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Cometta S, Hutmacher DW, Chai L. In vitro models for studying implant-associated biofilms - A review from the perspective of bioengineering 3D microenvironments. Biomaterials 2024; 309:122578. [PMID: 38692146 DOI: 10.1016/j.biomaterials.2024.122578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 04/01/2024] [Accepted: 04/13/2024] [Indexed: 05/03/2024]
Abstract
Biofilm research has grown exponentially over the last decades, arguably due to their contribution to hospital acquired infections when they form on foreign body surfaces such as catheters and implants. Yet, translation of the knowledge acquired in the laboratory to the clinic has been slow and/or often it is not attempted by research teams to walk the talk of what is defined as 'bench to bedside'. We therefore reviewed the biofilm literature to better understand this gap. Our search revealed substantial development with respect to adapting surfaces and media used in models to mimic the clinical settings, however many of the in vitro models were too simplistic, often discounting the composition and properties of the host microenvironment and overlooking the biofilm-implant-host interactions. Failure to capture the physiological growth conditions of biofilms in vivo results in major differences between lab-grown- and clinically-relevant biofilms, particularly with respect to phenotypic profiles, virulence, and antimicrobial resistance, and they essentially impede bench-to-bedside translatability. In this review, we describe the complexity of the biological processes at the biofilm-implant-host interfaces, discuss the prerequisite for the development and characterization of biofilm models that better mimic the clinical scenario, and propose an interdisciplinary outlook of how to bioengineer biofilms in vitro by converging tissue engineering concepts and tools.
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Affiliation(s)
- Silvia Cometta
- Max Planck Queensland Centre, Queensland University of Technology, Brisbane, QLD 4000, Australia; Faculty of Engineering, School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia; Australian Research Council (ARC) Training Centre for Multiscale 3D Imaging, Modelling, and Manufacturing (M3D Innovation), Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Dietmar W Hutmacher
- Max Planck Queensland Centre, Queensland University of Technology, Brisbane, QLD 4000, Australia; Faculty of Engineering, School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia; Australian Research Council (ARC) Training Centre for Multiscale 3D Imaging, Modelling, and Manufacturing (M3D Innovation), Queensland University of Technology, Brisbane, QLD 4000, Australia; Australian Research Council Training Centre for Cell and Tissue Engineering Technologies, Queensland University of Technology, Brisbane, QLD 4059, Australia.
| | - Liraz Chai
- Max Planck Queensland Centre, Queensland University of Technology, Brisbane, QLD 4000, Australia; The Hebrew University of Jerusalem, Institute of Chemistry, Jerusalem, 91904, Israel; The Harvey M. Krueger Family Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
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2
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Watson F, Wilks S, Keevil CW, Chewins J. Modelling hospital disinfectant against multi-drug-resistant dry surface biofilms grown under artificial human sweat. J Hosp Infect 2023; 141:190-197. [PMID: 37343768 DOI: 10.1016/j.jhin.2023.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 06/08/2023] [Accepted: 06/13/2023] [Indexed: 06/23/2023]
Abstract
BACKGROUND Dry surface biofilms (DSBs) have been found abundantly across hospital surfaces within intensive care units and may explain how nosocomial pathogens can remain virulent and persist on surfaces for extended periods. Testing standards governing the performance of disinfectant products employ planktonic models under routine growth conditions, which are known to be less tolerant than their biofilm counterpart. AIM To evaluate biofilm models cultured under artificial human sweat (AHS), a source of nutrient expected on touch surfaces, to assess the antimicrobial performance of common cleaning agents, including a quaternary ammonium, hydrogen peroxide and active chlorine. METHODS Five single-species biofilms, using pathogenic bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis, were generated on stainless-steel substrates using a sedimentation protocol under both AHS and nutrient-rich conditions for a direct comparison of phenotypic tolerance. The biofilm models were grown over five days followed by desiccation cycles, before being submerged into the disinfectant solutions for up to 25 min. Epifluorescence (EF) microscopy using LIVE/DEAD™ stain was used to visualize microcolony viability. FINDINGS The results revealed biofilms cultured under AHS exhibited a greater antimicrobial tolerance and reduced speed of kill for all cleaning agents compared with the routine media; an average reduction of 72.4% vs 96.9%, respectively. EF microscopy revealed traces of viable bacteria across all coupons after disinfection indicating a potential opportunity for regrowth and recontamination. CONCLUSION The notable difference in biocidal performance between the two growth conditions highlights potential pitfalls within current antimicrobial test standards, and the importance of accurate representation of the microbial challenge.
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Affiliation(s)
- F Watson
- School of Biological Sciences, University of Southampton, Southampton, UK; Bioquell UK Ltd, Andover, UK
| | - S Wilks
- School of Biological Sciences, University of Southampton, Southampton, UK; School of Health Sciences, University of Southampton, Southampton, UK
| | - C W Keevil
- School of Biological Sciences, University of Southampton, Southampton, UK
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3
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Watson F, Chewins J, Wilks S, Keevil B. An automated contact model for transmission of dry surface biofilms of Acinetobacter baumannii in healthcare. J Hosp Infect 2023; 141:175-183. [PMID: 37348564 DOI: 10.1016/j.jhin.2023.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 06/24/2023]
Abstract
BACKGROUND Dry surface biofilms (DSBs) have been recognized across environmental and equipment surfaces in hospitals and could explain how microbial contamination can survive for an extended period and may play a key role in the transmission of hospital-acquired infections. Despite little being known on how they form and proliferate in clinical settings, DSB models for disinfectant efficacy testing exist. AIM In this study we develop a novel biofilm model to represent formation within hospitals, by emulating patient to surface interactions. METHODS The model generates a DSB through the transmission of artificial human sweat (AHS) and clinically relevant pathogens using a synthetic thumb capable of emulating human contact. The DNA, glycoconjugates and protein composition of the model biofilm, along with structural features of the micro-colonies was determined using fluorescent stains visualized by epifluorescence microscopy and compared with published clinical data. RESULTS Micrographs revealed the heterogeneity of the biofilm across the surface; and reveal protein as the principal component within the matrix, followed by glycoconjugates and DNA. The model repeatably transferred trace amounts of micro-organisms and AHS, every 5 min for up to 120 h on to stainless-steel coupons to generate a biofilm model averaging 1.16 × 103 cfu/cm2 falling within the reported range for clinical DSB (4.20 × 102 to 1.60 × 107 bacteria/cm2). CONCLUSION Our in vitro DSB model exhibits many phenotypical characteristics and traits to those reported in situ. The model highlights key features often overlooked and the potential for downstream applications such as antibiofilm claims using more realistic microbial challenges.
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Affiliation(s)
- F Watson
- School of Biological Sciences, University of Southampton, Southampton, UK; Bioquell UK Ltd, Andover, UK.
