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Lichtenberg M, Coenye T, Parsek MR, Bjarnsholt T, Jakobsen TH. What's in a name? Characteristics of clinical biofilms. FEMS Microbiol Rev 2023; 47:fuad050. [PMID: 37656883 PMCID: PMC10503651 DOI: 10.1093/femsre/fuad050] [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: 06/10/2023] [Revised: 08/06/2023] [Accepted: 08/30/2023] [Indexed: 09/03/2023] Open
Abstract
In vitro biofilms are communities of microbes with unique features compared to individual cells. Biofilms are commonly characterized by physical traits like size, adhesion, and a matrix made of extracellular substances. They display distinct phenotypic features, such as metabolic activity and antibiotic tolerance. However, the relative importance of these traits depends on the environment and bacterial species. Various mechanisms enable biofilm-associated bacteria to withstand antibiotics, including physical barriers, physiological adaptations, and changes in gene expression. Gene expression profiles in biofilms differ from individual cells but, there is little consensus among studies and so far, a 'biofilm signature transcriptome' has not been recognized. Additionally, the spatial and temporal variability within biofilms varies greatly depending on the system or environment. Despite all these variable conditions, which produce very diverse structures, they are all noted as biofilms. We discuss that clinical biofilms may differ from those grown in laboratories and found in the environment and discuss whether the characteristics that are commonly used to define and characterize biofilms have been shown in infectious biofilms. We emphasize that there is a need for a comprehensive understanding of the specific traits that are used to define bacteria in infections as clinical biofilms.
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Affiliation(s)
- Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Matthew R Parsek
- Department of Microbiology, University of Washington School of Medicine, 1705 NE Pacific St., WA 98195 Seattle, United States
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Department of Clinical Microbiology, Copenhagen University Hospital, Ole Maaløes vej 26, 2100 Copenhagen, Denmark
| | - Tim Holm Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
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Jürgens M, Schou M, Hasbak P, Kjær A, Wolsk E, Zerahn B, Wiberg M, Brandt NH, Gæde PH, Rossing P, Faber J, Inzucchi S, Gustafsson F, Kistorp CM. Design of a randomised controlled trial of the effects of empagliflozin on myocardial perfusion, function and metabolism in type 2 diabetes patients at high cardiovascular risk (the SIMPLE trial). BMJ Open 2019; 9:e029098. [PMID: 31780586 PMCID: PMC6887087 DOI: 10.1136/bmjopen-2019-029098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
INTRODUCTION A diagnosis of type 2 diabetes (T2D) more than doubles the risk of cardiovascular disease (CVD), with heart failure (HF) being one of the most common complications with a severe prognosis. The landmark Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Paitients (EMPA-REG OUTCOME) study demonstrated that treatment with the sodium glucose cotransporter-2 (SGLT-2) inhibitor empagliflozin rapidly and significantly reduces CVD mortality and admission rates for HF. However, the mechanisms behind this reduction in clinical events are unknown.This study was designed to investigate the effects of the SGLT-2 inhibitor empagliflozin on myocardial perfusion and function in patients with T2D and high CVD risk. METHODS AND ANALYSIS In this investigator-initiated, randomised, double-blind controlled clinical trial, 92 patients with T2D and established CVD or high CVD risk will be randomised to treatment with empagliflozin 25 mg or a matching placebo for 13 weeks. The primary outcome measure is change in myocardial flow reserve measured quantitatively by Rubidium-82 position emission tomography. In a substudy, invasive haemodynamics at rest and during exercise will be measured at baseline and following the intervention, using right heart catheterisation. ETHICS AND DISSEMINATION The study protocol (v7, 02/08/2018) has been approved by the Ethics Committee of the Capital Region, Danish Data Protection Board and the Danish Medicines Agency, and it will be monitored according to the Good Clinical Practice regulations from the International Conference on Harmonization. The results be submitted to international peer-reviewed journals and be presented at conferences. The data will be made available to the public via EudraCT and www.clinicaltrials.gov. TRIAL REGISTRATION NUMBER NCT03151343.
