scholarly journals Review: Examining the Natural Role of Amphibian Antimicrobial Peptide Magainin

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5436
Author(s):  
Katelyn A. M. McMillan ◽  
Melanie R. Power Coombs
Keyword(s):  
Immune System ◽  
Batrachochytrium Dendrobatidis ◽  
Conservation Strategy ◽  
Population Declines ◽  
Small Peptides ◽  
Amphibian Species ◽  
Host Defense Peptides ◽  
African Clawed Frog ◽  
The North ◽  
Clawed Frog

Host defense peptides (HDPs) are a group of antimicrobial peptides (AMPs) that are crucial components of the innate immune system of many different organisms. These small peptides actively kill microbes and prevent infection. Despite the presence of AMPs in the amphibian immune system, populations of these organisms are in decline globally. Magainin is an AMP derived from the African clawed frog (Xenopus laevis) and has displayed potent antimicrobial effects against a wide variety of microbes. Included in this group of microbes are known pathogens of the African clawed frog and other amphibian species. Arguably, the most deleterious amphibious pathogen is Batrachochytrium dendrobatidis, a chytrid fungus. Investigating the mechanism of action of magainin can help understand how to effectively fight off infection. By understanding amphibian AMPs’ role in the frog, a potential conservation strategy can be developed for other species of amphibians that are susceptible to infections, such as the North American green frog (Rana clamitans). Considering that population declines of these organisms are occurring globally, this effort is crucial to protect not only these organisms but the ecosystems they inhabit as well.

scholarly journals The Effect of Aquatic and Terrestrial Environmental Factors on the Interaction Between Grand Teton Boreal Toads and a Lethal Fungal Pathogen

2008 ◽  
Vol 31 ◽  
pp. 125-131
Author(s):  
Peter Murphy ◽  
Sophie St-Hilaire ◽  
Charles Peterson
Keyword(s):  
Fungal Pathogen ◽  
Batrachochytrium Dendrobatidis ◽  
Chytrid Fungus ◽  
Population Declines ◽  
Amphibian Skin ◽  
Amphibian Species ◽  
American Bullfrog ◽  
The North ◽  
S 100 ◽  
Boreal Toads

Batrachochytrium dendrobatidis (Bd), the chytrid fungus which infects keratinized amphibian skin and causes the lethal disease chytridiomycosis, has been linked to population declines and extinctions worldwide (Lips et al. 2006). Amphibians infected with Bd may suffer a variety of outcomes. Individuals of some species have been killed by :S 100 Bd zoospores, while other species, such as the North American bullfrog Rana catesbiana, are highly resistant (Daszak et al. 2004). Within an amphibian species, populations may also respond differently to Bd, with some declining et al. remaining stable (Kriger and Hero 2006). Divergent outcomes among species and populations with respect to Bd may arise from at least three factors, or their interaction.

scholarly journals Ancestral chytrid pathogen remains hypervirulent following its long coevolution with amphibian hosts

2019 ◽  
Vol 286 (1904) ◽  
pp. 20190833 ◽  
Author(s):  
Minjie Fu ◽  
Bruce Waldman
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Population Declines ◽  
Amphibian Species ◽  
South Korean ◽  
Global Pandemic ◽  
Litoria Caerulea ◽  
Experimental Treatments ◽  
Amphibian Chytrid Fungus ◽  
Genomic Recombination ◽  
Blank Solution

Many amphibian species around the world, except in Asia, suffer morbidity and mortality when infected by the emerging infectious pathogen Batrachochytrium dendrobatidis (Bd). A lineage of the amphibian chytrid fungus isolated from South Korean amphibians (BdAsia-1) is evolutionarily basal to recombinant global pandemic lineages (BdGPL) associated with worldwide amphibian population declines. In Asia, the Bd pathogen and its amphibian hosts have coevolved over 100 years or more. Thus, resilience of Asian amphibian populations to infection might result from attenuated virulence of endemic Bd lineages, evolved immunity to the pathogen or both. We compared susceptibilities of an Australasian amphibian, Litoria caerulea , known to lack resistance to BdGPL, with those of three Korean species, Bufo gargarizans , Bombina orientalis and Hyla japonica , after inoculation with BdAsia-1, BdGPL or a blank solution. Subjects became infected in all experimental treatments but Korean species rapidly cleared themselves of infection, regardless of Bd lineage. They survived with no apparent secondary effects. By contrast, L. caerulea , after infection by either BdAsia-1 or BdGPL, suffered deteriorating body condition and carried progressively higher Bd loads over time. Subsequently, most subjects died. Comparing their effects on L. caerulea , BdAsia-1 induced more rapid disease progression than BdGPL. The results suggest that genomic recombination with other lineages was not necessary for the ancestral Bd lineage to evolve hypervirulence over its long period of coevolution with amphibian hosts. The pathogen's virulence may have driven strong selection for immune responses in endemic Asian amphibian host species.

