scholarly journals Metabolites Involved in Immune Evasion byBatrachochytrium dendrobatidisInclude the Polyamine Spermidine

2019 ◽  
Vol 87 (5) ◽  
Author(s):  
Louise A. Rollins-Smith ◽  
Antonio C. Ruzzini ◽  
J. Scott Fites ◽  
Laura K. Reinert ◽  
Emily M. Hall ◽  
...  
Keyword(s):  
Small Molecules ◽  
Immune Evasion ◽  
Lymphocyte Proliferation ◽  
Batrachochytrium Dendrobatidis ◽  
Alternative Pathway ◽  
Chytrid Fungus ◽  
Isolation And Identification ◽  
Major Pathway ◽  
Content Type ◽  
The World

ABSTRACTAmphibians have been declining around the world for more than four decades. One recognized driver of these declines is the chytrid fungusBatrachochytrium dendrobatidis, which causes the disease chytridiomycosis. Amphibians have complex and varied immune defenses againstB. dendrobatidis, but the fungus also has a number of counterdefenses. Previously, we identified two small molecules produced by the fungus that inhibit frog lymphocyte proliferation, methylthioadenosine (MTA) and kynurenine (KYN). Here, we report on the isolation and identification of the polyamine spermidine (SPD) as another significant immunomodulatory molecule produced byB. dendrobatidis. SPD and its precursor, putrescine (PUT), are the major polyamines detected, and SPD is required for growth. The major pathway of biosynthesis is from ornithine through putrescine to spermidine. An alternative pathway from arginine to agmatine to putrescine appears to be absent. SPD is inhibitory at concentrations of ≥10 μM and is found at concentrations between 1 and 10 μM in active fungal supernatants. Although PUT is detected in the fungal supernatants, it is not inhibitory to lymphocytes even at concentrations as high as 100 μM. Two other related polyamines, norspermidine (NSP) and spermine (SPM), also inhibit amphibian lymphocyte proliferation, but a third polyamine, cadaverine (CAD), does not. A suboptimal (noninhibitory) concentration of MTA (10 μM), a by-product of spermidine synthesis, enhances the inhibition of SPD at 1 and 10 μM. We interpret these results to suggest thatB. dendrobatidisproduces an “armamentarium” of small molecules that, alone or in concert, may help it to evade clearance by the amphibian immune system.

scholarly journals Inhibition of Local Immune Responses by the Frog-Killing Fungus Batrachochytrium dendrobatidis

2014 ◽  
Vol 82 (11) ◽  
pp. 4698-4706 ◽  
Author(s):  
J. Scott Fites ◽  
Laura K. Reinert ◽  
Timothy M. Chappell ◽  
Louise A. Rollins-Smith
Keyword(s):  
Immune Responses ◽  
Batrachochytrium Dendrobatidis ◽  
Single Injection ◽  
Delayed Type Hypersensitivity ◽  
Chytrid Fungus ◽  
Content Type ◽  
Adaptive Immune ◽  
Secondary Injection

ABSTRACTAmphibians are suffering unprecedented global declines. A leading cause is the infectious disease chytridiomycosis caused by the chytrid fungusBatrachochytrium dendrobatidis. Chytridiomycosis is a skin disease which disrupts transport of essential ions leading to death. Soluble factors produced byB. dendrobatidisimpair amphibian and mammalian lymphocytesin vitro, but previous studies have not shown the effects of these inhibitory factorsin vivo. To demonstratein vivoinhibition of immunity byB. dendrobatidis, a modified delayed-type-hypersensitivity (DTH) protocol was developed to induce innate and adaptive inflammatory swelling in the feet ofXenopus laevisby injection of killed bacteria or phytohemagglutinin (PHA). Compared to previous protocols for PHA injection in amphibians, this method induced up to 20-fold greater inflammatory swelling. Using this new protocol, we measured DTH responses induced by killed bacteria or PHA in the presence ofB. dendrobatidissupernatants. Swelling induced by single injection of PHA or killed bacteria was not significantly affected byB. dendrobatidissupernatants. However, swelling caused by a secondary injection of PHA, was significantly reduced byB. dendrobatidissupernatants. As previously describedin vitro, factors fromB. dendrobatidisappear to inhibit lymphocyte-mediated inflammatory swelling but not swelling caused by an inducer of innate leukocytes. This suggests thatB. dendrobatidisis capable of inhibiting lymphocytes in a localized response to prevent adaptive immune responses in the skin. The modified protocol used to induce inflammatory swelling in the present study may be more effective than previous methods to investigate amphibian immune competence, particularly in nonmodel species.

