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Abstract
Chronic, nonhealing wounds place an enormous burden on both the health care system and patients, with no definitive treatments available. There has been increasing evidence that the microbial composition of wounds may play an important role in wound healing. Culture-independent methods for bacterial detection and analysis have revealed the wound microbiome to be much more diverse and complex than culture alone. Such methods primarily rely on targeted amplification and sequencing of various hypervariable regions of the bacterial 16S rRNA for phylogenetic analysis. To date, there have been several studies utilizing culture-independent methods to investigate the microbiome of a variety of chronic wounds, including venous insufficiency ulcers, pressure ulcers, and diabetic foot ulcers. Major bacteria found include Staphylococcus, Streptococcus, Corynebacterium, Pseudomonas, and various anaerobes. Current studies suggest that improved healing and outcomes may be correlated with increased bacterial diversity and instability of the microbiome composition of a wound. However, the exact role of the microbiome in wound healing remains poorly understood. While the current research is promising, studies are very heterogeneous, hindering comparisons of findings across different research groups. In addition, more studies are needed to correlate microbiome findings with clinical factors, as well as in the relatively unexplored fields of acute wounds and nonbacterial microbiomes, such as the wound mycobiome and virome. Better understanding of the various aspects of the microorganisms present in wounds may eventually allow for the manipulation of the wound microbiota in such a way as to promote healing, such as through bacteriophage therapies or probiotics.
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Hewavitharana SS, Klarer E, Reed AJ, Leisso R, Poirier B, Honaas L, Rudell DR, Mazzola M. Temporal Dynamics of the Soil Metabolome and Microbiome During Simulated Anaerobic Soil Disinfestation. Front Microbiol 2019; 10:2365. [PMID: 31681226 PMCID: PMC6803440 DOI: 10.3389/fmicb.2019.02365] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/30/2019] [Indexed: 11/13/2022] Open
Abstract
Significant interest exists in engineering the soil microbiome to attain suppression of soil-borne plant diseases. Anaerobic soil disinfestation (ASD) has potential as a biologically regulated disease control method; however, the role of specific metabolites and microbial community dynamics contributing to ASD mediated disease control is mostly uncharacterized. Understanding the trajectory of co-evolutionary processes leading to syntrophic generation of functional metabolites during ASD is a necessary prelude to the predictive utilization of this disease management approach. Consequently, metabolic and microbial community profiling were used to generate highly dimensional datasets and network analysis to identify sequential transformations through aerobic, facultatively anaerobic, and anaerobic soil phases of the ASD process and distinct groups of metabolites and microorganisms linked with those stages. Transient alterations in abundance of specific microbial groups, not consistently accounted for in previous studies of the ASD process, were documented in this time-course study. Such events initially were associated with increases and subsequent diminution in highly labile metabolites conferred by the carbon input. Proliferation and dynamic compositional changes in the Firmicutes community continued throughout the anaerobic phase and was linked to temporal changes in metabolite abundance including accumulation of small chain organic acids, methyl sulfide compounds, hydrocarbons, and p-cresol with antimicrobial properties. Novel potential modes of disease control during ASD were identified and the importance of the amendment and "community metabolism" for temporally supplying specific classes of labile compounds were revealed.
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Affiliation(s)
| | - Emmi Klarer
- Department of Plant Pathology, Washington State University, Wenatchee, WA, United States
| | - Andrew J. Reed
- United States Department of Agriculture-Agricultural Research Service, Physiology and Pathology of Tree Fruits Research, Wenatchee, WA, United States
| | - Rachel Leisso
- United States Department of Agriculture-Agricultural Research Service, Physiology and Pathology of Tree Fruits Research, Wenatchee, WA, United States
| | - Brenton Poirier
- United States Department of Agriculture-Agricultural Research Service, Physiology and Pathology of Tree Fruits Research, Wenatchee, WA, United States
| | - Loren Honaas
- United States Department of Agriculture-Agricultural Research Service, Physiology and Pathology of Tree Fruits Research, Wenatchee, WA, United States
| | - David R. Rudell
- United States Department of Agriculture-Agricultural Research Service, Physiology and Pathology of Tree Fruits Research, Wenatchee, WA, United States
| | - Mark Mazzola
- United States Department of Agriculture-Agricultural Research Service, Physiology and Pathology of Tree Fruits Research, Wenatchee, WA, United States
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Shackleton M, Rees GN, Watson G, Campbell C, Nielsen D. Environmental DNA reveals landscape mosaic of wetland plant communities. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00689] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Karnik T, Dempsey SG, Jerram MJ, Nagarajan A, Rajam R, May BCH, Miller CH. Ionic silver functionalized ovine forestomach matrix - a non-cytotoxic antimicrobial biomaterial for tissue regeneration applications. Biomater Res 2019; 23:6. [PMID: 30834142 PMCID: PMC6387525 DOI: 10.1186/s40824-019-0155-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/06/2019] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Antimicrobial technologies, including silver-containing medical devices, are increasingly utilized in clinical regimens to mitigate risks of microbial colonization. Silver-functionalized resorbable biomaterials for use in wound management and tissue regeneration applications have a narrow therapeutic index where antimicrobial effectiveness may be outweighed by adverse cytotoxicity. We examined the effects of ionic silver functionalization of an extracellular matrix (ECM) biomaterial derived from ovine forestomach (OFM-Ag) in terms of material properties, antimicrobial effectiveness and cytotoxicity profile. METHODS Material properties of OFM-Ag were assessed by via biochemical analysis, microscopy, atomic absorption spectroscopy (AAS) and differential scanning calorimetry. The silver release profile of OFM-Ag was profiled by AAS and antimicrobial effectiveness testing utilized to determine the minimum effective concentration of silver in OFM-Ag in addition to the antimicrobial spectrum and wear time. Biofilm prevention properties of OFM-Ag in comparison to silver containing collagen dressing materials was quantified via in vitro crystal violet assay using a polymicrobial model. Toxicity of ionic silver, OFM-Ag and silver containing collagen dressing materials was assessed toward mammalian fibroblasts using elution cytoxicity testing. RESULTS OFM-Ag retained the native ECM compositional and structural characteristic of non-silver functionalized ECM material while imparting broad spectrum antimicrobial effectiveness toward 11 clinically relevant microbial species including fungi and drug resistant strains, maintaining effectiveness over a wear time duration of 7-days. OFM-Ag demonstrated significant prevention of polymicrobial biofilm formation compared to non-antimicrobial and silver-containing collagen dressing materials. Where silver-containing collagen dressing materials exhibited cytotoxic effects toward mammalian fibroblasts, OFM-Ag was determined to be non-cytotoxic, silver elution studies indicated sustained retention of silver in OFM-Ag as a possible mechanism for the attenuated cytotoxicity. CONCLUSIONS This work demonstrates ECM biomaterials may be functionalized with silver to favourably shift the balance between detrimental cytotoxic potential and beneficial antimicrobial effects, while preserving the ECM structure and function of utility in tissue regeneration applications.
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Affiliation(s)
- Tanvi Karnik
- Aroa Biosurgery, 2 Kingsford Smith Place, PO Box 107111, Auckland Airport, Auckland, 2150 New Zealand
| | - Sandi G. Dempsey
- Aroa Biosurgery, 2 Kingsford Smith Place, PO Box 107111, Auckland Airport, Auckland, 2150 New Zealand
| | - Micheal J. Jerram
- Aroa Biosurgery, 2 Kingsford Smith Place, PO Box 107111, Auckland Airport, Auckland, 2150 New Zealand
| | - Arun Nagarajan
- Aroa Biosurgery, 2 Kingsford Smith Place, PO Box 107111, Auckland Airport, Auckland, 2150 New Zealand
| | - Ravindra Rajam
- Aroa Biosurgery, 2 Kingsford Smith Place, PO Box 107111, Auckland Airport, Auckland, 2150 New Zealand
| | - Barnaby C. H. May
- Aroa Biosurgery, 2 Kingsford Smith Place, PO Box 107111, Auckland Airport, Auckland, 2150 New Zealand
| | - Christopher H. Miller
- Aroa Biosurgery, 2 Kingsford Smith Place, PO Box 107111, Auckland Airport, Auckland, 2150 New Zealand
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Trichophyton as a Rare Cause of Postoperative Wound Infection Resistant to Standard Empiric Antimicrobial Therapy. Case Rep Pediatr 2019; 2018:3483685. [PMID: 30671272 PMCID: PMC6317086 DOI: 10.1155/2018/3483685] [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: 10/15/2018] [Accepted: 11/13/2018] [Indexed: 11/18/2022] Open
Abstract
Fungal infections are rare causes of acute surgical wound infections, but Candida is not an infrequent etiology in chronic wound infections. Trichophyton species is a common cause of tinea capitis but has not been reported as a cause of neurosurgical wound infection. We report a case of Trichophyton tonsurans causing a nonhealing surgical wound infection in a 14-year-old male after hemicraniectomy. His wound infection was notable for production of purulent exudate from the wound and lack of clinical improvement despite empiric treatment with multiple broad-spectrum antibiotics targeting typical bacterial causes of wound infection. Multiple wound cultures consistently grew Trichophyton fungus, and his wound infection clinically improved rapidly after starting terbinafine and discontinuing antibiotics.
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Mahadik K, Yadav P, Bhatt B, Shah RA, Balaji KN. Deregulated AUF1 Assists BMP-EZH2-Mediated Delayed Wound Healing during Candida albicans Infection. THE JOURNAL OF IMMUNOLOGY 2018; 201:3617-3629. [PMID: 30429285 DOI: 10.4049/jimmunol.1800688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 10/16/2018] [Indexed: 11/19/2022]
Abstract
Tissue repair is a complex process that necessitates an interplay of cellular processes, now known to be dictated by epigenetics. Intriguingly, macrophages are testimony to a large repertoire of evolving functions in this process. We identified a role for BMP signaling in regulating macrophage responses to Candida albicans infection during wound repair in a murine model. In this study, the RNA binding protein, AU-rich element-binding factor 1, was posttranslationally destabilized to bring about ubiquitin ligase, NEDD4-directed activation of BMP signaling. Concomitantly, PI3K/PKCδ mobilized the rapid phosphorylation of BMP-responsive Smad1/5/8. Activated BMP pathway orchestrated the elevated recruitment of EZH2 at promoters of genes assisting timely wound closure. In vivo, the repressive H3K27 trimethylation was observed to persist, accompanied by a robust upregulation of BMP pathway upon infection with C. albicans, culminating in delayed wound healing. Altogether, we uncovered the signaling networks coordinated by fungal colonies that are now increasingly associated with the infected wound microbiome, resulting in altered wound fate.