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Affiliation(s)
- Mikkel Jürgens
- Department of Endocrinology, Rigshospitalet, Copenhagen, Denmark
| | - Morten Schou
- Department of Cardiology, Herlev Hospital, Herlev, Denmark
| | - Philip Hasbak
- Department of Clinical Physiology, Nuclear Medicine & PET 4011, Cluster of Molecular Imaging, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Andreas Kjær
- Department of Clinical Physiology, Nuclear Medicine & PET 4011, Cluster of Molecular Imaging, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Emil Wolsk
- Department of Cardiology-The Heart Centre, Rigshospitalet, Copenhagen, Denmark
| | - Bo Zerahn
- Department of Clinical Physiology and Nuclear Medicine, Herlev and Gentofte Hospital, University of Copenhagen, Herlev, Denmark
| | - Mikkel Wiberg
- Department of Medicine, Herlev Hospital, Herlev, Denmark
| | - Niels Høgh Brandt
- Department of Medicine, Herlev and Gentofte Hospital, University of Copenhagen, Herlev, Denmark
| | - Peter Haulund Gæde
- Department of Cardiology and Endocrinology, Slagelse Hospital, Slagelse, Sjaelland, Denmark
| | | | - Jens Faber
- Department of Medicine, Herlev Hospital, Herlev, Denmark
| | - Silvio Inzucchi
- Department of Endocrinology, Yale Shool of Medicine, New Haven, Connecticut, USA
| | - Finn Gustafsson
- Department of Cardiology-The Heart Centre, Rigshospitalet, Copenhagen, Denmark
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Daugbjerg N, Norlin A, Lovejoy C. Baffinella frigidus gen. et sp. nov. (Baffinellaceae fam. nov., Cryptophyceae) from Baffin Bay: Morphology, pigment profile, phylogeny, and growth rate response to three abiotic factors. J Phycol 2018; 54:665-680. [PMID: 30043990 DOI: 10.1111/jpy.12766] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 06/27/2018] [Indexed: 06/08/2023]
Abstract
Twenty years ago an Arctic cryptophyte was isolated from Baffin Bay and given strain number CCMP2045. Here, it was described using morphology, water- and non-water soluble pigments and nuclear-encoded SSU rDNA. The influence of temperature, salinity, and light intensity on growth rates was also examined. Microscopy revealed typical cryptophyte features but the chloroplast color was either green or red depending on the light intensity provided. Phycoerythrin (Cr-PE 566) was only produced when cells were grown under low-light conditions (5 μmol photons · m-2 · s-1 ). Non-water-soluble pigments included chlorophyll a, c2 and five major carotenoids. Cells measured 8.2 × 5.1 μm and a tail-like appendage gave them a comma-shape. The nucleus was located posteriorly and a horseshoe-shaped chloroplast contained a single pyrenoid. Ejectosomes of two sizes and a nucleomorph anterior to the pyrenoid were discerned in TEM. SEM revealed a slightly elevated vestibular plate in the vestibulum. The inner periplast component consisted of slightly overlapping hexagonal plates arranged in 16-20 oblique rows. Antapical plates were smaller and their shape less profound. Temperature and salinity studies revealed CCMP2045 as stenothermal and euryhaline and growth was saturated between 5 and 20 μmol photons · m-2 · s-1 . The phylogeny based on SSU rDNA showed that CCMP2045 formed a distinct clade with CCMP2293 and Falcomonas sp. isolated from Spain. Combining pheno- and genotypic data, the Arctic cryptophyte could not be placed in an existing family and genus and therefore Baffinellaceae fam. nov. and Baffinella frigidus gen. et sp. nov. were proposed.
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Affiliation(s)
- Niels Daugbjerg
- Marine Biological Section, Department of Biology, University of Copenhagen, Universitetsparken 4, Copenhagen, Ø DK-2100, Denmark
| | - Andreas Norlin
- Marine Biological Section, Department of Biology, University of Copenhagen, Universitetsparken 4, Copenhagen, Ø DK-2100, Denmark
| | - Connie Lovejoy
- Département de Biologie, Université Laval, 1045 avenue de la Médecine, Québec, Quebec, G1V 0A6, Canada
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