scholarly journals Single-Phase PacBio De Novo Assembly of the Genome of the Chytrid Fungus Batrachochytrium dendrobatidis, a Pathogen of Amphibia

2018 ◽  
Vol 7 (21) ◽  
Author(s):  
Nicholas Sumpter ◽  
Margi Butler ◽  
Russell Poulter
Keyword(s):  
New Zealand ◽  
Genome Assembly ◽  
De Novo Assembly ◽  
Single Phase ◽  
Batrachochytrium Dendrobatidis ◽  
De Novo ◽  
Chytrid Fungus ◽  
Content Type

Here, we present an updated genome assembly of the diploid chytrid fungus Batrachochytrium dendrobatidis strain RTP6. This strain is part of the global panzootic lineage (BdGPL) and was isolated in Dunedin, New Zealand.

Genotyping and differential bacterial inhibition of Batrachochytrium dendrobatidis in threatened amphibians in Costa Rica

Microbiology ◽  
2021 ◽  
Author(s):  
Juan G. Abarca ◽  
Steven M. Whitfield ◽  
Ibrahim Zuniga-Chaves ◽  
Gilbert Alvarado ◽  
Jacob Kerby ◽  
...  
Keyword(s):  
Costa Rica ◽  
Inhibitory Activity ◽  
Batrachochytrium Dendrobatidis ◽  
Mitigation Strategies ◽  
Chytrid Fungus ◽  
Fungal Isolation ◽  
Content Type ◽  
Bacterial Inhibition ◽  
Link Type ◽  
Skin Bacteria

Amphibians have declined around the world in recent years, in parallel with the emergence of an epidermal disease called chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). This disease has been associated with mass mortality in amphibians worldwide, including in Costa Rica, and Bd is considered an important contributor to the disappearance of this group of vertebrates. While many species are susceptible to the disease, others show tolerance and manage to survive infection with the pathogen. We evaluated the pathogen Bd circulating in Costa Rica and the capacity of amphibian skin bacteria to inhibit the growth of the pathogen in vitro. We isolated and characterized – genetically and morphologically – several Bd isolates from areas with declining populations of amphibians. We determined that the circulating chytrid fungus in Costa Rica belongs to the virulent strain Bd-GPL-2, which has been related to massive amphibian deaths worldwide; however, the isolates obtained showed genetic and morphological variation. Furthermore, we isolated epidermal bacteria from 12 amphibian species of surviving populations, some in danger of extinction, and evaluated their inhibitory activity against the collection of chytrid isolates. Through bioassays we confirmed the presence of chytrid-inhibitory bacterial genera in Costa Rican amphibians. However, we observed that the inhibition varied between different isolates of the same bacterial genus, and each bacterial isolation inhibited fungal isolation differently. In total, 14 bacterial isolates belonging to the genera Stenotrophomonas , Streptomyces , Enterobacter , Pseudomonas and Klebsiella showed inhibitory activity against all Bd isolates. Given the observed variation both in the pathogen and in the bacterial inhibition capacity, it is highly relevant to include local isolates and to consider the origin of the microorganisms when performing in vivo infection tests aimed at developing and implementing mitigation strategies for chytridiomycosis.