| | | | - S Wilks
- School of Biological Sciences, University of Southampton, Southampton, UK; School of Health Sciences, University of Southampton, Southampton, UK
| | - B Keevil
- School of Biological Sciences, University of Southampton, Southampton, UK
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4
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Yazdani-Ahmadabadi H, Yu K, Khoddami S, F. Felix D, Yeh HH, Luo HD, Moskalev I, Wang Q, Wang R, Grecov D, Fazli L, Lange D, Kizhakkedathu JN. Robust Nanoparticle-Derived Lubricious Antibiofilm Coating for Difficult-to-Coat Medical Devices with Intricate Geometry. ACS NANOSCIENCE AU 2023; 3:67-83. [PMID: 36820095 PMCID: PMC9936578 DOI: 10.1021/acsnanoscienceau.2c00040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 06/18/2023]
Abstract
A major medical device-associated complication is the biofilm-related infection post-implantation. One promising approach to prevent this is to coat already commercialized medical devices with effective antibiofilm materials. However, developing a robust high-performance antibiofilm coating on devices with a nonflat geometry remains unmet. Here, we report the development of a facile scalable nanoparticle-based antibiofilm silver composite coating with long-term activity applicable to virtually any objects including difficult-to-coat commercially available medical devices utilizing a catecholic organic-aqueous mixture. Using a screening approach, we have identified a combination of the organic-aqueous buffer mixture which alters polycatecholamine synthesis, nanoparticle formation, and stabilization, resulting in controlled deposition of in situ formed composite silver nanoparticles in the presence of an ultra-high-molecular-weight hydrophilic polymer on diverse objects irrespective of its geometry and chemistry. Methanol-mediated synthesis of polymer-silver composite nanoparticles resulted in a biocompatible lubricious coating with high mechanical durability, long-term silver release (∼90 days), complete inhibition of bacterial adhesion, and excellent killing activity against a diverse range of bacteria over the long term. Coated catheters retained their excellent activity even after exposure to harsh mechanical challenges (rubbing, twisting, and stretching) and storage conditions (>3 months stirring in water). We confirmed its excellent bacteria-killing efficacy (>99.999%) against difficult-to-kill bacteria (Proteus mirabilis) and high biocompatibility using percutaneous catheter infection mice and subcutaneous implant rat models, respectively, in vivo. The developed coating approach opens a new avenue to transform clinically used medical devices (e.g., urinary catheters) to highly infection-resistant devices to prevent and treat implant/device-associated infections.
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Affiliation(s)
- Hossein Yazdani-Ahmadabadi
- Department
of Chemistry, University of British Columbia, Vancouver V6T 1Z3, British Columbia, Canada
- Centre
for Blood Research, Life Science Institute, University of British Columbia, Vancouver V6T 1Z3, British
Columbia, Canada
| | - Kai Yu
- Centre
for Blood Research, Life Science Institute, University of British Columbia, Vancouver V6T 1Z3, British
Columbia, Canada
- Department
of Pathology and Laboratory Medicine, University
of British Columbia, Vancouver V6T 1Z7, British Columbia, Canada
| | - Sara Khoddami
- Department
of Urologic Sciences, University of British
Columbia, Vancouver V6H 3Z6, British Columbia, Canada
- The
Stone Centre at Vancouver General Hospital, Vancouver V5Z 1M9, British Columbia, Canada
| | - Demian F. Felix
- Department
of Urologic Sciences, University of British
Columbia, Vancouver V6H 3Z6, British Columbia, Canada
- The
Stone Centre at Vancouver General Hospital, Vancouver V5Z 1M9, British Columbia, Canada
| | - Han H. Yeh
- Department
of Mechanical Engineering, University of
British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Haiming D. Luo
- Department
of Chemistry, University of British Columbia, Vancouver V6T 1Z3, British Columbia, Canada
- Centre
for Blood Research, Life Science Institute, University of British Columbia, Vancouver V6T 1Z3, British
Columbia, Canada
| | - Igor Moskalev
- Vancouver
Prostate Centre, University of British Columbia, Vancouver V6H 3Z6, British Columbia, Canada
| | - Qiong Wang
- Department
of Materials Engineering, University of
British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Rizhi Wang
- Department
of Materials Engineering, University of
British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- School
of Biomedical Engineering, University of
British Columbia, Vancouver V6T 1Z3, British Columbia, Canada
| | - Dana Grecov
- Department
of Mechanical Engineering, University of
British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Ladan Fazli
- Vancouver
Prostate Centre, University of British Columbia, Vancouver V6H 3Z6, British Columbia, Canada
| | - Dirk Lange
- Department
of Urologic Sciences, University of British
Columbia, Vancouver V6H 3Z6, British Columbia, Canada
- The
Stone Centre at Vancouver General Hospital, Vancouver V5Z 1M9, British Columbia, Canada
| | - Jayachandran N. Kizhakkedathu
- Department
of Chemistry, University of British Columbia, Vancouver V6T 1Z3, British Columbia, Canada
- Centre
for Blood Research, Life Science Institute, University of British Columbia, Vancouver V6T 1Z3, British
Columbia, Canada
- Department
of Pathology and Laboratory Medicine, University
of British Columbia, Vancouver V6T 1Z7, British Columbia, Canada
- School
of Biomedical Engineering, University of
British Columbia, Vancouver V6T 1Z3, British Columbia, Canada
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Lila ASA, Rajab AAH, Abdallah MH, Rizvi SMD, Moin A, Khafagy ES, Tabrez S, Hegazy WAH. Biofilm Lifestyle in Recurrent Urinary Tract Infections. LIFE (BASEL, SWITZERLAND) 2023; 13:life13010148. [PMID: 36676100 PMCID: PMC9865985 DOI: 10.3390/life13010148] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/27/2022] [Accepted: 12/30/2022] [Indexed: 01/06/2023]
Abstract
Urinary tract infections (UTIs) represent one of the most common infections that are frequently encountered in health care facilities. One of the main mechanisms used by bacteria that allows them to survive hostile environments is biofilm formation. Biofilms are closed bacterial communities that offer protection and safe hiding, allowing bacteria to evade host defenses and hide from the reach of antibiotics. Inside biofilm communities, bacteria show an increased rate of horizontal gene transfer and exchange of resistance and virulence genes. Additionally, bacterial communication within the biofilm allows them to orchestrate the expression of virulence genes, which further cements the infestation and increases the invasiveness of the infection. These facts stress the necessity of continuously updating our information and understanding of the etiology, pathogenesis, and eradication methods of this growing public health concern. This review seeks to understand the role of biofilm formation in recurrent urinary tact infections by outlining the mechanisms underlying biofilm formation in different uropathogens, in addition to shedding light on some biofilm eradication strategies.
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Affiliation(s)
- Amr S. Abu Lila
- Department of Pharmaceutics, College of Pharmacy, University of Ha’il, Ha’il 81442, Saudi Arabia
- Molecular Diagnostics and Personalized Therapeutics Unit, University of Ha’il, Ha’il 81442, Saudi Arabia
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
- Correspondence: (A.S.A.L.); (W.A.H.H.)
| | - Azza A. H. Rajab
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Marwa H. Abdallah
- Department of Pharmaceutics, College of Pharmacy, University of Ha’il, Ha’il 81442, Saudi Arabia
- Molecular Diagnostics and Personalized Therapeutics Unit, University of Ha’il, Ha’il 81442, Saudi Arabia
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Syed Mohd Danish Rizvi
- Department of Pharmaceutics, College of Pharmacy, University of Ha’il, Ha’il 81442, Saudi Arabia
- Molecular Diagnostics and Personalized Therapeutics Unit, University of Ha’il, Ha’il 81442, Saudi Arabia
| | - Afrasim Moin
- Department of Pharmaceutics, College of Pharmacy, University of Ha’il, Ha’il 81442, Saudi Arabia
- Molecular Diagnostics and Personalized Therapeutics Unit, University of Ha’il, Ha’il 81442, Saudi Arabia
| | - El-Sayed Khafagy
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Shams Tabrez
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Wael A. H. Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
- Pharmacy Program, Department of Pharmaceutical Sciences, Oman College of Health Sciences, Muscat 113, Oman
- Correspondence: (A.S.A.L.); (W.A.H.H.)