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Affiliation(s)
- Kasturi Mahadik
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Preeti Yadav
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Bharat Bhatt
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Riyaz Ahmad Shah
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, Karnataka 560012, India
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Ghotaslou R, Memar MY, Alizadeh N. Classification, microbiology and treatment of diabetic foot infections. J Wound Care 2018; 27:434-441. [PMID: 30016139 DOI: 10.12968/jowc.2018.27.7.434] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Diabetic foot ulcers (DFUs) are a common complication of type-1 and type-2 diabetes. About 10-15% of patients with diabetes develop foot ulcers. A validated foot ulcer classification system that will support the development of treatment strategis is necessary for clinicians managing DFUs. More than 10 classification systems have been described by researchers. Another important aspect of the management of DFUs is the proper identification of causative pathogens that trigger infections. While conventional diagnostic methods, such as swabs, cultures and biopsies are more widely used, novel molecular techniques have been exploring bacterial identification and quantification. Knowledge of the microbial aetiologies in diabetic foot infections, and understanding of antibiotic resistance, is critical for the effective management and treatment of these infected wounds. Initial antibiotic regimens are usually selected empirically. A set of common principles may help avoid selecting either an unnecessarily broad or inappropriately narrow antibiotic treatment regimen. In this review we provide a comprehensive summary and description of classification systems of diabetic foot infections, and a comprehensive discussion of microbiology.
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Affiliation(s)
- Reza Ghotaslou
- Professor of Medical Microbiology; Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Yousef Memar
- Candidate of Medical Bacteriology; Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Students' Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Naser Alizadeh
- Candidate of Medical Bacteriology; Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Students' Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
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58
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Kalan L, Grice EA. Fungi in the Wound Microbiome. Adv Wound Care (New Rochelle) 2018; 7:247-255. [PMID: 29984114 DOI: 10.1089/wound.2017.0756] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 10/10/2017] [Indexed: 02/06/2023] Open
Abstract
Significance: Culture-independent methods have revealed the diverse and dynamic bacterial communities that colonize chronic wounds. Only recently have studies begun to examine fungal colonization and interactions with the bacterial component of the microbiome, their relationship with the host, and influence on wound outcomes. Recent Advances: Studies using culture-independent sequencing methods reveal that fungi often go undetected in wounds. Candida spp. and Cladosporidium spp. are the most commonly identified fungi in wounds. The wound environment may promote multispecies biofilm formation between bacteria and fungi in wounds, with implications for pathogenicity, treatment, and outcomes. Critical Issues: Identifying microorganisms that are problematic for healing will require a comprehensive understanding of all members of the polymicrobial wound community, including fungi and bacteria. Improved reference databases and bioinformatics tools for studying fungal communities will stimulate further research into the fungal microbiome. Future Directions: Continued study of polymicrobial wound communities using culture-independent methods will further our understanding of the relationships between microbial bioburden, the host response, and impact on healing, complications, and patient outcomes. Future studies should encompass all types of microbiota, including fungi, and focus on potential multi-kingdom interactions that contribute to pathogenicity, biofilm formation, and poor outcomes.
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Affiliation(s)
- Lindsay Kalan
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elizabeth A. Grice
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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Schlafer S, Kamp A, Garcia JE. A confocal microscopy based method to monitor extracellular pH in fungal biofilms. FEMS Yeast Res 2018; 18:4978430. [DOI: 10.1093/femsyr/foy049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/17/2018] [Indexed: 12/15/2022] Open
Affiliation(s)
- Sebastian Schlafer
- Department of Dentistry and Oral Health, Aarhus University, Vennelyst Boulevard 9, 8000 Aarhus, Denmark
- Section for Microbiology, Department of Bioscience, Aarhus University, Ny Munkegade 116, 8000 Aarhus, Denmark
| | - Anja Kamp
- AIAS, Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, 8000 Aarhus, Denmark
| | - Javier E Garcia
- Department of Dentistry and Oral Health, Aarhus University, Vennelyst Boulevard 9, 8000 Aarhus, Denmark
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Abstract
Candida species are the most common infectious fungal species in humans; out of the approximately 150 known species, Candida albicans is the leading pathogenic species, largely affecting immunocompromised individuals. Apart from its role as the primary etiology for various types of candidiasis, C. albicans is known to contribute to polymicrobial infections. Polymicrobial interactions, particularly between C. albicans and bacterial species, have gained recent interest in which polymicrobial biofilm virulence mechanisms have been studied including adhesion, invasion, quorum sensing, and development of antimicrobial resistance. These trans-kingdom interactions, either synergistic or antagonistic, may help modulate the virulence and pathogenicity of both Candida and bacteria while uniquely impacting the pathogen-host immune response. As antibiotic and antifungal resistance increases, there is a great need to explore the intermicrobial cross-talk with a focus on the treatment of Candida-associated polymicrobial infections. This article explores the current literature on the interactions between Candida and clinically important bacteria and evaluates these interactions in the context of pathogenesis, diagnosis, and disease management.
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Abstract
Fungi represent a large proportion of the genetic diversity on Earth and fungal activity influences the structure of plant and animal communities, as well as rates of ecosystem processes. Large-scale DNA-sequencing datasets are beginning to reveal the dimensions of fungal biodiversity, which seem to be fundamentally different to bacteria, plants and animals. In this Review, we describe the patterns of fungal biodiversity that have been revealed by molecular-based studies. Furthermore, we consider the evidence that supports the roles of different candidate drivers of fungal diversity at a range of spatial scales, as well as the role of dispersal limitation in maintaining regional endemism and influencing local community assembly. Finally, we discuss the ecological mechanisms that are likely to be responsible for the high heterogeneity that is observed in fungal communities at local scales.
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Affiliation(s)
- Kabir G Peay
- Department of Biology, Stanford University, Stanford, California 94305, USA
| | - Peter G Kennedy
- Department of Plant Biology, University of Minnesota.,Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, Minnesota 55108, USA
| | - Jennifer M Talbot
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA
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Padovan AC, Neave MJ, Munksgaard NC, Gibb KS. Multiple approaches to assess the safety of artisanal marine food in a tropical estuary. ENVIRONMENTAL MONITORING AND ASSESSMENT 2017; 189:125. [PMID: 28238170 DOI: 10.1007/s10661-017-5842-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 02/09/2017] [Indexed: 06/06/2023]
Abstract
In this study, metal and metalloid concentrations and pathogens were measured in shellfish at different locations in a tropical estuary, including sites impacted by sewage and industry. Oyster, mangrove snails and mud snails did not exceed Australian and New Zealand Food Standards maximum levels for copper, lead or estimated inorganic arsenic at any site although copper concentrations in oysters and mud snails exceeded generally expected levels at some locations. Bacterial community composition in shellfish was species-specific regardless of location and different to the surrounding water and sediment. In the snails Telescopium telescopium, Terebralia palustris and Nerita balteata, some bacterial taxa differed between sites, but not in Saccostrea cucullata oysters. The abundance of potential human pathogens was very low and pathogen abundance or diversity was not associated with site classification, i.e. sewage impact, industry impact and reference.
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Affiliation(s)
- A C Padovan
- Research Institute of the Environment and Livelihoods, Charles Darwin University, Ellengowan Drive, Darwin, NT, 0810, Australia.
| | - M J Neave
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory, Geelong, Vic, 3220, Australia
| | - N C Munksgaard
- Research Institute of the Environment and Livelihoods, Charles Darwin University, Ellengowan Drive, Darwin, NT, 0810, Australia
| | - K S Gibb
- Research Institute of the Environment and Livelihoods, Charles Darwin University, Ellengowan Drive, Darwin, NT, 0810, Australia
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Dryden MS, Cooke J, Salib RJ, Holding RE, Biggs T, Salamat AA, Allan RN, Newby RS, Halstead F, Oppenheim B, Hall T, Cox SC, Grover LM, Al-Hindi Z, Novak-Frazer L, Richardson MD. Reactive oxygen: A novel antimicrobial mechanism for targeting biofilm-associated infection. J Glob Antimicrob Resist 2017; 8:186-191. [PMID: 28213334 DOI: 10.1016/j.jgar.2016.12.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 12/04/2016] [Indexed: 11/24/2022] Open
Abstract
Reactive oxygen species (ROS) is a novel therapeutic strategy for topical or local application to wounds, mucosa or internal structures where there may be heavy bacterial bioburden with biofilm and chronic inflammation. Bacterial biofilms are a significant problem in clinical settings owing to their increased tolerance towards conventionally prescribed antibiotics and their propensity for selection of further antibacterial resistance. There is therefore a pressing need for the development of alternative therapeutic strategies that can improve antibiotic efficacy towards biofilms. ROS has been successful in treating chronic wounds and in clearing multidrug-resistant organisms, including methicillin-resistant Staphylococcus aureus (MRSA), and carbapenemase-producing isolates from wounds and vascular line sites. There is significant antifungal activity of ROS against planktonic and biofilm forms. Nebulised ROS has been evaluated in limited subjects to assess reductions in bioburden in chronically colonised respiratory tracts. The antibiofilm activity of ROS could have great implications for the treatment of a variety of persistent respiratory conditions. Use of ROS on internal prosthetic devices shows promise. A variety of novel delivery mechanisms are being developed to apply ROS activity to different anatomical sites.
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Affiliation(s)
- Matthew S Dryden
- Hampshire Hospitals NHS Foundation Trust, UK; University of Southampton Faculty of Medicine, Southampton, UK.
| | - Jonathan Cooke
- Imperial College London, London, UK; University of Manchester, Manchester, UK
| | - Rami J Salib
- Academic Unit of Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, UK; Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK; Department of Otolaryngology/Head & Neck Surgery, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Rebecca E Holding
- Academic Unit of Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, UK
| | - Timothy Biggs
- Academic Unit of Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, UK
| | - Ali A Salamat
- Academic Unit of Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, UK
| | - Raymond N Allan
- Academic Unit of Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, UK; Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Rachel S Newby
- Academic Unit of Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, UK
| | - Fenella Halstead
- Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Beryl Oppenheim
- Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Thomas Hall
- School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT, UK
| | - Sophie C Cox
- Mycology Reference Centre Manchester, Centre for Respiratory Medicine and Allergy, University of Manchester and University Hospital of Manchester, Manchester M23 9LT, UK
| | - Liam M Grover
- School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT, UK
| | - Zain Al-Hindi
- Mycology Reference Centre Manchester, Centre for Respiratory Medicine and Allergy, University of Manchester and University Hospital of Manchester, Manchester M23 9LT, UK
| | - Lilyann Novak-Frazer
- Mycology Reference Centre Manchester, Centre for Respiratory Medicine and Allergy, University of Manchester and University Hospital of Manchester, Manchester M23 9LT, UK
| | - Malcolm D Richardson
- Mycology Reference Centre Manchester, Centre for Respiratory Medicine and Allergy, University of Manchester and University Hospital of Manchester, Manchester M23 9LT, UK
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65
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Townsend EM, Sherry L, Rajendran R, Hansom D, Butcher J, Mackay WG, Williams C, Ramage G. Development and characterisation of a novel three-dimensional inter-kingdom wound biofilm model. BIOFOULING 2016; 32:1259-1270. [PMID: 27841027 DOI: 10.1080/08927014.2016.1252337] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/19/2016] [Indexed: 06/06/2023]
Abstract
Chronic diabetic foot ulcers are frequently colonised and infected by polymicrobial biofilms that ultimately prevent healing. This study aimed to create a novel in vitro inter-kingdom wound biofilm model on complex hydrogel-based cellulose substrata to test commonly used topical wound treatments. Inter-kingdom triadic biofilms composed of Candida albicans, Pseudomonas aeruginosa, and Staphylococcus aureus were shown to be quantitatively greater in this model compared to a simple substratum when assessed by conventional culture, metabolic dye and live dead qPCR. These biofilms were both structurally complex and compositionally dynamic in response to topical therapy, so when treated with either chlorhexidine or povidone iodine, principal component analysis revealed that the 3-D cellulose model was minimally impacted compared to the simple substratum model. This study highlights the importance of biofilm substratum and inclusion of relevant polymicrobial and inter-kingdom components, as these impact penetration and efficacy of topical antiseptics.
