Catheter-associated urinary tract infections

Fibrinolytic-deficiencies predispose hosts to septicemia from a catheter-associated UTI

Catheter-associated urinary tract infections (CAUTIs) are amongst the most common nosocomial infections worldwide and are difficult to treat partly due to development of multidrug-resistance from CAUTI-related pathogens. Importantly, CAUTI often leads to secondary bloodstream infections and death. A major challenge is to predict when patients will develop CAUTIs and which populations are at-risk for bloodstream infections. Catheter-induced inflammation promotes fibrinogen (Fg) and fibrin accumulation in the bladder which are exploited as a biofilm formation platform by CAUTI pathogens. Using our established mouse model of CAUTI, here we identified that host populations exhibiting either genetic or acquired fibrinolytic-deficiencies, inducing fibrin deposition in the catheterized bladder, are predisposed to severe CAUTI and septicemia by diverse uropathogens in mono- and poly-microbial infections. Furthermore, here we found that Enterococcus faecalis, a prevalent CAUTI pathogen, uses the secreted protease, SprE, to induce fibrin accumulation and create a niche ideal for growth, biofilm formation, and persistence during CAUTI.

The Efficacy and Safety of Intrasphincteric Botulinum Toxin-A Injections in Patients with Non-Spinal Cord Injury-Related Detrusor Sphincter Dyssynergia: A Retrospective Study

Botulinum toxin-A (BoNT-A) injections into the external urethral sphincter are an established therapeutic procedure for reducing bladder outlet obstruction in patients with detrusor sphincter dyssynergia (DSD) due to spinal cord injury (SCI). Given the paucity of data on patients with DSD but without SCI, we aimed to assess the efficacy of intrasphincteric BoNT-A injections in this cohort. For this retrospective study, we screened all patients who underwent their first intrasphincteric BoNT-A injection at our institution between 2015 and 2021. The inclusion criteria were patients aged 18 years or older with neurogenic detrusor overactivity (NDO) and DSD with a maximum detrusor pressure (Pdetmax) of >40 cmH2O, confirmed via video-urodynamic studies (VUDS). The primary outcome was a reduction in Pdetmax and detrusor overactivity leak point pressure (DOLPP) during NDO-associated urinary incontinence posttreatment. The secondary outcome was a reduction in patients relying on indwelling urinary catheters posttreatment. We included 13 eligible patients (all male, median age 31 years, with different underlying neurological disorders, except SCI). All underwent intrasphincteric BoNT-A injections with either 100 (n = 7) or 150 (n = 6) units, respectively. Pdetmax during voiding was significantly reduced posttreatment (median 105 vs. 54 cmH2O, p = 0.006), whereas DOLPP remained unchanged (i.e., median 50 cmH2O). While seven patients relied on indwelling urinary catheters pre-treatment, all were catheter-free posttreatment. Intrasphincteric BoNT-A injections in patients with non-SCI related DSD appear feasible for reducing bladder outlet obstruction to a certain degree in this cohort and subsequently for reducing the rate of indwelling catheters.

An Observational Study from Northern India to Evaluate Catheter-associated Urinary Tract Infection in Medical Intensive Care Unit at a Tertiary Care Center

Background

Healthcare-associated infections are the leading cause of morbidity and mortality in hospitalized patients. Catheter-associated urinary tract infection (CAUTI) is a leading infection in ICU settings. This study aims to evaluate the patient and catheter-related factors contributing to the urinary tract infection as well as implementing the preventive measures ultimately curbing down the burden of healthcare-associated infections.

Material and methods

This is a hospital-based observational study conducted in Department of Microbiology, from October 2020 to September 2021. A total of 150 patients admitted to Medical Intensive Care Unit (MICU) with the indwelling urinary catheter were included. Urine samples were collected with proper aseptic precautions and processed within 2 hours of collection. Identification and antimicrobial susceptibility testing of the isolated pathogens was done as per CLSI guidelines 2019.

Results

In this study, the CAUTI rate was 9.4 per 1000 urinary catheter days, while the overall magnitude was 14.67%. It was predominantly reported in 51-70-years age group (34%), and females (63.63%) outnumbered males (36.36%), with Escherichia coli being the commonest pathogen. The highest incidence was reported in the 3rd week of catheterization with diabetes being a predominant risk factor (17.24%).

Conclusion

This study provides baseline data on CAUTI rate, pathogens isolated, and risk factors at our institute. The overall goal is to identify, educate, and implement best-practice measures for prevention and curbing down the incidence rates of catheter-associated urinary tract infections.

How to cite this article

Parihar S, Sharma R, Kinimi SV, Choudhary S. An Observational Study from Northern India to Evaluate Catheter-associated Urinary Tract Infection in Medical Intensive Care Unit at a Tertiary Care Center. Indian J Crit Care Med 2023;27(9):642-646.

Study of Antimicrobial Resistance, Biofilm Formation, and Motility of Pseudomonas aeruginosa Derived from Urine Samples

Pseudomonas aeruginosa causes urinary tract infections associated with catheters by forming biofilms on the surface of indwelling catheters. Therefore, controlling the spread of the bacteria is crucial to preventing its transmission in hospitals and the environment. Thus, our objective was to determine the antibiotic susceptibility profiles of twenty-five P. aeruginosa isolates from UTIs at the Medical Center of Trás-os-Montes and Alto Douro (CHTMAD). Biofilm formation and motility are also virulence factors studied in this work. Out of the twenty-five P. aeruginosa isolates, 16% exhibited multidrug resistance, being resistant to at least three classes of antibiotics. However, the isolates showed a high prevalence of susceptibility to amikacin and tobramycin. Resistance to carbapenem antibiotics, essential for treating infections when other antibiotics fail, was low in this study, Notably, 92% of the isolates demonstrated intermediate sensitivity to ciprofloxacin, raising concerns about its efficacy in controlling the disease. Genotypic analysis revealed the presence of various β-lactamase genes, with class B metallo-β-lactamases (MBLs) being the most common. The bla_NDM, bla_SPM, and bla_VIM-VIM2 genes were detected in 16%, 60%, and 12% of the strains, respectively. The presence of these genes highlights the emerging threat of MBL-mediated resistance. Additionally, virulence gene analysis showed varying prevalence rates among the strains. The exoU gene, associated with cytotoxicity, was found in only one isolate, while other genes such as exoS, exoA, exoY, and exoT had a high prevalence. The toxA and lasB genes were present in all isolates, whereas the lasA gene was absent. The presence of various virulence genes suggests the potential of these strains to cause severe infections. This pathogen demonstrated proficiency in producing biofilms, as 92% of the isolates were found to be capable of doing so. Currently, antibiotic resistance is one of the most serious public health problems, as options become inadequate with the continued emergence and spread of multidrug-resistant strains, combined with the high rate of biofilm production and the ease of dissemination. In conclusion, this study provides insights into the antibiotic resistance and virulence profiles of P. aeruginosa strains isolated from human urine infections, highlighting the need for continued surveillance and appropriate therapeutic approaches.

The catheterized bladder environment promotes Efg1- and Als1-dependent Candida albicans infection

Catheter-associated urinary tract infections (CAUTIs) account for 40% of hospital-acquired infections (HAIs). As 20 to 50% of hospitalized patients receive catheters, CAUTIs are one of the most common HAIs, resulting in increased morbidity, mortality, and health care costs. Candida albicans is the second most common CAUTI uropathogen, yet relative to its bacterial counterparts, little is known about how fungal CAUTIs are established. Here, we show that the catheterized bladder environment induces Efg1- and fibrinogen (Fg)-dependent biofilm formation that results in CAUTI. In addition, we identify the adhesin Als1 as the critical fungal factor for C. albicans Fg-urine biofilm formation. Furthermore, we show that in the catheterized bladder, a dynamic and open system, both filamentation and attachment are required, but each by themselves are not sufficient for infection. Our study unveils the mechanisms required for fungal CAUTI establishment, which may aid in the development of future therapies to prevent these infections.