scholarly journals Cryptic diversity of a widespread global pathogen reveals expanded threats to amphibian conservation

2019 ◽  
Vol 116 (41) ◽  
pp. 20382-20387 ◽  
Author(s):  
Allison Q. Byrne ◽  
Vance T. Vredenburg ◽  
An Martel ◽  
Frank Pasmans ◽  
Rayna C. Bell ◽  
...  
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Biodiversity Loss ◽  
Amphibian Conservation ◽  
Degraded Dna ◽  
Chytrid Fungus ◽  
Remote Areas ◽  
The World ◽  
Globally Distributed ◽  
Shed Light ◽  
Lineage Diversity

Biodiversity loss is one major outcome of human-mediated ecosystem disturbance. One way that humans have triggered wildlife declines is by transporting disease-causing agents to remote areas of the world. Amphibians have been hit particularly hard by disease due in part to a globally distributed pathogenic chytrid fungus (Batrachochytrium dendrobatidis [Bd]). Prior research has revealed important insights into the biology and distribution of Bd; however, there are still many outstanding questions in this system. Although we know that there are multiple divergent lineages of Bd that differ in pathogenicity, we know little about how these lineages are distributed around the world and where lineages may be coming into contact. Here, we implement a custom genotyping method for a global set of Bd samples. This method is optimized to amplify and sequence degraded DNA from noninvasive skin swab samples. We describe a divergent lineage of Bd, which we call BdASIA3, that appears to be widespread in Southeast Asia. This lineage co-occurs with the global panzootic lineage (BdGPL) in multiple localities. Additionally, we shed light on the global distribution of BdGPL and highlight the expanded range of another lineage, BdCAPE. Finally, we argue that more monitoring needs to take place where Bd lineages are coming into contact and where we know little about Bd lineage diversity. Monitoring need not use expensive or difficult field techniques but can use archived swab samples to further explore the history—and predict the future impacts—of this devastating pathogen.

How Phillips saw the light

2020 ◽  
Vol 36 (8) ◽  
pp. 29-31
Keyword(s):  
Design Methodology ◽  
Reading Time ◽  
Daily Basis ◽  
Business World ◽  
Content Type ◽  
Freak Show ◽  
The World ◽  
Pertinent Information ◽  
The One ◽  
Practical Implications

Purpose Reviews the latest management developments across the globe and pinpoints practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings The problem with developing a reputation of being something of an oracle in the business world is that all of a sudden, everyone expects you to pull off the trick of interpreting the future on a daily basis. Like a freak show circus act or one-hit wonder pop singer, people expect you to perform when they see you, and they expect you to perform the thing that made you famous, even if it is the one thing in the world you don’t want to do. And when you fail to deliver on these heightened expectations, you are dismissed as a one trick pony, however good that trick is in the first place. Originality/value The briefing saves busy executives and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.

Can housing rights be applied to modern housing systems?

2010 ◽  
Vol 2 (2) ◽  
pp. 103-117 ◽  
Author(s):  
Padraic Kenna
Keyword(s):  
International Law ◽  
Case Law ◽  
Epistemic Communities ◽  
Policy Makers ◽  
Content Type ◽  
Housing Systems ◽  
Effective Implementation ◽  
Housing Rights ◽  
The World ◽  
Effective Translation