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Effect of phytate on crystallization on ureteral stents and bacterial attachment: an in vitro study. Urolithiasis 2022; 50:737-742. [PMID: 36064981 PMCID: PMC9584848 DOI: 10.1007/s00240-022-01350-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/05/2022] [Indexed: 11/10/2022]
Abstract
The use of double J ureteral stents can lead to several adverse effects, as urinary infection. Bacteria tend to colonize the stent surface, leading to the formation of bacterial biofilms. The presence of urease-producing bacteria increase the urine pH leading to the incrustation and blockage of the stent. On the other hand, these large crystalline masses function as niduses, allowing the attachment of even more bacteria and decreasing its exposure to antibiotics. The aim of this in vitro study was to assess the effect of phytate on the attachment of bacteria to the catheter surface under conditions that favor crystallization. Catheter sections were incubated in a synthetic urine medium (pH 6.5) in the presence or absence of Pseudomonas aeruginosa and phytate. Amount of calcium deposits was measured using an Arsenazo III colorimetric method and the number of attached bacteria to the stent was determined. Differences were assessed using an ANOVA with a Bonferroni post hoc test. The formation of calcium phosphate deposits (brushite and hydroxyapatite) and oxalate crystals (COM), as were as the amount of bacteria decreased when phytate was present. Thus, phytate successfully decreased bacterial adhesion by inhibiting the formation of crystalline deposits.
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7
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Gmiter D, Kaca W. Into the understanding the multicellular lifestyle of Proteus mirabilis on solid surfaces. Front Cell Infect Microbiol 2022; 12:864305. [PMID: 36118021 PMCID: PMC9478170 DOI: 10.3389/fcimb.2022.864305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 08/15/2022] [Indexed: 11/17/2022] Open
Abstract
Indwelling urinary catheterization can lead to the development of catheter-associated urinary tract infections (CAUTIs), an important type of nosocomial infection, as well as other medical issues among institutionalized adults. Recently, Proteus mirabilis was highlighted as the important cause of CAUTIs. The pathogenicity of P. mirabilis is dependent on two multicellular types of surface colonization: the adherence and swarming motility. Adhesion, mostly mediated by fimbrial and nonfimbrial adhesins, is important for the initiation of biofilm formation. Moreover, the production of urease frequently results in biofilm crystallization, which leads to the blockage of catheters. The heterologous polymeric matrix of the biofilm offers protection against antibiotics and the host immune system. P. mirabilis displays remarkable motility abilities. After contact with solid surfaces, hyper-flagellated cells are able to rapidly migrate. The importance of swarming motility in CAUTIs development remains controversial; however, it was indicated that swarming cells were able to co-express other virulence factors. Furthermore, flagella are strong immunomodulating proteins. On the other hand, both biofilm formation and swarming motility implicates multiple inter- and intraspecies interactions, which might contribute to the pathogenicity.
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8
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The effect of fluoroquinolones and antioxidans on biofilm formation by Proteus mirabilis strains. Ann Clin Microbiol Antimicrob 2022; 21:22. [PMID: 35655208 PMCID: PMC9161520 DOI: 10.1186/s12941-022-00515-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 05/03/2022] [Indexed: 11/18/2022] Open
Abstract
Background Fluoroquinolones are a group of antibiotics used in urinary tract infections. Unfortunately, resistance to this group of drugs is currently growing. The combined action of fluoroquinolones and other antibacterial and anti-biofilm substances may extend the use of this therapeutic option by clinicians. The aim of the study was to determine the effect of selected fluoroquinolones and therapeutic concentrations of ascorbic acid and rutoside on biofilm formation by Proteus mirabilis. Materials and methods The study included 15 strains of P. mirabilis isolated from urinary tract infections in patients of the University Hospital No. 1 dr A. Jurasz in Bydgoszcz (Poland). The metabolic activity of the biofilm treated with 0.4 mg/ml ascorbic acid, 0.02 µg/ml rutoside and chemotherapeutic agents (ciprofloxacin, norfloxacin) in the concentration range of 0.125–4.0 MIC (minimum inhibitory concentration) was assessed spectrophotometrically. Results Both ciprofloxacin and norfloxacin inhibited biofilm formation by the tested strains. The biofilm reduction rate was correlated with the increasing concentration of antibiotic used. No synergism in fluoroquinolones with ascorbic acid, rutoside or both was found. The ascorbic acid and rutoside combination, however, significantly decreased biofilm production. Conclusions Our research proves a beneficial impact of ascorbic acid with rutoside supplementation on biofilm of P. mirabilis strains causing urinary tract infections.
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9
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Mosayyebi A, Vijayakumar A, Mosayebi M, Lange D, Somani BK, Manes C, Carugo D. The accumulation of particles in ureteric stents is mediated by flow dynamics: Full-scale computational and experimental modeling of the occluded and unoccluded ureter. APL Bioeng 2022; 6:026102. [PMID: 35540726 PMCID: PMC9076127 DOI: 10.1063/5.0083260] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 04/11/2022] [Indexed: 01/19/2023] Open
Abstract
Ureteric stents are clinically deployed to restore urinary drainage in the presence of ureteric occlusions. They consist of a hollow tube with multiple side-holes that enhance urinary drainage. The stent surface is often subject to encrustation (induced by crystals-forming bacteria such as Proteus mirabilis) or particle accumulation, which may compromise stent's drainage performance. Limited research has, however, been conducted to evaluate the relationship between flow dynamics and accumulation of crystals in stents. Here, we employed a full-scale architecture of the urinary system to computationally investigate the flow performance of a ureteric stent and experimentally determine the level of particle accumulation over the stent surface. Particular attention was given to side-holes, as they play a pivotal role in enhancing urinary drainage. Results demonstrated that there exists an inverse correlation between wall shear stress (WSS) and crystal accumulation at side-holes. Specifically, side-holes with greater WSS levels were those characterized by inter-compartmental fluid exchange between the stent and ureter. These "active" side-holes were located either nearby ureteric obstructions or at regions characterized by a physiological constriction of the ureter. Results also revealed that the majority of side-holes (>60%) suffer from low WSS levels and are, thus, prone to crystals accumulation. Moreover, side-holes located toward the proximal region of the ureter presented lower WSS levels compared to more distal ones, thus suffering from greater particle accumulation. Overall, findings corroborate the role of WSS in modulating the localization and extent of particle accumulation in ureteric stents.
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Affiliation(s)
| | - Aravinthan Vijayakumar
- Department of Mechanical Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Maryam Mosayebi
- Department of Mechanical Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Dirk Lange
- Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver V6H 3Y8, Canada
| | - Bhaskar K. Somani
- Department of Urology, University Hospital Southampton NHS Trust, Southampton SO16 6YD, United Kingdom
| | - Costantino Manes
- Department of Environment, Land and Infrastructure Engineering, Politecnico di Torino, Turin 10129, Italy
| | - Dario Carugo
- Department of Pharmaceutics, UCL School of Pharmacy, University College London (UCL), London WC1N 1AX, United Kingdom
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10
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Artificial Human Sweat as a Novel Growth Condition for Clinically Relevant Pathogens on Hospital Surfaces. Microbiol Spectr 2022; 10:e0213721. [PMID: 35357242 PMCID: PMC9045197 DOI: 10.1128/spectrum.02137-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The emergence of biofilms on dry hospital surfaces has led to the development of numerous models designed to challenge the efficacious properties of common antimicrobial agents used in cleaning. This is in spite of limited research defining how dry surfaces are able to facilitate biofilm growth and formation in such desiccating and nutrient-deprived environments. While it is well established that the phenotypical response of biofilms is dependent on the conditions in which they are formed, most models incorporate a nutrient-enriched, hydrated environment dissimilar to the clinical setting. In this study, we piloted a novel culture medium, artificial human sweat (AHS), which is perceived to be more indicative of the nutrient sources available on hospital surfaces, particularly those in close proximity to patients. AHS was capable of sustaining the proliferation of four clinically relevant multidrug-resistant pathogens (Acinetobacter baumannii, Staphylococcus aureus, Enterococcus faecalis, and Pseudomonas aeruginosa) and achieved biofilm formation at concentration levels equivalent to those found in situ (average, 6.00 log10 CFU/cm2) with similar visual characteristics upon microscopy. The AHS model presented here could be used for downstream applications, including efficacy testing of hospital cleaning products, due to its resemblance to clinical biofilms on dry surfaces. This may contribute to a better understanding of the true impact these products have on surface hygiene. IMPORTANCE Precise modeling of dry surface biofilms in hospitals is critical for understanding their role in hospital-acquired infection transmission and surface contamination. Using a representative culture condition which includes a nutrient source is key to developing a phenotypically accurate biofilm community. This will enable accurate laboratory testing of cleaning products and their efficacy against dry surface biofilms.