scholarly journals First parasitological study of the African clawed frog (Xenopus laevis, Amphibia) in Chile

2017 ◽  
Vol 26 (2) ◽  
pp. 243-247 ◽  
Author(s):  
Cristóbal Castillo ◽  
Gabriel Lobos ◽  
Daniel González-Acuña ◽  
Lucila Moreno ◽  
Cynthya Elizabeth González ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Introduced Species ◽  
Batrachochytrium Dendrobatidis ◽  
First Record ◽  
Central Chile ◽  
African Clawed Frog ◽  
Parasite Richness ◽  
Native Birds ◽  
Clawed Frog ◽  
Parasitological Study

Abstract Introduced species can arrive into new territories with parasites; however, these species are expected to face lower parasite richness than in their original regions. Both introduced hosts and parasites can affect native fauna. Since their release into the wild in Chile following laboratory use, Xenopus laevis Daudin, 1802 has widely spread throughout central Chile. The only pathogen described on the host is the fungus Batrachochytrium dendrobatidis Longcore, Pessier, Nichols, 1999; thus, this is the first parasitological study of this species in Chile. In 10 localities in central Chile, 179 specimens of X. laevis were captured and examined for parasites in the gastrointestinal tube, cavities, lungs, liver, and skin. Only nine specimens of the genus Contracaecum Railliet, Henry, 1912 were found in six specimens of X. laevis from a private dam in La Patagua. It is likely that these parasites originated from species of native birds. This is the first record of Contracaecum sp. in Chilean amphibians.

scholarly journals Body size mediates latitudinal population differences in response to Bd infection in two amphibian species.

2021 ◽  
Author(s):  
Sara Meurling ◽  
Maria Cortazar-Chinarro ◽  
Mattias Siljestam ◽  
David Ahlen ◽  
Erik Agren ◽  
...  
Keyword(s):  
Body Size ◽  
Batrachochytrium Dendrobatidis ◽  
Geographical Origin ◽  
Bufo Bufo ◽  
Northern Region ◽  
Population Declines ◽  
Rana Arvalis ◽  
Amphibian Species ◽  
Survival Difference ◽  
Species Survival

Populations of the same species may differ in their sensitivity to pathogens but the factors behind this variation are poorly understood. Moreover, infections may cause sub-lethal fitness effects even in species resistant or tolerant to disease. The chytrid fungus Batrachochytrium dendrobatidis (Bd), is a generalist pathogen which has caused amphibian population declines worldwide. In many species, Bd infection causes the disease chytridiomycosis, often leading to high mortality. We investigated how geographical origin affects tolerance to Bd by exposing newly metamorphosed individuals of two North European amphibians (moor frog Rana arvalis, common toad Bufo bufo) from two latitudinal regions to two different BdGPL strains. Bd exposure strongly lowered survival in B. bufo, and in both species survival was lower in the northern region, this difference being much stronger in B. bufo. Northern individuals were smaller in both species, and the survival difference between the regions was size-mediated with smaller individuals being more sensitive to Bd. In both species, Bd exposure led to sub-lethal effects in terms of reduced growth suggesting that even individuals surviving the infection may have reduced fitness mediated by smaller body size. Bd strain affected size-dependent mortality differently in the two regions. We discuss the possible mechanisms how body size and geographical origin can contribute to the present results.

scholarly journals Climate change and outbreaks of amphibian chytridiomycosis in a montane area of Central Spain; is there a link?

2006 ◽  
Vol 274 (1607) ◽  
pp. 253-260 ◽  
Author(s):  
Jaime Bosch ◽  
Luís M Carrascal ◽  
Luis Durán ◽  
Susan Walker ◽  
Matthew C Fisher
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Batrachochytrium Dendrobatidis ◽  
Global Scale ◽  
Amphibian Species ◽  
The North ◽  
Natural Park ◽  
Circulation Patterns ◽  
The North Atlantic Oscillation

Amphibian species are declining at an alarming rate on a global scale in large part owing to an infectious disease caused by the chytridiomycete fungus, Batrachochytrium dendrobatidis . This disease of amphibians has recently emerged within Europe, but knowledge of its effects on amphibian assemblages remains poor. Importantly, little is known about the environmental envelope that is associated with chytridiomycosis in Europe and the potential for climate change to drive future disease dynamics. Here, we use long-term observations on amphibian population dynamics in the Peñalara Natural Park, Spain, to investigate the link between climate change and chytridiomycosis. Our analysis shows a significant association between change in local climatic variables and the occurrence of chytridiomycosis within this region. Specifically, we show that rising temperature is linked to the occurrence of chytrid-related disease, consistent with the chytrid-thermal-optimum hypothesis. We show that these local variables are driven by general circulation patterns, principally the North Atlantic Oscillation. Given that B. dendrobatidis is known to be broadly distributed across Europe, there is now an urgent need to assess the generality of our finding and determine whether climate-driven epidemics may be expected to impact on amphibian species across the wider region.