PurposeThe purpose of this paper is to outline and examine the growing corpus of housing rights and assess their relevance and applicability to complex contemporary housing systems across the world.Design/methodology/approachThe paper sets out the principal instruments and commentaries on housing rights developed by the United Nations, regional and other bodies. It assesses their relevance in the context of contemporary analysis of housing systems, organized and directed by networks of legal and other professionals within particular domains.FindingsHousing rights instruments are accepted by all States across the world at the level of international law, national constitutions and laws. The findings suggest that there are significant gaps in the international law conception and framework of housing rights, and indeed, human rights generally, which create major obstacles for the effective implementation of these rights. There is a preoccupation with one element of housing systems, that of subsidized or social housing. However, effective housing rights implementation requires application at meso‐, micro‐ and macro‐levels of modern, dynamic housing systems as a whole. Epistemic communities of professionals develop and shape housing law and policy within these domains. The housing rights paradigm must be further fashioned for effective translation into contemporary housing systems.Research limitations/implicationsThe development of housing rights precedents, both within international and national law, is leading to a wide and diffuse corpus of legislation and case law. More research is needed on specific examples of effective coupling between housing rights and elements of housing systems.Originality/valueThis paper offers housing policy makers and lawyers an avenue into the extensive jurisprudence and writings on housing rights, which will inevitably become part of the lexicon of housing law across the world. It also highlights the limitations of housing rights implementation, but offers some new perspectives on more effective application of these rights.

Identifying the best practices in green operations strategy of hospitals

2019 ◽  
Vol 26 (4) ◽  
pp. 1106-1131 ◽  
Author(s):  
Yazan Khalid Abed-Allah Migdadi ◽  
Abeer Ahmad Omari
Keyword(s):  
Best Practices ◽  
Waste Management ◽  
Electrical Power ◽  
Global Reporting Initiative ◽  
Operations Strategy ◽  
Content Type ◽  
Hazardous Waste Management ◽  
The World ◽  
Sustainability Reports ◽  
Two Stages

Purpose The purpose of this paper is to identify the best practices in the green operations strategy of hospitals. Design/methodology/approach A total of 25 cases from all over the world were investigated. The source of data was the annual sustainability reports that were retrieved from Global Reporting Initiative (GRI) database. The present research adopted the benchmarking method and the quantitative content analysis of sustainability reports. Then, the indicative models of best practices were developed by using two analysis approaches; within cluster analysis and across clusters analysis. Findings This study found four major taxonomies of green operation strategy in hospitals. The significant strategic groups were resources/waste management; electrical power management; non-hazardous waste management; and emissions/resources management. Indicative models for the relationship between actions and key green performance indicators were developed in the two stages of the analysis. Originality/value The best practices of green operations strategies in hospitals have not so far been investigated. Countries around the world should obey the new regulations for their environmental footprint; if they do, it will exert pressure on all sectors and organizations at all levels to take immediate steps to measure and improve their environmental performance.

Evaluation of the Skin Peptide Defenses of the Oregon Spotted Frog Rana pretiosa Against Infection by the Chytrid Fungus Batrachochytrium dendrobatidis

2013 ◽  
Vol 39 (6) ◽  
pp. 797-805 ◽  
Author(s):  
J. Michael Conlon ◽  
Laura K. Reinert ◽  
Milena Mechkarska ◽  
Manju Prajeep ◽  
Mohammed A. Meetani ◽  
...  
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Chytrid Fungus ◽  
Rana Pretiosa

scholarly journals Assessing the impact of libraries – the role of ISO 16439

2018 ◽  
Vol 119 (1/2) ◽  
pp. 87-93 ◽  
Author(s):  
Claire Creaser
Keyword(s):  
Design Methodology ◽  
International Standards ◽  
Content Type ◽  
International Standard ◽  
The World ◽  
The Difference ◽  
Library Impact ◽  
The Impact

Purpose Library impact and how to evaluate it has been debated for a number of years. While the activity – the busy-ness – of the library is now routinely measured and described, the difference the library makes is less tangible and harder to measure. Libraries in all sectors and worldwide are grappling with this issue, and the purpose of this paper is to summarise international standards available to support them. Design/methodology/approach The first international standard concerning library impact, ISO 16439 Information and documentation – methods and procedures for assessing the impact of libraries, was published in 2014 after several years in development. Findings The standard describes a range of methods for assessing library impact which have been used across the world in a variety of libraries in all sectors. Originality/value This paper summarises the key methods described in the standard, and gives references for further reading.

Sign in / Sign up

Export Citation Format

Share Document