State of the Art of Non-Invasive Technologies for Bladder Monitoring: A Scoping Review

Bladder monitoring, including urinary incontinence management and bladder urinary volume monitoring, is a vital part of urological care. Urinary incontinence is a common medical condition affecting the quality of life of more than 420 million people worldwide, and bladder urinary volume is an important indicator to evaluate the function and health of the bladder. Previous studies on non-invasive techniques for urinary incontinence management technology, bladder activity and bladder urine volume monitoring have been conducted. This scoping review outlines the prevalence of bladder monitoring with a focus on recent developments in smart incontinence care wearable devices and the latest technologies for non-invasive bladder urine volume monitoring using ultrasound, optical and electrical bioimpedance techniques. The results found are promising and their application will improve the well-being of the population suffering from neurogenic dysfunction of the bladder and the management of urinary incontinence. The latest research advances in bladder urinary volume monitoring and urinary incontinence management have significantly improved existing market products and solutions and will enable the development of more effective future solutions.

'Granulitis': defining a common, biofilm-induced, hyperinflammatory wound pathology

The hard-to-heal (chronic) wound condition, now believed to be inextricably linked to the presence of microbial biofilm, has posed challenges in translating scientific understanding to clinical practice in recent decades. During this time, multiple descriptive terms of the wound pathology have been described, including critical colonisation, biofilm infection and inflammatory stasis. However, the absence of naming this disease state as a specifically identified condition that is tangible to treat has led to some confusion and delay in possible therapeutic approaches. When there is clinical uncertainty of wound status, antibiotics are too often inappropriately administered as a precaution. We therefore propose that introducing the term 'granulitis' (inflamed, unhealthy granulation tissue) could be used to identify the biofilm-induced, persistent inflammatory wound condition. This will help to raise clinician and public awareness of the condition, guide appropriate and prompt local wound hygiene, and encourage allocation of adequate resources to improve wound healing outcomes globally.

Catheter-Associated Urinary Tract Infection (CAUTI)

One of the most prevalent health-related illnesses globally is catheter-associated urinary tract infection (CAUTI). CAUTIs account for almost half of all hospital-acquired diseases. Most of the healthcare-acquired urinary tract infections result from catheter tubes implantation. These tubes connect a collecting system and the urinary bladder via the urethra. These are known as indwelling urinary catheters. The length of catheterization has a key role in starting bacteriuria since biofilm eventually forms on all of these devices. Despite the low percentage of people with bacteriuria who start showing symptoms, there is nevertheless a significant burden associated with these contamination due to the repeated use of indwelling urinary devices. Minimizing indwelling device usage and stopping the catheter as soon as medically possible are the two most crucial preventative measures for bacteriuria and infection when device use is required. Efforts to avoid catheter-acquired urinary infections must be implemented and monitored by infection control guidelines in healthcare institutions. These approaches include monitoring device use, the suitability of device justifications, and problems. Ultimately, technological advancements in device substances that inhibit colony generation will be necessary to avoid these infestations. There is still some way by which we can bring down the increased phenomenon of catheter-associated urinary tract contamination by maintaining hygiene while handling the catheter and patients and keeping the infected patients away or isolated from unaffected patients as a precaution. This article mainly focuses on an overview that helps with discussing prevention, risk factors, diagnosis, control and management of CAUTI.

Nanotechnology as a tool to advance research and treatment of non-oncologic urogenital diseases

Nanotechnology represents an expanding area of research and innovation in almost every field of science, including Medicine, where nanomaterial-based products have been developed for diagnostic and therapeutic applications. Because of their small, nanoscale size, these materials exhibit unique physical and chemical properties that differ from those of each component when considered in bulk. In Nanomedicine, there is an increasing interest in harnessing these unique properties to engineer nanocarriers for the delivery of therapeutic agents. Nano-based drug delivery platforms have many advantages over conventional drug administration routes as this technology allows for local and transdermal applications of therapeutics that can bypass the first-pass metabolism, improves drug efficacy through encapsulation of hydrophobic drugs, and allows for a sustained and controlled release of encapsulated agents. In Urology, nano-based drug delivery platforms have been extensively investigated and implemented for cancer treatment. However, there is also great potential for use of nanotechnology to treat non-oncologic urogenital diseases. We provide an update on research that is paving the way for clinical translation of nanotechnology in the areas of erectile dysfunction (ED), overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), and catheter-associated urinary tract infections (CAUTIs). Overall, preclinical and clinical studies have proven the utility of nanomaterials both as vehicles for transdermal and intravesical delivery of therapeutic agents and for urinary catheter formulation with antimicrobial agents to treat non-oncologic urogenital diseases. Although clinical translation will be dependent on overcoming regulatory challenges, it is inevitable before there is universal adoption of this technology to treat non-oncologic urogenital diseases.

Retardation of Bacterial Biofilm Formation by Coating Urinary Catheters with Metal Nanoparticle-Stabilized Polymers

Urinary catheter infections remain an issue for many patients and can complicate their health status, especially for individuals who require long-term catheterization. Catheters can be colonized by biofilm-forming bacteria resistant to the administered antibiotics. Therefore, this study aimed to investigate the efficacy of silver nanoparticles (AgNPs) stabilized with different polymeric materials generated via a one-step simple coating technique for their ability to inhibit biofilm formation on urinary catheters. AgNPs were prepared and characterized to confirm their formation and determine their size, charge, morphology, and physical stability. Screening of the antimicrobial activity of nanoparticle formulations and determining minimal inhibitory concentration (MIC) and their cytotoxicity against PC3 cells were performed. Moreover, the antibiofilm activity and efficacy of the AgNPs coated on the urinary catheters under static and flowing conditions were examined against a clinical isolate of Escherichia coli. The results showed that the investigated polymers could form physically stable AgNPs, especially those prepared using polyvinyl pyrrolidone (PVP) and ethyl cellulose (EC). Preliminary screening and MIC determinations suggested that the AgNPs-EC and AgNPs-PVP had superior antibacterial effects against E. coli. AgNPs-EC and AgNPs-PVP inhibited biofilm formation to 58.2% and 50.8% compared with AgNPs-PEG, silver nitrate solution and control samples. In addition, coating urinary catheters with AgNPs-EC and AgNPs-PVP at concentrations lower than the determined IC50 values significantly (p < 0.05; t-test) inhibited bacterial biofilm formation compared with noncoated catheters under both static and static and flowing conditions using two different types of commercial Foley urinary catheters. The data obtained in this study provide evidence that AgNP-coated EC and PVP could be useful as potential antibacterial and antibiofilm catheter coating agents to prevent the development of urinary tract infections caused by E. coli.

The Role of Abdominal Drain Cultures in Managing Abdominal Infections

Intra-abdominal infections (IAI) are common in hospitalized patients, both in and outside of the intensive care unit. Management principles include antimicrobial therapy and source control. Typically, these infections are polymicrobial, and intra-operative samples will guide the targeted antimicrobial therapy. Although the use of prophylactic abdominal drains in patients undergoing abdominal surgery is decreasing, the use of drains to treat IAI, both in surgical and non-surgical strategies for abdominal infection, is increasing. In this context, samples from abdominal drains are often used to assist in antimicrobial decision making. In this narrative review, we provide an overview of the current role of abdominal drains in surgery, discuss the importance of biofilm formation in abdominal drains and the mechanisms involved, and review the clinical data on the use of sampling these drains for diagnostic purposes. We conclude that biofilm formation and the colonization of abdominal drains is common, which precludes the use of abdominal fluid to reliably diagnose IAI and identify the pathogens involved. We recommend limiting the use of drains and, when present, avoiding routine microbiological sampling.