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11
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Clark C, Haslam C, Malde S, Panicker JN. Urinary catheter management: what neurologists need to know. Pract Neurol 2021; 21:504-514. [PMID: 34753810 DOI: 10.1136/practneurol-2020-002772] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/2021] [Indexed: 12/22/2022]
Abstract
Patients with neurological disorders often have lower urinary tract dysfunction, manifesting as urinary retention or urinary incontinence, and so commonly use catheters. Neurologists should therefore be aware of the different types of catheters and appliances and their risks, benefits and complications. Clean intermittent self-catheterisation is preferable to an indwelling catheter; however, if this is not possible, then a suprapubic indwelling catheter is preferable to a urethral catheter for long-term management. We review the decision-making process when selecting catheters for neurological patients, the evidence base regarding the different options and how neurologists can recognise and address complications. We also discuss alternatives to catheterisation, such as non-invasive containment products and surgical treatments, and the indications for urological referral.
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Affiliation(s)
- Calum Clark
- Department of Urology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Collette Haslam
- Department of Uro-Neurology, The National Hospital for Neurology and Neurosurgery, London, UK
| | - Sachin Malde
- Department of Urology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Jalesh N Panicker
- Department of Uro-Neurology, The National Hospital for Neurology and Neurosurgery, London, UK .,Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, University College London, London, UK
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12
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Rice CJ, Kelly SA, O’Brien SC, Melaugh EM, Ganacias JCB, Chai ZH, Gilmore BF, Skvortsov T. Novel Phage-Derived Depolymerase with Activity against Proteus mirabilis Biofilms. Microorganisms 2021; 9:2172. [PMID: 34683494 PMCID: PMC8539402 DOI: 10.3390/microorganisms9102172] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 12/18/2022] Open
Abstract
The adherence of Proteus mirabilis to the surface of urinary catheters leads to colonization and eventual blockage of the catheter lumen by unique crystalline biofilms produced by these opportunistic pathogens, making P. mirabilis one of the leading causes of catheter-associated urinary tract infections. The Proteus biofilms reduce efficiency of antibiotic-based treatment, which in turn increases the risk of antibiotic resistance development. Bacteriophages and their enzymes have recently become investigated as alternative treatment options. In this study, a novel Proteus bacteriophage (vB_PmiS_PM-CJR) was isolated from an environmental sample and fully characterized. The phage displayed depolymerase activity and the subsequent genome analysis revealed the presence of a pectate lyase domain in its tail spike protein. The protein was heterologously expressed and purified; the ability of the purified tail spike to degrade Proteus biofilms was tested. We showed that the application of the tail spike protein was able to reduce the adherence of bacterial biofilm to plastic pegs in a MBEC (minimum biofilm eradication concentration) assay and improve the survival of Galleria mellonella larvae infected with Proteus mirabilis. Our study is the first to successfully isolate and characterize a biofilm depolymerase from a Proteus phage, demonstrating the potential of this group of enzymes in treatment of Proteus infections.
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Affiliation(s)
| | | | | | | | | | | | | | - Timofey Skvortsov
- School of Pharmacy, Queen’s University Belfast, Belfast BT9 7BL, UK; (C.J.R.); (S.A.K.); (S.C.O.); (E.M.M.); (J.C.B.G.); (Z.H.C.); (B.F.G.)
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13
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Gayani B, Dilhari A, Kottegoda N, Ratnaweera DR, Weerasekera MM. Reduced Crystalline Biofilm Formation on Superhydrophobic Silicone Urinary Catheter Materials. ACS OMEGA 2021; 6:11488-11496. [PMID: 34056304 PMCID: PMC8154006 DOI: 10.1021/acsomega.1c00560] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/09/2021] [Indexed: 05/14/2023]
Abstract
Crystalline biofilm formation in indwelling urinary catheters is a serious health problem as it creates a barrier for antibacterial coatings. This emphasizes the failure of antibacterial coatings that do not have a mechanism to reduce crystal deposition on catheter surfaces. In this study, trifluoropropyl spray-coated polydimethylsiloxane (TFP-PDMS) has been employed as an antibiofilm forming surface without any antibacterial agent. Here, TFP was coated on half-cured PDMS using the spray coating technique to obtain a durable superhydrophobic coating for a minimum five cycles of different sterilization methods. The crystalline biofilm-forming ability of Proteus mirabilis in artificial urine, under static and flow conditions, was assessed on a TFP-PDMS surface. In comparison to the commercially available silver-coated latex and silicone catheter surfaces, TFP-PDMS displayed reduced bacterial attachment over 14 days. Moreover, the elemental analysis determined by atomic absorption spectroscopy and energy-dispersive X-ray analysis revealed that the enhanced antibiofilm forming ability of TFP-PDMS was due to the self-cleaning activity of the surface. We believe that this modified surface will significantly reduce biofilm formation in indwelling urinary catheters and further warrant future clinical studies.
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Affiliation(s)
- Buddhika Gayani
- Department
of Chemistry, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda 10250, Sri Lanka
- Centre
for Advanced Material Research, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda 10250, Sri Lanka
| | - Ayomi Dilhari
- Department
of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda 10250, Sri Lanka
| | - Nilwala Kottegoda
- Department
of Chemistry, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda 10250, Sri Lanka
- Centre
for Advanced Material Research, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda 10250, Sri Lanka
| | - Dilru R. Ratnaweera
- Department
of Chemistry, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda 10250, Sri Lanka
- Centre
for Advanced Material Research, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda 10250, Sri Lanka
| | - Manjula Manoji Weerasekera
- Department
of Chemistry, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda 10250, Sri Lanka
- Department
of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda 10250, Sri Lanka
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14
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Biofilm Development on Urinary Catheters Promotes the Appearance of Viable but Nonculturable Bacteria. mBio 2021; 12:mBio.03584-20. [PMID: 33758085 PMCID: PMC8092313 DOI: 10.1128/mbio.03584-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Several antimicrobial urinary catheter materials have been developed, but, although laboratory studies may show a benefit, none have significantly improved clinical outcomes. The use of poorly designed laboratory testing and lack of consideration of the impact of VBNC populations may be responsible. Catheter-associated urinary tract infections have serious consequences, for both patients and health care resources. Much work has been carried out to develop an antimicrobial catheter. Although such developments have shown promise under laboratory conditions, none have demonstrated a clear advantage in clinical trials. Using a range of microbiological and advanced microscopy techniques, a detailed laboratory study comparing biofilm development on silicone, hydrogel latex, and silver alloy-coated hydrogel latex catheters was carried out. Biofilm development by Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis on three commercially available catheters was tracked over time. Samples were examined with episcopic differential interference contrast (EDIC) microscopy, culture analysis, and staining techniques to quantify viable but nonculturable (VBNC) bacteria. Both qualitative and quantitative assessments found biofilms to develop rapidly on all three materials. EDIC microscopy revealed the rough surface topography of the materials. Differences between culture counts and quantification of total and dead cells demonstrated the presence of VBNC populations, where bacteria retain viability but are not metabolically active. The use of nonculture-based techniques showed the development of widespread VBNC populations. These VBNC populations were more evident on silver alloy-coated hydrogel latex catheters, indicating a bacteriostatic effect at best. The laboratory tests reported here, which detect VBNC bacteria, allow more rigorous assessment of antimicrobial catheters, explaining why there is often minimal benefit to patients.
