newly designed low-profile urinary catheter has demonstrated a trend toward reducing the incidence of CAUTI in patients with indwelling urinary catheters. Further studies with larger sample sizes and follow-up are needed to confirm the benefits.

Use of a Novel Anti-Infective Noble Metal Alloy-Coated Titanium Orthopedic Nail in Patients with Open Fractures: A Case Series from Malaysia

Fracture-related infection is a serious complication in orthopedic surgery with severe consequences for the patient. We evaluated whether a novel noble metal nail-coating technology can prevent bacterial adhesion and biofilm formation without interfering with bony union. In this retrospective, single-center case series, we described the incidence of fracture-related infections and bony union achievement in patients who had Gustilo type IIIa or IIIb femoral or tibial fractures treated with noble metal alloy-coated titanium nails. Patients were treated between January 2017 and January 2019 at the Sultanah Aminah Hospital, Johor Bahru, Malaysia. Information on fracture-related infections and bone healing assessments was collected from patient records. Additionally, three independent experts retrospectively reviewed patient X-ray images from follow-up visits to further evaluate bony union achievement. Thirty-five patients were included. Infection developed in 3/35 (8.6%) patients; all cases were resolved by antibiotic therapy. Radiographs were available for 32 patients; these confirmed the presence of bone healing in 30/32 (93.8%) patients. However, according to patient records, bony union was achieved in all patients. No safety issues were recorded. This case series suggests that a noble metal alloy-coated titanium nail can prevent infection and facilitate bony union achievement in patients undergoing surgery for severe open fractures.

A Novel Device-Integrated Drug Delivery System for Local Inhibition of Urinary Tract Infection

Background: Catheter-associated urinary tract infection (CAUTI) is a frequent community-acquired infection and the most common nosocomial infection. Here, we developed a novel antimicrobial catheter concept that utilizes a silicone-based interpenetrating polymer network (IPN) as balloon material to facilitate a topical slow-release prophylaxis of antibacterial agents across the balloon to the urinary bladder.

Methods: The balloon material was achieved by modifying low shore hardness silicone tubes with a hydrogel interpenetrating polymer in supercritical CO₂ using the sequential method. Release properties and antibacterial efficacy of the IPN balloon treatment concept was investigated in vitro and in a porcine CAUTI model developed for the study. In the latter, Bactiguard Infection Protection (BIP) Foley catheters were also assessed to enable benchmark with the traditional antimicrobial coating principle.

Results: Uropathogenic Escherichia coli was undetectable in urinary bladders and on retrieved catheters in the IPN treatment group as compared to control that revealed significant bacteriuria (>10⁵ colony forming units/ml) as well as catheter-associated biofilm. The BIP catheters failed to prevent E. coli colonization of the bladder but significantly reduced catheter biofilm formation compared to the control.

Conclusion: The IPN-catheter concept provides a novel, promising delivery route for local treatment in the urinary tract.

Preventive Measures and Management of Catheter-Associated Urinary Tract Infection in Adult Intensive Care Units in Saudi Arabia

Catheter-associated Urinary Tract Infection (CAUTI) has been studied worldwide as part of device-related healthcare infection. CAUTI is one of the most commonly reported infections in the literature, which occurs during clinical practice in Intensive Care Units (ICUs) and non-ICU departments. Many studies have covered the CAUTI rate in Saudi Arabia mainly in the ICU covering single or multiple hospitals as surveillance for device-related infections in the ICU. Few studies have conducted an interventional approach that examined the implementation of infection control protocols and then compared them to international practice as a standard. This review aims to explore the literature to provide insight into the infection control practices that have been reported in Saudi Arabia during the last two decades on the preventive measures and clinical consequences of CAUTIs. Very few studies have recorded the pattern of resistant microorganisms that burdens clinical practice in ICUs concerning CAUTIs. Only one study compared the type of catheter materials and discussed the effect of these materials on reducing CAUTIs. It is essential to cover catheter utilization and to understand how a sufficient infection control protocol with educational programs for healthcare personnel can transform practice, for the better, regarding CAUTI rates in Saudi hospitals. There is a demand for more interventional and epidemiological studies on the causes and factors affecting the rate of CAUTI in the area. Studies may help reduce the CAUTI incidence rate, which consequently reduces the costs and morbidity associated with this type of infection and other healthcare-related infections.