Targeting Microbial Bio-film: an Update on MDR Gram-Negative Bio-film Producers Causing Catheter-Associated Urinary Tract Infections

In every age group, urinary tract infection (UTI) is found as a major recurrence infectious disorder. Bio-films produced by bacteria perform a vital role in causing infection in the tract of the urinary system, leading to recurrences and relapses. The purpose of this review is to present the role and mechanism of bio-film producing MDR Gram-negative bacteria causing UTI, their significance, additionally the challenges for remedy and prevention of catheter-associated UTI. This work appreciates a new understanding of bio-film producers which are having multi-drug resistance capability and focuses on the effect and control of bio-film producing uropathogenic bacteria related to catheterization. We have tried to analyze approaches to target bio-film and reported phytochemicals with anti-bio-film activity also updated on anti-bio-film therapy.

Urinary Tract Infections and Associated Factors among Patients with Indwelling Urinary Catheters Attending Bugando Medical Centre a Tertiary Hospital in Northwestern Tanzania

Complications of indwelling urinary catheterization (IUC) are associated with significant morbidity and mortality, thus affecting patient's well-being. Understanding the magnitude and factors associated with complications is crucial in designing appropriate preventive strategies. A cross-sectional study was conducted at Bugando Medical Centre, involving patients with long-term and short-term IUC from December 2016 to September 2017. The data were analyzed by STATA 13.0. Catheter-associated urinary tract infection (CA-UTI) was the leading (56.8%; 250/440) complication among patients with IUC. Gram-negative bacteria were predominantly isolated (98.1%, 252/257), whereas E. coli (30.7%, 79/257) and Klebsiella spp. (29.6%, 76/257) were the leading pathogens. CA-UTI was significantly higher among out-patients than in-patients (82.2% v 35.3%, p < 0.001). Older age (OR: 1.3, (95%CI: 1.1-1.5), p < 0.001), level of education (OR: 1.8, (95%CI: 1.1-3.1), p = 0.029) and catheter duration of ≥6 weeks (OR: 2.43, (95%CI: 1.1-5.5), p = 0.031) independently predicted CA-UTI among outpatients, while female gender (OR: 2.1, (95%CI: 1.2-3.7), p = 0.014), catheter bags not freely hanging (OR: 0.4, (95%CI: 0.2-0.7), p = 0.002) and residing outside Mwanza region (OR: 0.4, (95%CI: 0.2-0.6), p < 0.001) predicted CA-UTI among in-patients. CA-UTI is the common complication among patients with IUC, significantly higher in out-patients than in-patients. We recommend involving patients and carers in infection prevention and control measures in out-patients living with IUC.

Antibacterial, anti-biofilm, and anti-adhesive activities of melittin, a honeybee venom-derived peptide, against quinolone-resistant uropathogenic Escherichia coli (UPEC)

Here, we demonstrated the in vitro and in vivo antibacterial and anti-biofilm activities of melittin, a peptide derived from honeybee venom, against uropathogenic Escherichia coli (UPEC) resistant to quinolones. The minimum inhibitory concentration (MIC) of melittin varied from 0.5 to 8 μM. The bactericidal effect was considered rapid and potent (ranging from 3.0 to 6.0 h after incubation) against a quinolone-resistant and Extended Spectrum Beta-lactamase (ESBL)-producing UPEC strain. Prior exposure to melittin did not reduce the MIC of the quinolones tested, but it decreased the MIC of ceftizoxime by 8-fold due to its ability to form pores in the membrane. Furthermore, melittin disrupted mature biofilms (39.58% at 32 μM) and inhibited the adhesion of this uropathogen to the surfaces of urethral catheter. These results show that melittin is a promising molecule that can be incorporated into invasive urethral medical devices to prevent urinary infections caused by multidrug-resistant UPECs.

Bioengineered phytomolecules-capped silver nanoparticles using Carissa carandas leaf extract to embed on to urinary catheter to combat UTI pathogens

Rising incidents of urinary tract infections (UTIs) among catheterized patients is a noteworthy problem in clinic due to their colonization of uropathogens on abiotic surfaces. Herein, we have examined the surface modification of urinary catheter by embedding with eco-friendly synthesized phytomolecules-capped silver nanoparticles (AgNPs) to prevent the invasion and colonization of uropathogens. The preliminary confirmation of AgNPs production in the reaction mixture was witnessed by the colour change and surface resonance plasmon (SRP) band at 410nm by UV–visible spectroscopy. The morphology, size, crystalline nature, and elemental composition of attained AgNPs were further confirmed by the transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD) technique, Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The functional groups of AgNPs with stabilization/capped phytochemicals were detected by Fourier-transform infrared spectroscopy (FTIR). Further, antibiofilm activity of synthesized AgNPs against biofilm producers such as Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were determined by viability assays and micrographically. AgNPs coated and coating-free catheters performed to treat with bacterial pathogen to analyze the mat formation and disruption of biofilm formation. Synergistic effect of AgNPs with antibiotic reveals that it can enhance the activity of antibiotics, AgNPs coated catheter revealed that, it has potential antimicrobial activity and antibiofilm activity. In summary, C. carandas leaf extract mediated synthesized AgNPs will open a new avenue and a promising template to embed on urinary catheter to control clinical pathogens.

Comparison of the Incidence of Urinary Tract Infection by Replacement Time of the Urinary Drainage System

BACKGROUND

Urinary catheters (UCs) with a closed urinary drainage system have been widely used in patients for many years. However, the frequency of replacing and operating these devices may be associated with catheter-associated urinary tract infection (CAUTI).

PURPOSE

This study was designed to compare the incidence of CAUTI by replacement time (every 14 or ≥ 15 days) of the urinary drainage system.

METHODS

This 1-year prospective, nonrandomized controlled study was conducted in a major teaching hospital. The Transparent Reporting of Evaluations with Nonrandomized Designs Statement checklist was used. All of the patients with UCs were divided into two groups based on each patient's preference with regard to replacement time of the urinary drainage system.

RESULTS

Five hundred sixty-two patients were evaluated, and 341 patients with UCs were enrolled as participants in the study. In the per-protocol analysis, 16 patients (22.2%; 9.3 episodes/1,000 catheter-days) in the 14-day group and 15 patients (17.9%; relative risk = 1.24, 95% confidence interval [0.66, 2.34]) in the ≥ 15-day group (7.7 episodes/1,000 catheter-days; incidence density ratio 1.20, 95% confidence interval [0.60, 2.43]) had CAUTIs. A comparison of cleanliness within urinary bags showed no significant intergroup difference (p > .05). In the intention-to-treat analysis, the incidence of CAUTI between the two groups was also not significantly different (p > .05).

CONCLUSIONS

No statistically significant difference in the incidence of CAUTI was identified between patients who used the 14-day replacement interval and those who used the ≥ 15-day replacement interval for their urinary drainage system.

Synergistic activity of weak organic acids against uropathogens

BACKGROUND

Urinary tract infections (UTIs) are among the most common hospital-acquired infections, with an estimated 75% of UTIs caused by urinary catheters. In addition to the significant healthcare costs and patient morbidity, the escalating antimicrobial resistance reported among common uropathogens make the investigation of efficacious new antimicrobial strategies of urgent importance.

AIM

To examine the antibacterial activity of a suite of weak organic acids (WOAs) (citric acid, malic acid, propionic acid, mandelic acid, lactic acid, benzoic acid, pyruvic acid and hippuric acid), alone and in combination, against common nosocomial uropathogens (Proteus mirabilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa).

METHODS

Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm eradication concentration (MBEC), fractional inhibitory concentration index (FICI) values and kinetics of bactericidal activity of WOAs were determined by microdilution and time-kill assays.

