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Heidtmann CV, Fejer AR, Stærk K, Pedersen M, Asmussen MG, Hertz FB, Prabhala BK, Frimodt-Møller N, Klitgaard JK, Andersen TE, Nielsen CU, Nielsen P. Hit-to-Lead Identification and Validation of a Triaromatic Pleuromutilin Antibiotic Candidate. J Med Chem 2024; 67:3692-3710. [PMID: 38385364 DOI: 10.1021/acs.jmedchem.3c02153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Herein, we report the hit-to-lead identification of a drug-like pleuromutilin conjugate 16, based on a triaromatic hit reported in 2020. The lead arose as the clear candidate from a hit-optimization campaign in which Gram-positive antibacterial activity, solubility, and P-gp affinity were optimized. Conjugate 16 was extensively evaluated for its in vitro ADMET performance which, apart from solubility, was overall on par with lefamulin. This evaluation included Caco-2 cell permeability, plasma protein binding, hERG inhibition, cytotoxicity, metabolism in microsomes and CYP3A4, resistance induction, and time-kill kinetics. Intravenous pharmacokinetics of 16 proved satisfactory in both mice and pigs; however, oral bioavailability was limited likely due to insufficient solubility. The in vivo efficacy was evaluated in mice, systemically infected with Staphylococcus aureus, where 16 showed rapid reduction in blood bacteriaemia. Through our comprehensive studies, lead 16 has emerged as a highly promising and safe antibiotic candidate for the treatment of Gram-positive bacterial infections.
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Affiliation(s)
- Christoffer V Heidtmann
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Andreas R Fejer
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Kristian Stærk
- Department of Clinical Research, Research Unit of Clinical Microbiology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Maria Pedersen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Marco G Asmussen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Frederik B Hertz
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark
| | - Bala K Prabhala
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Niels Frimodt-Møller
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark
| | - Janne K Klitgaard
- Department of Clinical Research, Research Unit of Clinical Microbiology, University of Southern Denmark, DK-5230 Odense M, Denmark
- Department of Biochemistry and Molecular Biology, Research Unit of Molecular Microbiology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Thomas E Andersen
- Department of Clinical Research, Research Unit of Clinical Microbiology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Carsten U Nielsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Poul Nielsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
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Stærk K, Schrøder B, Jensen LK, Petersen T, Andersen TE, Nielsen LF. Catheter-associated bladder mucosal trauma during intermittent voiding: An experimental study in pigs. BJUI Compass 2024; 5:217-223. [PMID: 38371199 PMCID: PMC10869658 DOI: 10.1002/bco2.295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/23/2023] [Accepted: 09/09/2023] [Indexed: 02/20/2024] Open
Abstract
Objective The objective of this study is to characterize bladder mucosal trauma associated with intermittent catheterization with conventional eyelet catheters (CECs) and to assess if a microhole zone catheter (MHZC) design concept reduces this adverse effect. Materials and Methods A porcine model was developed to reflect human catheterization and bladder drainage. Nine pigs were randomized for catheterization with CEC (n = 6) or MHZC (n = 3). The bladder was drained repeatedly 20 times through the catheter. Cystoscopy was performed before and after the procedure, and bladders were analysed by histopathology. Two additional pigs were used for cystoscopy visualization of suction events in vivo. Cystoscopy, gross pathology, histopathological score, leucocyte infiltration, and intracatheter pressure at flow stops during voiding were compared for each group. Results A significant higher pressure gradient was measured inside the CECs compared with MHZCs during flow stop. Consequently, CECs resulted in suction events inflicting bladder trauma characterized by loss of epithelium, oedema, haemorrhage, and neutrophil tissue infiltration. No significant trauma was identified when using MHZC. Conclusions Considerable mucosal bladder trauma is inflicted by CECs which may be an overlooked risk factor for urinary tract infection. Catheters can be designed to minimize mucosal suction and reduce associated trauma. This may be a solution to reduce infection frequency and increase user comfort. Furthermore, the study demonstrates the potential of pigs as an attractive animal model for investigating urinary catheter performances.
