1
|
Messer LF, Bourne DG, Robbins SJ, Clay M, Bell SC, McIlroy SJ, Tyson GW. A genome-centric view of the role of the Acropora kenti microbiome in coral health and resilience. Nat Commun 2024; 15:2902. [PMID: 38575584 PMCID: PMC10995205 DOI: 10.1038/s41467-024-46905-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 03/13/2024] [Indexed: 04/06/2024] Open
Abstract
Microbial diversity has been extensively explored in reef-building corals. However, the functional roles of coral-associated microorganisms remain poorly elucidated. Here, we recover 191 bacterial and 10 archaeal metagenome-assembled genomes (MAGs) from the coral Acropora kenti (formerly A. tenuis) and adjacent seawater, to identify microbial functions and metabolic interactions within the holobiont. We show that 82 MAGs were specific to the A. kenti holobiont, including members of the Pseudomonadota, Bacteroidota, and Desulfobacterota. A. kenti-specific MAGs displayed significant differences in their genomic features and functional potential relative to seawater-specific MAGs, with a higher prevalence of genes involved in host immune system evasion, nitrogen and carbon fixation, and synthesis of five essential B-vitamins. We find a diversity of A. kenti-specific MAGs encode the biosynthesis of essential amino acids, such as tryptophan, histidine, and lysine, which cannot be de novo synthesised by the host or Symbiodiniaceae. Across a water quality gradient spanning 2° of latitude, A. kenti microbial community composition is correlated to increased temperature and dissolved inorganic nitrogen, with corresponding enrichment in molecular chaperones, nitrate reductases, and a heat-shock protein. We reveal mechanisms of A. kenti-microbiome-symbiosis on the Great Barrier Reef, highlighting the interactions underpinning the health of this keystone holobiont.
Collapse
Affiliation(s)
- Lauren F Messer
- Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, 4102, Australia.
- Division of Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK.
| | - David G Bourne
- College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
- Australian Institute of Marine Science, Townsville, QLD, 4810, Australia
| | - Steven J Robbins
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Megan Clay
- Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, 4102, Australia
| | - Sara C Bell
- College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
- Australian Institute of Marine Science, Townsville, QLD, 4810, Australia
| | - Simon J McIlroy
- Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, 4102, Australia
| | - Gene W Tyson
- Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, 4102, Australia.
| |
Collapse
|
2
|
O'Brien PA, Tan S, Frade PR, Robbins SJ, Engelberts JP, Bell SC, Vanwonterghem I, Miller DJ, Webster NS, Zhang G, Bourne DG. Validation of key sponge symbiont pathways using genome-centric metatranscriptomics. Environ Microbiol 2023; 25:3207-3224. [PMID: 37732569 DOI: 10.1111/1462-2920.16509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 08/31/2023] [Indexed: 09/22/2023]
Abstract
The sponge microbiome underpins host function through provision and recycling of essential nutrients in a nutrient poor environment. Genomic data suggest that carbohydrate degradation, carbon fixation, nitrogen metabolism, sulphur metabolism and supplementation of B-vitamins are central microbial functions. However, validation beyond the genomic potential of sponge symbiont pathways is rarely explored. To evaluate metagenomic predictions, we sequenced the metagenomes and metatranscriptomes of three common coral reef sponges: Ircinia ramosa, Ircinia microconulosa and Phyllospongia foliascens. Multiple carbohydrate active enzymes were expressed by Poribacteria, Bacteroidota and Cyanobacteria symbionts, suggesting these lineages have a central role in assimilating dissolved organic matter. Expression of entire pathways for carbon fixation and multiple sulphur compound transformations were observed in all sponges. Gene expression for anaerobic nitrogen metabolism (denitrification and nitrate reduction) were more common than aerobic metabolism (nitrification), where only the I. ramosa microbiome expressed the nitrification pathway. Finally, while expression of the biosynthetic pathways for B-vitamins was common, the expression of additional transporter genes was far more limited. Overall, we highlight consistencies and disparities between metagenomic and metatranscriptomic results when inferring microbial activity, while uncovering new microbial taxa that contribute to the health of their sponge host via nutrient exchange.
Collapse
Affiliation(s)
- Paul A O'Brien
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Townsville, Queensland, Australia
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Shangjin Tan
- BGI-Shenzhen, Beishan Industrial Zone, Shenzhen, China
| | | | - Steven J Robbins
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - J Pamela Engelberts
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
- Centre for Microbiome Research, Translational Research Institute, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Sara C Bell
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Inka Vanwonterghem
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - David J Miller
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
- Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
| | - Nicole S Webster
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Townsville, Queensland, Australia
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
- Australian Antarctic Division, Department of Climate Change, Energy, Environment and Water, Kingston, Tasmania, Australia
| | - Guojie Zhang
- Centre for Evolutionary & Organismal Biology and Women's Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China
| | - David G Bourne
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Townsville, Queensland, Australia
| |
Collapse
|
3
|
Nguyen TT, He C, Carter R, Ballard EL, Smith K, Groth R, Jaatinen E, Kidd TJ, Thomson RM, Tay G, Johnson GR, Bell SC, Knibbs LD. Quantifying the effectiveness of ultraviolet-C light at inactivating airborne Mycobacterium abscessus. J Hosp Infect 2023; 132:133-139. [PMID: 36309203 DOI: 10.1016/j.jhin.2022.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/26/2022] [Accepted: 10/06/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND Mycobacterium abscessus (MABS) group are environmental organisms that can cause infection in people with cystic fibrosis (CF) and other suppurative lung diseases. There is potential for person-to-person airborne transmission of MABS among people with CF attending the same care centre. Ultraviolet light (band C, UV-C) is used for Mycobacterium tuberculosis control indoors; however, no studies have assessed UV-C for airborne MABS. AIM To determine whether a range of UV-C doses increased the inactivation of airborne MABS, compared with no-UVC conditions. METHODS MABS was generated by a vibrating mesh nebulizer located within a 400 L rotating drum sampler, and then exposed to an array of 265 nm UV-C light-emitting diodes (LED). A six-stage Andersen Cascade Impactor was used to collect aerosols. Standard microbiological protocols were used for enumerating MABS, and these quantified the effectiveness of UV-C doses (in triplicate). UV-C effectiveness was estimated using the difference between inactivation with and without UV-C. FINDINGS Sixteen tests were performed, with UV-C doses ranging from 276 to 1104 μW s/cm2. Mean (±SD) UV-C effectiveness ranged from 47.1% (±13.4) to 83.6% (±3.3). UV-C led to significantly greater inactivation of MABS (all P-values ≤0.045) than natural decay at all doses assessed. Using an indoor model of the hospital environment, it was estimated that UV-C doses in the range studied here could be safely delivered in clinical settings where patients and staff are present. CONCLUSION This study provides empirical in-vitro evidence that nebulized MABS are susceptible to UV-C inactivation.
Collapse
Affiliation(s)
- T T Nguyen
- Faculty of Medicine, School of Public Health, University of Queensland, Brisbane, QLD, Australia.
| | - C He
- International Laboratory for Air Quality & Health, School of Earth and Atmospheric Sciences, Faculty of Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - R Carter
- Centre for Children's Health Research, Brisbane, QLD, Australia
| | - E L Ballard
- QIMR Berghofer Institute of Medical Research, Brisbane, QLD 4006, Australia
| | - K Smith
- Centre for Children's Health Research, Brisbane, QLD, Australia
| | - R Groth
- International Laboratory for Air Quality & Health, School of Earth and Atmospheric Sciences, Faculty of Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - E Jaatinen
- School of Chemistry and Physics, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - T J Kidd
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia; Pathology Queensland, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - R M Thomson
- The Prince Charles Hospital, Brisbane, QLD, Australia; Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia; Gallipoli Medical Research Foundation, Greenslopes Private Hospital, Brisbane, QLD, Australia
| | - G Tay
- The Prince Charles Hospital, Brisbane, QLD, Australia
| | - G R Johnson
- International Laboratory for Air Quality & Health, School of Earth and Atmospheric Sciences, Faculty of Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - S C Bell
- Centre for Children's Health Research, Brisbane, QLD, Australia; The Prince Charles Hospital, Brisbane, QLD, Australia; Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia; Translational Research Institute, Brisbane, QLD, Australia
| | - L D Knibbs
- Public Health Unit, Sydney Local Health District, Camperdown, NSW, Australia; Faculty of Medicine and Health, School of Public Health, University of Sydney, NSW, Australia
| |
Collapse
|
4
|
Cooke I, Ying H, Forêt S, Bongaerts P, Strugnell JM, Simakov O, Zhang J, Field MA, Rodriguez-Lanetty M, Bell SC, Bourne DG, van Oppen MJ, Ragan MA, Miller DJ. Genomic signatures in the coral holobiont reveal host adaptations driven by Holocene climate change and reef specific symbionts. Sci Adv 2020; 6:6/48/eabc6318. [PMID: 33246955 PMCID: PMC7695477 DOI: 10.1126/sciadv.abc6318] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 10/15/2020] [Indexed: 05/24/2023]
Abstract
Genetic signatures caused by demographic and adaptive processes during past climatic shifts can inform predictions of species' responses to anthropogenic climate change. To identify these signatures in Acropora tenuis, a reef-building coral threatened by global warming, we first assembled the genome from long reads and then used shallow whole-genome resequencing of 150 colonies from the central inshore Great Barrier Reef to inform population genomic analyses. We identify population structure in the host that reflects a Pleistocene split, whereas photosymbiont differences between reefs most likely reflect contemporary (Holocene) conditions. Signatures of selection in the host were associated with genes linked to diverse processes including osmotic regulation, skeletal development, and the establishment and maintenance of symbiosis. Our results suggest that adaptation to post-glacial climate change in A. tenuis has involved selection on many genes, while differences in symbiont specificity between reefs appear to be unrelated to host population structure.
Collapse
Affiliation(s)
- Ira Cooke
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia.
- Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
| | - Hua Ying
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Sylvain Forêt
- Research School of Biology, Australian National University, Canberra, ACT, Australia
- ARC Centre of Excellence for Coral Reef Studies, Australian National University, Canberra, ACT, Australia
| | - Pim Bongaerts
- California Academy of Sciences, Golden Gate Park, San Francisco, CA, USA
| | - Jan M Strugnell
- Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, Queensland, Australia
- Department of Ecology, Environment and Evolution, School of Life Sciences, La Trobe University, Melbourne, Australia
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | - Oleg Simakov
- Department of Molecular Evolution and Development, University of Vienna, Austria
| | - Jia Zhang
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
- Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
| | - Matt A Field
- Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Mauricio Rodriguez-Lanetty
- Institute of Environment and Department of Biological Sciences, Florida International University, Miami, Fl 33199, USA
| | - Sara C Bell
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - David G Bourne
- Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Madeleine Jh van Oppen
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- School of BioSciences, University of Melbourne, Melbourne, Australia
| | - Mark A Ragan
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - David J Miller
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia.
- Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
| |
Collapse
|
5
|
Bell SC, Heard GW, Berger L, Skerratt LF. Connectivity over a disease risk gradient enables recovery of rainforest frogs. Ecol Appl 2020; 30:e02152. [PMID: 32343856 DOI: 10.1002/eap.2152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 02/14/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Chytridiomycosis has been a key driver of global frog declines and extinctions, particularly for high-altitude populations across Australia and the Americas. While recent evidence shows some species are recovering, the extent of such recoveries and the mechanisms underpinning them remain poorly resolved. We surveyed the historical latitudinal and elevational range of four Australian rainforest frogs that disappeared from upland sites between 1989 and 1994 to establish their contemporary distribution and elevational limits, and investigate factors affecting population recovery. Five rainforest streams were surveyed from mountain-base to summit (30 sites in total), with swabs collected from the target species (Litoria dayi, L. nannotis, L. rheocola, and L. serrata) to determine their infection status, and data loggers deployed to measure microclimatic variation across the elevational gradient. Infection probability increased with elevation and canopy cover as it was tightly and inversely correlated with stream-side air temperature. Occupancy patterns suggest varying responses to this disease threat gradient. Two species, L. rheocola and L. serrata, were found over their full historical elevational range (≥1,000 m above sea level [asl]), while L. dayi was not detected above 400 m (formerly known up to 900 m asl) and L. nannotis was not detected above 800 m (formerly known up to 1,200 m asl). Site occupancy probability was negatively related to predicted infection prevalence for L. dayi, L. nannotis, and L. rheocola, but not L. serrata, which appears to now tolerate high fungal burdens. This study highlights the importance of environmental refuges and connectivity across disease risk gradients for the persistence and natural recovery of frogs susceptible to chytridiomycosis. Likewise, in documenting both interspecific variation in recovery rates and intraspecific differences between sites, this study suggests interactions between disease threats and host selection exist that could be manipulated. For example, translocations may be warranted where connectivity is poor or the increase in disease risk is too steep to allow recolonization, combined with assisted selection or use of founders from populations that have already undergone natural selection.
Collapse
Affiliation(s)
- Sara C Bell
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, 4811, Australia
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| | - Geoffrey W Heard
- Institute of Land, Water and Society, Charles Sturt University, Albury, New South Wales, 2640, Australia
- Victorian Department of Environment, Land, Water and Planning, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria, 3084, Australia
| | - Lee Berger
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| |
Collapse
|
6
|
Mayer-Hamblett N, van Koningsbruggen-Rietschel S, Nichols DP, VanDevanter DR, Davies JC, Lee T, Durmowicz AG, Ratjen F, Konstan MW, Pearson K, Bell SC, Clancy JP, Taylor-Cousar JL, De Boeck K, Donaldson SH, Downey DG, Flume PA, Drevinek P, Goss CH, Fajac I, Magaret AS, Quon BS, Singleton SM, VanDalfsen JM, Retsch-Bogart GZ. Building global development strategies for cf therapeutics during a transitional cftr modulator era. J Cyst Fibros 2020; 19:677-687. [PMID: 32522463 DOI: 10.1016/j.jcf.2020.05.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 05/18/2020] [Accepted: 05/27/2020] [Indexed: 12/30/2022]
Abstract
As CFTR modulator therapy transforms the landscape of cystic fibrosis (CF) care, its lack of uniform access across the globe combined with the shift towards a new standard of care creates unique challenges for the development of future CF therapies. The advancement of a full and promising CF therapeutics pipeline remains a necessary priority to ensure maximal clinical benefits for all people with CF. It is through collaboration across the global CF community that we can optimize the evaluation and approval process of new therapies. To this end, we must identify areas for which harmonization is lacking and for which efficiencies can be gained to promote ethical, feasible, and credible study designs amidst the changing CF care landscape. This article summarizes the counsel from core advisors across multiple international regions and clinical trial networks, developed during a one-day workshop in October 2019. The goal of the workshop was to identify, in consideration of the highly transitional era of CFTR modulator availability, the drug development areas for which global alignment is currently uncertain, and paths forward that will enable advancement of CF therapeutic development.
Collapse
Affiliation(s)
- N Mayer-Hamblett
- University of Washington, Seattle, WA; Seattle Children's Hospital, Seattle, WA.
| | - S van Koningsbruggen-Rietschel
- Cystic Fibrosis Center, Children's Hospital, University of Cologne; Faculty of Medicine and University Hospital Cologne, Cologne Germany
| | - D P Nichols
- University of Washington, Seattle, WA; Seattle Children's Hospital, Seattle, WA
| | - D R VanDevanter
- Case Western Reserve University School of Medicine, Cleveland, OH
| | - J C Davies
- National Heart & Lung Institute, Imperial College London, London, UK; Royal Brompton & Harefield NHS Foundation Trust, London, UK
| | - T Lee
- Leeds Regional Paediatric Cystic Fibrosis Centre, Leeds, UK
| | | | - F Ratjen
- University of Toronto, Toronto, Canada
| | - M W Konstan
- Case Western Reserve University School of Medicine, Cleveland, OH; Rainbow Babies and Children's Hospital, Cleveland, OH
| | - K Pearson
- Seattle Children's Hospital, Seattle, WA
| | - S C Bell
- Children's Health Research Centre, The University of Queensland, Brisbane, Australia
| | - J P Clancy
- Cystic Fibrosis Foundation, Bethesda, MD
| | | | | | - S H Donaldson
- University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - D G Downey
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, Northern Ireland
| | - P A Flume
- Medical University of South Carolina, Charleston, SC
| | - P Drevinek
- Charles University, Prague, Czechia, Motol University Hospital, Prague, Czechia
| | - C H Goss
- University of Washington, Seattle, WA; Seattle Children's Hospital, Seattle, WA
| | - I Fajac
- Université de Paris, Paris, France
| | - A S Magaret
- University of Washington, Seattle, WA; Seattle Children's Hospital, Seattle, WA
| | - B S Quon
- University of British Columbia, Vancouver, British Columbia
| | | | | | | |
Collapse
|
7
|
Engelberts JP, Robbins SJ, de Goeij JM, Aranda M, Bell SC, Webster NS. Characterization of a sponge microbiome using an integrative genome-centric approach. ISME J 2020; 14:1100-1110. [PMID: 31992859 PMCID: PMC7174397 DOI: 10.1038/s41396-020-0591-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 01/08/2020] [Accepted: 01/16/2020] [Indexed: 11/09/2022]
Abstract
Marine sponges often host diverse and species-specific communities of microorganisms that are critical for host health. Previous functional genomic investigations of the sponge microbiome have focused primarily on specific symbiont lineages, which frequently make up only a small fraction of the overall community. Here, we undertook genome-centric analysis of the symbiont community in the model species Ircinia ramosa and analyzed 259 unique, high-quality metagenome-assembled genomes (MAGs) that comprised 74% of the I. ramosa microbiome. Addition of these MAGs to genome trees containing all publicly available microbial sponge symbionts increased phylogenetic diversity by 32% within the archaea and 41% within the bacteria. Metabolic reconstruction of the MAGs showed extensive redundancy across taxa for pathways involved in carbon fixation, B-vitamin synthesis, taurine metabolism, sulfite oxidation, and most steps of nitrogen metabolism. Through the acquisition of all major taxa present within the I. ramosa microbiome, we were able to analyze the functional potential of a sponge-associated microbial community in unprecedented detail. Critical functions, such as carbon fixation, which had previously only been assigned to a restricted set of sponge-associated organisms, were actually spread across diverse symbiont taxa, whereas other essential pathways, such as ammonia oxidation, were confined to specific keystone taxa.
Collapse
Affiliation(s)
- J Pamela Engelberts
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Steven J Robbins
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Jasper M de Goeij
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Manuel Aranda
- Red Sea Research Center, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Sara C Bell
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Nicole S Webster
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.
- Australian Institute of Marine Science, Townsville, QLD, Australia.
| |
Collapse
|
8
|
Stockwell RE, Ballard EL, O'Rourke P, Knibbs LD, Morawska L, Bell SC. Indoor hospital air and the impact of ventilation on bioaerosols: a systematic review. J Hosp Infect 2019; 103:175-184. [PMID: 31279762 DOI: 10.1016/j.jhin.2019.06.016] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/28/2019] [Indexed: 10/26/2022]
Abstract
Healthcare-acquired infections (HAIs) continue to persist in hospitals, despite the use of increasingly strict infection-control precautions. Opportunistic airborne transmission of potentially pathogenic bioaerosols may be one possible reason for this persistence. Therefore, this study aimed to systematically review the concentrations and compositions of indoor bioaerosols in different areas within hospitals and the effects of different ventilation systems. Electronic databases (Medline and Web of Science) were searched to identify articles of interest. The search was restricted to articles published from 2000 to 2017 in English. Aggregate data was used to examine the differences in mean colony forming units per cubic metre (cfu/m3) between different hospital areas and ventilation types. A total of 36 journal articles met the eligibility criteria. The mean total bioaerosol concentrations in the different areas of the hospitals were highest in the inpatient facilities (77 cfu/m3, 95% confidence interval (CI): 55-108) compared with the restricted (13cfu/m3, 95% CI: 10-15) and public areas (14 cfu/m3, 95% CI: 10-19). Hospital areas with natural ventilation had the highest total bioaerosol concentrations (201 cfu/m3, 95% CI: 135-300) compared with areas using conventional mechanical ventilation systems (20 cfu/m3, 95% CI: 16-24). Hospital areas using sophisticated mechanical ventilation systems (such as increased air changes per hour, directional flow and filtration systems) had the lowest total bioaerosol concentrations (9 cfu/m3, 95% CI: 7-13). Operating sophisticated mechanical ventilation systems in hospitals contributes to improved indoor air quality within hospitals, which assists in reducing the risk of airborne transmission of HAIs.
Collapse
Affiliation(s)
- R E Stockwell
- Lung Bacteria Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia; Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - E L Ballard
- Statistical Support Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - P O'Rourke
- Statistical Support Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - L D Knibbs
- School of Public Health, The University of Queensland, Herston, Queensland, Australia
| | - L Morawska
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - S C Bell
- Lung Bacteria Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia; Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia; Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Chermside, Queensland, Australia.
| |
Collapse
|
9
|
Matson AG, Bunting JP, Kaul A, Smith DJ, Stonestreet J, Herd K, Hodgson RS, Bell SC. A non-randomised single centre cohort study, comparing standard and modified bowel preparations, in adults with cystic fibrosis requiring colonoscopy. BMC Gastroenterol 2019; 19:89. [PMID: 31195989 PMCID: PMC6567575 DOI: 10.1186/s12876-019-0979-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 04/08/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Adults with cystic fibrosis (CF) have been reported to be at five to ten-fold risk (25 to 30 fold risk after solid organ transplant) of colorectal cancer (CRC) than the general population. Limited publications to date have reported on practical aspects of achieving adequate colonic cleanse producing good visualisation. In this study, we compared two bowel preparation regimens, standard bowel preparation and a modified CF bowel preparation. METHODS A non-randomised study of adults with CF attending a single centre, requiring colonoscopy investigation were selected. Between 2001 and 2015, 485 adults with CF attended the clinic; 70 adults with CF had an initial colonoscopy procedure. After five exclusions, standard bowel preparation was prescribed for 27 patients, and modified CF bowel preparation for 38 patients. Demographic and clinical data were collected for all consenting patients. RESULTS There was a significant difference between modified CF bowel preparation group and standard bowel preparation group in bowel visualisation outcomes, with the modified CF bowel preparation group having a higher proportion of "excellent/good" GI visualisation cleanse (50.0% versus 25.9%) and lower rates of "poor" visualisation cleanse (10.5% versus 44.5%) than standard bowel preparation (p = 0.006). Rates of "fair" GI cleanse visualisation were similar between the two groups (39.4% versus 29.6%) (Additional file 1: Table S1). Detection rates of adenomatous polyps at initial colonoscopy was higher in modified CF bowel preparation cohort than with standard preparation group (50.0% versus 18.5%, p < 0.01). Positive adenomatous polyp detection rate in patient's age > 40 years of age was higher (62.5%) than those < 40 years of age (24.3%) (p = 0.003). Colonic adenocarcinoma diagnosis was similar in both groups. CONCLUSION This study primarily highlights that standard colonoscopy bowel preparation is often inadequate in patients with CF, and that colonic lavage using modified CF bowel preparation is required to obtain good colonic visualisation. A higher rate of polyps in patients over 40 years of age (versus less than 40 years) was evident. These results support adults with CF considered for colonoscopy screening at 40 years of age, or prior to this if symptomatic; which is earlier than CRC screening in the non-CF Australian population.