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Affiliation(s)
- Eleanor M Townsend
- a Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences , University of Glasgow , Glasgow , UK
- b Institute of Healthcare Policy and Practice , University of West of Scotland , Paisley , UK
| | - Leighann Sherry
- a Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences , University of Glasgow , Glasgow , UK
- b Institute of Healthcare Policy and Practice , University of West of Scotland , Paisley , UK
| | - Ranjith Rajendran
- a Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences , University of Glasgow , Glasgow , UK
| | - Donald Hansom
- a Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences , University of Glasgow , Glasgow , UK
| | - John Butcher
- b Institute of Healthcare Policy and Practice , University of West of Scotland , Paisley , UK
| | - William G Mackay
- b Institute of Healthcare Policy and Practice , University of West of Scotland , Paisley , UK
| | - Craig Williams
- b Institute of Healthcare Policy and Practice , University of West of Scotland , Paisley , UK
| | - Gordon Ramage
- a Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences , University of Glasgow , Glasgow , UK
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Budachetri K, Williams J, Mukherjee N, Sellers M, Moore F, Karim S. The microbiome of neotropical ticks parasitizing on passerine migratory birds. Ticks Tick Borne Dis 2016; 8:170-173. [PMID: 27802919 DOI: 10.1016/j.ttbdis.2016.10.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 10/17/2016] [Accepted: 10/24/2016] [Indexed: 02/01/2023]
Abstract
Seasonal migration of passerine birds between temperate North America and tropical Central and South America is an ecological phenomenon. Migration of birds has been associated with the introduction of ectoparasites like ticks or tick-borne pathogens across the avian migration routes. In this study, the microbial diversity was determined in the ticks and bird DNA samples using 454 pyrosequencing of bacterial 16S rRNA gene. Tick DNA samples showed the dominance of genera Lactococcus, Francisella, Raoultella, Wolbachia and Rickettsia across all the ticks, but birds DNA did not share common microbial diversity with ticks. Furthermore, "Candidatus Rickettsia amblyommii" infection in the 91 ticks collected off the songbirds was also quantified by qPCR assay. Interestingly, "Candidatus R. amblyommii" was tested positive in 24 ticks (26% infection), and infection varied from as low as three copies to thousands of copies, but bird blood samples showed no amplification. Our results provide evidence that songbirds serve as transport carrier for immature ticks, and less likely to be a reservoir for "Candidatus R. amblyommii".
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Affiliation(s)
- Khemraj Budachetri
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA
| | - Jaclyn Williams
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA
| | - Nabanita Mukherjee
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA
| | - Michael Sellers
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA
| | - Frank Moore
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA
| | - Shahid Karim
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA.
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Fugle CW, Zhang Y, Hong F, Sun S, Westwater C, Rachidi S, Yu H, Garret-Mayer E, Kirkwood K, Liu B, Li Z. CD24 blunts oral squamous cancer development and dampens the functional expansion of myeloid-derived suppressor cells. Oncoimmunology 2016; 5:e1226719. [PMID: 27853649 DOI: 10.1080/2162402x.2016.1226719] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/11/2016] [Accepted: 08/16/2016] [Indexed: 02/06/2023] Open
Abstract
CD24 expression has been implicated in the oncogenesis of multiple types of cancer and high tumor expression is considered a poor prognosis factor; however, the role of CD24 in oral cancer progression is unknown. Unlike other cancer types, we found that higher CD24 levels in human oral cancers are correlated to lower clinical stage and better overall survival. We then dissected the role of CD24 and mechanisms in oral cancer pathogenesis in mice using a genetic strategy and demonstrated that CD24 deficiency increased the oral cavity tumor burden in response to the carcinogen 4-nitroquioline 1-oxide (4-NQO). Immune profile analysis showed a significant expansion as well as increased suppressive function of myeloid-derived suppressor cells (MDSCs) in CD24-/- mice, but no apparent impairment in T cells, B cells, or dendritic cells. Further, studies with an orthotopically transplanted syngeneic squamous carcinoma model in the tongue of CD24-/- and CD24+/- mice confirmed the protective roles of CD24 against cancer. Moreover, the difference in tumor growth between CD24-/- and CD24+/- mice was blunted by immunodepletion of MDSCs. We conclude that CD24 expression impedes MDSC expansion and function, and thus slows oral cancer oncogenesis. This study is the first to examine the role of CD24 in a de novo oral cancer model, and it highlights the need to consider the immune regulatory roles of CD24 in the development of CD24-targeted therapy for cancer.
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Affiliation(s)
- Caroline W Fugle
- Department of Microbiology & Immunology, Medical University of South Carolina , Charleston, SC, USA
| | - Yongliang Zhang
- Department of Microbiology & Immunology, Medical University of South Carolina , Charleston, SC, USA
| | - Feng Hong
- Department of Microbiology & Immunology, Medical University of South Carolina , Charleston, SC, USA
| | - Shaoli Sun
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina , Charleston, SC, USA
| | - Caroline Westwater
- Department of Oral Health Sciences, Medical University of South Carolina , Charleston, SC, USA
| | - Saleh Rachidi
- Department of Oral Health Sciences, Medical University of South Carolina , Charleston, SC, USA
| | - Hong Yu
- Department of Oral Health Sciences, Medical University of South Carolina , Charleston, SC, USA
| | - Elizabeth Garret-Mayer
- Department of Public Health Sciences, Medical University of South Carolina , Charleston, SC, USA
| | - Keith Kirkwood
- Department of Oral Health Sciences, Medical University of South Carolina , Charleston, SC, USA
| | - Bei Liu
- Department of Microbiology & Immunology, Medical University of South Carolina , Charleston, SC, USA
| | - Zihai Li
- Department of Microbiology & Immunology, Medical University of South Carolina , Charleston, SC, USA
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Redefining the Chronic-Wound Microbiome: Fungal Communities Are Prevalent, Dynamic, and Associated with Delayed Healing. mBio 2016; 7:mBio.01058-16. [PMID: 27601572 PMCID: PMC5013295 DOI: 10.1128/mbio.01058-16] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Chronic nonhealing wounds have been heralded as a silent epidemic, causing significant morbidity and mortality especially in elderly, diabetic, and obese populations. Polymicrobial biofilms in the wound bed are hypothesized to disrupt the highly coordinated and sequential events of cutaneous healing. Both culture-dependent and -independent studies of the chronic-wound microbiome have almost exclusively focused on bacteria, omitting what we hypothesize are important fungal contributions to impaired healing and the development of complications. Here we show for the first time that fungal communities (the mycobiome) in chronic wounds are predictive of healing time, associated with poor outcomes, and form mixed fungal-bacterial biofilms. We longitudinally profiled 100, nonhealing diabetic-foot ulcers with high-throughput sequencing of the pan-fungal internal transcribed spacer 1 (ITS1) locus, estimating that up to 80% of wounds contain fungi, whereas cultures performed in parallel captured only 5% of colonized wounds. The “mycobiome” was highly heterogeneous over time and between subjects. Fungal diversity increased with antibiotic administration and onset of a clinical complication. The proportions of the phylum Ascomycota were significantly greater (P = 0.015) at the beginning of the study in wounds that took >8 weeks to heal. Wound necrosis was distinctly associated with pathogenic fungal species, while taxa identified as allergenic filamentous fungi were associated with low levels of systemic inflammation. Directed culturing of wounds stably colonized by pathogens revealed that interkingdom biofilms formed between yeasts and coisolated bacteria. Combined, our analyses provide enhanced resolution of the mycobiome during impaired wound healing, its role in chronic disease, and impact on clinical outcomes. Wounds are an underappreciated but serious complication for a diverse spectrum of diseases. High-risk groups, such as persons with diabetes, have a 25% lifetime risk of developing a wound that can become chronic. The majority of microbiome research related to chronic wounds is focused on bacteria, but the association of fungi with clinical outcomes remains to be elucidated. Here we describe the dynamic fungal communities in 100 diabetic patients with foot ulcers. We found that communities are unstable over time, but at the first clinical presentation, the relative proportions of different phyla predict healing times. Pathogenic fungi not identified by culture reside in necrotic wounds and are associated with a poor prognosis. In wounds stably colonized by fungi, we identified yeasts capable of forming biofilms in concert with bacteria. Our findings illuminate the associations of the fungal mycobiome with wound prognosis and healing.
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69
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Budachetri K, Gaillard D, Williams J, Mukherjee N, Karim S. A snapshot of the microbiome of Amblyomma tuberculatum ticks infesting the gopher tortoise, an endangered species. Ticks Tick Borne Dis 2016; 7:1225-1229. [PMID: 27460902 DOI: 10.1016/j.ttbdis.2016.07.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 07/18/2016] [Accepted: 07/18/2016] [Indexed: 02/01/2023]
Abstract
The gopher tortoise tick, Amblyomma tuberculatum, has a unique relationship with the gopher tortoise, Gopherus polyphemus, found in sandy habitats across the southeastern United States. We aimed to understand the overall bacterial community associated with A. tuberculatum while also focusing on spotted fever group Rickettsia. These tortoises in the Southern Mississippi region are a federally threatened species; therefore, we have carefully trapped the tortoises and removed the species-specific ticks attached to them. Genomic DNA was extracted from individual ticks and used to explore overall bacterial load using pyrosequencing of bacterial 16S rRNA on 454-sequencing platform. The spotted fever group of Rickettsia was explored by amplifying rickettsial outer membrane protein A (rompA) gene by nested PCR. Sequencing results revealed 330 bacterial operational taxonomic units (OTUs) after all the necessary curation of sequences. Four whole A. tuberculatum ticks showed Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes as the most dominant phyla with a total of 74 different bacterial genera detected. Together Rickettsiae and Francisella showed >85% abundance, thus dominating the bacterial community structure. Partial sequences obtained from ompA amplicons revealed the presence of an uncharacterized Rickettsia similar to the Rickettsial endosymbiont of A. tuberculatum. This is the first preliminary profile of a complete bacterial community from gopher tortoise ticks and warrants further investigation regarding the functional role of Rickettsial and Francisella-like endosymbionts in tick physiology.