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Affiliation(s)
- Kristian Stærk
- Department of Clinical Research University of Southern Denmark Odense Denmark
- Department of Clinical Microbiology Odense University Hospital Odense Denmark
| | - Brit Schrøder
- Preclinical, R&D, Innovation Coloplast A/S Humlebaek Denmark
| | | | - Troels Petersen
- Preclinical, R&D, Innovation Coloplast A/S Humlebaek Denmark
| | - Thomas Emil Andersen
- Department of Clinical Research University of Southern Denmark Odense Denmark
- Department of Clinical Microbiology Odense University Hospital Odense Denmark
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3
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Stærk K, Langhorn L, Halle B, Andersen TE. Urinary bladder catheterisation of female pigs: Influence of bladder content and Escherichia coli urinary tract infection on procedural outcome. Lab Anim 2024:236772231169344. [PMID: 38334709 DOI: 10.1177/00236772231169344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Catheterisation of the urinary bladder is needed in many types of human disease models in pigs. Based on our extensive experience with the pig as an infection model, we here demonstrate an approach of catheterising domestic pigs (40 attempts) and Göttingen minipigs (10 attempts) using a blinded method, that is, without speculums or videoscopes to visualise the urethral opening. The procedure was tested on control animals and pigs with experimental Escherichia coli urinary tract infection (UTI) to assess the potential influence of this condition on procedural outcome. Lastly, we performed cystoscopy in three animals to visualise the route to the urethra and to localise potential anatomical obstacles. All domestic pigs were catheterised successfully in an average of 2 minutes and 23 seconds, and this was not influenced by UTI (p = 0.06) or bladder urine content at the time of catheterisation (p = 0.32). All Göttingen minipigs were successfully catheterised in an average of 4 minutes and 27 seconds. We conclude that blinded catheterisation is a fast and reliable approach that can be performed in pigs with or without UTI with minimal risk of trauma or contamination.
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Affiliation(s)
- Kristian Stærk
- Department of Clinical Microbiology, Odense University Hospital, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Denmark
| | - Louise Langhorn
- Biomedical laboratory, University of Southern Denmark, Denmark
| | - Bo Halle
- Department of Neurosurgery, Odense University Hospital, Denmark
| | - Thomas Emil Andersen
- Department of Clinical Microbiology, Odense University Hospital, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Denmark
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4
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Schrøder B, Tentor F, Miclăuş T, Stærk K, Andersen TE, Spinelli M, Rendeli C, Del Popolo G, Bagi P, Nielsen LF. New micro-hole zone catheter reduces residual urine and mucosal microtrauma in a lower urinary tract model. Sci Rep 2024; 14:2268. [PMID: 38280939 PMCID: PMC10821950 DOI: 10.1038/s41598-024-52505-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 01/19/2024] [Indexed: 01/29/2024] Open
Abstract
Urinary tract infections (UTIs) are the main complication associated with clean intermittent catheterization (CIC) and are facilitated by post-void residual urine and trauma to the mucosa during voiding. The risk of UTI may be diminished by reducing the residual volumes and preventing microtrauma caused by mucosal suction through the eyelets of conventional eyelet catheters (CEC). A new micro-hole zone catheter (MHZC) was developed and tested in an ex vivo porcine lower urinary tract model and in vivo, in pigs, against a CEC. It was shown that, irrespective of the micro-hole diameter, the new catheter ensured increased flowrates and significantly lower residual volumes at the first flow-stop. Furthermore, with a micro-hole diameter of 0.4 mm, mucosal suction was virtually eliminated, regardless of the insertion depth or simulated intra-abdominal pressure mimicking sitting or standing humans. Pressure profile experiments and endoscopy studies indicated that the bladder gradually folds against the drainage tip of the new catheter, without blocking the flow, and, unlike with the CEC, sharp pressure variations and flow-stops did not occur during voiding. The MHZC outperformed the CEC in all tested scenarios and decreased residual volumes, thus potentially decreasing the risk of UTIs.
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Affiliation(s)
| | - Fabio Tentor
- Coloplast A/S, Holtedam 1, 3050, Humlebaek, Denmark
| | | | - Kristian Stærk
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
| | - Thomas Emil Andersen
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
| | | | - Claudia Rendeli
- Department of Pediatrics, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Giulio Del Popolo
- Neuro-Urology Department, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Per Bagi
- Department of Urology, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
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Kern K, Delaroque N, Boysen A, Puder M, Wendt R, Kölsch A, Ehrentreich-Förster E, Stærk K, Andersen TE, Andersen K, Lund L, Szardenings M. Glycosylation of bacterial antigens changes epitope patterns. Front Immunol 2023; 14:1258136. [PMID: 37954588 PMCID: PMC10637626 DOI: 10.3389/fimmu.2023.1258136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/21/2023] [Indexed: 11/14/2023] Open
Abstract
Introduction Unlike glycosylation of proteins expressed in mammalian systems, bacterial glycosylation is often neglected in the development of recombinant vaccines. Methods Here, we compared the effects of glycosylation of YghJ, an Escherichia coli protein important for mucus attachment of bacteria causing in urinary tract infections (UTIs). A novel method based on statistical evaluation of phage display for the identification and comparison of epitopes and mimotopes of anti-YghJ antibodies in the sera was used. This is the first time that the effect of glycosylation of a recombinant bacterial antigen has been studied at the peptide epitope level. Results The study identifies differences in the immune response for (non)-glycosylated antigens in rabbits and pigs and compares them to a large group of patients with UTI, which have been diagnosed as positive for various bacterial pathogens. We identified glycosylation-specific peptide epitopes, a large immunological similarity between different UTI pathogens, and a broad peptide epitope pattern in patients and animals, which could result in a variable response in patients upon vaccination. Discussion This epitope analysis indicates that the vaccination of rabbits and pigs raises antibodies that translate well into the human immune system. This study underlines the importance of glycosylation in bacterial vaccines and provides detailed immune diagnostic methods to understand individual immune responses to vaccines.