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15
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Ramachandra M, Mosayyebi A, Carugo D, Somani BK. Strategies to Improve Patient Outcomes and QOL: Current Complications of the Design and Placements of Ureteric Stents. Res Rep Urol 2020; 12:303-314. [PMID: 32802807 PMCID: PMC7403435 DOI: 10.2147/rru.s233981] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/19/2020] [Indexed: 12/13/2022] Open
Abstract
Ureteric stents have played a vital role in relieving urinary obstruction in many urological conditions. Although they are extremely successful, stents have been associated with complications and reduced patients' health-related quality of life (HRQoL). There are many factors that may affect the quality and longevity of stents. In this review, we have highlighted the journey and innovation of ureteric stents through the modern day. A literature review was conducted to identify relevant articles over the last 20 years. There is a plethora of evidence with various indications for the use of ureteral stents and how they affect QoL. There is still ongoing research to develop the ideal stent with reduced encrustation, one that resists infection and is also comfortable for the patients. Stents made from metal alloys, polymers and biodegradable materials have unique properties in their own right but also have certain deficiencies. These have been discussed along with an overview of newly developed stents. Certain pharmacological adjuncts have also been highlighted that may be useful to improve patient's tolerance to stents. In summary, this paper describes the features of the different types of stents and the problems that are frequently encountered, including effect on patients' HRQoL and financial burden to healthcare providers.
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Affiliation(s)
- Meghana Ramachandra
- Department of Urology, University Hospital Southampton NHS Trust, Southampton, UK
| | - Ali Mosayyebi
- Mechanical Engineering Department, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
- Institute for Life Sciences (IfLS), University of Southampton, UK
| | - Dario Carugo
- Mechanical Engineering Department, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
- Institute for Life Sciences (IfLS), University of Southampton, UK
| | - Bhaskar K Somani
- Department of Urology, University Hospital Southampton NHS Trust, Southampton, UK
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16
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Shaaban M, Abd El-Rahman OA, Al-Qaidi B, Ashour HM. Antimicrobial and Antibiofilm Activities of Probiotic Lactobacilli on Antibiotic-Resistant Proteus mirabilis. Microorganisms 2020; 8:microorganisms8060960. [PMID: 32604867 PMCID: PMC7355612 DOI: 10.3390/microorganisms8060960] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 06/20/2020] [Accepted: 06/23/2020] [Indexed: 12/01/2022] Open
Abstract
The emergence of biofilm-forming, multi-drug-resistant (MDR) Proteus mirabilis infections is a serious threat that necessitates non-antibiotic therapies. Antibiotic susceptibility and biofilm-forming activity of P. mirabilis isolates from urine samples were assessed by disc diffusion and crystal violet assays, respectively. Antimicrobial activities of probiotic Lactobacilli were evaluated by agar diffusion. Antibiofilm and anti-adherence activities were evaluated by crystal violet assays. While most P. mirabilis isolates were antibiotic-resistant to varying degrees, isolate P14 was MDR (resistant to ceftazidime, cefotaxime, amoxicillin-clavulanic acid, imipenem, ciprofloxacin, and amikacin) and formed strong biofilms. Cultures and cell-free supernatants of Lactobacillus casei and Lactobacillus reuteri exhibited antimicrobial and antibiofilm activities. The 1/16 concentration of untreated supernatants of L. casei and L. reuteri significantly reduced mature biofilm formation and adherence of P14 by 60% and 72%, respectively (for L. casei), and by 73% each (for L. reuteri). The 1/8 concentration of pH-adjusted supernatants of L. casei and L. reuteri significantly reduced mature biofilm formation and adherence of P14 by 39% and 75%, respectively (for L. casei), and by 73% each (for L. reuteri). Scanning electron microscopy (SEM) confirmed eradication of P14’s biofilm by L. casei. L. casei and L. reuteri could be utilized to combat Proteus-associated urinary tract infections.
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Affiliation(s)
- Mona Shaaban
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt;
| | - Ola A. Abd El-Rahman
- Department of Microbiology and Immunology, Faculty of Pharmacy (Girls), Al-Azhar University, Cairo 11651, Egypt;
| | - Bashair Al-Qaidi
- Madinah Maternity and Children Hospital, Madinah 42319, Saudi Arabia;
| | - Hossam M. Ashour
- Department of Biological Sciences, College of Arts and Sciences, University of South Florida St. Petersburg, St. Petersburg, FL 33701, USA
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
- Correspondence:
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17
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Lai HC, Chang SN, Lin HC, Hsu YL, Wei HM, Kuo CC, Hwang KP, Chiang HY. Association between urine pH and common uropathogens in children with urinary tract infections. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2019; 54:290-298. [PMID: 31604680 DOI: 10.1016/j.jmii.2019.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 08/19/2019] [Accepted: 08/31/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND/PURPOSE Urinary tract infections (UTIs) are one of the most common pediatric infections. Our objective in this study is to investigate the association between urine pH and uropathogens in pediatric patients. METHODS The source population comprised 26 066 paired urinalysis (UA) and urine culture (UC) samples obtained from pediatric patients. We classified the paired UA-UC samples into UTI positive (N = 6348) and UTI negative (N = 19 718) according to the colony forming units corresponding to the sampling source. We included UTI positive patients with infection caused by a single species of pathogen (N = 5201) and frequency matched them with UTI negative patients (N = 4729) by age, sex, sampling source, and visit type. RESULTS This study included 5201 pediatric patients with UTIs and found that urine with Proteus mirabilis or Pseudomonas aeruginosa demonstrated the least acidic pH (mean pH = 6.72 and 6.62, respectively), whereas urine with Escherichia coli or Klebsiella pneumoniae exhibited the most acidic pH (pH = 6.21 and 6.18). After stratifying the UTI samples by their pH range (<6, 6-6.9, 7-7.9, and ≥8). The prevalence of P. mirabilis increased significantly across increasing pH categories. CONCLUSION This research is the first epidemiological study that linked urine pH to specific uropathogens in a pediatric population. Both urine pH and age are associated with certain causative uropathogens. Urine that grew P. mirabilis or P. aeruginosa had the least acidic pH. Additional studies should validate the role of urine pH in predicting uropathogens and UTI.
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Affiliation(s)
- Huan-Cheng Lai
- Division of Pediatric Infectious Diseases, China Medical University Children's Hospital, China Medical University, Taichung, Taiwan
| | - Shih-Ni Chang
- Big Data Center, China Medical University Hospital, Taichung, Taiwan; The PhD Program for Cancer Biology and Drug Discovery, College of Medicine, China Medical University, Taichung, Taiwan
| | - Hsiao-Chuan Lin
- Division of Pediatric Infectious Diseases, China Medical University Children's Hospital, China Medical University, Taichung, Taiwan; School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan
| | - Yu-Lung Hsu
- Division of Pediatric Infectious Diseases, China Medical University Children's Hospital, China Medical University, Taichung, Taiwan
| | - Hsiu-Mei Wei
- Division of Pediatric Infectious Diseases, China Medical University Children's Hospital, China Medical University, Taichung, Taiwan
| | - Chin-Chi Kuo
- Big Data Center, China Medical University Hospital, Taichung, Taiwan; School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; Kidney Institute, China Medical University Hospital, Taichung, Taiwan
| | - Kao-Pin Hwang
- Division of Pediatric Infectious Diseases, China Medical University Children's Hospital, China Medical University, Taichung, Taiwan; School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan.
| | - Hsiu-Yin Chiang
- Big Data Center, China Medical University Hospital, Taichung, Taiwan.