FINDINGS

All tested WOAs displayed bactericidal activities against uropathogens in their planktonic and biofilm modes of growth when used individually. Moreover, WOAs in combination displayed synergistic activity against P. mirabilis, S. aureus and E. coli, with reductions in MIC values of up to 250-fold and significant reductions in biofilm formation.

CONCLUSION

The synergistic multi-mechanistic combinations identified herein are anticipated to play an important role in the treatment and prevention of catheter-associated UTIs.

Evaluation of Polyethylene Glycol-Based Antimicrobial Coatings on Urinary Catheters in the Prevention of Escherichia coli Infections in a Rabbit Model

Introduction and Objective: Catheter-associated urinary tract infections are a major cause of patient morbidity and mortality. Despite many attempts to design biomaterials that might reduce the risk, none has had a profound impact on reducing the incidence of this most common nosocomial infection. Recent in vitro work, however, has shown promise for a silver-based biomaterial coating composed of methoxylated polyethylene glycol 3,4-dihydroxyphenylalanine (mPEG-DOPA3) in reducing uropathogen attachment and biofilm formation. The aim of this work was to investigate whether these results translate into a meaningful impact on infection development and bacterial adherence in an in vivo rabbit model. Materials and Methods: New Zealand white rabbits were randomized into groups of 12 and had the following catheters inserted: Group 1-uncoated polyurethane, Group 2-Coating A (mPEG-DOPA3 + 2 mg/mL AgNO3), and Group 3-Coating B (mPEG-DOPA3 + 10 mg/mL AgNO3). Each rabbit was challenged with 108 colony-forming units of Escherichia coli GR-12 instilled directly into the bladder at the time of catheter insertion and urine was monitored over 7 days for bacterial counts. Catheters were retrieved and evaluated for encrustation and attachment analysis, and tissues collected for histopathologic characterization and bacterial invasion. Results: Urinary bacterial colony counts were lower among rabbits in the Coating A group vs controls (4/11 vs 10/12, respectively) (p = 0.029), and there were fewer rabbits with invasive infections (3/12 vs 9/12, p = 0.02). More encrustation was observed among animals in the Coating B group vs controls (7.22 vs 2.69 mg/cm2, p = 0.033). There were no significant differences in tissue effects between groups. Conclusions: The use of a mPEG-DOPA3 urinary catheter coating effectively reduced urinary pathogen counts, while not causing adverse tissue effects in this model. Further clinical evaluation is warranted.

Study of the Human Albumin Role in the Formation of a Bacterial Biofilm on Urinary Devices Using QCM-D

Catheter-associated urinary tract infections (CAUTIs) are the most common health care-associated infections due to rapid bacterial colonization+ and biofilm formation in urinary catheters. This behavior has been extensively documented in medical devices. However, there is a few literature works on CAUTI providing a model that allows the exhaustive study of biofilm formation in a urinary environment. The development of an effective model would be helpful to identify the factors that promote the biofilm formation and identify strategies to avoid it. In this work, we have developed a model to test biofilm formation on urinary medical device surfaces by simulating environmental and physical conditions using a quartz crystal microbalance with dissipation (QCM-D) module with an uropathogenic strain. Moreover, we used the developed model to study the role of human albumin present in artificial urine at high concentrations because of renal failure or heart-diseases in patients. Despite model limitations using artificial urine, these tests show that human albumin can be considered as a promoter of biofilm formation on hydrophobic surfaces, being a possible risk factor to developing a CAUTI.

Photodynamic treatment for multidrug-resistant Gram-negative bacteria: Perspectives for the treatment of Klebsiella pneumoniae infections

The emergence of multi-drug resistance for pathogenic bacteria is one of the most pressing global threats to human health in the 21st century. Hence, the availability of new treatment becomes indispensable to prevent morbidity and mortality caused by infectious agents. This article reviews the antimicrobial properties of photodynamic therapy (PDT), which is based on the use of photosensitizers compounds (PSs). The PSs are non-toxic small molecules, which induce oxidative stress only under excitation with light. Then, the PDT has the advantage to be locally activated using phototherapy devices. We focus on PDT for the Klebsiella pneumoniae, as an example of Gram-negative bacteria, due to its relevance as an agent of health-associated infections (HAI) and a multi-drug resistant bacteria. K. pneumoniae is a fermentative bacillus, member of the Enterobacteriaceae family, which is most commonly associated with producing infection of the urinary tract (UTI) and pneumonia. K. pneumoniae infections may occur in deep organs such as bladder or lungs tissues; therefore, activating light must get access or penetrate tissues with sufficient power to produce effective PDT. Consequently, the rationale for selecting the most appropriate PSs, as well as photodynamic devices and photon fluence doses, were reviewed. Also, the mechanisms by which PDT activates the immune system and its importance to eradicate the infection successfully, are discussed.

Evaluation and Management of Urinary Tract Infection in the Emergency Department

Urinary tract infection (UTI) affects patients of all ages and is a diagnosis that emergency physicians might make multiple times per shift. This article reviews the evaluation and management of patients with infections of the urinary tract. Definitions of asymptomatic bacteriuria, uncomplicated UTI, and complicated UTI are presented, as well as techniques for distinguishing them. The pathophysiology and clinical and laboratory diagnoses of UTI are described. Treatment of UTI is reviewed, with attention to bacteriuria and special populations, including pregnant, elderly/geriatric, and spinal cord injury patients.

Predicting the risk of sepsis and causative organisms following urinary stones removal using urinary versus stone and stent cultures

The association between foreign objects in the urinary system and urinary tract infections (UTI) is well established. The incidence of bacteriuria in patient with urinary catheters increases as dwelling time lengthens. The presence of ureteral stents and kidney stones is also associated with increased risk for bacteriuria and urinary tract infection. The aim of this study was to assess the bacterial characteristics of urine culture (UC) and foreign body culture (FBC), the concordance between them, and to identify risk factors for postoperative infections, in order to improve the treatment in these patients, using a prospectively collected database of patients who underwent ureteroscopy or percutaneous nephrolithotomy (PCNL) for the treatment of urinary stones between 2005 and 2016 at our institute. Preoperative UC was obtained from voided mid-stream urine for all patients. FBCs were obtained from ureteral stents removed and stones collected during the surgery. The cohort included 1011 patients. Mean age was 53 (SD 15.8), and 679 (67.2%) patients were male. Two hundred eighteen (21.6%) had a UTI in the year prior to the surgery. Among 795 patients who had sterile UC, 98 (12.3%) patients had positive FBC. Positive FBC was found in 53.7% of the patients with positive UC; however, FBC pathogens were similar to those identified in UC in 31% patients. The sensitivity of UC to detect FBC pathogens was 31.3%, and the PPV was 0.31. Urine cultures do not recognize all cases of pathogens colonizing foreign bodies in the urinary system. The colonization may be associated with an increased risk for SIRS. In more than one-quarter of the patients, the causative pathogen of sepsis is identified by FBC, but not by UC.

Analysis of measurement electrode location in bladder urine monitoring using electrical impedance

Purpose

The aim of this study was to document more appropriate electrode location of a four-electrode-based electrical impedance technology in the monitoring of bladder filling, and to characterize the relationship between bladder filling duration and the measured electrical impedances.

Methods

A simulation study, based on a 2-dimension computational model, was conducted to determine the preferable locations of excitation and measurement electrodes in a conventional four-electrode setup. A human observation study was subsequently performed on eight healthy volunteers during natural bladder urine accumulation to validate the result of the simulation study. The correlation between the bladder filling time and the measured electrical impedance values was evaluated.

Results

The preferable location of measurement electrodes was successively validated by the model simulation study and human observation study. Result obtained via the selected electrodes location revealed a significant negative correlation (R = 0.916 ± 0.059, P < 0.001) between the measured electrical impedance and the urine accumulation time, which was consistent with the result of simulation study.