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Affiliation(s)
- Khemraj Budachetri
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA
| | - Daniel Gaillard
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA
| | - Jaclyn Williams
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA
| | - Nabanita Mukherjee
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA
| | - Shahid Karim
- Department of Biological Sciences, University of Southern Mississippi, 118 College Drive #5018, Hattiesburg, MS 39406, USA.
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70
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Biological Low-pH Mn(II) Oxidation in a Manganese Deposit Influenced by Metal-Rich Groundwater. Appl Environ Microbiol 2016; 82:3009-3021. [PMID: 26969702 DOI: 10.1128/aem.03844-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/04/2016] [Indexed: 01/11/2023] Open
Abstract
UNLABELLED The mechanisms, key organisms, and geochemical significance of biological low-pH Mn(II) oxidation are largely unexplored. Here, we investigated the structure of indigenous Mn(II)-oxidizing microbial communities in a secondary subsurface Mn oxide deposit influenced by acidic (pH 4.8) metal-rich groundwater in a former uranium mining area. Microbial diversity was highest in the Mn deposit compared to the adjacent soil layers and included the majority of known Mn(II)-oxidizing bacteria (MOB) and two genera of known Mn(II)-oxidizing fungi (MOF). Electron X-ray microanalysis showed that romanechite [(Ba,H2O)2(Mn(4+),Mn(3+))5O10] was conspicuously enriched in the deposit. Canonical correspondence analysis revealed that certain fungal, bacterial, and archaeal groups were firmly associated with the autochthonous Mn oxides. Eight MOB within the Proteobacteria, Actinobacteria, and Bacteroidetes and one MOF strain belonging to Ascomycota were isolated at pH 5.5 or 7.2 from the acidic Mn deposit. Soil-groundwater microcosms demonstrated 2.5-fold-faster Mn(II) depletion in the Mn deposit than adjacent soil layers. No depletion was observed in the abiotic controls, suggesting that biological contribution is the main driver for Mn(II) oxidation at low pH. The composition and species specificity of the native low-pH Mn(II) oxidizers were highly adapted to in situ conditions, and these organisms may play a central role in the fundamental biogeochemical processes (e.g., metal natural attenuation) occurring in the acidic, oligotrophic, and metalliferous subsoil ecosystems. IMPORTANCE This study provides multiple lines of evidence to show that microbes are the main drivers of Mn(II) oxidation even at acidic pH, offering new insights into Mn biogeochemical cycling. A distinct, highly adapted microbial community inhabits acidic, oligotrophic Mn deposits and mediates biological Mn oxidation. These data highlight the importance of biological processes for Mn biogeochemical cycling and show the potential for new bioremediation strategies aimed at enhancing biological Mn oxidation in low-pH environments for contaminant mitigation.
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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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72
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Becerra SC, Roy DC, Sanchez CJ, Christy RJ, Burmeister DM. An optimized staining technique for the detection of Gram positive and Gram negative bacteria within tissue. BMC Res Notes 2016; 9:216. [PMID: 27071769 PMCID: PMC4828829 DOI: 10.1186/s13104-016-1902-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 02/02/2016] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Bacterial infections are a common clinical problem in both acute and chronic wounds. With growing concerns over antibiotic resistance, treatment of bacterial infections should only occur after positive diagnosis. Currently, diagnosis is delayed due to lengthy culturing methods which may also fail to identify the presence of bacteria. While newer costly bacterial identification methods are being explored, a simple and inexpensive diagnostic tool would aid in immediate and accurate treatments for bacterial infections. Histologically, hematoxylin and eosin (H&E) and Gram stains have been employed, but are far from optimal when analyzing tissue samples due to non-specific staining. The goal of the current study was to develop a modification of the Gram stain that enhances the contrast between bacteria and host tissue. FINDINGS A modified Gram stain was developed and tested as an alternative to Gram stain that improves the contrast between Gram positive bacteria, Gram negative bacteria and host tissue. Initially, clinically relevant strains of Pseudomonas aeruginosa and Staphylococcus aureus were visualized in vitro and in biopsies of infected, porcine burns using routine Gram stain, and immunohistochemistry techniques involving bacterial strain-specific fluorescent antibodies as validation tools. H&E and Gram stain of serial biopsy sections were then compared to a modification of the Gram stain incorporating a counterstain that highlights collagen found in tissue. The modified Gram stain clearly identified both Gram positive and Gram negative bacteria, and when compared to H&E or Gram stain alone provided excellent contrast between bacteria and non-viable burn eschar. Moreover, when applied to surgical biopsies from patients that underwent burn debridement this technique was able to clearly detect bacterial morphology within host tissue. CONCLUSIONS We describe a modification of the Gram stain that provides improved contrast of Gram positive and Gram negative microorganisms within host tissue. The samples used in this study demonstrate that this staining technique has laboratory and clinical applicability. This modification only adds minutes to traditional Gram stain with reusable reagents, and results in a cost- and time-efficient technique for identifying bacteria in any clinical biopsy containing connective tissue.
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Affiliation(s)
- Sandra C Becerra
- Extremity Trauma and Regenerative Medicine Task Area, United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX, 78234, USA
| | - Daniel C Roy
- Extremity Trauma and Regenerative Medicine Task Area, United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX, 78234, USA
| | - Carlos J Sanchez
- Extremity Trauma and Regenerative Medicine Task Area, United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX, 78234, USA
| | - Robert J Christy
- Extremity Trauma and Regenerative Medicine Task Area, United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX, 78234, USA
| | - David M Burmeister
- Extremity Trauma and Regenerative Medicine Task Area, United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX, 78234, USA.
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73
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Cooper R, Jenkins L. Binding of two bacterial biofilms to dialkyl carbamoyl chloride (DACC)-coated dressings in vitro. J Wound Care 2016; 25:76, 78-82. [DOI: 10.12968/jowc.2016.25.2.76] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- R. Cooper
- At Centre for Biomedical Sciences, Cardiff School of Health Sciences, Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB
| | - L. Jenkins
- At Centre for Biomedical Sciences, Cardiff School of Health Sciences, Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB
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74
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Jabari L, Gannoun H, Khelifi E, Cayol JL, Godon JJ, Hamdi M, Fardeau ML. Bacterial ecology of abattoir wastewater treated by an anaerobic digestor. Braz J Microbiol 2016; 47:73-84. [PMID: 26887229 PMCID: PMC4822766 DOI: 10.1016/j.bjm.2015.11.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 07/06/2015] [Indexed: 01/15/2023] Open
Abstract
Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens), and msbl6 (candidate division) were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published.
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Affiliation(s)
- Linda Jabari
- Université de Carthage, Laboratoire d'Ecologie et de Technologie Microbienne, Institut National des Sciences Appliquées et de Technologie (INSAT), 2 Boulevard de la terre, B.P. 676, 1080 Tunis, Tunisia; Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, MOI, UM 110, 13288 Marseille cedex 9, France
| | - Hana Gannoun
- Université de Carthage, Laboratoire d'Ecologie et de Technologie Microbienne, Institut National des Sciences Appliquées et de Technologie (INSAT), 2 Boulevard de la terre, B.P. 676, 1080 Tunis, Tunisia; Université Tunis El Manar, Institut Supérieur des Sciences Biologiques Appliquées de Tunis (ISSBAT) 9, avenue Zouhaïer Essafi, 1006 Tunis, Tunisia
| | - Eltaief Khelifi
- Université de Carthage, Laboratoire d'Ecologie et de Technologie Microbienne, Institut National des Sciences Appliquées et de Technologie (INSAT), 2 Boulevard de la terre, B.P. 676, 1080 Tunis, Tunisia
| | - Jean-Luc Cayol
- Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, MOI, UM 110, 13288 Marseille cedex 9, France
| | - Jean-Jacques Godon
- INRA U050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Étangs, F-11100 Narbonne, France
| | - Moktar Hamdi
- Université de Carthage, Laboratoire d'Ecologie et de Technologie Microbienne, Institut National des Sciences Appliquées et de Technologie (INSAT), 2 Boulevard de la terre, B.P. 676, 1080 Tunis, Tunisia
| | - Marie-Laure Fardeau
- Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, MOI, UM 110, 13288 Marseille cedex 9, France.
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75
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Williams C, Rajendran R, Ramage G. Aspergillus Biofilms in Human Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 931:1-11. [PMID: 27271678 DOI: 10.1007/5584_2016_4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The biofilm phenotype of Aspergillus species is an important and accepted clinical entity. While industrially these biofilms have been used extensively in important biofermentations, their role in clinical infection is less well defined. A recent flurry of activity has demonstrated that these interesting filamentous moulds have the capacity to form biofilms both in vitro and in vivo, and through various investigations have shown that these are exquisitely resistant to antifungal therapies through a range of adaptive resistance mechanisms independent of defined genetic changes. This review will explore the clinical importance of these biofilms and provide contemporary information with respect to their clinical management.
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Affiliation(s)
- Craig Williams
- Institute of Healthcare Policy and Practice, University of West of Scotland, High St, Paisley, PA1 2BE, UK.
| | - Ranjith Rajendran
- Infection and Immunity Research Group, Glasgow Dental School and Hospital, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland
| | - Gordon Ramage
- Infection and Immunity Research Group, Glasgow Dental School and Hospital, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland
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76
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Duran R, Bielen A, Paradžik T, Gassie C, Pustijanac E, Cagnon C, Hamer B, Vujaklija D. Exploring Actinobacteria assemblages in coastal marine sediments under contrasted Human influences in the West Istria Sea, Croatia. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:15215-29. [PMID: 25712885 DOI: 10.1007/s11356-015-4240-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 02/13/2015] [Indexed: 05/27/2023]
Abstract
The exploration of marine Actinobacteria has as major challenge to answer basic questions of microbial ecology that, in turn, will provide useful information to exploit Actinobacteria metabolisms in biotechnological processes. The ecological functions performed by Actinobacteria in marine sediments are still unclear and belongs to the most burning basic questions. The comparison of Actinobacteria communities inhabiting marine sediments that are under the influence of different contamination types will provide valuable information in the adaptation capacities of Actinobacteria to colonize specific ecological niche. In the present study, the characterization of different Actinobacteria assemblages according to contamination type revealed the ecological importance of Actinobacteria for maintaining both general biogeochemical functions through a "core" Actinobacteria community and specific roles associated with the presence of contaminants. Indeed, the results allowed to distinguish Actinobacteria genera and species operational taxonomic units (OTUs) able to cope with the presence of either (i) As, (ii) metals Ni, Fe, V, Cr, and Mn, or (iii) polycyclic aromatic hydrocarbons (PAHs) and toxic metals (Hg, Cd, Cu, Pb, and Zn). Such observations highlighted the metabolic capacities of Actinobacteria and their potential that should be taken into consideration and advantage during the implementation of bioremediation processes in marine ecosystems.