Collapse
Affiliation(s)
- A G Matson
- The Adult Cystic Fibrosis Centre. The Prince Charles Hospital. (TPCH), Queensland, Brisbane, Australia.
| | - J P Bunting
- The Adult Cystic Fibrosis Centre. The Prince Charles Hospital. (TPCH), Queensland, Brisbane, Australia
| | - A Kaul
- Department of Gastroenterology. TPCH, Queensland, Brisbane, Australia
| | - D J Smith
- The Adult Cystic Fibrosis Centre. The Prince Charles Hospital. (TPCH), Queensland, Brisbane, Australia
| | - J Stonestreet
- The Adult Cystic Fibrosis Centre. The Prince Charles Hospital. (TPCH), Queensland, Brisbane, Australia
| | - K Herd
- The Adult Cystic Fibrosis Centre. The Prince Charles Hospital. (TPCH), Queensland, Brisbane, Australia
| | - R S Hodgson
- Department of Gastroenterology. TPCH, Queensland, Brisbane, Australia
| | - S C Bell
- The Adult Cystic Fibrosis Centre. The Prince Charles Hospital. (TPCH), Queensland, Brisbane, Australia
| |
Collapse
|
10
|
Bell SC, Garland S, Alford RA. Increased Numbers of Culturable Inhibitory Bacterial Taxa May Mitigate the Effects of Batrachochytrium dendrobatidis in Australian Wet Tropics Frogs. Front Microbiol 2018; 9:1604. [PMID: 30072970 PMCID: PMC6058028 DOI: 10.3389/fmicb.2018.01604] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 06/27/2018] [Indexed: 11/20/2022] Open
Abstract
Symbiotic bacterial communities resident on amphibian skin can benefit their hosts. For example, antibiotic production by community members can control the pathogen Batrachochytrium dendrobatidis (Bd) and it is possible for these community members to be used as probiotics to reduce infection levels. In the early 1990s, the emergence of Bd caused declines and disappearances of frogs in the Australian Wet Tropics; the severity of its effects varied among species and sites. Some species have since recolonized despite enzootic Bd within their populations. This variation in history among species and sites provided an opportunity to investigate the role of anti-fungal cutaneous bacteria in protecting frogs against Bd infection. We collected cutaneous swab samples from three species of frogs at two upland and two lowland sites in the Wet Tropics, and used in vitro challenge assays to identify culturable Bd-inhibitory bacterial isolates for further analysis. We sequenced DNA from cultured inhibitory isolates to identify taxa, resulting in the classification of 16 Bd-inhibitory OTUs, and determined whether inhibitory taxa were associated with frog species, site, or intensity of infection. We present preliminary results showing that the upper limit of Bd infection intensity was negatively correlated with number of inhibitory OTUs present per frog indicating that increased numbers of Bd-inhibiting taxa may play a role in reducing the intensity of Bd infections, facilitating frog coexistence with enzootic Bd. One upland site had a significantly lower prevalence of Bd infection, a significantly higher proportion of frogs with one or more culturable Bd-inhibitory OTUs, a greater number of inhibitory bacterial genera present per frog, and statistically significant clustering of individual frogs with similar Bd-inhibitory signatures when compared to all other sites. This suggests that Bd-inhibitory taxa are likely to be particularly important to frogs at this site and may have played a role in their ability to recolonize following population declines. Our findings suggest that the use of multi-taxon Bd-inhibitory probiotics to support at-risk amphibian populations may be more effective than single-taxon alternatives.
Collapse
Affiliation(s)
- Sara C. Bell
- College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| | - Stephen Garland
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
| | - Ross A. Alford
- College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| |
Collapse
|
11
|
Laffy PW, Wood‐Charlson EM, Turaev D, Jutz S, Pascelli C, Botté ES, Bell SC, Peirce TE, Weynberg KD, van Oppen MJH, Rattei T, Webster NS. Reef invertebrate viromics: diversity, host specificity and functional capacity. Environ Microbiol 2018; 20:2125-2141. [DOI: 10.1111/1462-2920.14110] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 03/16/2018] [Accepted: 03/16/2018] [Indexed: 01/14/2023]
Affiliation(s)
- Patrick W. Laffy
- Australian Institute of Marine Science, PMB 3TownsvilleQLD 4810 Australia
| | | | - Dmitrij Turaev
- Department of Microbiology and Ecosystem Science, Division of Computational Systems BiologyUniversity of ViennaVienna Austria
| | - Sabrina Jutz
- Department of Microbiology and Ecosystem Science, Division of Computational Systems BiologyUniversity of ViennaVienna Austria
| | - Cecilia Pascelli
- Australian Institute of Marine Science, PMB 3TownsvilleQLD 4810 Australia
- College of Science and EngineeringJames Cook UniversityTownsville QLD Australia
- AIMS@JCU, Australian Institute of Marine Science and James Cook UniversityTownsville QLD Australia
| | | | - Sara C. Bell
- Australian Institute of Marine Science, PMB 3TownsvilleQLD 4810 Australia
| | - Tyler E. Peirce
- Australian Institute of Marine Science, PMB 3TownsvilleQLD 4810 Australia
| | - Karen D. Weynberg
- Australian Institute of Marine Science, PMB 3TownsvilleQLD 4810 Australia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine Science, PMB 3TownsvilleQLD 4810 Australia
- School of BiosciencesUniversity of Melbourne, ParkvilleMelbourneVIC 3010 Australia
| | - Thomas Rattei
- Department of Microbiology and Ecosystem Science, Division of Computational Systems BiologyUniversity of ViennaVienna Austria
| | - Nicole S. Webster
- Australian Institute of Marine Science, PMB 3TownsvilleQLD 4810 Australia
- Austalian Centre for Ecogenomics, University of QueenslandBrisbaneQLD 4072 Australia
| |
Collapse
|
12
|
Pereira ML, Knibbs LD, He C, Grzybowski P, Johnson GR, Huffman JA, Bell SC, Wainwright CE, Matte DL, Dominski FH, Andrade A, Morawska L. Sources and dynamics of fluorescent particles in hospitals. Indoor Air 2017; 27:988-1000. [PMID: 28303606 DOI: 10.1111/ina.12380] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 03/12/2017] [Indexed: 06/06/2023]
Abstract
Fluorescent particles can be markers of bioaerosols and are therefore relevant to nosocomial infections. To date, little research has focused on fluorescent particles in occupied indoor environments, particularly hospitals. In this study, we aimed to determine the spatial and temporal variation of fluorescent particles in two large hospitals in Brisbane, Australia (one for adults and one for children). We used an Ultraviolet Aerodynamic Particle Sizer (UVAPS) to identify fluorescent particle sources, as well as their contribution to total particle concentrations. We found that the average concentrations of both fluorescent and non-fluorescent particles were higher in the adults' hospital (0.06×106 and 1.20×106 particles/m3 , respectively) than in the children's hospital (0.03×106 and 0.33×106 particles/m3 , respectively) (P<.01). However, the proportion of fluorescent particles was higher in the children's hospital. Based on the concentration results and using activity diaries, we were able to identify sources of particle production within the two hospitals. We demonstrated that particles can be easily generated by a variety of everyday activities, which are potential sources of exposure to pathogens. Future studies to further investigate their role in nosocomial infection are warranted.
Collapse
Affiliation(s)
- M L Pereira
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Qld, Australia
- Department of Refrigeration and Air Conditioning, Federal Institute of Education, Science and Technology of Santa Catarina, Santa Catarina, Brazil
| | - L D Knibbs
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Qld, Australia
- School of Public Health, The University of Queensland, Herston, Qld, Australia
| | - C He
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Qld, Australia
| | - P Grzybowski
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Qld, Australia
- Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warsaw, Poland
| | - G R Johnson
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Qld, Australia
| | - J A Huffman
- Department of Chemistry and Biochemistry, University of Denver, Denver, CO, USA
| | - S C Bell
- Thoracic Medicine, Prince Charles Hospital, Chermside, Qld, Australia
- Lung Bacteria Group, QIMR Berghofer Medical Research Institute, Herston, Qld, Australia
| | - C E Wainwright
- School of Medicine, University of Queensland, Herston, Qld, Australia
- Department of Respiratory and Sleep Medicine, Lady Cilento Children's Hospital, South Brisbane, Qld, Australia
| | - D L Matte
- Center of Health Sciences and Sport, Santa Catarina State University, Florianópolis, Brazil
| | - F H Dominski
- Center of Health Sciences and Sport, Santa Catarina State University, Florianópolis, Brazil
| | - A Andrade
- Center of Health Sciences and Sport, Santa Catarina State University, Florianópolis, Brazil
| | - L Morawska
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Qld, Australia
| |
Collapse
|
13
|
Kidd TJ, Coulter C, Bell SC. Epidemiological Analysis of Methicillin-ResistantStaphylococcus aureusIsolates From Adult Patients With Cystic Fibrosis. Infect Control Hosp Epidemiol 2016; 27:201-3. [PMID: 16465641 DOI: 10.1086/501173] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2004] [Accepted: 07/21/2004] [Indexed: 11/03/2022]
Abstract
Using pulsed-field gel electrophoresis, we genotyped 21 methicillin-resistantStaphylococcus aureusisolates from patients attending an adult cystic fibrosis unit. Eleven patients exhibited pulsotypes related to 2 locally endemic strains. Eleven chronically colonized patients were assessed over a period of up to 2 years, and all demonstrated a retention of strain type.
Collapse
Affiliation(s)
- T J Kidd
- Microbiology Division, Queensland Health Pathology and Scientific Services, The Prince Charles Hospital, Brisbane, Australia.
| | | | | |
Collapse
|
14
|
Abstract
In many countries numbers of adults with cystic fibrosis (CF) exceed that of children, with median survival predicted to surpass 50 years. Increasing longevity is, in part, due to intensive therapies including eradication of early infection and suppressive therapies and pulmonary exacerbations. Initial infections with common CF pathogens are thought to arise from the natural environment. We review the impact of climate and environment on infection in CF. Specifically, several studies indicate that higher ambient temperatures, proximity to the equator and the summer season may be linked to the increased prevalence of Pseudomonas aeruginosa in people with CF. The environment may also play an important role in the acquisition of Gram negative organisms other than P. aeruginosa. There is emerging data suggesting that climatic and environmental factors are likely to impact on the risk of infection with NTM and fungi in people which are found extensively throughout the natural environment.