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Affiliation(s)
- Karolin Kern
- Ligand Development Unit, Fraunhofer Institute for Cell Therapy and Immunology (IZI), Leipzig, Germany
- Epitopic, Leipzig, Germany
| | - Nicolas Delaroque
- Ligand Development Unit, Fraunhofer Institute for Cell Therapy and Immunology (IZI), Leipzig, Germany
| | | | | | - Ralph Wendt
- Department of Nephrology, St. Georg Hospital Leipzig, Leipzig, Germany
| | - Andreas Kölsch
- MicroDiagnostics Unit, Fraunhofer Institute for Cell Therapy and Immunology (IZI), Leipzig, Germany
| | - Eva Ehrentreich-Förster
- Molekulare und Zelluläre Bioanalytik Unit, Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), Golm, Germany
| | - Kristian Stærk
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
| | - Thomas Emil Andersen
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
| | - Karin Andersen
- Department of Urology, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Lars Lund
- Department of Urology, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Michael Szardenings
- Ligand Development Unit, Fraunhofer Institute for Cell Therapy and Immunology (IZI), Leipzig, Germany
- Epitopic, Leipzig, Germany
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6
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Stærk K, Jensen LK, Andersen TE. Evaluation of urine dipstick tests in experimental porcine urinary tract infection with uropathogenic Escherichia coli. Sci Rep 2023; 13:12404. [PMID: 37524716 PMCID: PMC10390499 DOI: 10.1038/s41598-023-39239-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 07/21/2023] [Indexed: 08/02/2023] Open
Abstract
Urinary tract infection is a common disease in pigs and a major reason for sows to be culled. The disease, however, is difficult to diagnose due to lack of distinct clinical signs in the animals. We evaluated the diagnostic value of two commercial urine dipstick tests in 10 pigs using an experimental model of Escherichia coli urinary tract infection. Urine collected at baseline and 48 h after inoculation were analyzed. We show that dipstick tests positive of blood, leucocytes and particularly nitrite are very specific for E. coli UTI with a 100% positive predictive value.
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Affiliation(s)
- Kristian Stærk
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark.
- Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark.
| | | | - Thomas Emil Andersen
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
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7
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Tentor F, Grønholt Schrøder B, Nielsen S, Schertiger L, Stærk K, Emil Andersen T, Bagi P, Feldskov Nielsen L. Author Correction: Development of an ex-vivo porcine lower urinary tract model to evaluate the performance of urinary catheters. Sci Rep 2023; 13:6443. [PMID: 37081107 PMCID: PMC10119277 DOI: 10.1038/s41598-023-32920-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023] Open
Affiliation(s)
- Fabio Tentor
- Coloplast A/S, Holtedam 1, 3050, Humlebæk, Denmark.
| | | | | | | | - Kristian Stærk
- Research Unit of Clinical Microbiology, University of Southern Denmark, J.B. Winsløws Vej 21, 5000, Odense, Denmark
- Department of Clinical Microbiology, Odense University Hospital, J.B. Winsløws Vej 21, 5000, Odense, Denmark
| | - Thomas Emil Andersen
- Research Unit of Clinical Microbiology, University of Southern Denmark, J.B. Winsløws Vej 21, 5000, Odense, Denmark
- Department of Clinical Microbiology, Odense University Hospital, J.B. Winsløws Vej 21, 5000, Odense, Denmark
| | - Per Bagi
- Department of Urology, Centre for Cancer and Organ Diseases, Rigshospitalet, Blegdamsvej 9, 2100, København, Denmark
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8
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Agergaard CN, Jensen JM, Klein K, Rosenvinge FS, Stærk K. A comparative evaluation of commercial boric acid containers for preserving microorganisms in urine specimens. Clin Microbiol Infect 2023; 29:401-403. [PMID: 36470523 DOI: 10.1016/j.cmi.2022.11.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/31/2022] [Accepted: 11/26/2022] [Indexed: 12/03/2022]
Affiliation(s)
| | - Julie May Jensen
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
| | - Kasper Klein
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark; Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
| | - Flemming Schønning Rosenvinge
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark; Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
| | - Kristian Stærk
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark; Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark.