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18
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Pelling H, Nzakizwanayo J, Milo S, Denham EL, MacFarlane WM, Bock LJ, Sutton JM, Jones BV. Bacterial biofilm formation on indwelling urethral catheters. Lett Appl Microbiol 2019; 68:277-293. [PMID: 30811615 DOI: 10.1111/lam.13144] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/22/2019] [Accepted: 02/23/2019] [Indexed: 12/21/2022]
Abstract
Urethral catheters are the most commonly deployed medical devices and used to manage a wide range of conditions in both hospital and community care settings. The use of long-term catheterization, where the catheter remains in place for a period >28 days remains common, and the care of these patients is often undermined by the acquisition of infections and formation of biofilms on catheter surfaces. Particular problems arise from colonization with urease-producing species such as Proteus mirabilis, which form unusual crystalline biofilms that encrust catheter surfaces and block urine flow. Encrustation and blockage often lead to a range of serious clinical complications and emergency hospital referrals in long-term catheterized patients. Here we review current understanding of bacterial biofilm formation on urethral catheters, with a focus on crystalline biofilm formation by P. mirabilis, as well as approaches that may be used to control biofilm formation on these devices. SIGNIFICANCE AND IMPACT OF THE STUDY: Urinary catheters are the most commonly used medical devices in many healthcare systems, but their use predisposes to infection and provide ideal conditions for bacterial biofilm formation. Patients managed by long-term urethral catheterization are particularly vulnerable to biofilm-related infections, with crystalline biofilm formation by urease producing species frequently leading to catheter blockage and other serious clinical complications. This review considers current knowledge regarding biofilm formation on urethral catheters, and possible strategies for their control.
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Affiliation(s)
- H Pelling
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, UK
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - J Nzakizwanayo
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, UK
| | - S Milo
- Department of Chemistry, University of Bath, Claverton Down, Bath, UK
| | - E L Denham
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, UK
| | - W M MacFarlane
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - L J Bock
- National Infections Service, Public Health England, Porton Down, Salisbury, UK
| | - J M Sutton
- National Infections Service, Public Health England, Porton Down, Salisbury, UK
| | - B V Jones
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, UK
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19
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Abstract
Proteus mirabilis, a Gram-negative rod-shaped bacterium most noted for its swarming motility and urease activity, frequently causes catheter-associated urinary tract infections (CAUTIs) that are often polymicrobial. These infections may be accompanied by urolithiasis, the development of bladder or kidney stones due to alkalinization of urine from urease-catalyzed urea hydrolysis. Adherence of the bacterium to epithelial and catheter surfaces is mediated by 17 different fimbriae, most notably MR/P fimbriae. Repressors of motility are often encoded by these fimbrial operons. Motility is mediated by flagella encoded on a single contiguous 54-kb chromosomal sequence. On agar plates, P. mirabilis undergoes a morphological conversion to a filamentous swarmer cell expressing hundreds of flagella. When swarms from different strains meet, a line of demarcation, a "Dienes line," develops due to the killing action of each strain's type VI secretion system. During infection, histological damage is caused by cytotoxins including hemolysin and a variety of proteases, some autotransported. The pathogenesis of infection, including assessment of individual genes or global screens for virulence or fitness factors has been assessed in murine models of ascending urinary tract infections or CAUTIs using both single-species and polymicrobial models. Global gene expression studies performed in culture and in the murine model have revealed the unique metabolism of this bacterium. Vaccines, using MR/P fimbria and its adhesin, MrpH, have been shown to be efficacious in the murine model. A comprehensive review of factors associated with urinary tract infection is presented, encompassing both historical perspectives and current advances.
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20
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Laube N, Bernsmann F, Fisang C. Individualisierte Patientenversorgung mit urologischen Implantaten durch biofilmabweisende Oberflächenkonzepte. Urologe A 2019; 58:143-150. [DOI: 10.1007/s00120-018-0623-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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21
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Mosayyebi A, Lange D, Yann Yue Q, Somani BK, Zhang X, Manes C, Carugo D. Reducing deposition of encrustation in ureteric stents by changing the stent architecture: A microfluidic-based investigation. BIOMICROFLUIDICS 2019; 13:014101. [PMID: 30867872 PMCID: PMC6404931 DOI: 10.1063/1.5059370] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 12/18/2018] [Indexed: 05/08/2023]
Abstract
Ureteric stents are clinically deployed to retain ureteral patency in the presence of an obstruction of the ureter lumen. Despite the fact that multiple stent designs have been researched in recent years, encrustation and biofilm-associated infections remain significant complications of ureteral stenting, potentially leading to the functional failure of the stent. It has been suggested that "inactive" side-holes of stents may act as anchoring sites for encrusting crystals, as they are associated with low wall shear stress (WSS) levels. Obstruction of side-holes due to encrustation is particularly detrimental to the function of the stent, since holes provide a path for urine to by-pass the occlusion. Therefore, there is an unmet need to develop novel stents to reduce deposition of encrusting particles at side-holes. In this study, we employed a stent-on-chip microfluidic model of the stented and occluded ureter to investigate the effect of stent architecture on WSS distribution and encrustation over its surface. Variations in the stent geometry encompassed (i) the wall thickness and (ii) the shape of side-holes. Stent thickness was varied in the range 0.3-0.7 mm, while streamlined side-holes of triangular shape were evaluated (with a vertex angle in the range 45°-120°). Reducing the thickness of the stent increased WSS and thus reduced the encrustation rate at side-holes. A further improvement in performance was achieved by using side-holes with a triangular shape; notably, a 45° vertex angle showed superior performance compared to other angles investigated, resulting in a significant increase in WSS within "inactive" side-holes. In conclusion, combining the optimal stent thickness (0.3 mm) and hole vertex angle (45°) resulted in a ∼90% reduction in encrustation rate within side-holes, compared to a standard design. If translated to a full-scale ureteric stent, this optimised architecture has the potential for significantly increasing the stent lifetime while reducing clinical complications.
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Affiliation(s)
| | - D. Lange
- Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver V6H 3Y8, Canada
| | - Q. Yann Yue
- Department of Mechanical Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - B. K. Somani
- Department of Urology, University Hospital Southampton NHS Trust, Southampton SO16 6YD, United Kingdom
| | | | - C. Manes
- Department of Environment, Land and Infrastructure Engineering, Politecnico di Torino, Turin 10129, Italy
| | - D. Carugo
- Author to whom correspondence should be addressed:
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22
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Modelling vaporised hydrogen peroxide efficacy against mono-species biofilms. Sci Rep 2018; 8:12257. [PMID: 30115938 PMCID: PMC6095907 DOI: 10.1038/s41598-018-30706-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 07/30/2018] [Indexed: 01/14/2023] Open
Abstract
This pilot study investigates a novel approach towards efficacy testing of antimicrobial cleaning agents; focusing primarily on hydrogen peroxide vapour (HPV). Contaminated surfaces are recognised modes of pathogen transmission within healthcare environments and increase the risk of pathogen acquisition in newly admitted patients. Studies have shown these pathogens can survive on surfaces for extended periods of time in spite of cleaning. This resilience is characteristic of biofilm formation and recent publications have identified their presence in hospitals. In this study, biofilm models comprised of multidrug-resistant organisms (MDROs) were generated using a drip flow reactor and exposed to HPV decontamination. The MDROs included Acinetobacter baumannii, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. Upon exposure, samples were periodically removed and enumerated to generate kill curves for each species. Consequently revealing any inherent resistances; such as catalase-producing organisms which expressed reduced susceptibility. Epifluorescence microscopy revealed an abundance of viable and non-viable microcolonies before and after decontamination, respectively. Greater than 6-Log10 reduction was achieved within a 100 minutes exposure time. This pilot study puts forward a potential methodology for testing antimicrobial agents against biofilms and supports the efficacy of HPV.