Collapse
Affiliation(s)
- K A Ramsay
- a Lung Bacteria Group , QIMR Berghofer Medical Research Institute , Brisbane , Australia.,b Child Health Research Centre, The University of Queensland , Brisbane , Australia.,c School of Medicine , The University of Queensland , Brisbane , Australia
| | - R E Stockwell
- a Lung Bacteria Group , QIMR Berghofer Medical Research Institute , Brisbane , Australia
| | - S C Bell
- a Lung Bacteria Group , QIMR Berghofer Medical Research Institute , Brisbane , Australia.,c School of Medicine , The University of Queensland , Brisbane , Australia.,d Adult Cystic Fibrosis Centre , The Prince Charles Hospital , Brisbane , Australia
| | - T J Kidd
- b Child Health Research Centre, The University of Queensland , Brisbane , Australia.,e Centre for Infection and Immunity , Queen's University Belfast , Belfast , UK.,f School of Chemistry and Molecular Biosciences , The University of Queensland , Brisbane , Australia
| |
Collapse
|
15
|
Grogan LF, Phillott AD, Scheele BC, Berger L, Cashins SD, Bell SC, Puschendorf R, Skerratt LF. Endemicity of chytridiomycosis features pathogen overdispersion. J Anim Ecol 2016; 85:806-16. [PMID: 26847143 DOI: 10.1111/1365-2656.12500] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 01/20/2016] [Indexed: 11/26/2022]
Abstract
Pathogens can be critical drivers of the abundance and distribution of wild animal populations. The presence of an overdispersed pathogen load distribution between hosts (where few hosts harbour heavy parasite burdens and light infections are common) can have an important stabilizing effect on host-pathogen dynamics where infection intensity determines pathogenicity. This may potentially lead to endemicity of an introduced pathogen rather than extirpation of the host and/or pathogen. Overdispersed pathogen load distributions have rarely been considered in wild animal populations as an important component of the infection dynamics of microparasites such as bacteria, viruses, protozoa and fungi. Here we examined the abundance, distribution and transmission of the model fungal pathogen Batrachochytrium dendrobatidis (Bd, cause of amphibian chytridiomycosis) between wild-caught Litoria rheocola (common mist frogs) to investigate the effects of an overdispersed pathogen load distribution on the host population in the wild. We quantified host survival, infection incidence and recovery probabilities relative to infectious burden, and compared the results of models where pathogen overdispersion either was or was not considered an important feature of host-pathogen dynamics. We found the distribution of Bd load between hosts to be highly overdispersed. We found that host survival was related to infection burden and that accounting for pathogen overdispersion allowed us to better understand infection dynamics and their implications for disease control. In addition, we found that the pattern of host infections and recoveries varied markedly with season whereby (i) infections established more in winter, consistent with temperature-dependent effects on fungal growth, and (ii) recoveries (loss of infection) occurred frequently in the field throughout the year but were less likely in winter. Our results suggest that pathogen overdispersion is an important feature of endemic chytridiomycosis and that intensity of infection determines disease impact. These findings have important implications for our understanding of chytridiomycosis dynamics and the application of management strategies for disease mitigation. We recommend quantifying individual infectious burdens rather than infection state where possible in microparasitic diseases.
Collapse
Affiliation(s)
- Laura F Grogan
- One Health Research Group, College of Public Health, Medicine and Veterinary Sciences, James Cook University, 1 James Cook Drive, Townsville City, QLD, 4811, Australia.,Griffith Wildlife Disease Ecology Group, Environmental Futures Research Institute, School of Environment, Griffith University, 170 Kessels Road, Nathan, QLD, 4111, Australia
| | - Andrea D Phillott
- One Health Research Group, College of Public Health, Medicine and Veterinary Sciences, James Cook University, 1 James Cook Drive, Townsville City, QLD, 4811, Australia.,Biological Sciences, Asian University for Women, Mohammed Ali Road, Chittagong, Bangladesh
| | - Benjamin C Scheele
- One Health Research Group, College of Public Health, Medicine and Veterinary Sciences, James Cook University, 1 James Cook Drive, Townsville City, QLD, 4811, Australia.,Fenner School of Environment and Society, College of Medicine, Biology and Environment, Australian National University, Canberra, ACT, 0200, Australia
| | - Lee Berger
- One Health Research Group, College of Public Health, Medicine and Veterinary Sciences, James Cook University, 1 James Cook Drive, Townsville City, QLD, 4811, Australia
| | - Scott D Cashins
- One Health Research Group, College of Public Health, Medicine and Veterinary Sciences, James Cook University, 1 James Cook Drive, Townsville City, QLD, 4811, Australia
| | - Sara C Bell
- One Health Research Group, College of Public Health, Medicine and Veterinary Sciences, James Cook University, 1 James Cook Drive, Townsville City, QLD, 4811, Australia.,Australian Institute of Marine Science, 1526 Cape Cleveland Road, Cape Cleveland, Townsville City, QLD, 4810, Australia
| | - Robert Puschendorf
- School of Biological Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK
| | - Lee F Skerratt
- One Health Research Group, College of Public Health, Medicine and Veterinary Sciences, James Cook University, 1 James Cook Drive, Townsville City, QLD, 4811, Australia
| |
Collapse
|
16
|
Sato Y, Civiello M, Bell SC, Willis BL, Bourne DG. Integrated approach to understanding the onset and pathogenesis of black band disease in corals. Environ Microbiol 2016; 18:752-65. [PMID: 26549807 DOI: 10.1111/1462-2920.13122] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 10/27/2015] [Accepted: 11/02/2015] [Indexed: 10/22/2022]
Abstract
Emerging infectious diseases are contributing to global declines in coral reef ecosystems, highlighting a growing need for aetiological knowledge to develop effective management strategies. In this review, we focus on black band disease (BBD), one of the most virulent diseases and the only polymicrobial disease so far known to affect corals. A multipartite microbial consortium dominated by Cyanobacteria, but also including sulfur-cycling bacteria, other bacterial groups and members of the Archaea and Eukarya, forms a sulfide-rich anaerobic mat that migrates across the surface of coral colonies, killing the underlying tissues. The polymicrobial nature of the disease challenges classic aetiological approaches to unravelling disease causation. Here, we synthesize current knowledge on the range of pathogens forming the microbial consortium with recent studies on the transmission, biogeochemistry and environmental drivers of BBD to develop a conceptual model of BBD pathogenesis. The model illustrates how the development of BBD virulence factors is linked to a cascade of microbial community shifts and associated functional roles that progressively develop the microbial consortium from comparatively benign cyanobacterial patches to virulent BBD lesions. This review showcases how an approach that integrates multiple key aspects of the disease provides insights essential to elucidating the aetiology of BBD.
Collapse
Affiliation(s)
- Yui Sato
- Australian Institute of Marine Science, PMB 3, Townsville MC, Townsville, 4810, Australia
| | - Michael Civiello
- AIMS@JCU, James Cook University, Townsville, 4811, Australia.,ARC Centre of Excellence for Coral Reef Studies and College of Marine and Environmental Sciences, James Cook University, Townsville, 4811, Australia
| | - Sara C Bell
- Australian Institute of Marine Science, PMB 3, Townsville MC, Townsville, 4810, Australia
| | - Bette L Willis
- ARC Centre of Excellence for Coral Reef Studies and College of Marine and Environmental Sciences, James Cook University, Townsville, 4811, Australia
| | - David G Bourne
- Australian Institute of Marine Science, PMB 3, Townsville MC, Townsville, 4810, Australia
| |
Collapse
|
17
|
Jong T, Geake J, Yerkovich S, Bell SC. Idiosyncratic reactions are the most common cause of abnormal liver function tests in patients with cystic fibrosis. Intern Med J 2016; 45:395-401. [PMID: 25644776 DOI: 10.1111/imj.12707] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 01/25/2015] [Indexed: 01/23/2023]
Abstract
BACKGROUND Beta-lactam antibiotic-related liver enzyme derangement can limit treatment options for infective exacerbations in cystic fibrosis (CF) bronchiectasis. AIM To identify risk factors for elevated liver function tests (LFT) in CF patients receiving parenteral antibiotics. METHODS All patients attending The Prince Charles Hospital (TPCH) Adult CF Centre in 2012 were identified using the CF Research Database and CF Data Registry. Biochemistry and haematology panels between 1 January 2012 and 31 December 2012 for each patient were retrieved from Queensland Health Pathology and private pathology providers. Patients with LFT more than three times the upper limit of normal were identified. For each laboratory test, concurrently administered antibiotic(s) were analysed from TPCH pharmacy dispensing system for patients who received intravenous (IV) antibiotic treatment. RESULTS Abnormal liver enzymes were evident in significantly more patients receiving IV antibiotics than patients who did not (43% vs 18%, P < 0.001). Pre-existing CF-related liver disease and total IV antibiotic treatment days were not associated with abnormal LFT. Higher C-reactive protein and peripheral eosinophil counts were not more common in patients with abnormal LFT. Male sex, poorer lung function and lower leucocyte counts were associated with abnormal LFT; however, these variables only explained 4.2% of the variance in the multivariable logistic model. CONCLUSION Elevated LFT are common during IV antibiotic treatment in CF. Although specific antibiotic exposure may contribute to abnormal LFT in a minority of cases, our study demonstrates that antibiotic-induced liver injury is largely idiosyncratic and unpredictable.
Collapse
Affiliation(s)
- T Jong
- Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Brisbane, Queensland, Australia; Department of Pharmacy, The Prince Charles Hospital, Brisbane, Queensland, Australia
| | | | | | | |
Collapse
|
18
|
Woodhams DC, Bell SC, Bigler L, Caprioli RM, Chaurand P, Lam BA, Reinert LK, Stalder U, Vazquez VM, Schliep K, Hertz A, Rollins-Smith LA. Life history linked to immune investment in developing amphibians. Conserv Physiol 2016; 4:cow025. [PMID: 27928507 PMCID: PMC5001151 DOI: 10.1093/conphys/cow025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 05/09/2016] [Accepted: 05/14/2016] [Indexed: 05/03/2023]
Abstract
The broad diversity of amphibian developmental strategies has been shaped, in part, by pathogen pressure, yet trade-offs between the rate of larval development and immune investment remain poorly understood. The expression of antimicrobial peptides (AMPs) in skin secretions is a crucial defense against emerging amphibian pathogens and can also indirectly affect host defense by influencing the composition of skin microbiota. We examined the constitutive or induced expression of AMPs in 17 species at multiple life-history stages. We found that AMP defenses in tadpoles of species with short larval periods (fast pace of life) were reduced in comparison with species that overwinter as tadpoles and grow to a large size. A complete set of defensive peptides emerged soon after metamorphosis. These findings support the hypothesis that species with a slow pace of life invest energy in AMP production to resist potential pathogens encountered during the long larval period, whereas species with a fast pace of life trade this investment in defense for more rapid growth and development.