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9
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Stærk K, Grønnemose RB, Palarasah Y, Lund L, Andersen TE. Intracellular uropathogenic Escherichia coli are undetectable in urinary bladders after oral mecillinam treatment: An experimental study in a pig model of cystitis. Microb Pathog 2022; 173:105817. [DOI: 10.1016/j.micpath.2022.105817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/26/2022] [Accepted: 10/04/2022] [Indexed: 11/05/2022]
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10
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Stærk K, Langhorn L, Andersen TE. Clean-catching urine from pigs: A method for collecting quality specimens for urinalysis and microbiological culturing in a laboratory environment. Lab Anim 2022:236772221133433. [DOI: 10.1177/00236772221133433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Urine is an important biological specimen for assessing various metabolic functions and drug clearance. In urinary tract infection research, urine is particularly important as urinary bacterial titres constitute the main diagnostic outcome for assessing the course of infection. Collecting uncontaminated urine samples from pigs can be done by bladder catheterization or suprapubic bladder aspiration, which are both laborious and invasive procedures that require the need for anaesthesia. To improve animal welfare and optimize urine sampling protocols, we developed a method of clean-catching midstream urine specimens from pigs during spontaneous micturition. The quality of urine specimens collected by clean-catch, bladder catheter and suprapubic bladder aspiration were compared using microbiological culturing. We show that urine specimens collected by clean-catch are only minimally contaminated by skin- and vaginal-commensals with no influence on urinary bacterial titres during ongoing infection. In conclusion, we describe a method in which spontaneous micturition can be prompted in pigs, facilitating fast and reliable collection of quality specimens suitable for microbiological culturing. The method supersedes the need for anaesthesia, which not only represents a considerable refinement in terms of animal welfare but also facilitates more frequent collection of specimens that can enhance the scientific outcome of experimental animal studies in pigs.
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Affiliation(s)
- Kristian Stærk
- Department of Clinical Microbiology, Odense University Hospital, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
| | - Louise Langhorn
- Biomedical Laboratory, University of Southern Denmark, Odense, Denmark
| | - Thomas E Andersen
- Department of Clinical Microbiology, Odense University Hospital, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
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11
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Stærk K, Langhorn L, Palarasah Y, Andersen TE. A method for collecting high numbers of blood samples in standard vacuum tubes from non-heparinized pigs. Lab Anim 2022:236772221133431. [DOI: 10.1177/00236772221133431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Large animal models allow for collection of substantial amounts of biological material. However, the collection of larger volumes (>100 ml) of blood from pigs can be a challenge: (i) the peripheral veins are not suitable for collection of high numbers of standard blood tubes as the veins tend to collapse; and (ii) the alternative option of cannulating deeper veins mandates surgical exposure of the vessels and often the need for heparinization, which is undesirable for some blood analysis. During an immunization trial in 40 pigs, we assessed the femoral and saphenous arteries as practical vessels for collecting 250 ml of blood from each pig in standard collection tubes without heparinization. Blood collected from the saphenous artery by a standard butterfly needle proved particularly useful and 250 ml blood could be collected successfully in 24 of 25 pigs by this approach.
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Affiliation(s)
- Kristian Stærk
- Department of Clinical Microbiology, Odense University Hospital, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
| | - Louise Langhorn
- Biomedical Laboratory, University of Southern Denmark, Odense, Denmark
| | - Yaseelan Palarasah
- Unit for Thrombosis Research, Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Thomas E Andersen
- Department of Clinical Microbiology, Odense University Hospital, Denmark
- Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
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12
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Tentor F, Grønholt Schrøder B, Nielsen S, Schertiger L, Stærk K, Emil Andersen T, Bagi P, Feldskov Nielsen L. Development of an ex-vivo porcine lower urinary tract model to evaluate the performance of urinary catheters. Sci Rep 2022; 12:17818. [PMID: 36280778 PMCID: PMC9592621 DOI: 10.1038/s41598-022-21122-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 09/22/2022] [Indexed: 01/19/2023] Open
Abstract
Intermittent catheterization is the gold standard method for bladder management in individuals with urinary retention and/or incontinence. It is therefore important to understand the performance of urinary catheters, especially on parameters associated to risks of developing urinary tract infections, and that may impact the quality of life for urinary catheter users. Examples of such parameters include, urine flowrate, occurrence of flow-stops, and residual urine left in the bladder after flow-stop. Reliable in-vitro and/or ex-vivo laboratory models represent a strong asset to assess the performance of urinary catheters, preceding and guiding in-vivo animal studies and/or human clinical studies. Existing laboratory models are generally simplified, covering only portions of the catheterization process, or poorly reflect clinical procedures. In this work, we developed an ex-vivo porcine lower urinary tract model that better reflects the catheterization procedure in humans and allows to investigate the performance of standard of care catheters. The performance of three standard of care catheters was investigated in the developed model showing significant differences in terms of flowrate. No differences were detected in terms of residual volume in the bladder at first flow-stop also when tuning the abdominal pressure to mimic a sitting down and standing up position. A newly discovered phenomenon named hammering was detected and measured. Lastly, mucosal suction was observed and measured in all standard of care catheters, raising the concern for microtrauma during catheterization and a need for new and improved urinary catheter designs. Results obtained with the ex-vivo model were compared to in-vivo studies, highlighting similar concerns.