Conclusions

The findings in this study not only documented the desirable electrodes location to monitor the process of bladder urine accumulation using four-electrode measurement, but also validated the feasibility of utilizing electrical impedance technique to monitor and estimate the bladder urine volume for those with urological disorders.

Management of Urinary Retention in Patients with Benign Prostatic Obstruction: A Systematic Review and Meta-analysis

CONTEXT

Practice patterns for the management of urinary retention (UR) secondary to benign prostatic obstruction (BPO; UR/BPO) vary widely and remain unstandardized.

OBJECTIVE

To review the evidence for managing patients with UR/BPO with pharmacological and nonpharmacological treatments included in the European Association of Urology guidelines on non-neurogenic male lower urinary tract symptoms.

EVIDENCE ACQUISITION

Search was conducted up to April 22, 2018, using CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform. This systematic review included randomized controlled trials (RCTs) and prospective comparative studies. Methods as detailed in the Cochrane handbook were followed. Certainty of evidence (CoE) was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

EVIDENCE SYNTHESIS

Literature search identified 2074 citations. Twenty-one studies were included (qualitative synthesis). The evidence for managing patients with UR/BPO with pharmacological or nonpharmacological treatments is limited. CoE for most outcomes was low/very low. Only α1-blockers (alfuzosin and tamsulosin) have been evaluated in more than one RCT. Pooled results indicated that α1-blockers provided significantly higher rates of successful trial without catheter compared with placebo [alfuzosin: 322/540 (60%) vs 156/400 (39%) (odds ratio {OR} 2.28, 95% confidence interval {CI} 1.55 to 3.36; participants=940; studies=7; I²=41%; low CoE); tamsulosin: 75/158 (47%) vs 40/139 (29%) (OR 2.40, 95% CI 1.29 to 4.45; participants=297; studies=3; I²=30%; low CoE)] with rare adverse events. Similar rates were achieved with tamsulosin or alfuzosin [51/87 (59%) vs 45/84 (54%) (OR 1.28, 95% CI 0.68 to 2.41; participants=171; studies=2; I²=0%; very low CoE)]. Nonpharmacological treatments have been evaluated in RCTs/prospective comparative studies only sporadically.

CONCLUSIONS

There is some evidence that usage of α1-blockers (alfuzosin and tamsulosin) may improve resolution of UR/BPO. As most nonpharmacological treatments have not been evaluated in patients with UR/BPO, the evidence is inconclusive about their benefits and harms.

PATIENT SUMMARY

There is some evidence that alfuzosin and tamsulosin may increase the rates of successful trial without catheter, but little or no evidence on various nonpharmacological treatment options for managing patients with urinary retention secondary to benign prostatic obstruction.

Pathophysiology, Treatment, and Prevention of Catheter-Associated Urinary Tract Infection

Urinary tract infections (UTIs) are among the most common microbial infections in humans and represent a substantial burden on the health care system. UTIs can be uncomplicated, as when affecting healthy individuals, or complicated, when affecting individuals with compromised urodynamics and/or host defenses, such as those with a urinary catheter. There are clear differences between uncomplicated UTI and catheter-associated UTI (CAUTI) in clinical manifestations, causative organisms, and pathophysiology. Therefore, uncomplicated UTI and CAUTI cannot be approached similarly, or the risk of complications and treatment failure may increase. It is imperative to understand the key aspects of each condition to develop successful treatment options and improve patient outcomes. Here, we will review the epidemiology, pathogen prevalence, differential mechanisms used by uropathogens, and treatment and prevention of uncomplicated UTI and CAUTI.

Clinical predictors of candidemia in medical non-neutropenic, non-ICU patients. The CaMed score

INTRODUCTION

Candida species are the leading cause of invasive fungal infections in hospitalised patients and are the fourth most common isolates recovered from patients with bloodstream infection. Few data exist on risk factors for candidemia in non-ICU patients. We performed a population-based case-control study to evaluate the main predictors for candidemia in non-ICU patients.

METHODS AND FINDINGS

We included all non-neutropenic, non-critically ill and non-surgical adult patients with candidemia between January 2010 and June 2014. Patients with positive, non-candidal blood culture obtained at the same day (±2 days) were selected as controls. Cases and controls were matched according to hospital ward and clinical characteristics. Risk factors for candidemia were identified through a logistic regression. We included 56 candidemic and 512 bacteriemic non-candidemic patients. Most of candidemic patients (52) had received antibiotics prior to candidemia. Among them, the 30-day mortality rate was 34% (19/56). Multivariate analysis identified male sex, prior use of steroids, prior use of antibiotics, total parenteral nutrition and urinary catheterisation as independent predictors of candidemia. To develop the CaMed score, we rounded up weights of different risk factors as follows; total parenteral nutrition (+2), prior antibiotic therapy (+5), each of the other risk factors (+1). A score ≥ 7 identified patients at high risk of candidemia (P < 0.001; RR 29.805; CI 95% 10.652-83.397; sensitivity 79.2, specificity 82.6%, Youden index 0,62).

CONCLUSIONS

Our set of easy independent predictors of candidemia in non-neutropenic, non-ICU, non-surgical patients provide a rationale for early initiation of antifungals and could reduce candidemia-related mortality.

A poly(hydroxyethyl methacrylate)-Ag nanoparticle porous hydrogel for simultaneous in vivo prevention of the foreign-body reaction and bacterial infection

The use of implants or indwelling medical devices has greatly enhanced the quality and efficacy of health care. However, foreign-body reactions (FBRs) and infections can lead to potential failure or removal of the devices, or increased morbidity and mortality of patients. Herein, we develop a silver nanoparticle (AgNP) loaded poly(hydroxyethyl methacrylate) hydrogel with spherical, interconnected 40 μm pores. The resulting hydrogels displayed good antibacterial properties regarding both gram positive bacteria (Staphylococcus aureus) and gram negative bacteria (Escherichia coli (E. coli)) in vitro and were highly efficient at inhibiting bacterial cell growth. Moreover, they exhibited an in vivo resistance to FBRs by reducing the immune responses, and completely prevented the formation of collagen capsules. Finally, in vivo studies of the E. coli infected mouse model demonstrated that the AgNP loaded porous hydrogels were highly efficient at resisting the bacterial FBRs and infections, while they promoted cell mitigation and infiltration. Findings from this work suggest that AgNP loaded porous hydrogels hold promise in various biomedical applications including in the new generation of implantable biomedical devices and tissue engineering scaffolds.

Comparison of uropathogens and antibiotic susceptibility patterns in catheterized ambulant middle-aged and elderly Nigerian patients with bladder outlet obstruction

OBJECTIVE

Advanced age is one of the notable risk factors for catheter-associated urinary tract infections (CAUTIs), and differences between middle aged and elderly men with CAUTIs is poorly understood. This study aimed at comparing the pattern of urinary pathogens and antibiotic susceptibility in ambulant catheterized middle-aged and elderly Nigerian men.

MATERIAL AND METHODS

One hundred and fifty-four patients catheterized for >48 hours had provided clean catch mid-stream urine samples for microscopic analysis, culture and sensitivity tests. Eighty-two men aged <65, and 72 men aged ≥65 years matched for age, level of education, occupation and marital status were compared.

RESULTS

Prevalence of CAUTIs among middle-aged men was middle-aged men was higher than the elderly (90.2% and 80.6% respectively) but this was not statistically significant (p=0.086). CAUTIs in middle-aged men with suprapubic catheters were significantly more frequent than those with urethral catheters (p=0.000). The prevalence of CAUTIs in middle-aged men with urethral stricture was different from other causes of bladder outlet obstruction (p=0.004). Men with indwelling catheters longer than 2 weeks had higher CAUTIs (p=0.000). Escherichia coli was the commonest pathogen in both groups while nitrofurantoin was the most sensitive drug.