Foley catheter with noble metal alloy coating for preventing catheter-associated urinary tract infections: a large, multi-center clinical trial

Background

Catheter-associated urinary tract infections (CAUTI) are among the most frequent healthcare-associated infections in the world. They are associated with increased mortality, prolonged hospital stay and increased healthcare costs. The objective of this study was to evaluate the efficacy of the noble metal alloy (NMA) coated BIP Foley Catheter in preventing the incidence of symptomatic CAUTI in a large cohort of patients in India.

Methods

This multi-center, prospective study included 1000 adult patients admitted to six hospitals across India for urology, surgery and ICU requiring urethral catheterization and admission for ≥ 48 h. Patients were allocated to the NMA-coated BIP Foley Catheter group or a non-coated control catheter group, with a randomization ratio of 3:1. CAUTI surveillance was conducted at study entry, upon catheter removal, and 2 days after catheter removal. For statistical analysis, categorical data (e.g. gender) were compared using the chi-square or Fischer test, and numerical data were compared using the two-sample t-test. Associations were evaluated using logistic regression.

Results and conclusions

The incidence of symptomatic CAUTI was reduced by 69% in the BIP Foley Catheter group compared to the control group (6.5 vs 20.8 CAUTI/1000 catheter days), with an incidence rate ratio of 0.31 (95% confidence interval: 0.21–0.46; p < 0.001). A reduction in the cumulative CAUTI incidence was evident in the BIP Foley Catheter group within 3 days after catheterization; this reduction was maintained up to ~ 30 days, and the largest reductions were seen between 3 and 11 days. There were no serious adverse events related to either catheter, and the percentage of patients with ≥ 1 adverse event was significantly lower in the NMA-coated BIP Foley Catheter group than in the control group (21.6% vs. 48.4%; p = 0.001). In conclusion, the NMA-coated BIP Foley Catheter was effective in reducing CAUTI and was well tolerated, with a lower incidence of adverse events compared to the uncoated catheter.

Trial registration This study was registered prospectively (28 September 2015) in the Clinical Trials Registry of India (trial number CTRI/2015/09/006220; http://ctri.nic.in/Clinicaltrials/showallp.php?mid1=12631&EncHid=&userName=bactiguard).

A Glance at Antimicrobial Strategies to Prevent Catheter-Associated Medical Infections

Urinary and intravascular catheters are two of the most used invasive medical devices; however, microbial colonization of catheter surfaces is responsible for most healthcare-associated infections (HAIs). Several antimicrobial-coated catheters are available, but recurrent antibiotic therapy can decrease their potential activity against resistant bacterial strains. The aim of this Review is to question the actual effectiveness of currently used (coated) catheters and describe the progress and promise of alternative antimicrobial coatings. Different strategies have been reviewed with the common goal of preventing biofilm formation on catheters, including release-based approaches using antibiotics, antiseptics, nitric oxide, 5-fluorouracil, and silver as well as contact-killing approaches employing quaternary ammonium compounds, chitosan, antimicrobial peptides, and enzymes. All of these strategies have given proof of antimicrobial efficacy by modifying the physiology of pathogens or disrupting their structural integrity. The aim for synergistic approaches using multitarget processes and the combination of both antifouling and bactericidal properties holds potential for the near future. Despite intensive research in biofilm preventive strategies, laboratorial studies still present some limitations since experimental conditions usually are not the same and also differ from biological conditions encountered when the catheter is inserted in the human body. Consequently, in most cases, the efficacy data obtained from in vitro studies is not properly reflected in the clinical setting. Thus, further well-designed clinical trials and additional cytotoxicity studies are needed to prove the efficacy and safety of the developed antimicrobial strategies in the prevention of biofilm formation at catheter surfaces.

Role of noble metal-coated catheters for short-term urinary catheterization of adults: a meta-analysis

OBJECTIVE

To evaluate the efficacy of noble-metal coated catheters in reducing catheter-associated urinary tract infections (CAUTI) in adult patients requiring short term catheterization.

METHODS

An electronic literature search of PubMed, BioMed Central, Embase, Scopus, CENTRAL (Cochrane Central Register of Controlled Trials) and Google scholar was carried out from inception to 10th October 2019. Any prospective study or randomized controlled trial (RCT) on adult patients comparing noble-metal coated urinary catheters with any standard catheter and evaluating the incidence of CAUTI or bacteriuria was included.