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Affiliation(s)
- Robert Duran
- Equipe Environnement et Microbiologie, MELODY group, Université de Pau et des Pays de l'Adour, IPREM UMR CNRS 5254, BP 1155, 64013, Pau Cedex, France.
- Université de Pau et des Pays de l'Adour, Bâtiment IBEAS, BP1155, 64013, Pau Cedex, France.
| | - Ana Bielen
- Division of Molecular Biology, Institute Ruđer Bošković, Bijenička 54, 10000, Zagreb, Croatia
| | - Tina Paradžik
- Division of Molecular Biology, Institute Ruđer Bošković, Bijenička 54, 10000, Zagreb, Croatia
| | - Claire Gassie
- Equipe Environnement et Microbiologie, MELODY group, Université de Pau et des Pays de l'Adour, IPREM UMR CNRS 5254, BP 1155, 64013, Pau Cedex, France
| | - Emina Pustijanac
- Juraj Dobrila University of Pula, Zagrebačka 30, 52100, Pula, Croatia
| | - Christine Cagnon
- Equipe Environnement et Microbiologie, MELODY group, Université de Pau et des Pays de l'Adour, IPREM UMR CNRS 5254, BP 1155, 64013, Pau Cedex, France
| | - Bojan Hamer
- Center for Marine Research, Ruđer Bošković Institute, Giordano Paliaga 5, 52210, Rovinj, Croatia
| | - Dušica Vujaklija
- Division of Molecular Biology, Institute Ruđer Bošković, Bijenička 54, 10000, Zagreb, Croatia
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77
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Benbow ME, Pechal JL, Lang JM, Erb R, Wallace JR. The Potential of High-throughput Metagenomic Sequencing of Aquatic Bacterial Communities to Estimate the Postmortem Submersion Interval. J Forensic Sci 2015; 60:1500-10. [DOI: 10.1111/1556-4029.12859] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 11/10/2014] [Accepted: 11/14/2014] [Indexed: 12/29/2022]
Affiliation(s)
- Mark Eric Benbow
- Department of Entomology; Michigan State University; East Lansing MI 48824
| | - Jennifer L. Pechal
- Department of Entomology; Michigan State University; East Lansing MI 48824
| | - Jennifer M. Lang
- Department of Biology; University of Dayton; Dayton OH 45469-2320
| | - Racheal Erb
- Department of Biology; Millersville University; Millersville PA 17551
| | - John R. Wallace
- Department of Biology; Millersville University; Millersville PA 17551
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78
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Grob C, Taubert M, Howat AM, Burns OJ, Dixon JL, Richnow HH, Jehmlich N, von Bergen M, Chen Y, Murrell JC. Combining metagenomics with metaproteomics and stable isotope probing reveals metabolic pathways used by a naturally occurring marine methylotroph. Environ Microbiol 2015; 17:4007-18. [PMID: 26033676 DOI: 10.1111/1462-2920.12935] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 05/20/2015] [Accepted: 05/28/2015] [Indexed: 11/26/2022]
Abstract
A variety of culture-independent techniques have been developed that can be used in conjunction with culture-dependent physiological and metabolic studies of key microbial organisms in order to better understand how the activity of natural populations influences and regulates all major biogeochemical cycles. In this study, we combined deoxyribonucleic acid-stable isotope probing (DNA-SIP) with metagenomics and metaproteomics to characterize an uncultivated marine methylotroph that actively incorporated carbon from (13) C-labeled methanol into biomass. By metagenomic sequencing of the heavy DNA, we retrieved virtually the whole genome of this bacterium and determined its metabolic potential. Through protein-stable isotope probing, the RuMP cycle was established as the main carbon assimilation pathway, and the classical methanol dehydrogenase-encoding gene mxaF, as well as three out of four identified xoxF homologues were found to be expressed. This proof-of-concept study is the first in which the culture-independent techniques of DNA-SIP and protein-SIP have been used to characterize the metabolism of a naturally occurring Methylophaga-like bacterium in the marine environment (i.e. Methylophaga thiooxydans L4) and thus provides a powerful approach to access the genome and proteome of uncultivated microbes involved in key processes in the environment.
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Affiliation(s)
- Carolina Grob
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Martin Taubert
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Alexandra M Howat
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Oliver J Burns
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Joanna L Dixon
- Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth, Devon, PL1 3DH, UK
| | - Hans H Richnow
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Nico Jehmlich
- Department of Proteomics, Helmholtz-Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Martin von Bergen
- Department of Proteomics, Helmholtz-Centre for Environmental Research-UFZ, Leipzig, Germany.,Department of Metabolomics, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany.,Department of Chemistry and Bioscience, University of Aalborg, Fredrik Bajers Vej 7H, Aalborg East, 9220, Denmark
| | - Yin Chen
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - J Colin Murrell
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
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79
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Noor S, Zubair M, Ahmad J. Diabetic foot ulcer--A review on pathophysiology, classification and microbial etiology. Diabetes Metab Syndr 2015; 9:192-199. [PMID: 25982677 DOI: 10.1016/j.dsx.2015.04.007] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
As the prevalence of diabetes is increasing globally, secondary complications associated to this endocrinal disorder are also ascending. Diabetic foot ulcers are potentially modifying complications. Disruption of harmony in glucose homeostasis causes hyperglycemic status, results in activation of certain metabolic pathways which in their abnormal state subsequently leads to development of vascular insufficiency, nerve damages headed by ulceration in lower extremity due to plantar pressures and foot deformity. Insult to foot caused by trauma at the affected site goes unnoticeable to patient due to loss of sensation. Among the above mention causes, resistance to infection is also considered as chief modulator of pathophysiological image of diabetic foot lesions. Healing as well as non-healing nature of ulcer relies upon the wound microbial communities and the extent of their pathogenicity. A validated classification system of foot ulcer is primarily necessary for clinicians in management of diabetic foot problems. Another aspect which needs management is proper identification of causative pathogen causing infection. The way of approaches presently employed in the diagnosis for treatment of foot ulcer colonized by different microbes is conventional techniques. Conventional diagnostic methods are widely acceptable since decades. But in recent years newly invented molecular techniques are exploring the use of 16S ribosomal regions specific to prokaryotes in bacterial identification and quantification. Molecular techniques would be a better choice if engaged, in finding the specific species harboring the wound.
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Affiliation(s)
- Saba Noor
- Rajiv Gandhi Centre for Diabetes and Endocrinology, Faculty of Medicine, J.N. Medical College, Aligarh Muslim University, Aligarh, 202002, India.
| | - Mohammad Zubair
- Rajiv Gandhi Centre for Diabetes and Endocrinology, Faculty of Medicine, J.N. Medical College, Aligarh Muslim University, Aligarh, 202002, India.
| | - Jamal Ahmad
- Rajiv Gandhi Centre for Diabetes and Endocrinology, Faculty of Medicine, J.N. Medical College, Aligarh Muslim University, Aligarh, 202002, India.
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80
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Directly sampling the lung of a young child with cystic fibrosis reveals diverse microbiota. Ann Am Thorac Soc 2015; 11:1049-55. [PMID: 25072206 DOI: 10.1513/annalsats.201311-383oc] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
RATIONALE The airways of people with cystic fibrosis (CF) are chronically infected with a variety of bacterial species. Although routine culture methods are usually used to diagnose these infections, culture-independent, DNA-based methods have identified many bacterial species in CF respiratory secretions that are not routinely cultured. Many prior culture-independent studies focused either on microbiota in explanted CF lungs, reflecting end-stage disease, or those in oropharyngeal swabs, which likely sample areas in addition to the lower airways. Therefore, it was unknown whether the lower airways of children with CF, well before end-stage but with symptomatic lung disease, truly contained diverse microbiota. OBJECTIVES To define the microbiota in the diseased lung tissue of a child who underwent lobectomy for severe, localized CF lung disease. METHODS After pathologic examination verified that this child's lung tissue reflected CF lung disease, we used bacterial ribosomal RNA gene pyrosequencing and computational phylogenetic analysis to identify the microbiota in serial sections of the tissue. MEASUREMENTS AND MAIN RESULTS This analysis identified diverse, and anatomically heterogeneous, bacterial populations in the lung tissue that contained both culturable and nonculturable species, including abundant Haemophilus, Ralstonia, and Propionibacterium species. Routine clinical cultures identified only Staphylococcus aureus, which represented only a small fraction of the microbiota found by sequencing. Microbiota analysis of an intraoperative oropharyngeal swab identified predominantly Streptococcus species. The oropharyngeal findings therefore represented the lung tissue microbiota poorly, in agreement with findings from earlier studies of oropharyngeal swabs in end-stage disease. CONCLUSIONS These results support the concept that diverse and spatially heterogeneous microbiota, not necessarily dominated by "traditional CF pathogens," are present in the airways of young, symptomatic children with early CF lung disease.
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81
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Lecomte V, Kaakoush NO, Maloney CA, Raipuria M, Huinao KD, Mitchell HM, Morris MJ. Changes in gut microbiota in rats fed a high fat diet correlate with obesity-associated metabolic parameters. PLoS One 2015; 10:e0126931. [PMID: 25992554 PMCID: PMC4436290 DOI: 10.1371/journal.pone.0126931] [Citation(s) in RCA: 305] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 04/09/2015] [Indexed: 12/15/2022] Open
Abstract
The gut microbiota is emerging as a new factor in the development of obesity. Many studies have described changes in microbiota composition in response to obesity and high fat diet (HFD) at the phylum level. In this study we used 16s RNA high throughput sequencing on faecal samples from rats chronically fed HFD or control chow (n = 10 per group, 16 weeks) to investigate changes in gut microbiota composition at the species level. 53.17% dissimilarity between groups was observed at the species level. Lactobacillus intestinalis dominated the microbiota in rats under the chow diet. However this species was considerably less abundant in rats fed HFD (P<0.0001), this being compensated by an increase in abundance of propionate/acetate producing species. To further understand the influence of these species on the development of the obese phenotype, we correlated their abundance with metabolic parameters associated with obesity. Of the taxa contributing the most to dissimilarity between groups, 10 presented significant correlations with at least one of the tested parameters, three of them correlated positively with all metabolic parameters: Phascolarctobacterium, Proteus mirabilis and Veillonellaceae, all propionate/acetate producers. Lactobacillus intestinalis was the only species whose abundance was negatively correlated with change in body weight and fat mass. This species decreased drastically in response to HFD, favouring propionate/acetate producing bacterial species whose abundance was strongly correlated with adiposity and deterioration of metabolic factors. Our observations suggest that these species may play a key role in the development of obesity in response to a HFD.
