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CO 2 enhances the formation, nutrient scavenging and drug resistance properties of C. albicans biofilms. NPJ Biofilms Microbiomes 2021; 7:67. [PMID: 34385462 PMCID: PMC8361082 DOI: 10.1038/s41522-021-00238-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 07/16/2021] [Indexed: 02/07/2023] Open
Abstract
C. albicans is the predominant human fungal pathogen and frequently colonises medical devices, such as voice prostheses, as a biofilm. It is a dimorphic yeast that can switch between yeast and hyphal forms in response to environmental cues, a property that is essential during biofilm establishment and maturation. One such cue is the elevation of CO2 levels, as observed in exhaled breath for example. However, despite the clear medical relevance, the effect of CO2 on C. albicans biofilm growth has not been investigated to date. Here we show that physiologically relevant CO2 elevation enhances each stage of the C. albicans biofilm-forming process: from attachment through maturation to dispersion. The effects of CO2 are mediated via the Ras/cAMP/PKA signalling pathway and the central biofilm regulators Efg1, Brg1, Bcr1 and Ndt80. Biofilms grown under elevated CO2 conditions also exhibit increased azole resistance, increased Sef1-dependent iron scavenging and enhanced glucose uptake to support their rapid growth. These findings suggest that C. albicans has evolved to utilise the CO2 signal to promote biofilm formation within the host. We investigate the possibility of targeting CO2-activated processes and propose 2-deoxyglucose as a drug that may be repurposed to prevent C. albicans biofilm formation on medical airway management implants. We thus characterise the mechanisms by which CO2 promotes C. albicans biofilm formation and suggest new approaches for future preventative strategies.
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Pentland DR, Stevens S, Williams L, Baker M, McCall C, Makarovaite V, Balfour A, Mühlschlegel FA, Gourlay CW. Precision Antifungal Treatment Significantly Extends Voice Prosthesis Lifespan in Patients Following Total Laryngectomy. Front Microbiol 2020; 11:975. [PMID: 32508787 PMCID: PMC7251058 DOI: 10.3389/fmicb.2020.00975] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 04/22/2020] [Indexed: 11/13/2022] Open
Abstract
Indwelling silicone valves called voice prostheses (VPs) are the gold standard for speech rehabilitation in patients with laryngeal cancer following total laryngectomy. Reported VP lifespans amongst these patients are highly variable but when devices fail patients experience loss of voice and an increase risk of chest infection. Early failure of VP is a current clinical concern that is associated with regular hospital visits, reduced quality of life and associated medical cost. Poly-microbial biofilms comprised of both bacterial and fungal microorganisms readily colonize VPs and are linked to loss of device performance and its early failure in addition to providing a reservoir for potential infection. Our detailed analysis of poly-microbial biofilm composition on 159 early failing VPs from 48 total laryngectomy patients confirmed Candida albicans as the predominant fungal species and Staphylococcus aureus as the most common bacterial colonizer within our patient cohort. Using a combination of microbiological analysis, patient data and a high-throughput antifungal test assay mimicking in vivo conditions we established an evidence based precision antifungal treatment approach to VP management. Our approach has allowed us to implement a personalized VP management pathway, which increases device in situ lifespan by an average of 270%. Our study represents a significant step forward in both our understanding of the cause of VP failure and a new effective treatment pathway that offers tangible benefit to patients.