RESULTS

A total of 13 studies were included in the systematic review. 12 were RCTs and one was a prospective cross-over trial. Catheters employed in the study group were grouped into two sub-groups: Silver alloy coated or Noble metal alloy-coated (Gold, Silver, and Palladium) catheters. Bacteriuria was the most commonly studied outcome variable across trials. Meta-analysis indicated that silver alloy-coated catheters (RR 0.63, 95%CI 0.44-0.90, P = 0.01; I2 = 72%) and noble metal alloy catheters (RR 0.58, 95%CI 0.41-0.81, P = 0.001; I2 = 0%) significantly reduce the risk of bacteriuria. Sub-group analysis based on the duration of catheterization demonstrated that silver alloy catheters reduce the risk of bacteriuria with >1week of catheterization (RR 0.46, 95%CI 0.26-0.81, P = 0.007; I2 = 63%). Symptomatic CAUTI was evaluated only in four studies with variable results. The quality of the included studies was not high.

CONCLUSIONS

Our review indicates that bacteriuria may be reduced with the use of noble metal-coated catheters during short-term catheterization of adults, however, the quality of evidence is not high. It is not clear if these catheters reduce the risk of symptomatic CAUTI. Further homogenous RCTs are needed to provide clarity.

Long-term use of noble metal alloy coated urinary catheters reduces recurrent CAUTI and decreases proinflammatory markers

Background:

The objective of this study was to investigate a case of a permanently (suprapubic) catheterized woman with neurogenic bladder dysfunction. The patient had suffered from recurrent catheter-associated urinary tract infections (CAUTIs) since 2009, despite several prevention approaches and attempts. In 2013, the patient’s catheter was substituted for the BIP Foley Catheter, coated with a noble metal alloy (NMA) of gold, silver, and palladium.

Method:

This is a retrospective–prospective clinical case study covering 4 years history for the control catheters and up to 2.5 years for the anti-infective BIP Foley Catheter. CAUTI incidences, symptoms, antibiotics, catheter performance, and comfort were evaluated. Levels of proinflammatory cytokines were measured pre- and post-substitution to BIP Foley Catheter in urine of the case and of four other permanently catheterized patients. In addition, the levels of noble metals were assessed in urine of the case subject during use of the BIP Foley Catheter.

Results:

While using control catheters, the patient experienced symptomatic CAUTIs requiring antibiotics almost every month for 4 years. After 1 month with the BIP Foley Catheter, the symptoms disappeared, and the patient remained free of symptomatic CAUTIs and antibiotic treatment for the following 2.5 years, despite bacteriuria. The patient was satisfied with the comfort during insertion, use, and removal of the BIP Foley Catheter. Urinary levels of the proinflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor alpha (TNFα) decreased towards normal levels post catheter type substitution. Traces of noble metals detected in a few urine samples were ⩽4% of the permitted daily exposure. The levels of the noble metals gold, silver, and palladium remaining on the BIP Foley Catheter after use were the same as for unused catheters.

Conclusion:

Long-term use of a NMA-coated catheter was associated with cessation of frequent CAUTIs. The catheter was experienced as comfortable and inflammatory markers were reduced with time. The coating was stable, with no significant metal release into urine and is therefore safe for patient use.

Efficacy of bladder irrigation in preventing urinary tract infections associated with short-term catheterization in comatose patients: A randomized controlled clinical trial

BACKGROUND

Bladder irrigation can be performed to prevent catheter-associated urinary tract infections (CAUTI), but its efficacy has been not reported in short-term indwelling urinary catheterization. This clinical trial aimed to examine the efficacy of bladder irrigation with normal saline solution in preventing CAUTI in comatose patients admitted to intensive care units.

MATERIALS AND METHODS

Eligible patients were randomized to the experimental group or control group. The experimental group received daily bladder irrigation with 450 cc sterile normal saline, in 3 150-mL doses, for 3 consecutive days. Data on signs of CAUTI, including urine culture, axillary body temperature (primary outcomes), and other urine and blood parameters (secondary outcomes) were obtained at baseline and 5 days later.

RESULTS

Results of group comparisons and logistic regression analysis that controlled for fluid intake showed that the risk of CAUTI decreased by 99% in the experimental group compared with the control group (odds ratio, 0.01; P < .001). Additional findings indicated a decrease in axillary body temperature and improvements in urine appearance, urinary red cells and white cells, and erythrocyte sedimentation rates and white-cell counts in the blood following bladder irrigation.

CONCLUSION

Daily bladder irrigation with normal saline during 3 days demonstrated efficacy in preventing CAUTI in comatose patients.