Collapse
Affiliation(s)
- Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
- Corresponding author: Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA. Tel: +1 617 287 6679.
| | - Sara C Bell
- College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia
| | - Laurent Bigler
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Richard M Caprioli
- Mass Spectrometry Research Center and Department of Biochemistry, Vanderbilt University, Nashville, TN 37232-8575, USA
| | - Pierre Chaurand
- Department of Chemistry, Université de Montréal, Montreal, QC, Canada H3T 1J4
| | - Brianna A Lam
- Department of Biology, James Madison University, MSC 7801, Harrisonburg, VA 22807, USA
| | - Laura K Reinert
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
| | - Urs Stalder
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | | | - Klaus Schliep
- Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
| | - Andreas Hertz
- Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
| | - Louise A Rollins-Smith
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
- Department of Biological Science, Vanderbilt University, Nashville, TN 37235-1634, USA
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
| |
Collapse
|
19
|
Woodhams DC, Alford RA, Antwis RE, Archer H, Becker MH, Belden LK, Bell SC, Bletz M, Daskin JH, Davis LR, Flechas SV, Lauer A, Gonzalez A, Harris RN, Holden WM, Hughey MC, Ibáñez R, Knight R, Kueneman J, Rabemananjara F, Reinert LK, Rollins-Smith LA, Roman-Rodriguez F, Shaw SD, Walke JB, McKenzie V. Antifungal isolates database of amphibian skin-associated bacteria and function against emerging fungal pathogens. Ecology 2015. [DOI: 10.1890/14-1837.1] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
20
|
Daskin JH, Bell SC, Schwarzkopf L, Alford RA. Cool temperatures reduce antifungal activity of symbiotic bacteria of threatened amphibians--implications for disease management and patterns of decline. PLoS One 2014; 9:e100378. [PMID: 24941262 PMCID: PMC4062522 DOI: 10.1371/journal.pone.0100378] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 05/27/2014] [Indexed: 11/18/2022] Open
Abstract
Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), is a widespread disease of amphibians responsible for population declines and extinctions. Some bacteria from amphibians' skins produce antimicrobial substances active against Bd. Supplementing populations of these cutaneous antifungal bacteria might help manage chytridiomycosis in wild amphibians. However, the activity of protective bacteria may depend upon environmental conditions. Biocontrol of Bd in nature thus requires knowledge of how environmental conditions affect their anti-Bd activity. For example, Bd-driven amphibian declines have often occurred at temperatures below Bd's optimum range. It is possible these declines occurred due to reduced anti-Bd activity of bacterial symbionts at cool temperatures. Better understanding of the effects of temperature on chytridiomycosis development could also improve risk evaluation for amphibian populations yet to encounter Bd. We characterized, at a range of temperatures approximating natural seasonal variation, the anti-Bd activity of bacterial symbionts from the skins of three species of rainforest tree frogs (Litoria nannotis, Litoria rheocola, and Litoria serrata). All three species declined during chytridiomycosis outbreaks in the late 1980s and early 1990s and have subsequently recovered to differing extents. We collected anti-Bd bacterial symbionts from frogs and cultured the bacteria at constant temperatures from 8 °C to 33 °C. Using a spectrophotometric assay, we monitored Bd growth in cell-free supernatants (CFSs) from each temperature treatment. CFSs from 11 of 24 bacteria showed reduced anti-Bd activity in vitro when they were produced at cool temperatures similar to those encountered by the host species during population declines. Reduced anti-Bd activity of metabolites produced at low temperatures may, therefore, partially explain the association between Bd-driven declines and cool temperatures. We show that to avoid inconsistent antifungal activity, bacteria evaluated for use in chytridiomycosis biocontrol should be tested over a range of environmental temperatures spanning those likely to be encountered in the field.
Collapse
Affiliation(s)
- Joshua H. Daskin
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
- * E-mail:
| | - Sara C. Bell
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
| | - Lin Schwarzkopf
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
| | - Ross A. Alford
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
| |
Collapse
|
21
|
Joseloff E, Sha W, Bell SC, Wetmore DR, Lawton KA, Milburn MV, Ryals JA, Guo L, Muhlebach MS. Serum metabolomics indicate altered cellular energy metabolism in children with cystic fibrosis. Pediatr Pulmonol 2014; 49:463-72. [PMID: 23847148 DOI: 10.1002/ppul.22859] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 04/21/2013] [Indexed: 12/31/2022]
Abstract
BACKGROUND Cystic fibrosis (CF) is a multi-system disease affecting multiple organs and cells besides the respiratory system. Metabolomic profiling allows simultaneous detection of biochemicals originating from cells, organs, or exogenous origin that may be valuable for monitoring of disease severity or in diagnosis. AIM We hypothesized that metabolomics using serum from children would differentiate CF from non-CF lung disease subjects and would provide insight into metabolism in CF. METHODS Serum collected from children with CF (n = 31) and 31 age and gender matched children with other lung diseases was used for metabolomic profiling by gas- and liquid-chromatography. Relative concentration of metabolites was compared between the groups using partial least square discriminant analyses (PLS-DA) and linear modeling. RESULTS A clear separation of the two groups was seen in PLS-DA. Linear model found that among the 459 detected metabolites 92 differed between CF and non-CF. These included known biochemicals in lipid metabolism, oxidants, and markers consistent with abnormalities in bile acid processing. Bacterial metabolites were identified and differed between the groups indicating intestinal dysbiosis in CF. As a novel finding several pathways were markedly different in CF, which jointly point towards decreased activity in the β-oxidation of fatty acids. These pathways include low ketone bodies, low medium chain carnitines, elevated di-carboxylic acids and decreased 2-hydroxybutyrate from amino acid metabolism in CF compared to non-CF. CONCLUSION Serum metabolomics discriminated CF from non-CF and show altered cellular energy metabolism in CF potentially reflecting mitochondrial dysfunction. Future studies are indicated to examine their relation to the underlying CF defect and their use as biomarkers for disease severity or for cystic fibrosis transmembrane regulator (CFTR) function in an era of CFTR modifying drugs.
Collapse
Affiliation(s)
- Elizabeth Joseloff
- Cystic Fibrosis Foundation Therapeutics (CFFT), Inc., Bethesda, Maryland
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Stevenson LA, Alford RA, Bell SC, Roznik EA, Berger L, Pike DA. Variation in thermal performance of a widespread pathogen, the amphibian chytrid fungus Batrachochytrium dendrobatidis. PLoS One 2013; 8:e73830. [PMID: 24023908 PMCID: PMC3762749 DOI: 10.1371/journal.pone.0073830] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 07/31/2013] [Indexed: 12/05/2022] Open
Abstract
Rates of growth and reproduction of the pathogens that cause emerging infectious diseases can be affected by local environmental conditions; these conditions can thus influence the strength and nature of disease outbreaks. An understanding of these relationships is important for understanding disease ecology and developing mitigation strategies. Widespread emergence of the fungal disease chytridiomycosis has had devastating effects on amphibian populations. The causative pathogen, Batrachochytriumdendrobatidis (Bd), is sensitive to temperature, but its thermal tolerances are not well studied. We examined the thermal responses of three Bd isolates collected across a latitudinal gradient in eastern Australia. Temperature affected all aspects of Bd growth and reproduction that we measured, in ways that often differed among Bd isolates. Aspects of growth, reproduction, and their relationships to temperature that differed among isolates included upper thermal maxima for growth (26, 27, or 28 °C, depending on the isolate), relationships between zoospore production and temperature, and zoospore activity and temperature. Two isolates decreased zoospore production as temperature increased, whereas the third isolate was less fecund overall, but did not show a strong response to temperature until reaching the upper limit of its thermal tolerance. Our results show differentiation in life-history traits among isolates within Australia, suggesting that the pathogen may exhibit local adaptation. An understanding of how environmental temperatures can limit pathogens by constraining fitness will enhance our ability to assess pathogen dynamics in the field, model pathogen spread, and conduct realistic experiments on host susceptibility and disease transmission.
Collapse
Affiliation(s)
- Lisa A. Stevenson
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
| | - Ross A. Alford
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
| | - Sara C. Bell
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
- School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Townsville, Queensland, Australia
| | - Elizabeth A. Roznik
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
| | - Lee Berger
- School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Townsville, Queensland, Australia
| | - David A. Pike
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
| |
Collapse
|
23
|
Bell SC, Alford RA, Garland S, Padilla G, Thomas AD. Screening bacterial metabolites for inhibitory effects against Batrachochytrium dendrobatidis using a spectrophotometric assay. Dis Aquat Organ 2013; 103:77-85. [PMID: 23482387 DOI: 10.3354/dao02560] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Certain bacteria present on frog skin can prevent infection by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), conferring disease resistance. Previous studies have used agar-based in vitro challenge assays to screen bacteria for Bd-inhibitory activity and to identify candidates for bacterial supplementation trials. However, agar-based assays can be difficult to set up and to replicate reliably. To overcome these difficulties, we developed a semi-quantitative spectrophotometric challenge assay technique. Cell-free supernatants were prepared from filtered bacterial cultures and added to 96-well plates in replicated wells containing Bd zoospores suspended in tryptone-gelatin hydrolysate-lactose (TGhL) broth medium. Plates were then read daily on a spectrophotometer until positive controls reached maximum growth in order to determine growth curves for Bd. We tested the technique by screening skin bacteria from the Australian green-eyed tree frog Litoria serrata. Of bacteria tested, 31% showed some degree of Bd inhibition, while some may have promoted Bd growth, a previously unknown effect. Our cell-free supernatant challenge assay technique is an effective in vitro method for screening bacterial isolates for strong Bd-inhibitory activity. It contributes to the expanding field of bioaugmentation research, which could play a significant role in mitigating the effects of chytridiomycosis on amphibians around the world.
Collapse
Affiliation(s)
- Sara C Bell
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia.
| | | | | | | | | |
Collapse
|
24
|
Bletz MC, Loudon AH, Becker MH, Bell SC, Woodhams DC, Minbiole KPC, Harris RN. Mitigating amphibian chytridiomycosis with bioaugmentation: characteristics of effective probiotics and strategies for their selection and use. Ecol Lett 2013; 16:807-20. [PMID: 23452227 DOI: 10.1111/ele.12099] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 11/28/2012] [Accepted: 02/04/2013] [Indexed: 12/17/2022]
Abstract
Probiotic therapy through bioaugmentation is a feasible disease mitigation strategy based on growing evidence that microbes contribute to host defences of plants and animals. Amphibians are currently threatened by the rapid global spread of the pathogen, Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis. Bioaugmentation of locally occurring protective bacteria on amphibians has mitigated this disease effectively in laboratory trials and one recent field trial. Areas still naïve to Bd provide an opportunity for conservationists to proactively implement probiotic strategies to prevent further amphibian declines. In areas where Bd is endemic, bioaugmentation can facilitate repatriation of susceptible amphibians currently maintained in assurance colonies. Here, we synthesise the current research in amphibian microbial ecology and bioaugmentation to identify characteristics of effective probiotics in relation to their interactions with Bd, their host, other resident microbes and the environment. To target at-risk species and amphibian communities, we develop sampling strategies and filtering protocols that result in probiotics that inhibit Bd under ecologically relevant conditions and persist on susceptible amphibians. This filtering tool can be used proactively to guide amphibian disease mitigation and can be extended to other taxa threatened by emerging infectious diseases.