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Affiliation(s)
- Virginie Lecomte
- School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Nadeem O. Kaakoush
- School of Biotechnology and Biomolecular Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | | | - Mukesh Raipuria
- School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Karina D. Huinao
- School of Biotechnology and Biomolecular Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Hazel M. Mitchell
- School of Biotechnology and Biomolecular Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Margaret J. Morris
- School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
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82
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Panasevich MR, Kerr KR, Serao MCR, de Godoy MRC, Guérin-Deremaux L, Lynch GL, Wils D, Dowd SE, Fahey GC, Swanson KS, Dilger RN. Evaluation of soluble corn fiber on chemical composition and nitrogen-corrected true metabolizable energy and its effects on in vitro fermentation and in vivo responses in dogs. J Anim Sci 2015; 93:2191-200. [DOI: 10.2527/jas.2014-8425] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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83
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Mazzola M, Hewavitharana SS, Strauss SL. Brassica seed meal soil amendments transform the rhizosphere microbiome and improve apple production through resistance to pathogen reinfestation. PHYTOPATHOLOGY 2015; 105:460-9. [PMID: 25412009 DOI: 10.1094/phyto-09-14-0247-r] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Brassicaceae seed meal (SM) formulations were compared with preplant 1,3-dichloropropene/chloropicrin (Telone-C17) soil fumigation for the ability to control apple replant disease and to suppress pathogen or parasite reinfestation of organic orchard soils at two sites in Washington State. Preplant soil fumigation and an SM formulation consisting of either Brassica juncea-Sinapis alba or B. juncea-B. napus each provided similar levels of disease control during the initial growing season. Although tree growth was similar in fumigated and SM-amended soil during the initial growing season, tree performance in terms of growth and yield was commonly superior in B. juncea-S. alba SM-amended soil relative to that in fumigated soil at the end of four growing seasons. SM-amended soils were resistant to reinfestation by Pratylenchus penetrans and Pythium spp. relative to fumigated soils and corresponded with enhanced tree performance. Phytotoxic symptoms were observed in response to SM amendment at one of two orchard sites, were dependent upon season of application, and occurred in an SM formulation-specific manner. After 2 years, the rhizosphere microbiome in fumigated soils had reverted to one that was indistinguishable from the no-treatment control. In contrast, rhizosphere soils from the SM treatment possessed unique bacterial and fungal profiles, including specific microbial elements previously associated with suppression of plant-pathogenic fungi, oomycetes, and nematodes. Overall diversity of the microbiome was reduced in the SM treatment rhizosphere, suggesting that enhanced "biodiversity" was not instrumental in achieving system resistance or pathogen suppression.
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Affiliation(s)
- Mark Mazzola
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS) Tree Fruit Research Lab, 1104 N. Western Ave., Wenatchee, WA 98801
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84
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Trifilio S, Zhou Z, Fong J, Zomas A, Liu D, Zhao C, Zhang J, Mehta J. Polymicrobial bacterial or fungal infections: incidence, spectrum of infection, risk factors, and clinical outcomes from a large hematopoietic stem cell transplant center. Transpl Infect Dis 2015; 17:267-74. [DOI: 10.1111/tid.12363] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/22/2014] [Accepted: 01/19/2015] [Indexed: 11/28/2022]
Affiliation(s)
- S. Trifilio
- Feinberg School of Medicine; Northwestern University; Chicago Illinois USA
- Northwestern Memorial Hospital; Chicago Illinois USA
| | - Z. Zhou
- Feinberg School of Medicine; Northwestern University; Chicago Illinois USA
| | - J.L. Fong
- Northwestern Memorial Hospital; Chicago Illinois USA
| | - A. Zomas
- Northwestern Memorial Hospital; Chicago Illinois USA
| | - D. Liu
- Northwestern Memorial Hospital; Chicago Illinois USA
| | - C. Zhao
- Northwestern Memorial Hospital; Chicago Illinois USA
| | - J. Zhang
- Northwestern Memorial Hospital; Chicago Illinois USA
| | - J. Mehta
- Feinberg School of Medicine; Northwestern University; Chicago Illinois USA
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85
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Dana AN, Bauman WA. Bacteriology of pressure ulcers in individuals with spinal cord injury: What we know and what we should know. J Spinal Cord Med 2015; 38:147-60. [PMID: 25130374 PMCID: PMC4397196 DOI: 10.1179/2045772314y.0000000234] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Individuals with spinal cord injury (SCI) are at increased risk for the development of pressure ulcers. These chronic wounds are debilitating and contribute to prolonged hospitalization and worse medical outcome. However, the species of bacteria and the role that specific species may play in delaying the healing of chronic pressure ulcers in the SCI population has not been well characterized. This study will review the literature regarding what is known currently about the bacteriology of pressure ulcers in individuals with SCI. An electronic literature search of MEDLINE (1966 to February 2014) was performed. Eleven studies detailing bacterial cultures of pressure ulcers in the SCI population met inclusion criteria and were selected for review. Among these studies, bacterial cultures were often polymicrobial with both aerobic and anaerobic bacteria identified with culture techniques that varied significantly. The most common organisms identified in pressure ulcers were Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, and Enterococcus faecalis. In general, wounds were poorly characterized with minimal to no physical description and/or location provided. Our present understanding of factors that may alter the microbiome of pressure ulcers in individuals with SCI is quite rudimentary, at best. Well-designed studies are needed to assess appropriate wound culture technique, the impact of bacterial composition on wound healing, development of infection, and the optimum medical and surgical approaches to wound care.
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Affiliation(s)
- Ali N. Dana
- Correspondence to: Ali N. Dana, Dermatology Service, Suite 2F, James J. Peters Veterans Affairs Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA. Ali.Dana.@va.gov
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86
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Casey JM, Ainsworth TD, Choat JH, Connolly SR. Farming behaviour of reef fishes increases the prevalence of coral disease associated microbes and black band disease. Proc Biol Sci 2015; 281:20141032. [PMID: 24966320 DOI: 10.1098/rspb.2014.1032] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Microbial community structure on coral reefs is strongly influenced by coral-algae interactions; however, the extent to which this influence is mediated by fishes is unknown. By excluding fleshy macroalgae, cultivating palatable filamentous algae and engaging in frequent aggression to protect resources, territorial damselfish (f. Pomacentridae), such as Stegastes, mediate macro-benthic dynamics on coral reefs and may significantly influence microbial communities. To elucidate how Stegastes apicalis and Stegastes nigricans may alter benthic microbial assemblages and coral health, we determined the benthic community composition (epilithic algal matrix and prokaryotes) and coral disease prevalence inside and outside of damselfish territories in the Great Barrier Reef, Australia. 16S rDNA sequencing revealed distinct bacterial communities associated with turf algae and a two to three times greater relative abundance of phylotypes with high sequence similarity to potential coral pathogens inside Stegastes's territories. These potentially pathogenic phylotypes (totalling 30.04% of the community) were found to have high sequence similarity to those amplified from black band disease (BBD) and disease affected corals worldwide. Disease surveys further revealed a significantly higher occurrence of BBD inside S. nigricans's territories. These findings demonstrate the first link between fish behaviour, reservoirs of potential coral disease pathogens and the prevalence of coral disease.
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Affiliation(s)
- Jordan M Casey
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia
| | - Tracy D Ainsworth
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - J Howard Choat
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia
| | - Sean R Connolly
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia
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87
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Rajiv S, Drilling A, Bassiouni A, James C, Vreugde S, Wormald PJ. Topical colloidal silver as an anti-biofilm agent in aStaphylococcus aureuschronic rhinosinusitis sheep model. Int Forum Allergy Rhinol 2015; 5:283-8. [DOI: 10.1002/alr.21459] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/16/2014] [Accepted: 10/21/2014] [Indexed: 01/19/2023]
Affiliation(s)
- Sukanya Rajiv
- Department of Surgery-Otorhinolaryngology, Head and Neck Surgery; University of Adelaide; Adelaide Australia
| | - Amanda Drilling
- Department of Surgery-Otorhinolaryngology, Head and Neck Surgery; University of Adelaide; Adelaide Australia
| | - Ahmed Bassiouni
- Department of Surgery-Otorhinolaryngology, Head and Neck Surgery; University of Adelaide; Adelaide Australia
| | - Craig James
- Adelaide Pathology Partners; Adelaide Australia
| | - Sarah Vreugde
- Department of Surgery-Otorhinolaryngology, Head and Neck Surgery; University of Adelaide; Adelaide Australia
| | - Peter-John Wormald
- Department of Surgery-Otorhinolaryngology, Head and Neck Surgery; University of Adelaide; Adelaide Australia
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88
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Effect of exclusive enteral nutrition on the microbiota of children with newly diagnosed Crohn's disease. Clin Transl Gastroenterol 2015; 6:e71. [PMID: 25588524 PMCID: PMC4418409 DOI: 10.1038/ctg.2014.21] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 11/22/2014] [Indexed: 12/14/2022] Open
Abstract
Objectives: Exclusive enteral nutrition (EEN) is commonly used to treat pediatric Crohn's disease (CD). Meta-analysis of pediatric studies that have compared the effect of EEN with other treatments have shown that EEN induces remission in up to 80–85% of patients. We aimed to gain a comprehensive understanding of the effect of EEN on the microbiota of CD patients. Methods: We used 16S rRNA gene and whole-genome high throughout sequencing to determine changes in the fecal microbiota of five CD children, before, during, and after EEN therapy and compared this with five healthy controls. Results: The microbial diversity observed in CD patients tended to be lower than that in controls (CD: 2.25±0.24, controls: 2.75±0.14, P=0.11). In all CD patients, dysbiosis was observed prior to therapy. EEN therapy had a positive effect in all patients, with 80% going into remission. In some patients, the positive effect diminished following the conclusion of EEN therapy. Significantly, the number of operational taxonomic units (OTU) decreased dramatically upon starting EEN and this corresponded with CD remission. Recurrence of CD corresponded with an increase in OTUs. Six families within the Firmicutes were found to correlate with disease activity during and following EEN therapy, a finding that was confirmed by whole-genome high throughput sequencing. Conclusions: Our results demonstrate that EEN leads to common and patient-specific alterations in the microbiota of CD patients, a number of which correlate with disease activity.