CONCLUSION

There are differential rates of CAUTIs in both the middle-aged men and the elderly with bladder outlet obstruction in our environment. The knowledge of the common pathogens and the antibiotic susceptibility will prevent irrational antibiotic use. Middle-aged men had higher prevalence of CAUTIs when Proteus spp. was the infectious agent. However, E. coli was the commonest pathogen of CAUTIs in all men. Also, middle- aged men with suprapubic catheters had higher rates of CAUTIs. Nitrofurantoin was the best drug in all men with CAUTIs but elderly men had higher rates of multi-resistance.

Continuous bladder volume monitoring system for wearable applications

In this research, we propose a bladder volume monitoring system that can be effectively applied for various voiding dysfunctions. Whereas conventional systems lack consecutive measurements, the proposed system can continuously monitor a user's status even during unconscious sleep. For the convenience, we design a simple and comfortable waist-belt-type device by using the body impedance analysis (BIA) technique. To support various measurement scenarios, we develop applications by connecting the device to a smartphone. To minimize motion noises, which are inevitable when monitoring over an extended period, we propose a motion artifact reduction algorithm that exploits multiple frequency sources. The experimental results show a strong relationship between the impedance variation and the bladder volume; this confirms the feasibility of our system.

Use of Urinary Collection Devices in Community and Nursing Homes in Istria County

INTRODUCTION

This study is aimed at assessing the use of various types of urinary catheters, appropriateness of catheter placement and factors associated with antibiotic use in a population of chronically catheterized patients in Istria County.

MATERIALS AND METHODS

This cross-sectional study, conducted between March and June 2017 in Istria County, Croatia, was initiated through a network of general family medicine offices. Data were collected from general practitioners (GPs) and from medical managers in nursing homes. Participants were asked to review medical records of their patients and to complete a 10-item questionnaire designed to retrieve information on patients with urinary catheter.

RESULTS

All GPs in the county were surveyed. We identified 309 patients with urinary catheter: 216 men (70%) and 93 women (30%). The overall prevalence of individuals with urinary catheters was 0.18%: 4.7% in nursing home population and 0.1% among non-institutionalized adult population. Most common indication for catheterization was chronic urinary retention (52%). One hundred eighty-six patients (60.4%) reported antibiotic usage in the previous 3 months for treating urinary infection.

CONCLUSIONS

In Istria County, the prevalence of indwelling urinary catheters is highest in males, especially among patients in nursing homes. There is a need for focused education among GPs regarding urinary catheter maintenance and antibiotic prescription for suspected urinary tract infections.

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.

Role of neomycin polymyxin sulfate solution bladder wash for prevention of catheter associated urinary tract infection in traumatic brain injury patient admitted to Intensive Care Unit: A prospective randomized study

BACKGROUND

Catheter - associated urinary tract infection (CAUTI) remains a critical threat for patients in intensive care unit especially in traumatic brain injury patients with low Glasgow coma score (GCS). Almost all patients in ICU receive antibiotic either prophylactic or therapeutic based on local antibiogram of particular ICU or hospital. For prophylaxis, systemic antibiotics are used. It will be helpful to avoid systemic side effects by introducing antibiotics locally through bladder irrigation. The indwelling urinary catheter is an essential part of modern medical care.

AIMS AND OBJECTIVES

The primary objective was to study the effect of Neomycin and Polymyxin sulphate solution for bladder wash on CAUTI in traumatic brain injury patients. The secondary objectives was to study the various organisms causing CAUTI and their antibiotic sensitivity and resistance pattern.

MATERIALS AND METHODS

This was a prospective randomized controlled study performed on 100 patients who met the inclusion criteria at the trauma intensive care unit of Banaras Hindu University between September and February 2016. The patients were randomized into two groups - one was the study group which received Neomycin and Polymyxin Sulphate solution bladder wash, while the other was the control group that received Normal saline bladder wash. Urine samples were collected at certain days and sent for culture and sensitivity.

RESULTS

There was significant reduction in the incidence of CAUTI in neomycin/polymyxin test group in comparison to normal saline irrigated control group. Out of 50 patients in test group 8 patients and in control group 26 patients was identified as CAUTI positive and they were statistically significant. In our study pseudomonas aeruginosa (51%) was the commonest isolated pathogen.

CONCLUSIONS

Neomycin and Polymyxin Sulphate bladder wash was effective in preventing CAUTI. It can thus decrease the antibiotic usage thereby preventing the emergence of antibiotic resistance.

Host and bacterial proteases influence biofilm formation and virulence in a murine model of enterococcal catheter-associated urinary tract infection

Enterococcus faecalis is a leading causative agent of catheter-associated urinary tract infection (CAUTI), the most common hospital-acquired infection. Its ability to grow and form catheter biofilm is dependent upon host fibrinogen (Fg). Examined here are how bacterial and host proteases interact with Fg and contribute to virulence. Analysis of mutants affecting the two major secreted proteases of E. faecalis OG1RF (GelE, SprE) revealed that while the loss of either had no effect on virulence in a murine CAUTI model or for formation of Fg-dependent biofilm in urine, the loss of both resulted in CAUTI attenuation and defective biofilm formation. GelE⁻, but not SprE⁻ mutants, lost the ability to degrade Fg in medium, while paradoxically, both could degrade Fg in urine. The finding that SprE was activated independently of GelE in urine by a host trypsin-like protease resolved this paradox. Treatment of catheter-implanted mice with inhibitors of both host-derived and bacterial-derived proteases dramatically reduced catheter-induced inflammation, significantly inhibited dissemination from bladder to kidney and revealed an essential role for a host cysteine protease in promoting pathogenesis. These data show that both bacterial and host proteases contribute to CAUTI, that host proteases promote dissemination and suggest new strategies for therapeutic intervention.

Identifying bacterial and host enzymes that support biofilm formation may help prevent urinary tract infections caused by catheters. Enterococcus faecalis bacteria is a leading cause of catheter-associated urinary tract infections, the most common type of hospital-acquired infections. Michael Caparon and colleagues at Washington University School of Medicine in Missouri, USA, studied these infections in mice. They examined the effects of two protein-degrading enzymes, both from the bacterium and one can be activated by urine trypsin-like protease from the animals. Mutations that impaired either one of the enzymes had no effect on the infection, but when both the bacterial enzymes were impaired by mutation the formation of biofilms was significantly reduced. Treating the mice with chemicals that inhibited both bacterial and host enzymes dramatically reduced catheter-induced inflammation and related problems. This suggests drugs targeting these enzymes could be useful in clinical care.

Clinical Presentations and Epidemiology of Urinary Tract Infections

Urinary tract infection (UTI) is one of the most common bacterial infections, and the incidence in women is much higher than in men. The diagnosis of a UTI can be made based on a combination of symptoms and a positive urine analysis or culture. Most UTIs are uncomplicated UTIs, defined as cystitis in a woman who is not pregnant, is not immunocompromised, has no anatomical and functional abnormalities of the urogenital tract, and does not exhibit signs of tissue invasion and systemic infection. All UTIs that are not uncomplicated are considered to be complicated UTIs. Differentiation between uncomplicated and complicated UTIs has implications for therapy because the risks of complications or treatment failure are increased for patients with a complicated UTI. Asymptomatic bacteriuria (ASB) is defined as the presence of a positive urine culture collected from a patient without symptoms of a UTI. Concerning the complicated UTI, it is possible to make a differentiation between UTI with systemic symptoms (febrile UTI) and UTI in a host, which carries an increased risk to develop complications of this UTI. Febrile UTIs are urosepsis, pyelonephritis, and prostatitis. A complicated host is defined as one that has an increased risk for complications, to which the following groups belong: men, pregnant women, immunocompromised patients, or those who have an anatomical or functional abnormality of the urogenital tract (e.g., spinal cord-injury patients, renal stones, urinary catheter).