Collapse
Affiliation(s)
- Molly C Bletz
- Department of Biology, James Madison University, Harrisonburg, VA, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Woodhams DC, Bell SC, Kenyon N, Alford RA, Rollins-Smith LA. Immune evasion or avoidance: fungal skin infection linked to reduced defence peptides in Australian green-eyed treefrogs, Litoria serrata. Fungal Biol 2012; 116:1203-11. [PMID: 23245614 DOI: 10.1016/j.funbio.2012.10.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 10/15/2012] [Accepted: 10/29/2012] [Indexed: 02/04/2023]
Abstract
Many parasites and pathogens suppress host immunity to maintain infection or initiate disease. On the skin of many amphibians, defensive peptides are active against the fungus Batrachochytrium dendrobatidis (Bd), the causative agent of the emerging infectious disease chytridiomycosis. We tested the hypothesis that infection with the fungus may be linked to lower levels of defensive peptides. We sampled both ambient (or constitutive) skin peptides on the ventral surface immediately upon capture, and stored skin peptides induced from granular glands by norepinephrine administration of Australian green-eyed treefrogs, Litoria serrata. Upon capture, uninfected frogs expressed an array of antimicrobial peptides on their ventral surface, whereas infected frogs had reduced skin peptide expression. Expression of ambient skin peptides differed with infection status, and antimicrobial peptides maculatin 1.1 and 2.1 were on average three times lower on infected frogs. However, the repertoire of skin peptides stored in granular glands did not differ with infection status; on average equal quantities were recovered from infected and from uninfected frogs. Our results could have at least two causes: (1) frogs with reduced peptide expression are more likely to become infected; (2) Bd infection interferes with defence peptides by inhibiting release or causing selective degradation of peptides on the skin surface. Immune evasion therefore may contribute to the pathogenesis of chytridiomycosis and a mechanistic understanding of this fungal strategy may lead to improved methods of disease control.
Collapse
Affiliation(s)
- Douglas C Woodhams
- Department of Ecology and Evolutionary Biology, University of Colorado, N122 Ramaley, 334 UCB, Boulder, CO 80309-0334, USA.
| | | | | | | | | |
Collapse
|
26
|
Anuj SN, Whiley DM, Kidd TJ, Ramsay KA, Bell SC, Syrmis MW, Grimwood K, Wainwright CE, Nissen MD, Sloots TP. Rapid single-nucleotide polymorphism-based identification of clonal Pseudomonas aeruginosa isolates from patients with cystic fibrosis by the use of real-time PCR and high-resolution melting curve analysis. Clin Microbiol Infect 2011; 17:1403-8. [PMID: 21129101 DOI: 10.1111/j.1469-0691.2010.03439.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pseudomonas aeruginosa genotyping relies mainly upon DNA fingerprinting methods, which can be subjective, expensive and time-consuming. The detection of at least three different clonal P. aeruginosa strains in patients attending two cystic fibrosis (CF) centres in a single Australian city prompted the design of a non-gel-based PCR method to enable clinical microbiology laboratories to readily identify these clonal strains. We designed a detection method utilizing heat-denatured P. aeruginosa isolates and a ten-single-nucleotide polymorphism (SNP) profile. Strain differences were detected by SYBR Green-based real-time PCR and high-resolution melting curve analysis (HRM10SNP assay). Overall, 106 P. aeruginosa sputum isolates collected from 74 patients with CF, as well as five reference strains, were analysed with the HRM10SNP assay, and the results were compared with those obtained by pulsed-field gel electrophoresis (PFGE). The HRM10SNP assay accurately identified all 45 isolates as members of one of the three major clonal strains characterized by PFGE in two Brisbane CF centres (Australian epidemic strain-1, Australian epidemic strain-2 and P42) from 61 other P. aeruginosa strains from Australian CF patients and two representative overseas epidemic strain isolates. The HRM10SNP method is simple, is relatively inexpensive and can be completed in <3 h. In our setting, it could be made easily available for clinical microbiology laboratories to screen for local P. aeruginosa strains and to guide infection control policies. Further studies are needed to determine whether the HRM10SNP assay can also be modified to detect additional clonal strains that are prevalent in other CF centres.
Collapse
Affiliation(s)
- S N Anuj
- Queensland Paediatric Infectious Diseases Laboratory, Sir Albert Sakzewski Virus Research Centre, Royal Children's Hospital, Brisbane, Qld, Australia.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Fonseca BM, Correia-da-Silva G, Taylor AH, Lam PMW, Marczylo TH, Bell SC, Konje JC, Teixeira NA. The endocannabinoid 2-arachidonoylglycerol (2-AG) and metabolizing enzymes during rat fetoplacental development: a role in uterine remodelling. Int J Biochem Cell Biol 2010; 42:1884-92. [PMID: 20727980 DOI: 10.1016/j.biocel.2010.08.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/03/2010] [Accepted: 08/11/2010] [Indexed: 01/20/2023]
Abstract
The main endocannabinoids (EC) identified in mammalian tissues are N-arachidonoylethanolamide (AEA, anandamide), and 2-arachidonoylglycerol (2-AG). AEA levels are critical in pregnancy, especially during implantation, decidualization, and placental development. As 2-AG functions in pregnancy are still largely undefined, we hypothesized that it may also have a role during fetoplacental development. We showed that 2-AG is not only present in the rat mesometrial decidua and plasma during fetoplacental development, but that both 2-AG synthesizing (diacylglycerol lipase) and degradation (monoacylglycerol lipase) enzymes are expressed by decidual cells. While lower concentrations of 2-AG induced apoptosis of rat primary decidual cells, via the CB1 receptor, higher concentrations induced a dramatic effect on cell morphology, cell viability and lactate dehydrogenase release, triggered through a mechanism independent of CB1. This study provides evidences that 2-AG fluctuation in maternal tissues throughout normal pregnancy is primarily regulated by its metabolizing enzymes. Together, these data supports the hypothesis that a deregulation of the endocannabinoid system through aberrant cannabinoid signalling may impact normal uterine remodelling process and consequently normal pregnancy.
Collapse
Affiliation(s)
- B M Fonseca
- Departamento de Bioquímica, Faculdade de Farmácia da Universidade do Porto, Porto, Portugal
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Fonseca BM, Correia-da-Silva G, Taylor AH, Lam PMW, Marczylo TH, Konje JC, Bell SC, Teixeira NA. N-acylethanolamine levels and expression of their metabolizing enzymes during pregnancy. Endocrinology 2010; 151:3965-74. [PMID: 20534733 DOI: 10.1210/en.2009-1424] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Decidualization is essential for a successful pregnancy and is a tightly regulated process influenced by the local microenvironment. Lipid-based mediators, such as the endocannabinoid anandamide, and other compounds that have cannabimimetic actions may act on the decidua during early pregnancy. In this study, the levels of N-arachidonoylethanolamine (anandamide) and two other N-acylethanolamines, N-oleoylethanolamine and N-palmitoylethanolamine, were measured in rat plasma and maternal tissues between d 8 and 19 of pregnancy by ultraperformance liquid chromatography tandem mass spectrometry. The spatiotemporal expression of N-acylethanolamine metabolizing enzymes in implantation units were also determined by quantitative PCR, Western blot, and immunohistochemistry and shown to vary with gestation being mainly localized in decidual cells. The data also indicated that plasma and tissues levels of all three N-acylethanolamines fluctuate throughout pregnancy. Tissue levels of endocannabinoids did not correlate with plasma, suggesting that during pregnancy, maternal tissue levels of endocannabinoids are primarily regulated by in situ production and degradation to create endocannabinoid gradients conducive to successful pregnancy.
Collapse
Affiliation(s)
- B M Fonseca
- Departamento de Bioquímica, Faculdade de Farmácia, and Instituto de Biologia Molecular e Celular, Universidade do Porto, 4099-002 Porto, Portugal
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Bell SC, Turner JM. Bacterial catabolism of threonine. Threonine degradation initiated by l-threonine hydrolyase (deaminating) in a species of Corynebacterium. Biochem J 2010; 164:579-87. [PMID: 16743051 PMCID: PMC1164834 DOI: 10.1042/bj1640579] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
1. Three bacterial isolates capable of growth on l-threonine medium only when supplemented with branched-chain amino acids, and possessing high l-threonine dehydratase activity, were examined to elucidate the catabolic route for the amino acid. 2. Growth, manometric, radiotracer and enzymic experiments indicated that l-threonine was catabolized by initial deamination to 2-oxobutyrate and thence to propionate. No evidence was obtained for the involvement of l-threonine 3-dehydrogenase or l-threonine aldolase in threonine catabolism. 3. l-Threonine dehydratase of Corynebacterium sp. F5 (N.C.I.B. 11102) was partially purified and its kinetic properties were examined. The enzyme exhibited a sigmoid kinetic response to substrate concentration. The concentration of substrate giving half the maximum velocity, [S(0.5)], was 40mm and the Hill coefficient (h) was 2.0. l-Isoleucine inhibited enzyme activity markedly, causing 50% inhibition at 60mum, but did not affect the Hill constant. At the fixed l-threonine concentration of 10mm, the effect of l-valine was biphasic, progressive activation occurring at concentrations up to 2mm-l-valine, but was abolished by higher concentrations. Substrate-saturation plots for the l-valine-activated enzyme exhibited normal Michaelis-Menten kinetics with a Hill coefficient (h) of 1.0. The kinetic properties of the enzyme were thus similar to those of the ;biosynthetic' isoenzyme from Rhodopseudomonas spheroides rather than those of the enteric bacteria. 4. The synthesis of l-threonine dehydratase was constitutive and was not subject to multivalent repression by l-isoleucine or other branched-chain amino acids either singly or in combination. 5. The catabolism of l-threonine, apparently initiated by a ;biosynthetic' l-threonine dehydratase in the isolates studied, depended on the concomitant catabolism of branched-chain amino acids. The biochemical basis of this dependence appeared to lie in the further catabolism of 2-oxobutyrate by enzymes which required branched-chain 2-oxo acids for their induction.
Collapse
Affiliation(s)
- S C Bell
- Department of Biochemistry, University of Liverpool, P.O. Box 147, Liverpool L69 3BX, U.K
| | | |
Collapse
|
30
|
Mehasseb MK, Bell SC, Habiba MA. Neonatal administration of tamoxifen causes disruption of myometrial development but not adenomyosis in the C57/BL6J mouse. Reproduction 2010; 139:1067-75. [DOI: 10.1530/rep-09-0443] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We previously demonstrated that in the CD-1 mouse, which exhibits a high incidence of age-related adenomyosis, neonatal exposure to tamoxifen induced premature uterine adenomyosis and was associated with abnormal development particularly of the inner myometrium. In the present study, we examined the effect of neonatal tamoxifen administration upon uterine development in the C57/BL6J mouse strain that is not known to develop uterine adenomyosis. Female C57/BL6J pups (n=20) were treated with oral tamoxifen (1 mg/kg) from age 1 to 5 days. Uteri from control and treated mice were obtained on days 5, 10, 15 and 42 of age. We examined sections histologically using image analysis and immunohistochemistry for α-smooth muscle actin (ACTA2, α-SMA), desmin, vimentin, laminin, fibronectin and oestrogen receptor-α (ESR1). Following tamoxifen exposure, all uteri showed inner myometrium thinning, lack of continuity, disorganisation and bundling. However, adenomyosis was not seen in any uterus. ACTA2 immunostaining was less in the circular muscle layer of treated mice. The temporal pattern of desmin immunostaining found in control mice was absent in tamoxifen-treated mice. There was no difference in the localisation of laminin or fibronectin between control and tamoxifen-treated groups. However, laminin immunostaining was reduced in the circular muscle layer of treated mice. Vimentin could not be detected in either group. In conclusion, our results demonstrate that the development of the inner myometrium is particularly sensitive to oestrogen antagonism, and is affected by steroid receptor modulation. Although tamoxifen induces inner myometrial changes including that of ACTA2, desmin, ESR1 and laminin expression in C57/BL6J neonatal mice similar to those induced in CD-1 mice, C57/BL6J mice did not develop premature adenomyosis. Thus, disruption of the development and differentiation of the inner myometrium cannot alone explain the development of tamoxifen-associated adenomyosis, and this must be dependent upon its interaction with strain-dependent factors.