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Affiliation(s)
- Daniel R Pentland
- Kent Fungal Group, School of Biosciences, University of Kent, Kent, United Kingdom
| | - Sarah Stevens
- East Kent Hospitals, University NHS Foundation Trust, Kent, United Kingdom
| | - Leila Williams
- East Kent Hospitals, University NHS Foundation Trust, Kent, United Kingdom
| | - Mark Baker
- East Kent Hospitals, University NHS Foundation Trust, Kent, United Kingdom
| | - Carolyn McCall
- East Kent Hospitals, University NHS Foundation Trust, Kent, United Kingdom
| | | | - Alistair Balfour
- East Kent Hospitals, University NHS Foundation Trust, Kent, United Kingdom
| | | | - Campbell W Gourlay
- Kent Fungal Group, School of Biosciences, University of Kent, Kent, United Kingdom
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Azevedo AS, Almeida C, Melo LF, Azevedo NF. Impact of polymicrobial biofilms in catheter-associated urinary tract infections. Crit Rev Microbiol 2016; 43:423-439. [PMID: 28033847 DOI: 10.1080/1040841x.2016.1240656] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Recent reports have demonstrated that most biofilms involved in catheter-associated urinary tract infections are polymicrobial communities, with pathogenic microorganisms (e.g. Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) and uncommon microorganisms (e.g. Delftia tsuruhatensis, Achromobacter xylosoxidans) frequently co-inhabiting the same urinary catheter. However, little is known about the interactions that occur between different microorganisms and how they impact biofilm formation and infection outcome. This lack of knowledge affects CAUTIs management as uncommon bacteria action can, for instance, influence the rate at which pathogens adhere and grow, as well as affect the overall biofilm resistance to antibiotics. Another relevant aspect is the understanding of factors that drive a single pathogenic bacterium to become prevalent in a polymicrobial community and subsequently cause infection. In this review, a general overview about the IMDs-associated biofilm infections is provided, with an emphasis on the pathophysiology and the microbiome composition of CAUTIs. Based on the available literature, it is clear that more research about the microbiome interaction, mechanisms of biofilm formation and of antimicrobial tolerance of the polymicrobial consortium are required to better understand and treat these infections.
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Affiliation(s)
- Andreia S Azevedo
- a Department of Chemical Engineering, Faculty of Engineering , Laboratory for Process Engineering, Environment, and Energy and Biotechnology Engineering (LEPABE), University of Porto , Porto , Portugal
| | - Carina Almeida
- a Department of Chemical Engineering, Faculty of Engineering , Laboratory for Process Engineering, Environment, and Energy and Biotechnology Engineering (LEPABE), University of Porto , Porto , Portugal.,b Institute for Biotechnology and Bioengineering (IBB), Centre of Biological Engineering, Universidade do Minho , Braga , Portugal
| | - Luís F Melo
- a Department of Chemical Engineering, Faculty of Engineering , Laboratory for Process Engineering, Environment, and Energy and Biotechnology Engineering (LEPABE), University of Porto , Porto , Portugal
| | - Nuno F Azevedo
- a Department of Chemical Engineering, Faculty of Engineering , Laboratory for Process Engineering, Environment, and Energy and Biotechnology Engineering (LEPABE), University of Porto , Porto , Portugal
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Biofilm on the tracheoesophageal voice prosthesis: considerations for oral decontamination. Eur Arch Otorhinolaryngol 2016; 274:405-413. [PMID: 27400694 DOI: 10.1007/s00405-016-4193-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/30/2016] [Indexed: 10/21/2022]
Abstract
The tracheoesophageal puncture (TEP) restores verbal communication after total laryngectomy using a one-way valved voice prosthesis (VP). Microbial colonization can shorten VP device life. Our aims were to investigate patterns of prosthetic and oral colonization, and record changes in VP device life after targeted decontamination. We conducted a retrospective review of TEP clinic patients who underwent microbial analysis of the VP between 01/2003 and 07/2013. Two subgroups were analyzed: (1) patients with microbial analysis of the VP and the mouth were analyzed to identify patterns of common contamination, and (2) patients who were prescribed targeted oral decontamination on the basis of the microbial analysis of the VP were analyzed to evaluate effects on device life. Among 42 patients, 3 patients had only fungal, 5 only bacterial, and 33 had polyspecies fungal and bacterial colonization. In the TEP-oral microflora subgroup (n = 15), 7 had common microorganisms in the mouth and on the VP. Among the decontamination subgroup (n = 23), 6 patients received broad spectrum rinse, 16 antifungal agents and 13 antibiotics, or a combination thereof. After targeted decontamination, the median device life of prostheses improved from 7.89 to 10.82 weeks (p = 0.260). The majority of patients with a suboptimal VP device life in this pilot had polyspecies bacterial and fungal colonization. VPs rarely had fungal contamination alone (3 %), and non-albicans fungal species were more common than expected. For these reasons, we are exploring the use of targeted decontamination regimens that were associated with 1.4-fold improvement in VP duration.