A multi-defense strategy: Enhancing bactericidal activity of a medical grade polymer with a nitric oxide donor and surface-immobilized quaternary ammonium compound

Although the use of biomedical devices in hospital-based care is inevitable, unfortunately, it is also one of the leading causes of the nosocomial infections, and thus demands development of novel antimicrobial materials for medical device fabrication. In the current study, a multi-defense mechanism against Gram-positive and Gram-negative bacteria is demonstrated by combining a nitric oxide (NO) releasing agent with a quaternary ammonium antimicrobial that can be covalently grafted to medical devices. Antibacterial polymeric composites were fabricated by incorporating an NO donor, S-nitroso-N-acetyl-penicillamine (SNAP) in CarboSil® polymer and top coated with surface immobilized benzophenone based quaternary ammonium antimicrobial (BPAM) small molecule. The results suggest that SNAP and BPAM individually have a different degree of toxicity towards Gram-positive and Gram-negative bacteria, while the SNAP-BPAM combination is effective in reducing both types of adhered viable bacteria equally well. SNAP-BPAM combinations reduced the adhered viable Pseudomonas aeruginosa by 99.0% and Staphylococcus aureus by 99.98% as compared to the control CarboSil films. Agar diffusion tests demonstrate that the diffusive nature of NO kills bacteria beyond the direct point of contact which the non-leaching BPAM cannot achieve alone. This is important for potential application in biofilm eradication. The live-dead bacteria staining shows that the SNAP-BPAM combination has more attached dead bacteria (than live) as compared to the controls. The SNAP-BPAM films have increased hydrophilicity and higher NO flux as compared to the SNAP films useful for preventing blood protein and bacterial adhesion. Overall the combination of SNAP and BPAM imparts different attributes to the polymeric composite that can be used in the fabrication of antimicrobial surfaces for various medical device applications.

STATEMENT OF SIGNIFICANCE

A significant increase in the biomedical device related infections (BDRIs), inability of the currently existing antimicrobial strategies to combat them and a proportional rise in the associated morbidity demands development of novel antimicrobial surfaces. Some of the major challenges associated with the currently used therapeutics are: antibiotic resistance and cytotoxicity. In the current study, engineered polymeric composites with multi-defense mechanism were fabricated to kill bacteria via both active and passive mode. This was done by incorporating a nitric oxide (NO) donor S-nitroso-N-acetypenicillamine (SNAP) in a medical grade polymer (CarboSil®) and a benzophenone based quaternary ammonium antimicrobial small molecule (BPAM) was surface immobilized as the top layer. The developed biomaterial was tested with Gram-positive and Gram-negative strains and was found to be effective against both the strains resulting in up to 99.98% reduction in viable bacterial count. This preventative strategy can be used to fabricate implantable biomedical devices (such as catheters, stents, extracorporeal circuits) to not only significantly limit biofilm formation but also to reduce the antibiotic dose which are usually given post infections.

Failed Removal of Indwelling Urinary Catheters in Patients With Acute Stroke: Incidence and Risk Factors

BACKGROUND

Reducing the incidence of indwelling urinary catheter (IUC) use and early removal of the devices that are inserted are appropriate priorities for quality patient care. Just like symptomatic bacteriuria, failed catheter removal as a complication of IUC use is associated with considerable morbidity. In the ideal setting, patients who need IUCs have them, and patients who do not need them will have them removed safely, with the goal of reducing medical complications and facilitating the rehabilitation phase of care.

OBJECTIVE

To determine the incidence of failed removal of IUCs and the factors associated with failed removal in persons hospitalized with acute stroke.

DESIGN

Retrospective review of medical records and associated clinical data collection platforms.

SETTING

Comprehensive stroke center at a tertiary care hospital.

PATIENTS

The study cohort included 175 stroke patients admitted to the hospital and managed with IUCs. Mean age was 66.1 years (standard deviation = 15), 55% were female.

METHODS

Univariable and multiple logistic regression analyses were performed. Variables assessed included age, gender, race, duration of hospital stay, stroke subtype, National Institutes of Health Stroke Scale, and 6-Clicks Scale, which is a measure of functional status.

MAIN OUTCOME MEASUREMENTS

The dependent variable was occurrence of a failed attempt at removal of an IUC, defined as removal followed by a catheter reinsertion.

RESULTS

During the study period, 175 of 432 patients with acute hospital admission for new stroke had an IUC removal event. Of these patients, 46 (26%) experienced a failed catheter removal. On univariate analysis, factors significantly associated with failed removal included presence of a hemorrhagic stroke (P = .005), lower level of physical function (by 6-Clicks and NIHSS scores), hospital length of stay (P < .001), and discharge location (P = .005). Bedside bladder ultrasound testing by nursing staff was used more frequently in the group of patients who had unsuccessful IUC removals (95% confidence interval 4.56-21.67, P < .001). Length of stay (P < .001), white race (P = .001), and hemorrhagic stroke (P = .009) were associated independently with failed catheter removal after adjustment for other clinical variables.

CONCLUSIONS

This single-site study identified a high incidence of failed urinary catheter removal in patients with stroke, along with factors associated with failed removal. This is the first step in developing a predictive model that could reduce the incidence of this adverse event. Policies, penalties, and protocols designed to reduce catheter days must be sensitive to the special situations in which IUCs are medically necessary and equal consideration given to identifying the patients for which catheter removal poses a greater risk than continued catheter use.

LEVEL OF EVIDENCE

III.

Gram-Positive Uropathogens, Polymicrobial Urinary Tract Infection, and the Emerging Microbiota of the Urinary Tract

Gram-positive bacteria are a common cause of urinary-tract infection (UTI), particularly among individuals who are elderly, pregnant, or who have other risk factors for UTI. Here we review the epidemiology, virulence mechanisms, and host response to the most frequently isolated Gram-positive uropathogens: Staphylococcus saprophyticus, Enterococcus faecalis, and Streptococcus agalactiae. We also review several emerging, rare, misclassified, and otherwise underreported Gram-positive pathogens of the urinary tract including Aerococcus, Corynebacterium, Actinobaculum, and Gardnerella. The literature strongly suggests that urologic diseases involving Gram-positive bacteria may be easily overlooked due to limited culture-based assays typically utilized for urine in hospital microbiology laboratories. Some UTIs are polymicrobial in nature, often involving one or more Gram-positive bacteria. We herein review the risk factors and recent evidence for mechanisms of bacterial synergy in experimental models of polymicrobial UTI. Recent experimental data has demonstrated that, despite being cleared quickly from the bladder, some Gram-positive bacteria can impact pathogenic outcomes of co-infecting organisms. When taken together, the available evidence argues that Gram-positive bacteria are important uropathogens in their own right, but that some can be easily overlooked because they are missed by routine diagnostic methods. Finally, a growing body of evidence demonstrates that a surprising variety of fastidious Gram-positive bacteria may either reside in or be regularly exposed to the urinary tract and further suggests that their presence is widespread among women, as well as men. Experimental studies in this area are needed; however, there is a growing appreciation that the composition of bacteria found in the bladder could be a potentially important determinant in urologic disease, including susceptibility to UTI.