Collapse
|
31
|
Woodhams DC, Kenyon N, Bell SC, Alford RA, Chen S, Billheimer D, Shyr Y, Rollins-Smith LA. Adaptations of skin peptide defences and possible response to the amphibian chytrid fungus in populations of Australian green-eyed treefrogs, Litoria genimaculata. DIVERS DISTRIB 2010. [DOI: 10.1111/j.1472-4642.2010.00666.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
32
|
Bell SC, Junker M, Jasperse M, Turner LD, Lin YJ, Spielman IB, Scholten RE. A slow atom source using a collimated effusive oven and a single-layer variable pitch coil Zeeman slower. Rev Sci Instrum 2010; 81:013105. [PMID: 20113079 DOI: 10.1063/1.3276712] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We describe a simple slow atom source for loading a rubidium magneto-optical trap. The source includes an effusive oven with a long heated collimation tube. Almost all components are standard vacuum parts. The heating elements and thermocouples are external to the vacuum, protecting them from the hostile hot alkali environment and allowing repair without breaking vacuum. The thermal source is followed by a Zeeman slower with a single-layer coil of variable winding pitch. The single-layer design is simple to construct and has low inductance which allows for rapid switching of the magnetic field. The coil pitch was determined by fitting the analytic form of the magnetic field for a variable winding pitch to the desired magnetic field profile required to slow atoms. The measured magnetic field for the constructed coil is in excellent agreement with the desired field. The source produces atoms at 35 m/s with a flux up to 2 x 10(10) cm(-2) s(-1) at 200 degrees C.
Collapse
Affiliation(s)
- S C Bell
- ARC Centre of Excellence for Coherent X-ray Science, School of Physics, The University of Melbourne, Victoria 3010, Australia
| | | | | | | | | | | | | |
Collapse
|
33
|
Wainwright CE, France MW, O'Rourke P, Anuj S, Kidd TJ, Nissen MD, Sloots TP, Coulter C, Ristovski Z, Hargreaves M, Rose BR, Harbour C, Bell SC, Fennelly KP. Cough-generated aerosols of Pseudomonas aeruginosa and other Gram-negative bacteria from patients with cystic fibrosis. Thorax 2009; 64:926-31. [PMID: 19574243 PMCID: PMC2764123 DOI: 10.1136/thx.2008.112466] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Pseudomonas aeruginosa is the most common bacterial pathogen in patients with cystic fibrosis (CF). Current infection control guidelines aim to prevent transmission via contact and respiratory droplet routes and do not consider the possibility of airborne transmission. It was hypothesised that subjects with CF produce viable respirable bacterial aerosols with coughing. METHODS A cross-sectional study was undertaken of 15 children and 13 adults with CF, 26 chronically infected with P aeruginosa. A cough aerosol sampling system enabled fractioning of respiratory particles of different sizes and culture of viable Gram-negative non-fermentative bacteria. Cough aerosols were collected during 5 min of voluntary coughing and during a sputum induction procedure when tolerated. Standardised quantitative culture and genotyping techniques were used. RESULTS P aeruginosa was isolated in cough aerosols of 25 subjects (89%), 22 of whom produced sputum samples. P aeruginosa from sputum and paired cough aerosols were indistinguishable by molecular typing. In four cases the same genotype was isolated from ambient room air. Approximately 70% of viable aerosols collected during voluntary coughing were of particles <or=3.3 microm aerodynamic diameter. P aeruginosa, Burkholderia cenocepacia, Stenotrophomonas maltophilia and Achromobacter xylosoxidans were cultivated from respiratory particles in this size range. Positive room air samples were associated with high total counts in cough aerosols (p = 0.003). The magnitude of cough aerosols was associated with higher forced expiratory volume in 1 s (r = 0.45, p = 0.02) and higher quantitative sputum culture results (r = 0.58, p = 0.008). CONCLUSION During coughing, patients with CF produce viable aerosols of P aeruginosa and other Gram-negative bacteria of respirable size range, suggesting the potential for airborne transmission.
Collapse
Affiliation(s)
- C E Wainwright
- Department of Respiratory Medicine, Royal Children's Hospital and Health Service District, Brisbane, Australia.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Mehasseb MK, Bell SC, Habiba MA. The effects of tamoxifen and estradiol on myometrial differentiation and organization during early uterine development in the CD1 mouse. Reproduction 2009; 138:341-50. [PMID: 19451194 DOI: 10.1530/rep-09-0054] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We used a neonatal mouse model to examine the histogenesis of uterine adenomyosis, and to test whether adenomyosis is due to an abnormality in myometrial differentiation, or in extracellular matrix proteins expression. We also studied the effects of tamoxifen and estradiol on uterine development, myometrial differentiation, and organization. Female CD1 pups were treated with oral tamoxifen (1 mg/kg) (n=27) or estradiol (0.1 mg/kg) (n=24) from age 1 to 5 days. Uteri from control (n=27) and treated mice were obtained on days 2, 5, 10, 15, and 42 of age. We examined the sections histologically, using image analysis and immunohistochemistry for alpha-smooth muscle actin (alpha-SMA), desmin, vimentin, laminin, fibronectin, and estrogen receptor-alpha. Following tamoxifen exposure, all uteri showed adenomyosis by 6 weeks of age (seen as early as day 10). The inner myometrium showed thinning, lack of continuity, disorganization, and bundling. alpha-SMA expression was normal. Desmin expression normally showed a wave of maturation that was absent in tamoxifen-treated mice. In the estradiol group, adenomyosis was not observed. All uterine layers were normally developed, but hypertrophied. The inner myometrium retained its circular arrangement. There was no difference in the localization of laminin or fibronectin between groups (laminin expression was reduced in the tamoxifen treated uteri). Vimentin could not be detected in all groups. Our results suggest that the development of the inner myometrium is particularly sensitive to estrogen antagonism, and can be affected by steroid receptors modulation. Disruption of the inner myometrium may play a role in the development of uterine adenomyosis.
Collapse
Affiliation(s)
- Mohamed K Mehasseb
- Reproductive Sciences Section, Department of Cancer Studies and Molecular Medicine, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, UK.
| | | | | |
Collapse
|
35
|
Affiliation(s)
- D W Reid
- Menzies Research Institute, Hobart, Tasmania, Australia
| | - S C Bell
- The Prince Charles Hospital, Chermside, Brisbane, Queensland, Australia
| |
Collapse
|
36
|
|
37
|
Abstract
Maternal use of marijuana, in which the exocannabinoid Delta(9)-tetrahydrocannabinol is the most active psychoactive ingredient, is known to have adverse effects on various aspects of reproduction including ovulation, spermatogenesis, implantation and pregnancy duration. Endogenous cannabinoids of which Anandamide is the prototype are widely distributed in the body especially in the reproductive tract and pregnancy tissues and act through the same receptors as the receptor as Delta(9)-tetrahydrocannabinol. Anandamide, has been reported to have pleiotropic effects on human reproduction and in experimental animal models. It appears to be the important neuro-cytokine mediator synchronizing the embryo-endometrial development for timed implantation, the development of the embryo into the blastocyst and transport of the embryo across the fallopian tubes. The mechanisms by which it exerts these effects are unclear but could be via direct actions on the various sites within the reproductive system or its differential actions on vascular tone dependent. In this review article we bring together the current knowledge on the role of endoccanabinoids in reproduction and postulate on the potential mechanisms on how these affect reproduction. In addition, we examine its role on the endothelium and vascular smooth muscle as a potential mechanism for adverse pregnancy outcome.
Collapse
Affiliation(s)
- A H Taylor
- Department of Cancer Studies and Molecular Medicine, Robert Kilpatrick Clinical Sciences Building, University of Leicester, Leicester Royal Infirmary, PO Box 65, Leicester, Leicestershire LE2 7LX, UK
| | | | | | | |
Collapse
|
38
|
Abstract
A series of papers reviewing pulmonary exacerbations in CF and bronchiectasis
Collapse
|
39
|
Girling SL, Bell SC, Whitelock RG, Rayward RM, Thomson DG, Carter SC, Vaughan-Thomas A, Innes JF. Use of biochemical markers of osteoarthritis to investigate the potential disease-modifying effect of tibial plateau levelling osteotomy. J Small Anim Pract 2007; 47:708-14. [PMID: 17201821 DOI: 10.1111/j.1748-5827.2006.00150.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To evaluate the hypothesis that the concentration of the 1/20/5D4 epitope of keratan sulphate, cartilage oligomeric matrix protein and total sulphated glycosaminoglycans in synovial fluids from dogs with cranial cruciate ligament disease would be affected by tibial plateau levelling osteotomy. In addition, to evaluate the hypothesis that medial meniscal release or meniscal injury would alter the expression of these candidate biomarkers. METHODS Forty-one dogs with naturally occurring cranial cruciate ligament disease were recruited prospectively. Synovial fluids were collected from the index joint before surgery and six weeks and six months postsurgery. Following tibial plateau levelling osteotomy, synovial fluids were assayed for 1/20/5D4 epitope of keratan sulphate and cartilage oligomeric matrix protein concentration using an inhibition ELISA and for sulphated glycosaminoglycans using a direct dye-binding assay. RESULTS The sulphated glycosaminoglycans ratio did not change significantly during the study. Medial meniscal injury at entry was associated with lower concentrations of synovial fluid cartilage oligomeric matrix protein (P<0.05, unpaired t test). There was no association between medial meniscal release and the changes in marker concentrations, either from 0 to six weeks or 0 to six months. CLINICAL SIGNIFICANCE Tibial plateau levelling osteotomy did not significantly alter the expression of the named candidate biomarkers. These findings reflect the limited nature of the arthrotomy or indicate that tibial plateau levelling osteotomy does not influence the progression of osteoarthritis (OA). From these studies, there is no evidence that tibial plateau levelling osteotomy affects cartilage metabolism.
Collapse
Affiliation(s)
- S L Girling
- Small Animal Division, Faculty of Veterinary Science, University of Liverpool, Liverpool L69 0BX, UK
| | | | | | | | | | | | | | | |
Collapse
|
40
|
|
41
|
McParland PC, Kenyon S, Bell SC, Taylor DJ. A randomised controlled trial of metronidazole for the prevention of preterm birth in women positive for cervicovaginal fetal fibronectin: the PREMET Study. BJOG 2006; 113:976; author reply 976-7. [PMID: 16907946 DOI: 10.1111/j.1471-0528.2006.01005.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
42
|
Abstract
OBJECTIVE Short telomeres are associated with adult cardiovascular disease. Our aim was to determine whether small-for-gestational-age (SGA) newborns have shortened telomeres compared with appropriately grown controls. DESIGN Prospective cohort study. SETTING Large tertiary referral unit in Trent, UK. POPULATION Seventy-two women who delivered at 35-42 weeks of gestation were recruited; 34 delivered SGA babies (less than or equal to the third birthweight centile) and 38 had appropriately grown babies (greater than the tenth centile). METHODS Maternal and cord blood samples were collected at delivery. A Southern blot of DNA from these samples was hybridised with a 32P-labelled telomeric probe and telomere length was measured. MAIN OUTCOME MEASURES Mean maternal and newborn telomere length. RESULTS Maternal and newborn telomere lengths were significantly correlated in both the SGA and the control groups (r2 = 0.25, P < 0.0001). Telomere lengths were similar in both maternal (control 8.41 +/- 0.9 kb versus SGA 8.29 +/- 1.0 kb, P = 0.57) and newborn (control 10.36 +/- 1.5 kb versus SGA 10.33 +/- 1.3 kb, P = 0.93) cohorts in the two groups. CONCLUSIONS Intrauterine events associated with impaired fetal growth do not appear to be associated with increased telomere shortening.