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Affiliation(s)
- Fabio Tentor
- grid.424097.c0000 0004 1755 4974Coloplast A/S, Holtedam 1, 3050 Humlebæk, Denmark
| | | | - Simon Nielsen
- grid.424097.c0000 0004 1755 4974Coloplast A/S, Holtedam 1, 3050 Humlebæk, Denmark
| | - Lars Schertiger
- grid.424097.c0000 0004 1755 4974Coloplast A/S, Holtedam 1, 3050 Humlebæk, Denmark
| | - Kristian Stærk
- grid.10825.3e0000 0001 0728 0170Research Unit of Clinical Microbiology, University of Southern Denmark, J.B. Winsløws Vej 21, 5000 Odense, Denmark ,grid.7143.10000 0004 0512 5013Department of Clinical Microbiology, Odense University Hospital, J.B. Winsløws Vej 21, 5000 Odense, Denmark
| | - Thomas Emil Andersen
- grid.10825.3e0000 0001 0728 0170Research Unit of Clinical Microbiology, University of Southern Denmark, J.B. Winsløws Vej 21, 5000 Odense, Denmark ,grid.7143.10000 0004 0512 5013Department of Clinical Microbiology, Odense University Hospital, J.B. Winsløws Vej 21, 5000 Odense, Denmark
| | - Per Bagi
- grid.475435.4Department of Urology, Centre for Cancer and Organ Diseases, Rigshospitalet, Blegdamsvej 9, 2100 København, Denmark
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13
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Stærk K, Hjelmager JS, Alm M, Thomsen P, Andersen TE. A new catheter-integrated drug-delivery system for controlled intravesical mitomycin C release. Urol Oncol 2022; 40:409.e19-409.e26. [PMID: 35753849 DOI: 10.1016/j.urolonc.2022.05.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 04/01/2022] [Accepted: 05/24/2022] [Indexed: 10/17/2022]
Abstract
BACKGROUND Intravesical treatment of bladder cancer is preferred over systemic administration. However, the efficacy of intravesical instillations is challenged by the periodic voiding that flushes out the instilled drug and ultimately reduces drug exposure to the bladder epithelium. Here, we demonstrate a new catheter-integrated drug-delivery concept that utilizes a silicone-based interpenetrating polymer network (IPN) as material for the catheter balloon, to facilitate continuous release of the bladder cancer adjuvant, Mitomycin C, from a balloon-reservoir to the urinary bladder. METHODS Long-term release properties and anti-carcinoma cell efficacy of released drug was investigated in vitro. Short-term release experiments were performed in live pigs to evaluate the IPN prototype catheter in a physiological relevant environment in vivo. RESULTS Sustained zero-order release of Mitomycin C was achieved for 12 days in vitro without refilling the balloon. Mitomycin C was released from the IPN-balloons into the urinary bladder of live pigs in concentrations adequate to inhibit carcinoma cell growth. CONCLUSION The IPN catheter represents a new drug-delivery concept for prolonged Mitomycin C delivery to the urinary bladder.
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Affiliation(s)
- Kristian Stærk
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | | | | | | | - Thomas Emil Andersen
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark; Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark.
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14
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Andersen K, Arenholt LTS, Stærk K, Andersen TE, Lund L. [Simple, recurrent, and complicated urinary tract infections]. Ugeskr Laeger 2022; 184:V03220200. [PMID: 35959824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Urinary tract infection is a colonisation of the urinary tract with uropathogenic bacteria, leading to an inflammatory response. The increasing antimicrobial resistance presents major challenges for both the individual and our society. The goal is to reduce antimicrobial resistance and pave the way for a new era in the management of recurrent urinary tract infections. This review describes the definitions of urinary tract infection (simple, recurrent, and complicated) as well as examination and treatment recommendations. The future and most common non-antibiotic alternatives are discussed.
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Affiliation(s)
| | | | - Kristian Stærk
- Forskningsenheden Klinisk Mikrobiologisk Afdeling, Klinisk Institut, Syddansk Universitet
| | - Thomas Emil Andersen
- Forskningsenheden Klinisk Mikrobiologisk Afdeling, Klinisk Institut, Syddansk Universitet
| | - Lars Lund
- Urologisk Afdeling, Odense Universitetshospital
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15
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Abstract
Urinary tract infection (UTI) is one of the most common bacterial infections worldwide. Experimental models that accurately reflect the high susceptibility to UTI in humans have, however, been lacking. This situation has limited detailed research into the early bladder colonization by uropathogens and the early innate defence mechanisms elicited to prevent this. We recently presented a model of urinary tract infection in pigs, animals that are naturally susceptible to UTI and have greater similarity to the physiology and anatomy of the human urinary tract than traditional rodent UTI models. In the current study, we used the pig model to investigate the minimal infectious inoculum of uropathogenic Escherichia coli, the most common cause of urinary tract infection. We show that in this animal a few individual bacteria that come into contact with the urothelium can give rise to fulminant cystitis, indicating the high infectious potential of uropathogenic E. coli.