scholarly journals Composition of symbiotic bacteria predicts survival in Panamanian golden frogs infected with a lethal fungus

2015 ◽  
Vol 282 (1805) ◽  
pp. 20142881 ◽  
Author(s):  
Matthew H. Becker ◽  
Jenifer B. Walke ◽  
Shawna Cikanek ◽  
Anna E. Savage ◽  
Nichole Mattheus ◽  
...  
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Population Declines ◽  
Amphibian Species ◽  
Amphibian Population ◽  
New Approach ◽  
Skin Bacteria ◽  
Probiotic Treatment ◽  
Host Health ◽  
The Face ◽  
Inhibitory Bacteria

Symbiotic microbes can dramatically impact host health and fitness, and recent research in a diversity of systems suggests that different symbiont community structures may result in distinct outcomes for the host. In amphibians, some symbiotic skin bacteria produce metabolites that inhibit the growth of Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen that has caused many amphibian population declines and extinctions. Treatment with beneficial bacteria (probiotics) prevents Bd infection in some amphibian species and creates optimism for conservation of species that are highly susceptible to chytridiomycosis, the disease caused by Bd. In a laboratory experiment, we used Bd-inhibitory bacteria from Bd-tolerant Panamanian amphibians in a probiotic development trial with Panamanian golden frogs, Atelopus zeteki , a species currently surviving only in captive assurance colonies. Approximately 30% of infected golden frogs survived Bd exposure by either clearing infection or maintaining low Bd loads, but this was not associated with probiotic treatment. Survival was instead related to initial composition of the skin bacterial community and metabolites present on the skin. These results suggest a strong link between the structure of these symbiotic microbial communities and amphibian host health in the face of Bd exposure and also suggest a new approach for developing amphibian probiotics.

scholarly journals Infectious disease threats to amphibian conservation

2018 ◽  
Vol 27 (Supplement) ◽  
pp. 81-90
Author(s):  
A.A. Cunningham
Keyword(s):  
Infectious Disease ◽  
Batrachochytrium Dendrobatidis ◽  
Biodiversity Loss ◽  
Amphibian Conservation ◽  
Disease Spread ◽  
Population Declines ◽  
Amphibian Species ◽  
Late 20Th Century ◽  
Amphibian Population ◽  
In The Wild

The unexplained decline of amphibian populations across the world was first recognised in the late 20th century. When investigated, most of these “enigmatic” declines have been shown to be due to one of two types of infectious disease: ranavirosis caused by infection with FV3-like ranavirus or with common midwife toad virus, or chytridiomycosis caused by infection with Batrachochytrium dendrobatidis or B. salamandrivorans. In all cases examined, infection has been via the human-mediated introduction of the pathogen to a species or population in which it has not naturally co-evolved. While ranaviruses and B. salamandrivorans have caused regionally localised amphibian population declines in Europe, the chytrid fungus, B. dendrobatidis, has caused catastrophic multi-species amphibian population declines and species extinctions globally. These diseases have already caused the loss of amphibian biodiversity, and over 40% of known amphibian species are threatened with extinction. If this biodiversity loss is to be halted, it is imperative that regulations are put in place – and enforced – to prevent the spread of known and yet-to-be discovered amphibian pathogens. Also, it is incumbent on those who keep or study amphibians to take measures to minimise the risk of disease spread, including from captive animals to those in the wild.

scholarly journals Single infection with Batrachochytrium dendrobatidis or Ranavirus does not increase probability of co-infection in a montane community of amphibians

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jaime Bosch ◽  
Camino Monsalve-Carcaño ◽  
Stephen J. Price ◽  
Jon Bielby
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Disease Outbreaks ◽  
Single Infection ◽  
Chytrid Fungus ◽  
Population Declines ◽  
Emerging Pathogens ◽  
Amphibian Species ◽  
Management Interventions ◽  
Amphibian Chytrid Fungus ◽  
Common Situation