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23
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Mosayyebi A, Yue QY, Somani BK, Zhang X, Manes C, Carugo D. Particle Accumulation in Ureteral Stents Is Governed by Fluid Dynamics: In Vitro Study Using a “Stent-on-Chip” Model. J Endourol 2018; 32:639-646. [DOI: 10.1089/end.2017.0946] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
- Ali Mosayyebi
- Mechanical Engineering Department, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom
- Institute for Life Sciences (IfLS), University of Southampton, Southampton, United Kingdom
| | - Qi Yann Yue
- Mechanical Engineering Department, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom
| | - Bhaskar K. Somani
- Department of Urology, University Hospital Southampton NHS Trust, Southampton, United Kingdom
| | - Xunli Zhang
- Mechanical Engineering Department, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom
- Institute for Life Sciences (IfLS), University of Southampton, Southampton, United Kingdom
| | - Costantino Manes
- Department of Environment, Land and Infrastructure Engineering, Politecnico di Torino, Turin, Italy
| | - Dario Carugo
- Mechanical Engineering Department, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom
- Institute for Life Sciences (IfLS), University of Southampton, Southampton, United Kingdom
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24
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Murphy C. Innovating urinary catheter design: An introduction to the engineering challenge. Proc Inst Mech Eng H 2018; 233:48-57. [PMID: 29792114 DOI: 10.1177/0954411918774348] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Every day, people around the world rely on intermittent and indwelling urinary catheters to manage bladder dysfunction, but the potential or actual harm caused by these devices is well-recognised. Current catheter designs can cause urinary tract infection and septicaemia, bladder and urethral trauma and indwelling devices frequently become blocked. Furthermore, the devices can severely disrupt users' lives, limiting their daily activities and can be costly to manage for healthcare providers. Despite this, little significant design innovation has taken place in the last 80 years. In this article current catheter designs and their limitations are reviewed, common catheter-associated problems are outlined and areas of design ripe for improvement proposed. The potential to relieve the individual and economic burden of catheter use is high.
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Affiliation(s)
- Cathy Murphy
- Clinical Academic Facility, Faculty of Health Sciences, University of Southampton, Southampton, UK
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25
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Frant M, Dayyoub E, Bakowsky U, Liefeith K. Evaluation of a ureteral catheter coating by means of a BioEncrustation in vitro model. Int J Pharm 2018; 546:86-96. [PMID: 29752980 DOI: 10.1016/j.ijpharm.2018.04.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 04/11/2018] [Accepted: 04/12/2018] [Indexed: 02/01/2023]
Abstract
Biomaterials for applications in the urinary tract are challenged with both biofilm formation and encrustation, two highly interconnected processes. While great effort has been achieved developing promising materials there is only a limited choice of sophisticated in vitro models that are available to analyse the performance of biomaterials prior to performing delicate and expensive in vivo studies. In this study we present a complex BioEncrustation model that imitates both the processes of multi-species biofilm formation and encrustation in vitro. The resulting crystalline biofilms are compared to the deposits found on explanted ureteral stent surfaces (in vivo situation) and to deposits formed in an experimental set up that does not contain bacteria (Encrustator®). Further focus of this study is dedicated to employing the developed BioEncrustation model to evaluate the effect multifunctional coatings impose on the processes of biofilm formation and encrustation under in vitro conditions. The investigated TANP coating combines unspecific and broad band specific antibacterial properties with a degrading polymer matrix that is intended to inhibit crystal formation. The coating was prepared on both polyurethane and silicone tubes and the subsequent results of the in vitro BioEncrustation analyses reveal a promising potential for employing the coating to render ureteral stent surfaces more biocompatible.
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Affiliation(s)
- M Frant
- Department of Biomaterials, Institute for Bioprocessing and Analytical Measurement Techniques e.V. (iba), Rosenhof, 37308 Heilbad Heiligenstadt, Germany
| | - E Dayyoub
- Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, 35037 Marburg, Germany
| | - U Bakowsky
- Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, 35037 Marburg, Germany
| | - K Liefeith
- Department of Biomaterials, Institute for Bioprocessing and Analytical Measurement Techniques e.V. (iba), Rosenhof, 37308 Heilbad Heiligenstadt, Germany.
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Abstract
Purpose of Review There are three technological parameters that play a key role on the performance of an ideal stent. These are its material, design and surface coating. This article highlights some fundamental developments that took place in these three areas of stent’s technology, in order to contribute to the identification of an ideal stent. Recent Findings In addition to technological developments concerning stent’s material, design and surface coating, the flow dynamic performance of stents has recently attracted increasing attention. Notably, it has been postulated that the local flow field in a stent is correlated with the deposition of crystals and microorganisms. These findings could potentially revolutionise future stent’s designs, and complement developments made on materials and coatings. Summary The most relevant changes in materials, designs and surface coatings of ureteric stents are reviewed in this article. These are described in the context of a specific cause of stent’s failure they aim to address, with a particular focus on encrustation and biofilm formation.
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Affiliation(s)
- Ali Mosayyebi
- Bioengineering Science Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK. .,Institute for Life Sciences (IfLS), University of Southampton, Southampton, UK.
| | - Costantino Manes
- Department of Environment, Land and Infrastructure Engineering, Politecnico di Torino, Turin, Italy
| | - Dario Carugo
- Bioengineering Science Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK.,Institute for Life Sciences (IfLS), University of Southampton, Southampton, UK
| | - Bhaskar K Somani
- Department of Urology, University Hospital Southampton NHS Trust, Southampton, UK
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Shepherd AJ, Mackay WG, Hagen S. Catheter washout solutions for long-term urinary catheterisation in adults: A Cochrane review summary. Int J Nurs Stud 2018; 82:167-170. [PMID: 29510831 DOI: 10.1016/j.ijnurstu.2017.10.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | - William Gordon Mackay
- Institute of Healthcare Policy and Practice, University of the West of Scotland, United Kingdom
| | - Suzanne Hagen
- Nursing, Midwifery and Allied Health Professions Research Unit, Glasgow Caledonian University, United Kingdom
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28
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Evaluation of Biofilm Induced Urinary Infection Stone Formation in a Novel Laboratory Model System. J Urol 2018; 199:178-185. [DOI: 10.1016/j.juro.2017.08.083] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2017] [Indexed: 11/23/2022]
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29
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Milo S, Hathaway H, Nzakizwanayo J, Alves DR, Esteban PP, Jones BV, Jenkins ATA. Prevention of encrustation and blockage of urinary catheters by Proteus mirabilis via pH-triggered release of bacteriophage. J Mater Chem B 2017; 5:5403-5411. [PMID: 32264080 DOI: 10.1039/c7tb01302g] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The crystalline biofilms of Proteus mirabilis can seriously complicate the care of patients undergoing long-term indwelling urinary catheterisation. Expression of bacterial urease causes a significant increase in urinary pH, leading to the supersaturation and precipitation of struvite and apatite crystals. These crystals become lodged within the biofilm, resulting in the blockage of urine flow through the catheter. Here, we describe an infection-responsive surface coating for urinary catheters, which releases a therapeutic dose of bacteriophage in response to elevated urinary pH, in order to delay catheter blockage. The coating employs a dual-layered system comprising of a lower hydrogel 'reservoir' layer impregnated with bacteriophage, capped by a 'trigger' layer of the pH-responsive polymer poly(methyl methacrylate-co-methacrylic acid) (EUDRAGIT®S 100). Evaluation of prototype coatings using a clinically reflective in vitro bladder model system showed that catheter blockage time was doubled (13 h to 26 h (P < 0.05)) under conditions of established infection (108 CFU ml-1) in response to a 'burst-release' of bacteriophage (108 PFU ml-1). Coatings were stable both in the absence of infection, and in the presence of urease-negative bacteria. Quantitative and visual analysis of crystalline biofilm reduction show that bacteriophage constitute a promising strategy for the prevention of catheter blockage, a clinical problem for which there is currently no effective control method.
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Affiliation(s)
- Scarlet Milo
- Department of Chemistry, University of Bath, BA2 7AY, UK.