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Affiliation(s)
- Kristian Stærk
- Research unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
| | | | - Thomas Emil Andersen
- Research unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark.,Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
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16
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Torres-Puig S, García V, Stærk K, Andersen TE, Møller-Jensen J, Olsen JE, Herrero-Fresno A. “Omics” Technologies - What Have They Told Us About Uropathogenic Escherichia coli Fitness and Virulence During Urinary Tract Infection? Front Cell Infect Microbiol 2022; 12:824039. [PMID: 35237532 PMCID: PMC8882828 DOI: 10.3389/fcimb.2022.824039] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 01/19/2022] [Indexed: 12/21/2022] Open
Abstract
Uropathogenic Escherichia coli (UPEC) is the main etiological agent of urinary tract infection (UTI), a widespread infectious disease of great impact on human health. This is further emphasized by the rapidly increase in antimicrobial resistance in UPEC, which compromises UTI treatment. UPEC biology is highly complex since uropathogens must adopt extracellular and intracellular lifestyles and adapt to different niches in the host. In this context, the implementation of forefront ‘omics’ technologies has provided substantial insight into the understanding of UPEC pathogenesis, which has opened the doors for new therapeutics and prophylactics discovery programs. Thus, ‘omics’ technologies applied to studies of UPEC during UTI, or in models of UTI, have revealed extensive lists of factors that are important for the ability of UPEC to cause disease. The multitude of large ‘omics’ datasets that have been generated calls for scrutinized analysis of specific factors that may be of interest for further development of novel treatment strategies. In this review, we describe main UPEC determinants involved in UTI as estimated by ‘omics’ studies, and we compare prediction of factors across the different ‘omics’ technologies, with a focus on those that have been confirmed to be relevant under UTI-related conditions. We also discuss current challenges and future perspectives regarding analysis of data to provide an overview and better understanding of UPEC mechanisms involved in pathogenesis which should assist in the selection of target sites for future prophylaxis and treatment.
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Affiliation(s)
- Sergi Torres-Puig
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Vanesa García
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
- Laboratorio de Referencia de Escherichia coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela (USC), Lugo, Spain
| | - Kristian Stærk
- Research Unit of Clinical Microbiology, University of Southern Denmark and Odense University Hospital, Odense, Denmark
| | - Thomas E. Andersen
- Research Unit of Clinical Microbiology, University of Southern Denmark and Odense University Hospital, Odense, Denmark
| | - Jakob Møller-Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - John E. Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Ana Herrero-Fresno
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
- *Correspondence: Ana Herrero-Fresno,
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17
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Stærk K, Grønnemose RB, Nielsen TK, Petersen NA, Palarasah Y, Torres-Puig S, Møller-Jensen J, Kolmos HJ, Lund L, Andersen TE. Escherichia coli type-1 fimbriae are critical to overcome initial bottlenecks of infection upon low-dose inoculation in a porcine model of cystitis. Microbiology (Reading) 2021; 167. [PMID: 34623231 PMCID: PMC8698211 DOI: 10.1099/mic.0.001101] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Most uropathogenic Escherichia coli (UPEC) express type-1 fimbriae (T1F), a key virulence factor for urinary tract infection (UTI) in mice. Evidence that conclusively associates this pilus with uropathogenesis in humans has, however, been difficult to obtain. We used an experimental porcine model of cystitis to assess the role of T1F in larger mammals more closely related to humans. Thirty-one pigs were infected with UPEC strain UTI89 or its T1F deficient mutant, UTI89ΔfimH, at inoculum titres of 102 to 108 colony forming units per millilitre. Urine and blood samples were collected and analysed 7 and 14 days post-inoculation, and whole bladders were removed at day 14 and analysed for uroepithelium-associated UPEC. All animals were consistently infected and reached high urine titres independent of inoculum titre. UTI89ΔfimH successfully colonized the bladders of 1/6 pigs compared to 6/6 for the wild-type strain. Intracellular UPEC were detectable in low numbers in whole bladder explants. In conclusion, low doses of UPEC are able to establish robust infections in pigs, similar to what is presumed in humans. T1F are critical for UPEC to surpass initial bottlenecks during infection but may be dispensable once infection is established. While supporting the conclusions from mice studies regarding a general importance of T1F in successfully infecting the host, the porcine UTI models’ natural high, more human-like, susceptibility to infection, allowed us to demonstrate a pivotal role of T1F in initial establishment of infection upon a realistic low-inoculum introduction of UPEC in the bladder.