AbstractUnderstanding the occurrence and consequence of co-infections can be useful in designing disease management interventions. Amphibians are the most highly threatened vertebrates, and emerging pathogens are a serious threat to their conservation. The amphibian chytrid fungus and the viruses of the Ranavirus genus are already widely distributed, causing disease outbreaks and population declines worldwide. However, we lack information about the occurrence and consequences of coinfection with these pathogens across age-classes of amphibian hosts. Here, we analyze the occurrence of infection of the amphibian chytrid fungus and ranaviruses during one season in two susceptible amphibian species at two different locations at which outbreaks have occurred. We found that the co-occurrence of both pathogens in a particular host is not common except in highly susceptible life-stages, and that single infections are the most common situation. Moreover, we found that the occurrence of one pathogen in a particular host did not predict the occurrence of the other. We attribute these results to the niches in which both pathogens proliferate in amphibian hosts.

scholarly journals Cloning of Interleukin-10 from African Clawed Frog (Xenopus tropicalis), with the Finding of IL-19/20 Homologue in the IL-10 Locus

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Zhitao Qi ◽  
Qihuan Zhang ◽  
Zisheng Wang ◽  
Weihong Zhao ◽  
Qian Gao
Keyword(s):  
Amino Acids ◽  
Immune Response ◽  
Immune System ◽  
Genomic Structure ◽  
3D Structure ◽  
Interleukin 10 ◽  
Xenopus Tropicalis ◽  
African Clawed Frog ◽  
Clawed Frog ◽  
Sequence Identities

Interleukin-10 (IL-10) is a pleiotropic cytokine that plays an important role in immune system. In the present study, the IL-10 gene of African clawed frog (Xenopus tropicalis) was first cloned, and its expression pattern and 3D structure were also analyzed. The frog IL-10 mRNA encoded 172 amino acids which possessed several conserved features found in IL-10s from other species, including five-exon/four-intron genomic structure, conserved four cysteine residues, IL-10 family motif, and sixα-helices. Real-time PCR showed that frog IL-10 mRNA was ubiquitous expressed in all examined tissues, highly in some immune related tissues including kidney, spleen, and intestine and lowly in heart, stomach, and liver. The frog IL-10 mRNA was upregulated at 24 h after LPS stimulation, indicating that it plays a part in the host immune response to bacterial infection. Another IL, termed as IL-20, was identified from the frog IL-10 locus, which might be the homologue of mammalian IL-19/20 according to the analysis results of the phylogenetic tree and the sequence identities.

scholarly journals DNA-based biomonitoring in the tropics: Detection and control of Batrachochytrium dendrobatidis in Ecuadorian ecosystem

2021 ◽  
Vol 4 ◽  
Author(s):  
Lenin Riascos-Flores ◽  
Andrea Carrera ◽  
Leopoldo Naranjo ◽  
Jomira Yanez ◽  
Peter Goethals ◽  
...  
Keyword(s):  
Invasive Species ◽  
Water Samples ◽  
Large Scale ◽  
Batrachochytrium Dendrobatidis ◽  
Action Plan ◽  
Detection Methods ◽  
Population Declines ◽  
Amphibian Species ◽  
Tissue Samples ◽  
And Control

Batrachochytrium dendrobatidis (Bd) is a fungus that parasites vertebrates, and is associated with population declines worldwide in endemic amphibian species. As such, it is one of several invasive species which pose a serious threat to a variety of vertebrate hosts, in casu: amphibians. Detection of such invasive species is generally based on DNA-based methods where, for instance, swabs or tissue samples of candidate hosts are analysed for their presence. Any management strategy of these invasive species would greatly benefit from sensitive and rapid detection methods which can be applied at a large scale. The analysis of eDNA from the habitat of candidate host organisms may hold significant potential for this purpose. In this study, we compare the ability of eDNA from habitat samples with that of swab and/or tissue samples of candidate hosts to detect the presence of Bd in Ecuador. We collected individuals from the amphibians: Pristimantis (Anura: Craugastoridae), Rhinella (Anura: Bufonidae), Gastroteca (Anura: Hemiphractidae), from the endangered toad species of the genus Atelopus (Anura: Bufonidae) as well as water samples from different water bodies in Andean and coastal Ecuadorian areas. Samples were processed using a portable field molecular laboratory. Commercial primers for the internal transcribed spacer (ITS), in combination with a new set of primers designed from Bd sequences from tropical countries, were used. Positive PCR results from both types of samples were obtained within eight hours after sampling. Prevalence of BD was detected in eDNA, swab and tissue samples in four of the six ecosystems monitored -14 out of 26 water samples and 27 out of 43 amphibian of in total 12 species- including three endangered toad species (Atelopus balios, A. nanay, and the rediscovered A. bomolochos). Our results highlight the potential of eDNA-based monitoring to assess the presence and prevalence of Bd in Ecuadorian aquatic ecosystems, in accordance with the National Action Plan for the Conservation of Ecuadorian Amphibians. Furthermore, our field lab approach leads to reliable and fast results for the monitoring of invasive species in a tropical context of a pandemic.

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