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89
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Williams C, Ramage G. Fungal biofilms in human disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 831:11-27. [PMID: 25384660 DOI: 10.1007/978-3-319-09782-4_2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Craig Williams
- Institute of Healthcare Associated Infection, University of the West of Scotland, Paisley, UK,
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90
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Pereira DIA, Aslam MF, Frazer DM, Schmidt A, Walton GE, McCartney AL, Gibson GR, Anderson GJ, Powell JJ. Dietary iron depletion at weaning imprints low microbiome diversity and this is not recovered with oral Nano Fe(III). Microbiologyopen 2014; 4:12-27. [PMID: 25461615 PMCID: PMC4335973 DOI: 10.1002/mbo3.213] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 07/31/2014] [Accepted: 08/01/2014] [Indexed: 12/31/2022] Open
Abstract
Alterations in the gut microbiota have been recently linked to oral iron. We conducted two feeding studies including an initial diet-induced iron-depletion period followed by supplementation with nanoparticulate tartrate-modified ferrihydrite (Nano Fe(III): considered bioavailable to host but not bacteria) or soluble ferrous sulfate (FeSO4: considered bioavailable to both host and bacteria). We applied denaturing gradient gel electrophoresis and fluorescence in situ hybridization for study-1 and 454-pyrosequencing of fecal 16S rRNA in study-2. In study-1, the within-community microbial diversity increased with FeSO4 (P = 0.0009) but not with Nano Fe(III) supplementation. This was confirmed in study-2, where we also showed that iron depletion at weaning imprinted significantly lower within- and between-community microbial diversity compared to mice weaned onto the iron-sufficient reference diet (P < 0.0001). Subsequent supplementation with FeSO4 partially restored the within-community diversity (P = 0.006 in relation to the continuously iron-depleted group) but not the between-community diversity, whereas Nano Fe(III) had no effect. We conclude that (1) dietary iron depletion at weaning imprints low diversity in the microbiota that is not, subsequently, easily recovered; (2) in the absence of gastrointestinal disease iron supplementation does not negatively impact the microbiota; and (3) Nano Fe(III) is less available to the gut microbiota.
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Affiliation(s)
- Dora I A Pereira
- MRC Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, United Kingdom
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91
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Modulation of the faecal microbiome of healthy adult dogs by inclusion of potato fibre in the diet. Br J Nutr 2014; 113:125-33. [DOI: 10.1017/s0007114514003274] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Inclusion of fermentable fibres in the diet can have an impact on the hindgut microbiome and provide numerous health benefits to the host. Potato fibre (PF), a co-product of potato starch isolation, has a favourable chemical composition of pectins, resistant and digestible starch, cellulose, and hemicelluloses. The objective of the present study was to evaluate the effect of increasing dietary PF concentrations on the faecal microbiome of healthy adult dogs. Fresh faecal samples were collected from ten female dogs with hound bloodlines (6·13 (sem 0·17) years; 22·0 (sem 2·1) kg) fed five test diets containing graded concentrations of PF (0, 1·5, 3, 4·5 or 6 % as-fed; Roquette Frères) in a replicated 5 × 5 Latin square design. Extraction of DNA was followed by amplification of the V4–V6 variable region of the 16S rRNA gene using barcoded primers. Sequences were classified into taxonomic levels using Basic Local Alignment Search Tool (BLASTn) against a curated GreenGenes database. Inclusion of PF increased (P< 0·05) the faecal proportions of Firmicutes, while those of Fusobacteria decreased (P< 0·05). Similar shifts were observed at the genus level and were confirmed by quantitative PCR (qPCR) analysis. With increasing concentrations of PF, faecal proportions of Faecalibacterium increased (P< 0·05). Post hoc Pearson's correlation analysis showed positive (P< 0·05) correlations with Bifidobacterium spp. and butyrate production and Lactobacillus spp. concentrations. Overall, increases in the proportion of Faecalibacterium (not Lactobacillus/Bifidobacterium, as confirmed by qPCR analysis) and faecal SCFA concentrations with increasing dietary PF concentrations suggest that PF is a possible prebiotic fibre.
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92
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Levesque CL, Hooda S, Swanson KS, de Lange K. Alterations in ileal mucosa bacteria related to diet complexity and growth performance in young pigs. PLoS One 2014; 9:e108472. [PMID: 25247930 PMCID: PMC4172762 DOI: 10.1371/journal.pone.0108472] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 08/29/2014] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Evaluation of the prolonged impact of weaning diet on ileal mucosa bacteria and during periods of reduced and improved growth was conducted using 454 pyrosequencing. METHODOLOGY/PRINCIPAL FINDINGS Weaned pigs were fed HIGH or LOW complexity diets, with or without antibiotics, for 6 weeks, followed by a common grower diet. Pigs were killed at 2 (n = 4 or 5) and 8 (n = 6) weeks post-weaning (periods of reduced and improved growth, respectively). Mucosal bacteria were removed; DNA was extracted and amplified using the V1-V3 region of the 16S rRNA gene. Mucosal bacteria clustered more closely by week post-weaning than diet but 44% of bacterial species did not change from week 2 to 8. There was no effect of diet complexity or antibiotic inclusion on indices of bacterial diversity. Firmicutes made up 91 and 96% of total reads at week 2 and 8, respectively. The proportion of Clostridium paraputrificum increased (P = 0.003) from week 2 to 8 in pigs fed LOW but didn't change in pigs fed HIGH; whereas Clostridium leptum decreased (P = 0.02) from week 2 to 8 in pigs fed LOW but didn't change in pigs fed HIGH. The proportion of Sarcina genus was 3-fold higher in pigs fed A+ compared to A- at week 2 and 5-fold higher at week 8 despite the lack of in-feed antibiotics at that time. CONCLUSIONS/SIGNIFICANCE Shifts in mucosal bacteria populations may be related to dietary induced changes in growth performance during reduced and improved growth but further studies are required to confirm causative relationship. Weaning diet results in species specific prolonged alterations in mucosal bacteria, particularly where high levels of in-feed antibiotics are used. A considerable portion of ileal mucosal bacteria colonize early and remain stable over time despite changes in diet.
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Affiliation(s)
- Crystal L. Levesque
- Department of Animal Science, South Dakota State University, Brookings, South Dakota, United States of America
| | - Seema Hooda
- Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada
- Department of Animal Sciences, University of Illinois-Urbana Champaign, Urbana, Illinois, United States of America
| | - Kelly S. Swanson
- Department of Animal Sciences, University of Illinois-Urbana Champaign, Urbana, Illinois, United States of America
| | - Kees de Lange
- Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada
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93
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Butler É, Oien RF, Lindholm C, Olofsson TC, Nilson B, Vásquez A. A pilot study investigating lactic acid bacterial symbionts from the honeybee in inhibiting human chronic wound pathogens. Int Wound J 2014; 13:729-37. [PMID: 25196349 DOI: 10.1111/iwj.12360] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 07/29/2014] [Accepted: 08/03/2014] [Indexed: 12/17/2022] Open
Abstract
Treatment and management of chronic wounds is a large burden on the health sector and causes substantial suffering for the patients. We believe that 13 lactic acid bacteria (LAB) symbionts isolated from the honey crop of the honeybee are important players in the antimicrobial action of honey, by producing antimicrobial substances and can be used in combination with heather honey as an effective treatment in wound management. A total of 22 patients with chronic ulcers were included; culture-dependent and molecular-based (MALDI-MS and 16S rRNA gene sequencing) techniques were used to identify bacteria from chronic wounds. These clinical isolates were used for in vitro antimicrobial testing with standardised viable LAB and sterilised heather honey mixture. Twenty of the patients' wounds were polymicrobial and 42 different species were isolated. Patient isolates that were tested in vitro were inhibited by the LAB and honey combination with inhibitory zones comparable with different antibiotics. LAB and heather honey in combination presents a new topical option in chronic wound management because of the healing properties of honey, antimicrobial metabolite production from the LAB and their bactericidal effect on common chronic wound pathogens. This new treatment may be a stepping stone towards an alternative solution to antibiotics.
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Affiliation(s)
- Éile Butler
- Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden.
| | - Rut F Oien
- Blekinge Wound Healing Centre, Blekinge Hospital, Karlshamn, Sweden
| | | | - Tobias C Olofsson
- Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden
| | - Bo Nilson
- Labmedicin, Region Skåne, Clinical Microbiology, Lund, Sweden
| | - Alejandra Vásquez
- Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden
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94
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Barton LE, Auffan M, Bertrand M, Barakat M, Santaella C, Masion A, Borschneck D, Olivi L, Roche N, Wiesner MR, Bottero JY. Transformation of pristine and citrate-functionalized CeO2 nanoparticles in a laboratory-scale activated sludge reactor. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:7289-7296. [PMID: 24870403 DOI: 10.1021/es404946y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Engineered nanomaterials (ENMs) are used to enhance the properties of many manufactured products and technologies. Increased use of ENMs will inevitably lead to their release into the environment. An important route of exposure is through the waste stream, where ENMs will enter wastewater treatment plants (WWTPs), undergo transformations, and be discharged with treated effluent or biosolids. To better understand the fate of a common ENM in WWTPs, experiments with laboratory-scale activated sludge reactors and pristine and citrate-functionalized CeO2 nanoparticles (NPs) were conducted. Greater than 90% of the CeO2 introduced was observed to associate with biosolids. This association was accompanied by reduction of the Ce(IV) NPs to Ce(III). After 5 weeks in the reactor, 44 ± 4% reduction was observed for the pristine NPs and 31 ± 3% for the citrate-functionalized NPs, illustrating surface functionality dependence. Thermodynamic arguments suggest that the likely Ce(III) phase generated would be Ce2S3. This study indicates that the majority of CeO2 NPs (>90% by mass) entering WWTPs will be associated with the solid phase, and a significant portion will be present as Ce(III). At maximum, 10% of the CeO2 will remain in the effluent and be discharged as a Ce(IV) phase, governed by cerianite (CeO2).
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Affiliation(s)
- Lauren E Barton
- Department of Civil and Environmental Engineering, Duke University , Durham, North Carolina 27708-0287, United States
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95
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Rogers GB, Kozlowska J, Keeble J, Metcalfe K, Fao M, Dowd SE, Mason AJ, McGuckin MA, Bruce KD. Functional divergence in gastrointestinal microbiota in physically-separated genetically identical mice. Sci Rep 2014; 4:5437. [PMID: 24961643 PMCID: PMC4069701 DOI: 10.1038/srep05437] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 06/05/2014] [Indexed: 12/20/2022] Open
Abstract
Despite the fundamental contribution of the gut microbiota to host physiology, the extent of its variation in genetically-identical animals used in research is not known. We report significant divergence in both the composition and metabolism of gut microbiota in genetically-identical adult C57BL/6 mice housed in separate controlled units within a single commercial production facility. The reported divergence in gut microbiota has the potential to confound experimental studies using mammalian models.