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Affiliation(s)
- Kristian Stærk
- Research Unit of Clinical Microbiology, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Rasmus Birkholm Grønnemose
- Research Unit of Clinical Microbiology, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Thomas Kastberg Nielsen
- Research Unit of Urology, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Nicky Anúel Petersen
- Research Unit of Urology, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Yaseelan Palarasah
- Department of Cancer and Inflammation Research, Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Sergi Torres-Puig
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Jakob Møller-Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Hans Jørn Kolmos
- Research Unit of Clinical Microbiology, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Lars Lund
- Research Unit of Urology, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Urology, Odense University Hospital, Odense, Denmark
| | - Thomas Emil Andersen
- Research Unit of Clinical Microbiology, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
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18
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Stærk K, Grønnemose RB, Palarasah Y, Kolmos HJ, Lund L, Alm M, Thomsen P, Andersen TE. A Novel Device-Integrated Drug Delivery System for Local Inhibition of Urinary Tract Infection. Front Microbiol 2021; 12:685698. [PMID: 34248906 PMCID: PMC8267894 DOI: 10.3389/fmicb.2021.685698] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/26/2021] [Indexed: 11/29/2022] Open
Abstract
Background: Catheter-associated urinary tract infection (CAUTI) is a frequent community-acquired infection and the most common nosocomial infection. Here, we developed a novel antimicrobial catheter concept that utilizes a silicone-based interpenetrating polymer network (IPN) as balloon material to facilitate a topical slow-release prophylaxis of antibacterial agents across the balloon to the urinary bladder. Methods: The balloon material was achieved by modifying low shore hardness silicone tubes with a hydrogel interpenetrating polymer in supercritical CO2 using the sequential method. Release properties and antibacterial efficacy of the IPN balloon treatment concept was investigated in vitro and in a porcine CAUTI model developed for the study. In the latter, Bactiguard Infection Protection (BIP) Foley catheters were also assessed to enable benchmark with the traditional antimicrobial coating principle. Results: Uropathogenic Escherichia coli was undetectable in urinary bladders and on retrieved catheters in the IPN treatment group as compared to control that revealed significant bacteriuria (>105 colony forming units/ml) as well as catheter-associated biofilm. The BIP catheters failed to prevent E. coli colonization of the bladder but significantly reduced catheter biofilm formation compared to the control. Conclusion: The IPN-catheter concept provides a novel, promising delivery route for local treatment in the urinary tract.
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Affiliation(s)
- Kristian Stærk
- Research Unit of Clinical Microbiology, University of Southern Denmark and Odense University Hospital, Odense, Denmark
| | - Rasmus Birkholm Grønnemose
- Research Unit of Clinical Microbiology, University of Southern Denmark and Odense University Hospital, Odense, Denmark
| | - Yaseelan Palarasah
- Department of Cancer and Inflammation Research, University of Southern Denmark, Odense, Denmark
| | - Hans Jørn Kolmos
- Research Unit of Clinical Microbiology, University of Southern Denmark and Odense University Hospital, Odense, Denmark
| | - Lars Lund
- Research Unit of Urology, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | | | | | - Thomas Emil Andersen
- Research Unit of Clinical Microbiology, University of Southern Denmark and Odense University Hospital, Odense, Denmark
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19
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Nielsen TK, Petersen NA, Stærk K, Grønnemose RB, Palarasah Y, Nielsen LF, Kolmos HJ, Andersen TE, Lund L. A Porcine Model for Urinary Tract Infection. Front Microbiol 2019; 10:2564. [PMID: 31824442 PMCID: PMC6882375 DOI: 10.3389/fmicb.2019.02564] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 10/23/2019] [Indexed: 12/23/2022] Open
Abstract
Urinary tract infection (UTI) is the most common bacterial infectious disease with a high frequency of recurrence and the leading cause of septicemia. In vivo experimentation has contributed significantly to the present-day knowledge on UTI pathogenesis. This research has traditionally been based on murine models of UTI. Occasional conflicting results between UTI in mice and humans and increasing skepticism toward small rodent models in general warrant the need of novel large-animal infection models that better resemble the anatomy and physiology of humans, and thus better mimic the course of infection in humans. Here, we report, to our knowledge, the first large-animal model of cystitis. The model is based on pigs, and the protocol supports the establishment of persistent, non-ascending infection in this animal and is established without invasive surgical procedures, pain, and discomfort for the animal. The course of infection is monitored by cystoscopy, microscopy of bladder biopsies, and biochemical analysis of urine and blood samples. At termination, harvested whole bladders from infected pigs are analyzed for microbiological colonization using microscopy, histology, and viable bacterial counts. The model is a useful tool in future studies of UTI pathogenesis and opens up novel possibilities to bridge the current knowledge obtained from small-animal UTI models to UTI pathogenesis in humans.