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Abstract
Fungal biofilms have become an increasingly important clinical problem. The widespread use of antibiotics, frequent use of indwelling medical devices, and a trend toward increased patient immunosuppression have resulted in a creation of opportunity for clinically important yeasts and molds to form biofilms. This review will discuss the diversity and importance of fungal biofilms in the context of clinical medicine, provide novel insights into the clinical management of fungal biofilm infection, present evidence why these structures are recalcitrant to antifungal therapy, and discuss how our knowledge and understanding may lead to novel therapeutic intervention.
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The role of biofilm in chronic laryngitis and in head and neck cancer. Curr Opin Otolaryngol Head Neck Surg 2015; 23:448-53. [DOI: 10.1097/moo.0000000000000200] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Talpaert MJ, Balfour A, Stevens S, Baker M, Muhlschlegel FA, Gourlay CW. Candida biofilm formation on voice prostheses. J Med Microbiol 2014; 64:199-208. [PMID: 25106862 DOI: 10.1099/jmm.0.078717-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Laryngopharyngeal malignancy is treated with radiotherapy and/or surgery. When total laryngectomy is required, major laryngeal functions (phonation, airway control, swallowing and coughing) are affected. The insertion of a silicone rubber voice prosthesis in a surgically created tracheoesophageal puncture is the most effective method for voice rehabilitation. Silicone, as is the case with other synthetic materials such as polymethylmethacrylate, polyurethane, polyvinyl chloride, polypropylene and polystyrene, has the propensity to become rapidly colonized by micro-organisms (mainly Candida albicans) forming a biofilm, which leads to the failure of the devices. Silicone is used within voice prosthetic devices because of its flexible properties, which are essential for valve function. Valve failure, as well as compromising speech, may result in aspiration pneumonia, and repeated valve replacement may lead to either tract stenosis or insufficiency. Prevention and control of biofilm formation are therefore crucial for the lifespan of the prosthesis and promotion of tracheoesophageal tissue and lung health. To date, the mechanisms of biofilm formation on voice prostheses are not fully understood. Further studies are therefore required to identify factors influencing Candida biofilm formation. This review describes the factors known to influence biofilm formation on voice prostheses and current strategies employed to prolong their life by interfering with microbial colonization.
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Affiliation(s)
- Moira J Talpaert
- Kent Fungal Group, School of Biosciences, University of Kent, Canterbury CT2 7NJ, UK
| | - Alistair Balfour
- Ear, Nose and Throat Services, East Kent Hospitals University NHS Foundation Trust, The William Harvey Hospital, Kennington Road, Ashford TN24 0LZ, UK
| | - Sarah Stevens
- Macmillan Speech and Language Therapy Services, Kent and Canterbury Hospital, Ethelbert Road, Canterbury CT1 3NG, UK
| | - Mark Baker
- Clinical Microbiology Service, East Kent Hospitals University NHS Foundation Trust, The William Harvey Hospital, Kennington Road, Ashford TN24 0LZ, UK
| | - Fritz A Muhlschlegel
- Clinical Microbiology Service, East Kent Hospitals University NHS Foundation Trust, The William Harvey Hospital, Kennington Road, Ashford TN24 0LZ, UK
- Kent Fungal Group, School of Biosciences, University of Kent, Canterbury CT2 7NJ, UK
| | - Campbell W Gourlay
- Kent Fungal Group, School of Biosciences, University of Kent, Canterbury CT2 7NJ, UK
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