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Affiliation(s)
- G. B. Rogers
- Immunity, Infection, and Inflammation Program, Mater Research Institute – University of Queensland, Translational Research Institute, Woolloongabba, Australia
- King's College London, Institute of Pharmaceutical Science, London, SE1 9NH, UK
- SAHMRI Infection and Immunity Theme, School of Medicine, Flinders University, Bedford Park, Adelaide, Australia
| | - J. Kozlowska
- King's College London, Institute of Pharmaceutical Science, London, SE1 9NH, UK
| | - J. Keeble
- King's College London, Institute of Pharmaceutical Science, London, SE1 9NH, UK
| | - K. Metcalfe
- Charles River UK, Manston Rd. Margate, Kent CT9 4LT UK
| | - M. Fao
- Charles River UK, Manston Rd. Margate, Kent CT9 4LT UK
| | - S. E. Dowd
- Molecular Research MR DNA, Shallowater, TX 79363, USA
| | - A. J. Mason
- King's College London, Institute of Pharmaceutical Science, London, SE1 9NH, UK
| | - M. A. McGuckin
- Immunity, Infection, and Inflammation Program, Mater Research Institute – University of Queensland, Translational Research Institute, Woolloongabba, Australia
| | - K. D. Bruce
- King's College London, Institute of Pharmaceutical Science, London, SE1 9NH, UK
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96
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Cooper R, Jenkins L, Hooper S. Inhibition of biofilms of Pseudomonas aeruginosa by Medihoney in vitro. J Wound Care 2014; 23:93-6, 98-100, 102 passim. [PMID: 24633055 DOI: 10.12968/jowc.2014.23.3.93] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Pseudomonas aeruginosa has been linked to chronic wound infections, where its ability to form biofilms and to tolerate antimicrobial agents helps to facilitate its persistence. This study aimed to investigate the susceptibility of biofilms of Pseudomonas aeruginosa to Medihoney in vitro. METHOD Biofilms were cultivated in microtitre plates with and without a range of concentrations of Medihoney, and effects on biofilm were monitored by optical density (at 650nm), biomass (by staining with crystal violet), metabolic activity (using an esterase assay) and viability (by determining total cell counts). Structural effects on established biofilms were examined by scanning electron microscopy and epifluorescence following staining by LIVE/DEAD® BacLight, which also showed effects on vitality. RESULTS The lowest concentration of Medihoney found to prevent biofilm formation was 17%(w/v), whereas on average 35.5%(w/v) of Medihoney was required to inhibit established biofilms. Susceptibility did not vary with length of biofilm establishment between 24 and 72 hours. Extensive structural changes in established biofilms were seen in the sample with less than or equal to 30%(w/v) Medihoney using scanning electron microscopy and loss of viability was found in test samples with less than or equal to 20%(w/v) Medihoney concentration using fluorescent staining, together with loss of biofilm structure. CONCLUSION Using a range of methods to evaluate biofilm integrity, this study demonstrates that Medihoney inhibits Pseudomonas aeruginosa biofilms in vitro at concentrations that are attainable in clinical use. Whether Medihoney has the potential to disrupt Pseudomonas aeruginosa biofilms in cutaneous wounds must now be tested in patients. DECLARATION OF INTEREST This study was sponsored by Derma Sciences Inc, NJ. An unrestricted grant was provided and the sponsors were not involved in the design of the experiments or the preparation of this manuscript.
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Affiliation(s)
- R Cooper
- PhD, Cardiff School of Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
| | - L Jenkins
- BSc, Cardiff School of Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
| | - S Hooper
- PhD, Cardiff School of Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
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97
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Kaakoush NO, Sodhi N, Chenu JW, Cox JM, Riordan SM, Mitchell HM. The interplay between Campylobacter and Helicobacter species and other gastrointestinal microbiota of commercial broiler chickens. Gut Pathog 2014; 6:18. [PMID: 24940386 PMCID: PMC4060860 DOI: 10.1186/1757-4749-6-18] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 05/30/2014] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Poultry represent an important source of foodborne enteropathogens, in particular thermophilic Campylobacter species. Many of these organisms colonize the intestinal tract of broiler chickens as harmless commensals, and therefore, often remain undetected prior to slaughter. The exact reasons for the lack of clinical disease are unknown, but analysis of the gastrointestinal microbiota of broiler chickens may improve our understanding of the microbial interactions with the host. METHODS In this study, the fecal microbiota of 31 market-age (56-day old) broiler chickens, from two different farms, was analyzed using high throughput sequencing. The samples were then screened for two emerging human pathogens, Campylobacter concisus and Helicobacter pullorum, using species-specific PCR. RESULTS The gastrointestinal microbiota of chickens was classified into four potential enterotypes, similar to that of humans, where three enterotypes have been identified. The results indicated that variations between farms may have contributed to differences in the microbiota, though each of the four enterotypes were found in both farms suggesting that these groupings did not occur by chance. In addition to the identification of Campylobacter jejuni subspecies doylei and the emerging species, C. concisus, C. upsaliensis and H. pullorum, several differences in the prevalence of human pathogens within these enterotypes were observed. Further analysis revealed microbial taxa with the potential to increase the likelihood of colonization by a number of these pathogens, including C. jejuni. CONCLUSION Depletion of these taxa and the addition of taxa that compete with these pathogens, may form the basis of competitive exclusion strategies to eliminate them from the gastrointestinal tract of chickens.
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Affiliation(s)
- Nadeem O Kaakoush
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Nidhi Sodhi
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Jeremy W Chenu
- Birling Avian Laboratories, Bringelly, NSW 2556, Australia
| | - Julian M Cox
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia ; Faculty of Science, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Stephen M Riordan
- Gastrointestinal and Liver Unit, The Prince of Wales Hospital, Randwick, NSW 2031, Australia ; Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Hazel M Mitchell
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
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98
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Nieminen MT, Novak-Frazer L, Rautemaa V, Rajendran R, Sorsa T, Ramage G, Bowyer P, Rautemaa R. A novel antifungal is active against Candida albicans biofilms and inhibits mutagenic acetaldehyde production in vitro. PLoS One 2014; 9:e97864. [PMID: 24867320 PMCID: PMC4035295 DOI: 10.1371/journal.pone.0097864] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 04/25/2014] [Indexed: 12/21/2022] Open
Abstract
The ability of C. albicans to form biofilms is a major virulence factor and a challenge for management. This is evident in biofilm-associated chronic oral-oesophageal candidosis, which has been shown to be potentially carcinogenic in vivo. We have previously shown that most Candida spp. can produce significant levels of mutagenic acetaldehyde (ACH). ACH is also an important mediator of candidal biofilm formation. We have also reported that D,L-2-hydroxyisocaproic acid (HICA) significantly inhibits planktonic growth of C. albicans. The aim of the present study was to investigate the effect of HICA on C. albicans biofilm formation and ACH production in vitro. Inhibition of biofilm formation by HICA, analogous control compounds or caspofungin was measured using XTT to measure biofilm metabolic activity and PicoGreen as a marker of biomass. Biofilms were visualised by scanning electron microscopy (SEM). ACH levels were measured by gas chromatography. Transcriptional changes in the genes involved in ACH metabolism were measured using RT-qPCR. The mean metabolic activity and biomass of all pre-grown (4, 24, 48 h) biofilms were significantly reduced after exposure to HICA (p<0.05) with the largest reductions seen at acidic pH. Caspofungin was mainly active against biofilms pre-grown for 4 h at neutral pH. Mutagenic levels (>40 µM) of ACH were detected in 24 and 48 h biofilms at both pHs. Interestingly, no ACH production was detected from D-glucose in the presence of HICA at acidic pH (p<0.05). Expression of genes responsible for ACH catabolism was up-regulated by HICA but down-regulated by caspofungin. SEM showed aberrant hyphae and collapsed hyphal structures during incubation with HICA at acidic pH. We conclude that HICA has potential as an antifungal agent with ability to inhibit C. albicans cell growth and biofilm formation. HICA also significantly reduces the mutagenic potential of C. albicans biofilms, which may be important when treating bacterial-fungal biofilm infections.
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Affiliation(s)
- Mikko T. Nieminen
- Research Unit on Acetaldehyde and Cancer, University of Helsinki, Helsinki, Finland
- Department of Periodontology, Institute of Dentistry, University of Helsinki, Helsinki, Finland
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland
- The University of Manchester, Institute of Inflammation and Repair, Manchester Academic Health Science Centre, University Hospital of South Manchester, Wythenshawe Hospital, Manchester, United Kingdom
| | - Lily Novak-Frazer
- The University of Manchester, Institute of Inflammation and Repair, Manchester Academic Health Science Centre, University Hospital of South Manchester, Wythenshawe Hospital, Manchester, United Kingdom
| | - Vilma Rautemaa
- The University of Manchester, Institute of Inflammation and Repair, Manchester Academic Health Science Centre, University Hospital of South Manchester, Wythenshawe Hospital, Manchester, United Kingdom
| | - Ranjith Rajendran
- Infection and Immunity Research Group, Glasgow Dental School and Hospital, School of Medicine, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Timo Sorsa
- Department of Periodontology, Institute of Dentistry, University of Helsinki, Helsinki, Finland
- Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital Finland, Helsinki, Finland
| | - Gordon Ramage
- Infection and Immunity Research Group, Glasgow Dental School and Hospital, School of Medicine, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Paul Bowyer
- The University of Manchester, Institute of Inflammation and Repair, Manchester Academic Health Science Centre, University Hospital of South Manchester, Wythenshawe Hospital, Manchester, United Kingdom
| | - Riina Rautemaa
- Research Unit on Acetaldehyde and Cancer, University of Helsinki, Helsinki, Finland
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland
- Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital Finland, Helsinki, Finland
- The University of Manchester, Institute of Inflammation and Repair, Manchester Academic Health Science Centre, University Hospital of South Manchester, Wythenshawe Hospital, Manchester, United Kingdom
- * E-mail:
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99
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Uçkay I, Gariani K, Pataky Z, Lipsky BA. Diabetic foot infections: state-of-the-art. Diabetes Obes Metab 2014; 16:305-16. [PMID: 23911085 DOI: 10.1111/dom.12190] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 07/05/2013] [Accepted: 07/11/2013] [Indexed: 01/18/2023]
Abstract
Foot infections are frequent and potentially devastating complications of diabetes. Unchecked, infection can progress contiguously to involve the deeper soft tissues and ultimately the bone. Foot ulcers in people with diabetes are most often the consequence of one or more of the following: peripheral sensory neuropathy, motor neuropathy and gait disorders, peripheral arterial insufficiency or immunological impairments. Infection develops in over half of foot ulcers and is the factor that most often leads to lower extremity amputation. These amputations are associated with substantial morbidity, reduced quality of life and major financial costs. Most infections can be successfully treated with optimal wound care, antibiotic therapy and surgical procedures. Employing evidence-based guidelines, multidisciplinary teams and institution-specific clinical pathways provides the best approach to guide clinicians through this multifaceted problem. All clinicians regularly seeing people with diabetes should have an understanding of how to prevent, diagnose and treat foot infections, which requires familiarity with the pathophysiology of the problem and the literature supporting currently recommended care.
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Affiliation(s)
- I Uçkay
- Service of Infectious Diseases, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland; Orthopaedic Surgery Service, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
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Ramage G, Robertson SN, Williams C. Strength in numbers: antifungal strategies against fungal biofilms. Int J Antimicrob Agents 2014; 43:114-20. [DOI: 10.1016/j.ijantimicag.2013.10.023] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 10/28/2013] [Indexed: 10/26/2022]
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