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Affiliation(s)
- Thomas Kastberg Nielsen
- Research Unit of Urology, Department of Clinical Research, Odense University Hospital, University of Southern Denmark, Odense, Denmark
| | - Nicky Anúel Petersen
- Research Unit of Urology, Department of Clinical Research, Odense University Hospital, University of Southern Denmark, Odense, Denmark
| | - Kristian Stærk
- Research Unit of Clinical Microbiology, Department of Clinical Research, Odense University Hospital, University of Southern Denmark, Odense, Denmark
| | - Rasmus Birkholm Grønnemose
- Research Unit of Clinical Microbiology, Department of Clinical Research, Odense University Hospital, University of Southern Denmark, Odense, Denmark
| | - Yaseelan Palarasah
- Department of Cancer and Inflammation, University of Southern Denmark, Odense, Denmark
| | | | - Hans Jørn Kolmos
- Research Unit of Clinical Microbiology, Department of Clinical Research, Odense University Hospital, University of Southern Denmark, Odense, Denmark
| | - Thomas Emil Andersen
- Research Unit of Clinical Microbiology, Department of Clinical Research, Odense University Hospital, University of Southern Denmark, Odense, Denmark
| | - Lars Lund
- Research Unit of Urology, Department of Clinical Research, Odense University Hospital, University of Southern Denmark, Odense, Denmark
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20
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Pedersen RM, Grønnemose RB, Stærk K, Asferg CA, Andersen TB, Kolmos HJ, Møller-Jensen J, Andersen TE. A Method for Quantification of Epithelium Colonization Capacity by Pathogenic Bacteria. Front Cell Infect Microbiol 2018; 8:16. [PMID: 29450193 PMCID: PMC5799267 DOI: 10.3389/fcimb.2018.00016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/12/2018] [Indexed: 11/13/2022] Open
Abstract
Most bacterial infections initiate at the mucosal epithelium lining the gastrointestinal, respiratory, and urogenital tracts. At these sites, bacterial pathogens must adhere and increase in numbers to effectively breach the outer barrier and invade the host. If the bacterium succeeds in reaching the bloodstream, effective dissemination again requires that bacteria in the blood, reestablish contact to distant endothelium sites and form secondary site foci. The infectious potential of bacteria is therefore closely linked to their ability to adhere to, colonize, and invade epithelial and endothelial surfaces. Measurement of bacterial adhesion to epithelial cells is therefore standard procedure in studies of bacterial virulence. Traditionally, such measurements have been conducted with microtiter plate cell cultures to which bacteria are added, followed by washing procedures and final quantification of retained bacteria by agar plating. This approach is fast and straightforward, but yields only a rough estimate of the adhesive properties of the bacteria upon contact, and little information on the ability of the bacterium to colonize these surfaces under relevant physiological conditions. Here, we present a method in which epithelia/endothelia are simulated by flow chamber-grown human cell layers, and infection is induced by seeding of pathogenic bacteria on these surfaces under conditions that simulate the physiological microenvironment. Quantification of bacterial adhesion and colonization of the cell layers is then performed by in situ time-lapse fluorescence microscopy and automatic detection of bacterial surface coverage. The method is demonstrated in three different infection models, simulating Staphylococcus aureus endothelial infection and Escherichia coli intestinal- and uroepithelial infection. The approach yields valuable information on the fitness of the bacterium to successfully adhere to and colonize epithelial surfaces and can be used to evaluate the influence of specific virulence genes, growth conditions, and antimicrobial treatment on this process.
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Affiliation(s)
- Rune M Pedersen
- Research Unit of Clinical Microbiology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark
| | - Rasmus B Grønnemose
- Research Unit of Clinical Microbiology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark
| | - Kristian Stærk
- Research Unit of Clinical Microbiology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark
| | - Cecilie A Asferg
- Research Unit of Clinical Microbiology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark
| | - Thea B Andersen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Hans J Kolmos
- Research Unit of Clinical Microbiology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark
| | - Jakob Møller-Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Thomas E Andersen
- Research Unit of Clinical Microbiology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark
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Stærk K, Khandige S, Kolmos HJ, Møller-Jensen J, Andersen TE. Uropathogenic Escherichia coli Express Type 1 Fimbriae Only in Surface Adherent Populations Under Physiological Growth Conditions. J Infect Dis 2015; 213:386-94. [PMID: 26290608 DOI: 10.1093/infdis/jiv422] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 08/10/2015] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Most uropathogenic Escherichia coli (UPEC) strains harbor genes encoding adhesive type 1 fimbria (T1F). T1F is a key factor for successful establishment of urinary tract infection. However, UPEC strains typically do not express T1F in the bladder urine, and little is understood about its induction in vivo. METHODS A flow chamber infection model was used to grow UPEC under conditions simulating distinct infection niches in the bladder. Type 1 fimbriation on isolated UPEC was subsequently determined by yeast cell agglutination and immunofluorescence microscopy, and the results were correlated with the ability to adhere to and invade cultured human bladder cells. RESULTS Although inactive during planktonic growth in urine, T1F expression occurs when UPEC settles on and infects bladder epithelial cells or colonizes catheters. As a result, UPEC in these sessile populations enhances bladder cell adhesion and invasion potential. Only T1F-negative UPEC are subsequently released to the urine, thus limiting T1F expression to surface-associated UPEC alone. CONCLUSIONS Our results demonstrate that T1F expression is strictly regulated under physiological growth conditions with increased expression during surface growth adaptation and infection of uroepithelial cells. This leads to separation of UPEC into low-expression planktonic populations and high-expression sessile populations.
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Affiliation(s)
- Kristian Stærk
- Research Unit of Clinical Microbiology Odense University Hospital, Denmark
| | - Surabhi Khandige
- Department of Biochemistry and Molecular Biology, University of Southern Denmark
| | - Hans Jørn Kolmos
- Research Unit of Clinical Microbiology Odense University Hospital, Denmark
| | - Jakob Møller-Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark
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