Update on voiding dysfunction managed with suprapubic catheterization

As the population ages the prevalence of long-term urinary catheters, especially in the elderly, is going to increase. Urinary catheters are usually placed to manage urinary retention or incontinence that cannot be managed any other way. There is significant morbidity associated with an indwelling catheter. The commonest problems are catheter blockages, infection and bladder stones. These will occur with a similar incidence with either a suprapubic or a urethral catheter. Urethral complications such as strictures, scrotal infection and erosion are less common with suprapubic catheterization (SPC). However the benefit of having a SPC needs to be balanced against the risks involved in inserting the catheter suprapubically. Patient reported symptoms show that a SPC is more comfortable and better tolerated than a urethral catheter. However there needs to be more research into developing better catheters that reduce the frequency of urinary infections and blockages and hence catheter morbidity.

Urinary catheter-associated microbiota change in accordance with treatment and infection status

The use of long-term catheterisation to manage insensate bladders, often associated with spinal cord injury (SCI), increases the risk of microbial colonisation and infection of the urinary tract. Urinary tract infection (UTI) is typically diagnosed and treated based on the culturing of organisms from the urine, although this approach overlooks low titer, slow growing and non-traditional pathogens. Here, we present an investigation of the urinary tract microbiome in catheterised SCI individuals, using T-RFLP and metagenomic sequencing of the microbial community. We monitored three neurogenic patients over a period of 12 months, who were part of a larger study investigating the efficacy of probiotics in controlling UTIs, to determine how their urinary tract microbial community composition changed over time and in relation to probiotic treatment regimens. Bacterial biofilms adherent to urinary catheters were examined as a proxy for bladder microbes. The microbial community composition of the urinary tract differed significantly between individuals. Probiotic therapy resulted in a significant change in the microbial community associated with the catheters. The community also changed as a consequence of UTI and this shift in community composition preceded the clinical diagnosis of infection. Changes in the microbiota due to probiotic treatment or infection were transient, resolving to microbial communities similar to their pre-treatment communities, suggesting that the native community was highly resilient. Based on these results, we propose that monitoring a patient's microbial community can be used to track the health of chronically catheterized patients and thus, can be used as part of a health-status monitoring program.

Systematic Review of Interventions to Reduce Urinary Tract Infection in Nursing Home Residents

BACKGROUND

Urinary tract infections (UTIs) in nursing homes are common, costly, and morbid.

PURPOSE

Systematic literature review of strategies to reduce UTIs in nursing home residents.

DATA SOURCES

Ovid MEDLINE, Cochrane Library, CINAHL, Web of Science and Embase through June 22, 2015.

STUDY SELECTION

Interventional studies with a comparison group reporting at least 1 outcome for: catheter-associated UTI (CAUTI), UTIs not identified as catheter-associated, bacteriuria, or urinary catheter use.

DATA EXTRACTION

Two authors abstracted study design, participant and intervention details, outcomes, and quality measures.

DATA SYNTHESIS

Of 5794 records retrieved, 20 records describing 19 interventions were included: 8 randomized controlled trials, 10 pre-post nonrandomized interventions, and 1 nonrandomized intervention with concurrent controls. Quality (range, 8-25; median, 15) and outcome definitions varied greatly. Thirteen studies employed strategies to reduce catheter use or improve catheter care; 9 studies employed general infection prevention strategies (eg, improving hand hygiene, surveillance, contact precautions, reducing antibiotics). The 19 studies reported 12 UTI outcomes, 9 CAUTI outcomes, 4 bacteriuria outcomes, and 5 catheter use outcomes. Five studies showed CAUTI reduction (1 significantly); 9 studies showed UTI reduction (none significantly); 2 studies showed bacteriuria reduction (none significantly). Four studies showed reduced catheter use (1 significantly).

LIMITATIONS

Studies were often underpowered to assess statistical significance; none were pooled given variety of interventions and outcomes.

CONCLUSIONS

Several practices, often implemented in bundles, such as improving hand hygiene, reducing and improving catheter use, managing incontinence without catheters, and enhanced barrier precautions, appear to reduce UTI or CAUTI in nursing home residents. Journal of Hospital Medicine 2017;12:356-368.

Antibiotic resistance patterns of bacteria isolated from indwelling Foley catheters following tube cystostomy in goats with obstructive urolithiasis

Tube cystostomy is a surgical method used for managing obstructive urolithiasis and involves placement of a Foley catheter into the urinary bladder. We identified and evaluated the antibiotic resistance patterns of bacteria isolated from indwelling Foley catheters following tube cystostomy in goats with obstructive urolithiasis. Urine samples collected over a 10-y period from catheter tips at the time of removal were submitted for bacteriologic culture and antibiotic susceptibility testing. Resistance patterns to antibiotics, trends in the resistance patterns over the study period, and the probability of a bacterial isolate being resistant as a function of the identity of the isolate and antibiotic tested were determined. A total of 103 urine samples from 103 male goats with obstructive urolithiasis managed surgically with tube cystostomy were included in the study. Aerococcus (36.9%) and Enterococcus (30.1%) were isolated most frequently. The susceptibility patterns of all bacteria isolated did not change over the study period ( p > 0.05). Proportions of isolates resistant to 1, 2, and ≥3 antibiotics were 36.9%, 18.5%, and 23.3%, respectively. Thus, 41.8% of bacterial isolates were resistant to 2 or more antibiotics tested. The probability of Aerococcus spp., Escherichia coli, and Pseudomonas aeruginosa isolates to be resistant to ampicillin, ceftiofur, erythromycin, penicillin, or tetracycline ranged from 0.59 to 0.76.

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

More than 75% of hospital-acquired or nosocomial urinary tract infections are initiated by urinary catheters, which are used during the treatment of 15-25% of hospitalized patients. Among other purposes, urinary catheters are primarily used for draining urine after surgeries and for urinary incontinence. During catheter-associated urinary tract infections, bacteria travel up to the bladder and cause infection. A major cause of catheter-associated urinary tract infection is attributed to the use of non-ideal materials in the fabrication of urinary catheters. Such materials allow for the colonization of microorganisms, leading to bacteriuria and infection, depending on the severity of symptoms. The ideal urinary catheter is made out of materials that are biocompatible, antimicrobial, and antifouling. Although an abundance of research has been conducted over the last forty-five years on the subject, the ideal biomaterial, especially for long-term catheterization of more than a month, has yet to be developed. The aim of this review is to highlight the recent advances (over the past 10years) in developing antimicrobial materials for urinary catheters and to outline future requirements and prospects that guide catheter materials selection and design.

STATEMENT OF SIGNIFICANCE

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.

Does the presence of a urinary catheter predict severe sepsis in a bacteraemic cohort?

BACKGROUND

Sepsis is a major cause of mortality with an estimated 37,000 deaths in the UK each year. This study aimed to determine host factors that can predict severe sepsis in a bacteraemic cohort.

METHODS

From December 2012 to November 2013, demographic, clinical and microbiological data were collected on consecutive patients with bacteraemia at a London teaching hospital. These data were used to categorize patients as having severe or non-severe sepsis. Multi-variate logistic regression was used to determine the association between host factors and severe sepsis.

FINDINGS

Five hundred and ninety-four bacteraemic episodes occurred in 500 patients. The majority of cases were in patients aged >50 years (382/594, 64.3%) and in males (346/594, 58.2%). The most common isolates were Escherichia coli (207/594, 34.8%) and meticillin-susceptible Staphylococcus aureus (57/594, 9.6%). In logistic regression multi-variable analysis, site of infection was significantly associated with severe sepsis. For catheter-associated urinary tract infections, the association was significant after adjustment for age, sex, Charlson comorbidity index and where infection was acquired (odds ratio 3.94, 95% confidence interval 1.70-9.11).

CONCLUSIONS

Urinary catheters increase the risk of severe sepsis. They should only be used if clinically indicated. If inserted, a care bundle approach should be used and the anticipated removal date should be recorded unless a long-term catheter is required. In the context of sepsis, the presence of a urinary catheter should prompt immediate implementation of 'Sepsis Six' and consideration of transfer to a critical care unit.