Collapse
Affiliation(s)
- A Akkad
- Fetal Growth and Development Research Group, Reproductive Science Section, Department of Cancer Studies and Molecular Medicine, Univerity of Leicester, Leicester, UK
| | | | | | | | | | | |
Collapse
|
43
|
Almeida A, Correia-da-Silva G, Cepa M, Bell SC, Teixeira NA. Synergistic induction of apoptosis in primary rat decidual cells by INF-γ and TNF. Mol Reprod Dev 2006; 74:371-7. [PMID: 16967500 DOI: 10.1002/mrd.20524] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In the rat, in response to blastocyst implantation, stromal cells of the endometrium proliferate and differentiate into decidual cells, forming the decidua. After reaching its maximum development, the decidua undergoes regression. This phenomenon appears to be due to an active process involving apoptosis. As there is sparse knowledge concerning the mechanisms of induction of decidual cell death, the potential role of cytokines present in the uterine environment during pregnancy, such as tumor necrosis factor (TNF) and interferon-gamma (INF-gamma) was explored in primary cultures of rat decidual cells. The effects of these factors upon cellular viability, nuclear morphologic alterations, expression, and enzymatic activities of the effector caspases-3/7 were evaluated. The results obtained demonstrated that in contrast to TNF, which did not induce any alteration, INF-gamma and in association with TNF caused a decrease in cell viability and an increase in the appearance of apoptotic bodies in a time-dependent manner that was augmented in the co-presence of TNF. An increase in caspase-3/7 activities after 12 hr of TNF/INF-gamma treatment was also observed. These findings suggest that INF-gamma expressed in the uterine environment may play an important role in regulating apoptosis through potential synergistic mechanisms with TNF and thereby modulate decidual stability and regression during pregnancy.
Collapse
Affiliation(s)
- A Almeida
- Biochemistry Department, Faculty of Pharmacy and Institute of Molecular and Cellular Biology, University of Oporto, Porto, Portugal
| | | | | | | | | |
Collapse
|
44
|
Buntain HM, Schluter PJ, Bell SC, Greer RM, Wong JCH, Batch J, Lewindon P, Wainwright CE. Controlled longitudinal study of bone mass accrual in children and adolescents with cystic fibrosis. Thorax 2005; 61:146-54. [PMID: 16384878 PMCID: PMC2104575 DOI: 10.1136/thx.2005.046516] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND A study was undertaken to observe the gains in bone mass in children and adolescents with cystic fibrosis (CF) over 24 months and to examine the relationship between areal bone mineral density (aBMD) and associated clinical parameters including physical activity, nutrition, and 25-hydroxyvitamin D (25OHD). METHODS Areal BMD of the total body (TB), lumbar spine (LS), and total femoral neck (FNt) were repeatedly measured in 85 subjects aged 5-18 years with CF and 100 age and sex matched controls over 2 years. At each visit anthropometric variables, nutritional parameters, pubertal status, disease severity, physical activity, dietary calcium, caloric intake, and serum 25OHD were assessed and related to aBMD. RESULTS After adjusting for age, sex, and height Z-score, gains in LS aBMD in children (5-10 years) and TB and FNt aBMD in adolescents (11-18 years) with CF were significantly less than in controls. Lean tissue mass was significantly associated with TB and LS aBMD gains in children and adolescents and explained a significant proportion of the aBMD deficit observed. Lung function parameters were significantly associated with aBMD gains in adolescents with CF. CONCLUSIONS Inadequate bone mass accrual during childhood and adolescence contributes to the low bone mass observed in adults with CF. Accounting for the height discrepancy which is frequently observed in those with CF, in addition to age and sex, is important when assessing low bone mass in children and adolescents with CF. To optimise an individual's potential to acquire maximal bone mass, it is necessary to maximise nutritional status and limit the progression of chronic suppurative lung disease.
Collapse
Affiliation(s)
- H M Buntain
- Department of Respiratory Medicine, Royal Children's Hospital, Herston, QLD 4029, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Abstract
Macrolide antibiotics have been licensed since the 1950s and have an important role in the treatment of a diverse range of infectious diseases. Macrolide antibiotics have antibacterial activity against gram-positive bacteria, some gram-negative bacteria and intracellular pathogens. The spectrum of antibacterial activity combined with excellent intracellular and tissue penetration has led to the extensive use of this class of drugs in respiratory disease. Macrolide antibiotics also have demonstrated anti-inflammatory properties in various in vitro and in vivo model systems. Novel antimicrobial and anti-inflammatory properties of macrolide may result in clinical benefits, particularly in conditions where the infectious agent is inherently resistant to macrolides. Three randomized control trials have demonstrated improved lung function in patients treated with the macrolide antibiotic, azithromycin. Azithromycin was generally well tolerated and resulted in reduction in the inflammatory response which may be due to an immunomodulatory role. Short term studies (three to six months) have not demonstrated the development of increased bacterial resistance or the emergence of new pathogens following azithromycin.
Collapse
Affiliation(s)
- S C Bell
- Adult Cystic Fibrosis Unit, Department of Thoracic Medicine, The Prince Charles Hospital, Brisbane, Australia.
| | | | | |
Collapse
|
46
|
Correia-da-Silva G, Bell SC, Pringle JH, Teixeira NA. Patterns of expression of Bax, Bcl-2 and Bcl-xL in the implantation site in rat during pregnancy. Placenta 2005; 26:796-806. [PMID: 16226130 DOI: 10.1016/j.placenta.2004.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/21/2004] [Indexed: 11/25/2022]
Abstract
The uterine endometrium responds to blastocyst implantation with extensive proliferation and differentiation of stromal cells into decidual cells, forming the antimesometrial and mesometrial decidua. These undergo regression by apoptosis but as this process occurs at different time periods suggest that there is spatially dependent temporal control of apoptosis in these specific regions. To elucidate the role of the mitochondrion-dependent signalling pathway in tissue regression, we investigated the spatial and temporal pattern of expression of the Bcl-2 family members in uterine tissues of the implantation site, from the post-implantation period to parturition. Furthermore, the activities of the initiator caspases-8 and -9, and of the executioner caspase-3 were determined. Overall Bax and Bcl-2 were expressed from day 8 till day 19, whilst Bcl-x(L) was extinguished by day 16. In the antimesometrial and in the mesometrial decidua both Bcl-2 and Bax declined from days 10 to 12. In the latter Bcl-2 immunoreactivity decreased till the end of pregnancy, whilst for Bax a constant level remained thereafter. The pattern of variation of enzymatic activities throughout pregnancy for all the enzymes was similar, increasing from days 10 to 14 and decreasing towards the end of pregnancy. The increased levels of active caspase-9 correlated with Bax/Bcl-2 and Bcl-x(L) expression suggesting that the apoptotic mitochondrion-dependent pathway is involved in decidual regression during pregnancy progression.
Collapse
Affiliation(s)
- G Correia-da-Silva
- Biochemistry Department, Faculty of Pharmacy and Institute of Molecular and Cellular Biology, University of Oporto, Porto, Portugal
| | | | | | | |
Collapse
|
47
|
Abstract
Methicillin-resistant Staphylocosis aureus (MRSA) is an emerging infection in patients with cystic fibrosis (CF). MRSA may be a management dilemma for healthcare workers (HCWs) with CF. Eradication of MRSA with long-term rifampicin and fusidic acid can be achieved in patients with CF. We describe a case of recurrent MRSA infection in a HCW with CF. Molecular typing of the MRSA isolates supported re-infection rather than re-emergence of an earlier MRSA infection. Infection control advice for HCWs with CF who acquire MRSA remains controversial.
Collapse
Affiliation(s)
- D G Downey
- Adult Cystic Fibrosis Unit, Brisbane, QLD, Australia
| | | | | | | |
Collapse
|
48
|
Abstract
REASONS FOR PERFORMING STUDY Fell pony foals are affected by a congenital fatal disease that leads to profound anaemia and immunodeficiency. Previous studies comparing healthy and affected foals have shown normal T-cell populations, but a severe B-lymphopenia. OBJECTIVES To measure the levels of individual immunoglobulin subisotypes in normal and affected Fell ponies and correlate these levels with the number of peripheral B-lymphocytes. METHODS Serum levels of individual immunoglobulin subisotypes were measured by ELISA and correlated with the number of peripheral B-lymphocytes (measured by flow cytometry). RESULTS Affected foals had significantly reduced serum levels of IgM, IgGa, IgGb and IgG(T) that coincided with the normal reduction in maternally derived immunoglobulin in foals and, with the exception of IgGb, correlated strongly with the B-lymphopenia. CONCLUSIONS These data suggest that affected foals are unable to produce their own immunoglobulins. Therefore, once maternal immunity has waned, it may be the lack of specific foal-derived immunoglobulin that gives rise to the clinical signs of immunodeficiency. POTENTIAL RELEVANCE Measurement of IgM after age 4 weeks may provide a more accessible means of confirming the status of future affected Fell pony foals than the measurement of B-lymphocytes (a technique limited to a few specialist laboratories).
Collapse
Affiliation(s)
- G W Thomas
- Department of Veterinary Pathology, University of Liverpool, Crown Street, Liverpool L69 7ZJ, UK
| | | | | |
Collapse
|
49
|
O'Carroll MR, Syrmis MW, Wainwright CE, Greer RM, Mitchell P, Coulter C, Sloots TP, Nissen MD, Bell SC. Clonal strains of Pseudomonas aeruginosa in paediatric and adult cystic fibrosis units. Eur Respir J 2005; 24:101-6. [PMID: 15293611 DOI: 10.1183/09031936.04.00122903] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Despite recent reports of clonal strains of Pseudomonas aeruginosa in cystic fibrosis (CF) units, the need for routine microbiological surveillance remains contentious. Sputum was collected prospectively from productive patients attending the regional paediatric and adult CF units in Brisbane, Australia. All P. aeruginosa isolates were typed using pulsed-field gel electrophoresis. Spirometry, anthropometrics, hospitalisations and antibiotic sensitivity data were recorded. The first 100 sputum samples (first 50 patients at each clinic) harboured 163 isolates of P. aeruginosa. A total of 39 patients shared a common strain (pulsotype 2), 20 patients shared a strain with at least one other patient and 41 patients harboured unique strains. Eight patients shared a strain identical to a previously reported Australian transmissible strain (pulsotype 1). Compared with the unique strain group, patients harbouring pulsotype 2 were younger and had poorer lung function. Treatment requirements were similar in these two groups, as were the rates of multiresistance. In conclusion, 59% of patients harboured a clonal strain, supporting the need for routine microbiological surveillance. In contrast to previously described clonal strains, the dominant pulsotype was indistinguishable from nonclonal strains with respect to both colonial morphology and multiresistance. The clinical significance of clonal strains remains uncertain and requires longitudinal study.
Collapse
Affiliation(s)
- M R O'Carroll
- Adult Cystic Fibrosis Unit, The Prince Charles Hospital, Chermside, Australia
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
|