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30
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Shepherd AJ, Mackay WG, Hagen S. Washout policies in long-term indwelling urinary catheterisation in adults. Cochrane Database Syst Rev 2017; 3:CD004012. [PMID: 28262925 PMCID: PMC6464626 DOI: 10.1002/14651858.cd004012.pub5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND People requiring long-term bladder draining with an indwelling catheter can experience catheter blockage. Regimens involving different solutions can be used to wash out catheters with the aim of preventing blockage. This is an update of a review published in 2010. OBJECTIVES To determine if certain washout regimens are better than others in terms of effectiveness, acceptability, complications, quality of life and critically appraise and summarise economic evidence for the management of long-term indwelling urinary catheterisation in adults. SEARCH METHODS We searched the Cochrane Incontinence Group Specialised Trials Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE In-Process, MEDLINE Epub Ahead of Print, CINAHL, ClinicalTrials.gov, WHO ICTRP and handsearching of journals and conference proceedings to 23 May 2016. We also examined all reference lists of identified trials and contacted manufacturers and researchers in the field. SELECTION CRITERIA All randomised and quasi-randomised trials comparing catheter washout policies (e.g. washout versus no washout, different washout solutions, frequency, duration, volume, concentration, method of administration) in adults (aged 16 years and above) in any setting (i.e. hospital, nursing/residential home, community) with an indwelling urethral or suprapubic catheter for more than 28 days. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data. Disagreements were resolved by discussion. Data were assessed and analysed as described in the Cochrane Handbook. If data in trials were not fully reported, clarification was sought from the study authors. For categorical outcomes, the numbers reporting an outcome were related to the numbers at risk in each group to derive a risk ratio (RR). For continuous outcomes, means and standard deviations were used to derive mean differences (MD). MAIN RESULTS We included seven trials involving a total of 349 participants, 217 of whom completed the studies. Three were cross-over and four were parallel-group randomised controlled trials (RCTs). Of these, two trials were added for this update (one parallel-group RCT with 40 participants and one cross-over RCT with 67 participants). Analyses of three cross-over trials yielded suboptimal results because they were based on between-group differences rather than individual participants' differences for sequential interventions. Two parallel-group trials had limited clinical value: one combined results for suprapubic and urethral catheters and the other provided data for only four participants. Only one trial was free of significant methodological limitations, but there were difficulties with recruitment and maintaining participants in this study.The included studies reported data on six of the nine primary and secondary outcome measures. None of the trials addressed: number of catheters used, washout acceptability measures (including patient satisfaction, patient discomfort, pain and ease of use), or health status/measures of psychological health; very limited data were collected for health economic outcomes. Trials assessed only three of the eight intervention comparisons identified. Two trials reported in more than one comparison group.Four trials compared washout (either saline or acidic solution) with no washout. We are uncertain if washout solutions (saline or acidic), compared to no washout solutions, has an important effect on the rate of symptomatic urinary tract infection or length of time each catheter was in situ because the results are imprecise.Four trials compared different types of washout solution; saline versus acidic solutions (2 trials); saline versus acidic solution versus antibiotic solution (1 trial); saline versus antimicrobial solution (1 trial). We are uncertain if type of washout solution has an important effect on the rate of symptomatic urinary tract infection or length of time each catheter was in situ because the results are imprecise.One trial compared different compositions of acidic solution (stronger versus weaker solution). We are uncertain if different compositions of acidic solutions has an important effect on the rate of symptomatic urinary tract infection or length of time each catheter was in situ because only 14 participants (of 25 who were recruited) completed this 12 week, three arm trial.Four studies reported on possible harmful effects of washout use, such as blood in the washout solution, changes in blood pressure and bladder spasms.There were very few small trials that met the review inclusion criteria. The high risk of bias of the included studies resulted in the evidence being graded as low or very low quality. AUTHORS' CONCLUSIONS Data from seven trials that compared different washout policies were limited, and generally, of poor methodological quality or were poorly reported. The evidence was not adequate to conclude if washouts were beneficial or harmful. Further rigorous, high quality trials that are adequately powered to detect benefits from washout being performed as opposed to no washout are needed. Trials comparing different washout solutions, washout volumes, and frequencies or timings are also needed.
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Affiliation(s)
- Ashley J Shepherd
- University of StirlingFaculty of Health Sciences and SportBridge of AllanStirlingUKFK9 4LA
| | - William G Mackay
- University of the West of ScotlandInstitute of Healthcare Policy and Practice, Health, Nursing and MidwiferyHigh StreetPaisleyRenfrewshireUKPA1 2BE
| | - Suzanne Hagen
- Glasgow Caledonian UniversityNursing, Midwifery and Allied Health Professions Research UnitGlasgowUKG4 0BA
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Norsworthy AN, Pearson MM. From Catheter to Kidney Stone: The Uropathogenic Lifestyle of Proteus mirabilis. Trends Microbiol 2016; 25:304-315. [PMID: 28017513 DOI: 10.1016/j.tim.2016.11.015] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/17/2016] [Accepted: 11/28/2016] [Indexed: 12/15/2022]
Abstract
Proteus mirabilis is a model organism for urease-producing uropathogens. These diverse bacteria cause infection stones in the urinary tract and form crystalline biofilms on indwelling urinary catheters, frequently leading to polymicrobial infection. Recent work has elucidated how P. mirabilis causes all of these disease states. Particularly exciting is the discovery that this bacterium forms large clusters in the bladder lumen that are sites for stone formation. These clusters, and other steps of infection, require two virulence factors in particular: urease and MR/P fimbriae. Highlighting the importance of MR/P fimbriae is the cotranscribed regulator, MrpJ, which globally controls virulence. Overall, P. mirabilis exhibits an extraordinary lifestyle, and further probing will answer exciting basic microbiological and clinically relevant questions.
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Affiliation(s)
- Allison N Norsworthy
- Department of Microbiology, New York University Medical Center, New York, NY, USA
| | - Melanie M Pearson
- Department of Microbiology, New York University Medical Center, New York, NY, USA; Department of Urology, New York University Medical Center, New York, NY, USA; Current address: University of Michigan Medical School, Department of Microbiology and Immunology, 5641 Medical Science Building II, 1150 West Medical Center Dr., Ann Arbor, MI 48109-0620, USA.
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Li X, Lu N, Brady HR, Packman AI. Biomineralization strongly modulates the formation ofProteus mirabilisandPseudomonas aeruginosadual-species biofilms. FEMS Microbiol Ecol 2016; 92:fiw189. [DOI: 10.1093/femsec/fiw189] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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33
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Ipe DS, Horton E, Ulett GC. The Basics of Bacteriuria: Strategies of Microbes for Persistence in Urine. Front Cell Infect Microbiol 2016; 6:14. [PMID: 26904513 PMCID: PMC4744864 DOI: 10.3389/fcimb.2016.00014] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 01/22/2016] [Indexed: 01/09/2023] Open
Abstract
Bacteriuria, the presence of bacteria in urine, is associated with asymptomatic, as well as symptomatic, urinary tract infection (UTI). Bacteriuria underpins some of the dynamics of microbial colonization of the urinary tract, and probably impacts the progression and persistence of infection in some individuals. Recent molecular discoveries in vitro have elucidated how some key bacterial traits can enable organisms to survive and grow in human urine as a means of microbial fitness adaptation for UTI. Several microbial characteristics that confer bacteruric potential have been identified including de novo synthesis of guanine, relative resistance to D-serine, and catabolism of malic acid. Microbial characteristics such as these are increasingly being defined through the use of synthetic human urine (SHU) in vitro as a model to mimic the in vivo environment that bacteria encounter in the bladder. There is considerable variation in the SHU model systems that have been used to study bacteriuria to date, and this influences the utility of these models. In this review, we discuss recent advances in our understanding of bacteruric potential with a focus on the specific mechanisms underlying traits that promote the growth of bacteria in urine. We also review the application of SHU in research studies modeling UTI and discuss the chemical makeup, and benefits and limitations that are encountered in utilizing SHU to study bacterial growth in urine in vitro.
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Affiliation(s)
| | | | - Glen C. Ulett
- School of Medical Science, Menzies Health Institute Queensland, Griffith UniversityGold Coast, QLD, Australia
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